JP2015121641A - Cleaning device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an auxiliary cleaning member from being clogged with paper dust, inexpensively with a simple configuration, to stably clean an image carrier.SOLUTION: A cleaning device 11 includes a bias brush 27, a bar brush 28, and a spring 42 as a vibration member. The bias brush 27 is arranged in contact with a rotatable intermediate transfer belt 9 which carries a toner image, and is applied with a bias of a polarity opposite to that of residual toner on the intermediate transfer belt 9, to remove the residual toner from the surface of the intermediate transfer belt 9. The bar brush 28 is arranged upstream of the bias brush 27 in a rotation direction of the intermediate transfer belt 9, and is arranged to be brought into contact with the surface of the intermediate transfer belt 9. The spring 42 is configured so as to vibrate the bar brush 28 along a rotation direction of the intermediate transfer belt 9.

Description

  The present invention relates to a cleaning device for cleaning the surface of an image carrier and an image forming apparatus provided with the cleaning device.

  Conventionally, some electrophotographic image forming apparatuses employ an intermediate transfer method in order to form a color image. The intermediate transfer type image forming apparatus, for example, images a plurality of photoconductors on which toner images of different colors are formed, an image carrier in contact with the plurality of photoconductors, and a toner image formed on the plurality of photoconductors. A primary transfer portion that transfers while being superimposed on the surface of the carrier, a secondary transfer portion that collectively transfers the toner image primarily transferred to the surface of the image carrier onto the transfer paper, and a toner that has not been completely transferred to the transfer paper And a cleaning device that removes (hereinafter referred to as “residual toner”) from the surface of the image carrier.

  For example, in a color image forming apparatus described in Patent Document 1, a photosensitive belt as an image carrier is rotatably suspended on two rotating rollers, and a photosensitive belt is mounted on an outer peripheral portion of the photosensitive belt on the rotating roller side. A photoreceptor belt cleaning device for removing toner remaining on the surface is provided.

  Some cleaning devices for cleaning the surface of an intermediate transfer type image carrier remove the residual toner from the surface of the image carrier by a cleaning member to which a bias having a polarity opposite to that of the residual toner is applied. Further, an auxiliary cleaning member is disposed upstream of the cleaning member in the rotation direction of the image carrier, and the auxiliary cleaning member is brought into contact with the image carrier. When the auxiliary cleaning member disturbs the residual toner or frictionally charges the toner with a predetermined polarity (polarity during development), the cleaning member can easily remove the residual toner from the surface of the image carrier.

JP-A-11-052759

  In image forming apparatuses, low-quality transfer paper such as recycled paper may be used from the viewpoint of cost reduction and resource reuse. When such an image forming operation is repeatedly performed on low-quality transfer paper, paper dust from the transfer paper may adhere to the surface of the image carrier. As the image carrier rotates, the paper dust is transported to and attached to the auxiliary cleaning member, and the auxiliary cleaning member adheres and becomes clogged. If the auxiliary cleaning member clogged with paper dust is used in this way, the residual toner cannot be disturbed or frictionally charged, so that the residual toner cannot be efficiently removed by the cleaning member. As a result, an image forming operation is performed using an image carrier having residual toner, and the image quality of the output image is degraded.

  In addition, in order to more efficiently remove paper dust, a roller-type brush that is driven to rotate may be used as an auxiliary cleaning member. However, in this case, unless parameters such as the brush rotation speed, brush biting amount, yarn fineness, and density are set precisely, toner scattering and banding may cause jitter in the formed image. An image defect will occur.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to stably clean an image carrier by preventing the auxiliary cleaning member from being clogged with paper by an inexpensive and simple configuration.

  The cleaning device of the present invention is disposed so as to contact a rotatable image carrier that carries a toner image, and a bias having a polarity opposite to that of the residual toner adhering to the surface of the image carrier is applied. And a cleaning member that removes the residual toner from the surface of the image carrier, and disposed upstream of the cleaning member in the rotational direction of the image carrier, and can contact the surface of the image carrier. The auxiliary cleaning member is provided, and a vibration member that vibrates the auxiliary cleaning member along the rotation direction of the image carrier.

