US20120069540A1 - Electronic device with magnetic attachment - Google Patents

Abstract

A magnetic attachment mechanism and method is described. The magnetic attachment mechanism can be used to releasably attach at least two objects together in a preferred configuration without fasteners and without external intervention. The magnetic attachment mechanism can be used to releasably attach an accessory device to an electronic device. The accessory device can be used to augment the functionality of usefulness of the electronic device.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This U.S. patent application is a Continuation application and claims priority to U.S. patent application Ser. No. 12/971,589, filed Dec. 17, 2010, entitled “ELECTRONIC DEVICE WITH MAGNETIC ATTACHMENT”, by Lauder et al. U.S. patent application Ser. No. 12/971,589 is a Continuation in Part of U.S. Design patent application Ser. No. 29/375,197, filed Sep. 17, 2010 entitled “COVER” by Akana et al. U.S. patent application Ser. No. 12/971,589 also claims priority to U.S. Provisional Patent Application No. 61/384,179, filed Sep. 17, 2010, entitled “APPARATUS AND METHOD FOR MAGNETIC ATTACHMENT”, by Lauder et al. All of these applications are incorporated by reference in their entirety for all purposes.
FIELD OF THE DESCRIBED EMBODIMENTS
• The described embodiments generally relate to portable electronic devices. More particularly, the present embodiments describe various releasable attachment techniques well suited for portable electronic devices.
DESCRIPTION OF THE RELATED ART
• Recent advances in portable computing includes the introduction of hand held electronic devices and computing platforms along the lines of the iPad™ tablet manufactured by Apple Inc. of Cupertino, Calif. These handheld computing devices can be configured such that a substantial portion of the electronic device takes the form of a display used for presenting visual content leaving little available space for an attachment mechanism that can be used for attaching an accessory device.
• Conventional attachment techniques generally rely upon mechanical fasteners that typically require at least an externally accessible attaching feature on the electronic device to mate with a corresponding attaching feature on the accessory device. The presence of the external attaching feature can detract from the overall look and feel of the handheld computing device as well as add unwanted weight and complexity as well as degrade the appearance of the hand held computing device.
• Therefore a mechanism for releasably attaching together at least two objects is desired.
SUMMARY OF THE DESCRIBED EMBODIMENTS
• This paper describes various embodiments that relate to a system, method, and apparatus for releasably attaching an accessory to an electronic device.
• An electronic device includes first magnetic attachment feature enclosed within and near a first side wall of the electronic device. The first magnetic attachment feature includes a first magnetic element, and a retaining mechanism coupled to the housing and arranged to provide a retaining force, and wherein when changing from an inactive to an active state the magnetic element moves against the retaining force a distance Δx towards the first sidewall.
• A method of forming an electronic device can be carried out by providing a housing having side walls, attaching a retaining mechanism to the housing located at a first location and near a first side wall of the housing, attaching a first magnetic element to the retaining mechanism, wherein in an inactive state, the retaining mechanism applies a retaining force that maintains the magnetic element at a first position within the housing away from the first side wall, and wherein in an active state the magnetic element moves against the retaining force a distance Δx towards the first sidewall.
• In another embodiment, an electronic device includes at least a housing having side walls, a bottom surface and a top-side opening, a display device disposed within the opening, a protective layer on top of the display device, a first magnetic attachment mechanism enclosed within the housing and located at a first position near a first side wall of the housing. The first magnetic attachment mechanism includes a first magnetic element, and a retaining mechanism coupled to the housing and arranged to provide a retaining force that maintains the magnetic element at a first position away from the first side wall in an inactive state where a value of magnetic flux density at an exterior surface of the first side wall is less than a pre-determined threshold value, and wherein in an active state the magnetic element moves against the retaining force a distance Δx towards the first sidewall.
• An electronic device having a housing includes at least a dual state magnetic element disposed within the housing at a first side wall and arranged to provide a first magnetic surface at an exterior surface of the first side wall in a first state, the first magnetic surface being unsuitable for magnetic attachment and not substantially affecting a magnetically sensitive device, wherein in a second state, the dual state magnetic element provides a second magnetic surface ath the exterior surface of the first side wall, the second magnetic surface being suitable for magnetic attachment and a state retaining mechanism coupled to the housing and arranged to maintain the dual state magnetic element in the first state unless the dual state magnetic element is acted upon by an external activator.
• Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
• FIG. 1 is a simplified block diagram of an article and an electronic device that can be releasably attached to each other in a desired and repeatable manner.
• FIG. 2A is a simplified perspective view of an article that can be releasably attached to an electronic device via a side magnetic attachment system, in accordance with one described embodiment.
• FIG. 2B shows the article and the electronic device ofFIG. 2A attached in accordance with the side magnetic attachment system.
• FIG. 3A is a simplified perspective view of an article that is releasably attachable to an electronic device via a top magnetic attachment system in accordance with one described embodiment.
• FIG. 3B shows the article and the electronic device ofFIG. 3A magnetically attached to each to each other to form a cooperating system using the top magnetic attachment system.
• FIG. 4A is a simplified perspective view of an article that is releasably attachable to an electronic device via the top and side magnetic attachment systems.
• FIG. 4B shows a cooperating system of the attached article and the electronic device shown inFIG. 4A in a closed configuration.
• FIG. 4C shows the cooperating system ofFIG. 4B in an open configuration.
• FIG. 5 shows a top perspective view of an electronic device in accordance with the described embodiments.
• FIG. 6 shows another embodiment of a magnetic attachment feature.
• FIG. 7A shows an electronic device in proximity to another object in the form of an accessory device having a magnetic attachment feature.
• FIG. 7B shows a graphical representation of magnetic interaction between the electronic device and the accessory device ofFIG. 7A in accordance with the described embodiments.
• FIG. 7C shows a graphical representation of a cooperating system formed by the magnetic attachment of the accessory device and the electronic device as shown inFIGS. 7A and 7B.
• FIG. 8A shows an embodiment of an attachment feature in an electronic device.
• FIG. 8B shows an embodiment of an attachment feature in an accessory device corresponding to the attachment feature shown inFIG. 8A.
• FIG. 9A shows a representative device attachment feature in an inactive state.
• FIG. 9B shows the representative device attachment feature ofFIG. 9A activated by another magnetic attachment feature.
• FIG. 9C shows the magnetic attachment feature in the inactive state in the presence of magnetically active object.
• FIG. 10 shows an implementation of a device attachment feature that utilizes a leaf spring arrangement as a retaining mechanism.
• FIG. 11A shows an embodiment of a keyed magnetic attachment system in an inactive state and a matching magnetic attachment system.
• FIG. 11B shows the keyed magnetic attachment feature ofFIG. 11A activated by the matching magnetic attachment system.
• FIG. 12 shows a shifting position for the keyed magnetic attachment feature shown inFIG. 11A.
• FIG. 13 shows a graph summarizing a magnetic attachment force versus relative position of the keyed magnetic attachment feature.
• FIGS. 14 and 15 show various embodiments of magnetic elements used in the keyed magnetic attachment feature.
• FIG. 16A shows a first perspective view of the electronic device in the form of a tablet device and the accessory device in the form of a protective cover.
• FIG. 16B shows a second perspective view of the electronic device in the form of a tablet device and the accessory device in the form of a protective cover.
• FIG. 17A shows a closed configuration of the cooperating system formed by the tablet device and protective cover shown inFIGS. 16A and 16B.
• FIG. 17B shows an open configuration of the cooperating system shown inFIG. 17A.
• FIG. 18 shows a top view of an embodiment of a segmented cover assembly.
• FIGS. 19A-19C show a detailed view of a hinge span in accordance with the described embodiments.
• FIG. 20A shows a side view of the segmented cover assembly shown inFIG. 18 attached to a tablet device.
• FIG. 20B-20C show cross section views of the segmented cover assembly and tablet device ofFIG. 20A.
• FIG. 21A shows a cross sectional side view of one embodiment of the hinge span ofFIGS. 19A-19C magnetically attached to a housing having a curved surface.
• FIG. 21B shows a cross sectional side view of another embodiment of the hinge span magnetically attached to a housing having a flat surface.
• FIGS. 22A and 22B show cross sectional and perspective views of a fixture used to assemble the hinge span in accordance with the described embodiments.
• FIG. 23 shows a side view of a segmented cover configured to support a tablet device in a keyboard state.
• FIGS. 24A and 24B show side and perspective views, respectively, of the segmented cover configured to support a tablet device in a display state.
• FIGS. 25A-25B show the segmented cover assembly configured as various embodiments of a hanging apparatus.
• FIGS. 26A and 26B show rear and front views, respectively, of a tablet device having a front and rear image capture device held by the handle.
• FIGS. 27A-27C show a cooperating system of a segmented cover and tablet device configured to activate only uncovered portions of a display in a peek mode.
• FIGS. 28A-28D show various exploded views of portions of a pivoting hinge assembly in accordance with the described embodiments.
• FIG. 29 shows an exploded view of a top cover assembly in accordance with the described embodiments.
• FIG. 30 is a cross sectional view of the top cover assembly shown inFIG. 29 in place upon a tablet device highlighting the relationship between an embedded magnet in the top cover assembly and a magnetically sensitive circuit in the tablet device.
• FIG. 31A shows a cross sectional view of a hinge span magnetically engaged with a corresponding device attachment feature in an active state in accordance with the described embodiments.
• FIG. 31B shows a cross sectional view of the device attachment feature ofFIG. 31A in an inactive state.
• FIGS. 32-33 shows perspective views of a device attachment feature incorporating a leaf spring as a retaining mechanism in accordance with the described embodiments.
• FIG. 34 shows a flowchart detailing a process of magnetic attachment in accordance with the described embodiments.
• FIG. 35 shows a flowchart detailing a process for activating a coded magnetic attachment feature in accordance with the described embodiments.
• FIG. 36 shows a flowchart detailing a process for forming initiating a magnetic attachment in accordance with the described embodiments.
• FIG. 37 shows a flowchart detailing a process for a peek mode operation in accordance with the described embodiments.
• FIG. 38 shows a flowchart detailing a process for assembly of a hinge span in accordance with the described embodiments.
• FIG. 39 shows a flowchart detailing process for determining a configuration of magnetic elements in a magnetic stack used in a magnetic attachment system in accordance with the described embodiments.
• FIG. 40 is a block diagram of an arrangement of functional modules utilized by a portable media device.
• FIG. 41 is a block diagram of an electronic device suitable for use with the described embodiments.
DETAILED DESCRIPTION OF SELECTED EMBODIMENTS
• Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.
• The following description relates in general to a mechanism that can be used to attach together at least two suitably configured objects. In one embodiment, this can be accomplished without the use of conventional fasteners. Each of the objects can include an attachment feature arranged to provide a magnetic field having appropriate properties. When the attachment features are brought into proximity with each other, the magnetic fields can cooperatively interact based upon their respective properties, result in the objects magnetically attaching to each other in a desired and repeatable manner. For example, due at least in part to the cooperative nature of the interaction of the magnetic fields, the objects can attach to each other in a pre-determined position and relative orientation without external intervention. For example, the cooperative magnetic interaction can result in the objects self-aligning and self-centering in a desired orientation.
• The objects can remain in the magnetically attached state if and until a releasing force of sufficient magnitude is applied that overcomes the overall net attractive magnetic force. In some cases, however, it can be desirable to detach the objects serially (along the lines of a zipper) in which case, the releasing force only need be of sufficient magnitude to overcome the net magnetic attractive force of one pair of magnetic elements at a time. Connectors such as mechanical fasteners are not required to attach the objects together. Furthermore, to prevent undue interference to the magnetic interaction between the magnetic attachment features, at least a portion of the objects in the vicinity of the magnetic attachment features can be formed of magnetically inactive materials such as plastic or non-ferrous metals such as aluminum or non-magnetic stainless steel.
• The objects can take many forms and perform many functions. When magnetically attached to each other, the objects can communicate and interact with each other to form a cooperative system. The cooperating system can perform operations and provide functions that cannot be provided by the separate objects individually. In another embodiment, at least one device can be used as an accessory device. The accessory device can be magnetically attached to at least one electronic device. The accessory device can provide services and functions that can be used to enhance the operability of the electronic device(s). For example, the accessory device can take the form of a protective cover that can be magnetically attached to the electronic device. The protective cover can provide protection to certain aspects (such as a display) of the electronic device while enhancing the overall look and feel of the electronic device. The magnetic attachment mechanism used to magnetically attach the accessory and the electronic device can assure that the cover can only attach to the electronic device in a specific orientation. Moreover, the magnetic attachment mechanism can also assure proper alignment and positioning of the protective cover and the electronic device.
• The protective cover can include at least a hinge portion. The hinge portion can be magnetically attached to the electronic device using a magnetic attachment feature. The hinge portion can be pivotally connected to a flap that can be placed upon a portion of the electronic device to be protected. The protective cover can include electronic circuits or other elements (passive or active) that can cooperate with electronic elements in the electronic device. As part of that cooperation, signals can be passed between the protective cover and the electronic device that can, for example, be used to modify operations of the electronic device, operations of electronic circuits or elements of the protective cover, and so forth.
• As an example, the electronic device can include a magnetically sensitive circuit such as a Hall Effect sensor and as such can detect the presence of a magnetic field. The Hall Effect sensor can respond to the presence (or absence) of the magnetic field by generating a signal. The signal can be used to alter an operating state of the electronic device. Accordingly, the protective cover can include a magnetic element such as a permanent magnet having a magnetic field that can cause the Hall Effect sensor to generate the signal. The magnetic element can be positioned on the protective cover in a location that triggers the Hall Effect sensor to generate the signal when the cover is placed on or in proximity to a surface of the electronic device. The signal can indicate that the protective cover is in a predetermined position relative to the electronic device that can result in a change in an operating state of the electronic device. For example, with the portion of the protective cover having the magnetic element in proximity to the Hall Effect sensor, the magnetic field from the magnetic element can cause the Hall Effect sensor to generate a signal. The signal can, in turn, be used to alter the operating state to one consistent with the display of the electronic device being fully covered. On the other hand, when the portion of the protective cover having the magnetic element is removed to the point where the Hall Effect sensor no longer responds to the magnetic field of the magnetic element, then the Hall Effect sensor can generate another signal. The other signal can result in the electronic device entering another, different, operating state consistent with at least a portion of the display being uncovered and viewable.
• These and other embodiments are discussed below with reference toFIGS. 1-40. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. For the remainder of this discussion, a first and second object each suitably configured to magnetically attach to each other in accordance with the described embodiments will be described. It should be noted, however, that any number and type of suitably configured objects can be magnetically attached to each other in a precise and repeatable manner. In particular, for simplicity and clarity, for the remainder of this discussion, the first object is presumed to take the form of an electronic device and in particular a handheld electronic device.
• FIG. 1 is a simplified block diagram ofarticle10 andelectronic device12 that can be releasably attached to each other in a desired and repeatable manner. More specifically,article10 andelectronic device12 can attach to each other at a pre-determined position and relative orientation without external intervention and without the use of mechanical fasteners.Article10 andelectronic device12 can remain attached to each other if and until a releasing force is applied that overcomes the engagement between them. In some cases, however, it can be desirable to detacharticle10 andelectronic device12 serially (along the lines of a zipper) in which case, a releasing force can be applied that can undo the engagement betweenarticle10 andelectronic device12 about one attachment component at a time. For example, an attachment component can include a suitably matched pair of magnetic elements, one inarticle10 and a second inelectronic device12.
• Electronic device12 can take many forms. For example,electronic device12 can take the form of a portable electronic device. In some examples, the portable electronic device can includehousing15.Housing15 can enclose and provide support for components of the portable electronic device.Housing15 can also provide support for at least a large and prominent display occupying a substantial portion of a front face of the portable electronic device. The display can be used to present visual content. The visual content can include still images, visual, textual data, as well as graphical data that can include icons used as part of a graphical user interface, or GUI.
• In some cases, at least a portion of the display can be touch sensitive. By touch sensitive it is meant that during a touch event, an object (such as a finger, stylus, and so on) can be placed in contact with or in proximity to an upper surface of the display. The particulars of the touch event (location, pressure, duration, and so forth) can be used to provide information to the portable electronic device for processing. In some embodiments, in addition to or in place of information being provided to the portable electronic device, information can be provided by the portable electronic device in a tactile manner using, for example, haptic actuators. It should be appreciated however that this configuration is by way of example and not by way of limitation as the electronic device can be widely varied. In one example, the portable electronic device is a tablet computer such as, for example, the iPad™ manufactured by Apple Inc. of Cupertino, Calif.
• Article10 can be widely varied and can take many forms such as, for example, an accessory or accoutrement ofelectronic device12. As an accessory,article10 can be configured as a cover, a stand, a dock, a hanger, an input/output device and so on. In a particularly useful form,article10 can take the form of a protective cover that can include a member, such as a flap, that can be positioned over the display of the portable electronic device. Like theelectronic device12, thearticle10 can also includehousing17 that can enclose and provide support for components of thearticle10.
• Either one or both ofarticle10 andelectronic device12 can include attachment features. For example,article10 can includeattachment system13 andelectronic device12 can includecorresponding attachment system14.Attachment system13 can cooperate withcorresponding attachment system14 to attacharticle10 andelectronic device12 in a releasable manner. When attached to each other,article10 andelectronic device12 can operate as a single operating unit. On the other hand, in the detached mode,article10 andelectronic device12 can act separately, and if desired, as two individual parts.Attachment systems13 and14 can be configured in such a way thatarticle10 andelectronic device12 can attach to each other in a desired and repeatable manner. In other words,attachment systems13 and14 can repeatedly alignarticle10 andelectronic device12 together such that they are consistently in a pre-determined position relative to one another.
