Cleaning device and image forming apparatus

Abstract

To provide a cleaning device and an image forming apparatus that can more effectively prevent an increase in temperature inside the apparatus.SOLUTION: A cleaning device 426 comprises: a cleaning unit 80 that removes a foreign substance remaining on a surface of an image carrier; a foreign substance retaining unit that retains the foreign substance removed by the cleaning unit; and a heat conduction unit 98 that conducts heat to the outside of the device, the heat generated due to the foreign substance retaining operation performed by the foreign substance retaining unit. The foreign substance retaining unit includes a roller 90 that conveys the foreign substance removed by the cleaning unit, and a regulating member 92 that is in contact with the roller to regulate the movement of the foreign substance to be conveyed. Preferably, the regulating member is metal.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] In general, image forming devices (printers, copiers, facsimiles, etc.) that use electrophotographic process technology form an electrostatic latent image by irradiating (exposing) a charged photoconductor with laser light based on image data. Then, a developing device supplies toner to the photoconductor (image carrier) on which the electrostatic latent image has been formed, thereby visualizing the electrostatic latent image and forming a toner image. Furthermore, this toner image is directly or indirectly transferred to paper, and then heated and pressed to fix it, forming an image on the paper.

[0003] For example, in an image forming apparatus using an intermediate transfer belt, a toner image formed on a photosensitive drum is first transferred to an intermediate transfer belt, and the toner image transferred to the intermediate transfer belt is then transferred to a recording paper. During this process, the toner is not completely transferred to the recording paper and remains on the surface of the intermediate transfer belt. The remaining toner interferes with the formation of a new image, and is the cause of poor transfer images. For this reason, image forming apparatuses are equipped with a cleaning device to remove the toner.

[0004] For example, Patent Document 1 discloses a cleaning device including a cleaning blade having a tip that contacts the surface of an image carrier and removes waste toner adhering to the surface with the tip, a sheet member that, together with the surface of the image carrier and the tip of the cleaning blade, defines a storage section for storing the waste toner removed by the tip of the cleaning blade, and a discharge section that is positioned above the tip of the cleaning blade and discharges a portion of the waste toner stored in the storage section.

[0005] Conventionally, in a cleaning device, in order to discharge scraped waste toner and the like to the outside without leaking into the image forming apparatus, it is necessary to seal the space in the housing for temporarily storing the waste toner and the like.

[0006] On the other hand, frictional heat is generated between the image carrier to be cleaned and the cleaning member (blade or the like), and this heat tends to accumulate inside the sealed housing.

[0007] If heat builds up inside the housing of the cleaning device, foreign matter such as waste toner and paper powder adhering to the cleaning member (blade, etc.) may become stuck to the cleaning member (blade, etc.) by the heat, causing the tip of the blade to deform and allowing the foreign matter to slip through. Furthermore, if the stuck waste toner and other particles start to accumulate in the discharge path, the discharge path may become clogged. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2007-171395 A Summary of the Invention [Problem to be solved by the invention]

[0009] In order to address the above-mentioned problems, conventional cleaning devices have adopted a configuration in which a heat conductive member is brought into contact with the cleaning member (blade) that generates frictional heat, and the frictional heat generated by the blade is conducted (dissipated) through the heat conductive member to other areas within the housing or even to the outside.

[0010] On the other hand, in recent years, in response to the demand for energy saving, the adoption of so-called low-temperature fixing toner, which can be fixed to a recording medium at a lower temperature than before, has been promoted. In addition, in recent years, the demand for high speed, i.e., improved productivity, has been increasing, and the temperature inside the housing tends to rise due to the increase in the operating rate of the cleaning device, etc.

[0011] In such a situation, if the temperature inside the housing of the cleaning device rises, there is a risk that the waste toner collected by the cleaning member or the like will become stuck inside the housing, causing problems. For this reason, in recent years, there has been a demand for more effective suppression of the temperature rise inside the cleaning device.

[0012] An object of the present invention is to provide a cleaning device and an image forming apparatus that can more effectively suppress an increase in temperature inside the apparatus. [Means for solving the problem]

[0013] The cleaning device according to the present invention comprises: a cleaning unit that removes foreign matter remaining on the surface of the image carrier; a foreign matter storage section that stores the foreign matter removed by the cleaning section; a heat conduction section that conducts heat generated due to the storing operation of the foreign matter in the foreign matter storing section to the outside of the device, The foreign body storage section includes: a roller that conveys the foreign matter removed by the cleaning unit; a restricting member that contacts the roller so as to restrict the movement of the foreign matter being conveyed and causes the foreign matter removed by the cleaning unit to accumulate on the roller; Including, The heat conductive portion is disposed on an end side in a width direction of the foreign matter storage portion. The side where the foreign matter is discharged to the outside are located at.

[0014] The image forming apparatus according to the present invention comprises: an image forming section including the image carrier and forming an image on a recording medium; The cleaning device is as described above. Effect of the Invention

[0015] According to the present invention, the temperature rise inside the housing can be more effectively suppressed. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an overall configuration of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a main part of a control system of the image forming apparatus according to the present embodiment. [Diagram 3] 1 is a vertical cross-sectional view showing a schematic configuration of a belt cleaning device according to an embodiment of the present invention. [Figure 4] 1 is an external perspective view of a belt cleaning device according to an embodiment of the present invention; [Diagram 5] FIG. 4 is a cutaway perspective view showing an opening in the casing to which the heat conductive portion is attached. [Figure 6] FIG. 4 is a cutaway perspective view illustrating a state in which a heat conducting portion and a heat dissipating portion are connected to each other. [Figure 7] FIG. 4 is a cutaway perspective view for explaining the arrangement of a heat dissipation portion and the like. [Figure 8] 11A and 11B are diagrams illustrating a mode in which the fin cooling portion blows cooling air from above and below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the cleaning device and the image forming apparatus according to the present embodiment will be described in detail with reference to the drawings.

