JP2602353Y2 - Viewfinder diopter adjustment device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder diopter adjusting device used in a camera.

[0002]

2. Description of the Related Art In a camera developed recently, at least one lens group (generally an eyepiece lens group) of a plurality of lens groups constituting a finder optical system is arranged along a finder optical axis. There is a device provided with a diopter adjustment device that can continuously adjust the diopter of the finder by moving the finder.

FIG. 4 shows a diopter adjustment device 40 as a conventional example of this type of diopter adjustment device. A movable lens group (diopter adjustment lens) 41, which is one of a plurality of lens groups constituting the finder eyepiece optical system, includes a finder fixing section 42.
Is located in the lens guide passage 43 formed by The movable lens group 41 also includes the guided part 4 on the right side of the drawing.
The guided portion 41a is slidably fitted to a guide bar 45 fixed at both ends thereof to a fixed portion (not shown) of the finder. With this configuration, the movable lens group 41 is
3 is movable along the finder optical axis O. The movable lens group 41 is located between the lens guide passage 43 and the peripheral edge of the movable lens group 41.
A predetermined clearance is set so as to be able to move inside the lens guide passage 43 while sliding on the inner surface 43a of the lens 3.

The guided portion 41a integrally has a drive pin 46 formed so as to protrude in a direction orthogonal to the finder optical axis O. By moving the drive pin 46 back and forth in the direction of the finder optical axis O using a cam or the like (not shown),
Diopter adjustment is performed by changing the distance between the movable lens group 41 and another lens group (not shown) constituting the finder optical system.

In this conventional diopter adjusting device 40, in order to move the movable lens group 41 in parallel with the finder optical axis O in a stable state, the length of the guided portion 41a in the finder optical axis O direction is required. It is necessary to lengthen L and so on, which requires a lot of space inside the camera. This was one factor that hindered camera compactness.

[0006]

This invention has been made in view of the above problems, has a simple structure, does not require much space, and stabilizes a lens group to be moved for diopter adjustment. It is an object of the present invention to provide a finder diopter adjustment device that can be reliably moved in a state.

[0007]

[Summary of the Invention] The diopter adjusting device of the finder according to the present invention comprises:
A diopter adjusting lens of a finder which is supported so as to be able to move straight in the optical axis direction; a pair of driving pins which are located in a plane perpendicular to the optical axis and protrude in opposite directions from the diopter adjusting lens; A substantially U-shaped drive having a pair of drive arms each having a long hole into which a pair of drive pins are fitted, a connection arm connecting the pair of drive arms, and a rotation center provided on the pair of drive arms. And a means for rotating the driving member about the rotation center as an axis.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is an exploded perspective view showing a finder diopter adjusting device 10 to which the present invention is applied. The diopter adjustment device 10 provided near the finder eyepiece inside the camera (not shown) has a movable lens group (diopter adjustment lens) 11 that moves along the finder optical axis O. The movable lens 11 group is one of a plurality of lens groups constituting a finder eyepiece optical system, and the entire finder optical system is not shown in FIG.

The movable lens group 11 integrally has a pair of guided projections 12 formed to project in a direction orthogonal to the finder optical axis O. Each of the pair of guided protrusions 12 has guided surfaces 12a and 12b parallel to the finder optical axis O and parallel to each other.
(FIGS. 2 and 3) are formed.

The movable lens group 11 is also provided with a drive pin 13 integrally formed so as to further project from each end of the pair of guided projections 12 in a direction orthogonal to the finder optical axis O.

The movable lens group 11 is movably supported by a pair of upper and lower upper casing halves 15 and 16. These upper casing halves 1
As shown in FIG. 1, each of the 5 and the lower casing half 16 has a U-shaped cross section at least in a portion that movably supports the movable lens group 11. The upper casing half 15 has a notch 18 with a guide surface 17 (FIG. 2) parallel to the finder optical axis O, and the lower casing half 16 has a guide surface 1 parallel to the finder optical axis O.
9 (FIG. 2). These upper casing half 15 and lower casing half 16
2 and 3. In this joined state, a pair of guide grooves 22 whose upper and lower surfaces are guide surfaces 17 and 18 are formed as shown in FIGS.

The front end (left end in FIG. 3) of the guide groove 22 is defined by an end surface 23 formed on the upper casing half 15 and orthogonal to the guide surface 17, and has a rear end (right end in FIG. 2). ) Is defined by an end surface 24 formed on the lower casing half 16 and orthogonal to the guide surface 20. A corresponding guided protrusion 12 provided in the movable lens group 11 is fitted into each of the pair of guide grooves 22. With this configuration, the movable lens group 11 slides the guided surface 12 a against the guide surface 17 and slides the guided surface 12 b against the guide surface 20,
2, that is, along the finder optical axis O, the guide groove 22.
Is supported so as to be able to move in parallel within the length range.

The lower casing half 16 is provided with a pair of pivots 26 projecting in a direction parallel to the pair of drive pins 13. A drive member 30 having a pair of arms (drive arms) 31 and a connecting portion 32 connecting these arms 31 is attached to each of the pair of pivots 26.
A hole (rotation center) 33 formed on the shaft is pivotally mounted on the shaft. In the arm 31, in the upper part of the hole 33 in FIG.
A long cam hole 34 is formed. This cam long hole 34 is
The driving pins 13 of the corresponding movable lens group 11 are respectively engaged with the driving pins 13, and the driving pins 13 are slidable in the cam long holes 34. One of the arms 31 has a pivot 26
A protruding portion 31a extending in a direction parallel to the direction is provided integrally.

