JP2608566B2 - Wet electrophotographic equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wet electrophotographic apparatus, and more particularly to a developing apparatus or a cleaning apparatus of a wet electrophotographic copying machine.

2. Description of the Related Art Conventionally, wet electrophotographic copying machines are widely used. As shown in FIG. 8, for example, a wet electrophotographic copying machine has a photosensitive drum 51 which is driven to rotate at a constant speed in the direction of an arrow, and the photosensitive drum 51 is uniformly charged by a main charger 52, and is exposed to light. At the position 53, the original image is projected by the exposure device to form an electrostatic latent image, the charge outside the image forming area is removed by the eraser 54, the latent image is developed by the wet developing device 55, and sent out from a paper feeding device (not shown). The transfer charger 57 transfers the transfer paper 57 to the transfer paper 57 sent by the transfer roller 56, separates the transfer paper by the separation roller 59, transfers the transfer paper 60 by the transfer belt 60, fixes the toner by the fixing device, and discharges it. The drum 1 is configured so that the residual toner is removed by the cleaning device 61 and the residual potential is removed by the discharging lamp or the discharging charger 62.

The developing device 55 includes a first developing roller 63 and a second developing roller 64.
Are arranged, and each is separated from the photosensitive drum 51 by a small distance, for example,
Adjusted and held at 0.1 to 0.2 mm, the photosensitive drum 51 as shown by the arrow
Is rotated at a peripheral speed higher than that of the photosensitive drum in the opposite direction. A cleaning member fixed to the developing container 65, for example, a scraper 66, comes into contact with each of the developing rollers 63 and 64 to constantly clean the toner on the developing rollers 63 and 64. At the upper end of the toner container 65, a supply nozzle 67 as a liquid supply unit for supplying a developer is arranged, and the developer is supplied into the developer container 65. A developer is supplied from a developer tank 70 to a supply nozzle 67 through a conduit 68 by a supply device 69 such as a pump.

The developer supplied into the developing container 65 is the first developing roller 63.
And the scraper 66 cooperate with each other, and the second developing roller 64 and the scraper 66 cooperate with each other to carry it to the surface of the photosensitive drum 57.
It flows between the photosensitive drum 51 and the developing rollers 63 and 64 to develop the latent image on the photosensitive drum 1. The excess developer and the developer after development pass between the developing rollers 63 and 64 and the photosensitive drum 51, and are collected in a liquid receiving portion 71 formed as a bottom portion of the developing container 65. Further, the developer remaining on the surface of the photosensitive drum 51 is driven to rotate in the same direction as the photosensitive drum 51, and is scraped off from the photosensitive drum 51 by a squeeze roller 72 arranged at a minute interval of, for example, 0.05 mm. Then, the squeeze roller 72 scrapes the developing solution by the scraper 73.
The scraped developer is collected in the liquid receiving section 71.

The liquid receiving portion 71 is provided with a liquid outlet 74, and the liquid outlet 74
Is connected to the developer tank 70 by a recovery pipe 75, and the recovered developer in the liquid receiver 71 is returned to the developer tank 70, whereby the developer is circulated and supplied.

The cleaning device 61 has a cleaning roller 76 disposed in contact with the photosensitive drum 51, and has a cleaning liquid supply unit (not shown) as a liquid supply unit 78 formed at the upper end of the cleaning container 77. The cleaning liquid supplied from the liquid supply unit 78 is supplied to a cleaning roller 76, for example, a form roller. Cleaning roller
76 collects residual toner from the photosensitive drum 51, and the cleaning liquid containing the collected toner is squeezed by a squeeze roller 79 arranged in contact with the cleaning roller 76 and collected in a liquid receiving portion 80 formed at the bottom of the cleaning container 77. Is done. The aperture roller 79 is scraped off the toner and the cleaning liquid by the scraper 83. The liquid receiver 80 has a liquid outlet 87,
The collected cleaning liquid is discharged to a predetermined position. The liquid supplied from the liquid supply unit 78 is the cleaning roller 76 as it is.
Is supplied to the cleaning roller 76, the liquid diffusion plate 82 is disposed.

In such a conventional developing device and cleaning device, the ninth
As shown in FIG. 10 and FIG. 10, the cleaning liquid and the developing liquid collected from the cleaning roller 76 and the liquid diffusion plate 82 or from the developing roller and the squeeze roller (not shown) accumulate to generate sludge aggregated toner. However, in order to prevent this sludge-like aggregated toner, the liquid is discharged from the liquid outlets 74, 81.
It has an inclined surface with the liquid outlet side lowered so that it can flow easily. However, if it is an inclined surface, the highest position on the opposite side of the liquid discharge port becomes a dead space where the sludge-like aggregated toner 84 is generated. In order to avoid the occurrence of aggregated toner in the dead space, there are a method of increasing the total amount of liquid to be supplied and a method of providing a large number of nozzles as a supply unit. However, the output of the driving device is increased and the device is complicated. It's not a good solution.

