JP2008102248A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus mounted with a cleaning device in which a sufficient napping effect is always obtained over a long time by preventing stress from being applied to the tip portions of the bristles of a cleaning brush roller, in an irregular state, even while the cleaning brush roller is stopped to stand by. <P>SOLUTION: In the image forming apparatus provided with cleaning devices for cleaning toner remaining on an image carrier, at least one of the cleaning devices has: the cleaning brush roller which is rotated in contact with the image carrier against the running direction of the image carrier, to remove the toner remaining on the image carrier; a raised brush roller which comes into contact with the cleaning brush roller in such a manner that the tip portions of the bristles are overlapped with each other, is rotated in the same tangential direction in the contact position and has a circumferential speed higher than that of the cleaning brush roller; and a housing provided with a recovery section in which the toner recovered by the cleaning brush roller collects, in the bottom portion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus equipped with a cleaning device for cleaning an image carrier.

In an electrophotographic image forming apparatus, a cleaning brush roller is used to clean residual toner on an image carrier such as a photosensitive member or an intermediate transfer member. The cleaning brush roller contacts the image carrier and continues cleaning. Then, the tip of the hair changes from the state of straight hair, and slanted hair with a bedding occurs and the outer diameter becomes small. As a result, the contact nip state at the time of initial setting cannot be obtained, and the cleaning performance is deteriorated. If this is left as it is, durability cannot be expected. As a method for solving this problem, as shown in Patent Document 1, a toner removal roller having a blade formed in a gear shape to recover the slanted state of the cleaning brush roller is brought into contact with the cleaning brush roller to raise the brush. Means to make it take are taken. In addition, as shown in Patent Document 2, a means has been adopted in which a scraper roller having blades planted in a cross shape is brought into contact with the cleaning brush roller while rotating at high speed to raise the cleaning brush roller.
Japanese Utility Model Publication No. 5-30862 JP 2000-39820 A

  However, in the above-described conventional technology, since the wide abutting surface of the blade of the toner removing roller or the blade of the scraper roller continues to come into contact with the cleaning brush roller in the standby state, stress on the hair tip of the cleaning brush roller is caused. In spite of irregular conditions, there is a case where the action is promoted on the contrary to the normal raising, and a sufficient raising effect may not be obtained.

  The present invention solves such problems of the prior art, eliminates the hindering of the brushing even when the cleaning brush roller is in the standby stop, and forms an image mounted with a cleaning device capable of obtaining a sufficient brushing effect. An object is to provide an apparatus.

This object is achieved by any of the following technical means 1-6.
1. In an image forming apparatus including a cleaning device that cleans residual toner on an image carrier, at least one of the cleaning devices includes:
A cleaning brush roller that contacts and rotates against the running direction of the image carrier to remove residual toner of the image carrier;
An image forming system comprising: a brushed brush roller having biting portions that bite into contact with the cleaning brush roller, rotating in the same tangential direction at the contact position, and having a peripheral speed larger than that of the cleaning brush roller apparatus.
Item 2.1. The image forming apparatus according to Item 2.1, wherein at least one of the cleaning devices has a housing provided at the bottom with a collection unit for collecting the toner removed by the cleaning brush roller.
3.2. The image forming apparatus according to item 3.2, wherein the collecting unit is provided with a conveying screw for sending the collected toner to a developing device or a waste toner box.
4). A flicker is provided at a position downstream of the contact portion between the image carrier and the cleaning brush roller in the circumferential running direction of the cleaning brush roller and between the brushed brush roller and the brush brush roller. 4. The image forming apparatus according to any one of items 1 to 3, wherein
5. The image forming apparatus according to any one of claims 1 to 4, wherein the hair of the raised brush roller has a higher rigidity than the cleaning brush roller.
6). When the hair of the cleaning brush roller and the hair of the brushed brush roller are of the same material, the thickness of the hair of the brushed brush roller is larger than the thickness of the hair of the cleaning brush roller. 5. The image forming apparatus according to any one of items 4 to 4.

