JP2013156422A - Belt driving device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize tension generated on a belt member, and to prevent the deterioration of image quality.SOLUTION: A belt driving device includes: a drive roller; an idle roller; a belt member traveled by the drive roller and the idle roller; a cleaning portion arranged so as to freely move in a direction stretching the belt member, and removing deposits on the belt member; and an energizing member for energizing the cleaning portion in the direction stretching the belt member. The cleaning portion is arranged so as to freely move in the direction stretching the belt member, and energized in the direction stretching the belt member, thereby even if a load applied on the belt member in a transfer portion, or the rotation speed of the transfer member changes, the change of tension can be suppressed.

Description

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

  Conventionally, image forming apparatuses such as printers, copiers, facsimile machines, and multifunction machines, for example, color printers, are provided with four color image forming units of yellow, magenta, cyan, and black. An image is formed. A transfer belt (conveyance belt) is movably disposed along the image forming unit. As the transfer belt travels, the sheet is conveyed, and the toner images of the respective colors are sequentially superimposed and transferred to the sheet. The toner image is formed. In this case, the sheet is conveyed by being attached to the transfer belt by static electricity. Subsequently, the paper is sent to a fixing device, and a color toner image is fixed on the paper in the fixing device to form a color image (see, for example, Patent Document 1).

  By the way, a belt driving device is provided in which a color toner image is formed by sequentially transferring toner images of respective colors onto an intermediate transfer belt as a belt member, and transferring the color toner image onto a sheet. An intermediate transfer type color printer is provided.

  In the printer, the intermediate transfer belt is stretched by a drive roller, an idle roller, and a backup roller, and the plurality of image forming units and the primary transfer roller face each other through the intermediate transfer belt. The backup roller and the secondary transfer roller are made to face each other.

  As the intermediate transfer belt runs, the toner images of the respective colors are sequentially superimposed and transferred to the intermediate transfer belt in a primary transfer portion formed between the photosensitive drums and the intermediate transfer belt. An image is formed, and a color toner image is transferred onto a sheet in a secondary transfer portion formed between the intermediate transfer belt and the secondary transfer roller.

JP 2006-227227 A

  However, in the conventional intermediate transfer type color printer, when the load applied to the intermediate transfer belt in the secondary transfer portion changes or the rotation speed of the secondary transfer roller fluctuates, it occurs in the intermediate transfer belt. The tension changes and slip occurs between the drive roller and the intermediate transfer belt, or the running speed of the intermediate transfer belt changes. As a result, color misregistration, image disturbance, etc. occur, and the image quality deteriorates.

  The present invention solves the problems of the conventional intermediate transfer type color printer, can stabilize the tension generated in the belt member, and can prevent the image quality from deteriorating. An object of the present invention is to provide an image forming apparatus.

  Therefore, in the belt driving device of the present invention, a drive roller, an idle roller that is rotated by being driven by the drive roller, a belt member that is driven by the drive roller and the idle roller, and the belt member is stretched. A cleaning unit that is movably disposed in the direction in which the belt member is removed, and a biasing member that biases the cleaning unit in a direction in which the belt member is stretched.

  According to the present invention, in the belt drive device, the drive roller, the idle roller that is rotated by being driven by the drive roller, the belt member that is driven by the drive roller and the idle roller, and the belt member is stretched. A cleaning unit that is movably disposed in the direction in which the belt member is removed, and a biasing member that biases the cleaning unit in a direction in which the belt member is stretched.

  In this case, the cleaning unit is movably disposed in the direction in which the belt member is stretched, and is biased in the direction in which the belt member is stretched by the biasing member, so that a load applied to the belt member in the transfer unit is increased. Even if it changes or the rotational speed of the transfer member fluctuates, it is possible to suppress the tension from changing downstream from the cleaning portion in the running direction of the belt member.

  Therefore, it is possible to prevent a slip from occurring between the drive roller and the belt member and a change in the traveling speed of the belt member, and it is possible to prevent a reduction in image quality.