[0018] Fig. 1 is a diagram showing the overall configuration of an image forming apparatus 1 according to the present embodiment. Fig. 2 shows the main parts of a control system of the image forming apparatus 1 according to the present embodiment. The image forming apparatus 1 shown in Figs. 1 and 2 is a color image forming apparatus of an intermediate transfer type that utilizes electrophotographic process technology.

[0019] That is, the image forming apparatus 1 transfers (primary transfer) the toner images of each color, Y (yellow), M (magenta), C (cyan), and K (black), formed on the photosensitive drum 413 onto the intermediate transfer belt 421, superimposes the four color toner images on the intermediate transfer belt 421, and then transfers (secondary transfer) them onto the paper S to form an image.

[0020] In addition, the image forming apparatus 1 employs a tandem system in which photosensitive drums 413 corresponding to the four colors YMCK are arranged in series in the running direction of an intermediate transfer belt 421, and each color toner image is transferred sequentially to the intermediate transfer belt 421 in a single step.

[0021] As shown in FIG. 2, the image forming apparatus 1 includes an image reading unit 10, an operation display unit 20, an image processing unit 30, an image forming unit 40, a paper conveying unit 50, a fixing unit 60, a control unit 100, and a belt cleaning device 426, the details of which will be described later.

[0022] The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, etc. The CPU 101 reads out a program corresponding to the processing contents from the ROM 102, loads it in the RAM 103, and centrally controls the operation of each block of the image forming apparatus 1 in cooperation with the loaded program. At this time, various data stored in the storage unit 72 is referenced. The storage unit 72 is composed of, for example, a non-volatile semiconductor memory (so-called flash memory) or a hard disk drive.

[0023] The control unit 100 transmits and receives various data to and from an external device (e.g., a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. The control unit 100 receives, for example, image data transmitted from an external device, and forms an image on a sheet S based on this image data (input image data). The communication unit 71 is formed of, for example, a communication control card such as a LAN card.

[0024] The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

[0025] The automatic document feeder 11 conveys the document D placed on the document tray by a conveying mechanism and sends it to the document image scanning device 12. The automatic document feeder 11 makes it possible to continuously read images (including both sides) of multiple sheets of the document D placed on the document tray all at once.

[0026] The document image scanning device 12 optically scans the document conveyed from the automatic document feeder 11 onto the contact glass or the document placed on the contact glass, and forms an image of the reflected light from the document on the light receiving surface of a CCD (Charge Coupled Device) sensor 12a to read the document image. The image reading unit 10 generates input image data based on the reading result by the document image scanning device 12. The input image data is subjected to a predetermined image processing in the image processing unit 30.

[0027] The operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22. The display unit 21 displays various operation screens, image states, operation statuses of each function, etc., according to a display control signal input from the control unit 100. The operation unit 22 has various operation keys such as a numeric keypad and a start key, accepts various input operations by the user, and outputs operation signals to the control unit 100.

[0028] The image processing unit 30 includes a circuit for performing digital image processing on input image data according to initial settings or user settings. For example, the image processing unit 30 performs gradation correction based on gradation correction data (gradation correction table) under the control of the control unit 100. The image processing unit 30 also performs various correction processes such as color correction and shading correction, as well as compression processing, on the input image data in addition to gradation correction. The image forming unit 40 is controlled based on the image data that has been subjected to these processes.

[0029] The image forming section 40 includes image forming units 41Y, 41M, 41C, and 41K for forming images with color toners of Y, M, C, and K components based on input image data, an intermediate transfer unit 42, and the like.

[0030] The image forming units 41Y, 41M, 41C, and 41K for the Y, M, C, and K components have the same configuration. For convenience of illustration and explanation, common components are denoted by the same reference numerals, and when they are to be distinguished from one another, the reference numerals are denoted by the suffix Y, M, C, or K. In Fig. 1, reference numerals are given only to the components of the image forming unit 41Y for the Y component, and reference numerals are omitted for the components of the other image forming units 41M, 41C, and 41K.

[0031] The image forming unit 41 includes an exposure device 411, a developing device 412, a photoconductor drum 413, a charging device 414, a drum cleaning device 415, and the like.

[0032] The photoconductor drum 413 is a negatively charged organic photoconductor (OPC) in which an undercoat layer (UCL), a charge generation layer (CGL), and a charge transport layer (CTL) are sequentially laminated on the peripheral surface of an aluminum conductive cylinder (aluminum bare tube) having a drum diameter of, for example, 80 mm. The charge generation layer is made of an organic semiconductor in which a charge generation material (e.g., phthalocyanine pigment) is dispersed in a resin binder (e.g., polycarbonate), and generates a pair of positive and negative charges by exposure to light from the exposure device 411. The charge transport layer is made of a hole transport material (electron-donating nitrogen-containing compound) dispersed in a resin binder (e.g., polycarbonate resin), and transports the positive charges generated in the charge generation layer to the surface of the charge transport layer.

[0033] Photoconductor drum 413 rotates at a constant peripheral speed by control unit 100 controlling a drive current supplied to a drive motor (not shown) that rotates photoconductor drum 413.

[0034] Charging device 414 uniformly charges the surface of photoconductor drum 413, which has photoconductivity, to a negative polarity. Exposure device 411 is composed of, for example, a semiconductor laser, and irradiates photoconductor drum 413 with laser light corresponding to an image of each color component. Positive charges are generated in the charge generation layer of photoconductor drum 413, and are transported to the surface of the charge transport layer, whereby the surface charge (negative charge) of photoconductor drum 413 is neutralized. An electrostatic latent image of each color component is formed on the surface of photoconductor drum 413 due to the potential difference with the surroundings.

[0035] The developing device 412 is a two-component developing device, and visualizes the electrostatic latent image by attaching toner of each color component to the surface of the photoconductor drum 413, thereby forming a toner image.

