JPH0145917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic color proofing machine for making a copy using an electrophotographic method using a resolution mesh positive film as an original, using a contact exposure method, and performing proofreading before a draft. It is something.

At printing companies, the causes of errors during the underprinting of offset printing include (1) name-related errors, (2) errors due to new reprints, (3) mistakes in changing the flat screen (overlay) color, and marking unification errors. (4) Pasting-related mistakes, (5) Picture correction, correction mistakes, (6) Scratches, pinholes, stains, certification mistakes, (7)
There are mistakes such as peeling of the membrane.

The present invention addresses the above-mentioned causes of errors: (1) name-related errors, (2) errors due to new reprinting, (3) mistakes in flat mesh (crossing) color changes, mark unification errors, and (4) pasting. This paper relates to a color copying machine for the purpose of eliminating related errors and (5) film peeling errors.

Traditionally, in the case of offset printing of flyers, etc., a proof copy was submitted to the customer, and a judgment was made as to whether it met the customer's requirements. A proof print is made using the decomposed film and then submitted to the customer for review. In the case of partial corrections (which is the case in most cases), that is, in the case of liability, the corrected net positive film is blueprinted (on diazo paper) to check whether it has been corrected, and the inner third
Ask someone to confirm. In this case, the complicated thing is that when there is a combination of multiple colors in the corrected area, you have to compare the blueprints of each color, and for example, for the purple part, you have to inspect the blueprint of the eye version and the blueprint of the red version. Must be. In addition, when correcting a certain part to green, it must be confirmed that the pattern exists only in the eye version and the key version, and that the pattern does not exist in the red version and the error version.

As mentioned above, the current plate inspection work is very complicated, so it has no choice but to rely on experts. Moreover, it is a very time-consuming process.

The present invention was developed to eliminate the above-mentioned complexity and inefficiency, and by using the color proofing machine of the present invention, even unskilled persons can easily and efficiently perform plate inspection work.

In electrophotography, there are two types of exposure methods: exposure through a lens system and contact exposure, but the exposure through a lens method has problems with blurred images and reduced dimensional accuracy due to lens aberrations and the color of the original. On the other hand, according to the close-contact exposure method, a transparent original is used for close-contact exposure to directly reproduce a copy, so that the reproduced copy is faithful to the original and has good accuracy.

Therefore, the present invention employs a contact exposure method and has the following configuration. That is, a charging mechanism that charges a photoreceptor belt provided with a photoconductive layer, a fixing mechanism that fixes a decomposition net positive film to a pin bar attached to the photoreceptor belt, and a fixing mechanism that is located above the photoreceptor belt and whose arcuate portion is located above the photoreceptor belt. A transparent member that is longer than the film and rotates in synchronization with the photosensitive belt so as to press the film against the photosensitive belt immediately after the pin bar passes over the pressure roll and while the film is passing over the pressure roll. A contact slit exposure mechanism consisting of an arcuate member and an exposure lamp that exposes the film while it is in pressure contact with the photoreceptor belt; a separation mechanism that separates the film from the photoreceptor belt; and a separation mechanism that separates the film from the photoreceptor belt; A developing mechanism that moves a developing device that stores developer close to the photosensitive belt to develop the image, a transfer mechanism that transfers the developed image on the photosensitive belt to a sheet on a transfer drum, and a cleaning mechanism that cleans the photosensitive belt after transfer. , and a fixing mechanism that separates the transfer sheet from the transfer drum after the transfer is completed and fixes it. This is an electronic color proofing machine using a color transmission exposure method.

Furthermore, in order to facilitate understanding of the present invention, the present invention will be explained by specific examples with reference to the drawings.

FIG. 1 shows a transparent arc member 1 and an exposure lamp 2 in a close-contact slit exposure mechanism. I am made to do so. Further, the exposure lamp 2 is surrounded by a light shielding plate 7, and is fixed at a position suitable for slit exposure.

