JP2017111269A - Cleaning device and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device that can suppress the occurrence of image defects while suppressing a reduction in sealability of a sealing member, and an image forming apparatus including the same.SOLUTION: This belt cleaning unit (cleaning device) 19 comprises: a housing 40; a recovery roller 43; a cleaning blade 45; and a sheet-like sealing member 50 that suppresses backflow of a waste toner in the housing 40. The sealing member 50 has, at its end in contact with the recovery roller 43, a plurality of cuts 50a formed in one direction at a predetermined interval.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a cleaning device and an image forming apparatus including the same, and in particular, a cleaning device including a cleaning member that removes residual toner on the surface of an image carrier, and a seal member that is disposed in contact with the cleaning member. And an image forming apparatus including the same.

  In an image forming apparatus using an electrophotographic method such as a copying machine, a printer, or a facsimile, a powder developer is mainly used, and an electrostatic latent image formed on an image carrier such as a photosensitive drum using the developing apparatus. A general process is to make an image visible, transfer the visible image (toner image) onto a recording medium, and perform a fixing process. The toner remaining on the surface of the image carrier is removed by a cleaning device, and a new toner image is formed.

  The cleaning device includes a fur brush that removes toner from the surface of the image carrier, a cleaning member that includes a recovery roller that recovers toner from the fur brush, and a discharge screw that discharges toner scraped off from the surface of the recovery roller to the outside. And a seal member that partitions the inside of the housing into a collection roller side and a discharge screw side.

  The seal member guides the toner scraped off from the surface of the collection roller by the cleaning blade to the discharge screw side so as not to go to the collection roller side (outside of the housing). Therefore, the seal member is provided over the entire axial direction of the collection roller.

  A cleaning member that removes toner from the surface of the image carrier, a discharge screw that discharges toner scraped off from the surface of the cleaning member to the outside, and a seal member that partitions the inside of the housing into the cleaning member side and the discharge screw side Is disclosed in, for example, Patent Document 1.

JP 2014-109592 A

  Incidentally, in the cleaning device, the seal member needs to contact the collection roller with a contact pressure that does not scrape off the toner adhering to the collection roller. Specifically, if the sealing member is applied too strongly against the collection roller, the toner and paper powder on the surface of the collection roller are blocked and dropped. If the toner or paper dust that has fallen is collected until it comes into contact with the cleaning member, the toner or paper dust is carried to the image carrier via the cleaning member, causing an image defect. Note that if the thickness of the seal member is reduced in order to reduce the contact pressure of the seal member with respect to the recovery roller, the seal member swells (waves), which causes a problem that the sealing performance of the seal member with respect to the cleaning member is deteriorated. .

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to suppress the occurrence of image defects while suppressing a decrease in the sealing performance of the seal member. A cleaning device and an image forming apparatus including the same.

  In order to achieve the above object, a cleaning device according to a first configuration of the present invention includes an opening facing the image carrier, a waste toner container that stores toner scraped from the surface of the image carrier, Formed in the vicinity of the opening of the housing, a roller-shaped cleaning member that removes residual toner on the surface of the image carrier, a cleaning blade that scrapes off waste toner on the surface of the cleaning member, and a cleaning member A sheet-like sealing member that is disposed in contact with the cleaning member so as to extend in a first direction that is the longitudinal direction of the sheet, and that suppresses the backflow of the waste toner from the waste toner container to the opening side. A plurality of cuts are formed at a predetermined interval in the first direction at the end of the seal member that contacts the cleaning member.

  According to the first configuration of the present invention, a plurality of cuts are formed at a predetermined interval in the first direction at the end of the seal member that contacts the cleaning member. Thereby, since the contact pressure of the sealing member with respect to the cleaning member can be reduced, it is possible to suppress toner and paper dust on the surface of the cleaning member from being blocked by the sealing member and falling. For this reason, it is possible to suppress the toner and paper dust from accumulating until they come into contact with the cleaning member. Therefore, it is possible to suppress the occurrence of image defects due to the toner and paper dust being conveyed to the image carrier via the cleaning member. be able to.

