Actuator

Abstract

The invention provides an actuator. The present invention relates to an actuator for providing an extended two degree of freedom rotation range to an optical path folding element (OPFE) of a prism or mirror in a mobile device, such as a smartphone. The actuator includes a yaw subassembly having a yaw axis of rotation; a pitching sub-assembly carrying the optical path folding element, the pitching sub-assembly comprising a pivot rotation mechanism and having a pitching rotation axis; and a stationary subassembly wherein the actuator is operable to rotate the optical path folding element in two rotational directions, a first rotation for yawing about the yaw axis of rotation and a second rotation for pitching about the pitch axis of rotation, and the pitch rotation includes rotation using the pivot rotation mechanism.

Description

[0001] Related Applications

[0002] This application is a divisional application of “Actuator Providing Extended Two-Degree-of-Freedom Rotational Range”, filed on December 1, 2020, with application number 202080077128.1. This application claims priority to U.S. Provisional Patent Application No. 62 / 942,913 filed on December 3, 2019, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] The subject matter disclosed herein relates generally to digital cameras, and in particular to actuators for yaw and pitch rotation in a folded digital camera included in a smartphone. Background Art

[0004] Multi-cameras and folded cameras in electronic handheld devices (e.g., smartphones or tablets) are known. In folded cameras, a reflective or optical path folding element (OPFE) including a reflective surface, such as a prism or a mirror, is added to propagate light from a first optical path (e.g., perpendicular to the back of the smartphone) to a second optical path (e.g., parallel to the back of the smartphone) at an angle.

[0005] The jointly owned international patent application PCT / IB2019 / 053315 describes in detail a folding camera, including an actuator for rotating an optical path folding element with two first and second degrees of freedom within an extended rotation range around two corresponding rotation axes, and a dual camera, including such a folding camera and an upright camera.

[0006] What is needed and beneficial is a folded camera, wherein an optical path folding element carrying module allows a large extended rotation range around two respective rotation axes, such as yaw and pitch rotation, supports state-of-the-art industry standards, such as in drop testing, and has a low manufacturing cost compatible with smartphone costs. Summary of the invention

[0007] In various embodiments, a plurality of actuators are provided for providing an extended two-degree-of-freedom rotation range to an optical path folding element (OPFE) (e.g., a prism or a mirror) in a mobile device such as a smartphone, including: a yaw subassembly having a yaw rotation axis; a pitch subassembly carrying an optical path folding element, the pitch subassembly including a pivot rotation mechanism and having a pitch rotation axis; and a fixed subassembly, wherein the actuator is operable to rotate the optical path folding element in two rotational directions, a first rotation for yaw about the yaw rotation axis, and a second rotation for pitch about the pitch rotation axis, and the pitch rotation includes a rotation using the pivot rotation mechanism.

[0008] In some embodiments, the actuator, such as up or down, is integrated into a folding camera. The folding camera is a scanning telecamera capable of scanning a scene in two rotational directions.

[0009] In some embodiments, the yaw subassembly and the pitch subassembly form a master-slave arrangement, wherein the yaw subassembly acts as a master assembly and the pitch subassembly acts as a slave assembly.

[0010] In some embodiments, the pivot rotation mechanism includes a pivot located on opposite sides of the optical path folding element, and the pitch rotation axis is close to a center of gravity of a pitch subassembly.

[0011] In some embodiments, the pivot mechanism includes a ball guide mechanism.

[0012] In some embodiments, the pivot mechanism includes a pitch drive coil and a magnet.

[0013] In some embodiments, the pitch drive coil rotates about the yaw axis.

[0014] In some embodiments, the yaw subassembly includes at least one grooved ball mechanism.

[0015] In some embodiments, the plurality of grooves of the at least one groove ball mechanism are concentrically curved with a center of curvature on the yaw rotation axis.

[0016] In some embodiments, the plurality of balls of the at least one groove ball mechanism are guided by a plurality of groove pairs, the plurality of groove pairs respectively comprising a groove on the yaw subassembly and a groove on the fixed subassembly.

