ANTI-SHAKE COMPENSATION STRUCTURE FOR AUTO-FOCUS

Abstract

An anti-shake compensation structure is provided. The anti-shake compensation structure includes an auto-focus module driving a lens to move along a light entering path of the lens. The auto-focus module includes a lens holder holding the lens, a coil adjacent to the lens holder, and a magnet corresponding to the coil. The anti-shake compensation structure further includes an outer frame supporting the lens holder, and a compensation driving unit driving the lens to sway relative to the outer frame along a direction not parallel to the light entering path. The compensation driving unit includes a compensation coil corresponding to the magnet.

Claims

1. An anti-shake driving mechanism, comprising: a movable portion, for carrying a bottom plate, wherein the bottom plate carries an optical sensing element that corresponds to a light entering path, wherein the bottom plate has a plate-like shape and is perpendicular to the light entering path; a fixed portion, comprising a base adjacent to the bottom plate, wherein the base has a plate-like shape and is perpendicular to the light entering path, wherein the movable portion is movable relative to the fixed portion; a compensation driving assembly, driving the movable portion to move relative to the fixed portion along a direction that is not parallel to the light entering path, wherein the base bottom does not have a through hole that is corresponding to the light entering path.

2. The anti-shake driving mechanism as claimed in claim 1, wherein a gap is provided between the bottom plate and the base, so that the bottom plate is movable relative to the base.

3. The anti-shake driving mechanism as claimed in claim 2, wherein the bottom plate is located between the optical sensing element and the base when viewed along a direction that is perpendicular to the light entering path.

4. The anti-shake driving mechanism as claimed in claim 1, further comprising a suspension element, wherein the movable portion is movably connected to the fixed portion via the suspension element, and the bottom plate is located between a portion of the suspension element that is in direct contact with the fixed portion and the base when viewed along a direction that is perpendicular to the light entering path.

5. The anti-shake driving mechanism as claimed in claim 1, further comprising a suspension element, wherein the movable portion is movably connected to the fixed portion via the suspension element, and the bottom plate is located between a portion of the suspension element that is in direct contact with the movable portion and the base when viewed along a direction that is perpendicular to the light entering path.

6. The anti-shake driving mechanism as claimed in claim 1, further comprising a suspension element, wherein the movable portion is movably connected to the fixed portion via the suspension element, and the bottom plate is located between the suspension element and the base when viewed along a direction that is perpendicular to the light entering path.

7. The anti-shake driving mechanism as claimed in claim 1, further comprising a position sensing element, sensing the movement of the movable portion relative to the fixed portion, wherein the position sensing element does not overlap the optical sensing element when viewed along the light entering path.

8. The anti-shake driving mechanism as claimed in claim 7, wherein the position sensing element at least partially overlaps the compensation driving assembly when viewed along the light entering path.

9. The anti-shake driving mechanism as claimed in claim 7, wherein the position sensing element at least partially overlaps a compensation magnetic element of the compensation driving assembly when viewed along the light entering path.

10. The anti-shake driving mechanism as claimed in claim 7, wherein the position sensing element does not overlap a compensation coil of the compensation driving assembly when viewed along the light entering path.

11. The anti-shake driving mechanism as claimed in claim 7, wherein the movable portion carries a lens that is corresponding to the optical sensing element, wherein the lens is movable relative to the optical sensing element and the fixed portion.

12. The anti-shake driving mechanism as claimed in claim 11, further comprising a focus driving assembly, driving the lens to move relative to the optical sensing element along the light entering path, wherein the focus driving assembly at least partially overlaps the bottom plate when viewed along the light entering path.

13. The anti-shake driving mechanism as claimed in claim 12, wherein a focus coil of the focus driving assembly does not overlap the position sensing element when viewed along the light entering path.

14. The anti-shake driving mechanism as claimed in claim 12, wherein the focus driving assembly at least partially overlaps the position sensing element when viewed along the light entering path.

15. The anti-shake driving mechanism as claimed in claim 12, wherein a focus magnetic element of the focus driving assembly at least partially overlaps the position sensing element when viewed along the light entering path.

16. The anti-shake driving mechanism as claimed in claim 12, wherein the compensation driving assembly is at least partially located between the optical sensing element and the base when viewed along a direction that is perpendicular to the light entering path.

17. The anti-shake driving mechanism as claimed in claim 12, wherein the optical sensing element is at least partially located between the compensation driving assembly and the position sensing element when viewed along a direction that is perpendicular to the light entering path.

18. The anti-shake driving mechanism as claimed in claim 12, wherein the position sensing element is at least partially located between the optical sensing element and the base when viewed along a direction that is perpendicular to the light entering path.

