JP2013130785A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device capable of stably polishing the surface of an image forming apparatus by a toner layer of a cleaning roller, and suppressing intra-apparatus contamination due to overflow of toner; and an image forming apparatus.SOLUTION: A cleaning device brings a peripheral surface of a cleaning roller 20 on which a toner layer is formed into contact with the surface of a photoreceptor drum in order to clean the surface of the photoreceptor drum. A toner reception member 22 comprises: a retention part 22a1 that makes a height of a toner retained inside an image forming area X relating to a roller shaft direction higher than a height h1 of the center of a nip N; and a discharge part 22a2 that makes the height of the toner retained outside the image forming area X relating to the roller shaft direction lower than the height h1 of the center of the nip N.

Description

  The present invention relates to a cleaning device and an image forming apparatus.

  In electrophotographic image forming apparatuses such as copying machines and printers, an image forming unit is provided with a photosensitive drum (image carrier), and after an electrostatic latent image is formed on the surface of the photosensitive drum, The toner is developed to form a toner image. The toner image is transferred to a transfer medium such as paper, but the toner is not completely transferred and remains on the surface of the photosensitive drum, or the discharge product generated when forming the electrostatic latent image is exposed to light. It may remain attached to the body drum surface. Such residual toner and discharge products hinder the formation of a new image and cause a failure to obtain a good transfer image.

  Therefore, the image forming apparatus is provided with a cleaning device for removing deposits (toner, discharge products, etc.) on the surface of the photosensitive drum. The cleaning device is configured to clean the surface of the photosensitive drum by bringing the circumferential surface of the cleaning roller into contact with the surface of the photosensitive drum, for example. In addition to the function of removing the toner, this cleaning roller also has a function of holding the toner on its peripheral surface to form a toner layer and polishing the surface of the photosensitive drum.

  However, in the conventional cleaning device, when an image with a low printing rate is output continuously, or an image in which the printing position is biased in the axial direction of the cleaning roller (for example, one side in the axial direction is blank, the other in the axial direction) When the printer is repeatedly output, the part where the toner is insufficient is generated, the entire surface or part of the surface of the photosensitive drum cannot be polished, and the charged product adheres to the photosensitive drum. The dynamic friction coefficient on the surface of the body drum is increased, and an image flow image and a dash mark (toner fixation) image are sometimes generated.

In order to solve the above problem, as shown in FIG. 2, the following Patent Document 1 discloses a toner layer thickness for contacting the cleaning roller to supply toner to the surface of the cleaning roller and regulating the layer thickness. There is disclosed a cleaning device provided with a regulating roller and further provided with a toner receiving member for adhering toner to the toner layer thickness regulating roller.
According to this configuration, the toner once scraped from the cleaning roller is stored in the toner receiving member, the toner adheres to the surface of the toner layer thickness regulating roller, and the toner is supplied to the cleaning roller again and the layer is regulated. The toner layer is stably formed on the peripheral surface of the cleaning roller, and the polishing performance of the surface of the photosensitive drum can be improved.

JP 2011-154220 A

  By the way, a toner reservoir where toner is accumulated is formed in the valley of the nip between the cleaning roller and the toner layer thickness regulating roller. Part of the toner present in the toner reservoir part adheres to the cleaning roller by a physical force generated by the pressure contact between the cleaning roller and the toner layer thickness regulating roller. The amount of toner adhering here is larger than the amount of toner directly adhering from the toner receiving member to the toner layer thickness regulating roller and then moving to the cleaning roller, so that the toner layer can be stably formed on the peripheral surface of the cleaning roller. Is also important for the presence of toner in the toner reservoir.

  In the above Patent Document 1, the upper end of the toner receiving member extends to the height of the center position of the toner layer regulating roller. At this height, when a low printing rate image as described above is output. In addition, there is a possibility that the toner does not exist in the toner reservoir portion at the upper part of the nip between the cleaning roller and the toner layer thickness regulating roller shown in FIG. If there is no toner in the toner reservoir, the amount of toner that adheres to the circumferential surface of the cleaning roller is reduced, and it becomes difficult to polish the surface of the photosensitive drum.