• The attachment features can be widely varied. The attachment can be provided by various types of couplings including mechanical, electrical, static, magnetic, frictional, and/or the like. In one embodiment, the attachment cannot be seen from the outside of the article and/or electronic device. For example, the article and device can not include external visible attachment features that adversely affect the look and feel or ornamental appearance (e.g., snaps, latches, etc.), but rather attachment features that cannot be seen from the outside of the article or device and thus do not affect the look and feel or ornamental appearance of the article or device. By way of example, the attachment features can be provided by attraction surfaces that do not disturb the external surfaces of the article or device. In one embodiment, at least a portion of the attachment features utilize magnetic attraction to provide some or all of the attaching force.
• The attachment systems can include one or more attachment features. If multiple features are used, the manner in which they secure can be the same or different. For example, in one implementation, a first attachment feature utilizes a first attachment means while a second attachment feature utilizes a second attachment means that is different than the first attachment means. For example, the first attachment means can utilize a friction coupling while the second attachment means can utilize magnetism. In another implementation, a first attachment feature utilizes a first attachment means while a second attachment feature utilizes the same or similar attachment means. For example, the first and second attachment means can be provided by magnets. Although, the attachment means can be similar it should be appreciated that the configuration of the features can be different depending on the needs of the system. Further, any number and configuration of attachment means can be used.
• In the illustrated embodiment, theattachment systems13 and14 each include at least a first set of corresponding attachment features13a/14aand a second set of corresponding attachment features13b/14b.Attachment feature13acan cooperate with corresponding attachment feature14ato attacharticle10 and electronic device in a releasable manner. In one particular implementation this is accomplished with magnetic attraction. Further, attachment feature13bcan cooperate with corresponding attachment feature14bto further attacharticle10 and electronic device in a releasable manner. In one particular implementation this is accomplished with magnetic attraction. By way of example, attachment features13a/14acan be provided at a first location while attachment features13b/14bcan be provided at a second location.
• In a specific example, attachment feature14acan, in cooperation with attachment feature13a, secureelectronic device12 toarticle10. In another example, attachment feature13bcan securearticle10 to theelectronic device12 using attachment feature14b. It should be noted that theattachment systems13 and14 of this example can be separate or they can cooperate together to produce the attachment. If they cooperate, attachment features14aand14bcorrespond to or mate with one or more attachment features13aand13b. In any case, the attachment features in any of these examples can be accomplished through mechanical, static, suction, magnetic attachment and/or the like.
• The placement of the attachment systems and the attachment features within the attachment systems can be widely varied. Regardingelectronic device12,attachment system14 can be placed on front, back, top, bottom, and/or sides. Attachment features14aand14bcan be placed any location withinattachment system14. Accordingly, attachment features14aand14bcan be placed anywhere relative to the housing and/or the display. In one example, the attachment features14aand14bcan provide engagement along one or more of the sides of the housing (e.g., top, bottom, left, right). In another example, attachment features14aand14bcan provide engagement at the back ofelectronic device12. In yet another example, attachment features14aand14bcan provide engagement at the front (e.g., where, if present, a display is located) ofelectronic device12. In some cases, a combination of attachment features can be located at different regions ofelectronic device12 as for example at the sides and front. In one embodiment,attachment system14 including attachment features14aand14bdo not disturb the surfaces ofelectronic device12. Similarly,attachment system13 and in particular attachment features13aand13bdo not disturb the surfaces ofarticle10.
• In accordance with one embodiment, the attachment features can include magnetic elements. The magnetic elements can be configured to help inpositioning article10 relative toelectronic device12 into a mating arrangement. The magnetic elements can further help to securearticle10 andelectronic device12 into a mating engagement. It should be noted that the engagement ofarticle10 andelectronic device12 can be reversed by the application of an appropriate releasing force that allowsarticle10 andelectronic device12 to separate back into individual objects. However, the magnetic elements can permit thearticle10 andelectronic device12 to subsequently resume the mating engagement without the requirement of fasteners of any sort, mechanical or otherwise. In this way, the magnetic elements provide a repeatable and consistent engagement betweenarticle10 andelectronic device12.
• Article10 andelectronic device12 can further includecomponents16 and18 respectively.Components16 and18 typically depend on the configuration ofarticle10 andelectronic device12 and can, for example, be mechanical or structural components used to provide support or they can be operational/functional components that can provide a specific set of operations/functions. The components can be dedicated to their respective devices or they may be configured for coupling with aspects of the corresponding article or device (e.g., wired or wireless). Examples of structural components can include frames, walls, fasteners, stiffeners, movement mechanisms (hinge), etc. Examples of operational components can include processors, memory, batteries, antennas, circuitry, sensors, display, inputs, and so on. Depending on their desired configuration, the components can be external (i.e., exposed at the surface) and/or internal (e.g., embedded within housing).
• FIGS. 2A and 2B are simplified perspective views ofarticle20 that can be releasably attached toelectronic device22 via a magnetic attachment system, in accordance with one described embodiment.Article20 andelectronic device22 can generally correspond to those discussed with regards toFIG. 1. In one embodiment, the magnetic attachment system can be embodied as magnetic surface24 (shown by broken lines or shading) and more particularly asmagnetic surface24 at the sides ofelectronic device22.Magnetic surface24 can provide a magnetic field that can cooperate with a corresponding attachment feature inarticle20 when placed in proximity to one another. The magnetic field can establish a net magnetic attractive force that can pullarticle20 andelectronic device22 together into the mating engagement alongengagement surface26 as shown inFIG. 2B.
• In other words, the magnetic field provided bymagnetic surface24 can have properties such that the net magnetic attractive force betweenarticle20 andelectronic device22 is substantially perpendicular toengagement surface26. Moreover, the magnetic field can result in the net magnetic attractive force betweenarticle20 andelectronic device22 being applied uniformly alongengagement surface26. In order to releasearticle20 andelectronic device22, a releasing force can be applied to the two conjoined objects in order to overcome a net magnetic attractive force provided by the magnetic attachment system.
• It also should be appreciated that although only one side wall is shown, in some cases different sidewalls and possibly a combination of sidewalls may be used depending on the needs of the attachment interface. It should be noted that the use of magnetic attachment precludes the need for mechanical attachments such as fasteners. Moreover, the lack of mechanical attachments and the uniformity of the overall magnetic attractive force can leave the surfaces ofarticle20 andelectronic device22 undisturbed helping to create an appearance of oneness by in whicharticle20 andelectronic device22 can appear as a single, unified entity. The uniformity in appearance can improve the overall aesthetic appeal of botharticle20 andelectronic device22.
• In one embodiment, a magnetic surface can be created by embedding magnetically attractable elements in the form of the magnetic attachment feature within the sidewalls ofelectronic device22 and/orarticle20. That is, the magnetically attractable elements can be disposed withinarticle20 andelectronic device22 as for example within the housing ofelectronic device22. In this configuration, the housing can be formed of non-magnetic material such as plastic or non-ferrous metal such as aluminum. In this way, magnetic force lines can be configured to work through the walls of the housing. The magnetic attachment features do not disturb the physical appearance of the external surfaces ofarticle20 andelectronic device22. The magnetically attractable elements inarticle20 andelectronic device22 can be arranged to produce magnetic fields that can cooperate with each other to generate a magnetic attractive force that attachesarticle20 andelectronic device22 together in the mating engagement. The magnetic attractive force being configured to generate a magnetic attraction force normal toengagement surface26 betweenelectronic device22 andarticle20.
• The magnetic attractive force between corresponding magnetic elements inarticle20 andelectronic device22 can also be uniformly applied alongengagement surface26. The uniformity of the overall magnetic attractive force alongengagement surface26 can be a result of the uniformity of the separation distance between corresponding magnetic elements inarticle20 andelectronic device22. The uniformity can also be a result of the consistency of magnetic flux density between corresponding magnetic elements inarticle20 andelectronic device22. The uniformity of net magnetic attachment can be facilitated by the surfaces ofarticle20 andelectronic device22 each forming a well matched fit to each other. For example, one surface can be flat or have a concave geometry whereas the other surface can have a matching conforming convex geometry. In this way, by fitting tightly together, a separation distance between each of the corresponding magnetic elements inarticle20 andelectronic device22 can be reduced to a minimum. The conformity of surface shapes can also enhance the overall look and feel ofarticle20 andelectronic device22 by reducing or eliminating the appearance of a seam atengagement surface26. This seamless quality can provide an illusion of a single entity whenarticle20 andelectronic device22 are attached to each other.
• In addition to enhancing the overall look and feel, the consistency of the separation distance between the magnetic elements can render the attachment force betweenarticle20 andelectronic device22 uniform alongengagement surface26. In this way, the engagement force can be uniformly distributed acrossengagement surface26 preventing buckling, weak spots, and so on that might otherwise affect the overall integrity of the engagement betweenarticle20 andelectronic device22.
• FIGS. 3A and 3B are simplified perspective views ofarticle30 that can be releasably attached to anelectronic device32 viamagnetic attachment system34 andcorresponding attachment system36. It should be noted that this particular embodiment is similar to the embodiment described inFIGS. 2A,2B except that the magnetic surfaces that were previously located at the side walls are now located on a face ofelectronic device32 and, optionally, an opposing face onarticle30. For example, in the case of an electronic device including a display, the magnetic elements ofmagnetic attachment system34 can be embedded behind the display surface.
• FIG. 3B showsarticle30 andelectronic device32 magnetically attached to each to each other to form cooperatingsystem38. As part ofsystem38,electronic device32 andarticle30 can cooperate with each other to provide features not available byarticle30 orelectronic device32 separately. For example,article30 can take the form of a cover that can provide protective features. In one embodiment, protective cover can be used to support and protectelectronic device32 while being transported or stored (e.g., cover the display surface). Due to the releasable nature of the magnetic attachment betweenmagnetic attachment systems34 and36,article30 can be easily detached whenelectronic device32 is to be used and subsequently re-attached when desired.
• The placement of the magnetic elements can be such that only certain magnetically sensitive elements withinelectronic device32 are affected by the magnetic field generated by the embedded magnetic elements. For example, a Hall Effect sensor can be used to detect whether or notarticle30 is magnetically attached to and covering all or a portion of the display ofelectronic device32 using the magnetic field generated by a magnetic element located inarticle30. On the other hand, a magnetically sensitive element inelectronic device32 such as a compass that relies upon an external magnetic field (i.e., such as that provided by the Earth), must not be unduly affected by magnetic field lines generated by the embedded magnetic elements. Therefore, the magnetic elements can be limited to those locations inelectronic device32 positioned away from magnetically sensitive elements such as the compass.
• FIGS. 4A and 4C are simplified perspective views ofarticle40 that can be releasably attached toelectronic device42 via amagnetic system44. This embodiment is similar to that shown inFIGS. 2A,2B and3A,3B in thatmagnetic system44 can include multiple magnetically attractable elements and thatarticle40 andelectronic device42 generally correspond to those mentioned in previous Figures. For example, one set of magnetically attractablemagnetic elements44acan be placed relative to a side ofarticle40 andelectronic device42 while a second set of magneticallyattractable elements44bcan be placed relative to a face ofarticle40 andelectronic device42. As shown inFIG. 4B, cooperatingsystem46 can be formed by placingarticle40 andelectronic device42 in proximity to each other such thatmagnetic elements44aon the sides ofarticle40 andelectronic device42 magnetically attract each other in addition tomagnetic elements44blocated at the face ofelectronic device42 andarticle40. The overall magnetic attraction generated at the side and face can be sufficient to retainarticle40 andelectronic device42 in a mating engagement to form cooperatingsystem46.
• In one embodiment, as shown inFIG. 4C, cooperatingsystem46 is presented in an open configuration in whicharticle40 is used as a cover forelectronic device42 that can be opened and closed. That is,article40 can act as a protective cover ofelectronic device42. In this embodiment,article40 can include binding48 that attaches along the side ofelectronic device42 and flap50 that attaches to the front face ofelectronic device42 and more particularly,top face52.Top face52 can correspond to a display. In one implementation, flap50 can move relative to binding48. The moving can be widely varied. In one example, flap50 can pivot relative to binding48. The pivot can be widely varied. In one example, the pivot can be enabled by a hinge mechanism. In another example, the pivot can be enabled by a fold. Furthermore, the flap can be rigid, semi-rigid or flexible. In this manner,article40 can form an open configuration where flap50 is positioned away from electronic device42 (display52 can be viewed) and a closed configuration where flap50 is positioned adjacent electronic device42 (display52 is covered as represented by closed embodiment ofFIG. 4B).
• In one embodiment, binding48 is only located on one side while flap50 is only located attop face52. In so doing, the other surfaces ofelectronic device42 are left exposed. As a result, the beauty of the electronic device may be shown off while the article is attached to the electronic device. Further, it may leave better access for I/O and connectivity related functionality (e.g., buttons, connectors, etc.).
• Although the purpose of the magnetic elements is similar, i.e., attach article to electronic device, it should be appreciated that these mechanisms can widely vary. In some cases, the magnetic fields may be configured differently. By way of example, the side mounted magnetic surface may provide a first magnetic force and the front facing magnetic surface may provide a second magnetic force that is different than the first magnetic force. This may be in part due to different holding requirements as well as different surface areas, i.e., available space, and its effect on internal components of the electronic device. In one example, the side mounted magnetic surface provides a greater holding force for securing the article to the electronic device, i.e., it is the primary securing force while the front facing magnetic surface is the secondary securing force.
• In one example, flap50 includes multiple sections that are semi-rigid and bend relative to one another so as to make the flap movable and flexible. In one embodiment, flap50 can be folded into one or more different configurations, and in some cases can be held in these configurations using a magnetic system similar to what is described above. These and other embodiments will be described in greater detail below. Moreover, it should be appreciated that the described embodiments are not limited to covers and that other configurations can be used including for example as an accessory device used as a hanging apparatus, as a support mechanism for the electronic device to improve viewing the display and as a support mechanism for or inputting touch events at a touch sensitive portion of the display, and so on.
• The electronic device and article can take many forms. For the remainder of this discussion, the electronic device is described in terms of a handheld portable computing device. Accordingly,FIG. 5 shows a top perspective view ofelectronic device100 in accordance with the described embodiments.Electronic device100 can process data and more particularly media data such as audio, visual, images, etc. By way of example,electronic device100 can generally correspond to a device that can perform as a smart phone, a music player, a game player, a visual player, a personal digital assistant (PDA), a tablet computer and the like.Electronic device100 can also be hand held. With regards to being handheld,electronic device100 can be held in one hand while being operated by the other hand (i.e., no reference surface such as a desktop is needed). Hence,electronic device100 can be held in one hand while operational input commands can be provided by the other hand. The operational input commands can include operating a volume switch, a hold switch, or by providing inputs to a touch sensitive surface such as a touch sensitive display device or a touch pad.
• Electronic device100 can includehousing102. In some embodiments,housing102 can take the form of a single piece housing formed of any number of materials such as plastic or non-magnetic metal which can be forged, molded, or otherwise formed into a desired shape. In those cases whereelectronic device100 has a metal housing and incorporates radio frequency (RF) based functionality, a portion ofhousing102 can include radio transparent materials such as ceramic, or plastic. Housing102 can be configured to enclose a number of internal components. For example,housing102 can enclose and support various structural and electrical components (including integrated circuit chips) to provide computing operations forelectronic device100. The integrated circuits can take the form of chips, chip sets, or modules any of which can be surface mounted to a printed circuit board, or PCB, or other support structure. For example, a main logic board (MLB) can have integrated circuits mounted thereon that can include at least a microprocessor, semi-conductor memory (such as FLASH), and various support circuits and so on. Housing102 can include opening104 for placing internal components and as necessary can be sized to accommodate display assembly for presenting visual content, the display assembly being covered and protected byprotective layer106. In some cases, the display assembly can be touch sensitive allowing tactile inputs that can be used to provide control signals toelectronic device100. In some cases, the display assembly may be a large prominent display area that covers a majority of the real estate on the front of the electronic device.
• Electronic device100 can include a magnetic attachment system that can be used to magnetically attachelectronic device100 to at least one other suitably configured object. The magnetic attachment system can include a number of magnetic attachment features distributed within and in some cases connected tohousing102. For example, the magnetic attachment system can include firstmagnetic attachment feature108 and secondmagnetic attachment feature110 located on different sides ofelectronic device100. In particular, firstmagnetic attachment feature108 can be located in proximity toside wall102aofhousing102. Secondmagnetic attachment feature110 can be located within opening104near side wall102bofhousing102. In those embodiments whereelectronic device100 includes a display with cover glass substantially fillingopening104,second attachment feature110 can be placed beneath the cover glass.
• The placement of firstmagnetic attachment feature108 atside wall102acan facilitate the use ofmagnetic attachment feature108 to magnetically attachelectronic device100 to another suitably configured object such as another electronic device or an accessory device. Accordingly, without loss of generality, firstmagnetic attachment feature108 will henceforth be referred to asdevice attachment feature108.
• The placement of secondmagnetic attachment feature110, on the other hand, can facilitate the use of secondmagnetic attachment feature110 to secure aspects of another device attached toelectronic device100 by way ofdevice attachment feature108. In this way, the overall attachment between the other device andelectronic device100 can be more secure than attaching throughfirst attachment feature108 alone. Accordingly, and again without loss of generality,second attachment feature110 will henceforth be referred to as securingattachment feature110.
