JP3359683B2 - Camera zoom finder mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention, camera zoom phi <br/> Sunda mechanism, particularly, finder lenses relates to a zoom finder mechanism of the camera that enables advance and retreat in the optical axis direction.

[0002]

2. Description of the Related Art Hitherto, various proposals have been made for a finder mechanism of a camera having a structure in which a finder lens advances and retreats in an optical axis direction, with respect to a structure capable of positioning the finder lens with high accuracy. For example, the finder mechanism of Japanese Utility Model Application No. 4-9535 proposed earlier by the present applicant is as follows.
As shown in FIG. 6, the position accuracy of the two finder lenses L1 and L2 which advance and retreat along the optical axis O of the finder optical system is improved.

That is, in the above mechanism, the finder lenses L1 and L2 are slidably supported by a guide rod 58 supported by a finder mechanism main body 59, and one end of each of the finder lenses L1 and L2 is provided with a detent pin 53. , 5
4 are integrally provided. The detent pins 53, 54 are provided on guide surfaces 55,
It is slidably fitted in the straight guide groove formed by 56. Drive pins 51 and 52 that are driven in contact with a lens drive cam (not shown) are integrally provided on the guide rod 58 support side of the finder lenses L1 and L2. Then, a compression spring 63 is inserted into the guide rod 58, and is disposed in contact with the opposing surfaces 61, 62 of the support portions of the finder lenses L1, L2.

In the above-described conventional finder mechanism, the finder lenses L1 and L2 are driven by the drive pins 51 and 52 with the pins 53 and 54 being restricted from rotating by the grooves of the guide surfaces 55 and 56. Are brought into contact with the lens drive cam sandwiching it from the outside, and are driven forward and backward. At this time, the compression spring 63 is always set to the finder lenses L1 and L2.
Are biased in the direction to separate the lenses L1 and L2.
The backlash of the second finder in the direction of the optical axis O is driven while being absorbed.

[0005]

However, in the finder mechanism disclosed in Japanese Patent Application No. 4-9535, the optical axis O
Although the play in the direction can be removed, the play around the guide rod 58 on the part tolerance between the grooves of the guide surfaces 55 and 56 and the pins 53 and 54 remains. Therefore, during the forward and backward movement, the lenses L1, L
In the case of No. 2, vibration may occur around the axis and the field of view may be deviated, and optical performance may be degraded due to a shift of the lens center position.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has a play in the optical axis direction and the direction intersecting the optical axis when the two zoom finder lenses move forward and backward.
An object of the present invention is to provide a zoom finder mechanism for a camera, which is a mechanism capable of removing sticking, has a small number of constituent parts, and has a simple structure.

[0007]

Zoom viewfinder mechanism according to the present invention, in order to solve the problems] includes a guide shaft extending in the optical axis direction, the moth
A first drive pin having a fitting portion that slides by fitting with the guide shaft.
The first finder lens, which is moved in the optical axis direction by the displacement of the optical axis in the optical axis direction, slides while being fitted to the guide shaft.
Having a fitting portion, and by displacement of the second drive pin in the optical axis direction.
A second finder lens to be moved in the optical axis direction, abutment
The first and second drive pins are displaced in the optical axis direction.
It was a driving cam for zooming drive, the first file
A first detent portion provided in Ndarenzu, the second
A second detent portion provided on the finder lens of
The first and second detent portions are slidable in the optical axis direction.
Abuts on the first and second finder lenses.
A rotation restricting portion for restricting rotation around the guide shaft ;
Between the serial first finder lens and the second finder lens, are arranged wound on the guide shaft, and biased in a direction away from each other said first and second finder lens The first and second drive pins are
Presses and contacts the drive cam, slides on the guide shaft , and urges it in a direction to rotate around the guide shaft.
And the first and second detent portions are connected to the rotation restricting portion.
And a coil spring to be pressed against.

[0008]

[Work] The first and second zoom finder lenses are urged in the direction away from each other by the coil spring to remove the play in the optical axis direction, and the same spring is used to move the zoom finder lens around the guide axis. Also, the backlash in the direction intersecting the optical axis is urged in the direction of rotation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main part of a finder mechanism of a camera showing one embodiment of the present invention. FIG. 2 is a perspective view of a coil spring applied to the mechanism, and FIG. 3 is a layout view of the finder mechanism. It is assumed that the present finder mechanism is applied as a zoom finder.

As shown in FIGS. 1 and 3, the finder mechanism mainly includes a finder support 11, a guide shaft 9 which is a guide rod fixed to the support 11, and slidable on the guide shaft 9. And a finder lens 2 as a concave lens and a finder lens 3 as a convex lens, which constitute a finder optical system, a coil spring 5 inserted into the guide shaft 9, and move the lenses 2 and 3 in the direction of the optical axis O. The cams 10a and 10b of the cam member 10 to be driven and a guide groove 11a provided on the support body 11 for restricting the rotation of the lenses 2 and 3 around the optical axis O.

The finder lenses 2 and 3 have support portions 2c and 3c located outside the optical axis, respectively, and fitting portions 2d and 3c provided on the support portions 2c and 3c, respectively.
The guide shaft 9 is slidably fitted in 3d. The finder optical system includes the finder lenses 2 and 3 described above.
7 , the roof mirror 12 and the prism 13, and FIG.
Protective glass 1,1 shown on the top of this finder mechanism
5, a concave lens 4 disposed behind the convex lens 3, and an eyepiece
And a lens 14. The point EP in the figure is the
Shows the event.

The support portion 2 of the finder lenses 2 and 3
Drive pins 2b and 3b are integrally provided below c and 3c, and can contact the inner surfaces of the cams 10a and 10b of the cam member 10. Further, anti-rotation pins 2a, 3a projecting in a direction orthogonal to the finder optical axis O are provided integrally with the finder lenses 2, 3 at the opposite ends of the support portions 2c, 3c. The pins 2a and 3a are slidably fitted in the guide grooves 11a of the support 11.