  By adopting such a configuration, there is no need to separately provide an expensive and complicated member for removing the paper dust adhered to the auxiliary cleaning member, and a paper dust jam of the auxiliary cleaning member is prevented by an inexpensive and simple configuration. Therefore, the image carrier can be stably cleaned. In addition, by using an auxiliary cleaning member that is free from paper clogging, the residual toner on the image carrier can always be easily adhered by the cleaning member, so that it is possible to prevent the occurrence of poor cleaning. Furthermore, since the paper dust conveyed downstream from the auxiliary cleaning member is reduced, the paper dust entering the cleaning device is reduced by the cleaning member.

  The vibration member may be a spring attached to the auxiliary cleaning member, and the auxiliary cleaning member may be vibrated by a biasing force of the spring.

  By adopting such a configuration, it is possible to realize a vibrating member that prevents paper clogging of the auxiliary cleaning member with an inexpensive and simple configuration such as a spring.

  The spring has an urging force immediately after expansion / contraction from the natural length is equal to or less than a frictional force between the auxiliary cleaning member and the image carrier immediately after the start of rotation of the image carrier, and the urging force when the spring is expanded / contracted to a predetermined distance. The spring constant may be larger than the maximum frictional force between the auxiliary cleaning member and the image carrier.

  By adopting such a configuration, the vibration of the auxiliary cleaning member by the spring can be started using the frictional force between the auxiliary cleaning member and the image carrier. For example, the image carrier is activated. Can be configured to start when.

  The vibration member may be a vibration mechanism that vibrates the auxiliary cleaning member by a driving force of a motor.

  By adopting such a configuration, a vibration member that prevents paper dust clogging of the auxiliary cleaning member can be realized by an inexpensive and simple configuration such as a motor, and the image carrier can be stably cleaned. ing

  The vibrating member may vibrate the auxiliary cleaning member when the image carrier performs an aging operation.

  By adopting such a configuration, the paper dust jammed in the auxiliary cleaning member is dropped by the vibration of the auxiliary cleaning member during the aging operation, so that the paper dust is another member such as an image carrier during the image forming operation. The image carrier that is stably cleaned during the image forming operation is used. As a result, it is possible to avoid image formation defects caused by paper dust jammed in the auxiliary cleaning member.

  The auxiliary cleaning member may be a bar brush.

  When a roller type brush is used as an auxiliary cleaning member, it is formed by toner scattering or banding unless parameters such as brush rotation speed, brush biting amount, yarn fineness and density are precisely set. An image defect such as jitter may occur in the image. However, by using a bar brush as the auxiliary cleaning member, such an image defect does not occur, and since the vibration member is provided, the image defect does not occur due to paper clogging.

  An image forming apparatus according to the present invention includes any one of the cleaning devices described above and the image carrier.

  According to the present invention, the auxiliary cleaning member can be prevented from being clogged with an inexpensive and simple configuration, and the image carrier can be stably cleaned.

1 is a schematic diagram illustrating an outline of a configuration of a color printer according to an embodiment of the present invention. 1 is a cross-sectional view showing a color printer cleaning device and its surroundings according to an embodiment of the present invention. FIG. 5 is a cross-sectional view illustrating a state where a bar brush has moved in the color printer cleaning apparatus according to the embodiment of the present invention. 4 is a graph showing a relationship between a frictional force between a bar brush and an intermediate transfer belt and a biasing force of a spring attached to the bar brush in the color printer cleaning apparatus according to the embodiment of the present invention. 6 is a graph showing the relationship between the rotation speed of the intermediate transfer belt and the dynamic friction force between the bar brush and the intermediate transfer belt in the color printer cleaning apparatus according to the embodiment of the present invention. It is sectional drawing which shows the bar brush and its periphery in the cleaning apparatus of the color printer which concerns on other embodiment of this invention. It is sectional drawing which shows the state which the bar brush moved in the cleaning apparatus of the color printer which concerns on other embodiment of this invention.

  Hereinafter, a tandem type color printer 1 (image forming apparatus) according to an embodiment of the present disclosure will be described with reference to the drawings. For convenience of explanation, the front side in FIG. 1 is the front side (front side) of the color printer 1.

  First, the overall configuration of the color printer 1 will be described with reference to FIG. The color printer 1 includes a box-shaped printer main body 2. A paper feed cassette 3 storing transfer paper is provided below the printer main body 2, and a paper discharge tray 4 is provided above the printer main body 2. It has been.