  Further, since it is not necessary to reduce the thickness of the sealing member in order to reduce the contact pressure of the sealing member with respect to the cleaning member, it is possible to suppress the occurrence of undulation (waving) in the sealing member. Thereby, it can suppress that the sealing performance with respect to the cleaning member of a sealing member falls.

1 is a schematic diagram illustrating a structure of an image forming apparatus including a belt cleaning unit (cleaning apparatus) according to an embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of an image forming unit Pa in FIG. 1. FIG. 3 is a side sectional view of an intermediate transfer unit mounted on the image forming apparatus. FIG. 4 is an external perspective view of the belt cleaning unit shown in FIG. 3. It is the perspective view which showed the state which removed the fur brush and collection | recovery roller of the belt cleaning unit. It is side surface sectional drawing (AA 'arrow sectional drawing of FIG. 4) which shows the internal structure of a belt cleaning unit. It is the figure which showed the structure of the sealing member of the belt cleaning unit of one Embodiment of this invention. It is the figure which showed the structure of the sealing member of the belt cleaning unit of one Embodiment of this invention, a knocking piece, and a discharge screw.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus 100 including a belt cleaning unit 19 that is a cleaning apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of an image forming unit Pa in FIG. FIG. 3 is a side cross-sectional view of the intermediate transfer unit 30 mounted on the image forming apparatus 100. FIG. 3 shows a state in which the intermediate transfer unit 30 is viewed from the back side in FIG.

  The image forming apparatus 100 of FIG. 1 has the following configuration. In the main body of the image forming apparatus 100, four image forming portions Pa, Pb, Pc, and Pd are sequentially arranged from the upstream side in the transport direction (the right side in FIG. 1). These image forming portions Pa to Pd are provided corresponding to images of four different colors (cyan, magenta, yellow, and black), and cyan, magenta, and yellow are respectively performed by charging, exposure, development, and transfer processes. And a black image are sequentially formed.

  These image forming portions Pa to Pd are provided with photosensitive drums 1a, 1b, 1c and 1d which carry visible images (toner images) of the respective colors, and are further illustrated by a driving means (not shown). In FIG. 1, an intermediate transfer belt (image carrier) 8 that rotates in the clockwise direction is provided adjacent to each of the image forming portions Pa to Pd. The toner images formed on the photosensitive drums 1a to 1d are sequentially transferred onto the intermediate transfer belt 8 that moves while being in contact with the photosensitive drums 1a to 1d. As an example, the image is transferred onto a transfer paper (paper) P as an example, and further fixed on the transfer paper P in the fixing unit 7, and then discharged from the main body of the image forming apparatus 100. An image forming process for each of the photosensitive drums 1a to 1d is executed while rotating the photosensitive drums 1a to 1d in the counterclockwise direction in FIG.

  The transfer paper P onto which the toner image is transferred is accommodated in a paper cassette 16 at the lower part of the main body of the image forming apparatus 100, and is conveyed to the secondary transfer roller 9 via the paper feed roller 12a and the registration roller pair 12b. . A sheet made of dielectric resin is used for the intermediate transfer belt 8, and a (seamless) belt having no seam is mainly used.

  Next, the image forming units Pa to Pd will be described. Around and below the photosensitive drums 1a to 1d arranged to be rotatable, chargers 2a, 2b, 2c and 2d for charging the photosensitive drums 1a to 1d, and image information to each of the photosensitive drums 1a to 1d. The exposure unit 4 for exposing the toner, the developing units 3a, 3b, 3c and 3d for forming toner images on the photosensitive drums 1a to 1d, and the developer (toner) remaining on the photosensitive drums 1a to 1d are removed. Cleaning devices 5a, 5b, 5c and 5d are provided.

  Hereinafter, the image forming unit Pa will be described in detail with reference to FIG. 2. However, the image forming units Pb to Pd have basically the same configuration, and thus description thereof is omitted. As shown in FIG. 2, a charger 2a, a developing unit 3a, and a cleaning device 5a are disposed around the photosensitive drum 1a along the drum rotation direction (counterclockwise direction in FIG. 1). A primary transfer roller 6 a is disposed with 8 interposed therebetween. Further, a belt cleaning unit 19 facing the tension roller 11 with the intermediate transfer belt 8 interposed therebetween is disposed on the upstream side in the rotation direction of the intermediate transfer belt 8 with respect to the photosensitive drum 1a.

