JPH09120181A - Electrophotographic engraving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extremely restrain stain, etc., from adhering to a carrying roller and an elecctrophotographic planographic printing plate (PS plate) by providing a brush body brought into slidably contact with the back surface of a printing plate and removing an adhering material adhering to the back surface of the printing plate in accordance with wet toner developing on a cooling part. SOLUTION: At the cooling part 60, the back surface of the electrophotographic planographic printing plate 10 (PS plate) is sprayed with cool water a spray nozzle 61 so as to be cooled, and a cleaning brush roller 62 is brought into slidably contact with the back surface of the plate 10. The roller 62 scrapes and surely removes toner adhering to the back surface of the plate 10 in accordance with the wet toner developing, so that the transferring of the toner, etc., to the carrying rollers 21, 31, 41, and 51 and the PS plate 10, and the occurrence of printing stain by the toner, etc., transferred to the PS plate 10 are surely prevented. The circumferential speed of the roller 62 may equal to a carrying speed, but it is desirable that the circumferential speed is faster than the carrying speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic plate making apparatus for producing an original plate for printing by subjecting an electrophotographic lithographic printing plate to a predetermined treatment. The present invention relates to a structure for removing adhered matters such as toner adhered to the back surface.

[0002]

2. Description of the Related Art As a conventional electrophotographic plate making apparatus, an electrophotographic lithographic printing plate (hereinafter referred to as PS plate) is provided with a charging section, an exposing section, a developing section, a first drying section, a fixing section, a cooling section, an elution section,
There is one in which a predetermined process is sequentially performed in each part while being continuously conveyed by rotation of a conveying roller to a second drying part through a water washing part and a gum solution application part.

That is, in the charging section and the exposing section, P
The S plate is charged and exposed. In the developing section, P
The S plate is developed by wet toner. The PS plate is dried and fixed in the first drying unit and the fixing unit. FIG.
In the cooling unit 80, the PS plate 81 is
Cooling water is sprayed by the spray nozzle 82 and cooled. In the elution portion 83, the PS plate 81 is sprayed onto the surface (upper surface in FIG. 3) of the elution liquid from the spray nozzle 84, and the elution promoting brush roller 85 is slidably contacted with the surface of the PS plate 81 and the squeeze roller. The excess eluent adhering to the surface is removed by 86. In the water washing section 87, the PS plate 81 is sprayed with washing water by the spray nozzle 88 on the front surface and the back surface thereof, and a washing brush roller 89 is slidably contacted with the front surface thereof. Gum solution application part 9
In No. 0, the PS plate 81 has the spray nozzle 9 on the surface.
1 to spray gum solution. In a second drying unit (not shown), the PS plate 81 is dried with warm air such as a dryer.

[0004]

In the above-described conventional electrophotographic plate making apparatus, toner is inevitably attached to the back surface of the PS plate 81 with wet toner development in the developing section.
Therefore, when the apparatus is continuously operated for a long time, the toner attached to the back surface of the PS plate 81 is transferred and accumulated on the transport roller, particularly at the elution portion 83, and is also transferred to the PS plate 81 via the transport roller. However, there is a problem that it causes printing stains. In view of such a problem, it has been proposed to provide a cleaning brush roller at the elution portion to clean the back surface of the PS plate (for example, Japanese Patent Laid-Open No. 14166/1992).
No. 8).

The structure of this type of device is shown in FIG.
In the elution section 83, the PS plate 81 conveyed by the conveying roller 31 has a spray nozzle 84 on the front surface and the back surface.
While the eluate ejected from is sprayed, the elution promoting brush roller 85 is slidably contacted with the front surface and the cleaning brush roller 34 is slidably contacted with the rear surface.

The cleaning brush rollers 34 are provided at a position facing the back surface of the PS plate 81 as a pair of upper and lower sides with the facing member 38 and the PS plate 81 interposed therebetween. The facing member 38 is, for example, an idle roller, and is provided in contact with the surface of the PS plate 81 at predetermined intervals along the transport direction A. The cleaning brush roller 34 is brought into sliding contact with the back surface of the PS plate 81 sprayed with the eluent, and scrapes off the toner and the like attached to the back surface of the PS plate 81 in association with the wet toner development. After that, the PS plate 81 is removed by the squeeze roller 86 of the attached excess eluate.

