JP2005091393A - Cleaning device and image forming apparatus equipped with same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device which has a contacting/leaving means of contacting and leaving an image carrier and realizes a paper powder removing device or member of simple constitution without dripping of a collected body and restrictions on its layout, and also to provide an image forming apparatus equipped with the same. <P>SOLUTION: The cleaning device which has the image carrier 6 and contact/leaving mechanisms 24 and 25 allowing a cleaning part to contact and leave the surface of the image carrier 6, and cleans the surface of the image carrier 6, is provided with: removing means 16 and 20 of removing residues on the image carrier 6; and friction members 21 and 23 which are provided upstream of the removing means 16 and 20, and contact and leave the surface of the image carrier 6, and the friction members 21 and 23 are arranged where the residues are not accumulated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cleaning device such as a sub-photo copying machine, a printer, and a facsimile, and an image forming apparatus including the same.

In an electrophotographic image forming apparatus, it is conventionally known to install a thin plate member for removing paper dust (blade for paper dust removal) separately from a roller and blade for cleaning toner (for example, Patent Documents). 1).
In an image forming apparatus having a cleaning device for cleaning toner remaining after image transfer to an image carrier such as a photosensitive member or an intermediate transfer belt, it is a paper dust or paper component when transferring an image to transfer paper. Calcium carbonate or the like often adheres to the image carrier.
When the adhered matter (hereinafter referred to as foreign matter) enters each image forming unit, it causes various problems for image formation. Therefore, it is important to clean not only the residual toner but also the adhered matter.
However, the adhering matter is very small, hard, or sharp with respect to the toner, so that it is easy to be embedded in the image carrier and difficult to clean them. For these reasons, it is difficult to achieve compatibility with toner cleaning performance.

FIG. 7 is a schematic configuration diagram showing a general full-color electrophotographic apparatus. In this electrophotographic apparatus having a well-known configuration, the photosensitive belt 1 rotates in the clockwise direction indicated by the arrow A, and the photosensitive body 1 is uniformly charged by the charging charger 2, and the photosensitive body is exposed by exposure from the optical writing device 3. An electrostatic latent image is formed on 1.
This latent image is visualized by each color toner 9 (not shown) when passing through each color developing device 4. The visualized images of the respective colors are transferred onto the intermediate transfer belt 6 that is sequentially moving in the direction of arrow B. In the case of a full-color image, the image formation is repeated for each color, and the image is superimposed on the intermediate transfer belt 6 to form a full-color image.
On the other hand, the image is transferred by the paper transfer unit 7 onto the transfer paper 14 fed from the main body paper feed cassette 12 in the direction of arrow C, and becomes a permanent image. The toner that has not been transferred from the photoreceptor 1 to the intermediate transfer belt 6 by the primary transfer unit 13 is scraped off by the cleaning blade 5 to prepare for the next image formation.
When the image is transferred from the intermediate transfer belt 6 to the transfer paper at the paper transfer unit 7, the toner remaining without being transferred is cleaned by the intermediate transfer belt cleaning device 11.
The belt cleaning device 11 includes a bias roller (mostly a brush roller), a cleaning blade, and a contact / separation mechanism (contact / separation cam 24, rotating shaft 25, etc.). The cleaning device 11 needs to be separated from the surface of the intermediate transfer belt 6 by the contact / separation mechanism while the image is transferred to the intermediate transfer belt 6.
At a timing when the image is not transferred to the intermediate transfer belt 6, the intermediate transfer belt cleaning device 11 comes into contact with the intermediate transfer belt 6 to perform cleaning.

