JP2984186B2 - Multi-sided shooting method of copy camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-side photographing method of a diffusion transfer type copying camera used for producing a printing plate.

[0002]

2. Description of the Related Art In a diffusion transfer type copying camera, a latent image is formed by exposing a planar image of an original to a photosensitive material called negative paper, and an image receiving material called positive paper is formed on the exposed photosensitive material. Are superimposed on each other, and this is put into a developer, and the image recorded on the photosensitive material is diffused and transferred to the image receiving material. In order to form a latent image on the photosensitive material, the type of photographing a document with a camera, it is necessary to undistorted can accurately record up large document about A ₃ size, and to have a scaling function Therefore, the copying camera becomes very large and heavy.

For this purpose, a scanning unit scans the surface of a document placed on a transparent glass platen from below into a slit shape, and exposes a slit-shaped image of the document to a conveyed sheet-like photosensitive material via a lens. By doing so, the apparatus can be simplified and downsized, and can be duplicated as if it were a copy. Also, in order to provide a reduction / enlargement function, the ratio of the optical path length from the original to the lens and from the lens to the photosensitive material can be changed, and the ratio between the scanning speed of the scanning unit and the feeding speed of the photosensitive material can be adjusted. It is.

In such a diffusion transfer type copying camera,
In principle, one document is exposed to one photosensitive material. However, multi-sided photographing in which a plurality of documents are exposed to one photosensitive material is also performed. In this multi-side photographing, first, a slit-shaped image of a document obtained by scanning a document in a slit shape by a scanning unit is exposed to a sheet-like photosensitive material conveyed in a horizontal direction, and then the photosensitive material is stopped. At the same time, the scanning unit is reversed to return to the initial position, the scanning unit and the photosensitive material are moved again to expose the slit image of the original to the photosensitive material, and this is repeated a predetermined number of times to form a plurality of images on one photosensitive material. Expose.

[0005]

In such multi-side photographing, an image-impossible area is formed between the exposed images as described below, and this image-impossible area is formed on an image receiving material to which the image has been transferred. The margin between the images is reduced. The narrower the margin is, the smaller the loss of the photosensitive material is. The smaller the margin is, the larger the number of images can be. I can shoot.

Since the motor for driving the photosensitive material does not use a pulse motor, it does not stop immediately after the exposure of the document is completed, but stops while reducing the rotation speed. That is,
The photosensitive material moves a certain distance from the speed at which the exposure can be accurately performed until it stops, but as shown in FIG. 2, the motor rotates at a regular speed, and stops at the point a where the exposure of the document is completed. Until the image is not possible. Also, light is applied to the stopped photosensitive material by the slit width, but the slit width is b.
No image is possible between point c and point c. In other words, the area from point a to point c is an image-impossible area when the exposure of the previous document is completed and the photosensitive material is stopped.

The same is true at the start of exposing the next document, and no image can be formed from the point c at the start to the point d at which the number of rotations allows the motor to perform accurate exposure. Therefore, since the exposure of the next document starts from the point d, the area from the point a to the point d is an image-impossible area after all, and becomes a blank portion between images on the image receiving material.

Accordingly, the present invention provides a multi-sided photographing method for a copying camera capable of photographing a large number of images with a single photosensitive material by reducing margins between images during multi-sided photographing, reducing loss of photosensitive material. The purpose is to provide.

[0009]

In order to achieve the above object, according to the present invention, a slit-like image of a document obtained by scanning a document in a slit shape by a scanning unit is converted into a sheet-like image conveyed in a horizontal direction. The photosensitive material is exposed, then the photosensitive material is stopped, the scanning unit is returned to the initial position, the slit image of the document is again exposed to the photosensitive material, and the exposure is repeated a predetermined number of times to form a plurality of photosensitive materials on one photosensitive material. In the multi-sided shooting method of a diffusion transfer type copying camera that exposes an image, when returning the scanning unit to the initial position, the photosensitive unit is exposed to the maximum distance that the motor that drives the photosensitive material moves from the start up to the normal rotation speed. The material is once conveyed in the reverse direction.