  According to the present invention, the bending of the cleaning brush roller due to the bevel is restored to normal and the uprightness of the tip of the tip to the contact surface is maintained, and this state is continued for a long period of time. Moreover, since the hair tips overlap each other even during the stop, a stable raising effect can be maintained.

  Furthermore, the collected toner contained in the brush by the cleaning brush roller is shaken off by the brushed brush roller that also acts as flicker when the brush tips bounce off each other, improving collection efficiency and cleaning quality. To do.

  Although embodiments of the present invention will be described, the following description does not limit the technical scope of the claims and the meaning of terms. In addition, the following assertive description in the embodiment of the present invention shows the best mode, and does not limit the meaning or technical scope of the terms of the present invention.

  First, an outline of an image forming apparatus GS for color electrophotography as an image forming apparatus of the present invention equipped with cleaning apparatuses 190 and 190A will be described with reference to FIG.

  This image forming apparatus GS is called a tandem type color image forming apparatus, and arranges image forming units for forming respective color toner images of yellow, magenta, cyan and black along the moving direction of the intermediate transfer member. The color toner images formed on the image carrier of each image forming unit are transferred onto the intermediate transfer member and superimposed, and then transferred onto the recording medium at once.

  In the figure, a document image placed on an image reading device SC arranged at a position occupying the upper portion of the image forming device GS is scanned and exposed by an optical system, read by a line image sensor CCD, and read by the line image sensor CCD. The analog signal subjected to photoelectric conversion is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in an image processing unit, and then an image data signal is sent to the exposure optical system 3 serving as an image writing unit.

  The intermediate transfer member includes a drum type and an endless belt type, both of which have the same function. However, in the following description, an endless belt type intermediate transfer member 6 is used as the intermediate transfer member. I will point to it.

  In the drawing, four sets of process units 100 are formed on the peripheral edge of the endless belt-shaped intermediate transfer body 6 for image formation for each color of yellow (Y), magenta (M), cyan (C) and black (K). Are arranged in tandem in the vertical direction along the intermediate transfer belt 6 with respect to the rotational direction of the intermediate transfer belt 6 in the vertical direction indicated by the arrows in FIG. Arranged in order.

  Each of the four process units 100 has a common structure, and each includes a photosensitive drum 1 as an image carrier, a charger 2 as a charging unit, an exposure optical system 3 as an image writing unit, and development. The apparatus 4 and a photoreceptor cleaning device 190 as an image carrier cleaning means.

  The photosensitive drum 1 that is an image carrier is a layer thickness (film thickness) as a photosensitive layer thickness on the outer periphery of a cylindrical base formed of a metallic member such as aluminum having an outer diameter of about 40 to 100 mm. A photoconductive layer of an organic photoreceptor layer (OPC) having a thickness of about 20 to 40 μm is formed. The photosensitive drum 1 is rotated by power from a driving source (not shown) in a direction indicated by an arrow with the conductive layer grounded, for example, at a linear velocity of about 80 to 280 mm / s, preferably 220 mm / s. .

  Around the photosensitive drum 1, an image forming unit including a charger 2 as a charging unit, an exposure optical system 3 as an image writing unit, and a developing device 4 is set as a photosensitive drum indicated by an arrow in the figure. 1 with respect to the rotation direction.

  The charger 2 as a charging unit is attached in close proximity to the photosensitive drum 1 in a direction parallel to the rotation axis of the photosensitive drum 1. The charger 2 includes a discharge wire as a corona discharge electrode that applies a predetermined potential to the organic photoreceptor layer of the photoreceptor drum 1 and is charged by a corona discharge having the same polarity as the toner (in this embodiment, negatively charged). To apply a uniform potential to the photosensitive drum 1.

  An exposure optical system 3 serving as an image writing means rotationally scans laser light emitted from a semiconductor laser (LD) light source (not shown) in a main scanning direction by a rotating polygon mirror (no symbol), and an fθ lens (no symbol). ), Exposure on the photosensitive drum 1 through an electric signal corresponding to the image signal (image writing) through a reflecting mirror (not shown), etc., and corresponding to the original image on the photosensitive layer on the surface of the photosensitive drum 1. An electrostatic latent image is formed.

