JPH0219952B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for a printing original plate. More specifically, the present invention relates to a developing device suitable for use in a developing step in a lithographic printing plate manufacturing device that uses a printing original plate having a photoconductive photosensitive layer and develops a toner image by an electrophotographic method.

The present inventors previously published Japanese Patent Application No. 56-124128,
No. 56-124129, we proposed a method for manufacturing lithographic printing plates that does not require negative film, shortens plate-making time, and reduces plate-making costs. This previously proposed technique uses a conductive metal plate such as an aluminum plate as a support, and a photoconductive photosensitive layer, in particular copper phthalocyanine, is formed on the support by dispersing a photoconductive organic pigment in a resin such as a phenolic resin. Using a printing original plate coated with a photoconductive photosensitive layer in which is dispersed in a novolac resin, the electrostatic latent image is formed on the photosensitive layer by completing the charging and exposure process using an electrophotographic method. This is a technology in which a Nato image is obtained by passing through a developing process. The present invention relates to a developing device suitable for use in such a developing step.

Regarding liquid developing devices using electrophotography,
Conventionally, the support for recording paper and the like has been paper in most cases, and as far as the present inventors know, no liquid developing device has been put into practical use using a conductive metal plate such as an aluminum plate as the support. There are no examples. Therefore, the current situation is that there are many problems associated with its practical application.

For example, in both the transportation and development of the printing original plate and the squeezing of the liquid developer, no damage is allowed to the electrostatic latent image surface or the Nato visible image surface on the photosensitive layer side of the original plate. Further, it is important to ensure that the developer contacts the original plate in a uniform manner so that uneven development does not occur. Further, there are other problems such as the need to sufficiently squeeze the liquid developer and prevent it from being carried into the next process (for example, a rinsing process with a rinsing liquid or a fixing process such as heat fixing).

The present invention has been made in order to solve the various problems mentioned above, and provides a printing original plate developing device that prevents damage to the electrostatic latent image surface or the NATO image surface and enables uniform development. The purpose is to Other objects of the present invention will become clear from the following description of this specification.

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

1 and 2 are schematic side views and plan views showing a typical embodiment of the present invention, and FIGS. 3 to 5.
The figures are enlarged cross-sectional views taken along lines - line, - line, and - line, respectively.

In each figure, a printing original plate 1 is formed by coating a photoconductive photosensitive layer on a support such as an aluminum plate.
With the electrostatic latent image surface facing upward, it is guided and conveyed to the developing device according to the present invention, and after being subjected to Nato development with the liquid developer filled in the developer tank 2, it is guided and conveyed to the next process. . That is, FIGS. 1 and 2
In the figure, the developing device according to the present invention enters from the left side and is delivered from the right side. Therefore, in this specification, the words "front", "back", "left", "right", and "upper" and "lower" are used for each member based on the transport path or trajectory of the original 1.

The developer tank 2 of the present invention has an inlet 3A and an outlet 3B that are open at the front and rear ends, respectively, and the upper and lower sides thereof are located at a very small distance (several times the thickness of the original printing plate) from each other. An upper guide plate 4A (for example, a planar conductive metal plate such as an aluminum plate) and a lower guide plate 4B (not necessarily conductive There is no need to make the upper and lower guide plates electrically insulated by insulating members 5A and 5B (for example, acrylic resin or other material) at the left and right ends thereof. (synthetic resins, etc.). A slit-shaped liquid developer supply port 6 is provided in the upper guide plate 4A in a direction perpendicular to the plate transport path.
is provided between both ends thereof. This developer supply port 6 communicates with a chamber 7 that forms a reservoir of liquid developer D, and an overflow from the chamber 7 introduces the liquid developer into the space g in the developer tank 2. Incidentally, above the chamber 7, there is provided a liquid reservoir container 9 housing an introduction tube 8 having developer inlets at both left and right ends, and the liquid developer D introduced into the introduction tube 8 is transferred to its outlet. 10 into the container 9, and then fall into the chamber 7 through small holes 11 arranged in parallel on the bottom of the container 9.

On the other hand, the left and right insulating members 5A and 5B constituting the developer tank 2 have protruding portions that protrude to the upper portions of both left and right end portions of the printing original plate 1 to create a gap between them and the upper guide plate 4A. 5a and 5b to prevent the electrostatic latent image surface of the original plate 1 from coming into contact with the upper guide plate 4A and being damaged. Note that the upper guide plate 4
A is applied with a positive or negative potential.

