CAMERA MODULE AND METHOD FOR CONTROLLING THE SAME

Abstract

A camera module is provided, including a holder, a base, a bottom, an image sensor, and a first biasing element. The holder holds an optical lens and is disposed on the base. The bottom supports the image sensor and connects to the base via the first biasing element. The bottom and the image sensor can be moved with respect to the base by the first biasing element.

Claims

1. A camera module disposed in an electronic device, comprising: a base immovably connected to the electronic device; a movable part connected to an optical lens and an image sensor, wherein the movable part is movable relative to the base; a drive assembly driving the movable part to move relative to the base, wherein when the drive assembly drives the movable part to move relative to the base, the movable part makes the optical lens and the image sensor move relative to the base simultaneously; wherein the drive assembly comprises a first drive element and a second element, and when viewed from an optical axis of the optical lens, the base is polygonal, and the first drive element and the second element are located on different sides of the base.

2. The camera module as claimed in claim 1, wherein the first drive element and the second drive element comprise shape memory alloy (SMA), respectively.

3. The camera module as claimed in claim 1, further comprising a frame surrounding the base, wherein the frame comprises a first accommodation portion and a second accommodation portion for accommodating the first drive element and the second element, respectively.

4. The camera module as claimed in claim 3, further comprising a first guiding member and a second guiding member located in the first accommodation portion and the second accommodation portion, respectively.

5. The camera module as claimed in claim 4, wherein the first drive element winds around the first guiding member, and the second drive element winds around the second guiding member.

6. The camera module as claimed in claim 1, further comprising a bottom disposed under the base and configured with the image sensor.

7. The camera module as claimed in claim 6, further comprising an elastic element connected to the bottom and the base.

8. The camera module as claimed in claim 7, wherein the elastic element is substantially perpendicular to the optical axis of the optical lens, the elastic element has an outer section, an inner section, and a middle section connected to the outer section and the inner section, and the outer section and the inner section are respectively affixed to the base and the bottom.

9. The camera module as claimed in claim 8, wherein the outer section is connected to a lower surface of the base, and the inner section is connected to a lower surface of the bottom.

10. The camera module as claimed in claim 6, further comprising a frame, wherein the base is surrounded by the frame.

11. The camera module as claimed in claim 10, wherein a gap is formed between the frame and the base.

12. The camera module as claimed in claim 10, further comprising a plurality of conductive blocks affixed to the bottom and the frame.

13. The camera module as claimed in claim 12, wherein the first drive element and the second drive element are movably connected to the bottom and the frame via the conductive blocks.

14. The camera module as claimed in claim 10, wherein the bottom that is affixed to the base, the image sensor that is disposed on the bottom, the movable part that is located on the base, and the optical lens that is held by the movable part move together in a direction of a central axis of the frame relative to the frame.

15. The camera module as claimed in claim 10, wherein the bottom that is affixed to the base, the image sensor that is disposed on the bottom, the movable part that is located on the base, and the optical lens that is held by the movable part move together relative to a central axis of the frame with an angular displacement.

16. The camera module as claimed in claim 10, further comprises a circuit board disposed on the base, the frame, or the electronic device.

17. The camera module as claimed in claim 16, further comprises a first optical coupling element and a second optical coupling element disposed on the image sensor and the circuit board, respectively.

18. The camera module as claimed in claim 1, wherein there are two first drive elements and two second drive elements, when viewed from the optical axis of the optical lens, the base is quadrilateral, and the first drive elements are located on two sides of the base, and the second elements are located on two sides of the base on which the first drive elements are not located.

19. The camera module as claimed in claim 1, further comprising a biasing element connected to the base and the movable part.

