JP2007304420A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of appropriately preventing the occurrence of image flow. <P>SOLUTION: The image forming apparatus includes: a photoreceptor made of amorphous silicon forming an electrostatic latent image; a polishing means (S13) which polishes part of the photoreceptor; potential difference measuring means (S14, S15) which give the prescribed potential to the photoreceptor and measure the potential difference between the potential of the polished portion polished by the polishing means and the potential in the unpolished portion not polished by the same; and a determining means (S16) which determines the need or not of the polishing of the unpolished portion of the photoreceptor by the polishing means corresponding to the potential difference measured by the potential difference measuring means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a photosensitive member made of amorphous silicon.

  The image forming apparatus irradiates a charged photosensitive member with light to form an electrostatic latent image, supplies developer to the electrostatic latent image for visualization, and then transfers the visible image to paper for printing. To do. Photoconductors for forming an electrostatic latent image include organic photoconductors, selenium photoconductors, amorphous silicon photoconductors, and the like, which are properly used depending on the application.

  Amorphous silicon photoconductors are excellent in terms of long life and low cost, but oxides and the like are likely to adhere to the surface. Then, depending on use conditions and environmental conditions, an image flow, that is, a phenomenon in which the formed image is blurred or blurred occurs, and a high-quality image cannot be formed. Such image flow is caused by the charge flowing from the surroundings to a part of the surface of the appropriately charged photoconductor. The image flow phenomenon occurs particularly in a high-temperature and high-humidity environment or when the number of durable sheets is large. Become prominent. In such a case, the surface of the photoreceptor is polished to expose a new part of the photosensitive layer, and the surface state can be recovered to prevent image flow.

Here, a technique for polishing the surface of a photoconductor made of amorphous silicon to prevent image flow is disclosed in Japanese Patent Application Laid-Open No. 2004-126295 (Patent Document 1). According to Patent Document 1, the surface of a photoreceptor to which oxide is attached is scraped with a polishing roller to expose a new photosensitive layer to prevent image flow and to form an appropriate electrostatic latent image.
JP 2004-126295 A (paragraph numbers 0045 to 0060, FIGS. 3 to 6)

  According to Patent Document 1, when the image forming apparatus is in a certain condition, for example, in a high temperature and high humidity environment, a pattern image for potential measurement is formed on the surface of the photoreceptor. The surface potential of the pattern image is measured with a potential sensor, and if the potential of the pattern image is less than the reference value, the image is formed as it is. On the other hand, if the potential is equal to or higher than the reference value, it is determined that an image flow occurs, and the surface of the photoreceptor is polished. In this way, a new photosensitive layer is exposed, the surface state is recovered, and an appropriate image is formed.

  However, even if the potential of the pattern image is equal to or higher than the reference value, image flow does not always occur. That is, the potential value of the pattern image does not necessarily match the surface state of the photoconductor on which image flow occurs. For example, even in a high temperature and high humidity environment, the number of image formations is extremely small, When the temperature is slightly higher and the humidity is higher than the normal temperature and the normal humidity, the image may not flow. In such a case, the photoconductor may be polished in spite of the state where no image flow occurs.

  An object of the present invention is to provide an image forming apparatus capable of appropriately preventing the occurrence of image flow.

  An image forming apparatus according to the present invention includes an amorphous silicon photoconductor for forming an electrostatic latent image, a polishing unit for polishing the photoconductor, and a polishing applied by applying a predetermined potential to the photoconductor and being polished by the polishing unit. Based on the potential difference measured by the potential difference measuring means and the potential difference measured by the potential difference measuring means, it is determined whether the polishing means needs to polish the unpolished portion of the photoreceptor. Determination means.

  Preferably, the determination unit controls the polishing unit to polish the entire circumference of the photoconductor according to the potential difference measured by the potential difference measurement unit.

  More preferably, the judging means adjusts the amount of polishing by the polishing means according to the potential difference measured by the potential difference measuring means.

  More preferably, a temperature and humidity sensor for detecting the temperature and humidity in the image forming apparatus is provided, and the judging means uses the polishing means if the temperature and humidity values detected by the temperature and humidity sensor are higher than the reference value. It is determined whether or not the unpolished portion of the photoconductor needs to be polished.

