JP2005202003A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a means for utilizing, as an abrasive, a part of waste toner scraped by a blade and re-supplying it to the blade is employed without changing the physical properties of toner especially, and consequently filming on an intermediate transfer body is prevented without damaging the edge of the blade thereby white streak on transfer paper is eliminated. <P>SOLUTION: An image forming apparatus develops toners of four different colors, Y, M, C, and K, onto an image carrier, successively transfers (primarily transfers) toner images of the respective colors from the image carrier onto one intermediate transfer body that is common to the four colors, then retransfers (secondarily transfers) them from the intermediate transfer body to a recording medium in the subsequent step, and clears away transfer residual toner on the intermediate transfer body with the blade. In the image forming apparatus, a waste-toner scatter prevention sheet is provided which has a free end on the face unabutting on the intermediate transfer body of the leading end of the blade. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus which prevents filming due to toner generated on an intermediate transfer member and does not cause image defects such as white stripes.

  The primary transfer from the drum-shaped photosensitive member to the intermediate transfer member and the secondary transfer from the intermediate transfer member to the transfer material as the recording medium are performed, and the secondary transfer residual toner remaining on the intermediate transfer member has heretofore been removed by a cleaning blade. A cleaning technique is common. The toner is made of a mixture of a base material and an external additive. The base material is made of a pigment, WAX, resin, etc., and the external additive is an abrasive particle for applying a charge such as silica or titania, calcium stearate, It consists of a lubricant such as zinc stearate. When cleaning the residual toner on the intermediate transfer member with the blade, the residual toner is scraped off at the blade edge, and a part of the toner adheres to the edge. The abrasive contained in the toner also serves as a lubricant, and a small amount enters the gap between the cleaning blade edge and the intermediate transfer member, thereby reducing the coefficient of friction μ between the cleaning blade and the intermediate transfer member, resulting in blade turning over. It can be said that it is an ideal state to keep cleaning constantly without waking up.

  However, in reality, the Wax and the lubricant contained in the toner partially adhered to the intermediate transfer member, and the film was stretched without being sufficiently polished and removed by the blade to form a thin film, causing filming in the traveling direction. Further, the friction coefficient μ at the place corresponding to the filming increased, the edge of the cleaning blade contacting the part was damaged, and the Wax and the sliding material further slipped from the place to accelerate the filming.

  In addition, it is necessary that the toner always stays at the edge of the cleaning blade, but if it is deficient, the coefficient of friction μ between the blade and the intermediate transfer member will increase, so the edge of the cleaning blade corresponding to the deficient part will be damaged. Then, Wax and the sliding material slipped from the place and filming occurred.

  When filming occurs on the intermediate transfer body, the resistance of the portion increases, and as a result, the charge preferentially flows where no filming occurs in primary transfer or secondary transfer. It became worse and white streaks on the transfer paper.

In order to avoid such a phenomenon, in Patent Documents 1, 2 and 3, a toner having a small variation in particle size is generated and dealt with without causing Wax and external additives to be released. Improvement in development quality was not always sufficient.
JP 09-244292 A JP-A-10-123754 JP 2000-47432 A

  The present invention adopts a means for utilizing a part of waste toner from the blade as an abrasive and supplying it to the cleaning blade again without changing the toner preparation conditions and physical properties, and without damaging the edge of the cleaning blade. An object of the present invention is to eliminate the occurrence of filming on the transfer body and to eliminate white streaks on the transfer material.

  This object is achieved by any one of the following technical means (1) to (5).

(1) Four color toners of YMCK are developed on an image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors. In an image forming apparatus that retransfers (secondary transfer) from an intermediate transfer member to a recording medium and cleans transfer residual toner on the intermediate transfer member with a cleaning blade.
An image forming apparatus comprising: a waste toner scattering prevention sheet having a free end on a surface not contacting the intermediate transfer member at the tip of the cleaning blade.

  (2) The image forming apparatus according to item (1), wherein the distance between the tip of the anti-scattering sheet and the belt is 0 to 2 mm.