  The charger 2 a includes a charging roller 22 that contacts the photosensitive drum 1 a and applies a charging bias to the drum surface, and a charging cleaning roller 23 for cleaning the charging roller 22. The developing unit 3a includes two agitating and conveying screws 24, a magnetic roller 25, and a developing roller 26, and a developing bias having the same polarity (positive) as that of toner is applied to the developing roller 26 so as to apply to the drum surface. Let the toner fly.

  The cleaning device 5 a includes a rubbing roller 27, a drum cleaning blade 28, and a collection screw 29. The rubbing roller 27 is in pressure contact with the photosensitive drum 1a at a predetermined pressure, and is driven to rotate in the same direction on the contact surface with the photosensitive drum 1a by a driving means (not shown). The speed is controlled faster than the peripheral speed of 1a (1.2 times here).

  A drum cleaning blade 28 is fixed in contact with the photosensitive drum 1a on the surface of the photosensitive drum 1a downstream of the contact surface with the rubbing roller 27 in the rotation direction.

  Residual toner removed from the surface of the photosensitive drum 1 a by the rubbing roller 27 and the drum cleaning blade 28 is discharged to the outside of the cleaning device 5 a as the recovery screw 29 rotates, and is conveyed to a toner recovery container (not shown). And stored. As the toner used in the present invention, silica, titanium oxide, strontium titanate, alumina or the like is embedded in the toner particle surface as an abrasive and held so as to partially protrude on the surface. Those that are electrostatically attached to the surface are used.

  As shown in FIG. 3, the intermediate transfer unit 30 includes an intermediate transfer belt 8 stretched between a downstream drive roller 10 and an upstream tension roller 11, and the photosensitive drums 1 a to 1 d via the intermediate transfer belt 8. Primary transfer rollers 6a to 6d in contact with 1d. A belt cleaning unit 19 for removing toner remaining on the surface of the intermediate transfer belt 8 is disposed at a position facing the tension roller 11. The detailed configuration of the belt cleaning unit 19 will be described later.

  Next, an image forming procedure in the image forming apparatus 100 will be described. When the start of image formation is input by the user, first, the surfaces of the photosensitive drums 1a to 1d are uniformly charged by the chargers 2a to 2d. Next, the exposure unit 4 irradiates the surfaces of the photosensitive drums 1a to 1d to form electrostatic latent images corresponding to the image signals on the photosensitive drums 1a to 1d. Each of the developing units 3a to 3d is filled with a predetermined amount of cyan, magenta, yellow, and black toner by a replenishing device (not shown). The toner is supplied onto the photosensitive drums 1a to 1d by the developing units 3a to 3d and electrostatically attached, whereby a toner image corresponding to the electrostatic latent image formed by exposure from the exposure unit 4 is formed. It is formed.

  The primary transfer rollers 6a to 6d apply an electric field at a predetermined transfer voltage between the primary transfer rollers 6a to 6d and the photosensitive drums 1a to 1d, and cyan, magenta, yellow, and yellow on the photosensitive drums 1a to 1d. A black toner image is primarily transferred onto the intermediate transfer belt 8. These four color images are formed with a predetermined positional relationship predetermined for forming a predetermined full-color image. Thereafter, the toner remaining on the surfaces of the photosensitive drums 1a to 1d is removed by the cleaning devices 5a to 5d in preparation for the subsequent formation of a new electrostatic latent image.

  When the intermediate transfer belt 8 starts to rotate clockwise as the drive roller 10 is rotated by a drive motor (not shown), the transfer paper P is provided adjacent to the intermediate transfer belt 8 from the registration roller 12b at a predetermined timing. The full-color image is transferred to the secondary transfer roller 9 thus transferred. The transfer paper P onto which the toner image is transferred is conveyed to the fixing unit 7. The toner remaining on the surface of the intermediate transfer belt 8 is removed by the belt cleaning unit 19.

