JPH04104260A - Lithographic plate output device - Google Patents

Abstract

PURPOSE:To manufacture a lithographic machine plate at low cost by forming an electrostatic latent image with light modulated by image data for printing of respective colors of image data for printing on a flexible recording medium and forming dot images by the colors. CONSTITUTION:On a work station 5, image processes of adjustments of layout and hues, editing, etc., are performed with digital image data stored in a storage 7 while looking at a color image on a display unit by using an image processor 6. The lithographic plate output device 8 which is supplied with the digital image data from the work station 5 uses the digital image data as image data for printing of digital image data corresponding to the dot images of the respective colors to output the lithographic plate. When the lithographic plate output device 8 outputs the lithographic plate, the lithographic plate formed by forming the dot images by the colors individually on the flexible recording medium for electrophotography which has a photoconductive layer member with high moisture resistance by using lipophiolic developing toner is outputted. Consequently, inexpensive manufacture becomes possible.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a one-color plate output device.

(Prior Art) FIG. 6 is a diagram showing the general flow of the printing process when a color image is lithographically printed according to a conventional printing system. Supplied in condition.

In the printing system shown in FIG. 6, a color photographic film of a color image original is scanned by a prepress camera (e.g., an image scanner or a drum scanner) in an image capture section in a plurality of colors (usually , the three subtractive primary colors, namely yellow (Y) and magenta (M).

It is said to be 4 colors including cyan (C) and black (BL))
When the colors are separated and digital image data corresponding to a halftone dot image for each color is output from the image capture unit, the digital image data is stored in the storage of the workstation (MT, hard disk, etc.).

The workstation described above uses the digital image data stored in the storage described above to create a layout,
Perform image processing such as color adjustment 1 editing, check the results on the display or the output image from the digital color blueprint, and if it is OK, print it out using the photo film output device or the recorder section of the drum scanner. Create a color separation film.

With this color separation film, PS plates (e.g. aluminum printing plates), silver masters, paper plates (e.g. ZnO paper plates)
The image is transferred by exposure to light, and through a development process, a lithographic plate for actual printing is made, and the final printing is performed using the completed lithographic printing plate. This method is currently commonly used.

(Problems to be Solved by the Invention) By the way, in the conventional printing system explained with reference to FIG. Printing plates are also expensive, making it financially difficult for the light offset industry, which prints only a small number of sheets.

On the other hand, since a ZnO paper plate was used, there were problems such as poor reproducibility of halftone dots, easy stretching, and easy occurrence of moiré.

(Means for Solving the Problems) The present invention prints using image information for each predetermined number of colors obtained by color-separating image information to be printed and digital image data for each color corresponding to the image information for each color. A photoconductor for electrophotography having at least a highly moisture-resistant photoconductive layer member, in which a toner image is formed according to an electronic four-page process using light modulated by printing image data generated by a printing image data generating means. An electrostatic latent image is formed on a flexible recording medium and this flexible recording medium for electrophotography by light modulated by the printing image data for each color in the printing image data, and a lipophilic visible image is formed. The present invention provides an electrophotographic printing apparatus comprising means for outputting a printing plate formed by forming a halftone image for each color using toner for printing, and an electrophotographic printing apparatus having a photoconductive layer member containing at least titanium dioxide. The present invention provides a lithographic output device comprising a flexible recording medium for use in printing.

(Function) Generates digital image data for each color that corresponds to image information for each color necessary for multicolor printing from image information targeted for printing (monochrome digital image data can also be generated). good).

Digital image data for each color for printing is generated using image information for each color and a corresponding digital image button.

Due to the printing image data for each color in the printing image data according to the electrophotographic process that includes the step of exposing using light modulated by the printing image data, secondary progress of etching is reduced and dampening water is A halftone dot image for each color is formed individually using a lipophilic developing toner on a flexible recording medium for electrophotography having a photoconductive layer member with at least high moisture resistance in which the amount of impregnation is difficult to increase beyond a certain level. Outputs 51 and version.

(Example) Hereinafter, specific contents of the reprint output device of the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a printing system including a reprint output device of the present invention, FIGS. 2 and 3 are diagrams for explaining the schematic configuration of the planographic output device of the present invention, and FIGS. 4 and 5
This figure is a diagram for specifically explaining the operation of the lithographic output apparatus of the present invention shown in FIGS. 2 and 3.