  The developing device 4 as a developing unit is configured to supply a two-component developer of each color of yellow (Y), magenta (M), cyan (C), or black (K) charged to the same polarity as the charging polarity of the photosensitive drum 1. Each is provided with a developing roller 4a which is a developer carrying member formed of, for example, a cylindrical nonmagnetic stainless steel or aluminum material having a thickness of 0.5 to 1 mm and an outer diameter of 15 to 25 mm. The developing roller 4a is kept in contact with the photosensitive drum 1 with a predetermined gap (for example, 100 to 1000 μm) by an abutting roller (not shown), and rotates in the same direction as the rotational direction of the photosensitive drum 1. At the time of development, a photoconductor drum is applied by applying to the developing roller 4a a DC voltage having the same polarity as the toner (negative polarity in the present embodiment) or a developing bias voltage that superimposes an AC voltage on the DC voltage. The reversal development is performed on the upper exposed portion. As the developer (toner) used for the reversal development, styrene acrylic polymerized toner is used.

The endless belt-shaped intermediate transfer member 6 has a volume resistivity of about 1.0 × 10 ^{7 to} 1.0 × 10 ⁹ Ω · cm and a surface resistivity of 1.0 × 10 ^{10 to} 1.0 × 10 ¹² Ω. / □ About semi-conductive endless (seamless) resin belt members are used, for example, conductive materials for engineering plastics such as modified polyimide, thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, nylon alloy, etc. Is a semiconductive resin film substrate having a thickness of 0.05 to 0.5 mm. As the base of the endless belt-shaped intermediate transfer member 6, a semiconductive rubber belt having a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber or urethane rubber can also be used. The endless belt-shaped intermediate transfer body 6 is wound around a plurality of roller members including a guide roller 6A, a tension roller 6a, and a backup roller 6B facing the secondary transfer roller 7A, and is supported to be rotatable in the vertical direction. It is also possible to use a drum-shaped intermediate transfer member.

  The primary transfer roller 7 serving as a primary transfer unit for each color is made of a roller-like conductive member using foamed rubber such as silicon or urethane, for example, and the photosensitive drum 1 for each color with the endless belt-like intermediate transfer 6 interposed therebetween. The transfer area is formed between the endless belt-like intermediate transfer 6 and the photosensitive drum 1 by pressing the back surface of the endless belt-like intermediate transfer 6. A DC constant current having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied to the primary transfer roller 7 by constant current control, and a toner image on the photosensitive drum 1 is formed by a transfer electric field formed in the transfer area. The image is transferred onto the endless belt-shaped intermediate transfer body 6.

  The image forming process (image forming process) will be described below.

  When the image recording is started, the photosensitive drum drive motor (not shown) is rotated to rotate the Y photosensitive drum 1 in the direction indicated by the arrow in the figure, and a potential is applied to the Y photosensitive drum 1 by the Y charger 2. . After the Y photosensitive drum 1 is applied with a potential, the Y exposure optical system 3 performs exposure (image writing) with an electrical signal corresponding to the first color signal, that is, the Y image data. An electrostatic latent image corresponding to a yellow (Y) image is formed on the body drum 1. The latent image is reversely developed by the Y developing device 4 to form a toner image made of yellow (Y) toner on the Y photosensitive drum 1. The Y toner image formed on the Y photosensitive drum 1 is transferred onto the endless belt-shaped intermediate transfer body 6 by a primary transfer roller 7 as a primary transfer means.

