JPH0117148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a contact exposure copying machine for making a copy using an electrophotographic method using a resolution mesh positive film as an original, using a contact exposure method, and for proofreading the original. It is related to.

At printing companies, the causes of errors during the underprinting of offset printing are: (1) Name-related mistakes (2) Mistakes due to new reprints (3) Mistakes in changing the color of flat mesh (crossing) and unifying marks (4) Pasting-related mistakes (5) Pattern correction, correction mistakes (6) Scratches, pinholes, stains, correction mistakes (7) Peeling mistakes in the film pasting, etc.

Of the above-mentioned error causes, (1) name-related errors, (2) mistakes due to new reprinting, (3) flat mesh (crossing) color changes, mark unification errors, and (4) pasting-related errors ( Five)
The present invention relates to a contact exposure copying machine for the purpose of eliminating errors such as peeling of information stickers.

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. Repair positive film. In the case of major corrections, a proof is made using the corrected decomposition film and submitted to the customer again 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 contact exposure copying machine of the present invention, even an unskilled person can easily and efficiently perform plate inspection work.

There are two types of exposure methods in electrophotography: exposure through a lens system and contact exposure. However, 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.
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.

The present invention consists of the following configuration. That is, a charging device that charges a photosensitive belt provided with a photoconductive layer, a movable original holder maintained at a constant distance from the photosensitive belt, a fixed original holder equipped with a pin bar, and a transmissive original fixed to the pin bar of the fixed original holder and moved. After placing the transparent original on the original stand, the contact exposure device performs slit exposure while keeping the transparent original in close contact with the photoreceptor belt using a pressure roll. A developing device that develops with a developer of a corresponding color, a transfer device that transfers the developed image on the photosensitive belt to a transfer sheet attached to a transfer drum, a cleaning device that cleans the photosensitive belt after transfer, and a cleaning device that cleans the photosensitive belt after transfer. This is a contact exposure copying machine consisting of a fixing device that separates a transfer sheet from a transfer drum and fixes it.

Below, a series of operations of the contact exposure copying machine of the present invention will be described in detail. First, a transparent original is placed on a movable original holder that is maintained at a constant distance from the photosemiconductor photosensitive belt, and the leading edge of the transparent original is Fix it to the pin bar of the fixed document table. Next, the photosensitive belt is charged while moving and stopped directly below the moving document table, and a pressure roll is moved from the leading edge of the transparent original to bring the transparent original and the photosensitive belt into close contact from the leading edge, and at the same time, Slit exposure is performed by an exposure lamp that moves in synchronization with the pressure roll, and at the same time, the movable document holder is moved parallel to the photosensitive belt in synchronization with the pressure roll, and the moving document is placed at the rear end of the transparent document. The pressure roll, exposure lamp, and moving document stand are stopped before the tip of the stand reaches, and after the slit exposure process is completed, the pressure roll, exposure lamp, and moving document stand are moved to their original positions. , the transparent original that is in close contact with the original is separated from the photosensitive belt, and is developed with a developer of a color corresponding to the transparent original.

Here, the transfer sheet is sent out and attached to the transfer drum, and the developed photosensitive belt is moved and brought into contact with the transfer sheet on the transfer drum to transfer the developed image onto the transfer sheet. After transfer, the photosensitive belt is neutralized and cleaned. When a separation mesh positive film is used as the transmission original, the same procedure is repeated three more times for the separation positive films of the other three colors. Next, the transfer sheet on which the toner image has been transferred is separated from the transfer drum and fixed by a fixing device.

In conventional color copying machines, color-separated images of a reflective original are sequentially projected onto a photoreceptor, but the spectral energy distribution of the light source, the spectral sensitivity distribution of the photoreceptor,
The spectral energy distribution of the color separation filter is significantly different for each color separation image, so to adjust the difference in overall sensitivity of blue, green, and red, it is necessary to adjust the exposure time of each color or the exposure amount of each color by adjusting the aperture of the ND filter or lens. Methods have been used to change the
On the other hand, in the copying machine of the present invention, since separation mesh positive film is used for the original, color separation filters are not necessary, and the exposure time of each color or
There is no need to change the exposure amount of each color by adjusting the ND filter or lens aperture.