  On the other hand, if the upper end of the toner receiving member should be as high as possible, this is not the case. When the upper end of the toner receiving member is raised, toner is present around the cleaning roller in a full state, and toner drops from the cleaning device, particularly from both ends in the roller axial direction, are likely to occur. In this case, the toner may overflow from the cleaning device to the photosensitive drum side, resulting in a problem of in-machine contamination.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. A cleaning apparatus and an image forming apparatus that can stably polish the surface of an image carrier with a toner layer of a cleaning roller and suppress in-machine contamination due to toner overflow. An object is to provide an apparatus.

  In order to solve the above-described problems, the present invention is a cleaning apparatus that cleans the surface of the image carrier by bringing the peripheral surface of the cleaning roller on which the toner layer is formed into contact with the surface of the image carrier. A toner receiving member having a surface for receiving the toner, and a toner receiving member for collecting the toner, and a peripheral surface of the cleaning roller so as to form a nip, and supplying the toner of the toner receiving member to the nip. A toner layer thickness regulating roller for forming the regulated toner layer, and the toner receiving member is configured to control a height of the accumulated toner in the nip in an image forming area with respect to the image carrier in the roller axial direction. Toner that is stored outside the image forming area with respect to the image bearing member in the roller axial direction, and a reservoir portion that is higher than the center height. The height to adopt a configuration of having a discharge portion for lower than the height of the center of the nip.

  In the present invention, the discharge portion has a configuration in which at least one of a notch portion and an opening portion formed at least in a portion lower than the height of the center of the nip on the toner receiving surface is employed. .

  In the present invention, the toner receiving member employs a configuration in which the discharge portion is provided at both ends in the roller axial direction.

  In the present invention, a configuration is adopted in which the discharge portion has a shape that lowers the height of the accumulated toner as it moves away from the image forming area.

  In the present invention, a configuration is adopted in which the toner receiving member is provided along the peripheral surface of the toner layer thickness regulating roller.

  In the present invention, the image carrier is a photosensitive drum whose surface is formed of amorphous silicon.

  According to another aspect of the present invention, there is provided an image forming apparatus comprising: an image carrier that carries a transfer image formed of toner; and a cleaning device that removes toner remaining on the surface of the image carrier. As described above, a configuration having the above-described cleaning device is employed.

According to the cleaning device of the present invention, in the image forming region with respect to the image bearing member in the roller axis direction, the toner height is higher than the nip center height between the cleaning roller and the toner layer thickness regulating roller by the reservoir of the toner receiving member. Since the toner is held high, the toner can be always stored in the toner storage portion formed by the valley of the nip. On the other hand, outside the image forming area for the image carrier with respect to the roller axis direction, the toner height is held lower than the height of the nip center between the cleaning roller and the toner layer thickness regulating roller by the discharge portion of the toner receiving member. It is possible to prevent toner from being accumulated in the toner reservoir formed by the valley of the nip. This can be easily understood by considering a fluid toner in a powder aggregate as a fluid fluid (for example, water). If it is liquid, if the height of the toner receiving member is higher than the center of the nip, the liquid is accumulated in the valley of the nip, and if it is lower than the center of the nip, the liquid is not accumulated in the valley of the nip. In this way, in the image forming area in the roll axis direction, toner is accumulated in the valleys of the nip, and the toner is stably supplied to the cleaning roller. Therefore, the area of the image carrier that affects the image quality is stably polished. be able to. On the other hand, outside the image forming area in the roll axis direction, the toner does not collect in the valley of the nip, so that the toner does not exist around the cleaning roller in a full state, and the overflow of the toner can be suppressed. Note that since this area is outside the image forming area, the image quality is not affected, and the cleaning is not affected even if the toner does not collect in the valley of the nip.
Therefore, according to the present invention, it is possible to obtain a cleaning device capable of stably polishing the surface of the image carrier with the toner layer of the cleaning roller and suppressing in-machine contamination due to overflow of toner. Further, according to the present invention, since the surface of the image carrier is stably polished, the occurrence of image defects such as image flow and dash marks can be suppressed, and an image forming apparatus with little in-machine contamination can be obtained.

1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. It is a block diagram of the cleaning apparatus in embodiment of this invention. FIG. 4 is a perspective view of a toner receiving member in the embodiment of the present invention. FIG. 3 is a front view illustrating an outer shape of a toner receiving member according to an exemplary embodiment of the present invention. FIG. 6 is a front view illustrating a configuration of a toner receiving member according to another embodiment of the present invention. FIG. 6 is a front view illustrating a configuration of a toner receiving member according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, an example in which the cleaning apparatus of the present invention is applied to a printer (image forming apparatus) will be described.