  In addition, even when the belt member is stretched and the tension is changed to cause slack, the cleaning unit moves according to the slack of the belt member, so that the tension of the belt member can be maintained.

  Further, since the tension is generated by the cleaning unit, it is not necessary to provide a device for generating the tension in addition to the cleaning unit. Therefore, the cost of the belt driving device and the image forming apparatus can be reduced.

It is a principal part enlarged view of the belt cleaning part in the 1st Embodiment of this invention. 1 is a schematic diagram of a color printer according to a first embodiment of the present invention. It is a figure for demonstrating operation | movement of the belt cleaning part in the 1st Embodiment of this invention. It is a principal part enlarged view of the belt cleaning part in the 2nd Embodiment of this invention. It is a figure for demonstrating operation | movement of the belt cleaning part in the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a color printer as an image forming apparatus will be described.

  FIG. 2 is a schematic diagram of a color printer according to the first embodiment of the present invention.

  In the figure, 10 is a printer, and Cs is a housing of the printer 10. A standard tray Sm1 as a first paper feeder is disposed in the main body of the printer 10, that is, in the lower part of the apparatus main body.

  The first sheet feeding device Sm1 is a sheet cassette 11 serving as a first medium stacking section that is detachably disposed with respect to the housing Cs, and a medium accommodating section. And a motor 14 as a lift-up driving unit for lifting the paper P in the paper cassette 11.

  The paper cassette 11 is swingably arranged with the support shaft sh1 as a swing center, a paper stacking plate 12 as a first medium stacking plate on which the paper P is stacked, and the paper on the paper stacking plate 12 A lift-up lever 13 is provided on the feeding side of P so as to be swingable about the support shaft sh2 as a swing center, and the tip of the lift-up lever 13 is brought into contact with the back surface of the sheet stacking plate 12. Further, the support shaft sh2 and the motor 14 are engaged with each other in a freely detachable manner.

  When the paper cassette 11 is inserted into the housing Cs, the support shaft sh2 and the motor 14 are engaged, and when a control unit (not shown) drives the motor 14, the support shaft sh2 is rotated and lifted up. The front end of the lever 13 lifts the paper stacking plate 12 and the front end of the paper P stacked on the paper stacking plate 12 is raised. When the front end of the paper P reaches a predetermined height and the rising detection unit 21 as the first medium detection unit detects the paper P and sends the sensor output to the control unit, the control unit turns the motor 14 on. Stop.

  Subsequently, the control unit operates the paper feeding unit 20 to feed out the paper P one by one and separate it to feed paper. For this purpose, the sheet feeding unit 20 is brought into contact with the uppermost sheet P when the rising detection unit 21 detects the sheet P, and the pickup roller 22 as a first feeding member that feeds the sheet P, and A feed roller 23 and a retard roller 24 that are disposed in contact with each other and constitute a first separation element are provided in front of the pickup roller 22.

  The pickup roller 22 and the feed roller 23 are rotated in the direction of the arrow by a motor (not shown) as a first paper feed driving unit. The retard roller 24 is rotated in the direction of the arrow (the same direction as the pickup roller 22 and the feed roller 23) by a torque generator (not shown) to generate torque. The pickup roller 22 and the feed roller 23 incorporate a one-way clutch mechanism (not shown) so that the pickup roller 22 and the feed roller 23 can idle in the direction of the arrow even when the rotation from the motor is not transmitted.

  Accordingly, the paper P fed from the paper cassette 11 by the pickup roller 22 is separated one by one by the feed roller 23 and the retard roller 24 and fed to the first transport path Rt1.

  Then, on the downstream side of the sheet feeding unit 20 in the conveyance direction of the sheet P, a sheet sensor 31 as a second medium detection unit and a pair of conveyance rollers as a first conveyance roller for correcting skew of the sheet P in order. 32, a sheet sensor 33 serving as a third medium detection unit, and a sheet sensor 33 that is rotated at the timing when the sheet P is detected by the sheet sensor 33 and that feeds the sheet P to the image forming unit 39. A writing sensor 36 serving as a fourth medium detecting unit that detects the sheet P in order to take the timing of image formation in the conveying roller pairs 34 and 35 and the image forming unit 39, that is, the writing timing, is provided.