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, it is a combination of four colors, yellow, red, eye, and dark, similar to general offset printing, and not a combination of three colors, cyan, magenta, and yellow, as in conventional color copying machines. .

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

FIGS. 1a and 1b show the movements of the pressure rolls 1 and 2, the exposure lamp 3, and the movable document stand 4. FIG.
Here, the movable document stand 4 and the photosensitive belt 5 are kept at a constant distance. Figure 1a shows the photosensitive belt 5.
A transparent original 6 is placed on the movable original stand 4 which is maintained at a constant interval, and the leading edge of the transparent original is placed on the fixed original stand 7.
The pressure rollers 1 and 2 and the exposure lamp 3 are integrated into a contact exposure device 9 for slit exposure, and are kept stationary and on standby. FIG. 1b shows a state in which the pressure rolls 1 and 2, the exposure lamp 3, and the movable original holder 4 are stopped before the tip of the moving original holder 4 reaches the rear end of the transparent original 6, and the slit exposure process is completed. It is something. Also, if the material of the crimping rolls 1 and 2 is made of conductive rubber and grounded,
When moving the pressure rolls 1, 2, exposure lamp 3, and movable document stand 4 to their original positions, thereby separating the transparent document 6 that is in close contact with the photosensitive belt 5, the static electricity on the transparent document 6 is removed by the pressure rollers. 1 and 2, the electrostatic latent image formed on the photosensitive belt 5 is not disturbed. Further, if a freely rotating free roll 10 or the like is attached to the tip of the movable document holder 4, the transparent document 6 can be moved smoothly. Furthermore, it is advantageous to attach a sensor such as a limit switch to the tip of the movable document holder 4 to act as a safety device so that the rear end of the transparent document 6 never comes off the tip of the movable document holder 4.

Here, if an inclined movable original stand 4' is used, as shown in FIG. 6 is easy to attach, and it is also easy to separate the transparent original 6 that is in close contact with the photosensitive belt 5.

FIG. 3 shows a contact exposure copying machine according to the present invention, and the process of selecting a separation mesh positive film as a transmission original and obtaining a color copy will be explained as an example. first,
A red version (or eye version) decomposed positive film 6' is attached to the pin bar 8 of the fixed original table 7 and placed on the movable original table 4. Next, the photosensitive belt 5 is charged while being moved by the charging device 11, and stopped under the moving document stand 4, and the pressure rolls 1, 2,
By moving the exposure lamp 3 and the movable original stand 4, slit exposure is carried out while bringing the separation net positive film 6' into close contact with the photosensitive belt 5. Before reaching the photosensitive belt 5, the pressure rolls 1 and 2, the exposure lamp 3, and the movable original stand 4 are stopped and moved to their original positions to separate the decomposable mesh positive film 6' from the photosensitive belt 5. The belt 5 is moved and the developing devices 12, 13, 14, 1
Developed with red (or eye) toner. Developing devices 12, 13,
14 and 15 show the magnetic brush method in the figure, but the method is not limited thereto, and they are adapted to move in correspondence with the resolving mesh positive film 6'. The developed photosensitive belt 5 moves to a transfer device 16. On the other hand, the transfer sheet 17 is sent out along guide plates 21 and 22 by pick-up rolls 18 and feed rolls 19 and 20, and is held on a transfer drum 23. Next, the photosensitive belt 5 is brought into contact with the transfer sheet 17 mounted on the transfer drum 23, and a voltage is applied to the transfer drum 23 to electrostatically transfer the developed image. In addition, the transfer drum 2
The transfer sheet 17 is attracted to the transfer sheet 17 by an electrostatic adsorption charger 24, and the transfer sheet 17 is electrostatically attached by applying a corona discharge from the back surface of the transfer sheet 17. The transfer drum 23 is generally a metal roll coated with conductive rubber. After the transfer, the photosensitive belt 5 is neutralized by a static eliminating lamp 25 and cleaned by a cleaning device 26. During this time, a decomposition mesh positive film of the eye version (or red version) is attached to the pin bar 8 of the fixed original table 7 and placed on the movable original holder 4. Thereafter, the eye (or red) image is transferred to the transfer sheet using the same procedure.
Next, perform the same procedure for the clear and black versions. Next, the transfer sheet 17 on which the toner images of the four colors of red, eye, yellow, and dark have been transferred is transferred to the transfer drum 2.
3 by the separating claw 27, and the conveyor belt 2
8, is fixed by a fixing device 29, and is discharged onto a tray 30 to obtain a four-color reproduction. Note that although the figure shows an open fixing method as the fixing device, fixing using a heating roll is also effective.