  More preferably, the determination unit determines whether or not it is necessary to polish the unpolished portion of the photoreceptor by the polishing unit when a predetermined time has elapsed.

  More preferably, the polishing means includes a polishing roller capable of contacting the photosensitive member, and the judging means stops the photosensitive member and makes the polishing roller contact with the photosensitive member while rotating the polishing roller. The polishing means is controlled to polish a part.

  More preferably, the determination unit controls the polishing unit so that the toner adheres to the photosensitive member and is polished.

  According to the present invention, the necessity of polishing of the photoconductor is determined based on the potential difference between the circumferential portion of the polished photoconductor and the unpolished portion that has not been polished. The photoconductor is polished only when it is determined that the image flow is generated based on the surface state of the surface. Accordingly, it is possible to appropriately prevent image flow.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a digital multifunction peripheral 10 when an image forming apparatus according to an embodiment of the present invention is applied to the digital multifunction peripheral 10. Referring to FIG. 1, the digital multifunction peripheral 10 displays a control unit 11 that controls the entire digital multifunction peripheral 10, a DRAM 12 for writing and reading image data and the like, and information that the digital multifunction peripheral 10 has. An operation unit 13 that includes a display unit and serves as an interface with the user in the digital multifunction peripheral 10, a document feeding device 14 that automatically transports a document to a predetermined document reading position, and a document that has been transported by the document feeding device 14 An image reading unit 15 that reads the image at a predetermined reading position and operates as a reading unit, an image forming unit 16 that forms and outputs the image from a document read by the image reading unit 15, and image data Etc. for a long period of time, a FAX communication unit 18 connected to the public line 20, and a network 21. And a network IF (interface) unit 19 of the fit. The image forming unit 16 includes a photoconductor 31 made of amorphous silicon.

  The control unit 11 compresses and writes the original data supplied from the image reading unit 15 in the DRAM 12, reads out the data written in the DRAM 12, decompresses and encodes it, and outputs it by the developing device 16.

  The digital multi-function peripheral 10 operates as a copier by forming an image in the image forming section 16 via the DRAM 12 using the document read by the image reading section 15. Further, the digital multifunction peripheral 10 forms an image in the image forming unit 16 via the DRAM 12 using the image data transmitted from the personal computer 22 connected to the network 21 through the network IF unit 19, thereby serving as a printer. Operate. Further, the digital multifunction peripheral 10 forms an image in the image forming unit 16 through the DRAM 12 using the image data transmitted from the public line 20 through the FAX communication unit 18, and also by the image reading unit 15. The image data of the read original is transmitted to the public line 20 through the FAX communication unit 18 to operate as a facsimile machine.

  In FIG. 1, thick arrows indicate the flow of image data, and thin arrows indicate the flow of control signals or control data.

  Next, a specific configuration of the image forming unit 16 provided in the digital multifunction peripheral 10 will be described. FIG. 2 is a schematic cross-sectional view showing the image forming unit 16. Referring to FIG. 2, the image forming unit 16 includes a charging roller 32 that applies a potential to the photoreceptor 31, an exposure unit 33 that exposes the surface of the photoreceptor 31, and a probe (not shown) at the tip. A potential sensor 34 for measuring the surface potential of the photoconductor 31, a developing roller 35 for supplying toner to the photoconductor 31, a transfer roller 36 for transferring the toner on the photoconductor 31 to a sheet, and a photoconductor 31. A polishing roller 37 that is capable of contacting and polishing the surface of the photoconductor 31; a cleaning blade 38 that presses against the photoconductor 31 and removes toner remaining on the surface of the photoconductor 31; and image formation. And a temperature / humidity sensor 39 having both a temperature sensor for detecting the temperature in the unit 16 and a humidity sensor for detecting the humidity. The polishing roller 37 is normally separated from the photoconductor 31, but abuts when the surface of the photoconductor 31 is polished as will be described later. The photoconductor 31 rotates in the direction of arrow A in FIG. 2, and the polishing roller 37 rotates in the direction of arrow B in FIG. The length of the photoconductor 31 and the polishing roller 37 in the rotation axis direction is the same or the length of the polishing roller 37 is longer, and the polishing roller 37 can polish the entire portion of the photoconductor 31 in the rotation axis direction.

