US20210333521A9 - An optical-path folding-element with an extended two degree of freedom rotation range - Google Patents

Abstract

Actuators for rotating an optical-path-folding-element with two, first and second, degrees of freedom in an extended rotation range around two respective rotation axes, folded cameras including such actuators and dual-cameras including a folded camera as above together with an upright camera.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a 371 application from international patent application PCT/IB2019/053315 filed Apr. 22, 2018, and is related to and hereby claims the priority benefit of commonly-owned and co-pending U.S. Provisional Patent Application No. 62/661,158 filed Apr. 23, 2017, which is incorporated herein by reference in its entirety.
FIELD
• The subject matter disclosed herein relates in general to a folded-lens and to digital cameras with one or more folded lens.
BACKGROUND
• In recent years, mobile devices such as cell-phones (and in particular smart-phones), tablets and laptops have become ubiquitous. Many of these devices include one or two compact cameras including, for example, a main rear-facing camera (i.e. a camera on the back face of the device, facing away from the user and often used for casual photography), and a secondary front-facing camera (i.e. a camera located on the front face of the device and often used for video conferencing).
• Although relatively compact in nature, the design of most of these cameras is similar to the traditional structure of a digital still camera, i.e. it comprises a lens module (or a train of several optical elements) placed on top of an image sensor. The lens module refracts the incoming light rays and bends them to create an image of a scene on the sensor. The dimensions of these cameras are largely determined by the size of the sensor and by the height of the optics. These are usually tied together through the focal length (“f”) of the lens and its field of view (FOV)—a lens that has to image a certain FOV on a sensor of a certain size has a specific focal length. Keeping the FOV constant, the larger the sensor dimensions (e.g. in a X-Y plane), the larger the focal length and the optics height.
• A “folded camera module” structure has been suggested to reduce the height of a compact camera. In the folded camera module structure, an optical path folding element (referred to hereinafter as “OPFE” that includes a reflection surface such as a prism or a mirror; otherwise referred to herein collectively as a “reflecting element”) is added in order to tilt the light propagation direction from a first optical path (e.g. perpendicular to the smart-phone back surface) to a second optical path, (e.g. parallel to the smart-phone back surface). If the folded camera module is part of a dual-aperture camera, this provides a folded optical path through one lens module (e.g. a Tele lens). Such a camera is referred to herein as a “folded-lens dual-aperture camera” or a “dual-aperture camera with a folded lens”. In some examples, the folded camera module may be included in a multi-aperture camera, e.g. together with two “non-folded” camera modules in a triple-aperture camera.
• A folded-lens dual-aperture camera (or “dual-camera”) with an auto-focus (AF) mechanism is disclosed in Applicant's US published patent application No. 20160044247.
SUMMARY
• According to one aspect of the presently disclosed subject matter there is provided an actuator for rotating an OPFE in two degrees of freedom in an extended rotation range a first sub-assembly, a second sub-assembly and a stationary sub-assembly, the first sub-assembly configured to rotate the OPFE relative to the stationary sub-assembly in an extended rotation range around a yaw rotation axis and the second sub-assembly configured to rotate the OPFE relative to the first sub-assembly in an extended rotation range around a pitch rotation axis that is substantially perpendicular to the yaw rotation axis; a first sensor configured to sense rotation around the yaw rotation axis and a second sensor configured to sense rotation around the pitch rotation axis, the first and second sensors being fixed to the stationary sub-assembly, wherein at least one of the first sensor or the second sensor is a magnetic flux sensor; and a voice coil motor (VCM) comprising a magnet and a coil, wherein the magnet is fixedly attached to one of the first sub-assembly or the second sub-assembly, wherein the coil is fixedly attached to the stationary sub-assembly, wherein a driving current in the coil creates a force that is translated to a torque around a respective rotation axis, and wherein the second sensor is positioned such that sensing by the second sensor is decoupled from the rotation of the OPFE around the yaw rotation axis.
• In addition to the above features, the actuator according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (i) to (xxv) listed below, in any technically possible combination or permutation:
• • i. wherein the actuator is adapted to be installed and operable in a folded digital camera for rotating the OPFE within the camera,
  • ii. wherein the actuator comprises a first actuation mechanism (including a first VCM) configured to rotate the first sub-assembly around the yaw rotation axis and a second actuation mechanism (including a second VCM) configured to rotate the second sub-assembly around the yaw rotation axis,
  • iii. wherein the actuator comprises a first sensing mechanism that comprises the first sensor and a respective first magnet configured to sense the rotation around the yaw rotation axis and a second sensing mechanism that comprises the second sensor and a second magnet configured to sense the rotation around the pitch rotation axis,
  • iv. wherein the yaw rotation axis passes through the second sensor to thereby decouple the second sensor from rotation around the yaw axis,
  • v. wherein the yaw rotation axis passes through a center of the second sensor,
  • vi. wherein the actuator further comprises a first curved ball-guided mechanism operative to enable the rotation around the pitch axis, and a second curved ball-guided mechanism operative to enable the rotation around the yaw axis,
  • vii. wherein the actuator further comprises a curved ball-guided mechanism operative to enable the rotation around the yaw axis, the curved ball-guided mechanism is located on a side of the OPFE which is opposite to side facing an image sensor,
  • viii. wherein the extended rotation range is equal to or greater than ±5 degrees around the pitch and yaw rotation axes,
  • ix. wherein the extended rotation range is equal to or greater than ±10 degrees the pitch and yaw rotation axes,
  • x. wherein the extended rotation range is between ±15-40 degrees around the pitch and yaw rotation axes,
  • xi. wherein the extended rotation range around the pitch rotation axis is different from the extended rotation range around the second rotation axis,
  • xii. wherein the at least one voice coil motor includes a pitch magnet and a coil dedicated for generating the rotation around the pitch rotation axis and wherein the pitch magnet is designed with a flat surface facing the coil,
  • xiii. wherein the magnetic sensor is a magnetic flux sensor such as a Hall sensor.
  • xiv. wherein the actuator comprises a sensing mechanism that includes the first sensor and a magnet (e.g. yaw sensing magnet), the magnet is shaped or formed such that a central part of the sensing magnet is further away from a projection line of motion of the first sensor, relative to an end of the sensing magnet,
  • xv. wherein the actuator comprises a sensing magnet (e.g. yaw sensing magnet) shaped such that width of a cross section of the sensing magnet increases from a point substantially at its center towards each end of the magnet, thereby resulting in a variable distance between the first sensor and the magnet when relative movement occurs between the sensing magnet and the sensor,
  • xvi. wherein the actuator further comprises a first magnet-yoke pair which pulls the first sub-assembly to the second sub-assembly in a radial direction relative to the pitch rotation axis and a second magnet-yoke pair which pulls the first sub-assembly to the stationary sub-assembly in a radial direction relative to the yaw rotation axis,
  • xvii. wherein the first sub-assembly comprises a middle moving frame, the second sub-assembly comprises an OPFE holder, and the stationary sub-assembly comprises a base; wherein the first magnet-yoke pair pulls the OPFE holder to middle moving frame and the second magnet-yoke pair pulls the middle moving frame to the base,
  • xviii. wherein the first sub-assembly comprises a middle moving frame and the second sub-assembly comprises an OPFE holder, and the stationary sub-assembly comprises a base; wherein rotation around the yaw rotation axis is generated by rotating the middle moving frame relative to the base and rotation around the pitch rotation axis is generated by rotating the OPFE holder relative to the middle moving frame.,
  • xix. wherein the actuator comprises a magnet characterized by a cut sphere shape and a coil characterized by a circular shape, the coil is symmetrically positioned around the cut sphere,
  • xx. wherein the actuator comprises a single magnet that is used for creating an actuation force for rotation around the yaw rotation axis, creating a pre-load force in a magnet-yoke pair for holding together the first sub-assembly and the stationary sub-assembly, and sensing the rotation around the yaw rotation axis.
  • xxi. wherein the actuator comprises only one magnetic flux sensor that is used for sensing rotation around the yaw rotation axis,
  • xxii. wherein the single magnet is a polarization magnet characterized by continuous changes in direction of a magnetic field of the magnet along the magnet's length. wherein the first and second sensing mechanisms are decoupled from each other,
  • xxiii. wherein the actuator is designed to be installed in a folded camera that comprises a lens module accommodating a plurality of lens elements along an optical axis; wherein the OPFE redirects light that enters the folded camera from a direction of a view section along a first optical path to a second optical path that passed along the optical axis,
  • xxiv. wherein the actuator comprises a pitch magnet located at a side of the OPFE that is opposite to the side facing the view section,
  • xxv. wherein the actuator comprises a yaw magnet located at a side of the OPFE that is opposite to the side facing the lens module,
• According to another aspect of the presently disclosed subject matter there is provided a folded camera comprising the actuator according to the previous aspect.
• In addition to the above features, the folded camera according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (i) to (xxv) listed above, in any technically possible combination or permutation.
• According to yet another aspect of the presently disclosed subject matter there is provided an actuator for rotating an OPFE with a first degree of freedom (DOF) around a first rotation axis and a second DOF around a second rotation axis, comprising:
• • a) a first actuation mechanism for rotation in the first DOF;
  • b) a first sensing mechanism for sensing movement in the first DOF;
  • c) a second actuation mechanism for rotation in the second DOF; and
