Cleaning apparatus and image forming apparatus

Abstract

The system effectively agitates foreign matter while preventing contact between the agitator and the surface of the component to be cleaned. [Solution] The cleaning device 10 includes a cleaning member 31 that cleans the surface of the member to be cleaned 11, a sealing member 32 that contacts the surface of the member to be cleaned 11, a conveying member 33 that conveys the removed foreign matter, a stirring member 34 that stirs the removed foreign matter, and a contact prevention member 36 between the cleaning member 31 and the sealing member 32 that prevents the stirring member 34 from contacting the surface of the member to be cleaned 11. The stirring member 34 has a fixing part 340 fixed to the housing 35, a first stirring part 341 that extends from the fixing part 340 via a first bending part 34c, and a second stirring part 342 that extends from the tip of the first stirring part 341 via a second bending part 34d. The bending angle θ of the second bending part 34d changes as the stirring member 34 contacts and moves in conjunction with the conveying member 33.

Description

Technical Field

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

Background Art

[0002] As an image forming apparatus such as a copying machine or a printer, an electrophotographic image forming apparatus that forms a toner image on the surface of an image carrier and transfers the toner image on the image carrier to a recording medium such as paper is known.

[0003] In such an image forming apparatus, a cleaning device for cleaning the surface of the image carrier is mounted in order to remove foreign substances such as toner remaining on the surface of the image carrier after image transfer.

[0004] The cleaning device includes, for example, a cleaning member that removes foreign substances from the surface of the image carrier, a transport member that transports the foreign substances removed from the surface of the image carrier to a recovery container or the like, and a seal member that prevents the removed foreign substances from leaking out of the cleaning device.

[0005] Also, in some cleaning devices, in order to suppress a decrease in fluidity due to aggregation of toner or the like contained in the recovered foreign substances, there is provided a stirring member that stirs the foreign substances. For example, in Patent Document 1 (Japanese Patent No. 7465437), a configuration of a cleaning device including a shaking member that loosens toner in the cleaning device by shaking in conjunction with the rotational drive of a transport screw is disclosed.

[0006] By the way, the closer the stirring member that stirs the foreign substances in the cleaning device is arranged close to the surface of the cleaning target member such as the image carrier, the wider the stirring range can be expanded to near the surface of the cleaning target member. Therefore, it is possible to effectively suppress a decrease in the fluidity of foreign substances due to aggregation of toner or the like.

[0007] However, on the other hand, when the stirring member approaches the surface of the member to be cleaned, there is a risk that the stirring member may come into contact with the surface of the member to be cleaned and damage it. [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, the objective of the present invention is to effectively agitate foreign matter while preventing contact between the agitator and the surface of the member to be cleaned. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a cleaning device comprising: a cleaning member that contacts the moving surface of a member to be cleaned to clean the surface of the member to be cleaned; a sealing member that contacts the surface of the member to be cleaned upstream of the point where the cleaning member contacts the surface of the member to be cleaned in the direction of surface movement of the member to be cleaned; a conveying member that conveys foreign matter removed from the surface of the member to be cleaned by the cleaning member; and a stirring member that stirs the removed foreign matter, wherein a contact prevention member is provided between the cleaning member and the sealing member to prevent the stirring member from contacting the surface of the member to be cleaned, and the stirring member has a fixed part fixed to the housing, a first stirring part extending from the fixed part via a first bent part, and a second stirring part extending from the tip in the extension direction of the first stirring part via a second bent part, and the bending angle of the second bent part changes when the stirring member contacts and is linked with the conveying member. [Effects of the Invention]

[0010] According to the present invention, foreign matter can be effectively stirred while preventing contact between the stirring member and the surface of the member to be cleaned. [Brief explanation of the drawing]

[0011] [Figure 1]This is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of a belt cleaning device according to an embodiment of the present invention. [Figure 3] This is a perspective view of a stirring member according to an embodiment of the present invention. [Figure 4] This is a perspective view showing the stirring member and the conveying screw arranged side by side according to an embodiment of the present invention. [Figure 5] This figure shows one state of operation of the stirring member according to an embodiment of the present invention. [Figure 6] This figure shows another state of operation of the stirring member according to an embodiment of the present invention. [Figure 7] This is a perspective view of a contact prevention member according to an embodiment of the present invention. [Figure 8] This is a schematic diagram of a belt cleaning device according to another embodiment of the present invention. [Figure 9] This is a perspective view of a contact prevention member according to another embodiment of the present invention. [Figure 10] This is a schematic diagram of the belt cleaning device relating to a comparative example. [Modes for carrying out the invention]

[0012] The present invention will be described below with reference to the attached drawings. In each drawing used to explain the present invention, components such as members and parts having the same function or shape will be denoted by the same reference numerals as far as possible to distinguish them, and their description will be omitted after they have been described once.

[0013] <Configuration of an image forming apparatus> First, the configuration of an image forming apparatus according to one embodiment of the present invention will be described based on Figure 1.

