This patent document claims priority from a co-pending and commonly assigned U.S. patent application No. 14/629,191 (attorney docket No. 146651/QUALP278), entitled "Display Drive Scheme Without Reset" filed by Wen et al on 23/2/2015, which is incorporated herein by reference in its entirety and for all purposes.
Detailed Description
The following description relates to certain embodiments for the purpose of describing innovative aspects of the present invention. However, it belongs toThose skilled in the art will readily recognize that the teachings herein may be applied in a number of different ways. The described implementations may be implemented in any device, apparatus, or system that may be configured to display an image, whether in motion (e.g., video) or stationary (e.g., still image), and whether textual, graphical, or pictorial. Rather, it is contemplated that the described implementations may be included in or associated with a variety of electronic devices such as, but not limited to: mobile phone, cellular phone with multimedia internet function, mobile television receiver, wireless device, smart phone,Devices, Personal Data Assistants (PDAs), wireless email receivers, handheld or portable computers, netbooks, notebook computers, smart notebook computers, tablet computers, printers, copiers, scanners, facsimile devices, Global Positioning System (GPS) receivers/navigators, cameras, digital media players (e.g., MP3 player), camcorders, game consoles, wrist watches, clocks, calculators, television monitors, flat panel displays, electronic reading devices (e.g., electronic readers), computer monitors, auto displays (including odometer and speedometer displays, etc.), cockpit controls and/or displays, display of camera views (e.g., display of a rear view camera in a vehicle), electronic photographs, electronic billboards or signs, projectors, architectural structures, computer systems, and computer systems, Microwaves, refrigerators, stereos, cassette recorders or players, DVD players, CD players, VCRs, radios, portable memory chips, washing machines, dryers, washer/dryers, parking meters, packaging (e.g., in electromechanical systems (EMS) applications, including micro-electromechanical systems (MEMS) applications and non-EMS applications), aesthetic structures (e.g., display of images about a piece of jewelry or clothing), and various EMS devices. The teachings herein may also be used in non-display applications such as, but not limited to, electronic switching devices, radio frequency filters, sensors, accelerationA meter, a gyroscope, a motion sensing device, a magnetometer, an inertial component for a consumer electronic device, a part of a consumer electronic product, a varactor, a liquid crystal device, an electrophoresis device, a drive scheme, a manufacturing process, and electronic test equipment. Thus, the teachings are not intended to be limited to the implementations depicted in the figures, but instead have broad applicability as will be readily apparent to those skilled in the art.
An Interferometric Modulator (IMOD) may include a movable element, such as a mirror, that may be positioned at multiple points (or locations) to reflect light at a particular wavelength at each particular point. For example, the movable element may move from an initial position associated with a first color (e.g., red) to a second position associated with a second color (e.g., blue).
In some embodiments, the IMOD has three (3) ends. The movable element may be positioned by applying voltages to three terminals of the IMOD. However, moving directly from the initial position to the second position may be inaccurate due to process variations, imperfections, noise, calibration issues, and/or other conditions affecting the voltage received through the ends of the IMOD. For example, if the movable element should transition from a position corresponding to red to a position corresponding to blue, it may be desirable to apply 5V to the electrodes. However, the electrode may actually receive 4.98V (due to the above conditions), and thus the movable element may be positioned at a slightly incorrect position which is not the intended position. As another example, while 5V may be a common or expected voltage that is typically applied to the transitions, some electrodes associated with other movable elements may require slightly different voltages, e.g., 4.98V, due to process variations (between movable elements) or errors from calibration. This may be problematic because the system may provide a voltage to the electrodes of the IMOD based on the expected position of the mirror (i.e., the expected second position, rather than a slightly incorrect position). If the movable element is at an incorrect position and the mirror is moved to a third position, the voltage applied to the electrodes will be based on the movable element at the second position rather than at the incorrect position, and thus the movable element may be positioned to another incorrect position. These positioning errors may accumulate such that eventually the actual position of the movable element is further offset and further away from the intended position.
The mechanical reset may be used to position the movable element to the reset position before the movable element is moved to the second position. The reset position may be an intermediate position between moving the movable element from the first position to the second position. Since the movable element will always be moved to the reset position before being moved to the second position, an accumulation of positioning errors can be avoided. However, mechanical resetting may require additional circuitry, reduce color saturation, and may create visual artifacts.
Some implementations of the subject matter described herein provide for positioning a movable element without a mechanical reset. The movable element is movable from a first position associated with a first color to a second position associated with a second color and within a range of the second position by applying a voltage associated with a transition from the first color to the second color. Thereafter, a second voltage may be applied to stabilize the movable element within the range to a particular second position.
Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. Positioning the movable element without moving to the reset position may achieve increased color saturation. In addition, visual artifacts from moving to the reset position may be avoided. In addition, dedicated reset circuitry may also be eliminated.
An example of a suitable EMS or MEMS device or apparatus to which the described implementations are applicable is a reflective display device. Reflective display devices may incorporate Interferometric Modulator (IMOD) display elements that may be implemented to selectively absorb and/or reflect light incident thereon using principles of optical interference. An IMOD display element may include a partial optical absorber, a reflector movable relative to the absorber, and an optical resonant cavity defined between the absorber and the reflector. In some implementations, the reflector can be moved to two or more different positions that can change the size of the optical resonant cavity and thereby affect the reflectance of the IMOD. The reflectance spectrum of IMOD display elements can produce a fairly broad spectral band that can be shifted across the visible light wavelength to produce different colors. The position of the spectral band can be adjusted by changing the thickness of the optical resonator. One way to change the optical resonant cavity is by changing the position of the reflector relative to the absorber.
FIG. 1 is an isometric view illustration depicting two adjacent Interferometric Modulator (IMOD) display elements in a series or array of display elements of an IMOD display device. IMOD display devices include one or more interferometric EMS (e.g., MEMS) display elements. In these devices, the interferometric MEMS display elements may be configured in either a bright or dark state. In the bright ("relaxed", "open" or "on", etc.) state, the display element reflects a large portion of incident visible light. Conversely, in the dark ("actuated," "closed," or "open," etc.) state, the display element reflects little incident visible light. MEMS display elements can be configured to reflect predominantly at specific wavelengths of light, allowing for color displays in addition to black and white displays. In some implementations, by using multiple display elements, color primaries and gray scale can be achieved.
IMOD display devices may include an array of IMOD display elements that may be arranged in rows and columns. Each display element in the array can include at least a pair of reflective and semi-reflective layers, such as a movable reflective layer (i.e., a movable layer, also referred to as a mechanical layer) and a fixed partially reflective layer (i.e., a stationary layer), positioned at varying and controllable distances from each other to form an air gap (also referred to as an optical gap, chamber, or optical resonant cavity). The movable reflective layer is movable between at least two positions. For example, in a first position (i.e., the relaxed position), the movable reflective layer may be positioned at a distance from a fixed partially reflective layer. In the second position (i.e., the actuated position), the movable reflective layer can be positioned closer to the partially reflective layer. Incident light that reflects from the two layers can constructively and/or destructively interfere depending on the position of the movable reflective layer and the wavelength of the incident light, producing either a fully reflective or non-reflective state for each display element. In some implementations, when the display element is unactuated, the display element can be in a reflective state, reflecting light within the visible spectrum, and when the display element is actuated, the display element can be in a dark state, absorbing and/or destructively interfering with light within the visible range. However, in some other implementations, IMOD display elements may be in a dark state when unactuated, and in a reflective state when actuated. In some implementations, the introduction of an applied voltage can drive the display element to change states. In some other implementations, the applied charge can drive the display element to change states.