If the sludge-like agglomerated toner is left unused for a long period of time, it will form flakes of toner, causing clogging at the liquid discharge port, which may cause the developer or cleaning liquid to overflow, and even black solid white lines. This may cause abnormal images such as white spots and white spots. This also poses a problem in terms of toner consumption, since a large amount of unusable toner exists. Further, there is also a problem that a service person spends a long time for cleaning during pre-maintenance.

OBJECT The present invention solves the above-mentioned conventional problems and aims to provide an electrophotographic apparatus which does not cause toner aggregation.

Configuration In order to achieve the above object, the present invention has a liquid collecting member provided between a liquid supply unit and a liquid receiving unit of at least one of a developing device and a cleaning device, and the liquid collecting member Is characterized in that the liquid discharge portion is arranged in the vicinity of the position where the toner is likely to remain in the liquid receiving portion.

In the cleaning device shown in FIG. 1, the photosensitive drum 1, the cleaning roller 2, the squeezing roller 3, the scraper 4, the liquid supply unit 5 for supplying the cleaning liquid, the liquid diffusion plate 6, the liquid receiving unit 7, and the liquid discharge port 8 The points provided are the same as those of the copying machine shown in FIG. However, between the liquid supply unit 5 and the liquid receiving unit 7, for example, a liquid collecting member 9 is provided below the squeezing roller 3 to collect the cleaning liquid falling from above. As shown in FIG. 2, the liquid collecting member 9 is located on the opposite side of the inclined surface 11 inclined downward toward the liquid discharge port 10 of the liquid receiving portion 7 from one end in the axial direction of the cleaning roller 2 to the other end. The liquid discharge end is located near the highest position of the inclined surface 11 of the liquid receiving portion 7, that is, above a portion where a dead space is generated.

The cleaning liquid needs to be uniformly supplied from the liquid supply unit 5 over the entire length of the cleaning roller 2. For this purpose, the liquid diffusion plate 6 or the like is used.

For this reason, the cleaning liquid drops from the cleaning roller 2 to the liquid collecting member 9 in a state where the cleaning liquid is dispersed from each position over the entire length. The same applies to the liquid squeezed or scraped by the squeezing roller 3. When the liquid is dispersed, the respective positions are not enough to wash away the toner accumulated in the liquid receiving portion 7, but the liquid receiving portion 7 is inclined so that the liquid is increased in the downstream side and the washing force is increased. Is insufficient on the upstream side. However, by collecting the liquid by the liquid collecting member 9 and discharging the liquid to the position upstream of the liquid receiving portion 7, it was possible to prevent the accumulation of sludge-like aggregated toner on the liquid receiving portion 7.

In the developing device shown in FIG. 3, the first developing roller 21,
The scraper 22, the second developing roller 23, the scraper 24, the squeeze roller 25, the scraper 26, the liquid supply unit 27 for supplying the developing liquid, the liquid receiving unit 28, and the liquid discharge port 29 are arranged in the same manner as in the copying machine shown in FIG. Have been. However, the liquid supply unit 27 and the liquid receiving unit 28
And the liquid collecting member 30 below the second developing roller 23, for example.
And collects the developer falling from above. The liquid collecting member 30 can be formed as the same inclined surface as the liquid collecting member 9 shown in FIG. 1 and FIG. The obtained effect is exactly the same as that of the liquid collecting member of FIG.

According to the results of the experiment using the liquid collecting member 9 shown in FIGS. 1 and 2, under the experimental condition 1 (the sludge-like liquid after copying 100% duty 200,000 sheets), the sludge-like toner is not generated in this apparatus. On the other hand, the conventional product produced a difference that the amount of sludge-like toner was 10 g or less. Experiment condition 2 (1 day
2,000 copies were made for 2.5 months, and after 100,000 total copies, the difference was that no sludge-like toner was generated with this machine, whereas the sludge-like toner of 20 g or more was generated with the conventional product. It turned out to be.

Similarly, the results of an experiment on the case of the developing device of FIG. 3 formed in accordance with the example of FIG. 2 show that no sludge-like toner was generated under both the experimental condition 1 and the experimental condition 2 according to the present device. It has been found that there is a difference in that the conventional product generates a sludge-like toner of 10 g or less under the experimental condition 1 and generates 10 to 20 g of the sludge-like toner under the experimental condition 2.

