JP2005301019A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus equipped with a cleaning apparatus having a compact constitution, for performing auxiliary cleaning before removing toner by a cleaning blade, and also, carrying the toner. <P>SOLUTION: The cleaning means is provided with the cleaning blade 21 for removing the residual toner, and a brush roller 31 arranged on the upstream side of the cleaning blade 21 so as to assist the removal of the residual toner, and also, carry the toner to a recovery part, and the bristles of the brush roller 31 are helically planted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile, and more particularly to an image forming apparatus provided with a cleaning unit that removes residual toner on an image carrier.

  Conventionally, as a cleaning device that forms an electrostatic latent image on an image carrier such as a drum-like or belt-like photoconductor based on an electrophotographic system, and removes residual toner on the surface of the image carrier after development and transfer processing. A blade method is generally used in which an elastic cleaning blade is brought into contact with an image carrier to perform cleaning. In such a cleaning device, the residual toner collected by the cleaning blade increases as image processing is performed. The cleaning device provided on the peripheral portion of the photosensitive member is required to be small in size in relation to other installed equipment, and the toner collected in the cleaning device is accumulated and cleaned by a conveying means such as a conveying screw. A collecting unit provided outside the apparatus or a recycled toner is carried out to the developing device.

  When the cleaning device is disposed at the lateral position of the photosensitive drum, the toner removed and collected by the cleaning blade is accumulated in the lower part of the device by its own weight. Therefore, a transport screw is provided at the location to clean the collected toner. Discharging out of the device.

  When the cleaning device is disposed above the photosensitive drum, the toner collected by the cleaning blade does not fall and is deposited near the blade tip.

  Patent Document 1 discloses a configuration in which toner collected by a cleaning blade is sent to a conveying unit provided adjacent by a toner scraping paddle, and is discharged out of the cleaning device by a toner conveying screw provided in the conveying unit. Is disclosed.

Also, in Patent Document 2, a cleaning roller for assisting the removal of residual toner on the photosensitive member is provided upstream of the cleaning blade facing the rotating photosensitive member, and the toner attached to the cleaning roller is provided in the partition wall. The structure which is peeled off and discharged to the outside of the cleaning device by a conveying screw positioned via a partition is disclosed.
JP 2000-315039 A JP 2003-98924 A

  The toner collected by the cleaning blade is conveyed by a toner scoop paddle in Patent Document 1 to a separate conveying unit by a cleaning roller in Patent Document 2, and is removed from the cleaning device by a conveying screw provided in the conveying unit. It is being carried out.

  Although it is effective in terms of cleaning performance to supplementarily clean the surface of the photosensitive member with a cleaning roller prior to toner removal by the cleaning blade, it is inevitable that the cleaning device becomes large.

  An object of the present invention is to provide an image forming apparatus provided with a compact cleaning device that performs auxiliary cleaning and toner transport prior to toner removal by a cleaning blade.

  In order to solve the above-described problems and achieve the object, the present invention is configured as follows.

(Claim 1)
A photosensitive member that forms a toner image; a transfer unit that transfers the toner image formed on the photosensitive member to a sheet; and residual toner remaining on the photosensitive member after being transferred by the transfer unit. And an image forming apparatus having a cleaning unit.
The cleaning means includes a cleaning blade that removes residual toner, and a brush roller that is provided on the upstream side of the cleaning blade, assists the removal of residual toner, and conveys the toner to a recovery unit, and the brush of the brush roller An image forming apparatus characterized by being implanted in a spiral shape.

(Claim 2)
The image forming apparatus according to claim 1, wherein the brush roller has a conductive brush implanted in a grounded metal roller.

(Claim 3)
The image forming apparatus according to claim 1, wherein the cleaning unit is located above the photoconductor, and a brush of the brush roller contacts the photoconductor.

  According to the first to third aspects of the present invention, the auxiliary cleaning is performed prior to the cleaning by the cleaning blade, and the compact and good cleaning is continuously performed, and the good image recording is performed. have.

