JPH0772794B2 - Proofing machine for electrophotographic recording media - Google Patents

Description

TECHNICAL FIELD The present invention relates to a proof printing method using an electrophotographic recording medium.

(Prior art) A charge latent image is formed on a photosensitive member including a photoconductor by utilizing a photoconductive phenomenon, and charged fine particles (toner) are attached to the charge latent image to visualize it. As a method of forming an electrophotographic image by an electrophotographic process in which a latent charge image is a visible image, a recording medium formed by stacking a support member and a photosensitive member including a photoconductor has been conventionally used. On the other hand, a CPC method for forming a toner image by an electrophotographic process and a toner image formed by an electrophotographic process on a transfer recording medium provided with a photosensitive member including, for example, a photoconductor are used. A PPC method is known in which transfer is performed on plain paper.

In the CPC method described above, the recording medium itself has photosensitivity and a toner image is directly formed on the recording medium by an electrophotographic process. Therefore, a high-resolution image can be easily formed on the recording medium. However, depending on the color of the surface of the recording medium, there is a problem in that color reproduction of a color image is disturbed.

On the other hand, in the above-mentioned PPC method, for example, the toner image formed on the photoconductor drum is transferred to plain paper, so even if a high-resolution toner image is formed on the photoconductor drum, However, when the toner image is transferred onto the plain paper, the final image on the plain paper has a reduced resolution.However, as the transfer paper onto which the toner image is to be transferred, good color reproduction of the color image is performed. Since the white paper that can be obtained is freely selectable, it is difficult to obtain a good color image in the CPC method.
It is clear that the law can solve it, but this PPC
As described above, the method has a problem that the resolution is lowered during the transfer process, and therefore it is difficult to obtain a good color image with high resolution.

By the way, in a so-called total printing system, a printed matter is designed to be obtained through each process of image capturing, editing processing, proofreading, plate making, plate making, and printing. When an image is lithographically printed, the color photographic film of the original is used by a plate making camera (for example, an image scanner or a drum scanner) in the image capturing section to provide a plurality of colors required for multicolor printing (used for multicolor printing There are multiple colors
Normally, black (BL) is added in addition to the three subtractive primary colors, that is, yellow (Y), magenta (M), and cyan (C).
When the color separation film is made by the halftone image for each color by color separation, the color separation film is sent to proofreading and the plate is made based on the color separation film. And proofreading is done based on the film, and if the proofprint is OK, lithographic plate making for main printing is performed based on the color separation film, The printing of this machine is performed by the lithographic printing plate thus obtained.

By the way, as described above, proofreading using a color separation film, or making a printing plate using a color separation film,
So, in a system where all motion is based on the presence of a color separation film, the color separation film requires a long time and a lot of effort to form an image on it, and at the same time saves it. There are also various problems in terms of management and management, and also the proofreading work performed based on the color separation film requires skill, and it is not easy for anyone to operate. As a machine, there is a problem that separate and expensive devices are required.

In order to solve the above-mentioned problems, it has been proposed in the past that proof printing is performed by applying an electrophotographic process, and even the applicant company of proof printing and planographic printing. A device capable of producing a printing plate by applying an electrophotographic process, that is, each color corresponding to a predetermined number of color image information obtained by color-separating image information to be printed. A toner image is formed according to an electrophotographic process by using a printing image data generating unit that generates image data for each color for printing using the digital image data and the light modulated by the printing image data. A recording medium for electrophotography having a structure in which at least an electrode and a photoconductive layer member are laminated as described above and having a white surface, and the white surface described above.
A proof print is formed by sequentially forming a halftone dot image for each color on the recording medium for electrophotography by using the image developing toner for each color in accordance with the printing image data for each color in the printing image data. By the output means and the printing image data for each color in the printing image data, each one of the electrophotographic toners is individually applied to each electrophotographic recording medium.
There is proposed an output device for a proof and a lithographic plate, which comprises a means for outputting a lithographic plate formed by forming a halftone image for each color.