(3) Four color toners of YMCK are developed on the image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors. In an image forming apparatus that retransfers (secondary transfer) from an intermediate transfer member to a recording medium and cleans transfer residual toner on the intermediate transfer member with a cleaning blade.
An image forming apparatus, wherein a conductive brush roller is installed upstream of the cleaning blade, and a part of the transfer residual toner scraped off by the cleaning blade is again attached to the intermediate transfer member.

(4) Four color toners of YMCK are developed on the image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors. In an image forming apparatus that retransfers (secondary transfer) from an intermediate transfer member to a recording medium and cleans transfer residual toner on the intermediate transfer member with a cleaning blade.
An image forming apparatus, wherein a conductive brush roller and a brush receiving sheet are installed upstream of the cleaning blade, and a distance between the brush receiving sheet and the intermediate transfer member is set to 0.5 to 2 mm.

(5) Four color toners of YMCK are developed on the image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors, and then in the next step In an image forming apparatus that retransfers (secondary transfer) from an intermediate transfer member to a recording medium and cleans transfer residual toner on the intermediate transfer member with a cleaning blade.
A conductive brush roller and a brush receiving sheet are installed upstream of the cleaning blade, an adjustment hole for the amount of waste toner on the brush receiving sheet is provided in an intermediate portion of the brush receiving sheet, and the tip of the brush receiving sheet is intermediately transferred. An image forming apparatus which is brought into contact with a body.

  Transfer residual toner (waste toner) scraped from the intermediate transfer member at the edge of the cleaning blade is collected in the cleaning unit case and sent to the waste toner box by a screw. In the present invention, a waste toner scattering prevention sheet is provided. As a result, waste toner accumulates in the space between the intermediate transfer member, the cleaning blade, and the scattering prevention sheet, and is efficiently supplied again to the edge of the cleaning blade. As a result, the toner on the edge portion of the cleaning blade is not deficient, and the polishing effect of the surface of the intermediate transfer member by the abrasive particles is enhanced and filming does not occur.

  A conductive brush roller and further a brush receiving sheet are provided on the upstream side of the cleaning blade, and the residual toner from the conductive brush roller is efficiently returned to the intermediate transfer member, thereby depleting the toner at the edge of the cleaning blade. Without any effect, the polishing effect of the surface of the intermediate transfer member by the abrasive particles is increased, and filming does not occur.

  Embodiments of the present invention will be described below. The description in this column does not limit the technical scope of the claims or 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.

  FIG. 1 is a cross-sectional configuration diagram showing a color image forming apparatus as an embodiment of the image forming apparatus of the present invention.

  This color image forming apparatus is called a tandem type color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, and an endless belt-shaped intermediate transfer body unit 7 as a unit of an intermediate transfer body. , And a belt type fixing device 24 as a fixing means. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  An image forming unit 10Y that forms a yellow image as one of toner images of different colors formed on each photoconductor that is an image carrier is a drum-like photoconductor 1Y as an image carrier, the photoconductor A charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, a primary transfer roller 5Y as a primary transfer unit, and a cleaning unit 6Y are disposed around 1Y. An image forming unit 10M that forms a magenta image as another different color toner image includes a drum-shaped photoconductor 1M as an image carrier, and a charge disposed around the photoconductor 1M. Means 2M, exposure means 3M, developing means 4M, primary transfer roller 5M as primary transfer means, and cleaning means 6M. In addition, an image forming unit 10C that forms a cyan image as another different color toner image is disposed around a drum-shaped photoconductor 1C as an image carrier and the photoconductor 1C. It has a charging means 2C, an exposure means 3C, a developing means 4C, a primary transfer roller 5C as a primary transfer means, and a cleaning means 6C. Further, an image forming unit 10K that forms a black image as one of other different color toner images includes a drum-shaped photoconductor 1K as an image carrier, and a charging unit disposed around the photoconductor 1K. 2K, an exposure unit 3K, a developing unit 4K, a primary transfer roller 5K as a primary transfer unit, and a cleaning unit 6K.

  The endless belt-shaped intermediate transfer body unit 7 includes a semiconductive endless belt-shaped intermediate transfer body 70 that is wound around a plurality of rollers and is rotatably supported as an intermediate transfer body.

