JPH05100304A - Bifocal camera - Google Patents

Abstract

PURPOSE:To provide a bifocal camera in which space is saved and a cost is lowered without complicating a camera constitution by attaining a bifocal photographing function by using a photographing system having a simple constitution and a pair of finders. CONSTITUTION:When a camera main body 1 is set in a state where a finder system is made a Galilean finder, the photographing system is constituted of a photographing lens 4 for wide, a shutter 6 for wide, a half mirror 8 and a film 9 in that order from an object side, so that short focus photographing can be executed. And when the camera main body 1 is set in a state where the finder system is made an inverted Galilean finder, the photographing system is constituted of a photographing lens 3 for telephoto, a shutter 5 for telephoto, a total reflecting mirror 7, the half mirror 8 and the film 9 in that order from the object side, so that long focus photographing can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a bifocal photographing system, and more particularly to a camera applicable to a disposable camera or the like.

[0002]

2. Description of the Related Art Conventionally, in this type of bifocal compact camera, two sets of taking lenses, films and exposure mechanisms are provided, respectively, and a bifocal taking system is constructed with two sets of viewfinders. As a wide-angle / telephoto switching means, there is a conversion lens for changing the focal length, or a conversion lens by rotating the finder in front of the photographing lens (for example, Japanese Utility Model Publication No. 63-58236). (See the official gazette and Japanese Utility Model Laid-Open No. 1-135431).

[0003]

By the way, in a camera having a bifocal photographing function such as a plurality of photographing lenses, films, an exposure mechanism, and a viewfinder as described above, the camera structure is complicated, and the size and cost are reduced. It was a bottleneck in doing it. Further, in a camera having a bifocal photographing function that changes the focal length by a conversion lens to switch between wide-angle and telephoto, the configuration of the camera becomes complicated and the conversion lens may be lost. .. The present invention solves the above-mentioned problems, and in a single-use camera or the like, a dual focus shooting function is achieved by using a shooting system having a simple structure and a set of viewfinders, thereby making the camera structure complicated. It is an object of the present invention to provide a bifocal camera that saves space and costs without doing so.

[0004]

In order to achieve the above object, the present invention provides two sets of photographing lenses having different focal lengths, exposure means capable of switching the operation corresponding to each photographing lens, and an optical path from a subject. A bifocal camera with a finder system composed of a switching total reflection mirror and a half mirror, a film-forming system composed of film, and a finder system composed of a lens group having negative power and a lens group having positive power The photographing system at the time of photographing is composed of a short focus lens of the photographing lenses, a short focus exposure means of the exposure means, the half mirror, and the film in this order from the subject side, and the viewfinder system is the subject side. To the lens group having the negative power and the lens group having the positive power in this order. Long focal lens of the taking lens from the side, the long focal exposure unit of the exposure means,
The total reflection mirror, the half mirror, and the film are arranged in this order, and the finder system is composed of a lens group having the positive power and a lens group having the negative power in this order from the subject side. ..

[0005]

According to the above construction, when the camera body is arranged so that the viewfinder system is of a type in which the virtual image of the object by the lens group having negative power is viewed by the lens group having positive power in the eyepiece, The photographing system is composed of a short focus lens of the photographing lenses, a short focus exposure means of the exposure means, a half mirror, and a film in this order from the subject side, and short focus photography becomes possible. Also, if you set the camera body so that the viewfinder system is reverse Galileo type,
The photographing system is composed of a long focus lens of the photographing lenses, a long focus exposure means of the exposure means, a total reflection mirror, a half mirror, and a film in this order from the subject side, and long focus photography becomes possible. Since the short focus shooting lens, the long focus shooting lens, and the viewfinder lens group are located in front of and behind the camera body, the camera body can be turned upside down during short focus shooting and long focus shooting. I will take a picture.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the bifocal camera of the present invention is applied to a disposable camera will be described below with reference to the drawings. Figure 1
Shows an optical path of a photographing system at the time of long-focus shooting (hereinafter referred to as tele time) in this camera, and FIG. Further, FIG. 3 shows an optical path of an image pickup system in short-focus shooting (hereinafter referred to as wide time) in the present camera, and FIG. 4 shows an optical path of a finder system in wide angle in the present camera.

In these figures, a camera body 1 having a bifocal photographing function is packaged with a packaging member 2, and a telephoto lens 3 and a wide-angle lens 4 are provided.
The packaging member 2 is symmetrically arranged on the front surface and the back surface, respectively. The telephoto taking lens 3 and the wide-angle taking lens 4 respectively include a telescopic shutter 5 and a wide-angle shutter 6 as an exposure mechanism. The telescopic shutter 5 and the wide shutter 6 are controlled by a release button (not shown) provided on the packaging member 2. The camera also
Total reflection mirror 7 and half mirror 8 constituting the Z optical system
Is provided. The total reflection mirror 7 reflects the light flux from the telephoto lens 3 to the half mirror 8 during telephoto. Further, the half mirror 8 is a total reflection mirror 7 during telephoto.
From the taking lens 4 for wide, and transmits the light from the taking lens 4 for wide. In front of the half mirror 8,
The film 9 on which the subject is imaged is set on the inner surface of the packaging member 2 so as to face the above. On the other hand, a finder convex lens 10 (a lens having a positive power) and a finder concave lens 11 (a lens having a negative power) are provided on the front surface and the back surface of the packaging member 2, respectively, so that they can be seen from behind or in front of the camera body. It constitutes a set of finder system. This makes it possible to provide a viewfinder magnification suitable for both tele and wide shooting.

