Cleaning apparatus and image forming apparatus

Abstract

To suppress reduction in cleaning performance when the temperature is low in comparison to a case where a metal roll is used as a counter roll when a roll different from the counter roll arranged so as to be opposed via an endless belt to a blade-like cleaning member being an elastic body is a drive roll.SOLUTION: A cleaning device 60 comprises: a blade-like cleaning member 62 which is arranged such that a tip formed of an elastic body is pressed against an intermediate transfer belt 22 and which cleans a surface of the intermediate transfer belt 22; and a driven roll 65 being the driven roll 65 which is arranged so as to be opposed via the intermediate transfer belt 22 to the cleaning member 62 and is driven to rotate by the movement of the intermediate transfer belt 22, and whose outer peripheral surface is formed of an elastic body.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cleaning device and an image forming apparatus.

Background Art

[0002] Patent Document 1 discloses a cleaning device including a blade-shaped cleaning member arranged such that an edge portion thereof contacts the surface of an endless belt member stretched between a plurality of rolls, and a member that supports the back surface side of the endless belt member with which the edge portion of the blade-shaped cleaning member contacts. When the edge portion of the blade-shaped cleaning member is deformed in a direction in which it bites into the surface of the endless belt member, the cleaning device is provided with an opposing member provided with a relief portion that allows the endless belt member to escape from the blade-shaped cleaning member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a metal roll is used as an opposing roll that is arranged to face a blade-shaped cleaning member made of an elastic body via an endless belt, if the tip of the cleaning member hardens at low temperatures, the tip of the cleaning member does not take the aimed posture, and the cleaning performance deteriorates.

[0005] The present invention is directed to a case where a roll different from an opposing roll arranged to face a blade-shaped cleaning member made of an elastic body via an endless belt is a driving roll, and an object thereof is to suppress a decrease in cleaning performance at low temperatures as compared with a case where a metal roll is used as the opposing roll.

Means for Solving the Problems

[0006] A cleaning device according to the first embodiment comprises a blade-shaped cleaning member positioned on an endless belt with a tip made of an elastic material pressed against it to clean the surface of the endless belt, and a driven roll positioned opposite the cleaning member via the endless belt, which rotates in accordance with the movement of the endless belt, and whose outer surface is made of an elastic material.

[0007] In the cleaning apparatus according to the second embodiment, the tip of the cleaning member is embedded in the outer circumferential surface of the driven roll via the endless belt when the endless belt is stopped.

[0008] The cleaning apparatus according to the third embodiment is the cleaning apparatus according to the first or second embodiment, wherein the hardness of the solid rubber, which is the elastic body of the driven roll, is 30 or more, and the thickness is less than 0.5 mm.

[0009] The cleaning apparatus according to the fourth embodiment is the cleaning apparatus according to the first or second embodiment, wherein the hardness of the foamed rubber, which is the elastic body of the driven roll, is 30 or more, and the thickness is less than 5.0 mm.

[0010] The cleaning device according to the fifth embodiment is the cleaning device described in any one of the first to fourth embodiments, wherein the endless belt is an intermediate transfer belt.

[0011] The cleaning apparatus according to the sixth embodiment is the cleaning apparatus described in any one of the first to fifth embodiments, wherein the driven roll is a tension roll that applies tension to the endless belt.

[0012] In the cleaning apparatus according to the seventh embodiment, the relative position between the cleaning member and the tension roll is maintained, as in the cleaning apparatus described in the sixth embodiment.

[0013] The cleaning apparatus according to the eighth embodiment is the cleaning apparatus according to any one embodiment from the first to the seventh embodiment, wherein the driven roll is formed such that its outer diameter decreases toward one end in the axial direction.

[0014] The cleaning device according to the ninth embodiment is a cleaning device according to any one embodiment from the first to the eighth embodiment, and includes a cleaning member that is provided so as to contact the driven roll and cleans the surface of the driven roll.

[0015] The cleaning apparatus according to the tenth embodiment is the cleaning apparatus described in the ninth embodiment, wherein the cleaning member is a cleaning roll in which foam is wound in a spiral shape.