The coil spring 5 has hooks 5a, 5a at its ends extending in the axial direction of the coil winding as shown in FIG.
b. The coil spring is inserted into the guide shaft 9 and the coil portion is compressed.
It is mounted on the finder lenses 2 and 3 while being twisted in the winding direction. Therefore, the coil end of the coil spring 5 comes into contact with and presses the inner surfaces of the supporting portions 2c and 3c of the lenses 2 and 3. The urging force F acts in a direction to separate the finder lenses 2 and 3. The driving pins 2b, 3
Since b is pressed against the drive cams 10a and 10b, no rattling occurs between the drive cams 10a and 10b and the drive pins 2b and 3b even if the lenses 2 and 3 move in the optical axis direction in this state. .

Further, the coil spring 5 is mounted on the finder lenses 2 and 3 in a twisted state as described above, and the hook portions 5a and 5b are respectively supported by the support portions 2 of the lenses 2 and 3.
c, 3c because it is suspended and attached to the arm,
The lens 2 has a counterclockwise torque T with respect to the guide shaft 9.
Acts on the lens 3, and a clockwise torque T opposing the torque acts on the lens 3. Due to the torque T, the detent pin 2a comes into contact with the upper surface of the guide groove 11a, and the detent pin 3a comes into pressure contact with the lower surface of the guide groove 11a. Therefore, even if the lenses 2 and 3 move in the optical axis direction in this state, rattling around the guide shaft 9 of the lenses 2 and 3 does not occur.

FIGS. 4 and 5 are longitudinal sectional views showing the advancing / retreating state of the finder lenses 2 and 3 of the finder mechanism of this embodiment along the optical axis O, and show only the zoom optical system. 4 shows a zooming wide state, and FIG. 5 shows a zooming telephoto state.

When the wide state is changed to the telephoto state, the driving positions of the finder lenses 2 and 3 are determined by the distance D1 between the protective glass 1 and the lens 2, the distance D2 between the lenses 2 and 3, and
The distance D3 between the lens 3 and the lens 4 changes as shown in FIGS. 4 and 5, and a finder image is observed in EP.

In this embodiment, when the finder lenses 2 and 3 are moved, as described above, the backlash in the direction of the optical axis O is caused by the urging force of the coil spring 5 in the direction F (see FIG. 2). 2b and 3b are removed by sliding against the cams 10a and 10b. Further, the ratcheting force of the coil spring 5 causes the rotation preventing pins 2a, 3a to move up and down in the guide grooves 11a. It is removed by sliding against the respective inner surfaces. And the finder lenses 2 and 3
Is the optical axis of each lens and the optical axis O of the finder optical system.
Move without shifting.

As described above, the finder mechanism of the present embodiment does not increase the number of components and uses a simple component configuration to move the finder lenses 2 and 3 between the optical axis O direction and the guide axis. A finder that can observe an accurate zooming finder image without blurring the field of view without sliding backlash is provided. Although the finder mechanism of the present embodiment has been described as an example applied to a zoom finder, it is needless to say that the present invention is not limited to this, and can be applied to other finder mechanisms having a structure in which two or more finder lenses are moved. It is.

[0019]

Effects of the Invention] According to the camera of the zoom finder mechanism of the present invention as described above, first, urging the coil spring allowed to intervene between the second two zoom finder lens, in the direction in which the lens is separated from each other At the same time, by mounting the lens so as to urge it around the guide axis , play of the lens in the direction intersecting the optical axis and the optical axis is performed, without increasing the number of urging members, and A zoom finder mechanism having a simple configuration can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a finder mechanism of a camera showing one embodiment of the present invention.

FIG. 2 is a perspective view of a coil spring applied to the finder mechanism of FIG. 1;

FIG. 3 is a layout diagram of the finder mechanism of FIG. 1;

FIG. 4 is a longitudinal sectional view of the finder mechanism of FIG. 1 in a wide state.

FIG. 5 is a longitudinal sectional view of the finder mechanism of FIG. 1 in a telephoto state.

FIG. 6 is an exploded perspective view of a conventional finder mechanism.

FIG. 7 is a view showing a finder optical system of the finder mechanism shown in FIG. 1;

[Explanation of symbols]

 9 Guide shaft (guide rod) 2, 3 Finder lens 5 Coil spring 2d, 3d Fitting part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 13/06 G02B ⁷ /02-7/16

Claims (1)

(57) [Claims] A first guide shaft extending in the optical axis direction, and a first fitting portion slidingly fitted with the first guide shaft ;
It is moved in the optical axis direction by the displacement of the drive pin in the optical axis direction
A first finder lens having a fitting portion that slides by fitting with the guide shaft;
It is moved in the optical axis direction by the displacement of the drive pin in the optical axis direction
The second finder lens and the first and second drive pins to be contacted are changed in the optical axis direction.
A driving cam for performing a zooming operation by moving the first finder lens, and a first rotation stop provided on the first finder lens.
And a second detent provided on the second finder lens
And the first and second detent portions are slidable in the optical axis direction.
Abuts on the first and second finder lenses.
A rotation restricting portion for restricting the rotation of the guide axis, between said first finder lens and the second finder lens, are arranged wound on the guide shaft, the first and The second finder lens is biased in a direction away from each other, and the first and second drive pins are moved in the direction described above.
Presses and contacts the drive cam, slides on the guide shaft , and urges it in a direction to rotate around the guide shaft.
And the first and second detent portions are connected to the rotation restricting portion.
A zoom finder mechanism for a camera, comprising: a coil spring to be pressed against;