19. The anti-shake driving mechanism as claimed in claim 18, wherein the focus driving assembly comprises a focus coil and a focus magnetic element, the compensation driving assembly comprises an compensation coil and an compensation magnetic element, wherein the focus magnetic element and the compensation magnetic element are formed as an integrated structure, and the position sensing element is corresponding to the compensation magnetic element to sense the movement of the movable portion relative to the fixed portion.

20. The anti-shake driving mechanism as claimed in claim 1, wherein the movable portion carries a lens that is corresponding to the optical sensing element, the movable portion brings the lens and the optical sensing element to move relative to the fixed portion when the movable portion moves relative to the fixed portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

[0031] FIG. 1 is an exploded perspective view of an anti-shake auto-focus modular structure disclosed in U.S. patent application Ser. No. 12/630,688;

[0032] FIG. 2 is a sectional perspective view of an anti-shake compensation structure for auto-focus module according to a first embodiment of the present invention;

[0033] FIG. 3 is a schematic plan view of FIG. 2;

[0034] FIG. 4 is a perspective view showing an embodiment of an elastic supporting member used in the present invention;

[0035] FIG. 5 is a schematic plan view of an anti-shake compensation structure for auto-focus module according to a second embodiment of the present invention; and

[0036] FIG. 6 is a schematic plan view of an anti-shake compensation structure for auto-focus module according to a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The present invention will now be described with some preferred embodiments thereof and with reference to the accompanying drawings. It is understood the accompanying drawings are illustrated only for assisting in describing the present invention and not intended to limit the present invention. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals.

[0038] Please refer to FIG. 2 that is a partial sectional perspective view of an anti-shake compensation structure for auto-focus module according to a first embodiment of the present invention; and to FIG. 3 that is a schematic plan view of FIG. 2. The present invention uses a center of an auto-focus module as a fulcrum to sway the auto-focus module leftward and rightward on x-axis or forward and rearward on y-axis for compensating any shake caused by hands, so as to improve the anti-shake auto-focus modular structure disclosed in U.S. patent application Ser. No. 12/630,688 that horizontally moves an auto-focus module in x-axis or y-axis direction for compensating any shake caused by hands while shooting a picture.

[0039] The anti-shake compensation structure for auto-focus module according to the first embodiment of the present invention includes an auto-focus module 10, an outer frame 20, an elastic supporting member 30, a compensation driving unit 40, and a shake sensor (not shown). A lens 11 is held to the auto-focus module 10 for capturing light and image. The lens 11 and an image sensor 12 are aligned with each other on z-axis, that is, on a line along which light enters into the lens 11. The auto-focus module 10 drives the lens 11 to move forward and rearward in the light entering path (i.e. z-axis direction), so that the lens 11 can focus the captured image on the image sensor 12.

[0040] The auto-focus module 10 is preferably a driving structure formed of a voice coil motor (VCM); and includes a lens holder for holding and locking the lens 11 thereto. A coil 14 is arranged around the lens holder, and the lens holder is connected to a movable portion of at least one plate spring 15, while the at least one plate spring 15 is connected at a fixed portion thereof to a base 16. Four magnets 17 are arranged in the base 16 corresponding to the coil 14.

[0041] The outer frame 20 encloses the auto-focus module 10. The elastic supporting member 30 is arranged on an inner upper end of the outer frame 20 and connected to an upper end of the auto-focus module 10, so as to suspend the auto-focus module 10 in the outer frame 20. With the elastic supporting member 30 arranged in the above-described manner, the auto-focus module 10 is allowed to sway forward and rearward or leftward and rightward with a center of the elastic supporting member 30 acting as a fulcrum.

[0042] Please refer to FIG. 4 that is a perspective view showing an embodiment of an elastic supporting member used in the present invention. As shown, the elastic supporting member 30 includes an outer fixed portion 31, a first inner movable portion 32, and a second inner movable portion 33. The outer fixed portion 31 is fixedly connected to the inner upper end of the outer frame 20; the first inner movable portion 32 is located at an inner side of the outer fixed portion 31, and is connected at two opposite and symmetrical first pivot portions 321 to the outer fixed portion 31; and the second inner movable portion 33 is located at an inner side of the first inner movable portion 32, and is connected at two opposite and symmetrical second pivot portions 331 to the first inner movable portion 32. It is noted the two second pivot portions 331 are respectively located at an angular position of 90 degrees relative to the first pivot portions 321, and the second inner movable portion 33 is connected to the upper end of the auto-focus module 10.