[0016] The image forming apparatus according to the 11th embodiment comprises a cleaning apparatus described in any one of the first to tenth embodiments, and a drive roll that drives the endless belt and whose outer surface is formed of an elastic material. [Effects of the Invention]

[0017] According to the cleaning apparatus of the first embodiment, the drive roll is a different roll from the opposing roll which is positioned opposite to the elastic, blade-shaped cleaning member via an endless belt, and compared to the case in which a metal roll is used as the opposing roll, the deterioration of cleaning performance at low temperatures is suppressed.

[0018] According to the cleaning device of the second embodiment, compared to a configuration in which the outer circumference of the opposing rolls remains circular when viewed from the axial direction while the endless belt is stopped, the deterioration of cleaning performance at low temperatures is suppressed.

[0019] According to the cleaning apparatus of the third embodiment, the deterioration of cleaning performance is suppressed compared to the case where the hardness of the solid rubber, which is the elastic body on the outer circumference of the driven roll, is less than 30 and the thickness is 5.0 mm or more.

[0020] According to the cleaning device according to the fourth aspect, wear and reversal of the tip of the cleaning member can be suppressed as compared with the case where the hardness of the foamed rubber, which is an elastic body on the outer periphery of the driven roll, is less than 30 and the thickness is 5.0 mm or more.

[0021] According to the cleaning device according to the fifth aspect, in a configuration where the endless belt is an intermediate transfer belt, when the drive roll is a roll different from the opposing roll disposed to face the blade-shaped cleaning member via the intermediate transfer belt with an elastic body, the cleaning performance at low temperatures is suppressed from decreasing as compared with the case where a metal roll is used as the opposing roll.

[0022] According to the cleaning device according to the sixth aspect, the number of parts is smaller as compared with the case where a driven roll dedicated to the opposing roll is provided.

[0023] According to the cleaning device according to the seventh aspect, as compared with the case where the cleaning member is fixed to the apparatus main body, a decrease in cleaning performance at low temperatures is suppressed regardless of the position of the driven roll.

[0024] According to the cleaning device according to the eighth aspect, twisting of the endless belt is suppressed as compared with the case where the diameter of the driven roll is constant.

[0025] According to the cleaning device according to the ninth aspect, foreign matter adhering to the surface of the driven roll is more easily removed as compared with the case where a cleaning member for cleaning the surface of the driven roll is not provided.

[0026] According to the cleaning device according to the tenth aspect, foreign matter adhering to the surface of the driven roll is more easily removed as compared with the case where the cleaning roll is cylindrical.

[0027] According to the image forming apparatus according to the eleventh aspect, a decrease in cleaning performance is suppressed as compared with the case where a drive roll is used as the opposing roll disposed to face the blade-shaped cleaning member via the endless belt with an elastic body. [Brief explanation of the drawing]

[0028] [Figure 1] This is a side view showing the configuration of an image forming apparatus according to the first embodiment. [Figure 2] This is a cross-sectional view showing a cleaning apparatus according to the first embodiment. [Figure 3] This is a cross-sectional view showing an enlarged portion of the cleaning apparatus according to the first embodiment, indicating that the intermediate transfer belt is stopped. [Figure 4] This is a cross-sectional view showing an enlarged portion of the cleaning apparatus according to the first embodiment, illustrating the state in which the intermediate transfer belt is in operation. [Figure 5] This is a cross-sectional view showing an enlarged portion of the cleaning apparatus related to the comparative example, indicating that the intermediate transfer belt is stopped. [Figure 6] This is a cross-sectional view showing an enlarged portion of the cleaning device related to the comparative example, illustrating the state in which the intermediate transfer belt is in operation. [Figure 7] This is a schematic diagram showing a cleaning apparatus according to the second embodiment. [Figure 8] This is a schematic diagram showing a cleaning apparatus according to the third embodiment. [Modes for carrying out the invention]

[0029] [First Embodiment] The image forming apparatus according to the first embodiment will be described below with reference to the drawings. In the first embodiment, an example in which the image forming apparatus includes an intermediate transfer belt will be described. Arrows D shown as appropriate in each figure indicate the circumferential direction D of the intermediate transfer belt 22, and arrows W indicate the axial direction W of the driven roll.