  An intermediate transfer unit 5 is provided at the center of the printer body 2. The intermediate transfer unit 5 includes a driving roller 6 provided on one end side (right end side) in the longitudinal direction, a driven roller 7 provided on the other end side (left end side) in the longitudinal direction, a lower left side of the driving roller 6, and a driven roller 7. Provided between a pair of tension rollers 8, a pair of tension rollers 8 provided on the lower right side, a driving roller 6, a driven roller 7, and an intermediate transfer belt 9 (image carrier) wound around the pair of tension rollers 8. And four primary transfer rollers 10. A cleaning device 11 is provided on the left side of the intermediate transfer unit 5.

  Four image forming units 12 are provided below the intermediate transfer unit 5 at the center of the printer main body 2. The image forming unit 12 is provided for each toner color (for example, four colors of magenta, cyan, yellow, and black). Each image forming unit 12 is rotatably provided with a photosensitive drum 13 (photosensitive member). The photosensitive drum 13 is in contact with the surface of the intermediate transfer belt 9 such that the intermediate transfer belt 9 is sandwiched between each of the primary transfer rollers 10. Around the photosensitive drum 13, a charger 14, a developing device 15, a cleaning unit 16, and a static eliminator 17 are arranged.

  An exposure device 18 is disposed below the four image forming units 12 below the printer body 2. The exposure device 18 is constituted by, for example, a laser scanning unit (LSU).

  Four toner containers 20 are provided above the intermediate transfer unit 5 in the upper part of the printer main body 2. The toner container 20 is provided for each toner color (for example, four colors of magenta, cyan, yellow, and black).

  A transfer paper transport path 21 is provided on one side (right side in the drawing) of the printer main body 2. A paper feeding unit 22 is provided at the upstream end of the conveyance path 21, a secondary transfer roller 23 is provided at one end side of the intermediate transfer unit 5 at a middle portion of the conveyance path 21, and fixing is performed at a downstream part of the conveyance path 21. A device 24 is provided, and a discharge port 25 is provided at the downstream end of the transport path 21.

  Next, an image forming operation of the color printer 1 having such a configuration will be described. When the color printer 1 is turned on, various parameters are initialized, and initial settings such as temperature setting of the fixing device 24 are executed. When image data is input from a computer or the like connected to the color printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  First, after the surface of the photosensitive drum 13 is charged by the charger 14, an electrostatic latent image is formed on the surface of the photosensitive drum 13 by laser light (see arrow P) from the exposure device 18. Next, the electrostatic latent image is developed into a toner image of a corresponding color by the developing device 15 with the toner supplied from the toner container 20. As a result, a toner image is formed on the photosensitive drum 13.

  By performing the operation as described above in each image forming unit 12, toner images having different colors are formed on the photosensitive drums 13 of each image forming unit 12. This toner image is primarily transferred onto the surface of the intermediate transfer belt 9 by each primary transfer roller 10. As a result, a full-color toner image is carried on the intermediate transfer belt 9.

  On the other hand, the transfer paper taken out from the paper feed cassette 3 by the paper feed unit 22 is conveyed to the downstream side of the conveyance path 21 in synchronism with the image forming operation described above, and is transferred by the secondary transfer roller 23 to the intermediate transfer belt 9. The upper full color toner image is secondarily transferred onto the transfer paper. The transfer sheet on which the full-color toner image is secondarily transferred is conveyed downstream in the conveyance path 21 and enters the fixing device 24, where the toner image is fixed on the transfer sheet. The transfer sheet on which the toner image is fixed is discharged from the discharge outlet 25 onto the discharge tray 4.

  Next, the intermediate transfer belt 9 will be described. The intermediate transfer belt 9 includes, for example, a base material layer, an elastic layer provided around the base material layer, and a release layer that covers the elastic layer. The base material layer of the intermediate transfer belt 9 is made of, for example, PVDF (polyvinylidene fluoride), polyimide resin, or the like. The elastic layer of the intermediate transfer belt 9 is made of, for example, hydrin rubber, chloroprene rubber, polyurethane rubber, or the like. The release layer of the intermediate transfer belt 9 is made of, for example, acrylic, silicon, fluorine resin, or the like.

  Next, the cleaning device 11 will be described with reference to FIGS. 2 and 3.

  The cleaning device 11 is fixed to the left end portion of the intermediate transfer unit 5 and integrated with the intermediate transfer unit 5 (see FIG. 1). As shown in FIG. 2, the cleaning device 11 includes a casing 26, a bias brush 27 (cleaning member) accommodated in the right side portion of the casing 26, and a bar brush 28 (auxiliary cleaning) disposed on the upper right side of the bias brush 27. Member), a collection roller 30 arranged at the lower left of the bias brush 27, a blade 31 arranged at the lower left of the collection roller 30, a regulation sheet 32 arranged at the lower right of the collection roller 30, and a collection roller And a recovery screw 33 disposed below 30.