  The images of the respective colors formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially transferred and synthesized on the rotating endless belt-shaped intermediate transfer body 70 by the primary transfer rollers 5Y, 5M, 5C, and 5K. A color image is formed. A transfer material P such as a sheet as a recording medium accommodated in the sheet feeding cassette 20 is fed by a sheet feeding means 21, passes through a plurality of intermediate rollers 22 A, 22 B, 22 C, 22 D, and a registration roller 23, and is subjected to secondary transfer. The color image is transferred onto the transfer material P by being conveyed to the means 5A. The transfer material P onto which the color image has been transferred is fixed by a belt-type fixing device 24, is sandwiched between paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus.

  On the other hand, after the color image is transferred to the transfer material P by the secondary transfer roller 5A as the secondary transfer means, the residual toner is removed by the cleaning means 6A from the endless belt-shaped intermediate transfer body 70 from which the transfer material P is separated by curvature. The

  During the image forming process, the primary transfer roller 5K is always in pressure contact with the photoreceptor 1K. The other primary transfer rollers 5Y, 5M, and 5C are in pressure contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roller 5A is in pressure contact with the endless belt-shaped intermediate transfer body 70 only when the transfer material P passes through the secondary transfer roller 5A.

  Further, the housing 8 can be pulled out from the apparatus main body A through the support rails 82L and 82R.

  The housing 8 accommodates image forming units 10Y, 10M, 10C, and 10K and an endless belt-shaped intermediate transfer body unit 7.

  The image forming units 10Y, 10M, 10C, and 10K are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is arranged on the left side of the photoreceptors 1Y, 1M, 1C, and 1K in the figure. The endless belt-shaped intermediate transfer body unit 7 includes an endless belt-shaped intermediate transfer body 70 that can be rotated by winding rollers 71, 72, 73, 74, 76, and 77, primary transfer rollers 5Y, 5M, 5C, and 5K, and cleaning. Means 6A.

  The image forming units 10Y, 10M, 10C, and 10K and the endless belt-shaped intermediate transfer body unit 7 are integrally pulled out from the main body A by the drawer operation of the housing 8.

  In this way, a toner image is formed on the photoreceptors 1Y, 1M, 1C, and 1K by charging, exposing, and developing, and the toner images of each color are superimposed on the endless belt-shaped intermediate transfer body 70, and are collectively applied to the transfer material P. The image is transferred and fixed by a belt-type fixing device 24 by pressing and heating. The endless belt-shaped intermediate transfer body 70 and the photoreceptors 1Y, 1M, 1C, and 1K after the toner image is transferred to the transfer material P are endless belt-shaped intermediates at the time of transfer by the cleaning means 6A, 6Y, 6M, 6C, and 6K, respectively. After the toner remaining on the transfer body 70 and the photoreceptors 1Y, 1M, 1C, and 1K is cleaned, the charging, exposure, and development cycle is entered, and the next image formation is performed.

The process speed of this image forming apparatus is 220 mm / s when A4 size is used, the primary transfer roller is a sponge roller having a resistance value of 1 × 10 ⁷ Ω and a diameter of 20 mm, and transfer control is constant voltage control. In the full color mode, as shown in the cross-sectional configuration diagram of FIG. 1 and the schematic diagram of FIG. 2, the photoreceptors 1Y, 1M, 1C, and 1K are respectively connected to the primary transfer rollers 5Y, 5M, and 5M via the endless belt-shaped intermediate transfer body 70. It is pressed by 5C and 5K. The transfer rollers 5Y, 5M, 5C, and 5K are rotatably attached to the bases 5T. The bases 5T are slid in the guides 5G by the pins D and moved in the direction of the arrow A, and the springs S also act. Thus, each primary transfer roller 5Y, 5M, 5C, 5K is pressed against each photoconductor via the endless belt-like intermediate transfer body 70. The pressing can be released by moving the pin D in the direction opposite to the arrow A.