  The conveying roller pairs 32, 34, and 35 are composed of two rollers that are rotatably disposed in contact with each other, and a not-illustrated gear train as a drive transmission system from a not-illustrated conveying motor as a conveying drive unit. Rotation is transmitted through and is rotated in the direction of the arrow. Further, a second transport path Rt2 is connected between the transport roller pair 32 and the paper sensor 33 in the first transport path Rt1, and the second transport path Rt2 serves as a second paper feeding device. Multipurpose tray (MPT) 60 is provided.

  The multi-purpose tray 60 includes a paper stacking plate 64 as a second medium stacking plate on which the paper P is stacked, a pickup roller 62 as a second feeding member with which the uppermost paper P is brought into contact, and the pickup A feed roller 61 and a retard roller 63 are provided in front of the roller 62 so as to be in contact with each other and constitute a second separation element.

  The pickup roller 62 and the feed roller 61 are rotated in the direction of the arrow by a motor (not shown) as a second paper feeding drive unit. The retard roller 63 is rotated in the direction of the arrow (the same direction as the pickup roller 62 and the feed roller 61) by a torque generator (not shown) to generate torque.

  Accordingly, the paper P fed from the paper stacking plate 64 by the pickup roller 62 is separated one by one by the feed roller 61 and the retard roller 63 and fed to the second transport path Rt2.

  The image forming unit 39 is arranged in four image forming units 40Y, 40M, 40C, and 40Bk that respectively form yellow, magenta, cyan, and black images, and the image forming units 40Y, 40M, 40C, and 40Bk. The image forming units 40Y, 40M, 40C, and 40Bk are disposed along the LED head 43 serving as an exposure device and the image forming units 40Y, 40M, 40C, and 40Bk disposed so as to face the respective photosensitive drums 41 serving as image bearing members. In addition, a primary transfer belt unit 70 as a primary transfer unit that sequentially superimposes and transfers toner images as developer images of respective colors onto an intermediate transfer belt 71 as an intermediate transfer medium to form a color toner image, the intermediate transfer A secondary transfer roller as a secondary transfer unit for transferring the color toner image formed on the belt 71 onto the paper P. In the present embodiment, the first unit that removes the foreign matter remaining on the intermediate unit 80 and the intermediate transfer belt 71 and adhering to the intermediate transfer belt 71, that is, the adhered matter on the intermediate transfer belt 71, in this embodiment, is removed. A belt cleaning unit 90 as a cleaning unit. The primary transfer belt unit 70, the secondary transfer roller unit 80, and the belt cleaning unit 90 constitute a belt driving device.

  Next, the image forming units 40Y, 40M, 40C, and 40Bk will be described. Since the image forming units 40Y, 40M, 40C, and 40Bk have the same structure, only the black image forming unit 40Bk will be described.

  The image forming unit 40Bk is detachably disposed on the main body of the image forming unit 40Bk, that is, the image forming unit main body 40 and the image forming unit main body 40, and a toner cartridge as a developer container that stores toner. 46 (in the figure, for convenience, it is described separately from the image forming unit main body 40). In the present embodiment, the image forming unit main body 40 and the toner cartridge 46 are formed separately, but can be formed integrally.

  In the image forming unit main body 40, the photosensitive drum 41 is rotatably arranged in the direction of the arrow. Around the photosensitive drum 41, a photosensitive member is sequentially arranged from the upstream side in the rotational direction of the photosensitive drum 41. A black roller is attached to the surface of the photosensitive drum 41 on which the electrostatic latent image as a latent image is formed by the charging roller 42 and the LED head 43 as a charging device for uniformly charging the surface of the drum 41. A developing roller 44 as a developer carrying member that forms an image, and a drum cleaning unit as a second cleaning unit that removes toner remaining on the surface of the photosensitive drum 41 after transferring the toner image, that is, residual toner. 45 etc. are arranged. The developing roller 44 constitutes a developing device together with a toner supply roller 44a as a developer supply member.

