JPS6334529A - Process camera - Google Patents

Abstract

PURPOSE:To permit formation of a negative film allowed for the deviation generated at the time of printing by providing a photographing part which exists behind a slit, is positioned on the optical axis of a lens part and is movable in the direction parallel with the moving direction of the slit. CONSTITUTION:The image of a block copy original A imposed on an original part 2 is projected by a lens part 1 to the photographing part 4 and is focused thereto. After a film B is mounted to the photographing part 4, the slit 3 is moved and the film B is exposed. The light except the light entering through the slit is shielded by a shielding film 12 in this case. The negative film of the same size as the size of the block copy original A is obtd. if the photographing part 4 is held stopped during the exposure. On the other hand, the negative film reduced or enlarged in the moving direction of the photographing part 4 is formed when the photographing part is moved in the same direction as the direction of the slit 3 or the direction opposite thereform during the exposure. The negative film preliminarily allowed for the deviation to be generated at the time of printing is thereby formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plate-making camera for producing a negative film used primarily in producing a photosensitive resin printing plate.

Conventional technology A conventional prepress camera has a lens section whose focus is adjustable, a document section located in front of the lens section and on the optical axis of the lens section, and a document section located behind the lens section and located on the optical axis of the lens section. It consisted of an imaging section located on the optical axis.

Problems that the invention aims to solve When making a resin plate for printing, a negative film is tightly exposed to a photosensitive resin plate that hardens only where the light hits it, and then the unexposed areas are washed away and printed. The usual method is to make a version for

When printing using this plate, this plate is wrapped around a printing drum and printed, but at this time, this plate made of photosensitive resin is...

Since it has elasticity, when it is wrapped around the printing drum, the upper part of the plate expands into a fan shape, and printing is performed in this state, so if the thickness of the plate is t, there is a deviation of approximately πt in the circumferential direction of the printing drum. This caused the inconvenience that the print was stretched by that amount.

In order to overcome this inconvenience, it would be possible to prepare negative film for plate making by anticipating the deviation in advance, but due to the structure of conventional plate making cameras, it is only possible to make negative film of the same size as the original. , it was not possible to eliminate the deviation.

In addition, in conventional plate-making cameras, the ratio of the dimensions of the original plate and the negative film is 1:1, so if there is a discrepancy in the dimensions of the original plate itself, the negative film and its There was also the inconvenience that the produced version would be inconsistent.

Furthermore, with conventional plate-making cameras, when producing several plates with the same printing content but differing only in size, it is necessary to create a draft manuscript and negative film of a size corresponding to each plate. This work was very troublesome.

Means for Solving the Problems The present invention was developed in view of these concerns, and it makes it possible to create a negative film that takes into account the deviations that occur during printing, and also corrects the deviations in the draft manuscript. This is a plate-making camera that can create negative films of various sizes from a single original.

To explain the plate-making camera according to the present invention, its configuration includes a lens part (1) whose focus is adjustable, and a lens part (1) located in front of the lens part and located on the optical axis of the lens part (1). a slit (3) located behind the lens portion (1) and movable in a direction perpendicular to the optical axis of the lens portion (1); The slit (
Photographing unit (4) movable in a direction parallel to the moving direction of 3)
It consists of

Function: A conventional plate-making camera uses a lens unit to project the image of the original placed on the original unit onto the photographing unit, and after loading film into the photographing unit, the image of the original is projected through the shutter of the lens unit. The entire image was exposed to film at once.

On the other hand, the plate-making camera according to the present invention has a lens section (
Project the image of the draft manuscript (A) placed on the manuscript section (2) according to step 1 (this image is now the same size as the draft manuscript (A)) onto the photographing section (4). , focus, and press the camera (
After mounting the film (B) on the 0, the slit (3) is moved to expose the film (B). In this case, the Wii film (12) shields the outside view from the slit.
is shielded by

In this way, a bar-shaped image of a portion of the draft original (A) that has passed through the slit (3) is sequentially exposed to the film (B) from one end, and when the slit (3) has moved to the end, Then, the entire image of the draft manuscript (A) is exposed onto the film (B).

If the photographing section (4) is stopped during this exposure, a negative film of the same size as the original (A) is obtained, as in a conventional plate-making camera (see @ Figures 5 and 6).