  • d) a second sensing mechanism for sensing movement in the second DOF;
  • wherein first and second actuation mechanisms are configured to rotate the OPFE around the respective first or second rotation axis in an extended rotation range,
  • and wherein in some examples the first and second actuation mechanism are voice coil motors and the second sensing mechanism comprises a sensor positioned such that rotation of the OPFE around the first rotation axis is decoupled from the second sensor.
• In addition to the above features, the camera according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (i) to (xxv) listed above, in any technically possible combination or permutation.
• According to another aspect of the presently disclosed subject matter there is provided a sensing mechanism for sensing rotation movement around a rotation axis, comprising a magnet and a magnetic sensor configured to detect a magnetic flux of the magnet and to determine a relative shift between the magnet and the magnetic sensor based on change in the detected magnetic flux, wherein the magnet is shaped such that a cross section of the magnet has a width that increases from a point substantially at a center of the magnet towards each end of the magnet, thereby increasing a range of detectable change in the magnetic flux and increasing a corresponding detectable range of the relative shift between the magnet and the magnetic sensor.
• In addition to the above features, the actuator according to this aspect of the presently disclosed subject matter can optionally comprise one or more of features (i) to (iv) listed below, in any technically possible combination or permutation:
• • i. wherein the detectible range of relative shift between the magnet and the magnetic sensor is of more than 0.8 mm,
  • ii. wherein the detectible range of relative shift between the magnet and the magnetic sensor is of more than 1.0 mm,
  • iii. wherein the detectible range of relative shift between the magnet and the magnetic sensor is of more than 2.0 mm, and
  • iv. wherein the magnetic sensor is a Hall bar sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
• Non-limiting examples of the presently disclosed subject matter are described below with reference to figures attached hereto that are listed following this paragraph. Identical structures, elements or parts that appear in more than one figure may be labeled with the same numeral in the figures in which they appear. The drawings and descriptions are meant to illuminate and clarify embodiments disclosed herein, and should not be considered limiting in any way.
• FIG. 1A illustrates a folded camera with an optical path folding element (OPFE) with an extended 2 degrees-of-freedom (DOF) rotation range, according to some examples of the presently disclosed subject matter;
• FIG. 1B shows the folded camera ofFIG. 1A with an OPFE actuator, according to some examples of the presently disclosed subject matter;
• FIG. 1C shows a dual-camera the includes a folded camera as inFIG. 1A together with an upright (non-folded) camera, according to according to some examples of the presently disclosed subject matter;
• FIG. 2A shows an OPFE actuator of the folded camera ofFIG. 1 in an isometric view, according to some examples of the presently disclosed subject matter;
• FIG. 2B shows the actuator inFIG. 2A without a shield, according to some examples of the presently disclosed subject matter;
• FIG. 3A shows a top actuated sub-assembly of the actuator ofFIGS. 2A and 2B from one side, according to some examples of the presently disclosed subject matter;
• FIG. 3B shows the top actuated sub-assembly ofFIG. 3A from an opposite side, according to some examples of the presently disclosed subject matter;
• FIG. 3C shows the top actuated sub-assembly ofFIG. 3A in an exploded view, according to some examples of the presently disclosed subject matter;
• FIG. 4A shows a bottom actuated sub-assembly of the actuator ofFIGS. 2A and 2B from one side, according to some examples of the presently disclosed subject matter;
• FIG. 4B shows the bottom actuated sub-assembly ofFIG. 4A from an opposite side, according to some examples of the presently disclosed subject matter;
• FIG. 4C shows the bottom actuated sub-assembly in an exploded view, according to some examples of the presently disclosed subject matter;
• FIG. 5A shows the top and bottom actuated sub-assemblies installed together in an isometric view, according some examples of the presently disclosed subject matter;
• FIG. 5B shows the top and bottom actuated sub-assemblies installed together in a cut along a line A-B shown inFIG. 5A, according to some examples of the presently disclosed subject matter;
• FIG. 6A shows a stationary sub-assembly of the actuator ofFIGS. 2A and 2B from one side, according to some examples of the presently disclosed subject matter;
• FIG. 6B shows the stationary sub-assembly ofFIG. 6A from an opposite side, according to some examples of the presently disclosed subject matter;
• FIG. 6C shows the stationary actuated sub-assembly in an exploded view, according to some examples of the presently disclosed subject matter;
• FIG. 7 shows the actuator ofFIG. 2B along a cut along line A-B shown inFIG. 2A, according to some examples of the presently disclosed subject matter;
• FIG. 8 shows details of an electronic circuitry included in the stationary sub-assembly ofFIGS. 6A-6C, according to some examples of the presently disclosed subject matter;
• FIG. 9A shows a pitch actuation and sensing mechanism of the actuator inFIGS. 2A-2B in an isometric view, according to some examples of the presently disclosed subject matter;
• FIG. 9B shows a side cut along a line A-B shown inFIG. 9A of the pitch actuation and sensing mechanism ofFIG. 9A, according to some examples of the presently disclosed subject matter;
• FIG. 10A shows a pitch actuation and sensing mechanism of the actuator inFIGS. 2A-2B in an isometric view, according to other examples of the presently disclosed subject matter;
• FIG. 10B shows a side cut of the pitch actuation and sensing mechanism ofFIG. 10A along a line A-B shown inFIG. 10A, according to some examples of the presently disclosed subject matter;
• FIG. 11A shows a yaw sensing mechanism of the actuator inFIGS. 2A-2B, according to some examples of the presently disclosed subject matter;
• FIG. 11B shows a yaw rotation range β, a distance R_YAWbetween a yaw Hall bar element and a yaw rotation axis, and a trajectory of a yaw sensing magnet of the yaw sensing mechanism ofFIG. 11A in the Y-Z plane, according to some examples of the presently disclosed subject matter;
• FIG. 11C shows one magnetic configuration for the yaw sensing magnet ofFIG. 11B in a cut along a line A-B shown inFIG. 11A, according to some examples of the presently disclosed subject matter;
• FIG. 11D shows another magnetic configuration for the yaw sensing magnet ofFIG. 11B in a cut along a line A-B shown inFIG. 11A, according to some examples of the presently disclosed subject matter;
• FIG. 11E shows yet another magnetic configuration for the yaw sensing magnet ofFIG. 11B in a cut along a line A-B shown inFIG. 11A, according to some examples of the presently disclosed subject matter;
• FIG. 11F shows the magnetic field as a function of rotation along a given trajectory for the cases presented inFIGS. 11C-E, according to some examples of the presently disclosed subject matter;
• FIG. 11-i toFIG. 11-vi show various possible alternative examples of magnetic configuration for the yaw sensing magnet.
• FIG. 12A shows a yaw magnetic actuation mechanism in an isometric view from one side, according to some examples of the presently disclosed subject matter
• FIG. 12B shows the yaw magnetic actuation mechanism ofFIG. 12A in an isometric view from another side, according to some examples of the presently disclosed subject matter;
• FIG. 12C shows magnetic field directions in a Y-Z plane along a cut A-B inFIG. 12A, according to some examples of the presently disclosed subject matter;
• FIG. 13 shows additional magnetic yoke positioned next to yaw magnet, according to some examples of the presently disclosed subject matter;
• FIG. 14A is a schematic illustration of a stitched image generated from four Tele images, according to some examples of the presently disclosed subject matter;
• FIG. 14B is a schematic illustration of a stitched image generated from six Tele images, according to some examples of the presently disclosed subject matter;
• FIG. 14C is a schematic illustration of a stitched image generated from nine Tele images, according to some examples of the presently disclosed subject matter;
• FIG. 15A is a cross section of top actuated sub-assembly and bottom actuated sub-assembly installed together along a cut along line A-B shown inFIG. 15B, according to other examples of the presently disclosed subject matter;
• FIG. 15B is an isometric view of top actuated sub-assembly and bottom actuated sub-assembly installed together of the example shown inFIG. 15A, according to other examples of the presently disclosed subject matter;
• FIG. 15C is an isometric view of top actuated sub-assembly and bottom actuated sub-assembly installed together, showing an external yoke, according to other examples of the presently disclosed subject matter;
• FIG. 15D is a schematic illustration of a single polarization magnet, according to some examples of the presently disclosed subject matter; and
• FIG. 15E is a schematic illustration of the magnetic field lines directions in a Y-Z plane of the single polarization magnet illustrated inFIG. 15D, according to some examples of the presently disclosed subject matter.
DETAILED DESCRIPTION
• For the sake of clarity, the term “substantially” is used herein to imply the possibility of variations in values within an acceptable range as would be known to a person skilled in the art. According to one example, the term “substantially” used herein should be interpreted to imply possible variation of up to 10% over or under any specified value. According to another example, the term “substantially” used herein should be interpreted to imply possible variation of up to 5% over or under any specified value. According to a further example, the term “substantially” used herein should be interpreted to imply possible variation of up to 2.5% over or under any specified value. For example, the phrase substantially perpendicular should be interpreted to include possible variations from exactly 90°.
• FIG. 1A illustrates a foldedcamera100 with a 2 degrees-of-freedom (DOF) optical path folding element (OPFE) with an extended rotation range, according to an example of the presently disclosed subject matter. An orthogonal X-Y-Z coordinate (“axis”) system shown applies also to all following drawings. This coordinate system is exemplary only and should not be construed as limiting. In some examples, the term “extended rotation range” used herein is used to describe a rotation range larger than the 2-3 degrees necessary for another application, for example optical image stabilization (OIS). In an example, an extended rotation range may be a range equal to or greater than ±5 degrees in each DOF relative to an OPFE zero state (as defined below). According to another example, an extended rotation range may be a range equal to or greater than ±10 degrees in each DOF relative to an OPFE zero state (as defined below). According to yet another example, an extended rotation range may be a range between ±15-40 degrees in each DOF relative to an OPFE zero state (as defined below). The extended rotation range may or may not be equal in the two DOF. In an example, the extended rotation range may be twice or more in the yaw DOF than in the pitch DOF, because the optical effect (shift of image on the image sensor) of pitch rotation is double the optical effect of yaw rotation.