  The casing 26 includes a main body 34 and a lid body 35 disposed above the main body 34, and a spring mounting portion 36 is provided on the right side portion of the lid body 35.

  The main body 34 of the casing 26 has a box shape in which the upper side and the right side are opened. The main body 34 is provided with a protruding portion 37 that protrudes downward, and a screw accommodating portion 38 is formed in a space inside the protruding portion 37. In the main body 34, a blade attachment portion 40 is provided at the upper left of the protrusion 37, and a seat attachment portion 41 is provided at the upper right of the protrusion 37.

  The lid 35 of the casing 26 is supported by the main body 34 so as to be openable and closable so as to cover the upper opening of the main body 34. For example, when performing maintenance of the bias brush 27 and the collection roller 30, the lid 35 is configured such that the bias brush 27 and the collection roller 30 can be exposed by opening the lid 35. .

  One end of a spring 42 (vibration member) is attached to the spring attachment portion 36 of the casing 26, and the other end of the spring 42 is attached to a bar brush attachment portion 43 (bar brush 28). In other words, the bar brush 28 is attached to the casing 26 via the spring 42.

  The spring 42 attached to the casing 26 is arranged so as to generate an urging force along the rotation direction of the intermediate transfer belt 9 (see arrow A in FIG. 2). For example, the urging force is generated in the left-right direction of the rotation direction. In this way, the spring mounting portion 36 is disposed so as to extend rightward. The spring 42 regulates the movement of the bar brush 28 in the rotation direction of the intermediate transfer belt 9, but the bar brush 28 can be vibrated along the rotation direction of the intermediate transfer belt 9 by the biasing force of the spring 42. In FIG. 2, only one spring 42 is shown, but two or more springs 42 may be provided at a predetermined interval in the longitudinal direction with respect to the bar brush 28 that is long in the front-rear direction.

  The spring 42 has, for example, a static friction between the bar brush 28 and the intermediate transfer belt 9 immediately after the start of rotation of the intermediate transfer belt 9 (when the rotation speed is substantially zero). The spring constant is such that the urging force is less than or equal to the force, and the urging force when expanded or contracted to a predetermined distance is greater than the maximum static friction force (maximum friction force) between the bar brush 28 and the intermediate transfer belt 9.

  The bias brush 27 faces the driven roller 7 with the intermediate transfer belt 9 interposed therebetween. The bias brush 27 includes a brush shaft 44, a cylindrical body 45 provided around the brush shaft 44, and a large number of brush threads 46 implanted on the outer peripheral surface of the cylindrical body 45.

  The brush shaft 44 of the bias brush 27 is formed in a long shape in the front-rear direction. Both front and rear ends of the brush shaft 44 are pivotally supported by the main body 34 of the casing 26. Thereby, the bias brush 27 is rotatably supported by the casing 26. The cylindrical body 45 of the bias brush 27 is fitted to the outer peripheral surface of the brush shaft 44. The brush thread 46 of the bias brush 27 is composed of a conductive thread. Specifically, the brush yarn 46 is preferably made of a polyester, nylon or acrylic yarn. The tip of the brush thread 46 is in contact with the surface of the intermediate transfer belt 9.

  The bar brush 28 is disposed upstream of the bias brush 27 in the rotational direction of the intermediate transfer belt 9 and faces the driven roller 7 with the intermediate transfer belt 9 interposed therebetween. The bar brush 28 is attached to the bar brush attachment portion 43 and includes a base portion 47 and a large number of brush hairs 48 implanted on the lower surface of the base portion 47.

  The bar brush attachment portion 43 to which the bar brush 28 is attached has a long shape in the front-rear direction and is formed in an L-shaped cross section. The other end of the spring 42 is attached to the left side surface of the bar brush attachment portion 43 as described above. The bar brush mounting portion 43 is supported from above by a support mechanism (not shown), for example, and the tip (lower end) of the bristles 48 of the bar brush 28 is brought into contact with the surface of the intermediate transfer belt 9 by this support mechanism. ing. This support mechanism does not restrict the movement of the bar brush attachment portion 43 in the rotation direction of the intermediate transfer belt 9.