Here, the photosensitive belt is an endless belt-like thing, and is made of a flexible thin plate of non-magnetic metal such as nickel or stainless steel, and is made of ZnO-resin.
Those provided with a photoconductive layer such as a CdS-resin system, a Se vapor deposition system, or an organic optical semiconductor can be used.

Furthermore, although the transfer sheet is generally paper, it goes without saying that various types of plastic films can also be used.

Further, a transparent original is generally made of a transparent plastic film as a base material, and it must be able to be evenly adhered to the original without wrinkles by a pressure roll.

Although the contact exposure copying machine of the present invention requires an annual operation of fixing a transparent original to a fixed original pinper and placing it on a movable original stand, there is no risk of touching the photosensitive layer on the photosensitive belt. ,
No problems such as damage to the photosensitive layer or disturbance or disappearance of the electrostatic latent image occur. Furthermore, since the time from charging to exposure and from exposure to development is almost constant, a stable image reproduction can always be obtained. Furthermore, for example, when color overlapping is performed using separation mesh positive film as an original, by fixing the separation mesh positive film of each color, which has already been registered and has pin holes drilled, to the pin bar of the stationary document table, it is possible to eliminate shadows, eyes, etc. The registration between the four-color images of black and white is accurate, and since the contact exposure method is used, the resulting color reproductions are of high quality.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS. 1a and 1b are explanatory diagrams showing the movements of the pressure roll, the exposure lamp, and the movable document holder, and FIG. 2 is an explanatory diagram illustrating the tilted movable document holder. and FIG. 3 are explanatory views for explaining the contact exposure copying machine of the present invention. 1, 2...Crimping roll, 3...Exposure lamp, 4
...Moving original stand, 4'...Slanted moving original stand, 5... Photosensitive belt, 6... Transparent original, 6'...
...Disassembly net positive film, 7...Fixed document table, 8...
... Pin bar, 9 ... Contact exposure device, 10 ... Free roll, 11 ... Charging device, 12, 13, 1
4, 15...Developing device, 16...Transfer device, 17
...Transfer sheet, 18...Pitsukatsuprol,
19, 20...Feed roll, 21, 22...Guide plate, 23...Transfer drum, 24...Charger for electrostatic adsorption, 25...Static elimination lamp, 26...Cleaning device, 27...Separation claw, 28... Conveyor belt, 29... Fixing device, 30... Tray.

Claims (1)

[Claims] 1. A charging device that charges the photosensitive belt, a movable original holder kept at a constant distance from the photosensitive belt, a fixed original holder with a pin bar attached, and a contact exposure device that performs slit exposure while keeping the transparent original in close contact with the photosensitive belt with a pressure roll. , a contact exposure copying machine comprising a developing device that develops with a developer of a color corresponding to the transparent original, a transfer device that transfers the image to a transfer sheet on a transfer drum, a fixing device that fixes the transfer sheet, and a cleaning device that cleans the photosensitive belt. .