JP2013101196A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately prevent, by a simple configuration, an increase in friction between a cleaning member and an image holding member when residual toner on the surface of the image holding member is removed and recovered by the cleaning member.SOLUTION: The cleaning device 20 removes residual toner t on the surface of the photoreceptor drum 11 by use of the cleaning member 21 and recovers it into a toner recovery part 22. The cleaning device comprises a circulation conveyance part 23 that conveys and circulates recovered toner ta recovered into the toner recovery part. Also, the cleaning device is provided with a rotary brush 27 that supplies the recovered toner, conveyed in this circulation conveyance part, to the surface of the image holding member in a position upstream of the cleaning member in the direction of movement of the image holding member.

Description

  In the present invention, after a toner image is transferred from an image holding member such as a photosensitive drum or an intermediate transfer member that holds and moves the toner image, the toner remaining on the surface of the image holding member is imaged by a cleaning member. The present invention relates to a cleaning device that is removed from the surface of a holding member and is collected by a toner collecting unit, and an image forming apparatus using such a cleaning device. In particular, a cleaning member is pressed against the surface of an image holding member such as a photosensitive drum or an intermediate transfer member, and toner remaining on the surface of the image holding member is removed from the surface of the image holding member and collected. In the cleaning device, the frictional force between the cleaning member and the image holding member is increased, so that wear on the cleaning member is increased, the cleaning member is chipped, and a large load is applied to move the image holding member. And the toner remaining on the surface of the image holding member can be stably and appropriately removed.

  Conventionally, in an image forming apparatus such as a copying machine or a printer, a toner image formed on an image holding member such as a photosensitive drum or an intermediate transfer member is generally transferred and then remains on the surface of the image holding member. The toner that has been removed from the surface of the image holding member by a cleaning device is collected.

  Here, after the toner image is transferred as described above, when the toner remaining on the surface of the image holding member is removed by the cleaning device, conventionally, as shown in FIG. A plate-shaped cleaning member 2a along the width direction of the image holding member 1 is pressed against the surface of the image holding member 1 that moves while holding the toner t, and the toner t on the surface of the image holding member 1 is moved by the cleaning member 2a. The toner is removed and collected in the cleaning device 2, and the collected toner ta collected in this manner is conveyed by the conveying member 2b and guided to a waste toner box (not shown) or the like.

  Further, when the cleaning member 2a is pressed against the surface of the image holding member 1 in this way to remove the toner t on the surface of the image holding member 1, a part of the removed toner t is partly removed from the image holding member 1 and the cleaning member 2a. The frictional resistance between the image holding member 1 and the cleaning member 2a is reduced by a lubricant or the like externally added to the toner t.

  However, it is difficult to stably hold a part of the toner t removed from the surface of the image holding member 1 between the image holding member 1 and the cleaning member 2a. The frictional resistance with the member 2a is increased, thereby increasing the wear of the cleaning member 2a, causing the cleaning member 2a to be chipped, and applying a large load to move the image holding member 1. There has been a problem that a large amount of power is required to move the image holding member 1.

  In particular, in recent years, in order to enhance the durability of the image holding member 1 such as the photosensitive drum or the intermediate transfer member used in the image forming apparatus, the hardness on the surface is increased or the surface is smoothed. As a result, the frictional resistance between the surface of the image holding member 1 and the cleaning member 2a is further increased, and the above-described problem is likely to occur.

  For this reason, conventionally, a lubricant application device is provided at a position upstream of the cleaning member in the moving direction of the image holding member in the cleaning device, and the image holding member is provided by the lubricant application member provided in the lubricant application device. In this proposal, a lubricant is applied to the surface of the image bearing member and the frictional resistance between the surface of the image holding member and the cleaning member is reduced by the lubricant.

  However, when the lubricant application device is provided at a position upstream of the cleaning member in the moving direction of the image holding member, the size of the device is increased and the lubricant needs to be replenished at an appropriate time. The cost is high, and the toner remaining on the surface of the image holding member adheres to the lubricant application member, making it impossible to properly apply the lubricant to the surface of the image holding member. There was a problem.

  In recent years, as disclosed in Patent Document 1, the toner removed from the surface of the image holding member by the cleaning member is collected and accumulated in the cleaning device, and thus accumulated in the cleaning device. The collected toner is supplied by the supply member to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member, and the recovered toner thus supplied is supplied between the surface of the image holding member and the cleaning member. In order to reduce the frictional resistance between the surface of the image holding member and the cleaning member, there has been proposed.