According to such a configuration, P
Although the toner adhering to the back surface can be removed by rubbing the back surface of the S plate 81, the following problems occur when continuous processing is performed.

In the elution section 83, the photosensitive layer in the non-image area is dissolved and removed by the eluate, but the photosensitive layer contains an insoluble substance and is dispersed in the solution. However, since the insoluble matter has a small particle size and does not cause any trouble even if it is not completely removed by filtration, only a simple mesh filter is attached to the liquid circulation system. However, when the toner on the back surface of the plate is scraped off with a brush and continuously processed, a large amount of toner dust is dispersed in the liquid. Since this toner dust has a large particle size and reattaches to the plate surface, it causes printing stains. Therefore, it is necessary to provide a filter in the liquid circulation path for complete filtration. However, when the filter is clogged with the toner dust, the insoluble matter from the photosensitive layer that has been passing through then is also filtered, and the filter is clogged rapidly.

According to the present invention, it is possible to surely remove the deposits attached to the back surface of the electrophotographic lithographic printing plate due to the wet toner development, and thereby to attach the dirt and the like to the transport roller and the electrophotographic lithographic printing plate. It is an object of the present invention to provide an electrophotographic plate making apparatus capable of suppressing the above problems as much as possible and preventing the harmful effects of the removed deposits.

[0010]

The above object of the present invention is to charge a printing plate on which an image forming layer comprising a photoconductive layer is formed on one side of an aluminum support after graining and hydrophilizing the aluminum support. Exposure, wet toner development, drying, fixing, cooling,
In an electrophotographic plate making apparatus that performs non-image area elution, washing with water, and finishing treatment, wet toner is obtained by slidingly contacting the back surface of the printing plate with a cooling unit that cools the printing plate that has undergone wet toner development and is then dried and fixed. This is achieved by an electrophotographic plate-making apparatus including a brush body for removing deposits attached to the back surface of the printing plate as it is developed.

[0011]

In the electrophotographic plate making apparatus according to the present invention, the electrophotographic lithographic printing plate is subjected to predetermined processing to carry out plate making. That is, in the cooling section, the image forming layer formed on the surface of the electrophotographic planographic printing plate is charged, exposed to light, developed with a wet toner, and then dried and fixed. In the elution section, the cooled electrophotographic lithographic printing plate is subjected to an elution treatment to elute the non-image area of the image forming layer. The brush body provided in the cooling unit
By being brought into sliding contact with the back surface of the electrophotographic lithographic printing plate, the adhering substances attached to the back surface of the electrophotographic lithographic printing plate with the wet toner development are scraped off. As in the present invention, if the adhering matter is scraped off in the cooling unit, only the adhering matter (toner dust having a large particle size) scraped off there is present in the cooling water. Therefore, even when the cooling water is circulated and used, Does not clog rapidly. Also,
When cooling with running water that is not circulated, it is not necessary to install a filter.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic sectional view showing a part of an electrophotographic plate making apparatus according to a first embodiment of the present invention. In this figure, an electrophotographic lithographic printing plate 10 (hereinafter referred to as PS plate 10) includes a charging unit (not shown), an exposure unit (not shown), a developing unit (not shown), a first drying unit (not shown), and a fixing unit. Part (not shown), cooling part 60, elution part 6
3, the washing roller 40, and the gum solution applying section 50 to the second drying section (not shown) to the conveying rollers 21, 31, 41, 5
One rotation continuously conveys in a predetermined conveying direction (direction of arrow A), and each unit sequentially performs a predetermined process.

In the PS plate 10, an image forming layer (not shown) is provided on the support 11. The support 11 is
The aluminum material is formed by graining one surface (the upper surface in FIG. 1) and then hydrophilizing the surface. The image forming layer is a photoconductive layer containing a photoconductive substance and an alkali-soluble binder, and is laminated on the upper surface of the support 11 in FIG. The PS plate 10 has an image forming layer as an upper surface in FIG.
The surface of the S plate 10), and the support 11 is shown in FIG.
The medium is conveyed in a state of being the inner bottom surface (hereinafter, referred to as the back surface of the PS plate 10).

In the charging section and the exposing section, the PS plate 10
Are charged and exposed. In the developing section, the PS plate 10
Is wet-developed by the action of the liquid toner. The PS plate 10 is dried and fixed in the first drying unit and the fixing unit.