  In the present invention, in order to prevent filming on the surface of the endless belt-shaped intermediate transfer member 70 and thereby eliminate the occurrence of white stripes on the transfer screen, as shown in the partial cross-sectional view of FIG. Means for fixing and providing a waste toner scattering prevention sheet 64 having a free end on a surface 63B that is not in contact with the endless belt-shaped intermediate transfer member 70 at the front end, and a cleaning blade as shown in the partial sectional view of FIG. A means in which a brush roller 66 is installed upstream of 63 and a part of the transfer residual toner scraped off by the cleaning blade 63 is again attached to the endless belt-like intermediate transfer member 70 and supplied to the tip of the cleaning blade 63; At the same time, a brush receiving sheet 67 that abuts against the brush roller 66 is provided to increase the supply amount of the transfer residual toner from the brush roller 66. The distance between the tip and the endless belt intermediate transfer member 70 attempts to means for setting a 0.5 to 2 mm. Further, as shown in FIG. 5 which is a XX view of FIG. 4, the brush receiving sheet 67 is provided with an amount adjusting hole 67A. In this case, the brush receiving sheet 67 and the endless belt-shaped intermediate transfer body 70 are provided. We also tried to reduce the distance to zero. Specific examples of these and test results will be described below.

Example 1)
Using the above-mentioned tandem full-color copier, the line speed is 220 mm / s, the outer diameter of the drum-shaped photoreceptors 1Y, 1M, 1C, and 1K is 60 mm, and the surface is an organic semiconductor layer in which a phthalocyanine pigment is dispersed in polycarbonate. The film thickness of the photoreceptor layer including the charge transport layer is 25 μm.

  The potentials of the non-image portions of the photoreceptors 1Y, 1M, 1C, and 1K are detected by a potential sensor, and feedback control is performed (the controllable range is −500 V to −900 V), and the total exposure potential is set to −50 to 0 V. .

  Exposure is a laser scanning method, using a semiconductor laser (LD), and its power is 300 μW.

Development is a two-component development system,
The endless belt-shaped intermediate transfer body 70 uses a seamless semiconductive resin belt, and has a surface resistivity of 1 × 10 ¹¹ Ω / □ and a volume resistivity of 1 × 10 ⁸ Ω · cm.

Primary transfer rollers 5Y, 5M, 5C, and 5K as primary transfer means are provided with a foam roller having an outer diameter of 20 mm and a resistance of 1 × 10 ⁷ Ω on the back of the intermediate transfer member, and a current in which a matrix is formed by temperature and humidity and a counter. A predetermined current value was selected from the value table and applied.

  The tension of the endless belt-shaped intermediate transfer member is 49N.

  As described above, the conductive member for primary transfer uses a conductive firing roller, and the roller pressure is 4.9N.

The secondary transfer means has a configuration in which an endless belt-shaped intermediate transfer body 70 is sandwiched between a backup roller 74 and a secondary transfer roller 5A, both have a resistance value of 1 × 10 ⁷ Ω, and a current value table in which a matrix is formed by temperature and humidity and a counter. A predetermined current value was selected and applied.

  The intermediate transfer member cleaning blade 63 was a urethane blade having a length of 9 mm, a thickness of 2 mm, and a contact angle of 17 degrees.

  The anti-scattering sheet 64 has a surface 63B opposite to the cleaning blade surface 63A that contacts the endless belt-shaped intermediate transfer body 70, and a PET having a length in the direction perpendicular to the edge of the blade 63 of 3 to 8 mm and a thickness of 50 μm. Affixed to form a free end.

  Here, the transfer residual toner (waste toner) scraped by the edge of the cleaning blade is accumulated in the cleaning unit case 61 and sent to the waste toner box by the screw 62. The waste toner scattering prevention sheet 64 is provided. As a result, waste toner accumulates in the space between the endless belt-shaped intermediate transfer body 70, the cleaning blade 63, and the scattering prevention sheet 64, and is efficiently supplied again to the edge of the cleaning blade. As a result, the toner on the edge of the cleaning blade is not deficient, and silica and titania as external additives act as abrasive particles, and it is assumed that the polishing effect on the surface of the endless belt-shaped intermediate transfer member is increased and filming does not occur. .

Using the transfer material of A4 size in the above configuration, a set of 5 sheets was repeated intermittently, and a test of 100,000 copies was performed. (The original used a character chart with a color printing rate of 5%.)
And every 10,000 copies, the front half of blue (M and C), green (C and Y), red (Y and M), and three-color process black (Y, M and C) on the entire A3 size transfer material Each tone image was output at a PWM 20% density, and no white streaks were examined. Further, no streaking due to filming was observed on the endless belt-shaped intermediate transfer member 70.

