JP2009282375A - Lens drive unit, camera module, and mobile terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module equipped with a lens drive unit having high impact resistances along both an optical axis direction and a direction orthogonal to an optical axis of an imaging optical system, and a mobile terminal equipped with the camera module of excellent impact resistance. <P>SOLUTION: This lens drive unit has a lens barrel for holding the imaging optical system for guiding a subject light, and an actuator for moving the lens barrel along optical axis of the imaging optical system, is arranged with an extendable member formed of a material having 10 N/mm<SP>2</SP>or less of Young's modulus, in at least one part on an outer face of the lens barrel, and is constituted to support the lens barrel via the extendable member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a small camera module equipped with a lens driving device suitable for being incorporated in a portable terminal.

  Conventionally, a small and thin camera module is mounted on a portable terminal such as a cellular phone, and it is possible to transmit not only shooting but also audio information as well as image information to a remote place. . Some of such camera modules are provided with a lens driving device for moving the photographing optical system along the optical axis to enable autofocus photographing.

As such a lens driving device for a camera module, there is known one in which a spring member formed of a plate material is attached at two positions on the front and rear of a lens frame, and the photographing optical system is moved against the urging force of the spring member. (For example, refer to Patent Document 1). In the lens driving device described in Patent Document 1, a curved connecting portion is formed at a portion having a spring property of a plate material formed by pressing or etching to hold a lens frame, and an impact in the direction perpendicular to the optical axis is formed. It is also intended to respond to.
JP 2006-201525 A

  However, in the lens driving device described in Patent Document 1, since the spring member is a plate material, the impact resistance in the direction substantially parallel to the plate surface of the spring member that is orthogonal to the optical axis of the imaging optical system is There is a problem that it is weaker than the impact resistance in the direction perpendicular to the angle, tends to cause plastic deformation, and hinders normal focusing operation.

  In view of the above problems, the present invention provides a camera module including a lens driving device having high impact resistance in both the optical axis direction and the optical axis orthogonal direction of an imaging optical system, and a camera excellent in impact resistance. The object is to obtain a mobile terminal equipped with a module.

  The above object is achieved by the invention described below.

1. A lens frame that holds an imaging optical system that guides subject light, and an actuator that moves the lens frame in the optical axis direction of the imaging optical system, and has a Young's modulus of 10 N on at least a part of the outer surface of the lens frame. A lens driving device characterized in that a telescopic member formed of a material of / mm ² or less is disposed, and the lens frame is supported via the telescopic member.

  2. The elastic member is elastically deformed when the lens frame is moved by the actuator. The lens drive device described in 1.

  3. The above-described 1. The expansion and contraction member is disposed on a surface orthogonal to the optical axis of the imaging optical system. Or 2. The lens drive device described in 1.

  4). The above-described 1. The expansion / contraction member is disposed on a plane parallel to the optical axis of the imaging optical system. Or 2. The lens drive device described in 1.

  5). 1 above. ~ 4. A camera module comprising: the lens driving device according to claim 1; and an image sensor that photoelectrically converts subject light.

  6). 5. above. A portable terminal comprising the camera module described in 1.

  According to the present invention, it is possible to obtain a camera module including a lens driving device having high impact resistance in both the optical axis direction and the optical axis orthogonal direction of the imaging optical system, and the camera having excellent impact resistance. It becomes possible to obtain a portable terminal equipped with a module.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a lens driving device 1 according to the first embodiment. FIG. 2 is a front view of the lens driving device 1 shown in FIG. 1 as viewed from the subject side.

  As shown in FIGS. 1 and 2, a coil 33 is provided on the outer peripheral surface side of the flange portion 22 t formed on the lens frame 22 that holds the imaging optical system 10, and the magnet 32 faces the coil 33. Is arranged. The magnet 32 is held by a U-shaped yoke 31. The yoke 31 is held by the upper casing 11 and the lower casing 12 which are casings disposed outside the lens frame 22.

The lens frame 22 is supported by the yoke 31 via an elastic member 25 formed of an expandable material. The stretchable material referred to in the present application refers to a material having a Young's modulus of 10 N / mm ² or less. The surface of the elastic member 25 on the side of the yoke 31 is fixed with an adhesive portion 25S on the imaging element side, and the surface on the side of the lens frame 22 is fixed with an adhesive portion 25h on the subject side. This fixing is performed by, for example, adhesion. As a material of the elastic member 25, for example, rubber, gel material, urethane material, or the like is preferable.