In the cooling unit 60, a plurality of spray nozzles 61 are arranged facing the back surface of the PS plate 10 along the carrying direction A at predetermined intervals (in this embodiment, 2).
It is provided. The cleaning brush roller 62 is provided in the PS plate 1 at approximately the center in the transport direction A between the spray nozzles 61.
It is provided so as to face the back surface of 0. Each spray nozzle 61
Is a water receiving tank 2 by a circulation pump or the like (not shown).
The cooling water pumped up from 3 is sprayed on the back surface of the PS plate 10. Note that the sprayed cooling water drops from the PS plate 10 and then is collected in the water receiving tank 23.

Two pairs of transport rollers 21 are provided on the upstream side and the downstream side in the transport direction A with the spray nozzle 61 sandwiched therebetween, one pair above and one below the PS plate 10, respectively. The pair of transport rollers 21 transport the PS plate 10 in the transport direction A by rotating while sandwiching the PS plate 10.

In such a cooling unit 60, the PS plate 1
No. 0 has its back surface sprayed with cooling water by a spray nozzle 61 to be cooled, and a cleaning brush roller 62 is slidably contacted with the back surface. The cleaning brush roller 62 reliably scrapes off the toner and the like adhering to the back surface of the PS plate 10 along with the wet toner development, and the transport roller 2
1, 31, 41, 51 and the transfer of the toner or the like to the PS plate 10 and the occurrence of print stains due to the toner or the like transferred to the PS plate 10 are reliably prevented. The cleaning brush roller 62 may rotate in the forward direction or the reverse direction of the carrying direction. The peripheral speed of the cleaning brush roller 62 may be equal to the conveying direction, but is preferably higher than the conveying speed.

In the elution section 63, the PS plate 10 conveyed by the conveyance roller 31 is brought into sliding contact with the elution promoting brush roller 33 while the eluate ejected from the spray nozzle 64 is sprayed on the surface thereof. After that, PS version 1
For 0, the squeeze roller 35 removes the attached excess eluate.

The conveying roller 31 is provided with PS on the upstream side and the downstream side of the elution promoting brush roller 33 in the conveying direction A, respectively.
A total of two pairs are provided, one above and one below the plate 10. The pair of transport rollers 31 transport the PS plate 10 in the transport direction A by rotating while sandwiching the PS plate 10.

The spray nozzles 64 are arranged on the front surface and the back surface of the PS plate 10 so as to face each other, and a large number (a total of five in this embodiment) are provided at predetermined intervals along the transport direction A. Each spray nozzle 64
The eluate pumped from the elution tank 36 by a circulation pump or the like (not shown) is sprayed onto the front surface and the back surface of the PS plate 10.

The elution promoting brush roller 33 is a PS plate 1.
It is provided at a position facing the surface of 0 with the facing plate 37 and the PS plate 10 sandwiched therebetween. The elution promoting brush roller 33 is brought into sliding contact with the surface of the PS plate 10 sprayed with the eluate,
The elution treatment of the non-image area of the image forming layer on the surface of the S plate 10 is promoted. The elution promoting brush roller 33 may rotate in the forward direction or the reverse direction with respect to the conveying direction. Also,
The peripheral speed of the elution promoting brush roller 33 may be equal to the conveying direction, but is preferably higher than the conveying speed.

A pair of upper and lower squeeze rollers 35 are provided on the most downstream side of the elution portion 63 in the conveying direction A with the PS plate 10 interposed therebetween. By rotating the squeeze roller 35 while sandwiching the PS plate 10, the squeeze roller 35 conveys the PS plate 10 in the conveyance direction A, and removes excess eluate adhering to the front surface and the back surface of the PS plate 10 so as to squeeze it out. To do. The excess eluate removed by the squeeze roller 35 is collected in the elution tank 36.

In the washing section 40, the PS plate 10 conveyed by the conveying rollers 41 is sprayed with washing water by the spray nozzles 42, and a washing brush roller 43 is brought into sliding contact with the surface thereof.

The transport roller 41 is a washing brush roller 43.
PS is placed on the upstream side and the downstream side in the transport direction A with the PS sandwiched therebetween.
A total of two pairs are provided, one above and one below the plate 10. The pair of transport rollers 41 transport the PS plate 10 in the transport direction A by rotating while sandwiching the PS plate 10. A plurality of (four in this embodiment) spray nozzles 42 are provided so as to face the front surface and the back surface of the PS plate 10, respectively.
The cleaning water pumped up from No. 4 is sprayed on the front surface and the back surface of the PS plate 10. The cleaning water sprayed on the PS plate 10 is collected in the water receiving tank 44 after falling from the PS plate 10.