The depicted portion of the array in FIG. 1 includes two adjacent interferometric MEMS display elements in the form of IMOD display elements 12. In the display element 12 on the right, as illustrated, the movable reflective layer 14 is illustrated in an actuated position near, adjacent to, or in contact with the optical stack 16. The voltage V applied across the display element 12 on the rightBiasingSufficient to move and maintain the movable reflective layer 14 in the actuated position. In the display element 12 on the left, as illustrated, the movable reflective layer 14 is illustrated in a relaxed position at a distance (which may be predetermined based on design parameters) from an optical stack 16, which includes a partially reflective layer. The voltage V applied across the left display element 120Is insufficient to cause actuation of the movable reflective layer 14 to the actuated position as is the case with the display element 12 on the right.
In fig. 1, the reflection characteristics of the IMOD display elements 12 are generally illustrated by arrows indicating light 13 incident on the IMOD display elements 12 and light 15 reflected from the display elements 12 on the left. Most of the light 13 incident on the display element 12 may be transmitted through the transparent substrate 20 towards the optical stack 16. A portion of the light incident on the optical stack 16 may be transmitted through the partially reflective layer of the optical stack 16 and a portion of the light will be reflected back through the transparent substrate 20. A portion of the light 13 transmitted through the optical stack 16 may be reflected back from the movable reflective layer 14 toward (and through) the transparent substrate 20. Interference (constructive and/or destructive) between light reflected from the partially reflective layer of the optical stack 16 and light reflected from the movable reflective layer 14 will determine, in part, the intensity of the wavelength of light 15 reflected from the display element 12 on the viewing or substrate side of the device. In some implementations, the transparent substrate 20 can be a glass substrate (sometimes referred to as a glass plate or panel). The glass substrate may be or include, for example, borosilicate glass, soda lime glass, quartz, Pyrex, or other suitable glass material. In some embodiments, the glass substrate may have a thickness of 0.3, 0.5, or 0.7 millimeters, but in some embodiments, the glass substrate may be thicker (e.g., tens of millimeters) or thinner (e.g., less than 0.3 millimeters). In some embodiments, non-glass substrates may be used, for example, polycarbonate, acrylic, polyethylene terephthalate (PET), or Polyetheretherketone (PEEK) substrates. In such implementations, the non-glass substrate will likely have a thickness of less than 0.7 millimeters, but the substrate may be thicker depending on design considerations. In some implementations, a non-transparent substrate, such as a metal foil or stainless steel based substrate, may be used. For example, a reverse IMOD-based display, which includes a fixed reflective layer and a partially transmissive and partially reflective movable layer, may be configured to be viewed from a side of the substrate opposite the display elements 12 of fig. 1 and may be supported by a non-transparent substrate.
The optical stack 16 may comprise a single layer or several layers. The layers may include one or more of the following: an electrode layer, a partially reflective and partially transmissive layer, and a transparent dielectric layer. In some implementations, the optical stack 16 is electrically conductive, partially transparent, and partially reflective, and can be fabricated, for example, by depositing one or more of the above layers onto a transparent substrate 20. The electrode layer may be formed of a variety of materials, such as various metals, such as Indium Tin Oxide (ITO). The partially reflective layer can be formed from a variety of materials that are partially reflective, such as various metals (e.g., chromium and/or molybdenum), semiconductors, and dielectrics. The partially reflective layer may be formed from one or more layers of material, and each of the layers may be formed from a single material or a combination of materials. In some implementations, certain portions of the optical stack 16 may include a single semi-transparent thickness of metal or semiconductor that serves as both a partial optical absorber and an electrical conductor, while different, more conductive layers or portions (e.g., conductive layers or portions of the optical stack 16 or other structures of the display element) may be used to bus signals between IMOD display elements. The optical stack 16 may also include one or more insulating or dielectric layers covering one or more conductive layers or conductive/partially absorbing layers.
In some implementations, at least some of the layers of the optical stack 16 may be patterned into parallel strips, and may form row electrodes in a display device as described further below. As will be understood by those skilled in the art, the term "patterned" is used herein to refer to masking as well as etching processes. In some implementations, a highly conductive and reflective material, such as aluminum (Al), may be used for the movable reflective layer 14, and these strips may form column electrodes in a display device. The movable reflective layer 14 may be formed as a series of parallel strips of a deposited one or more metal layers (orthogonal to the row electrodes of the optical stack 16) to form columns deposited over supports, such as the illustrated posts 18, and an intervening sacrificial material located between the posts 18. When the sacrificial material is etched away, a defined gap 19 or optical cavity may be formed between the movable reflective layer 14 and optical stack 16. In some embodiments, the spacing between posts 18 may be about 1 to 1000 μm, and gap 19 may be less than about 10,000 angstroms
In some implementations, each IMOD display element (whether in an actuated or relaxed state) can be considered a capacitor formed by the fixed and moving reflective layers. When no voltage is applied, the movable reflective layer 14 remains in a mechanically relaxed state, as illustrated by the display element 12 on the left in FIG. 1, with the gap 19 between the movable reflective layer 14 and optical stack 16. However, when a potential difference (i.e., voltage) is applied to at least one of the selected row and column, the capacitor formed at the intersection of the row and column electrodes of the corresponding display element becomes charged, and electrostatic forces pull the electrodes together. If the applied voltage exceeds a threshold, the movable reflective layer 14 can deform and move near or against the optical stack 16. A dielectric layer (not shown) within the optical stack 16 may prevent shorting and control the separation distance between layers 14 and 16, as illustrated by actuated display element 12 on the right in fig. 1. The behavior may be the same regardless of the polarity of the applied potential difference. Although a series of display elements in an array can be referred to in some cases as a "row" or a "column," one skilled in the art will readily appreciate that the reference to one direction as a "row" and another direction as a "column" is arbitrary. To reiterate, in some orientations, a row may be considered a column, and a column may be considered a row. In some implementations, the rows may be referred to as "common" lines and the columns may be referred to as "segmented" lines, or vice versa. Further, the display elements may be arranged uniformly in orthogonal rows and columns ("array"), or in a non-linear configuration, e.g., with some positional offset relative to each other ("mosaic"). The terms "array" and "mosaic" may refer to either configuration. Thus, although the display is referred to as comprising an "array" or "mosaic", the elements themselves need not be arranged orthogonal to each other in any case, or disposed in a uniform distribution, but may comprise an arrangement of elements having an asymmetric shape and a non-uniform distribution.
Fig. 2 is a system block diagram illustrating an electronic device incorporating an IMOD-based display including a three-element-by-three-element array of IMOD display elements. The electronic device includes a processor 21 that may be configured to execute one or more software modules. In addition to executing an operating system, the processor 21 may be configured to execute one or more software applications, including a web browser, a telephone application, an email program, or any other software application.