  The transfer paper P conveyed to the fixing unit 7 is heated and pressurized by the fixing roller pair 13 so that the toner image is fixed on the surface of the transfer paper P, and a predetermined full color image is formed. The transfer paper P on which the full-color image is formed is distributed in the transport direction by the branching portion 14 that branches in a plurality of directions. When an image is formed on only one side of the transfer paper P, it is discharged as it is onto the discharge tray 17 by the discharge roller 15.

  On the other hand, when images are formed on both sides of the transfer paper P, a part of the transfer paper P that has passed through the fixing unit 7 is once projected from the discharge roller 15 to the outside of the apparatus. Thereafter, the transfer paper P is distributed to the paper transport path 18 by the branching portion 14 by rotating the discharge roller 15 in the reverse direction, and is transported again to the secondary transfer roller 9 with the image surface reversed. Then, after the next image formed on the intermediate transfer belt 8 is transferred by the secondary transfer roller 9 to the surface of the transfer paper P where the image is not formed, and conveyed to the fixing unit 7 to fix the toner image. , And discharged to the discharge tray 17.

  4 is an external perspective view of the belt cleaning unit 19 shown in FIG. 3, FIG. 5 is a perspective view showing a state in which the fur brush 41 and the collection roller 43 of the belt cleaning unit 19 are removed, and FIG. FIG. 5 is a side cross-sectional view (cross-sectional view taken along the line AA ′ in FIG. 4) showing the internal configuration of the belt cleaning unit 19.

  The belt cleaning unit 19 includes a fur brush (cleaning brush) 41, a collection roller 43, a cleaning blade 45, and a discharge screw 47 in a housing 40. The fur brush 41, the collection roller 43, and the discharge screw 47 are provided at one end of the housing 40. A drive input gear train 49 for inputting drive force to the discharge screw 47 is arranged. The fur brush 41 is disposed opposite to the tension roller 11 via the intermediate transfer belt 8 on the opening 40 a side of the housing 40. The fur brush 41 rotates in the counter direction (counterclockwise direction in FIG. 6) with respect to the moving direction of the intermediate transfer belt 8 to thereby remove foreign matters such as toner and paper dust remaining on the intermediate transfer belt 8 (hereinafter, toner). Etc.). The scraped toner or the like adheres to the brush portion of the fur brush 41.

  The collection roller 43 rotates in the opposite direction (clockwise direction in FIG. 6) to the fur brush 41 while being in contact with the surface of the fur brush 41, and a bias having a polarity opposite to that of the toner is applied to the fur brush 41. Collect the adhered toner. The cleaning blade 45 contacts the collection roller 43 from the upstream side with respect to the rotation direction of the collection roller 43 (counter direction with respect to the moving direction of the surface of the collection roller 43) and scrapes off toner collected by the collection roller 43. The collection roller 43 is cleaned. The discharge screw 47 is disposed in the waste toner container 40 b of the housing 40. The discharge screw 47 includes a rotation shaft 47 a and a spiral blade 47 b provided on the peripheral surface of the rotation shaft 47 a. The toner and the like scraped off from the collection roller 43 by the cleaning blade 45 are removed from the housing 40. Transport to.

  As shown in FIG. 6, a seal member 50 that contacts the entire longitudinal direction of the collection roller 43 is disposed in the housing 40 so as to extend in the longitudinal direction of the collection roller 43 (arrow X direction, first direction). Yes. The seal member 50 is a sheet-like member formed of, for example, polyurethane or polyethylene terephthalate (PET). The seal member 50 is provided to prevent the toner scraped off by the cleaning blade 45 from flowing backward from the waste toner container 40b to the collection roller 43 side (opening portion 40a side), and has a predetermined contact pressure. In contact with the collection roller 43. Further, at both ends in the longitudinal direction (arrow X direction) of the seal member 50, end seals 51 (see FIGS. 6 and 7) formed of an elastic member such as urethane foam are provided with the seal member 50 and the recovery roller 43. It is provided in contact with. The end seal 51 is provided in order to prevent waste toner from leaking out from both ends of the housing 40 in the longitudinal direction (arrow X direction).