• Although not expressly shown, it is understood that the various magnetic attachment features of the magnetic attachment system can be located at any appropriate location ofhousing102. For example, magnetic attachment features can be located at an interior bottom surface ofhousing102 or alongsides102cand102dofhousing102.
• As shown inFIG. 6,device attachment feature108 and securingattachment feature110 can each include one or more magnetic elements. In one example,device attachment feature108 can multiple magnetic elements that can magnetically interact with each other to provide magnetic field112 (only a portion of which is shown). In other words, the properties (shape, field strength, and so on) ofmagnetic field112 can be based upon the interaction of the magnetic fields generated by each of the magnetic elements. In this way, the properties ofmagnetic field112 can be altered simply by arranging the properties (i.e., physical layout, relative size, and constituent magnetic polarities) of each of the magnetic elements. For example, each of the magnetic elements can have varying sizes and can be disposed along an axis. In this way, the magnetic properties of each of the plurality of magnetic elements can act together to establish the overall properties ofmagnetic field112.
• In some cases, the portion ofmagnetic field112 that is used in the magnetic attachment betweendevice attachment feature108 and another device can be enhanced with the use of a magnetic shunt (not shown). The magnetic shunt can be formed of magnetically active material, such as steel or iron, and be placed in a position that causes magnetic field lines that would otherwise be directed away from the attachment region to be at least partially re-directed towards the attachment region. The re-direction of the magnetic field lines can have the effect of increasing the average magnetic flux density in the attachment region.
• Device attachment feature108 can operate in an active state as in well as an inactive state. Magnetic flux density B₁₁₂can equal or exceed a magnetic flux density threshold B_thresholdinside the exterior surface ofhousing102 but not outside in the inactive state. In other words, magnetic flux density B₁₁₂ofmagnetic field112 at an exterior surface ofhousing102 is less than a magnetic flux density threshold B_threshold. Magnetic flux density threshold B_thresholdrepresenting a magnetic flux value below which magnetically sensitive devices (such a magnetic strip on a credit card) can remain substantially unaffected. In addition, the presence of a magnetically active material (such as steel) in the region outside ofelectronic device100 will not by itself trigger device attachment feature108 to transition from the inactive state to the active state.
• As noted above, whendevice attachment feature108 is inactive, magnetic flux density B₁₁₂ofmagnetic field112 at the exterior surface ofside102aofhousing102 is less than magnetic flux density threshold B_threshold. More particularly, with regards todevice attachment feature108, magnetic flux density B₁₁₂can vary as a function of distance x (i.e., B=B₁₁₂(x)) from the magnetic elements. Therefore, whendevice attachment feature112 is inactive, magnetic flux density B₁₁₂(x) can satisfy Eq. (1).
• 
  B₁₁₂(x=x_o+t)<B_threshold,  Eq. (1)
• where t is thickness ofhousing102 atside102a, and
• • x_odistance from interior ofside102ato the magnetic elements.
• Whendevice attachment feature108 is inactive, any magnetic flux leakage in the near region outside of electronic device100 (i.e., B₁₁₂(x>x_o+t)) is low enough that there is little likelihood that magnetically sensitive devices in the near region are adversely affected. However, it should be noted that even in the inactive state,magnetic field112 can have a value of magnet flux B₁₁₂(x=x_o+t) that satisfies Eq (1), and yet is sufficiently high to interact with the magnetic field of another device placed in relatively close proximity thereto. In this way, the other appropriately configured magnetic attachment feature in the other device can be used to activate devicemagnetic attachment feature108 even though Eq. (1) is satisfied.
• The properties ofmagnetic field112 can include at least field strength, magnetic polarity, and so on. The properties ofmagnetic field112 can be based upon the combination of the magnetic fields from each of the magnetic elements included inmagnetic attachment feature108 The combined magnetic fields can form in the aggregatemagnetic field112. For example, the magnetic elements can be arranged in such a way that the combination of the respective magnetic fields results inmagnetic field112 having desirable magnetic field properties (such as field strength). For example, the combination of one arrangement of magnetic elements can result inmagnetic field112 having characteristics (such a polarity and strength) that are for the most part symmetric about a particular axis (such as a geometric center line).
• On the other hand, the magnetic elements can be arranged in such a way that the combination of the magnetic fields of the magnetic elements can result inmagnetic field112 having at least one property that is anti-symmetric about the center line. For example, a magnetic element on one side of the centerline can be positioned with a North magnetic pole pointing up whereas a corresponding magnetic element on the other side of the centerline can be arranged with a South magnetic pole pointing up. Hence, the magnetic properties ofmagnetic field112 can be adjusted in any manner deemed appropriate to provide a desired mating engagement. For example, the magnetic properties ofmagnetic field112 can be modified by arranging the magnetic elements in such a way thatmagnetic field112 can cooperatively interact with another magnetic field (from another magnetic attachment system, for example). The cooperative interaction between the two magnetic fields can result in the two objects being magnetically attached to each other in a well-defined, precise, and repeatable manner.
• The properties ofmagnetic field112 can be stable. By stable it is meant that the properties of the magnetic field can remain essentially unchanged for an extended period of time. Hence, a stable version ofmagnetic field112 can be created using magnetic elements having properties that are essentially constant (or nearly constant) over an extended period of time or at least any changes in one component is offset by a corresponding change in another component. The magnetic elements can be physically arranged in a fixed or at least substantially fixed configuration with respect other magnetic elements. For example, the magnetic elements can each have fixed sizes and polarities arranged in a specific order relative to each other providing the desired properties (shape, strength, polarity, etc.) ofmagnetic field112. Hence, depending upon the properties and the nature of the magnetic elements, the shape ofmagnetic field112 can remain substantially unchanged over the extended period of time (such as the anticipated operating life of electronic device100).
• In some embodiments, however, the properties ofmagnetic field112 can be varied by modifying a magnetic or other physical property of at least one of the magnetic elements. When at least one magnetic element has magnetic properties (e.g., a polarity or field strength) that can be modified, the resulting magnetic field can also be modified. Accordingly, in some embodiments at least one of the magnetic elements can be characterized as having dynamic magnetic properties. By dynamic it is meant that at least one magnetic property, such as polarity, can be modified. In this way, the magnetic field properties of the resulting magnetic field can also vary. The resulting magnetic field, in turn, can alter the magnetic characteristics ofmagnetic field112 that, in turn, can alter how the magnetic attachment system causes the objects to magnetically attach to each other (alignment, orientation, centering, and so forth). An electromagnet is one example of such a magnetic element whose magnetic properties can be modified as desired. Other examples include a malleable non-magnetic substrate impregnated with magnetic dopant (such as magnetite). In this way, the malleable substrate can be formed into a physical shape that can affect the nature of the magnetic field produced by the magnetic dopant material.
• Turning now to other aspects of the magnetic attachment system, securingattachment feature110 can include one or more ofmagnetic elements116. When a plurality of magnetic elements is used, the arrangement of the plurality ofmagnetic elements116 can be widely varied and can magnetically interact with a cooperating feature on another device. In one embodiment, the plurality ofmagnetic elements116 associated with securingfeature110 can assist in securing at least a portion of another device otherwise attached toelectronic device100 by way ofdevice attachment feature108.
• At least some of the plurality ofmagnetic elements116 can have a fixed size and polarity (along the lines of a simple bar magnet) whereas other of the plurality ofmagnetic elements116 can have magnetic properties that can vary (such as an electromagnet) while still others can be shaped to provide specific magnetic characteristics. For example, at least one of the plurality ofmagnetic elements116 can be positioned and shaped (if need be) to interact with a magnetically responsive circuit included in the other device. Hence, the magnetically responsive circuit can respond to the presence (or absence) of a particular magnetic element(s) of securingfeature110. An example of the magnetically responsive circuit is described above with regards to theHall Effect sensor118.
• It should be noted that the magnetic field generated bymagnetic elements116 should not extend so far that magnetically sensitive circuits within electronic device100 (such as Hall Effect sensor118) are adversely affected. This is particularly important since the magnetic field is not generally contained withinhousing102 since at least a portion of the magnetic field must extend in the z direction in order to interact with the magnetically active portion of other devices. Therefore, the magnetic field in {x,y} must be limited in extent to avoid magnetically sensitive circuits such asHall Effect sensor118 andcompass120.
• In a particular implementation, the magnetic elements ofdevice attachment feature108 can be grouped into distinct magnetic regions. In this way, the magnetic fields from the magnetic regions can superpose to formmagnetic field112. The magnetic regions can include various magnetic elements that can be arranged into groups represented bymagnetic elements126 and128. By grouping the magnetic element into separate magnetic regions, the ability of the magnetic attachment system to provide a magnetic field having desired characteristics can be substantially enhanced.Magnetic elements126 and128 can interact with each other to formmagnetic field112. In the one embodiment, the interaction can take the form of combination of magnetic properties of each ofmagnetic elements126 and128. In some cases, the arrangement ofmagnetic elements126 and128 can be related to each other in order to providemagnetic field112 with desired characteristics. For example,magnetic elements126 can128 can be arranged in such a way relative to one another thatmagnetic field112 is anti-symmetric (or symmetric) about a horizontal center line ofmagnetic attachment feature108. In another embodiment,magnetic field112 can be anti-symmetric (or symmetric) about a vertical center line ofattachment feature108. In still another embodiment,magnetic field112 can be anti-symmetric (or symmetric) both horizontally and vertically.
• FIG. 7A showselectronic device100 in proximity to object200 havingmagnetic attachment feature202. Magnetic attachment feature202 ofobject200 can include magnetic elements each generating an individual magnetic field that can interact with the other to form in the aggregate a resulting magnetic field. The resulting magnetic field can have magnetic characteristics (such as field strength and shape) that can interact withmagnetic field112 ofelectronic device100 to attachelectronic device100 and object200 together in a well-defined, precise, and repeatable manner without mechanical fasteners and nor require external assistance. It should be noted thatmagnetic field208 can be about 2500 Gauss whereasmagnetic field112 can be on the order of about 1400 Gauss whendevice attachment feature108 is inactive.
• Object200 can take many forms including an accessory, peripheral, electronic device or the like. In one embodiment, object200 can take the form of an electronic device along the lines ofelectronic device100. Accordingly,electronic device100 andelectronic device200 can be magnetically attached to each other usingdevice attachment feature108 andmagnetic attachment feature202 to form a cooperative electronic system. The cooperative electronic system can be one in which electronic elements inelectronic device100 and corresponding electronic elements inelectronic device200 cooperate with the other to perform functions that cannot be performed by either of the electronic devices separately. In one embodiment, information can be passed betweenelectronic devices100 and200.
• More specifically,magnetic attachment feature202 can include at leastmagnetic elements204 and206 each of which can generate magnetic fields that cooperate with each other to provide magnetic field208 (only a portion of which is shown). The properties ofmagnetic field208 can be based upon the interaction of each of the plurality ofmagnetic elements204 and206. In this way,magnetic field208 can have properties based upon the physical layout, relative size, and constituent magnetic polarities of each of the plurality ofmagnetic elements204 and206. For example,magnetic elements204 and206 can be disposed along a center line and have magnetic properties that superpose to providemagnetic field208 with desired properties. Magnetic flux density B₂₀₈ofmagnetic field208 ofobject200 can vary as a function of distance x (i.e., B=B₂₀₈(x)) frommagnetic elements204 and206.
• Whenobject200 takes the form of an electronic device such aselectronic device100, then magnetic flux density B₂₀₈satisfies Eq. (1). However, whenobject200 takes the form of an accessory device, then unlike magnetic flux density B₁₁₂ofelectronic device100, which satisfies Eq. (1), magnetic flux density B₂₀₈(x) ofaccessory device200 can satisfy Eq. (2).
• 
  B₂₀₈(x=x₁+s)>B_threshold  Eq. (2)
• where s is thickness ofhousing212 atside212a, and
• • x₁interior separation distance.
• In this way,accessory device200 can magnetically interact withelectronic device100 further removed fromelectronic device100 than would otherwise be possible. Hence,accessory device200 can be placed near but not necessarily close toelectronic device100 in order forelectronic device100 and object200 to magnetically attach to each other in a well-defined, predictable, and repeatable manner.
• In addition tomagnetic attachment feature202,accessory device200 can further includemagnetic attachment feature216 that can be used to interact with securingattachment feature110. Magnetic attachment feature216 can include a variety of magnetically active components. Some of the magnetic elements can take the form of magnetic elements arranged to cooperatively interact with corresponding magnetic elements in securingattachment feature110. Other of the magnetic element can be more passive in nature in that they provide a mechanism for completing a magnetic circuit with magnetically active elements in securingattachment feature110. An example of a magnetically passive element is a ferromagnetic material, such as iron or steel, that can be interact with a magnetic element actively providing an associated magnetic field. In this way, the ferromagnetic material can interact with the magnetic field to complete a magnetic circuit between the passive element inattachment feature216 and the active element in securingattachment feature110.
• FIG. 7B shows thataccessory device200 can be used to provide support functions and services forelectronic device100. By allowing a portion ofmagnetic field208 having magnetic flux density B₂₀₈satisfying Eq. (2) to extend intoregion214, magnetic attractive force F_netbetweendevice attachment feature108 andaccessory attachment feature202 can be created where net attractive force F_netsatisfies Eq. (3a) and Eq. (3b).
• 
  F_net=(L_total)·B²/μ₀  Eq. (3a)
• 
  B/B₀=f(x_sep)  Eq. (3b)
• where
• • L_totalis total surface area of magnetic elements
  • B is total magnetic flux density (B₂₀₈+B₁₁₂)
  • x_sepis separation distance between magnetic elements,
  • B₀is magnetic flux density at surface of magnetic regions.
• Net magnetic attraction force F_netdue to the interaction ofmagnetic field208 andmagnetic field112, attachment feature202 can be used to activatedevice attachment feature108. Moreover, whendevice attachment feature108 is activated, magnetic flux density B₁₁₂now satisfies Eq. (4).
• 
  B₁₁₂(x=x_o+t)>B_threshold,  Eq. (4) in active state.
• This increase in magnetic flux density B₁₁₂inregion214 can result in a substantial increase in net magnetic attractive force F_netbetweenaccessory device200 andelectronic device100. Moreover, since net attractive force F_netvaries with total magnetic flux density B (B₂₀₈+B₁₁₂) and flux density B in general can vary inversely with the separation distance (i.e., Eq. 3(b)), aselectronic device100 andaccessory device200 approach each other and separation distance x_sepdecreases to a limiting value consistent with physical contact ofelectronic device100 andaccessory device200, the increase in net attractive force F_netcan increase sharply in a relatively short amount of time. This sharp increase in net attractive force F_netcan cause the devices to quickly snap together in what can be referred to as “snapping into place” as shown inFIG. 7C showing cooperatingsystem300 in the form ofelectronic device100 magnetically attached toaccessory device200 alongengagement surface218. It should be noted that in a representative embodiment, the magnetic elements indevice attachment feature108 can be N52 type magnets whereas magnetic elements inattachment feature216 can be N35 type magnets. Moreover, the net magnetic attractive force can be on the order of about 10 newtons to at least20 newtons where it can require about 3 newtons to activatedevice attachment feature108.
• The overall magnetic attractive force F_NETbetweendevice100 anddevice200 atengagement surface218 can be derived as the summation of all the net magnetic attractive forces F_net, for all actively coupled magnetic elements. In other words, the overall net magnetic attractive force F_NETsatisfies Eq. (5).
• 
  F_NET=Σ₁ⁿF_neti  Eq. (5)
• where F_netiis the net magnetic attractive force for each of n components. In one embodiment, net magnetic attractive force F_netiis substantially perpendicular to that portion ofengagement surface218 intersected bymagnetic field112 andmagnetic field208.
• In order to assure that overall magnetic attachment force F_NETis uniform along the engagement surface betweendevice100 anddevice200, the separation distances between each corresponding magnetic element in attachment features108 and202 are well controlled. The separation distance can be well controlled by, for example, shaping the magnetic elements to conform to the shape of the devices. For example, ifdevice100 has a spline (curved) shaped housing, the magnetic elements indevice100 can be shaped to conform to the curved shape. In addition, the magnetic elements can be formed in such a way that the magnetic vectors of corresponding magnetic elements align with each other. In this way, the magnitude and direction of the net magnetic attractive force can be controlled as desired.
• One result of the aligning of the magnetic vectors is that the direction of the net magnetic force between each magnetic element can be well controlled. Moreover, by reducing the separation distance between corresponding magnetic elements to a minimum, the net attractive magnetic force F_netibetween each magnetic element can be maximized. In addition, maintaining a substantially uniform separation distance between the various magnetic elements, a correspondingly uniform magnetic attachment force can be provided alongengagement surface218. Moreover, by appropriately adjusting the corresponding magnetic vectors, F_netcan be applied normally to the engagement surface.
• In addition to minimizing the separation distance between corresponding magnetic elements, the magnetic flux density between the corresponding magnetic elements can be increased by using magnetic shunts. A magnetic shunt formed of magnetically active material such as iron or steel can be placed on or near a magnetic element having the effect of directing magnetic flux lines in a desired direction. In this way, for example, magnetic flux lines that would otherwise propagate in a direction away from a corresponding magnetic element can be partially re-directed towards a desired direction, such as towards a magnetic attachment region between the devices thereby increasing the overall magnetic flux density. Hence, increasing the available magnetic flux density between the magnetic elements can result in a substantial increase in the net magnetic attractive force.
• FIG. 8A shows an embodiment ofattachment feature110. In particular, attachment feature110 can be part ofhousing102. In particular, attachment feature can includemagnetic elements402 that can be mounted toledge404 ofhousing102Magnetic elements402 can be widely varied. For example,magnetic elements402 can be spatially arranged as an array onledge404 to be used to attach and secure at least a portion of an accessory device to a particular aspect ofelectronic device100. For example, when the accessory device takes the form of a flap, themagnetic elements402 can be used to magnetically secure the flap toelectronic device100 to cover at least a portion of a display. The size and shape of the array can also be widely varied. In the embodiment shown inFIG. 8A, the array can be rectangular and sized to encompass a substantial portion ofledge404.
• FIG. 8B shows a plurality ofmagnetic elements410 that can be incorporated into an accessory device as part ofattachment feature216. Some but not all of the plurality ofmagnetic elements410 can correspond tomagnetic elements402 and be used to magnetically attachaccessory200 toelectronic device100. In another embodiment, all or most of the plurality ofmagnetic elements410 can be used to secure portions ofaccessory device200 together to form other support structures that can be used in conjunction withelectronic device100. In one embodiment,magnetic element414 can be used to activate a magnetically sensitive circuit such asHall Effect sensor118.