The processor 21 may be configured to communicate with an array driver 22. The array driver 22 may include a row driver circuit 24 and a column driver circuit 26 that provide signals to, for example, a display array or panel 30. A cross-section of the IMOD display device illustrated in figure 1 is shown by line 1-1 in figure 2. Although fig. 2 illustrates a 3 x 3 array of IMOD display elements for clarity, the display array 30 may contain a large number of IMOD display elements and may have a different number of IMOD display elements in a row than in a column, and vice versa.
In some implementations, the packaging of EMS components or devices (e.g., IMOD-based displays) may include a backplane (alternatively referred to as a backplane, a back glass, or a recessed glass) that may be configured to protect the EMS components from damage (e.g., from mechanical interference or potentially damaging substances). The backing sheet may also provide structural support for a wide range of components including, but not limited to: driver circuitry, processors, memory, interconnect arrays, vapor barriers, product enclosures, and the like. In some implementations, the use of a backplate can facilitate integration of components and thereby reduce the volume, weight, and/or manufacturing cost of the portable electronic device.
Fig. 3A and 3B are schematic exploded partial perspective views of a portion of an EMS package 91 including the array 36 of EMS elements and a backplate 92. Fig. 3A shows a case where two corners of the rear plate 92 are cut away to better explain some portions of the rear plate 92, and fig. 3B shows a case where the corners are not cut away. The EMS array 36 can include a substrate 20, support posts 18, and a movable layer 14. In some implementations, the EMS array 36 can comprise an array of IMOD display elements having one or more optical stack portions 16 on a transparent substrate, and the movable layer 14 can be implemented as a movable reflective layer.
The back plate 92 may be substantially planar or may have at least one contoured surface (e.g., the back plate 92 may be formed with recesses and/or protrusions). The backplate 92 can be made of any suitable material, whether transparent or opaque, conductive or insulative. Suitable materials for the back plate 92 include, but are not limited to, glass, plastic, ceramic, polymer, laminate, metal foil, Kovar, and plated Kovar.
As shown in fig. 3A and 3B, the backplate 92 may include one or more backplate components 94a and 94B, which may be partially or fully embedded in the backplate 92. As can be seen in fig. 3A, a backplate assembly 94a is embedded in the backplate 92. As can be seen in fig. 3A and 3B, the backplate component 94B is disposed within a recess 93 formed in the surface of the backplate 92. In some embodiments, the backplate components 94a and/or 94b may protrude from the surface of the backplate 92. Although the backplate component 94b is disposed on the side of the backplate 92 facing the substrate 20, in other implementations, the backplate component can be disposed on the opposite side of the backplate 92.
The backplane components 94a and/or 94b may include one or more active or passive electrical components, such as transistors, capacitors, inductors, resistors, diodes, switches, and/or Integrated Circuits (ICs), such as packaged, standard, or discrete ICs. Other examples of backplate components that may be used in various implementations include antennas, batteries, and sensors, such as electrical, touch, optical, or chemical sensors, or thin film deposition devices.
In some implementations, the backplate components 94a and/or 94b can be in electrical communication with portions of the EMS array 36. Conductive structures, such as traces, bumps, posts, or vias, may be formed on one or both of the backplate 92 or the substrate 20, and may contact each other or other conductive components to form electrical connections between the EMS array 36 and the backplate components 94a and/or 94 b. For example, FIG. 3B includes one or more conductive vias 96 on the backplate 92 that may be aligned with electrical contacts 98 extending upward from the movable layer 14 within the EMS array 36. In some implementations, the backplate 92 may also include one or more insulating layers that electrically insulate the backplate components 94a and/or 94b from other components of the EMS array 36. In some embodiments in which back panel 92 is formed of a breathable material, the interior surface of back panel 92 may be coated with a moisture barrier (not shown).
The backplate components 94a and 94b may include one or more desiccants for absorbing any moisture that may enter into the EMS package 91. In some implementations, the desiccant (or other hygroscopic material, such as a getter) can be provided separately from any other backplate components, e.g., as a sheet mounted to the backplate 92 (or in a recess formed in the backplate) with an adhesive. Alternatively, the desiccant may be integrated into the backplate 92. In some other implementations, the desiccant can be applied directly or indirectly to other backplate components, for example, by spraying, screen printing, or any other suitable method.
In some implementations, the EMS array 36 and/or the backplate 92 can include mechanical standoffs 97 to maintain the distance between the backplate components and the display elements and thereby prevent mechanical interference between those components. In the implementation illustrated in fig. 3A and 3B, the mechanical standoffs 97 are posts formed to protrude from the backplate 92 in alignment with the support posts 18 of the EMS array 36. Alternatively or additionally, mechanical supports such as rails or posts may be provided along the edges of the EMS package 91.
Although not illustrated in fig. 3A and 3B, a seal may be provided that partially or completely surrounds the EMS array 36. The seal, along with the backplate 92 and the substrate 20, may form a protective chamber that encloses the EMS array 36. The seal may be a semi-hermetic seal, such as a conventional epoxy-based adhesive. In some other embodiments, the seal may be a hermetic seal, for example, a thin film metal weld or a glass frit. In some other embodiments, the seal may comprise Polyisobutylene (PIB), polyurethane, liquid spin-on glass, solder, polymer, plastic, or other material. In some embodiments, a reinforced sealant may be used to form the mechanical standoff.
In alternative embodiments, the seal ring may comprise an extension of one or both of the backplate 92 or the substrate 20. For example, the seal ring may comprise a mechanical extension (not shown) of the back plate 92. In some embodiments, the sealing ring may comprise a separate component, such as an O-ring or other annular component.
In some implementations, the EMS array 36 and the backplate 92 are formed separately before they are attached or coupled together. For example, the edge of the substrate 20 may be attached and sealed to the edge of the backplate 92, as discussed above. Alternatively, the EMS array 36 and the backplate 92 may be formed and bonded together as an EMS package 91. In some other implementations, the EMS package 91 can be fabricated in any other suitable manner, such as by depositing components that form the backplate 92 over the EMS array 36.
FIG. 4 is an example of a system block diagram illustrating an electronic device incorporating an IMOD-based display. Fig. 4 depicts an embodiment of the row and column driver circuits 24, 26 of the array driver 22 as previously described providing signals to a display array or panel 30.
Embodiments of the display modules 710 in the display array 30 may include a variety of different designs. As an example, the display module 710 in the fourth row may include a switch 720 and a display unit 750. The display module 710 may provide row signals, reset signals, bias signals, and general signals from the row driver circuit 24. The display module 710 may also provide data or column signals from the column driver circuit 26. In some implementations, the display unit 750 can be coupled with a switch 720, e.g., a transistor having its gate coupled to a row signal and its drain coupled with a column signal. Each display unit 750 may include an IMOD display element as a pixel.
