JPH04287081A - Image forming device - Google Patents

Abstract

PURPOSE:To effectively and surely remove a nitrogen oxide or the like stuck to the surface of a photosensitive body without being restricted by the classification of the photosensitive body neither shaving the surface of the photosensitive body and to effectively remove remaining toner without toner scattering by using water or aqueous solution to clean the surface of the photosensitive body. CONSTITUTION:A cleaning means 6 is provided with a liquid tank 63 where water or aqueous solution is so stored that its liquid surface can be brought into contact with a cleaning roll 61 and a removing roll 62. With respect to the cleaning roll 61, a liquid absorber 61b like sponge is stuck to the surface of a supporting body 61a like a hollow drum, and this roll 61 transfers remaining toner, paper powder, products due to discharging, etc., stuck to its own surface to the cleaning roll 61 while rubbing the surface of the photosensitive drum 1 with water or the like impregnated from the liquid tank 63. A diluted nitric acid or ammonium nitrate aqueous solution or the like having the same molecular structure as products due to discharging stuck to the surface of the photosensitive body 1 is preferable as the aqueous solution used in this case but it is not limited.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus equipped with a photoreceptor having a photoconductor layer, and more particularly to an image forming apparatus capable of preventing image deletion of an exposed image carried on the photoconductor layer. .

0002

2. Description of the Related Art Conventionally, an exposed image is formed on a drum-shaped or belt-shaped photoreceptor by using light output corresponding to an original image or image information, and the exposed image is processed using a developing device. 2. Description of the Related Art Electrophotographic apparatuses configured to be able to transfer a toner image onto plain paper or other recording material after forming a toner image are well known and are widely used in printers, copying machines, and other image forming apparatuses.

However, in the above device, after the toner image is transferred, residual toner adheres to the surface of the photoreceptor, so generally a knife-edge cleaning blade is brought into contact with the surface of the photoreceptor to remove the toner. There are, but
Since the blade is configured to remove toner while scraping the surface of the photoreceptor, toner is inevitably likely to scatter.

[0004] In addition, in the above-mentioned apparatus, a corona discharger is generally used in order to uniformly charge the surface of the photoreceptor and as a means for transferring the recording material, but ozone generated by corona discharge and its discharge products are Nitrogen oxides and ammonium salts are adsorbed onto the surface of the photoreceptor, which tends to cause image deletion.

In order to eliminate such drawbacks, a technique has been disclosed in which the surface of the photoreceptor is polished at appropriate times to remove the discharge products (Japanese Patent Application Laid-open No. 112153/1983, etc.). Polishing the body surface basically not only leads to deterioration of the lifespan, but also the polishing causes changes in the thickness of the photoconductor layer, etc., and the charging voltage etc. must be changed accordingly. The control mechanism becomes complicated.

A technique has also been proposed in which discharge products adhering to the surface of the photoreceptor are cleaned with polyhydric alcohol or its dielectric. (Unexamined Japanese Patent Publication No. 2-2
No. 93885)

[0007]

[Problems to be Solved by the Invention] In this technique, when an organic drum such as an OPC drum is used as the photoreceptor, cleaning with the alcohol melts the surface layer of the drum and generates electrical discharge. However, when using an a-Si or other inorganic photoreceptor drum, it is possible to wipe off the discharge products with the alcohol, but it is difficult to melt and remove them. Therefore, the effect as a cleaning means cannot be completely satisfied.

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art, it is an object of the present invention to provide an image forming apparatus that can effectively remove residual toner without causing the toner scattering. Another object of the present invention is to effectively and reliably remove nitrogen oxides, etc. attached to the surface of a photoreceptor, regardless of the type of photoreceptor and without scraping the surface of the photoreceptor. The purpose is to provide an image forming apparatus that can

[0009]

[Means for Solving the Problems] The present invention is configured to clean the surface of a photoreceptor using the water or aqueous solution, and more specifically, the absorber impregnated with water or an aqueous solution is used to clean the surface of a photoreceptor. The device is characterized in that it is configured to perform cleaning by contacting the surface. In this case, the aqueous solution is preferably a dilute nitric acid or ammonium nitrate aqueous solution having a molecular structure similar to that of the discharge products attached to the surface of the photoreceptor, but is not limited thereto.