In addition, when creating a negative film of the same size as the original manuscript (A), the photographing section (0) should be stopped and the slit (3) and shielding film (12) should be moved to one side so as not to block the image. If you set it up, you can take pictures using exactly the same principle as a conventional plate-making camera, so you can also create a negative film of the same size as the original (A).

On the other hand, if the photographing section (0) is slightly moved in the same direction as the slit (3) during exposure, the image projected onto the photographing section (0) through the slit (3) will not change; Since it moves as if chasing the bar-shaped image that has passed through the slit (3), the image is exposed onto the film in a reduced form in the moving direction by the amount that this photographing section (0 has moved). In the figure, S indicates the width of the original (A), and S'' indicates the width of the image of the original (A) exposed to film (B).

On the other hand, if the photographing section (0) is moved in the opposite direction to the slit (3) during exposure, the photographing section (4) will move so that it rubs against the rod-shaped image that has passed through the three-piece (3). The image is exposed on the film in a stretched form in the direction of movement by the amount that the photographing section (4) has moved.Figure 8 shows this effect, where S indicates the width of the original (A); S'' indicates the width of the image of the original (A) exposed on the film (B).

As described above, by moving the photographing section (0) in the same direction as the slit (3) or in the opposite direction during exposure, it is possible to create a negative film that is reduced or enlarged in the moving direction.

Further, the invention according to the present invention provides that the original part (2) is connected to the lens part (
1), so by moving the original part (2) closer to or away from the lens part (1), the image to be exposed on the film can be moved in the vertical and horizontal directions. The size of the image can be enlarged or reduced at the same rate, and as a result, negative films of various sizes can be created from a single original.

Furthermore, the plate-making camera according to the present invention can create a negative film whose vertical and horizontal dimensions are reduced or enlarged at different rates by combining the above-mentioned functions. (Movement direction of photographing unit (4))
When creating a negative film that is enlarged by 10% only in the vertical direction, the image of the draft manuscript (A) is enlarged by 10% and the image of the draft manuscript (A) is enlarged by 10%, and the image of the draft manuscript (A) is enlarged by 10%,
). Then, when exposing, the photographing section (4) is slit (
Move in the same direction as 3). If the width of the draft manuscript (A) is 100 cm, this moving distance is 10% of this distance.
It is 10cs+. In this way, a negative film enlarged only in the vertical direction can be obtained.

In addition, it is also possible to create negative films of different sizes vertically and horizontally from a single original.

Example Examples of the present invention will be described.

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of a portaple-type plate-making camera, FIG. 2 is a side view of the same, FIG. 3 is a side view of a floor-type plate-making camera, and FIG. 4 is a plane view of the same. 5 to 8 are process diagrams showing the operation of the present invention.

The plate-making camera shown in FIGS. 1 and 2 is of a portaple type, and is used when photographing a manuscript of A3 to A2 size. First, this portaple-type plate-making camera will be explained.

(1) in Figures 1 and 2 is the lens part, and the box body (5
) is provided facing downward inside the upper part. This lens part (1
) is designed so that the focus can be adjusted.

(2) is the manuscript section, which is located below the lens section (1) and on the optical axis of the lens section (1), and is provided inside the box body (5) so as to be movable in the vertical direction. . The draft manuscript (A) loaded in this manuscript section (2) is usually a reflective manuscript, and a lamp (6) is provided inside the box (5) to illuminate it.Also, positive film manuscripts are also used. In order to make this possible, a transmission lamp (7) is provided in the document section (2).

(3) is a slit, with a hole in the buttocks,
This slit (3) is provided at the top of the box (5) so as to be located above the lens section (1) and movable in a direction perpendicular to the optical axis of the lens section (1). This slit (3
) connects the slitting motor (9) via the chain (8)
It is designed to be driven by This slit motor (
As for 9), a variable motor whose speed can be adjusted is used, and the slit driving speed is adjusted according to the slit width, film sensitivity, camera lens aperture, strength of lamp light, etc. The width of the slit (minimum width of the hole) is preferably about 2 mm.

(4) is an imaging section, which is located above the slit (3) and on the optical axis of the lens section (1), and is a box that is movable in a direction parallel to the moving direction of the slit (3). It is provided on the upper part of the body (5). This imaging unit (0) has a female threaded portion (4a), and a male threaded power shaft (10a) of the imaging unit motor (10) is screwed into this female threaded portion (4a). The photographing section (4) is moved by rotating the photographing section motor (10) in forward and reverse directions.A film suction plate is used as the photographing section (0), and A variable motor is used as the motor (10).

