JPH0924596A - Heat fixing device for plate making machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat fixing device for a plate making machine which can not only dry an image formed by a developing device completely but also can discharge the back of a master plate in a completely dried state. SOLUTION: A plate making machine forms an electrostatic latent image on the surface of a master plate and develops the latent image by a wet type developing device F. In the heat fixing device of the plate making machine, a pair of semi-cylindrical ceramic heaters which can radiate far ultraviolet rays to both upper and lower sides of the passed master plate is arranged, endless ladder chains 33A-33D which are in a state surrounding the lower side ceramic heater B are installed, and the master plate is heat-dried in a state in which the back of the master plate is supported by these ladder chains 33A-33D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making machine for producing a printing master, and more particularly to a heat fixing device for a plate making machine using a master plate having a foil plate such as an aluminum plate as a base material.

[0002]

2. Description of the Related Art As is well known, in a plate making machine for producing an image master used in a printing machine, a master paper having a surface of a synthetic resin sheet coated with a photosensitive material such as zinc oxide is used. Master paper has considerable expansion and contraction depending on temperature and humidity. Therefore, when a plurality of color separation masters made of master paper is used in a printing machine that performs color printing, color misregistration may occur due to expansion and contraction of the master paper.

[0003]

For this reason, recently,
A master plate based on an aluminum plate that is not affected by temperature conditions and humidity is provided.However, when a master was created using a conventional plate making machine using this master plate, the excess toner adhered to the master plate It was found that the worker's hands and peripherals were damaged.

The reason for this is that the developing device used in the plate making machine is
Since it is wet development in which the master plate is passed through the developing solution, not only the surface of the master plate that is difficult to dry but also the back surface of the master plate is not sufficiently dried only by drying the heating panel, and it becomes a floating state due to residual moisture. Although the cause is that the toner stains the surroundings, when such an unstable state of the toner occurs, it also causes disturbance of the toner image itself and causes a problem that the print image quality deteriorates.

In view of the problems of the conventional plate making machine as described above, the object of the present invention is not only to completely dry the image formed by the developing device, but also to completely dry the back surface of the master plate. To obtain a heat fixing device of a plate making machine that can be discharged in a state.

[0006]

To achieve this object, the present invention forms an electrostatic latent image on the surface of a master plate,
In a plate making machine that develops the same electrostatic latent image with a wet developing device,
A pair of semi-cylindrical ceramic heaters that can radiate far infrared rays are arranged on the upper and lower sides of the passing master plate, and a plurality of endless ladders surrounding the lower ceramic heater are provided, and the master plate is formed by these ladders. The present invention proposes a heating and fixing device of a plate making machine that heats and dries the master plate while supporting the back surface of the plate. Further, in a preferred embodiment of the present invention described later, a structure in which the ceramic heater is attached to a reflecting mirror having a reflecting plate of a roof type whose cross section faces the passage of the master plate will be described.

[0007]

Therefore, according to the present invention, the developed master plate is irradiated with far-infrared rays from above and below while being supported by the highly air-permeable ladder chain. The deep part of the layer and the back surface of the master plate are surely dried.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show the whole of the digital plate making machine according to the present invention, and the whole of the digital plate making machine and the plate making process will be described with reference to the drawings.

A horizontal installation base 3 is provided at a substantially middle portion in the vertical direction of the machine body frame 2 inside the plate-making machine body, which is entirely covered with a light-shielding panel 1, and a master 3 is provided on the right side of the installation base 3. An exposure stage A having a pair of positioning pins 4A and 4B capable of accurately positioning and fixing the plate X is arranged. Therefore, the operator has the same positioning pins 4A, 4
After manually positioning the master plate X on the surface of the exposure stage A using B, the slide cover 5 covering the upper side of the exposure stage A can be closed to prepare the master plate X for exposure.

A pair of parallel guide rods 6A and 6B extending in the left-right direction of FIG. 1, that is, the sub-scanning direction are fixed in front of and behind the installation table 3, and these guide rods 6 are arranged.
A laser scanner C having a charger B for charging the surface of the master plate X is supported by A and 6B so as to be movable in the sub-scanning direction. This laser scanner C is equipped with a laser scan unit 7 capable of performing a main scan with a laser beam α downward. Inside the laser scan unit 7, a main scanning direction perpendicular to the sub-scanning direction, that is, a drawing A polygon mirror 8 for main-scanning the laser beam α in a direction perpendicular to the paper surface of No. 1 is incorporated. The laser scan unit 7 is supplied with digitized image information from a computer (not shown) or the like, but when manufacturing a master for color printing, the laser scan unit 7 is provided with image information for each decomposed dye. Then, a plurality of masters of the same image are created for each decomposed dye.

