JPH0244061B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of printing a light-transmissive original in close contact with a plate-making material such as a metal plate or resin plate on the surface of which a photosensitive layer is formed for use in lithography, letterpress printing, etc.

Generally, when multiple printing plates are successively created from a light-transmissive original (hereinafter referred to simply as the original) such as a photographic original plate, the original is brought into close contact with the photosensitive layer of the plate-making material using a printing frame during printing. After that, I try to bake it. Since the size of the conventional original is approximately the same as the plate-making material, it is not possible to directly vacuum the original and bring it into close contact with the plate-making material, so the following means are used.

That is, a transparent acrylic plate that is sufficiently larger than the plate-making material is prepared with an original pasted in a predetermined position, and this is superimposed on the plate-making material placed on the printing table so that the original corresponds to the plate-making material, and the printing process described above is carried out. The transparent acrylic plate is suctioned through a vacuum groove formed on the top surface of the stand, and the original is brought into close contact with the plate-making material for printing. however,
When using this method, a flat acrylic plate is evacuated, so it takes time to reach the desired degree of vacuum.Also, if the acrylic plate is brought into perfect contact with the plate-making material, the acrylic plate will be distorted, so the degree of vacuum cannot be adjusted. For this reason, printing blurring is likely to occur, and furthermore, when the vacuum state is released after printing, the separation between the plate-making material and the acrylic plate is poor.
There is a problem in that workability decreases when baking is performed continuously.

There is also a method in which a document of approximately the same size as the plate-making material is attached to a cover film made of vinyl chloride or the like which is larger than the plate-making material, and this is pressed onto the plate-making material using a squeegee roller, followed by vacuuming.
According to this method, the evacuation time can be reduced compared to the above-mentioned method, and the burning blur can be improved to some extent, but it cannot be said to be sufficient. In addition, even with this method, the plate-making material and cover film (manuscript) after printing are
There is a problem that it is not easy to separate them from each other.

Further, one end of the cover film to which the above-mentioned manuscript is attached is fixed on a printing table, and the cover film is wound around a squeegee roller, and then the manuscript is spread out on the plate-making material by rolling it on the plate-making material. ,
There is also a method of vacuum sealing after this. However, with this method, there is a problem in that misalignment is likely to occur due to the difference in the winding diameters of the cover film and the document and the difference in expansion and contraction thereof, making it difficult to align the document and the plate-making material.

In any of the above methods, the original must be attached to a cover film or acrylic board, and this work requires great care and time, and the acrylic board or cover film may be baked. absorbs light when Therefore, there is also the disadvantage that the exposure time must be increased.

The present invention was made in order to solve the above-mentioned conventional problems, and its purpose is to prevent the original and plate-making materials from being mixed at the time of printing when producing a plurality of printing plates from one original. It is easy to align, reduce both vacuuming time and exposure time, and it is easy to separate the original from the plate-making material after printing.
It is an object of the present invention to provide a contact printing method that does not cause printing blur.

In order to achieve such an object, the contact printing method according to the present invention involves printing a light-transmissive manuscript, which is larger than the plate-making material and which is large enough to cover the vacuum groove formed on the top surface of the printing table, onto an acrylic plate or a cover film. The gist of the document is that it is spread directly onto the plate-making material using a squeegee roller without being attached to the plate-making material, and during this development, the edges of the document are sequentially pressed onto the printing table to make them adhere to each other under vacuum. There is.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 4 show a baking frame implementing the first embodiment of the present invention, of which FIG. 1 is a front view of the baking frame, FIG. 2 is a side view, and FIG. 3 is a side view of the baking frame. The plan view and FIG. 4 are longitudinal cross-sectional views of the printing table.

In the figure, reference numeral 1 denotes a printing table, and on the upper surface of this printing table 1, grooves 2 connected to a vacuum pump or the like are formed vertically and horizontally, as shown in FIG. Then, the plate-making material 3 is placed on the upper surface of the printing table 1 so that the ends of the vacuum suction grooves 2 protrude from the periphery of the plate-making material 3.

Further, the base end of a light-transmitting original 4 is fixed to the base end side of the upper surface of the printing table 1 with a pin 5 or adhesive tape, and the tip is urged upward by a spring 6. are doing. This manuscript 4 has longer side lengths on the top, bottom, left and right sides than the above-mentioned plate-making material 3,
Specifically, the side length in the left and right direction is approximately smaller than that of plate-making material 3.
When making printing plates for newspapers, etc., it is preferable to make the plate longer by 10 mm or more and to make the top and bottom sides longer by about 20 mm or more.

From this state, use the squeegee roller 7 to remove the document 4.
is pressed onto the plate-making material 3. That is, the squeegee roller 7 is made of an elastic material such as rubber, and has large diameter portions 7a, 7a at both ends, and a small diameter portion 7b at the middle portion. The length in the axial direction of the small diameter portion 7b is approximately equal to the length in the width direction of the plate making material 3, and the difference in radius between the large diameter portion 7a and the small diameter portion 7b makes the thickness of the plate making material 3 approximately equal. ing. Then, the squeegee roller 7 having the above-mentioned shape is rolled from the state shown in FIG. 1 toward the leading edge of the document, that is, to the left in the figure. Then, as shown in FIG. 2, the squeegee roller 7 presses the original 4 onto the plate making material 3 by fitting the plate making material 3 between the small diameter portion 7b and the printing table 1, and at the same time, the squeegee roller 7 presses the original 4 onto the plate making material 3. The ends of the original 4 are sequentially pressed onto the printing table 1 by the large diameter portion 7a. In this case, the end of the vacuum suction groove 2 protruding from the periphery of the plate-making material 3 is covered by the end of the original 4, so the original 4 is placed on the printing table 1 and the printing table 1. It is brought into close contact with the plate-making material placed on the plate.