[0014] The image forming apparatus 1000 shown in FIG. 1 is an electrophotographic image forming apparatus that forms an image using toner as a developer. Note that the "image forming apparatus" according to the present invention includes, in addition to a printer, a copier, a facsimile machine, or a printing machine, a multifunction machine that combines two or more of these. Further, "image formation" in the following description includes forming an image having a meaning such as characters and figures, as well as forming an image having no meaning such as a pattern.

[0015] As shown in FIG. 1, the image forming apparatus 1000 according to an embodiment of the present invention includes an image forming unit 100, a fixing unit 200, a sheet feeding unit 300, and a sheet discharging unit 400.

[0016] (Image Forming Unit) In the image forming unit 100, four image forming units 1Y, 1M, 1C, 1Bk, an exposure device 6, and a transfer device 8 are arranged.

[0017] The four image forming units 1Y, 1M, 1C, 1Bk all have basically the same configuration. Specifically, each of the image forming units 1Y, 1M, 1C, 1Bk includes a photoreceptor 2, a charging member 3, a developing device 4, a photoreceptor cleaning device 5, and the like.

[0018] The photoreceptor 2 is an electrostatic latent image carrier that carries an electrostatic latent image and is an example of an image carrier that carries a toner image. As the photoreceptor 2, in addition to a drum-shaped member as shown in FIG. 1, an endless belt member wound around a plurality of rollers and rotationally driven may be used.

[0019] The charging member 3 is a member that applies a voltage to the surface of the photoreceptor 2 to uniformly charge it. As the charging member 3, for example, a conductive or semiconductive charging roller or the like is used. Further, the charging member 3 is not particularly limited as long as it can charge the surface of the photoreceptor 2, and may be a contact-type charging member such as a magnetic brush, a fur brush, a film, or a rubber blade, or a non-contact-type charging member using corona discharge.

[0020] The developing device 4 is a device that supplies toner, which acts as a developer, to the surface of the photoreceptor 2. In this case, the developing device 4 contains toners of different colors, such as yellow, magenta, cyan, and black, for each imaging unit 1Y, 1M, 1C, and 1Bk.

[0021] The photoreceptor cleaning device 5 is a cleaning device that cleans the photoreceptor 2 by removing foreign matter such as residual toner remaining on the surface of the photoreceptor 2. The photoreceptor cleaning device 5 includes, for example, a cleaning blade that contacts the surface of the photoreceptor 2 as a cleaning member that removes foreign matter from the surface of the photoreceptor 2. Alternatively, the cleaning member may be a brush roller or the like that rotates while in contact with the surface of the photoreceptor 2.

[0022] The exposure apparatus 6 is a device that uses an optical system to irradiate the surface of the photoreceptor 2 with laser light, thereby forming an electrostatic latent image on the surface of the photoreceptor 2. The optical systems included in the exposure apparatus 6 include a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system.

[0023] The transfer device 8 is a device that transfers the toner image formed on the surface of the photoreceptor 2 to a sheet used as a recording medium. In this case, the transfer device 8 includes an intermediate transfer belt 11, a primary transfer roller 12, a secondary transfer roller 13, a belt cleaning device 10, and the like.

[0024] The intermediate transfer belt 11 is an example of an image carrier that holds the transferred toner image. The intermediate transfer belt 11 is an endless belt member and is stretched and supported by a plurality of rollers, including the primary transfer roller 12. Furthermore, one of the plurality of rollers supporting the intermediate transfer belt 11 rotates as a drive roller, causing the intermediate transfer belt 11 to rotate in the direction of arrow A in Figure 1. The belt member constituting the intermediate transfer belt 11 may be a single-layer structure or a multi-layer structure. If it is a multi-layer structure, it is preferable that the base layer, made of a fluororesin with low elongation, or PVDF (polyvinylidene fluoride), or a polyimide-based resin, is covered with a coating layer made of a smooth material such as a fluororesin. If it is a single-layer structure, it is preferable that the belt member be made of PVDF (polyvinylidene fluoride), PC (polycarbonate), or polyimide.

[0025] Four primary transfer rollers 12 are provided inside the intermediate transfer belt 11 and are positioned to contact each photoreceptor 2 via the intermediate transfer belt 11. This forms a primary transfer nip between the intermediate transfer belt 11 and each photoreceptor 2, where the intermediate transfer belt 11 and each photoreceptor 2 come into contact. Note that the primary transfer rollers 12 may not only contact the intermediate transfer belt 11 at the position of the primary transfer nip, but may also contact the intermediate transfer belt 11 at a position offset by a predetermined distance (for example, 4 mm to 5 mm) downstream from the primary transfer nip in the surface movement direction of the intermediate transfer belt 11.

[0026] The secondary transfer roller 13 is positioned to face one of the multiple rollers supporting the intermediate transfer belt 11. When the secondary transfer roller contacts the opposing roller via the intermediate transfer belt 11, a secondary transfer nip is formed between the secondary transfer roller 13 and the intermediate transfer belt 11 where the secondary transfer roller 13 and the intermediate transfer belt 11 come into contact.