In FIG. 1 schematically showing a printing system including a reprint output device of the present invention, 1 is an original (original), and this original 1 is a film of a color image to be printed (for example, a color photographic film). It is.

The above-mentioned original 1 is processed by a prepress camera (for example, an image scanner 3 or a drum scanner 4) at an image capture unit 2 to obtain a plurality of colors required for multicolor printing (usually three primary colors of subtractive color mixture, i.e., The image is separated into four colors (yellow (Y), magenta (M), cyan (C), and black (BL)), and the image for each color and the corresponding digital image data are captured. When the digital image data is output from the unit 2, the digital image data is stored in the storage (MT, hard disk, etc.) 7 of the work station 5, and the digital image data corresponding to the halftone dot image for each color is output from the image capture unit 2. When output, the digital image data is stored in the storage (MT, hard disk, etc.) 7 of the workstation 5.

The workstation 5 uses the image processing device 6 to
While viewing the color image displayed on the display, image processing such as layout, color tone adjustment and editing is performed using the digital image data stored in the storage 7.

The digital image data supplied to the reprint output device 8 after the predetermined image processing has been performed at the workstation 5 described above is also processed from the image capture unit 2 to the workstation 5 (as in the case of the data supplied to B). , digital image data corresponding to an image for each color, digital image data corresponding to a halftone image for each color, or data in any signal form, but digital image data corresponding to an image for each color. When the data is supplied to the planographic output device w8, the data supplied thereto is converted into digital image data corresponding to a halftone image for each color and used within the planographic output device 8.

Note that in the case of document 1 whose image information to be printed is monochrome, the workstation 5 described above
It goes without saying that the digital image data supplied from the workstation 5 to the lithographic output device 8 after the predetermined image processing is performed thereon corresponds to a monochrome image.

The planographic output device 8 to which the digital image data is supplied from the workstation 5 converts the digital image data into digital image data corresponding to a halftone dot image for each color (or digital image data corresponding to a monochrome halftone dot image). ) outputs a flat plate as printing image data.

When the reprint output device 8 performs the operation of outputting a flat plate, the secondary progress of etching is small and the dampening water impregnation m increases above a certain level due to the printing image data of each color in the printing image data. A flexible recording medium for electrophotography having a photoconductive layer member having at least high moisture resistance,
A 114-plate is output in which a halftone image for each color is individually formed using lipophilic developer toner, and a detailed explanation of each operation as described above in this 11-plate output device 8 is given below. Please refer to Figures 2 to 5 (described below).

As mentioned above, the reprint output device 8 forms a toner image according to an electrophotographic process in which the reprint output from the reprint output device 8 is exposed using light that is adjusted according to image data for printing. A flexible recording medium for electrophotography is used, which has a photoconductive layer member with at least a high moisture resistance, in which the secondary progress of etching is small, and the amount of impregnated dampening water is difficult to increase beyond a certain level. .

The lithographic printing plate made by the above-mentioned reprint output device 8 is subjected to a treatment in an etching device (hydrophilic treatment device) 9 to make the portions of the reprint printing plate other than the oil-based toner image hydrophilic. After that, actual printing 10 is performed.

Next, with reference to FIGS. 2 to 5, a specific example of the configuration and specific operation of the planographic output device 8 described above will be explained.

FIG. 2 shows a paper feed unit (supply unit for flexible recording media for electrophotography) 11, a laser scan unit 12, and an exposure table 3 in the 517-plate output device 8.

FIG. 2 is a schematic configuration diagram of the reprint output device 8, which is illustrated for convenience in explaining the operation mode of each section such as the transport section 14 and the unloading section 15. FIG.

Further, FIG. 3 is a schematic configuration diagram of the lithographic output device 8, which is illustrated for convenience in explaining the operation mode of the developing station (developing section) 16, which is not shown in the above-mentioned figure ff12. If the part of the developing station 16 as illustrated in the figure is included in FIG. It is divided into Figures 2 and 3).

Further, FIG. 4 is an explanatory diagram for facilitating a sequential explanation of the operation of each component in the lithographic output device 8 illustrated in FIGS. 2 and 3 described above.

That is, in the lithographic output device 8 illustrated in FIGS. 2 and 3, the same conveying device 14 is used for both the sheet feeding operation and the unloading operation, as will be described later. In order to avoid difficulty in understanding the operation of the parts, FIG. 4 is modified so that the paper feed section 11 is placed on the left side of the figure, and the delivery section 15 is placed on the right side of the figure.
The operations of band m-exposure, development, fixing, and conveyance are shown as being performed in one direction in the figure to facilitate understanding of the operations of each part.