  A predetermined voltage can be applied to the charging roller 32 and the developing roller 35. A predetermined voltage can also be applied to the transfer roller 36, and a predetermined voltage and a reverse voltage can be switched and applied by the switch 40.

  Here, an image forming process in the digital multi-function peripheral 10 will be briefly described. First, a high voltage potential is applied to the photoreceptor 31 by the charging roller 32. Next, the charged photosensitive member 31 is irradiated with light from the exposure unit 33 based on the image read by the image reading unit 15 described above. As a result, an electrostatic latent image is formed on the photoreceptor 31. Next, toner is supplied onto the photoreceptor 31 by the developing roller 35 to visualize the electrostatic latent image. Thereafter, the toner image visualized by the transfer roller 36 is transferred to a sheet and output. The toner that is not transferred and remains on the photoreceptor 31 is removed by the cleaning blade 38. In this way, an image is formed by the image forming unit 16. The potential sensor 34 measures the potential of the surface of the photoconductor 31 during image adjustment or the like.

  An oxide film adheres to the surface of the photoconductor 31 made of amorphous silicon due to usage conditions, specifically, mainly due to discharge of the charging roller 32 and the transfer roller 36. This oxide film is firmly attached on the surface of the photoreceptor 31. If an oxide film adheres to the surface of the photoconductor 31, moisture in the air is absorbed to reduce the surface resistance of the photoconductor 31 and so-called image flow occurs, so that an appropriate electrostatic latent image is formed. I can't. Therefore, in order to prevent such an image flow phenomenon and form an appropriate electrostatic latent image, the surface of the photoreceptor 31 is actively polished by the polishing roller 37 or the like to remove the oxide film, and a new one is obtained. It is necessary to recover the surface state of the photoreceptor 31 by exposing the photosensitive layer.

  Here, a method for preventing the image flow will be described in detail. FIG. 3 is a flowchart showing the operation of the control unit 11 in this case.

  1 to 3, first, the temperature and humidity in the image forming unit 16 are detected by the temperature / humidity sensor 39 (in FIG. 3, step S11, hereinafter, steps are omitted). Next, it is determined whether the temperature and humidity are equal to or higher than a reference value (S12). FIG. 4 is a diagram illustrating the relationship between temperature and humidity and a reference value. In FIG. 4, the vertical axis indicates humidity (%), the horizontal axis indicates temperature (° C.), the vertical axis indicates 10 (%), and the horizontal axis indicates 5 (° C.). Moreover, the area | region 42 in FIG. 4 shows the part whose temperature and humidity are more than a reference value. Referring to FIG. 4, if the temperature and humidity in image forming unit 16 are equal to or higher than the reference value, that is, in region 42 (YES in S 12), a part of circumferential direction of photoconductor 31 is polished by roller 37. Is polished so that the surface state is completely recovered (S13). Then, an appropriate electrostatic latent image can be formed on a part of the polished photoreceptor 31 in the circumferential direction.

  Here, a method of polishing a part of the surface of the photoreceptor 31 in the circumferential direction will be described. First, the toner supplied from the developing roller 35 is attached on the photoreceptor 31. The toner has a function of visualizing the electrostatic latent image, but also has a function as a polishing powder when the surface of the photoreceptor 31 is polished. This is because the component of the surface treatment agent such as titanium oxide contained in the toner has a function as an abrasive powder. Therefore, the surface of the photoconductor 31 can be easily polished by attaching such toner to the surface of the photoconductor 31 and polishing the surface of the photoconductor 31. In this case, a voltage opposite to the voltage used when transferring the toner onto the paper is applied to the transfer roller 36 by switching the switch 40. As a result, the toner adhering to the photoconductor 31 is not transferred to the transfer roller 36 side, and remains adhering to the photoconductor 31.

  After the toner is deposited on the photoconductor 31, the polishing roller 37 is brought into contact with the photoconductor 31, and the photoconductor 31 is rotated while stopped. In this manner, the surface of the nip portion 41 (see FIG. 2), which is a part of the circumferential direction of the photoconductor 31 nipped with the polishing roller 37, is polished. By so doing, a part of the circumferential direction of the photoreceptor 31 can be easily polished. The polishing amount depends on the toner adhesion amount, the rotation speed of the polishing roller 37, the hardness of the photoconductor 31, and the like. Here, the polishing amount depends on the polishing time.