• Camera100 includes a lens assembly or lens module (or simply “lens”)102, anOPFE104 and animage sensor106. Ingeneral lens module102 comprises a plurality of lens elements positioned along an optical axis, for example between 3 to 7 lens elements. In some examples,lens102 has a fixed focal length “f”. In other examples,lens102 has a variable focal length (zoom lens). In some examples,lens102 may be a lens designed for folded cameras described for example in co-owned U.S. Pat. No. 9,392,188.OPFE104 has a reflection surface (e.g. it may be a mirror or a prism).
• OPFE104 folds light from a first optical path108 to a secondoptical path110. First optical path108 extends from the direction of a view section114 (facing an object or scene) towardsOPFE104 and is substantially parallel to the X axis (in the exemplary coordinate system). Secondoptical path110 extends fromOPFE104 towardsimage sensor106 and is substantially parallel to the Z axis (in the exemplary coordinate system).
• View section114 may include, for example, one or more objects, a scene and/or a panoramic view, etc. According to the illustrated example,axis110 is aligned with the optical axis oflens102, and therefore is also referred to herein as “lens optical axis”.Image sensor106 may be aligned with a plane substantially perpendicular to axis110 (a plane that includes the X and Y axes).Image sensor106 may output an output image. The output image may be processed by an image signal processor (ISP—not shown), the processing including for example, demosaicing, white balance, lens shading correction, bad pixel correction and other processes that may be carried out by an ISP. In some embodiments, the ISP (or some functionalities of the ISP) may be part ofimage sensor106.
• It is noted that while the OPFE and some of the parts described below may be configured to rotate in two DOF, all the figures, the description and the directions therein show the OPFE in a “zero” state (without rotation) unless otherwise mentioned.
• For the sake of clarity of the description and by way of a non limiting example only, it is defined that at zero state the first optical path108 extending from the direction ofview section114 towards theOPFE104 is perpendicular to a zero plane. The term “zero plane” as used herein refers to an imaginary plane on which anactuator202 described below is positioned and is parallel to the lens optical axis. For example, in a mobile phone, the zero plane is a plane parallel to the screen of the phone.
• Furthermore, in zero state the reflecting surface of the OPFE is positioned such that light along the first optical path108 is redirected to a second optical path108 that coincides with lensoptical axis110. Notably, the above definition is assumed to be true for the center of the field of view (FOV).
• Yaw rotation can be defined as rotation around an axis substantially parallel to the first optical path in zero state. Pitch rotation can be defined as rotation around an axis substantially perpendicular to the yaw rotation axis and the lens optical axis.
• In some examples,camera100 may further include a focus or autofocus (AF) mechanism (not shown), allowing to move (or “shift” or “actuate”)lens102 alongaxis110. The AF mechanism may be configured to adjust the focus of the camera onview section114. Adjusting the focus onview section114 may bring into focus one or more objects and/or take out of focus one or more objects that may be part ofview section114, depending on their distance fromOPFE104. For simplicity, the description continues with reference only to AF mechanisms, with the understanding that it also covers regular (manual) focus.
• An AF mechanism may comprise an AF actuation mechanism. The AF actuation mechanism may comprise a motor that may impart motion such as a voice coil motor (VCM), a stepper motor, a shape memory alloy (SMA) actuator and/or other types of motors. An AF actuation mechanism that comprises a VCM may be referred to as a “VCM actuator”. Such actuation mechanisms are known in the art and disclosed for example in Applicant's co-owned international patent applications PCT/IB2015/056004 and PCT/IB2016/055308. In some embodiments,camera100 may include an optical image stabilization (OIS) actuation mechanism (not shown) in addition to, or instead of, the AF actuation mechanism. In some embodiments, OIS may be achieved by shiftinglens102 and/orimage sensor106 in one or more directions in the X-Y plane, compensating for tilt ofcamera100 around the Z and Y directions. A three-degrees of freedom (3-DOF) OIS and focus actuation mechanism (which performs two movements for OIS and one for AF) may be of VCM type and known in the art, for example as disclosed in international patent application PCT/US2013/076753 and in US patent application 2014/0327965. In other embodiments, OIS may be achieved by shifting the lens in one direction (i.e. the Y direction), perpendicular to both the first and second optical paths, compensating for tilt ofcamera100 around the Z direction (lens optical axis). In this case, a second OIS operation, compensating for tilt ofcamera100 around the Z direction may be done by tilting the OPFE around the Y axis, as demonstrated below. More information on auto-focus and OIS in a compact folded camera may be found in Applicant's co-owned international patent applications PCT/IB2016/052143, PCT/IB2016/052179 and PCT/IB 2016/053335.
• Camera100 is designed with a capability to rotateOPFE104 with at least two DOF (2-DOF) in an extended rotation range. Rotation can be done for example usingOPFE actuator120, seen inFIG. 1B. Two-DOF rotation may be used to describe rotation of the prism around two axes (each axis being a DOF); incamera100, the degrees of freedom are ayaw rotation132 aroundyaw rotation axis122 which is parallel to first optical path108 (X axis) when in zero state as defined above, and apitch rotation134 around apitch rotation axis124 which is parallel to the Y axis. Incamera100,yaw rotation axis122 andpitch rotation axis124 may intersect, which may reduce coupling between a pitch sensing mechanism and yaw rotation, as described below with reference toFIG. 9. Incamera100, lensoptical axis110 intersects the intersection point ofyaw rotation axis122 andpitch rotation axis124. In other embodiments, this may not be the case.
• As shown inFIG. 1C,camera100 may be a part of a dual-camera180. Dual-camera180 comprisescamera100 and anupright camera190.Upright camera190 includes alens192 and animage sensor194.Upright camera190 may further include other parts such as a shield, a focus or AF mechanism, and/or an OIS mechanism (all of which are not shown), as known in the art.Cameras100 and190 may share some or all of respective fields of view (FOVs). According to some examples,camera190 may have a wider FOV thancamera100. In such an example,camera100 will be referred as a “Tele camera”, whilecamera190 will be referred as a “Wide camera”. In such an example, a scanning mechanism ofcamera100 may be used to cover some or all of the FOV ofcamera190, as explained in the description below ofFIGS. 14A-14C. In other examples,camera100 may be a part of a multiple aperture camera (multi-camera) comprising more than two cameras, e.g. comprising two or more additional upright and/or two or more additional folded cameras. Notably, while characterized by extended rotation ranges,camera100 andactuator120 may also be capable of performing small range (1-2 degree) actuations with high accuracy, which enable OIS around any position in the extended rotation range.
• FIGS. 2A-B show OPFE actuator120 with more details according to some non-limiting examples of the presently disclosed subject matter.FIG. 2A showsOPFE actuator120 in an isometric view.OPFE actuator120 may be covered by ashield202 with anopening204 through which light can enter intoOPFE104 and anopening206 through which light can exit fromOPFE104.FIG. 2B showsactuator120 withoutshield202.Actuator120 further includes a bottom actuated sub-assembly220 (also referred to herein as “yaw sub-assembly” or “first sub-assembly”), a top actuated sub-assembly210 (also referred to herein as “pitch sub-assembly” or “second sub-assembly”), and astationary sub-assembly230. Top actuated sub-assembly210 may be operable to be rotated, and thus rotateOPFE104, around the pitch rotation axis (parallel to the Y axis) relative to bottom actuated sub-assembly220 (pitch rotation134), as described below. Bottom actuated sub-assembly220 may be operable to be rotated, and thus rotateOPFE104, around the yaw rotation axis (parallel to the X axis) relative to stationary sub-assembly230 (yaw rotation132), as described below.
• As described in more detail below, according to one example, the bottom (yaw) actuatedsub-assembly220 rotates relative to a stationary sub-assembly and the top (pitch) actuatedsub-assembly210 rotates relative to the bottom sub-assembly, thus the bottom sub-assembly acts as a master and the top sub-assembly acts as a slave. Applicant has found that this design, with the bottom actuated sub-assembly used for yaw rotation and the top actuated sub-assembly used for pitch rotation, and with the bottom actuated sub-assembly serving as a master and the top actuated sub-assembly serving as a slave, enables to maintain a lower overall height of the actuator and thus to mitigate a penalty on the folded camera height.
• FIGS. 3A-C show top (pitch) actuated sub-assembly210 with more details in an isometric view from one side (FIG. 3A), an isometric view from another side (FIG. 3B), and an exploded view (FIG. 3C), according to some non-limiting examples of the presently disclosed subject matter. Topactuated sub-assembly210 includes an OPFE holder (or carrier)302 that can be made, for example, by a plastic mold that fits the shape ofOPFE104. Top actuated sub-assembly210 further includes a permanent (fixed)pitch magnet304.Pitch magnet304, as well as all other magnets in this application, can be for example a permanent magnet, made from a neodymium alloy (e.g. Nd₂Fe₁₄B) or a samarium-cobalt alloy (e.g. SmCo₅), and can be made by sintering. According to one example,pitch magnet304 is fixedly attached (e.g. glued) toOPFE carrier302 from below (negative X direction inFIG. 3A). Hereinafter, the term “below” used with reference to the position ofOPFE104 refers to a side of the OPFE opposite to the side facing the view section (in the negative X direction relative to the view). Details ofpitch magnet304 and its operation are given below. In some examples,OPFE carrier302 includes (e.g. is molded with) twopins308.