Some IMODs are three-terminal devices that use multiple signals. Fig. 5 is a circuit schematic of an example of a three-terminal IMOD. In the example of fig. 5, the display module 710 includes a display unit 750 (e.g., IMOD). The circuit of fig. 5 also includes the switch 720 of fig. 4 implemented as an n-type metal oxide semiconductor (NMOS) transistor T1810. The gate of transistor T1810 is coupled to VLine of830 (i.e., the control terminal of transistor T1810 is coupled to V providing a row select signalLine of830)，VLine of830 may be the voltage provided by the row driver circuit 24 of fig. 4. The transistor T1810 is also coupled to VColumn(s) of820，VColumn(s) of820 may be the voltage provided by the column driver circuit 26 of figure 4. If offset VLine of830 (providing a row select signal) to turn on transistor T1810, then at VColumn(s) of820 can be applied to VdAnd an electrode 860. The circuit of fig. 5 further comprises a further switch implemented as an NMOS transistor T2815. The gate (or control terminal) and V of the transistor T2815Reset895 are coupled. The other two terminals of the transistor T2815 and VSharing the sameElectrodes 865 and VdThe electrodes 860 are coupled. When the transistor T2815 is biased to turn on (e.g., by V applied to the gate of the transistor T2815Reset895 voltage of the reset signal), VSharing the sameElectrodes 865 and VdThe electrodes 860 may be shorted together.
The display unit 750 may be a three-terminal IMOD including three terminals or electrodes: vBiasingElectrode 855, VdElectrodes 860 and VSharing the sameAn electrode 865. Display unit 750 may also include movable element 870 and dielectric 875. As previously described, movable element 870 may include a mirror. Movable member 870 may be coupled to VdThe electrodes 860 are coupled. Additionally, the air gap 890 may be at VBiasingElectrodes 855 and VdBetween the electrodes 860. Air gap 885 may be at VdElectrodes 860 and VSharing the sameBetween electrodes 865. In some implementations, the display unit 750 may also include one or more capacitors. For example, one or more capacitors may be coupled at VdElectrodes 860 and VSharing the sameBetween electrodes 865 and/or coupled at VBiasingElectrodes 855 and VdBetween the electrodes 860. Other configurations of display unit 750 may include dielectric 875 or near VSharing the sameAnother dielectric of electrode 865.
Movable element 870 may be positioned at VBiasingElectrodes 855 and VSharing the sameAt a plurality of points between the electrodes 865, light at a particular wavelength is reflected and thus a colour is provided. In particular to VBiasingElectrodes 855,VdElectrodes 860 and VSharing the sameThe voltage of electrode 865 may determine the position of movable element 870. VReset895、VColumn(s) of820、VLine of830、VSharing the sameElectrodes 865 and VBiasingThe voltages for electrodes 855 may be provided by driver circuitry, such as row driver circuitry 24 and column driver circuitry 26. In some embodiments, VSharing the sameThe electrode 865 may be coupled to ground instead of being driven by the row driver circuit 24 or column driver circuit 26. Thus, movable element 870 may be positioned at VBiasingElectrodes 855 and VSharing the sameBetween electrodes 865, and air gaps 885 and 890 can vary in size based on the position of movable element 870.
In some embodiments, positioning movable element 870 may cause an accumulation of positioning errors that result in the actual position of movable element 870 deviating from the expected position. For example, movable element 870 may cause display unit 750 to provide the color red at the first position. The display unit 750 may be required to provide the color blue next. Thus, it may be desirable to change the position of movable element 870 to a new second position to provide the color blue. Thus, a voltage can be applied to VSharing the sameElectrodes 865, VdElectrodes 860 and VBiasingElectrode 855 such that movable element 870 is positioned from a first position associated with the color red to a new second position. Movable element 870 may then be positioned from the second position to a third position to provide another color.
However, positioning movable element 870 directly from the first position to the second position may cause positioning errors. In particular, the voltage applied to the electrodes may deviate from the expected voltage due to process variations, imperfections, noise, calibration errors, and other conditions. As an example, it may be desirable to bias V at 5VdElectrode 860 to position movable element 870 to the second position to provide the color blue. However, VdThe electrode 860 may actually be biased at 4.98V, slightly deviating from the expected 5V. Therefore, movable element 870 may be positioned at an incorrect location, whichA slightly different color is provided than the intended color. When movable element 870 is positioned to the third position, the voltage applied to the electrodes is based on movable element 870 being at the expected position, and therefore movable element 870 may be positioned to another incorrect position. Because movable element 870 is repeatedly positioned, positioning errors may accumulate such that the actual position of movable element 870 shifts away from its expected position.
6A, 6B, and 6C illustrate examples of accumulated positioning error. In fig. 6A, 6B, and 6C, the left side depicts an expected position of movable element 870, and the right side depicts an actual position of movable element 870, e.g., due to V biased at a slight offset voltagedAnd an electrode 860.
In fig. 6A, movable element 870 may be at the same initial position as in the intended and actual context. Thus, Δ D905, which represents the difference in position between movable element 870 in the expected context and movable element 870 in the actual context, is zero. Next, in fig. 6B, movable element 870 may need to be positioned so that display unit 750 provides a new color, and thus a new voltage may be applied to one or more of the three electrodes. However, Δ D905 in FIG. 6B shows a non-zero difference between the positions of movable element 870 of the two contexts, as indicated by the dotted line. That is, the actual position of movable element 870 deviates from the expected position Δ D905 because the electrode (e.g., V) is alloweddElectrode 860) is biased at a slightly incorrect voltage. Next, in fig. 6C, movable element 870 may need to be positioned again to provide another color. However, since movable element 870 is expected to be at the expected position of FIG. 6B, the electrodes may be biased at a voltage to position movable element 870 from the expected position in FIG. 6B to the expected position in FIG. 6C. Since the actual position of movable element 870 is different from the expected position in FIG. 6B, the voltage applied to the electrodes may not be appropriate (i.e., moving from the actual position in FIG. 6B to the expected position in FIG. 6C may not need to be)The same voltage). Thus, the actual position of movable element 870 in fig. 6C is shifted farther away from the expected position, which is indicated by a larger Δ D905.
A reset scheme that positions movable element 870 to an intermediate reset position between positions may be used to reduce the accumulation of positioning errors. 7A-E illustrate an example of positioning a movable element with an intermediate reset position. Some embodiments of this method are described in more detail in U.S. patent application publication No. 14/021,866 entitled "reset USING reverse polarity display element (DISPLAY ELEMENT RESET USING reverse) filed by Chan et al on 9.9.2013, which is incorporated herein by reference in its entirety and for all purposes.
In fig. 7A, movable element 870 may be in an initial position. Movable element 870 may need to be positioned to a new second position so that display unit 750 provides a new second color. However, rather than positioning movable element 870 directly from the initial position to the second position, movable element 870 may be moved to the reset position in fig. 7B prior to being positioned to the second position in fig. 7C. In fig. 7B, movable element 870 is positioned to dielectric 875 and/or movable element 870 is resting against dielectric 875 as a reset position. In particular, voltages may be applied to the electrodes such that movable element 870 moves to VBiasingElectrodes 855 (e.g., by a force created by an electric field generated after application of a voltage applied to the electrodes) and movable element 870 can rest against dielectric 875. Dielectric 875 may act as a "stop" for movable element 870, and thus may provide a reset position or a constant starting point for movable element 870 to move to a new position. Thus, after movable element 870 has been positioned to the reset position in fig. 7B, it may be positioned to the second position to provide the second color in fig. 7C. Next, when movable element 870 needs to be moved to a third new position to provide a third color, it may be repositioned from the second position in FIG. 7C back to the reset position in FIG. 7D, followed by repositioning itPositioned in the third position in fig. 7E.