FIG. 5 shows the states of the photographing system and the finder system of the camera having the above-mentioned structure at the time of telephoto. In the drawing, in the shooting system, the light flux from the subject passes through the telephoto shooting lens 3 and is then reflected by the total reflection mirror 7 and the half mirror 8 to form an image on the film 9. Here, since the light flux from the subject is reflected by the Z optical system an even number of times, the light flux does not act from the back surface of the film 9,
In addition, since the wide shutter 6 (not shown in FIG. 5) is closed during telephoto, the wide photographing lens 4
There is no fear that the light flux from the light reaches the film 9. In the finder system, the light flux of the subject from the finder convex lens 10 reaches the pupil using the finder concave lens 11 as an eyepiece, forming a so-called Galileo finder, and a finder magnification larger than the same magnification can be obtained. This allows the photographer to obtain a finder image suitable for telephoto shooting.

FIG. 6 shows the states of the photographing system and the finder system when the camera is wide. In the drawing, in the photographing system, the light flux from the subject passes through the wide-angle photographing lens 4 and then passes through the half mirror 8 to form an image on the film 9. Here, the light flux from the subject is the half mirror 8.
Since the light beam does not act from the back surface of the film 9 and the telescopic shutter 5 (not shown in FIG. 6) is closed at the time of widening, the light beam from the telescopic lens 3 is not transmitted. There is no fear of reaching the film 9. In the finder system, the light flux of the subject through the finder concave lens 11 is the finder convex lens 10
The so-called reverse Galilean finder that reaches the pupil using the eyepiece as the eyepiece is configured, and a finder magnification smaller than the same magnification can be obtained. This allows the photographer to
It is possible to obtain a finder image suitable for wide-angle shooting.

The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, although a disposable camera is shown in the above embodiment, a normal camera having a bifocal photographing mechanism may be used. Good. Further, the two exposure means of the tele shutter 5 and the wide shutter 6 may be composed of one release button and its switching mechanism.
It may be configured by individual release buttons.

[0011]

As described above, according to the present invention, in a camera having a bifocal photographing function, the photographing system includes two photographing lenses and an exposure mechanism, one film and a Z optical system,
Furthermore, since the viewfinder is a set of finder system composed of a lens group having a negative power and a lens group having a positive power, one set of finder system can be used for wide angle and telephoto without complicating the camera configuration. Both can be taken. Further, since the finder magnification is changed by one finder system without using a conversion lens, there is no fear of losing the conversion lens which is apt to occur in a bifocal camera having a complicated camera configuration.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an optical path of a photographing system during telephoto in a two-focus disposable camera according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an optical path of a finder system in the same camera at the time of telephoto.

FIG. 3 is a cross-sectional view showing an optical path of a photographing system of the same camera when it is wide.

FIG. 4 is a cross-sectional view showing an optical path of a finder system when the camera is wide.

FIG. 5 is a perspective view showing a state of a photographing system and a viewfinder system of the same camera during telephoto.

FIG. 6 is a perspective view showing a state of a photographing system and a finder system of the same camera during telephoto.

[Explanation of symbols]

 1 Camera body 3 Tele shooting lens 4 Wide shooting lens 5 Tele shutter 6 Wide shutter 7 Total reflection mirror 8 Half mirror 10 Viewfinder convex lens 11 Viewfinder concave lens

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Uno 2-3-13 Azuchi-cho, Chuo-ku, Osaka, Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Junichi Tanii 2-chome, Azuchi-cho, Chuo-ku, Osaka No. 13 Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Yasumasa Sugihara 2-3-3 Azuchicho, Chuo-ku, Osaka City Osaka International Building Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. Two sets of photographing lenses having different focal lengths,
The photographic system is composed of an exposure unit that can switch the operation corresponding to each photographic lens, a total reflection mirror and a half mirror that switch the optical path from the subject, and a film, and the finder system has a lens group with negative power and positive power. In a bifocal camera in which a finder system is configured with a lens group having a lens group having a , The half mirror, and the film in this order, and the finder system is configured in the order of the lens group having the negative power and the lens group having the positive power from the subject side in the long-focus shooting. Is a long focus lens of the shooting lens, a long focus exposure unit of the exposure unit, and the total reflection mirror. , The half mirror, the film, and the finder system is composed of a lens group having the positive power and a lens group having the negative power in this order from the object side. camera.