JP2002086669A - Multi-color printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a printing failure attributed to the mixing difficulty of inks when ink is printed in a superposition fashion immediately after another ink is printed. SOLUTION: Full color image data entered in a personal computer 38 are sorted out into four prints such as Y(yellow), M(magenta), C(cyan) and Bk(black) with the help of a PC controller 40 and the image data thus undergoing the color sorting process are sent to an image processing means 36. Further, the image processing part 36a of the image processing means 36 performs the process to eliminate data relative to Bk(black) from image memory data such as Y(yellow), M (magenta) and C(cyan). A master is made up based on the makeup image data which are through with the elimination process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multicolor printing apparatus such as a multicolor stencil printing apparatus.

[0002]

2. Description of the Related Art In a multicolor stencil printing apparatus, a full-color image obtained by reading a document is color-separated to correspond to Y (yellow), M (magenta), C (cyan), and Bk (black). The plate making image data is prepared, and each plate making image data is sent to plate making means provided for each color, and each master making means makes a master plate. The plate-making master is wound around the outer periphery of each printing drum for each color. The printing drums are arranged so that printing is performed in the order of Y (yellow), M (magenta), C (cyan), and Bk (black), and multicolor overlapping is performed by passing printing paper through the printing section of each printing drum. Imprint printing is performed.

[0003] Plate making image data corresponding to four plates of Y (yellow), M (magenta), C (cyan) and Bk (black) include Y (yellow) and M ( There is data for each of magenta) and C (cyan). By printing these data in a superimposed manner, black is created, and Bk (black) ink is printed last.

[0004]

The ink for stencil printing is an emulsion ink in which water and oil are in an emulsion state and exhibit water properties as a whole. For this reason, when another color ink is superimposed and printed where the ink in the image portion of the printing paper immediately after printing has been permeated, the ink printed later is favorably because of the ink that has permeated the printing paper earlier. There was a problem that printing was not possible. Since the ink transferred to the printing paper absorbs moisture in the printing paper,
Immediately after printing, the emulsion state is broken and shows the properties of oil. This is because the next printing ink to be superimposed thereon does not mix well because it shows water properties in an emulsion state.

Accordingly, an object of the present invention is to provide a multicolor printing apparatus capable of improving the image quality by minimizing inconvenience caused by superimposing the next ink immediately after printing.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, there are provided a plurality of plate making means corresponding to a plurality of ink colors, and a full-color image of a document is subjected to color separation / image processing. Process to create plate making image data for each color, send these plate making image data to each of the plate making means for each color to make a master, and use these color masters to overlay the multiple ink colors and print A multi-color printing device,
In a multicolor printing apparatus in which a specific ink exists in which a plurality of other inks are superimposed on each other to produce a single color of the ink, the multicolor printing apparatus includes: With regard to plate making image data that does not correspond, data excluding data relating to the specific ink color is sent as actual plate making image data to each of the above plate making means to make plate making.

According to a second aspect of the present invention, in the multicolor printing apparatus according to the first aspect, a configuration is adopted in which the color of the specific ink is black.

According to the third aspect of the present invention, the first or second aspect is provided.
The multicolor printing apparatus described above adopts a configuration in which the plate making image data is created by image processing means provided in the apparatus.

According to a fourth aspect of the present invention, there is provided the multicolor printing apparatus according to the third aspect, further comprising a document reading means in the apparatus, and the image data read by the document reading means is sent to the image processing means. , Is adopted.

According to a fifth aspect of the present invention, in the multicolor printing apparatus according to the third aspect, a document is read by document reading means provided outside the apparatus, and the read image data is taken into a personal computer outside the apparatus. And
The image data is sent to the image processing means via the controller of the personal computer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, an outline of an overall configuration of a multicolor stencil printing apparatus as a multicolor printing apparatus according to the present embodiment and a control system will be described based on FIG. As shown in FIG.
The multicolor stencil printing apparatus 2 includes a first color (yellow) print drum 4, a second color (magenta) print drum 6, and a third color (cyan) print drum 8 arranged side by side on a horizontal plane. And a fourth color (black) printing drum 10.

The printing drum 4 corresponds to the printing drum 4.
A plate discharging means 12 for peeling off the used master, a plate making means 14 for performing plate making of a master not shown based on yellow plate making image data and supplying the master having been made plate to the printing drum 4, and a contact / separation mechanism not shown. The printing drum 4 is provided with a press roller 16 for pressing the printing paper P. Similarly, in the printing drum 6, the plate discharging means 1
8. A plate making means 20 and a press roller 22 for performing plate making of a master (not shown) based on magenta plate making image data and supplying the plate-making finished master to the printing drum 6. The printing drum 8 is also provided with a plate discharging means 24, plate making means 26 for performing plate making of a master (not shown) based on cyan plate making image data, and supplying plate-making masters to the printing drum 8, and press rollers 28. I have. The printing drum 10 also includes a plate discharging means 30, a plate making means 32 for performing plate making of a master (not shown) based on black plate making image data, and supplying a plate finished master to the printing drum 10, and a press roller 34. Have been.

