JP4835598B2 - Cleaning device, image forming apparatus, and image carrier unit - Google Patents

Description

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

  In a general electrophotographic image forming apparatus represented by a copying machine or a laser printer, for example, a toner image formed on a photosensitive layer on the surface of an image carrier is recorded on a recording sheet or the like through an intermediate transfer member. It is designed to be transferred to the medium. Then, the transfer residual toner which is not transferred and remains on the surface of the image carrier is removed by a cleaning device.

As a cleaning device, a method of removing a transfer residual toner remaining on the surface of the image holding member by pressing a rubber cleaning blade against the surface of the image holding member is well known (for example, patents). Reference 1). Such a cleaning method using a cleaning blade is simple in configuration, small in size and low in cost, and excellent in cleaning performance and reliability. In recent years, it has been most widely used from low speed processors to high speed processors. Yes.
JP 2007-47400 A

  An object of the present invention is to obtain a cleaning device in which an elastic cleaning member for cleaning the surface of an image carrier is less likely to bend or chipped, and an image forming apparatus and an image carrier unit having the same.

In order to achieve the above object, a cleaning device according to claim 1 of the present invention is provided on the surface of an image holding body, which is a rotating body that holds an image, on an edge portion from the downstream side in the rotation direction of the image holding body. contacting a said plate-shaped elastic cleaning member for cleaning the surface at the edge portion, the support base wherein the edge portion of the fixed support over the opposite side in the axial direction of the image carrier of the elastic cleaning member comprising a timber, and a support member for supporting a plurality of surfaces in the edge portion of the elastic cleaning member, the elastic cleaning member is adjacent to the edge portion, facing the upstream side in the rotational direction of the image carrier a first surface, at the downstream side in the rotational direction of the image carrier with respect to the edge portion, adjacent to the first surface opposite the second surface and the second surface adjacent to the edge portion A third surface, wherein the first surface and the third surface are It is characterized in that it is fixed to the support member.

According to a second aspect of the present invention, there is provided an image forming apparatus that exposes an image carrier, a charging device that charges a surface of the image carrier, and a surface of the image carrier that is charged by the charging device. An exposure device that forms an electrostatic latent image on the surface, a developing device that develops the electrostatic latent image formed by the exposure device with a developer, and a surface of the image carrier that is developed by the developing device. image stored is provided an intermediate transfer member to be transferred, and a cleaning device according to claim 1 for removing the developer remaining on the surface of the image carrier without being transferred to the intermediate transfer member It is characterized by that.

According to a third aspect of the present invention, there is provided an image forming apparatus that exposes an image carrier, a charging device that charges a surface of the image carrier, and a surface of the image carrier that is charged by the charging device. An exposure device that forms an electrostatic latent image on the surface, a developing device that develops the electrostatic latent image formed by the exposure device with a developer, and a surface of the image carrier that is developed by the developing device. and a cleaning apparatus according to claim 1 in which images held removes the intermediate transfer member to be transferred, the developer remaining on the surface of the intermediate transfer member without being transferred onto the recording medium from the intermediate transfer member, It is characterized by having.

According to a fourth aspect of the present invention, there is provided an image carrier unit comprising: an image carrier; and the cleaning device according to the first aspect integrated with the image carrier; It is characterized by being detachable.

According to the first aspect of the present invention, in the elastic cleaning member of the cleaning device, it is possible to suppress the occurrence of wrinkles and to suppress the sag (deterioration with time) as compared with the case where this configuration is not provided. be able to.

According to the second aspect of the present invention, the elastic cleaning member of the cleaning device can suppress the occurrence of curling, chipping, sag, and abnormal noise as compared with the case where this configuration is not provided. Therefore, it is possible to extend the life and reliability of the image forming apparatus.

According to the third aspect of the present invention, the elastic cleaning member of the cleaning device can suppress the occurrence of curling, chipping, sag, and abnormal noise as compared with the case where this configuration is not provided. Therefore, it is possible to extend the life and reliability of the image forming apparatus.

According to the fourth aspect of the present invention, the elastic cleaning member of the cleaning device can suppress the occurrence of curling, chipping, sag, and abnormal noise as compared with the case where this configuration is not provided. Accordingly, it is possible to extend the life and reliability of the image carrier unit.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus 10 according to the present embodiment, and FIG. 2 is a schematic side view schematically illustrating a configuration of a cleaning device 28. FIG. 3 is an enlarged schematic side view showing the periphery of the elastic cleaning member 60 in the first embodiment of the cleaning device 28. In each figure, when an arrow UP is shown, it is an upward direction, and when an arrow IN is shown, it is an inward direction, and based on these, vertical and internal expressions are used.

  First, the configuration of the image forming apparatus 10 according to the present embodiment will be briefly described, but portions common to the respective colors will be described without adding alphabetic characters indicating the respective colors after the reference numerals. As shown in FIG. 1, the image forming apparatus 10 transfers a toner image of each color based on input image data to an endless belt-like intermediate transfer belt 24 described later, and forms a full-color image. The image forming unit 12 of the type is included.

  The image forming unit 12 outputs an image of each color of yellow (Y), magenta (M), cyan (C), and black (K) sequentially from the upstream side in the conveyance direction of the recording paper P that is an example of a recording medium. Image forming units 14Y, 14M, 14C, and 14K, and the image forming units 14Y to 14K are separated from each other by a predetermined distance along the moving direction of the intermediate transfer belt 24 (indicated by an arrow B). It is installed side by side.

  Each of the image forming units 14Y to 14K has photosensitive drums 16Y to 16K as image carriers, and the photosensitive drums 16Y to 16K are formed on the surface (peripheral surface) of a conductive metal cylinder. A photosensitive layer made of an organic photoconductor or the like is laminated, and is driven to rotate in a direction indicated by an arrow A (clockwise direction) at a predetermined process speed.

  This photosensitive layer is a function-separated type in which a charge generation layer and a charge transport layer are sequentially laminated, and usually has a high resistance. However, when irradiated with a laser beam, the specific resistance of the portion irradiated with the laser beam is reduced. It has a changing nature. Further, it is desirable that the diameter of each of the photosensitive drums 16Y to 16K is in a range of 20 mm to 100 mm.

  Around each of the photosensitive drums 16Y to 16K, chargers 18Y to 18K as charging devices that uniformly charge the surface (circumferential surface) of the photosensitive drum 16 to a predetermined potential in order from the upstream side in the rotation direction. The surface (circumferential surface) of the uniformly charged photoconductive drums 16Y to 16K is irradiated with a laser beam (image light) based on color-separated image data (image signal), and an electrostatic latent image is formed by exposure. Exposure devices 20Y to 20K, developing devices 22Y to 22K that transfer (develop) charged toner (developer) to an electrostatic latent image to form toner images, and paths that contact the photosensitive drums 16Y to 16K An endless belt-like intermediate transfer belt 24 stretched around the belt, primary transfer rolls 26Y to 26K for transferring the toner images formed on the photosensitive drums 16Y to 16K to the intermediate transfer belt 24, and primary transfer. And a cleaning device 28Y~28K to remove residual untransferred toner Nt (see FIG. 2) on the surface (circumferential surface) of the photosensitive drum 16Y～16K, is arranged after.

  The cleaning devices 28Y to 28K are provided with elastic cleaning members 60Y to 60K that are pressed against the surfaces (circumferential surfaces) of the photosensitive drums 16Y to 16K and scrape (scrap off) the transfer residual toner Nt from the photosensitive drums 16Y to 16K. Is provided. The cleaning device 28 (elastic cleaning member 60) will be described in detail later.

  Further, the primary transfer rolls 26Y to 26K are arranged inside the intermediate transfer belt 24, and are provided at positions facing the photosensitive drums 16Y to 16K, respectively. A contact portion between the photosensitive drums 16Y to 16K and the intermediate transfer belt 24 by the primary transfer rolls 26Y to 26K is a primary transfer portion (primary transfer position) T1.

  Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 26Y to 26K. Further, each bias power source is controlled by a control unit (not shown) which is a control means, so that the primary transfer bias applied to each primary transfer roll 26Y to 26K can be changed. The illustrated chargers 18Y to 18K are roll-shaped contact chargers, but non-contact chargers such as a scorotron and a solid discharge device can also be used.

  On the other hand, an intermediate transfer belt 24 as an intermediate transfer member includes primary transfer rolls 26Y to 26K, a drive roll 32 that is rotationally driven by a drive source (not shown), a driven roll 33, and a secondary transfer section (secondary transfer section described later). Position) It is wound around a backup roll 34 disposed at T2, and is rotated and moved (circulated) in the direction of arrow B in synchronization with the rotation of the photosensitive drum 16.

The intermediate transfer belt 24 has a surface resistivity of 10 by dispersing a material for imparting conductivity such as carbon or an ion conductive material in a resin material such as polyimide, polyamideimide, polycarbonate, or fluorine resin. It is formed by adjusting to about ¹⁰ Ω / □ to 10 ¹² Ω / □ (measurement voltage: 100 V).

  Further, a transfer for transferring the toner image on the intermediate transfer belt 24 onto a recording sheet P conveyed by a conveyance mechanism 42 as a conveyance means described later at a position facing the backup roll 34 with the intermediate transfer belt 24 interposed therebetween. A secondary transfer roll 36 as a means is provided. A contact portion between the secondary transfer roll 36 and the intermediate transfer belt 24 is a secondary transfer portion (secondary transfer position) T2.