20. The camera module as claimed in claim 19, further comprising a position member, wherein the biasing element is in contact with the position member and winds around the position member.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0020] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

[0021] FIG. 1 is an exploded diagram of a camera module according to an embodiment of the invention;

[0022] FIG. 2A is a schematic diagram of the camera module in FIG. 1 after assembly (the housing thereof is omitted);

[0023] FIG. 2B is another perspective schematic diagram of the camera module (the housing thereof is omitted) in FIG. 2A:

[0024] FIG. 3 is a sectional view diagram taken along line A-A in FIG. 2B;

[0025] FIG. 4 is a schematic diagram of the bottom and the image sensor linearly moving along the direction of the first central axis;

[0026] FIG. 5 is a schematic diagram of the second central axis having an angular displacement with respect to the first central axis:

[0027] FIG. 6 is a schematic diagram of the holder linearly moving along the direction of the optical axis:

[0028] FIG. 7 is a schematic diagram of the optical axis having an angular displacement with respect to the first central axis;

[0029] FIG. 8 is a schematic diagram of a camera module according to another embodiment of the invention;

[0030] FIG. 9 is a bottom plan view diagram of the camera module in FIG. 8;

[0031] FIG. 10 is a sectional view diagram taken along line B-B in FIG. 8; and

[0032] FIG. 11 is a schematic diagram of an optical transceiver assembly is arranged on a circuit board and the image sensor.

DETAILED DESCRIPTION OF INVENTION

[0033] The making and using of the embodiments of the camera modules are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the embodiments, and do not limit the scope of the disclosure.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. It should be appreciated that each term, which is defined in a commonly used dictionary, should be interpreted as having a meaning conforming to the relative skills and the background or the context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless defined otherwise.

[0035] FIG. 1 is an exploded-view diagram of a camera module 1 according to an embodiment of the invention, and FIGS. 2A-2B are schematic diagrams of the camera module 1 in FIG. 1 after assembly and a housing 40 thereof is omitted. The camera module 1 can be disposed in an electronic device J, such as a camera, a tablet computer, or a cell phone, and it can be configured with an optical lens (not shown) and an image sensor IM disposed therein. The optical lens and the image sensor are movable with respect to each other, so that the camera module 1 has an auto-focusing (AF) function and optical image stabilization (OIS).

[0036] As shown on FIGS. 1 and 2A-2B, the camera module 1 primarily comprises a base 10, a bottom 20, a holder 30, a housing 40, an image sensor IM, a plurality of first elastic elements S1, a plurality of first biasing elements W1, a plurality of second elastic elements S2, and a plurality of second biasing elements W2. The bottom 20 is disposed under the base 10 and can be configured with the image sensor IM. The holder 30 is disposed on the base 10 and can be configured with an optical lens (not shown). The image sensor IM is configured to receive light from the outside of the camera module 1 and through the optical lens so that an image is acquired. The connection between the base 10 and the bottom 20 is described below. The connection between the holder 30 and the base 10 will be described later.

[0037] The base 10 and the bottom 20 respectively have a first central axis C1 and a second central axis C2. In a normal condition, the first central axis C1 coincides with the second central axis C2. The first elastic elements S1 (such as metal springs) are connected to the base 10 and the bottom 20 and are substantially perpendicular to the optical axis O of the optical lens. In particular, each of the first elastic elements S1 has an outer section S11, an inner section S12, and a middle section S13 (as shown in FIG. 2B), wherein the inner and outer sections S11 and S12 are respectively affixed to a lower surface 101 of the base 10 and a lower surface 201 of the base 20. The middle section S13 connects to the outer and inner sections S11 and S12, so that the bottom 20 is movably connected to the base 10.

[0038] The first biasing elements W1, such as wires comprising a shape-memory alloy (SMA), are also connected to the base 10 and the bottom 20, and their lengths can be changed by applying one or more driving signals (e.g., electrical current) to them from an external power source. For example, when applying driving signals to heat the first biasing elements W1, the first biasing elements W1 are deformed (e.g., elongated or shortened). When the application of the driving signals is stopped, the deformed first biasing elements W1 will recover to their original lengths. In other words, by applying one or more appropriate driving signals, the lengths of the first biasing elements W1 can be controlled to alter the posture of the bottom 20. The first biasing elements W1, for example, may comprises a titanium-nickel (TiNi) alloy, a titanium-palladium (TiPd) alloy, a titanium-nickel (TiNiCu) alloy, a titanium-nickel-palladium (TiNiPd) alloy, or a combination thereof.