[0036] Drum cleaning device 415 has a drum cleaning blade or the like that is in sliding contact with the surface of photoconductor drum 413, and removes transfer residual toner remaining on the surface of photoconductor drum 413 after primary transfer. A lubricant application device that applies lubricant, which has been scraped off with a lubricant application brush and turned into powder, to photoconductor drum 413 is provided in the drum unit including photoconductor drum 413 (photoconductor).

[0037] The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

[0038] The intermediate transfer belt 421 is an endless belt that is stretched around a plurality of support rollers 423 in a loop shape. At least one of the support rollers 423 is a drive roller, and the others are driven rollers. For example, it is preferable that the roller 423A, which is disposed downstream of the primary transfer roller 422 for the K component in the belt running direction, is the drive roller. This makes it easier to maintain a constant running speed of the intermediate transfer belt 421 in the primary transfer section. The rotation of the drive roller 423A causes the intermediate transfer belt 421 to run at a constant speed in the direction of the arrow A.

[0039] Intermediate transfer belt 421 is a conductive and elastic belt, and has a high resistance layer with a volume resistivity of 8 to 11 [log Ω·cm] on its surface. Intermediate transfer belt 421 is driven to rotate by a control signal from control unit 100. Note that there are no limitations on the material, thickness, hardness, etc. of intermediate transfer belt 421, so long as it is conductive and elastic.

[0040] Primary transfer roller 422 faces photoconductor drum 413 of each color component and is disposed on the inner peripheral surface side of intermediate transfer belt 421. Primary transfer roller 422 is pressed against photoconductor drum 413 with intermediate transfer belt 421 sandwiched therebetween, thereby forming a primary transfer nip for transferring a toner image from photoconductor drum 413 to intermediate transfer belt 421.

[0041] Secondary transfer roller 424 is disposed on the outer circumferential surface side of intermediate transfer belt 421, facing roller 423B (hereinafter referred to as "backup roller 423B") disposed downstream of drive roller 423A in the belt running direction. By sandwiching intermediate transfer belt 421 between secondary transfer roller 424 and backup roller 423B, a secondary transfer nip for transferring a toner image from intermediate transfer belt 421 to paper S is formed.

[0042] When the intermediate transfer belt 421 passes through the primary transfer nip, the toner images on the photoconductor drum 413 are primarily transferred onto the intermediate transfer belt 421 in a sequentially overlapping manner. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge of the opposite polarity to the toner is applied to the back side of the intermediate transfer belt 421 (the side that contacts the primary transfer roller 422), so that the toner images are electrostatically transferred onto the intermediate transfer belt 421.

[0043] Thereafter, when the paper S passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred to the paper S. Specifically, a secondary transfer bias is applied to the secondary transfer roller 424, and a charge of the opposite polarity to the toner is applied to the back side of the paper S (the side that contacts the secondary transfer roller 424), so that the toner image is electrostatically transferred to the paper S. The paper S to which the toner image has been transferred is transported toward the fixing unit 60.

[0044] The belt cleaning device 426 removes residual toner remaining on the surface of the intermediate transfer belt 421 (corresponding to the "image carrier" of the present invention) after the secondary transfer. A specific configuration of the belt cleaning device 426 will be described later. Note that instead of the secondary transfer roller 424, a configuration in which a secondary transfer belt is stretched in a loop shape around a plurality of support rollers including a secondary transfer roller (a so-called belt-type secondary transfer unit) may be used.

[0045] Fixing section 60 includes upper fixing section 60A having a fixing surface side member arranged on the fixing surface side (surface on which a toner image is formed) of paper S, lower fixing section 60B having a back surface side support member arranged on the back surface side (surface opposite to the fixing surface) of paper S, and heating source 60C. The back surface side support member is pressed against the fixing surface side member to form a fixing nip that holds and transports paper S.

[0046] The fixing section 60 heats and presses the transported paper S, to which the toner image has been secondarily transferred, in a fixing nip, thereby fixing the toner image to the paper S. The fixing section 60 is disposed as a unit within the fixing device F. The fixing device F may also be provided with an air separation unit that blows air to separate the paper S from the fixing surface side member or the back surface side support member.

[0047] The paper transport section 50 includes a paper feed section 51, a paper discharge section 52, and a transport path section 53. The three paper feed tray units 51a to 51c that make up the paper feed section 51 store paper S (standard paper, special paper) identified based on basis weight, size, etc., by preset type. The transport path section 53 has a plurality of transport roller pairs, such as a registration roller pair 53a.

[0048] The sheets S stored in the sheet feed tray units 51a to 51c are sent out one by one from the top, and are transported to the image forming section 40 by the transport path section 53. At this time, the inclination of the fed sheets S is corrected and the transport timing is adjusted by the registration roller section in which the registration roller pair 53a is arranged. Then, in the image forming section 40, the toner images on the intermediate transfer belt 421 are secondarily transferred all at once onto one side of the sheets S, and a fixing process is performed in the fixing section 60. The sheets S on which the images have been formed are discharged outside the apparatus by the sheet discharge section 52 equipped with the sheet discharge rollers 52a.

[0049] Next, a general configuration of the belt cleaning device 426 will be described with reference to Fig. 3. The belt cleaning device 426 includes a cleaning blade 80 as a cleaning member, a cleaning blade support metal plate 84, a waste toner screw 88, a toner storage roller 90, a regulating member 92, a regulating member support metal plate 94, and a casing 95 as a housing.

[0050] The cleaning blade 80 , the cleaning blade supporting metal plate 84 , the waste toner screw 88 , the toner storage roller 90 , the regulating member 92 and the regulating member supporting metal plate 94 are provided within a casing 95 .

[0051] The control unit 100 and the belt cleaning device 426 function as the "cleaning device" of the present invention. The control unit 100 and the belt cleaning device 426 may be configured as a unit and attached to the image forming apparatus 1, or may be separately incorporated into the image forming apparatus 1 and function as the "cleaning device" of the present invention.