[0010]

That is, the photosensitive material is once conveyed in the reverse direction by a distance at which the motor for driving the photosensitive material moves from the rising to the normal rotation speed, so that, as shown in FIG. When the exposure starts, the motor starts rotating at the point c ', and at the point d, at which the motor can accurately rotate, the image becomes incapable at the end of the exposure of the previous document.
The image-impossible area is reduced by the distance that the photosensitive material is conveyed in the reverse direction, which coincides with the point.

[0011]

FIG. 1 conceptually shows a diffusion transfer type copying camera. In Figure 1, on the upper surface of the casing 10, for example up to A ₃ platen 11 clear glass of the document 50 can be mounted in size and is located, has become tabletop. A scanning unit 20 is arranged directly below the document table 11 so as to be movable at a variable speed V. The scanning unit 20 is of a two-lamp type equipped with two tube-shaped light source lamps 21 each surrounded by a gutter-shaped mirror 22, and scans the original 50 in a slit shape. M ₁ is disposed.
Therefore, the scanning unit 20 is the entire surface of which the document 50 moves is scanned, the reflected light of the original 50 is reflected in a horizontal direction by the mirror M _1. The light source lamp 21 has a rated voltage of 85
V, rated power consumption is 330W.

The first mirror unit 31 and the second mirror unit 32 have a pair of flat mirrors M ₂ and M ₃ and a pair of flat mirrors M ₄ and M ₅ mounted on a roof at an angle of 45 °. The optical axis is disposed on both sides of the lens 40 in the horizontal direction. Accordingly, the lens optical reflection of the original 50 is reflected by the mirror M ₁ is reflected by the mirror M _2, M ₃ 40
Incident on the lens 40 and exiting the lens 40 are mirrors M ₄ and M ₅
In reflected and further reflected by the plane mirror M _6. Then, on the exposure stage A, a slit-shaped image of the document 50 is formed on the photosensitive material 60 moving in the horizontal direction at the speed V ₀ .

The first mirror unit 31 has a speed of 1/2
V, that is, it moves in the same direction as the scanning unit 20 at half the speed of the scanning unit 20, so that the optical path length from the document 50 to the lens 40 does not change with the movement of the scanning unit 20. And the first mirror unit 3
The initial position of (1) (position to start moving) and the installation position of the second mirror unit 32 can be changed, thereby changing the optical path length from the original 50 to the lens 40 and from the lens 40 to the photosensitive material 60. , A reduction / enlargement ratio can be set. However, scanning unit 2
The scan 0 and the reduction / magnification in the direction perpendicular to the original can be set by changing the optical path length from the original 50 to the lens 40 and from the lens 40 to the photosensitive material 60. It is necessary to adjust the ratio between the scanning speed V of the original 50 and the moving speed V ₀ of the photosensitive material 60. For this reason, the scanning speed V is changed in conjunction with the reduction / enlargement magnification, and the reduction / enlargement magnification in the scanning direction and the direction perpendicular to the scanning are made the same.

The photosensitive material 60 is obtained by coating a photosensitive layer on the surface of a support made of paper or film. When exposed on the exposure stage A as described above, a latent image corresponding to the image of the original 50 is exposed. Formed in layers. This photosensitive material 60
Is stored in a magazine 61 in the form of a roll, but is sent out horizontally by a conveying roller 63 driven by a motor (not shown), and cut into a predetermined length by a cutter 62 to form a sheet. Then, as described above, the slit-shaped image of the original 50 is sequentially exposed on the sheet-shaped photosensitive material 60.

