JP2006209032A - Lens drive device, solid-state imaging apparatus having same and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive device capable of preventing lens displacement and to provide a solid-state imaging apparatus having the lens drive device. <P>SOLUTION: The lens drive device includes: lenses (9a, 9b and 9c); guide shafts (7a, and 7b) extending parallel to the optical axis of the lenses; a lens holder (6) holding the lenses and disposed so as to be freely slidable along the guide shafts; a ring cam member (10) abutting on the lens holder; cam faces (10a, 10b, and 10c) formed on the upper face of the cam member; a lens moving means for moving the lens holder in the direction of the optical axis in accordance with a change in the position of the cam member; and an elastic member (11) for pressing the lens holder to the guide shafts and the cam member at an angle in the direction of the optical axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens driving device capable of preventing a lens position shift, a solid-state imaging device including the same, and an electronic apparatus.

In general, a lens driving device for moving a lens to a desired position is incorporated in a solid-state imaging device such as a camera. Patent Document 1 discloses a solid-state imaging device in which such a lens driving device is incorporated. FIG. 6 is a diagram showing a configuration of the lens driving device 50 disclosed in Patent Document 1. As shown in FIG. The lens driving device 50 includes a lens 51, a moving frame 52 that holds and moves the lens 51, a cam member 53 that engages with the moving frame 52, a motor 54 that rotates the cam member 53, and the moving frame 52. A guide shaft portion 55 that extends in the axial direction and a spring 56 that urges the moving frame 52 in the optical axis direction are provided. The moving frame is advanced and retracted in the optical axis direction according to the rotation of the cam member 53.
JP-A-6-273656

  Here, in the lens driving device 50 of Patent Document 1, a predetermined space (so-called play) is secured between the guide shaft portion 55 and the moving frame 52 in order to move the moving frame 52 smoothly. In addition, this space may be larger than the design value due to a dimensional tolerance or the like generated in the machining process. Such a space acts as a backlash when the lens is moved during photographing, which causes the lens position to shift. If the lens position shifts during shooting, a problem that the captured image becomes unclear occurs.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens driving device that can move a lens while suppressing displacement of the lens, and a solid-state imaging device and an electronic apparatus including the lens driving device.

  In order to achieve the above object, the invention according to claim 1 is directed to a lens, a guide shaft extending parallel to an optical axis direction of the lens, and holding the lens and sliding with respect to the guide shaft. A lens holder that is freely arranged, a ring-shaped cam member that abuts on the lens holder, a cam surface formed on the upper surface of the cam member, and the lens holder according to a change in position of the cam member. A lens driving device comprising: a lens moving unit that moves the lens holder in a direction; and an elastic member that biases the lens holder toward the cam member in a direction inclined with respect to the optical axis direction.

  With such a configuration, an elastic member that urges the lens holder in a direction inclined with respect to the guide shaft is provided, so that the lens holder is pressed against the guide shaft when the lens is moved in the optical axis direction. Is done. Therefore, even if there is a space between the guide shaft and the lens holder, it is possible to prevent displacement. Further, since the elastic member urges the lens holder toward the cam member, the lens holder is reliably pressed by the cam member, and the lens holder can be reliably driven in the optical axis direction.

  According to a second aspect of the present invention, in the lens driving device according to the first aspect, the inclined direction is a direction sandwiched between the optical axis direction and a normal direction of the cam surface. is there.

With such a configuration, it is possible to prevent the lens holder from being inclined due to the pressure from the lens holder against the guide shaft being too strong, and the lens holder can be slid more smoothly. Thereby, the inclination of an optical axis can also be prevented.
The invention according to claim 3 is the lens driving device according to claim 1, wherein the inclined direction is a direction in which the cam surface is lowered with respect to the optical axis direction. With this configuration, the positional deviation between the guide shaft and the lens holder can be prevented more reliably.

