JPH07230110A - Finder capable of switching visual field frame - Google Patents

Abstract

PURPOSE:To reduce darkness in a visual field image even when a visual field frame is switched and to prevent the visual field frames from coexsiting in an Albada type finder capable of switching two kinds of visual field frames. CONSTITUTION:A panoramic display board 3 where a panoramic frame is vapor- deposited is turnably supported ahead of a full size frame 2a for ordinary photographing which is vapor-deposited to an ocular 2 so that it can get in/out of the optical path of the finder by a shaft 3a. When the panoramic frame is superposed on the full size frame 2a at the time of panoramic photographing, the upper and lower frame parts of the full size frame 2a and a parallax compensation frame are not seen because they are covered with the panoramic frame by forming the panoramic frame of a half mirror whose reflectance is 60-80%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an albada type viewfinder of a camera, and more particularly to a viewfinder capable of switching a field frame.

[0002]

2. Description of the Related Art Conventionally, an albada-type viewfinder of a camera capable of switching a visual field frame is arranged in front of a lens surface forming a visual field frame as described in Japanese Utility Model Laid-Open No. 3-71334.
A type in which a member that covers an unnecessary portion of the field frame and exposes a necessary portion is arranged, and the field frame is switched by moving the member, or an actual flat frame 3-7133
There is known a type in which the visual field frames are switched by attaching and detaching a member having a second visual field frame formed in front of the first visual field frame as described in Japanese Patent Laid-Open No. 5 and the like. Further, a type in which the above two types are combined is also known.

[0003]

By the way, in the above-mentioned prior art, since there is always a member that blocks light rays in the optical path of the finder, the real image of the member that blocks light rays becomes eclipsed in the visual field image, which is favorable. No field image can be obtained. Alternatively, when switching the view frame, two types are mixed in one view frame (for example, full frame can be seen in panorama frame).
There was that. Alternatively, in the method in which the light blocking member and the second visual field frame are integrally attached and detached, the pupil diameter is reduced due to the large light blocking portion during the second visual field frame.
It had the drawback of being difficult to look into.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks of the prior art, and to provide an albada type finder in which even if at least two types of visual field frames are switched and used, the two visual field frames do not coexist and are easy to see. To do.

[0005]

In order to achieve the above object, the present invention has at least two types of field frames, and
In the albada-type finder of the camera of the type in which the field frame is switched by attaching and detaching the member having the second field frame formed in front of the field frame, the second field frame has a reflectance of 6%.
It is a half mirror of 0 to 80%. Further, the second visual field frame is formed of a total reflection mirror, a part thereof covers the first visual field frame, and a light transmitting portion is provided in a part other than the concealed part and the second visual field frame. You may

[0006]

The albada-type finder having the above-described structure is a finder which has less shading, does not mix two visual field frames, and has a large pupil diameter for easy viewing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
It will be described based on. 1 and 2 are sectional views of the albada type finder of the present embodiment on the optical axis of the finder. FIG. 1 shows a normal (full size) shooting state, FIG. 2 shows a panoramic shooting state, and FIG. 3 shows a panoramic display panel. There is. This albada type finder is composed of an objective lens 1 and an eyepiece lens 2, and a panoramic display plate 3 which is rotatable about an axis 3a in front of the eyepiece lens 2 and is detachably laid out in the optical path of the finder is provided. Has been. A stopper 3b is provided on the side of the panoramic display plate 3 facing the eyepiece lens 2.
And a panorama frame 3d is formed.

A semitransparent reflection film 1a is vapor-deposited on the photographer side surface of the objective lens 1, and a full-size frame reflection film 2a is vapor-deposited on the object side surface of the eyepiece lens 2. Reference numeral 4 denotes a panoramic display lever, which is rotatably supported about a shaft 4a and is constantly urged counterclockwise by a spring (not shown). The pin 4b is provided at one end of the panoramic display lever, and the other end thereof is provided. A long hole 4c is provided and engaged with a crank portion 3c extending from the shaft 3a of the panoramic display plate 3. Reference numeral 5 is an interlocking pin whose head 5a presses the pin 4b of the panorama display lever 4 to restrict the rotation of the panorama display lever 4. The interlocking pin 5 moves up and down in conjunction with a mask that covers the film surface during panorama (not shown), and in the normal shooting state shown in FIG. 1, the mask is retracted out of the shooting optical path and shown in conjunction with it. It is pushed up and the panoramic display plate 3 is kept retracted to the outside of the finder optical path.