[0039] Referring to FIGS. 2A-2B and 3, FIG. 3 is a sectional view diagram taken along line A-A in FIG. 2B. As shown in FIG. 2A, the base 10 has a substantially rectangular main body 11, four grooves R are respectively formed on four different sides of the upper surface of the main body 11, and four guiding members G (for example, cylinder rollers) are disposed in the grooves R, respectively. As shown in FIG. 3, the first biasing elements W1 are positioned between the base 10 and the bottom 20 in a direction that is perpendicular to the second central axis C2, and are respectively disposed around the guiding members G and have a U-shaped structure. Two conductive blocks L are electrically connected to two ends of each of the first biasing elements W1, and the conductive blocks L are affixed to the base 10 and the bottom plate 20, respectively (for example, they are affixed to the base 10 and the bottom 20 by an engaging means or an adhesive). Therefore, the first biasing elements W1 can be connected to the base 10 and the bottom 20, and when the external power source applies the drive signal to one or a plurality of first biasing elements W1 to deform, the posture of the bottom 20 can be adjusted, and the image sensor IM disposed on the bottom 20 is also moved or rotated with the bottom 20.

[0040] It should be noted that a plurality of conductive wires (not shown) can be formed on the base 10 and the bottom 20 by insert molding or 3D molded interconnect device (MID) technology and are electrically connected to the conductive blocks L. Thus, the four first biasing elements W1 form four respective independent circuits, whereby driving signals (e.g., current) can be supplied to them respectively from an external power source via the wires, and the lengths of the first biasing elements W1 can be changed to adjust the posture of the bottom 20, to achieve optical image stabilization (OIS).

[0041] It should be understood that each of the first biasing elements W1 is electrically independent and connects to an external power source. Thus, a plurality of different driving signals can be respectively supplied to the first biasing elements W1 by the external power source, and the first biasing elements W1 can be independently controlled to have different or the same length variations. For example, when applying driving signals to the first biasing elements WL, the first biasing elements W1 are deformed with different or the same length variations, so that the first biasing elements W1 can force the bottom 20 and the image sensor IM to linearly move along the first central axis C1 of the base 10 relative to the base 10, or force the bottom 20 and the image sensor IM to move so that the second central axis C2 of the bottom 20 has an angular displacement relative to the first central axis C1, to achieve optical image stabilization.

[0042] Specifically, as shown in FIG. 4, when the driving signals are applied to the first biasing elements W1 disposed on the four sides of the main body 11 so that they have the same length variation, the first biasing elements W1 force the bottom 20 and the image sensor IM to move relative to the base 10 in the direction of the first central axis C1 and the optical axis O. When the driving signals are applied to the first biasing elements W1 so that they have different length variations, the second central axis C2 of the bottom 20 has an angular displacement θ1 (as shown in FIG. 5) with respect to the first central axis C1 of the base 10. In other words, by applying the driving signals and controlling the length variations of the first biasing elements W1, the image sensor IM can be moved or rotated to compensate for the shift caused by the shaking of the camera module 1, so that image quality can be enhanced.

[0043] Furthermore, since the bottom 20 and the base 10 are connected via the first elastic elements S1, when the drive signals have not yet been applied to the first biasing elements W1, the bottom 20 can be positioned at an initial position with respect to the base 10 by the first elastic elements S1.

[0044] The connection relationship between the base 10 and the holder 30 is described below. Please refer to FIGS. 1 and 2, the holder 30 is disposed on the base 10, and a receiving space 301 is extended through the holder 30, so that an optical lens (not shown) can be disposed therein. The base 10 further has a stage portion 12 with a substantially square or rectangular structure disposed on the main body 11 and four protrusions 13. The protrusions 13 are respectively disposed at the four corners of the stage portion 12 and protrude from the stage portion 12 toward the holder 30. The holder 30 connects to the four protrusions 13 of the base 10 by the four first elastic elements S1 (such as metal springs).

