JPH05341353A - Visual field frame switching device for albada finder - Google Patents

Abstract

PURPOSE:To display only either of a visual field frame for a 1st size and a visual field frame for a 2nd size according to whether it is the photographing of the 1st size or the photographing of the 2nd size. CONSTITUTION:As for a visual field frame switching device for an Albada finder having the visual field frame 22 for a normal size on the front of an ocular 20, a visual field frame plate 30 is inserted in or pulled out from space between an objective lens 10 and the ocular 20 according to whether it is the photographing of the normal size or the photographing of a panoramic size. Namely, in the case of the photographing of the normal size, the plate 30 is retreated out of an optical path so as to display the visual field frame for the normal size. On the other hand, in the case of the photographing of the panoramic size, the plate 30 is inserted and the visual field frame 22 for the normal size is shielded by the light shielding frame 36 of the plate 30, so that the virtual image of the visual field frame for the panoramic size is formed. Thus, only the visual field frame according to whether it is the photographing of the normal size or the photographing of the panoramic size is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field frame switching device for an alvada type viewfinder, and more particularly to a field frame switching device for an alvada type viewfinder applied to a camera capable of photographing normal size and panoramic size.

[0002]

2. Description of the Related Art Conventionally, a finder applied to a camera capable of shooting normal size and panoramic size is
A field frame as shown in FIG. 5 is used. In the figure, 2 is a normal size field frame, 4 is a field frame for parallax correction during short-distance shooting, 6 is a panoramic size field frame, and 8 is a target mark.

That is, when taking a normal-size image, the composition is determined so that the subject is in the field frame 2, and in the case of short-distance image capturing, the composition is determined so that the object is not above the field frame 4. Further, in the case of panoramic size photography, the composition is determined so that the subject is within the field frame 6. still,
The aspect ratio of normal size is 2: 3, and the aspect ratio of panoramic size is 1: 2.6.

[0004]

However, in the case of the above-mentioned conventional viewfinder, since both field-of-view frames are always visible, the photographer selects the field-of-view frame according to whether normal-size shooting or panoramic-size shooting is required. The composition must be determined so that the subject can enter the selected field frame, and it is necessary to always pay attention to the selection of the field frame.Also, when using normal size shooting, use the field frame for panorama size, There is a problem that mistakes such as using a normal size field frame during panorama shooting are likely to occur.

In the visual field frame switching device of Japanese Patent Application No. 1-131886, it is disclosed that the normal visual field frame is shielded by the light shielding portion of the panoramic visual field frame plate during panoramic photographing. No specific shielding means is described. Further, during normal shooting, there is a drawback that the finder image becomes difficult to see due to the reflection of light rays on the retracted panoramic field frame plate.

In the visual field frame switching device of Japanese Patent Application No. 1-131887, a normal visual field frame and a panoramic visual field frame are formed on the same surface, and a blind member is used to selectively cover unnecessary frames. Therefore, due to space limitations, there is little freedom in the stroke and shape of the blind member, and it is difficult to completely switch between the panoramic field frame and the normal field frame.

In the visual field frame switching device of Japanese Patent Application No. 2-60778, the normal visual field frame and the panoramic visual field frame are provided independently of each other, so that the visual field frames can be freely designed. Since the display is switched completely, the display is easy for the user to understand, but it is difficult to manufacture a block-shaped transparent display body, and reflection by the upper and lower surfaces of the block-shaped transparent body becomes a problem.

Further, the visual field frame switching device of Japanese Patent Application No. 2-7746 requires a high-priced component such as a prism because it is a real image type finder, and both of them have the drawback of increasing the cost. The present invention has been made in view of the above circumstances, and whether the first size field frame or the second size field frame is used depending on whether the first size image capturing or the second size image capturing is performed. It is an object of the present invention to provide a visual field frame switching device for an albada-type finder that can display only one of the visual field frames.

[0009]

In order to achieve the above-mentioned object, the present invention is directed to an alvada type finder applied to a camera capable of photographing a first size and a second size. A first size field frame disposed on the front surface of the lens, and a second size field frame plate which is disposed between the objective lens and the eyepiece lens of the Albada finder so as to be freely inserted and removed. When shooting the first size, the field frame for the second size is retracted out of the optical path of the finder, and when shooting the second size, the field frame for the second size is provided between the objective lens and the eyepiece. And a field frame plate switching mechanism which is disposed in the finder optical path and shields at least a part of the first size field frame with a light blocking portion formed on the second size field frame plate. as a feature That.