  Next, a potential is applied to the M photosensitive drum 1 by the M charger 2. After the potential is applied to the M photoconductor drum 1, the M exposure optical system 3 performs exposure (image writing) with an electrical signal corresponding to the first color signal, that is, the M image data, and the M photosensitivity. An electrostatic latent image corresponding to a magenta (M) image is formed on the body drum 1. The latent image is reversely developed by the M developing device 4 to form a toner image made of magenta (M) toner on the M photoconductor drum 1. The M toner image formed on the M photoconductor drum 1 is transferred onto the endless belt-shaped upper intermediate transfer body 6 by being superimposed on the Y toner image by a primary transfer roller 7 as a primary transfer unit.

  By a similar process, a toner image made of cyan (C) toner formed on the C photoconductive drum 1 and a toner image made of black (K) toner formed on the K photoconductive drum 1 are obtained. Sequentially formed on the endless belt-shaped intermediate transfer body 6 in an overlapping manner, and a superimposed color toner image composed of Y, M, C, and K toners is formed on the peripheral surface of the endless belt-shaped intermediate transfer body 6. .

  The toner remaining on the peripheral surface of each photoconductor drum 1 after the transfer is cleaned by a photoconductor cleaning device 190.

  On the other hand, the recording medium P as recording paper accommodated in the paper feed cassettes 20A, 20B, and 20C is fed by the feed roller 21 and the paper feed roller 22A provided in the paper feed cassettes 20A, 20B, and 20C, respectively, and conveyed. A secondary transfer roller serving as a secondary transfer unit that is transported on the path 22 by transport rollers 22B, 22C, and 22D, to which a voltage having a polarity opposite to that of the toner (a positive polarity in this embodiment) is applied via the registration roller 23. The superimposed color toner images (color images) formed on the endless belt-shaped intermediate transfer body 6 are transferred onto the recording medium P in a lump in the transfer area of the secondary transfer roller 7A.

  The recording medium P onto which the color image has been transferred is heated and pressed at a fixing nip portion NA formed by the heating roller 17a and the pressure roller 17b of the fixing device 17 and is fixed by the paper discharge roller 24. It is placed on the outer paper discharge tray 25.

  The above describes the state in which image formation is performed on the first side, which is one side of the recording medium P. In the case of double-sided copying, the sheet discharge switching member 26 is switched, the sheet guiding portion 26A is opened, and recording is performed. The medium P is conveyed in the direction of the broken line arrow.

  Further, the recording medium P is conveyed to the lower conveying path 27B by the conveying mechanism 27A, switched back by the sheet reversing unit 27C, and the conveying path is switched by the branching unit 27D. And is conveyed into the duplex copying paper feed unit 130.

  The recording medium P moves in a paper feeding direction through a conveyance guide 131 provided in the duplex copying paper feeding unit 130, and the recording medium P is re-fed by the paper feeding roller 132 and guided to the conveyance path 22.

  Then, again, as described above, the recording medium P is conveyed in the direction of the secondary transfer roller 7A, the toner image is transferred to the second surface which is the back surface of the recording medium P, fixed by the fixing device 17, and then the paper discharge tray. 25 is discharged.

  The endless belt-shaped intermediate transfer body 6 that has separated the curvature of the recording medium P after the color image is transferred onto the recording medium P by the secondary transfer roller 7A as the secondary transfer means is a cleaning device 190A for the intermediate transfer body. Thus, residual toner is removed.

  As described above, there are a photosensitive member and an intermediate transfer member as the image carrier, and in this embodiment, the photosensitive drum 1 is used as the photosensitive member, and an endless belt-like intermediate transfer member 6 is used as the intermediate transfer member. In the following description regarding the cleaning device, the cleaning device 190A for the endless belt-shaped intermediate transfer member 6 will be mainly described. The configuration of the cleaning device 190 with respect to the photosensitive drum 1 can also be exactly the same as that of the cleaning device except that the image carrier is different.

  A cleaning brush roller 192 and a cleaning blade are used to clean the residual toner on the image carrier such as the photosensitive drum 1 and the endless belt-shaped intermediate transfer body 6 in the electrophotographic image forming apparatus GS. The cleaning device to be used is of a type using a cleaning brush roller 192.

