JP2000047290A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device capable of stably moving a lens in an optical axial direction, without shaking a finder image. SOLUTION: The optical device is provided with first and second lenses 16 and 18, first and second rotation stopping parts 30 and 32 provided in the first and second lenses 16 and 18 respectively and a rotation stopping groove 34 which is engaged with the first and second rotation stopping parts 30 and 32, to guide the first and second lenses 16 and 18 in their axial directions in a state of detent and constituted so that the first and second detents 30 and 32 are engaged with the rotation stopping groove 34 under the condition where biasing forces in opposite directions are imparted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device for changing the field of view of a finder of a camera with a zoom lens, for example.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, an optical device of this kind moves a first lens 1 and a second lens 2 relative to each other in an optical axis direction A so that a field of view of a viewfinder can be obtained. It is possible to change the magnification. The first lens 1 and the second lens 2 are provided with detent portions 3 and 4 for preventing them from rotating around the guide member 6, respectively. , 4 are engaged with the grooves 5 for stopping rotation. Then, the first lens 1 and the second lens 2 are relatively moved in the optical axis direction A as the rotation preventing portions 3 and 4 slide in the optical axis direction A with respect to the rotation stopping groove 5, The viewfinder magnification can be changed.

[0003]

By the way, the dimension a of the rotation stopping groove 5 in the direction perpendicular to the optical axis direction A is set so that the rotation stopping portions 5 and 4 can smoothly slide with the rotation stopping portions 3 and 4. The stop portions 3 and 4 are slightly larger than the dimension b in the same direction.
However, due to the dimensional allowance, there is a problem that the detents 3 and 4 are loosened (tilted) when sliding with respect to the groove 34, and the finder image is shaken.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical device capable of stably moving a lens along the optical axis direction without causing a finder image to fluctuate. Is to provide.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an optical apparatus for performing a zooming operation by moving a plurality of optical elements in the direction of the optical axis thereof.
Optical element and second optical element, and a bar-shaped member arranged in parallel with the optical axis direction of the first and second optical elements, for guiding the first and second optical elements in the optical axis direction. And a support member formed integrally with the first and second optical elements and having a plurality of spaced apart sliding portions sliding on the guide member, and the first and second optical elements. A first detent part and a second detent part disposed parallel to the optical axis direction of the element and provided on the first and second optical elements, respectively, and the first and second detent parts And a rotation stopper that guides the first and second optical elements in the direction of the optical axis in a detented state.
The second detent portion is engaged with the detent portion in a state where biasing forces in opposite directions are applied to the detent portion.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an example in which the optical device of the present embodiment is applied to a camera with a zoom lens having a finder having an optical axis different from the optical axis of a photographing lens (not shown).

As shown in FIG. 1, in a camera with a zoom lens, an optical device according to the present embodiment includes an optical system having a plurality of (two as an example in the present embodiment) A rod-shaped guide member 12 (for example, for guiding each optical element along the optical axis direction A of the optical system and performing a predetermined zooming operation (telescopic operation, wide operation))
Rod etc.).

The guide member 12 extends along the optical axis direction A of the optical system, and both ends thereof are supported by support frames 14a and 14b provided on both sides of the optical device main body. The support frames 14a and 14b extend from the optical device main body so as to face each other along a direction crossing the guide member 12.

In the present embodiment, as the two optical elements, for example, first and second rectangular lenses 16 and 18 which are cut so as to have four sides are applied. The first lens 16 is formed integrally with the first support member 20, and the first support member 20 includes a plurality of sliding portions 22 a and 2 slidably formed on the guide member 12.
2b. In the present embodiment, as an example, the first support member 20 includes the first and second sliding portions 2.
2a and 22b are provided, and the first and second sliding portions 22a and 22b are separated from each other via a connecting portion 24 extending a predetermined length along the optical axis direction A. Are connected by

The second lens 18 includes a second support member 26
The second support member 26 includes a sliding portion 28 configured to be slidable on the guide member 12. In the present embodiment, as an example, one sliding portion 28 is provided on the second support member 26,
The sliding portion 28 is provided on the first and second support members 20.
Are disposed between the sliding portions 22a and 22b.

The optical device according to the present embodiment has a first
A rotation preventing mechanism is provided for preventing the second and second lenses 16 and 18 and the first and second support members 20 and 26 from rotating around the guide member 12.

The anti-rotation mechanism includes a first lens 1 and a second lens 1.
6, 18 or the first and second support members 20, 26, and the first and second lenses 16, 18 or the first lens 16 and 18 And a rotation stopper that guides the second support members 20 and 26 in the optical axis direction A in a detented state. In the present embodiment, as an example, the first and second lenses 16 and 18 are provided with first and second detent portions 30 and 32, respectively, and the first and second detent portions 3 are provided.
0 and 32 each have a convex shape. Further, as an example of the rotation stopping portion, as an example, the rotation stopping groove 34 having a size that can be engaged with the first and second rotation stopping portions 30 and 32 and extending along the optical axis direction A. Has been applied.

The first and second detent portions 30, 3
2. The anti-rotation groove 34 is shown enlarged in the drawing so as to clarify its configuration, but the size is appropriately reduced and applied in accordance with the shape and size of the camera and the viewfinder. It goes without saying that it can be done.

The optical device according to the present embodiment has a first
And a moving mechanism for relatively moving the second lenses 16 and 18 along the optical axis direction A. The moving mechanism includes a cam shaft 36 disposed along the optical axis direction A in parallel with the guide member 12 and rotatably supported by the support frames 14a and 14b of the optical device main body, and a cam fixed to the cam shaft 36. The cam body 38 has first and second cams 38 provided on both sides thereof with inclined surfaces that change in the axial direction.
Cam surfaces 38a and 38b are formed. The first
And the second cam surfaces 38a and 38b are linear.
But it is non-linear.