  Next, an embodiment of an image forming apparatus provided with the cleaning device of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of an image forming apparatus equipped with an automatic document feeder DF and an image reading device (scanner) SC.

  The illustrated image forming apparatus main body A includes an image forming unit 1, an image processing unit 2, an image writing unit 3, a high voltage power supply unit 4, a paper feeding / conveying unit 5, a fixing device 6, a paper discharging unit 7, and automatic duplex copying. A re-transport means (ADU) 8 is provided.

  An image reading device SC and an automatic document feeder DF are mounted on the upper part of the image forming apparatus main body A. A paper discharge tray 7C or a paper post-processing device (not shown) can be connected to the paper discharge unit 7 at the upper left of the image forming apparatus main body A shown in the drawing.

  A document d placed on the document table of the automatic document feeder DF with the first surface facing upward is conveyed in the direction of the arrow, and an image on one or both sides of the document is read by the optical system of the image reading device SC. It is read into the CCD image sensor C1.

  The analog signal photoelectrically converted by the CCD image sensor C1 is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2 and then sent to the image writing unit 3.

  In the image writing unit 3, output light from the semiconductor laser is applied to the image carrier 10 of the image forming unit 1 to form a latent image. In the image forming unit 1, processing such as charging, exposure, development, transfer, separation, and cleaning is performed, and the image is transferred to the paper S conveyed from the paper feed conveyance unit 5. The paper S carrying the image is fixed by the fixing device 6 and discharged from the paper discharge unit 7 to the paper discharge tray 7C. Alternatively, the single-sided image processed paper S sent to the re-conveying means 8 by the paper discharge path switching plate 7A is again subjected to double-sided image processing in the image forming unit 1 and then discharged by the paper discharge roller 7B of the paper discharge unit 7. It is discharged to the tray 7C.

  In FIG. 1, on the right side in the image forming apparatus main body A, the paper feed cassette 5 </ b> A of the paper feeding / conveying section 5 is located above the image forming apparatus main body A in the height direction with the image forming section 1 as the center. A fixing device 6 and a paper discharge unit 7 are provided. With this vertical arrangement configuration, a substantially vertical sheet conveyance path L1 is formed. The sheet S sent out from the sheet feeding cassette 5A is transported along the vertically upward sheet transport path L1 and is discharged out of the image forming apparatus main body A.

  A sheet conveying path L2 by the re-conveying means 8 is formed substantially parallel to the vertical sheet conveying path L1. By forming the vertical sheet conveyance paths L1 and L2, the sheet conveyance path of the shortest distance from the sheet feeding cassette 5A to the sheet discharge unit 7 is configured.

  FIG. 2 is a cross-sectional view of the main part of the image forming apparatus main body A to which the embodiment of the present invention is applied.

  In the figure, reference numeral 10 denotes a photoconductor as an image carrier, which is a photoconductor provided with an organic or inorganic photoconductive layer on the surface of a substrate. A photoconductive layer is provided in the image forming area of the photoconductor 10, but no photoconductive layer is provided at both ends of the image carrier.

  The photoreceptor 10 is driven to rotate in the direction of the arrow. A corona charger 12 uniformly charges the surface of the photoreceptor 10. An image exposure unit 13 irradiates the photoconductor 10 with a light image to form an electrostatic latent image. A developing unit 14 develops the electrostatic latent image formed on the photoreceptor 10 to form a toner image. Reference numeral 5B denotes a registration roller that feeds the sheet S fed from the sheet feeding cassette 5A to the transfer position in synchronization with the formation of the electrostatic latent image on the photoconductor 10. A transfer corona discharger 15 transfers the toner image on the photoreceptor 10 onto the paper S. Reference numeral 16 denotes a separation corona discharger, which peels off the transferred paper P from the surface of the photoreceptor 10. Reference numeral 17 denotes a separation claw that comes into pressure contact with the surface of the photoconductor 10 and peels off the paper S attached on the photoconductor 10. Reference numeral 18 denotes a pre-charging static elimination means, and 19 a transfer simultaneous exposure means. 6 is a fixing device, and 20 is a cleaning device to which an embodiment of the present invention is applied.