• FIGS. 9A-9C show representativemagnetic attachment feature500 in accordance with a described embodiment. Magnetic attachment feature500 can, for example, correspond to device attachment feature108 shownFIG. 6 andFIGS. 7A-7C. In the inactive state, the magnetic elements withinmagnetic attachment feature500 can be positioned away fromhousing102 to minimize the magnetic field lines that propagate through102. On the other hand, in the active state, the magnetic elements can move towardshousing102 in order to increase the number of magnetic field lines that propagate throughhousing102 thereby satisfying Eq. (2).
• The manner in which the magnetic elements moves can be widely varied. For example, the magnetic elements can rotate, pivot, translate, slide or the like. In one example, the magnetic elements can be positioned within a channel that allows the magnetic elements to slide from a first position corresponding to the inactive state to a second position corresponding to the active state.
• In the particular embodiment shown inFIGS. 9A-9C, attachment feature500 can includemagnetic element502 having magnetic properties that can remain stable over a period of time. For example, it can be desired that the magnetic attachment properties remain stable over the expected operating life ofelectronic device100. In this way, the magnetic field formed by the interaction of the magnetic fields of each of the magnets will also remain stable. The stability of the magnetic field can result in a very repeatable attachment process. This repeatability is particularly useful whenelectronic device100 undergoes numerous and repeated attachment cycles (attach/detach) with other appropriately configured objects such asaccessory device200 that requires a consistently accurate placement.
• In the representative embodiment shown,magnetic element502 can take many forms. For example,magnetic element502 can take the form of a number of magnets arranged in a specific order and configuration having stable magnetic properties (such as polarity and intrinsic magnetic strength). However, in order to satisfy Eq. (1) whenmagnetic attachment feature500 is inactive,magnetic element502 must remain at least distance x=(x₀+t) from the exterior ofhousing102. In other words, in order to satisfy Eq. (1), the dimensions ofdevice attachment feature500 must take into consideration at least the magnetic properties and physical layout ofmagnetic element502.
• Accordingly,magnetic element502 can be attached to retainingmechanism504 arranged to exert retaining force F_retain. Retaining force F_retaincan be used to retainmagnetic element502 at a position withindevice attachment feature500 resulting in little or no magnetic flux leakage outside of electronic device100 (i.e., Eq. (1) is satisfied) whendevice attachment feature500 is inactive. In one embodiment, retainingmechanism504 can take the form of a spring arranged to provide retaining force F_retainaccording to Eq. (6):
• 
  F_retain=k·Δx  Eq. (6)
• where k is spring constant of retainingmechanism504, and
• • Δx is spring displacement from equilibrium.
• For example,FIG. 9B shows representativemagnetic attachment feature500 in an active state. By appropriately configuringmagnetic element502 and those inaccessory attachment feature204, the resulting magnetic interaction of the magnetic field ofmagnetic element502 and that generated byaccessory attachment feature204 can create a net attractive magnetic force at least as great as that required to activatemagnetic attachment feature500. In other words, the net attractive magnetic force can have a magnitude at least that of activation force F_actsatisfying Eq. (7) thereby overcoming retaining force F_retaincausingmagnetic element502 to move from the inactive position (i.e., x=0) to the active position (i.e., x=x₀),
• 
  F_act≧F_retain(Δx=x_o)  Eq. (7).
• However, only another magnetic attachment feature that generates a magnetic field having properties that “match” the magnetic field properties ofmagnetic element502 can activatemagnetic attachment feature500. Therefore, as shown inFIG. 9C, the presence ofobject506 formed of magnetically active material (such as steel) located at the exterior surface of housing102 (i.e., x=x₀+t) cannot activatemagnetic attachment feature500. More specifically, in one embodiment the net magnetic attractive force generated betweenobject506 andmagnetic attachment feature500 less than 2 NT, whereas activation force F_ACTcan be on the order of about 3 NT.
• More specifically, in order to transition from the inactive to the active state, the magnetic force created betweenmagnetic element502 and object506 must be greater than activation force F_act. However, since the magnetic flux density of the magnetic field generated bymagnetic element502 at the exterior surface ofhousing102 is less than B_threshold, any magnetic force generated betweenobject506 andmagnetic element502 is substantially less than F_retainand therefore fails to satisfy Eq. (7). Hence,magnetic element502 remains fixed in place at about x=0 andmagnetic attachment feature500 cannot undergo the transition from the inactive to the active state.
• It should be appreciated that the spring can be widely varied. For example, it may vary depending on the type of movement. Examples include tension, compression, torsion, leaf and the like. In one particular implementation, leaf springs are used.
• It should also be noted that in some embodiments,magnetic element502 can be fixed in such a way that no spring is needed. In these embodiments, although Eq. (1) may not be satisfied, it can nonetheless be a practical arrangement.
• FIG. 10 shows an embodiment of device attachment feature600 in accordance with one embodiment of the present invention.Attachment feature600 can correspond toelement208 inFIG. 6 andFIGS. 7A-7C. This embodiment is similar to the embodiment shown inFIGS. 9A-9C except that instead of a single mechanism, multiple mechanisms and more particularly a pair of mechanisms in the form ofmagnetic element602 andmagnetic element604 are used. In particular,FIG. 10 shows device attachment feature600 in the active state. More specifically,spring606 attached tomagnetic element602 and spring608 attached tomagnetic element604 are each extended by distance Δx.
• In this system, the two mechanisms cooperate to form the magnetic field. They can move independently or they can be connected together and move as a unit. The spring forces and the magnetic forces can vary. For example, system can be symmetric or asymmetric. The arrangement of magnetic elements may be similar or different. Again being symmetric or asymmetric. The configuration may depend on the needs of the system.
• The magnetic attachment system can take many forms each of which provides for a repeatable and precise magnetic attachment mechanism that can be used to attach multiple suitably configured objects together.
• FIGS. 11A-11B show a specific implementation of device attachment feature108 in the form of device attachment feature700 in accordance with one embodiment. The device attachment feature can correspond toelement108 shown inFIG. 6 andFIGS. 7A-7C. In some cases,device attachment feature700 can be used in conjunction withsprings606 and608 as shown inFIG. 10. As shown inFIG. 11A,device attachment feature700. In particular,device attachment feature700 is shown in the inactive state having magnetic elements in the form ofmagnetic assembly702 that can be enclosed within an enclosure. In this way, a retaining mechanism (not shown) attached tomagnetic assembly702 can exert associated retaining force F_retain. Retaining force F_retaincan be used to maintainmagnetic assembly702 at a position consistent with device attachment feature700 being in the inactive state (i.e., satisfying Eq. (1)).
• Magnetic assembly702 can each include individual magnets. In the described embodiment, the individual magnets can be arranged in a structure in which the polarities of the magnets can be oriented to form a coded magnetic structure. The coded magnetic structure can be formed of a sequence of magnetic polarities and in some cases magnetic strength. In other words, the sequence of magnetic polarities can be represented, for example, as {+1, +1, −1, +1, −1, +1, −1, −1}. For this particular example, “+1” indicates the direction and strength of the magnet. Hence, a positive sign “+” can indicate that the corresponding magnet is aligned having a magnetic vector in a particular direction, a negative sign “−” can indicate a magnetic vector in an opposite direction and “1” indicates a strength of one unit magnet.
• When a plurality of magnets of the same polarity are placed next to each other, the magnetic fields from each of the plurality of magnets can combine such that the plurality of magnets can be considered equivalent to a single magnet, the single magnet having the combined properties of the plurality of magnets. For example, the coded magnetic sequence {+1, +1, −1, +1, −1, +1, −1, −1} representing eight individual magnets can be considered equivalent to the coded magnetic sequence {+2, −1, +1, −1, +1, −2} embodied as an array of six individual magnets. In one embodiment, the magnets in a first and last position can possess the same magnetic strength as the other magnets in the array but twice their respective size. On the other hand, the magnets in the first and last position can have about the same size as the other magnets but possess twice the magnetic strength of the other magnets. In any case, the equivalency of magnetic properties can provide for a more compact coded sequence of magnets. The smaller size can help reduce weight as well as preserve the amount of valuable internal real estate required to house the magnetic attachment feature. In addition, since magnetic flux density is directly related to that area through which magnetic field lines propagate, as the area through which a given magnetic flux propagates decreases, the resulting magnetic flux density increases.
• In one embodiment,magnetic assembly702 can includeindividual magnets712a,712b, and712chaving relative sizes of 2L, 1L, and 1L, respectively, where “L” represents a unit length. It should be noted that as discussed above a magnet having a relative size of “2L” can be embodied as either a single magnet having a physical length of “2L”, two magnets side by side each having a length “1L” with the magnetic poles aligned with each other, or a magnet of unit length L having twice the magnetic strength of the other magnets. Accordingly, for the remainder of this discussion, with regards to theterms 2L and 1L, “L” can represent a unit length and the relative strength of the magnet can be represented by the associated digit. For example, a magnet having a relative magnetic strength of “1” but a length of “2L” can be considered equivalent to a magnet having a relative strength of “2” and a length of “1L”. In this way, both the relative magnetic strengths, and orientation can be used to form the coded magnetic structure.
• For example,magnet712acan have an overall length of approximately twice that ofmagnets712bor712c. On the other hand,magnet712acan have the same length asmagnets712band712cbut have an inherent magnetic strength twice that ofmagnets712band712c. In yet another embodiment,magnet712acan be an equivalent magnet formed of two (or more) constituent magnets having their respective polarities aligned.
• In one embodiment,magnets712a, b, ccan each be spaced apart from each other a predetermined distance. For example, in one implementation, the magnets can be spaced equidistant from each other. This spacing is, of course, predicated upon the desired magnetic properties of the magnetic field generated. In another embodiment, those magnets having anti-aligned polarities can be magnetically attached to each other. In this way, the magnetic bond formed between the adjacent magnets can be used to maintain the integrity of the sequence of magnets in the magnetic assembly. However, those magnets having aligned polarities must be held together by an externally applied force to overcome the repulsive magnetic force generated between the two aligned magnets.
• In addition to size and positioning, the magnetic polarities ofmagnets712a, b, ccan be selected based upon the desired properties of the magnetic field generated. In the embodiment shown, however, the magnetic elements are magnetically coupled to each other end to end thereby reducing the amount of space required and increasing the magnetic flux density by reducing an overall region in which the magnetic field lines are propagated.
• In particular,magnetic assembly702 can have a specific magnetic polarity pattern set in which each ofmagnets712a, b, care oriented in such a way that their N or S magnet poles are aligned (or anti-aligned) in a particular manner. For example, the magnets inmagnetic assembly702 can be arranged to form first coded magnetic structure {+1, −1, +1} in which the magnetic poles ofmagnets712a, b, care aligned according to first magnetic polarity pattern {P1, P2, P1} by which it is meant that the magnetic pole ofmagnet712ais anti-aligned relative to magnet712bwhich in turn is anti-aligned withmagnet712c.
• Magnetic assembly702 can also includeindividual magnets714a,b,cand having relative sizes of 1L, 1L, and 2L, respectively. Furthermore,magnets714a, b, ccan be arranged to have their respective magnetic poles aligned in accordance with second magnetic polarity pattern {P2, P1, P2} that is the inverse (or complement) of first magnetic polarity pattern {P1, P2, P1}. In terms of coded magnetic structure,magnets714a,b,ccan be aligned according to second coded magnetic sequence {−1, +1, −1} that is the inverse, or complement, of first coded magnetic structure {+1, −1, +1}. This anti-symmetric relationship betweenmagnets712a,b,cand714a,b,cprovides a magnetic field that is anti-symmetric with respect tocenter line716.
• FIGS. 11A and 11B also show specific implementation ofaccessory attachment feature800 that can, for example, correspond toelement202 shown inFIG. 6 andFIGS. 7A-7C.Magnetic assemblies802 can include a number of magnetic elements. The magnetic elements can be arranged in such a way that the combined magnetic field matches the magnetic field ofmagnetic assembly702.
• Magnetic assembly802 can includemagnets802a,802b, and802ceach being about the same size as correspondingmagnet712a,712b, and712cinmagnetic assembly702. However, in order to maximize net attraction force F_netand drive the magnetic interaction between the magnetic fields to a desired equilibrium,magnets802a, b, care aligned based upon second magnetic polarity pattern {P2, P1, P2}.Magnetic assembly802 can also includemagnets804a,804b, and804ceach being about the same size as correspondingmagnets714a,714b, and714c. Moreover, in keeping with the overall goal of the magnetic interaction between the magnetic fields to equilibrate at the desired configuration of the devices,magnets804a, b, ccan be aligned according to first magnetic polarity pattern {P1, P2, P1}.
• FIG. 11B shows device attachment feature700 in the active state due to the magnetic interaction betweenmagnetic assemblies702 and802. In particular, since the arrangement of magnetic elements betweenattachment feature700 and those inaccessory attachment feature800 “match”, then the magnetic interaction between the magnetic fields can causemagnetic assemblies702 to move from the inactive state (i.e., x=0) to the active state (i.e., x=x₀).
• FIG. 12 illustrates a sequence of relative shift positions for the magnetic structure ofmagnetic assembly702 and the complementary magnet structure ofmagnetic assembly802.Magnetic assembly702 is shown to be encoded with coded magnetic sequence {+2, −1, +1, −1, +1, −2}.Magnetic assembly802 is shown to be encoded with complementary coded magnetic sequence {−2, +1, −1, +1, −1, +2}. For this example, the magnets can have the same or substantially the same magnetic field strength (or amplitude), which for the sake of this example is provided a unit of 1 (where A=Attract, R=Repel, A=−R, A=1, R=−1). In this example,magnetic assemblies702 and802 are moved relative to each other one “1L” length at a time (note that the anti-symmetry aboutcenter line716 of the coded magnetic sequence allows that the results of a leftward shift mirror the results of a rightward shift, therefore, only a rightward shift is shown).
• For each relative alignment, the number of magnets that repel plus the number of magnets that attract is calculated, where each alignment has a total force in accordance with a magnetic force function based upon the magnetic field strengths of the magnets. In other words, the total magnetic force between the first and second magnet structures can be determined as the sum from left to right along the structure of the individual forces, at each magnet position, of each magnet or magnet pair interacting with its directly opposite corresponding magnet in the opposite magnet structure. Where only one magnet exists, the corresponding magnet is zero, and the force is zero. Where two magnets exist, the force is R for equal poles or A for opposite poles for each unit magnet.
• The total magnetic force can be computed for each of the figures and shown with each figure along with the relative shift value. Accordingly, using a specific coded magnetic sequence {+2, −1, +1, −1, +1, −2} can result in net magnetic attractive force F_netvarying from −3 (i.e., 3R) to +8 (i.e., +8A) where the peak occurs whenmagnetic assemblies702 and802 are aligned such that their respective codes are also aligned. It should be noted that the off peak net magnetic force can vary from −3 to +4. As such, the net magnetic force can causemagnetic assemblies702 to generally repel each other unless they are aligned such that each of their magnets is correlated with a complementary magnet (i.e., a magnet's South pole aligns with another magnet's North pole, or vice versa). In other words,magnetic assemblies702 and802 highly correlate when they are aligned such that they substantially mirror each other.
• It should also be noted that whenmagnetic assemblies702 and802 are 180° out of phase (i.e., something akin to top to bottom mis-alignment also referred to as upside down) the net magnetic force generated can be on the order of 8R. Hence, it is highly unlikely that devices being magnetically attached to each other usingmagnetic assemblies702 and802 can be attached upside down.
• FIG. 13 illustratesgraph900 of function F_NET(L). Function F_NET(L) describes net magnetic force F_NETas a function of shift displacement (L) shown inFIG. 12 for the coded magnet structures inmagnetic assembly702 andmagnetic assembly802. It should be noted that the symmetric nature of the coded magnetic structures inmagnetic assemblies702 and802 aboutcenter line716 provides that function F_NET(L) is also anti-symmetric aboutcenter line716. In this way, the results ofFIG. 12 can be plotted on the right side ofcenter line716 and reflected aboutcenter line716 to populate the left side ofgraph900.
• As shown inFIG. 13, function F_NET(L) has a global maximum value whenmagnetic assemblies702 and802 correlate at a position corresponding tocenter line716. In other words, function F_NET(L=0) reaches a maximum (i.e., 8A) when all magnetic elements inmagnetic assemblies702 and802 having opposite polarities align with each other. Any other configuration (i.e., F_NET(L≠0) results in net magnetic force F_NETbeing less than the global maximum value (of 8A). It should further be noted, however, that function F_NET(L) has at least two local maxima values (i.e., F_NET(L=±3)) that permits a weak attachment betweenmagnetic assemblies702 and802. However, a strong, durable attachment can only occur when devicemagnetic attachment feature700 associated withmagnetic assembly702 is properly activated. Therefore, by establishing activation force F_ACTsatisfying Eq. (8), a “false activations” of devicemagnetic attachment feature700 or a weak attachment betweenmagnetic assemblies702 and802 can be avoided.
• 
  F_NET(L=local maxima)<F_ACT<F_NET(L=global maximum)  Eq. (8).
• It should also be noted that activation force F_ACTis related to retaining force F_retainthrough Eq. (6). In this way, Eq. (6) and Eq. (8) in view of function F_NET(L) can be can be used to determine a suitable value for spring constant k.
• FIGS. 14 and 15 show other embodiments where magnetic elements can be arranged vertically and horizontally. In addition, the magnetic elements can be sized to have polarities that also extend both horizontally and vertically. For example,arrangement1000 shows two rows of magnetic elements where each magnetic element extends height H in the vertical direction. In the arrangement shown, each vertically arranged magnetic element has the same magnetic polarity forming equivalentmagnetic structure1002. In other words, botharrangement1000 andarrangement1002 can be both be characterized as having the coded magnetic sequence {+2, −2, +2, −2, +2, −2}.
• FIG. 15 shows a top view of magnetic array configured as two dimensional codedmagnetic sequence1004 in accordance with the described embodiments. Two dimensional codedmagnetic sequence1004 can be used to extend the combined magnetic field over an area that extends in both the x and y directions. This extended area can result in an overall increase in the area available to propagate magnetic field lines that can result in an increase in magnetic flux and a commensurate increase in net magnetic attractive force. In addition to providing an improved magnetic attachment, two dimensional codedmagnetic sequence1004 can approximate non-integer values of magnetic properties, such as magnetic strength. For example, withmagnetic arrangement1004, the magnetic fields of the various components can combine to approximate the coded magnetic sequence {+1.5, −1.5, +1.5, −1.5, +1.5, −1.5}. Furthermore, two dimensional codedmagnetic sequence1004 can assist in providing a vertical alignment in addition to a horizontal alignment.
• For the remainder of this discussion, various embodiments ofaccessory device200 are discussed.
• In one embodiment,accessory device200 can include a number of protective elements that can be used to protect certain aspects ofelectronic device100. For example,accessory device200 can take the form of a protective cover. The protective cover can include a flap pivotally connected to a hinge assembly. The hinge assembly can, in turn, be coupled toelectronic device100 by way ofaccessory attachment feature202. In this way, the flap portion can be used as a protective cover to protect aspects ofelectronic device100 such as a display. The flap can be formed of various materials such as plastic, cloth, and so forth. The flap can be segmented in such a way that a segment of the flap can be lifted to expose a corresponding portion of the display. The flap can also include a functional element that can cooperate with a corresponding functional element inelectronic device100. In this way, manipulating the flap can result in an alteration in the operation ofelectronic device100.