  The base portion 47 of the bar brush 28 is formed in a plate shape with synthetic resin, for example. The upper surface of the base portion 47 is fixed to the lower surface of the bar brush attachment portion 43, so that the bar brush 28 can vibrate together with the bar brush attachment portion 43. The bristles 48 of the bar brush 28 are made of insulating yarn. Specifically, the bristles 48 are preferably composed of polyester or acrylic yarns. When the toner is charged to a predetermined polarity, the brush bristles 48 preferably have a polarity located on the opposite side of the predetermined polarity in the charging series. For example, when the toner is a positively charged toner, the brush bristles 48 preferably have a polarity that is located on the minus side of the toner in a charging series.

  The collection roller 30 includes a roller shaft 50 and a roller body 51 that is provided around the roller shaft 50.

  The roller shaft 50 of the collection roller 30 is formed in a long shape in the front-rear direction. Both front and rear ends of the roller shaft 50 are pivotally supported by the main body 34 of the casing 26. Thereby, the collection roller 30 is rotatably supported by the casing 26. The roller body 51 of the collection roller 30 is made of, for example, rubber or soft synthetic resin. The outer peripheral surface of the roller body 51 is in contact with the brush thread 46 of the bias brush 27.

  The blade 31 is made of, for example, a plate-shaped synthetic resin. The blade 31 is disposed in a posture inclined downward to the right. The base end portion (left end portion) of the blade 31 is attached to the blade attachment portion 40 of the main body 34 of the casing 26 via an attachment 49. The tip (right end) of the blade 31 is in contact with the outer peripheral surface of the roller body 51 of the collection roller 30.

  The restriction sheet 32 is made of a film, for example. The restriction sheet 32 is arranged in a posture that is inclined downward to the left. The base end portion (right end portion) of the restriction sheet 32 is attached to the sheet attachment portion 41 of the main body 34 of the casing 26. The front end portion (left end portion) of the restriction sheet 32 is in contact with the outer peripheral surface of the roller main body 51 of the collection roller 30. The restriction sheet 32 is provided so as to partition the screw accommodating portion 38 of the main body 34 of the casing 26 with respect to the space on the bias brush 27 side.

  The recovery screw 33 is accommodated in the screw accommodating portion 38 of the main body 34 of the casing 26. The recovery screw 33 has a long shape in the front-rear direction. The collection screw 33 is connected to a collection box (not shown).

  Next, in the color printer 1 configured as described above, an operation for removing residual toner from the surface of the intermediate transfer belt 9 by the cleaning device 11 will be described.

  On the surface of the intermediate transfer belt 9, after the toner image formed by the image forming unit 12 in the image forming operation described above is secondarily transferred to the transfer paper by the secondary transfer roller 23, the residual toner is attached. is there. Even after the secondary transfer, the rotation continues for the cleaning process of the intermediate transfer belt 9, and the residual toner adhering to the surface of the intermediate transfer belt 9 first comes into contact with the bristles 48 of the bar brush 28. At this time, the residual toner is disturbed by the bar brush 28 and the adhesion force to the intermediate transfer belt 9 is reduced, and the polarity of the residual toner is unified to the polarity opposite to the applied voltage of the bias brush 27.

  Subsequently, the residual toner on the intermediate transfer belt 9 contacts the brush thread 46 of the bias brush 27. At this time, an electrostatic adsorption force acts between the brush thread 46 of the bias brush 27 and the residual toner, and the residual toner attached to the surface of the intermediate transfer belt 9 moves to the brush thread 46 of the bias brush 27. Along with this, residual toner is removed from the surface of the intermediate transfer belt 9.

  Thereafter, the residual toner moves from the bias brush 27 to the roller body 51 of the collection roller 30, is scraped off from the roller body 51 of the collection roller 30 by the blade 31, and moves to the screw accommodating portion 38. The residual toner that has moved to the screw accommodating portion 38 is conveyed to a recovery box (not shown) by the recovery screw 33.

  In the color printer 1 configured as described above, an operation for removing paper dust from the bar brush 28 of the cleaning device 11 (an auxiliary cleaning member vibration operation) will be described with reference to FIGS.

This auxiliary cleaning member vibration operation is performed before the image forming operation, and is performed, for example, when the intermediate transfer belt 9 is activated or during an aging operation. As shown in FIG. 4, before the start of the intermediate transfer belt 9 or before the start of the aging operation (see FIG. 2), a static frictional force F1 is generated between the stationary intermediate transfer belt 9 and the bar brush 28. Yes. Thus, immediately after the start of activation or immediately after aging operation of the intermediate transfer belt 9, bar brush 28 is subject to such a static frictional force F _N1 from the intermediate transfer belt 9. The static friction force F _N1 is expressed by the formula F _N1 = μ ₀ using, for example, the static friction coefficient μ ₀ between the intermediate transfer belt 9 and the bar brush 28 and the pressure contact force N 1 of the bar brush 28 against the intermediate transfer belt 9. X Determined by N1.