  Although the distance between the tip of the scattering prevention sheet 64 and the endless belt-shaped intermediate transfer body 70 was changed to 0 to 2 mm, white streaks on the image and streaks on the endless belt-shaped intermediate transfer body 70 were observed. There wasn't. However, when it exceeded 2 mm, it turned out that an effect tends to reduce.

Example 2)
The difference from the first embodiment is that a nylon conductive brush roller 66 (wire diameter: 320d / 10, density: 567 loops / 6.45 cm ² ) is installed upstream of the blade 63 instead of the scattering prevention sheet 64, and an endless belt-shaped intermediate Abutting on the transfer body 70, the amount of biting was set to 0.5 mm.

Using the transfer material of A4 size in the above configuration, a set of 5 sheets was repeated intermittently, and a test of 100,000 copies was performed. (The original used a character chart with a color printing rate of 5%.)
And every 10,000 copies, the front half of blue (M and C), green (C and Y), red (Y and M), and three-color process black (Y, M and C) on the entire A3 size transfer material Each tone image was output at a PWM 20% density, and one white streak was generated at 20,000 copies and two at 60,000 copies. Filming streaks occurred at the same position on the belt.

Example 3)
The difference from the first embodiment is that a nylon conductive brush roller 66 (wire diameter: 320d / 10, density: 567 loops / 6.45 cm ² ) is installed upstream of the blade 63 instead of the scattering prevention sheet 64, and an endless belt-shaped intermediate Abutting on the transfer body 70, the biting amount was set to 0.5 mm. A PET brush receiving sheet 67 having a thickness of about 50 μm was placed under the conductive brush roller 66, and the distance between the tip of the brush receiving sheet 67 and the endless belt-shaped intermediate transfer body 70 was set to 1 mm.

Using the transfer material of A4 size in the above configuration, a set of 5 sheets was repeated intermittently and a test of 100,000 copies was performed. (The original used a character chart with a color printing rate of 5%.)
The front half of blue (M and C), green (C and Y), red (Y and M), and three-color process black (Y, M, and C) is printed on the entire A3 size transfer material every 10,000 copies. Tone images were output at a PWM 20% density, and white streaks were examined, but there was no occurrence. No filming streaks were found on the endless belt-shaped intermediate transfer member 70. Although the distance between the tip of the brush receiving sheet 67 and the intermediate transfer member 70 was changed from 0.5 mm to 2 mm, white streaks and filming streaks did not occur as in the case of 1 mm. However, when the thickness was less than 0.5 mm, the waste toner was excessively accumulated on the conductive brush roller 66 and packing was caused. This is because the amount of waste toner falling on the screw 62 in FIG. 4 has decreased. Moreover, when it exceeded 2 mm, it turned out that an effect tends to reduce.

Example 4)
The difference from Example 3 is that the tip of a brush receiving sheet 67 made of PET having a thickness of 50 μm and the endless belt-shaped intermediate transfer body 70 are brought into contact with each other.

  During the test, the waste toner is periodically discharged through an adjustment hole 67A formed in the brush receiving sheet 67 from the opposite side of the brush away from the contact position between the endless belt-shaped intermediate transfer member 70 and the tip of the brush receiving sheet 67. I tried not to wake up.

Using a transfer material of A4 size in the above configuration, a set of 5 sheets was repeated intermittently, and 100,000 copies were tested. (The original used a character chart with a color printing rate of 5%.)
And every 10,000 copies, the front half of blue (M and C), green (C and Y), red (Y and M), and three-color process black (Y, M and C) on the entire A3 size transfer material Each tone image was output at a PWM 20% density, and the occurrence of white streaks was examined, but there was no occurrence. No filming streaks were found on the endless belt-shaped intermediate transfer member 70.

Comparative Example 1)
When a test similar to the above was performed without providing the conductive brush roller 66 and the brush receiving sheet 67, about 20 white streaks having a width of about 2 mm were generated. Filming also occurred on the endless belt-shaped intermediate transfer body 70 at the same position.