[0030] [Configuration of the image forming apparatus] As shown in Figure 1, the image forming apparatus 10 has a housing 12, and an image forming unit 14, a transfer device 16, a fixing device 18, a paper feed device 20, and a cleaning device 60 are arranged inside the housing 12. A transport path 47 for transporting paper P, which is an example of a recording medium, is formed inside the housing 12.

[0031] The image forming unit 14 employs an electrophotographic method to form an image on the paper P. The image forming unit 14 has, for example, four image forming units 24. The four image forming units 24 form toner images of different colors, such as yellow, magenta, cyan, and black.

[0032] The image forming unit 24 has a photoreceptor drum 26. The photoreceptor drum 26 is an example of an image holder and rotates while holding the toner image to be transferred to the paper P on its outer surface. The image forming unit 24 is equipped with a charging device 28 for charging the photoreceptor drum 26, an exposure device 29 for forming an electrostatic latent image, a developing device 30 for developing the charged latent image with toner, and a cleaning device 32 for cleaning the photoreceptor drum 26 after transfer.

[0033] The transfer device 16 has an intermediate transfer belt 22, which is an example of an endless belt. Toner images are first transferred to the intermediate transfer belt 22 from the photoreceptor drum 26 by the primary transfer roll 36. The first transferred toner images are then secondarily transferred to the paper P by the secondary transfer roll 38.

[0034] The intermediate transfer belt 22 is wrapped around a drive roll 40 that rotates, a driven roll 65 that rotates in accordance with the movement of the intermediate transfer belt 22, and a primary transfer roll 36, and is configured to move in the circumferential direction D. The outer surface of the drive roll 40 is formed of solid rubber 42, which is an example of an elastic material. The outer surface of the drive roll 40 is covered with solid rubber 42. The thickness of the solid rubber 42 can be, for example, 0.5 to 2.0 mm.

[0035] The fixing device 18 fixes the toner image transferred to the paper P to the paper P using, for example, heat and pressure.

[0036] The paper feeder 20 includes a storage section 45 for storing stacked sheets of paper P, and a pickup roll 46 for feeding the sheets of paper P stored in the storage section 45 toward the transport path 47. The transport path 47 passes through a secondary transfer position between the secondary transfer roll 38 and the drive roll 40, and a fixing position by the fixing device 18, before being discharged to an outlet section 48 outside the housing 12.

[0037] [Operation of the image forming apparatus] In the image forming apparatus 10 configured as described above, the toner images formed on the outer surface of the photoreceptor drum 26 are first transferred to the intermediate transfer belt 22, the toner images first transferred to the intermediate transfer belt 22 are secondarily transferred to the paper P, and the toner images secondarily transferred to the paper P are fixed to the paper P by the fuser 18. The paper P, which is stacked in the paper feeder 20, is fed out by the pickup roll 46, transported through the transport path 47 to between the secondary transfer roll 38 and the drive roll 40, further transported to the fuser 18, and discharged to the discharge section 48.

[0038] Foreign matter 70 (see Figure 3) adhering to the surface of the intermediate transfer belt 22 after secondary transfer to paper P is cleaned by the cleaning device 60.

[0039] [Configuration of the cleaning device] As shown in Figure 2, the cleaning device 60 comprises a cleaning member 62 and a driven roll 65.

[0040] (Cleaning component 62) The cleaning member 62 is made of solid rubber, which is an example of an elastic material. The hardness (JIS-A) of the cleaning member 62 can be 50 or more and less than 90. The cleaning member 62 is formed in the shape of a long strip extending in the axial direction W of the driven roll 65. The cleaning member 62 is formed in the shape of a rectangular cross-section perpendicular to the axial direction W, with a thickness T (e.g., 2 mm) and a width L (e.g., 10 mm).

[0041] The cleaning member 62 is formed in a blade shape. The cleaning member 62 has an outer corner portion 62C formed on its first surface 62A and second surface 62B. In the range F where the intermediate transfer belt 22 is in contact with the driven roll 65, the cleaning member 62 is positioned so that its tip, the outer corner portion 62C, is pressed against the intermediate transfer belt 22.