At the inlet 3A and outlet 3B sides of the developer tank 2, there are upper conveyance rolls 12A for conveying the original plate 1.
A plurality of pairs of conveyor rolls consisting of a lower conveyor roll 12B and a lower conveyor roll 12B are arranged, and each of the lower conveyor rolls 12B is a full-face conveyor roll made of rubber or the like, while the upper conveyor roll 12A is a plate conveyor roll. The edge conveying roll is configured to contact and convey only the left and right end portions of 1, and is similarly made of rubber or the like. In addition, 13 in the figure is
It is a guide member that is placed on the outlet side of the developer tank 2 and slides while supporting the support side (i.e., the lower surface side) of the plate 1. It is a guide member that is arranged parallel to the plate conveying direction in order to prevent Nato stains on the lower surface side of the plate. It has a plurality of protrusions 14.

Squeezing of the liquid developer in the present invention is carried out, for example, as follows. First, the entrance 3 of the developer tank 2
The liquid developer D flowing out from A and propagating through the original plate 1 is prevented from flowing back by an inlet side air squeeze member 15 that blows out pressurized air in the direction of the developer tank 2. On the other hand, the liquid developer D remaining on the original plate 1 that has passed through the developer tank 2 is air-squeezed by an outlet-side air squeeze member 16 that blows out pressurized air in the direction of the developer tank 2 . When the original printing plate 1 is conveyed within the developing layer 2, it is slid on the lower guide plate 4B of the developing layer 2. At this time, the lower guide plate 4
Although some developer is present between B and the original printing plate 1, if the upper surface of the lower guide plate 4B is flat, the two may come into close contact with each other, creating resistance during conveyance. In order to prevent this, as shown in FIG. 6, a plurality of protrusions 19 are provided on the upper surface of the guide plate to reduce the resistance between the printing original plate 1 and the lower guide plate 4B.
The printing original plate 1 can be conveyed smoothly.

In the figure, 17 is a tank for storing the liquid developer D, 18 is a return tank for returning the used developer D to the tank 17, and P is the developer D in the tank 17.
B indicates a blower.

Although the configuration of a typical embodiment of the present invention has been described above, the present invention is not limited to the above, and of course may have other embodiments. for example,
The developer tank has a two-stage configuration, specifically, two or more sets of the developer tank and the transport roll are arranged in parallel along the plate transport path, that is, from the entrance to the exit of the device. In order to ensure sufficient development time, or instead of arranging the developer tank 2 substantially horizontally, the developer tank 2 is arranged slightly inclined so that either the inlet 3A or the outlet 3B (for example, the outlet 3B side) is lowered, and By blowing pressurized air from the lowered position side, the liquid developer D in the developer tank 2 is prevented from leaking beyond the supplied amount, and the developer tank 2 is always filled with liquid developer. It is also possible to adopt a configuration in which the

The operation of the present invention having the above configuration is as follows.

The upper guide plate 4A constituting the developer tank is used as a developing electrode for its developing function. In this case, a positive potential is applied depending on the Nato polarity of the developer,
It is also possible to load a negative potential or set it to zero potential by grounding, and by applying an arbitrary charge in this way, the liquid developer is used to visualize the electrostatic latent image on the original plate 1. It is possible to control the Nato image and obtain a good image. That is, the original plate 1 on which the electrostatic latent image has been formed is placed on rolls 12A and 12B.
The liquid developer D enters the developer tank 2 filled with the liquid developer D through the inlet 3A, is brought into contact with the developer D while being conveyed, and exits through the outlet 3B. and guided by the guide 13 to the next process (e.g. rinsing process,
(not shown). At this time, the space g of the developer tank 2 is always filled with developer. That is, the developer D passes through the tank 17, the pump P, the introduction pipe 8, the container 9, and its small hole 11, and is stored in the chamber 7, air bubbles are removed, and the developer D is led out to the supply port 6 by overflow, and the developer D passes through the tank 17, the pump P, the introduction pipe 8, the container 9, and its small hole 11. flows into and fills up. Excess liquid D is inlet 3A of tank 2.
The liquid D on the plate 1 flows out from the air squeeze portions 15 and 16, respectively, from the outlet 3B.
The liquid is squeezed by the water tank 18, collected into the tank 17 through the return tank 18, and recycled for use.