(Problems to be Solved by the Invention) In the above-mentioned proof printing and planographic output device proposed by the applicant company, at least the electrode and the photoconductive layer member are laminated so that a toner image is formed according to an electrophotographic process. The proof printing by a color image is output by the recording medium for electrophotography having the above-mentioned structure and having a white surface, or the planographic printing plate for each color forming the color image is output. For this reason, a lithographic printing plate for each color can be obtained by processing the image signal as described above without using a color separation film as in the conventional case and for printing the color image as described above. Therefore, although the above-mentioned conventional problems can be solved well, the proofs output from the output device of the already proposed proof and the planographic printing described above can be printed according to the electrophotographic process as described above. A toner image of each color is stacked by an electrophotographic process on a recording medium for electrophotography having a structure in which at least an electrode and a photoconductive layer member are laminated so that a toner image is formed and having a white surface. Since a color image is formed by this, the proof print described above is different in the kind of paper from the printed matter actually printed by this machine, and the printed matter actually printed by this machine, that is, the printing ink. Compared with the color printed matter by lithographic printing using, it is different in terms of color development and dot gain.

Therefore, even better proofing, that is, a color print in the same state as the color print obtained when lithographic printing is actually performed using printing ink on the paper actually used for printing with this machine A request was made to get a close proof.

(Means for Solving the Problem) The present invention provides a support member, an electrode layer formed on the support member, and a white photoconductive layer containing titanium dioxide as a main component formed on the electrode layer. A predetermined number obtained by color-separating the image information to be printed on one electrophotographic recording medium consisting of a member and the overcoat layer formed on the white photoconductive layer member. The toner image for each color is sequentially formed by the electrophotographic process using the light modulated by the image data for each color for printing, which is generated based on the digital image data for each color corresponding to the image information for each color And a means for applying heat and pressure to the toner image formed on the overcoat layer of the recording medium for electrophotography as described above to bury the toner image in the overcoat layer. Calibration of the recording medium itself for photographs The first proof printing means for printing and the toner image in the overcoat layer in the state where the toner image is formed on the overcoat layer of one electrophotographic recording medium as described above are formed. The surface and the surface of the transferred member are heated in close contact with each other to transfer the overcoat layer on which the toner image is formed onto the transferred member, and the overcoat layer is white in the recording medium for electrophotography. Recording medium for electrophotography, which comprises a second proof printing means for proofing the part where the member to be transferred and the overcoat layer on which the toner image is formed are separated from the photoconductive layer member. Providing an apparatus for producing proofs.

(Function) One electron formed by laminating a white photoconductive layer member and a peelable overcoat layer on the white photoconductive layer member on a supporting member having conductivity. Printing generated on the overcoat layer of a photographic recording medium based on digital image data for each color corresponding to a predetermined number of image information for each color obtained by color separation of the image information targeted for printing A toner image for each color is sequentially formed by an electrophotographic process using light modulated with image data for each color for use.

As described above, the toner image formed on the overcoat layer of one electrophotographic recording medium is subjected to heat and pressure so that the toner image is embedded in the overcoat layer, and the electrophotographic recording is performed. Use the media itself as a proof.

In addition, as described above, the surface of the overcoat layer on which the toner image is formed and the surface of the transfer target member in the state where the toner image is formed on the overcoat layer of one electrophotographic recording medium are The overcoat layer on which the toner image is formed is transferred to the transfer target member by heating in a state of being in close contact, and the above-mentioned overcoat layer is peeled off from the white photoconductive layer member in the electrophotographic recording medium. The portion in which the transferred member and the overcoat layer on which the toner image is formed are integrated is used as a proof.

(Example) Hereinafter, specific contents of a proof printing apparatus using the recording medium for electrophotography of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view of an electrophotographic recording medium used in a proof printing apparatus using the electrophotographic recording medium of the present invention, and FIG. 2 is an explanatory diagram of an operation of burying a toner image in an overcoat layer, FIG. 3 is a diagram for explaining the operation of transferring the toner image together with the overcoat layer to the transfer target member, and FIG. 4 is the output of a proof and a lithographic plate to which the apparatus for producing a proof using the electrophotographic recording medium of the present invention can be applied. FIG. 5 is a block diagram showing a printing system including the apparatus, and FIGS. 5 to 8 are diagrams for showing a difference in reflected light amount of an image.

