JPH0680460B2 - How to make a film master for printing plates - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing a film original plate of a printing plate for producing a printing plate used for printing from block information.

(Technical background of the invention and its problems) In the conventional plate-making process, line drawings such as illustrations and color originals (photo-like images) are processed separately to create respective film originals, and finally composited. is doing.

In the case of line drawings such as illustrations, the predetermined area of the line drawing is YMCK.
It is necessary to create a plate for obtaining a printed matter colored in a color specified by the numerical value indicating the halftone dot density, and therefore the operator has to make a mask plate and paste a predetermined halftone plate. I am doing a lot of work.

On the other hand, in the case of color originals, the originals are scanned using a scanner, electronically separated into YMCK, and if necessary, corrections such as color correction and gradation correction are made, and then output to the film. is doing.

A general process for creating a film original plate from a print manuscript relating to this line drawing is as shown in FIG. 1. When the line drawing creation work 2 is performed from the manuscript 1 and the line drawing is completed, a color separation instruction is given. In accordance with No. 3, the respective colors of yellow, magenta, cyan and black are instructed based on experience and intuition through color separation instructions according to the density of the colors. Then, a block copy of the original 1 is created by the block copy creation 4, a mask plate is created by the mask plate creation 5 based on this block copy, and a net is pasted on the mask plate by the flat mesh sticking operation 6. This net is
The type of mesh is determined according to the color separation instruction. Finally, the mask plates to which the nets corresponding to the densities are attached are collected into one sheet, and a film original plate 7 is prepared for each color of yellow, magenta, cyan and black.

Figure 2 is a more detailed description of the process from the block making 4 to the film master 7. First, when the block 8 is photographed and the positive 9 and the negative 10 are completed, these positive films are produced. Masks 11 are prepared one by one in the areas of the same color of the image based on 9 and the negative film 10. From these masks 11, for each of yellow, magenta, cyan, and black, a halftone plate having a mesh corresponding to the density of those colors
Create 12. Here, when four kinds of each of yellow, magenta, and cyan and one kind of black are completed, these halftones are pasted, and one film original plate 7 (for yellow, magenta, cyan, and black) ( 7Y, 7M, 7C, 7B) is completed. Printed using these film masters 7 and printed in color 13
Is completed. This FIG. 2 describes the steps in the case of producing the film original plate 7 for a picture as shown in FIG. 3, for example. When the color separation instruction 3 is given to the picture of FIG. The color separation result as shown in the figure is obtained. This figure shows the ratio of each color in the area, that is, the information of the color separation instruction. For example, when the color density of the area A2 is decomposed, yellow 20%, magenta 50%, cyan 30%, and black 0%. This means that halftone dots or continuous tone halftone plates 12 corresponding to these ratios are created. It should be noted that 0% shown here means that no printing ink is passed through, for example, a scathie film, and 100% means that 100% printing ink is passed in a so-called solid state, not in a half-like shape. Shows.

As described above, according to the conventional method for producing the film original plate 7, the steps from the block copy 8 to the completion of the film original plate 7 are mostly manual work, and the mask plate production 5 shown in FIG. There was a strong demand for rationalization of the process of the flat screen pasting work 6.

(Object of the Invention) The present invention has been made under the circumstances described above.
It is an object of the present invention to provide a method for producing a film original plate for a printing plate, which is a rational process in which a manual process for the film original plate for a printing plate is stopped as much as possible.

(Summary of the Invention) This invention inputs a line drawing drawn on a block by an image input device to obtain image data and displays it on a display.
Areas obtained by dividing the image data into a plurality of areas and color separation instruction information for the respective colors of yellow, magenta, cyan, and black for each area are input and stored in a storage device. According to the information of the color separation instruction corresponding to this area, the film recording device prepares a film original plate including a halftone plate for each color.

(Embodiment of the Invention) FIG. 5 is a block diagram showing steps for realizing the present invention. When the line drawing creation work 2 is performed from the manuscript 1 and the line drawing (for example, the picture as shown in FIG. 3) is completed, By the color separation instruction 3, an operator or the like issues a color separation instruction for each color of yellow, magenta, cyan and black. Next, a block copy of the original 1 is created by the block copy creation 4, the block copy data is input to the computer as block copy information, and is processed by the computer calculation processing 20 to form the film original plate 7.