  FIG. 3 is a cross-sectional view of the photoconductor 10 and the cleaning device 20.

  In FIG. 3, reference numeral 21 denotes a cleaning blade (hereinafter referred to as a blade) made of an elastic material such as urethane rubber, which removes toner remaining on the photoconductor 10 after transfer from the photoconductor 10. The blade 21 is sandwiched between holder members 22A and 22B.

  The tip of the blade 21 is in pressure contact with the outer peripheral surface of the rotating photoconductor 10 in the counter direction on the upstream side of the vertical upper position that is the antigravity direction of the rotation center of the photoconductor 10.

  The holder member 22A is fixed to a toner transport guide member 23 that constitutes a part of the outer peripheral member of the cleaning device 20. Protrusions protrude from both end portions of the holder member 22A, and the rotating shaft bodies 24F and 24R are fitted. The inner surface side of the toner conveyance guide member 23 is opposed to an outer peripheral surface of a brush roller 31 having a toner conveyance function described later with a predetermined gap.

  On the bottom surface side of the holder member 22B, a holder member 22C having a flexible thin plate 26 attached thereto is fixed with screws or the like. The distal end portion of the flexible thin plate 26 made of a polyurethane sheet is always in contact with the outer peripheral surface of the photoconductor 10 to prevent leakage of residual toner on the photoconductor 10.

  The holder member 22A is pressurized by a coil spring 28 as a pressure member interposed in a part of the housing (housing) 30 of the cleaning device 20, and the blade 21, the holder members 22A, 22B, 22C, the toner conveyance guide member. The unit 23 is rotated around the rotation shafts 24F and 24R, and presses the blade 21 against the photosensitive member 10.

  A packing 29 made of an elastic foam material is affixed to the upper portion of the rotatable toner conveyance guide member 23 and presses against the inner wall of the housing 30 to prevent toner leakage.

  In a space surrounded by the inner wall of the housing 30 and the wall of the cover member 32 that shields the inner wall of the toner conveyance guide member 23 and the opening of the housing 30, a brush roller 31 planted in a spiral is provided with a predetermined photoconductor. It is rotatably supported at an upper position enabling 10 sliding.

  A toner guide member 35 made of a polyethylene terephthalate (PET) sheet is attached to the bottom of the cover member 32. The front end portion of the toner guide member 35 is in contact with the outer peripheral surface of the photoreceptor 10 in a trail shape. Therefore, in the usable state of the image forming apparatus, the upper part of the outer peripheral surface of the photoconductor 10 is shielded by the tip of the blade 21 and the tip of the toner guide member 35.

  The upper surfaces of the tip portions at both ends of the blade 21 are pressed by the pressing members 27F and 27R to prevent toner leakage at both ends.

  The rear ends of the pressing members 27F and 27R are joined and fixed to the upper surface of the front end of the holder member 22A. The tip portions of the pressing members 27F and 27R press the upper surface in the vicinity of the tip portions at both ends of the blade 21. As a result, the pressing force of the blade is larger at both ends than at the center, and toner leakage can be prevented.

  FIG. 4 shows a main part of the brush roller 31, and FIG. 5 shows a cross-sectional view of the photoconductor 10 and the peripheral member, and the brush roller 31 in contact with the photoconductor 10.

  The brush roller 31 has a lead having a pitch p on the circumferential surface of a metal roller having an outer diameter D, and is planted in a spirally axial direction in a planted region 31B having a width pb. The non-planted ground portion 31A has a width of pa (p-pb) in the axial direction, and in this embodiment, pa: pb = 1: 2.

  In the brush roller 31, the brush in the flocked region 31 </ b> B is in contact with the circumferential surface of the photoconductor 10 and rotates in a direction opposite to the photoconductor 10 to assist in removing residual toner.