The washing brush rollers 43 are provided at a position facing the surface of the PS plate 10 as a pair of upper and lower sides with the facing plate 45 and the PS plate 10 interposed therebetween. The washing brush roller 43 is brought into sliding contact with the surface of the PS plate 10 sprayed with washing water,
The washing process of the plate 10 with water is promoted. In the gum solution applying section 50, the PS plate 10 conveyed by the conveying roller 51.
However, the gum solution is sprayed by the spray nozzle 52.

Two pairs of conveying rollers 51 are provided on the upstream side and the downstream side in the conveying direction A with the spray nozzle 52 sandwiched therebetween, one pair above and one below the PS plate 10 respectively. Each pair of the transport rollers 51 transports the PS plate 10 in the transport direction A by rotating while sandwiching the PS plate 10. The spray nozzle 52 is arranged so as to face the surface of the PS plate 10, and sprays the gum solution drawn up from the gum solution tank 53 by a circulation pump or the like (not shown) onto the image forming layer on the surface of the PS plate 10. The sprayed gum solution is collected from the PS plate 10 and then collected in the gum solution tank 53.

In the second drying section, the PS plate 10 is dried by hot air such as a drier (not shown).

The operation of this embodiment will be described. PS plate 1 in which an electrostatic latent image is formed on the image forming layer by charging and exposure
0 is transported in the transport direction A with the image forming layer as the upper surface, and wet toner development is performed in the developing unit, and
After the development, the first drying unit and the fixing unit are dried and fixed. After the PS plate 10 is cooled in the cooling unit 60, the elution unit 63, the water washing unit 40, and the gum solution application unit 50 are sequentially subjected to predetermined processing, and the second drying unit dries the applied gum solution. To be done. P after drying
The S plate 10 is conveyed and accumulated on a tray or the like (not shown).

That is, in the cooling unit 60, the PS plate 10
The cooling water is sprayed on the back surface by the spray nozzle 61 to be cooled, and at the same time, the cleaning brush roller 62 is brought into sliding contact with the back surface to remove the attached toner.
Next, in the elution section 63, the PS plate 10 is subjected to an elution treatment to elute the non-image area of the image forming layer. That is, P
The S plate 10 is sprayed on its surface with the eluate ejected from the spray nozzle 64, and at the same time, the elution promoting brush roller 3
3 is slid on. Then, in the water washing section 40, the PS plate 1
No. 0 is washed with water to remove the eluate, and is applied with a gum solution in the gum solution application section 50 for finishing treatment.

FIG. 2 is a schematic sectional view showing a part of an electrophotographic plate making apparatus according to the second embodiment of the present invention. In this figure, the cleaning brush rollers 62 and 74 are the cooling unit 60.
And the elution section 63, respectively. That is, in the cooling unit 60 of the present embodiment, a plurality (two in the present embodiment) of spray nozzles 61 are arranged facing the back surface of the PS plate 10 at predetermined intervals along the transport direction A. To be The cleaning brush roller 62 is provided substantially in the center between the spray nozzles 61 in the transport direction A so as to face the back surface of the PS plate 10.

In the elution section 63, the cleaning brush rollers 74 are provided at a position facing the back surface of the PS plate 10 in a pair in the upper and lower sides with the facing member 75 and the PS plate 10 interposed therebetween.
A plurality of facing members 75 (two in the present embodiment) are provided facing the surface of the PS plate 10 at predetermined intervals along the transport direction A. The spray nozzle 64 is a PS plate 10.
Are arranged so as to face each other on the front surface and the back surface, and a large number (a total of nine in this embodiment) are provided along the transport direction A at predetermined intervals. Each spray nozzle 64 sprays the eluate pumped up from the elution tank 36 by a circulation pump or the like (not shown) onto the front surface and the back surface of the PS plate 10. Other configurations are the same as those in the first embodiment described above.