  As shown in the cross-sectional configuration diagram of the main part in FIG. 1 and the partial front view in FIG. 2, the image forming apparatus GS removes the residual toner T on the endless belt-shaped intermediate transfer body 6 that is wound around the guide roller 6A and conveyed. A cleaning device 190A for cleaning is provided.

  Then, as shown in the front view of FIG. 2, the cleaning device 190A rotates in contact with the running direction of the endless belt-shaped intermediate transfer body 6 to remove the residual toner T on the endless belt-shaped intermediate transfer body 6. A cleaning brush roller 192 is provided.

  Further, the cleaning device 190A is in contact with the cleaning brush roller 192 with the hair ends overlapping each other and rotates in the same tangential direction at the contact position, and the peripheral speed and bristle rigidity (from the cleaning brush roller 192) A brushed brush roller 194 having a larger thickness (if the same material is used may be compared by the thickness of the hair) is provided. FIG. 2 and FIG. 3 which is a partial front view thereof show the operation in operation in which the raised brush roller 194 recovers the oblique hair caused by the contact of the cleaning brush roller 192 with the endless belt-shaped intermediate transfer body 6. Has been. Further, in the partial front view of FIG. 4 showing the situation when the operation is stopped, the hair tips of the brushed brush roller 194 and the cleaning brush roller 192 promote each other without raising the slanted hair or conversely raising the hair. It shows the situation where it goes straight into the hair ends. Therefore, when the operation is resumed, the raising is surely performed.

  As a result, the phenomenon that the brushing effect has been disturbed due to the stress in the irregular direction on the bristles of the brush because the cleaning brush roller keeps contacting with the cross-shaped scraper and the gear-shaped scraper during standby stop conventionally. It has been resolved.

  2, 3, and 4, the cleaning brush roller 192 and the brushed brush roller 194 are horizontally arranged with straight lines connecting the centers of the axes, but these straight lines are within a range of ± 45 ° with respect to the horizontal line. If it is good.

  The cleaning device 190A is housed in a housing 193 provided with a recovery portion 193A for collecting toner removed by the cleaning brush roller 192 at the bottom.

  It is possible to make a hole in the lower part of the collecting part and connect it to a pipe so that the collected toner is sequentially removed to an external container. However, as shown in FIG. 2, it is preferable to provide the collecting unit 193A with a conveying screw 196 and sequentially send it out to the developing device or the waste toner box.

  As described above, in this image forming apparatus GS, the linear velocity is set to 220, 330, and 440 mm / s, and accordingly, the rotation speed (rpm) of the brushed brush roller 194 is set to 525.4, 788.2, and 1051 rpm, respectively. The rotation speed (rpm) of the cleaning brush roller 192 is 262.2, 394.1, 525.5 rpm, respectively. That is, the rotation speed of the corresponding raised brush roller 194 is larger than the rotation speed of the cleaning brush roller 192.

  Further, the thickness of the hair of the raised brush roller 194 is larger than the thickness of the hair of the cleaning brush roller 192 made of the same material. Accordingly, the density is coarse in the former and dense in the latter.

  The former was tested for 10, 20, 30 denier and the latter was tested for 2, 6, 8, 10, 15 denier.

  The linear velocity mm / s of the image forming apparatus GS and the endless belt-shaped intermediate transfer body 6 shown in FIG. 1 used for the test, the corresponding rotation speed rpm of the brushed brush roller 194 and the cleaning brush roller 192, the hair material, thick Table 1 summarizes the length, density, outer diameter of each roller, and pile hair length.

(Experimental example 1)
The linear velocity of the image forming apparatus GS and the endless belt-shaped intermediate transfer body 6 is set to 220 mm / s, the amount of biting (overlapping amount) between the brushed brush roller 194 and the cleaning brush roller 192 is set to 1 mm, and each of the brush rollers described above. The number of rotations of 194 and 192 is 525.4 rpm and 262.7 rpm, the thickness is 30 denier and 6 denier, the density per square inch is 15,000 and 100,000, Under the conditions shown in Table 1, first, the case where only the cleaning brush roller 192 is attached and the case where the brushed brush roller 194 is also attached are incorporated into the image forming apparatus of FIG. The decrease in the outer diameter of each was measured. As a result, as shown in the graph of FIG. 5, both of them are accompanied by a decrease in the outer diameter, but the latter decreased by 0.6 mm up to 300,000 sheets, and there was no subsequent decrease even if continued up to 400,000 sheets. On the other hand, in the former, it decreased by 1.3 mm with 300,000 sheets, and after that, it continued to decrease further and even after reaching 400,000 sheets, there was a tendency to continue decreasing.