  The image forming apparatus 10 includes a toner removing device (cleaning device) 38 that removes transfer residual toner remaining on the intermediate transfer belt 24 after the toner image is transferred onto the recording paper P by the secondary transfer roll 36. And a fixing device 40 as fixing means for fixing the toner image transferred onto the recording paper P by the secondary transfer roll 36.

  The transport mechanism 42 includes a pickup roll 46 that transports the recording paper P accommodated in the paper feed unit 44 one by one, a guide member 50 and a pair of transport rolls 48 that are provided in the transport path of the recording paper P, a secondary roll A transport belt 56 disposed on the downstream side of the transport path of the recording paper P relative to the transfer roll 36 and upstream of the transport path of the recording paper P relative to the fixing device 40; A pair of paper discharge rolls 58 provided on the downstream side of the fixing device 40, a paper discharge unit (not shown), and the like are included.

  By the transport mechanism 42, the recording paper P accommodated in the paper feeding unit 44 is fed to a secondary transfer unit (secondary transfer position) T2 where the secondary transfer roll 36 and the backup roll 34 face each other with the intermediate transfer belt 24 interposed therebetween. , Transported from the secondary transfer portion (secondary transfer position) T2 to the fixing device 40, and transported from the fixing device 40 to the paper discharge portion.

  The image forming apparatus 10 configured as described above operates as follows to form a full-color image. Since the image forming units 14Y to 14K for the respective colors have substantially the same configuration, the operation of forming a yellow toner image by the image forming unit 14Y will be described here.

  First, the surface of the photosensitive drum 16Y is uniformly charged to a potential of about -600V to -800V by the charger 18Y. The surface of the uniformly charged photoreceptor drum 16Y is irradiated with a laser beam by the exposure device 20Y in accordance with yellow image data sent from the control unit. That is, an electrostatic latent image of a yellow print pattern is formed on the photosensitive layer of the photosensitive drum 16Y.

  The electrostatic latent image is an image formed on the surface (photosensitive layer) of the photosensitive drum 16Y by charging. In the photosensitive layer, the specific resistance of the portion irradiated with the laser beam decreases, and the photosensitive drum 16Y. This is a so-called “negative latent image” formed by the fact that the charged charge flows on the surface of the film while the charge remaining in the portion not irradiated with the laser beam remains.

  Thus, the electrostatic latent image formed on the photosensitive drum 16Y is conveyed to a predetermined development position by the rotation of the photosensitive drum 16Y. At this development position, the electrostatic latent image on the photosensitive drum 16Y is converted into a visible image (toner image) by the developing device 22Y. In the developing device 22Y, for example, yellow toner having a volume average particle diameter of at least 3 μm to 6 μm including at least a yellow colorant and a binder resin is accommodated.

  The yellow toner is triboelectrically charged by being agitated inside the developing device 22Y, and has a charge of the same polarity (−) as the charge on the surface of the photosensitive drum 16Y. Therefore, when the surface of the photosensitive drum 16Y passes through the developing device 22Y, the yellow toner is electrostatically attached only to the latent image portion on the surface of the photosensitive drum 16Y, and the latent image becomes yellow toner. It is developed by. Thereafter, the photosensitive drum 16Y continues to rotate, and the toner image developed on the surface thereof is conveyed to the primary transfer portion (primary transfer position) T1.

  When the yellow toner image on the surface of the photoreceptor drum 16Y is conveyed to the primary transfer portion (primary transfer position) T1, a predetermined primary transfer bias is applied to the primary transfer roll 26Y, and the photoreceptor drum 16Y applies the primary transfer roll 26Y. The heading electrostatic force acts on the toner image, and the toner image on the surface of the photosensitive drum 16Y is transferred to the surface of the intermediate transfer belt 24. The primary transfer bias applied at this time has a polarity (+) opposite to the polarity (−) of the toner. For example, in the image forming unit 14Y, constant current control is performed to about +20 μA to +30 μA by the control unit.

  The transfer residual toner Nt on the surface of the photosensitive drum 16Y is cleaned by the cleaning device 28Y. The primary transfer bias applied to the primary transfer rolls 26M to 26K of the image forming units 14M to 14K is also controlled in the same manner as described above. In this way, the intermediate transfer belt 24 onto which the yellow toner image has been transferred by the image forming unit 14Y is sequentially conveyed to the remaining color image forming units 14M to 14K, and transferred so that the toner images of the respective colors are overlapped. Multiple transcription).

  The intermediate transfer belt 24 on which the toner images of all the colors have been transferred in multiple passes through the image forming units 14Y to 14K are circumferentially conveyed in the direction of the arrow B shown in the figure, and contact the inner surface (back surface) of the intermediate transfer belt 24. The secondary transfer portion (secondary transfer position) T2 configured by the backup roll 34 and the secondary transfer roll 36 disposed on the image holding surface side of the intermediate transfer belt 24 is reached.

  On the other hand, the recording paper P is fed by the transport mechanism 42 between the secondary transfer roll 36 and the intermediate transfer belt 24 at a predetermined timing, and a predetermined secondary transfer bias is applied to the secondary transfer roll 36. The secondary transfer bias applied at this time has a polarity (+) opposite to the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 24 toward the recording paper P acts on the toner image, and the intermediate transfer belt 24. Is transferred onto the surface of the recording paper P.

  Further, the secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) for detecting the resistance of the secondary transfer portion (secondary transfer position) T2, and is controlled by a constant voltage. ing. Thereafter, the recording paper P is sent to the fixing device 40, the toner image is heated and pressurized, and the color-superposed (multi-transferred) toner image is melted and permanently fixed on the surface of the recording paper P. . Thus, the recording paper P on which the fixing of the full-color image is completed is carried out toward the paper discharge unit, and a series of full-color image forming operations is completed.

  Next, the cleaning device 28 in the image forming apparatus 10 as described above will be described in detail. First, the first embodiment will be described. As shown in FIGS. 2 and 3, the cleaning device 28 includes a cleaner housing 30 that is disposed in the vicinity of the surface (circumferential surface) of the photosensitive drum 16 and opens on the side facing the surface of the photosensitive drum 16. ing.

  The cleaning device 28 is configured as at least a photosensitive unit (image holding unit) 27 integrated with the photosensitive drum 16, and is attached to and detached from the image forming apparatus 10 in the state of the photosensitive unit 27. It is possible. Further, the cleaning device 28 may be unitized as a single unit and configured to be detachable from the image forming apparatus 10. Further, the cleaning device 28 is detachably attached to the image forming apparatus 10, and a photosensitive drum is provided. 16 may be configured to be detachable from the image forming apparatus 10.

  On the inner surface of the opening end 30B on the lower side of the cleaner housing 30, a seal member 72 for preventing waste toner and the like stored in the cleaning device 28 from leaking to the outside is disposed. That is, the seal member 72 extends toward the photoconductor drum 16 so as to substantially close the gap between the photoconductor drum 16 and the cleaner housing 30 and does not contact the photoconductor drum 16. Has been. For the seal member 72, for example, a thermoplastic polyurethane film having a thickness of 0.2 mm is used.

  In addition, an auger screw 74 that is a conveying means for conveying the collected waste toner and the like to a waste toner discharge portion (not shown) provided outside the cleaner housing 30 is disposed on the lower side in the cleaner housing 30. . An elastic cleaning member 60 is disposed downstream of the seal member 72 of the cleaner housing 30 in the rotational direction (arrow A direction) of the photosensitive drum 16.

  That is, the base (one end side) 62 of the elastic cleaning member 60 is provided on the lower outer surface of the sheet metal 76 as a support base provided in the axial direction of the photosensitive drum 16 and having an L-shaped cross-sectional view. The sheet metal 76 is fixed to the upper outer surface of the cleaner housing 30 by a set screw 78.

  The elastic cleaning member 60 is formed into a plate shape (blade shape) having a predetermined thickness by an elastic material. For example, the elastic cleaning member 60 has a thickness of 2.0 mm and a free length (a width (not fixed to the sheet metal 76)). The length in the vertical direction)) is 10.0 mm, and the axial length of the photosensitive drum 16 is 330 mm.

  As the elastic material, for example, thermosetting polyurethane rubber having excellent mechanical properties such as wear resistance, fracture resistance, and creep resistance can be used. In addition, as an elastic material of the elastic cleaning member 60, for example, a functional rubber material such as silicone rubber, fluorine rubber, ethylene / propylene / diene rubber, or the like can be used.

  The elastic cleaning member 60 has a lower surface (first surface) 64 </ b> A located on the upstream side in the rotation direction of the photosensitive drum 16 with respect to the edge portion 65 facing the photosensitive drum 16 at the front end portion (lower end portion) 64. An outer surface (second surface) 64B located on the downstream side in the rotation direction of the photosensitive drum 16, and an inner surface (third surface) 64C opposite to the outer surface 64B and adjacent to the lower surface 64A, have.