  In the image forming unit 40Bk, the rotation of the photosensitive drum 41, the charging roller 42, and the developing roller 44 is transmitted from a drum motor (not shown) as a driving unit for image formation via a gear train (not shown) as a drive transmission system. It is rotated in the direction of the arrow.

  Next, the primary transfer belt unit 70 will be described.

  The primary transfer belt unit 70 transfers each color toner image formed by the image forming units 40Y, 40M, 40C, and 40Bk to the intermediate transfer belt 71. For this purpose, the primary transfer belt unit 70 includes a drive roller 72 as a first roller connected to a belt motor (not shown) as a drive unit for running the belt, and the drive roller 72 as the drive roller 72 rotates. A backup roller as a third roller, which is disposed opposite to the idle roller 73 and the secondary transfer roller unit 80 as a second roller to be driven and rotated, and is rotated in accordance with the rotation of the drive roller 72. The intermediate transfer belt 71 stretched by the roller 74, the drive roller 72, the idle roller 73, and the backup roller 74, and the photoreceptors of the image forming units 40Y, 40M, 40C, and 40Bk via the intermediate transfer belt 71. Opposed to the drum 41 and pressed against the intermediate transfer belt 71 As a first transfer member disposed, and includes a primary transfer roller 75 as a primary transfer member. A primary transfer portion serving as a first transfer portion is formed between the photosensitive drums 41 of the image forming units 40Y, 40M, 40C, and 40Bk and the intermediate transfer belt 71.

  When the drive roller 72 is rotated in the direction of the arrow in response to the rotation from the belt motor, the intermediate transfer belt 71 is caused to travel in the direction of the arrow. As the intermediate transfer belt 71 is traveled, the idle roller 73 and the backup roller 74 are driven. Is rotated in the direction of the arrow.

  The intermediate transfer belt 71 runs between the photosensitive drum 41 and the primary transfer roller 75 while abutting on the photosensitive drums 41 of the image forming units 40Y, 40M, 40C, and 40Bk. At this time, each primary transfer roller A predetermined voltage is applied to 75, and the toner images of the respective colors formed on the respective photosensitive drums 41 are sequentially superimposed and transferred to the intermediate transfer belt 71, thereby forming a color toner image.

  Next, the secondary transfer roller unit 80 will be described.

  The secondary transfer roller unit 80 is disposed on the downstream side of the drive roller 72 in the traveling direction of the intermediate transfer belt 71 and on the upstream side of the idle roller 73 so as to face the backup roller 74 and to be rotatable. A secondary transfer roller 81 as a second transfer member for transferring a color toner image on the intermediate transfer belt 71 to the paper P and as a secondary transfer member, and the secondary transfer roller 81 on the backup roller 74 side. The spring sp1 as an urging member that is urged toward the primary transfer belt unit 70 and the secondary transfer roller 81 is disposed in contact with the secondary transfer roller 81, and adsorbs toner adhering to the secondary transfer roller 81. A cleaner shaft 82 as a developer collecting member to be collected, and scrapes toner collected by the cleaner shaft 82. Comprising a cleaning member 83 such that. Note that a secondary transfer portion as a second transfer portion is formed between the intermediate transfer belt 71 and the secondary transfer roller 81. The cleaner shaft 82 and the cleaning member 83 constitute a secondary transfer cleaning unit as a third cleaning unit.

  A fixing device 50 as a fixing device is disposed downstream of the image forming unit 39 in the first transport path Rt1 (downstream of the primary transfer unit). The fixing device 50 is disposed in contact with the upper roller 51 as a first fixing roller whose surface is formed of an elastic body, and a second fixing whose surface is formed of an elastic body. The upper roller 51 is provided with a halogen lamp 53a as a first heat source, and the lower roller 52 is provided with a halogen lamp 53b as a second heat source. The upper roller 51 and the lower roller 52 are rotated in the direction of the arrow to heat and press the color toner image on the paper P discharged from the image forming unit 39 to melt the color toner image and fix it on the paper P. Forming a color image.