  According to a fourth aspect of the present invention, the cam surface includes a plurality of surfaces having the same inclination angle and the same height with respect to a surface perpendicular to the optical axis direction in the circumferential direction. 4. The lens driving device according to claim 1, wherein the lens holder is provided with a collar portion that abuts on each of the plurality of surfaces. 5. With such a configuration, the lens holder can be prevented from being tilted by the biasing force of the elastic member.

  The invention as set forth in claim 5 is the lens driving device according to claims 1 to 4, wherein the elastic member is provided in the same number as the number of the guide shafts. With this configuration, the positional deviation between the guide shaft and the lens holder can be prevented more reliably.

A sixth aspect of the present invention is a solid-state imaging device including the lens driving device according to any one of the first to fifth aspects. Thereby, the position shift of a lens holder can be prevented and the solid-state imaging device which can prevent the shift | offset | difference of an optical axis is realizable.
A seventh aspect of the invention is an electronic apparatus comprising the solid-state imaging device according to the sixth aspect. Thereby, the position shift of a lens holder can be prevented and the electronic device which can prevent the shift | offset | difference of an optical axis is realizable.

  According to the present invention, it is possible to realize a lens driving device capable of preventing a lens position shift, a solid-state imaging device and an electronic apparatus including the lens driving device.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view of the solid-state imaging device 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 4 is a cross-sectional view taken along line BB in FIG.

  The solid-state imaging device 1 includes a substrate, an imaging element (both not shown), a base plate 2, an optical filter 3, and a lens driving device. The image sensor is mounted on a substrate. The base plate 2 is formed on the substrate so as to surround the imaging device. The optical filter 3 is held so as to close the opening of the base plate 2 so as to face the imaging element. The lens driving device is mounted on the base plate 2. For example, a CCD sensor or a COMS sensor is used as the image sensor.

  The base plate 2 is integrally formed with a locking portion 4b and a pair of guide shafts 7a and 7b. The locking part 4 b locks one end of the elastic member 11. The base plate 2 is formed of a resin such as plastic. The guide shafts 7a and 7b slide the lens holder 6 in the direction of the optical axis of the lens.

  The lens driving device includes a lens module, a cam member 10, a motor (not shown), and two elastic members 11. Here, the lens module includes a plurality of lenses 9a to 9c and a lens holder 6 that holds each lens. The lens holder 6 has a cylindrical shape. The cam member 10 includes a cam surface 10 that engages with the lens holder 6. The cam surface 10 includes a first cam surface 10a, a second cam surface 10b, and a third cam surface 10c. Each cam surface has the same inclination angle and the same height with respect to a surface perpendicular to the optical axis direction of the lens, and is arranged in the circumferential direction. Further, the cam member 10 is provided with a gear portion on the outer peripheral side surface. The motor is integrally provided with a gear that meshes with the gear portion of the cam member 10. Therefore, the cam member 10 rotates by driving the motor.

  Here, the lens holder 6 is formed with a first protrusion 14a and a second protrusion 14b. The first protrusion 14a has a through hole that protrudes in the radial direction on the outer peripheral surface of the lens holder 6 and engages with the first guide shaft 7a, and includes a first collar portion 13a that contacts the cam surface. . Further, the second projecting portion 14b is formed with a sandwiching portion 16 that projects in the radial direction of the outer peripheral surface and sandwiches the second guide shaft 7b. Further, the lens holder 6 includes a second collar portion 13b and a third collar portion 13c that protrude in the radial direction at the other two locations on the outer peripheral surface and abut against the cam surface. The first collar portion 13a abuts on the first cam surface 10a of the cam member 10, the second collar portion 13b abuts on the second cam surface 10b, and the third collar portion 13c abuts on the third cam surface 10c. Accordingly, when the cam member 10 rotates, the flange portions 13a to 13c that contact the cam surfaces 10a to 10c move in the optical axis direction. Therefore, the lens holder 6 slides in the optical axis direction along the guide shafts 7a and 7b.