FIG. 1 is a side sectional view of an electrophotographic recording medium P used in a proof printing apparatus using the electrophotographic recording medium of the present invention. In FIG. 1, 11 is an appropriate material, for example, a thickness of 100. Support made of micron polyester membrane, 12
Is an electrode made of a thin film of a conductive material, and 13 is a white photoconductive layer member composed mainly of titanium dioxide and a binder.

Titanium dioxide used in the above-mentioned photoconductive layer member 13 has a large dielectric constant, and has a larger charge holding amount than other photoconductors. Since it can be made to have sensitivity, a hard copy of a good color image can be easily obtained by the CPC method with a recording medium using titanium dioxide as a photoreceptor.

Further, 14 is an overcoat layer provided on the above-mentioned photoconductive layer member 13, and as this overcoat layer,
Although thermoplastics of the type called thermoplastics (polyester, acrylic, polystyrene, silicone) can be used, vinyl acetate, styrene resin, and acrylic resin are suitable because of their optical characteristics and ease of processing. There is.

The overcoat layer 14 has a light refractive index of 2.0 or less (preferably a refractive index of 1.2 to 1.5) and a glass transition temperature lower than the softening temperature of the toner used during the phenomenon of the recording medium. It is required to be composed of materials.

As an example of the constitution of the above-mentioned overcoat layer 14, for example, an acrylic resin having a softening point of 60 ° C. to 70 ° C. is dissolved in toluene and the thickness thereof is 5 μm to 5 μm by a bar coater.
It is constructed by coating to give a 30 micron film.

The above-mentioned overcoat layer 14 was a constitutional example in the case where it was constituted as a transparent layer, but with the titanium dioxide used in the constitution of the above-mentioned photoconductive layer member 13 as the above-mentioned overcoat layer 14. You may comprise using a binder. However, when the titanium dioxide and the binder used in the construction of the photoconductive layer member 13 described above are used as the overcoat layer 14, the binder is added to improve the transparency of the overcoat layer 14. Increase the ratio. Also,
In this case, a thin layer of silicon resin having a thickness of, for example, about 0.1 μm to 1 μm may be provided as a peeling layer between the photoconductive layer member 13 and the overcoat layer 14.

Next, a block diagram of an entire printing system including an output device for a proof and a lithographic plate, which is used in an apparatus for producing a proof from a recording medium for electrophotography of the present invention, is shown.
With reference to the drawings, an outline of a case where a proof print or a planographic printing plate is output by an electrophotographic recording medium by an electrophotographic process will be described.

In FIG. 4, reference numeral 1 is an original (original), and this original 1 is a film of a color image to be printed (for example, a color photographic positive film). A camera (for example, the image scanner 3 or the drum scanner 4) uses a plurality of colors (usually three subtractive primary colors, that is, yellow (Y), magenta (M), and
When the digital image data corresponding to the image of each color is output from the image capturing unit 2, the color is separated into four colors including black (BL) in addition to cyan (C)}. When the digital image data is stored in the storage 7 of the workstation 5 and the digital image data corresponding to the halftone image for each color is output from the image capturing unit 2, the digital image data is stored in the workstation 5. It is stored in the storage 7.

The workstation 5 uses the image processing device 6 to perform image processing such as layout, hue adjustment, and editing using the digital image data recorded in the storage 7 while watching the color image displayed on the display. .

In the case where the digital image data supplied to the output device 8 for proof and lithographic printing after the predetermined image processing is performed in the workstation 5 is also the data supplied from the image capturing unit 2 to the workstation 5. Similarly, with digital image data corresponding to the image for each color,
Even with digital image data corresponding to halftone images for each color,
The data may be in any signal form, but from the viewpoint of data interchange compatibility, the digital image data corresponding to each color image is output as digital image data in the DDES format between the proof and the lithographic plate. Output device 8 for proof and lithographic plate so that it is supplied to device 8.
It is preferable that the data supplied thereto be converted into digital image data corresponding to the halftone image for each color and used.