[0027] The belt cleaning device 10 is a cleaning device that cleans the intermediate transfer belt 11 by removing foreign matter such as residual toner remaining on the surface of the intermediate transfer belt 11. The belt cleaning device 10 is positioned downstream of the secondary transfer nip (secondary transfer roller 13) in the surface movement direction (direction of arrow A) of the intermediate transfer belt 11, and upstream of the uppermost primary transfer nip (primary transfer roller 12) in the surface movement direction (direction of arrow A). The detailed configuration of the belt cleaning device 10 will be described later.

[0028] (Fixing part) The fixing unit 200 is equipped with a fixing device 20 that heats the sheet to fix the image onto the sheet. The fixing device 20 includes a fixing rotating body 21 that is heated by a heat source such as a heater, and a pressurizing rotating body 22 that is pressed by the fixing rotating body 21 to form a fixing nip.

[0029] (Sheet supply unit) The sheet supply unit 300 is equipped with a paper feed cassette 14 for storing the paper P and a paper feed roller 15 for feeding the paper P from the paper feed cassette 14. Here, the "sheet" on which the image is formed is described as "paper," but the "sheet" is not limited to paper (paper), and may also be an OHP sheet, fabric, metal sheet, plastic film, or a prepreg sheet made by pre-impregnating carbon fiber with resin. In addition to plain paper, "paper" also includes cardboard, postcards, envelopes, thin paper, coated paper (such as coated paper and art paper), tracing paper, etc.

[0030] (Sheet discharge section) The sheet discharge section 400 is equipped with a pair of paper discharge rollers 17 for discharging the paper P, and a paper discharge tray 18 for placing the discharged paper P.

[0031] <Image Formation Process> Next, with reference to Figure 1, the image forming operation of the image forming apparatus 1000 according to an embodiment of the present invention will be described.

[0032] When an image formation command is received, the image formation operation of each image formation unit 1Y, 1M, 1C, and 1Bk begins. Specifically, the photoreceptors 2 of each image formation unit 1Y, 1M, 1C, and 1Bk begin rotating clockwise as shown in Figure 1, and the surface of each photoreceptor 2 is charged to a uniform high potential by the charging member 3. Then, based on the image information of the original document read by the document reader or the image information printed from an external terminal, the exposure unit 6 exposes the surface (charged surface) of each photoreceptor 2. As a result, the potential of the exposed area decreases, and an electrostatic latent image is formed on the surface of each photoreceptor 2. Subsequently, toner is supplied from each developing unit 4 to each photoreceptor 2, and toner images of each color are formed on each photoreceptor 2.

[0033] The toner images formed on each photoreceptor 2 reach the primary transfer nip (position of the primary transfer roller 12) as the photoreceptor 2 rotates. At this time, a primary transfer bias with the opposite polarity to the toner charging polarity of the toner image is applied to each primary transfer roller 12, so that the toner images on each photoreceptor 2 are transferred sequentially onto the intermediate transfer belt 11, which rotates in sync with each photoreceptor 2. Thus, a full-color toner image is formed on the intermediate transfer belt 11. Note that image formation is not limited to forming a full-color image using the four imaging units 1Y, 1M, 1C, and 1Bk; a monochrome image may be formed using any one of the imaging units 1Y, 1M, 1C, and 1Bk, or a two-color or three-color image may be formed using any two or three imaging units. After the toner image is transferred to the intermediate transfer belt 11, each photoreceptor 2 is cleaned by the photoreceptor cleaning device 5, and foreign matter such as residual toner is removed from the surface of each photoreceptor 2.

[0034] Furthermore, the toner image transferred onto the intermediate transfer belt 11 is transported to the secondary transfer nip (the position of the secondary transfer roller 13) as the intermediate transfer belt 11 rotates, and transferred to the paper P transported from the sheet supply unit 300. Specifically, when the paper P is fed from the paper cassette 14 by the paper feed roller 15, the paper P hits the timing roller pair 16 and the transport stops temporarily. Then, as the timing roller pair 16 starts rotating at a predetermined timing, the paper P is transported to the secondary transfer nip in sync with the toner image on the intermediate transfer belt 11. At this time, a secondary transfer bias with the opposite polarity to the toner charge polarity of the toner image is applied to the secondary transfer roller 13, thereby transferring the toner image from the intermediate transfer belt 11 to the paper P. After the toner image is transferred to the paper P, any foreign matter such as residual toner remaining on the intermediate transfer belt 11 is removed by the belt cleaning device 10.

[0035] Subsequently, the paper P is transported to the fixing unit 200 and enters the fixing nip between the fixing rotor 21 and the pressurizing rotor 22. As a result, the paper P is heated and pressurized by the fixing rotor 21 and the pressurizing rotor 22, and the toner image on the paper P is fixed to the paper P. Then, the paper P is transported to the sheet discharge unit 400 and discharged onto the paper discharge tray 18 by the paper discharge roller 17. In this way, the series of image forming operations is completed.

[0036] <Challenges in belt cleaning devices> Here, we will explain the problems in a belt cleaning device with reference to a comparative example other than the present invention.

[0037] Figure 10 is a schematic diagram of a belt cleaning device according to a comparative example.