In the present embodiment having the above-mentioned structure, in the normal photographing state of FIG. 1, the reflection film 2a for full-size frame formed on the eyepiece 2 by the light entering from the objective lens 1
Is illuminated and further reflected by the semitransparent reflection film 1a formed on the objective lens 1. With the eyepiece 2, the photographer can observe the reflected image of the virtual image of the full-size frame and the subject image in an overlapping manner. FIG. 4 shows the viewfinder field image in this state, especially the reflection film 2a for the full-size frame.
Indicates the state of. In the figure, 2a1 is a full-size field frame,
Reference numeral 2a2 is a parallax correction frame for short-distance shooting, and 2a3 is a distance measurement frame.

Next, the panoramic photographing state shown in FIG. 2 will be described. In order to switch from the normal shooting state to the panoramic shooting state in FIG. 1, a user generally switches an operation member provided outside the camera so that a mask (not shown) covering the upper and lower portions of the screen of the film surface enters the shooting optical path. Then, the upper and lower sides of the film are covered. Therefore, when switching the viewfinder field frame, the interlocking pin 5 which moves up and down in conjunction with the mask is lowered downward as shown in FIG. 2, whereby the panoramic display lever 4 is released from the rotational position restriction and is rotated by a spring (not shown). Rotate clockwise. Then, the panorama display plate 3 rotates clockwise about the shaft 3a in conjunction with the rotation of the panorama display lever 4, and stops with the stopper 3b abutting the subject side surface of the eyepiece lens 2.

Here, a panorama frame 3d having a reflectance of 60 to 80% as shown in FIG. 3 is formed on the eyepiece surface side of the panoramic display plate 3, and this size is superposed on the full size frame. At times, as shown in FIG. 5, the upper and lower visual field frames 2a1 and parallax correction frame 2a2 of the full-size frame 2a are covered.

In this case, the image of the frame reflected by the reflective film 1a of the objective lens 1 and seen by the photographer's eyes is the panorama frame 3d formed on the panorama display plate 3 and the full-size frame 2a1 formed on the eyepiece 2. Of these, the left and right frames and the distance measuring frame 2a3. The upper and lower frames of the full-size frame 2a1 covered by the panorama frame 3d and the parallax correction frame 2a2 are 60-80 in the panorama frame 3d.
% Of the half mirror, and when it reaches the eyes of the photographer, it passes through the half mirror twice. Therefore, the amount of light is (1-0.6) ² to (1 -0.8) ² = 16% to 4%
Therefore, it is almost invisible to the photographer.

If the panorama frame 3d is formed of a total reflection mirror instead of a half mirror of 60 to 80% reflection, or if the portion covering the full size frame is formed of a member that does not transmit light, the effective optical path A large light-shielding portion is generated inside, and the light-shielding portion becomes a real image for the photographer, and the view image becomes obscured or the pupil diameter becomes small, resulting in a viewfinder that is very difficult to see.

On the contrary, when the panorama frame 3d is formed by a half mirror having a reflectance of 50% or less, the frame reflected as a virtual image on the photographer has a small amount of light because the reflectance is low, so-called thin. You can see it,
The visibility will be poor. In addition, since the reflectance of the portion covering the full-size frame is low, the transmittance is not high, and the full-size frame looks thin. In this way, the panorama frame and the full-size frame are mixed and the panorama frame is thin, so that a so-called vignetting picture is produced in which the subject is framed outside the frame. Therefore, by forming the panorama frame with a half mirror having a reflectance of 60 to 80%, it is possible to obtain a viewfinder with no shading, a large pupil diameter, and good frame visibility.