FIG. 1 is a schematic configuration diagram of a printer A according to an embodiment of the present invention.
The printer A according to the present embodiment employs a direct transfer method in which a toner image formed on the peripheral surface of the photosensitive drum (image carrier) 10 is directly transferred to a recording sheet. The printer A includes a photosensitive drum 10, a charging device 11, an exposure device 12, a developing device 13, a transfer roller 14, a cleaning device 15, a fixing device 16, a paper feed cassette 17, and a paper feed tray 18. And a paper discharge tray 19.

  The photosensitive drum 10 is a cylindrical rotating body having a circumferential surface formed of a predetermined photosensitive material, and an electrostatic latent image and a toner image (transfer image) based on the electrostatic latent image are formed on the circumferential surface (surface). Is formed. The surface of the photosensitive drum of this embodiment is formed of amorphous silicon. The charging device 11 is disposed so as to face the photosensitive drum 10 and charges the peripheral surface of the photosensitive drum 10.

The exposure device 12 emits laser light based on predetermined image data input from the outside, and scans the laser light on the peripheral surface of the charged photosensitive drum 10. The developing device 13 develops a toner image based on the electrostatic latent image on the peripheral surface of the photosensitive drum 10 by supplying toner to the peripheral surface of the photosensitive drum 10. The developing device 13 includes a toner container 13a. The toner container 13a of the present embodiment stores magnetic toner containing an abrasive such as titanium oxide (TiO ₂ ).

  The transfer roller 14 is disposed to face the photosensitive drum 10 and transfers the toner image developed on the photosensitive drum 10 onto a recording sheet. The cleaning device 15 removes the toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer. The cleaning device 15 is configured to bring the peripheral surface of the cleaning roller 20 on which the toner layer is formed into contact with the peripheral surface of the photosensitive drum 10 to clean the peripheral surface of the photosensitive drum 10.

  The fixing device 16 includes a pair of rollers, and fixes the toner image on the recording paper by applying heat and pressure to the toner image on the recording paper transferred from the photosensitive drum 10. The paper feed cassette 17 is a container for storing a bundle of recording paper. The paper feed tray 18 is a storage unit that receives manually fed recording paper. The paper discharge tray 19 is a storage unit that receives the recording paper on which the image has been supplied supplied from the fixing device 16.

Next, the configuration of the cleaning device 15 will be described in detail with reference to FIGS.
FIG. 2 is a configuration diagram of the cleaning device 15 according to the embodiment of the present invention. FIG. 3 is a perspective view of the toner receiving member 22 according to the embodiment of the present invention. FIG. 4 is a front view showing the outer shape of the toner receiving member 22 in the embodiment of the present invention.

As shown in FIG. 2, the cleaning device 15 is provided to face the photosensitive drum 10. The cleaning device 15 includes a cleaning roller 20, a toner layer thickness regulating roller 21, and a toner receiving member 22. The cleaning roller 20, the toner layer thickness regulating roller 21, and the toner receiving member 22 are accommodated in the housing 30.
The housing 30 also includes a cleaning blade 31 that scrapes off deposits (toner, discharge products, etc.) on the peripheral surface of the photosensitive drum 10, and a collection screw 32 that conveys the removed waste toner to a toner collection container (not shown). It is equipped with.

  The cleaning roller 20 rotates in contact with the peripheral surface of the photosensitive drum 10. In addition to the function of removing the toner remaining on the peripheral surface of the photosensitive drum 10, the cleaning roller 20 holds the toner and forms a toner layer on the peripheral surface of the cleaning roller 20. It also has a function of polishing. A plate-like toner regulating plate 23 is in contact with the peripheral surface of the cleaning roller 20. The toner regulating plate 23 is provided to regulate the thickness of the toner layer formed on the peripheral surface of the cleaning roller 20 to a predetermined thickness or less.