  Here, in the one disclosed in Patent Document 1, since the collected toner collected and accumulated in the cleaning device is directly supplied to the surface of the image holding member by the supply member, the same collected toner is imaged. In particular, when continuously forming images with a small amount of toner remaining on the surface of the image holding member and a low printing rate, the same recovered toner is immediately supplied by the supplying member. The toner is supplied to the surface of the image holding member and is guided many times between the surface of the image holding member and the cleaning member.

  When the same recovered toner is guided between the surface of the image holding member and the cleaning member many times in this way, the lubricant externally added to the recovered toner is gradually peeled off from the toner, thus reducing the lubricant. Even if the toner thus held is held between the image holding member and the cleaning member, the frictional resistance between the image holding member and the cleaning member cannot be sufficiently reduced, and the wear of the cleaning member still remains. There have been problems such as an increase in size, chipping in the cleaning member, a large load applied to move the image holding member, and a large amount of power required to move the image holding member.

JP 2005-308939 A

  In an image forming apparatus such as a copying machine or a printer, the present invention transfers a toner image from an image holding member such as a photosensitive drum or an intermediate transfer member that holds and moves the toner image, and then the surface of the image holding member. It is an object of the present invention to solve the above-described problems in the case of using a cleaning device in which the toner remaining in the toner is removed from the surface of the image holding member by the cleaning member and collected.

  That is, in the present invention, when the toner remaining on the surface of the image holding member as described above is removed from the surface of the image holding member by the cleaning member and collected, the toner between the cleaning member and the image holding member is recovered. Image retention can be appropriately suppressed by increasing frictional force, increasing wear on the cleaning member, chipping of the cleaning member, and applying a large load to move the image holding member. An object of the present invention is to stably and appropriately remove the toner remaining on the surface of the member.

  In the cleaning device according to the present invention, in order to solve the above-described problem, the toner remaining on the surface of the moving image holding member is removed from the surface of the image holding member by the cleaning member and is collected by the toner collecting unit. In the apparatus, the toner collection unit is provided with a circulation conveyance unit that conveys and circulates the collected toner, and the collected toner conveyed in the circulation conveyance unit is more upstream than the cleaning member in the moving direction of the image holding member. A recovered toner supply member for supplying the surface of the image holding member at the side position is provided.

  In the cleaning device according to the present invention, the collected toner removed from the surface of the image holding member by the cleaning member and collected in the toner collection unit is conveyed and circulated in the circulation conveyance unit, and thus collected. Part of the toner is sequentially supplied to the collected toner supply member, and the collected toner is supplied to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member. Will come to be.

  Here, in the above-described cleaning device, the recovered toner supply member that supplies the recovered toner to the surface of the image holding member is, for example, rotating while contacting the surface of the image holding member, A rotating brush or the like to be supplied can be used.

  Further, when the collected toner is supplied to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member by the collected toner supply member as described above, it remains on the surface of the image holding member. It is preferable to control the amount of recovered toner supplied from the recovered toner supply member to the surface of the image holding member by the supply amount control means in accordance with the amount of toner.

  In the image forming apparatus according to the present invention, the toner remaining on the surface of the moving image holding member is removed from the surface of the image holding member by the cleaning member and collected by the toner collecting unit as described above. A cleaning device was used.

  In the cleaning device according to the present invention, the collected toner removed from the surface of the image holding member by the cleaning member and collected by the toner collecting unit as described above is conveyed and circulated in the circulation conveyance unit, and thus circulated. Part of the collected toner is guided to the collected toner supply member, and the collected toner supply member sequentially supplies the collected toner to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member. Therefore, the collected toner is not repeatedly supplied to the surface of the image holding member and held between the image holding member and the cleaning member, but is held between the image holding member and the cleaning member. The lubricant externally added to the collected toner does not gradually peel off from the toner.

  Then, while the collected toner is circulated in the circulation conveyance unit in this way, the collected toner is sequentially supplied to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member. As a result of being held between the surface of the member and the cleaning member, the cleaning member, the image holding member, and the image holding member are formed even when images with a low amount of toner remaining on the surface of the image holding member are continuously formed. Friction resistance is appropriately reduced by the collected toner, and even if a lubricant application device is not provided separately, the wear on the cleaning member increases, the cleaning member becomes chipped, or the image holding member moves. It is possible to appropriately suppress a large load from being applied and to stably and appropriately remove the toner remaining on the surface of the image holding member. To become.