[0052] The intermediate transfer belt 421 is configured to be capable of rotating forward and reverse by a drive unit 75 (e.g., a motor) under the control of the control unit 100. The intermediate transfer belt 421 rotates in the direction of the arrow in the figure (for example, forward direction) at a predetermined rotation speed (e.g., 460 [mm / s]) during an image formation process of the image forming apparatus 1 (when a print job is executed).

[0053] The cleaning blade 80 abuts the tip portion (blade edge portion) of the cleaning blade 80 against the surface of the intermediate transfer belt 421 in a counter direction to the forward rotation direction (rotation direction during image formation processing) of the intermediate transfer belt 421. In one specific example, the contact angle of the cleaning blade 80 with respect to the intermediate transfer belt 421 is 25°, and the contact load of the cleaning blade 80 is 25 N / m.

[0054] In one specific example, the cleaning blade 80 has a thickness of 2 mm and a free length of 10 mm. The material of the cleaning blade 80 is, for example, urethane rubber, but any other elastic material may be used.

[0055] The cleaning blade 80 scrapes off and removes foreign matter, including toner, (for example, paper powder of the paper S, and aggregates of external additives and lubricants contained in the toner) remaining on the surface of the intermediate transfer belt 421. Such cleaning blade 80 corresponds to the "cleaning unit" of the present invention.

[0056] The cleaning blade 80 is attached to a cleaning blade support metal plate 84 that supports the cleaning blade 80. This cleaning blade support metal plate 84 is supported by a shaft so as to be rotatable in the clockwise and counterclockwise directions in the drawing.

[0057] Under the control of the control unit 100, the cleaning blade support metal plate 84 rotates in either of the above directions by the transmission of driving force from a part of the drive unit 77 (in this example, a first motor not shown), thereby moving the cleaning blade 80.

[0058] Here, as the cleaning blade support metal plate 84 rotates counterclockwise in the figure, the tip of the cleaning blade 80 comes into contact with the surface of the intermediate transfer belt 421. Note that Fig. 3 shows a state in which the tip of the cleaning blade 80 comes into contact with the surface of the intermediate transfer belt 421.

[0059] On the other hand, the cleaning blade support metal plate 84 rotates in the clockwise direction in the figure, so that the tip of the cleaning blade 80 separates from the surface of the intermediate transfer belt 421 .

[0060] On the upstream side of the cleaning blade 80 in the forward rotation direction of the intermediate transfer belt 421, a “foreign matter storage section” is formed to temporarily store foreign matter such as toner scraped off by the cleaning blade 80 (hereinafter referred to as “waste toner 120”).

[0061] In relation to the present invention, the "foreign matter storage section" is defined by the shapes of the toner storage roller 90, the regulating member 92, and the image carrier (in this example, the intermediate transfer belt 421). In other words, the foreign matter storage section is a space formed by the toner storage roller 90, the regulating member 92, and the intermediate transfer belt 421.

[0062] Here, the toner storage roller 90 is rotatably disposed in contact with the intermediate transfer belt 421, upstream of the contact position between the cleaning blade 80 and the intermediate transfer belt 421 in the forward rotation direction of the intermediate transfer belt 421. In the rotation direction of the intermediate transfer belt 421, the distance from the contact position between the cleaning blade 80 and the intermediate transfer belt 421 to the contact position between the intermediate transfer belt 421 and the toner storage roller 90 is, for example, 75 mm.

[0063] The regulating member 92 is an elastic or flexible member, and is fixed to a regulating member support metal plate 94 that supports the regulating member 92. The material of the regulating member 92 is generally a resin such as polyethylene terephthalate (PET). In contrast, in this embodiment, the regulating member 92 is made of a material different from the conventional one, which will be described later.

[0064] The tip side of the regulating member 92 extends upward, and is pushed by the toner storage roller 90 and bent to come into contact with the surface of the toner storage roller 90. In other words, the toner storage roller 90 is sandwiched between the intermediate transfer belt 421 and the regulating member 92.

[0065] The regulating member 92 comes into contact (surface contact) with the toner storage roller 90 so as to regulate the movement of foreign matter such as the waste toner 120 transported by the toner storage roller 90.

[0066] Thus, under the control of the control unit 100, the toner storage roller 90 rotates counterclockwise in FIG. 3 by the transmission of the driving force of a part of the drive unit 77 (a second motor, not shown in this example).

[0067] Further, a waste toner screw 88 is rotatably provided below the toner storage roller 90 and the regulating member 92. This waste toner screw 88 rotates in the clockwise direction in FIG. 3 by the driving force of the second motor being transmitted thereto, and transports and discharges foreign matter such as waste toner 120 delivered from the foreign matter storage section to the outside of the casing 95.

[0068] Specifically, as shown in Fig. 4, a gear 88a connected to the shaft of the waste toner screw 88 and a gear 90a connected to the shaft of the toner storage roller 90 are provided on the outer surface side of one side plate 96 of the casing 95 so as to mesh with each other. When the driving force of the second motor is transmitted to the gear 88a, for example, the waste toner screw 88 rotates in the clockwise direction in Fig. 3, and the toner storage roller 90 rotates counterclockwise in Fig. 3 in conjunction with the gears.

[0069] 4, on the outer surface side of the other side plate 96 of the casing 95, a discharge path portion 88b for discharging or temporarily storing foreign matter transported by the waste toner screw 88 is provided.

[0070] When a print job is executed, the control unit 100 controls the first motor so as to bring the tip of the cleaning blade 80 into contact with the surface of the intermediate transfer belt 421, and also controls the driving of the second motor.

[0071] At this time, foreign matter including waste toner 120 remaining on the surface of intermediate transfer belt 421 is scraped off by cleaning blade 80, and falls onto toner storage roller 90 and is stored there (gradually stored there) (see FIG. 3 as appropriate).

