JP2583987Y2 - Camera zoom finder device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a zoom finder device for a camera, and in particular, has a fixed lens group, a movable zoom lens group, and a drive mechanism for driving the movable zoom lens group. The present invention relates to a zoom finder device.

"Prior art and its problems" This kind of zoom finder device is used particularly for a variable focus lens shutter camera. This zoom finder device is installed in the camera body without being particularly separated from the photographing optical system and other driving devices, because the variable magnification lens group is moved in response to a change in the focal length caused by the photographing optical system. For this reason, even when it is desired to disassemble only the zoom finder device for inspection or the like, it is necessary to disassemble other parts such as the camera body and the lens block of the photographing lens system, and the work is very troublesome. .

The purpose of the present invention is to solve such a problem of the conventional camera zoom finder device and to obtain a zoom finder device which can be easily assembled and disassembled without affecting other parts. With the goal.

Another object of the present invention is to provide a zoom finder device capable of protecting the movable variable power lens group and the driving mechanism from dust.

The present invention provides a fixed lens group, a movable zoom lens group, and a camera zoom finder device having a driving mechanism for driving the movable zoom lens group.
At least at the forefront and the rearmost in the optical axis direction, a fixed finder unit before and after these, and a plurality of dividable divided frame bodies constitute a closed finder unit as a whole, and inside this finder unit To provide a moving guide for the movable zoom lens group and a driving mechanism thereof, and furthermore, a positioning fixing means for determining and fixing a relative position between the outer surface of the finder unit and the camera body. Has features.

According to this zoom finder device, the zoom finder device can be sub-assembled and independently attached to or detached from the camera body. Further, the movable variable power lens group and the driving mechanism are provided in the closed finder unit, and can be protected from dust.

Note that the above “closed state” does not mean “sealed state”.

"Embodiments of the invention" The invention will be described below based on illustrated embodiments. As shown in FIG. 3, the camera body 50 has a lens barrel 51, and a distance measuring device 52 is provided above the lens barrel 51.
A circuit board 53 is provided above the distance measuring device 52. The camera body 50 has a screw hole 55, and a positioning hole 57 is formed in a substrate 56 which is a part of the camera body 50. The unitized zoom finder device 11, which is a feature of the present invention, has a positioning pin 59 fixed to the rear wall in the optical axis direction fitted into a positioning hole 57, and a screw hole of a fixing bracket 58 provided at a front portion thereof. Screw through the screw hole
By screwing into the camera 55, the camera body 50 is fixed in a correctly positioned state.

The zoom finder device 11 will be described in detail with reference to FIGS.

The zoom finder device 11 has a unit case 9 including a finder lower frame 12, a finder middle frame 13, and a finder upper frame 15. The finder lower frame 12, the finder middle frame 13, and the finder upper frame 15 are assembled together with the fixed lens groups 14, 37, and 40 in the front-to-rear direction of the optical axis, thereby closing the finder unit. Can be configured as And
Movable zoom lens group 33 provided in this viewfinder unit
And its driving device 60 can be protected from dust.
The above-mentioned “closed state” does not refer to “closed state”, but refers to enclosing at least so that dust does not enter.

The finder lower frame 12 has the fixing bracket 58 at the front (left side in the figure), and a lens frame into which the fixed lens group 14 is fitted.
16 are formed. Further, moving guides 17 are formed on left and right inner walls of the finder lower frame 12.

The finder lower frame 12 is formed with a small through hole 19 through which the drive shaft 20 passes. One end of a lens drive lever 22 is mounted inside the finder lower frame of the drive shaft 20. At the other end of the lens drive lever 22, a cam pin 18 is provided upward. Further, inside the finder lower frame 12, a driving cam lever 26 constituting a driving mechanism 60 with a tension spring 24 and a lens driving lever 22 is pivotally supported by a rotation fulcrum 25.
It is arranged to overlap a part of 22.

The driving cam lever 26 is urged to rotate counterclockwise in the figure by a tension spring 24. This drive cam lever
A guide groove 29 is formed at the tip end of 26 along the radial direction centering on the pivot 25, and a guide pin 30 is slidably fitted in the guide groove 29. On one side of the drive cam lever 26, an arc-shaped cam surface which engages with the cam pin 18 is provided.
27 are formed. On the rotation locus of the drive cam lever 26, a rotation restricting pin 31 for sandwiching the lever 26 from both sides is provided.

A drive gear train 10 including lens drive gears 21 and 23 is provided on a lower surface of the finder lower frame 12. The lens drive gear 21 is attached to the drive shaft 20 by a spline or a key so that the lens drive gear 21 cannot rotate relative to the drive shaft 20, that is, rotates integrally. The lens drive gear 21 is connected via a lens drive gear 23 to a zoom motor as a drive source.

The movable zoom lens group 33 is fitted into a movable lens holder 44, and guide ribs are provided on the left and right sides of the movable lens holder 44.
35 are provided. The guide rib 35 is placed on the moving guide 17 in a state where the guide pin 30 is fitted in the fitting hole formed on the lower surface of the movable lens holder.

The finder middle frame 13 is shaped to cover the upper part of the finder lower frame 12. A lens frame 36 that forms an opening 61 into which the first fixed lens group 14 is fitted with the lens frame 16 is formed in the front direction of the optical axis. A lens frame 39 that fits the second fixed lens group 37 and a lens frame 41 that forms an opening 62 that fits the third fixed lens group 40 are formed in the rear direction of the optical axis. Although not shown, the movement guide 17 of the finder lower frame 12
The portions corresponding to slidably support the left and right guide ribs 35 placed on the moving guide 17.