At this time, since the spring 42 that restricts the movement of the bar brush 28 in the left-right direction is in a natural length state, the bar brush 28 receives the urging force F _x0 immediately after expansion / contraction from the natural length by the spring 42. Biasing force of the spring 42 is determined by the expansion and contraction distance x spring coefficient k and the spring 42 of the spring 42, since expansion and contraction distance x after expansion and contraction of the spring 42 is substantially zero, the biasing force F _x0 just after stretching is substantially Zero.

Since the above-mentioned static friction force F _N1 is larger than the biasing force F _x0 , the bar brush 28 receives the static friction force F _N1 against the biasing force F _x0 of the spring 42 and is held on the intermediate transfer belt 9, As the transfer belt 9 rotates, it moves to the rotation direction side (left side). As a result, the spring 42 is compressed by the bar brush 28 that moves in the rotational direction of the intermediate transfer belt 9 (see FIG. 3).

Thereafter, when the compression distance of the spring 42 reaches the predetermined distance x1, the urging force F _x1 (repulsive force) of the spring 42 at the time of compression is based on the maximum static frictional force F _Nmax between the intermediate transfer belt 9 and the bar brush 28. growing. At this time, the spring 42 is vibrated along the rotational direction of the intermediate transfer belt 9 by releasing the compression of the spring 42 by the _urging force F _x1 against the maximum static frictional force F _Nmax . As a result, the bar brush 28 attached to the spring 42 vibrates together with the spring 42.

  According to the present embodiment, as described above, the cleaning device 11 includes the bias brush 27, the bar brush 28, and the spring 42 as the vibration member. The bias brush 27 is disposed so as to contact the rotatable intermediate transfer belt 9 carrying the toner image, and a bias having a polarity opposite to that of the residual toner attached to the surface of the intermediate transfer belt 9 is applied. Thus, the residual toner is removed from the surface of the intermediate transfer belt 9. The bar brush 28 is disposed on the upstream side of the bias brush 27 in the rotation direction of the intermediate transfer belt 9 and is provided so as to be in contact with the surface of the intermediate transfer belt 9. The spring 42 is configured to vibrate the bar brush 28 along the rotation direction of the intermediate transfer belt 9. As described above, the spring 42 attached to the bar brush 28 is used as a vibration member that vibrates the bar brush 28, and is configured to vibrate the bar brush 28 by the biasing force of the spring 42. As a result, it is not necessary to separately provide an expensive and complicated member for removing the paper dust adhered to the bar brush 28, and a vibration member that prevents paper dust clogging of the bar brush 28 is realized by an inexpensive and simple configuration such as a spring. Therefore, the intermediate transfer belt 9 can be stably cleaned.

  Further, since the bar brush 28 free from paper clogging is used, the residual toner on the intermediate transfer belt 9 can always be easily attached by the bias brush 27, so that the occurrence of cleaning failure can be prevented. Furthermore, since paper dust conveyed downstream from the bar brush 28 is reduced, the paper dust entering the casing 26 of the cleaning device 11 by the bias brush 27 is reduced. As a result, it is possible to prevent paper dust from being clogged between the outer peripheral surface of the roller main body 51 of the collection roller 30 and the leading end portion of the regulation sheet 32. Therefore, it is possible to prevent a phenomenon (see the two-dot chain line in FIG. 2) that the leading end of the restriction sheet 32 is lifted from the outer peripheral surface of the roller main body 51 of the collecting roller 30, and the residual toner in the screw accommodating portion 38. Therefore, it is possible to avoid such a problem that the battery returns to the space on the bias brush 27 side.

  Further, according to the present embodiment, as described above, the spring 42 of the cleaning device 11 has the urging force immediately after expansion / contraction from the natural length, the bar brush 28 and the intermediate transfer belt 9 immediately after the rotation of the intermediate transfer belt 9 starts. The spring constant is such that the urging force when it is expanded or contracted to a predetermined distance is greater than the maximum friction force between the bar brush 28 and the intermediate transfer belt 9. Thereby, the vibration of the bar brush 28 by the spring 42 can be started using the frictional force between the bar brush 28 and the intermediate transfer belt 9, for example, when the intermediate transfer belt 9 is started. Can be configured.