  Here, the seal member 50 is formed to a thickness that does not cause undulation (waving), and the seal member 50 has an upper end portion (an end portion on the side in contact with the collection roller 43) at the upper end portion of the seal member 50. A plurality of cuts 50a (see FIGS. 5 and 7) are formed at predetermined intervals in the longitudinal direction (arrow X direction). As shown in FIG. 7, the cut 50a is formed so as to avoid the position P1 corresponding to the end of the seal member 50 in the width direction (arrow X direction) of the transfer paper P. Specifically, the two cuts 50a adjacent to the position P1 are arranged at an equal distance from the position P1. The cuts 50a are formed so as to avoid the positions P1, P2,... Corresponding to the end portions in the width direction of the transfer sheets P having a standard size such as A4 and B5.

  Further, the notch 50 a is not formed in a portion that contacts the end seal 51 of the seal member 50. The interval W1 of the notch 50a in the vicinity of the end seal 51 is larger than the interval W2 of the notch 50a in the center portion in the longitudinal direction of the seal member 51. In addition, in this specification and a claim, the space | interval of a notch means the space | interval of adjacent notches other than the both ends of a sealing member, and it adjoins from the end surface of a sealing member in the both ends of a sealing member. It means the interval until cutting.

  The length of the notch 50a in the arrow Y direction (second direction) orthogonal to the arrow X direction is formed to be substantially the same as the overlap amount of the seal member 50 with respect to the collection roller 43.

  The waste toner container 40 b is provided with a plurality of strip-shaped tapping pieces 53 (see FIG. 5) between the discharge screw 47 and the seal member 50. For easy understanding, the knocking piece 53 is omitted in FIG. As shown in FIG. 8, the knock-off piece 53 is formed so as to be insertable between the spiral blades 47b of the discharge screw 47, and when the discharge screw 47 rotates, the outermost peripheral surface of the spiral blade 47b and the rotation shaft 47a. It moves to and from the outer peripheral surface of the motor and operates so as to hit the discharge screw 47. When the tapping piece 53 is inserted between the spiral blades 47b, the tapping piece 53 knocks out the waste toner adhering to the outer peripheral surface of the rotating shaft 47a. Further, the knock-off piece 53 is disposed so as to avoid a position facing the notch 50 a of the seal member 50.

  In the present embodiment, as described above, the plurality of cuts 50a are formed at the end of the seal member 50 on the side in contact with the collection roller 43 with a predetermined interval in the arrow X direction. Thereby, since the contact pressure with respect to the collection | recovery roller 43 of the sealing member 50 can be made small, it can suppress that the toner and paper powder of the surface of the collection | recovery roller 43 are blocked by the sealing member 50, and fall. For this reason, it is possible to prevent toner and paper dust from accumulating until they contact the fur brush 41, so that the toner and paper dust are conveyed to the intermediate transfer belt 8 via the fur brush 41 and image defects occur. Can be suppressed.

  Further, since it is not necessary to reduce the thickness of the seal member 50 in order to reduce the contact pressure of the seal member 50 with respect to the collection roller 43, it is possible to suppress the occurrence of undulation (waving) in the seal member 50. Thereby, it can suppress that the sealing performance with respect to the collection | recovery roller 43 of the sealing member 50 falls.

  Further, as described above, the cut 50a is formed so as to avoid the position P1 corresponding to the end of the seal member 50 in the width direction (arrow X direction) of the transfer paper P. Paper dust is particularly likely to accumulate at a position corresponding to the end of the collection roller 43 in the width direction of the transfer paper P. For this reason, by not forming the notch 50a at the position P1 corresponding to the end of the transfer paper P in the width direction of the seal member 50, it corresponds to the end of the transfer roller P in the width direction of the recovery roller 43. It is possible to suppress the paper dust accumulated at the position from being scraped off by the portion of the cut 50a of the seal member 50 (the edge constituting the cut 50a).

  Further, as described above, the interval W1 of the notch 50a in the vicinity of the end seal 51 is set larger than the interval W2 of the notch 50a in the central portion in the longitudinal direction (arrow X direction) of the seal member 50. Accordingly, it is possible to prevent the both end portions of the seal member 50 (the portion in contact with the end portion seal 51) from being bent to the right side in FIG. It is possible to suppress the leakage of paper powder.