  Further, a test was performed in which the amount of biting (overlapping amount) between the cleaning brush roller 192 and the raised brush roller 194 was 0.5 and 2.0 mm in addition to the above 1 mm. Results were obtained.

  In this way, the tip ends of the brush tips of each brush roller engulf smoothly without interfering with each other regardless of whether they are rotating or stopped, and bend in contact with an image carrier such as a photoreceptor during cleaning. The bristles of the cleaning brush roller 192 that had been laid down were recovered by the bristles of the brushed brush roller 194, so that the normal state of straight hair was maintained for a long time. In the case of a method using a conventional scraper, since the tip surface and side surface of the scraper are large, the raising effect was somewhat unstable during operation, but the tip of the hair was crushed or bent in the opposite direction when stopped. However, the brushing effect was unstable due to the phenomenon of promoting the slanted hair state. However, this phenomenon has been solved by the present invention.

Further, the results of the tests with the linear velocities of the image forming apparatus GS and the endless belt-shaped intermediate transfer body 6 set at 330 mm / s and 440 mm / s were almost the same.
(Experimental example 2)
Further, under the same conditions as those in Table 1 performed in Experimental Example 1, first, the linear velocity of the image forming apparatus is set to 220 mm / s, and based on this, the rotational speeds of the brushed brush roller 194 and the cleaning brush roller 192 are respectively set. The cleaning performance was tested by setting 525.4 and 262.7 rpm, and the biting amount of the bristles of both rollers was 1 mm. A halftone dot image was formed by combining various denier values of the hairs of the cleaning brush roller 192 and the raised brush roller 194. As an evaluation method, in order to confirm the influence of passing through the cleaning brush roller after cleaning, samples were collected with cello tape (registered trademark) every 200,000 copies and 400,000 copies, and adhered to the cello tape (registered trademark). Tested using the method of judging by color. The results are shown in Table 2.

○: No color is maintained even after 400,000 copies (good)
Δ: No color at 200,000 copies, but a slight color at 400,000 copies (may be practical)
×: Clear color at 200,000 copies (failed)
It is.

  In the combination of the brushed brush roller 194 and the cleaning brush roller 192 as shown in Table 2, the brushed brush roller 194 having 10 denier hair and the cleaning brush roller 192 having 10 and 15 denier hair, The cleaning performance in which the 15 denier hair of the brushed brush roller 194 is combined with the 15 denier hair of the cleaning brush roller 192 is not good at all. However, with other combinations, it can be seen that good cleaning performance can be obtained, and that evaluation results can be obtained that are within the range that does not impede practical use even if defects occur.

  For the above results, the amount of biting (overlapping amount) between the brushed brush roller 194 and the cleaning brush roller 192 is set to 0.5 to 2.0 in addition to the above 1 mm, and the rotation speed (rpm ) Was set to 788.2, 394.1 rpm and 1051, 525.5 rpm in addition to 525.4 and 262.7 rpm, and a similar evaluation result was obtained.

  Here, in the case where the outer diameters of the brushed brush roller 194 and the cleaning brush roller 192 are the same, the comparison of the peripheral speeds of the rollers may be performed by comparing the rotation speeds. That is, in the present invention, the circumferential speed of the brushed brush roller 194 is larger than the circumferential speed of the cleaning brush roller 192, and the rigidity of the hair of the brushed brush roller 194 is larger than the rigidity of the hair of the cleaning brush roller 192. is necessary.