  Here, one end of the elastic member 11 is locked to the locking portion 4 b of the base plate 2, and the other end is locked to the locking portion 4 a of the lens holder 6. As shown in FIG. 2, the elastic member 11 is disposed in an inclined state with respect to the optical axis direction. In this way, by arranging the elastic member 11 so as to be inclined with respect to the optical axis direction, when the lenses 9a to 9c are moved in the optical axis direction, the urging force of the elastic member 11 is moved stably. Can be used efficiently. When the elastic member 11 is tilted with respect to the optical axis direction, the biasing force based on the elastic member 11 is changed to a force (first component force) acting in a direction parallel to the optical axis direction and a direction perpendicular to the optical axis direction. It can be used by dividing it into acting force (second component force). The first component force acting in a direction parallel to the optical axis direction acts as a force that urges (presses) the flange portions 13a to 13c provided on the lens holder 6 toward the cam surfaces 10a to 10c. . Therefore, the lens holder can be reliably moved to a predetermined position according to the rotation of the cam member 10. That is, the lens can be accurately moved to a predetermined position.

  The second component force acting in the direction perpendicular to the optical axis direction is biased (pressed) so as to press the through hole of the first protrusion 14a provided in the lens holder 6 against a part of the guide shaft 7a. Then, it acts as a force for urging (pressing) the pressing portion 16 of the second protrusion 14b to be pressed against a part of the guide shaft 7b. Here, in order to slide the lens holder 6 along the guide shafts 7a and 7b, a certain amount of space needs to be secured around the guide shafts 7a and 7b. This space causes a lens position shift when the lens moves. However, in this embodiment, the second component force acts so as to press the first protrusion 14a and the second protrusion 14b against the guide shafts 7a and 7b, so the through hole of the first protrusion 14a and the guide shaft 7a. Can always be brought into contact with each other, and the holding portion 16 of the second protrusion 14b and the guide shaft 7b can always be brought into contact with each other. As a result, the lens holder 6 can move smoothly without rattling in the optical axis direction. Accordingly, the lens can be moved to a desired position in the optical axis direction while preventing the lens from being displaced. If the inclination angle of the elastic member 11 is too large, the second component force becomes too large. Thereby, the lens holder may be inclined with respect to the optical axis.

  Here, the inclination of the elastic member 11 will be described with reference to FIG. FIG. 3 is a schematic diagram of the first cam surface 10a of the cam member 10 and the first collar portion 13a of the lens holder 6 that contacts the first cam surface 10a. In FIG. 3, 1A indicates the optical axis direction, and 1B indicates the normal direction with respect to the cam surface 10a. 1C is obtained by taking the same angle as the angle between the optical axis direction 1A and the normal direction 1B in the direction of ascending the first cam surface 10a from the normal direction 1B. Accordingly, the angle between the optical axis direction 1A and the normal direction 1B and the angle between the normal direction 1B and the direction 1C are the same.

  The inclination of the elastic member 11 of the solid-state imaging device 1 according to the present embodiment is between the normal direction 1B and the direction 1C shown in FIG. The urging force of the elastic member 11 includes a component force acting on the first cam surface 10a in the normal direction (component force of 1a) and a component force acting in a direction parallel to the first cam surface 10a (component force of 2a). ) And can be divided. Here, the magnitude of the urging force of the elastic member 11 is related to the elongation of the elastic member 11. Specifically, the urging force increases as the elongation of the elastic member 11 increases. Here, the case where the elastic member 11 is inclined between the normal direction 1B and the direction 1C is more elastic than the case where the elastic member 11 is inclined between the optical axis direction 1A and the normal direction 1B shown in FIG. The elongation of the member 11 is increased. Therefore, the elastic member 11 is inclined more in the direction between the normal direction 1B and the direction 1C than in the case where the elastic member 11 is inclined between the optical axis direction 1A and the normal direction 1B shown in FIG. The urging force of 11 is increased. As a result, the component force of 1a acting in the normal direction with respect to the 1st cam surface 10a becomes large. Accordingly, the first collar portion 13a of the lens holder 6 can be firmly in contact with the first cam surface 10a.