FIG. 10 is a schematic explanatory view showing a state in which a cleaning member is pressed against the surface of an image holding member and toner remaining on the surface of the image holding member is removed by the cleaning device in a conventional cleaning device. 2 is a schematic explanatory diagram of an image forming apparatus that uses a cleaning device according to an exemplary embodiment of the present invention to collect toner remaining on the surface of a photosensitive drum. FIG. In the cleaning device according to the above-described embodiment, the toner remaining on the surface of the photosensitive drum is collected by the cleaning member, and the collected toner is supplied to the surface of the photosensitive drum upstream of the cleaning member by the rotating brush. It is the shown schematic explanatory drawing. FIG. 5 is a schematic explanatory diagram illustrating an example in which the collected toner collected from the surface of the photosensitive drum is circulated in a circulation conveyance unit including a lower conveyance unit and an upper conveyance unit in the cleaning device according to the embodiment. FIG. 6 is a schematic explanatory view showing another example in which the collected toner collected from the surface of the photosensitive drum is circulated in a circulation conveyance unit including a lower conveyance unit and an upper conveyance unit in the cleaning device according to the embodiment. In the cleaning device according to the above-described embodiment, a schematic explanatory view showing an example in which the amount of recovered toner supplied to the surface of the photosensitive drum is controlled by the rotating brush according to the amount of toner remaining on the surface of the photosensitive drum. It is. FIG. 4 is a schematic explanatory view showing a state in which the cleaning device according to the above embodiment is used to collect toner remaining on the surface of the intermediate transfer belt.

  Next, a cleaning device and an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. The cleaning device and the image forming apparatus according to the present invention are not limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range that does not change the gist thereof.

  In the image forming apparatus using the cleaning device 20 according to this embodiment, as shown in FIG. 2, the surface of the image holding member composed of the rotating photosensitive drum 11 is charged by the charging device 12 and charged in this way. The surface of the photosensitive drum 11 is exposed in accordance with image information by a latent image forming device 13 using a laser or the like, and an electrostatic latent image is formed on the surface of the photosensitive drum 11.

  Then, toner is supplied from the developing device 14 to the portion of the electrostatic latent image formed on the surface of the photosensitive drum 11 in this way, and a toner image corresponding to the electrostatic latent image is formed on the surface of the photosensitive drum 11. Like to do.

  Next, the toner image thus formed on the surface of the photosensitive drum 11 is guided to a position facing the roller-shaped transfer device 15, and a recording sheet is provided between the photosensitive drum 11 and the transfer device 15. S is guided, and the toner image formed on the surface of the photosensitive drum 11 is transferred to the recording sheet S by the transfer device 15.

  Then, the recording sheet S to which the toner image is transferred in this way is guided to a fixing device (not shown), and the toner image is fixed to the recording sheet S in this fixing device.

  Further, the toner remaining on the surface of the photosensitive drum 11 without being transferred to the recording sheet S is removed from the surface of the photosensitive drum 11 by the cleaning device 20 and collected.

  Here, in the cleaning device 20 according to this embodiment, as shown in FIGS. 2 and 3, a plate-shaped cleaning member 21 is pressed against the surface of the photosensitive drum 11 after the toner image is transferred. The toner t remaining on the surface of the photosensitive drum 11 is removed from the surface of the photosensitive drum 11 by the cleaning member 21.

  The toner t removed from the surface of the photosensitive drum 11 in this way is collected by the toner collecting unit 22 of the cleaning device 20, and the collected toner ta collected in this way is guided to the circulation conveyance unit 23. .

  Further, in the cleaning device 20 of this embodiment, a partition wall 24 along the axial direction of the photosensitive drum 11 is provided in the circulation transport unit 23, and the circulation transport unit 23 is separated from the lower transport unit 23 a by the partition wall 24. As shown in FIG. 4, the separation ports 24a and 24b are used to circulate the collected toner ta between both ends of the partition wall 24 between the lower conveyance unit 23a and the upper conveyance unit 23b. Is provided.

  Then, the lower conveying unit 23a and the upper conveying unit 23b are provided with conveying members 25 and 26 provided with conveying screws 25b and 26b on the outer circumferences of the rotary shafts 25a and 26a, respectively, and the conveying members 25 and 26 are rotated. Thus, the collected toner ta is conveyed in the opposite direction in the lower conveying unit 23a and the upper conveying unit 23b, and the collected toner ta is passed through the circulation ports 24a and 24b provided at both ends of the partition wall 24. It is made to circulate between 23a and the upper conveyance part 23b.

