JPH05346609A - Fitting mechanism for finder - Google Patents

Abstract

PURPOSE:To derive the fitting accuracy of a finder optical system by simple structure. CONSTITUTION:A guide shaft 26 guiding a lens group, which changes the magnification of a finder, in freely movably in an optical axis direction is used as a guide for positioning and fitting a finder main body 20 with respect to a photographing lens. Since the shaft 26 is the member being the main reference of the finder optical system, the fitting accuracy is improved by using the shaft 26 also as the guide for positioning and fitting the finder main body 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder mounting mechanism, and more particularly to a finder mounting mechanism for changing a finder magnification in accordance with a focus movement of a taking lens.

[0002]

2. Description of the Related Art Conventionally, when a finder of this type is attached to a lens barrel of a taking lens, a guide boss or the like is provided on the body of the finder, and the guide boss is fitted into a positioning hole provided in the lens barrel of the taking lens. The finder is positioned with respect to the lens, and then the finder is fixed to the lens barrel with a set screw.

[0003]

However, in recent compact cameras, as the taking lens is made to have two focal points and zoomed, the positioning accuracy between the optical axis of the taking optical system and the optical axis of the finder optical system becomes strict. Accordingly, there is a problem in that sufficient accuracy cannot be obtained when the guide boss or the like is used for positioning and assembled.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a finder mounting mechanism capable of improving the positional accuracy of the photographing optical system and the finder optical system with a simple structure. And

[0005]

In order to achieve the above object, the present invention provides a lens group for changing the finder magnification,
A lens moving frame that supports and moves the lens group, a guide shaft that movably guides the lens moving frame in the optical axis direction, and moves the lens moving frame in the optical axis direction as the focal point of the photographing lens moves. A finder mounting mechanism having a drive mechanism, characterized in that the guide shaft is used as a positioning guide and a mounting guide for the finder with respect to the taking lens.

[0006]

According to the present invention, the guide shaft for movably guiding the lens group for changing the finder magnification in the direction of the optical axis,
It is used as a positioning and mounting guide for the finder with respect to the taking lens. Since this guide shaft is a main reference member of the finder optical system, by using this guide shaft as the finder positioning and mounting guide, the mounting accuracy can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a finder mounting mechanism according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a first embodiment of a finder mounting mechanism according to the present invention, showing a state in which a lens barrel 10 and a finder body 20 are separated.

In the lens barrel 10, a T / W lens capable of switching between telephoto and wide-angle bifocals is provided as a photographing lens (not shown). Incidentally, 12 is the T /
It is a solid-state image sensor arranged such that its light receiving surface is located at the image forming position of the W lens. Further, finder mounting portions 14 and 16 are provided on the side of the lens barrel 10. The finder mounting portion 14 has a mounting guide hole 14
A is bored and a finder opening 14B is formed, and the finder mounting portion 16 has a screw hole 16A.
Has been drilled.

On the other hand, in the finder body 20, lens moving frames 22 and 24 for moving a lens group for changing the finder magnification are provided so as to be movable in the finder optical axis direction. A mounting portion 28 for mounting the finder body 20 on the lens barrel 10 is provided below the finder body 20. The finder body 20 is also provided with a focusing screen, a field mask, an eyepiece lens and the like, which are not shown.

Guide portions 22A and 24A are formed on the lens moving frames 22 and 24, respectively, and these guide portions 22A and 24A are inserted through a guide shaft 26. That is, the lens moving frames 22 and 24 are movably arranged in the finder optical axis direction by inserting the guide portions 22A and 24A into the guide shaft 26.

The guide portions 22A and 24A are provided with cam followers 22B and 24B, respectively, and these cam followers 22B and 24B are provided with cams (not shown) which are interlocked with focus switching of the T / W lens. Engaged. Therefore, the lens moving frames 22 and 24 are moved along with the focus switching of the T / W lens, and thereby the finder magnification is changed.

