JP2794424B2 - Lens moving device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens moving device using a cam mechanism, and more particularly, to an optical axis tilt adjusting device for the moving lens barrel.

<Prior Art> Conventionally, an apparatus for adjusting the optical axis tilt of a movable lens barrel in a lens moving apparatus is disclosed in Japanese Utility Model Laid-Open Publication No. Sho 61-4915, in which a moving member driven by a cam is provided with a cam pin. And a lens barrel holding the lens.

The moving body position adjusting device described in Japanese Utility Model Laid-Open Publication No. 52-43430 is configured such that a cam pin can be eccentrically rotated so as to adjust the position of the moving body in the optical axis direction. is there.

<Problems to be Solved by the Invention> However, in the former conventional example, at least two or more members constituting the moving body are required, and the tilting of the optical axis can be adjusted. Since adjustment is not possible, there is a risk that the configuration of the member may be eccentric by the complexity.

In the latter conventional example, it is impossible to adjust the tilt of the optical axis of the moving body with one cam pin, and when there are a plurality of cam pins, when the cam pins are eccentrically rotated, the angle around the optical axis of each cam pin changes. As a result, clogging occurs between the cam ring and the cam groove, so that the cam pin cannot be eccentrically rotated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens moving device which eliminates the above-mentioned drawbacks of the prior art and can easily adjust the tilt of the optical axis of the moving lens barrel.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a guide groove provided in a guide tube, a cam groove provided in a cam tube, and an intersection of the guide groove and the cam groove. In the lens moving device that moves the movable lens barrel by the joint action of the cam pin located in the moving lens barrel, the movable lens barrel is provided with a circumferential groove on the outer periphery,
The cam pin has a first radius and a second radius, the first radius fits into the circumferential groove, and the second radius fits into the guide groove and the cam groove. The cam pins are fitted and eccentric with respect to the first diameter portion, so that the cam pins can be rotated around a central axis of the second diameter.

It is effective that the cam pin has a slot on an end face or a spline shape on an inner diameter portion.

Further, it is preferable that the slit or spline shape provided on the cam pin is aligned so that the eccentric direction of the eccentric portion of the cam pin can be identified.

<Operation> In the lens moving device configured as described above, when the cam pin is rotated, the second diameter portion of the cam pin fitted to the intersection of the cam groove and the guide groove cannot change its position, and cannot move at the fixed position. Rotate. The first radial portion performs an eccentric motion about the second radial portion, but the circumferential motion of the movable lens barrel in which the first radial portion is fitted is absorbed by the circumferential groove. The force is not transmitted, and the force is transmitted only in the direction of the optical axis, which is a direction perpendicular to the circumferential groove. As a result, the movable lens barrel can adjust the tilt of the optical axis.

Further, by providing a slit on the end face of the cam pin or a spline shape on the inner diameter portion, the rotation of the cam pin in the eccentric direction can be surely adjusted.

Further, by using such a slit or a spline shape, the eccentric direction of the cam pin can be easily identified.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the figure, reference numeral 1 denotes a guide cylinder having a guide groove 1a along the optical axis direction. Reference numeral 2 denotes a cam cylinder which is rotatably held on the outer diameter of the guide cylinder 1 and has a cam groove 2a. Reference numeral 3 denotes a movable lens barrel, which supports the lens L, is held movably in the optical axis direction at the inner diameter of the city guide cylinder 1, and has a circumferential groove 3a at the outer diameter. . Reference numeral 4 denotes a cam pin, which is fixed to a circumferential groove 3a of the movable lens barrel 3 with a screw 5,
At the intersection of the guide groove 1a of the fixed cylinder 1 and the cam groove 2a of the cam cylinder 2, they are fitted into both grooves. Further, the cam pin 4 fits without looseness into the guide groove 1a and the cam groove 2a and loosely fits into the circumferential groove 3a, and It has an eccentric second diameter portion 4b, and its end face is an arrow A in FIG. 5 (a) which is an eccentric direction of the second diameter portion 4b.
A slot 4c is formed so as to match the direction and is also a mark at the time of eccentricity adjustment, and a hole 4d for screwing is provided on the inner diameter side concentrically with the first diameter portion 4a. .

In this embodiment having the above-described configuration, when the cam barrel 2 is rotated about the optical axis, the cam pin 4 located at the intersection of the cam groove 2a and the guide groove 1a of the fixed barrel 1 moves in the optical axis direction. The lens barrel 3 moves in the optical axis direction.