  The toner layer thickness regulating roller 21 rotates in contact with the circumferential surface of the cleaning roller 20. The toner layer thickness regulating roller 21 abuts on the peripheral surface of the cleaning roller 20 to form a nip N, and supplies the toner of the toner receiving member 22 to the nip N, and the toner layer whose thickness is regulated is removed from the cleaning roller 20. It is the structure formed in a surrounding surface. The toner layer thickness regulating roller 21 of the present embodiment has a diameter smaller than the diameter of the cleaning roller 20 and is disposed at a position that is not on a vertical line passing through the center of rotation of the cleaning roller 20 (in the present embodiment, obliquely above). . For this reason, in this embodiment, the toner reservoir C is formed by the valley of the nip N that opens upward.

  In the cleaning device 15 according to this embodiment, the rotation directions of the photosensitive drum 10, the cleaning roller 20, and the toner layer thickness regulating roller 21 are preferably rotated in the same direction at the respective contact portions (FIG. 2). Arrow direction). By doing so, wear of each roller due to rubbing can be reduced as compared with the case of reverse rotation.

  The toner receiving member 22 is provided in the vicinity of the toner layer thickness regulating roller 21 so that the toner can be supplied to the toner layer thickness regulating roller 21. The toner receiving member 22 is configured to receive the toner removed from the peripheral surface of the photosensitive drum 10 and to define the height at which the toner is stored by the height of the upper end thereof. The toner receiving member 22 of the present embodiment is provided along the peripheral surface of the toner layer thickness regulating roller 21. The toner receiving member 22 is provided with a receiving surface (a surface for receiving toner) 22 b serving as a toner receiving tray with a substantially constant gap with respect to the peripheral surface of the toner layer thickness regulating roller 21.

  If the toner receiving member 22 is too close to the toner layer thickness regulating roller 21, the two may contact each other. On the other hand, if the toner receiving member 22 is too far from the toner layer thickness regulating roller 21, the toner may not properly adhere to the toner layer thickness regulating roller 21, and further, the toner receiving member 22 may move to the toner layer thickness regulating roller 21. It takes time to be supplied stably. For this reason, it is preferable to manage the gap between the receiving surface 22b and the peripheral surface of the toner layer thickness regulating roller 21 within a certain range (for example, within a range of 0.5 mm or more and less than 3.0 mm).

  As shown in FIG. 3, the receiving surface 22 b of the toner receiving member 22 has a size that can cover the peripheral surface of the toner layer thickness regulating roller 21 in the roller axial direction. A toner regulating plate 23 is provided on the toner receiving member 22. Further, the toner receiving member 22 is provided with an attachment portion 24. The attachment portion 24 has a hook shape that is caught at both ends of the rotation shaft of the cleaning roller 20. The attachment unit 24 supports the toner receiving member 22 on the rotation shaft of the cleaning roller 20 and positions the toner regulating plate 23 with respect to the peripheral surface of the cleaning roller 20.

  As shown in FIG. 4, the toner receiving member 22 has a reservoir portion 22a1 that makes the height of the toner stored on the receiving surface 22b higher than the height h1 of the center N1 of the nip N, and the height of the center N1 of the nip N. a discharge portion 22a2 lower than h1. Here, the height h1 of the center N1 of the nip N intersects with the nip N and a straight line connecting the rotation center of the cleaning roller 20 and the rotation center of the toner layer thickness regulating roller 21, as shown in FIG. It means the height of the point to be done. The reservoir 22a1 and the discharge portion 22a2 extend to the opposite side of the nip N across a vertical plane passing through the rotation center of the toner layer thickness regulating roller 21.

  The reservoir 22a1 is configured such that the height of the toner to be stored is higher than the height h1 of the center N1 of the nip N in the image forming region X (indicated by a dot pattern) in the roller axis direction (left and right direction in FIG. 4). It has become. Here, the roller axial direction means the axial direction of the cleaning roller 20 or the toner layer thickness regulating roller 21. The roller axial direction corresponds to the axial direction of the photosensitive drum 10 and also corresponds to the width direction orthogonal to the recording paper conveyance direction. Further, the image forming area X means an area having the maximum width in which a toner image (transfer image) can be formed on the surface of the photosensitive drum 10.

  The upper end of the reservoir 22a1 of the toner receiving member 22 is provided at a position higher than the height h1 of the center N1 of the nip N. Further, the upper end of the reservoir 22a1 of the toner receiving member 22 of the present embodiment is further provided at a position higher than the height h2 of the upper end N2 of the nip N (see FIG. 2). Here, the height h2 of the upper end N2 of the nip N means the height of a boundary point where the peripheral surface of the cleaning roller 20 and the peripheral surface of the toner layer thickness regulating roller 21 do not contact each other. In other words, the height h2 of the upper end N2 of the nip N means the height of the apparent bottom of the valley of the nip N that becomes the toner reservoir C.

