JPH0380274A - Excess developer removing device - Google Patents

Abstract

PURPOSE:To prevent excess developer from remaining in a sponge and to form an excellent output image by providing a roller made of sponge which has hollow structure and can suck the developer and a means for sucking the developer which infiltrates into the sponge by applying negative pressure to the hollow part of the roller. CONSTITUTION:When a sponge part 101 starts to suck the developer, a suction pump 104 is actuated and the negative pressure is applied to the hollow part 102 in a squeeze roller 5 through a suction tube 103 so as to exhaust the developer sucked in the sponge part 101 to the hollow part 102 and collect it in a tank part 8 through the suction tube 103 and the pump 104. In the sponge part 101 the developer sucked from a photosensitive body is rapidly sucked to the hollow part 102 and the excess developer on the photosensitive body is removed in a state where it is not saturated at any time. Thus, the excess developer does not remain in the sponge and the excellent image is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a surplus developer removing device that removes surplus developer on a photoreceptor using a sponge roller provided in a wet type developing device.

[Prior Art 1] Conventionally, this type of device has had a configuration as shown in FIG. A developing tank 2 is installed below the drum 1 so as to be movable up and down by an elevating bottle 3. Adjacent to the developing tank 2, there is another developing tank having the same configuration storing toners of other colors.
is transported directly below the drum 1 by a transport device (not shown), and raised to a developing position by an elevating bin 3.

A developing electrode 4 is provided on the left side of each developing tank 2, and a squeeze roller 5 is provided on the right side, each supported by a spring 6.7. When the developing tank 2 is raised to the developing position, the electrode 4 and The rollers 5 are each pressed against the drum 1 by a spring 6.7.

There is a tank section 8 below the developing tank 2 that stores a liquid developer, and is configured such that the developer can be supplied to the developing electrode 4 by a pump 9 from here.

The squeeze roller 5 has a roller stand 10 supported by a spring 7.
is attached to. A blade 11 is mounted on the roller stand 10.
is placed pressed against the roller 5.

The photosensitive paper wound around the drum 1 passes through charging and exposure steps and reaches a developing position. By this time, the developer tank 2 containing the developer of the required color has been selected, conveyed directly below the drum 1, and raised to the developing position by the lifting bin 3.

Further, the developing electrode 4 is supplied with a developer in a tank section 8 by a pump 9, and the photosensitive paper on the drum 1 is developed. When the drum 1 further rotates and the photosensitive paper comes into contact with the squeeze roller 5, the squeeze roller 5 rotates in the direction of the arrow in the figure and sucks the excess developer remaining on the photosensitive paper into the roller 5 and removes it. When the excess developer sucked into the roller 5 passes through the part that comes into contact with the blade 11,
It is squeezed out by the blade and returns to the tank section 8.

When the development is completed, the elevating bin is lowered and the developing tank 2 is replaced with one of the next color.

As the drum 1 continues to rotate, the photosensitive paper passes through the steps of static elimination, charging, and exposure, and then returns to the development step.

These operations were repeated three to four times to output a full color image.

[Problem to be Solved by the Invention J] However, in such a surplus developer removing device, if the squeeze roller separates from the drum or photosensitive paper after the development process, the roller does not rotate, and the developer sucked in just before the squeeze roller separates from the drum or photosensitive paper. The liquid remains inside the roller, and if it dries in this state, it will stick as dirt.
This will adversely affect the next output image.

Furthermore, if the roller is left unrotated and the blade is pressed against a portion of the roller for a long period of time, the roller deforms, which again has a negative effect on the output image.

The present invention has been made in order to solve the above-mentioned problems, and by providing the above-mentioned hollow sponge roller, a suction means, and a roller cover, the Lisbonsi squeeze roller can be used uniformly and sufficiently. It is an object of the present invention to provide a surplus developer removing device capable of suctioning and producing a good output image without leaving surplus developer in a sponge.

[Method R for Solving the Problem] To achieve this object, the surplus developer removing device of the present invention includes a sponge roller having a hollow structure capable of sucking the developer from inside, and the sponge roller. It is equipped with a suction means that applies negative pressure to the hollow part and sucks up the developer that has permeated into the sponge, and a roller cover that covers up unnecessary parts of the squeeze roller.