• The flap can include magnetic material that can be used to activate a magnetically sensitive circuit inelectronic device100 based upon, for example, the Hall Effect. The magnetically sensitive circuit can respond by generating a signal that can, in turn, be used to alter an operating state ofelectronic device100. Since the cover can be easily attached directly to the housing of the tablet device without fasteners, the cover can essentially conform to the shape ofelectronic device100. In this way, the cover will not detract or otherwise obscure the look and feel ofelectronic device100.
• In one embodiment,accessory device200 can be used to enhance the overall functionality ofelectronic device100. For example,accessory device200 can be configured to act as a hanging apparatus. When magnetically attached toelectronic device100,accessory device200 can be used to hangelectronic device100. In this way,electronic device100 can be used as a display for presenting visual content such as art, movies, photos and so forth on a wall or suspended from a ceiling. As a hanging apparatus,accessory device200 can be used to hangelectronic device100 from a wall or a ceiling.Electronic device100 can be easily removed by simply exerting a releasing force sufficient to overcome the net magnetic attractive force F_NET. Accessory device200 can be left in place and be used to reattach electronic device100 (or another device) at a later time.
• In one embodiment,accessory device200 can also take the form of a holding mechanism for attaching objects that are not by themselves equipped to magnetically attach toelectronic device100. For example,accessory device200 can be configured to carry a stylus or other such input device. The stylus can be used to provide inputs to the electronic device. In some cases,accessory device200 can provide a signal toelectronic device100 indicating the presence of the stylus. The signal can causeelectronic device100 to enter into a stylus recognition state, for example. More particularly, whenaccessory device200 is magnetically attached toelectronic device100,electronic device100 can activate a stylus input state in order to recognize stylus type inputs. Whenaccessory device200 is removed,electronic device100 can de-activate the stylus input state. In this way, the stylus can be conveniently attached/detached toelectronic device100 when needed.
• Accessory device200 can take the form of a support that can be used to enhance the functionality ofelectronic device100. For example,accessory device200 can be configured to act as a display stand on which a display ofelectronic device100 can be viewed at a comfortable viewing angle such as 75°. In other words, when placed upon a horizontal surface such as a table or desk,accessory device200 can supportelectronic device100 in such a way that the visual content presented at the display can be viewed at about a viewing angle of approximately 75°.
• Accessory device200 can also take the form of a support that can be used to enhance the functionality ofelectronic device100 in a keyboard state. In the keyboard state,accessory device200 can be used to present a touch pad surface at an angle that is ergonomically friendly. In this way, input touch events can be applied (to a virtual keyboard, for example) at an angle that does not overtax a user's wrist, hands, arms, etc.
• The remainder of this discussion will describe particular embodiments of devices that can use the magnetic attachment system. In particular,FIG. 16A andFIG. 16B showelectronic device100 presented in terms oftablet device1100 andaccessory device200 is shown ascover assembly1200 each in perspective top views These elements may generally correspond to any of those previously mentioned. In particular,FIGS. 16A and 16B shows two perspective views oftablet device1100 and coverassembly1200 in the open configuration. For example,FIG. 16A shows device attachment feature108 included intablet device1100 and its relationship totablet device1100.FIG. 16B, on the other hand, is the view presented inFIG. 16A rotated about 180° to provide a second view ofattachment feature202 and its relationship withcover assembly1200.
• Tablet device1100 can take the form of a tablet computing device such as the iPad™ manufactured by Apple Inc. of Cupertino, Calif. Referring now toFIG. 16A,tablet device1100 can includehousing1102 that can enclose and supportdevice attachment feature108. In order to not interfere with the magnetic field generated bydevice attachment feature108, at least that portion ofhousing1102 nearestdevice attachment feature108 can be formed of any number of non-magnetic materials such as plastic or non-magnetic metal such as aluminum.Housing1102 can also enclose and support internally various structural and electrical components (including integrated circuit chips and other circuitry) to provide computing operations fortablet device1100.Housing1102 can includeopening1104 for placing internal components and can be sized to accommodate a display assembly or system suitable for providing a user with at least visual content as for example via a display. In some cases, the display assembly can include touch sensitive capabilities providing the user with the ability to provide tactile inputs totablet device1100 using touch inputs. The display assembly can be formed of a number of layers including a topmost layer taking the form oftransparent cover glass1106 formed of polycarbonate or other appropriate plastic or highly polished glass. Using highly polished glass,cover glass1106 can take the form ofcover glass1106 substantially fillingopening1104.
• Although not shown, the display assembly underlyingcover glass1106 can be used to display images using any suitable display technology, such as LCD, LED, OLED, electronic or e-inks, and so on. The display assembly can be placed and secured within the cavity using a variety of mechanisms. In one embodiment, the display assembly is snapped into the cavity. It can be placed flush with the adjacent portion of the housing. In this way, the display can present visual content that can include visual, still images, as well as icons such as graphical user interface (GUI) that can provide information the user (e.g., text, objects, graphics) as well as receive user provided inputs. In some cases, displayed icons can be moved by a user to a more convenient location on the display.
• In some embodiments, a display mask can be applied to, or incorporated within or undercover glass1106. The display mask can be used to accent an unmasked portion of the display used to present visual content and can be used to make less obviousdevice attachment feature108 and securingattachment feature110.
• Tablet device1100 can include various ports that can be used to pass information betweentablet device1100 and the external environment. In particular,data port1108 can facilitate the transfer of data and power whereasspeakers1110 can be used to output audio content.Home button1112 can be used to provide an input signal that can be used by a processor included intablet device1100. The processor can use the signal fromhome button1112 to alter the operating state oftablet device1100. For example,home button1112 can be used to reset a currently active page presented by the display assembly.
• In one embodiment,accessory device200 can take theform cover assembly1200.Cover assembly1200 can have a look and feel that complements that of thetablet device1100 adding to overall look and feel oftablet device1100.Cover assembly1200 is shown inFIGS. 16A and 16B attached totablet device1100 in an open configuration in whichcover glass1106 is fully viewable.Cover assembly1200 can includeflap1202. In one embodiment,flap1202 can have a size and shape in accordance withcover glass1106.Flap1202 can be pivotally connected toaccessory attachment feature202 by way of a hinge assembly (not shown). The magnetic attachment force betweenattachment feature202 anddevice attachment feature108 can maintaincover assembly1200 andtablet device1100 in a proper orientation and placement vis-a-vis flap1202 andcover glass1106. By proper orientation it is meant thatcover assembly1200 can only properly attach totablet device1100 havingflap1202 andcover glass1106 aligned in a mating engagement. The mating arrangement betweencover glass1106 andflap1202 is such thatflap1202 covers substantially all ofcover glass1106 whenflap1202 is placed in contact withcover glass1106 as shown inFIG. 17A below.
• FIGS. 17A and 17B showcover assembly1200 andtablet device1100 magnetically attached to each other.FIG. 17A shows a closed configuration in whichcover glass1106 is fully covered by and in contact withflap1202.Cover assembly1200 can pivot abouthinge assembly1204 from the closed configuration ofFIG. 17A to an open configuration ofFIG. 17B. In the closed configuration,inner layer1206 ofcover assembly1200 can come in direct contact withcover glass1106. In one embodiment,inner layer1206 can be formed of material that can passivelyclean cover glass1106. The passive cleaning byinner layer1206 ofcover glass1106 can be accomplished by movements of those portions ofinner layer1206 in contact withcover glass1106. In a particular embodiment,inner layer1206 can be formed of a microfiber material.
• In order to transition from the closed to the open configuration, releasing force F_releasecan be applied toflap1202. Releasing force F_releasecan overcome the magnetic attractive force between attachment feature216 inflap1202 and attachment feature110 intablet device1100. Hence,cover assembly1200 can be secured totablet device1100 until releasing force F_releaseis applied toflap1202. In this way,flap1202 can be used to protectcover glass1106. For example,cover assembly1200 can be magnetically attached totablet device1100.Flap1202 can then be placed upon and magnetically secured to coverglass1106 by the magnetic interaction between magnetic attachment features110 and216.Flap1202 can be detached fromcover glass1106 by the application of releasing force F_releasedirectly toflap1202. Releasing force F_releasecan overcome the magnetic attraction between magnetic attachment features110 and216. Hence,flap1202 can then move away fromcover glass1106 unhindered.
• In order to maintain a good magnetic attachment betweenflap1202 andmagnetic attachment feature110,flap1202 can include a number of magnetic elements. Some of the magnetic elements inflap1202 can interact with corresponding magnetic elements inmagnetic attachment feature110. The net magnetic attractive force generated between the magnetic elements can be strong enough to prevent inadvertent release offlap1202 fromcover glass1106 during normal handling. The net magnetic attractive force, however, can be overcome by releasing force F_release.
• FIG. 18 shows a top view of a specific embodiment ofcover assembly1200 in the form ofsegmented cover assembly1300.Segmented cover assembly1300 can includebody1302.Body1302 can have a size and shape in accordance withcover glass1106 oftablet1100.Body1302 can be formed from a single piece of foldable or pliable material.Body1302 can also be divided into segments separated from each other by a folding region. In this way, the segments can be folded with respect to each other at the folding regions. In one embodiment,body1302 can be formed layers of material attached to one another forming a laminate structure. Each layer can take the form of a single piece of material that can have a size and shape in conformance withbody1302. Each layer can also have a size and shape that correspond to only a portion ofbody1302. For example, a layer of rigid or semi-rigid material about the same size and shape of a segment can be attached to or otherwise associated with the segment. In another example, a layer of rigid or semi-rigid material having a size and shape in accordance withbody1302 can be used to providesegmented cover assembly1300 as a whole with a resilient foundation. It should be noted that the layers can each be formed of materials having desired properties. For example, a layer ofsegmented cover assembly1300 that comes in contact with delicate surfaces such as glass can be formed of a soft material that will mar or otherwise damage the delicate surface. In another embodiment, a material such as micro-fiber can be used that can passively clean the delicate surface. On the other hand, a layer that is exposed to the external environment can be formed of a more rugged and durable material such as plastic or leather.
• In a specific embodiment,segmented body1302 can be partitioned into a number of segments1304-1310 interspersed with thinner,foldable portions1312. Each of the segments1304-1310 can include one or more inserts disposed therein. By way of example, the segments can include a pocket region where the inserts are placed or alternatively the inserts may be embedded within the segments (e.g., insert molding). If pockets used, the pocket region can have a size and shape to accommodate corresponding inserts. The inserts can have various shapes but are most typically shaped to conform to the overall look of segmented body1302 (e.g., rectangular). The inserts can be used to provide structural support forsegmented body1302. That is, the inserts can provide stiffness to the cover assembly. In some cases, the inserts may be referred to as stiffeners. As such, the cover assembly is relatively stiff except along the foldable regions that are thinner and do not include the inserts (e.g., allows folding) makingsegmented cover assembly1300 more robust and easier to handle. In oneembodiment segments1304,1306, and1310 can be related tosegment1308 in size in the proportion of about 0.72 to 1 meaning thatsegments1304,1306 and1310 are sized in width to be about 72% of the width ofsegment1308. In this way, a triangle having a appropriate angles can be formed (i.e., about 75° for display stand and about 11° for keyboard stand discussed below).
• Segments1306,1308, and1310 can includeinserts1314,1316, and1318, respectively (shown in dotted lines form). Inserts1314-1318 can be formed of rigid or semi-rigid material adding resiliency tobody1302. Examples of materials that can be used include plastics, fiber glass, carbon fiber composites, metals, and the like.Segment1304 can includeinsert1320 also formed of resilient material such as plastic but also arranged to accommodatemagnetic elements1322 some of which can interact with magnetic elements intable device1100 and more specificallyattachment feature110.
• Due to the ability ofsegmented body1302 to fold and more particularly the various segments to fold with respect to each other, most ofmagnetic elements1322 can be used to magnetically interact with magneticallyactive insert1324 embedded ininsert1318. By magnetically binding bothactive insert1324 andmagnetic elements1322 various support structures can be formed some of which can be triangular in shape. The triangular support structures can aid in the use oftablet device1100. For example, one triangular support structure can be used to supporttablet device1100 in such a way that visual content can be presented at a desirable viewing angle of about 75° from horizontal. However, in order be able to appropriately fold segmentedcover1300,segment1308 can be sized to be somewhat larger thansegments1304,1306 and1310 (which are generally the same size). In this way, the segments can form a triangle having two equal sides and a longer third side, the triangle having an interior angle of about 75°.
• One approach to forming at least one triangular support structure can includesegment1304 folding with respect to segments1306-1310 in such a way that most ofmagnetic elements1322 embedded ininsert1320 magnetically attract the magneticallyactive insert1324. In this way,segment1304 andsegment1310 can be magnetically bound together forming a triangular support structure having the appropriate dimensions. The triangular support structure can be used as a stand onto whichtablet device1100 can be placed such that visual content can be displayed at about 75°. In another example,segmented cover1300 can be folded to form a triangular support structure that can be used as a keyboard support.Segmented cover1300 can also be folded to form a triangular support structure that can be used to hangtablet device1100 from a horizontal support piece (such as a ceiling) or a vertical support piece (such as a wall).
• Cover assembly1300 can pivotally attach toaccessory attachment feature202 by way of a hinge assembly. The hinge assembly can provide one or more pivots to allow the cover to fold over on the device while the cover assembly is attached to the device through the magnets. In the illustrated embodiment, the hinge assembly can include first hinge portion (also referred to as first end lug)1328 and a second hinge portion (or second end lug)1330 disposed opposite the first end lug.First end lug1328 can be rigidly connected tosecond end lug1330 by way of connecting rod1332 (shown in dotted line form) incorporated into a tube portion ofsegmented body1302. The longitudinal axis of connectingrod1332 can act aspivot line1333 about which the segmented body can pivot relative to the hinge assembly.Connecting rod1332 can be formed of metal or plastic strong enough to rigidly supportcover assembly1300 as well as any objects, such astablet device1100, magnetically attached tomagnetic attachment feature202.
• In order to prevent metal on metal contact,first end lug1328 andsecond end lug1330 can each haveprotective layers1336 and1338, respectively, attached thereto. Protective layers (also referred to as bumpers)1336 and1338 can prevent direct contact betweenfirst end lug1328 andsecond end lug1330 withhousing1102. This is particularly important when end lugs1328,1330 andhousing1102 are formed of metal. The presence ofbumpers1336 and1338 can prevent metal to metal contact between the end lugs andhousing1102 thereby eliminating the chance of substantial wear and tear at the point of contact that can degrade the overall look and feel oftablet device1100.
• In order to maintain their protective qualities,bumpers1336 and1338 can be formed of material that is resilient, durable, and resists marring the finish of the exterior surface oftablet device1102. This is particularly important due to the tight tolerances required for good magnetic attachment and the number of attachment cycles expected during the operational life oftablet device1100. Accordingly,bumpers1336 and1338 can be formed of soft plastic, cloth or paper that can be attached to the end lugs using any suitable adhesive. It should also be noted that in some cases, the bumpers can be removed and replaced with fresh bumpers when needed.
• First end lug1328 andsecond end lug1330 can be magnetically connected to the electronic device by way ofhinge span1340 that is configured to pivot with respect to the end lugs. The pivoting can be accomplished using hinge posts1342 (a portion of which can be exposed).Hinge posts1342 can rotatably securehinge span1340 to bothfirst end lug1328 andsecond end lug1330.Hinge span1304 can include magnetic elements. The magnetic elements can be arranged to magnetically attachhinge span1340 to a magnetic attachment feature having a matching arrangement of magnetic elements in the electronic device. In order to fix the magnetic elements in place withinhinge span1340,hinge posts1342 can be used to secure magnetic elements located at both ends ofhinge span1340 reducing the likelihood that the magnetic elements inhinge span1340 will move about having the potential for disrupting the magnetic attachment betweenhinge span1340 and the magnetic attachment feature in the electronic device.
• In order to assure that there is no interference between the magnetic elements inhinge span1340 and the corresponding magnetic elements in the electronic device,hinge span1340 can be formed of magnetically inactive material such as plastic or non-magnetic metal such as aluminum. Whenhinge span1340 is formed of magnetically inactive metal, such as aluminum, metal to metal contact betweenhinge span1340 andhousing1102 ofelectronic device1100 can be prevented with the use ofprotective layer1344.Protective layer1344 can be applied to the surface ofhinge span1340 that faceshousing1102 whenhinge span1340 andelectronic device1100 are magnetically attached to each other. Protective layer1344 (also referred to as label1344) can be formed of many materials that will not mar the finish ofhousing1102. Such materials can include, for example, paper, cloth, plastic, and so forth.
• FIGS. 19A and 19B show a more detailed view of two embodiments ofhinge span1340. More specifically,FIG. 19A showsembodiment1400 of the hinge span where magnetically inert spacers are used to separate and fix the magnetic elements. In particular,hinge span1400 can enclose and supportmagnetic elements1402 used bymagnetic attachment feature202 to magnetically attachsegmented cover assembly1300 totablet device1100.Magnetic elements1402 can be arranged in a specific configuration that matches corresponding magnetic elements in device attachment feature108 intablet device1100. In this way,segmented cover assembly1300 andtablet device1100 can precisely and repeatedly attach to each other.
• In order to maintain repeatable and stable magnetic engagement over an extended period of time,magnetic elements1402 can remain in a stable configuration. In other words,magnetic elements1402 inhinge span1400 should remain in their relative positions and polarities vis-à-vis the corresponding magnetic elements in the magnetic attachment system intablet1100 for an extended period of time. This is particularly important when repeated attachment cycles are anticipated to occur over an expected operating life ofcover assembly1300 and/ortablet device1100.
• Hence, to assure the integrity of the magnetic engagement over the course of many attachment cycles, the configuration ofmagnetic elements1402 can remain essentially fixed with respect to each other and to the corresponding magnetic elements indevice attachment feature108. Hence, in order to assure that the physical layout ofmagnetic elements1402 remain essentially fixed,filler material1404 can be inserted between the various magnetic elements inhinge span1400.Filler material1404 can be non-magnetic material such as plastic.Filler material1404 can be shaped to tightly fit in the interstitial spaces between the magnetic elements. In this way,magnetic elements1402 remain in a fixed and stable configuration for an extended period of time.
• On the other hand,FIG. 19B shows another embodiment ofhinge span1340 in the form ofhinge span1410 that utilizes the mutual magnetic attraction between physically adjacent magnetic elements for fixing the magnetic elements in place. In this way, the number of component parts is reduced. Furthermore, due to the reduced area taken up bymagnetic elements1402, the corresponding magnetic flux density can increased. However, end plugs1412 can be used to fix those magnetic elements located at either end ofhinge span1410 End plugs1412 can be necessary to overcome a net magnetic repulsive force when the magnetic elements at either end ofhinge span1410 have aligned polarities. In addition to endplugs1412, an alternative embodiment can provide for centrally located spacer1414. Centrally located spacer1414 can be formed of magnetically inert material and be used to fixmagnetic elements1402 in place.