Next, while the original 4 is kept in close contact with the plate-making material 3, light is irradiated from above to perform printing.

In the above embodiment, the leading edge of the original is supported by the spring 6, but the original 4 is supported by a guide roller fixed near the printing table 1.
The distal end of the document 4 may hang down to the rear side of the proximal end secured by the pin 5 or the like, or the distal end of the document 4 may be inserted into a slit etc. formed in the width direction of the squeegee roller 7. The document 4 may be fixed by a similar means, the document 4 may be wound around the squeegee roller 7, and the wound document 4 may be spread out on the plate-making material 3 as the squeegee roller 7 rolls.

FIG. 5 is a side view showing a schematic structure of a baking frame for carrying out another embodiment. The roller 17 is provided with a pressing member such as small rollers 18, 18 or a pressing plate for pressing the edge of the document 4.

Then, the base end of the original 4 is fixed on the printing table 1 with a pin or adhesive tape, and the leading end of the original 4 is fixed on the squeegee roller 17, and the original is wound around the squeegee roller 17. The plate-making material 3 is caused to roll and travel. Then, the original 4 wound around the squeegee roller 17 is sequentially spread out onto the plate-making material 3, and at the same time, the edge of the original 4 is pushed out from the periphery of the plate-making material 3 by the pressing member 18 for vacuum suction. The document 4 is sequentially pressed onto the printing table 1 so as to cover the groove 2 of the document 4, and the document 4 is brought into close contact with the printing table 1 and the plate-making material 3. Then, in this state, baking is performed in the same manner as described above.

FIG. 6 is a front view of a baking frame for carrying out yet another embodiment.
Approximately equal to the size of the plate-making material 3, in the center of the upper surface of
In addition, a recess 1a whose depth is approximately equal to the thickness of the plate-making material 3 is formed so that when the plate-making material 3 is fitted into the recess 1a, the plate-making material 3 and the top surface of the printing table 1 are flush with each other. .

Then, the plate-making material 3 is fitted into the recess 1a, the base end of the original 4 is fixed to the side of the printing table 1 with a pin 5, etc., and the leading end of the original 4 is held with a cylindrical squeegee. The squeegee roller 27 is rolled while being wound around the roller 27, and the document 4 is placed on the plate-making material 3.
will be expanded sequentially. And at the same time, manuscript 4
The end of the document 4 is pressed onto the printing table 1 so as to sequentially cover the vacuum groove 2 formed around the recess 1a, and the original 4 is placed on the printing table 1 and the plate-making material fitted into the recess 1a. Closely attached to 3. Then,
Printing is performed by irradiating the original 4 from above.

The above is merely an example of the implementation of the present invention, and the present invention is not limited to the above.
A durable film with low expansion and contraction, such as polyethylene terephthalate film, is pasted around the
This portion may be pressed against the printing table so as to cover the vacuum suction groove protruding from the periphery of the plate-making material. In this case, if the auxiliary film is in the form of a frame, bonding will be easier. Further, the squeegee roller is not limited to being made of an elastic body, and may be made of steel.

As described above, according to the present invention, the edge of a translucent original (or the auxiliary film if an auxiliary film is attached) is removed from the periphery of the plate-making material placed on the printing table using a squeegee roller or the like. Since the protruding groove for vacuum suction is pressed so as to be covered, the time for vacuuming can be shortened, the original can be brought into close contact with the plate-making material, and the alignment of the original and the plate-making material can be facilitated. In addition, it is possible to improve adhesion, preventing the occurrence of printing blur, and furthermore, when the vacuum is released after printing, it is easier to separate the original from the plate-making material, and there is no need to use an acrylic plate or cover sheet as in the past. Therefore, the light for printing is not absorbed by these, and therefore, when printing is performed continuously, many effects such as being able to shorten the working time are exhibited.

[Brief explanation of drawings]

Fig. 1 is a front view of a baking frame for implementing the contact baking method according to the present invention, Fig. 2 is a side view of the baking frame, Fig. 3 is a plan view of the baking frame, and Fig. 4 is a baking table. FIG. 5 is a side view of a baking frame used in another embodiment, and FIG. 6 is a front view of a baking frame used in another embodiment. In the drawing, 1 is a printing table, 1a is a recess, 2 is a groove for vacuum suction, 4 is a light-transparent original, 7, 17, 27
1 is a squeegee roller, 7a is a large diameter portion of the squeegee roller, 7b is a small diameter portion of the squeegee roller, and 18 is a pressing member.

Claims (1)

[Scope of Claims] 1. A plate-making material is placed on a printing table with a groove for vacuum suction formed on the top surface, and then a squeegee roller is used to make a plate that is larger than the plate-making material and has a size that covers the groove for vacuum suction. A contact printing method characterized in that the edges of a light-transparent document are successively pressed against a printing table, stacked on a plate-making material, and brought into close contact with suction, and then light is irradiated from above the light-transparent document. . 2. The squeegee roller has both ends thereof a large diameter part that presses the edge of the light-transmitting document, and a space between these large diameter parts is a small diameter part, and the axial length of this small diameter part is approximately equal to the width of the plate-making material. 2. The contact baking method according to claim 1, wherein the radius difference between the large diameter portion and the small diameter portion is approximately equal to the thickness of the plate-making material. 3. The contact printing method according to claim 1, wherein the squeegee roller includes a pressing member that presses an edge of a light-transmissive document. 4. Close-contact baking according to claim 1, characterized in that a recessed portion is formed in which the upper surface of the printing table and the upper surface of the plate-making material are substantially flush when the plate-making material is fitted into the printing table. Method. 5. The contact printing method according to claim 1, wherein the light-transmissive original has a film pressed on at least a portion of its periphery by a squeegee roller.