[0038] As shown in Figure 10, the belt cleaning device 90 according to the comparative example includes a cleaning blade 91 that removes foreign matter such as residual toner from the surface of the intermediate transfer belt 11, a sealing member 92 that prevents the removed foreign matter from leaking out of the cleaning device 90, a conveying screw 93 that transports the foreign matter inside the cleaning device 90 toward a collection container, and a stirring member 94 that agitates the foreign matter inside the cleaning device 90.

[0039] The cleaning blade 91 is in contact with the surface (outer surface) of the intermediate transfer belt 11 such that its tip 91a faces in the opposite direction (counter direction) to the surface movement direction (direction of arrow A) of the intermediate transfer belt 11. On the other hand, the sealing member 92 is positioned so that its tip 92a faces the surface movement direction of the intermediate transfer belt 11 and contacts the surface (outer surface) of the intermediate transfer belt 11 upstream of the cleaning blade 91 in the surface movement direction of the intermediate transfer belt 11. The conveying screw 93 is housed in the housing 95 of the belt cleaning device 90 and conveys foreign matter in the axial direction by rotational drive. The stirring member 94 is configured to be displaced between the position shown by the solid line and the position shown by the dotted line in Figure 10 by contacting the rotationally driven conveying screw 93.

[0040] Thus, in the comparative example, the stirring member 94 is displaced in conjunction with the rotational drive of the conveying screw 93, and the foreign matter inside the housing 95 is stirred by the displaced stirring member 94, thereby suppressing the aggregation of toner and other substances contained in the foreign matter. This makes it possible to suppress the decrease in the fluidity of the foreign matter that occurs due to aggregation.

[0041] Incidentally, if the type of component being cleaned changes, or if the arrangement of the cleaning blades changes according to the specifications of the belt cleaning device, it may become difficult to effectively agitate foreign matter that accumulates near the surface of the component being cleaned. In particular, when using paper containing a large amount of paper dust as the recording medium, the amount of paper dust adhering to the intermediate transfer belt increases, resulting in a larger amount of paper dust being recovered from the intermediate transfer belt into the belt cleaning device, which tends to reduce the fluidity of foreign matter within the belt cleaning device. Therefore, if foreign matter cannot be effectively agitated, there is a concern that it may overflow from the belt cleaning device.

[0042] To address this issue of reduced fluidity, one solution is to extend the stirring range of the stirring member to effectively stir foreign matter. For example, extending the tip of the stirring member to near the surface of the material to be cleaned can effectively stir foreign matter near the surface, improving the fluidity of the foreign matter. However, extending the tip of the stirring member to near the surface of the material to be cleaned may cause the stirring member to come into contact with the surface of the material to be cleaned and damage it. For example, in the comparative example shown in Figure 10, the surface of the intermediate transfer belt 11 is exposed to the inside of the belt cleaning device 90 between the cleaning blade 91 and the sealing member 92. Therefore, extending the tip 94a of the stirring member 94 may cause the tip 94a of the stirring member 94 to come into contact with the exposed surface of the intermediate transfer belt 11 and damage the surface of the intermediate transfer belt 11.

[0043] Therefore, in order to prevent damage to the components to be cleaned while effectively agitating foreign matter, the present invention proposes a belt cleaning device with the following configuration. The features of the present invention will be described below using a belt cleaning device according to an embodiment of the present invention as an example.

[0044] <Configuration of the belt cleaning device> Figure 2 is a schematic diagram of a belt cleaning device according to an embodiment of the present invention.

[0045] First, with reference to Figure 2, the basic configuration of the belt cleaning device 10 according to an embodiment of the present invention will be described.

[0046] As shown in Figure 2, the belt cleaning device 10 according to an embodiment of the present invention, like the comparative example above, includes a cleaning blade 31 that removes foreign matter such as residual toner from the surface of the intermediate transfer belt 11, a sealing member 32 that prevents the removed foreign matter from leaking out of the belt cleaning device 10, a conveying screw 33 that transports the foreign matter inside the belt cleaning device 10 toward a collection container, a stirring member 34 that agitates the foreign matter inside the belt cleaning device 10, and a housing 35 that houses the conveying screw 33.

[0047] The cleaning blade 31 is an example of a cleaning member that contacts the surface of the intermediate transfer belt 11 to clean the surface of the intermediate transfer belt 11. In this case, the cleaning blade 31 is formed in a blade shape made of urethane or the like, but the material and shape of the cleaning blade 31 can be changed as appropriate. As shown in Figure 2, the cleaning blade 31 is held by a cleaning blade holder 37 such that its tip 31a faces in the opposite direction (counter direction) to the surface movement direction (arrow A direction) of the intermediate transfer belt 11. In addition, a cleaning backup roller 40 that supports the tip 31a of the cleaning blade 31 is positioned on the inner circumferential surface side of the intermediate transfer belt 11 opposite the tip 31a of the cleaning blade 31. The cleaning backup roller 40 supports the tip 31a of the cleaning blade 31 via the intermediate transfer belt 11, so that the tip 31a of the cleaning blade 31 makes stable contact with the surface of the intermediate transfer belt 11. In this state, when the intermediate transfer belt 11 moves (rotates) in the direction of arrow A in Figure 2, foreign matter such as residual toner adhering to the surface of the intermediate transfer belt 11 is blocked and removed by the cleaning blade 31.

