VCM OIS ACTUATOR MODULE

• US 20140009631A1
• Filed: 10/25/2012
• Published: 01/09/2014
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Topliss, Richard J.
• Granted Patent: US 9,134,503 B2
• Time in Patent Office: Days
• US Class Current: 348/208.11
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G03B 2205/0007 Movement of one or more optical elements for control of motion blur
• CPC Class Codes: G03B 2205/0069 using electromagnetic actuators, e.g. voice coils
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

A lens actuator module including an autofocus (AF) mechanism capable of moving a lens according to at least three degrees of freedom and an optical image stabilization (OIS) mechanism capable of moving the lens according to at least two degrees of freedom. The AF mechanism may have a coil and a magnet assembly for driving movement of the lens according to the at least three degrees of freedom. The optical image stabilization (OIS) mechanism may include a coil and a magnet assembly for driving movement of the lens according to the at least two degrees of freedom.

Claims

1. A lens actuator module comprising:

an autofocus (AF) mechanism capable of moving a lens according to at least three degrees of freedom, the AF mechanism having a coil and a magnet assembly for driving movement of the lens according to the at least three degrees of freedom; and

an optical image stabilization (OIS) mechanism capable of moving the lens according to at least two degrees of freedom, the at least two degrees of freedom different from the at least three degrees of freedom, the OIS mechanism having a coil and a magnet assembly for driving movement of the lens according to the at least two degrees of freedom.

2. The actuator module of claim 1 wherein the coil and magnet assembly of the AF mechanism comprises at least four separate coils that may be driven with an electric current and at least four separate magnets, wherein the coils and the magnets together control the focus position of the lens.

3. The actuator module of claim 1 wherein the at least three degrees of freedom comprise movement of the lens in a direction parallel to the optical axis of the lens relative to an image sensor, and rotation of the lens relative to the image sensor about two axes orthogonal to the optical axis.

4. The actuator module of claim 2 wherein the four separate coils are mounted on the lens or a lens carrier, and the four magnets are mounted on a fixed support structure of the AF mechanism.

5. The actuator module of claim 1 wherein the coil and magnet assembly of the OIS mechanism comprises at least four separate coils and at least four separate magnets, wherein the coils and the magnets together move the lens to compensate for user handshake.

6. The actuator module of claim 1 wherein the at least two degrees of freedom comprise movement of the lens in at least two different directions orthogonal to the optical axis.

7. The actuator module of claim 1 further comprising:

an upper spring assembly and a lower spring assembly, which in combination, suspend the lens or a lens carrier on the AF mechanism.

8. The actuator module of claim 1 wherein each magnet comprises at least two regions that are poled in opposite directions so as to generate Lorentz forces in the same direction on both sides of each corresponding coil.

9. The actuator module of claim 1 wherein the OIS mechanism further comprises:

a plurality of ball bearings to minimize parasitic motions of the OIS mechanism and limit OIS mechanism movements to directions orthogonal to an optical axis of the lens.

10. The actuator module of claim 9 wherein the plurality of ball bearings are maintained in contact by a magnetic attraction between the OIS mechanism magnets mounted on a moving portion of the OIS mechanism, and a magnetic material the forms part of a fixed portion of the OIS mechanism.

11. The actuator module of claim 1 wherein the actuator module is dimensioned for use within a miniature camera of a hand-held device.

12. An actuator module for controlling a position of a lens in a miniature camera, the actuator module comprising:

an autofocus (AF) mechanism having a plurality of separate coil members and corresponding magnet members for controlling a focus position of a lens along an optical axis of the lens relative to an image sensor and a rotational position of the lens about one or more axes orthogonal to the optical axis; and

an optical image stabilization (OIS) mechanism having a plurality of separate coil members positioned orthogonal to the coils members of the AF mechanism and corresponding magnet members for controlling a linear position of the lens relative to the image sensor in directions orthogonal to the optical axis, the linear position being used to compensate for user handshake.

13. The actuator module of claim 12 wherein the plurality of separate coil members of the AF mechanism comprises at least four coils mounted on the lens or a lens carrier, and the plurality of magnets of the AF mechanism comprises at least four magnets mounted on a fixed support structure of the AF mechanism.

14. The actuator module of claim 13 further comprising:

an upper flexure and a lower flexure, which in combination both suspend the lens or the lens carrier on the fixed support structure of the AF mechanism, and wherein the lower flexure forms an AF spring of the AF mechanism and an OIS spring of the OIS mechanism which facilitate movement of the lens or lens carrier according to the desired degree of freedom.

15. The actuator module of claim 14 wherein the upper flexure and the lower flexure are formed from a sheet of material and are configured so that the notional planes of the sheets of the two flexure members, when undeformed, are parallel to each other and separated from each other along the optical axis so that one is mounted further from the image sensor and the other closer.

16. The actuator module of claim 14 wherein the lower flexure comprises a plurality of flexure assemblies, each of the flexure assemblies having a fixed mount portion linking the lens or lens carrier to a fixed portion of the AF mechanism, and a terminal end portion that links the fixed portion of the AF mechanism to a fixed portion of the OIS mechanism.

17. The actuator module of claim 12, wherein an electrical terminal of each coil of the AF mechanism are all electrically connected together.

18. The actuator module of claim 14 wherein an electrical terminal of each coil of the AF mechanism are all electrically connected to the upper spring member.

19. The actuator module of claim 12 wherein each magnet in the AF mechanism and the OIS mechanism comprises at least two regions that are poled in opposite directions so as to generate Lorentz forces in the same direction on both sides of each corresponding coil.

20. The actuator module of claim 12 wherein the OIS mechanism comprises ball bearings to minimize parasitic motions of the OIS mechanism and limit movement to directions orthogonal to the optical axis of the lens.

21. The actuator module of claim 20 wherein the ball bearing are maintained in contact with the OIS mechanism by a magnetic attraction between magnets of the OIS mechanism mounted on a moving portion of the OIS mechanism that is positioned over the ball bearings, and a conductive body forming part of a fixed portion of the OIS mechanism below the ball bearings.

22. The actuator module of claim 21 wherein the magnets of the OIS mechanism have recesses dimensioned to receive the ball bearings and surfaces that form rolling contact surfaces for the moving portion of the OIS mechanism.

23. The actuator module of claim 21 wherein portions of the conductive body on the OIS mechanism fixed portion act as contact surfaces between the ball bearings and the OIS mechanism fixed portion.

24. A lens actuator module comprising:

an autofocus (AF) mechanism capable of moving a lens according to at least three degrees of freedom, the AF mechanism comprising (1) a first portion having a plurality of AF coils positioned around a lens carrier and an upper flexure assembly and a lower flexure assembly positioned along opposing sides of the lens carrier to suspend the lens carrier within the AF mechanism, and (2) a second portion having a plurality of AF magnets positioned within a yoke member, wherein the yoke member is positioned around the second portion such that the AF magnets are along a side of the AF coils opposite the lens carrier and the first portion is movable with respect to the second portion; and

an optical image stabilization (OIS) mechanism capable of shifting the lens according to at least two degrees of freedom, the at least two degrees of freedom different from the at least three degrees of freedom, the OIS mechanism comprising (1) a base member having a plurality of OIS coils positioned around the base member, wherein the OIS coils are orthogonal to the AF coils, and (2) a plurality of OIS magnets attached to a bottom side of the first portion and positioned over the OIS coils so as to shift the first portion according to the at least two degrees of freedom with respect to the base member.