[0010]

According to the present invention, the second size is used when shooting the first size.
Since the size field frame plate is retracted from the finder optical path, the second size field frame is not visible and only the first size field frame is visible. When shooting the second size, the first size field frame is hidden by the light shielding frame of the second size field frame plate, so the first size field frame cannot be seen, only the second size field frame. appear. As a result, it is possible to display only the field frame depending on whether the first-size shooting or the second-size shooting is performed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a field frame switching device for an albada type finder according to the present invention will be described in detail below with reference to the accompanying drawings. First, the principle of the field frame switching device of the albada type finder according to the present invention will be described with reference to FIGS.

As shown in FIG. 2, the field frame switching device of the albada type finder is composed of an objective lens 10, a half mirror lens 12 and an eyepiece lens 20, and the inside surface 12A of the half mirror lens 12 is semitransparent. A reflective film is vapor-deposited so as to be a concave mirror, and a field frame 22 is vapor-deposited on the inner surface 20A of the eyepiece lens 20. The field frame 22 is a normal size field frame shown in FIG.

Therefore, when photographing for normal size,
The field frame 22 is illuminated by the light entering from the objective lens 10,
The virtual image of the field frame 22 is formed at a distance by being reflected by the inner surface 12A of the half mirror lens 12. Then, the virtual image of the field frame 22 and the image of the subject are simultaneously observed by the eyepiece lens 20. In the field frame switching device for the albada type finder according to the present invention, as shown in FIG. 2, a field frame plate 30 is arranged between the half mirror lens 12 and the eyepiece lens 20 so as to be freely inserted and removed. That is, the field frame plate 30 is rotatably arranged via the support shaft 30A, and when it is rotated counterclockwise, it is inserted between the half mirror lens 12 and the eyepiece lens 20 (see FIG. (State indicated by a solid line 2), when rotated in the clockwise direction, it is retracted from between the half mirror lens 12 and the eyepiece lens 20 (state indicated by a chain double-dashed line in FIG. 2).

The field frame plate 30 has a panoramic lens 32 shown in FIG. 3B, and a panoramic field frame 34 is formed on the panoramic lens 32. The panoramic visual field frame 34 is illuminated by the light entering from the objective lens 10 when the visual field frame plate 30 is inserted between the half mirror lens 12 and the eyepiece lens 20 as shown in FIG. As a result, a virtual image of the panoramic size field frame 34 is formed.

The field frame plate 30 functions as a light-shielding frame 36 at the frame part thereof, that is, the part other than the panoramic lens 32, and the field frame plate 30 has the half mirror lens 12 as shown in FIG.
The field frame plate 30 when inserted between the eyepiece lens 20 and the eyepiece lens 20.
The light-shielding frame 36 of the normal field frame 22 of the eyepiece 20
And covers the field frame 22 on the front side of. As a result, the normal field frame 22 is hidden during panoramic photography, and
As shown in (C), only the panoramic field frame 34 is visible.
In this case, the left and right lines 22A are also used as a normal size field frame.

As described above, when the combined field-of-view frame is used, the design is such that the corners of the field-of-view frame do not overlap, as in the embodiment, so that the diopter difference between the field-of-view frames 22A and 34 does not become apparent. It is desirable to do. Further, it is not always necessary to use the same size, and the normal size field frame 22 may be entirely blocked and the panoramic size field frame may be displayed on four sides.

Further, in this embodiment, since the normal field frame 22 is covered with the light-shielding frame 36 of the field frame plate 30 during panoramic photography, the width of the panoramic lens 32 of the field frame plate 30 can be narrowed accordingly. .. As a result, the reflected light on the retracted surface of the panoramic lens 32 can be reduced during normal shooting, so that the viewfinder is easy to see without extra reflected light.

FIG. 1 is a perspective view of a main part of a switching mechanism to which the field frame switching device of the albada type finder shown in FIG. In FIG. 1, this camera is switched to a state in which panoramic size shooting is possible by a switching knob 40 that switches between panoramic size shooting and normal size shooting, and the panoramic size field frame 34 can be seen as described above. Is becoming In addition, the upper and lower light blocking members 42A,
42B shields the upper and lower portions of the film not shown,
It can be exposed in a panoramic size aspect ratio. Next, a case of switching from the panoramic size shooting state to the normal shooting state will be described.

In this case, the switching knob 40 is moved from the panoramic position P to the normal position N as shown by the arrow. By the movement of the switching knob 40, the members described below move or rotate in the directions P → N indicated by the arrows. That is, the lever 44 moves in the arrow N direction, and the lever 46 held by the engaging portion 44A rotates in the N direction around the shaft 46A. By the rotation of the lever 46 in the N direction, the lever 48 held by the engagement portion 46B is rotated in the arrow N direction about the shaft 48A. By the rotation of the lever 48, the rod 49 held in the elongated hole 48B of the lever 48 is rotated in the direction of the arrow N, and the rotation of the rod 49 causes the field frame plate 30 to resist the urging force of the spring 50. It is rotated in the direction of arrow N about 30A. As a result, the field frame plate 30 inserted between the half mirror lens 12 and the eyepiece lens 20 is retracted, and the panoramic size field frame 34 is switched to the normal size field frame 22. The spring 50 is configured as a click spring and holds the field frame plate 30 at the normal position or the panoramic position.