[0048] The sealing member 32 is positioned to contact the surface (outer circumferential surface) of the intermediate transfer belt 11 upstream of the point where the cleaning blade 31 contacts the surface of the intermediate transfer belt 11 in the direction of surface movement of the intermediate transfer belt 11. The sealing member 32 is fixed to the housing 35 so that its tip 32a faces the direction of surface movement of the intermediate transfer belt 11. In this way, by having the sealing member 32 contact the surface of the intermediate transfer belt 11 upstream of the point of contact of the cleaning blade 31, foreign matter blocked by the cleaning blade 31 is prevented from leaking out of the housing 35. Here, a sheet-like material is used as the sealing member 32, but the sealing member 32 may be made of a material other than a sheet.

[0049] The conveying screw 33 is an example of a conveying member that conveys foreign matter removed from the surface of the intermediate transfer belt 11 to a collection container or the like. Here, a screw with spiral blades 331 on the outer circumference of a rotating shaft 330 is used as the conveying screw 33. Note that the conveying member may be of a shape other than a screw. When the conveying screw 33 rotates, the rotating blades 331 convey the foreign matter inside the housing 35 in the axial direction, and the foreign matter is collected in the collection container through the conveying path inside the image forming apparatus body.

[0050] The stirring member 34 is a component that stirs foreign matter inside the housing 35 to improve the fluidity of the foreign matter. In this case, the stirring member 34 is constructed by bending a thin, elastically deformable sheet-like component. The stirring member 34 is also installed such that its rear end 34b portion is sandwiched and fixed between the cleaning blade holder 37 and the housing 35, and its tip 34a is a displaceable free end. Specifically, the stirring member 34 has a fixed portion 340 on the rear end 36b side that is sandwiched and fixed between the cleaning blade holder 37 and the housing 35, a first stirring portion 341 that extends from the tip of the fixed portion 340 via a first bent portion 34c in a direction toward the rotation axis 330 of the conveying screw 33 or toward the intermediate transfer belt 11, and a second stirring portion 342 that extends from the tip in the extending direction of the first stirring portion 341 via a second bent portion 34d in a direction toward the rotation axis 330 of the conveying screw 33 or toward the intermediate transfer belt 11. The first stirring section 341 and the second stirring section 342 are configured to swing around the first bending section 34c and the second bending section 34d, which are the first and second bending sections, respectively, relative to the fixed section 340.

[0051] Figure 3 is a perspective view of a stirring member according to an embodiment of the present invention.

[0052] As shown in Figure 3, the first stirring section 341 and the second stirring section 342 have a plurality of projections 345 that are spaced apart from each other along the longitudinal direction of the stirring section 342. Also, as shown in Figure 4, when the stirring member 34 and the conveying screw 33 are assembled, the plurality of projections 345 are arranged so as to be spaced apart along the axial direction (foreign matter conveying direction) of the conveying screw 33. Therefore, when the conveying screw 33 is rotated, the plurality of projections 345 alternately contact the rotation axis 330 and the blade portion 331 of the conveying screw 33. In other words, when the conveying screw 33 is driven to rotate, the rotating shaft 330 and the blade portion 331 are positioned to alternately face each projection portion 345, so that each projection portion 345 (the first stirring portion 341 shown in Figure 2) switches between a state in contact with the rotating shaft 330 (the state shown by the solid line in Figure 2) and a state in contact with the blade portion 331 (the state shown by the dotted line in Figure 2). As a result, the stirring member 34 is repeatedly displaced or deformed between the state shown by the solid line and the state shown by the dotted line in Figure 2, and foreign matter inside the housing 35 is stirred by the stirring member 34. Note that the stirring member 34 may be configured to be displaced or deformed not only in conjunction with the rotational drive of the conveying screw 33, but also by a dedicated drive source.

[0053] In the belt cleaning device 10 according to an embodiment of the present invention, a contact prevention member 36 is provided to prevent the stirring member 34 from coming into contact with the surface of the intermediate transfer belt 11, so that the stirring member 34 does not come into contact with the surface of the intermediate transfer belt 11 (see Figure 2).

[0054] As shown in Figure 2, the contact prevention member 36 is fixed by being sandwiched between the cleaning blade holder 37 and the housing 35 at its rear end 36b, and is mounted so as to extend toward the sealing member 32. The tip 36a of the contact prevention member 36 is a displaceable free end.

[0055] Thus, in this embodiment of the present invention, the contact prevention member 36 is provided so as to extend from the portion sandwiched between the cleaning blade holder 37 and the housing 35 toward the sealing member 32, and the contact prevention member 36 is positioned to be interposed between the surface of the intermediate transfer belt 11 and the stirring member 34 in the region between the cleaning blade 31 and the sealing member 32. Therefore, as shown by the dotted line in Figure 2, when the stirring member 34 is displaced in a direction toward the intermediate transfer belt 11, the tip 34a of the stirring member 34 abuts against the contact prevention member 36, thereby preventing the stirring member 34 from contacting the intermediate transfer belt 11.