Furthermore, FIG. 5 is a diagram illustrating and explaining the sequential operation mode of each component shown in FIG. 2, and the diagrams indicated by (1) to (13) in FIG. , shows the operation mode of each part at each position indicated by the corresponding numbers (1) to (13) enclosed in parentheses in FIG.

In FIG. 2, the paper feed section 11 is equipped with a flexible photoconductive layer for electrophotography that has at least a highly moisture-resistant photoconductive layer member that is less prone to secondary etching and is less likely to be impregnated with dampening water beyond a certain level. For example, a thin electrophotographic flexible recording medium P having a laminated structure of a photoconductive layer member made of titanium dioxide and a binder and an electrode (in FIG. A roll 17 (as shown) is provided.

The flexible recording medium P for electrophotography provided in the paper feed section 11 described above is fed out by a predetermined length from the paper standby state shown in (1) in FIG.
After the paper is cut by the paper cutter 8, the paper is sucked by the suction belt 19 in the conveyance section 14, and the paper is conveyed as shown in FIG. 5(2).

One suction belt provided in the conveyance section 14 is stretched between a drive roller 20 and a driven roller 21, and when the drive roller 20 is rotationally driven, the suction belt 1
The flexible recording medium P for electrophotography, which is attracted to the flexible recording medium P for electrophotography, is conveyed to a predetermined position.

The above-mentioned suction belt 19 has a flexible recording medium P for electrophotography on its surface, for example, by suctioning air from the back side with a vacuum device through a large number of holes with minute diameters provided through the suction belt 19. The transport operation can be carried out in a state where the material is attracted.

The flexible recording medium P for electrophotography is conveyed from above to below in FIG. It is moved in the direction of the large arrow in (3) of FIG. The suction and holding operation of the flexible recording medium P for electrophotography on the exposure table 13 is similar to the suction and holding operation of the flexible recording medium P for electrophotography on the suction belt 19 described above.
This can be done by suctioning air from the inside of 3 using a vacuum device.

As described above, the exposure table 13 in a state where the 1-+■ flexible recording body P for electrophotography is being sucked and held is shown in (4) of FIG. 5, which is a diagram showing the movement of the exposure table. When the exposure table 13 is moved in the direction of the large arrow from the position (3) in FIG. 2 to the position (4) in FIG. The exposure table 13 is rotated by 90 degrees in the direction of the large arrow in (5) of FIG.
5), and then the exposure table 13 is moved in the direction of the large arrow in (6) of FIG. 5, which is a diagram showing the movement (charging) of the exposure table.

At position (6) in FIG. 2, a charger (not shown) corona charges the electrophotographic flexible recording medium P on the exposure table 13 with χJ. It may be provided within the developing station 16 shown in FIG. The state of corona charging of the electrophotographic flexible recording medium P on the exposure table 13 is illustrated by the power source 22 and charger 23 in FIG.

Here, the electrophotographic flexible recording medium P corona-charged on the exposure table 13 moves in the direction of the large arrow in (7) of FIG. The exposure table 13 is rotated by 90'' to make it vertical as shown in (7) in FIG.・Unit 1
It is exposed by scanning laser light from 2.

The scanning laser light from the laser scanning unit 12 used to expose the flexible recording medium P for electrophotography is scanning light modulated by image data for printing, and is a scanning laser beam used for exposing the flexible recording medium P for electrophotography. A charge latent image with a high resolution of, for example, +200 apl is formed on the recording medium P by the scanning laser beam from the laser scan φ unit 12 described above.

The light source used for exposing the flexible recording medium P for electrophotography may be scanning light other than a laser, but it is possible to use a scanning light source other than a laser to expose the flexible recording medium P for electrophotography. In order to form a photoconductive layer, it is preferable to use a scanning laser beam, and at least a highly moisture-resistant photoconductive material with little secondary etching progress and with which the amount of dampening water impregnated is difficult to increase beyond a certain level. As a flexible recording medium P for electrophotography having a layer member, a thin flexible recording medium for electrophotography has a structure in which a photoconductive layer member made of titanium dioxide and a binder and an electrode are laminated. When P is used, it is desirable to use a semiconductor laser that emits light with a wavelength longer than 550 nl as a light source for exposure.