  The spiral direction for flocking the brush roller 31 is a direction in which the toner removed and collected by the rotation of the brush roller 31 is conveyed to the back side of the image forming apparatus.

A brush using conductive resin bristles is implanted in the flocked region 31B. In this embodiment, the hair length is 5.5 mm and the thickness of the bristles with respect to the base metal portion having the outer diameter D = 9.4 mm. A brush using resin bristles of 15d and a density of 8000 pieces / cm ² is provided with a lead of pitch p = 15 mm and in a spiral axial direction between pb = 10 mm to form a brush roller 31 having an outer diameter of 22.4 mm. doing.

  The shaft portions 31F and 31R at both ends of the brush roller 31 are fitted to bearing members 311F and 311R fixed to the side plate 40F and the side plate 40A provided outside the side plate 40R, respectively, and fixed to the shaft portion 31R. The provided gear G41 meshes with a drive source (not shown), and power is transmitted from the drive source, so that the brush roller 31 rotates.

  In FIG. 5, the right side of the brush roller 31 protrudes from the side plate 40 </ b> R, and the protruding roller portion rotates in a fixed roller case 312. The end of the roller case 312 is engaged with the shaft portion 31R in a state where no toner leaks, and the other is closed, and an opening 313 opened downward near the end is connected to the opening 313. A toner transfer tube 314 is provided.

  The brush roller 31 is rotated at a peripheral speed of 230 mm / sec in this embodiment by power transmission from the drive source, and the surface of the photoconductor 10 is preliminarily cleaned and recovered by the recovered toner and the cleaning blade 21. The toner is conveyed rightward in FIG. 5, and the toner conveyed in the roller case 312 falls in the conveyance tube 314 from the opening 313 and is collected in a collecting unit (not shown).

  In FIG. 5, a toner leakage prevention member is slidably contacted with the entire circumference of each end face of the flange members 11F and 11R to prevent toner leakage from the end faces of the flange members 11F and 11R of the photoreceptor 10.

  The left-side toner leakage prevention member 391F shown in FIG. 5 holds the seal member 361F that is in sliding contact with the entire circumference of the end surface of the flange member 11F, the elastic member 371F that is bonded to the back surface of the seal member 361F, and the elastic member 371F. It is formed in a unit having a three-layer structure including a holding member 381F.

  Similarly, the toner leakage preventing member 391R shown on the right side of the drawing is formed in a three-layer unit including a sealing member 361R, an elastic member 371R, and a holding member 381R.

  With this configuration, toner leakage from the side surfaces of the flange portions 11F and 11R into the apparatus is prevented.

1 is an overall configuration diagram of an image forming apparatus. FIG. 3 is a cross-sectional view of a main part of the image forming apparatus main body. Sectional drawing of a photoreceptor and a cleaning apparatus. The principal part figure of a brush roller. Sectional drawing of a photoconductor and a brush roller.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
11F, 11R Flange part 12 Corona charger 20 Cleaning device 21 Cleaning blade 31 Brush roller 31A Background part (brush roller)
31B Flocking area (Brush roller)
312 Roller case 313 Opening 314 Toner transport tube

Claims (3)

A photosensitive member that forms a toner image; a transfer unit that transfers the toner image formed on the photosensitive member to a sheet; and residual toner remaining on the photosensitive member after being transferred by the transfer unit. And an image forming apparatus having a cleaning unit.
The cleaning means includes a cleaning blade that removes residual toner, and a brush roller that is provided on the upstream side of the cleaning blade, assists the removal of residual toner, and conveys the toner to a recovery unit, and the brush of the brush roller An image forming apparatus characterized by being implanted in a spiral shape. The image forming apparatus according to claim 1, wherein the brush roller has a conductive brush implanted in a grounded metal roller. The image forming apparatus according to claim 1, wherein the cleaning unit is located above the photoconductor, and a brush of the brush roller contacts the photoconductor.

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