The printing paper P is fed one by one from a paper feeding means (not shown). The fed printing paper P is temporarily stopped by a pair of registration rollers (not shown), and after correcting the oblique displacement or the like, the timing at which the leading end of the image of the printing drum 4 of the first color matches the predetermined position in the feeding direction. To the print nip portion of the print drum 4. In synchronization with this timing, the press roller 16 moves up and presses the printing paper P against the printing drum 4. The printing paper P on which the yellow ink image has been transferred by the printing drum 4 subsequently enters the printing nip portion of the printing drum 6 for the second color. In synchronization with this timing, the press roller 22 moves up and presses the printing paper P against the printing drum 6. The printing paper P on which the magenta ink image has been transferred by the printing drum 6 subsequently enters the printing nip portion of the third color printing drum 8. The press roller 28 rises in synchronization with this timing, and presses the printing paper P against the printing drum 8. The printing paper P on which the cyan ink image has been transferred by the printing drum 8 subsequently enters the printing nip portion of the printing drum 10 for the fourth color. In synchronization with this timing, the press roller 34 rises and presses the printing paper P against the printing drum 10. Printing paper P after printing
Are conveyed by a conveying unit (not shown) and stacked on a sheet discharge table (not shown).

The printing drums 4, 6, 8, and 10 have a well-known drum configuration. That is, although not shown, one or more mesh screen layers are provided on the outer peripheral surface of the porous cylindrical substrate, and the master is wound around the outer peripheral surface. An ink supply means is provided inside the cylindrical substrate, and the ink supplied by the ink supply means oozes out from the perforated portions of the respective masters by the pressing force of the press rollers 16, 22, 28, and 34.
The image is transferred onto the printing paper P.

The multicolor stencil printing apparatus 2 has an image processing means 36 in the apparatus (claim 3). Outside the multicolor stencil printing apparatus 2, a scanner (not shown) as document reading means, a personal computer 38 to which full-color image data read by the scanner is input, and a LAN connection to the personal computer 38 A PC controller 40 is provided. The full-color image data input to the personal computer 38 is color-separated by the PC controller 40 into four plates of Y (yellow), M (magenta), C (cyan), and Bk (black). It is sent to the image processing means 36 (claim 5). In the image processing means 36, the color-separated image data is stored in respective image memories.

Next, the image processing unit 36a performs a process of removing data relating to black, which is a specific ink color, from the Y (yellow) image memory data. The final (actual) plate making image data after the removal processing is stored in the plate making data memory of Y (yellow). Similarly, M
A process for removing black data from the (magenta) image memory data is performed. The final (actual) plate making image data after the removal processing is stored in the plate making data memory of M (magenta). Similarly, a process of removing data relating to black from the C (cyan) image memory data is performed. The final (actual) plate making image data after the removal processing is stored in a plate (C) cyan plate making data memory. The Bk (black) image memory data is stored as it is in the Bk (black) plate making data memory.

At the time of plate making, Y (yellow) plate making image data is called from the plate making data memory of Y (yellow) and sent to plate making means 14 corresponding to the printing drum 4 for the first color. In the plate making means 14, a thermal head (not shown) is driven based on the plate making image data, and plate making is performed on a master (not shown). The master that has been made is supplied to the printing drum 4 at a predetermined timing, and is wound around the outer peripheral surface of the printing drum 4 with its leading end portion held between clampers (not shown) of the printing drum 4. Further, the M (magenta) platemaking image data is called from the platemaking data memory of M (magenta), sent to the platemaking means 20 corresponding to the printing drum 6 for the second color, and the platemaking and plate feeding are similarly performed. Also, C
The C (cyan) plate making image data is called from the (cyan) plate making data memory, sent to the plate making means 26 corresponding to the third color printing drum 8, and the plate making and plate feeding are similarly performed. Also, Bk (black) plate making image data is called from the Bk (black) plate making data memory,
The sheet is sent to the plate making means 32 corresponding to the color printing drum 10, and the plate making and plate feeding are similarly performed. When full-color printing is performed by such a plate-making method, black portions are printed with only Bk (black) ink, so that no trouble due to overprinting occurs and good printing is achieved.

