JPH0354584A - Wet developing device - Google Patents

Abstract

PURPOSE:To speedily remove a developer remaining inside a sponge developing roller by air after development is completed by supplying air with pressure to the inside of the developing roller together with a developer. CONSTITUTION:A photographic sheet sucked by a drum 1 is electrified and exposed through the rotation of the drum 1, and arrives at a developing position. In development, the developing roller 2 is pushed against the drum 1, and a developer pumped by a pump 9 from a developer tank 10 is supplied to a sponge 4 through the nozzles 5 of an inner tube 3 in the developing roller 2. Upon the completion of development, the developing roller 2 is separated from the drum 1, and the developer supply pump 9 stops operation. At this time, an air supplying pump 12 is activated and pressurizes the inner tube 3 to supply air. Ultimately, an excessive developer residing in the sponge 4 is pushed out.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wet-type developing device that supplies a developer from inside a developing roller and brings it into contact with the electrostatic latent image surface of a photoreceptor to develop the image. be.

[Prior Art] Conventionally, a contact type wet developing device uses a sponge developing roller.

The center portion of the sponge developing roller has a hollow structure in the direction of the rotation axis, and small holes are provided around this hollow portion for supplying a developing solution to the sponge portion. A developer is supplied to this hollow part, and by applying pressure, the developer is supplied from the hollow part to the surface of the sponge roller.

The developing roller rotates while contacting the electrostatic latent image surface of the photoreceptor during the development process, and the developer supplied to the surface of the roller is transferred to the electrostatic latent image surface of the photoreceptor that is in contact with the roller surface. It came into contact with the image surface and realized contact wet development.

[Problems to be Solved by the Invention] However, in this method, even after the development is completed and the development branch supply means stops operating, some developer remains in the sponge portion of the development roller, and the mouth roller If the sponge portion of the sponge portion dries out, it not only stains the developing roller, but also clogs the small holes for supplying the developer and the small holes in the sponge with toner particles.

For this reason, there have been problems such as not being able to supply a sufficient amount of developer during the next development, and causing toner clumps that were blocking the small holes to come into contact with the surface of the photosensitive paper, resulting in image deterioration.

The present invention has been made in order to solve the above-mentioned problems, and is a wet-type developer that can quickly remove the developer that remains inside the sponge developing roller after the development is completed, and can form a good image. The purpose is to provide equipment.

[Means for Solving the Problems] In order to achieve this object, the wet type developing device of the present invention includes an air supply means capable of supplying air with pressure in the same manner as the developer into the inside of the developing roller, and the developer supply means. and a selection means for selecting, as necessary, the developer supplied from the developer and the air supplied from the air supply means, and supplying the selected developer to the developing roller.

[Function] In the present invention having the above structure, the selection means selects a developer during development, and the developer supply means supplies the developer to the developing roller. After the development is completed, the supply of the developing section is stopped, then air is selected, and the air is supplied to the developing roller by the air supply means.

The air supply means, when selected by the selection means, supplies air with pressure to the hollow part inside the developing roller in the same manner as the developer supply means, and drains the developer remaining inside the roller. Remove outside.

[Example] Hereinafter, examples embodying the present invention will be described with reference to the drawings.

In the figure, a developing roller 2 placed below a drum 1
is composed of a hollow inner tube 3 and a sponge 4. The inner tube 3 is provided with a large number of small holes 5 through which the developer is supplied to the sponge 4. One end of the supply pipe 6 is connected to the inner pipe 3, and the other end is connected to a branch part 7 and a developer valve 8.
It is connected to the developer supply pump 9 through the developer tank 10, and the developer pumped up from the developer tank 10 is supplied to the inner tube 3 by applying pressure.
It is now possible to supply to

The other end of the branch 7 provided on the supply pipe 6 is connected to an air supply bomb 12 via an air valve 11, and supplies air to the inner pipe 3 under pressure in the same way as the developer. I'm starting to get it. That is, in this embodiment, the air supply bomb 12 constitutes the air supply means.

The developer valve 8 and the air valve 11 can be opened and closed by a developer solenoid 13 and an air solenoid 14, respectively, and the solenoids 13 and 14 are controlled and driven by a control microcomputer 15. That is,
In this embodiment, a developer valve 8, an air valve 1
1. A developer solenoid 13, an air solenoid 14, and a microcomputer 15 constitute a selection means.

Next, the operation of this embodiment will be explained.

The photosensitive paper attracted to the drum 1 is charged and exposed as the drum 1 rotates, and reaches a developing position.

At this time, the microcomputer 15 drives the developer solenoid 13 and the air solenoid 14 so that the developing valve 8 is "open" and the air valve 11 is "closed". When both valves are set, the developer supply pump 9 connected to the supply pipe 6 is activated, thereby drawing up the developer from the developer tank IO and supplying it to the inner pipe 3 under pressure. As a result, the toner supplied to the inner tube 3 passes through the small holes 5 and diffuses into the sponge 4. When enough toner is supplied to the sponge 4, the developing roller 2 is pressed against the drum 1. In this state, the photosensitive paper reaches the development position,
Development is performed. Note that the toner supplied to the inner tube 3 is
The supply continues under pressure until the development process is completed.

When the development is completed, the developing roller 2 pressed against the drum 1 separates from the drum 1, and at the same time, the developer supply pump 9 stops operating. At this time, the microcomputer 15
Next, the developer solenoid 13 and air solenoid 14 are driven so that the developer valve 8 is closed and the air valve 11 is opened.The air supply bomb 12 is activated to apply pressure to the inner tube 3. The supplied air passes through the small hole 5 from the inner tube 3 like the developer, passes through the sponge 4, and pushes out the excess developer remaining in the sponge 4.

When the excess developer has been sufficiently removed from the developing roller 2, the microcomputer 15 drives the air solenoid 14 and closes the air valve 11 in preparation for the next developing process.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, the excess developer remaining in the developing roller can be removed after the development is completed, so even if the developing roller dries, the developing roller can be removed. It is also possible to prevent dirt from sticking to the roller and toner in the developer from solidifying and clogging the small hole in the inner tube and the small hole in the sponge in the developing roller. This makes it possible to form a good image.

[Brief explanation of drawings]

The drawing is a sectional view showing the overall configuration. In the figure, 8.13 is a developer valve, 11 is an air valve,
12 is an air supply pump, and 14 is an air solenoid.

Claims (1)

[Claims] 1. In developing the electrostatic latent image on the photoreceptor, a developer supply means is provided which supplies the developer with pressure into the inside of a developing roller rotatably provided opposite to the photoreceptor; In a wet type developing device, a developer is supplied from the inside of the developer roller to the surface thereof through a small hole in the developer roller, and the supplied developer is brought into contact with the electrostatic latent image surface of the photoreceptor to perform development. An air supply means capable of supplying air with pressure in the same manner as the developer into the inside of the developer, a developer supplied from the developer supply means, and air supplied from the air supply means are selected as necessary. , and selection means for supplying to the developing roller.