In the case of the original 1 whose image information to be printed is monochrome, after the predetermined image processing is performed in the workstation 5, the proof printing and planographic output device 8 is output from the workstation 5. It goes without saying that the digital image data supplied to the digital image data is digital image data corresponding to a monochrome image.

In the proof and lithographic output device 8 to which the digital image data is supplied from the workstation 5, the digital image data provided thereto is converted into digital image data (or monochrome halftone dot) corresponding to the halftone dot image of each color. As printing image data (digital image data corresponding to an image), the printing image data is used to output a proof or a lithographic plate.

Then, when the above-mentioned proof and lithographic output device 8 performs an operation to output a proof from it,
For the printing according to the electrophotographic process including the step of exposing the recording medium P for electrophotography having the structure as described above with reference to FIG. 1 to the light modulated by the image data for printing. Output a proof print by forming a halftone dot image for each color in sequence using toner for image development of each color according to the print image data for each color in the image data, and output the proof print and the planographic printing plate. When the device 8 performs an operation for outputting a lithographic plate, it has a configuration in which at least an electrode and a photoconductive layer member are laminated according to the printing image data for each color in the printing image data. A lithographic printing plate is formed by forming a halftone dot image for each color on a single electrophotographic recording medium with a lipophilic toner for image development.

When the proof is OK, the recording medium for electrophotography to be used during plate making of the lithographic plate for main printing, which is subsequently performed by the output device 8 for the proof and the lithographic plate, has the surface thereof Although it is not necessary to be white, a recording medium for electrophotography, which has a pure white surface used for proof printing, may be used as a recording medium for electrophotography used when making a lithographic plate for main printing. Of course.

That is, since the color of the toner image formed on the recording medium for electrophotography by using the oil-based toner according to the electrophotographic process at the time of plate making for each color for main printing may be any color, The color of the electrophotographic recording medium used for plate making of each color may be any number.

On the other hand, in the output device 8 for proof and lithographic printing plates, the same components are used for both proof printing and lithographic printing plate making. It is advantageous from the point of view of the structure of the apparatus that the type is a kind because the paper feeding mechanism is simplified.

The lithographic printing plate produced by the proof printing and lithographic output device 8 is subjected to a treatment in the developing processor 9 so that a portion of the lithographic printing plate other than the oily toner image portion becomes hydrophilic. The machine printing 10 is performed from.

By the way, the proof printing apparatus using the recording medium for electrophotography uses the one proof sheet described above with reference to FIG. 1 when obtaining the proof output in the above description described with reference to FIG. Overcoat layer 14 in recording medium P for electrophotography
Heat and pressure are applied to the toner image 15 formed by the electrophotographic process on the toner image 15 by the rollers 16 and 17 as shown in the second figure, so that the toner image 15 is embedded in the overcoat layer 14 for electrophotography. In the overcoat layer 14 in the state where the toner image 15 is formed on the overcoat layer 14 of one electrophotographic recording medium P as shown in FIG. Toner image 15
The surface on which the toner image is formed and the surface of the transfer target member 20 are heated while being pressed by, for example, rollers 18 and 19, and the overcoat layer 14 on which the toner image 15 is formed is transferred to the transfer target member 20. The above-mentioned overcoat layer 14 is peeled off from the white photoconductive layer member 13 in the recording medium P for electrophotography, and the transferred member 20 and the overcoat layer 14 on which the toner image 15 is formed are integrated. This is a proof press production apparatus in which the above portion is used as a proof press, and the contents will be specifically described below.

As described with reference to FIG. 4, when the proof printing method using the recording medium for electrophotography of the present invention is applied to output the proof by the recording medium P for electrophotography by the electrophotographic process, the above-mentioned process is performed. With respect to the overcoat layer 14 in the electrophotographic recording medium P having the structure described above with reference to FIG. 1, the digital image data (or the monochrome image data corresponding to the halftone image of each color) According to the electrophotographic process including the step of exposing with light modulated by the printing image data of the halftone image and the corresponding digital image data), by the printing image data for each color in the printing image data After a halftone dot image for each color is sequentially formed as a toner image 15 using toners for developing images of respective colors, the toner image 15 is electronically formed as shown in FIG. It is embedded in the overcoat layer 14 of the genuine recording medium P, or the toner image 15 is transferred together with the overcoat layer 14 to the transfer target member 20 as shown in FIG. The photoconductive layer member 13 is peeled off.

