JP2904375B2 - Viewfinder mounting mechanism - 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 mounting mechanism, and more particularly to a finder mounting mechanism for changing a finder magnification in accordance with a focal point movement of a photographing lens.

[0002]

2. Description of the Related Art Conventionally, when a finder of this type is mounted on a lens barrel of a photographic lens, a guide boss or the like is provided on the finder body, and this is fitted into a positioning hole provided on the lens barrel of the photographic 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, with recent compact cameras, the focus of the photographing lens has been increased to two focal points and zooming, and the positioning accuracy between the optical axis of the photographing optical system and the optical axis of the finder optical system has become severe. Along with this, there has been a problem that when assembled using a guide boss or the like for positioning, sufficient accuracy cannot be obtained.

The present invention has been made in view of such circumstances, and has as its object to provide a finder mounting mechanism that can improve the positional accuracy between a photographing optical system and a finder optical system with a simple structure. And

[0005]

According to the present invention, there is provided a lens group for changing a finder magnification.
A lens moving frame that supports and moves the lens group, a guide shaft that guides the lens moving frame movably 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, wherein the guide shaft is used as a guide for positioning and mounting the finder with respect to the photographing lens.

[0006]

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

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a finder mounting mechanism according to the present invention will be described below in detail 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 where a lens barrel 10 and a finder main body 20 are separated.

In the lens barrel 10, a T / W lens (not shown) capable of switching between a telephoto and a wide-angle two-focal point is provided as a photographing lens (not shown). In addition, 12 is the T /
This 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 formed, an opening 14B for the finder is formed, and a screw hole 16A is formed in the finder mounting portion 16.
Are drilled.

On the other hand, within the finder body 20, lens moving frames 22, 24 for moving a lens group for changing the finder magnification are arranged movably in the finder optical axis direction. Further, an attachment portion 28 for attaching the finder body 20 to the lens barrel 10 is provided below the finder body 20. The finder body 20 is also provided with a not-shown focusing screen, a field mask, an eyepiece, and the like.

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 arranged so as to be movable in the direction of the finder optical axis when the respective guide portions 22A and 24A are inserted into the guide shaft 26.

The guide portions 22A and 24A are provided with cam followers 22B and 24B, respectively. The cam followers 22B and 24B are provided with a cam (not shown) which is interlocked with the focus switching of the T / W lens. Is engaged. Accordingly, the lens moving frames 22 and 24 are moved in accordance with the switching of the focus of the T / W lens, and thereby the finder magnification is changed.

Next, a 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 member serving as a main reference 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 improved.

Next, the finder mounting portion 1 on the lens barrel side
6 and a mounting portion 28 on the finder main body side are screwed together with set screws 29. Thus, 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 in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The lens barrel 30 shown in FIG.
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
In this embodiment, a guide shaft 42 is different from the guide shaft 26 of the finder main body 20 shown in FIG. This finder body 4
When the lens mount 30 is mounted on the lens barrel 30, the tip of the guide shaft 42 of the finder body 40 is inserted into the mounting guide hole 14A of the lens barrel 10 and the guide shaft 42 is
Is fitted into the guide groove 32A of the lens barrel 30. This makes it possible to increase the accuracy in the position between the photographing optical system and the finder optical system and in the optical axis direction.

Next, the finder mounting portion 1 on the lens barrel side
The viewfinder body 20 is attached to the lens barrel 10 by screwing the mounting member 6 to the mounting portion 28 on the finder body side with a set screw 29. The taking lens is not limited to the T / W lens,
A zoom lens that continuously moves the focal point may be used. Further, the mounting guide holes and the guide grooves are not limited to those directly formed in the lens barrel, but may be formed in a front base plate, a rear base plate or the like on which the lens barrel or the like is mounted.

[0016]

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

[Brief description of the 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 part 14A ... mounting guide hole 16A ... screw hole 20, 40 ... finder body 22, 24 ... lens moving frame 22A, 24A ... guide part 26, 42 ... guide shaft 28 ... Mounting part 29: Set screw

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mitsushi Misawa 3--11-46 Izumi, Asaka-shi, Saitama Fuji Photo Film Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) G03B 13 / 12

Claims (3)

(57) [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 focal point of a photographing lens. A finder mounting mechanism having a drive mechanism for moving the lens moving frame in the optical axis direction with the movement, wherein the guide shaft is used as a guide for positioning the finder with respect to the photographing lens and as a mounting guide. 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 the optical axis direction, and a focal point of the photographing lens. A finder mounting mechanism having a drive mechanism for moving the lens moving frame in the optical axis direction with the movement, wherein a mounting guide hole is formed in a lens barrel of the photographing lens or a base plate to which the lens barrel is fixed, A finder mounting mechanism, wherein one end of the guide shaft is inserted into the guide hole, and the finder is fixed with a set screw. 3. A guide groove is formed in a lens barrel of the photographing lens or a base plate to which the lens barrel is fixed, and the other end of the guide shaft is fitted into the guide groove. Item 2. A finder mounting mechanism.