  A part (the other end side) of the lower surface 64A on the cleaner housing 30 side of the lower end 64A of the distal end portion 64 of the elastic cleaning member 60 and an inner side surface (the other end side) 64C of the distal end portion 64 of the elastic cleaning member 60 are supported by the support member 70. It is glued (fixed) to. The support member 70 is formed in an “L” shape in a sectional view, and an inner side surface 70 </ b> C opposite to the outer side surface to which the distal end portion 64 of the elastic cleaning member 60 is bonded is above the cleaner housing 30. The elastic cleaning member 60 hits (contacts) the outer surface of the opening end 30A on the side when the elastic cleaning member 60 is pressed against the surface of the photosensitive drum 16 and deformed.

  In other words, the elastic cleaning member 60 has an opening end 30 </ b> A on the upper side of the cleaner housing 30 in which the movement of the tip 64 (movement in a direction away from the surface of the photosensitive drum 16) via the support member 70. Is now regulated by. Note that the support member 70 may be configured to adhere to the outer surface of the opening end 30A rather than to contact (contact) the outer surface of the opening end 30A of the cleaner housing 30.

  In any case, the elastic cleaning member 60 pressurizes the photosensitive drum 16 by a constant displacement method having a simple structure and a low cost, and the applied pressure is, for example, 39.2 N / m (4 gf / mm). ) Is set. In addition, this pressurization method is not limited to the constant displacement method, and a constant load method in which there is almost no change in the applied pressure with time may be used. Further, the cleaning device 28 can also use a conductive fiber brush or a magnetic brush (both not shown) together with the elastic cleaning member 60.

  Next, the operation of the cleaning device 28 of the first embodiment having such a configuration will be described. First, a comparative example will be described. As shown in FIG. 19, when the blade-like elastic cleaning member 160 is used, generally, the set angle θ of the elastic cleaning member 160, that is, the angle θ formed by the elastic cleaning member 160 and the tangent line on the surface of the photosensitive drum 116. As this increases, the blocking force for the transfer residual toner remaining on the surface of the photosensitive drum 116 increases, and the cleaning performance of the elastic cleaning member 160 tends to increase.

  However, when the setting angle θ of the elastic cleaning member 160 becomes too large and the frictional force of the edge portion 165 of the elastic cleaning member 160 against the surface of the photosensitive drum 116 becomes excessive, the tip 164 of the elastic cleaning member 160 becomes the photosensitive member. The so-called “spinning” that swells away from the drum 116 tends to occur. When drooling occurs, the blocking function does not act, so the cleaning function is not exhibited.

  On the other hand, the elastic cleaning member 60 of the first embodiment is separated from the photosensitive drum 16 by the distal end portion 64 (the outer surface 64B including the edge portion 65) being in pressure contact with the surface of the photosensitive drum 16. The bending deformation is regulated by the opening end 30 </ b> A on the upper side of the cleaner housing 30 via the support member 70.

  Therefore, as shown in FIG. 2, the untransferred toner Nt remaining on the surface of the photosensitive drum 16 passes through the front end portion of the seal member 72 as it is, and passes through the front end portion 64 (the edge portion 65 of the elastic cleaning member 60). Scraped by the lower surface 64A). The scraped transfer toner Nt that has been scraped off is temporarily accommodated in the cleaner housing 30, and conveyed / discharged to the outside of the cleaning device 28 (waste toner discharge portion) by the auger screw 74.

  Further, the elastic cleaning member 60 has its tip end portion 64 movement (movement in a direction away from the surface of the photosensitive drum 16) regulated by the opening end portion 30 </ b> A on the upper side of the cleaner housing 30 via the support member 70. Therefore, the pressure applied to the photosensitive drum 16 by the elastic cleaning member 60 is secured. Therefore, the elastic cleaning member 60 can be prevented from curling or sagging (deterioration with time). That is, in the elastic cleaning member 60 according to the first embodiment, since it is difficult for the pressurizing force to decrease with time, the cleaning performance is prevented from decreasing.

  This also suppresses so-called “squeaking”, which is an abnormal sound caused by minute vibration (stick / slip) when the elastic cleaning member 60 and the surface of the photosensitive drum 16 slide. That is, a plurality of vibration modes having different frequencies are generated in the elastic cleaning member 60 made of rubber and in the shape of a blade. This squeal phenomenon is caused by various factors such as the configuration and setting conditions of the elastic cleaning member 60, the holding method, the peripheral frame configuration, the friction coefficient with the surface of the photosensitive drum 16, the peripheral speed of the photosensitive drum 16, and the temperature and humidity environment. It is generated by self-excited vibration in a vibration mode determined by (single or coupled).

  In the first embodiment, cleaning is performed by the elastic cleaning member 60 in a high-temperature and high-humidity environment where squealing is likely to occur, and further supplied to the charger 18 for the purpose of increasing the friction coefficient of the surface of the photosensitive drum 16 as a stress condition. The amount of discharge product generated was increased by doubling the normal current. Further, the amount of toner coverage per print, which is a stress condition for the elastic cleaning member 60, is set to 1% for each color, and the amount of toner that becomes a lubricant reaches the elastic cleaning member 60 is reduced. .

  As a result, even under the above-described conditions, the distal end portion 64 of the elastic cleaning member 60 is bonded to the support member 70 that is in contact with (or bonded to) the opening end portion 30A of the cleaner housing 30 (the movement is Therefore, the minute vibrations are suppressed, thereby suppressing the generation of vibration modes. That is, until now, the above squealing phenomenon has occurred from the initial state (when the photosensitive drum 16 is started or stopped, and during stable running, etc.), but the elastic cleaning member 60 of this first embodiment does not squeal. Occurrence was suppressed.

  The support member 70 includes a part (the other end side) on the cleaner housing 30 side of the lower surface 64A of the distal end portion 64 of the elastic cleaning member 60 and an inner side surface (the other end side) 64C of the distal end portion 64 of the elastic cleaning member 60. By adhering (fixing) to the above, the above-mentioned effect can be obtained. If these surfaces are not bonded (fixed) and are only in contact with the support member 70, the contact surfaces are displaced, and the above effects cannot be obtained sufficiently.

  In the first embodiment, the mode in which the lower surface (first surface) 64A and the inner surface (third surface) 64C of the elastic cleaning member 60 are substantially orthogonal to each other is described. The same effect can be obtained even in the mode connected with the.

  Next, a second embodiment will be described. 4 is an enlarged schematic side view showing the periphery of the elastic cleaning member 66 in the second embodiment of the cleaning device 28. FIG. 5 shows the elastic cleaning member 66 and the support member 70 in the second embodiment of the cleaning device 28. It is a schematic perspective view shown. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Example, and detailed description is abbreviate | omitted.

  The elastic cleaning member 66 of the second embodiment has a short shape that is shorter in the vertical direction than the elastic cleaning member 60 of the first embodiment. That is, the elastic cleaning member 66 can be manufactured by appropriately cutting the long (blade-shaped) elastic cleaning member 60 shown in the first embodiment, and the material thereof is the same as that of the first embodiment. Is the same. The dimensions of the elastic cleaning member 66 having a rectangular shape (short shape) are, for example, a rectangle having a thickness of 2.0 mm (same as in the first embodiment) and a width (length in the vertical direction) of 4.0 mm. A cross-sectional one can be used.

  The elastic cleaning member 66 according to the second embodiment has a lower surface (first surface) 66A positioned on the upstream side in the rotation direction of the photosensitive drum 16 with respect to the edge portion 67 facing the photosensitive drum 16, and a photosensitive member. An outer surface (second surface) 66B located on the downstream side of the body drum 16 in the rotation direction, and an inner surface (third surface) 66C opposite to the outer surface 66B and adjacent to the lower surface 66A. ing. The edge portion 67 is cut at 90 degrees.

  The reason why the edge portion 67 is cut at 90 degrees is to obtain edge accuracy as the elastic cleaning member 66. That is, in order to apply a blocking force to the transfer residual toner Nt and the like, the edge portion 67 that is in pressure contact with the surface (circumferential surface) of the photosensitive drum 16 needs to be processed with high accuracy. This is because cutting at 90 degrees is most likely to provide edge accuracy. It should be noted that the angle other than the edge portion 67 is not necessarily 90 degrees.

  Further, a part of the lower surface 66A of the elastic cleaning member 66 on the cleaner housing 30 side and the inner side surface 66C are bonded (fixed) to the outer side surface of the support member 70, and the inner side surface 70C of the support member 70 is The cleaner housing 30 is bonded (fixed) to the outer surface of the opening end 30A on the upper side. That is, the elastic cleaning member 66 is held by the cleaner housing 30 via the support member 70.

  Further, as shown in FIG. 5, in the second embodiment, the length L of the elastic cleaning member 66 in the axial direction of the photosensitive drum 16 is 330 mm (same as in the first embodiment), and the length of the support member 70. The one with J of 334 mm is used. The length J of the support member 70 may be the same as the length L of the elastic cleaning member 66. However, a length longer by about several mm (in this case, 4 mm) is easier to fix the elastic cleaning member 66. desirable.

  Further, since the elastic cleaning member 66 has a short shape as described above, the edge portion 67 which is a boundary portion between the lower surface 66A and the outer surface 66B is not formed on the surface of the photosensitive drum 16 without being deformed. It is assembled so as to be in pressure contact. In other words, the elastic cleaning member 66 bites the edge portion 67 in the radial direction of the photosensitive drum 16 in order to ensure a desired pressing force on the surface of the photosensitive drum 16 (without bending deformation). ) Necessary pressure is obtained by elastic deformation (compression deformation).