[0042] (Driven Roll 65) The driven roll 65 is positioned opposite the outer corner portion 62C of the cleaning member 62 via an intermediate transfer belt 22. The driven roll 65 is configured to rotate in accordance with the movement of the intermediate transfer belt 22.

[0043] The driven roll 65 is composed of a cylindrical core material 66 and a covering 68 that covers the outer surface of the core material 66. The core material 66 is made of a material harder than the covering 68, such as metal or hard resin.

[0044] The coating 68 is made of solid rubber, which is an example of an elastic material. Solid rubber is made of a material that hardens at low temperatures, such as ethylene propylene rubber (EPDM) or acrylonitrile butadiene rubber (NBR). The thickness E of the coating 68 is 0.5 mm or more and less than 5.0 mm, and the hardness (JIS-A) of the coating 68 can be 30 or more and less than 90. In other words, the outer surface of the driven roll 65 is made of solid rubber, which is an example of an elastic material.

[0045] The bearing 65A of the driven roll 65 and the axial end W of the cleaning member 62 are fixed to the bracket 64. The driven roll 65 and the cleaning member 62 are connected by the bracket 64. The bracket 64 is configured to be movable relative to the housing 12. A spring 69, as an example of a biasing means, is connected to the bracket 64. The spring 69 is connected to a frame supported by the housing 12.

[0046] The driven roll 65 functions as a tension roll, applying tension to the intermediate transfer belt 22 through the biasing force of the spring 69. The cleaning member 62 moves together with the driven roll 65 when the driven roll 65 applies and releases tension to the intermediate transfer belt 22, and when the posture of the intermediate transfer belt 22 changes during switching between four colors and monochrome. In other words, the relative position of the cleaning member 62 and the driven roll 65 is maintained.

[0047] [Cleaning device operation] (When the intermediate transfer belt stops) At low temperatures, the cleaning member 62 hardens compared to when it is at room temperature. As shown in Figure 3, at low temperatures, in the stopped state S1 when the intermediate transfer belt 22 is stopped, the protruding corner portion 62C at the tip of the hardened cleaning member 62 is pressed against the intermediate transfer belt 22 and crushed. In addition, the covering 68 of the driven roll 65 is crushed as the tip of the cleaning member 62 presses against it.

[0048] In other words, at low temperatures, in the stopped state S1 when the intermediate transfer belt 22 is stopped, the protruding corner portion 62C of the tip of the cleaning member 62 bites into the outer surface of the driven roll 65 via the intermediate transfer belt 22.

[0049] (When the intermediate transfer belt is in operation) As shown in Figure 4, at low temperatures, in the movement state S2 when the intermediate transfer belt 22 is moving in the circumferential direction D, the protruding corner portion 62C of the tip of the hardened cleaning member 62 bites into the outer surface of the driven roll 65 via the intermediate transfer belt 22, and is positioned facing downstream in the circumferential direction D of the intermediate transfer belt 22. The area around the protruding corner portion 62C of the first surface 62A then contacts the intermediate transfer belt 22 at an inclined position with respect to the circumferential direction D. As a result, the cleaning member 62 cleans foreign matter 70 adhering to the intermediate transfer belt 22. Note that even at room temperature, in the movement state S2 when the intermediate transfer belt 22 is moving in the circumferential direction D, the cleaning member 62 is positioned facing downstream in the circumferential direction D of the intermediate transfer belt 22. Examples of foreign matter 70 include toner 72, calcium carbonate 74, and silica 76.

[0050] [Operation of the First Embodiment] The cleaning device 60 of the first embodiment includes a blade-shaped cleaning member 62 positioned on the intermediate transfer belt 22 with its elastic tip pressed against it to clean the surface of the intermediate transfer belt 22, and a driven roll 65 positioned opposite the cleaning member 62 via the intermediate transfer belt 22, which rotates in accordance with the movement of the intermediate transfer belt 22, and whose outer circumferential surface is formed of an elastic material (see Figure 3).