As a modified example of the cleaning device, the liquid diffusion plate 6 is swingably supported by a fulcrum 13 extending substantially parallel to the axis of the cleaning roller 2, and the liquid diffusion plate 6 is swung by a drive solenoid such as a solenoid (not shown). The liquid diffusing plate 6 is arranged in the vicinity of the tip end portion thereof so as to be able to come into contact with the cleaning roller 2, and in the copy state, as shown by the solid line, the tip end portion comes into contact with the cleaning roller 2 and moves to the photosensitive drum 1. The remaining toner adhered is captured by the cleaning roller 2, diluted with the cleaning liquid sent by the liquid diffusion plate 6, and dropped and collected. At least at the end of copying, the liquid diffusion plate 6 is separated from the cleaning roller 2 as shown by a broken line. To the position where the cleaning liquid is moved to the rear of the liquid diffusion plate 6, and the cleaning liquid is moved to the liquid diffusion plate 6
In a case where the liquid collecting member 9 'is configured to be dropped backward, the liquid collecting member 9' is disposed between the rear end of the liquid diffusion plate 6 and the liquid receiving portion 7 as shown in FIG. It can also be configured as an inclined surface similar to the case. As a result, the cleaning liquid from the liquid supply unit 5 is collected by the liquid collecting member 9 ′ at the stage of falling from the rear end of the liquid diffusion plate 6, guided to the upstream position of the liquid receiving unit 7, and concentrated in the dead space. The flow prevents sludge-like toner from accumulating.

Further, as shown in FIG. 6, as a modified example of the cleaning device of FIG. 4, a liquid collecting member 9 ″ can be formed integrally with the rear end of the liquid diffusion plate 6. In this case, the liquid collecting member 9 ″
Swings up and down together with the liquid diffusion plate 6. The liquid collecting member 9 ″ can be fixed to the liquid diffusing plate 6, or can be formed integrally from a single plate as shown in FIG.

In order to prevent the sludge-like toner accumulation in the dead space of the liquid receiving part, it is possible to arrange a liquid supply nozzle above the dead space to flow the liquid, but in this case it is necessary to supply the liquid excessively and Liquid or cleaning liquid tank capacity will be increased and a large tank will be required,
The liquid discharge path requires thick pipes to allow a sufficient amount of liquid to flow, which complicates the liquid supply system such as the supply pipe and increases the size of the apparatus, which is not preferable.

The above-described solenoid of the present invention does not require such a complicated device, and can achieve the same effect with a compact device.

Effect According to the present invention, the falling liquid can be collected and concentrated in the dead space portion by the simple structure of providing the liquid collecting member, and the accumulation of the sludge toner can be prevented. If the liquid collecting member has a structure having an inclined surface through which the liquid flows, the structure is simplified.

[Brief description of the drawings]

1 is a sectional view of a cleaning device for an electrophotographic copying machine according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional view of a developing device, and FIG. 4 is a cleaning device. FIG. 5 is a cross-sectional view taken along line VV of FIG. 4, FIG. 6 is a view corresponding to FIG. 1 of another modification of the cleaning device, and FIG. 7 is a liquid. Perspective view of a diffusion plate and a liquid collecting member,
FIG. 8 is a schematic sectional view of a conventional electrophotographic copying machine utilizing the present invention, FIG. 9 is a drawing corresponding to FIG. 2 of the cleaning apparatus of FIG. 8, and FIG. 10 is a cleaning apparatus of FIG. It is a figure corresponding to FIG. 1 ... photoreceptor, 5 ... liquid supply part 6 ... liquid diffusion plate, 7 ... liquid receiving part 8 ... liquid outlet, 9,9 ', 9 "... liquid collecting member 21,23 .. Developing roller 27 …… Liquid supply part, 28 …… Liquid receiving part 29 …… Liquid discharge port

Claims (4)

(57) [Claims] A developing roller for supplying a developing solution to the photoreceptor for developing an electrostatic latent image formed on the photoreceptor; a liquid supply unit for supplying the developing solution to the developing roller; And a cleaning device having a cleaning roller for removing the developing material from the photoconductor, a liquid supply unit for supplying a cleaning liquid to the cleaning roller, and a liquid receiving unit having a liquid discharge port. In an electrophotographic apparatus, a liquid collection member is provided between a liquid supply unit and a liquid reception unit of at least one of a developing device and a cleaning device, and the liquid collection unit has a liquid discharge unit. The wet electrophotographic apparatus is disposed in the vicinity of the position where the toner is likely to remain. 2. The cleaning device according to claim 1, wherein the liquid supply section of the cleaning device has a liquid diffusion plate for uniformly supplying the liquid over the entire length of the cleaning roller, and the liquid diffusion plate is vertically tiltable about an axis substantially parallel to the cleaning roller. The liquid collecting plate is arranged so that the vicinity of the front end of the liquid diffusing plate can be brought into contact with the cleaning roller, and the liquid collecting member is arranged below the rear end of the liquid diffusing plate. 2. The wet electrophotographic apparatus according to claim 1. 3. A liquid discharging end of the liquid collecting member, wherein the liquid receiving portion has an inclined surface that descends toward a liquid discharging port, and the liquid collecting member is formed as an inclined surface opposite to the liquid receiving portion. 3. The wet electrophotographic apparatus according to claim 1, wherein the liquid electrophotographic apparatus is located above the highest position of the liquid receiving section. 4. The wet electrophotographic apparatus according to claim 2, wherein the liquid receiving portion is integrally provided at the rear end of the liquid diffusion plate.