2 and 3, P is a recording medium P for electrophotography having the structure as described above with reference to FIG. 1, and the electrophotography shown in FIG. 2 and FIG. The recording medium P for use has a toner image 15 formed on its overcoat layer 14 by an electrophotographic process.

First, in FIG. 2, a toner image is formed on the overcoat layer 14.
The recording medium P for electrophotography in which 15 is formed is
The heating and pressing rollers 16 and 17 are rotated to move from the right side to the left side in the figure.

The toner image 15 and the overcoat layer 14 on the overcoat layer 14 in the electrophotographic recording medium P are heated and pressed by the heating and pressing rollers 16 and 17 described above, so that the overcoat layer 14 has a glass transition temperature or higher. The toner image 15 is buried in the overcoat layer 14 by being heated to the temperature of.

Thus, when the toner image 15 is buried in the overcoat layer 14 as shown in FIG.
Problems such as deterioration of color reproduction and graininess due to the uneven structure peculiar to electrophotography, which has been a problem in the normal electrophotographic image in the state shown in Fig. 7 in which the toner image is attached on the substrate surface, are good. Will be resolved to. FIG. 6 is a distribution diagram of the amount of reflected light in the electrophotographic image shown in FIG. 5 in which the toner image 15 is buried in the overcoat layer 14, and FIG. 8 is a diagram showing the toner image deposited on the substrate surface. 7 is a distribution chart of the amount of reflected light in a normal electrophotographic image in the state shown in FIG. 7, showing the amount of reflected light when the toner image 15 is buried in the overcoat layer 14 as shown in FIG. Unlike FIG. 8 showing the distribution state of the reflected light amount in the normal electrophotographic image in the state shown in FIG. 7 in which the toner image is attached on the substrate surface, FIG. When it is buried in the overcoat layer 14 as shown in FIG. 5, a large improvement in halftone characteristics and density gradation is achieved, and color development equivalent to color printing is easy. Can be obtained.

Next, in FIG. 3, a toner image is formed on the overcoat layer 14.
The recording medium P for electrophotography in which 15 is formed is
The surface of the overcoat layer 14 on which the toner image 15 is formed and the surface of the transferred material 20 are brought into close contact with each other by rotating the heating / pressurizing rollers 18 and 19 from the left side to the right side in the drawing. Be moved to.

Then, the toner image 15 and the overcoat layer 14 on the overcoat layer 14 in the electrophotographic recording medium P are heated and pressed by the heating and pressing rollers 18 and 19, and the surface of the overcoat layer 14 is transferred. The toner image 15 on the surface of the body 20 is closely attached, and the entire toner image 15 on the overcoat layer 14 is transferred to the surface of the body 20 to be transferred.

In this way, the overcoat layer 14 in the electrophotographic recording medium P is separated from the photoconductive layer member 13 in the electrophotographic recording medium P together with the toner image 15 and integrated with the transfer target 20. So toner image 15 is 10 of it
Since 0% is transferred to the transfer target 20, the image quality is improved and the dot gain is adjusted well.

In addition, since it is possible to directly perform proof printing on the paper used for printing on this machine (for example, cardboard, newspaper, film, etc.), it can be used as a proof printing (out-school) to be given to the person who requested printing. Can be used, and other advantages can be obtained.