  According to the present embodiment, as described above, the cleaning device 11 is configured such that the spring 42 vibrates the bar brush 28 when the intermediate transfer belt 9 performs an aging operation. As a result, the paper dust jammed in the bar brush 28 is dropped by the vibration of the bar brush 28 during the aging operation, so that the paper dust does not fall on other members such as the intermediate transfer belt 9 during the image forming operation. During operation, the intermediate transfer belt 9 that is stably cleaned is used. As a result, it is possible to avoid image formation defects caused by paper dust jammed in the bar brush 28.

  Further, according to the present embodiment, as described above, the cleaning device 11 uses the bar brush 28 as the auxiliary cleaning member of the intermediate transfer belt 9. When a roller type brush is used as an auxiliary cleaning member, it is formed by toner scattering or banding unless parameters such as brush rotation speed, brush biting amount, yarn fineness and density are precisely set. An image defect such as jitter may occur in the image. However, the configuration using the bar brush 28 does not cause the above-described image failure when using the roller-type brush, and the above-described vibration member such as the spring 42 is provided. It does not occur.

  In the present embodiment, the configuration in which the spring constant of the spring 42 is determined based on the relationship between the static frictional force between the bar brush 28 and the intermediate transfer belt 9 and the biasing force of the spring 42 has been described. It is not limited to the configuration. For example, when the intermediate transfer belt 9 rotates, a dynamic friction force is generated between the bar brush 28 and the intermediate transfer belt 9. The relationship between the dynamic friction force and the biasing force of the spring 42 is the same as in the above-described embodiment. That is, when the dynamic friction force is larger than the biasing force of the spring 42, the bar brush 28 receives the dynamic friction force against the biasing force of the spring 42 and is held on the intermediate transfer belt 9. Along with this, it moves to the rotation direction side (left side). When the compression distance of the spring 42 reaches a predetermined distance and the urging force becomes larger than the dynamic friction force between the intermediate transfer belt 9 and the bar brush 28, the compression of the spring 42 is released by the urging force against the dynamic friction force, and the spring. 42 vibrates along the rotational direction of the intermediate transfer belt 9. As a result, the bar brush 28 attached to the spring 42 vibrates.

  At this time, since the intermediate transfer belt 9 is rotating, the bar brush 28 compresses the spring 42 in the rotation direction side by the dynamic friction force with the intermediate transfer belt 9 while sliding on the rotating intermediate transfer belt 9. When the spring 42 is compressed to a predetermined distance, the compression of the spring 42 is released and the spring 42 vibrates, and the bar brush 28 vibrates together with the spring 42.

  Incidentally, the dynamic frictional force between the bar brush 28 and the intermediate transfer belt 9 decreases as the rotational speed of the intermediate transfer belt 9 increases as shown in FIG. At the start of rotation, the rotation speed is slow and the dynamic frictional force is large, so that the bar brush 28 can be easily moved. Further, when the rotational speed is increased, the dynamic friction force is reduced. Therefore, even when the biasing force of the spring 42 is relatively low, the compression of the spring 42 can be released by the biasing force against the dynamic friction force, and the spring 42 is a bar brush. 28 and vibrates along the rotational direction of the intermediate transfer belt 9.

  Therefore, in the configuration in which the bar brush 28 is vibrated using the dynamic friction force between the bar brush 28 and the intermediate transfer belt 9, the spring 42 for vibrating the bar brush 28 has a short maximum extension or a small biasing force. Can be adopted. Thereby, the range of what can be adopted as the spring 42 in the cleaning device 11 of the present invention is expanded, in other words, the present invention can be applied to various cleaning devices 11.

  Moreover, although this embodiment demonstrated the structure which utilizes the spring 42 as a vibration member which vibrates the bar brush 28, it is not limited to this structure. For example, in another embodiment, as the vibration member, as illustrated in FIGS. 6 and 7, a vibration mechanism 53 that uses a driving force of a driving source may be applied. The vibration mechanism 53 includes a drive source such as a motor 54 and a transmission member such as a cam 55.

  The cam 55 is formed in a substantially elliptical shape and has a rotation shaft connected to the motor 54. 6 and 7, the protruding portion 56 that forms an ellipse in the cam 55 is provided on one side of the outer peripheral surface of the cam 55, but the protruding portion 56 may be provided on both sides. The cam 55 is disposed on the right side of the bar brush attachment portion 57 for attaching the bar brush 28.