  Thus, the scattering prevention sheet 64 is used in the first embodiment, the conductive brush roller 66 is used in the second embodiment, and the brush receiving sheet 67 is added in addition to the conductive brush roller 66 in the third and fourth embodiments. The transfer residual toner is efficiently returned to the intermediate transfer member, so that the toner at the edge of the cleaning blade 63 is not deficient, and silica or titania as an external additive acts as abrasive particles and is an endless belt-like intermediate transfer member The surface polishing effect is enhanced, filming does not occur, and therefore no white streaking occurs on the screen.

  In Example 2, although the occurrence of white streaks and filming was observed slightly, it was drastically reduced as compared with the comparative example.

1 is a cross-sectional configuration diagram illustrating a color image forming apparatus as an embodiment of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating an arrangement of a photoconductor and a primary transfer unit when a full-color image is formed in a color image forming apparatus as an embodiment of the image forming apparatus of the present invention. FIG. 4 is a partial cross-sectional configuration diagram illustrating a state in which a scattering prevention sheet is attached to a cleaning blade of an endless belt-shaped intermediate transfer member cleaning unit. It is a partial cross-sectional block diagram which shows the state which mounted | wore with the conductive brush roller and the brush receiving sheet to the cleaning means of an endless belt-shaped intermediate transfer body. FIG. 5 is a XX view of FIG. 4.

Explanation of symbols

1Y, 1M, 1C, 1K Photosensitive members 4Y, 4M, 4C, 4K Developing means 5Y, 5M, 5C, 5K Primary transfer roller as primary transfer means 5A Secondary transfer roller as secondary transfer means 6Y, 6M, 6C, 6K cleaning means 7 endless belt-like intermediate transfer unit 24 belt type fixing device 61 cleaning unit case 62 screw 63 cleaning blade 64 scattering prevention sheet 66 conductive brush roller 67 brush receiving sheet 67A adjustment hole 70 endless belt-like intermediate transfer body

Claims (5)

Each of the four color toners of YMCK is developed on an image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors, and then the intermediate transfer member in the next step. In the image forming apparatus, the toner is transferred again to the recording medium (secondary transfer) and the transfer residual toner on the intermediate transfer member is cleaned with a cleaning blade.
An image forming apparatus comprising: a waste toner scattering prevention sheet having a free end on a surface not contacting the intermediate transfer member at the tip of the cleaning blade. The image forming apparatus according to claim 1, wherein a distance between the tip of the scattering prevention sheet and the belt is 0 to 2 mm. Each of the four color toners of YMCK is developed on an image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors, and then the intermediate transfer member in the next step. In the image forming apparatus, the toner is transferred again to the recording medium (secondary transfer) and the transfer residual toner on the intermediate transfer member is cleaned with a cleaning blade.
An image forming apparatus, wherein a conductive brush roller is installed upstream of the cleaning blade, and a part of the transfer residual toner scraped off by the cleaning blade is again attached to the intermediate transfer member. Each of the four color toners of YMCK is developed on an image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors, and then the intermediate transfer member in the next step. In the image forming apparatus, the toner is transferred again to the recording medium (secondary transfer) and the transfer residual toner on the intermediate transfer member is cleaned with a cleaning blade.
An image forming apparatus, wherein a conductive brush roller and a brush receiving sheet are installed upstream of the cleaning blade, and a distance between the brush receiving sheet and the intermediate transfer member is set to 0.5 to 2 mm. Each of the four color toners of YMCK is developed on an image carrier, and each toner image is sequentially transferred (primary transfer) from the image carrier onto one intermediate transfer member common to the four colors, and then the intermediate transfer member in the next step. In the image forming apparatus, the toner is transferred again to the recording medium (secondary transfer) and the transfer residual toner on the intermediate transfer member is cleaned with a cleaning blade.
A conductive brush roller and a brush receiving sheet are installed upstream of the cleaning blade, an adjustment hole for the amount of waste toner on the brush receiving sheet is provided in an intermediate portion of the brush receiving sheet, and the tip of the brush receiving sheet is transferred intermediately. An image forming apparatus which is brought into contact with a body.

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