[0072] Here, the foreign matter storage section has a configuration in which, when the amount of stored waste toner 120 increases, the foreign matter storage section forcibly discharges the waste toner 120 and supplies the waste toner 120 to the waste toner screw 88. In this example, the foreign matter storage section is configured in such a way that, when the volume of the stored waste toner 120 becomes higher than the height of the regulating member 92, the upper waste toner 120 spills over the upper end of the regulating member 92 and delivers the waste toner 120 to the waste toner screw 88.

[0073] Alternatively, the foreign matter storage section may be configured so that when the volume of waste toner 120 increases, the waste toner 120 leaks out from an opening (not shown) formed near the other end side (the side of the regulating member supporting plate 94) of the regulating member 92. Also, for example, the foreign matter storage section may be configured like a pressure regulating valve in which, when the stored waste toner 120 exceeds a certain amount, the contact state between the regulating member 92 and the toner storage roller 90 is released by pressure, causing the waste toner 120 to break down.

[0074] Thus, the waste toner 120 forcibly discharged from the foreign matter storage portion is transported to the outside of the belt cleaning device 426 by the rotating waste toner screw 88 (see FIG. 4 as appropriate).

[0075] Incidentally, immediately after shipment from the factory or after replacing the belt cleaning device 426 during maintenance work, a solid image of a predetermined length is formed on the intermediate transfer belt 421 at the maximum print width, and the untransferred image is allowed to reach the cleaning blade 80 and removed, resulting in a state in which an appropriate amount of waste toner 120 is stored in the foreign matter storage section. After that, an appropriate amount of transfer residual toner is generated during image formation, and a constant amount of waste toner 120 is constantly stored in the foreign matter storage section.

[0076] The amount of penetration of the toner storage roller 90 into the intermediate transfer belt 421 is, for example, 0.3 mm. The rotational speed ratio θ (=V1 / V2) between the rotational speed (V1) of the toner storage roller 90 and the rotational speed (V2) of the intermediate transfer belt 421 is 0.5.

[0077] The material of the toner storage roller 90 is, for example, NBR rubber (hardness: 40 degrees), but any other elastic material may be used. As the toner storage roller 90, in addition to a rubber roller, for example, a sponge roller or a resin roller may be used.

[0078] In this example, the toner storage roller 90 is connected to a drive motor (second motor) and is configured to be rotated independently of the intermediate transfer belt 421. As another example, the toner storage roller 90 may be configured to rotate together with the movement of the intermediate transfer belt 421.

[0079] However, in the belt cleaning device 426, a problem has been pointed out in the past in which frictional heat is generated between the intermediate transfer belt 421 (image carrier) to be cleaned and the cleaning blade 80, and such heat tends to accumulate inside the sealed casing 95.

[0080] Here, if heat accumulates inside the casing 95 of the belt cleaning device 426, foreign matter such as waste toner 120 adhering to the cleaning blade 80 may become fixed by the heat, causing the tip side of the cleaning blade 80 to appear deformed, allowing the foreign matter to slip through. Furthermore, if the fixed waste toner etc. starts to accumulate in the discharge path of the waste toner screw 88, etc., there is a possibility that the discharge path may become clogged.

[0081] To address the above-mentioned problems, in conventional cleaning devices, it has been proposed to bring a heat conductive member into contact with the cleaning blade 80, which was thought to be the main source of frictional heat, and to transfer the frictional heat generated by the cleaning blade 80 mainly to other areas in the housing (to dissipate the heat). An example of such a configuration is the technology described in JP 2017-68080 A, in which a photosensitive drum is cleaned with a cleaning member.

[0082] On the other hand, in recent years, in response to the demand for energy saving, the adoption of so-called low-temperature fixing toner, which can be fixed to a recording medium at a lower temperature than before, has been promoted. In addition, in recent years, the demand for high speed, i.e., improved productivity, has been increasing, and the temperature inside the housing tends to rise due to the increase in the operating rate of the cleaning device, etc.

[0083] In such a situation, if the temperature inside the housing of the cleaning device rises, the waste toner 120 collected by the cleaning member or the like may become stuck inside the housing, causing a problem. Therefore, in recent years, there has been a demand for further suppression of the temperature rise inside the cleaning device.

[0084] As a result of intensive research conducted by the inventors in order to solve this problem, it was found that the conventional configuration and its advanced configuration, i.e., the configuration for dissipating heat generated by the cleaning blade 80 and an advanced version of said configuration, do not provide sufficient effects and cannot adequately respond to the changes in the device environment described above.

[0085] Furthermore, as a result of intensive research, the inventors have found that the heat generated in conjunction with the storage operation in the foreign matter storage portion described above, more specifically, the frictional heat between the members forming the foreign matter storage portion, particularly the frictional heat generated between the toner storage roller 90 and the regulating member 92, is greater than expected. Based on this finding, the inventors have found that it is extremely effective to provide a configuration for dissipating the frictional heat generated between the toner storage roller 90 and the regulating member 92.

[0086] Thus, in this embodiment, a heat conductive section is provided to conduct heat generated due to the storage operation of foreign matter such as waste toner 120 in the foreign matter storage section, particularly frictional heat generated between the toner storage roller 90 and the regulating member 92, to the outside of the belt cleaning device 426 (outside the device).

[0087] From the viewpoint of increasing thermal conductivity and heat dissipation as much as possible, it is desirable for such a heat conductive portion to be made of a metal such as aluminum or an aluminum alloy.

[0088] In one specific example, the heat conduction section is disposed inside the casing 95 (housing) of the belt cleaning device 426, and is configured to include a heat conducting section that conducts heat generated by friction in the foreign matter storage section, and a heat dissipation section that contacts the heat conducting section and dissipates heat to the outside of the casing 95 (housing).

[0089] In this case, the heat conducting portion is preferably provided so as to be in contact with the regulating member 92 (for example, in surface contact).

[0090] Furthermore, from the viewpoint of thermal conductivity, etc., it is preferable to use metal as the material for the regulating member 92. That is, conventionally, the regulating member 92 has generally been made of a flexible resin, particularly PET (Polyethylene terephthalate), and for this reason has also been called "retention PET."