  As described above, the cam member 10 has a ring shape and rotates in conjunction with the operation of the motor. A first cam surface 10a, a second cam surface 10b, and a third cam surface 10c having different heights in the circumferential direction are provided at three locations on the upper surface of the cam surface. The three cam surfaces are in contact with the first collar portion 13a, the second collar portion 13b, and the third collar portion 13c of the lens holder 6, respectively. Therefore, the lens holder 6 can be more stably brought into contact with the cam member 10. Therefore, even when the biasing force of the elastic member 11 is too large, the lens holder can be prevented from tilting.

  Further, as shown in FIG. 1, two elastic members 11 are provided corresponding to the two guide shafts 7a and 7b. Therefore, rattling between the through hole of the lens holder 6 and the first guide shaft 7a can be prevented, and rattling between the clamping portion 16 of the lens holder 6 and the second guide shaft 7b can be prevented.

  In addition, the other structure of the solid-state imaging device 1 which concerns on a present Example is demonstrated using FIG. 4 is a cross-sectional view taken along line BB in FIG. A cylindrical portion 5 is formed on the base plate 2. The cylindrical portion 5 protrudes in the optical axis direction and comes into contact with the inner surface of the cam member 10. The lens holder 6 has a cylindrical shape, and a concave portion for applying an adhesive 12a for fixing the lens cap 12 is formed on an end surface on the subject side (upper side in FIG. 4). In the lens holder 6, a first lens 9a, a second lens 9b, a third lens 9c, a light blocking member 8, and a spacer 15 are inserted. The lens on the subject side is the first lens 9a. The lens on the image sensor side (lower side in FIG. 4) is the third lens 9c, and the lens in the middle of the first lens 9a and the third lens 9c is the second lens 9b. The spacer 15 is sandwiched between the first lens 9a and the second lens 9b. The light shielding member 8 is sandwiched between the second lens 9b and the third lens 9c. The 3rd lens 9c and the element side end surface of the lens holder 6 are adhere | attached with the adhesive agent 12b. The spacer 15 and the light shielding member 8 are ring-shaped. A lens cap 12 is adhered to the subject side of the lens holder 6 so as to cover the first lens 9a.

  Next, a solid-state imaging device of Example 2 will be described. The difference between the solid-state imaging device of the second embodiment and the solid-state imaging device 1 of the first embodiment is the inclination angle of the elastic member 11. Other configurations are the same.

  Here, the inclination of the elastic member 11 of the solid-state imaging device according to the second embodiment will be described with reference to FIG. The inclination of the elastic member 11 of the solid-state imaging device according to the second embodiment is installed between the vertical direction 1A and the normal direction 1B shown in FIG. Here, it compares with the case where the inclination direction of the elastic member 11 exists between the normal line direction 1B and the direction 1C. As described above, when the inclination direction of the elastic member 11 is between the normal direction 1B and the direction 1C, the first component force of the urging force of the elastic member 11 is perpendicular to the inclination direction of the elastic member 11. It is larger than the first component force when it is between the direction 1A and the normal direction 1B. Accordingly, when the inclination direction of the elastic member 11 is between the normal direction 1B and the direction 1C, the guide shaft is inclined more than when the inclination of the elastic member 11 is between the vertical direction 1A and the normal direction 1B. The urging force for 7a and 7b is large. Here, if the biasing force against the guide shafts 7a and 7b is too large, the guide shafts 7a and 7b may slide while the lens holder 6 is tilted. However, when the inclination direction of the elastic member 11 is set between the vertical direction 1A and the normal direction 1B as in the solid-state imaging device of the second embodiment, the normal direction 1B is in the direction 1C. Compared with a certain case, the biasing force with respect to the guide shafts 7a and 7b is small. Therefore, it is possible to prevent the tilt of the lens holder 6 that occurs when the urging force against the guide shafts 7a and 7b is too large. Therefore, the solid-state imaging device according to the second embodiment can prevent the lens holder 6 from being tilted.