The cam shaft 36 is configured to be driven to rotate in conjunction with a zooming operation of a photographic lens (not shown). By driving the cam shaft 36 to rotate, the cam shaft 36 is integrally formed with the cam shaft 36. The body 38 can be arbitrarily rotated in a predetermined direction by a predetermined amount.

As a structure of the moving mechanism, the first supporting member 20 is provided with a first moving member 40 which can slide on the first cam surface 38a. The member 26 is provided with a second moving member 42 that can slide on the second cam surface 38b. Then, the first moving member 40 is connected to the first sliding portion 22 a of the first support member 20.
The second moving member 42 extends from the sliding portion 28 of the second support member 26 toward the second cam surface 38b. I have.

Further, as a structure of the moving mechanism, the first moving member 40 is always slid with the first cam surface 38a at a predetermined pressure, and at the same time, the second moving member 42 is moved to the second cam surface. A biasing spring 52 for always slidingly contacting a predetermined pressure with the pressure 38b
(Coil spring) is provided.

The optical device according to the present embodiment has a first
And the first and second lenses 16, 18 and the first and second support members 20, 2 without rattling of the first and second lenses 16, 18 and the first and second support members 20, 26.
A play removing mechanism for stably moving (sliding) the guide member 6 in the optical axis direction A along the guide member 12 is provided.

At the upper right portion of the side surface B of the first sliding portion 22a and the lower left portion of the side surface C of the sliding portion 28, substantially L-shaped projections 50 and 51 are provided, respectively. And projection 5
A biasing spring 52 is wound around each of the base ends of 0 and 51, and the biasing spring 52 is installed obliquely so as to form a predetermined angle with respect to the optical axis. The biasing spring 52
Is a metal member formed on a coil.
The above-mentioned play is configured by the projections 50 and 51 and the biasing spring 52.

The urging spring 52 urges the sliding portion 28 in the direction of the arrow S1. The urging force is further transmitted to the second rotation preventing portion 32 via the second lens 18. . Similarly, a force in the direction of arrow S <b> 2 is urged to the first sliding portion 22 a, and the urged force is transmitted to the first rotation preventing portion 30 via the first lens 16.

At this time, the second detent part 32 is
As shown in the figure, the upper end surface 34b of the rotation stopping groove 34 is pressed against by the force in the direction of the arrow S1 '. On the other hand, the first rotation preventing portion 30 is pressed against the lower end surface 34a of the rotation preventing groove 34 by the force in the direction of the arrow S2 '.

As described above, the first and second detent portions 3
0 and 32 are pressed against the lower end surface 34a and the upper end surface 34b of the rotation stopping groove 34, thereby the first and second rotations are stopped.
Lenses 16, 18 and first and second support members 2
It is possible to maintain the state in which the backlash of 0, 26 is removed. As a result, the first and second lenses 16 and 18 and the first and second support members 20 and 26 can be stably moved along the guide member 12 in the optical axis direction A without rattling. Become.

As described above, according to the optical apparatus of the present embodiment, the first and second lenses 16, 18 and the first and second supports are provided by providing the rotation preventing mechanism and the backlash removing mechanism described above. The members 20 and 26 can be stably moved along the guide member 12 in a state where they are prevented from rotating in the optical axis direction A and without rattling.

The present invention is not limited to the above-described embodiment. For example, the biasing spring 52 may have any form other than a coil-shaped one as long as it has elasticity. In addition, the projections 50 and 51 may be provided on the lower right portion of the side surface B of the first sliding portion 22a and the upper left portion of the side surface C of the sliding portion 28, respectively. The urging force of the urging spring 52 against the second rotation preventing portion 32 is applied to the lower end surface 3 of the rotation preventing groove 34.
4a and the upper end surface 34b may be provided so as to be added to each one. In addition, the detent portions 30 and 32 may be merely small protrusions, and correspondingly, the detent grooves may not be grooves but may be mere surfaces on which the detent portions 30 and 32 can abut.

[0025]

As described above, according to the present invention, it is possible to provide an optical device capable of stably moving a lens along the optical axis direction without causing a finder image to fluctuate. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an optical device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which first and second detent portions are pressed against each other on an upper end surface and a lower end surface of a detent groove;

FIG. 3 is a perspective view showing a configuration of a conventional optical device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Guide member 16 1st lens 18 2nd lens 20 1st support member 22a 1st slide part 22b 2nd slide part 26 2nd support member 28 slide part 30 1st detent part 32 second detent part 34 detent groove 50 projection 51 projection 52 biasing spring

Claims (3)

[Claims] 1. An optical apparatus for performing a zooming operation by moving a plurality of optical elements in the direction of the optical axis thereof, comprising: a first optical element, a second optical element, and light beams of the first and second optical elements. A rod-shaped guide member disposed in parallel with the axial direction for guiding the first and second optical elements in the optical axis direction; and a molded member integrally formed with the first and second optical elements, A support member having a plurality of sliding portions that slide on the member and spaced apart from each other; and a support member arranged in parallel with the optical axis direction of the first and second optical elements. The first and second detents provided are engaged with the first and second detents, and the first and second optical elements are prevented from rotating in the detented state. A detent part for guiding in the axial direction, the first and second detent parts An optical apparatus characterized by being engaged in a state in which the urging force of the opposite direction is applied to each other with respect to the rotation stop portion. 2. The device according to claim 1, wherein the first and second rotation preventing portions are biased in opposite directions by elastic members provided on the plurality of sliding portions. Optical device. 3. The elastic member according to claim 2, wherein the elastic member is obliquely formed at a predetermined angle with respect to an optical axis direction of the first and second optical elements. Optical device.