  Next, the operation of the cleaning device 28 of the second embodiment having such a configuration will be described. The detailed description of the operation equivalent to that of the first embodiment is omitted. As described above, the elastic cleaning member 66 of the second embodiment is supported by being bonded to the outer surface of the support member 70 bonded to the outer surface of the cleaner housing 30, and its edge portion is formed on the surface of the photosensitive drum 16. 67 (see FIG. 8A).

  Therefore, the elastic cleaning member 66 is elastically deformed as shown in FIG. 8B by the rotational drive of the photosensitive drum 16, whereby the transfer residual toner Nt remaining on the surface of the photosensitive drum 16 is removed. It is scraped off. Here, since the elastic cleaning member 66 has a short shape as described above, the elastic cleaning member 66 is less likely to bend or sag when it has a long shape (blade shape). Moreover, since it is hard to bend and deform, the vibration mode which becomes a cause of a squeal hardly occurs.

  Actually, in order to confirm the suppression effect of the squeal, cleaning was performed under the same evaluation conditions as in the first embodiment, but when the cleaning device 28 provided with the elastic cleaning member 66 of the second embodiment was used. There was almost no squealing. In addition, in order to confirm basic cleaning performance, three sheets of solid A3 paper (an image formed with an image density of 100% on the entire image area) were continuously passed to evaluate the occurrence of toner slippage. However, there was no problem with the initial cleaning performance because no toner slipped.

  Next, a third embodiment will be described. FIG. 6 is an enlarged schematic side view showing the periphery of the elastic cleaning member 68 in the third embodiment of the cleaning device 28. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Example, and detailed description is abbreviate | omitted. The elastic cleaning member 68 according to the third embodiment has a short shape, like the elastic cleaning member 66 according to the second embodiment, and has a quadrangular (substantially square) cross-sectional shape.

  By making the cross-sectional shape into a substantially equilateral square shape (substantially square shape), as compared with the case where the long side is present like the elastic cleaning member 66 shown in the second embodiment, the bending deformation of the long side is present. Is a configuration in which is suppressed. For the purpose of preventing bending deformation, it is desirable that the elastic cleaning member 68 has a substantially equilateral rectangular shape (substantially square shape) in cross section. However, the elastic cleaning member 68 does not necessarily need to be equilateral if it does not undergo deformation. Further, when the elastic cleaning member 68 has a substantially square shape, the ratio of each side is preferably about 1: 1 to 1.2, for example, from the viewpoint of preventing bending deformation.

  The elastic cleaning member 68 has at least an edge portion 69 that contacts the photosensitive drum 16 cut at 90 degrees. The reason why the edge portion 69 is cut at 90 degrees is to obtain edge accuracy as the elastic cleaning member 68. That is, in order to apply a blocking force to the transfer residual toner Nt and the like, the edge portion 69 that is in pressure contact with the surface (circumferential surface) of the photosensitive drum 16 needs to be processed with high accuracy. This is because cutting at 90 degrees is most likely to provide edge accuracy. It should be noted that the angle other than the edge portion 69 is not necessarily 90 degrees.

  The elastic cleaning member 68 of the third embodiment includes a lower surface (first surface) 68A positioned on the upstream side in the rotation direction of the photosensitive drum 16 with respect to the edge portion 69 facing the photosensitive drum 16, and a photosensitive drum. 16, the outer surface (second surface) 68B located downstream in the rotational direction, the inner surface (third surface) 68C adjacent to the lower surface 68A on the opposite side to the outer surface 68B, and the lower surface 68A are opposite to each other. And an upper surface (fourth surface) 68D adjacent to the outer side surface 68B and the inner side surface 68C.

  The support member 80 in this case has a holder shape that contacts the elastic cleaning member 68 on three sides. That is, a part of the lower surface 68A of the elastic cleaning member 68 on the cleaner housing 30 side, an inner surface 68C, and a part of the upper surface 68D on the cleaner housing 30 side are bonded to the concave outer surface of the support member 80 ( Fixed). The inner surface 80C of the support member 80 is bonded (fixed) to the outer surface of the opening end 30A on the upper side of the cleaner housing 30, and the elastic cleaning member 68 is attached to the cleaner housing 30 via the support member 80. Is retained.

  Further, since the elastic cleaning member 68 has a short shape as described above, the edge portion 69 that is a boundary portion between the lower surface 68A and the outer surface 68B is formed on the surface of the photosensitive drum 16 without being deformed. It is assembled so as to be in pressure contact. That is, the elastic cleaning member 68 has the edge portion 69 in the radial direction of the photosensitive drum 16 in order to ensure a desired pressure on the surface of the photosensitive drum 16 as in the second embodiment. Necessary pressurizing force is obtained by encroaching and elastically deforming (compressing deformation) (without bending deformation).

  Next, the operation of the cleaning device 28 of the third embodiment having such a configuration will be described. The detailed description of the operation equivalent to that of the first embodiment is omitted. As described above, the elastic cleaning member 68 of the third embodiment is supported by being bonded to the outer surface of the support member 80 which is bonded to the outer surface of the cleaner housing 30. Further, the edge portion 69 is bitten (see FIG. 8A).

  Therefore, the elastic cleaning member 68 is elastically deformed as shown in FIG. 8B by the rotational drive of the photosensitive drum 16, whereby the transfer residual toner Nt remaining on the surface of the photosensitive drum 16 is removed. It is scraped off. Here, since the elastic cleaning member 68 has a short shape as described above, the elastic cleaning member 68 is less likely to bend or sag when it has a long shape (blade shape).

  In particular, since the elastic cleaning member 68 has three surfaces of the lower surface 68A, the inner surface 68C, and the upper surface 68D held by the support member 80, the elastic cleaning member 60 of the first embodiment in which the two surfaces are held by the support member 70. And the movement is further restricted than the elastic cleaning member 66 of the second embodiment. Therefore, the elastic cleaning member 68 is further prevented from being bent or sag compared to the elastic cleaning member 60 of the first embodiment and the elastic cleaning member 66 of the second embodiment.

  Further, since the elastic cleaning member 68 is unlikely to bend and deform as in the second embodiment, a vibration mode that causes a squeal is also unlikely to occur. In particular, since the elastic cleaning member 68 has three surfaces of the lower surface 68A, the inner surface 68C, and the upper surface 68D held by the support member 80, and its movement is further restricted, the squeal is further suppressed.

  Actually, in order to confirm the suppression effect of the squeal, cleaning was performed under the same evaluation conditions as in the first embodiment, but when the cleaning device 28 provided with the elastic cleaning member 68 of the third embodiment was used. There was almost no squealing. Further, in order to confirm the basic cleaning performance, three sheets of A3 paper (an image formed at an image density of 100% on the entire image area) are continuously passed in the same manner as in the evaluation method of the second embodiment. Then, the presence or absence of toner slipping was evaluated, but there was no toner slipping and there was no problem in the initial cleaning performance.

  Furthermore, a running test was conducted to evaluate the durability of the elastic cleaning member 68 of the third embodiment. The evaluation scale is the number of running cycles (rotations) of the photosensitive drum 16 until defective cleaning occurs, which is a conventional cleaning device, for example, a cleaning device provided with a blade-like elastic cleaning member 160 as shown in FIG. The comparison was obtained by running test. In this running test, consumables other than the elastic cleaning members 68 and 160 were appropriately replaced in order to remove factors other than the elastic cleaning members 68 and 160.

  As a result, in the conventional cleaning device provided with the blade-like elastic cleaning member 160, a cleaning failure occurred in 355k cycles (355,000 rotations), whereas the cleaning provided with the elastic cleaning member 68 of the third embodiment. In the device 28, cleaning failure occurred in 1120k cycles (1120,000 rotations). That is, in the cleaning device 28 provided with the elastic cleaning member 68 of the third embodiment, it was confirmed that the durability was improved about three times.

  Further, after the running test is completed, the elastic cleaning member 68 is taken out from the photoreceptor unit 27 and the cause of the cleaning failure is investigated. In the blade-like elastic cleaning member 160, the applied pressure due to sag (aging over time) and wear is reduced. Although there was a decrease, it was found that the elastic cleaning member 68 of the third embodiment was caused by the wear of the edge portion 69. Thereby, the durability improvement of the elastic cleaning member 68 without a bending deformation was confirmed anew.

  Further, important dimensions in the elastic cleaning member 68 of the third embodiment are the height α and the protrusion amount β shown in FIG. As a result of detailed deformation analysis of the edge portion 69, it was found that the region involved in the deformation was at least about 500 μm on both the lower surface 68A side and the outer surface 68B side from the tip of the edge portion 69. Therefore, in order to apply a pressing force necessary for cleaning, it is desirable that the height α is 500 μm or more and the protrusion amount β is 500 μm or more.

  Further, from the viewpoint of preventing bending deformation, it is desirable that the protrusion amount β ≦ height α. This is because if the height α is smaller than the protrusion amount β, a structure like a cantilever is formed and bending deformation (dripping) is likely to occur. The upper limits of the height α and the protrusion amount β are not particularly limited in terms of the cleaning function, but are desirably about 20 mm or less from the viewpoint of space for arranging the elastic cleaning member 68 and cost reduction.