(Effects of the Invention) As is clear from the above description, in the proof printing apparatus using the electrophotographic recording medium of the present invention, the supporting member and the electrode layer formed on the supporting member are provided. A sheet of electrophotographic recording medium comprising a white photoconductive layer member containing titanium dioxide as a main component formed on the electrode layer, and an overcoat layer formed on the white photoconductive layer member. In addition, modulation is performed with image data for each color for printing generated based on digital image data for each color corresponding to a predetermined number of image information for each color obtained by color-separating the image information to be printed. The toner image for each color is sequentially formed by the electrophotographic process using the generated light, and heat and pressure are applied to the toner image formed on the overcoat layer of one electrophotographic recording medium as described above. And the toner image The electrophotographic recording medium itself is buried in the overcoat layer to be used as a proof, or a toner image is formed on the overcoat layer of one electrophotographic recording medium as described above. The surface of the overcoat layer on which the toner image is formed and the surface of the transferred member are heated in close contact with each other, and the overcoat layer on which the toner image is formed is transferred to the transferred member. Then, the above-mentioned overcoat layer is peeled off from the white photoconductive layer member in the recording medium for electrophotography, and the portion where the transferred member and the overcoat layer on which the toner image is formed are integrated is proof-printed. Therefore, the toner image formed on the overcoat layer of the recording medium for electrophotography can be overcoated with heat and pressure. When the electrophotographic recording medium itself is directly buried as it is used as a proof, it is possible to easily form a color image with excellent halftone and density gradation on a white recording medium. It can be easily done, and the overcoat layer is peeled off from the white photoconductive layer member in the recording medium for electrophotography, and the transferred member and the overcoat layer on which the toner image is formed are integrated to make a proof print. If this is used, the toner image will be 100% transferred to the same paper used when printing with this machine, and the dot gain state will be closer to that in actual color printing. It is possible to perform good calibration well.

[Brief description of drawings]

FIG. 1 is a side sectional view of an electrophotographic recording medium used in a proof printing apparatus using the electrophotographic recording medium of the present invention,
FIG. 2 is an explanatory view of the operation of burying the toner image in the overcoat layer, FIG. 3 is an explanatory view of the operation of transferring the toner image together with the overcoat layer to a transfer target member, and FIG. 4 is an electrophotographic image of the present invention. FIG. 5 to FIG. 8 are block diagrams showing a printing system including an output device for a proof and a lithographic plate, to which a device for producing a proof by a recording medium can be applied, and FIGS. 5 to 8 are explanatory views for showing a difference in reflected light amount of an image. . 1 ... manuscript (original), 2 ... image capture part, 3 ...
… Image scanner, 4… Drum scanner, 5…
... Work station, 6 ... Image processing device, 7 ... Storage, 8 ... Output device for proof and lithographic plate, 9 ...
Development processor, 10 …… Printer, 11 …… Support, 12…
... Electrodes made of thin film of conductive material, 13 ... White photoconductive layer member composed mainly of titanium dioxide and a binder, 14 ... Overcoat layer, 15 ... Toner image, 16 to 19 …… Roller, 20 …… Transfer material,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromichi Tai, 3-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Kanagawa, Japan Victor Company of Japan, Ltd. (56) Reference JP-A-63-92965 (JP, A) JP 62-80683 (JP, A) JP-A-1-281464 (JP, A) JP-A-57-79946 (JP, A) Practical application Sho-58-100342 (JP, U)

Claims (1)

[Claims] 1. A support member, an electrode layer formed on the support member, a white photoconductive layer member containing titanium dioxide as a main component formed on the electrode layer, and the white light. Corresponds to a predetermined number of image information for each color obtained by color-separating the image information to be printed on a single electrophotographic recording medium consisting of an overcoat layer formed on a conductive layer member. Means for sequentially forming a toner image for each color by an electrophotographic process using light modulated with image data for each color for printing, which is generated based on digital image data for each color, and as described above. The electrophotographic recording medium itself is calibrated by applying heat and pressure to the toner image formed on the overcoat layer of one electrophotographic recording medium to bury the toner image in the overcoat layer. First proof press to be printed As described above, the surface of the overcoat layer on which the toner image is formed and the surface of the transfer target member in the state where the toner image is formed on the overcoat layer of the recording medium for electrophotography as described above. The overcoat layer on which the toner image is formed is transferred to the transfer target member by heating in a state of being in close contact, and the above-mentioned overcoat layer is peeled off from the white photoconductive layer member in the electrophotographic recording medium. An apparatus for producing a proof by a recording medium for electrophotography, which comprises a second proof printing means for proofing a portion in which a transferred member and an overcoat layer on which a toner image is formed are integrated.