  Next, a solid-state imaging device according to Embodiment 3 will be described. The difference between the solid-state imaging device of the third embodiment and the solid-state imaging device 1 of the first embodiment is the inclination angle of the elastic member 11. Other configurations are the same.

  The inclination of the elastic member 11 of the solid-state imaging device according to the third embodiment will be described with reference to FIGS. 5 is a cross-sectional view taken along the line AA in FIG. The inclination direction of the elastic member 11 of the present embodiment is set in the direction 1D (left direction in FIG. 3) in which the first cam surface 10a is lower than the vertical direction 1A. If it does in this way, with the component force (2nd component force) which acts in the direction parallel to the 1st cam surface 10a of the urging | biasing force of the elastic member 11, the 1st collar part 13a will be in the direction which descends the 1st cam surface 10a. Since it is biased (pressed), the through hole of the lens holder 6 and the first guide shaft 7a, and the clamping portion 16 and the second of the lens holder 6 are compared with the case of biasing in the upward direction (right direction in FIG. 3). The guide shaft 7b can be contacted more reliably. Therefore, rattling between the through hole of the lens holder 6 and the first guide shaft 7a and rattling between the clamping portion 16 of the lens holder 6 and the second guide shaft 7b can be prevented more reliably.

  Note that the present invention is not limited to the above-described embodiments, and those skilled in the art can implement the present invention in various modes within the scope of the gist of the invention described in the claims. The lens driving device and the solid-state imaging device of the present invention can be used by being mounted on an electronic device such as a mobile phone.

1 is a front view of a solid-state imaging device 1 according to an embodiment. It is AA sectional drawing of FIG. FIG. 3 is a schematic diagram of a first cam surface 10a of the cam member 10 and a first collar portion 13a of the lens holder 6 that contacts the first cam surface 10a. It is BB sectional drawing of FIG. It is AA sectional drawing of the solid-state imaging device 1 which concerns on the other Example of this invention. It is a figure which shows the structure of the conventional lens drive device 50. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state imaging device 2 Base plate 3 Optical filter 4a, 4b System stop part 5 Cylindrical part 6 Lens holder 7a 1st guide shaft 7b 2nd guide shaft 8 Light-shielding member 9a 1st lens 9b 2nd lens 9c 3rd lens 10 Cam member 10a 1st cam surface 10b 2nd cam surface 10c 3rd cam surface 11 Elastic member 12 Lens cap 12a, 12b Adhesive agent 13a 1st collar part 13b 2nd collar part 13c 3rd collar part 14a 1st projection part 14b 2nd projection Part 15 spacer 16 clamping part

Claims (7)

A lens,
A guide shaft extending parallel to the optical axis direction of the lens;
A lens holder that holds the lens and is slidably disposed with respect to the guide shaft;
A ring-shaped cam member that contacts the lens holder;
A cam surface formed on the upper surface of the cam member;
Lens moving means for moving the lens holder in the optical axis direction in accordance with a change in position of the cam member;
A lens driving device comprising: an elastic member that urges the lens holder toward a direction inclined with respect to the optical axis direction and toward the cam member. 2. The lens driving device according to claim 1, wherein the inclined direction is a direction sandwiched between the optical axis direction and a normal direction of the cam surface. The lens driving device according to claim 1, wherein the inclined direction is a direction in which the cam surface is lower than the optical axis direction. The cam surface is arranged in the circumferential direction with a plurality of surfaces having the same inclination angle and the same height with respect to a surface perpendicular to the optical axis direction,
4. The lens driving device according to claim 1, wherein the lens holder is provided with a flange portion that comes into contact with each of the plurality of surfaces. 5. 5. The lens driving device according to claim 1, wherein the number of the elastic members is the same as the number of the guide shafts. A solid-state imaging device comprising the lens driving device according to claim 1. An electronic apparatus comprising the solid-state imaging device according to claim 6.

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