  In the second and third embodiments, the state of the edge portions 67 and 69 during cleaning is particularly important from the viewpoint of cleaning performance. FIG. 8A shows the static state of the edge portions 67 and 69 in the elastic cleaning member 66 of the second embodiment and the elastic cleaning member 68 of the third embodiment, and FIG. 8B shows the photosensitive drum. The dynamic deformation state of each edge part 67 and 69 in each elastic cleaning member 66 and 68 when 16 is moving to the arrow A direction is shown.

  As shown in FIG. 8 (B), the edge portions 67 and 69 of the elastic cleaning members 66 and 68 are greatly deformed in the region of several tens of μm from the tip. Pressure is obtained. In other words, if each elastic cleaning member 66, 68 has a desired deformation in an area of several tens of μm from the tip, the required pressing force is obtained and a good cleaning function is exhibited. In order to apply such pressure, as described above, it is necessary to press the surface of the photosensitive drum 16 in the radial direction and bite the edge portions 67 and 69 to cause elastic deformation (compression deformation).

  This elastic deformation (compression deformation) state is basically the same as the tip deformation state of the edge portion 65 obtained by bending and deforming the plate-like (blade-like) elastic cleaning member 60 of the first embodiment. . However, since the elastic cleaning members 66 and 68 of the second and third embodiments are rectangular and do not cause a wrinkle phenomenon, they can be used even under a condition where the set angle θ (see FIG. 19) is large. It is possible to further improve the cleaning performance.

  By the way, the back side (inner side surfaces 70C, 80C) side of the support members 70, 80 is a fixed end in the pressurization method of the elastic cleaning members 60, 66, 68 to the photosensitive drum 16 according to the first to third embodiments. Since only the edge portions 65, 67, 69 are elastically deformed, the large foreign matter G (see FIG. 12) adhering to the surface (circumferential surface) of the photosensitive drum 16 is caused by the elastic cleaning member 60, When entering the contact portion between 66 and 68 and the photosensitive drum 16, the edge portions 65, 67 and 69 have a weak point that it is difficult to avoid the foreign matter G.

  That is, as a result of the elastic cleaning members 60, 66, 68 not being able to avoid the foreign matter G, the edge portions 65, 67, 69 are likely to be chipped. Image quality defects such as color lines / color bands (black lines / black bands) may occur. Therefore, in the following fourth to sixth embodiments, the configuration of the cleaning device 28 that can also suppress “chips” of the edge portions 65, 67, and 69 will be described.

  First, the fourth embodiment will be described. FIG. 9 is an enlarged schematic side view showing the periphery of the elastic cleaning member 84 in the fourth embodiment of the cleaning device 28, and FIG. 10 is a schematic sectional side view showing conditions when the cleaning device 28 is attached to the image forming apparatus 10. FIGS. 11 and 11 are schematic front views showing the elastic cleaning member 84 and the support member 70 in the fourth embodiment of the cleaning device 28. FIG. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 1st Example, and detailed description is abbreviate | omitted.

  The elastic cleaning member 84 of the fourth embodiment has a short shape similar to that of the elastic cleaning member 66 of the second embodiment. For example, the thickness is 2.0 mm (same as the first embodiment), and the width ( The length in the vertical direction is 4.0 mm. And the elastic cleaning member 84 of this 4th Example is comprised with the elastic material same as the elastic cleaning member 66 of the said 2nd Example.

  Further, the elastic cleaning member 84 includes a lower surface (first surface) 84 </ b> A located upstream of the edge portion 85 facing the photoconductive drum 16 in the rotation direction of the photoconductive drum 16 and the rotation of the photoconductive drum 16. It has an outer surface (second surface) 84B located on the downstream side in the direction, and an inner surface (third surface) 84C opposite to the outer surface 84B and adjacent to the lower surface 84A. The edge portion 85 is cut at 90 degrees.

  The reason why the edge portion 85 is cut at 90 degrees is to obtain edge accuracy as the elastic cleaning member 84. That is, in order to apply a blocking force to the transfer residual toner Nt and the like, the edge portion 85 that is in pressure contact with the surface (circumferential surface) of the photosensitive drum 16 needs to be processed with high accuracy. This is because cutting at 90 degrees is most likely to provide edge accuracy. It should be noted that the angle other than the edge portion 85 is not necessarily 90 degrees.

  Further, a part of the lower surface 84A of the elastic cleaning member 84 on the cleaner housing 30 side and the inner side surface 84C are bonded (fixed) to the outer side surface of the support member 70, and the inner side surface 70C (back surface) of the support member 70 is fixed. ) Is attached with one end of a coil spring 90 as a pressure applying means. For example, as shown in FIG. 11, the coil spring 90 is attached to the inner surface 70 </ b> C (rear surface) of the support member 70 at a plurality of locations (two locations in the drawing) at a predetermined interval. The pressure is adjusted so that the pressure is evenly applied in the direction of the rotation axis.

  As described above, when the pressure applying means (coil spring 90) is attached to the inner side surface 70C (back surface) of the support member 70, for example, from both ends in the longitudinal direction of the support member 70 which is the rotation direction of the photosensitive drum 16. Compared to a configuration in which a shaft (not shown) is protruded and the pressure applying means is provided on the shaft, it is not necessary to take extra space near both ends in the longitudinal direction. That is, if the configuration shown in FIG. 11 is used, the image forming apparatus 10 can be downsized.

  Further, the pressure applied by the coil spring 90 (pressing application means) is determined by the cleaning property, the discharge product removal property and its maintenance property under various conditions, and the photosensitive drum of the elastic cleaning member 84 in the fourth embodiment. The pressure applied to 16 is set to 19.6 N / m (2 gf / mm), for example. This pressure is suppressed to ½ of the pressure applied to the photosensitive drum 16 by the elastic cleaning member 60 in the first embodiment.

  Here, the reason why the pressing force of the elastic cleaning member 84 may be smaller than the pressing force of the elastic cleaning member 60 of the first embodiment (for example, it may be 1/2) is that the elastic cleaning member is caused by bending deformation. This is because there is no sag of 84, and unlike the elastic cleaning member 60 of the first embodiment, it is not necessary to increase the initial value in anticipation of sag, and even if the elastic cleaning member 84 is worn out. This is because a constant load (pressure) is always applied by the coil spring 90.

  On the other hand, the other end portion of the coil spring 90 is attached to an inner bottom surface 82C of an elongated rectangular box-shaped holding member 82 that is slidably accommodated in the support member 70 and is open on one side. The coil spring 90 is slidably held inside the holding member 82 while being urged toward the photosensitive drum 16 by the coil spring 90. The outer bottom surface 82D of the holding member 82 is attached (adhered) to the outer surface of the open end 30A on the upper side of the cleaner housing 30.

  Here, the pressing direction with respect to the surface (circumferential surface) of the photosensitive drum 16 of the elastic cleaning member 84 in the fourth embodiment is set as follows. That is, as shown in FIG. 10, the rotation center point Q1 of the photosensitive drum 16 and the contact point Q2 where the edge portion 85 of the elastic cleaning member 84 contacts (opposes) the surface (circumferential surface) of the photosensitive drum 16 are formed. It is set to be substantially parallel to the extending direction of the connected virtual straight line L1.

  This mainly contributes to the scraping property and maintainability at the time of cleaning by the elastic cleaning member 84, and is the stress (pressure) in the direction toward the rotation center point Q1 of the photosensitive drum 16, and this stress (pressure) is reduced. This is because the pressure is applied efficiently. As shown in FIG. 10, the angle γ formed by the virtual center line L2 and the virtual straight line L1 in the horizontal direction of the photosensitive drum 16 is always constant in the rotation axis direction of the photosensitive drum 16.

  Further, the material of the support member 70 and the holding member 82 is a resin material having high slidability such as polyacetal (POM) so that the support member 70 can smoothly slide inside the holding member 82. Is desirable. 9, the upper rubbing surfaces 70A and 82A and the lower rubbing surfaces 70B and 82B of the support member 70 and the holding member 82 are parallel to each other, and both rubbing surfaces 70A and 82A are parallel to each other. , 70B and 82B are set to be parallel to the virtual straight line L1. Thus, the pressing direction of the elastic cleaning member 84 against the photosensitive drum 16 is always constant.

  That is, the elastic cleaning member 84 is assembled so that the edge portion 85 which is a boundary portion between the lower surface 84A and the outer surface 84B is in pressure contact with the surface (circumferential surface) of the photosensitive drum 16 without being deformed. The edge force 85 is caused to bite in the radial direction of the photosensitive drum 16 by the pressing force (biasing force) of the coil spring 90, and elastic deformation (compression deformation) is performed (without bending deformation). Trying to get.

  When the photosensitive drum 16 rotates, a frictional force acts on the elastic cleaning member 84. Since this frictional force acts in a direction orthogonal to the pressurizing direction, the elastic cleaning member 84 has a frictional force. It is difficult to be affected, and the necessary pressure can be constantly applied to the photosensitive drum 16 at a constant level.

  Strictly speaking, however, the position of the contact point Q2 is due to the effect of the gap between the sliding support member 70 and the holding member 82 and due to the elastic deformation of the elastic cleaning member 84 accompanying the rotation / stop of the photosensitive drum 16. It is displaced on the surface (circumferential surface) of the photosensitive drum 16. However, the amount of displacement is as small as several tens of μm to several hundreds of μm and can be ignored.