FIG. 2 shows the color proofing machine of the present invention in a stationary state, in which a separated mesh positive film 9, 1 with pin holes drilled therein is registered in advance on a document tray 8.
0, 11, and 12 are stacked in the order of key 9, red 10, eye 11, and corner 12 from the bottom and set in a fixed position. The static elimination lamp 13, the cleaning device 14, and the charger 15 are fixed. The transparent arc member 1 and the photosensitive belt 16 advance in the direction of the arrow. A pin bar 17 attached to the photosensitive belt 16 is in a position in front of the static elimination lamp 13 in a stationary state. Decomposed mesh positive film 9,1 already registered and pin-hole-drilled to pin bar 17
Attachment and detachment of 0, 11, and 12 is carried out by vacuum suction using suction wheels 18 and 19. Developing devices 20, 21, 22, and 23 each containing four color developers are placed in a developing unit 24 at a position farthest from the photoreceptor belt 16. FIG. 3 shows that while the photosensitive belt 16 is moving, the static electricity is removed by the static elimination lamp 13, the cleaning device 14 is used to clean it, the charger 15 is used to charge the electricity, and the decomposition mesh positive film 12 of the black plate is transferred from the original tray 8 by the carrier 18. vacuum suction and move it to above the photosensitive belt 16,
The color proofing machine is shown inserted and fixed onto a pin bar 17 attached to the photosensitive belt 16 while synchronizing with the moving speed of the photosensitive belt 16. FIG. 4 shows the transparent arc member 1 and the photoreceptor belt 16 moved in synchronism, and after the pin bar 17 passes over an elastic pressure roll 25 so as not to contact the transparent arc member 1, the transparent arc member 1 The color proofing machine is shown in a state in which the leading end of the color proofing machine is rotated and the separation net positive film 9 is brought into close contact with the photoreceptor belt 16 by the pressure roll 25 while being subjected to close slit exposure by the exposure lamp 2. .

FIG. 5 shows that after exposure, the separation net positive film 12 is moved while being vacuum-adsorbed by a sucker 19 to be separated from the photosensitive belt 16, and the photosensitive belt 16 on which the electrostatic latent image has been formed is moved to the developing unit 24. The color proofing machine is shown in a state in which a developing device 20 containing a dark-colored developer is moved close to the photosensitive belt 16 to perform development. Developer 2
0, 21, 22, 23 indicate the magnetic brush method in the figure, but the method is not limited thereto, and separation mesh positive films 9, 10, 11,
12. The developed photosensitive belt 16 moves to proceed through the transfer process. On the other hand, the sheet 26 is sent out along guide plates 30 and 31 by a pick-up roll 27 and feed rolls 28 and 29, and is held on a transfer drum 32. Next, the sheet 2 mounted on the transfer drum 32
6, the photosensitive belt 16 is brought into contact with the transfer drum 32.
The developed image is electrostatically transferred by applying a voltage to. The sheet 26 is attached to the transfer drum 32 using an electrostatic adsorption charger 33, and the sheet 26 is electrostatically attached by applying a corona discharge from the back surface of the sheet 26. The transfer drum 32 is generally a metal roll coated with conductive rubber. After the transfer, the photosensitive belt 16
The pin bar 17 attached to the static elimination lamp 13
Stop at the point you came to before. Next, after the transfer, the photosensitive belt 16 is neutralized by the static eliminating lamp 13 and cleaned by the cleaning device 14, and then charged again by the charging device 15, and the eye plate decomposition mesh positive film 11 is transferred from the document tray 8 to the carrier 18. The pin bar 17 is attached to the photosensitive belt 16 while being synchronized with the moving speed of the photosensitive belt 16.
The image of the eye is then transferred to the sheet 26 using the same procedure. Next, perform the same procedure for the red version and the key version. Next, sheet 2 on which the toner images of the four colors of black, eye, red, and yellow have been transferred.
6 is separated from the transfer drum 32 by a separation claw 34, conveyed by a conveyor belt 35, fixed by a fixing device 36, and discharged onto a tray 37.
Obtain color reproductions of colors. Although the fixing device 36 uses an oven fixing method in the figure, fixing using a heating roll is also effective.