The reset scheme depicted in fig. 7A-E may reduce the accumulation of positioning errors because movable element 870 is moved to a constant starting point (e.g., resting against dielectric 875) between relocations. Accordingly, if positioning errors occur in the transition from the reset position in fig. 7B to the second position in fig. 7C, then positioning errors may not be accumulated because movable element 870 will be repositioned to the reset position in fig. 7D before being repositioned again to fig. 7E. By repositioning to the reset position in fig. 7D before repositioning for the third position associated with the third color in fig. 7E, positioning errors from the transition from the position of fig. 7B to the position of fig. 7C may be reduced or eliminated.
In some embodiments, even if movable element 870 should remain at the same position to provide the same color (e.g., between different frames), it may still be positioned to a reset position and then repositioned back to the same position. The polarity of the electric field of the display unit 750 may be switched to reduce charge accumulation, and thus the movable element 870 associated with a color or position in a first frame may move to a reset position and then move back to the same position in a second frame to provide the same color, but may change the voltage on the electrodes of the display unit 750. The polarity may also be switched when movable element 870 is moved to a new position.
However, positioning movable element 870 to the reset position may introduce visual artifacts, reduce color saturation, and require additional circuitry to provide the reset function. For example, if the display or array 30 is operated at a lower frequency (e.g., a refresh frequency of 1 Hz), a "tearing" process involving biasing each row of display modules 710 one by one so that each row of display cells 750 is positioned in the proper location may be visible due to the reset positioning.
FIGS. 8A, 8B, and 8C illustrate positioning of a movable element without an intermediate reset positionExamples of (3). Positioning movable element 870 without a reset position may avoid visual artifacts associated with intermediate reset positions and provide more saturated colors. In particular, movable element 870 may be directly positioned from a first position associated with a first color to a second position associated with a second color by applying a voltage to, for example, V multiple timesdAnd an electrode 860. In some embodiments, a first voltage may be applied to begin positioning movable element 870 to a new desired position and within a range of desired positions. Next, a second voltage may be applied to position the movable element 870 within a stable range or to a desired position within the range, and thus the display unit 750 may provide a desired color. The second voltage applied may be V for the desired positiondThe target voltage at which the electrode 860 should be. Accordingly, movable element 870 may be repositioned without an intermediate reset position. Furthermore, movable element 870 may be repositioned without accumulated error.
In more detail, the position to which movable element 870 may be positioned may be within ranges 1105a-h in FIG. 8A. If VBiasingElectrodes 855 and VSharing the sameThe range of movement of movable element 870 between electrodes 865 allows different colors (or wavelengths) of the visible spectrum of the electromagnetic spectrum to be colors provided by respective display units 750, then each of the middle of ranges 1105a-h may be capable of providing different colors. For example, if movable element 870 is positioned in the middle of range 1105a, the color red may be provided. If movable element 870 is positioned in the middle of range 1105g, the color blue may be provided. If movable element 870 is positioned in the middle of range 1105d, the color green may be provided. Although the examples described herein use the middle of the ranges 1105a-1105h, in other contexts, any location within the ranges may be used. The middle portion of the example is chosen for illustrative purposes.
As previously described, to move movable element 870 to a different position, one may moveDifferent voltages are applied to the electrodes of the display unit 750. For example, if movable element 870 of display unit 750 is at the middle of range 1105a reflecting the color red and is desired to be repositioned to the middle of range 1105d to reflect the color green, 4.5V to V may be applieddAnd an electrode 860. However, if movable element 870 should be positioned to another color than green, then other voltages may be applied (e.g., positioning from red to blue in the middle of range 1105g may require applying 5V to VdElectrode 860). Thus, each transition from one location associated with one color to another location associated with another color may be performed by applying a particular voltage to the electrodes. For example, VSharing the sameElectrode 865 may be at 0V, VBiasingThe electrodes may be switched between 12V and-12V depending on polarity (as discussed later herein), and VdThe electrodes 860 may apply a voltage corresponding to a transition between position and color.
In fig. 8B, movable element 870 may need to be repositioned from position 1110, which provides the color red in the middle of range 1105a, to position 1115, which provides the color green in the middle of range 1105 d. Thus, the array driver 22 (including the column driver circuit 26 and the row driver circuit 24) may drive VdThe electrode 860 reaches 4.5V because it can be supplied with 4.5V to VdElectrodes 860 perform the conversion from position 1110 and red to position 1115 and green. However, as previously mentioned, at VdThe voltage at electrode 860 may be slightly offset, for example, 4.4V. Thus, movable element 870 may be moved from position 1110 to position 1115, but, rather than being positioned at desired position 1115, movable element 870 may be at a slightly different position within range 1105d, as in fig. 8B. Next, in FIG. 8C, the array driver 22 may be biased with a second voltage VdElectrodes 860 may stabilize movable element 870 to a desired position within range to reflect the colored green from position 1120 (i.e., incorrect position of movable element 870 in fig. 8B). For example, when movable element 870 is within range 1105d, an application of 2V may beAllowing it to converge or relocate to the middle of position 1115 in range 1105 d. That is, at any point within range 1105d, the application of 2V may stabilize movable element 870 at the middle of range 1105d at position 1115. In general, proximity to a desired location (e.g., within range) may allow movable element 870 to converge after application of a voltage.
As another example, while 4.5V may be a common or expected voltage that is typically applied to the transition from position 1110 corresponding to red to position 1115 corresponding to green, some electrodes associated with other movable elements 870 may require slightly different voltages, e.g., 4.4V, due to process variations or errors from calibration. If 4.5V to V is applieddElectrodes 860, then movable element 870 may also be positioned at location 1120 instead of location 1115. Accordingly, a similar process as in FIGS. 8A-C may also be performed.
If a voltage is applied to V for the first timedElectrode 860 positions movable element 870 at the correct desired position 1115 (i.e., no positioning error occurs), then a voltage is applied to V a second timedThe electrodes 860 will maintain the position of the movable element 870.
Each of the ranges 1105a-1105h may be associated with a voltage range or multiple voltages. If movable element 870 is within range, application of a particular voltage may allow movable element 870 to settle to a particular position within range (e.g., the middle of the range). For example, if movable element 870 is within range 1105a, application of 2V may position it to the middle. The application of 2.2V can position the location to a non-central location. Similarly, if movable element 870 is within 1105f, 2V may position it to the middle of range 1105 f. If movable element 870 is within range 1105b, 2.4V may position it to the middle of range 1105 b.
Thus, if the current position of movable element 870 is known, then the desired position may be provided next by: determining the proper application of the voltage to position the movable element between positions (e.g., transition between the current position to the desired position), providing a voltage for positioning or driving movable element 870 to the desired position and within the range of the desired position (e.g., as in fig. 8B), and then stabilizing it to the desired and desired position by the application of subsequent voltages (e.g., as in fig. 8C). Thus, a two-part technique may be performed with an initial drive portion that moves movable element 870 to a desired position and within a range of desired positions, followed by a stabilization portion that positions movable element 870 to a final desired position within the range. Thus, the two-part technique may position movable element 870 without using an intermediate reset position.