  FIG. 5 is a diagram illustrating the relationship between the temperature and humidity in the image forming unit 16 and the polishing time required to completely recover the surface state of the nip portion 41 that is a part of the circumferential direction of the photoconductor 31. . In FIG. 5, the vertical axis and the horizontal axis are the same as those in FIG. Referring to FIG. 5, regions 43a, 43b, and 43c are required to completely recover the surface state of nip portion 41, which is a part in the circumferential direction of photoconductor 31, according to temperature and humidity conditions. Indicates the polishing time. The region 43a is in a state where the surface state can be completely recovered by polishing the polishing roller 37 for 15 seconds. The regions 43b and 43c are in a state where the surface state can be completely recovered by polishing by rotating the polishing roller 37 for 20 seconds and 25 seconds, respectively. Depending on the temperature and humidity in the image forming unit 16, a part of the circumferential direction of the photoreceptor 31 is polished under the above-described conditions, so that the surface state of a part of the photoreceptor 31 is completely recovered, and the image flow is improved. Set to a level that does not occur. In this case, since only a part in the circumferential direction of the photoconductor 31 is polished, the amount of polishing may be small, and accordingly, the surface state can be completely recovered in a relatively short time.

  Here, the surface state of the portion of the photoconductor 31 that has been polished by the polishing roller 37 has recovered, and image flow does not occur, but the remaining portion, that is, the unpolished portion, has a surface state. Remains contaminated and image flow may still occur.

  Next, after rotating the photoconductor 31 and charging the photoconductor 31 with the charging roller 32, the exposure unit 33 irradiates the entire circumference of the photoconductor 31 with light for forming a pattern image, and measures the surface potential. A pattern image is formed (S14). The pattern image is a half pattern, that is, an image that easily causes a difference in surface potential on the photoconductor 31 so as to become a gray image when output. Next, the surface potential of the entire circumference of the photoreceptor 31 on which the pattern image is formed is measured by the potential sensor 34 (S15).

  FIG. 6 is a diagram illustrating the relationship between the measured potential of the photoconductor 31 and the measurement time in a state after a part of the photoconductor 31 is polished. The vertical axis represents the surface potential of the photoreceptor 31, and the horizontal axis represents the measurement time. In FIG. 6, the width indicated by the arrow C indicates the time required to measure the circumference of the photoreceptor 31. Note that the potential first applied by the charging roller 32 is Vp.

  Referring to FIG. 6, in partial polishing portion 44 a that is a portion where the surface state has been completely recovered, the surface potential is reduced to an appropriate potential according to the pattern image. The potential at the partial polishing portion 44a is close to the potential Vmin1, which is an appropriate potential according to the pattern image. On the other hand, in the unpolished part 44b, since electric charges flow from the surroundings, the surface potential does not decrease to an appropriate potential, and the potential remains high. Here, in the unpolished portion 44b, the maximum potential is Vmax1, and the potential difference Vmax1-Vmin1 is measured. The control unit 11 and the potential sensor 34 operate as a potential difference measuring unit.

  Next, it is determined whether or not the potential difference measured by the potential difference measuring means is greater than or equal to a reference value (S16). Here, the control unit 11 operates as a determination unit. If it is determined that the potential difference is less than the reference value, it is determined that the image does not flow and an image is formed as it is (NO in S16). On the other hand, if the potential difference is greater than or equal to the reference value, the entire circumference of photoreceptor 31 including the unpolished portion is polished (YES in S16).

  By doing so, it is possible to determine whether or not the entire circumference of the photoconductor 31 needs to be polished according to the surface state of the photoconductor 31. Further, when the entire circumference of the photoconductor 31 is polished, the polishing roller 37 is rotated while the photoconductor 31 is rotated for polishing, and the polishing amount, specifically, the polishing time is adjusted according to the potential difference. (S17).

  Table 1 shows the polishing time for the entire circumference of the photoreceptor 31 according to the above-described potential difference Vmax1−Vmin1. Referring to Table 1, if the potential difference is large, it is determined that the image flow is severe, and the entire circumference of the photoconductor is polished by increasing the polishing time. If the potential difference is small, it is determined that the image flow is slight, and the entire circumference of the photoconductor is polished by reducing the polishing time.