6 and 7 show a panorama frame portion in the second embodiment of the present invention. In order to simplify the description, the same parts as those in the first embodiment will be designated by the same reference numerals. In the first embodiment described above, the panorama frame 3d of the panorama display plate 3 is formed by a half mirror having a reflectance of 60 to 80%, whereas in this embodiment, the panorama frame 11a of the panorama display plate 3 is formed by a total reflection mirror. In addition to the formation, the full-size frame is covered by a part of the panorama frame 11b, and a light transmitting part 11c is provided in the other part. Other configurations not shown are the same as those in the first embodiment.

By the way, the thickness of the frame frame generally used in the Albada finder is 0.1 to 0.2 mm.
Since the thickness is only about 0.4 to 0.5 mm, it is sufficient to consider an error in assembling in order to cover it. Therefore, when the light-shielding portion (covering portion) is used as a separate member, 0.6 to 0.8 mm or more is required for manufacturing both the resin and the metal, which causes a peeling.

On the other hand, when the panorama frame is formed by vapor deposition of the total reflection mirror as in the present embodiment having the above-mentioned structure, generally, a minimum distance of about 0.1 mm is possible.
A thin light-shielding portion of 0.4 to 0.5 mm is possible. For this reason, it is possible to allow light to sufficiently pass through the portions other than the necessary portions, and it becomes possible to provide a viewfinder with less shading and in which no field frame is mixed. That is, as in the viewfinder image of the full-size frame 11a shown in FIG. 7, the full-size frame 2a is covered with a part of the cover-up portion 11b and the photographer is informed that the full-size frame 2a is in the panoramic state (P). Is also useful for preventing the light transmission part 1
A field image with less shading is obtained by 1c.

In each of the above embodiments, the first visual field frame has a full size and the second visual field frame has a panoramic size.
For the second visual field frame, for example, half size, cine size, or high definition size may be selected as necessary.

[0019]

As described above, according to the present invention, the field frame is switched by attaching and detaching the member having at least two kinds of field frames and having the second field frame formed in front of the first field frame. In the arvada type viewfinder of the camera of the type that performs the second view frame, the second view frame is formed of a half mirror having a reflectance of 60 to 80% or a total reflection mirror, and a part of the second view frame is used for the first view field. By covering the frame and forming the light-transmitting part in a part other than the covering part and the second visual field frame, it is possible to obtain an alvada-type viewfinder with less shading, which is easy to look into and has good visibility. effective.

[Brief description of drawings]

FIG. 1 is a sectional view of a finder capable of switching field frames according to a first embodiment of the present invention in a normal (full size) shooting state.

FIG. 2 is a cross-sectional view of a panoramic image capturing state.

FIG. 3 is a perspective view of the panoramic display plate.

FIG. 4 is a viewfinder field image in the full size state.

FIG. 5 is a viewfinder field image in the panoramic state.

FIG. 6 is a configuration diagram of a panorama frame according to a second embodiment of the present invention.

FIG. 7 is a viewfinder image in the panoramic state.

[Explanation of symbols]

1 ... Objective lens, 1a ... Semi-transparent reflective film, 2 ... Eyepiece, 2a ... Full size frame reflective film, 3 ... Panorama display panel, 3d, 11a ... Panorama frame, 4
..Panorama display lever, 5 ...

Claims (2)

[Claims] 1. A first frame having at least two types of field frames.
In the albada-type finder of the camera of the type in which the field frame is switched by attaching and detaching the member having the second field frame formed in front of the field frame, the second field frame has a reflectance of 6%.
A viewfinder with a switchable field-of-view frame, which is characterized by being formed from a 0 to 80% half mirror. 2. A first frame having at least two types of field frames.
In an albada-type viewfinder of a camera of a type in which the field frame is switched by attaching and detaching a member having a second field frame formed in front of the field frame, the second field frame is formed by a total reflection mirror, A viewfinder capable of switching view fields, characterized in that it partially covers the first view frame, and has a light transmitting part in a part other than the cover and the second view frame.