[0091] In contrast, according to the results of experiments conducted by the inventors, it was found that by constructing the regulating member 92, which is a component of the foreign matter storage section, from metal, the heat generated from the foreign matter storage section can be conducted more efficiently through the thermal conductive section.

[0092] In order to provide flexibility to the regulating member 92, spring steel may be used as the metal material, or a metal plate (for example, a thin aluminum plate) may be attached to a conventional storage pet.

[0093] Furthermore, in order to more efficiently conduct the heat generated by friction in the foreign matter storage section to the outside of the casing 95 (housing) through the heat conduction section (heat dissipation section), it is advisable to provide an opening in the casing 95 (housing) and bring the heat conduction section and the heat dissipation section into contact at the opening.

[0094] In this case, the heat conducting portion and the heat dissipating portion are connected or joined so that their outer surfaces are in contact with each other, and the area of ​​the outer surface of the heat conducting portion is larger than the area of ​​the outer surface of the heat dissipating portion.

[0095] The height of the heat conducting portion should be set to a height equal to or higher than the position where heat (particularly heat due to friction) is generated in the foreign matter storage portion.

[0096] Alternatively, the outer surface of the heat conducting portion may be configured to contact the inner surface of the casing 95 at a position above the position where friction occurs in the foreign matter storage portion.

[0097] From the viewpoint of thermal conductivity, it is considered desirable to dispose the heat conductive portion (heat conducting portion and heat dissipating portion) over the entire area in the width direction of the regulating member 92. However, with such a configuration, problems may occur, such as the heat conducting portion interfering with the transport of foreign matter such as the waste toner 120 or interfering with existing components inside the casing 95, or the heat dissipating portion interfering with components inside the image forming apparatus 1.

[0098] In view of the above, it is advisable to configure the heat conduction section (heat conduction section and heat dissipation section) to be limited to a certain area in the width direction of the regulating member 92, specifically, an area within the casing 95 (housing) where heat is likely to accumulate, or an area where the heat is highest in actual operation.

[0099] In this regard, the inventors measured and confirmed the temperature inside the casing 95 (distribution of heat inside the housing) and found that in actual operation, the end side in the width direction of the regulating member 92, where the waste toner 120 etc. are discharged outside the belt cleaning device 426, becomes the area where the heat becomes the highest.

[0100] In other words, it has been conventionally believed that the main source of heat in a cleaning device is the cleaning blade 80, and that heat is distributed approximately evenly across the entire width of the cleaning blade 80.

[0101] In response to this, the inventors of the present invention conducted actual measurements and found that there is a bias in the heat distribution in the cleaning device. Also, it was found that the place where the most heat accumulates in the cleaning device is a place other than the cleaning blade 80, specifically, the downstream side of the space between the toner storage roller 90 and the regulation member 92 of the foreign matter storage section where foreign matter temporarily accumulates.

[0102] Based on the interference with the internal components and the actual measurement results described above, in this embodiment, as described later in Figure 4 etc., the heat conduction section (heat conduction section and heat dissipation section) is provided in a limited area in the width direction of the regulating member 92.

[0103] Next, a specific example of the above-mentioned schematic configuration will be described in detail with reference to FIGS.

[0104] 3, the belt cleaning device 426 of this embodiment is provided with a heat-conducting member 97 as a "heat-conducting portion" that conducts heat generated by friction of the foreign matter storage portion inside the casing 95. Also, on the outer surface of the casing 95, a heat-dissipating fin 98 is provided as a "heat-dissipating portion" that is connected to the heat-conducting member 97 (heat-conducting portion) and dissipates the heat conducted to the heat-conducting member 97 to the outside of the casing 95 (housing).

[0105] Of the above, the heat-conducting member 97 (heat-conducting portion) has a substantially U-shaped outer shape in a plan view, and is disposed so that the outer surface of one end 97a abuts (is fixed to) the lower surface of the restricting member 92. In contrast, the wide outer surface (the outer surface having the length D in FIG. 3) on the other end side of the heat-conducting member 97 is disposed so as to abut (is fixed to) the inner surface of the casing 95. In this example, the surface of one end 97a and the surface on the other end side of the heat-conducting member 97 are substantially parallel to each other.

[0106] As shown in FIG. 3, the outer surface of one end 97a of the heat-conducting member 97 abuts against the surface of the regulating member 92 opposite to the surface that abuts against the above-mentioned regulating member support metal plate 94 (the surface that does not contact the toner storage roller 90).

[0107] With this configuration, frictional heat generated by the regulating member 92 and further by the toner storage roller 90 in contact with the regulating member 92 can be absorbed and conducted by the heat conducting member 97 .

[0108] 3, the position of the lower end (the position of the lower auxiliary line) of the wide surface (the outer surface having the length D) on the other end side of the heat-conducting member 97 is substantially equal to the position of the upper end of one end 97a of the heat-conducting member 97. Furthermore, the position of the upper end (the position of the upper auxiliary line) of the outer surface having the length D of the heat-conducting member 97 is substantially equal to the position of the upper end of the cleaning blade 80 described above.

[0109] In general, the area (see arrow D) along the vertical direction of the surface on the other end side of the heat conduction member 97 (heat conduction section) includes the position where friction occurs in the foreign matter storage section (the position where the toner storage roller 90 and the regulating member 92 contact each other) and reaches a position higher than that position.

[0110] With this configuration, heat that cannot be conducted from the surface in contact with the regulating member support metal plate 94, such as heat generated by friction between the toner storage roller 90 and the regulating member 92, and that diffuses into the air inside the casing 95 or rises, can be absorbed and conducted by the heat-conducting member 97.

[0111] In this embodiment, the toner storage roller 90, the regulating member 92, and the regulating member support metal plate 94 extend in the width direction of the belt cleaning device 426 (see the left-right direction in FIG. 4), whereas the surfaces on one end side and the other end side of the heat conducting member 97 are provided in a partial area (on the end side) in the width direction. This also applies to the heat dissipating fins 98 (heat dissipating portion) described later.