In order to drive the laser scanner C, two pairs of timing sprockets 9A, 9B, 10A and 10B facing each other in the sub-scanning direction are installed in front of and behind the mounting table 3 described above, and the timing of each of these pairs. Sprocket 9A, 9
Endless timing belt 1 between B, 10A and 10B
1A and 11B are passed over. The timing belts 11A and 11B are provided with timing sprockets 9A and 9B,
It is synchronously driven by the sub-scanning drive gear (FIG. 2) via synchronous shafts 12A and 12B connecting between 10A and 10B, and a movable base 13 of the laser scanner C is provided on a part of these timing belts 11A and 11B. The joint piece 13a extending from is fixed. Therefore, by the forward rotation of the sub-scanning drive gear 14, the laser scanner C is moved forward from the standby position shown by the solid line to the sub-scanning end position shown by the phantom line, and the surface of the master plate X positioned on the exposure stage A during this time. At the same time as the charging is performed, the digitized image is formed into a latent image by the main scanning of the laser beam α and the sub-scanning of the movable table 13.

Further, the exposure stage A is provided with a perforated platen 16 which can be tilted about a pivot shaft 15 arranged on the side opposite to the standby position of the laser scanner C as a fulcrum.
A plurality of endless feed belts 17 that can settle under the perforated plate 16 when the exposure stage A is at the exposure position indicated by the solid line are hung on the stage 6. These feed belts 17 are relatively moved onto the perforated platen 16 when the tilting cylinder 18 is in a tilted position indicated by an imaginary line, and bear the master plate X to convey it to the left in FIG. The master plate X is supplied to the transport roller D.

FIG. 3 shows the details of the positioning unit 19 for operating the positioning pins 4A and 4B provided on the exposure stage A. The positioning unit 19 is the porous surface plate 16 described above.
The support bracket 20 is fixed to the lower part of the electromagnetic brake, and an electromagnetic solenoid 21 having a core rod 21a oriented vertically is fixed to the support bracket 20.
The base ends of the positioning pins 4A and 4B described above are fixed to the tip of the core rod 21a via a joint sleeve 22, and the positioning pins 4A and 4B guided in the vertical direction by the thrust sleeve 23 are moved upward by the compression spring 24. Be energized. Therefore, the positioning pins 4A, 4
When the exposure stage A is at the exposure position in FIG. 1, the tip end portion of B can be projected onto the surface of the porous platen 16 by the compression spring 24. Therefore, the tip end portions of the positioning pins 4A and 4B have the same diameter. A master plate X having a perforated plate 16
Can be accurately positioned on the surface of. Also, the exposure stage A
Is set to an inclined position indicated by a virtual line, the electromagnetic solenoid 21 is excited and the positioning pins 4A and 4B are moved to the perforated plate 1
6 is retracted below the surface, the master plate X becomes free, and the feed roller 17 feeds the feed roller D.
Sent to.

Below the installation table 3 corresponding to the laser scanner C in the standby position, a plurality of process devices for performing the subsequent plate making process of the latent imaged master plate X are incorporated. That is, immediately after the conveying roller D, a black frame removing unit E that removes charges other than the image portion on the surface of the master plate X is positioned, and the master plate X that has passed through the black frame removing unit E is Developing section entrance roller 25
And the developer spray head 2 of the developing device F.
The electrostatic latent image on the master plate X is toner-developed by spraying the developing solution from 6, and a visualized image is formed on the surface of the master plate X.

After that, while the master plate X passes through the squeeze roller G of the developing device F, excess developer on the surface of the master plate X is removed, and the master plate X is fed by the developing section outlet roller 27. The toner image on the surface of the master plate X is heated and fixed by being sent to the heat fixing device H and drying the master plate X while passing through the heat fixing device H. And
The completed master is ejected to the ejection chute 28 by the rotational movement of the ejection roller I on the left side of the machine body, and sent to the printing process.