  In this embodiment, the rotational speed of the cleaning brush roller is 262.7 to 525.4 rpm, the rotational speed of the brushed brush roller is 525.4 to 1051 rpm, and the rotational speed ratio between the brushed brush roller and the cleaning brush roller is twice. However, the present invention is not limited to this.

  In addition, according to the present invention, the oblique hair generated in the cleaning brush roller is recovered by the raised brush roller, so that the life of the brush can be reliably extended and the image quality can be stably improved.

  Further, as described above, when the hair material of the brushed brush roller 194 and the cleaning brush roller 192 is the same, the comparison of the hair rigidity of each brush roller may be performed by comparing the thickness of the hair.

  In the embodiment of the present invention, since the brushed brush roller 194 and the cleaning brush roller 192 are made of the same material, the thickness of the hair is compared in terms of denier as the stiffness of the hair. When hairs made of different materials are used, rigidity may increase even if the hair is thin. As described above, in the present invention, the rigidity of the hair of the brushed brush roller 194 is preferably larger than the rigidity of the hair of the cleaning brush roller 192, even when the materials of the hairs of the two rollers are different. Making the raised brush roller 194 more rigid than the cleaning brush roller 192 also contributes to extending the life of the raised brush roller 194.

  Further, an intermediate position between the contact portion of the cleaning brush roller 192 and the endless belt-shaped intermediate transfer body 6 and the contact portion of the cleaning brush roller 192 and the raised brush roller 194 on the downstream side of the cleaning brush roller 192. A flicker 195 can be arranged on the screen. In this case, the collection efficiency of the toner in the collecting unit is increased, but the tendency of the bevel hair of the cleaning brush roller 192 is increased.

1 is a cross-sectional configuration diagram of a main part of an image forming apparatus including an image carrier cleaning device according to the present invention. FIG. 4 is a front view of an endless belt-shaped intermediate transfer member cleaning device in the image forming apparatus of the present invention. It is a partial front view which shows the state in operation of the cleaning brush roller of the cleaning apparatus used for this invention, a raising brush roller, and flicker. It is a partial front view which shows the state in the stop of the cleaning brush roller of the cleaning apparatus used for this invention, a raising brush roller, and flicker. It is a graph which shows the change of the outer diameter of the cleaning brush roller by paper passing with and without using a raising brush roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device 3 Exposure optical system 4 Developing device 6 Endless belt-shaped intermediate transfer body 190, 190A Cleaning device 192 Cleaning brush roller 193 Housing 193A Collection unit 194 Brushed brush roller 195 Flicker 196 Conveying screw GS Image forming device P Recording medium T Residual toner (collected toner)

Claims (6)

In an image forming apparatus including a cleaning device that cleans residual toner on an image carrier, at least one of the cleaning devices includes:
A cleaning brush roller that contacts and rotates against the running direction of the image carrier to remove residual toner of the image carrier;
An image forming device comprising: a brushed brush roller having biting portions that bite into contact with the cleaning brush roller, rotating in the same tangential direction at the contact position, and having a peripheral speed larger than that of the cleaning brush roller apparatus. The image forming apparatus according to claim 1, wherein at least one of the cleaning devices includes a housing provided at a bottom portion of the collecting portion where the toner removed by the cleaning brush roller is collected. The image forming apparatus according to claim 2, wherein the collecting unit is provided with a conveying screw that sends the collected toner to a developing device or a waste toner box. A flicker is provided at a position downstream of the contact portion between the image carrier and the cleaning brush roller in the circumferential running direction of the cleaning brush roller and between the brushed brush roller and the brush brush roller. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 5. The image forming apparatus according to claim 1, wherein the hair of the raised brush roller has a higher rigidity than the hair of the cleaning brush roller. When the hair of the cleaning brush roller and the hair of the brushed brush roller are made of the same material, the thickness of the hair of the brushed brush roller is made larger than the thickness of the hair of the cleaning brush roller. Item 5. The image forming apparatus according to any one of Items 1 to 4.

Images