[0112] In other words, it is not necessary to provide the heat conducting member 97 and the heat dissipating fins 98 in the entire area in the width direction. By providing them in a part of the width direction (typically the area where the temperature rises the most), a sufficient cooling effect can be obtained that can also accommodate the use of the low-temperature fixing toner mentioned above.

[0113] Depending on the model of the cleaning device, the region in the foreign matter storage section where the temperature due to frictional heat is the highest may be on the opposite side (upstream side) from this example, or may be distributed in multiple locations. Therefore, the number of heat-conducting members 97 and heat-dissipating fins 98 and their arrangement in the width direction are arbitrary and are not particularly limited.

[0114] On the other hand, if excessively many (or wider) heat-conducting members 97 and heat-dissipating fins 98 are provided in an existing device, various problems may occur, such as interference with other components that make up the cleaning device, unstable surface pressure on the regulating member 92, or even an effect on the discharge path of the waste toner 120.

[0115] In this embodiment, taking the above-mentioned problems into consideration, the heat conduction section (heat-conducting member 97 and heat-dissipating fins 98) is configured so as to obtain the maximum heat dissipation and cooling effect with the minimum necessary width size. The configuration of the heat-dissipating fins 98 as the heat-dissipating section will be described in detail below.

[0116] The heat dissipation fin 98 (heat dissipation portion) is a member having a substantially U-shaped external shape in side view as shown in Figures 3 and 4. In one specific example, the heat dissipation fin 98 (heat dissipation portion) can be manufactured by forming grooves and holes in a metal plate and then bending the plate.

[0117] As shown in FIG. 4, the heat dissipation fins 98 (heat dissipation section) and the heat conduction member 97 are arranged on the inner end side in the width direction of the casing 95, in other words, on the side where foreign matter such as waste toner 120 is discharged to the outside of the belt cleaning device 426 through the waste toner screw 88.

[0118] 3, the length of the heat dissipation fins 98 (heat dissipation portion) in the up-down direction is shorter than the length D of the other end side of the above-mentioned heat conducting member 97. Similarly, the width of the heat dissipation fins 98 (heat dissipation portion) in the horizontal direction is also shorter than the horizontal width of the above-mentioned heat conducting member 97 (see FIG. 6).

[0119] This configuration takes into consideration that if the contact surface of the heat dissipating fins 98 with the heat conducting member 97 is made excessively large, the opening portion of the casing 95 (see FIG. 5) becomes large and the rigidity of the casing 95 decreases.

[0120] The main role of the heat dissipation fins 98 (heat dissipation section) is to dissipate the heat conducted from the heat conducting member 97 through the fin portions extending from the position of the casing 95. In consideration of this function and interference with other components of the image forming apparatus 1, the interval between the fin portions may be set to a necessary and sufficient value as exemplified in FIG.

[0121] From the viewpoint of heat dissipation performance, it is desirable that the length and area of ​​the fin portion of the heat dissipation fins 98 extending from the position of the casing 95 be longer (wider). On the other hand, in consideration of the above-mentioned problem of interference with other components of the image forming apparatus 1, it is sufficient to ensure that the size of the heat dissipation fins 98 is only necessary and sufficient (see FIGS. 3, 7, etc.).

[0122] Thus, in the present embodiment, the area of ​​the outer surface of the heat-conducting member 97 that contacts the heat-dissipating fins 98 is larger than the area of ​​the corresponding outer surface (contact surface) of the heat-dissipating fins 98. With this configuration, more heat inside the casing 95 can be absorbed and conducted to the heat-dissipating fins 98, and can be dissipated to the outside of the casing 95 through the heat-dissipating fins 98.

[0123] 5, in this embodiment, a rectangular window-shaped opening 95a is formed in the region on the inner end side of the above-mentioned casing 95. Here, the opening 95a of the casing 95 has a shape that is substantially the same as or slightly larger than the above-mentioned contact surface of the heat dissipation fin 98 (heat dissipation portion).

[0124] Therefore, according to the present embodiment, the outer surfaces (contact portions with the heat-conducting member 97) of the heat-dissipating fins 98 can be attached so as to be fitted into the openings 95a of the casing 95 (see Figs. 5 and 4), and at this time, the outer surfaces of the heat-dissipating fins 98 contact the outer surface of the other end side of the heat-conducting member 97, as shown in Fig. 6. In one specific example, the heat-conducting member 97 and the heat-dissipating fins 98 can be fixed by screwing.

[0125] In the present embodiment, air is circulated inside (inside the housing) of image forming apparatus 1. Such air is used as cooling air for belt cleaning device 426 and various other components, and the air circulates horizontally in a direction from the front side to the back side in the depth direction of image forming apparatus 1.

[0126] In consideration of this point, in this embodiment, the heat dissipation fin 98 is attached to the outer surface of the other end side of the heat conduction member 97 so that the surface orientation of each fin of the heat dissipation fin 98 is oriented along the air flow direction (each extends horizontally).

[0127] By arranging the heat dissipation fins 98 in the above-mentioned orientation, the flow of the air is effectively prevented from being blocked by the heat dissipation fins 98 (in other words, cooling of the parts behind or in front of the belt cleaning device 426 is prevented from being hindered), while the heat inside the casing 95 transferred to the heat dissipation fins 98 can be efficiently dissipated to the outside of the belt cleaning device 426 via air.

[0128] Thus, according to the belt cleaning device 426 of the present embodiment, the frictional heat generated by the contact (pressure contact) between the toner storage roller 90 and the regulating member 92 is transmitted to the heat conducting member 97 connected to the regulating member 92 and further to the heat dissipating fin 98 connected to the heat conducting member 97, and can be diffused into the air circulating around the heat dissipating fin 98.

[0129] In addition, by cooling the heat dissipation fins 98 exposed on the outer surface of the casing 95, the heat conduction member 97 arranged inside the casing 95 in face-to-face contact with the heat dissipation fins 98, and ultimately the regulating member 92 connected to the heat conduction member 97 can also be cooled.