The finder upper frame 15 is shaped to cover the rear part of the finder middle frame 13. The finder upper frame 15 is a lens frame that presses the second fixed lens group 37 fitted on the lens frame 39 from above.
42, and a lens frame (not shown) that presses the third fixed lens group 40 from above and forms the opening 62.

Therefore, the drive mechanism 60 for the movable variable-magnification lens group 33 is assembled to the lower frame 12 of the finder, and the movable variable-magnification lens group 33 is
17 and these are enclosed by a finder middle frame 13 and a finder upper frame 15 from above and from the front and back in the optical axis direction by a first fixed lens group 14 and a third fixed lens group 40 to be closed. By. The drive mechanism 60 and the movable zoom lens group 33 can be protected from dust. The work of assembling or removing the camera from the camera body is performed independently of other parts such as the zoom photographing optical system using the zoom finder device 11 as a finder unit.

Then, the zoom finder device 11 assembled to the camera body 50 and connecting the lens driving gear 23 of the driving gear train 10 to a zoom motor as a driving source operates as follows.

When the zoom motor on the camera body side is driven, the rotation is transmitted to a lens driving gear 23 serving as input means, and a rotating lens driving gear 21 of the gear 23 and a driving shaft 20 are driven.
Through the lens drive lever 22 in the unit case 9.

When the rotation of the lens drive lever 22 is, for example, counterclockwise in the drawing, the cam pin 18 that rotates in the same direction
27 against the tension spring 24 and drive cam lever 26
Is rotated clockwise in the figure. Then the drive cam lever
26, while appropriately sliding the guide pin 30 in the guide groove 29,
The movable variable power lens group 33 is moved rearward (rightward in the figure) along the movement guide 17. As a result, the distance between the first fixed lens group 14 and the movable variable power lens group 33 is changed, and the angle of view in the finder field viewed from the third fixed lens group 40 is changed according to the focal length.

When the zoom motor rotates in the opposite direction, the lens drive lever 22 rotates clockwise in the figure, and the cam pin 18 moves to the cam surface 27.
It gradually goes away from. Thus, the driving cam lever 26 rotates counterclockwise in the figure while the cam surface 27 is brought into contact with the cam pin 18 by the urging force of the tension spring 24. Accordingly, the movable changeable lens group 33 is moved forward along the optical axis along the movement guide 17, and the angle of view in the finder is changed according to the focal length.

In the above embodiment, the present invention was applied to the zoom finder device having only one movable variable power lens group.
The present invention is not limited to this, and the present invention may be applied to a zoom finder device having a plurality of movable variable power lens groups.

[Effects of the Invention] As described above, the zoom finder device for the camera of the present invention can be sub-assembled at the time of assembling. It can be fixed in the correct position. Therefore, also at the time of inspection and repair, it is possible to simply and accurately return the zoom finder device to the camera main body after performing necessary work by removing only the zoom finder device from the camera main body. Further, since the movable zoom lens group and the driving mechanism can be provided in the closed finder unit, the movable zoom lens group and the driving mechanism can be reliably protected from dust.

[Brief description of the drawings]

1 is an exploded perspective view showing the entire zoom finder device according to the present invention, FIG. 2 is an enlarged perspective view showing a finder lower frame portion, and FIG. 3 is a supporting structure of a camera body supporting the zoom finder device. FIG. 9, 14, 40: finder case, first fixed lens group, third fixed lens group (finder unit), 10: drive gear train, 11: zoom finder device, 12, 13, 15 ... finder lower frame , Finder middle frame, finder upper frame (divided frame), 16 ... lens frame, 17 ... movement guide, 18 ... cam pin, 19 ... through hole, 20 ... drive shaft, 21, 23 ...
Lens drive gear, 22, 26, 24 ... Lens drive lever, drive cam lever 26, tension spring (drive mechanism), 25 ... Rotating fulcrum, 27 ... Cam surface, 29 ... Guide groove, 30 ... Guide pin , 33 ... movable zoom lens group, 34 ... fitting hole, 35 ... guide rib, 37 ... second fixed lens group, 39 ... lens frame,
40: Third fixed lens group, 41, 42: Lens frame, 44:
Movable lens holder, 50 ... Camera body, 51 ... Lens barrel, 52 ... Distance measuring device, 55 ... Screw hole, 56 ... Board, 57 ...
... Positioning holes (positioning and fixing means), 58 ... Fixing brackets (positioning and fixing means), 59 ... Positioning pins (positioning and fixing means), 61,62 ... Lens openings.

Claims (2)

(57) [Scope of request for utility model registration] 1. A zoom finder device for a camera having a fixed lens group, a movable variable-power lens group, and a drive mechanism for driving the movable variable-power lens group, wherein the fixed lens group is provided at least in the front in the optical axis direction. Finder unit, which is located at the rear and rear parts, and a fixed finder unit which is closed as a whole by the front and rear fixed lens groups and a plurality of splittable frame bodies. The movable variator lens is provided in the finder unit. A camera provided with a group movement guide and a driving mechanism thereof, and further comprising positioning fixing means for determining and fixing a relative position between the outer surface of the finder unit and the camera body. Zoom finder device. 2. A zoom finder device for a camera according to claim 1, wherein said plurality of divided frames are a finder lower frame having said moving guide and a driving mechanism, and a frontmost fixed lens group between said finder lower frame. And a finder upper frame that holds the rearmost fixed lens group between the finder middle frame and the finder middle frame.