The cooling unit 60 of such an electrophotographic plate making apparatus
In the PS plate 10, cooling water is sprayed onto the back surface of the PS plate 10 by a spray nozzle 61, and the PS plate 10 is cooled, and a cleaning brush roller 62 is brought into sliding contact with the back surface. The cleaning brush roller 62 scrapes off the toner and the like adhering to the back surface of the PS plate 10 in association with the wet toner development to surely remove the toner. In the elution portion 63, the PS plate 10 is sprayed with the eluate ejected from the spray nozzle 64 on the front surface and the back surface thereof, and the cleaning brush roller 74 is slidably contacted with the back surface thereof. The cleaning brush roller 74 scrapes off the toner and the like attached to the back surface of the PS plate 10 in association with the wet toner development, and reliably removes it.

By sliding contact of the cleaning brush rollers 62, 74 in the cooling section 60 and the elution section 63 with the back surface of the PS plate 10, the conveying rollers 21, 31, 41, 51 and the PS.
The transfer of toner or the like onto the plate 10 and the occurrence of print stains due to the toner or the like transferred onto the PS plate 10 are more reliably prevented.

As described above, according to the above embodiments, the cleaning brush rollers 62 and 74 are provided in the cooling unit 60 in the first embodiment, and in the second embodiment, the cooling unit 60 and the elution unit 63.
The cleaning brush rollers 62 and 74 are provided on both sides of the PS plate 10 by slidingly contacting the back surface of the PS plate 10 to remove the toner and the like attached to the back surface of the PS plate 10 with wet toner development. Since it is removed by scraping, P
It is possible to reliably remove the toner and the like on the back surface of the S plate 10. As a result, it is possible to suppress the attachment of dirt or the like to the transport rollers 21, 31, 41, 51 and the PS plate 10 as much as possible. That is, even when the apparatus is continuously operated for a long time, the toner and the like attached to the back surface of the PS plate 10 are transferred to the transport rollers 21, 31, 41, 51 and accumulated,
It can be reliably prevented, and it is possible to reliably prevent the toner and the like from being transferred to the PS plate 10 via the transport rollers 21, 31, 41, 51 and causing printing stains.

In particular, according to the first embodiment, even if the filter for catching the removed toner dust is provided in the circulation path of the cooling water, the filter is not rapidly clogged with the toner dust. Further, when the cooling water is not circulated and is cooled by running water, it is not necessary to provide a filter. Further, according to the second embodiment, the cleaning brush rollers 62 and 74 are provided in both the cooling unit 60 and the elution unit 63, so that the toner and the like attached to the back surface of the PS plate 10 can be removed more reliably. Yes, therefore the transport rollers 31, 4
It is possible to more reliably prevent the transfer of toner or the like to the PS plates 10 and 51 and the occurrence of print stains due to the toner or the like transferred to the PS plate 10.

[0036]

As described above, according to the present invention, the brush body provided in the cooling portion is brought into sliding contact with the back surface of the electrophotographic lithographic printing plate, so that the electrophotographic lithographic printing is performed in association with the wet toner development. Since the adhered matter on the back side of the plate is removed, the adhered matter on the back side of the electrophotographic planographic printing plate can be surely removed, and as a result, the adherence of dirt and the like to the transport roller and the electrophotographic planographic printing plate can be minimized. It is possible to suppress, and it is possible to prevent a harmful effect due to the removed deposits.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a part of an electrophotographic plate making apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a part of an electrophotographic plate making apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a part of a conventional electrophotographic plate making apparatus.

FIG. 4 is a schematic sectional view showing a part of another conventional electrophotographic plate making apparatus.

[Explanation of symbols]

 10 Electrophotographic planographic printing plate 60,80 Cooling part 21,31,41,51 Conveying roller 63,83 Elution part 33 Elution promoting brush roller 34,62,74 Cleaning brush roller 40 Water washing part 43 Water washing brush roller 50 Gum solution Application section

Claims (1)

[Claims] 1. A grained aluminum support on one side,
A printing plate on which an image forming layer composed of a photoconductive layer has been subjected to a hydrophilic treatment is subjected to charging, exposure, wet toner development, drying, fixing, cooling, non-image area elution, washing, and finishing treatment. In the photoengraving machine, a cooling unit that cools the printing plate that has undergone wet toner development, drying and fixing, is brought into contact with the back surface of the printing plate by sliding contact with the back surface of the printing plate. An electrophotographic plate making apparatus comprising a brush body for removing a kimono.