In addition, a focusing glass (11) is movably provided under the photographing section (0), and when adjusting the focus, flip up the photographing section (4) and place the focusing glass (10) on the photographing section (4). The focus glass (11) is then moved to the desired location, and the focus is adjusted while looking at the focusing glass (11).Also, between the lens section (1) and the photographing section (4), there are slits (3) provided on both sides of the lens section (1). It is partitioned by a bellows-shaped shield Il! (12), but this shield 11 (12) is designed to be drawn to one side, and when adjusting the focus etc., this shielding film (12) is pulled to one side. It looks like this.

In addition, when adjusting the reduction rate or magnification in the lateral direction, it is preferable to keep the moving speed of the slit (3) constant and adjust it by changing the moving speed of the imaging section (0). Adjust the speed of the slit motor (9) so that the slit (3) moves 100 cm per minute, keep this speed unchanged, and when you want to reduce the size by 10%, turn the imaging section (4). 1 per minute in the same direction as three y (3)
All you have to do is adjust the speed of the imaging unit motor (10) so that the slit motor (9) and the imaging unit motor (lO) move at the same time. It is a good idea to place a speed scale or a 1x reduction rate scale on the speed controller (10).

Next, we will explain the floor-type plate-making camera shown in Figures 3 and 4. ).

This floor-type prepress camera is used when photographing originals of B2 size or larger, and its configuration is almost the same as the portaple-type prepress camera shown in FIG. However, the floor-type prepress camera shown in Figures 3 and 4 has a lens section (
The optical axis of 1) is oriented horizontally, and the lens section (1) and document section (2) are mounted on a frame (13) so that they can move freely in the optical axis direction.
The lens section (1) and the manuscript section (2) are
) is in the light room. On the other hand, the slit (3) and the imaging section (0 etc. are located in a dark room, and the bright room and dark room are separated by a shielding plate (14). Similarly to the slit motor (9
), and is driven by a photographing section motor (10). A shielding film (12) is provided on both sides of the slit (3) as in the portaple type, and the photographing section (4) is provided so as to be replaceable with a focusing glass (11).

Effects of the Invention The present invention having the above configuration has the following effects.

The plate-making camera according to the present invention can create a negative film that takes into account deviations that occur during printing in advance. Therefore, by making a plate using this negative film and printing by wrapping this plate around a printing drum, a printed matter having exactly the same size as the original is obtained.

In addition, the plate-making camera according to the present invention can create a negative film that has been reduced and enlarged separately in the vertical and horizontal directions, so even if there is a dimensional error in the original, this error can be corrected when creating the negative film. can do. It is also possible to create various negative films with different vertical and horizontal sizes from a single original.

Furthermore, the plate-making camera according to the present invention can create a negative film in which the reduced acid is enlarged at the same ratio in the vertical and horizontal directions, so negative films of various sizes can be created from a single original.

As described above, the present invention has extremely excellent functions (1).
This is a prepress camera. (3)・

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and the first (5) figure is a front view of the portaple-type plate-making camera, the second (7) figure is a side view of the same, and the third figure is a side view of the floor-type plate-making camera. (9)・Side view, Figure 4 is the same plan view, Figures 5 to 8 (lO)・
1 is a process diagram showing the effect of the present invention. (1
1) Patent application human hair
Yutaka Toshi... Lens section (2)...
・Manuscript part - battle ・Slit...Photographing part (4d)...Acid screw part...
Box body (8) Φ... Lamp... Transparent lamp (8)... Chain... Motor for slit... Motor for photography (10a), Power shaft...
Focus glass...shielding film

Claims (1)

[Claims] 1) a lens part (1) whose focus can be adjusted; a document part (2) which exists in front of the lens part and is located on the optical axis of the lens part (1) and is movable in the direction of the optical axis; a slit (3) located behind the lens part (1) and movable in a direction perpendicular to the optical axis of the lens part (1); and a slit (3) located behind the slit and said lens part (1); The photographing section (4) is located on the optical axis of the camera and is movable in a direction parallel to the direction of movement of the slit (3).
).