  The elastic member 25 may be bonded using the entire surface on the yoke 31 side and the surface on the lens frame 22 side according to the amount of movement, the thickness, and the length in the optical axis direction.

  The lens frame 22 is movable toward the subject side in the optical axis O direction against the elastic force of the telescopic member 25 by electromagnetic force generated by energizing the coil 33. When the coil 33 is not energized, the lens frame 22 is in contact with the lower housing 12 and stopped.

  As shown in FIG. 2, the elastic members 25 are arranged at four locations on the side surface of the substantially rectangular lens frame 22.

  FIG. 3 is a perspective view showing a state in which the telescopic member 25 is fixed to the lens frame 22 of the lens driving device 1 according to the first embodiment. In the drawing, the flange portion 22t formed on the lens frame 22 is omitted so that the shape of the elastic member 25 can be seen.

  In the example shown in FIG. 3, an equal thickness elastic member 25 is used.

  FIG. 4 is an enlarged schematic cross-sectional view showing a state where the coil 33 is not energized and a state of the expandable member 25 when energized.

  FIG. 4 shows the state of the telescopic member 25 and the lens frame 22 when the left side of the optical axis O is not energized, and shows the state of the telescopic member 25 and the lens frame 22 when energized to the right side of the optical axis O.

  When the coil 33 is energized, the lens frame 22 moves by F (for example, 0.1 mm) toward the subject side in the optical axis O direction against the elastic force of the telescopic member 25 as shown in the figure by the generated electromagnetic force. The elastic member 25 is elastically deformed as shown. When energization of the coil is stopped, the elastic member 25 is restored to its original state as shown in the figure.

  A specific example of the elastic member 25 of the lens driving device 1 formed as described above will be described.

For example, when the length / width × thickness of one stretchable member 25 is 2 mm × 2 mm × 0.5 mm and the generated electromagnetic force is 0.05 N and the lens frame 22 is desired to be moved 0.1 mm, the stretchable member 25 A material having a Young's modulus of 0.25 N / mm ² may be selected and used. If the generated electromagnetic force is 0.5 N and the lens frame 22 is to be moved by 0.1 mm, a material having a Young's modulus of 2.5 N / mm ² may be selected and used as the material of the elastic member 25.

  As described above, the expansion / contraction member 25 is arranged and the lens frame 22 is supported, so that the impact in the direction perpendicular to the optical axis is brought into contact with the yoke in the thickness direction of the expansion / contraction member 25 and the impact of the expansion / contraction member 25 is applied. It is possible to absorb and absorb the impact in the optical axis direction by the expansion / contraction of the expansion / contraction member 25. Further, the elasticity of the telescopic member 25 in the optical axis direction can be used as the biasing force of the lens frame 22 in the optical axis direction.

  Furthermore, it has a damping effect in which the transitional vibration during the movement of the lens frame 22 is absorbed by the elastic member 25. As a result, it is possible to shorten the time from when the coil is energized until the lens frame 22 is stabilized at a predetermined position.

  That is, the telescopic member 25 of the lens driving device according to the present embodiment provides a high impact resistance to the lens driving device and also functions as a spring having a damping effect related to the operation of the lens frame 22 in the optical axis direction. It is what you have.

  FIG. 5 is a perspective view showing a modification of the elastic member 25 shown in FIG.

  The elastic member shown in FIG. 5 is formed so that the cross section is crank-shaped and the surfaces other than the adhesive portions 25 s and 25 h have minute gaps with the lens frame 22 and the yoke 31. The elastic member 25 is not equal in thickness, and may have such a shape.

  FIG. 6 is a front view of a modified example of the lens driving device 1 according to the first embodiment viewed from the subject side. FIG. 7 is a perspective view showing a state in which the telescopic member 25 is fixed to the lens frame 22 shown in FIG. In the drawing, the flange portion 22t formed on the lens frame 22 is omitted so that the shape of the elastic member 25 can be seen. The cross section of the lens driving device 1 is the same as that in FIG.