  Further, at a position upstream of the cleaning member 21 in the moving direction of the photosensitive drum 11, the recovered toner supply member that supplies the recovered toner ta to the surface of the photosensitive drum 11 is provided along the upper conveying portion 23 b. A rotating brush 27 is provided, and the rotating brush 27 rotates in contact with the surface of the photosensitive drum 11 at a position upstream of the cleaning member 21 in the moving direction of the photosensitive drum 11.

  Then, a part of the collected toner ta conveyed along the upper conveying portion 23 b is supplied to the rotating brush 27, the rotating brush 27 is rotated, and the collected toner ta is cleaned by the rotating brush 27 by the cleaning member. The photosensitive drum 11 is supplied to the surface of the photosensitive drum 11 at a position upstream of the photosensitive drum 11 in the moving direction of the photosensitive drum 11.

  In this way, the collected toner ta is circulated between the lower conveyance unit 23a and the upper conveyance unit 23b, and at the position upstream of the cleaning member 21 in the movement direction of the photosensitive drum 11, the rotating brush 27 is used. The collected toner ta is sequentially supplied to the surface of the photosensitive drum 11, and the collected toner ta is sequentially guided and held between the surface of the photosensitive drum 11 and the cleaning member 21. For this reason, the same recovered toner ta is repeatedly introduced between the surface of the photosensitive drum 11 and the cleaning member 21 and externally added to the recovered toner ta, as shown in Patent Document 1 above. The lubricant does not peel off.

  As a result, the friction between the cleaning member 21 and the photosensitive drum 11 can be achieved even when images with a small amount of toner t remaining on the surface of the photosensitive drum 11 and a low printing rate are continuously formed as described above. The resistance is appropriately reduced by the collected toner ta guided one after another, and even if a lubricant application device is not provided separately, the wear on the cleaning member 21 increases, the cleaning member 21 is chipped, the photosensitive member A large load applied to move the body drum 11 is appropriately suppressed, and the toner t remaining on the surface of the photoreceptor drum 11 can be stably and appropriately removed.

  Further, in this embodiment, the scraper is in contact with the rotary brush 27 at a position downstream of the rotary brush 27 in the rotation direction with respect to the position where the rotary brush 27 is in contact with the surface of the photosensitive drum 11. 28, and the scraper 28 removes the collected toner ta adhering to the rotating brush 27 from the rotating brush 27 and collects it in the toner collecting section 22.

  Further, in the cleaning device 20 of this embodiment, a recovered toner discharge portion 23c continuous with the upper conveying portion 23b is provided beyond the circulation port 24b on the downstream side in the conveying direction of the collected toner ta in the upper conveying portion 23b. At the same time, a conveying member 26 provided in the upper conveying portion 23b is extended into the collected toner discharging portion 23c. Then, the transport member 26 guides the excess collected toner ta beyond the circulation port 24b into the collected toner discharge portion 23c, and the excess collected toner ta is discharged to the collected toner discharge portion 23c. The outlet 23d is led to a waste toner box (not shown).

  Further, as described above, the extended conveying member 26 provided in the upper conveying portion 23b is provided in the collected toner discharge portion 23c provided on the downstream side in the conveying direction of the collected toner ta in the upper conveying portion 23b. As shown in FIG. 5, the reverse conveying screw 26c in the opposite direction to the conveying screw 26b in the conveying member 26 in the portion on the inlet side of the collected toner discharging portion 23c through which the collected toner ta is guided from the upper conveying portion 23b. The collected toner ta guided from the upper transport unit 23b to the collected toner discharge unit 23c can be suppressed.

  In this manner, when the amount of the collected toner ta that is continuously formed and the toner collection unit 22 collects an image with a low printing rate is small, an image with a high printing rate is formed continuously and the toner collection unit 22. In any case where the amount of the collected toner ta collected in the second stage is large, the amount of the collected toner ta in the circulation conveyance unit 23 constituted by the lower conveyance unit 23a and the upper conveyance unit 23b is made constant. In the upper conveyance unit 23b that supplies the collected toner ta to the rotating brush 27, variation in the amount of the collected toner ta in the conveyance direction of the collected toner ta is also suppressed. As a result, a fixed amount of collected toner ta is supplied to the surface of the photosensitive drum 11 by the rotating brush 27, and the frictional resistance between the cleaning member 21 and the photosensitive drum 11 is stably reduced. .

