JP4181779B2 - Lens drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens driving device and an optical apparatus using the lens driving device.
[0002]
[Prior art]
Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 8-240758, a lens driving device uses a moving ring held by two guide bars as a feed screw by screwing a motor and an output shaft from the motor. The rack member meshes with the feed screw and an elastic member that biases the rack member in the thrust direction.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional lens driving device, in order to move the moving ring smoothly and with high accuracy, the feed screw requires high surface accuracy and is an expensive part, which is an expensive lens driving device. .
[0004]
In addition, the configuration of the feed screw and the rack member has a problem that it is weak against static pressure and impact on the moving ring.
[0005]
[Means for Solving the Problems]
In the lens driving device of the present invention is therefore, a lens holding member for holding a plurality of lenses, a cam member for moving the front Symbol lens holding member in the optical axis direction, a base member that rotatably supports the cam member, wherein a driving means for rotating the cam member, a first biasing member biasing previous SL toward said base member cam contact portion elastically in the optical axis direction of the lens holding member to the cam member, A second urging member provided on a substantially symmetric side across the cam contact portion and the lens holding member and elastically urging the cam member toward the base member;
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1, 2, and 3 are cross-sectional views of the lens driving device according to the present embodiment. Reference numerals 1 and 2 are photographing lenses, 3 is a lens holding member that holds the photographing lenses 1 and 2, and 4 is not shown. A diaphragm drive unit that can be switched to a plurality of aperture diameters and a shutter drive unit that drives an aperture diameter (not shown) to be opened and closed, and can be incorporated in a direction perpendicular to the optical axis of the lens holding member, 5 Is a cam member having a cam portion 5a for moving the lens holding member 3 in the optical axis direction, 6 is a base member (first guide component) for rotatably holding the cam member 5, and 7 is a base member 6. A cover member (second guide constituent member) 8 positioned and attached to the lens, 8 is a lens holding member configured to be engaged with the arm portions 3a and 3b of the lens holding member 3 and held by the base member 6 and the cover member 7. Light of 3 Direction guide member (third guide component), 9 is an elastic member for urging the cam contact portion 3c of the lens holding member 3 to the cam portion 5a of the cam member 5, and 10 is the cam contact portion 3c. An elastic member for biasing the cam member 5 toward the base member 6 at a substantially symmetrical position, 11 is a motor attached to the cover member 7, 12 is a pinion gear press-fitted and fixed to the output shaft of the motor 11, and 13 is a cover member 7 is a photo interrupter (PI) attached to 7, 14 is a gear member incorporated in the base member 6, 15 is a CCD, 16 is a CCD holding member attached to the base member 6, and 17 is a CCD holding member attached to the base member 6. Shield members positioned between them, 18 and 19 are finder lenses incorporated in the cover member 7, and 20 is a finder cover member. It is.
[0010]
In the configuration as described above, the output from the motor 11 is transmitted to the pinion gear 12, the gear member 14, and the gear portion 5b of the cam member 5, and when the cam member 5 is rotated, the lens holding member 3 is guided. The lens holding member 3 is guided in the optical axis direction by two guide portions of the member 8 and the arm portions 3a and 3b and the guide portion 6a formed integrally with the base member 6 and the arm portion 3d of the lens holding member 3. Driven in the direction of the optical axis.
[0011]
Further, since the convex portion 5c of the cam member 5 passes through the PI 13, it is possible to detect a predetermined position in the rotation direction of the cam member 5 and detect a predetermined position in the optical axis direction of the photographing lenses 1 and 2.
[0012]
When the cam member 5 is rotated, the cam member 5 is biased to the base member 6 by the elastic member 9 at the position of the cam contact portion 3c and by the elastic member 10 at a position substantially symmetrical to the position of 3c. Therefore, it is possible to drive the lens with high accuracy regardless of the posture of the camera. Further, since the projection 7a formed integrally with the cover member 7 is set so that the play in the optical axis direction is minimized, even when static pressure or impact is applied to the lens holding member 3, It is possible to take power.
[0013]
Further, since the driving of the lens in the optical axis direction is performed by the cam member 5 which is easy to manufacture and inexpensive, a lens driving device having an inexpensive configuration can be obtained.
[0014]
Furthermore, since the motor 11, the PI 13, and the viewfinder lenses 18 and 19 are configured to be attached to the cover member 7, the number of parts can be reduced and the size can be reduced.
[0015]
【The invention's effect】
As described above, in the present invention, the cam member 5 is elastically biased in the optical axis direction on the substantially symmetrical side of the abutting portion 5c of the lens holding member 3 and the cam member 5, and the convex portion of the cover member 7 is provided. By restricting the amount of movement in the optical axis direction by 7a, it is possible to obtain a highly accurate lens driving device that is resistant to static pressure and impact and that has an inexpensive component configuration.
[0016]
Further, since the motor 11, the PI 13, and the finder lenses 18 and 19 are configured to be attached to the cover member 7, the number of parts can be reduced and the size can be reduced.
[Brief description of the drawings]
FIG. 1 is a transverse central sectional view showing a first embodiment of the present invention.
FIG. 2 is a longitudinal center sectional view showing a first embodiment of the present invention.
FIG. 3 is a cross-sectional view of a driving unit representing a first embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Shooting lens 3 Lens holding member 4 Aperture / shutter unit 5 Cam member 6 Base member 7 Cover member 8 Guide member 9 Elastic member 10 Elastic member 11 Motor 12 Pinion gear 13 photo interrupter
14 Gear member 15 CCD
16 CCD holding member 17 Shield members 18, 19 Viewfinder lens 20 Viewfinder cover member

Claims (1)

A lens holding member for holding a plurality of lenses, a cam member for moving the front Symbol lens holding member in the optical axis direction, a base member that rotatably supports the cam member, a driving means for rotating said cam member Prepared,
A first urging member for urging the base member cam contact portion elastically optical axis direction of the lens holding member before Symbol cam member,
A lens drive comprising: a second urging member that is provided on a substantially symmetrical side across the cam contact portion and the lens holding member and elastically urges the cam member to the base member. apparatus.

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