  The paper P on which the color image is formed is conveyed by a pair of discharge rollers 54a to 54d as first to fourth discharge rollers, discharged outside the apparatus main body, and stacked on a stacker 55 as a medium stacking unit. . The discharge roller pairs 54a to 54d are rotated in the direction of an arrow by being transmitted from a discharge motor (not shown) as a discharge drive unit via a gear train (not shown) as a drive transmission system.

  In addition, a paper sensor 56 as a fifth medium detection unit is disposed at the exit of the fixing device 50. When the paper sensor 56 detects the paper P, the sensor output is sent to the control unit. When the sensor output is received, the drive timing of the discharge motor for rotating the discharge roller pairs 54a to 54d is set.

  Next, the belt cleaning unit 90 will be described.

  FIG. 1 is an enlarged view of a main part of the belt cleaning unit in the first embodiment of the present invention, and FIG. 3 is a diagram for explaining the operation of the belt cleaning unit in the first embodiment of the present invention.

  As shown in the figure, the belt cleaning unit 90 is disposed so as to be movable in a direction in which the intermediate transfer belt 71 is stretched, that is, in a direction perpendicular to the traveling direction of the intermediate transfer belt 71. A blade frame 94 as a frame member disposed downstream of the backup roller 74 (FIG. 1) and upstream of the idle roller 73 in the traveling direction of FIG. 1, and a holding portion attached to the blade frame 94 Blade holder 95, a cleaning blade 96 that is held by the blade holder 95, is disposed with its tip abutting against the surface of the intermediate transfer belt 71, and scrapes off the toner on the intermediate transfer belt 71, and has a spiral shape And a toner discharge chamber as a developer discharge chamber surrounded by the blade frame 94. In the chamber rm, the toner that is rotatably supported by the rotation shaft sh3 and is extended and disposed. The toner scraped off by the cleaning blade 96 with the rotation and dropped into the toner discharge chamber rm, that is, waste. An auger 97 as an adhering material conveying member that conveys toner, and an auger 97 as a developer conveying member, is disposed in contact with the intermediate transfer belt 71 on the inner side of the intermediate transfer belt 71, and is disposed on the blade by a rotation shaft sh4 A support shaft 93 is provided as a contact member that is rotatably supported with respect to the frame 94 and as a rotation support member.

  Further, a spring 92 as an urging member is disposed on the inner side of the intermediate transfer belt 71, and the spring 92 faces the support shaft 93, the blade frame 94, etc. outward (the support shaft 93 is transferred to the intermediate transfer belt 71). (Toward the belt 71 side) to generate a predetermined tension on the intermediate transfer belt 71. The cleaning blade 96 is disposed at a position facing the support shaft 93, and the tip is pressed against the support shaft 93 via the intermediate transfer belt 71 with a predetermined pressure.

  A base portion 98 as a structure that rotatably supports the drive roller 72, the idle roller 73, the backup roller 74, the primary transfer roller 75, and the like is fixed to the casing Cs in the apparatus main body. Is done. The blade frame 94 is formed with a protruding portion am as an engaged portion and as a guided portion that protrudes inward from the intermediate transfer belt 71. The base portion 98 is formed with a guide portion 91 that is engaged with the protruding portion am and guides the protruding portion am as an engaging portion and a guiding portion. The spring 92 is accommodated in a space between the bottom portion 91 a of the guide portion 91. The protruding portion am and the guide portion 91 are engaged with each other so that the protruding portion am can stably advance and retreat in the guide portion 91, and the protruding portion am is connected to the inner wall w1 of the guide portion 91. A correspondingly shaped outer wall w2 is provided, and a slight gap is formed between the inner wall w1 and the outer wall w2.

  Therefore, as shown in FIG. 3, the spring 92 urges the protruding portion am toward the outside of the guide portion 91 to thereby move the support shaft 93 toward the intermediate transfer belt 71 as described above. The intermediate transfer belt 71 is urged to generate a predetermined tension.