  Further, as described above, the length of the cut 50a in the arrow Y direction is formed to be the same length as the overlap amount of the seal member 50 with respect to the collection roller 43. Thereby, it is possible to suppress the leakage of the toner from the notch 50a while reducing the contact pressure of the seal member 50 to the collection roller 43.

  In addition, as described above, the knock-off piece 53 is disposed so as to avoid a position facing the notch 50a. Thereby, when the knock-off piece 53 is displaced toward the seal member 50 side, it is possible to prevent the toner and paper powder existing in the vicinity of the notch 50a from being pushed out from the notch 50a toward the collecting roller 43 by the hit-off piece 53. it can.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, although an example in which the present invention is applied to a color printer has been described, the present invention is not limited to this. Needless to say, the present invention can be applied to various image forming apparatuses including a cleaning device including a cleaning member and a seal member, such as a monochrome printer, a color copying machine, a monochrome copying machine, and a facsimile machine.

  In the above embodiment, the cleaning member is composed of the fur brush 41 and the collection roller 43. However, a cleaning blade that uses only the cleaning roller as the cleaning member and scrapes off the toner from the surface of the cleaning roller is shown. The same applies to the configuration provided.

  In the above-described embodiment, the example in which the present invention is applied to the belt cleaning unit 19 that removes the residual toner on the surface of the intermediate transfer belt 8 has been described. However, the residual surfaces of the photosensitive drums (image carriers) 1a to 1d are described. Of course, the present invention can be similarly applied to the cleaning devices 5a to 5d for removing the toner.

8 Intermediate transfer belt (image carrier)
19 Belt cleaning unit (cleaning device)
40 housing 40a opening 40b waste toner container 41 fur brush (cleaning brush, cleaning member)
43 Recovery roller (cleaning member)
45 Cleaning blade 47 Discharge screw 47a Rotating shaft 47b Spiral blade 50 Seal member 50a Notch 51 End seal 53 Tap-off piece 100 Image forming apparatus P Transfer paper (recording medium)
W1, W2 interval

Claims (7)

A housing formed with an opening facing the image carrier, and a waste toner container for storing toner scraped off from the surface of the image carrier;
A roller-shaped cleaning member that is disposed near the opening of the housing and removes residual toner on the surface of the image carrier;
A cleaning blade for scraping off the waste toner on the surface of the cleaning member;
A sheet-like sealing member that is disposed in contact with the cleaning member so as to extend in a first direction that is a longitudinal direction of the cleaning member, and that suppresses the backflow of waste toner from the waste toner storage portion to the opening side; ,
With
A cleaning device, wherein a plurality of cuts are formed at predetermined intervals in the first direction at an end of the seal member on a side in contact with the cleaning member.   2. The cut is formed by avoiding a position corresponding to an end portion in the first direction of a recording medium onto which a toner image formed on the image carrier is transferred. Cleaning device. End seals that are in contact with the seal member and the cleaning member and suppress leakage of waste toner from both ends of the housing are provided at both ends in the first direction of the seal member,
The notch is not formed in a portion that contacts the end seal of the seal member,
3. The cleaning device according to claim 1, wherein an interval between the notches in the vicinity of the end seal is larger than an interval between the notches in a center portion in a longitudinal direction of the seal member.   The length of the second direction perpendicular to the first direction of the cut is formed to be the same length as the overlap amount of the sealing member with respect to the cleaning member. The cleaning device according to claim 1. The waste toner storage unit has a rotation shaft and a spiral blade, and is inserted between the discharge blade for discharging the waste toner to the outside of the waste toner storage unit, and the rotation shaft of the discharge screw. A plurality of knocking pieces for knocking off the waste toner adhering to the outer peripheral surface, and
The cleaning device according to claim 1, wherein the hit-off piece is disposed so as to avoid a position facing the notch. The cleaning member includes a cleaning brush that scrapes residual toner on the surface of the image carrier, and a recovery roller that recovers waste toner attached to the cleaning brush.
The cleaning device according to claim 1, wherein the cleaning blade and the seal member are disposed in contact with the collection roller.   An image forming apparatus comprising the cleaning device according to claim 1.

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