  Next, the operation of the cleaning device 28 of the fourth embodiment having such a configuration will be described. The detailed description of the operation equivalent to that of the second embodiment is omitted. The elastic cleaning member 84 of the fourth embodiment is supported by being bonded to the outer surface of a support member 70 slidably provided on a holding member 82 bonded to the outer surface of the cleaner housing 30, and is a photoreceptor by a coil spring 90. The edge portion 85 is urged toward the surface (circumferential surface) of the drum 16 to bite into the surface (circumferential surface) of the photosensitive drum 16 with a predetermined pressure.

  For this reason, the elastic cleaning member 84 is elastically deformed by the rotational drive of the photosensitive drum 16, whereby the transfer residual toner Nt remaining on the surface of the photosensitive drum 16 is scraped off. Here, since the elastic cleaning member 84 has a short shape as described above, the elastic cleaning member 84 is less likely to bend or sag when it has a long shape (blade shape). Moreover, since it is hard to bend and deform, the vibration mode which becomes a cause of a squeal hardly occurs.

  Actually, in order to confirm the effect of suppressing the wobbling, the current supplied to the charger 18 is doubled as usual to increase the friction coefficient of the surface of the photosensitive drum 16 as a stress condition. Increased the amount generated. Further, the amount of toner that reaches the elastic cleaning member 84 is set so that the amount of toner coverage per print, which is a stress condition for the elastic cleaning member 84, is 0.5% for each color. I reduced it.

  As a result, when the conventional cleaning device provided with the elastic cleaning member 160 (see FIG. 19) of the comparative example is used, the three photoconductor units 27 out of the four photoconductor units 27 are wrinkled during running. Was confirmed. On the other hand, when the cleaning device 28 according to the fourth embodiment was used, the elastic cleaning member 84 did not bend and deformed, so that the four photoconductor units 27 did not bend at all.

  Next, in order to confirm the effect of suppressing chipping, as a stress condition, a foreign matter G having a height of about 50 μm is adhered on the surface of the photosensitive drum 16, and whether there is chipping every 500 cycles (rotations) of the photosensitive drum 16. Checked. In addition, in order to confirm basic cleaning performance, three sheets of solid A3 paper (an image formed with an image density of 100% on the entire image area) were continuously passed to evaluate the occurrence of toner slippage. .

  As a result, when the cleaning device 28 provided with the elastic cleaning member 60 of the first embodiment was used, toner slipping was observed after 500 cycles in all four photoconductor units 27. Moreover, as a result of observing the elastic cleaning member 60, a chip was observed in a portion corresponding to slipping through.

  On the other hand, when the cleaning device 28 provided with the elastic cleaning member 84 of the fourth embodiment was used, no toner slipped out after 500 cycles in all of the four photoreceptor units 27. Further, as a result of observing the elastic cleaning member 84, slight edge damage was observed, but no chipping occurred.

  Therefore, in the cleaning device 28 provided with the elastic cleaning member 84 of the fourth embodiment, toner slipping was checked every 500 cycles. As a result, in the four photoconductor units 27, variations were observed at the start of toner slippage occurrence, but toner slippage occurred approximately between 1500 cycles and 2500 cycles. Moreover, as a result of observing the elastic cleaning member 84, a chip was found in a portion corresponding to slipping through. In other words, it was confirmed that the elastic cleaning member 84 of the fourth embodiment has a chipping prevention effect of 3 to 5 times that of the elastic cleaning member 60 of the first embodiment.

  As shown in the simulation results of FIG. 12, in the elastic cleaning member 60 of the first embodiment, the foreign matter G is avoided by the elasticity of the rubber at the edge portion 65, and therefore, it tends to be chipped due to fatigue failure. Because there is. That is, in the elastic cleaning member 84 of the fourth embodiment, since the pressure is applied to the photosensitive drum 16 by the coil spring 90, as shown in the simulation result of FIG. This is because it is easy to retract (avoid) to the holding member 82 side, and the applied pressure (load) may be, for example, 1/2 of that in the first embodiment.

  Further, in order to confirm the effect of suppressing the squeal, the cleaning device 28 provided with the elastic cleaning member 84 of the fourth embodiment was cleaned under the same evaluation conditions as the first embodiment. As a result, when the cleaning device 28 provided with the elastic cleaning member 84 of the fourth embodiment was used, almost no squeal occurred. Thereby, it was confirmed that there is no problem in the initial cleaning performance.

  Next, a fifth embodiment will be described. FIG. 14 is a schematic side view showing the periphery of the elastic cleaning member 86 in the fifth embodiment of the cleaning device 28, and FIG. 15 is a schematic front view showing the elastic cleaning member 86 and the support member 70 in the fifth embodiment of the cleaning device 28. FIG. The fifth embodiment is different from the fourth embodiment only in that the pressure applying means is a leaf spring 92 having a substantially “U” shape in side view. Therefore, parts equivalent to those in the fourth embodiment are denoted by the same reference numerals, and detailed description (including operation) is omitted. The elastic cleaning member 86 of the fifth embodiment is equivalent to the elastic cleaning member 84 of the fourth embodiment.

  As shown in FIG. 15, the leaf spring 92 has a long shape extending in the rotation axis direction of the photosensitive drum 16. Therefore, as shown in FIG. 14, the elastic cleaning member 86 supported by the support member 70 is urged (pressurized) by the urging force of the plate spring 92, and its edge portion 87 is the surface of the photosensitive drum 16 ( In this case, the pressure is uniformly applied in the direction of the rotation axis of the photosensitive drum 16. Therefore, in the case of the cleaning device 28 according to the fifth embodiment, toner slippage is further less likely to occur.

  Also in this case, since the pressure application means (plate spring 92) is attached to the inner side surface 70C (back surface) of the support member 70, for example, both longitudinal ends of the support member 70 that are the rotation direction of the photosensitive drum 16 Compared with a configuration in which a shaft (not shown) is protruded from the shaft and a pressure applying means is provided on the shaft, it is not necessary to take extra space near both ends in the longitudinal direction. That is, if the configuration as shown in FIG. 15 is adopted, the image forming apparatus 10 can be downsized as in the fourth embodiment.

  Next, a sixth embodiment will be described. FIG. 16 is a schematic side view showing the periphery of the elastic cleaning member 88 in the sixth embodiment of the cleaning device 28, and FIG. 17 is a schematic side view showing the elastic cleaning member 88 in the sixth embodiment of the cleaning device 28 in an enlarged manner. FIG. 18 is an explanatory view showing a contact state of the elastic cleaning member 88 with respect to the photosensitive drum 16 in the sixth embodiment. In addition, the same code | symbol is attached | subjected to the site | part equivalent to the said 3rd Example, and detailed description is abbreviate | omitted.

  The elastic cleaning member 88 of the sixth embodiment is made of the same elastic material as that of the elastic cleaning member 68 of the third embodiment, and, like the elastic cleaning member 68, the cross-sectional shape is a rectangular shape with substantially equal sides ( (Substantially square shape). By making the cross-sectional shape a substantially equilateral square shape (substantially square shape), as compared with the case where the long side is present like the elastic cleaning members 84 and 86 shown in the fourth and fifth embodiments, It is the structure by which the bending deformation of the long side is suppressed.

  For the purpose of preventing bending deformation, it is desirable that the elastic cleaning member 88 has a square shape (substantially square shape) having a substantially equal cross-sectional shape, but is not necessarily equal if it does not bend and deform. Further, when the elastic cleaning member 88 has a substantially square shape, the ratio of each side is preferably about 1: 1 to 1.2 from the viewpoint of preventing bending deformation. The elastic cleaning member 88 has at least an edge portion 89 that contacts the photosensitive drum 16 cut at 90 degrees.

  The reason why the edge portion 89 is cut at 90 degrees is to obtain edge accuracy as the elastic cleaning member 88. That is, in order to apply a blocking force to the transfer residual toner Nt or the like, the edge portion 89 that is in pressure contact with the surface (circumferential surface) of the photosensitive drum 16 needs to be processed with high accuracy. This is because cutting at 90 degrees is most likely to provide edge accuracy. Note that the angle other than the edge portion 89 is not necessarily 90 degrees.

  Further, the elastic cleaning member 88 of the sixth embodiment has a lower surface (first surface) 88A located on the upstream side in the rotation direction of the photosensitive drum 16 with respect to the edge portion 89 facing the photosensitive drum 16, and a photosensitive member. An outer surface (second surface) 88B located downstream of the body drum 16 in the rotational direction, an inner surface (third surface) 88C adjacent to the lower surface 88A on the side opposite to the outer surface 88B, and a lower surface 88A Has an upper surface (fourth surface) 88D adjacent to the outer surface 88B and the inner surface 88C on the opposite side.

  In this case, the support member 80 has a holder shape in contact with the elastic cleaning member 88 on three sides. That is, a part on the cleaner housing 30 side of the lower surface 88A of the elastic cleaning member 88, a part on the cleaner housing 30 side of the upper surface 88D, and a part on the cleaner housing 30 side of the upper surface 88D are bonded to the concave outer surface of the support member 80 ( Fixed). Thereby, the minute vibration of the elastic cleaning member 88 is more reliably suppressed.