[0043] The first inner movable portion 32 allows the auto-focus module 10 to sway leftward and rightward on x-axis; and the second inner movable portion 33 allows the auto-focus module 10 to sway forward and rearward on y-axis. Alternatively, the present invention can be differently designed for the first inner movable portion 32 to allow the auto-focus module 10 to sway forward and rearward on y-axis; and for the second inner movable portion 33 to allow the auto-focus module 10 to sway leftward and rightward on x-axis.

[0044] Please refer to FIGS. 2 and 3 at the same time again. The compensation driving unit 40 is located behind the auto-focus module 10 for driving the auto-focus module 10 to sway leftward and rightward on x-axis or forward and rearward on y-axis within the outer frame 20, so as to compensate any image deviation due to shake caused by hands.

[0045] The compensation driving unit 40 includes a compensation magnet assembly 41, a compensation coil assembly 42, and a displacement sensor assembly. The compensation magnet assembly 41 is arranged beneath an outer bottom face of the auto-focus module 10, and includes at least one x-axis compensation magnet and at least one y-axis compensation magnet.

[0046] The compensation coil assembly 42 is arranged on an inner bottom face of the outer frame 20, and includes at least one x-axis compensation coil and at least one y-axis compensation coil corresponding to the x-axis compensation magnet and the y-axis compensation magnet, respectively, for separately generating an electromagnetic field to drive the auto-focus module 10 to tilt on x-axis or y-axis.

[0047] The displacement sensor assembly is arranged on a central area of the inner bottom face of the outer frame 20, and includes a displacement sensor 43 and a sensing magnet 44. Preferably, the displacement sensor 43 is a two-axis sensing IC. The displacement sensor 43 corresponds to the sensing magnet 44 for detecting a volume of displacement in x-axis direction or y-axis direction, so that the auto-focus module 10 can be driven to reach at a precise compensation position.

[0048] Preferably, the displacement sensor 43 can be a Hall sensor, a magneto-resistive (MR) sensor, a fluxgate sensor, an optical position sensor, or an optical encoder.

[0049] An advanced hand-held device is generally provided with a shake sensor, such as a Gyro sensor, an accelerometer, etc., for generating a shake signal in response to any shake of the hand-held device and sending the shake signal to the compensation driving unit for use as a basis to determine an angle by which the auto-focus module should be driven to tilt on x-axis or y-axis. The present invention may utilize the shake sensor provided in the advanced hand-held device in the case the present invention is provided on the hand-held device. Alternatively, the anti-shake compensation structure of the present invention can be directly provided with a shake sensor.

[0050] FIG. 5 is a schematic plan view of an anti-shake compensation structure for auto-focus module according to a second embodiment of the present invention, in the second embodiment, the compensation driving unit 40 includes a compensation coil assembly 42, and a displacement sensor 43. And, the magnets 17 in the auto-focus module 10 are also used as the compensation magnet assembly. That is, the compensation driving unit 40 and the auto-focus module 10 use the same set of magnets.

[0051] The compensation coil assembly 42 is arranged on an inner wall surface of the outer frame 20, and includes at least one x-axis compensation coil and at least one y-axis compensation coil separately corresponding to one of the magnets 17 in the auto-focus module 10 for respectively generating an electromagnetic field to drive the auto-focus module 10 to tilt on x-axis or y-axis.

[0052] The displacement sensor 43 is arranged on the inner bottom face of the outer frame 20, and includes an x-axis sensor and a y-axis sensor separately corresponding to one of the magnets 17 in the auto-focus module 10 for detecting a volume of displacement in x-axis direction or y-axis direction, so that the auto-focus module 10 can be driven to reach at a precise compensation position.

[0053] FIG. 6 is a schematic plan view of an anti-shake compensation structure for auto-focus module according to a third embodiment of the present invention. In the third embodiment, the compensation driving unit 40 includes a compensation magnet assembly 41, a compensation coil assembly 42, and a displacement sensor 43. The compensation magnet assembly 41 is arranged on an outer lower end of the auto-focus module 10, and includes at least one x-axis compensation magnet and at least one y-axis compensation magnet.

[0054] The compensation coil assembly 42 is arranged on an inner lower end of the outer frame 20, and includes at least one x-axis compensation coil and at least one y-axis compensation coil corresponding to the x-axis compensation magnet and the y-axis compensation magnet, respectively, for separately generating an electromagnetic field to drive the auto-focus module to tilt on x-axis or y-axis.

[0055] The displacement sensor 43 is arranged on the inner bottom face of the outer frame 20, and includes an x-axis sensor and a y-axis sensor corresponding to the x-axis compensation magnet and the y-axis compensation magnet, respectively, for detecting a volume of displacement in x-axis direction or y-axis direction, so that the auto-focus module 10 can be driven to reach at a precise compensation position.

[0056] The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.