  Further, the upper end of the reservoir portion 22a1 of the toner receiving member 22 of the present embodiment is provided at a position lower than the height h3 of the apex 20a on the peripheral surface of the cleaning roller 20. Here, the height h3 of the apex 20a on the peripheral surface of the cleaning roller 20 means the height of the highest point on the peripheral surface of the cleaning roller 20 with the rotation axis provided horizontally. In other words, the height h3 of the apex 20a of the circumferential surface of the cleaning roller 20 is the height at which the circumference (upper half) of the cleaning roller 20 intersects the vertical line passing through the rotation center of the cleaning roller 20. Means.

  As described above, the upper end of the reservoir 22a1 of the toner receiving member 22 is provided within a range that is higher than the height h1 of the center N1 of the nip N and lower than the height h3 of the vertex 20a of the peripheral surface of the cleaning roller 20. It has been. In the present embodiment, the upper end of the reservoir 22a1 of the toner receiving member 22 is higher than the height h2 of the upper end N2 of the nip N and lower than the height h3 of the apex 20a of the peripheral surface of the cleaning roller 20. Is provided.

  On the other hand, as shown in FIG. 4, the discharge portion 22 a 2 is configured such that the height of the accumulated toner is lower than the height h 1 of the center N 1 of the nip N outside the image forming region X in the roller axis direction. The toner receiving member 22 of the present embodiment has discharge portions 22a2 at both ends in the roller axial direction. The discharge portions 22a2 are provided on both sides of the reservoir portion 22a1 outside the image forming region X in the roller axis direction.

The discharge portion 22a2 of the present embodiment is configured by a cutout portion 25. The notch 25 is formed at least in a portion of the receiving surface 22b that is lower than the height h1 of the center N1 of the nip N. The notch 25 of the present embodiment cuts the end of the toner receiving member 22 with a predetermined width from a height corresponding to the upper end of the reservoir 22a1 to a height equal to or lower than the height h1 of the center N1 of the nip N. It is formed with.
Examples of the material constituting the toner receiving member 22 include resins such as polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE), and metals such as aluminum (Al) and stainless steel (SUS).

Next, the operation of the cleaning device 15 configured as described above will be described.
The toner remaining on the peripheral surface of the photosensitive drum 10 after the toner image transfer is removed by the cleaning roller 20 and the cleaning blade 31 and accommodated in the housing 30 as shown in FIG. Part of the stored toner is collected on the receiving surface 22 b of the toner receiving member 22, and the remaining portion is conveyed to a toner collecting container (not shown) by a collecting screw 32.

  The cleaning roller 20 removes toner remaining on the peripheral surface of the photosensitive drum 10, holds the toner, forms a toner layer on the peripheral surface of the cleaning roller 20, and polishes the peripheral surface of the photosensitive drum 10. When an amorphous silicon photoconductor is used as the photoconductor drum 10, discharge products are likely to adhere. When this discharge product absorbs moisture, the electrical characteristics of the photoconductive drum 10 may deteriorate, and a problem of image flow that disturbs the electrostatic latent image may occur. Therefore, the cleaning device 15 cleans the peripheral surface of the photoconductive drum 10 by polishing the surface of the photoconductive drum 10 with a toner layer containing a small amount of abrasive formed on the peripheral surface of the cleaning roller 20. .

  The toner layer thickness regulating roller 21 regulates the thickness of the toner layer on the circumferential surface of the cleaning roller 20 by rotating in contact with the circumferential surface of the cleaning roller 20. More specifically, when the toner layer thickness regulating roller 21 rotates in contact with the peripheral surface of the cleaning roller 20, the thick part of the toner layer is preferentially thinned, and the difference between the thick part and the thin part of the toner layer is different. Less. For this reason, a toner layer having a uniform thickness is formed on the peripheral surface of the cleaning roller 20.