  The bar brush attachment portion 57 is formed in a U-shaped cross section, and the other end of a spring 58 having one end attached to the spring attachment portion 36 of the casing 26 is attached to the left side surface of the bar brush attachment portion 57. The bar brush mounting portion 57 is biased rightward by a spring 58, and the right side surface of the bar brush mounting portion 57 is always in contact with the outer peripheral surface of the cam 55. Since the other structure of the bar brush attachment part 57 is the same as that of the bar brush attachment part 43 of the said embodiment, description is abbreviate | omitted.

  Next, the vibration operation (auxiliary cleaning member vibration operation) of the bar brush 28 according to another embodiment will be described with reference to FIGS. 6 and 7.

  When the cam 55 is rotated by the rotational force (driving force) from the motor 54 and the protrusion 56 of the cam 55 presses the bar brush mounting portion 57, the bar brush mounting portion 57 resists the biasing force of the spring 58 and the intermediate transfer belt 9. (See FIG. 7).

  On the other hand, if the protrusion 56 stops pressing away from the bar brush mounting portion 57 due to the rotation of the cam 55, the bar brush mounting portion 57 is biased by the spring 58 and moves to the right (see FIG. 6). Therefore, as the cam 55 rotates, the bar brush mounting portions 57 are alternately moved in the left-right direction to vibrate the bar brush 28. When the motor 54 does not transmit the driving force, the cam 55 may idle so that the bar brush mounting portion 57 is biased by the spring 58 and moves to the right.

  According to such another embodiment, as described above, the cleaning device 11 vibrates the bar brush 28 by the vibration mechanism 53 that converts the driving force from the motor 54 into the vibration motion along the rotation direction of the intermediate transfer belt 9. I am letting. Accordingly, a vibration member that prevents paper dust clogging of the bar brush 28 is realized by an inexpensive and simple configuration such as the motor 54, and the intermediate transfer belt 9 can be stably cleaned.

  In this embodiment, the case where the intermediate transfer belt 9 is used as an image carrier has been described. However, in a further embodiment, a photoconductor such as the photoconductor drum 13 may be used as an image carrier.

  In this embodiment, the case where the configuration of the present invention is applied to the color printer 1 has been described. However, in other different embodiments, the present invention is applied to other image forming apparatuses such as a monochrome printer, a copier, a facsimile machine, and a multifunction machine. It is also possible to apply a configuration.

1 Color printer (image forming device)
9 Intermediate transfer belt (image carrier)
11 Cleaning Device 26 Casing 27 Bias Brush (Cleaning Member)
28 Bar brush (auxiliary cleaning member)
36 Spring mounting part 42 Spring (vibrating member)
43 Bar brush mounting part 53 Vibration mechanism (vibration member)
54 Motor (drive source)

Claims (7)

The surface of the image carrier is arranged so as to be in contact with the rotatable image carrier carrying the toner image, and a bias having a polarity opposite to that of the residual toner adhering to the surface of the image carrier is applied. A cleaning member for removing the residual toner from:
An auxiliary cleaning member disposed upstream of the cleaning member in the rotational direction of the image carrier and provided so as to be in contact with the surface of the image carrier;
And a vibrating member that vibrates the auxiliary cleaning member along a rotation direction of the image carrier.   The cleaning device according to claim 1, wherein the vibration member is a spring attached to the auxiliary cleaning member, and the auxiliary cleaning member is vibrated by a biasing force of the spring.   The spring has an urging force immediately after expansion / contraction from the natural length is equal to or less than a frictional force between the auxiliary cleaning member and the image carrier immediately after the start of rotation of the image carrier, and the urging force when the spring is expanded / contracted to a predetermined distance. 3. The cleaning device according to claim 2, wherein the cleaning device has a spring constant that is larger than a maximum frictional force between the auxiliary cleaning member and the image carrier.   The cleaning device according to claim 1, wherein the vibration member is a vibration mechanism that vibrates the auxiliary cleaning member by a driving force of a motor.   The cleaning device according to claim 1, wherein the vibration member vibrates the auxiliary cleaning member when the image carrier performs an aging operation.   The cleaning apparatus according to claim 1, wherein the auxiliary cleaning member is a bar brush. The cleaning device according to any one of claims 1 to 6,
An image forming apparatus comprising: the image carrier.

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