[0017] In some embodiments, the at least one groove ball mechanism includes at least three balls.

[0018] In some embodiments, the plurality of balls of the at least one grooved ball mechanism are located in a plane perpendicular to the yaw rotation axis.

[0019] In some embodiments, the yaw rotation is sensed by at least one Hall sensor.

[0020] In some embodiments, the at least one Hall sensor is located below the yaw subassembly and fixedly connected to the fixed subassembly.

[0021] In some embodiments, the yaw rotation is performed by an actuation mechanism including a yaw drive coil and a yaw drive magnet.

[0022] In some embodiments, the yaw drive magnet is concentrically curved.

[0023] In some embodiments, the yaw drive magnet is curved with a center of curvature proximate the yaw rotation axis.

[0024] In some embodiments, the yaw drive magnet is fixedly connected to the yaw subassembly and the drive coil is fixedly connected to the housing.

[0025] In some embodiments, the yaw drive magnet has two different polarization directions of the magnet, and the two different polarization directions are perpendicular to the yaw rotation axis.

[0026] In some embodiments, the yaw rotation axis is proximate to a common center of mass of the yaw subassembly and the pitch subassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Non-limiting examples of the embodiments disclosed herein are described below with reference to the drawings listed after this paragraph. The drawings and descriptions are intended to illustrate and describe the embodiments disclosed herein and should not be considered limiting in any way. The same elements in different drawings may be represented by the same numbers. The elements in the drawings are not necessarily drawn to scale. In the drawings:

[0028] Figure 1A A known folded camera is shown with an optical path folding element (OPFE) having an extended two-degrees-of-freedom (DOF) rotation range;

[0029] Figure 1B Shows Figure 1A A folded camera with an optical path folding element actuator;

[0030] Figure 1C Shows Figure 1A the folding camera as part of a dual-camera system;

[0031] Figure 2A An embodiment of the optical path folding element actuator disclosed herein is shown in an exploded view;

[0032] Figure 2B Shows Figure 2A Details of the yaw, pitch and fixed subassemblies of the optical path folding element actuator;

[0033] Figure 2C An exploded view of the yaw and pitch subassemblies is shown;

[0034] Figure 2D The pitch subassembly and the optical path folding element in two rotation states are shown;

[0035] Figure 2E An embodiment of the optical path folding element actuator disclosed herein is shown in a perspective view;

[0036] Figure 3 A yaw drive magnet of an optical path folding element actuator is shown;

[0037] Figure 4 Various views showing more details of portions of the yaw subassembly and the stationary subassembly of the optical path folding element actuator;

[0038] Figure 5 In (a) the yaw subassembly is shown without the pitch subassembly; and in (b), (c) and (d) details of the yaw sensing magnet are shown;

[0039] Figure 6 shows a pitch subassembly including an exemplary magnetic Hall bar arrangement;

[0040] Figure 7 Details of two different embodiments using two controllers / drivers to control and drive various functions of the actuator are shown; and

[0041] Figure 8 The pitch subassembly is shown, along with the yaw drive magnets. DETAILED DESCRIPTION

[0042] Figure 1AA folded camera 100 with an optical path folding element (OPFE) with two degrees-of-freedom (DOF) disclosed in PCT / IB2019 / 053315 is shown, which has an extended rotation range. The term "extended rotation range" describes a rotation range that is greater than the 2 to 3 degrees required for other applications (e.g., optical image stabilization (OIS)). Relative to the zero (non-rotated) state of the optical path folding element, the extended rotation range can be equal to or greater than ±5 degrees, ±10 degrees, or even a range between 15 and 40 degrees in each degree of freedom.

[0043] The camera 100 includes a lens 102 having a lens optical axis, an optical path folding element 104, and an image sensor 106. The optical path folding element 104 has a reflective surface and can be, for example, a mirror or a prism. The optical path folding element 104 folds light from a first optical path 108 to a second optical path 110. The first optical path 108 extends from the direction of an observation portion 114 (facing an object or scene) toward the optical path folding element 104 and is substantially parallel to the X-axis (in an example coordinate system). The second optical path 110 extends from the optical path folding element 104 to the image sensor 106 and is substantially parallel to the Z-axis (in an example coordinate system). Yaw rotation can be defined as a rotation around an axis substantially parallel to the first optical path in a zero optical path folding element state. Pitch rotation can be defined as a rotation around an axis substantially perpendicular to the yaw rotation axis and the optical axis of the lens.