• Sub-assembly210 may further include twoferromagnetic yokes306.Ferromagnetic yokes306 may be attached (e.g. glued) toOPFE holder302 onpins308.Ferromagnetic yokes306 may be made of a ferromagnetic material (e.g. iron) and have an arced (curved) shape with a center onpitch rotation axis124.Ferromagnetic yokes306 are pulled by pitch-pull magnets408 (seeFIGS. 4A, 4C) to attach top actuated sub-assembly210 to bottom actuated sub-assembly220 as described below with reference toFIGS. 5A-5C.OPFE holder302 may further include (e.g. is molded with) two parallel arc-shaped (curved)grooves310aand310b(FIG. 3B) positioned at two opposite sides ofOPFE holder302, each arc-shaped groove having an angle α′>α, where angle α is a desired pitch stroke, as defined by optical needs. Angle α′ is shown inFIG. 5B. Arc-shapedgrooves310aand310bhave a center of curvature on pitch rotation axis124 (seeFIGS. 3A, 5A, 5B).OPFE holder302 further includes (e.g. is molded with) two stoppers312 (FIG. 3A) positioned at two opposite sides ofOPFE holder302.Stoppers312 are used to stopOPFE104 in a required position.
• FIGS. 4A-C show bottom (yaw) actuated sub-assembly220 with more details in an isometric view from one side (FIG. 4A), an isometric view from another side (FIG. 4B), and an exploded view (FIG. 4C). Bottom actuated sub-assembly220 includes a middle movingframe402 which can be made, for example, by a plastic mold. Bottom actuated sub-assembly220 further included four permanent (fixed) magnets: ayaw actuation magnet404, ayaw sensing magnet406, and two pitch-pull magnets408. All magnets are fixedly attached (e.g. glued) to middle movingframe402. Notably,yaw magnet404 is located on a side of the OPFE that is opposite to the side facinglens module102 incamera100. Details of all magnets and their operation are given below.
• Bottom actuated sub-assembly220 further includes twostoppers410, made for example from a non-magnetic metal.Stoppers410 are fixedly attached (e.g. glued) to middle movingframe402.Stoppers410 help to prevent top actuated sub-assembly210 from detaching from bottom actuated sub-assembly220 in case of a strong external impact or drop, as described in more detail below. Middle movingframe402 includes (i.e. is molded with) two parallel arc-shaped (curved) grooves412 (FIG. 4A) positioned at two opposite sides of middle movingframe402, each arc-shaped groove having an angle α″>α. Angle α″ is shown inFIG. 5B. Arc-shapedgrooves412 have a center of curvature on yaw rotation axis122 (FIG. 5B) in common with arc shaped grooves310. Middle movingframe402 further includes (e.g. is molded with) two parallel arc-shaped (or “curved”) grooves414 (FIG. 4B) positioned at a back side of middle moving frame402 (negative Z axis), each arc-shaped groove having an angle β′>β, where angle β is a required yaw stroke, as defined by optical needs. Angle β′ is shown inFIG. 7. Arc-shaped grooves414 have a center of curvature on yaw rotation axis122 (FIG. 7).
• FIGS. 5A-B show top actuated sub-assembly210 and bottom actuated sub-assembly220 installed together.FIG. 5A shows an isometric view andFIG. 5B shows a cut along line A-B inFIG. 5A. The figures also show various elements described above.FIG. 5B showsactuator120 with three balls512a,514aand516apositioned in the space betweengrooves310aand412a, and threeballs512b,514band516bpositioned in the space betweengrooves310band412b.FIG. 5B shows onlyballs512b,514band516bandgrooves310band412b, while balls512a,514aand516aandgrooves310aand412aare not seen (being in the unseen back side of the drawing), with understanding of them being symmetric along plane Z-Y. The number of balls (here 3) shown in the drawing is for the sake of example only and should not be construed as limiting. In other embodiments, an actuator such asactuator120 may have more or fewer of three balls (e.g. 2-7 balls) in the space between adjacent grooves. The balls may be made of Alumina, another ceramic material, metal, plastic or other suitable materials. The balls may have for example a diameter in the range of 0.3-1 mm. Inactuator120,grooves310a,301b,412a,412bandballs512a,512b,514a,514b,516aand516bform a curved ball-guidedmechanism560 operative to impart a rotation or tilt movement to an optical element (e.g. OPFE104) upon actuation by the VCM actuator (see below). More details on ball-guided mechanisms in actuators may be found in co-owned international patent applications PCT/IB2017/052383 and PCT/IB2017/054088.
• In some embodiments, balls having different sizes (e.g. two different ball sizes) may be used to provide smoother motion. The balls can be divided into a large diameter (LD) group and a small diameter (SD) group. The balls in each group may have the same diameter. LD balls may have for example a 0.1-0.3 mm larger diameter than SD balls. A SD ball may be positioned between two LD balls to maintain the rolling ability of the mechanism. For example,balls512band516bmay be LD balls andball514bmay be a SD ball (and similarly for balls512a-516a). As described above, two metallicferromagnetic yokes306 that may be fixedly attached toOPFE holder302 face two pitch-pull magnets408 that may be attached tomiddle frame402.Ferromagnetic yokes306 may pull magnets408 (and thus pull top actuated sub-assembly210 to bottom actuated sub assembly220) by magnetic force and hold a curved ball-guidedmechanism560 from coming apart. The magnetic force (e.g. acting betweenyoke306 and magnets408) that is used for preventing two parts of a moving mechanism to be detached is referred to herein as “pre-load force”. A pitch-pull magnet408 and itsrespective yoke306 may be referred to as “first magnet-yoke pair”.Ferromagnetic yokes306 and pitch-pull magnets408 both have arc shapes, with a center onpitch rotation axis124. The magnetic direction of pitch-pull magnets408 is alongpitch rotation axis124, e.g. with a north pole towardOPFE104 and a south pole away fromOPFE104. Due to the geometric and magnetic design presented, the magnetic force (pre-load force) betweenferromagnetic yokes306 and pitch-pull magnets408 is kept substantially in aradial direction520 with a center onpitch rotation axis124, and negligible tangent force, at all rotation positions, as can be seen inFIG. 5A.
• Balls512a-516aand512b-516bprevent top actuated sub-assembly210 from touching bottom actuatedsub-assembly220. Topactuated sub-assembly210 is thus confined with a constant distance from bottom actuatedsub-assembly220. Curved ball-guidedmechanism560 further confines top actuated sub-assembly210 alongpitch rotation axis124. Top actuated sub-assembly210 can only move along the path defined by curved ball-guidedmechanism560, namely in apitch rotation134 aroundpitch rotation axis124.
• FIGS. 6A-C showstationary sub-assembly230 with more details, in an isometric view from one side (FIG. 6A), an isometric view from another side (FIG. 6B) and an exploded view (FIG. 6C).Stationary sub-assembly230 includes a base602 that can be made, for example, by plastic mold.Stationary sub-assembly230 further includes electronic circuitry608attached tobase602, shown inFIG. 6C. Details ofelectronic circuitry608 are given below with reference toFIG. 8.Stationary sub-assembly230 further includes aferromagnetic yoke606.Ferromagnetic yoke606 is made by ferromagnetic material (e.g. iron) and is pulled by yaw actuation magnet404 (seeFIGS. 6B and 7C) to attach bottom actuated sub-assembly220 tostationary sub-assembly230 as described in more detail below.Ferromagnetic yoke606 andyaw actuation magnet404 may be referred to as “second magnet-yoke pair”.
• Stationary actuated sub-assembly230 further include astopper610.Stopper610 is made for example from a non-magnetic metal.Stopper610 is attached (e.g. glued) to based602.Stopper610 helps to prevent bottom actuated sub-assembly220 from detaching frombase602 in case of a strong external impact or drop, as described in more detail below. In some examples,base602 includes (i.e. is molded with) two parallel arc-shaped (curved) grooves612a-d(FIG. 6A), each arc-shaped groove having an angle β″>β, where angle β is a required tilt stroke, as defined by optical needs. Angle β″ is shown inFIG. 7. Arc-shaped grooves612a-dmay further include a center of curvature on yaw rotation axis122 (FIGS. 2C, 6A and 7), in common with arc-shaped grooves414a-b.
• FIG. 7 shows actuator120 without the shield along a cut along line A-B seen inFIG. 2A. Grooves612a-dare shown to share a center with grooves414a-bon yaw rotation axis122 (612cand612d, which are shown inFIGS. 6B and 6C are hidden inFIG. 7). Angles β′ and β″ are demonstrated. Groves612a-bare adjacent to groove414awhile grooves612c-dare adjacent to groove414b. Four balls712 (two are shown inFIG. 7) are positioned between adjacent groove pairs612aand414a,612band414a,612cand414b, and612dand414b, one ball between each adjacent groove pair. In other embodiments,actuator120 may have more than one ball pair in each adjacent groove pair, e.g. in the range of 1-4 balls. The considerations for size and materials of all balls are similar to those described above. Grooves414a-b,612a-dandballs712 form a second curved ball-guidedmechanism760 ofactuator120. As shown inFIG. 6 andFIG. 7, the second curved ball-guided mechanism is situated such that the grooves612 for rotating around the yaw axis are located behindOPFE104 i.e. in the positive direction along the Z axis relative to OPFE104 (a side opposite to the side facing the lens module).
• As described above,ferromagnetic yoke606 is fixedly attached to base602 facing magnet404 (illustrated for example inFIG. 4aandFIG. 4c).Ferromagnetic yoke606 pulls magnet404 (and thus pulls bottom actuated sub-assembly220) tostationary sub-assembly230 by magnetic force702 (pre-load force) and thus holds curved ball-guidedmechanisms760 from coming apart. The direction ofmagnetic force702 is marked inFIG. 7 as the Z direction.Balls712 prevent bottom actuated sub-assembly220 from touchingstationary sub-assembly230. Bottom actuated sub-assembly220 is thus confined with a constant distance fromstationary sub-assembly230. Second curved ball-guidedmechanism760 further confines bottom actuated sub-assembly220 along the Y-axis. Bottom actuated sub-assembly220 can only move along the path defined by the curved ball-guidedmechanism760, namely in a yaw rotation aroundyaw rotation axis122.
• The curved ball-guidedmechanisms560 and760 disclosed herein provides flexibility when defining the pitch and yaw rotation axes respectively, as the curve can be adapted to the required rotation axis. Furthermore, curved ball-guidedmechanisms560 and760 enable to execute movement of the top actuated sub-assembly and the bottom actuated sub-assembly by rolling over the balls confined within the grooves (rails) along the path prescribed by the grooves, and thus help to reduce or eliminate friction that may otherwise exist during movement between the balls and the moving parts.
• FIG. 8 showselectronic circuitry608 with more details, according to some examples of the presently disclosed subject matter.Electronic circuitry608 includes a printed circuit board (PCB)802 and may include processing circuitry.PCB802 allows sending input and output currents tocoils806 and804 and toHall bar elements808 and810 (described below), the currents carrying both power and electronic signals needed for operation.PCB802 may be connected electronically to host camera (camera100 or similar cameras) or host device (e.g. phone, computer, not shown) e.g. by wires (not shown).PCB802 may be a flexible PCB (FPCB) or a rigid flex PCB (RFPCB) and may have several layers (e.g. 2-6) as known in the art.Electronic circuitry608 further includes three coils, apitch coil804 and two yaw coils806.Electronic circuitry608 further includes two Hall bar sensing elements, a pitchHall bar element808 and a yawHall bar element810.Coils804 and806 andHall bar elements808 and810 are all connected (e.g. soldered) toPCB802. Inactuator120,pitch coil804 and pitchHall bar element808 are positioned belowpitch magnet304. Notably, some of the components mentioned as part of the electronic circuitry are also considered as part of an actuation and sensing mechanism.
