JPS5997129A - Small sized camera - Google Patents

Abstract

PURPOSE:To form a small-sized camera which uses an image reversal type miniature film having no parallax by providing a luminous flux splitting member having about 45 deg. angle at the intermediate of an imaging optical system. CONSTITUTION:A photographing lens system 1 is formed of an imaging optical system having a front lens 1a, an intermediate lens 1b having internally a splitting member 1c and a rear lens 1d on the optical axis bent at a right angle by a splitting member 1c. The member 1c is a semitransparent mirror which forms a finder optical system together with an eyepiece lens 7 provided on the optical axis which has transmitted the partial luminous flux incident to the lens 1a and advanced straightforwardly. A shutter 8 is installed between the intermediate lens 1b on the curved optical axis of the photographing system and the lens 1d. The need for a largesized reflecting mirror is thus eliminated and the height of the camera is decreased, whereby the size thereof is reduced and the operation is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small camera using an image reversal film that takes pictures using an image reversal film and performs self-developing processing.

In the image reversal type self-developing camera, as shown in the folding camera of FIG. This is a type of camera in which the image is developed and sent outside the camera.
Since the screen size of the image reversal film is larger than the 35 m format, a photographing lens 1 with a long focal length is required. Therefore, in order to prevent the reflection mirror 2 from becoming large and causing a large reduction in the height of the camera, the reflection mirror 2 must be provided slightly apart from the film cassette 3, which further increases the height of the camera.

For these reasons, the height of the camera in the shooting state is significantly higher than that of a general camera, and operation tends to become unstable.

This type of camera also has a viewfinder (not shown).
is provided in the camera body 5, but due to the structure of the camera body to accommodate the large film cassette 3 and rollers 4, the front and back dimensions are large. Therefore, if a simple reverse Galileo type finder is used, a large objective lens is required, making it difficult to assemble. If it is crowded, it will not be compact. On the other hand, when a real-image type finder is used, since this type of camera has a large angle of view, the viewing angle of the finder must also be large, which tends to increase aberrations and deteriorate visibility.

In any case, when the viewfinder is incorporated into the camera body 5, it is far away from the photographic lens 1, so the parallax will be poor, and in close-up photography where this type of camera is often used, the balax will be It is also larger and is considered to be the weak point of this type of camera. FIG. 2 is a side sectional view showing the camera in a folded state.

The present invention aims to improve each of the drawbacks of the image reversal type self-processing camera of the conventional structure described above, and to provide a compact camera using a self-reversing type film that is compact and free of parallax. The purpose of this is to provide a light beam splitting member at an angle of approximately 45° in the middle of the imaging optical system in a camera using film, and use the reflected light from the splitting member as an optical system to the photosensitive surface. Did you use transmitted light as a finder optical system? This is achieved using a compact camera that uses a distinctive image reversal film.

The present invention will be explained in detail below with reference to the drawings.

FIGS. 3 and 4 are side sectional views of a foldable image-reversing self-developing camera shown as one embodiment of the present invention in a shooting state and a folded state, respectively.

In the figure, the photographic lens system includes an intermediate lens 1b having a dividing member 1c in the front lens la and r'1 part, and the dividing member 1.
It consists of an imaging optical system having a rear lens 1d on the optical axis bent at a right angle by c. The light beam splitting member 1c is a semi-transparent piece that forms a finder optical system together with the eyepiece lens 7 provided on the optical axis that passes a part of the light beam incident on the front lens 1a and travels straight, and also forms a finder optical system. A shutter 8 is installed between the intermediate lens 1b and the rear lens 1d on the optical axis of the system.

By attaching the photographing lens using the imaging optical system, the two large reflecting mirrors in the conventional image reversing type self-developing camera shown in FIGS. 1 and 2 are no longer required, and the reflecting mirror 2 is The disadvantage of decreased contrast due to unnecessary exposure is also eliminated. Therefore, the incident optical axis of the photographic lens can be set low and placed close to the film cassette 3, making it possible to use a short focal length lens, and the height of the camera can be adjusted as shown in Figures 1 and 2. Compared to conventional cameras, it is significantly lower and more compact, making operation more stable.

Furthermore, when the handle 10 is moved along the guide groove 11 and the end arm 12 is rotated to fold the movable part 6 into the camera body 5, a photograph can be taken in the same manner as the conventional camera shown in FIGS. 1 and 82. The movable member 6 provided with an optical system and a finder optical system can be folded to become a compact camera that can be carried.

In addition, since the finder is placed in alignment with the photographing optical axis, there is no variax at all, and it is possible to accurately determine the screen range and take photographs not only for general photography but also for close-up photography. It became so.

As is clear from the above description, the present invention has made it possible to realize a compact camera using an image reversal film that is short in height and can provide a clear image without any variation.

Note that in this embodiment, the light beam splitting member 1c is the intermediate lens 1b.
is cut with an angle change of 45 degrees, a thin metal film etc. is deposited on the polished cut surface, and then glued again. Most of the light flux that passes through the front lens 1 is reflected by the light flux splitting member 1c. and enters the photographing optical system, and a part of the light beam splitting member IC
The light passes through and enters the finder optical system. The intermediate lens 1b is a concave lens for the transmitted light beam, and the front lens 1a and the intermediate lens 1b combine to form a concave lens for the transmitted light beam, and serve as an objective lens system of the finder optical system.

In this example, the light beam splitting member IC was provided inside the lens or prism, but it is also possible to use a semi-transparent body made of an extremely thin resin such as polynyster film, a metal thin film, or a dielectric multilayer [1] as the light flux splitting member. , it may be used for mounting at an angle of 45° to the optical axis.

Further, in this embodiment, the shutter 8 is provided between the intermediate lens 1b and the rear lens 1d, but it can also be of a so-called behind shutter type provided between the rear lens 1d and the photosensitive surface.

[Brief explanation of the drawing]

FIGS. 1 and 2 are side sectional views showing a conventional foldable image-reversing self-developing camera in a photographing state and a folded state, respectively. FIG. M3 and FIG. 4 are side sectional views showing one embodiment of the camera according to the present invention in a shooting state and a folded state, respectively. 1...Photographing lens 1a...r Front lens 1b...Intermediate lens 1c...Light beam splitting member 1d...Rear lens 3...
Film cassette 4...Feeding roller 5
...Camera body 6...Movable part
7... Eyepiece 8... Shutter
10...Tasuki 11...Guide groove 12...Arm 13...Yoshimi Kuwabara, the bellows agent

Claims (3)

[Claims] (1) A beam splitting member with an angle of approximately 45° is provided in the middle of the optical system, the reflected light from the splitting member is used as an optical system for the photosensitive surface, and the transmitted light from the splitting member is used as a finder optical system. A small camera that uses image reversal film. (2) A small camera using an image reversal film according to claim 1, characterized in that a shutter is provided between the dividing member and the photosensitive surface. (3) The optical system provided with the dividing member is movable with respect to the photosensitive surface, and is foldable when not in a photographing state. A small camera using an image reversal film as described in Section 1.