[0044] The rotation of the optical path folding element can be accomplished, for example, using an optical path folding element actuator 120, such as Figure 1B Two degrees of freedom rotation can be used to describe the rotation of the prism about two axes (each axis is a degree of freedom); in the camera 100, the degrees of freedom are the yaw rotation 132 about the yaw rotation axis 122 parallel to the first optical path 108 (X axis) when in the zero state as defined above; and the pitch rotation 134 about the pitch rotation axis 124 parallel to the Y axis.

[0045] like Figure 1C As shown, camera 100 may be part of a dual camera 180. Dual camera 180 includes camera 100 and vertical camera 190. Vertical camera 190 includes lens 192 and image sensor 194. Cameras 100 and 190 may share some or all of their respective fields of view (FOV).

[0046] In the following description, reference is made to Figure 1A Directions are defined. "Top" is the direction toward (facing) viewing portion 114. "Bottom" is the opposite direction.

[0047] Figure 2A An embodiment of the optical path folding element actuator 200 disclosed herein is shown in an exploded view. The actuator 200 includes a yaw subassembly 210, a pitch subassembly 220, and a fixed subassembly 230. Figure 2B Details of each subassembly are shown. The yaw subassembly 210 and the pitch subassembly 220 are shown in two different perspective views in (a), and the fixed subassembly 230 is shown in a perspective view (rotated 45 degrees about the axis 208 relative to the top view) in (b). The yaw subassembly 210 is included in the fixed subassembly 230, and the pitch subassembly 220 is included in the yaw subassembly 220 in a master-slave arrangement. The yaw subassembly 210 is "dynamic", i.e., it can rotate about the yaw rotation axis 206 (e.g., parallel to the X-axis), while the fixed subassembly 230 (as its name suggests) is fixed, i.e., it does not move. The pitch subassembly 220 is rigidly connected to the optical path folding element 204 and can rotate about the pitch rotation axis 208 perpendicular to the axis 206 (e.g., parallel to the Y-axis). When operable to rotate, the yaw subassembly 220 rotates the optical path folding element 204 relative to the fixed subassembly 230 about the axis 206, and the pitch subassembly 220 (and the optical path folding element connected thereto) rotates relative to the yaw subassembly and the fixed subassembly about the axis 208. In some embodiments, the yaw rotation axis 206 can be close to the common center of mass of the yaw subassembly 210 and the pitch subassembly 220. The distance close to the common center of mass of the yaw subassembly 210 and the pitch subassembly 220 can refer to a distance of less than 1.5 millimeters (mm). In other examples, it can refer to a distance of less than 2 mm or less than 5 mm.

[0048] In yet another example, the distance close to the center of mass of the pitch subassembly 220 may refer to a distance less than 15% of the module height MH. In other examples, it may refer to a distance less than 30% or 10% of the module height MH. Figure 2EMH is defined in . The yaw rotation uses a flat surface curved track 205 and two curved V-grooves 212, which are formed in the bottom surface 214 of the yaw subassembly 210 below the optical path folding element 204 (top view in Figure 2(a)). The track 205 and the curved V-grooves 212 are operably connected to three V-grooves 216 and are included in the fixed subassembly 230. This arrangement of 205, 212 and 216 is known in the art as "tolerance compensation" or "tolerance release". The track 205 and the V-grooves 212 are concentrically curved, with the center of curvature being the rotation axis 206. The connected track and V-grooves form a groove-ball mechanism for yaw rotation of the optical path folding element.

[0049] exist Figure 2A , a plurality of balls 218 are shown positioned within a plurality of V-grooves 212 and a flat surface curved track 205. The balls may have an exemplary diameter of greater than 1.2 mm, as compared to 0.8 mm in a standard smartphone camera, and due to their larger diameter, allow for improved drop resistance, as their larger diameter provides a larger surface or contact area for the balls in the track and is less sensitive to drops.