  The toner layer is formed by adhering to the cleaning roller 20 with a physical force generated by the pressure contact between the cleaning roller 20 and the toner layer thickness regulating roller 21. The toner adhering here is (1) the toner adhering from the toner receiving member 22 to the toner layer thickness regulating roller 21 and then moving directly to the cleaning roller 20, (2) the cleaning roller 20 and the toner layer thickness regulating roller 21 There are some that move to the cleaning roller 20 after being collected in the toner reservoir C formed in the valley of the nip N of the toner, but the amount of toner adhering in (2) is more than the amount of toner adhering in (1). In order to stably form a toner layer on the peripheral surface of the cleaning roller 20, the presence of toner in the toner reservoir C in (2) is important.

  The toner receiving member 22 of the present embodiment has a reservoir portion 22a1 that makes the height of the toner to be stored higher than the height h1 of the center N1 of the nip N in the image forming region X with respect to the photosensitive drum 10 in the roller axis direction. . As a result, in the image forming area X with respect to the photosensitive drum 10 in the roller axis direction, the toner height is set to the center N1 of the nip N between the cleaning roller 20 and the toner layer thickness regulating roller 21 by the reservoir 22a1 of the toner receiving member 22. Therefore, the toner can be always stored in the toner storage portion C formed by the valley of the nip N. This can be easily understood by considering a fluid toner in a powder aggregate as a fluid fluid (for example, water).

  If it is liquid, when the height of the upper end of the reservoir 22a1 is made higher than the center N1 of the nip N, the liquid (toner) accumulates in the valley of the nip N. The center N1 of the nip N is the point where the cleaning roller 20 and the toner layer thickness regulating roller 21 are closest to each other, and corresponds to the actual bottom of the valley of the nip N that becomes the toner reservoir C. Therefore, by setting the height of the upper end of the reservoir 22a1 higher than the center N1 of the nip N, toner is always present in the valley of the nip N in the image forming region X in the roll axis direction. The amount of adhering toner can be secured, and the toner is stably supplied to the cleaning roller. Therefore, the image forming area X of the photosensitive drum 10 that affects the image quality can be stably polished with the toner layer.

  Further, as shown in FIG. 2, the upper end of the reservoir portion 22a1 of the present embodiment is provided at a position higher than the height h2 of the upper end N2 of the nip N. The upper end N2 of the nip N corresponds to the apparent bottom of the valley of the nip N that becomes the toner reservoir C. The area above the upper end N2 of the nip N is an area in which the peripheral surface of the cleaning roller 20 and the peripheral surface of the toner layer thickness regulating roller 21 are gradually separated from each other. Is formed. Therefore, by making the height of the upper end of the reservoir 22a1 higher than the upper end N2 of the nip N, the toner can be sufficiently stored in the toner reservoir C, more stably supplying the toner to the cleaning roller 20, The image forming area X of the photosensitive drum 10 that affects the image quality can be stably polished with the toner layer.

  On the other hand, in order to keep the toner in the toner reservoir C at all times, the height of the toner receiving member 22 should be as high as possible. When the upper end of the toner receiving member 22 becomes high, the toner is present around the cleaning roller 20 in a full state, and toner drops from the cleaning device 15, particularly from both ends in the roller axial direction, are likely to occur. As a result, the toner overflows from the cleaning device 15 toward the photosensitive drum 10 and may cause a problem of in-machine contamination.

  Therefore, the toner receiving member 22 of the present embodiment has a discharge unit 22a2 that sets the height of the accumulated toner to be lower than the height h1 of the center N1 of the nip N outside the image forming area X with respect to the photosensitive drum 10 in the roller axis direction. Have Thus, outside the image forming area X with respect to the photosensitive drum 10 in the roller axial direction, the toner height is set at the center N1 of the nip N between the cleaning roller 20 and the toner layer thickness regulating roller 21 by the discharge portion 22a2 of the toner receiving member 22. Therefore, the toner can be prevented from being accumulated in the toner accumulation portion C formed by the valley of the nip N.