On the other hand, when the lever 46 rotates in the direction of arrow N, the lever 54 held by the engaging portion 46C rotates in the direction of arrow N around the shaft 54B against the biasing force of the spring 55. .. At the same time, the lever 56 that engages with the engagement pin 54A of the lever 54 rotates in the direction of arrow N about the shaft 56A against the biasing force of the spring 55 due to the rotation of the lever 54.
The rod 58 held by the engaging portion of the lever 54 is rotated in the N direction by the rotation of the lever 54, and the rod 60 held by the engaging portion 56B of the lever 56 is rotated in the N direction. When the rods 58 and 60 respectively rotate in the N direction, the light blocking members 42A and 42B rotate in the N direction. Then, when the upper and lower light shielding members 42A and 42B are rotated in the direction of arrow N and retracted, the film (not shown) can be exposed with the normal size aspect ratio. The spring 55 is configured as a click spring and holds the light blocking members 42A and 42B at the normal position or the panoramic position. To switch from the normal position N to the panoramic position P, the reverse operation is performed.

FIG. 4 shows a field frame applied to a camera that can be used by switching between full-size shooting and half-size shooting. That is, in FIG. 4A, a full-size field frame 60 is displayed, and like the field frame 22, this field frame 60 is vapor-deposited on the inner surface 20A of the eyepiece lens 20. A half size lens 64 is provided on the field frame plate 62 shown in FIG. 4B, and a half size field frame 66 is vapor-deposited on the half size lens 64. In the field frame 62, a light shielding frame 68 is formed around the half size lens 64.

The field frame plate 62 operates in the same manner as the field frame plate 30, and is retracted to the outside of the optical path during full-size photography as shown in FIG.
Only the full-size visual field frame 60 of (A) is displayed, and it is inserted into the optical path during half-size shooting, and the visual field frame 60 is shielded by the light-shielding frame 68. As shown in FIG. The field frame 66 is displayed. In this case, the upper and lower lines 6
0A is also used as a full-size field frame.

Although the first size is the normal size and the second size is the panoramic size in the embodiment of the present invention, the second size may be a cine size or a high definition size. In addition, the first, the second, or the like from the normal size, panorama size, cine size, and high-definition size is appropriately
You may choose the size of.

[0024]

As described above, according to the visual field frame switching device of the albada-type finder according to the present invention, the visual field for the first size is selected depending on whether the image is of the first size or the second size. Only one of the frame and the field frame for the second size can be displayed, which makes it easier to see the field frame and solves the problem that the field frame is mistaken for composition.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a switching mechanism of a camera to which a field frame switching device for an albada-type finder according to the present invention is applied and which is capable of shooting normal size and panoramic size.

FIG. 2 is a diagram showing an optical system of a field frame switching device of an albada type finder according to the present invention.

3 (A), (B), and (C) are front views of a field frame.

FIGS. 4A, 4B, and 4C are front views of the field frame of another embodiment.

FIG. 5 is a plan view of a field frame of a conventional finder applied to a camera capable of shooting normal size and panoramic size.

[Explanation of symbols]

 10 ... Objective lens 20 ... Eyepiece 22 ... Normal size field frame 30 ... Field frame plate 34 ... Panorama size field frame 36 ... Light-shielding frame

Claims (2)

[Claims] 1. An arvada type finder applied to a camera capable of photographing a first size and a second size, wherein a field of view for the first size disposed in front of an eyepiece lens of the albada type finder. A frame, a second size field frame plate that is freely inserted and removed between the objective lens and the eyepiece lens of the Albada finder, and a second size field frame plate when photographing the first size To the outside of the viewfinder optical path, and when the second size image is taken, the second size field frame is arranged between the objective lens and the eyepiece lens in the viewfinder optical path, and at the same time, the second size field of view is used. A visual field frame switching device for an albada-type finder, comprising: a visual field frame plate switching mechanism that shields at least a part of the visual field frame of the first size by a light shielding portion formed on the frame plate. 2. When blocking a part of the first-size field frame with a light-shielding portion formed on the second-size field frame plate, a part of the first and second size field frames is provided. 2. The field frame switching device for an albada finder according to claim 1, wherein the field frames are commonly used, and the corners of the field frames commonly used do not overlap.