The laser scanning unit 12 illustrated in FIG. 4 converts laser light emitted from a semiconductor laser 24, modulated by information to be recorded, into parallel light using a collimator lens 25. After being deflected in the main scanning direction by the rotating polygon mirror 26, the flexible recording medium P for electrophotography is irradiated via the fθ lens 27, and the laser scanning unit 12 is moved in the sub-scanning direction. , it is possible to form a charge latent image based on the information to be recorded on the flexible recording medium P for electrophotography.

Next, the electrophotographic flexible recording medium P exposed on the exposure table 13 is rotated 90 degrees in the direction of the large arrow in (8) of FIG. 5, which is shown as a diagram of the rotation of the exposure table. The exposure table 13 is turned upside down and horizontal as shown by (8) in FIG.

The exposure table 13 is moved from the position (8) in FIG. 2 in the direction of the large arrow in (9) in FIG. 5, which shows the movement (development) of the exposure table. When the flexible recording medium P for electrophotography is moved to the position (9) in FIG. A developing device 28 (in which liquid toner is stored) is provided in the developing station 16.
When passing above the flexible recording medium P for electrophotography (FIG. 3), it is visualized by liquid toner stored in a developing device below the flexible recording medium P for electrophotography.

The developing station 16 illustrated in FIG. 3 includes a developing device 28 containing liquid toner and an etching device 9 supported by an endless belt. The belt may be moved to a selected specific position in the vertical direction in the figure, and together with these, the developing station 16 as a whole is moved in the direction of the arrow in FIG. The rotation operation of the exposure table 13 is not obstructed, and the exposure table 13 and the developing station 1 are
By moving relative to 6, the charger 0, developing operation, etc. can be performed at high speed.

It goes without saying that the etching device 9 may be provided separately outside the planographic output device 8.

Up to now, a toner image has been formed on the electrophotographic flexible recording medium P on the exposure table 13 according to steps (1) to (9) in FIG.

Now, for example, if the process of forming a flexible recording medium P for m-child photographs is shown according to FIG. 5, (1) in FIG.
Paper standby state - (2) Paper transport → (3) Paper movement to exposure table → (4) Exposure table movement - (5) Exposure table rotation - (6) Exposure table movement (charging) = (7) Exposure corresponding to print image data → (8) Rotation of exposure table → (9)
Development with toner → looks like this.

Once a halftone image is formed on the flexible recording medium P for electrophotography using toner according to the printing image data in this way, the image shown in FIG. (10) Rotated by 90″ in the direction of the large arrow inside,
The exposure table 13 is placed in a vertical position as shown at 10) in FIGS. 5 and 2.

Next, the exposure table 13 is moved (surface drying).
In the direction of the large arrow in (11) in Figure 5, which is shown as a diagram, from the position (IO) in Figure 2 to (1) in Figure 2
It is moved to the position 1) and the surface of the flexible recording medium P for electrophotography is dried.

Next, the flexible recording medium P for electrophotography, which had been attracted to the exposure table 13, is moved in the direction of the large arrow in (12) in FIG. Then, the back surface of the electrophotographic flexible recording medium P is dried by being moved from the position (11) in FIG. 2 to the position (12) in FIG.

A blower as shown at 29 in FIG. 4 may be used to dry the front and back surfaces of the flexible recording medium P for electrophotography.

Next, see Figure 5 ((
13) As shown by the arrow inside, the electrophotographic flexible recording medium P attracted to the suction belt 19 is carried out to the unloading section 15 by the conveyance operation of the suction belt 19.

Until now, (1) in Figures 2 and 3 and Figure 5
Although the series of operations in the lithographic output device 8 has been explained with reference to (13), FIG.
) to (13), paper feeding (3), charging (6),
Only the 62 steps of development (9), drying (12), and transport (13) are shown.

According to FIG. 4, paper feeding (3) - charging (6) - exposure of image (7) - development (9) - drying (12) - transport of IIJ flexible recording medium P for electrophotography This will be explained as (13). When producing a lithographic printing plate using the lithographic output device 8, a lipophilic toner image is formed on a flexible recording medium P for electrophotography based on printing image data of each specific color. A one-color reprint plate is produced.

Here, for example, if this printing plate is separated into 4 colors, 4
Color separation is required. Furthermore, in the case of outputting printing plates of each color, it goes without saying that the above-described process may be repeated for each color data for each color separation.