  In the lens driving device 1 shown in FIG. 6, the elastic member 25 is formed so as to cover the outer surface of the lens frame 22. 6 and 7 has an adhesive portion 25s fixed to the yoke 31 on the imaging element side, and an unshown adhesive portion 25h fixed to the lens frame 22 on the subject side.

  A specific example of the elastic member 25 of the lens driving device 1 formed in this way will be described.

For example, H × V × T of the lens frame 22 shown in FIG. 7 is 4 mm × 4 mm × 2 mm, the thickness of the expansion / contraction member 25 is 0.5 mm, the generated electromagnetic force is 0.05 N, and the lens frame 22 is set to 0. When it is desired to move 1 mm, a material having a Young's modulus of 0.125 N / mm ² may be selected as the material of the elastic member 25.

  Even with such a shape, the same effect as described above can be obtained.

  FIG. 8 is a perspective view showing a modification of the elastic member 25 shown in FIG. In the drawing, the flange portion 22t formed on the lens frame 22 is omitted so that the shape of the elastic member 25 can be seen.

  In the extendable member 25 shown in FIG. 8, a convex portion 25 s formed on the imaging element side is fixed to the yoke 31, and a convex portion 25 h (not shown) formed on the subject side is fixed to the lens frame 22. Surfaces other than the bonding portions 25s and 25h have minute gaps with the lens frame 22 and the yoke 31. The elastic member 25 is not equal in thickness, and may have such a shape.

(Second Embodiment)
FIG. 9 is a cross-sectional view illustrating a schematic configuration of the lens driving device 1 according to the second embodiment. The lens driving device 1 shown in FIG. 9 will be described only for parts different from those shown in FIG.

  The lens driving device 1 shown in FIG. 9 includes a telescopic member between a surface on the imaging element side of the lens frame 22 and the lower housing 12, and between a surface on the subject side of the lens frame 22 and the upper housing 11, respectively. 25 is arranged so as to support the lens frame 22.

  FIG. 10 is a perspective view showing a state in which the telescopic member 25 is fixed to the lens frame 22 of the lens driving device 1 according to the second embodiment. In the drawing, the flange portion 22t formed on the lens frame 22 is omitted so that the shape of the elastic member 25 can be seen.

  The telescopic member 25 is formed and fixed in a shape having an opening that avoids the light beam passing through the imaging optical system 10 on the imaging element side surface and the subject side surface of the lens frame 22.

  A specific example of the elastic member 25 of the lens driving device 1 formed in this way will be described.

For example, the H × V of the lens frame 22 shown in FIG. 10 is 9 mm × 9 mm, the diameter D of the opening is 6 mm, the thickness of the expansion / contraction member 25 is 0.5 mm, and the generated electromagnetic force is 0.1 N. Assume that 22 is to be moved by 0.1 mm. In addition, when the upper housing 11 and the lower housing 12 are in contact with the entire surface of the elastic member 25, the material of the elastic member 25 may be selected with a Young's modulus of 0.0047 N / mm ^2. .

  Even with such a configuration, the same effect as described above can be obtained.

  FIG. 11 is a perspective view showing a modification of the telescopic member 25 fixed to the lens frame 22 of the lens driving device 1 according to the second embodiment. Also in this figure, the flange 22t formed on the lens frame 22 is omitted so that the shape of the elastic member 25 can be seen.

  The figure shows an example in which the extendable member 25 is disposed only between the subject-side surface of the lens frame 22 and the upper housing 11. The telescopic member 25 may be disposed only between the surface of the lens frame 22 on the image sensor side and the lower housing 12. In this case, the side where the elastic member 25 is not disposed is in contact with the upper or lower casing.

  Even with such a configuration, the same effect as described above can be obtained.

  In the specific examples of the first and second embodiments described above, the Young's modulus of the expansion / contraction member is obtained from the electromagnetic force to be generated, the amount of movement of the lens frame, and the dimension of the expansion / contraction member. The remaining one may be determined from any three of the electromagnetic force to be generated, the amount of movement of the lens frame, the dimension of the elastic member and the Young's modulus.

  Moreover, although the description has been given with the lens frame 22 having a rectangular parallelepiped shape, the present invention is not limited to this, and the elastic members of the first and second embodiments can be applied to a cylindrical shape.