Therefore, when adjusting the tilt of the optical axis of the movable lens barrel 3, the second diameter portion 4b of the cam pin 4 is fitted into the guide groove 1a and the cam groove 2a without play as shown in FIG. When the cam pin 4 is rotated using the slit 4c, the cam pin 4 rotates about the center axis of the second diameter portion 4b. At this time, the first diameter portion 4a eccentric with respect to the second diameter portion 4b rotates eccentrically about the second diameter portion 44b, but the first diameter portion 4a fits into the movable lens barrel 3. The portion that is formed is the circumferential groove 3a, so that the cam pin 4 can freely rotate in the circumferential direction. Since the first radial portion 4a of the cam pin 4 is fitted into the circumferential groove 3a of the movable lens barrel 3 without play, when the first radial portion 4a of the cam pin 4 makes an eccentric movement, the circumferential direction is reduced. The force is transmitted only in the optical axis direction perpendicular to the groove 3a, and the movable lens barrel 3 can be moved and adjusted in the optical axis direction.

FIG. 6 shows a cam pin according to another embodiment of the present invention.

The cam pin 14 in this embodiment has a first diameter portion 14a and a second diameter 14b eccentric with respect to the first diameter portion 14a. The shape portion 14c is a means for adjusting the rotation of the cam pin 14, and has a special spline shape in order to identify the eccentric direction so as to match the phase with the eccentric direction of the second radial portion 14b. Other configurations and operations are exactly the same as those of the above-described embodiment.

FIG. 7 shows still another embodiment of the present invention, particularly showing a movable lens barrel.

The movable lens barrel 13 in the present embodiment is provided with a plurality of circumferential grooves 13a at intervals in the circumferential direction.
Other configurations and operations are exactly the same as those of the embodiment shown in FIGS. 1 to 5.

Such a movable lens barrel 13 is effective when manufactured by molding a plastic material or the like.

<Effects of the Invention> As described above, the present invention provides the cooperative action of the guide groove provided in the guide cylinder, the cam groove provided in the cam cylinder, and the cam pin located at the intersection of the guide groove and the cam groove. In the lens moving device for moving the movable lens barrel by the above, the movable lens barrel is provided with a circumferential groove on the outer periphery, the cam pin has a first diameter part and a second diameter part, One diameter part is fitted in the circumferential groove, the second diameter part is fitted in the guide groove and the cam groove and is eccentric with respect to the first diameter part, and the second diameter part is eccentric to the second diameter part. By being able to rotate the cam pin around the center axis of the diameter portion, the tilt of the optical axis can be easily adjusted without rotating the movable lens barrel,
Further, since it is not necessary to add a new part only by changing the shape of the part itself, it can be manufactured at low cost.

Furthermore, when used in a lens moving device that does not perform optical axis tilt adjustment, there are errors in the angle of manufacture of the plurality of cam grooves and guide grooves and the angle errors in the mounting screw holes for mounting the cam pins of the moving lens barrel. This is extremely effective in reducing the component accuracy and the assembly time, which have conventionally been problems when adjusting the lens moving device of this type.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a lens moving device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, FIG. 3 is a transverse sectional view of a cam pin portion thereof, and FIG. FIG. 5 is a top view, FIG. 5B is a longitudinal sectional view, and FIG. 6 is a vertical sectional view of the cam pin of the lens moving device according to another embodiment of the present invention. FIG. 7 is a perspective view of a moving lens barrel of a lens moving device according to still another embodiment of the present invention. 1 ... guide tube, 1a ... guide groove, 2 cam tube, 2a ... cam groove, 3, 13 ... moving lens barrel, 3a, 13a ... circumferential groove,
4,14 ... Cam pin, 4a, 14a ... First diameter part, 4b, 14b ...
2nd diameter part, 4c ... slot, 14c ... spline-shaped part, 5 ... screw, L ... lens.

Claims (4)

(57) [Claims] A movable lens barrel is moved by the cooperative action of a guide groove provided in a guide tube, a cam groove provided in a cam tube, and a cam pin located at an intersection of the guide groove and the cam groove. In the lens moving device, the moving lens barrel is provided with a circumferential groove on an outer periphery, the cam pin has a first radial portion and a second radial portion, and the first radial portion is in the circumferential direction. The second diameter part is fitted in the guide groove and the cam groove and is eccentric with respect to the first diameter part, and the cam pin is formed around a center axis of the second diameter part. A lens moving device capable of rotating a lens. 2. The lens moving device according to claim 1, wherein said cam pin has a slit on an end face thereof. 3. The lens moving device according to claim 1, wherein said cam pin has a spline shape at an inner diameter portion thereof. 4. The lens moving device according to claim 2, wherein the shape of the slit or spline provided on the cam pin is adjusted so that the eccentric direction of the cam pin can be identified.