[0051] Incidentally, as shown in Figure 5, when the outer surface of the driven roll 565 is formed of metal, the driven roll 565 is not crushed in the stopped state S1 when the intermediate transfer belt 22 is stopped at low temperatures. Therefore, the outer corner portion 62C of the hardened cleaning member 62 does not bite into the outer surface of the driven roll 565 via the intermediate transfer belt 22.

[0052] In this state, as shown in Figure 6, when the intermediate transfer belt 22 moves in the circumferential direction D, the protruding corner portion 62C at the tip of the hardened cleaning member 62 remains crushed while moving relative to it. As a result, the area around the protruding corner portion 62C of the first surface 62A comes into contact with the intermediate transfer belt 22 parallel to the circumferential direction D, preventing it from assuming the desired position, and the foreign matter 70 slips through the cleaning member 62.

[0053] In the first embodiment, the outer circumferential surface of the driven roll 65, which is positioned opposite the cleaning member 62 via an intermediate transfer belt 22, is formed of solid rubber. As a result, the tip of the cleaning member 62 bites into the driven roll 65 via the intermediate transfer belt 22. Therefore, even if the tip of the cleaning member 62, which is made of an elastic material, hardens at low temperatures, the tip of the cleaning member 62 bites into the driven roll 65 via the intermediate transfer belt 22, and the tip of the cleaning member 62 assumes the desired position. Consequently, in the cleaning device 60 of the first embodiment, the driving roll is a different roll from the opposing roll positioned opposite the blade-shaped cleaning member 62 made of an elastic material via an intermediate transfer belt 22, and compared to the case where a metal roll is used as the opposing roll, the deterioration of cleaning performance at low temperatures is suppressed.

[0054] Incidentally, when a drive roll is used as an opposing roll to the cleaning member 62 via the intermediate transfer belt 22, vibrations caused by the rotational drive of the drive roll are transmitted to the cleaning member 62 via the intermediate transfer belt 22. As a result, the tip of the cleaning member 62 may become unstable, potentially reducing its cleaning performance.

[0055] In the first embodiment, the member positioned opposite the cleaning member 62 via the intermediate transfer belt 22 is a driven roll 65 that rotates in accordance with the movement of the intermediate transfer belt 22, thereby suppressing vibrations when the driven roll 65 rotates. As a result, vibrations transmitted from the driven roll 65 to the cleaning member 62 via the intermediate transfer belt 22 are suppressed. Consequently, compared to the case where the member positioned opposite the cleaning member 62 via the intermediate transfer belt 22 is a drive roll, the cleaning device 60 of the first embodiment suppresses the tip of the cleaning member 62 from wobbling and prevents a decrease in cleaning performance.

[0056] Incidentally, if the outer surface of the driven roll is made of metal, when foreign matter 70 adheres to the driven roll, the foreign matter 70 adhering to the driven roll will create irregularities on the surface of the intermediate transfer belt 22. As a result, the cleaning performance of the surface of the intermediate transfer belt 22 may be impaired.

[0057] In the first embodiment, the outer surface of the driven roll 65 is formed of an elastic material, so that when foreign matter 70 adheres to the driven roll 65, the foreign matter 70 bites into the elastic material of the driven roll 65. As a result, the formation of irregularities on the surface of the intermediate transfer belt 22 by the foreign matter 70 adhering to the driven roll 65 is suppressed. Consequently, the cleaning device 60 of the first embodiment suppresses a decrease in cleaning performance compared to the case where the outer surface of the driven roll 65 is formed of metal.

[0058] Furthermore, because the outer surface of the driven roll 65 is formed of an elastic material, the deformation of the outer surface of the driven roll 65 makes the tip of the cleaning member 62 more easily deformable. Therefore, the hardness of the tip of the cleaning member 62 can be increased compared to the case where the outer surface of the driven roll 65 is formed of metal. As a result, the cleaning device 60 of the first embodiment suppresses wear of the cleaning member 62 compared to the case where the outer surface of the driven roll is formed of metal.