[0056] As described above, in the embodiment of the present invention, even if the stirring member 34 is displaced due to the rotational drive of the conveying screw 33, it is possible to prevent the stirring member 34 from coming into contact with the surface of the intermediate transfer belt 11, thereby preventing damage to the intermediate transfer belt 11 caused by the stirring member 34 coming into contact with the surface of the intermediate transfer belt 11. Therefore, according to the embodiment of the present invention, the function of the intermediate transfer belt 11 can be maintained in good condition. Furthermore, according to the embodiment of the present invention, since it is possible to prevent the stirring member 34 from coming into contact with the surface of the intermediate transfer belt 11, the tip 34a of the stirring member 34 can be brought closer to the surface of the intermediate transfer belt 11. This makes it possible to effectively stir foreign matter that remains near the surface of the intermediate transfer belt 11, thereby improving the fluidity of the foreign matter and enabling smooth transport of the foreign matter to the collection container. In addition, even when using paper containing a large amount of paper dust, the paper dust recovered from the intermediate transfer belt 11 can be transported smoothly, so it is possible to prevent foreign matter such as paper dust from overflowing from the belt cleaning device 10 and causing image defects due to foreign matter adhering to components in the image forming apparatus.

[0057] In this embodiment of the present invention, when the stirring member 34 moves in conjunction with the rotational drive of the conveying screw 33, the tip 34a of the stirring member 34 comes into contact with the contact prevention member 36, causing the first stirring section 341 and the second stirring section 342 to oscillate around the first bent section 34c and the second bent section 34d. As a result, the bending angles of the first bent section 34c and the second bent section 34d change, respectively.

[0058] In this case, the bending angle θ of the second bent portion 34d (the angle θ on the contact prevention member 36 side formed between the first stirring portion 341 and the second stirring portion 342 shown in Figure 2) changes between the acute angle θ1 (0° < θ1 < 90°) shown in Figure 5 and the obtuse angle θ2 (90° < θ2 < 180°) shown in Figure 6, causing a large displacement of the tip 34a of the stirring member 34.

[0059] Thus, in the embodiment of the present invention, the bending angle θ of the second bent portion 34d changes significantly, which widens the stirring range by the stirring member 34 and allows for effective stirring of foreign matter. Therefore, according to the embodiment of the present invention, the fluidity of foreign matter in the belt cleaning device 10 can be improved, and the foreign matter can be smoothly transported to the collection container.

[0060] The magnitude of the bending angle θ in the second bending section 34d can be set arbitrarily. Therefore, the bending angle θ1 in the state shown in Figure 5 is not limited to an acute angle, but may be set arbitrarily from a range of 60° to 100°, which includes both acute and obtuse angles. Furthermore, it is preferable that the bending angle θ of the second bending section 34d changes significantly, as this increases the stirring range. For example, it is preferable that the angle difference between the bending angle θ1 in the state shown in Figure 5 and the bending angle θ2 in the state shown in Figure 6 is 40° or more. Also, the bending angle θ of the second bending section 34d is not limited to changing between an acute angle and an obtuse angle, but may also change between a relatively small obtuse angle and a relatively large obtuse angle.

[0061] Furthermore, in the embodiment of the present invention, since the contact prevention member 36 is made of a thin, elastically deformable sheet-like material, when the tip 34a of the stirring member 34 comes into contact with the contact prevention member 36, the contact prevention member 36 bends in a direction that approaches the surface of the intermediate transfer belt 11, as shown by the dotted line in Figure 2. In this case, compared to the case where the contact prevention member 36 does not bend, the tip 34a of the stirring member 34 can be brought closer to the intermediate transfer belt 11, thereby enabling effective stirring of foreign matter near the surface of the intermediate transfer belt 11. In addition, since the foreign matter is stirred by the bending of the contact prevention member 36, aggregation of toner and other substances contained in the foreign matter can be effectively suppressed.

[0062] However, if the contact prevention member 36 bends significantly toward the intermediate transfer belt 11, there is a risk that the contact prevention member 36 may come into contact with the surface of the intermediate transfer belt 11. Therefore, in this embodiment of the present invention, when the contact prevention member 36 bends toward the intermediate transfer belt 11, the contact prevention member 36 comes into contact with the cleaning blade 31 and the sealing member 32, as shown in Figure 6. As a result, the contact prevention member 36 is supported by the cleaning blade 31 and the sealing member 32, preventing contact between the contact prevention member 36 and the surface of the intermediate transfer belt 11, thus preventing damage to the intermediate transfer belt 11 caused by the contact prevention member 36 coming into contact with the surface of the intermediate transfer belt 11. Here, the contact prevention member 36 is made to come into contact with both the cleaning blade 31 and the sealing member 32, but as long as contact between the contact prevention member 36 and the intermediate transfer belt 11 can be prevented, the contact prevention member 36 may come into contact with only one of the cleaning blade 31 or the sealing member 32.