[0045] The second biasing elements W2 (which may comprise shape-memory alloy (SMA) material) also connect to the base 10 and the holder 30. Specifically, two columnar position members P1 and P2 are disposed on each side of the stage portion 12 of the base 10. As with the second biasing elements W2 at the bottom of FIG. 2A, the second biasing elements W2 are in contact with and extended around the position members P1 and P2. All the second biasing elements W2 can be divided into three sections: a first section W21, a second section W22, and a third section W23. The first section W21 is substantially parallel to the first central axis C1, and the second section W22 has a U-shaped structure and connects to the first section W21. The third section W23 is substantially perpendicular to the first central axis C1, wherein the second section W22 is connected to the first section W21 and the third section W23, and the second section W22 and the third section W23 are respectively situated at the left and right sides of the first section W21. As the second biasing elements W2 extend around the position members P1 and P2 to form the three sections W21, W22, and W23, the lengths of the second biasing elements W2 disposed on each side of the stage portion 12 can be increased. Therefore, when the second biasing elements W2 are deformed, more variation in length can be generated. Furthermore, due to the distance between the position members P1 and P2 in the direction of the first central axis C1, short-circuits between the first, second, and third sections W11, W12, and W13 can be avoided. Furthermore, as shown in FIGS. 1 and 3, the first biasing elements W1 and the second biasing elements W2 are situated in different positions in the direction of the first central axis C1.

[0046] Still referring to FIG. 2A, a plurality of conductors E (such as conductive wires) are formed on the base 10 (the protrusions 13 of the base 10) by insert molding or 3D molded interconnect device technology. The conductors E are electrically connected to the second elastic elements S2 and the second biasing elements W2, respectively, to form four independent circuits. As the deformation of the first biasing elements W1, driving signals (e.g., current) can be supplied to the second biasing elements W2 from an external power source, and the lengths of the second biasing elements W2 can be changed to adjust the posture of the holder 30. It should be noted that, since the second elastic elements S2 are electrically conductive (such as springs comprising metal), the second biasing elements W2 and the conductors E can be electrically connected to each other, so that no additional wires are required, saving space.

[0047] It should be understood that, when applying driving signals to the second biasing elements W2, the second biasing elements W2 may deform and have length variations that are the same or different. Thus, the second biasing elements W2 can force the holder 30 and the optical lens to move in the direction of the optical axis O with respect to the base 10, or force the optical axis O to have an angular displacement relative to the first central axis C1 of the base 10, to achieve the function of fast optical focus or optical image stabilization (OIS). As shown in FIG. 6, when the driving signals are applied to the second biasing elements W2 on the four sides of the stage portion 12, if the length variations thereof are substantially the same, the second biasing elements W2 can force the holder 30 and the optical lens to move relative to the base 10 in the direction of the optical axis O. On the other hand, if the length variations thereof are different from each other, the holder 30 and the optical axis O of the optical lens can have an angular displacement θ2 relative to the first central axis C1 of the base 10 (as shown in FIG. 7).

[0048] As described above, by appropriately applying different drive signals to the first biasing elements W1 and the second biasing elements W2, the length variations can be appropriately controlled, so that: (1) the bottom 20 and the image sensor IM can move relative to the base 10, the holder 30 and the optical lens, and (2) the holder 30 and the optical lens can move relative to the base 10, thereby providing fast optical focus and optical image stabilization.

[0049] Furthermore, in another embodiment, the camera module 1 may have only one first biasing element W1 and one second biasing element W2. When a driving signal is applied to the first biasing element W1, the first biasing element W1 is deformed, and the second central axis C2 of the bottom 20 can be angularly shifted by an angular displacement θ1 relative to the first central axis C1 of the base 10; when a driving signal is applied to the second biasing element W2, the first biasing element W2 is deformed, and the optical axis O can be angularly shifted by an angular displacement θ2 relative to the first central axis C1, so that tilt angle compensation of the camera module 1 can be accomplished.