• Notably,yaw rotation axis122 is positioned as closely as possible to the pitch sensor (e.g. Hall bar element808). According to one example,yaw rotation axis122 passes throughpitch sensor808, in order to decouple the sensing of the pitch sensor from the rotation around the yaw axis. When decoupled, the influence on the sensing of the pitch sensor by rotation around the yaw axis is reduced or eliminated. More specifically, according to one example,yaw rotation axis122 passes through the center ofpitch sensor808. By positioning the yaw rotation axis so it passes through the center of the pitch sensor, the influence of yaw rotation on the sensing of pitch sensor can be completely eliminated. In addition, in some designs,yaw rotation axis122 may optionally pass through the center ofpitch coil804.
• FIGS. 9A-B show an example of a pitch actuation and sensing mechanism (PAASM)900 that includespitch magnet304,pitch coil804 and pitchHall bar element808.PAASM900 may be included inactuator120. In some embodiments,PAASM900 may be used only for actuation (acting as an actuation mechanism for one DOF).FIG. 9A showsPAASM900 in an isometric view andFIG. 9B shows a side cut ofpitch magnet304 along a line A-B. According to one example,pitch magnet304 may be symmetric along a plane that includespitch rotation axis124 and first optical axis108. In an example,pitch magnet304 may be fabricated (e.g. sintered) such that it has a changing magnetic field direction along its mechanical symmetry plane, e.g. a north magnetic field facing the positive X direction on the left side and a north magnetic field facing the negative X direction on the right side.Pitch magnet304 may have a length R_PITCHof a few millimeters (for example 2-6 mm) in parallel to pitchrotation axis124 and substantially longer thanpitch coil804, such that its magnetic field on most lines parallel to pitchrotation axis124 may be considered constant. Upon driving a current inpitch coil804, a Lorentz force is created onpitch magnet304; a current in a clockwise direction will create force in the positive Z direction (along the Z axis), while a current in counter clockwise direction will create a force in the negative Z direction. Any force onpitch magnet304 is translated to torque aroundpitch rotation axis124, and thus top actuatedsubassembly210 will rotate relative to bottom actuatedsub-assembly220.
• Pitch Hall bar element (sensor)808, which is positioned insidepitch coil804, can sense the intensity and direction of the magnetic field ofpitch magnet304 radially directed away frompitch rotation axis124. In other words, for any pitch orientation of top actuatedsub-assembly210, pitch Hall bar measures the intensity of the magnetic field directed in the X direction only. Sinceyaw rotation axis122 passes through pitchHall bar element808, the effect of the yaw rotation of bottom actuated sub-assembly220 on the magnetic field in the X direction applied bypitch magnet304 is reduced (e.g. eliminated) and thus any change on the measurement of pitchHall bar element808 is reduced (e.g. eliminated) as well. By positioning theHall bar element808 such that theyaw rotation axis122 passes through its center, the effect of the yaw rotation of bottom actuated sub-assembly220 on the magnetic field in the X direction applied bypitch magnet304 is reduced (e g minimized) and thus any change on the measurement of pitchHall bar element808 is mitigated. PitchHall bar element808 can thus measure the respective pitch rotation of top actuatedsub-assembly210 while being unaffected by the yaw rotation of bottom actuated sub-assembly.
• FIGS. 10A-B show another exemplary embodiment of a PAASM numbered1000, similar toPAASM900.PAASM1000 may be included inactuator120, to replacePAASM900. According to one example, apitch magnet1004 replacespitch magnet304.Pitch magnet1004 is a cut of a sphere with its center positioned substantially on the intersection point ofyaw rotation axis122 andpitch rotation axis124. According to one example, apitch coil1006 that replacespitch coil804 has a circular shape with a center substantially on yaw rotation axis122 (in some examples the yaw rotation axis passes exactly through the center of the coil).Pitch coil1006 may be made (fabricated) with similar considerations presented above forpitch coil804. Due to the symmetry of the pitch magnet aroundyaw rotation axis122, any yaw rotation will not influence the magnetic field of the pitch coil and thus will not change the force applied bypitch coil1006 onpitch magnet1004. Having a constant force for various yaw positions may facilitate and simplify pitch position control (close loop control or open loop control). As mentioned above, yaw rotation axis passes throughsensor808 to thereby reduce the effect of yaw rotation of bottom actuated sub-assembly220 on the magnetic field in the X direction applied bypitch magnet1004.
• FIG. 11A shows a yaw sensing mechanism numbered1100.Yaw sensing mechanism1100 includesyaw sensing magnet406 and yawHall bar element810. YawHall bar element810 can measure the intensity and direction of the magnetic field ofyaw sensing magnet406 directed alongyaw rotation axis122. In other words,Hall bar element810 measures the intensity of magnetic field directed in the X direction only.
• FIG. 11B shows a yaw rotation range β, a distance R_YAWbetween yawHall bar element810 andyaw rotation axis122, and atrajectory1108 ofyaw sensing magnet406 in the Y-Z plane. In some examples, yaw rotation range β is more than 10 degrees. The distance R_YAWis e.g. in the range of 2-5 mm. As an example, a case in which β=40° (meaning ±20° from the “zero” position) and R_YAW=2.75 mm is analyzed inFIGS. 11C-F below. As bottom actuatedsub-assembly220 is yaw-rotated,trajectory1108 is in the Y-Z plane.Trajectory1108 has an arc projection in the Y-Z plane (FIG. 11B) with length β×R_YAW, where β is calculated in radians.Trajectory1108 has a line shape projection on the X-Y plane (FIGS. 11C-E) with length 2×R_YAW×cos(β).
• Yaw sensing magnet406 is designed such that is has dimensions along Z-Y directions and such that it coverstrajectory1108 from the top view (Y-Z plane).Yaw sensing magnet406 can have different configurations.
• FIGS. 11C-E show three different examples of magnetic configurations foryaw sensing magnet406 in a cross section along X-Y plane ofyaw sensing mechanism1100. In the configuration ofFIG. 11C,yaw sensing magnet406 has a rectangular cross section and the magnetic field ofyaw sensing magnet406 changes direction in the middle, e.g. the north magnetic field facing the positive X direction on the left side and the north magnetic field facing the negative X direction on the right side. In the configuration ofFIG. 11D,yaw sensing magnet406 has a rectangular cross section, and the magnetic field ofyaw sensing magnet406 is directed in the Y direction.
• In the configuration shown inFIG. 11E,yaw sensing magnet406 is characterized, along the Y direction, by a thinner cross section (the Y-X plane) in the middle and a thicker cross section on the sides. The varying width results in a varying distance between the sensor and the magnet positioned near the magnet (the sensor is located towards the negative X direction relative to the magnet) and thus a varying magnetic field along a projection of trajectory1108 (line1114) on the Y-X plane. In some examples, the variation around the magnetic field is symmetrical around its center such that the thickness of the cross section of the magnet increases from a point substantially at its center towards each end of the magnet. Various examples of magnets constructed according to this principle are illustrated inFIGS. 11-i to11-vi.
• In addition, in some examples of the configuration ofFIG. 11E (or any one ofFIGS. 11-i to11-vi), the magnetic field ofyaw sensing magnet406 changes direction in the middle, e.g. the north magnetic field faces the positive X direction on the left side and the north magnetic field faces the negative X direction on the right side. This results in zero magnetic field in the X direction in yawhall bar element810 facing the center of magnet406 (along the center line).
• FIG. 11F shows the magnetic field as a function of rotation alongtrajectory1108, for the 3 cases presented inFIGS. 11C-E. The projection oftrajectory1108 on plane X-Y (representing a lateral shift component of the magnet shift relative to the sensor) is shown byline1110 inFIG. 11C,line1112 inFIG. 11D andline1114 inFIG. 11E. Forline1110, the maximal magnetic field change along ±20 degrees trajectory is ±0.28 Tesla. However, most of the magnetic field change is obtained in a ±7 degrees trajectory and the magnetic field gradient at higher yaw angles is lower than at lower yaw angles. This limits the ability to sense changes with high accuracy in high yaw angles. Forprojection line1112, the magnetic field gradient is more uniform along the trajectory of ±20, comparing toprojection line1110. However, the magnetic field total change is limited to under ±0.08 Tesla. Forprojection line1114 the magnetic field gradient is more uniform than for bothlines1110 and1112, and the total magnetic field change is ±0.25 Tesla, which can give high accuracy for position measurements. Thus, the magnetic configuration presented inFIG. 11E is superior for position sensing at large strokes, relative to the distance between the Hall bar and the corresponding magnet (e.g. in 1-4 mm range) using changes in magnetic field. Thus, by shaping the magnet with a variable thickness as shown inFIGS. 11E and 11-i to11-vi, the range of detectable change in magnetic flux in increased. Accordingly, the corresponding detectable range of relative (lateral) shift of the magnet and sensor is increased as well.
• FIGS. 12A-C shows a yaw magnetic actuation mechanism numbered1200. This actuation mechanism is for a second DOF.FIG. 12A show isometric view from one side,FIG. 12B shows isometric view from another side. Yawmagnetic actuation mechanism1200 includeyaw actuation magnet404, yaw coils806 andferromagnetic yoke606.FIG. 12C shows the magnetic field directions is Y-Z plane, along a cut A-B inFIG. 12A.Yaw actuation magnet404 may be sintered such that its magnetic field is pointed toward negative Z direction. Each ofcoils806 has one part (1202,1204) which is positioned in close proximity to yaw actuation magnet404 (e.g. distance of 100-300 μm), and one part (1206,1208) which is further apart fromyaw magnet404.Coils806 may be connected in serial, such that the current in the two coil is equal. When current in1202 is in the positive X direction the current in1204 is also in the positive X direction, and the current inparts1206 and1208 is in the negative X direction. Upon driving a current in Yaw coils806, a Lorentz force is created on theyaw magnet404, according to d{right arrow over (F)}=Id{right arrow over (l)}×{right arrow over (B)}. The direction of the magnetic field is demonstrated inFIG. 12C. The Lorentz force is translated into torque aroundyaw rotation axis122.