Here, the photosensitive belt is an endless belt-like one, and is coated with a flexible thin plate of non-magnetic metal such as nickel or stainless steel, and is coated with ZnO-resin, CdS-resin, Se evaporation-based, or organic light. A material provided with a photoconductive layer of semiconductor or the like can be used. moreover,
After the transfer, the length of the photosensitive belt is equal to the circumference of the moving locus of the transparent arc member, and the circumference of the transparent arc member is at least shorter than the distance between the transfer position and the cleaning position of the photosensitive belt.
The photosensitive belt can be stopped at the point where the pin bar attached to the photosensitive belt is in front of the static elimination lamp, and the photosensitive belt can be kept in a state where it can quickly respond to the next repetition.

Moreover, paper, synthetic paper, various plastic films, etc. can be used as the sheet.

In addition, the transparent arc member is made of transparent resin or glass, but unlike a cylindrical transparent drum, it can be manufactured by bending a flat plate rather than by molding, so it can be manufactured at low cost and with high precision. The reason why the shape of the transparent arc member is an arc is, in addition to the above-mentioned manufacturing reasons, to prevent the transparent arc member from being damaged by pressing the pin bar attached to the photosensitive belt. Therefore, the transparent circular arc member and the photosensitive belt are moved in synchronization, and the decomposition net positive film is moved onto the photosensitive belt while avoiding the pin bar attached to the photosensitive belt, and is brought into close contact with the elastic pressure roll. This allows for highly accurate slit exposure.

Next, a series of operations of the color proofing machine of the present invention will be described in detail. First, the separation net positive film that has been registered in advance on the document tray and has pin holes drilled is placed in the order of black, red, eye, and dark. Stack them from the bottom and set them in place. Next, the photosensitive belt is charged while moving, and the decomposed film of the black plate is adsorbed from the original tray by a suction roller and moved onto the photosensitive belt. The transparent circular arc member is inserted and fixed onto a pin bar attached to the transparent circular arc member, and the transparent circular arc member is rotated and moved in synchronization with the photosensitive belt, so that the pin bar does not come into contact with the transparent circular arc member. Immediately after passing directly above the pressure roll, the decomposition network positive film is brought into pressure contact with the photosensitive belt while the decomposition network positive film is passing over the pressure roll, and the decomposition network positive film is pressed against the photoreceptor belt. While they are being pressed together, the contact slit is exposed to light using an exposure lamp, and then the decomposable net positive film is moved and adsorbed by a sucker to separate it from the photoreceptor belt, thereby removing the photoreceptor belt on which the electrostatic latent image has been formed. The photosensitive belt is moved to a developing unit, and a developing device containing a dark-colored developer is moved close to the photosensitive belt to perform development. Here, the sheet is sent out and mounted on a transfer drum, and the developed photosensitive belt is moved and brought into contact with the sheet on the transfer drum to transfer the developed image onto the sheet. Next, the photosensitive belt after transfer is neutralized, cleaned, and charged again, and the eye plate's decomposed positive film is adsorbed from the original tray by a suction roller and moved onto the photosensitive belt, synchronizing with the moving speed of the photosensitive belt. The eye image is transferred onto the sheet by following the same procedure as above, and then inserting and fixing the eye onto the pin bar attached to the photosensitive belt while removing the image.

Next, perform the same procedure for the red version and the key version. Next, the sheet on which the toner images of the four colors of black, eye, red, and yellow have been transferred is separated from the transfer drum and fixed by a fixing device to obtain a four-color reproduction.

A copy obtained by the above operations can be used for plate inspection and proofreading before the final version.