  Further, one end of a coil spring 90 as a pressure applying means is attached to the inner side surface 80C (back surface) of the support member 80. Similar to the fourth embodiment, the coil spring 90 is attached to the inner side surface 80C (back surface) of the support member 80 at a plurality of locations (for example, two locations) at a predetermined interval. It is adjusted so that pressure is applied evenly in the direction.

  The pressure applied by the coil spring 90 (pressing application means) is determined by the cleaning performance, discharge product removal performance and maintenance performance under various conditions, and the elastic cleaning member 88 in the sixth embodiment with respect to the photosensitive drum 16. The applied pressure is also set to 19.6 N / m (2 gf / mm), for example. That is, the pressing force of the elastic cleaning member 88 of the sixth embodiment is also suppressed to ½ of the pressing force of the elastic cleaning member 60 of the first embodiment.

  Here, the reason why the pressing force of the elastic cleaning member 88 may be smaller than the pressing force of the elastic cleaning member 60 of the first embodiment (for example, it may be 1/2) is the same as in the fourth embodiment. This is because there is no sag of the elastic cleaning member 88 due to bending deformation, and it is not necessary to increase the initial value in anticipation of the sag, unlike the elastic cleaning member 60 of the first embodiment, and This is because even if the elastic cleaning member 88 is worn, a constant load (pressure) is always applied by the coil spring 90.

  On the other hand, the other end of the coil spring 90 is attached to the inner bottom surface 82C of an elongated rectangular box-shaped holding member 82 that is open on one side and slidably accommodates the support member 80. The coil spring 90 is slidably held inside the holding member 82 while being urged toward the photosensitive drum 16 by the coil spring 90. The outer bottom surface 82D of the holding member 82 is attached (adhered) to the outer surface of the open end 30A on the upper side of the cleaner housing 30.

  Here, the pressing direction of the elastic cleaning member 88 in the sixth embodiment with respect to the surface (circumferential surface) of the photosensitive drum 16 is the same as that in the fourth embodiment. That is, as shown in FIG. 16, the rotation center point Q1 of the photosensitive drum 16 and the contact point Q2 where the edge portion 89 of the elastic cleaning member 88 contacts (opposes) the surface (circumferential surface) of the photosensitive drum 16 are formed. It is set to be substantially parallel to the extending direction of the connected virtual straight line L1.

  This mainly contributes to the scraping property and maintainability at the time of cleaning by the elastic cleaning member 88, and is the stress (pressure) in the direction toward the rotation center point Q1 of the photosensitive drum 16, and this stress (pressure) is reduced. This is because the pressure is applied efficiently. As shown in FIG. 16, the angle γ formed by the virtual center line L2 and the virtual straight line L1 in the horizontal direction of the photosensitive drum 16 is always constant in the rotation axis direction of the photosensitive drum 16.

  Further, the material of the support member 80 and the holding member 82 is a resin material having high slidability such as polyacetal (POM) so that the support member 80 can slide smoothly inside the holding member 82. Is desirable. Further, as shown in FIG. 17, the upper rubbing surfaces 80A and 82A and the lower rubbing surfaces 80B and 82B of the support member 80 and the holding member 82 are parallel to each other, and both rubbing surfaces 80A and 82A. , 80B and 82B are set to be parallel to the virtual straight line L1. Thus, the pressing direction of the elastic cleaning member 88 against the photosensitive drum 16 is always constant.

  That is, since the elastic cleaning member 88 has a short shape similar to that of the third embodiment, the edge portion 89 which is a boundary portion between the lower surface 88A and the outer surface 88B does not undergo bending deformation, and the photosensitive drum 16 The edge portion 89 is bitten in the radial direction of the photosensitive drum 16 by the pressure (biasing force) of the coil spring 90 and is elastic (without bending deformation). Necessary pressure is obtained by deformation (compression deformation).

  When the photosensitive drum 16 rotates, a frictional force acts on the elastic cleaning member 88. Since this frictional force acts in a direction perpendicular to the pressurizing direction, the elastic cleaning member 88 has a frictional force. It is difficult to be affected, and the necessary pressure can be constantly applied to the photosensitive drum 16 at a constant level.

  Strictly speaking, however, the position of the contact point Q2 is due to the effect of the gap between the sliding support member 80 and the holding member 82 and due to the elastic deformation of the elastic cleaning member 88 accompanying the rotation / stop of the photosensitive drum 16. It is displaced on the surface (circumferential surface) of the photosensitive drum 16. However, the amount of displacement is as small as several tens of μm to several hundreds of μm and can be ignored.

  Next, the operation of the cleaning device 28 of the sixth embodiment having such a configuration will be described. The detailed description of the operation equivalent to that of the third embodiment is omitted. The elastic cleaning member 88 of this sixth embodiment is supported by being bonded to the outer surface of a support member 80 slidably provided on a holding member 82 bonded to the outer surface of the cleaner housing 30, and is a photoreceptor by a coil spring 90. The edge portion 89 is urged toward the surface (circumferential surface) of the drum 16 to bite into the surface (circumferential surface) of the photosensitive drum 16 with a predetermined pressure.

  For this reason, the elastic cleaning member 88 is elastically deformed by the rotational drive of the photosensitive drum 16, whereby the transfer residual toner Nt remaining on the surface of the photosensitive drum 16 is scraped off. Here, since the elastic cleaning member 68 has a short shape as described above, the elastic cleaning member 68 is less likely to bend or sag when it has a long shape (blade shape).

  In particular, since the elastic cleaning member 88 has three surfaces of the lower surface 88A, the inner surface 88C, and the upper surface 88D held by the support member 80, the elastic cleaning member 84 of the fourth embodiment in which the two surfaces are held by the support member 70. And the movement is further regulated than the elastic cleaning member 86 of the fifth embodiment. Therefore, the elastic cleaning member 88 is further prevented from being bent or sag compared to the elastic cleaning member 84 of the fourth embodiment and the elastic cleaning member 86 of the fifth embodiment.

  In addition, since the elastic cleaning member 88 is unlikely to bend and deform similarly to the third embodiment, a vibration mode that causes a squeal is also unlikely to occur. In particular, since the elastic cleaning member 88 has three surfaces of the lower surface 88A, the inner surface 88C, and the upper surface 88D held by the support member 80 and its movement is further restricted, the squeal is further suppressed.

  Actually, in order to confirm the suppression effect of the squeal, cleaning was performed under the same evaluation conditions as in the first embodiment, but when the cleaning device 28 provided with the elastic cleaning member 88 of the sixth embodiment was used. There was almost no squealing. In addition, in order to confirm the basic cleaning performance, as in the evaluation method of the third embodiment, three sheets of A3 paper (an image formed with an image density of 100% over the entire image area) are continuously passed. Then, the presence or absence of toner slipping was evaluated, but there was no toner slipping and there was no problem in the initial cleaning performance.

  Moreover, in order to confirm the chipping prevention effect of the elastic cleaning member 88 of the sixth embodiment, a confirmation experiment was performed under the same evaluation conditions as in the fourth embodiment. As a result, when the cleaning device 28 provided with the elastic cleaning member 88 of the sixth embodiment is used, the four photoreceptor units 27 do not show any slip-through phenomenon up to 1500 cycles. Compared with the cleaning apparatus 28 provided with the elastic cleaning member 60, the chipping prevention effect 3 times or more was confirmed.

  Furthermore, a running test was conducted to evaluate the durability of the elastic cleaning member 88 of the sixth embodiment. The evaluation scale is the number of running cycles (rotations) of the photosensitive drum 16 until a cleaning failure occurs, and is obtained by a running test by comparing with the conventional cleaning device (equipped with the elastic cleaning member 160 of the comparative example). . In this running test, consumables other than the elastic cleaning members 88 and 160 were appropriately replaced in order to remove factors other than the elastic cleaning members 88 and 160.

  As a result, in the conventional cleaning device provided with the elastic cleaning member 160 of the comparative example, the cleaning failure occurred in 355 k cycles (355,000 rotations), whereas the cleaning provided with the elastic cleaning member 88 of the sixth embodiment. In the apparatus 28, cleaning failure occurred in 1820k cycles (1820,000 rotations). That is, in the cleaning device 28 provided with the elastic cleaning member 88 of the sixth embodiment, it was confirmed that the durability was improved about 5 times.

  Further, after the running test is completed, the elastic cleaning member 88 is taken out from the photoreceptor unit 27 and the cause of the cleaning failure is investigated. In the conventional (comparative example) elastic cleaning member 160, due to sag (aging deterioration) and wear. Although there was a decrease in the applied pressure, it was found that the elastic cleaning member 88 of the sixth example was due to wear of the edge portion 89. Thereby, the durability improvement of the system which uses the elastic cleaning member 88 which does not accompany bending deformation, and provides pressure application means (coil spring 90, leaf | plate spring 92, etc.) and applies a pressure was confirmed anew.

  Further, important dimensions in the elastic cleaning member 88 of the sixth embodiment are the height α and the protrusion amount β shown in FIG. As a result of detailed analysis of the deformation of the edge portion 89, it has been found that the region involved in the deformation is at least about 500 μm on both the lower surface 88A side and the outer surface 88B side from the tip of the edge portion 89. Therefore, in order to apply a pressing force necessary for cleaning, it is desirable that the height α is 500 μm or more and the protrusion amount β is 500 μm or more.