One of the pivots 26 has a torsion spring 35.
Are fitted. One end 35b of the torsion spring 35 is bent at a right angle and is engaged with the bottom surface 16a of the lower casing half, and the other end 35c is in contact with the back surface 32a of the connection portion 32 of the drive member 30. With the above configuration, the movable lens group 11 is in a state shown in FIG. 2 in a normal case where no force is applied from the outside. That is,
In the state shown in FIG. 2, the driving member 30 is rotated counterclockwise in FIG. 2 around the pivot 26 by the action of the torsion spring 35. Thereby, the movable lens group 11 is located at the left end of FIG. 2 along the finder optical axis O via the cam long hole 34 and the drive pin 13.

When an external force is applied to the protruding portion 31a in the direction of arrow D shown in FIG. 2 from the state shown in FIG.
Rotates clockwise in FIG. 2 against the spring force of the torsion spring 35. By the rotation of the driving member 30, the movable lens group 11 moves rightward in FIG. FIG.
This shows a state in which the driving member 30 has been turned clockwise most and the movable lens group 11 has been moved to the right end.

The means for applying an external force to the protruding portion 31a is a slide operation member (not shown) for moving the protruding portion 31a in the direction of arrow D by sliding the inclined cam surface in contact with the protruding portion 31a. Or a diopter adjusting operation member that can be operated by the photographer from outside the camera body, such as a rotation operation member (not shown) that moves the protrusion 31a in the direction of arrow D using a screw. What is necessary is just to be able to move and adjust 31a in the direction of arrow D.

The diopter adjusting device for a finder to which the invention of the present application having the above configuration is applied operates as follows. When the photographer operates a diopter adjusting operation member (not shown) provided on the camera, the protruding portion 31a is moved in the left-right direction of FIGS. It rotates around 26. With this rotation, the movable lens group 11 moves back and forth (left and right in FIGS. 2 and 3) along the finder optical axis O. Since the distance between the movable lens group 11 and another lens group (not shown) constituting the finder optical system changes when the movable lens group 11 is moved back and forth, a desired diopter adjustment operation member is operated by operating the diopter adjustment operation member. Adjustments can be made to obtain a viewfinder diopter.

In the conventional diopter adjusting device shown in FIG. 4, the movable lens group 41 has a cantilevered structure with a guided portion 41a slidably fitted to the guide bar 45, so that the movable lens group 41 is in a stable state. As described above, it is necessary to increase the length L of the guided portion 41a in order to be moved by the above. However, according to the diopter adjustment device of the finder to which the present invention is applied, There is no need to provide a guided portion 41a or the like extending long in the direction of the finder optical axis O, and both ends of the movable lens group 11, that is, the pair of drive pins 13 are securely supported by the arm portions 31 of the drive member 30. It can be reliably moved in the state.

The positional relationship between the cam long hole 34, the hole 33, and the connecting portion 32 provided in the driving member 30 is not limited to the present embodiment. That is, the driving member is not limited to the driving member 30 of the present embodiment, and a driving member having another shape may be provided as long as it has a similar function.

In the above embodiment, the diopter adjustment device of the finder has been described with reference to the diopter adjustment device of the finder provided in the camera. However, the present invention is not limited to this, and devices other than the camera having the finder are provided. May be applied.

[0021]

As described above, according to the finder diopter adjusting device of the present invention, the finder diopter adjusting lens supported so as to be able to move straight in the optical axis direction; A pair of drive pins positioned in a plane perpendicular to the axis and protruding in opposite directions; a pair of drive arms each having a long hole into which the pair of drive pins are fitted, and a connection connecting the pair of drive arms A substantially U-shaped drive member having an arm and a center of rotation provided on the pair of drive arms; and means for rotating the drive member about the center of rotation as an axis. It has a simple structure, does not require much space, and can reliably move the lens group moved for diopter adjustment in a stable state.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main part of a diopter adjusting device for a finder to which the present invention is applied.

FIG. 2 is a side view of the main part shown in FIG. 2 as viewed from another angle.

FIG. 3 is a side view showing a main part of the same figure in a different state.

FIG. 4 is a perspective view showing a conventional diopter adjustment device for a finder.

[Explanation of symbols]

 Reference Signs List 10 diopter adjusting device 11 movable lens group (diopter adjusting lens) 15 upper casing half 16 lower casing half 22 guide groove 32 rotating member 35 torsion spring

Claims (2)

(57) [Scope of request for utility model registration] 1. A device that is supported so as to be able to move straight in the optical axis direction.
A diopter adjustment lens for a finder; a pair of drive pins protruding from the diopter adjustment lens in a plane perpendicular to the optical axis and projecting in opposite directions to each other; and a long hole into which the pair of drive pins are fitted. A substantially U-shaped drive member having a pair of drive arms, a connection arm for connecting the pair of drive arms, and a rotation center provided on the pair of drive arms; Means for rotating around a shaft; and a diopter adjustment device for a finder. 2. A diopter adjusting device for a finder according to claim 1, further comprising: a spring member for constantly urging the driving member in a predetermined rotation direction about the rotation center as an axis; and a pair of driving arms. A projecting portion formed on the opposite side to the elongated hole with respect to the center of rotation of one drive arm; and an external force is applied to the projecting portion to oppose the spring force of the spring member. The diopter adjustment device of the finder in which the diopter rotates, whereby the diopter adjustment lens moves.