In conventional color copying machines for obtaining color reproductions, color-separated images of a reflective original are sequentially projected onto a photoreceptor. The spectral energy distribution of the filter differs significantly for each color separation image, so to adjust the difference in overall sensitivity of blue, green, and red, it is necessary to change the exposure time of each color or the exposure amount of each color by adjusting the ND filter or lens aperture. A method has been used to On the other hand, in the color proofing machine of the present invention, since a separation net positive film is used for the original, a color separation filter is not necessary. There is no need to change the amount. Furthermore, since the exposure method of the present invention is not a method of exposing through a lens, but a contact exposure method using a transparent original, the reproduction is faithful to the original and has good accuracy. Further, the color of the toner of the developer used in the present invention must be close to that of the ink actually used in offset printing. In the case of full-color printing, just like general offset printing, it is a combination of four colors: yellow, red, eye, and black, and uses toner of a different tone than the three-color combination toner used in conventional color copying machines. It is what you use.

The color proofing machine of the present invention takes as an original the separation mesh positive film of each color that has already been registered and has pinholes made, and fixes the original to the pin bar of the photosensitive belt, thereby eliminating the dark spots, red spots, dark spots, and smudges. The registration between the four-color images is accurate, and because of the contact exposure method, the resulting color reproductions are of high quality.

In addition, the separation mesh positive film is automatically attached to and removed from the photosensitive belt, and the photosensitive belt is moved continuously without stopping, and charging, exposure, development, and transfer are repeated, so that color reproductions can be obtained in a short time. In addition, the developing units are separated for each color and are moved close to the photosensitive belt to perform development in response to the separation mesh positive film, so there is a risk that toner of a different color may mix in each developing unit. You can obtain clear color reproductions with fewer copies.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram illustrating a transparent circular arc member and exposure lamp in a close slit exposure mechanism, and FIG. 2 is an explanatory diagram illustrating a color proofing machine in a stationary state. Figure 3 is an explanatory diagram illustrating a color proofing machine with a separated mesh positive film inserted and fixed in the pin bar, and Figure 4 shows a state in which slit exposure is performed while the separated mesh positive film is tightly attached to the photosensitive belt. FIG. 5 is an explanatory diagram illustrating the color proofing machine, and FIG. 5 is an explanatory diagram illustrating the color proofing machine in a state after the separation mesh positive film is separated from the photosensitive belt after exposure. 1... Transparent circular arc member, 2... Exposure lamp, 3, 4...
Side plate, 5, 6... Rotating shaft, 7... Light shielding plate, 8... Document tray, 9, 10, 11, 12... Decomposition net positive film, 13... Static elimination lamp, 14... Cleaning device, 15... Charger, 16... Photosensitive Belt, 17...pin bar, 18,19...satsuka, 20,21,2
2, 23...Developer, 24...Developer unit, 25...
Pressure roll, 26... Sheet, 27... Pick-up roll, 28, 29... Feed roll, 30, 31...
Guide plate, 32... Transfer drum, 33... Electrostatic adsorption charger, 34... Separation claw, 35... Conveyance belt, 36
...Fixing device, 37...Tray.

Claims (1)

[Claims] 1. A charging mechanism that charges a photosensitive belt provided with a photoconductive layer; a fixing mechanism that fixes a printed color separation net positive film to a pin bar attached to the photosensitive belt;
A lower pressure roll and a transparent upper arcuate member, which are closely opposed to each other with the running surface of the photosensitive belt in between, and which rotate in synchronization with the belt while bringing the decomposition net positive film attached to and running on the belt into close contact with the belt; A close-contact slit exposure mechanism consisting of an exposure lamp that irradiates a slit at a close position between the belt and the positive film, a separation mechanism that separates the film from the photosensitive belt, and development using a developer of a printing color corresponding to the film. a developing mechanism that transfers the developed image on the photosensitive belt to a sheet on a transfer drum, a cleaning mechanism that cleans the photosensitive belt after transfer, and a fixing mechanism that separates and fixes the sheet after transfer from the transfer drum. An electronic color proofing machine that uses a transmission exposure method.