[0050] The optical path folding element actuator 200 further includes a yaw drive coil 222 and a pitch drive coil 224, as shown in the bottom view of FIG2(a). The pitch drive coil 224 rotates around the yaw axis 206. The yaw drive coil 222 is positioned in a hole 226 of the stator assembly 230 (and is part of the stator assembly 230), i.e., fixedly connected to the stator assembly 230.

[0051] Figure 2C Exploded views of the yaw subassembly and the pitch subassembly are shown, wherein (a) shows the yaw subassembly 210 without the pitch subassembly, (b) shows the pitch subassembly 220, and (c) shows a cross-section of the yaw subassembly 210 in the YZ plane.

[0052] Figure 2D The pitch subassembly 210 with the optical path folding element 204 is shown in two rotation states, rotated downward and rotated upward. The pitch rotation about the axis 208 is achieved by a pivot mechanism 232, which includes pivots located on both sides of the optical path folding element, where the rotation axis is close to the center of mass of the pitch subassembly (and in some cases located at the center of mass of the pitch subassembly). Close to the center of mass of the pitch subassembly can mean, for example, a distance of less than 1 mm. In other examples, it can mean, for example, a distance of less than 2 mm or less than 4 mm.

[0053] In yet another example, being close to the center of mass of the pitch subassembly 220 may refer to, for example, a distance less than 10% of the module height MH. In other examples, it may refer to, for example, a distance less than 30% or 7.5% of the module height MH.

[0054] The pivot mechanism 232 is formed by a plurality of sockets 234 in the yaw subassembly 210, a plurality of sockets 236 in the pitch subassembly 220, and balls 238 secured in the plurality of sockets 234 and 236. Like the balls 218, the balls 238 have an exemplary diameter greater than 1.2 mm, allowing for improved drop resistance because their larger diameter provides a larger surface or contact area and is less sensitive to drops.

[0055] The use of a pivot ball to guide the pitch rotation of the mechanism is in contrast to the track-based pitch motion in PCT / IB2019 / 053315. The pivot ball-based design disclosed herein has advantages due to its small size and allows for robust manufacture of the pivot rotation mechanism.

[0056] Figure 2E An embodiment of the optical path folding element actuator 200 disclosed herein is shown in a perspective view. The actuator 200 includes a yaw subassembly 210, a pitch subassembly 220 carrying an optical path folding element 204, and a fixed subassembly 230. The module height (MH) can be 6.0 to 8.5 mm. The prism width (PW) can be 60 mm to 140 mm.

[0057] The optical path folding element actuator 200 further includes a yaw drive magnet 228 ( Figure 3 ). Exemplarily and as Figure 3 As shown, the yaw drive magnet 228 can be a quadrupole single magnet. In contrast, in PCT / IB2019 / 053315, the yaw drive magnet has only two poles. The arrows indicate the direction of magnetic polarization. The design disclosed herein is advantageous because it provides a higher magnetic field resulting in a higher actuation force.

[0058] Figure 4Various views showing more details of the yaw subassembly 210 and the fixed subassembly 230 are shown. Views (a) and (b) show cross sections through the optical path folding element actuator 200, and views (c) and (d) show cross sections through the fixed subassembly 230. As described above, the yaw subassembly 210 is carried by the fixed subassembly 230. The optical path folding element actuator 200 also includes a yaw stop mechanism, which is divided into a drop stop mechanism and a rotation stop mechanism. The drop stop mechanism includes a drop stopper 402, which prevents the yaw subassembly 210 from falling out of the fixed subassembly 230 in the event that the optical path folding element actuator (or a device including a camera and an actuator, such as a smartphone) falls. Exemplarily, the stopper 402 can be made of plastic, and a portion of the fixed subassembly 230 that contacts the stopper 402 can be made of metal. The rotation stop mechanism includes a rotation stopper 406 that limits the rotation range of the yaw subassembly 210. For example, the rotating stopper 406 can be made of plastic, while a portion of the fixed subassembly 230 that contacts the stopper 406 can be made of metal. In contrast, in PCT / IB2019 / 053315, there is only one metal stopper that performs all functions. The design disclosed herein is advantageous because if a device such as a smartphone including a camera and an actuator is dropped or due to any other event that may generate unwanted particles, there are no plastic parts that may impact the metal.