  Specifically, as shown in FIG. 4, the discharge portion 22a2 of the present embodiment is configured by a notch portion 25 in which the receiving surface 22b is notched lower than the height h1 of the center N1 of the nip N. For this reason, as in the liquid principle described above, outside the image forming region X in the roll axis direction, toner does not accumulate in the valley of the nip N, and the toner does not exist around the cleaning roller 20 in a full state. Toner overflow can be suppressed. Further, the toner receiving member 22 of the present embodiment has discharge portions 22a2 at both ends in the roller axial direction. According to this configuration, it is possible to effectively prevent the toner from dropping from both ends in the roller axial direction. For this reason, the cleaning apparatus 15 and the printer A with little in-machine contamination are obtained. Note that the area where the discharge portion 22a2 is provided is outside the image forming area X, so that the image quality is not affected, and even if toner does not accumulate in the valley of the nip N, the cleaning is not affected.

  Furthermore, the upper end of the reservoir 22a1 of the present embodiment is provided at a position lower than the height h3 of the apex 20a of the peripheral surface of the cleaning roller 20. The apex 20a of the peripheral surface of the cleaning roller 20 corresponds to the edge of the toner reservoir C. Accordingly, by reducing the height of the upper end of the reservoir 22a1 to be less than the uppermost portion (vertex 20a) of the cleaning roller 20, the toner reservoir C may be filled with toner based on the liquid principle described above. In addition, even in the image forming area X, it is possible to more reliably prevent the toner from overflowing.

  Thus, according to the above-described embodiment, the cleaning device that cleans the surface of the photosensitive drum 10 by bringing the circumferential surface of the cleaning roller 20 on which the toner layer is formed into contact with the surface of the photosensitive drum 10. 15 having a receiving surface 22b for receiving toner, forming a nip N in contact with the peripheral surface of the cleaning roller 20 and a toner receiving member 22 for storing the toner, and for removing the toner of the toner receiving member 22 from the nip And a toner layer thickness regulating roller 21 for forming the toner layer having a regulated thickness, and the toner receiving member 22 has the reservoir in the image forming area X with respect to the photosensitive drum 10 in the roller axial direction. A reservoir 22a1 that makes the height of the toner to be higher than the height h1 of the center N1 of the nip N, and a photoconductor in the roller axial direction. The toner of the cleaning roller 20 is configured to have a discharge portion 22a2 that makes the height of the accumulated toner lower than the height h1 of the center N1 of the nip N outside the image forming region X with respect to the ram 10. The cleaning device 15 can be obtained which can stably polish the surface of the photosensitive drum 10 by the layer and can suppress in-machine contamination due to overflow of toner. Further, according to this embodiment, since the surface of the image carrier is stably polished, the occurrence of image defects such as image flow and dash marks can be suppressed, and the printer A with less in-machine contamination can be obtained.

[Example]
Hereinafter, an embodiment of the present invention will be described. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

The specifications of each component of the image forming apparatus and the cleaning apparatus of the present embodiment are as follows.
<Monochrome MFP>
Photosensitive drum: a-Si drum φ30 (mm)
Line speed 410mm / s
Development method: Magnetic one-component development transfer member: Outer diameter φ20 (mm) roller
φ8 metal shaft + EPDM foam (foam thickness 6.0mm)
Resistance 6.5logΩ
Charging method: Contact charging roller method
Epichlorohydrin rubber φ12mm (shaft φ6mm)

<Cleaning device>
Cleaning blade: Urethane rubber Thickness t = 1.6mm
Cleaning roller: EPDM φ14mm (shaft φ8mm)
Photoreceptor linear speed ratio = 1.2 (forward rotation)
Load on photoconductor drum Drive side 15N Driven side 9N
Toner layer thickness regulating roller: EPDM φ 10 mm (shaft 6 mm)
Linear speed ratio to cleaning roller = 1.0 (forward driven rotation)
Biting amount into the cleaning roller = 0.5 mm
Toner regulating plate: SUS thickness = 0.1 mm
Biting amount into the cleaning roller = 0.5 mm

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, it has been described that the notch 25 is formed by notching the end of the toner receiving member 22 with a predetermined width, but the present invention is not limited to this configuration. For example, the configuration shown in FIG.
FIG. 5 is a front view illustrating the configuration of the toner receiving member 22 according to another embodiment of the present invention.