Next, the case where the finder body 20 is attached to the lens barrel 10 will be described. First, the tip of the guide shaft 26 of the finder body 20 is fitted into the mounting guide hole 14A formed in the lens barrel 10. still,
The guide shaft 26 of the finder body 20 is a main reference member of the finder optical system. Therefore, this guide shaft 2
By inserting 6 into the mounting guide hole 14A of the lens barrel 10, the positional accuracy between the photographing optical system and the finder optical system can be obtained.

Next, the finder mounting portion 1 on the lens barrel side
6 and the mounting portion 28 on the finder body side are screwed together with a set screw 29. As a result, the finder body 20 is attached to the lens barrel 10. FIG. 2 is a perspective view showing a second embodiment of the finder mounting mechanism according to the present invention. The same parts as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The lens barrel 30 shown in FIG. 2 has a guide groove 3
It differs from the lens barrel 10 shown in FIG. 1 in that it has a guide portion 32 having 2A. On the other hand, the finder body 40
The guide shaft 42 mainly differs from the guide shaft 26 of the finder body 20 shown in FIG. This finder body 4
When 0 is attached to the lens barrel 30, the tip end of the guide shaft 42 of the finder body 40 is fitted into the attachment guide hole 14A of the lens barrel 10 and the guide shaft 42 is attached.
The rear end is fitted into the guide groove 32A of the lens barrel 30. As a result, the position between the photographing optical system and the finder optical system and the accuracy in the optical axis direction can be obtained.

Next, the finder mounting portion 1 on the lens barrel side
6 and the mounting portion 28 on the finder body side are screwed together with a set screw 29, and the finder body 20 is attached to the lens barrel 10. The shooting lens is not limited to the T / W lens,
A zoom lens that continuously moves the focus may be used. Further, the mounting guide hole, the guide groove and the like are not limited to those directly formed in the lens barrel, but may be formed in the front base plate, the rear base plate or the like to which the lens barrel is mounted.

[0016]

As described above, according to the finder mounting mechanism of the present invention, the guide shaft for movably guiding the lens group for changing the finder magnification in the optical axis direction is used for positioning the finder with respect to the photographing lens. Since it is also used as a mounting guide, the mounting accuracy of the finder optical system can be obtained with a simple structure without increasing the number of parts.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a finder mounting mechanism according to the present invention.

FIG. 2 is a perspective view showing a second embodiment of a finder mounting mechanism according to the present invention.

[Explanation of symbols]

 10, 30 ... Lens barrel 14, 16 ... Finder mounting portion 14A ... Mounting guide hole 16A ... Screw hole 20, 40 ... Finder body 22, 24 ... Lens moving frame 22A, 24A ... Guide portion 26, 42 ... Guide shaft 28 ... Mounting part 29 ... Set screw

Front Page Continuation (72) Inventor Mitsufumi Misawa 3-1146 Izumi, Asaka-shi, Saitama Fuji Shashin Film Co., Ltd.

Claims (3)

[Claims] 1. A lens group for changing a finder magnification, a lens moving frame for supporting and moving the lens group, a guide shaft for movably guiding the lens moving frame in an optical axis direction, and a focus of a photographing lens. A finder mounting mechanism having a drive mechanism for moving the lens moving frame in the optical axis direction with movement, wherein the guide shaft is used as a positioning guide and a mounting guide for the finder with respect to the photographing lens. Characteristic finder mounting mechanism. 2. A lens group for changing a finder magnification, a lens moving frame for supporting and moving the lens group, a guide shaft for movably guiding the lens moving frame in an optical axis direction, and a focus of a photographing lens. A mounting mechanism of a finder having a drive mechanism for moving the lens moving frame in the optical axis direction with movement, wherein a mounting guide hole is formed in a lens barrel of the photographing lens or a main plate to which the lens barrel is fixed, The finder mounting mechanism is characterized in that one end of the guide shaft is inserted into the guide hole and then the finder is fixed by a set screw. 3. A guide groove is formed in a lens barrel of the taking lens or a base plate to which the lens barrel is fixed, and the other end of the guide shaft is fitted in the guide groove. Item 2 finder mounting mechanism.