[0059] Yaw rotation position sensing:

[0060] Figure 5 A yaw subassembly 210 is shown in (a) without a pitch subassembly 220, and details of yaw sensing magnets 502 and 504 for sensing yaw rotational position at three different yaw rotational positions are shown in (b), (c), and (d). View (b) is in a negative rotational position, view (c) is in a zero rotational position, and view (d) is in a positive rotational position. Magnets 502 and 504 are fixedly connected to the yaw subassembly 210 and are flat, in contrast to the non-flat magnets used for the same purpose in PCT / IB2019 / 053315. Flat magnets may be beneficial from a manufacturing or cost perspective. The flat yaw sensing magnets 502 and 504 have a conical shape 508 to enable sensing of large movements. In some embodiments, only one yaw sensing magnet may be used.

[0061] The yaw sensing magnet can be combined with a Hall effect bar sensor (or "Hall bar") 506 for rotational position sensing. The Hall bar sensor 506 is fixedly connected to the fixed subassembly 230 and is placed below the yaw subassembly 210, as shown in (d). Compared to PCT / IB2019 / 053315, where the curved drive magnet is also the sensing magnet, the drive mechanism and the sensing mechanism here are separated, allowing more accurate sensing using smaller components. The separated drive mechanism and sensing mechanism allow a large rotation radius of the driving force and allow a small rotation radius of rotation to be sensed with higher accuracy.

[0062] Embodiments of the yaw subassembly disclosed herein may support a yaw rotation range of, for example, ±10 to ±35 degrees.

[0063] Pitch rotation position sensing:

[0064] Figure 6 A pitch subassembly 220 including an exemplary magnetic Hall bar arrangement is shown. The pitch drive and sensing magnet 602 is fixedly connected to the pitch subassembly 220, and the pitch sensing Hall bar 604 is fixedly connected to the yaw subassembly 210. On each axis, multiple Hall sensors can be used to allow each A2D controller (driver) to read data from the Hall bar for small rotations and improve the linearity of the sensing. In contrast, in PCT / IB2019 / 05331, a single Hall bar is used for each axis.

[0065] Embodiments of the pitch subassembly disclosed herein may support a pitch rotation range of, for example, ±2 to ±20 degrees.

[0066] Figure 7 Details of two different embodiments using two controllers / actuators (X (yaw) and Y (pitch) controllers) are shown, which receive inputs from, for example, a smartphone application processor (AP) and an inertial sensor (e.g., gyroscope) and provide current to two coils of the drive mechanism (actuator). The pitch subassemblies form a master-slave arrangement, with the yaw subassembly acting as the master and the pitch subassembly acting as the slave.

[0067] Figure 8Pitch subassembly 220 and yaw drive magnet 228 are shown. Yaw drive magnet 228 also serves as a pitch preload magnet. "Preload" refers to the force connecting pitch subassembly 220 to pivot mechanism 232. Yoke assembly 802, including two yokes, yoke 804 and yoke 806, is connected to pitch subassembly 220 to minimize restoring torque / force and simplify the design. In some embodiments, the distance between yoke 804 and yoke 806 is used to define the return force. In other embodiments, the distance between yoke assembly 802 and yaw drive magnet 228 is used to define the return force. In alternative embodiments, a single yoke can be used for pitch preload.

[0068] Although the present disclosure has been described in terms of certain embodiments and generally associated methods, changes and permutations of the embodiments and methods will be apparent to those skilled in the art. The present disclosure should be understood not to be limited to the particular embodiments described herein, but only to the scope of the appended claims.

[0069] All references mentioned in this specification are incorporated by reference in their entirety into this specification, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference herein. In addition, the citation or identification of any reference in this application should not be construed as an admission that the reference can be used as prior art for this application.