Since the present invention has the above-described structure and operation, the present invention described at the beginning can be achieved. Further, the printing original plate treated according to the present invention is extremely easily damaged due to its physical properties, but according to the present invention, the electrostatic latent image surface or the Nato image surface of the original plate is not damaged, and printing performance is improved. No adverse effects. To be more specific, the printing master plate is attached to the printing press cylinder during printing using an automatic plate making machine, etc., but at this time, it is common to attach the plate by inserting both ends of the plate into the plate insertion part. Both end portions of the original plate inserted into the plate insertion portion are located at positions unrelated to the printing surface of the plate cylinder. Therefore, according to the present invention, even if the edge portion is damaged by the transport roll, printing performance etc. are not affected.

[Brief explanation of drawings]

1 and 2 are schematic side views and plan views showing a typical embodiment of the present invention, and FIGS. 3 to 5 are enlarged cross-sectional views taken along lines -, -, and -, respectively. FIG. 6 is a sectional view showing another embodiment of the developer tank inlet portion. In the figure, 1 is a printing original plate, 2 is a developer tank, 3A is an inlet, 3B is an outlet, 4A is an upper guide plate, 4B is a lower guide plate, 5A and 5B are insulating members, 6 is a developer supply port, and D is a A liquid developer, 12A and 12B are transport rolls, and 15 and 16 are air squeeze parts.

Claims (1)

[Scope of Claims] 1. A printing original plate formed by coating a photoconductive photosensitive layer on a support, which is developed by being conveyed with the electrostatic latent image surface facing upward while passing through a developing tank. In the developing device, the front and rear ends of the developer tank are open to form an inlet and an outlet, respectively, and the upper and lower sides thereof are arranged facing each other in a substantially horizontal direction and separated from each other by a small distance. The upper and lower guide plates are constructed of upper and lower guide plates, and the left and right end portions thereof are composed of insulating members that electrically insulate the upper and lower guide plates. 1. A printing original plate developing device, characterized in that the developer is filled with liquid developer supplied from a developer supply port. 2. An insulating member is interposed between the printing original plate passing through the developer tank and the upper guide plate, and forms a gap between the two to prevent the electrostatic latent image surface of the printing original plate from coming into contact with the upper guide plate. 2. A printing original plate developing device according to claim 1, wherein said printing original plate developing device prevents the above-mentioned problems. 3. Claim 1 or 2, characterized in that the developer supply port is constituted by a slit bored in the upper guide plate in a direction perpendicular to the plate transport direction. A developing device for original printing plates. 4. Any one of claims 1 to 3, wherein the liquid developer supplied to the developer supply port is supplied by overflow from a chamber that forms a reservoir of the liquid developer. The printing original plate developing device described in . 5. The printing original plate is transported by transport rolls arranged on the entrance side and the exit side of the developer tank,
Claims 1 to 4, characterized in that the roll is an edge conveying roll configured to convey the electrostatic latent image surface of the plate in contact with only the left and right side edges of the plate.
A developing device for a printing original plate according to any one of paragraphs. 6. Printing according to any one of claims 1 to 5, characterized in that the upper guide plate is a developing electrode formed of a conductive material, and a positive or negative potential is applied thereto. Original development device. 7. The printing original plate developing device according to any one of claims 1 to 6, wherein a plurality of developer tanks are arranged in parallel along the plate transport path. 8. A patent characterized in that the printing original plate is transported by sliding the printing original plate on a guide member whose support side is disposed on the exit side of the developer tank and has a plurality of protrusions parallel to the plate transport direction. A developing device for a printing original plate according to any one of claims 1 to 7. 9. Claims 1 to 9, characterized in that the liquid developer flowing out from the inlet of the developer tank and propagating on the printing original plate is prevented from flowing back by spraying pressurized air. The printing original plate developing device according to any one of Item 8. 10. Any of claims 1 to 9, characterized in that the liquid developer remaining on the printing original plate that has passed through the developer tank is air squeezed by spraying pressurized air. A developing device for a printing original plate described in . 11. Claim No. 1, characterized in that the printing original plate is transported in the developer tank by sliding the printing original plate on the lower guide plate having a plurality of protrusions on the support side parallel to the printing plate transport direction. A developing device for a printing original plate according to any one of items 1 to 9.