[0063] Furthermore, as shown in Figure 7, in the embodiment of the present invention, the contact prevention member 36 is configured to have a shape having a plurality of protruding pieces 365 that are spaced apart from each other along its longitudinal direction. These protruding pieces 365 are arranged at intervals from each other along the axial direction (foreign matter conveying direction) of the conveying screw 33, similar to the protruding pieces 345 of the stirring member 34 (see Figures 3 and 4), and are positioned to face each protruding piece 345 of the stirring member 34. Therefore, when the stirring member 34 is displaced to approach the intermediate transfer belt 11, each protruding piece 345 of the stirring member 34 comes into contact with each protruding piece 365 of the contact prevention member 36, thereby preventing contact between the stirring member 34 (each protruding piece 345) and the intermediate transfer belt 11.

[0064] Furthermore, as shown in Figure 7, there is a gap between adjacent protruding portions 365, allowing foreign matter from the cleaning blade 31 to be moved to the conveying screw 33 through this gap. This enables smooth transport of foreign matter removed by the cleaning blade 31 by the conveying screw 33, and effectively prevents aggregation of foreign matter due to accumulation on the cleaning blade 31 side. In addition, the spacing between adjacent protruding portions 365 is preferably 1 mm or more to ensure smooth movement of foreign matter from the cleaning blade 31 to the conveying screw 33. Note that the contact prevention member 36 is not limited to having a shape with multiple protruding portions 365 as shown in Figure 7, but may have other shapes.

[0065] <Configuration of other embodiments> Next, the configuration of other embodiments of the present invention will be described. In the following description, we will mainly describe parts that differ from the above embodiments of the present invention, and will omit descriptions of parts that are the same as those described above as appropriate.

[0066] Figure 8 is a schematic diagram of a belt cleaning device according to another embodiment of the present invention.

[0067] As shown in Figure 8, in another embodiment of the present invention, the contact prevention member 36 has a bent tip portion 361 that bends away from the surface of the intermediate transfer belt 11. Otherwise, the configuration is the same as in the above embodiment.

[0068] Figure 9 is a perspective view of a contact prevention member according to another embodiment of the present invention.

[0069] As shown in Figure 9, the contact prevention member 36 has a plurality of projections 365 arranged in its longitudinal direction, and a bent tip portion 361 is provided on the tip 36a side of each projection 365. Here, the bent tip portion 361 is provided on all projections 365, but the bent tip portion 361 may be provided on only some of the projections 365.

[0070] Thus, in another embodiment of the present invention, the contact prevention member 36 has a bent tip portion 361 that bends away from the surface of the intermediate transfer belt 11, thereby widening the range in which foreign matter can be stirred by the contact prevention member 36. That is, when the conveying screw 33 is driven to rotate, as shown in Figure 8, the contact prevention member 36 is repeatedly displaced and deformed by contact with the stirring member 34, and the foreign matter in the belt cleaning device 10 is stirred by the behavior of the bent tip portion 361 accompanying the displacement or deformation. As a result, the stirring range is widened, and the aggregation of toner and other substances contained in the foreign matter can be suppressed more effectively.

[0071] Furthermore, the presence of a bent tip 361 in the contact prevention member 36 prevents incorrect assembly in which the tip positions of the sealing member 32 and the contact prevention member 36 are reversed. As shown in Figure 8, normally the tip 36a of the contact prevention member 36 is positioned above the tip 32a of the sealing member 32 (on the opposite side from the intermediate transfer belt 11). However, because the free ends of the tip 36a of the contact prevention member 36 and the tip 32a of the sealing member 32 are positioned close to each other, incorrect assembly may occur when assembling the contact prevention member 36 and the sealing member 32, where the tip 32a of the sealing member 32 is mistakenly positioned above the tip 36a of the contact prevention member 36. However, as in other embodiments of the present invention, the presence of a bent tip portion 361 on the tip 36a side of the contact prevention member 36 that bends away from the surface of the intermediate transfer belt 11 prevents the tip 32a of the sealing member 32 from interfering with the tip 32a of the sealing member 32 and the bent tip portion 361 of the contact prevention member 36, even if the tip 32a of the sealing member 32 is to be positioned above the tip 36a of the contact prevention member 36. This prevents incorrect assembly in which the tip 32a of the sealing member 32 is positioned above. As a result, problems such as sealing defects caused by the sealing member 32 not being positioned correctly can be avoided.

[0072] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, the present invention can be applied not only to a belt cleaning device 10 for cleaning the surface of an intermediate transfer belt 11, but also to a photoreceptor cleaning device 5 for cleaning the surface of a photoreceptor 2 as shown in Figure 1.

[0073] Furthermore, the present invention is applicable not only to cleaning devices for cleaning the surface of an image carrier that carries an image on its surface, such as an intermediate transfer belt 11 or a photoreceptor 2, but also to cleaning devices for cleaning the surface of other cleaning target members besides the image carrier. By applying the present invention when cleaning the surface of such cleaning target members, it becomes possible to effectively agitate foreign matter while preventing damage to the surface of the cleaning target member due to contact with the agitating member, similar to the above embodiment.