FIG. 8 is a schematic diagram for explaining a cleaning method of the intermediate transfer belt which is a blade method. FIG. 9 is a schematic diagram for explaining a cleaning method of the intermediate transfer belt which is a bias roller method.
As shown in FIGS. 8 and 9, the cleaning method for the intermediate transfer belt 6 can be roughly divided into a blade method (FIG. 8) and a bias roller method (FIG. 9). The blade system is a system in which a transfer body surface is applied to the tip of the blade 15 to generate a shearing force between the transfer body surface and the residual toner, and the surface is cleaned by scraping.
On the other hand, the bias roller method is a method in which a bias having a polarity opposite to the charge of the residual toner 17 is applied to the roller 16 to collect and clean the residual toner 17 by electrostatic force.
FIG. 10 is a schematic view showing a state where foreign matters such as paper dust adhere to or stick to the intermediate transfer member. In the color image forming apparatus configured as described above, when the image formed on the intermediate transfer body is transferred to the paper by the paper transfer unit, the paper additives such as paper powder and calcium carbonate, and the adhering matter are transferred by the friction to the intermediate transfer. Adhere to or stick to the body.
FIG. 11 is a schematic diagram for explaining the movement of the foreign matter adhered or stuck in FIG. A part of the foreign matter stuck in FIG. 10 moves to the primary transfer portion without being collected by the bias roller 16.
FIG. 12 is a schematic view showing a gap between the photosensitive member and the intermediate transfer belt. FIG. 13 is a schematic view showing the gap in FIG. 12 in an enlarged manner. The paper dust and calcium carbonate that have reached the primary transfer portion cause minute scratches on the photoconductor due to the frictional force caused by a slight linear velocity difference between the photoconductor 1 and the intermediate transfer belt 6.
FIG. 14 is a schematic view showing the vicinity of the photoreceptor and the cleaning device. If minute scratches are repeatedly formed on the photoreceptor due to frictional force, minute irregularities are formed on the entire surface of the photoreceptor. As a result, the contact of the cleaning blade 15 installed on the photoconductor 1 with the surface of the photoconductor 1 is deteriorated, resulting in a problem of poor photoconductor cleaning.
Therefore, as in Patent Document 1, it is generally used to install a thin plate member (paper dust removing blade) for removing paper dust separately from a roller and blade for cleaning toner.
JP 2001-194920 A

However, for an image carrier that requires the cleaning device to be separated from the intermediate transfer surface when the image forming surface is transferred, such as the intermediate transfer belt 6 in FIG. The structure needs to be able to contact and separate.
Problems with blade-type toner cleaning and paper dust cleaning devices include toner drop and paper dust drop due to blade contact and separation. In the blade system, the force for holding the cleaned toner and paper dust is due to the damming of the blade tip, so when the abutment is released, the damped toner hangs down.
FIG. 15 is a schematic diagram for explaining toner dropping. When the blade 15 is positioned above the intermediate transfer belt 6, the toner that has been kept away from the blade drips down on the surface of the intermediate transfer body and stains the image forming surface. As a result, the image transferred on the paper becomes an image soiled by the toner drop.
For this reason, the blade type toner cleaning and paper dust cleaning device needs to be arranged below or on the side of the intermediate transfer member as shown in FIG.
When the tip of the thin plate member (blade for paper dust removal) is applied as in Patent Document 1 and the belt deposit is scraped off at the edge, the deposit accumulated at the tip during contact and separation Such a device needs to be disposed below the intermediate transfer belt because it spills.
In addition, toner or paper dust that hangs down when touching or disposing is attached to another unit in the image forming apparatus such as a paper feed cassette unit. To prevent this, toner or paper It is necessary to provide a powder recovery unit.
FIG. 16 is a schematic view showing a configuration having both a toner cleaning blade and a paper dust removing blade. If there are two toner cleaning blades 15 and paper dust removing blades 19, it is necessary to provide a recovery unit for each of them, resulting in an increase in space and the number of parts.
Accordingly, an object of the present invention is to provide a contact / separation means for contacting / separating the image carrier so as to solve the above-described problems, so that the paper dust removing device or member does not sag the collected material. Another object of the present invention is to provide a cleaning device that has no layout restrictions and can be realized with a simple configuration, and an image forming apparatus including the same.

In order to solve the above-mentioned problem, in the invention according to claim 1, the image carrier and a cleaning mechanism for cleaning the surface of the image carrier having a contact / separation mechanism capable of contacting and separating the cleaning unit with respect to the surface of the image carrier. In the apparatus, a removing means for removing the residue on the image bearing member and a friction member provided upstream of the removing means and capable of contacting and separating from the surface of the image bearing member are provided. It is characterized by a cleaning device arranged at a position where no residue is collected.
According to a second aspect of the present invention, the cleaning device according to the first aspect is characterized in that the removing means is bias-controlled.
The invention according to claim 3 is characterized in that the removing means is a bias roller.
According to a fourth aspect of the invention, there is provided the cleaning device according to the first aspect, wherein the removing means is a brush member.
The invention according to claim 5 is characterized in that the friction member is an acrylic flocking.
The invention according to claim 6 is characterized by the cleaning device according to claim 1, wherein the friction member has an elastic body containing an abrasive.
According to a seventh aspect of the invention, there is provided an image forming apparatus including the cleaning device according to any one of the first to sixth aspects.