FIG. 6 specifically shows the steps of the computer arithmetic processing 20 described above, and is an example of the configuration for realizing the method of the present invention. In the figure, the entire system is arithmetically processed by the computer 21. Then, the block copy 8 is photographed by the TV camera 2, and the obtained image signal is A / D converted by the camera controller 3 and sent to the data bus. This image data is sent to the computer 21,
This data is displayed as an image on the display 24, and by operating the keyboard 25 or the tablet, each information of the mask plate and halftone plate of the block copy 8 is stored in the external storage device 27, and then the film of the photo plotter 28 or the like. It is output to a recording device and the original film is prepared.

In such a structure, the method of the present invention will be described. First, the block copy 8 is converted into image data and displayed.
Displayed on 24. As an example, the case where the image shown in FIG. 3 is displayed will be described. Since the color separation instruction as shown in FIG. 4 has already been made, the tablet 26 and the keyboard 25 are operated in the areas A1 to A5 in the figure. By doing so, the color separation instruction information is input. That is, the tablet 26 is operated to specify the area A1 first, and then the information of 100% black is input by the keyboard 25. Next, after operating the tablet 26 to specify the area A2, the color-specific information of yellow 20%, magenta 50%, and cyan 30% is input by the keyboard 25. In the same manner, the areas A3 to A5 are selected. After specifying and inputting each color-specific information and storing it,
By manipulating 25, the plotter 28 outputs halftone dots or continuous tones as a film original plate including halftone plates of all kinds. That is, the mask original 11 or the halftone 12 as shown in FIG.
(7Y, 7M, 7C, 7B) can be completed. Here, by storing the information of the film original plate in the external storage device 27, the film original plate can be stored as software information for a long time. If it deteriorates, it can be immediately regenerated.

In addition, here, we explained the flat mesh as the halftone version,
As described above, even if the color density does not change within one area and the color density changes, if the color separation instruction corresponding to the density is input, the information can be input to the same area. The method can be applied. Also, in the image displayed on the display 24, if there is the same color separation instruction in the area at a distant point, enter the color separation instruction information once, and then enter it with the repeat key. You can also

(Effects of the Invention) As described above, according to the method for producing a film original plate for a printing plate of the present invention, the information of the color separation instruction for the area of each line image and the area of the block image displayed on the display is input. As a result, the film storage device creates a screened film original plate for each color, so that the area of the line drawing under the block can be specified without the need to create many mask plates or halftone plates that were conventionally done manually. Since a film original plate which is half-tone-printed can be obtained, a printing plate for a color image can be produced with high efficiency and rationally.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional process, FIG. 2 is a diagram showing a conventional mask plate and halftone plate manufacturing process, FIG. 3 is a diagram showing an example of a master copy, and FIG. FIG. 5 is a diagram showing an example of a color instruction, FIG. 5 is a diagram showing steps for explaining the present invention, and FIG. 6 is a configuration diagram for realizing the present invention. 1 ... manuscript, 2 ... line drawing creation work, 3 ... color separation instruction, 4
…… Making a block copy, 5 …… Making a mask version, 6 …… Platform embedding work, 7,7Y, 7M, 7C, 7B …… Film original plate, 8 …… Work block, 9
...... Positive film, 10 ...... Negative film, 11 ...... Mask, 12 ...... Ami plate, 13 ...... Printed matter, 20 ...... Computer processing, 21 ...... Computer, 22 ...... Camera controller, 23 ...... TV camera , 24 …… Display, 25 …… Keyboard, 26 …… Tablet, 27 …… External storage device, 28
...... Plotter.

Claims (1)

[Claims] 1. A line drawing drawn on a block is input by an image input device to obtain image data and displayed on a display,
Areas obtained by dividing the image data into a plurality of areas and color separation instruction information for the respective colors of yellow, magenta, cyan, and black for each area are input and stored in a storage device. A method for producing a film original plate for a printing plate, comprising producing a film original plate including a halftone plate for each color by a film recording device according to information of color separation instructions corresponding to this area.