  Specifically, when the potential difference is 50 V or more, assuming that the image flow level is severe, the polishing roller 37 is rotated for 300 seconds to polish the entire surface of the photoreceptor 31. Further, even when the potential difference is about 30 V, assuming that the image flow level is severe, the polishing roller 37 is rotated for 150 seconds to polish the entire surface of the photoreceptor 31. When the potential difference is about 15 V, it is assumed that the image flow level is slight, and the polishing roller 37 is rotated for 90 seconds to polish the entire surface of the photoreceptor 31. If the potential difference is about 10 V, the photoconductor 31 is not polished on the assumption that the image does not flow.

  As described above, when the entire circumference of the photoconductor 31 is polished by adjusting the polishing amount for polishing the entire circumference of the photoconductor 31 according to the potential difference, an appropriate amount is determined according to the surface state of the photoconductor 31. The entire circumference of the photoreceptor 31 can be polished with the polishing amount.

  Next, returning to S14, a pattern image is formed, and a potential difference is calculated. FIG. 7 is a diagram showing the relationship between the measured potential and the measurement time in a state after the entire circumference of the photoconductor 31 is polished. In FIG. 7, the vertical axis and the horizontal axis are the same as those in FIG. Referring to FIG. 7, since the entire circumference of photoconductor 31 is polished, it becomes close to an appropriate potential according to the formed pattern image. Therefore, the value of the maximum and minimum potential difference Vmax2−Vmin2 in polishing is about the same as the sensitivity difference of the photoconductor 31 on the entire circumference, and is very small. In this way, the entire circumference of the photoconductor is polished until the potential difference Vmax2−Vmin2 becomes less than the reference value. If the potential difference is less than the reference value, an image is formed.

  Next, a specific example will be described. Here, the linear velocity of the photosensitive member 31 is 100 mm / second, the linear velocity of the polishing roller 37 is 120 mm / second, the nip width between the photosensitive member 31 and the polishing roller 37 is 4 mm, and the surface potential Vp is 300V. . First, the temperature and humidity in the image forming unit 16 are detected by the temperature / humidity sensor 39. When the temperature is 28 ° C. and the humidity is 65%, it is assumed from FIG. 2 that the temperature and humidity are within the region 42 and are at a level at which image flow occurs. First, a part of the photoreceptor 31 is polished. Here, under the above-described conditions, the polishing time required for completely recovering a part of the photoconductor 31 is 20 seconds from FIG. 3, so the polishing roller 37 is rotated for 20 seconds to A part is polished to completely recover the surface state of the nip portion 41. Next, a 25% half pattern image for potential measurement is formed. Thereafter, the potential is measured by the potential sensor 34 on the entire circumference of the photoconductor 31.

  Here, since the potential Vmax1 of the unpolished portion 44b shown in FIG. 6 is 220V and the value of the potential Vmin1 of the partially polished portion 44a is 204V, the potential difference Vmax1 between the unpolished portion 44b and the partially polished portion 44a. -Vmin1 is 16V, and it is determined from Table 1 that this is a level at which a slight image flow occurs. Then, as shown in FIG. 5, in order to completely recover the surface state of the entire circumference of the photoconductor 31, it is determined that the polishing aura 37 should be used for 90 seconds, and the polishing roller 37 is rotated for 90 seconds, so that the photoconductor is rotated. The entire circumference of 31 is polished. Thereafter, a pattern image is formed again on the photoconductor 31, and the potential difference is measured. Here, since the potential difference is 10 V or less, it is determined that the surface state of the photoconductor 31 is completely recovered and no image flow occurs, and an image is formed.

  From the above, it is possible to determine whether or not the entire circumference is to be polished according to the surface state of the photoreceptor in a high temperature and high humidity environment in which image flow is likely to occur. Accordingly, it is possible to appropriately prevent image flow. In the case of polishing, the polishing can be performed with an appropriate polishing amount in accordance with the potential difference.