  By providing a friction member that comes in contact with and separates from the surface of the image carrier in an integral manner with the contact and separation of the cleaning device, and abuts against the image carrier by abdominal contact, and friction is caused by the friction member. Since the toner and paper dust are scraped from the belt and rub through the friction member, it is easy for the cleaning device to collect paper dust and the like without causing the toner to fall off from the friction member when the cleaning device comes in contact with or separates from the belt. Therefore, paper dust cleaning can be satisfactorily established with a simple mechanism.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a configuration in which a blade containing an abrasive in an elastic body is disposed integrally with a bias roller cleaning device. Reference is also made to FIG.
As shown in FIG. 1, a blade 20 containing an abrasive in an elastic body is disposed integrally with the bias roller cleaning device 11. The blade 20 is arranged in the stomach rest (trailing direction).
In contrast to the method (counter direction) in which the adhered material is scraped off by the blade edge portion (friction member) 21 against the tip of the edge and the adhered material is collected on the blade edge portion 21 (in the counter direction), in the present invention, the adhered material is deposited on the blade. Pass through without passing through.
FIG. 2 is a schematic view schematically showing a bias roller and a blade of the bias roller cleaning device. The blade 20 includes an edge portion (friction member). The material structure of the edge portion 21 is urethane rubber as a base material, and an abrasive 22 is applied to a contact surface with the intermediate transfer belt 6 (hereinafter referred to as a polishing blade). ).
The particle size of the abrasive 22 is smaller than that of the toner and is preferably about the same as that of foreign matters such as calcium carbonate. Residual toner 17 and paper additive 18 after paper transfer reaches the cleaning section.
Since the polishing blade 21 is applied to the intermediate transfer belt 6, the residual toner 17 rubs through without causing a shearing force between the intermediate transfer belt 6 and the toner or foreign matter unlike the counter blade. The residual toner 17 that has passed is collected by a bias roller (removing means) 16 on the downstream side.

FIG. 3 is a schematic view for explaining the scraping of the fiber, calcium carbonate, etc. of the paper stuck in the intermediate transfer belt. As shown in FIG. 3, foreign matter 18 such as paper fiber and calcium carbonate stuck in the intermediate transfer belt 6 is scraped by the abrasive 22 when passing through the polishing blade 21.
A part of the scraped foreign matter 18 is caught by the abrasive for a while, while the other passes through the polishing blade 21. Since the foreign matter that has passed through the polishing blade 21 has been scraped, the adhesion force to the intermediate transfer belt 6 is much smaller than before the passage. Such foreign matter can also be easily collected by the bias roller 16.
Even if the toner passes through the primary transfer portion 13 without being collected at that time, the adhesion force of the foreign matter is reduced and the intermediate transfer belt 6 is easily moved. Foreign matter rolls due to the friction of the belt 6, making it difficult to damage the photoreceptor 1.
The foreign matter that has passed through the primary transfer portion 13 goes around once and reaches the belt cleaning device again to be collected. Since the friction member has a configuration in which an abrasive is contained in an elastic body (blade), it is possible to achieve both the breaking of paper dust and the removal of toner.

FIG. 4 is a schematic view showing an example in which a flocking sheet is used instead of the polishing blade shown in FIG. As shown in FIG. 4, a means for contacting the flocked sheet 23 in place of the polishing blade is also effective. The flocking sheet has the same mechanism as the polishing blade and does not have the ability to scrape toner, but has the ability to scrape foreign matter from the intermediate transfer belt 6.
In particular, acrylic flocking sheets are susceptible to electrostatic adsorption due to frictional charging with paper dust, and paper dust can be collected electrically. For this reason, the paper dust adhering to the acrylic due to the shock when the belt cleaning device is separated is unlikely to sag and does not cause image smear due to a large amount of foreign matter falling.
Similar to the polishing blade, the flocked sheet can be provided even if installed upstream or downstream of the bias roller. Since the friction member is an acrylic flocking sheet, it is possible to satisfy both of the pulverization of the paper powder and the toner scraping.
When the image is transferred to the intermediate transfer belt 6, the belt cleaning device is separated from the intermediate transfer belt 6. At this time, the integral polishing blade 21 is also separated from the intermediate transfer belt 6. At this time, since foreign matters such as toner and paper dust are only slightly adhered to the abrasive particles on the polishing blade 21, even if they are separated by shock and fall on the intermediate transfer belt 6, Deterioration that causes image smearing is never confirmed.