  In this case, since the protruding portion am and the guide portion 91 are engaged, the belt cleaning unit 90 stretches the intermediate transfer belt 71 while sliding the protruding portion am and the guide portion 91 (arrows). A direction), that is, a direction in which the tension of the intermediate transfer belt 71 is increased, and a direction in which the intermediate transfer belt 71 is loosened (a direction opposite to the arrow A direction), that is, a direction in which the tension of the intermediate transfer belt 71 is decreased. Can do. Further, when the belt cleaning unit 90 moves, the positional relationship among the support shaft 93, the intermediate transfer belt 71, and the cleaning blade 96 is maintained.

  The spring 92 urges the protrusion am formed on the blade frame 94 of the belt cleaning unit 90 in the direction of increasing the tension of the intermediate transfer belt 71. Therefore, even if the intermediate transfer belt 71 is slack, the belt cleaning unit 90 moves according to the slack of the intermediate transfer belt 71, so that the tension of the intermediate transfer belt 71 can be maintained.

  Note that the toner remaining on the intermediate transfer belt 71 after the color toner image is transferred is scraped off by the cleaning blade 96 and dropped into the toner discharge chamber rm as described above, and the toner is discharged into the toner discharge chamber rm. By the auger 97 rotated in step 1, the toner is conveyed as waste toner to a toner collecting unit (not shown).

  By the way, if the load applied to the intermediate transfer belt 71 in the secondary transfer portion changes or the rotational speed of the secondary transfer roller 81 fluctuates, the tension applied to the intermediate transfer belt 71 changes. At this time, the drive roller If slip occurs between the intermediate transfer belt 71 and the intermediate transfer belt 71 or the running speed of the intermediate transfer belt 71 changes, color misregistration, image disturbance, and the like occur, and image quality deteriorates.

  Therefore, in the present embodiment, the intermediate transfer belt 71 is sandwiched between the cleaning blade 96 and the support shaft 93, and accordingly, the belt cleaning unit 90 that applies the maximum load to the drive roller 72 when the intermediate transfer belt 71 is driven. Are arranged downstream of the backup roller 74 and upstream of the idle roller 73 in the traveling direction of the intermediate transfer belt 71 so as to generate a predetermined tension on the intermediate transfer belt 71.

  In this case, a large tension is generated in a region downstream of the belt cleaning unit 90 in the traveling direction of the intermediate transfer belt 71 and upstream of the drive roller 72, and downstream of the drive roller 72 and the belt cleaning unit. A small tension is generated in a region upstream of 90.

  Therefore, even if the load applied to the intermediate transfer belt 71 in the secondary transfer unit changes or the rotational speed of the secondary transfer roller 81 fluctuates, the downstream side of the belt cleaning unit 90 in the traveling direction of the intermediate transfer belt 71 And since the big tension | tensile_strength is generated in the area | region upstream from the drive roller 72, it can suppress that a tension | tensile_strength changes. As a result, it is possible to prevent a slip between the drive roller 72 and the intermediate transfer belt 71 and a change in the traveling speed of the intermediate transfer belt 71, and to reduce the tension generated in the intermediate transfer belt 71. It can be stabilized. In addition, color misregistration, image disturbance, and the like do not occur, and deterioration of image quality can be prevented.

  In addition, even if the intermediate transfer belt 71 is stretched and the tension changes to cause slack, the belt cleaning unit 90 moves according to the slack of the intermediate transfer belt 71, so that the tension of the intermediate transfer belt 71 can be maintained. it can.

  Further, since tension is generated in the intermediate transfer belt 71 by the belt cleaning unit 90, it is not necessary to provide a device for generating tension in addition to the belt cleaning unit 90. Therefore, the cost of the belt driving device and the printer 10 can be reduced.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  FIG. 4 is an enlarged view of a main part of the belt cleaning unit in the second embodiment of the present invention, and FIG. 5 is a diagram for explaining the operation of the belt cleaning unit in the second embodiment of the present invention.