[0059] In the cleaning device 60 of the first embodiment, the tip of the cleaning member 62 bites into the outer surface of the driven roll 65 via the intermediate transfer belt 22 when the intermediate transfer belt 22 is stopped (see Figure 3).

[0060] When the intermediate transfer belt 22 is stopped, the tip of the cleaning member 62 bites into the outer surface of the driven roll 65 via the intermediate transfer belt 22. When the intermediate transfer belt 22 moves, the tip of the cleaning member 62 catches in the recess of the intermediate transfer belt 22 formed by biting into the driven roll 65, thereby achieving the desired position. As a result, the cleaning device 60 of the first embodiment suppresses a decrease in cleaning performance at low temperatures compared to a configuration in which the outer surface of the driven roll maintains a circular shape when viewed from the axial direction when the intermediate transfer belt 22 is stopped.

[0061] In the cleaning apparatus 60 of the first embodiment, the hardness of the solid rubber, which is the elastic body of the driven roll, is 30 or higher, and the thickness is less than 5.0 mm.

[0062] By the way, since the tip of the cleaning member 62 is pressed against the elastic body of the driven roll 65 via the intermediate transfer belt 22, if the elastic body of the driven roll is made too thick... 、 If the material is made too soft, the elastic body of the driven roll may deform and fail to return to its original shape.

[0063] In the first embodiment, the hardness of the solid rubber, which is the elastic body of the driven roll, is 30 or higher, and the thickness is less than 5.0 mm, so that the tip of the cleaning member can bite into the endless belt appropriately. Therefore, the cleaning device of the first embodiment suppresses the deterioration of cleaning performance at low temperatures compared to the case where the hardness of the solid rubber, which is the elastic body on the outer circumference of the driven roll, is less than 30 and the thickness is 5.0 mm or higher.

[0064] In the cleaning apparatus 60 of the first embodiment, the driven roll 65 is a tension roll that applies tension to the intermediate transfer belt 22.

[0065] By using a tension roll instead of a driven roll 65, a function to apply tension to the intermediate transfer belt 22 is added. Therefore, the cleaning device 60 of the first embodiment has fewer parts compared to the case where a driven roll dedicated to the opposing roll is provided.

[0066] In the cleaning device 60 of the first embodiment, the relative position between the cleaning member 62 and the driven roll 65 is maintained.

[0067] By maintaining the relative position between the cleaning member 62 and the driven roll 65, the gap between the cleaning member 62 and the driven roll 65 remains constant even when the driven roll 65 moves. As a result, the tip of the cleaning member 62 remains in contact with the intermediate transfer belt 22, and the tip of the cleaning member 62 is positioned in the desired orientation. Consequently, the cleaning device 60 of the first embodiment suppresses the deterioration of cleaning performance at low temperatures, regardless of the position of the driven roll 65, compared to the case where the cleaning member 62 is fixed to the housing 12.

[0068] [Second Embodiment] The cleaning device 160 of the second embodiment differs from the cleaning device of the first embodiment in that the configuration of the driven rolls is different. In addition, the same terms or reference numerals will be used to describe parts that are the same as or equivalent to those described in the first embodiment.

[0069] [Configuration of the second embodiment] As shown in Figure 7, the driven roll 165 comprises a core material 166 and a covering 68.

[0070] The core material 166 is formed as a frustoconical shape that continuously decreases in diameter toward one end in the axial direction W. In other words, the core material 166 is formed so that its outer diameter decreases toward one end in the axial direction W. That is, the driven roll 165 is formed so that its outer diameter decreases toward one end in the axial direction W. Note that Figure 7 is an exaggerated diagram, and the difference between the maximum and minimum outer diameters of the driven roll 165 can be, for example, 1.0 mm.

[0071] A protrusion 166A is formed on the other end of the core material 166 in the axial direction W, projecting toward the other end in the axial direction W. On the back surface of the intermediate transfer belt 22, a protrusion 22A is formed on the other end in the axial direction W, projecting toward the thickness direction. The protrusion 166A and the protrusion 22A constitute a limiting member that restricts the movement of the intermediate transfer belt 22. Similarly, the drive roll 40 may also be formed so that its outer diameter decreases toward one end in the axial direction, and a limiting member may be provided therein.