[0130] Therefore, according to this embodiment, the temperature rise inside the casing 95 of the belt cleaning device 426 can be more effectively suppressed, and thus the device can adequately respond to changes in the device environment, such as the use of low-temperature fixing toner and increased operating rate.

[0131] Optionally or additionally, a fin cooling section 99 (see FIG. 2) for blowing cooling air onto the heat dissipation fins 98 may be provided.

[0132] In one specific example, the fin cooling unit 99 can use a small blower (such as a fan) to blow air only onto the heat dissipation fins 98, and operates under the control of the above-mentioned control unit 100. In this case, as shown in Fig. 8, blowers can be provided above and below the heat dissipation fins 98, and air can be blown directly (i.e., vertically) onto each surface of the upper fins and the lower fins.

[0133] With the above-mentioned configuration, the surface area of ​​the heat dissipating fins 98 with which the air hits is increased, so that the heat dissipation or cooling effect inside the housing of the belt cleaning device 426 can be further improved.

[0134] As described above in detail, the belt cleaning device 426 in this embodiment is equipped with a heat conduction section (heat conductive member 97 and heat dissipation fins 98) that conducts heat generated due to the foreign matter storage operation in the foreign matter storage section to the outside of the belt cleaning device 426.

[0135] According to the belt cleaning device 426 having such a configuration, the temperature rise inside the device can be more effectively suppressed.

[0136] In the above-described embodiment, an example in which the present invention is applied to belt cleaning device 426 has been described. However, the above-described characteristic configuration for heat conduction and heat dissipation (cooling) may also be provided in drum cleaning device 415 that cleans photosensitive drum 413, which is another image carrier.

[0137] Alternatively, in the case where the image forming apparatus 1 is provided with a secondary transfer body (secondary transfer roller, secondary transfer belt) for transferring the toner on the intermediate transfer belt 421 to the paper S, the drum cleaning device 415 for cleaning the secondary transfer body may be provided with the characteristic configuration for heat conduction and heat dissipation (cooling) described above.

[0138] In addition, the above-mentioned embodiment is merely an example of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted as being limited by the above embodiment. In other words, the present invention can be embodied in various forms without departing from the gist or main characteristics of the present invention. [Explanation of symbols]

[0139] 1. Image forming device 10 Image reading unit 20 Operation display section 21 Display section 22 Control section 30 Image processing section 40 Image forming section 50 Paper transport section 60 Fixing unit 71 Communications Department 72 Memory section 75,77 Drive unit 80 Cleaning blade (cleaning part) 84 Cleaning blade support metal plate 88 Waste toner screw 88a Gear 88b Discharge path section 90 Toner storage roller (foreign matter storage section) 90a gear 92 Restriction member (foreign matter storage section) 94 Regulatory member support plate 95 Casing 95a aperture 96 Side Panel 97 Heat conduction member (heat conduction part) 97a End 98 Heat dissipation fin (heat dissipation part) 99 Fin cooling section 100 Control section (cleaning device) 101 CPU 102 ROM 103 RAM 120 Waste Toner 421 Intermediate transfer belt 426 Belt cleaning device (cleaning device)

Claims

1. a cleaning unit that removes foreign matter remaining on the surface of the image carrier; a foreign matter storage section that stores the foreign matter removed by the cleaning section; a heat conduction section that conducts heat generated due to the storing operation of the foreign matter in the foreign matter storing section to the outside of the device, The foreign body storage section includes: a roller that conveys the foreign matter removed by the cleaning unit; a restricting member that contacts the roller so as to restrict the movement of the foreign matter being conveyed and causes the foreign matter removed by the cleaning unit to accumulate on the roller; Including, The heat conductive portion is disposed on one of the end portions in the width direction of the foreign matter storage portion, on a side from which the foreign matter is discharged to the outside. Cleaning equipment.

2. The regulating member is made of metal. The cleaning device according to claim 1 .

3. The heat conductive portion is made of metal.

3. The cleaning device according to claim 1 or 2.

4. The metal includes aluminum. The cleaning device according to claim 3.

5. The heat conductive portion is a heat conducting part disposed inside a housing of the cleaning device and configured to conduct the heat of the foreign matter storage part; a heat dissipation portion that is in contact with the heat conduction portion and dissipates the heat to the outside of the housing; The cleaning device according to claim 1 or 2, comprising:

6. The heat conducting portion is in contact with the regulating member. The cleaning device according to claim 5.

7. The heat dissipation portion is in contact with the heat conduction portion through an opening of the housing.

7. The cleaning device according to claim 5 or 6.

8. The heat conducting part and the heat dissipating part are connected so that their outer surfaces are in contact with each other, and an area of ​​the outer surface of the heat conducting part is larger than an area of ​​the outer surface of the heat dissipating part. A cleaning device according to any one of claims 5 to 7.

9. The height of the heat conducting portion is equal to or higher than the position where friction occurs in the foreign matter storage portion. A cleaning device according to any one of claims 5 to 8.

10. The outer surface of the heat conducting portion is in contact with the inner surface of the housing at a position above a position where friction occurs in the foreign matter storage portion. The cleaning device according to claim 8.

11. The heat dissipation portion is a member having a substantially U-shaped side surface. A cleaning device according to any one of claims 5 to 10.

12. The heat dissipation portion includes a heat dissipation fin, a surface of the fin is oriented along a flow direction of air flowing through an image forming apparatus in which the cleaning device is installed; A cleaning device according to any one of claims 5 to 10.

13. A fin cooling unit is provided which blows cooling air onto the fins. The cleaning device according to claim 12.

14. The fin cooling unit blows the cooling air in a direction intersecting with the surface of the fin. The cleaning device according to claim 13.

15. an image forming section including the image carrier and forming an image on a recording medium; A cleaning device according to any one of claims 1 to 14; An image forming apparatus comprising:

Images