• FIG. 19C shows that portion ofhinge span1340 that forms part of the engagement surface when segmentedcover assembly1300 is magnetically attached totablet device1100. In particular,label1344 is shown attached to hingespan1340 using adhesive such as glue. It should be noted, thatlabel1344 is arranged to conform to the shape of that portion ofhousing1102 that also forms part of the engagement surface. In this way, the separation distance between corresponding magnetic elements can be minimized.
• FIG. 20A shows a representative side view ofsegmented cover assembly1300 magnetically attached totablet device1100.FIGS. 20B show representative cross sectional views ofsegmented cover assembly1300/tablet device1100 along line AA shown inFIG. 18.FIG. 20B shows a covered configuration andFIG. 20C shows a folded back configuration that fully exposesprotective layer1106 oftablet device1100.
• FIG. 21A shows a crosssectional side view1500 ofhinge span1340 magnetically attached tohousing1102 having a curved shape. In this embodiment,housing1102 can have a curved shape and is formed of non-magnetic material such as aluminum.Magnetic element1502 can be incorporated into device attachment feature108 intablet device1102. In some embodiments, in order to prevent metal to metal contact, in those embodiments in whichmagnetic element1502 is metal, a protective film can be attached to an engagement surface ofmagnetic element1502 that preventsmagnetic element1502 from contactinghousing1102 directly. The protective film can be thin enough to be neglected when considering the magnetic engagement force between corresponding magnetic elements. The protective film can be unnecessary ifmagnetic element1502 is not formed of metal or if that portion ofhousing1102 that contactsmagnetic element1502 is not metal.
• Magnetic element1502 can magnetically interact with correspondingmagnetic element1504 inhinge span1340.Magnetic element1504 can have thickness of about 2 mm. The magnetic interaction can create net magnetic attractive force F_NETsatisfying Eq. (3a) in which separation distance x_sepis about equal to the total of the thickness t ofhousing1102 and thickness “l” oflabel1344. Thickness “l” can be on the order of about 0.2 mm. Therefore in order to minimize separation distance x_sep(and thereby increase F_NET),magnetic element1502 can be shaped to conform tointerior surface1506 ofhousing1102. Furthermore,label1344 andmagnetic element1504 can each be shaped to conform toexterior surface1508 ofhousing1102. In this way, the distance betweenmagnetic element1502 andmagnetic element1504 can be reduced to about the thickness t ofhousing1102 and thickness l oflabel1344.
• In order to further improve net attractive magnetic force F_NETbetweenmagnetic elements1502 and1504,magnetic shunt1510 can be glued to and enclose that portion ofmagnetic element1504 facing away fromhousing1102.Magnetic shunt1510 can be formed of magnetically active material such as steel or iron. The magnetically active material can redirect magnetic flux lines that would otherwise be directed away frommagnetic element1502 towardshousing1102 thereby increasing the total magnetic flux density B_TOTALbetweenmagnetic element1502 andmagnetic element1504 resulting in a commensurate increase in net magnetic attractive force F_NET.Magnetic shunt1510 can, in turn, be glued tohousing1512 ofhinge span1340. It should be noted, that in order to assure that only label1344contacts exterior surface1508 of housing1102 (to avoid metal to metal contact),label1344 is proud (i.e., protrudes) ofhousing1512 ofhinge span1340 by about distance “d”. Nominally, distance d can be on the order of about 0.1 mm.
• Since net magnetic force F_NETdepends in part on separation distance between cooperating magnetic elements, the overall integrity of the magnetic attachment between the magnetic attachment system intablet device1100 and the magnetic elements inhinge span1340 can be affected by the actual separation distance between cooperating magnetic elements as well as the consistency of the separation distance along length L ofhinge span1340. In order to provide a highly correlated magnetic attractive force alonghinge span1340, the separation distances between the magnetic elements inhinge span1340 and those of the magnetic attachment system intablet device1100 are well controlled.
• FIG. 21B shows crosssectional view1550 ofhinge span1340 magnetically attached tohousing1102 having a flat surface. In this arrangement,label1344 andmagnet1554 can each conform to the flat shape ofhousing1102.
• In order to assure consistency of the net magnetic attractive force along length L ofhinge span1340, the components ofhinge span1340 can be assembled usingfixture1600 shown in cross section inFIG. 22A and in perspective view inFIG. 22B.Fixture1600 can havesurface1602 that conforms to the shape of the exterior surface ofhousing1102. In order to assemblehinge span1340 in a manner that assures consistent magnetic attractive force along the length L of hinge span1340 (as well as to provide an aesthetically pleasing look),label1344 can be temporarily attached to surface1602 offixture1600. Sincesurface1602 substantially conforms to the shape ofexterior surface1508,label1344 will have a shape that also conforms to the shape ofexterior surface1508. In one embodiment, a partial vacuum can be created withinfixture1600 that causeslabel1344 to attach tosurface1602 under suction. In this way, the assembled hinge span can be detached fromsurface1602 by simply removing the partial vacuum.
• Oncelabel1344 is secured to surface1602 offixture1600,magnetic element1504 can be placed in direct contact with and attached to label1344 using any appropriate adhesive. In order to reduce separation distance as much as possible,magnetic element1504 can have a shape that conforms to that of bothlabels1344 andsurface1602. In this way, the conformal shaping of bothlabel1344 andmagnetic element1504 assures a minimum separation distance betweenmagnetic element1506 and1502.Magnetic element1504 can then be glued tomagnetic shunt1510 formed of magnetically active materials such as steel to focus magnetic flux towardsmagnetic element1502.Metal shunt1510 can then be enclosed by and glued to hingespan housing1512 leaving about d=0.1 mm oflabel1344 protruding fromhousing1512.
• In addition to providing protection totablet device1100, segmentedcover assembly1300 can be manipulated to form useful support structures. Accordingly,FIGS. 23 through 26 show useful arrangements ofcover assembly1300 in accordance with the described embodiments.
• For example, as shown inFIG. 23,segmented cover assembly1300 can be folded such that the magnetically active portion ofinsert1324 magnetically interacts withmagnetic elements1322. It should be noted that the magnetic force used to maintaintriangular support structure1700 is about in the range of 5-10 newtons (NT). In this way,triangular support structure1700 can be prevented from unwrapping inadvertently.Triangular support structure1700 can be formed that can be used in many ways to augmenttablet device1100. For example,triangular support structure1700 can be used to supporttablet device1100 in such a way that touch sensitive surface1702 is positioned relative to a support surface at an ergonomically advantageous angle. In this way, using touch sensitive surface1702 can be a user friendly experience. This is particularly relevant in those situations where the touch sensitive surface is used over an extended period of time. For example, a virtual keyboard can be presented at touch sensitive surface1702. The virtual keyboard can be used to input data totablet device1100. By usingtriangular support structure1700 to supporttablet device1100 at the ergonomically friendly angle, the deleterious effects of repetitive movements can be reduced or even eliminated.
• FIGS. 24A and 24B show another folded implementation ofsegmented cover assembly1300 in whichtriangular support structure1700 can be used to supporttablet device1100 in a viewing state. By viewing state it is meant that visual content (visual, stills, animation, etc.) can be presented at a viewer friendly angle of about 75° from horizontal. In this “kickstand” state, visual content can be presented for easy viewing. A viewable area oftablet device1100 can be presented at an angle of about 75° which has been found to be within a range of viewing angles considered optimal for a good viewing experience.
• FIGS. 25A-25B show segmentedcover assembly1300 folded into various hanging embodiments. By hanging embodiments, it is meant that by foldingsegmented cover assembly1300 into an appropriate triangular shape,tablet device1100 can be suspended from above as shown inFIG. 26A in the form ofhanger1900.Hanger1900 can be used to suspendtablet device1100 from above. For example,hanger1900 can be suspended directly from a ceiling using a support piece such as a rod.Hanger1900 can be created simply by foldingsegmented cover assembly1300 in a first direction until embeddedmagnets1322 magnetically engage magneticallyactive insert1324 that can be formed of steel or iron. The magnetic circuit formed by the engagement of embeddedmagnets1322 and magneticallyactive insert1324 can provide sufficient support for safely suspendingtablet device1100 from any horizontally aligned support structure.
• FIGS. 25B shows hanger embodiments suitable for hangingtablet device1100 from a vertically aligned support structure such as a wall. In particular,hanger1910 can be mechanically attached to a wall or other vertical support structure.Hanger1910 can then be used to suspendtablet device1100 along the lines of a wall mount. In this way,tablet device1100 can be used to present visual content along the lines of a visual display for visual content, or wall hanging for still images such as photos, art, and the like.
• FIGS. 26A-26B show showsarrangement2000 wheretriangular support structure1700 can be used as a handle. Again by foldingsegmented cover assembly1300 such that segmented portions interact with each other to form triangular support structure that can be used as a handle. As such,tablet device1100 can be picked up as one would pick up a book for viewing. The body ofsegmented cover assembly1300 can provide convenient grasping features that can be used to more firmly grasptriangular support structure1700 when being used to holdtablet device1100 as a book.
• In those cases wheretablet device1100 includes image capture devices, such as afront facing camera2002 andrear facing camera2004, visual content can be presented bytablet device1100. In this way,triangular support structure1700 can be used as a holder along the lines of a camera handle. As such,triangular support structure1700 can provide a convenient and effective mechanism for aiding in the image capture process. For example, when used to capture images,tablet device1100 can be firmly held by way oftriangular support structure1700 andrear facing camera2004 can be pointed at a subject. The image of the subject can then be presented bytablet device1100 at the display shown inFIG. 25B. In this way, bothfront facing camera2002 and/orrear facing camera2204 can be used to capture still images or video such as in a video chat or simply view a video presentation. As part of a video chat, a visual chat participant can easily carry on a video conversation while usingtriangular support structure1700 to holdtablet device1100.
• FIGS. 27A-27C show configuration2100 ofcover assembly1300 andtablet device1100 illustrating what is referred to as a peek mode of operation oftablet device1100. More particularly, whensegment1304 is lifted fromglass cover1106, sensors intablet device1100 can detect thatsegment1304 and only that segment has been lifted fromglass layer1106. Once detected,tablet device1100 can activate only the exposedportion2102 of the display. For example,tablet device1100 can utilize a Hall Effect sensor to detect thatsegment1304 has been lifted fromglass cover1106. Additional sensors, such as optical sensors can then detect ifonly segment1304 has been lifted or if additional segments have been lifted.
• As shown inFIG. 27B, whentablet device1100 has determined thatonly segment1304 has been lifted, thentablet device1100 can change operating state to “peek” state in which only the exposedportion2102 of the display actively presents visual content in the form oficons2104. Hence, information in the form of visual content such as time of day, notes, and so forth can be presented for viewing on only that portion of display viewable. Once the sensors detect thatsegment1304 has been placed back onglass layer1106,tablet1100 can return to the previous operational state such as a sleep state. Furthermore, in another embodiment, when an icon arranged to respond to a touch is displayed, then that portion of a touch sensitive layer corresponding to the visible portion of the display can also be activated.
• Furthermore, as shown inFIG. 27C, when additional segments are lifted fromcover glass1106 to further exposesecond portion2106 ofcover glass1106,second portion2106 of the display can be activated. In this way, in the “extended” peek mode, additional visual information, such asicons2108, can be presented in the portions of the display activated. It should be noted that as segments are lifted fromcover glass1106, additional segments of the display can be activated. In this way, an extended peek mode can be provided.
• Alternatively, thetablet device1100 can respond to the signals from the Hall Effect sensor(s) by simply powering up the display when the flap is moved away from the display and power down (sleep) when the display is covered by the flap. In one embodiment, a subset ofmagnetic elements1322 can be used in conjunction with correspondingmagnetic elements402 inattachment feature110 to securecover assembly1300 totablet device1100 oncover glass1106. Furthermore, atleast magnet1326 can be used to activate magneticallysensitive circuit404. For example, when segmentedcover1300 is placed upontablet device1100 atcover glass1106, the magnetic field frommagnet1326 can be detected by magneticallysensitive circuit404 that can take the form of a Hall Effect sensor. The detection of the magnetic field can causeHall Effect sensor118 to generate a signal that can result in a change in the operating state oftablet device1100.
• For example, whenHall Effect sensor118 detects thatsegmented cover1300 is in contact withcover glass1106 indicating that the display is not viewable, then the signal sent byHall Effect sensor118 can be interpreted by a processor intablet device1100 to change the current operating state to sleep state. On the other hand, whensegment1304 is lifted fromcover glass1106,Hall Effect sensor118 can respond to the removal of the magnetic field from magnetic1326 by sending another signal to the processor. The processor can interpret this signal by again altering the current operating state. The altering can include changing the operating state from the sleep state to an active state. In another embodiment, the processor can interpret the signal sent byHall Effect sensor118 in conjunction with other sensors by altering the operating state oftablet device1100 to a peek mode in which only that portion of the display exposed by the lifting ofsegment1304 is activated and capable of displaying visual content and/or receiving (or sending) tactile inputs.
• In some cases, whensegment1306 is lifted fromcover glass1106 at the same time thatHall Effect sensor118 indicates thatsegment1304 is also lifted, the presence of sensors in addition toHall Effect sensor118 can cause the processor to enter into an extended peek mode in which additional display resources corresponding to the additional exposed portion of the display are also activated. For example, iftablet device1100 includes other sensors (such as optical sensors) that can detect the presence of a particular segment, then signals fromHall Effect sensor118 in combination with other sensor signals can provide an indication to the processor that a particular portion or portions of the display assembly are currently viewable and can thus be enabled to present visual content.
• FIG. 28A showscover assembly2200 in accordance with a particular embodiment.Cover assembly2200 can includesegmented cover2202 attached to pivotingassembly2204 shown in an exploded view. Pivotingassembly2204 can include end lugs2206 and2208 pivotally connected to each other by way ofhinge span2210 and connecting rod2212 (which can be enclosed withinsleeve2214 that can in turn be connected to or enclosed withinsegmented cover2202 and not seen). In this way, at least twopivot lines2216 and2218 can be provided for pivotally movingend lugs2206 and2208,hinge span2210 and connectingrod2212. For example, hinge span2210 (and endlugs2206 and2208) can rotate aboutpivot line2216 whereas connecting rod2212 (and endlugs2206 and2208) can rotate aboutpivot line2218. It should be noted that connectingrod2212 andhinge span2210 can pivot independent of each other. The pivoting can occur at the same time or at different times givingpivoting assembly2204 at least four independent directions of axial rotation.
• In order to prevent metal on metal contact whenhinge span2210 is magnetically coupled totablet1100,label2220 can be affixed to an external surface ofhinge span2210 andbumpers2222 can be affixed to an external surface of end lugs2206 and2208.Label2220 andbumper2222 can be formed of material that can undergo repeated contact withhousing102 without marring or otherwise damaging the appearance ofhousing102. Accordingly,label2220 andbumpers2222 can be formed of paper, cloth, plastic and adhered to hingespan2210 and endlugs2206 and2208 using an adhesive such as glue. In some cases, the adhesive can have properties that allow for easy replacement oflabel2220 and/orbumpers2222 when needed.
• FIG. 28B shows an assembled embodiment of pivotingassembly2204showing pivot line2216 about which end lugs2206,2208 and connecting rod2212 (in sleeve2214) can rotate in two axial directions (i.e., clockwise and counter-clockwise). It should be noted that end lugs2206,2208 andhinge span2210 can rotate in two axial directions (i.e., clockwise and counter-clockwise) with respect to pivotline2218. In this way, end lugs2206 and2208 can rotate aboutpivot line2216 andpivot line2218 with a total of four axial directions.
• FIG. 28C showshinge span2210 illustrating in moredetail end pins2224 and2226 that can be used to mounthinge span2210 intoend lug2206 andend lug2208, respectively. Although not viewable in this figure, end pins2224 and2226 can further be used in conjunction with internal plugs to secure end unit magnetic elements incorporated withinhinge span2210. This is particularly useful in those situations where the coded magnetic sequence of the magnetic elements incorporated withinhinge span2210 causes the end unit magnetic elements to magnetically repel an adjacent neighbor magnetic element.
• FIG. 28D shows an exploded view ofhinge span2210 in accordance with the described embodiments.Magnetic elements2228 can be configured as a coded magnetic structure in which individual magnetic elements can be arranged in a specific pattern of magnetic polarity, strength, size and so forth. In the embodiment shown, those magnets next to each other having anti-aligned polarity can rely upon their mutual magnetic attraction to maintain their position with the coded magnetic structure. However, magnetic elements placed next to each other having aligned magnetic polarity can require an external force to overcome the mutual magnetic repulsive force in order to maintain their position within the coded magnetic structure. For example, magnetic element2228-1 and2228-2 can each be formed of two magnets having aligned magnetic poles. In this situation, each of the two magnets that form magnetic element2228-1 (and2228-2), for example, will have magnetic poles that are aligned and therefore will generate a net magnetic repulsive force between them. Therefore, an externally applied constraint can be applied using, for example, plugs2232-1 and2232-2, respectively. The magnetic attractive force provided by magnets2228-3 and2228-4 (that are anti-aligned with respect to magnets2228-1 and2228-2, respectively) can help in stabilizing the coded magnetic structure enclosed withinhinge span2210.Spacer2234 formed of magnetically inert material can be used to provide additional physical integrity to the coded magnetic structure formed bymagnetic elements2228.
• In order to improve an overall net magnetic attractive force,magnetic shunt2236 formed of magnetically active material such as steel, can be adhesively attached to a back end ofmagnetic elements2228. The back end placement ofshunt2236 can help to re-direct magnetic field lines that would otherwise propagate away from the engagement surface betweenhinge span2210 andhousing1102. By deflecting the magnetic field lines back towards the engagement surface, the magnetic flux density provided bymagnetic elements2228 at the engagement surface can be commensurably increased resulting in an increased net magnetic attractive force betweenmagnetic elements2228 and the corresponding magnetic components withinhousing1102.
• As discussed previously,label2220 can be adhesively attached to magnetic elements2228 (andspacer2234, if present) which can, in turn, be adhesively attached tomagnetic shunt2236.Magnetic shunt2236 can be adhesively attached to opening2238 inhinge span2210leaving label2220 proud by about a distance “d” which can be on the order of about 0.1-0.2 mm preventing metal to metal contact betweenhinge span2210 andhousing1102.
• It should be noted that in the keyboard arrangement and display arrangement,hinge span2210 can experience a shearing force due to the placement oftablet device1100 on a supporting surface at an angle. The shearing force can be resisted by the net magnetic attractive force generated betweenhinge span2210 and the device attachmentfeature tablet device1100.
• FIG. 29 shows an exploded view ofsegmented cover2202.Bottom layer2250 can come in direct contact with a protected surface such as a cover glass for a display.Bottom layer2250 can be formed of a material that can passively clean the protected surface. The material can be, for example, a microfiber material.Bottom layer2250 can be attached tostiffening layer2252 formed of resilient material such as plastic.Stiffening layer2252 can, in turn, be adhesively attached to inserts2254 to form a laminate structure includingadhesive layer2256,laminate material2258 and insert2254. Some of inserts2254 can accommodate embedded components. For example, insert2254-1 can accommodatemagnets2260 some of which can cooperate withcorresponding attachment feature110 embedded intablet device1100 for securingsegmented cover2202 totablet device1100. At least one magnet2260-1 can be positioned and sized to interact with a magnetically sensitive circuit (such as a Hall Effect sensor) incorporated withintablet device1100. It should be noted that whereas some ofmagnets2260 are specifically allocated to interact only withattachment feature110, substantially all ofmagnets2260 can magnetically interact with magneticallyactive plate2262 embedded in segment2254-2 used to form various triangular support structures. In this way, a strong magnetic force can be generated providing a stable foundation for the triangular support structure.