FIGS. 4 and 5 show a heat fixing device H according to the present invention. The heat fixing device H is a pair of reflecting mirrors 29A and 29 which are vertically opposed to each other with the passage of the master plate X interposed therebetween.
B, and both ends of these reflecting mirrors 29A and 29B are fixed to the developing section frame 31 with fixing screws 29a. That is, the frame-shaped developing section frame 31 has a pair of upper and lower reflecting mirrors 29A and 29B extending in the transverse direction of the passage of the master plate X.
Is fixed, and the roof-shaped reflectors 29a of the reflectors 29A and 29B are directly opposed to the passage direction of the master plate X. In addition, a semi-cylindrical ceramic heater 32 that radiates far infrared rays is provided at the center of each of the reflecting mirrors 29A and 29B.
A and 32B are attached, and the passing master plate X can be heated by energizing the heater wire 32a built in these ceramic heaters 32A and 32B.

Further, the developing unit frame 31 has the lower reflecting mirrors 29A and 29B and the ceramic heater 32.
A and 32B are surrounded by a plurality of sprocket shafts 33A,
Ladder sprockets 34A, 34B, 34C, 3 on which 33B, 33C, 33D are installed and supported by these sprocket shafts 33A, 33B, 33C, 33D, respectively.
A plurality of ladder chains 35A, 35B, 35C, 35D extending in a direction parallel to the passage of the master plate X are bridged over 4D, and the ladder chains 35A, 35B, 35C, 3 are provided.
5D is sprocket shaft 33A, 33B, 33C, 33D
4 is driven in the counterclockwise direction in FIG.

A heat fixing device H of a plate making machine according to the illustrated embodiment.
Has a structure as described above, the master plate X which is wet with the developing solution has a plurality of ladder chains 35 on the back surface.
It is conveyed while being supported by A, 35B, 35C and 35D. That is, since the rudder chains 35A, 35B, 35C, and 35D are only partially hit on the back surface of the master plate X being conveyed, the air permeability of the back surface of the master plate X is sufficiently ensured.

Therefore, both ceramic heaters 3 are provided on the front surface and the back surface of the master plate X passing through the heat fixing device H.
Far infrared rays from 2A and 32B and reflecting mirrors 29A and 29B
Since the far infrared rays reflected by are irradiated, the image layer on the surface of the master plate X is also dried by the far infrared rays having penetrability, so that a sufficiently dry and stable toner image can be obtained. You can

Although far-infrared rays are also radiated to the back side of the master plate X, the rudder chains 35A, 35B, 35C and 35D are only partially in contact with the back side of the master plate X as described above. Therefore, the heat fixing device H
The back side is also completely dried while passing through, so that the hands and peripheral devices are prevented from being soiled by the undried developer.

[0021]

As is apparent from the above description, according to the present invention, it is possible to completely dry the image layer on the front surface of the master plate X and the residual developing solution on the back surface, which are difficult to dry completely. It is possible to prevent stains on hands and peripheral devices by the master created by the machine.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a digital plate making machine according to the present invention.

FIG. 2 is an overall cross-sectional view of the digital plate making machine substantially along the line 2-2 in FIG.

FIG. 3 is an enlarged cross-sectional view of a positioning pin of the digital plate making machine.

FIG. 4 is a sectional view of a heat fixing device of the digital plate making machine.

5 is a cross-sectional view of the heat fixing device, which is taken substantially along the line 5-5 of FIG.

[Explanation of symbols]

 X Master Plate A Exposure Stage B Charger C Laser Scanner F Developing Device G Aperture Roller H Heat Fixing Device I Paper Ejection Roller 29A, 29B Reflecting Mirror 29b Reflecting Plate 31 Developing Section Frame 32A, 32B Ceramic Heater 35A-35D Ladder Chain

Claims (2)

[Claims] 1. An electrostatic latent image is formed on the surface of a master plate,
In a plate making machine that develops the same electrostatic latent image with a wet developing device,
A pair of semi-cylindrical ceramic heaters that can radiate far infrared rays are arranged on the upper and lower sides of the passing master plate, and a plurality of endless ladders surrounding the lower ceramic heater are provided, and the master plate is formed by these ladders. A heating and fixing device of a plate making machine, which heats and dries the master plate while supporting the back surface of the master plate. 2. The heating and fixing device for a plate making machine according to claim 1, wherein the ceramic heater is mounted on a reflecting mirror having a reflecting plate having a roof-shaped cross section with a reflecting surface facing the passage of the master plate.