  Further, from the viewpoint of preventing bending deformation, it is desirable that the protrusion amount β ≦ height α. This is because if the height α is smaller than the protrusion amount β, a structure like a cantilever is formed and bending deformation (dripping) is likely to occur. The upper limits of the height α and the protrusion amount β are not particularly limited in terms of the cleaning function, but are desirably about 20 mm or less from the viewpoint of space for placing the elastic cleaning member 88 and cost reduction.

  In the configurations of the fourth to sixth embodiments, the state of the edge portions 85, 87, and 89 during cleaning is particularly important from the viewpoint of cleaning performance. FIG. 18 shows, as an example, the static state of the edge portion 89 in the elastic cleaning member 88 of the sixth embodiment. Each elastic cleaning member 84, 86, when the photosensitive drum 16 is moving in the direction of arrow A, FIG. The dynamic deformation states of the edge portions 85, 87, 89 in 88 are the same as those in FIG.

  That is, as shown in FIG. 8B, the edge portions 85, 87, 89 of the elastic cleaning members 84, 86, 88 are also greatly deformed in the region of several tens of μm from the tip. The required pressure is obtained by the deformation. In other words, the elastic cleaning members 84, 86, and 88 can obtain the required pressure and exhibit a good cleaning function as long as the region of several tens of μm from the tip is deformed in a desired manner. .

  In order to apply such a pressing force, the surface of the photosensitive drum 16 may be pressed in the radial direction, and the edge portions 85, 87, and 89 may be bitten into elastic deformation (compression deformation). In the fourth to sixth embodiments, the pressing force is adjusted by the press applying means (coil spring 90 and leaf spring 92). The elastic cleaning members 84, 86, and 88 in the fourth to sixth embodiments are rectangular and do not cause a drooping phenomenon, so that they can be used even under a condition where the set angle θ (see FIG. 19) is large. Yes, it is possible to further improve the cleaning performance.

  In addition, the elastic cleaning members 60, 66, 68, 84, 86, 88 of the first embodiment to the sixth embodiment are toner removal devices (cleaning devices) that remove transfer residual toner remaining on the intermediate transfer belt 24. 38). Moreover, each surface (1st surface-4th surface) in each elastic cleaning member 60, 66, 68, 84, 86, 88 of the said 1st Example-6th Example is limited to the plane of illustration. It is not a thing, The aspect comprised from a curved surface or several planes is also included.

  Further, the shape of the opening end 30A on the upper side of the cleaner housing 30 is not limited to the shape shown in the drawing. Further, the portion where the support members 70 and 80 and the holding member 82 are brought into contact with or bonded to each other, The housing 30 may be configured separately and may be integrally fixed to the cleaner housing 30.

  In addition, in the case of the elastic cleaning member 60 of the first embodiment, it can be manufactured simply by improving an existing cleaning device (for example, a cleaning device provided with a blade-like elastic cleaning member 160). There is. Further, in the case of the elastic cleaning members 66, 68, 84, 86, 88 of the second to sixth embodiments, both have a short shape, so that the manufacturing is applied to the elastic cleaning members 66, 68, 84, 86, 88. There is an advantage that the cost can be reduced.

  Further, in the second to sixth embodiments, a static eliminator (not shown) can be arranged using the space in which the blade-like elastic cleaning member 60 is disposed, as compared with the first embodiment. Therefore, there is an advantage that the space can be used effectively. Furthermore, in the case of the second to sixth embodiments, since the elastic cleaning members 66, 68, 84, 86, 88 having a rectangular shape can be equipped only by fixing the support members 70, 80 to the first, Compared to the case of the embodiment, there is an advantage that a supporting base material such as a sheet metal 76 for fixing and supporting the blade-like elastic cleaning member 60 is not required.

Schematic configuration diagram showing an image forming apparatus according to the present embodiment Schematic side view schematically showing the configuration of the cleaning device The schematic side view which expands and shows the periphery of the elastic cleaning member in 1st Example of a cleaning apparatus. The schematic side view which expands and shows the periphery of the elastic cleaning member in 2nd Example of a cleaning apparatus. The schematic perspective view which shows the elastic cleaning member and support member in 2nd Example of a cleaning apparatus. The schematic side view which expands and shows the periphery of the elastic cleaning member in 3rd Example of a cleaning apparatus. The schematic side view which expands and shows the elastic cleaning member in 3rd Example of a cleaning apparatus. Explanatory drawing which shows the contact state with respect to the photosensitive drum of the elastic cleaning member in 2nd Example and 3rd Example. The schematic side view which expands and shows the periphery of the elastic cleaning member in 4th Example of a cleaning apparatus. Schematic side sectional view showing conditions for attaching the cleaning device of the fourth embodiment to the image forming apparatus The schematic front view which shows the elastic cleaning member and support member in 4th Example of a cleaning apparatus Explanatory drawing which shows the contact state with respect to the photosensitive drum of the elastic cleaning member in 1st Example. Explanatory drawing which shows the contact state with respect to the photosensitive drum of the elastic cleaning member in 4th Example. Schematic side view showing the periphery of the elastic cleaning member in the fifth embodiment of the cleaning device The schematic front view which shows the elastic cleaning member and support member in 5th Example of a cleaning apparatus The schematic side view which shows the periphery of the elastic cleaning member in 6th Example of a cleaning apparatus The schematic side view which expands and shows the elastic cleaning member in 6th Example of a cleaning apparatus. Explanatory drawing which shows the contact state with respect to the photosensitive drum of the elastic cleaning member in 6th Example. Explanatory drawing which shows the contact state with respect to the photosensitive drum of the elastic cleaning member in a comparative example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming means 14 Image forming unit 16 Photosensitive drum (image holding body)
18 Charger (Charging device)
20 Exposure device 22 Development device 24 Intermediate transfer belt (intermediate transfer member)
26 Primary transfer roll 27 Photosensitive unit (image carrier unit)
28 Cleaning Device 30 Cleaner Housing 34 Backup Roll 36 Secondary Transfer Roll 38 Toner Removal Device (Cleaning Device)
DESCRIPTION OF SYMBOLS 40 Fixing device 42 Conveying mechanism 60 Elastic cleaning member 62 Base 64 Tip 64A Lower surface (first surface)
64B outer surface (second surface)
64C inner surface (third surface)
65 Edge portion 66 Elastic cleaning member 66A Lower surface (first surface)
66B outer surface (second surface)
66C inner surface (third surface)
67 Edge portion 68 Elastic cleaning member 68A Lower surface (first surface)
68B outer surface (second surface)
68C inner surface (third surface)
68D Upper surface (fourth surface)
69 Edge part 70 Support member 76 Sheet metal (support base material)
80 support member 82 holding member 84 elastic cleaning member 84A bottom surface (first surface)
84B outer surface (second surface)
84C Inner surface (third surface)
86 Elastic cleaning member 86A Lower surface (first surface)
86B outer surface (second surface)
86C Inner surface (third surface)
88 elastic cleaning member 88A bottom surface (first surface)
88B outer surface (second surface)
88C Inner surface (third surface)
88D Upper surface (fourth surface)
90 Coil spring (pressing means)
92 leaf spring (pressing means)
P Recording paper (recording medium)

Claims (4)

On the surface of the image carrier is a rotating body that holds the image is brought into contact with the edge portion from the downstream side in the rotational direction of the image holding member, a plate-shaped elastic cleaning member for cleaning the surface with the edge section,
A support base material that fixes and supports the opposite side of the elastic cleaning member to the edge portion side in the axial direction of the image carrier;
A support member that supports a plurality of surfaces on the edge portion side of the elastic cleaning member;
With
The elastic cleaning member is
A first surface adjacent to the edge portion and facing the upstream side in the rotational direction of the image carrier;
A second surface adjacent to the edge portion on the downstream side in the rotation direction of the image carrier relative to the edge portion;
A third surface adjacent to the first surface on the opposite side of the second surface;
With
The cleaning apparatus, wherein the first surface and the third surface are fixed to the support member. An image carrier,
A charging device for charging the surface of the image carrier;
An exposure device that exposes the surface of the image carrier charged by the charging device and forms an electrostatic latent image on the surface;
A developing device for developing the electrostatic latent image formed by the exposure device with a developer;
An intermediate transfer body to which an image developed by the developing device and held on the surface of the image holding body is transferred;
The cleaning device according to claim 1, wherein the developer remaining on the surface of the image carrier without being transferred to the intermediate transfer member is removed;
An image forming apparatus comprising the. An image carrier,
A charging device for charging the surface of the image carrier;
An exposure device that exposes the surface of the image carrier charged by the charging device and forms an electrostatic latent image on the surface;
A developing device for developing the electrostatic latent image formed by the exposure device with a developer;
An intermediate transfer body to which an image developed by the developing device and held on the surface of the image holding body is transferred;
The cleaning device according to claim 1, wherein the developer remaining on the surface of the intermediate transfer body without being transferred from the intermediate transfer body to a recording medium is removed;
An image forming apparatus comprising the. An image carrier,
The cleaning device according to claim 1, wherein the cleaning device is integrated with the image carrier.
With
An image carrier unit configured to be detachable from an image forming apparatus .

Images