Fig. 9 is a flow chart illustrating a method of positioning a movable element without an intermediate reset position. In method 1200, at block 1205, a first voltage may be applied to the electrodes of display unit 750 to position the movable element to a new position. For example, V, which may provide a voltage to the display unit 750dElectrodes 860, the voltages associated with positioning movable element 870 from a first position providing a first color to a second position providing a second color. At block 1210, a second voltage may be applied to V of the display cell 750dElectrodes 860 to stabilize movable element 870 in range such that it is positioned to a desired position from within range (i.e., a second position providing a second color). At block 1215, the method ends.
In some embodiments, variations of the two-part technique may be performed. For example, positioning movable element 870 from some positions and colors to some other positions and colors may involve a three-part technique. In particular, some positions and colors may not be able to be directly converted to another position and color due to hysteresis. For example, in one implementation, an IMOD display element may use a potential difference of about 5 volts to cause the movable reflective layer or movable element 870 (including a mirror) to change from a 4 volt state (or position) to a 5 volt state (or position). However, the movable reflective layer can remain at the 5 volt state as the potential difference drops below (in this example) 5 volts because the movable reflective layer does not relax completely until the potential difference drops below (in this example) 3 volts. Thus, in this example, the movable reflective layer cannot be directly transitioned from the 5-volt state to the 4-volt state. In practice, it must first transition to a state below 3 volts and then to a state of 4 volts. 10A, 10B, and 10C are diagrams illustrating examples of positioning a movable element in a hysteresis region.
In FIG. 10A, a graph shows the position of movable element 870 on the y-axis and the pulsed voltage (e.g., applied to V) on the x-axisdThe voltage of electrode 860). In addition, the chart shows the color associated with the location.
In some implementations, movable element 870 at a location associated with the color white may not be able to directly transition to some colors until movable element 870 is "released" from hysteresis. Releasing movable element 870 from hysteresis may involve positioning movable element 870 away from the hysteresis loop (i.e., to a color outside of the hysteresis loop), which may prevent movable element 870 from moving directly to a particular position within the hysteresis loop. After movable element 870 is released, a two-part technique may be implemented. Thus, transitioning to some positions and colors may require a three-part technique that includes releasing movable element 870 from hysteresis, driving movable element 870 to a desired position, and settling to a desired position.
For example, in fig. 10B, movable element 870 may be at a position 1305 associated with the color white. If movable element 870 needs to be positioned to a position associated with black or blue (i.e., a color associated with a position in the hysteresis region), it may not be able to move directly to that position. Indeed, movable element 870 may need to be released, for example, by first being positioned to location 1310 associated with the color green outside the hysteresis zone. Thus, the hysteresis region in FIG. 10B may be a hysteresis loop such that if movable element 870 is at position 1305 associated with the color white, it cannot be repositioned to a position providing black or blue in a single transition. When movable element 870 is at a position that provides a color green, it may be away from the hysteresis region, and thus may be able to be positioned to any available position (including returning into the hysteresis region). For example, in fig. 10B, movable element 870 may then be able to reposition to a position 1315 associated with the color blue.
11A-D illustrate examples of positioning a movable element within a hysteresis region. In FIG. 11A, movable element 870 may be at position 1305 in range 1105h, causing display unit 750 to provide the color white. A location 1315 within range 1105f may provide the color blue. Ranges 1105e-h may be in a hysteresis region such that movable element 870 may not be able to reposition directly from white position 1305 in range 1105h to a position within range 1105 e-g. In effect, movable element 870 may be repositioned to provide a colored green position 1310 (i.e., outside of range 1105e-h in the hysteresis region) to be released from the hysteresis region. Thus, in FIG. 11B, movable element 870 is moved from position 1305, which provides the color white, to position 1310, which provides the color green. Next, movable element 870 may be driven to the desired color of range 1105f and settle at position 1315. For example, in fig. 11C, movable element 870 may be positioned from position 1310 to within range 1105f at position 1315. Next, in fig. 11D, movable element 870 may settle at position 1320 in range 1105f to provide the color blue.
However, not all positions and colors may be within the hysteresis region. For example, in fig. 10C, movable element 870 may be repositioned from a position associated with white in the hysteresis region to a position associated with red without first repositioning to the release position (i.e., position 1310 and color green). In fact, since the color red is outside the hysteresis region, a two-part technique as previously described may be performed.
FIG. 12 isA flow chart illustrating a method of positioning a movable element in a hysteresis region. In method 1500, at block 1505, a voltage may be provided (e.g., to V)dElectrodes 860) to release movable element 870 from the hysteresis zone. In block 1510, a second voltage can be provided to position the movable element toward the desired position and within a range of the desired position. In block 1515, a third voltage may be provided to stabilize the movable element to a desired position within range. The method ends at block 1520.
Fig. 13 is an example of a system block diagram for driving a display element. In fig. 13, system 1600 may include circuitry to determine to apply to, for example, VdThe voltage of electrode 860, such that movable element 870 may be positioned without a reset position.
In FIG. 13, the system 1600 includes a frame buffer 28, a storage device for storing a voltage look-up table (LUT)1610, a driver controller 29, and an array driver 22. Frame buffer 28 may include information regarding current image characteristics (e.g., color), as described later herein. The voltage LUT 1610 may be a voltage data source that may include data indicative of a voltage for converting from one color to another. Driver controller 29 may receive image data 1615, which may include information about what color each movable element 870 of each display unit 750 should next be. The driver controller 29 may determine the current color of the movable element 870 by finding its corresponding data in the frame buffer 28 and may determine the next color that the movable element 870 should provide based on the image data 1615. Thus, driver controller 29 may know how each movable element 870 should transition. For example, if movable element 870 of display unit 750 is at a position that provides the color green as indicated in frame buffer 28 and the same movable element 870 should next provide the color red as indicated in image data 1615, then a transition from green to red may need to occur. The voltage LUT 1610 may be accessed by the driver controller 29 to determine the arrayThe driver 22 may need to apply for a green to red transition to VColumn(s) of820 voltage when VLine of830 may be used to bias V when biased to turn on transistor T1810 in fig. 5dElectrodes 860 and hence movable element 870.
The voltage LUT 1610 may include providing information for applying three voltages to VdThe LUT of electrode 860. Fig. 14A, 14B, and 14C illustrate examples of look-up tables (LUTs) for driving display elements.
In fig. 14A, 14B and 14C, the LUT may be used to implement a two-part technique including drive and stabilize and to implement a three-part technique including release, drive and stabilize. For example, the LUT may indicate to be applied to VdThe electrodes 860 are in a sequence of three voltages for each color-to-color conversion.
For movable element 870 in the hysteresis region (e.g., at color white) and transitioning to another position within the hysteresis region, the first voltage in the first LUT may indicate the voltage to be applied to release movable element 870. A second voltage in the second LUT may be indicative of a voltage that positions movable element 870 to a position associated with a desired color. A third voltage in the third LUT may be indicative of a voltage that stabilizes movable element 870 to a position associated with the desired color.