Claims

1. An actuator, characterized in that: The actuator comprises: a yaw subassembly having a yaw rotation axis; A pitch subassembly, carrying an optical path folding element, wherein the pitch subassembly includes a pivot rotation mechanism and has a pitch rotation axis; as well as a fixed subassembly, wherein the actuator is operable to rotate the optical path folding element in two rotational directions, a first rotation for yaw about the yaw rotation axis, and a second rotation for pitch about the pitch rotation axis, and the rotation of the pitch comprises a rotation using the pivoting mechanism, wherein the position of the yaw subassembly relative to the fixed subassembly is measured by a first plurality of Hall sensors, and The position of the pitch subassembly relative to the yaw subassembly is measured by a second set of multiple Hall sensors.

2. The actuator according to claim 1, characterized in that: The first plurality of Hall sensors includes four Hall sensors.

3. The actuator according to claim 1, characterized in that: The second plurality of Hall sensors includes three Hall sensors.

4. The actuator according to claim 1, characterized in that: The invention is formed by a first yaw socket in the yaw subassembly, a first pitch socket in the pitch subassembly, a first ball located at the first yaw socket and the first pitch socket, a second yaw socket in the yaw subassembly, a second pitch socket in the pitch subassembly, and a second ball located at the second yaw socket and the second pitch socket, wherein the first yaw socket corresponds to the first pitch socket, and the second yaw socket corresponds to the second pitch socket.

5. The actuator according to claim 1, characterized in that: The actuator is integrated into a folded camera.

6. The actuator according to claim 1, characterized in that: The folding camera is a scanning telephoto camera capable of scanning a scene in the two rotation directions.

7. The actuator according to claim 1, characterized in that: The yaw subassembly and the pitch subassembly form a master-slave arrangement, wherein the yaw subassembly acts as a master assembly and the pitch subassembly acts as a slave assembly.

8. The actuator according to claim 1, characterized in that: The pivot rotation mechanism includes a pivot, the pivot is located on opposite sides of the optical path folding element, and the pitch rotation axis is close to a center of gravity of a pitch subassembly.

9. The actuator according to claim 1, characterized in that: The pivot mechanism includes a pitch drive coil and a magnet, wherein the pitch drive coil surrounds the yaw rotation axis.

10. The actuator according to claim 1, characterized in that: The yaw subassembly includes at least one groove ball mechanism.

11. The yaw actuator according to claim 10, characterized in that: The plurality of grooves of the at least one groove ball mechanism are concentrically curved with a center of curvature on the yaw rotation axis.

12. The actuator according to claim 10, characterized in that: The multiple balls of the at least one groove ball mechanism are guided by a plurality of groove pairs, and the plurality of groove pairs respectively include a groove on the yaw subassembly and a groove on the fixed subassembly.

13. The actuator according to claim 10, characterized in that: The at least one groove ball mechanism includes at least three balls.

14. The actuator according to claim 10, characterized in that: The plurality of balls of the at least one groove ball mechanism are located in a plane perpendicular to the yaw rotation axis.

15. The actuator according to claim 1, characterized in that: The yaw rotation is performed by an actuation mechanism including a yaw drive coil and a yaw drive magnet, and wherein the yaw drive magnet is concentrically curved.

16. The actuator according to claim 15, characterized in that: The yaw drive magnet is fixedly connected to the yaw subassembly, and the drive coil is fixedly connected to the stator subassembly.

17. The actuator according to claim 15, characterized in that: The yaw drive magnet has two different polarization directions of the magnet, and the two different polarization directions are perpendicular to the yaw rotation axis.

18. An actuator according to any one of claims 1 to 17, characterized in that: The yaw rotation axis is proximate to a common center of mass of the yaw subassembly and the first pitch subassembly.

19. An actuator according to any one of claims 1 to 17, characterized in that: The optical path folding element is a prism.

20. An actuator according to any one of claims 1 to 17, characterized in that: The actuator is included in a moving device.

21. The actuator according to claim 20, characterized in that: The mobile device is a smart phone.

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