Next, another embodiment will be described with reference to FIGS. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description of the already-described configuration and function will be omitted unless otherwise required. In the above-described embodiment, the final platemaking image data is created by the image processing means 36 in the multicolor stencil printing apparatus 2. In this embodiment, the final platemaking image data is created in the PC controller 40. It is characterized by creating. As shown in FIG. 3, the PC controller 40 is provided with an image processing means 42. The full-color image data input to the personal computer 38 is converted into Y (yellow), M
(Magenta), C (cyan) and Bk (black) are color-separated, and the color-separated image data is sent to image processing means 44 in the PC controller 42 (claim 6). In the image processing means 44, the color-separated image data is stored in each image memory.

Next, the image processing section 44a performs a process of removing data relating to black, which is a specific ink color, from the Y (yellow) image memory data. The final (actual) plate making image data after the removal processing is stored in the plate making data memory of Y (yellow). Similarly, M
A process for removing black data from the (magenta) image memory data is performed. The final (actual) plate making image data after the removal processing is stored in the plate making data memory of M (magenta). Similarly, a process of removing data relating to black from the C (cyan) image memory data is performed. The final (actual) plate making image data after the removal processing is stored in the plate (C) plate making data memory. The Bk (black) image memory data is stored as it is in the Bk (black) plate making data memory.

At the time of plate making, Y (yellow) plate making image data is called from a plate making data memory of Y (yellow) and sent to plate making means 14 corresponding to the printing drum 4 for the first color. In the plate making means 14, a thermal head (not shown) is driven based on the plate making image data, and plate making is performed on a master (not shown). The master that has been made is supplied to the printing drum 4 at a predetermined timing, and is wound around the outer peripheral surface of the printing drum 4 with its leading end portion held between clamps (not shown) of the printing drum 4. Further, the M (magenta) plate making image data is called from the M (magenta) plate making data memory, sent to the plate making means 20 corresponding to the printing drum 6 for the second color, and the plate making and plate feeding are similarly performed. Also, C
The platemaking image data of C (cyan) is called from the platemaking data memory of (cyan), sent to the platemaking means 26 corresponding to the printing drum 8 for the third color, and platemaking and plate feeding are similarly performed. Also, Bk (black) plate making image data is called from the Bk (black) plate making data memory, and 4k
The sheet is sent to the plate making means 32 corresponding to the color printing drum 10 and the plate making and plate feeding are similarly performed.

The original may be read by a scanner provided in the apparatus, and the read image data may be sent to image processing means in the apparatus to create plate making image data.

[0022]

According to the present invention, problems due to overprinting can be partially avoided, so that the quality of full-color printing can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an outline of a configuration and a control system of a multicolor stencil printing apparatus as a multicolor printing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an outline of a configuration and a control system of a multicolor stencil printing apparatus according to another embodiment.

FIG. 3 is a diagram showing an image processing unit in the PC controller in the embodiment shown in FIG.

[Explanation of symbols]

 14, 20, 26, 32 Plate making means 36, 44 Image processing means 38 Personal computer 40, 42 Controller

Claims (6)

[Claims] The present invention has a plurality of plate making means corresponding to a plurality of ink colors, performs color separation and image processing of a full-color image of an original to produce plate making image data for each color, and separates these plate making image data for each color. The master is made by sending it to the above plate making means,
A multi-color printing apparatus that superimposes and prints the colors of the plurality of inks using the masters for each of the colors, in which a single color of the ink is output by superimposing another ink among the plurality of inks. In a multi-color printing apparatus in which a specific ink is present, among the plate making image data, for plate making image data that does not correspond to the color of the specific ink, data excluding data relating to the color of the specific ink is actually used. A multi-color printing apparatus which sends plate making image data to each of the above plate making means for plate making. 2. The multicolor printing apparatus according to claim 1, wherein the color of the specific ink is black. 3. A multicolor printing apparatus according to claim 1, wherein said plate making image data is created by image processing means provided in said apparatus. 4. A multi-color printing apparatus according to claim 3, further comprising a document reading means in said apparatus, wherein image data read by said document reading means is sent to said image processing means. Color printing device. 5. A multi-color printing apparatus according to claim 3, wherein a document is read by document reading means provided outside the apparatus, and the read image data is taken into a personal computer outside the apparatus. A multicolor printing apparatus which is sent to the image processing means via a controller. 6. A multi-color printing apparatus according to claim 1, wherein the document is read by document reading means provided outside the apparatus, and the read image data is taken into a personal computer outside the apparatus. A multicolor printing apparatus wherein the plate making image data is created by a controller of a computer.