For movable element 870 that is initially outside the hysteresis region or that transitions to a subsequent position outside the hysteresis region, a first voltage in the first LUT may indicate the application of a voltage for positioning movable element 870 toward a position associated with a desired color. A second voltage in the second LUT may indicate a voltage applied to stabilize movable element 870 in a desired position. The third voltage in the third LUT may be the same as the second voltage. Since movable element 870 need not be released from the hysteresis region, only the application of two different voltages is required, and thus the third voltage may be a repetition of the second voltage. In other embodiments, the first application of voltage may alternatively be applied twice.
For movable element 870 to stay at the same position and color, each voltage indicated in each of the three LUTs may be the same, such that movable element 870 does not move to another position.
For example, in fig. 14A, 14B, and 14C, each box represents V to be applied to the display unit 750dThe voltage of electrodes 860 allows movable element 870 to be properly positioned. The y-axis represents the converted current color of movable element 870 and the x-axis represents the converted next desired color of movable element 870. The LUTs in fig. 14A and 14B indicate the voltages to be applied for the indicated color conversion. The LUT in fig. 14C indicates the voltage to be applied based on the desired color (i.e., the color to be converted to).
In FIG. 14A, the transition from green to red indicates that 2.2V should be applied to VdAnd an electrode 860. This may be a voltage that positions movable element 870 from a position that provides the color green to a position that provides the color red. However, as previously mentioned, VdThe electrode 860 may receive a voltage slightly deviating from 2.2V. Next, in fig. 14B, the second LUT indicates that 4.8V should be applied to position movable element 870 so that it settles to the position providing the color red. In fig. 14C, the third LUT indicates the same voltage as the second LUT for the desired color.
The conversion from green to green should apply 5V to VdElectrode 860, which may be a voltage already applied to it, since movable element 870 should not move. Thus, each of the LUTs in fig. 14A, 14B, and 14C indicates 5V for green-to-green conversion and the final desired green color.
In FIG. 14A, the transition from white to blue indicates that 6.2V should be applied to VdAnd an electrode 860. This may be a voltage that positions movable element 870 to a position that provides a green color outside of the hysteresis region, causing movable element 870 to be released from the hysteresis. In fig. 14B, the white to blue conversion in the second LUT indicates that 8V should be applied. This may be to move the elementMember 870 is positioned from a green color providing position to a blue color providing position. Next, in fig. 14B, 2V may be applied. This may be a voltage that stabilizes movable element 870 to a position that provides blue.
LUTs can be organized in different ways. Fig. 15A, 15B, and 15C illustrate another example of an LUT for driving a display element. In fig. 15A, 15B, and 15C, the box with the label "1" may be used for the green to red transition (i.e., transition outside the hysteresis region), the box with the label "2" may be used for the white to blue transition (i.e., transition inside the hysteresis region to another location within the hysteresis region), and the box with the label "3" may be used for the green to green transition (i.e., stay at the same color). For example, in fig. 15A, the green-to-red transition may first apply a voltage corresponding to the green-to-red transition in fig. 15A to position movable element 870 toward the desired position that provides red. Next, in fig. 15B, the voltage indicated in the red-to-red transition may indicate that the next voltage for stabilizing movable element 870 is applied, because movable element 870 should be in a range including red. In fig. 15C, the voltage indicated by the desired color red is then applied, which may be the same as indicated in fig. 15B.
The above examples of voltages are provided for illustrative purposes. Other embodiments may involve other voltages and/or LUTs.
In some embodiments, three voltages may be applied in three different "tears" through each row of display cells 750 of the display. For example, in a first tear, each V of each display element 750 in a first rowdThe electrode 860 may apply a first voltage as indicated in the first LUT, followed by each movable element 870 of each display unit 750 in the second row, and so on, up to each V of each display unit 750dElectrodes 860 are biased to allow corresponding movable element 870 to be released (if in the hysteresis region and switched to another position and color in the hysteresis region), oriented to a desired position andcolor drive (if switching to positions and colors outside the hysteresis region), or hold (if color should not change). Next, a second voltage, as indicated in the second LUT, may be applied to each row by row. After providing the second voltage for each row in the display, each row may then provide the voltage as indicated in the third LUT.
In addition, the polarity of the electric field of the display unit 750 may also be switched between tears. For example, if VSharing the sameElectrode 865 is 0V and the voltage indicated in the LUT is provided to VdElectrode 860, then applied to VBiasingThe voltage of electrode 855 may be alternated between positive and negative voltages (e.g., 12V and-12V) to reverse the direction of the electric field and thus reduce charge accumulation across display element 750. For example, to VBiasingThe voltage of electrode 855 can be applied to V at a voltagedThe electrode 860 is switched before or after.
In some embodiments, a third tear may not be performed. In particular, the second tear may stabilize movable element 870 for colors outside of the hysteresis. For colors within the lag and switching to another color within the lag, sufficient stability can be provided by first releasing to a position and color outside the lag region. However, in other embodiments the application of the third tear may be repeated to provide further stability.
Although only three LUTs are shown in the previous example, more may be used. For example, additional LUTs may be used to further consider polarity. For example, a positive frame with a positive polarity of the display unit 750 may be converted into a negative frame with a negative polarity of the display unit 750, and vice versa. The conversion to the same location and color but with different polarity may have different LUTs.
Additionally, the LUT may indicate any number of colors that may be converted or translated therefrom. For example, the LUT herein includes eight colors, but any number of colors may be used with the LUT.
Fig. 16A and 16B are system block diagrams illustrating a display device 40 including a plurality of IMOD display elements. Display device 40 may be, for example, a smartphone, cellular or mobile phone. However, the same components of display device 40 or slight variations thereof are also illustrative of various types of display devices, such as televisions, computers, tablet computers, e-readers, handheld devices, and portable media devices.
The display device 40 includes a housing 41, a display 30, an antenna 43, a speaker 45, an input device 48, and a microphone 46. The housing 41 may be formed from any of a variety of manufacturing processes including injection molding and vacuum forming. Additionally, the housing 41 may be made from any of a variety of materials, including but not limited to: plastic, metal, glass, rubber, and ceramic, or a combination thereof. The housing 41 may include removable portions (not shown) that may be interchanged with other removable portions of different color, or containing different logos, pictures, or symbols.
Display 30 may be any of a variety of displays, including a bi-stable or analog display, as described herein. The display 30 may also be configured to include a flat panel display such as a plasma, EL, OLED, STN LCD, or TFT LCD, or a non-flat panel display such as a CRT or other tube device. Additionally, the display 30 may comprise an IMOD-based display, as described herein.