• In some examples, an additionalmagnetic yoke1302 may be located next toyaw magnet404. This yoke may increase the intensity of the magnetic field incoils806 and increase the torque created by yawmagnetic actuation mechanism1200.FIG. 13 shows this case.
• In some examples, rotation of the reflecting element around one or two axes moves the position of the camera FOV, wherein in each position a different portion of a scene is captured in an image having the resolution of the digital camera. In this way a plurality of images of adjacent camera FOVs (e.g. partially overlapping FOVs) are captured and stitched together to form a stitched (also referred to as “composite”) image having an overall image area of an FOV greater than digital camera FOV.
• In some examples the digital camera can be a folded Tele camera configured to provide a Tele image with a Tele image resolution, the folded Tele camera comprising a Tele image sensor and its Tele lens assembly is characterized with a Tele field of view (FOV_T).
• According to some examples, the folded Tele camera is integrated in a multiple aperture digital camera that comprises at least one additional upright Wide camera configured to provide a Wide image with a Wide image resolution, being smaller than the Tele image resolution, the Wide camera comprising a Wide image sensor and a Wide lens module with a Wide field of view (FOV_W); wherein FOV_Tis smaller than FOV_W, wherein rotation of the OPFE moves FOV_Trelative to FOV_W, for example as shown in of co-owned international patent applications PCT/IB2016/056060 and PCT/IB2016/057366.
• The description of these PCT applications includes a Tele camera with an adjustable Tele field of view. As described in PCT/IB2016/056060 and PCT/IB2016/057366, rotation of the reflecting element around one or two axes moves the position of Tele FOV (FOV_T) relative to the Wide FOV (FOV_W), wherein in each position a different portion a scene (within FOV_W) is captured in a “Tele image” with higher resolution. According to some examples, disclosed in PCT/IB2016/056060 and PCT/IB2016/057366, a plurality of Tele images of adjacent non-overlapping (or partially overlapping) Tele FOVs are captured and stitched together to form a stitched (also referred to as “composite”) Tele image having an overall image area of an FOV greater than FOV_T. According to some examples, the stitched Tele image is fused with the Wide image generated by the Wide camera.
• Digital camera100 can further comprise or be otherwise operatively connected to a computer processing circuitry (comprising one or more computer processing devices), which is configured to control the operation of the digital camera (e.g. camera CPU). The processing circuitry, can comprise for example a controller operatively connected to the actuator of the rotating OPFE configured to control its operation.
• The processing circuitry can be responsive to a command requesting an image with a certain zoom factor and control the operation of the digital camera for providing images having the requested zoom. As mentioned in applications PCT/IB2016/056060 and PCT/IB2016/057366, in some examples a user interface (executed for example by the processing circuitry) can be configured to allow input of user command being indicative of a requested zoom factor. The processing circuitry can be configured to process the command and provide appropriate instructions to the digital camera for capturing images having the requested zoom.
• In some cases, if the requested zoom factor is a value between the FOV_Wof a wide camera and FOV_Tof a tele camera, the processing circuitry can be configured to cause the actuator of the reflecting element to move the reflecting element (by providing instruction to the controller of the actuator) such that a partial area of the scene corresponding to the requested zoom factor is scanned and a plurality of partially overlapping or non-overlapping Tele images, each having a Tele resolution and covering a portion of the partial area, are captured. The processing circuitry can be further configured to stitch the plurality of captured imaged together in order to form a stitched image (composite image) having Tele resolution and an FOV greater than the FOV_Tof the digital camera. Optionally the stitched image can then be fused with the Wide image.
• FIG. 14A is a schematic illustration of an example of a stitchedimage1400 generated by scanning, capturing and stitching together four Tele images with FOV_T, compared to the FOV_Wof a Wide camera, as in the example ofFIG. 1C, wherecamera190 represents a Wide FOV camera with a FOV_Wcoupled to foldedTele camera100 with a FOV_T. InFIG. 14A, 1402 denotes FOV_W,1404 denotes FOV_Tat the center of FOV and1406 indicates the size of the requested zoom factor. In the illustrated example, four partially overlappingTele images1408 are captured.
• Notably, the overall area of capturedTele images1408 is greater than the area of thezoom image1406 in the requested zoom. The central part of the captured Tele images is extracted (e.g. by the computer processing circuitry as part of the generation of the stitched image) for generating stitchedimage1400. This helps to reduce the effect of image artefacts resulting from transition from an image area covered by one image to an image area covered by a different image.
• FIG. 14B is a schematic illustration of an example of a stitchedimage1400′ generated by capturing and stitching together six Tele images.FIG. 14C is a schematic illustration of an example of a stitchedimage1400′ generated by capturing and stitching together nine Tele images. The same principles described with reference toFIG. 14A apply toFIGS. 14B and 14C. Notably, the output image resulting from the stitching can have a different width to height ratio than the single image proportion. For example, as illustrated inFIG. 14B, a single image can have a 3:4 ratio and the output stitched image can have a 9:16 ratio.
• It is noted that image stitching per se is well known in the art and therefore it is not explained further in detail.
• An alternative design of the top and bottom actuated sub-assemblies described above is now described with reference toFIGS. 15A-15E. Notably, as would be apparent to any person skilled in the art, unless stated otherwise, some of the details described above with reference to the previous figures can also be applied to the example described with reference toFIGS. 15A-15E.
• According to this design, asingle magnet1510 serves for three purposes: 1) as a pre-load magnet in magnet-yoke pair, dedicated for fastening the bottom actuated sub-assembly to the stationary sub-assembly; 2) as a yaw actuation magnet dedicated for generating yaw movement of bottom actuated sub-assembly; and 3) as a yaw sensing magnet for sensing yaw movement.
• FIG. 15A shows amagnet1506 and a yoke (e.g. a ferromagnetic plate such as iron)1504, where the magnet and yoke are pulled together by pre-load force (indicated by black double head arrow) and thus fasten top actuated sub-assembly210 to bottom actuatedsub-assembly220. In some examples,magnet1506 andyoke1504 are positioned substantially at the center (relative to the Y axis direction) of the top actuated sub-assembly. Pitch rotation axis relative to the bottom actuated sub-assembly is demonstrated by thecircular arrow1508.
• FIG. 15B shows top and bottom actuated sub-assemblies in isometric view.FIG. 15B illustratesmagnet1510 located at the internal part of bottom actuated sub-assembly, sensor1512 and acoil1514, which is located at the back of bottom actuated sub-assembly (in the positive Z direction relative to magnet1510). According to one example, a single coil can be used for actuation.
• As shown inFIG. 15C,yoke1516, is fastened to the stationary sub-assembly.Magnet1510 andyoke1516 are attracted by pre-load force to thereby fasten bottom actuated sub-assembly220 tostationary sub-assembly230.Coil1514 is positioned in close proximity to yaw actuation magnet1510 (e.g. distance of 100-300 μm). When current is applied incoil1514, a Lorentz force is created onyaw magnet1510 according to d{right arrow over (F)}=Id{right arrow over (l)}×{right arrow over (B)}, where the Lorentz force is translated into torque around yaw rotation axis122 (not shown) as explained above.
• Magnet1510 moves along the yaw direction as part of the bottom actuated sub-assembly. In addition of being more compact, this type of yaw actuation mechanism also provides better efficiency, as it does not generate force in the opposite direction to the desired yaw movement.
• As explained above, in some examples top actuatedsub-assembly210 includes an OPFE holder (or carrier)302 and bottom actuated sub-assembly includes a middle movingframe402. According to an example,yoke1504 is attached (e.g. glued) to the holder and the first magnet-yoke pair (1506-1504) pulls the OPFE holder to the middle moving frame. Alternatively, the position of the magnet and yoke can be switched. The stationary sub-assembly includes a base and the yoke is attached to the based in a manner that the second magnet-yoke pair (1510-1516) pulls the middle moving frame to the base. Also, in anexample coil1514 and sensor1512 are fixed (e.g. glued) to the base.
• According to some examples of the presently disclosed subjectmatter yaw magnet1510, which also serves as yaw sensing magnet, is made to have an increased detection range. To this end,magnet1510 is made to have a single magnetic polarization direction as indicated by the back arrow extending from the south pole to the north pole ofmagnet1510 shown inFIG. 15D. The directions of the magnetic field lines are indicated by arrows a-e inFIG. 15D and in more detail inFIG. 15E, which is a top view ofmagnet1510. As indicated by arrows a-e, as a result of the single magnetic polarization direction ofmagnet1510, the angle of the magnetic field relative to the magnet surface changes continuously along the length of magnet. The illustration shows the angle changing from being substantially perpendicular in the positive direction at one end, to being in a parallel direction at the magnet center and to being substantially perpendicular in the negative direction at the other one. Since the relative changes (e.g. of magnetic flux) are detectable at each of the points where change in the direction of the magnetic field occurs, yaw movement of the magnet relative to sensor1512 can be detected over an increased range. The increased detection range of the yaw magnet as disclosed herein enables to use the same magnet for both actuation and sensing, eliminating the need for two separate magnets.
• Note that unless stated otherwise terms such as “first” and “second” as used herein are not meant to imply a particular order but are only meant to distinguish between two elements or actions in the sense of “one” and “another”.
• While this disclosure has been described in terms of certain embodiments and generally associated methods, alterations and permutations of the embodiments and methods will be apparent to those skilled in the art. The disclosure is to be understood as not limited by the specific embodiments described herein, but only by the scope of the appended claims.
• All references mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual reference was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present application.