  Hereinafter, an example of a mobile terminal including a camera module in which an imaging element is assembled to the lens driving device of the above embodiment will be described.

  FIG. 12 is an external view of a mobile phone 100 that is an example of a mobile terminal including the camera module 15 according to the present embodiment.

  In the mobile phone 100 shown in the figure, an upper casing 71 as a case having display screens D1 and D2 and a lower casing 72 having an operation button 60 as an input unit are connected via a hinge 73. Yes. The camera module 15 is built below the display screen D <b> 2 in the upper casing 71, and is arranged so that the camera module 15 can capture light from the outer surface side of the upper casing 71.

  The position of the camera module 15 may be disposed above or on the side of the display screen D2 in the upper housing 71. Of course, the mobile phone is not limited to a folding type.

  FIG. 13 is a control block diagram of the mobile phone 100.

  As shown in the figure, the camera module 15 is connected to the control unit 101 of the mobile phone 100 and outputs image signals such as luminance signals and color difference signals to the control unit 101.

  On the other hand, the mobile phone 100 controls each part in an integrated manner, and also executes a control part (CPU) 101 that executes a program corresponding to each process, an operation button 60 that is an input part for inputting a number and the like, Display screens D1 and D2 for displaying predetermined data and captured images, a wireless communication unit 80 for realizing various information communications with an external server, a system program for mobile phone 100, various processing programs, and a terminal A storage unit (ROM) 91 that stores necessary data such as an ID, and various processing programs and data executed by the control unit 101 or processing data, image data by the camera module 15 and the like are temporarily stored. Or a temporary storage unit (RAM) 92 used as a work area.

  In addition, the image signal input from the camera module 15 is stored in the nonvolatile storage unit (flash memory) 93 by the control unit 101 of the mobile phone 100, or displayed on the display screens D1 and D2, The image information is transmitted to the outside via the wireless communication unit 80.

It is sectional drawing which shows schematic structure of the lens drive device which concerns on 1st Embodiment. It is the front view which looked at the lens drive device shown in FIG. 1 from the to-be-photographed object side. It is a perspective view which shows the state by which the expansion-contraction member was fixed to the lens frame of the lens drive device which concerns on 1st Embodiment. It is an expanded sectional schematic diagram which shows the state of the expansion-contraction member when not energizing a coil and energizing. It is a perspective view which shows the modification of the expansion-contraction member shown in FIG. It is the front view which looked at the modification of the lens drive device which concerns on 1st Embodiment from the to-be-photographed object side. It is a perspective view which shows the state by which the expansion-contraction member was fixed to the lens frame shown in FIG. It is a perspective view which shows the modification of the expansion-contraction member shown in FIG. It is sectional drawing which shows schematic structure of the lens drive device which concerns on 2nd Embodiment. It is a perspective view which shows the state by which the expansion-contraction member was fixed to the lens frame of the lens drive device which concerns on 2nd Embodiment. It is a perspective view which shows the modification of the expansion-contraction member fixed to the lens frame of the lens drive device which concerns on 2nd Embodiment. It is an external view of a mobile phone which is an example of a mobile terminal provided with the camera module according to the present embodiment. It is a control block diagram of a mobile phone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens drive device 10 Imaging optical system 11 Upper housing | casing 12 Lower housing | casing 15 Camera module 22 Mirror frame 25 Telescopic member 31 Yoke 32 Magnet 33 Coil 100 Mobile phone O Optical axis

Claims (6)

A lens frame that holds an imaging optical system that guides subject light, and an actuator that moves the lens frame in the optical axis direction of the imaging optical system,
An elastic member made of a material having a Young's modulus of 10 N / mm ² or less is disposed on at least a part of the outer surface of the lens frame, and the lens frame is supported via the elastic member. Lens drive device. The lens driving device according to claim 1, wherein the telescopic member is elastically deformed when the lens frame is moved by the actuator. The lens driving device according to claim 1, wherein the expandable member is disposed on a surface orthogonal to the optical axis of the imaging optical system. The lens driving device according to claim 1, wherein the expandable member is disposed on a surface parallel to the optical axis of the imaging optical system. 5. A camera module comprising: the lens driving device according to claim 1; and an imaging device that photoelectrically converts subject light. A portable terminal comprising the camera module according to claim 5.

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