• An additional laminate structure can be formed of adhesive layer(s)2256,laminate material2258 andtop layer2264. In some embodiments, an intervening layer of material can be provided having a knitted structure that can aid in the attachment oftop layer2264.Top layer2264 can be formed of many materials such as plastic, leather, and so forth in keeping with the overall look and feel oftablet device1100. In order to provide additional structural support,top layer2264 can have edges reinforced byreinforcement bars2266 that can be formed of plastic or other rigid or semi-rigid material.
• FIG. 30 shows a partial cross sectional view ofsegmented cover2200 shown inFIG. 29 placed in position uponcover layer1106 oftablet device1100. Of particular note is the relative positioning of magnet2260-1 andHall Effect sensor118. In this way, when segmentedcover2200 is placed uponcover layer1106, the magnetic field from magnet2260-1 can interact withHall Effect sensor118 that can respond by generating a signal. The signal can, in turn, be processed in such a way that the operating state oftablet device1100 can change in accordance with the presence ofcover2200. On the other hand, the removal ofcover2200 can cause the operating state to revert to the previous operating state, or another operating state such as peek mode. It should be noted that the magnetic field density between magnetic element2260-1 andHall Effect sensor118 can be on the order of about 500 gauss. However, in those embodiments wherecover2202 is flipped over to the back ofhousing1102, the magnetic flux density atHall Effect sensor118 can be on the order of about 5 Gauss.
• FIG. 31A shows cross sectional view ofhinge span2210 in active engagement withdevice attachment feature2300 incorporated intotablet device1100. In particular,magnetic attachment feature2300 includes at leastmagnetic element2302 forming a magnetic circuit with magnetic element2228 (which is part of the coded magnetic structure incorporated into hinge span2210).Magnetic shunt2304 can be used to re-direct magnetic field lines that propagate frommagnetic element2302 in a direction other than that ofmagnetic element2228. In this way, the magnetic flux density atengagement surface2306 can be commensurably increased thereby increasing net magnetic attractive force F_net.Magnetic attachment feature2300 can be incorporated intobarrel2308 inhousing1102 sized to accommodate bothmagnetic element2302 andshunt2304. In the described embodiment,barrel2308 can provide support formagnetic element2302 andshunt2304.Barrel2308 can also direct the motion ofmagnetic element2302 andshunt2304 whenmagnetic attachment feature2300 transitions between the active state and the inactive states.
• In order to ensure that net attractive force F_NETis applied substantially normal toengagement surface2306, the magnetization ofmagnetic element2228 andmagnet element2302 can be configured such that their respective magnetization vectors M substantially align. By magnetization it is meant that the magnets can be manufactured having magnetic domains that are substantially aligned in the same direction. By aligning the magnetization vectors M₁and M₂ofmagnetic element2302 andmagnetic element2228, respectively, net magnetic force F_NETcan be generated substantially normal toengagement surface2306.
• FIG. 31B showsmagnetic attachment feature2300 in an inactive state. When in the inactive state,magnetic attachment feature2300 is located at least distance x₀from exterior surface ofhousing1102 in order to satisfy Eq. (1). Therefore,barrel2308 must be able to accommodate the movement ofmagnetic element2302 and shunt2304 from x=0 in the inactive state to about x=x₀in the active state.
• FIGS. 32 shows a representation of an embodiment of device attachment feature108 in the form ofattachment feature2400. In particular,attachment2400 can includemagnetic elements2402/shunt2404 in attached toleaf spring2406.Leaf spring2406 can be secured directly to shunt2404 by way offasteners2408 and end supports2410 by way offasteners2412. End supports2410 can be attached to a support structure such as a housing to provide support forattachment feature2400. In one embodiment,alignment posts2414 can be used during assembly to provide alignment for both end supports2410 andleaf spring2406.FIG. 33 shows a close up view of thesupport structure2410/leaf spring2406 interface.
• FIG. 34 shows a flowchart detailing a process2500 in accordance with the described embodiments. The process can begin at2502 by providing a first coded magnetic attachment feature in an inactive state. At2504, using a second magnetic attachment feature to activate the first coded first magnetic attachment feature. At2506, causing a magnetic field from the activated first magnetic attachment feature to interact with a magnetic field from the second magnetic attachment feature. At2508, generating a net magnetic attachment force in accordance with the interaction of the magnetic fields. At2510, magnetically binding the first and second magnetic attachment features in accordance with the net magnetic attachment force.
• FIG. 35 shows aflowchart detailing process2600 in accordance with the described embodiments.Process2600 can begin at2602 by providing a coded magnetic attachment feature in an inactive state. In the inactive state, magnetic flux density at a pre-determined distance for magnetic elements in the coded magnetic attachment feature is less than a threshold value. At2604, an external magnetic field is received at the coded magnetic attachment feature. At2606, if it is determined that the external magnetic field corresponds to magnetic elements that correlate with the magnetic elements in the coded magnetic attachment feature, then at2608, the coded magnetic attachment feature is activated, otherwise,process2600 ends.
• FIG. 36 shows aflowchart detailing process2700 in accordance with the described embodiments.Process2700 can begin at2702 by placing an electronic device having a first and an accessory having second coded magnetic attachment features in proximity to each other. At2704, if the magnetic elements in the first and second coded magnetic attachment features correlate with each other, then at2706, the first coded magnetic attachment feature is activated. When the first coded magnetic attachment feature is activated, then a magnetic flux density of a magnetic field generated by the first coded magnetic attachment feature increases to a value above a threshold. The magnetic field interaction between the magnetic elements in the first and second magnetic attachment features cause the electronic device and accessory to magnetically attach to each other at2708.
• FIG. 37 shows a flowchart detailing apeek mode process2800 in accordance with the described embodiments.Process2800 can begin at2802 by determining if a first portion of a display is uncovered. By uncovered it is meant that visual content presented at the first portion can be viewed. When it is determined that the first portion of the display is uncovered, then at2804, only that portion of the display that is determined to be uncovered can present visual content. In other words, a set of icons or other visual content can be displayed in the uncovered portion of the display, where the remainder of the display can remain blank or off. Next at2806, visual content is displayed by the activated portion of the display. Next at2808, a determination is made if a second portion of the display is uncovered, the second portion being different than the first portion. When it is determined that the second portion of the display is uncovered, then a second portion of the display is activated at2810. Visual content is then displayed at the second activated portion at2812.
• FIG. 38 shows aflowchart detailing process2900 for forming a magnetic stack incorporated intohinge span1340 in accordance with the described embodiments.Process2900 for forming the magnetic stack incorporated intohinge span1340 can begin at2902 by providing a fixture. The fixture having a shape in accordance with an exterior shape of the housing that defines the electronic device upon which the hinge span will magnetically attach. The fixture can also be connected to a vacuum source that can be used to subsequently secure a protective film at2904. The protective film can be used to provide protection against metal to metal contact between the hinge span and the housing of the electronic device. The protective film (also referred to as a label) can be formed of resilient material and have a length consistent with that of the hinge span. Once the label has been secured to the fixture using the vacuum, the label conforms to the contour of the fixture, and thus the shape of the housing of the electronic device.
• At2906, a magnet is attached to the label at a first surface shaped to conform to the fixture (and the housing). In one embodiment, the label and magnet can be glued to each other using adhesive. In another embodiment, the label can have an adhesive inner layer impregnated with glue that can attach the label to the magnet upon curing. At2908, a magnetic shunt is glued to the magnet and label assembly. The magnetic shunt can be formed of magnetically active material such as steel. The magnetic shunt can interact with those magnetic field lines from the magnet initially directed away from the engagement surface between the housing and the hinge span. The magnetic shunt can interact with the magnetic field lines by re-directing at least some of the magnetic field lines in a direction towards the magnet and the engagement surface. The re-directed magnetic field lines can increase the magnetic flux density at the engagement surface thereby increasing the net attractive magnetic force between magnetic elements in the electronic device and the hinge span.
• At2910, a hinge span enclosure can be glued to the magnetic shunt. The hinge span enclosure can be used to support and protect the magnetic elements used to magnetically attach the hinge span to the electronic device. It should be noted that the after the attachment of the hinge span enclosure, the label is proud of the hinge span enclosure by which it is meant that the label protrudes a distance “d” from the hinge span enclosure. In this way, there is no contact between the metal hinge span enclosure and the metal housing of the electronic device.
• FIG. 39 shows a flowchart detailing process for determining a configuration of magnetic elements in a magnetic stack used in a magnetic attachment system in accordance with the described embodiments.Process3000 begins at3002 by providing a first plurality of magnetic elements in accordance with a first configuration. At3004, a second plurality of magnetic elements in accordance with a second configuration is provided. By first and second configuration, what is meant is that the first and second plurality of magnetic elements can be arranged in any manner deemed appropriate. For example, the first and second configuration can relate to a physical size, a magnetic polarity, a magnetic strength, a relative position with respect to other magnetic elements, and so on. Next, at3006, a net magnetic force is created in one embodiment by positioning each of the first and second plurality of magnetic elements with respect to each other. In so doing, those corresponding magnetic elements having the same polarity will generate a negative (repulsive) magnetic force whereas those corresponding magnetic elements having opposite polarities will generate a positive (attractive) magnetic force. At3008, a total value of the net magnetic force for each of the corresponding one of the first and second plurality of magnetic elements is determined. As mentioned above, since some magnetic elements can generate a negative magnetic force whereas others a positive magnetic force for the same position, the total value of the net magnetic force can be either positive, negative, or zero (indicating the positive and negative magnetic forces cancel each other out to give no overall net magnetic force).
• At3010, a difference between a global maximum net total magnetic force and first local maximum net total magnetic force is determined. For example, as shown inFIG. 13, the global maximum corresponds with a total net magnetic force of about 8A (“A” being a unit magnetic attractive force where “8A” is equivalent to “+8” where “+” indicates attractive force). Moreover, a first local maximum net total value is about 4A and a second local maximum net total value is about 1A. In order to avoid a “false activation” that can result in a weak magnetic attraction, the difference between the global maximum net total magnetic force and the first local maximum net total magnetic force can indicate a probability that the magnetic attachment system will equilibrate at the global maximum net total magnetic force (representing the strongest net magnetic attraction) and the first local maximum net total magnetic force (representing a weak net magnetic attraction).
• Therefore, if at3012, the difference is acceptable (meaning that the global maximum is the likely equilibrium point), then process3000 stops, otherwise, the configuration of magnetic elements is changed at3014 and control is passed directly to3006 for further evaluation.
• FIG. 40 is a block diagram of anarrangement3100 of functional modules utilized by an electronic device. The electronic device can, for example, betablet device1100. Thearrangement3100 includes anelectronic device3102 that is able to output media for a user of the portable media device but also store and retrieve data with respect todata storage3104. Thearrangement3100 also includes a graphical user interface (GUI)manager3106. TheGUI manager3106 operates to control information being provided to and displayed on a display device. Thearrangement3100 also includes acommunication module3108 that facilitates communication between the portable media device and an accessory device. Still further, thearrangement3100 includes anaccessory manager3110 that operates to authenticate and acquire data from an accessory device that can be coupled to the portable media device.
• FIG. 41 is a block diagram of anelectronic device3150 suitable for use with the described embodiments. Theelectronic device3150 illustrates circuitry of a representative computing device. Theelectronic device3150 includes aprocessor3152 that pertains to a microprocessor or controller for controlling the overall operation of theelectronic device3150. Theelectronic device3150 stores media data pertaining to media items in afile system3154 and acache3156. Thefile system3154 is, typically, a storage disk or a plurality of disks. Thefile system3154 typically provides high capacity storage capability for theelectronic device3150. However, since the access time to thefile system3154 is relatively slow, theelectronic device3150 can also include acache3156. Thecache3156 is, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to thecache3156 is substantially shorter than for thefile system3154. However, thecache3156 does not have the large storage capacity of thefile system3154. Further, thefile system3154, when active, consumes more power than does thecache3156. The power consumption is often a concern when theelectronic device3150 is a portable media device that is powered by abattery3174. Theelectronic device3150 can also include aRAM3170 and a Read-Only Memory (ROM)3172. TheROM3172 can store programs, utilities or processes to be executed in a non-volatile manner. TheRAM3170 provides volatile data storage, such as for thecache3156.
• Theelectronic device3150 also includes auser input device3158 that allows a user of theelectronic device3150 to interact with theelectronic device3150. For example, theuser input device3158 can take a variety of forms, such as a button, keypad, dial, touch screen, audio input interface, visual/image capture input interface, input in the form of sensor data, etc. Still further, theelectronic device3150 includes a display3160 (screen display) that can be controlled by theprocessor3152 to display information to the user. Adata bus3166 can facilitate data transfer between at least thefile system3154, thecache3156, theprocessor3152, and theCODEC3163.
• In one embodiment, theelectronic device3150 serves to store a plurality of media items (e.g., songs, podcasts, etc.) in thefile system3154. When a user desires to have the electronic device play a particular media item, a list of available media items is displayed on thedisplay3160. Then, using theuser input device3158, a user can select one of the available media items. Theprocessor3152, upon receiving a selection of a particular media item, supplies the media data (e.g., audio file) for the particular media item to a coder/decoder (CODEC)3163. TheCODEC3163 then produces analog output signals for aspeaker3164. Thespeaker3164 can be a speaker internal to theelectronic device3150 or external to theelectronic device3150. For example, headphones or earphones that connect to theelectronic device3150 would be considered an external speaker.
• Theelectronic device3150 also includes a network/bus interface3161 that couples to adata link3162. Thedata link3162 allows theelectronic device3150 to couple to a host computer or to accessory devices. Thedata link3162 can be provided over a wired connection or a wireless connection. In the case of a wireless connection, the network/bus interface3161 can include a wireless transceiver. The media items (media assets) can pertain to one or more different types of media content. In one embodiment, the media items are audio tracks (e.g., songs, audio books, and podcasts). In another embodiment, the media items are images (e.g., photos). However, in other embodiments, the media items can be any combination of audio, graphical or visual content.Sensor3176 can take the form of circuitry for detecting any number of stimuli. For example,sensor3176 can include a Hall Effect sensor responsive to external magnetic field, an audio sensor, a light sensor such as a photometer, and so on.
• The magnetic attachment feature can be used to magnetically attach at least two objects. The objects can take many forms and perform many functions. When magnetically attached to each other, the objects can communicate and interact with each other to form a cooperative system. The cooperating system can perform operations and provide functions that cannot be provided by the separate objects individually. For example, at least a first object and a second object can be magnetically attached to each other such that the first object can be configured to provide a support mechanism to the second object. The support mechanism can be mechanical in nature. For example, the first object can take the form of a stand that can be used to support the second object on a working surface such as a table. In another example, the first object can take the form of a hanging apparatus. As such, the first object can be used to hang the second object that can then be used as a display for presenting visual content such as a visual, still images like a picture, art work, and so on. The support mechanism can also be used as a handle for conveniently grasping or holding the second object. This arrangement can be particularly useful when the second object can present visual content such as images (still or visual), textual (as in an e-book) or has image capture capabilities in which case the second object can be used as an image capture device such as a still or visual camera and the first object can be configured to act as a support such as a tripod or handle.
• The described embodiments can take many forms. For example, the attachment can occur between a first and second object where the first object and second object can take the form of electronic devices. The electronic devices can be magnetically attached to each other to form a cooperative electronic system in which the electronic devices can communicate with each other. As part of this communication, information can be passed between the first and second electronic devices. The information can be processed in whole or in part at either the first or second electronic device depending upon the nature of the processing. In this way, the cooperative electronic system can take advantage of the synergistic effect of having multiple electronic devices magnetically attached and in communication with each other. In one implementation, the communication can be carried out wirelessly using any suitable wireless communication protocol such as Bluetooth (BT), GSM, CDMA, WiFi, and so on.
• The cooperative electronic system can take the form of an array of electronic devices. In one embodiment, the array of electronic devices can act as a single unified display (along the lines of a mosaic). In another embodiment, the array of electronic devices can provide a single or a set of functions (such as virtual keyboard). In still another embodiment, at least one of the electronic devices can take the form of a power providing device that can be attached to the electronic device using the magnetic attachment feature. The power providing device can utilize a mechanical connection such as a power port, or in some cases a magnetically based charging mechanism, to provide current to the electronic device. The current can be used to charge a battery if necessary while providing power to operate the cooperative electronic system. The power provided can be passed from one device to another as in a bucket brigade to even out the power distribution and battery charge levels in the cooperative electronic system.
• The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a non-transitory computer readable medium. The computer readable medium is defined as any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
• The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.
• The advantages of the embodiments described are numerous. Different aspects, embodiments or implementations can yield one or more of the following advantages. Many features and advantages of the present embodiments are apparent from the written description and, thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the embodiments should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents can be resorted to as falling within the scope of the invention.