Note that the light source for exposure used in carrying out the present invention includes a semiconductor laser that emits light in the wavelength range that is sensitive to a photoconductor that includes a photoconductor, as well as a semiconductor laser that emits light in the wavelength range that is sensitive to a photoconductor that includes a photoconductor. Gas lasers, LED arrays, EL arrays, etc. that emit light in the wavelength range that is sensitive to the photoreceptor configured can also be used.

In addition, as toner for proof printing, the particle size is 081~
In addition to the 1 micron wet toner (liquid toner), a dry 1 micron particle size may also be used. Further, the above-mentioned toner can be used even if it is colored with a pigment, and as a toner for planographic production, it is desirable that the toner has excellent lipophilicity and rigidity resistance.

In addition to titanium dioxide, which has the characteristics of little secondary etching progress, difficulty in increasing the amount of dampening water impregnated beyond a certain level, and excellent continuous tone performance and dot reproducibility, oxidized photoreceptors are used as photoreceptors. Infrared sensitized zinc or PVK (polyvinyl carbazole) may also be used.

It goes without saying that a combination of these photoreceptors and a moisture-resistant substrate may also be used.

(Effects of the Invention) As described above in detail, the reprint output device of the present invention has image information for each predetermined number of colors obtained by color-separating image information to be printed, and image information for each color corresponding to the image information for each color. At least a highly moisture-resistant photoconductive layer member is provided in which a toner image is formed according to an electrophotographic process using light modulated by printing image data generated by a printing image data generating means using digital image data. a flexible recording medium for electrophotography, and an electrostatic latent image is formed on the flexible recording medium for electrophotography by light modulated by the printing image data for each color in the printing image data. , a means for outputting a lithographic plate formed by forming a halftone image for each color using lipophilic developing toner, so a color separation film is not involved during the process of producing a lithographic printing plate. Since the production of lithographic printing plates is proceeded by electrical signal processing without the need for a high level of skill and long time, the production of lithographic printing plates can be done easily. In addition, especially as a flexible recording medium for electrophotography, it has a photoconductive layer member containing at least titanium dioxide, so it has good halftone reproducibility,
It has the effect that it does not stretch and does not easily cause moire, and also has the effect of improving dot reproducibility because etching (hydrophilic treatment) progresses during printing and does not contain too much dampening water.

In the embodiment of the present invention, a flat one was used as the exposure stage 13, but it goes without saying that the same effect can be achieved even if the photoreceptor is wrapped around a drum-shaped one. Of course, the generating means may be placed within the lithographic output device 8 or may be placed outside.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a printing system including a lithographic output device of the present invention, FIGS. 2 and 3 are diagrams for explaining the schematic configuration of the lithographic output device of the present invention, and FIGS. 4 and 5
The drawings are diagrams specifically explaining the operation of the lithographic output apparatus of the present invention shown in FIGS. 2 and 3, and FIG. 6 is a block diagram showing a conventional printing system. 1... Original (original), 2... Image capture unit,
5... Workstation, 6... Image processing device,
8... Planographic output device, 9... Etching device (hydrophilic treatment device), 10... Main printing, 11... Paper feeding unit (
supply unit for flexible recording media for electrophotography), 12... laser scan unit, 13... exposure table, 14...
... Conveyance section, 15 ... Unloading section, 16 ... Development station (development section), 17 ... Roll, 18 ... Cutter, 19 ... Adsorption belt, 20 ... Drive roller, 21
... Driven roller, 22 ... Power supply, 23 ... Charger,
24... Semiconductor laser, 25... Collimator lens,
26...Rotating polygon mirror, 27...fθ lens, 28...
・Developer, P...Flexible recording medium for electrophotography.

Claims (3)

[Claims] (1) Printing generated by a printing image data generating means using image information for each predetermined number of colors obtained by color-separating image information to be printed and corresponding digital image data for each color. A flexible recording medium for electrophotography having at least a highly moisture-resistant photoconductive layer member on which a toner image is formed according to an electrophotographic process using light modulated by image data for electrophotography; Forming an electrostatic latent image on a flexible recording medium using light modulated by printing image data for each color in the printing image data, and forming a halftone dot image for each color using lipophilic developer toner. A lithographic output device comprising means for outputting a lithographic plate. (2) The lithographic output device according to claim 1, comprising: a flexible recording medium for electrophotography having a photoconductive layer member containing at least titanium dioxide. (3) Claim 1 in which liquid toner is used as the toner for visualization.
The lithographic output device described in .