The components of the display device 40 are schematically illustrated in fig. 16A. The display device 40 includes a housing 41 and may include additional components at least partially enclosed therein. For example, the display device 40 includes a network interface 27, the network interface 27 including an antenna 43 that may be coupled to a transceiver 47. The network interface 27 may be a source of image data that may be displayed on the display device 40. Thus, network interface 27 is one example of an image source module, although the processor 21 and the input device 48 can also serve as an image source module. The transceiver 47 is connected to the processor 21, and the processor 21 is connected to the conditioning hardware 52. The conditioning hardware 52 may be configured to condition the signal (e.g., filter or otherwise manipulate the signal). The conditioning hardware 52 may be connected to a speaker 45 and a microphone 46. The processor 21 may also be connected to an input device 48 and a driver controller 29. A driver controller 29 may be coupled to the frame buffer 28 and to the array driver 22, which in turn may be coupled to a display array 30. One or more elements in display device 40, including elements not specifically depicted in fig. 16A, may be configured to act as memory devices and configured to communicate with processor 21. In some implementations, the power supply 50 can provide power to substantially all components in a particular display device 40 design.
The network interface 27 includes the antenna 43 and the transceiver 47 so that the display device 40 can communicate with one or more devices over a network. The network interface 27 may also have some processing capabilities to relieve data processing requirements of the processor 21, for example. The antenna 43 can transmit and receive signals. In some implementations, the antenna 43 transmits and receives RF signals according to the IEEE 16.11 standard, including IEEE 16.11(a), (b), or (g), or the IEEE 802.11 standard, including IEEE 802.11a, b, g, n, and further implementations thereof. In some other embodiments, the antenna 43 is according toStandards transmit and receive RF signals. In the case of a cellular telephone, the antenna 43 may be designed to receive Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), global system for mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), terrestrial trunked radio (TETRA), wideband-CDMA (W-CDMA), evolution-data optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), evolved high speed packet access (HSPA +), Long Term Evolution (LTE), AMPS, or other known signals for communication within a wireless network, such as a system utilizing 3G, 4G, or 5G technologies. The transceiver 47 may pre-process the signals received from the antenna 43 so that the processor 21 may receive and further manipulate the signals. The transceiver 47 may also process signals received from the processor 21 so that they may be transmitted from the processor via the antenna 43The display device 40 emits.
In some embodiments, the transceiver 47 may be replaced with a receiver. Additionally, in some implementations, network interface 27 can be replaced with an image source, which can store or generate image data to be sent to the processor 21. The processor 21 may control the overall operation of the display device 40. The processor 21 receives data, such as compressed image data, from the network interface 27 or an image source, and processes the data into raw image data or into a format that can be readily processed into raw image data. The processor 21 may send the processed data to the driver controller 29 or to frame buffer 28 for storage. Raw data generally refers to information that identifies the image characteristics at each location within an image. Such image characteristics may include color, saturation, and gray-scale level, for example.
The processor 21 may include a microcontroller, CPU, or logic unit for controlling the operation of the display device 40. Conditioning hardware 52 may include amplifiers and filters for transmitting signals to the speaker 45, and for receiving signals from the microphone 46. Conditioning hardware 52 may be discrete components within the display device 40, or may be incorporated within the processor 21 or other components.
The driver controller 29 may take the raw image data generated by the processor 21 either directly from the processor 21 or from the frame buffer 28 and may reformat the raw image data appropriately for high speed transmission to the array driver 22. In some implementations, the driver controller 29 can reformat the raw image data into a data flow having a raster-like format, such that it has a time order suitable for scanning across the display array 30. The driver controller 29 then sends the formatted information to the array driver 22. Although a driver controller 29, such as an LCD controller, is typically associated with the system processor 21 as a stand-alone Integrated Circuit (IC), such a controller may be implemented in a variety of ways. For example, the controller may be embedded in the processor 21 as hardware, embedded in the processor 21 as software, or fully integrated in hardware with the array driver 22.
The array driver 22 may receive the formatted information from the driver controller 29 and may reformat the video data into a parallel set of waveforms that are applied many times per second to the hundreds and sometimes thousands (or more) of leads coming from the display element's x-y matrix of the display.
In some implementations, the driver controller 29, array driver 22, and display array 30 are appropriate for any of the types of displays described herein. For example, the driver controller 29 may be a conventional display controller or a bi-stable display controller (e.g., an IMOD display element controller). Additionally, the array driver 22 may be a conventional driver or a bi-stable display driver (e.g., an IMOD display element driver). Further, the display array 30 can be a conventional display array or a bi-stable display array (e.g., a display including an array of IMOD display elements). In some implementations, the driver controller 29 can be integrated with the array driver 22. Such implementations may be used in highly integrated systems, such as mobile phones, portable electronic devices, watches, or small area displays.
In some implementations, input device 48 may be configured to allow, for example, a user to control the operation of display device 40. Input device 48 may include a keypad, such as a QWERTY keyboard or a telephone keypad, a button, a switch, a rocker arm, a touch-sensitive screen integrated with display array 30, or a pressure-or heat-sensitive membrane. The microphone 46 may be configured as an input device for the display device 40. In some implementations, voice commands through the microphone 46 may be used to control the operation of the display device 40.
The power supply 50 may include a variety of energy storage devices. For example, the power source 50 may be a rechargeable battery, such as a nickel cadmium battery or a lithium ion battery. In implementations using rechargeable batteries, the rechargeable batteries may be charged using power from, for example, a wall outlet or a photovoltaic device or array. Alternatively, the rechargeable battery may be charged wirelessly. Power supply 50 may also be a renewable energy source, a capacitor, or a solar cell, including a plastic solar cell or solar-cell paint. The power supply 50 may also be configured to receive power from a wall outlet.
In some implementations, control programmability resides in the driver controller 29, which can be located in several places in the electronic display system. In some other implementations control programmability resides in the array driver 22. The optimizations described above may be implemented in any number of hardware and/or software components and in various configurations.
As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including individual components. As an example, "at least one of a, b, or c" is intended to encompass: a. b, c, a-b, a-c, b-c and a-b-c.
The various illustrative logics, logical blocks, modules, circuits, and algorithm steps described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Interchangeability of hardware and software has been described generally in terms of their functionality, and illustrated in the various illustrative components, blocks, modules, circuits, and steps described above. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
The hardware and data processing apparatus for implementing the various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with: a general purpose single-or multi-chip processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, certain steps and methods may be performed by circuitry that is specific to a given function.
In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents, or any combination thereof. Implementations of the subject matter described in this specification can also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on computer storage media for execution by, or to control the operation of, data processing apparatus.
If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The steps of a method or algorithm disclosed herein may be embodied in a processor-executable software module, which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can enable transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as any one or any combination or set of codes and instructions on a machine readable medium and computer readable medium, which may be incorporated into a computer program product.
Various modifications to the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein but are to be accorded the widest scope consistent with the invention, the principles and novel features disclosed herein. Additionally, those skilled in the art will readily understand that the terms "upper" and "lower" are sometimes used for ease of describing the figures, and indicate relative positions corresponding to the orientation of the figures on a properly oriented page, and may not reflect the proper orientation of, for example, an implemented IMOD display element.
Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, those skilled in the art will readily recognize that such operations need not be performed in the particular order shown or in sequential order, or that all illustrated operations should be performed, to achieve desirable results. Additionally, the drawings may schematically depict one or more example processes in flow chart form. However, other operations not depicted may be incorporated in the schematically illustrated example process. For example, one or more additional operations may be performed before, after, concurrently with, or between the illustrated operations. In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.