[0072] In the cleaning device 160 configured in this way, the intermediate transfer belt 22 moves in the circumferential direction D and also moves toward one end of the axial direction W. When the intermediate transfer belt 22 moves toward one end of the axial direction W, the protruding portion 22A of the intermediate transfer belt 22 comes into contact with the convex portion 166A of the driven roll 165. This restricts the movement of the intermediate transfer belt 22 in the axial direction W, and thus restricts the meandering of the intermediate transfer belt 22 compared to the case where the driven roll is cylindrical and not inclined.

[0073] [Operation of the second embodiment] In the cleaning device 160 of the second embodiment, the driven roll 165 is formed such that its outer diameter decreases toward one end in the axial direction W (see Figure 7).

[0074] By the way, for example, if the drive roll and the driven roll, which are wrapped in rubber, are tilted in opposite directions, the intermediate transfer belt 22 may become twisted.

[0075] In the second embodiment, the driven roll 165 is formed such that its outer diameter decreases toward one end of the axial direction W, thereby causing the intermediate transfer belt 22 to move toward one end of the axial direction W. Therefore, the direction in which the intermediate transfer belt 22 moves is restricted. As a result, in the cleaning device 160 of the second embodiment, twisting of the intermediate transfer belt 22 is suppressed compared to the case where the outer diameter of the driven roll 65 is constant.

[0076] Furthermore, in the cleaning device 160 of the second embodiment, since the intermediate transfer belt 22 moves toward one end of the axial direction W, it is not necessary to provide a limiting member to restrict the movement of the intermediate transfer belt 22 on one end of the axial direction W of the intermediate transfer belt 22.

[0077] Furthermore, the other configurations and effects are substantially the same as those of the first embodiment described above, so their explanation will be omitted.

[0078] [Third Embodiment] The cleaning device 260 of the third embodiment differs from the cleaning device of the first embodiment in that it is provided with a cleaning member for cleaning the driven rolls. In addition, the same terms or reference numerals will be used to describe parts that are the same or equivalent as those described in the first embodiment.

[0079] [Configuration of the third embodiment] As shown in Figure 8, the cleaning device 260 of the third embodiment includes a cleaning roll 270, which is an example of a cleaning member. The cleaning roll 270 comprises a shaft 272 and an elastic layer 274 spirally wound around the outer circumferential surface of the shaft 272.

[0080] The elastic layer 274 of the cleaning roll 270 is positioned in contact with the covering 68 of the driven roll 65. The cleaning roll 270 is configured to rotate in conjunction with the rotation of the driven roll 65.

[0081] The elastic layer 274 is a foam made of a material containing air bubbles. The elastic layer 274 is arranged spirally on the outer surface of the shaft 272, from one end to the other in the axial direction W.

[0082] In the cleaning device 260 configured in this way, when the cleaning roll 270 rotates in conjunction with the driven roll 65, foreign matter 70 adhering to the outer surface of the coating 68 of the driven roll 65 is removed by the cleaning roll 270 which rotates in conjunction with the driven roll 65.

[0083] Specifically, foreign matter 70 adhering to the outer surface of the coating 68 of the driven roll 65 is removed by being wiped away by the outer surface of the elastic layer 274 of the cleaning roll 270 and scraped off by the edge of the elastic layer 274.

[0084] [Operation of the third embodiment] The cleaning device 260 of the third embodiment includes a cleaning roll 270 that is provided to contact the driven roll 65 and cleans the surface of the driven roll 65 (see Figure 7).

[0085] By providing a cleaning roll 270 for cleaning the surface of the driven roll 65, foreign matter 70 adhering to the driven roll 65 is cleaned by the edge portion of the elastic layer 274 of the cleaning roll 270. Therefore, the cleaning device 260 of the third embodiment makes it easier to remove foreign matter 70 adhering to the surface of the driven roll 65 compared to the case where the cleaning roll is cylindrical.

[0086] Furthermore, the other configurations and effects are substantially the same as those of the first embodiment described above, so their explanation will be omitted.