Claims (9)

1. An electronic device having a housing, comprising:

a dual state magnetic element disposed within the housing at a first side wall and arranged to provide a first magnetic surface at an exterior surface of the first side wall in an inactive state, the first magnetic surface not substantially affecting a magnetically sensitive device at the exterior surface, wherein in an active state, the dual state magnetic element provides a second magnetic surface at the exterior surface of the first side wall, the second magnetic surface suitable for generating a peak magnetic attachment force for forming a magnetic attachment between the electronic device and a first magnetic element in a first part of an accessory unit; and

a state maintaining means coupled to the housing and arranged to maintain the dual state magnetic element in the inactive state by providing a retaining force, wherein an off peak magnetic attachment force has a force value that is equal to or greater than one half of a force value of the peak magnetic attachment force, wherein the dual state magnetic element changes from the inactive state to the active state only when the first magnetic element in the first part of the accessory device aligns with corresponding ones of the first plurality of magnetic components and the second plurality of magnetic components, and wherein when the dual state magnetic element changes from the inactive to the active state, the dual state magnetic element moves from a first position to a second position against the retaining force a distance Δx towards the first sidewall wherein the state maintaining means comprises a spring having a spring constant k, and wherein the retaining force is directly related to the distance Δx and the spring constant k.

2. The electronic device as recited inclaim 1, wherein the dual state magnetic element comprises:

a first plurality of magnetic components arranged adjacent one another in a first relative size order along a first line and arranged according to a first polarity pattern of magnetic polarities; and

a second plurality of polarity magnetic components arranged adjacent to one another in a second relative size order along the first line and according to a second polarity pattern of magnetic polarities, wherein the first and second size orders and the first and second polarity patterns are complementary of each other.

3. The electronic device as recited inclaim 2, wherein the first polarity pattern is at least {P1,P2,P1} and wherein the second polarity pattern is at least {P2,P1,P2} and wherein P1 is a first polarity and P2 is an opposite polarity wherein the first relative size order is at least {2L,1L,1L} and wherein the second relative size order is at least {1L,1L,2L}, wherein 1L corresponds to a an effective unit magnet length and wherein 2L corresponds to about twice the effective unit magnet length.

4. The electronic device as recited inclaim 1 wherein the dual state magnetic element is activated when an activating force that is greater than the retaining force is generated between the first magnetic element in the first part of the accessory device and the dual state magnetic element causing the dual state magnetic element to move from the first position towards the first wall the distance Δx.

5. The electronic device as recited inclaim 4, wherein the activating force has a value that is greater than or equal to the off peak magnetic attachment force value and less than the peak magnetic force value.

6. The electronic device as recited inclaim 2, wherein the dual state magnetic element is activated when an activating force that is greater than the retaining force is generated between the first magnetic element in the first part of the accessory device and the dual state magnetic element causing the dual state magnetic element to move from the first position towards the first wall the distance Δx.

7. The electronic device as recited inclaim 3, wherein the dual state magnetic element is activated when an activating force that is greater than the retaining force is generated between the first magnetic element in the first part of the accessory device and the dual state magnetic element causing the dual state magnetic element to move from the first position towards the first wall the distance Δx.

8. The electronic device as recited inclaim 6, wherein the activating force has a value that is greater than or equal to the off peak magnetic attachment force value and less than the peak magnetic force value.

9. The electronic device as recited inclaim 7, wherein the activating force has a value that is greater than or equal to the off peak magnetic attachment force value and less than the peak magnetic force value.

Images