FIG. 5 is a schematic view showing a polishing blade disposed downstream of the belt cleaning unit. The polishing blade 21 crushes paper dust and the like by this mechanism and weakens its adhesion, making it difficult to damage the photoconductor 1. Therefore, the polishing blade 21 is disposed downstream of the belt cleaning unit as shown in FIG. The effect can be obtained.
By providing the abutting polishing blade 21 in this way, toner drop due to a shock when the polishing blade 21 is brought into and out of contact is prevented, and there is no need to newly provide a collection unit, and paper dust or the like is scraped with an abrasive. As a result, it is possible to prevent the image forming unit from deteriorating, such as poor cleaning of the photosensitive member 1, because it can be easily collected by the belt clip.
FIG. 6 is a schematic view showing a blade type cleaning device provided with a flocking sheet. In the embodiment described above, the description has been given of adding the friction member of the present invention to the bias roller cleaning device.
However, in the blade-type cleaning device as shown in FIG. 6, it is possible to easily collect the paper dust and the like that have been crushed by the friction member to the belt cleaning device 11, and the simple mechanism makes good paper dust. Cleaning can be established.

Schematic which shows the structure which arrange | positions the braid | blade which made the elastic body contain the abrasive | polishing agent integrally with a bias roller cleaning apparatus. Schematic which shows typically the bias roller and blade of a bias roller cleaning apparatus. FIG. 3 is a schematic diagram for explaining the scraping of fiber, calcium carbonate, and the like of paper stuck in an intermediate transfer belt. Schematic which shows the example which used the flocking sheet instead of the grinding | polishing blade. Schematic which shows the grinding | polishing blade arrange | positioned downstream of a belt cleaning unit. Schematic which shows the cleaning apparatus of the blade system provided with the flocking sheet. 1 is a schematic configuration diagram showing a general full-color electrophotographic apparatus. FIG. 3 is a schematic diagram illustrating a cleaning method for an intermediate transfer belt that is a blade method. FIG. 3 is a schematic diagram illustrating a cleaning method for an intermediate transfer belt that is a bias roller method. Schematic which shows the state which a deposit | attachment adheres to or sticks to an intermediate transfer body. Schematic explaining the movement of the foreign material adhered or stuck in FIG. FIG. 3 is a schematic diagram illustrating a gap between a photoconductor and an intermediate transfer belt. Schematic which expands and shows the clearance gap of FIG. FIG. 2 is a schematic diagram showing the vicinity of a photoreceptor and a cleaning device. FIG. 6 is a schematic diagram illustrating toner dropping. Schematic which shows the structure which has both a toner cleaning blade and a blade for paper dust removal.

Explanation of symbols

1 Photoconductor 6 Image carrier (intermediate transfer belt)
11 Intermediate transfer belt cleaning device 13 Primary transfer unit 16 Removal means (bias roller)
20 Removal means (blade)
21 Friction member (elastic body, polishing blade)
22 Abrasive agent 23 Friction member (flocking brush)

Claims (7)

  In a cleaning apparatus that has an image carrier and a contact / separation mechanism that allows a cleaning unit to come in contact with and separate from the surface of the image carrier, and removes the residue on the image carrier in a cleaning device that cleans the image carrier And a friction member provided on the upstream side of the removing means and capable of coming into contact with and separating from the surface of the image carrier, and the friction member is disposed at a position that does not collect the residue. Cleaning device to do.   The cleaning apparatus according to claim 1, wherein the removing unit is bias-controlled.   The cleaning apparatus according to claim 1, wherein the removing unit is a bias roller.   The cleaning device according to claim 1, wherein the removing unit is a brush member.   The cleaning device according to claim 1, wherein the friction member is acrylic flocking.   The cleaning device according to claim 1, wherein the friction member is configured to contain an abrasive in an elastic body.   An image forming apparatus comprising the cleaning device according to claim 1.

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