Furthermore, it is necessary to remove the water or aqueous solution adhering to the surface of the photoreceptor before forming a toner image. It is characterized by the points placed at certain points. Such a removal means is not limited to heating/drying the photoreceptor surface, but may also include mechanical removal means such as a blade that comes into contact with the photoreceptor surface.

[0011]

[Operation] According to this technical means, since the nitrogen oxides and ammonium salts of the discharge products are both water-soluble,
Unlike the alcohols mentioned above, it can be easily removed.

In this case, by forming the cleaning with an absorber that comes into contact with the surface of the photoreceptor, it is possible to remove not only the discharge products but also residual toner and paper dust attached to the surface of the photoreceptor. Therefore, a cleaning blade for removing these particles can be omitted.

Furthermore, since the absorbent body is impregnated with water or the like, there is no toner scattering or toner slipping through when the toner is removed, which makes it possible to reliably prevent contamination inside the machine, and toner removal. can be reliably prevented. Further, according to the present invention, the surface layer of the photoreceptor is not scraped off by the abrasive, and unlike alcohol, the surface layer of the OPC layer is not melted, so that no deterioration in the life of the photoreceptor occurs.

In addition, in recent years, an exposure head for generating light output corresponding to image information has been installed on the inner circumferential side of a photosensitive drum, which is formed by laminating a transparent conductive layer and a photoconductor layer on a transparent support. An image forming apparatus (hereinafter referred to as a back exposure apparatus) has been proposed (Japanese Unexamined Patent Application Publication No. 58-153957 and others, hereinafter referred to as a back exposure apparatus), but in such an apparatus, since the photoconductor layer is a thin layer, a mechanical polishing method is adopted. The present invention is also suitable for such devices.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in this example are not intended to limit the scope of this invention, but are merely illustrative examples. Not too much. Figure 1
1 is an image forming apparatus using an electrophotographic method according to an embodiment of the present invention, in which a photoconductor drum 1 is formed with a photoconductor layer 1b made of a-Si on a cylindrical drum-shaped support 1a. The charger 2 consists of a charger 2 made of a corona discharger, an exposure means 3 made of an optical system, a developer 4 facing the drum 1 via a developing sleeve 4a, and a transfer device 5. Uniformly charged photoconductor layer 1
In a, an exposed image corresponding to the image information is formed using the exposure means 3, and the exposed image is converted into a toner image using the developing device 4, and then guided to a transfer position in synchronization with the toner image. The toner image is configured to be transferable onto a recording material.

A cleaning means 6 is installed along the rotational direction of the photoreceptor drum 1 facing the circumferential surface of the photoreceptor drum 1 from the transfer position to the charging position, and the cleaning means 6 removes a liquid film such as water that has adhered to the surface of the drum 1. Removal means 70 for removing
is installed.

The cleaning means 6 includes a cleaning roller 61 that rotates in contact with the photosensitive drum 1 in the direction of the arrow.
, a removal roller 62 for removing paper powder and residual toner adhering to the cleaning roller 61, and a liquid tank 63 in which water or an aqueous solution is stored so that the liquid surface can come into contact with both rollers.

The cleaning roller 61 has a sponge or other liquid absorbing material 61 on the surface of a hollow drum-shaped support 61a.
b is pasted, and the surface of the photosensitive drum 1 is rubbed using water impregnated from the liquid tank 63 to remove residual toner, paper powder, discharge products, etc. adhering to the surface of the photosensitive drum 1 using a cleaning roller. It becomes possible to transfer to the 61 side. In this embodiment, since the sponge layer 61b is supported by the rigid drum-shaped support 61a, the contact thickness with the photoreceptor drum 1 can be maintained constant, and the cleaning efficiency can be improved. It is possible to plan.