  In the above embodiment, when the temperature and humidity are equal to or higher than the reference value, it is determined whether or not to polish the unpolished part. Alternatively, it may be determined whether or not to polish when a predetermined time elapses, such as immediately after the image forming apparatus is turned on, or when an image formed by the image forming apparatus exceeds a specified amount. By doing so, it is possible to determine whether or not image flow occurs regardless of temperature and humidity. Further, the entire circumference of the photoconductor is polished as the unpolished portion. However, the present invention is not limited to this, and a portion having a high contamination level, for example, a portion of the photoconductor that becomes Vmax1 is intensively polished. You may decide.

  In the above-described embodiment, the toner is used when polishing the photoreceptor. However, the present invention is not limited to this, and the toner may not be used during polishing. Further, the recovered toner recovered by the cleaning blade or other abrasive powder may be used.

  In the above-described embodiment, the surface of the photoreceptor is polished by the polishing roller that is a roller-shaped member as the polishing unit. However, the present invention is not limited to this, and other polishing units such as a blade-shaped member are used. The photosensitive member may be polished by bringing the polishing member into contact with the photosensitive member. Further, the polishing roller used for the polishing means may be a polishing roller shorter than the axial length of the photosensitive member. By doing so, the polishing portion for measuring the potential difference can be made smaller, so that the time required for polishing can be shortened.

  In the above-described embodiment, the polishing time is changed to three stages. However, the present invention is not limited to this, and the polishing time may be changed in multiple stages.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1 is a block diagram showing an overall configuration of a digital multifunction peripheral according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an image forming unit included in the image forming apparatus. It is a flowchart which shows the process of recovering the surface state of a photoreceptor. It is a figure which shows the relationship between temperature and humidity, and a reference value. It is a figure showing the relationship between the temperature and humidity in an image formation part, and the grinding | polishing time required in order to fully recover the surface state of a part of photoreceptor. It is a figure showing the relationship between the measured electric potential and measurement time in the state after grinding a part. It is a figure showing the relationship between the measured electric potential and measurement time in the state after grind | polishing the perimeter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Digital multifunction device, 11 Control part, 12 DRAM, 13 Operation part, 14 Document feeder, 15 Image reading part, 16 Image formation part, 17 Hard disk, 18 FAX communication part, 19 Network IF part, 20 Public line, 21 Network , 22 PC, 31 Photoconductor, 32 Charging roller, 33 Exposure unit, 34 Potential sensor, 35 Developing roller, 36 Transfer roller, 37 Polishing roller, 38 Cleaning blade, 39 Temperature / humidity sensor, 40 Switch, 41 Nip part, 42, 43a, 43b, 43c region, 44a partially polished portion, 44b unpolished portion.

Claims (7)

An amorphous silicon photoconductor that forms an electrostatic latent image;
Polishing means for polishing the photoreceptor;
A potential difference measuring unit that applies a predetermined potential to the photoreceptor and measures a difference in potential between a polished portion polished by the polishing unit and an unpolished portion that has not been polished;
An image forming apparatus comprising: a determination unit configured to determine whether the polishing unit needs to polish an unpolished portion of the photosensitive member according to the potential difference measured by the potential difference measuring unit. The image forming apparatus according to claim 1, wherein the determination unit controls the polishing unit to polish the entire circumference of the photoconductor according to the potential difference measured by the potential difference measurement unit. The image forming apparatus according to claim 1, wherein the determination unit adjusts a polishing amount by the polishing unit according to a potential difference measured by the potential difference measurement unit. A temperature and humidity sensor for detecting the temperature and humidity in the image forming apparatus;
The determination unit determines whether or not the polishing unit needs to polish an unpolished portion of the photoconductor if the temperature and humidity values detected by the temperature and humidity sensor are higher than a reference value. The image forming apparatus according to claim 3. The image forming apparatus according to claim 1, wherein the determination unit determines whether the polishing unit needs to polish an unpolished portion of the photoreceptor when a predetermined time has elapsed. The polishing means includes a polishing roller capable of contacting the photoconductor,
The said judging means controls the said grinding | polishing means to stop the said photoconductor and to contact | abut to the said photoconductor while rotating the said grinding | polishing roller, and to polish a part of circumferential direction of the said photoconductor. The image forming apparatus according to any one of? The image forming apparatus according to claim 1, wherein the determination unit controls the polishing unit so that the toner adheres to the photosensitive member for polishing.

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