The cutout portion 25 shown in FIG. 5A has a first cutout portion 25a1 cut out shallowly and a second cutout portion 25a2 cut out deeply. According to the shape of the notch portion 25 shown in FIG. 5A, the height of the toner accumulated can be gradually decreased as the distance from the image forming area X increases.
The cutout portion 25 shown in FIG. 5 (b) has an inclined portion 25b cut out obliquely. According to the shape of the notch 25 shown in FIG. 5B, the height of the toner accumulated can be gradually lowered as the distance from the image forming region X increases.
In this way, by adopting a shape in which the height of the toner accumulated as the distance from the image forming area X decreases in the discharging portion 22a2, the toner is rapidly discharged in an area adjacent to the image forming area X. Therefore, the influence of the discharge on the height of the toner accumulated in the image forming area X can be reduced.

Further, for example, in the above-described embodiment, it has been described that the discharge portion 22a2 is configured by the cutout portion 25 formed at least in a portion lower than the height h1 of the center N1 of the nip N in the receiving surface 22b. The invention is not limited to this configuration. For example, the configuration shown in FIG. 6 may be used.
FIG. 6 is a front view illustrating the configuration of the toner receiving member 22 according to another embodiment of the present invention.

The discharge portion 22a2 shown in FIG. 6A has an opening 26 formed at least in a portion of the receiving surface 22b lower than the height h1 of the center N1 of the nip N. According to this configuration, similarly to the cutout portion 25, the height of the accumulated toner is made lower than the height h1 of the center N1 of the nip N outside the image forming area X with respect to the photosensitive drum 10 in the roller axis direction. Can do.
If the shape shown in FIG. 6B is employed, the height of the accumulated toner can be reduced as the distance from the image forming area X increases, as in FIG. In FIG. 6B, the diameter of the opening 26 is adjusted, but it is also possible to adjust the density of the openings 26.
Further, the present invention is not limited to this configuration, and the discharge portion 22a2 may have a configuration including both the notch portion 25 and the opening portion 26 described above.

  For example, the material of the photosensitive drum 10 with which the cleaning roller 20 abuts is not limited to amorphous silicon, and an organic photosensitive member (OPC) or the like can be used. When amorphous silicon is used, the outermost layer may be amorphous carbon or the like.

  Further, for example, in the above embodiment, a printer is exemplified as the image forming apparatus, but the present invention is also applicable to an image forming apparatus such as a copying machine and a facsimile apparatus.

  DESCRIPTION OF SYMBOLS 10 ... Photosensitive drum (image carrier), 15 ... Cleaning device, 20 ... Cleaning roller, 21 ... Toner layer thickness control roller, 22 ... Toner receiving member, 22a1 ... Reserving part, 22a2 ... Discharging part, 22b ... Receiving surface, 25 ... Notch, 26 ... Opening, A ... Printer (image forming apparatus), C ... Toner reservoir, N ... Nip, N1 ... Center of nip, h1 ... Height of center of nip

Claims (7)

A cleaning device for cleaning the surface of the image carrier by bringing the peripheral surface of the cleaning roller on which the toner layer is formed into contact with the surface of the image carrier,
A toner receiving member having a surface for receiving toner and storing the toner;
A toner layer thickness regulating roller that forms a nip in contact with the peripheral surface of the cleaning roller, and supplies toner of the toner receiving member to the nip to form the toner layer with a regulated thickness.
The toner receiving member is
In the image forming area with respect to the image bearing member in the roller axis direction, a reservoir portion that makes the height of the accumulated toner higher than the height of the center of the nip;
A cleaning device, comprising: a discharge unit that lowers the height of the accumulated toner to be lower than the height of the center of the nip outside the image forming region with respect to the image carrier in the roller axis direction.   2. The discharge unit according to claim 1, wherein the discharge unit includes at least one of a notch and an opening formed at least in a portion lower than a height of a center of the nip on a surface that receives the toner. Cleaning device.   The cleaning device according to claim 1, wherein the toner receiving member has the discharge portion at both ends in a roller axial direction.   4. The cleaning device according to claim 1, wherein the discharge unit has a shape in which a height of the accumulated toner is lowered as the distance from the image forming region increases. 5.   The cleaning device according to claim 1, wherein the toner receiving member is provided along a peripheral surface of the toner layer thickness regulating roller.   The cleaning apparatus according to claim 1, wherein the image carrier is a photosensitive drum having a surface formed of amorphous silicon. An image forming apparatus comprising: an image carrier that carries a transfer image formed with toner; and a cleaning device that removes toner remaining on the surface of the image carrier,
An image forming apparatus comprising the cleaning device according to claim 1 as the cleaning device.

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