The removal roller 62 is made of a water-absorbing sponge roller, and is rotated in the direction of the arrow with a relative movement difference while in contact with the cleaning roller 61 to remove residual toner etc. attached to the cleaning roller 61. After being transferred to the side, the roller 62 comes into contact with the liquid surface side and is melted and removed into the liquid tank 63, and the above operation is repeated thereafter. Note that the liquid tank 63 has a partition wall 63c erected at the part that contacts the removal roller 62, and the rear side is connected to the waste liquid tank 6.
3a, by making the front side function as a fresh water tank 63b,
The residual toner transferred to the removal roller 62 is transferred to the waste liquid tank 6.
The toner remaining in the liquid in contact with the cleaning roller 61 can be melted/removed in the contact liquid of the cleaning roller 61, and the toner remaining in the liquid in contact with the cleaning roller 61 can be further immersed in clear water while being brushed off to the waste liquid tank 63 side at the abutting part of the partition wall 63c. This can further improve cleaning efficiency and reliably prevent secondary contamination. Further, the cleaning means 6
Since residual toner accumulates in the form of sludge in the waste liquid layer 63a, contamination due to toner scattering does not occur even when the cleaning means 6 is replaced.

The liquid film that has adhered to the surface of the photosensitive drum 1 due to the contact with the cleaning roller 61 is dried and removed by the contact with the drying roller 70. That is, the drying roller 70 has a sponge layer 70a supported by a rigid drum-shaped support 70b and has a heater 70c inserted therein to dry the sponge layer 70a which has absorbed moisture through contact with the drum 1.

Note that, instead of using heat as described above, the liquid film can also be removed using a blade 71 as shown in FIG. In this case, the blade pressure is used only to remove the liquid film, so unlike the known cleaning blade for removing residual toner, the blade pressure may be set low, which makes it possible to extend the life of the blade 71. Become. Further, in any of the embodiments described above, since the liquid film is removed by contacting with the photosensitive drum 1, the removing means 7 can function as the second cleaning means 6.

FIG. 3 shows another embodiment in which the present invention is applied to a back exposure device, in which a transparent conductive layer 10 is formed on a transparent support 10a.
A photosensitive drum 10 formed by laminating a photoconductor layer 10c and a photoconductor layer 10c.
An exposure head 11 that generates a light output corresponding to image information is disposed on the inner peripheral side of the photoconductor layer 10c, and the light output of the exposure head 11 is focused to form a latent image on the photoconductor layer 10c at the same time or at the same time. Immediately after, the latent image is made into a visible image (toner image) via a developing device 12 disposed facing the photosensitive drum 10, and then the toner image is transferred to plain paper via a transfer roller 13. are doing. Between the transfer position of the photosensitive drum 10 and the exposure position, the cleaning means 6 having the above-mentioned structure is provided, and a heater 72 is provided downstream thereof facing the surface of the drum 1. Even in such a configuration, the same effect as described above can be obtained.

[0023]

Effects of the Invention As described above, according to the present invention, water-soluble discharge products such as ammonia salts and nitrogen oxides can be effectively removed since the surface of a photoreceptor is cleaned using water or an aqueous solution. As a result, image blur caused by these factors can be prevented.

Furthermore, by bringing the liquid absorber into contact with the photoreceptor for cleaning, it is possible to remove residual toner, paper dust, etc. in addition to the products, and the liquid absorber is brought into contact with the photoreceptor through the liquid. Therefore, there is no occurrence of scratches on the photoreceptor, there is no reduction in film thickness, and the photoreceptor can be used semi-permanently. Cleaning with a liquid absorber also prevents residual toner from slipping through and toner scattering, leading to prevention of internal contamination. It has various effects such as

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of main parts of an image forming apparatus using an electrophotographic method according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of main parts of an image forming apparatus according to a modification of FIG. 1;

FIG. 3 is a schematic diagram of main parts of a back exposure device according to another embodiment of the present invention.

[Explanation of symbols]

1, 10 Photoreceptor 6 Cleaning means 70, 71, 72 Liquid film removing means 61 Absorber

Claims (3)

[Claims] 1. An image forming apparatus equipped with a photoreceptor having a photoconductor layer, characterized in that the image forming apparatus is configured to clean the surface of the photoreceptor using water or an aqueous solution. 2. The apparatus according to claim 1, wherein means for removing water or aqueous solution adhering to the surface of the photoreceptor is disposed downstream of the cleaning position in the direction of movement of the photoreceptor. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured to perform cleaning by bringing an absorber impregnated with water or an aqueous solution into contact with the surface of the photoreceptor. The apparatus according to claim 3), characterized in that the apparatus is configured such that water or aqueous solution adhering to the surface of the photoreceptor can be removed from the body contact position to the toner image generation position.