  Further, as a supply amount control means 30 for controlling the amount of recovered toner ta supplied from the rotary brush 27 to the surface of the photosensitive drum 11 in correspondence with the amount of toner t remaining on the surface of the photosensitive drum 11, As shown in FIG. 6, a detection device 31 that detects the amount of toner t remaining on the surface of the photosensitive drum 11 according to the printing rate and the like, and the residual on the surface of the photosensitive drum 11 detected by the detection device 31. A rotation control device 32 that controls the rotation speed of the rotary brush 27 can be provided in accordance with the amount of toner t to be processed.

  When the amount of toner t remaining on the surface of the photosensitive drum 11 is small, this is detected by the detection device 31, and based on this, the rotation speed of the rotary brush 27 is determined by the rotation control device 32. The amount of the collected toner ta supplied to the surface of the photosensitive drum 11 can be increased, and an appropriate amount of the collected toner ta can be held between the cleaning member 21 and the photosensitive drum 11. Further, in this case, the rotational speeds of the transport members 25 and 26 provided in the lower transport unit 23a and the upper transport unit 23b are also changed, and the amount of toner t remaining on the surface of the photosensitive drum 11 is small. Alternatively, the rotational speed of each of the transport members 25 and 26 can be increased so that the collected toner ta in the circulation transport unit 23 is promptly supplied from the upper transport unit 23b to the rotary brush 27.

  In the initial stage of using the cleaning device 20, since the collected toner ta does not exist in the circulation conveyance unit 23, a predetermined amount of toner t is accommodated in the circulation conveyance unit 23 in the initial stage. It is preferable to do so.

  Further, in this embodiment, the case where the toner t remaining on the surface of the image holding member including the photosensitive drum 11 is removed and collected by the cleaning device 20 has been described. An intermediate transfer member such as an intermediate transfer belt to which a toner image is transferred from a drum or the like may be used.

  For example, as shown in FIG. 7, an intermediate transfer belt 16 is used as an image holding member, and the toner t remaining on the intermediate transfer belt 16 is removed from the surface of the intermediate transfer belt 16 by the cleaning device 20 and collected. The collected toner ta collected in this way is supplied to the surface of the intermediate transfer belt 16 at a position upstream of the cleaning member 21 in the movement direction of the intermediate transfer belt 16 by the rotating brush 27 as described above. You can also

11 Photosensitive drum (image holding member)
12 Charging Device 13 Latent Image Forming Device 14 Developing Device 15 Transfer Device 16 Intermediate Transfer Belt (Image Holding Member)
DESCRIPTION OF SYMBOLS 20 Cleaning apparatus 21 Cleaning member 22 Toner collection part 23 Circulation conveyance part, 23a Lower conveyance part, 23b Upper conveyance part, 23c Collected toner discharge part, 23d Discharge port 24 Partition, 24a, 24b Circulation port 25 Conveyance member, 25a Rotating shaft, 25b conveying screw 26 conveying member, 26a rotating shaft, 26b conveying screw, 26c reverse conveying screw 27 rotating brush (collected toner supply member)
28 Scraper 30 Supply amount control means 31 Detection device 32 Rotation control device S Recording sheet t Toner, ta Collected toner

Claims (4)

  In a cleaning device in which toner remaining on the surface of the moving image holding member is removed from the surface of the image holding member by a cleaning member and collected by the toner collecting unit, the collected toner collected by the toner collecting unit is conveyed. A circulation toner supply member that circulates and supplies the collected toner conveyed in the circulation conveyance unit to the surface of the image holding member at a position upstream of the cleaning member in the moving direction of the image holding member. A cleaning device comprising:   2. The cleaning apparatus according to claim 1, wherein the collected toner supply member rotates while contacting the surface of the image holding member to supply the collected toner to the surface of the image holding member. .   3. The cleaning device according to claim 1, wherein the amount of recovered toner supplied from the recovered toner supply member to the surface of the image holding member is set in correspondence with the amount of toner remaining on the surface of the image holding member. A cleaning device comprising supply amount control means for controlling. An image forming apparatus comprising a cleaning device that removes toner remaining on the surface of a moving image holding member from the surface of the image holding member by a cleaning member and collects the toner in a toner collecting unit. An image forming apparatus using the cleaning device according to claim 1.

Images