[0087] As described above, specific embodiments of the present invention have been explained, but the present invention is not limited to the above embodiments, and various modifications, changes, and improvements are possible within the scope of the technical idea of ​​the present invention.

[0088] In the first to third embodiments, examples were shown in which the driven rolls 65 and 165 were tension rolls that applied tension to the intermediate transfer belt 22. However, it is also possible to provide separate tension rolls and not have the driven rolls perform the function of tension rolls.

[0089] In the first to third embodiments, examples were shown in which the coating 68 of the driven rolls 65 and 165 was made of solid rubber. However, the coating of the driven rolls may also be made of foamed rubber, which is an example of an elastic material. In this case, the hardness (JIS-A) of the foamed rubber can be 30 or more, and the thickness can be less than 5.0 mm. By making the hardness of the foamed rubber of the driven roll 30 or more and the thickness less than 5.0 mm, the tip of the cleaning member bites more deeply into the driven roll via the endless belt. Therefore, when foamed rubber with a hardness of 30 or more and a thickness of less than 5.0 mm is used as the coating of the driven roll, wear and inversion of the tip of the cleaning member can be suppressed compared to when foamed rubber with a hardness of less than 30 and a thickness of 5 mm or more is used.

[0090] In the third embodiment, an example was shown in which the cleaning member is a cleaning roll 270 in which foam is wound in a spiral shape. However, the cleaning member is not limited to this embodiment, and for example, the foam may be wound so as to cover the outer circumference of a shaft.

[0091] In the first to third embodiments, an example was shown in which the endless belt is used as an intermediate transfer belt 22. However, the endless belt is not limited to this embodiment, and may, for example, be used as a secondary transfer belt or as a conveyor belt for transporting paper P.

[0092] In the first to third embodiments, an example was shown in which the image forming apparatus 10 is an intermediate transfer type equipped with an intermediate transfer belt 22. However, the image forming apparatus may also be a direct transfer type in which a cleaning device cleans the surface of the conveyor belt that transports the paper P. [Explanation of Symbols]

[0093] 10 Image forming apparatus 22. Intermediate transfer belt (an example of an endless belt) 40 Drive Roll 60 Cleaning device 62 Cleaning parts 65 Driven Roll 270 Cleaning Roll (Example of a cleaning component)

Claims

1. A blade-shaped cleaning member is positioned so that its tip, made of an elastic material, is pressed against the endless belt to clean the surface of the endless belt. The cleaning member is provided with a driven roll, which is positioned opposite to the cleaning member via the endless belt and rotates in accordance with the movement of the endless belt, and whose outer surface is formed of an elastic material. Equipped with, The driven roll is, The bearing is fixed to the bracket, and the bracket is biased by a biasing means, thereby providing tension to the endless belt, thus forming a tension roll. The cleaning member is A cleaning device in which the endless belt is fixed to the bracket and its relative position to the tension roll is set such that, when the endless belt is stopped, the tip of the belt remains embedded in the outer surface of the tension roll via the endless belt.

2. The cleaning apparatus according to claim 1, wherein the hardness of the solid rubber, which is the elastic body of the tension roll, is 30 or more, and its thickness is less than 5.0 mm.

3. The cleaning apparatus according to claim 1, wherein the foamed rubber, which is the elastic body of the tension roll, has a hardness of 30 or more and a thickness of less than 5.0 mm.

4. The cleaning device according to any one of claims 1 to 3, wherein the endless belt is an intermediate transfer belt.

5. The cleaning apparatus according to any one of claims 1 to 4, wherein the tension roll is formed such that its outer diameter decreases toward one end in the axial direction.

6. A cleaning device according to any one of claims 1 to 5, comprising a cleaning member provided so as to contact the tension roll and for cleaning the surface of the tension roll.

7. The cleaning device according to claim 6, wherein the cleaning member is a cleaning roll in which foam is wound in a spiral shape.

8. A cleaning device according to any one of claims 1 to 7, The drive roll, whose outer surface is formed of an elastic material, drives the aforementioned endless belt. An image forming apparatus equipped with the following features.

Images