Claims (45)

1. A folded camera comprising an actuator for rotating an optical path folding element (OPFE), the actuator comprising:

a) a first sub-assembly, a second sub-assembly and a stationary sub-assembly, the first sub-assembly configured to rotate the OPFE relative to the stationary sub-assembly in an extended rotation range around a yaw rotation axis and the second sub-assembly configured to rotate the OPFE relative to the first sub-assembly in an extended rotation range around a pitch rotation axis that is substantially perpendicular to the yaw rotation axis;

b) a first sensor configured to sense rotation around the yaw rotation axis and a second sensor configured to sense rotation around the pitch rotation axis, the first and second sensors being fixed to the stationary sub-assembly, wherein at least one of the first sensor or the second sensor is a magnetic flux sensor; and

c) a voice coil motor (VCM) comprising a magnet and a coil, wherein the magnet is fixedly attached to one of the first sub-assembly or the second sub-assembly, wherein the coil is fixedly attached to the stationary sub-assembly, wherein a driving current in the coil creates a force that is translated to a torque around a respective rotation axis, and wherein the second sensor is positioned such that sensing by the second sensor is decoupled from the rotation of the OPFE around the yaw rotation axis.

2. The folded camera ofclaim 1, wherein the second sensor position is such that the yaw rotation axis passes through the second sensor.