  In this case, in the toner discharge chamber rm as the developer discharge chamber surrounded by the blade frame 94 as the frame member, the auger 97 as the adhering material transfer member and as the developer transfer member is rotated by the rotation shaft sh3. It is supported freely and is extended.

  In addition, an arm part 99 as a support member is formed at a predetermined position in the base part 98 as a structure, and the blade frame 94 is formed with respect to the arm part 99 with the rotation shaft sh3 as a swing center. And can be swung freely. That is, the belt cleaning unit 90 as the first cleaning unit is used as a belt member and the intermediate transfer belt 71 as an intermediate transfer medium is stretched (arrow B direction), that is, the tension of the intermediate transfer belt 71. And a direction in which the intermediate transfer belt 71 is loosened (a direction opposite to the arrow B direction), that is, a direction in which the tension of the intermediate transfer belt 71 is reduced.

  A spring 92 as an urging member is disposed between the protruding portion am as the engaged portion formed on the blade frame 94 and as the guided portion and the base portion 98. Urges the protrusion am toward the outside of the intermediate transfer belt 71. Therefore, the support shaft 93, the blade frame 94, and the like as the contact member and the rotation support member are urged outward (the support shaft 93 is directed toward the intermediate transfer belt 71), and the intermediate transfer belt A predetermined tension is generated in 71.

  The auger 97 is rotated in a toner discharge chamber rm as a developer discharge chamber, so that the toner as the developer that has fallen into the toner discharge chamber rm is collected as waste toner through a transport pipe (not shown). In this embodiment, the blade frame 94 is rotatably supported by the rotation shaft sh3, and the position of the auger 97 is set by the arm portion 99 and does not change. The toner does not leak at the connecting portion between the toner discharge chamber rm and the transport pipe.

  In each of the above embodiments, the color printer 10 including the four image forming units 40Y, 40M, 40C, and 40Bk has been described. However, the present invention is applied to a single-color printer including one image forming unit. Can be applied.

  In each of the above embodiments, the printer having the intermediate transfer belt 71 is described. However, the paper P as a medium is conveyed by the transfer belt, and the toner images of the respective colors are sequentially transferred onto the paper P. Can be applied to the printer.

  Further, in each of the above embodiments, a printer has been described. However, the present invention can be applied to an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

70 Primary transfer belt unit 71 Intermediate transfer belt 72 Drive roller 73 Idle roller 80 Secondary transfer roller unit 90 Belt cleaning unit 92 Spring

Claims (7)

(A) a drive roller;
(B) an idle roller that is rotated by being driven by the drive roller;
(C) a belt member driven by the drive roller and the idle roller;
(D) a cleaning unit that is movably disposed in a direction in which the belt member is stretched and removes deposits on the belt member;
(E) A belt driving device comprising: a biasing member that biases the cleaning unit in a direction in which the belt member is stretched. (A) the cleaning unit includes a contact member disposed in contact with the belt member;
(B) The belt driving device according to claim 1, wherein the biasing member biases the abutting member toward the belt member. (A) a primary transfer member that transfers the developer image formed on the image carrier to the belt member;
The belt driving device according to claim 1, further comprising: a secondary transfer member that transfers a developer image formed on the belt member to a medium.   The said cleaning part is provided with the blade member which scrapes off the deposit | attachment on a belt member, and the deposit | attachment conveyance member which conveys the deposit | attachment scraped off by this blade member. Belt drive device.   The belt driving device according to claim 4, wherein the attached matter conveying member is an auger that is formed in a spiral shape and conveys the attached matter as it rotates.   The belt driving device according to claim 5, wherein the frame member of the cleaning unit is swingably disposed about a rotation shaft of the auger as a swing center. (A) a drive roller;
(B) an idle roller that is rotated by being driven by the drive roller;
(C) a belt member driven by the drive roller and the idle roller;
(D) a cleaning unit that is movably disposed in a direction in which the belt member is stretched and removes deposits on the belt member;
(E) An image forming apparatus comprising: an urging member that urges the cleaning unit in a direction in which the belt member is stretched.

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