[0050] According to the foregoing embodiment, a method for controlling the camera module 1 is provided. One significant step of the method is to apply a plurality of drive signals to the first biasing elements W1 respectively to move the bottom 20 and the image sensor IM along the first central axis C1 or the optical axis O, or to move the bottom 20 and the image sensor IM so that the second central axis C2 of the bottom 20 relative to the first central axis C1 has an angular displacement θ1. Furthermore, the method comprises applying a plurality of driving signals to the respective second biasing elements W2, so that the holder 30 and the optical lens are moved in the direction of the optical axis O, or the optical axis O of the optical lens has an angular displacement θ2 with respect to the first central axis C1 of the base 10.

[0051] FIG. 8 is a schematic diagram of a camera module 2 according to another embodiment of the invention. The main difference between the camera module 2 in the present embodiment and the camera module 1 in the aforementioned embodiment is that the base 10′ of the camera module 2 is different from the base 10, and the camera module 2 further comprises a frame 50, wherein the same elements corresponding to the aforementioned embodiment (FIGS. 1 and 2A-2B) are not described again here in detail.

[0052] Referring to FIGS. 8-10, a lower surface 501 of the frame 50, such as the one affixed to a casing of an electronic device J, is connected to the bottom 20 via the first elastic elements S1, and the bottom 20 is affixed to a lower surface 101′ of the base 10. The base 10′ and the bottom 20 are surrounded by the frame 50, and a gap AP is formed between the frame 50 and the base 10′. FIG. 10 is a sectional view diagram taken along line B-B in FIG. 8, the first biasing elements W1 is movably connected to the bottom 20 and the frame 50 via the conductive blocks L respectively affixed to the bottom 20 and the frame 50. Thus, when applying driving signals to the first biasing elements W1, the bottom 20 affixed to the base 10′ (and the image sensor IM disposed on the bottom) and the holder 30 located on the base 10′ (and the optical lens held by the holder 30) move together in the direction of a third central axis C3 of the frame 50 relative to the frame 50, or move together relative to the third central axis C3 with an angular displacement, for auto-focusing or optical image stabilization.

[0053] FIG. 11 is a schematic diagram of an optical transceiver assembly RC that is arranged on a circuit board F and the image sensor IM. It should be noted that an optical signal can be bi-directionally transmitted through the optical transceiver assembly RC between the image sensor IM in the foregoing embodiments and the circuit board F (e.g., a flexible printed circuit board, FPCB) disposed in an electronic device J. The circuit board F, for example, may be provided on the base 10 or the frame 50, or may be affixed to a casing of the electronic device J. The optical transceiver assembly RC includes a first optical coupling element RC1 and a second optical coupling element RC2 disposed on the image sensor IM and the circuit board F, respectively. When an image is acquired by the image sensor IM, the optical transceiver assembly RC will transmit the image information to the circuit board F in the form of optical signals, so that there is no need to set an additional physical wire to achieve signal transmission, thereby saving space.

[0054] In summary, a camera module and a method for controlling the camera module are provided. The camera module comprises a holder for holding an optical lens, a base, an image sensor and at least one first biasing element. The holder is disposed on the base, and the bottom carries the image sensor and is connected to the base via the first biasing element. When the length variation of the first biasing element occurs, the bottom and the image sensor move relative to the base in the direction of a first central axis of the base, or a second central axis of the bottom has an angular displacement relative to the first central axis. Therefore, by effecting various changes to the posture of the bottom, an optical shaking compensation can be accomplished.

[0055] In addition, the camera module further comprises at least a second biasing element disposed on the base and connected to the base and the holder. When the second biasing element forces the holder to move by the length variation thereof, the holder and the optical lens move relative to the base in a direction that is substantially parallel to the first central axis, or the optical axis of the optical lens has an angular displacement relative to the first central axis, so that the functions of optical focus or optical shaking compensation can be accomplished.

[0056] Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having the same name (but for use of the ordinal term) to distinguish the claim elements.

[0057] It will be apparent to those skilled in the art that various modifications and variations can be made in the invention. It is intended that the standard and examples be considered as exemplary only, with a true scope of the disclosed embodiments being indicated by the following claims and their equivalents.