[Function] In the present invention having the above-described configuration, the hollow portion of the sponge roller is applied with negative pressure by the suction means, and sucks the developer that has permeated into the surrounding sponge portion and sends it to the suction means.

The suction means applies negative pressure to the hollow part within the roller, collects the developer sucked out into the hollow part, and prevents it from remaining in the sponge.

By covering the area around the roller that does not face the photoreceptor, the roller cover prevents air from flowing into the sponge and canceling out the negative pressure.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

A developing tank 2 is disposed below a drum 1, and can be raised and lowered by an elevator bin 3, as in the prior art, the construction of which is shown in FIG. The developing electrode 4 and the squeeze roller 5 are supported by springs 6 and 7, respectively, and the developing solution can be supplied to the electrode 4 from a tank portion 8 by a pump 9. The roller 5 is attached to a roller stand 10.

The squeeze roller 5 has a configuration as shown in FIG. A hollow portion 1 is formed inside the sponge portion 101 in the direction of the rotation axis.
02, and the hollow portion 102 is connected to a suction pump 104 via a suction W103. The tip of the pump 104 is connected to the tank section 8. That is, in this embodiment, 5 is a hollow sponge roller;
Also, the suction tube 103. The suction pump 104 controls the suction means.

A cover 105 is provided around the entry quiz roller 5 to cover almost the entire area except for the portion where the roller 5 contacts the drum 1.
When 04 suctions the inside of the sponge, a large amount of air flows in and prevents the negative pressure from being canceled out.

That is, in this embodiment, the cover 105 functions as a roller cover.

Next, the operation of this embodiment will be explained.

The photosensitive paper attached to the drum 1 reaches the developing position after passing through each step of charging and exposure. By this time, the developer tank 2 containing the developer of the required color has been conveyed directly below the selected drum 1 and raised to the developing position by the lifting pin 3.

Further, the developing electrode 4 is supplied with a developer in a tank section 8 by a pump 9, and the photosensitive paper on the drum 1 is developed.

When the drum 1 further rotates and the photosensitive paper comes into contact with the squeeze roller 5, the squeeze roller 5 rotates in the direction of the arrow in FIG. Inhale.

When the sponge portion 101 begins to suck in the developer, the suction pump 104 is activated to apply negative pressure to the hollow portion 102 in the squeeze roller 5 through the suction tube 103. In the hollow part 102, a negative pressure rises, and the developer that has been sucked into the sponge part 101 is sucked out into the hollow part 102 and is drained. The sucked out developer is passed through the suction tube 103. It passes through the suction pump 104 and is collected into the tank section 8 . In the sponge part 101, the developer absorbed from above the photoconductor is quickly absorbed into the hollow part 10.
2, and removes excess developer on the photoreceptor while keeping it in an unsaturated state.

When the development is completed, the elevator pin 3 lowers the developer tank 2, and when the developer in the sponge portion 101 is completely absorbed, the suction pump 104 stops.

Drum 1 continues to rotate, and the photosensitive paper is neutralized and charged.

After passing through each exposure process, it returns to the development position.

By this time, the developing tank 2 of the next color has been transported to the developing position, and the developing process is performed here.

These operations are repeated three to four times to output a full color image.

[Effect of the Invention 1] As is clear from the detailed description above, according to the present invention, during the development process, the developer in the sponge is quickly suctioned away, so a good squeezing action is always possible. ,
In addition, since the entire roller is uniformly and sufficiently suctioned after the squeeze operation is completed, excess developer does not remain inside the sponge roller, and even if it dries, stains are less likely to stick to it, making it possible to produce good images.

[Brief explanation of drawings]

1 to 2 show embodiments embodying the present invention. FIG. 1 is a sectional view showing the entire NIT, FIG. 2 is a sectional view of the main part, and FIG. FIG. 3 is a diagram showing the configuration of a conventional example.

Claims (1)

[Scope of Claims] 1. In a surplus developer removing device that removes surplus developer on a photoconductor using a sponge roller rotatably provided in a wet developing device and facing the photoconductor, the sponge A suction means that makes the sponge roller have a hollow structure capable of sucking the developer from inside thereof, and applies negative pressure to the hollow portion of the sponge roller to suck the developer that has permeated into the sponge; A surplus developer removing device characterized by comprising a roller cover that covers unnecessary parts of the developer.