[0074] To summarize the embodiments of the present invention described above, the present invention includes at least the following embodiments.

[0075] [First aspect] The first embodiment is a cleaning device comprising: a cleaning member that contacts the moving surface of a member to be cleaned to clean the surface of the member to be cleaned; a sealing member that contacts the surface of the member to be cleaned upstream of the point where the cleaning member contacts the surface of the member to be cleaned in the direction of surface movement of the member to be cleaned; a conveying member that conveys foreign matter removed from the surface of the member to be cleaned by the cleaning member; and a stirring member that stirs the removed foreign matter, wherein a contact prevention member is provided between the cleaning member and the sealing member to prevent the stirring member from contacting the surface of the member to be cleaned, and the stirring member has a fixed part fixed to the housing, a first stirring part extending from the fixed part via a first bent part, and a second stirring part extending from the tip in the extension direction of the first stirring part via a second bent part, and the bending angle of the second bent part changes when the stirring member contacts and is linked with the conveying member.

[0076] [Second aspect] In the second embodiment, the bending angle of the second bent portion changes between an acute angle and an obtuse angle.

[0077] [Third aspect] In the third embodiment, in the first or second embodiment, when the stirring member comes into contact with the contact prevention member, the contact prevention member comes into contact with the cleaning member, thereby preventing the contact prevention member from coming into contact with the surface of the member to be cleaned.

[0078] [Fourth aspect] The fourth embodiment is configured such that, in any one of the first to third embodiments, when the stirring member comes into contact with the contact prevention member, the contact prevention member comes into contact with the sealing member, thereby preventing the contact prevention member from coming into contact with the surface of the member to be cleaned.

[0079] [Fifth aspect] The fifth embodiment is configured such that, in any one of the first to fourth embodiments, when the stirring member comes into contact with the contact prevention member, the contact prevention member bends in a direction toward the surface of the member to be cleaned.

[0080] [Sixth aspect] The sixth embodiment is one of the first to fifth embodiments, wherein the contact prevention member has a plurality of projections that are spaced apart from each other in the foreign object transport direction in which the foreign object is transported by the transport member.

[0081] [Seventh aspect] The seventh embodiment is one of the first to eighth embodiments, wherein the contact prevention member has a bent tip portion that bends away from the surface of the member to be cleaned.

[0082] [Eighth aspect] The eighth aspect is an image forming apparatus comprising a cleaning device according to any one of the first to seventh aspects. [Explanation of symbols]

[0083] 10. Belt cleaning device (cleaning device) 11. Intermediate transfer belt (component to be cleaned) 31 Cleaning blade (cleaning component) 32 sealing member 33. Conveyor screw (conveyor component) 34 Stirring member 34c 1st bending part 34d 2nd bend 35 Contact prevention member 340 Fixed part 341 First stirring section 342 Second stirring section 361 Bent tip 365 Projection part 1000 Image forming apparatus θ bending angle [Prior art documents] [License]

[0084] [License 1] Patent No. 7465437

Claims

1. A cleaning member that contacts the moving surface of the member to be cleaned and cleans the surface of the member to be cleaned, A sealing member that contacts the surface of the member to be cleaned at a point upstream in the surface movement direction of the member to be cleaned from the point where the cleaning member contacts the surface of the member to be cleaned, A conveying member for conveying foreign matter removed from the surface of the member to be cleaned by the cleaning member, A stirring member for stirring the removed foreign matter, A cleaning device comprising, Between the cleaning member and the sealing member, a contact prevention member is provided to prevent the stirring member from coming into contact with the surface of the member to be cleaned. The stirring member has a fixing portion fixed to the housing, a first stirring portion extending from the fixing portion via a first bent portion, and a second stirring portion extending from the tip of the first stirring portion in the extending direction via a second bent portion. A cleaning device characterized in that the bending angle of the second bent portion changes as the stirring member comes into contact with and moves in conjunction with the conveying member.

2. The cleaning device according to claim 1, wherein the bending angle of the second bent portion changes between an acute angle and an obtuse angle.

3. The cleaning apparatus according to claim 1, wherein when the stirring member comes into contact with the contact prevention member, the contact prevention member comes into contact with the cleaning member, so that the contact prevention member does not come into contact with the surface of the member to be cleaned.

4. The cleaning apparatus according to claim 1, wherein when the stirring member comes into contact with the contact prevention member, the contact prevention member comes into contact with the sealing member, so that the contact prevention member does not come into contact with the surface of the member to be cleaned.

5. The cleaning apparatus according to claim 1, wherein when the stirring member comes into contact with the contact prevention member, the contact prevention member is configured to bend in a direction that approaches the surface of the member to be cleaned.

6. The cleaning device according to claim 1, wherein the contact prevention member has a plurality of protruding parts provided at intervals from each other in the foreign object transport direction in which the foreign object is transported by the transport member.

7. The cleaning device according to claim 1, wherein the contact prevention member has a bent tip portion that bends away from the surface of the member to be cleaned.

8. An image forming apparatus characterized by comprising the cleaning device described in claim 1.

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