The image receiving material 70 is formed by coating an image receiving layer on the surface of a support made of paper or film, and is sent out from a magazine 71 by a transport roller 73. Then, the image receiving material 70 is superimposed on the exposed photosensitive material 60, and
After the developer enters the developer solution 80, it is pressed by the squeeze roller 81. In this developing solution, the latent image of the photosensitive layer is developed into blackened silver, while the silver halide in the unexposed portion is changed to a water-soluble silver salt and diffuses into the image receiving layer of the image receiving material 70. Then, the silver salt in the image receiving layer is reduced by the developer to form a black silver image. Then, the image of the original 50 is transferred to the image receiving material 70 on the paper output frame 82 in the paper output cover 12, and the image receiving material 70 and the photosensitive material 60 are taken out by opening the paper output cover 12.

In such a diffusion transfer type copying camera,
For example, when performing multi-sided photography in which three images are exposed on one photosensitive material, the length of the original 50 is about １ ／ of the length of the photosensitive material 60 cut into a sheet at the same-size photography. And
When the scanning of the document 50 is completed, the photosensitive material 60 stops and the scanning unit 20 returns to the initial position. However, in the present invention, as shown in FIG. Until the normal rotation speed is reached
The photosensitive material 60 is once conveyed in the reverse direction by the distance the 60 moves (the distance from the point c 'to the point d). And again the manuscript
50 is scanned to expose the moving photosensitive material 70. This operation is repeated twice to expose three images on one photosensitive material. Therefore, at the start of the second or third exposure of the document 50, the point d, at which the motor can accurately expose, coincides with the point c at which the image becomes incapable at the end of the exposure of the previous document 50, For one manuscript 50, d from point c '
The non-image area becomes smaller by the distance to the point.

As an example of the numerical values, in FIG. 2, the distance from the point a at which the exposure of the document ends to the point b at which the exposure of the document ends is 14 m.
m, slit width bc is 4 mm, c at start
The distance from the point to the point d, at which the motor can accurately perform the exposure, is 11 mm, and 29 mm is the non-imageable area. On the other hand, according to the present embodiment, as shown in FIG. 3, the photosensitive material 60 is conveyed in the reverse direction by a maximum of 11 mm, so that the area where the image cannot be formed becomes 18 mm. It is not necessary to convey in the reverse direction from point c at the start to point d at which the motor can accurately perform the exposure, but the non-imageable area is reduced by the distance conveyed in the reverse direction.

[0018]

As described above, according to the multi-sided photographing method of the copying camera of the present invention, when the scanning unit is returned to the initial position, the motor for driving the photosensitive material is moved from the rising edge to the normal rotation speed at the maximum. Since the photosensitive material is once conveyed in the reverse direction by the distance it travels, the non-imageable area is reduced by the distance that the photosensitive material is conveyed in the reverse direction. Thus, the loss of the photosensitive material is small, and a large number of images can be photographed with one photosensitive material.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a diffusion transfer type copying camera.

FIG. 2 is an explanatory diagram of a conventional image impossible area.

FIG. 3 is an explanatory diagram of a non-imageable area according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 casing 11 platen 20 scanning unit 21 light source lamp 40 lens 50 document 60 photosensitive material 70 image receiving material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-287255 (JP, A) JP-A-3-191336 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 27/50 G03B 27/32

Claims (1)

(57) [Claims] 1. A slit-shaped image of a document obtained by scanning a document in a slit shape by a scanning unit is exposed to a sheet-shaped photosensitive material conveyed in a horizontal direction, and then the photosensitive material is stopped. Return the scanning unit to the initial position,
A slit image of a document is again exposed on a photosensitive material, and this is repeated a predetermined number of times to expose a plurality of images on a single photosensitive material. In a multi-sided photographing method of a diffusion transfer type copying camera, the scanning unit is returned to an initial position. A multi-sided photographing method for a copying camera, characterized in that the photosensitive material is once conveyed in the reverse direction at the maximum at a distance from the rising of the motor for driving the photosensitive material to the normal rotation speed.