3. The folded camera ofclaim 2, wherein the yaw rotation axis passes through a center of the second sensor.

4. The folded camera ofclaim 1, wherein the actuator further comprises a first curved ball-guided mechanism operative to enable the rotation around the pitch rotation axis and a second curved ball-guided mechanism operative to enable the rotation around the yaw rotation axis.

5. The folded camera ofclaim 4, wherein the curved ball-guided mechanism is located on a side of the OPFE that is opposite to a side of the OPFE facing an image sensor.

6. The folded camera ofclaim 1, wherein the extended rotation range is equal to or greater than ±5 degrees around the pitch and yaw rotation axes.

7. The folded camera ofclaim 1, wherein the extended rotation range is equal to or greater than ±10 degrees the pitch and yaw rotation axes.

8. The folded camera ofclaim 1, wherein the extended rotation range is between ±15-40 degrees around the pitch and yaw rotation axes.

9. The folded camera ofclaim 1, wherein the extended rotation range around the pitch rotation axis is different from the extended rotation range around the second rotation axis.

10. The folded camera ofclaim 1, wherein the magnet and the coil are used for the rotation around the pitch rotation axis and wherein the magnet is designed with a flat surface facing the coil.

11. The folded camera ofclaim 1, further comprising a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the actuator further comprises a pitch magnet located at a side of the OPFE that is opposite to a side facing the view section.

12. The folded camera ofclaim 1, further comprising a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the actuator further comprises a yaw magnet located at a side of the OPFE that is opposite to a side facing the lens module.

13. The folded camera ofclaim 1, wherein the magnetic flux sensor is a Hall sensor.

14. The folded camera ofclaim 1, wherein the actuator comprises a second magnet shaped or formed such that a central part of the magnet is further away from a projection line of motion of the first sensor relative to an end of the second magnet.

15. The folded camera ofclaim 1, wherein the actuator comprises a second magnet shaped such that width of a cross section of the second magnet increases from a point substantially at its center towards each end of the second magnet, thereby resulting in a variable distance between the first sensor and the second magnet when relative movement occurs between the second magnet and the sensor.

16. The folded camera ofclaim 1, wherein the actuator further comprises a first magnet-yoke pair that pulls the first sub-assembly to the second sub-assembly in a radial direction relative to the pitch rotation axis, and a second magnet-yoke pair that pulls the first sub-assembly to the stationary sub-assembly in a radial direction relative to the yaw rotation axis.

17. The folded camera ofclaim 16, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the first magnet-yoke pair pulls the OPFE holder to the middle moving frame and wherein the second magnet-yoke pair pulls the middle moving frame to the base.

18. The folded camera ofclaim 1, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the rotation around the yaw rotation axis is generated by rotating the middle moving frame relative to the base, and wherein rotation around the pitch rotation axis is generated by rotating the OPFE holder relative to the middle moving frame.

19. The folded camera ofclaim 1, wherein the magnet is characterized by a cut sphere shape, wherein the coil is characterized by a circular shape and wherein the coil is symmetrically positioned with the circular shape around the cut sphere.

20. The folded camera ofclaim 1, wherein the magnet is a single magnet used for creating an actuation force for rotation around the yaw rotation axis, creating a pre-load force in a magnet-yoke pair for holding together the first sub-assembly and the stationary sub-assembly, and sensing the rotation around the yaw rotation axis.

21. The folded camera ofclaim 20, wherein the magnetic flux sensor is a single magnetic flux sensor used for sensing the rotation around the yaw rotation axis.

22. The folded camera ofclaim 20, wherein the single magnet is a polarization magnet characterized by continuous changes in direction of a magnetic field of the magnet along a length of the magnet.

23. An actuator for rotating an optical path folding element (OPFE), the actuator comprising:

a) a first sub-assembly, a second sub-assembly and a stationary sub-assembly, the first sub-assembly configured to rotate the OPFE relative to the stationary sub-assembly in an extended rotation range around a yaw rotation axis and the second sub-assembly configured to rotate the OPFE relative to the first sub-assembly in an extended rotation range around a pitch rotation axis that is substantially perpendicular to the yaw rotation axis;

b) a first sensor configured to sense rotation around the yaw rotation axis and a second sensor configured to sense rotation around the pitch rotation axis, the first and second sensors being fixed to the stationary sub-assembly, wherein at least one of the first sensor or the second sensor is a magnetic flux sensor; and

c) a voice coil motor (VCM) comprising a magnet and a coil, wherein the magnet is fixedly attached to one of the first sub-assembly or the second sub-assembly, wherein the coil is fixedly attached to the stationary sub-assembly, wherein a driving current in the coil creates a force that is translated to a torque around a respective rotation axis, and wherein the second sensor is positioned such that sensing by the second sensor is decoupled from the rotation of the OPFE around the yaw rotation axis.

24. The actuator ofclaim 23, wherein the second sensor position is such that the yaw rotation axis passes through the second sensor.

25. The actuator ofclaim 24, wherein the yaw rotation axis passes through a center of the second sensor.

26. The actuator ofclaim 23, further comprising a first curved ball-guided mechanism operative to enable the rotation around the pitch rotation axis and a second curved ball-guided mechanism operative to enable the rotation around the yaw rotation axis.

27. The actuator ofclaim 26, wherein the curved ball-guided mechanism is located on a side of the OPFE that is opposite to a side of the OPFE facing an image sensor.

28. The actuator ofclaim 23, wherein the extended rotation range is equal to or greater than ±5 degrees around the pitch and yaw rotation axes.

29. The actuator ofclaim 23, wherein the extended rotation range is equal to or greater than ±10 degrees the pitch and yaw rotation axes.

30. The actuator ofclaim 23, wherein the extended rotation range is between ±15-40 degrees around the pitch and yaw rotation axes.

31. The actuator ofclaim 23, wherein the extended rotation range around the pitch rotation axis is different from the extended rotation range around the second rotation axis.

32. The actuator ofclaim 23, wherein the magnet and the coil are used for the rotation around the pitch rotation axis and wherein the magnet is designed with a flat surface facing the coil.

33. The actuator ofclaim 23, designed to be installed in a folded camera that comprises a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the actuator further comprises a pitch magnet located at a side of the OPFE that is opposite to a side facing the view section.

34. The actuator ofclaim 23, designed to be installed in a folded camera that comprises a lens module accommodating a plurality of lens elements along a lens optical axis, wherein the OPFE redirects light that enters the folded camera from the direction of a view section along a first optical path toward a second optical path along the lens optical axis, and wherein the actuator further comprises a yaw magnet located at a side of the OPFE that is opposite to a side facing the lens module.

35. The actuator ofclaim 23, wherein the magnetic flux sensor is a Hall sensor.

36. The actuator ofclaim 23, further comprising a second magnet shaped or formed such that a central part of the second magnet is further away from a projection line of motion of the first sensor relative to an end of the second magnet.

37. The actuator ofclaim 23, further comprising a second magnet shaped such that width of a cross section of the second magnet increases from a point substantially at its center towards each end of the second magnet, thereby resulting in a variable distance between the first sensor and the second magnet when relative movement occurs between the second magnet and the sensor.

38. The actuator ofclaim 23, further comprising a first magnet-yoke pair that pulls the first sub-assembly to the second sub-assembly in a radial direction relative to the pitch rotation axis, and a second magnet-yoke pair that pulls the first sub-assembly to the stationary sub-assembly in a radial direction relative to the yaw rotation axis.

39. The actuator ofclaim 38, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the first magnet-yoke pair pulls the OPFE holder to the middle moving frame and wherein the second magnet-yoke pair pulls the middle moving frame to the base.

40. The actuator ofclaim 23, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the first sub-assembly comprises a middle moving frame, wherein the second sub-assembly comprises an OPFE holder, wherein the stationary sub-assembly comprises a base, wherein the rotation around the yaw rotation axis is generated by rotating the middle moving frame relative to the base, and wherein rotation around the pitch rotation axis is generated by rotating the OPFE holder relative to the middle moving frame.

41. The actuator ofclaim 23, wherein the magnet is characterized by a cut sphere shape, wherein the coil is characterized by a circular shape and wherein the coil is symmetrically positioned with the circular shape around the cut sphere.

42. The actuator ofclaim 23, wherein the magnet is a single magnet used for creating an actuation force for rotation around the yaw rotation axis, creating a pre-load force in a magnet-yoke pair for holding together the first sub-assembly and the stationary sub-assembly, and sensing the rotation around the yaw rotation axis.

43. The actuator ofclaim 42, wherein the magnetic flux sensor is a single magnetic flux sensor used for sensing the rotation around the yaw rotation axis.

44. The actuator ofclaim 42, wherein the single magnet is a polarization magnet characterized by continuous changes in direction of a magnetic field of the magnet along a length of the magnet.

45-49. (canceled)

Images