JP2011248203A - Cleaning device for intermediate transfer belt - Google Patents

Abstract

Provided is an intermediate transfer belt cleaning device capable of extending the life of a cleaning blade with a simple configuration.
A cleaning device includes a casing, a cleaning blade disposed in the casing, and a waste toner carrying pipe having a waste toner collecting port. The cleaning blade 25 is in contact with the surface of the intermediate transfer belt 8 at a portion of the intermediate transfer belt 8 that is stretched over the driving roller 21, and scrapes and removes the waste toner 46 adhering to the surface of the intermediate transfer belt 8. The waste toner 46 is accumulated to a position above the contact portion 43 with the surface of the intermediate transfer belt 8. The waste toner discharge pipe 45 sequentially collects the waste toner 46 accumulated in the housing 42 above the contact portion 43 of the cleaning blade 25 by the waste toner collection port 44. The lubricating action of the waste toner 46 reduces the wear of the cleaning blade 25.
[Selection] Figure 2

Description

  The present invention relates to an intermediate transfer belt cleaning device, and more particularly, to an intermediate transfer belt cleaning device that achieves a long service life of a cleaning blade with a simple configuration.

  2. Description of the Related Art Conventionally, there is an image forming apparatus that prints an image by using an electrophotographic method using toner (hereinafter also referred to as printing). Among such image forming apparatuses, in recent years, the toner image formed on the photosensitive drum by electrophotography is primarily transferred to an intermediate transfer belt, and the toner image on the intermediate transfer belt is secondarily transferred to a sheet. The number of image forming apparatuses of the next transfer type is increasing.

  The intermediate transfer belt used in the secondary transfer type image forming apparatus has untransferred toner remaining without being transferred to the paper due to jamming, residual transfer toner remaining after transfer onto the paper, or at the start of operation. When toner for density adjustment adheres, it is necessary to clean these toners from the intermediate transfer belt.

  In this belt cleaning, two brush rollers are provided in an intermediate transfer belt cleaner that removes residual toner, and the surface speed of the brush roller disposed on the upstream side in the belt rotation direction is increased at a high speed and the brush roller disposed on the downstream side. There has been proposed a brush cleaning method in which the surface speed is lowered and the cleaning property of the intermediate transfer member is improved regardless of the amount of remaining toner. (For example, refer to Patent Document 1.)

  However, the brush cleaning method is not easy to control by providing two brush rollers as described above, or changing the direction of the brush roller in various cases.

  On the other hand, a blade cleaning method has been proposed in which a blade is pressed against a belt surface on which toner remains to scrape off the toner on the belt surface. (For example, see Patent Document 2.)

  In this blade cleaning method, as the belt conveyance time increases, the portion of the blade that is in contact with the surface of the conveyance belt wears down, so that the amount of toner that remains on the conveyance belt gradually increases. When the residual toner adhesion amount increases, problems such as image smearing occur.

  Therefore, in Patent Document 2, a predetermined image pattern is formed on the conveyance belt, and after this is cleaned by a belt cleaner unit (blade), an image pattern formation region on the conveyance belt is detected by a registration sensor, and the image is formed on the conveyance belt. When the remaining toner amount exceeds the specified value, the belt cleaner unit needs to be replaced.

JP 2006-267283 A JP 11-327384 A

  Incidentally, in the case of the blade cleaning method, generally, a lubricant is added to the contact portion between the blade and the belt in order to suppress the wear of the blade. Since the waste toner itself has lubricity, it is possible to substitute the lubricant by adding the waste toner to the contact portion between the blade and the belt immediately after the start of the apparatus.

  However, since the belt cleaner originally removes the waste toner on the belt, the waste toner lubricant attached at the start is eventually removed from the contact portion between the blade and the belt. As a result, the friction between the blade and the belt increases and the blade is worn.

  Always adding a lubricant to the contact part between the blade and the belt requires a dedicated device for that purpose, and not only the part cost but also the problem of maintaining and controlling the device configuration is a good idea. There are some aspects that cannot be said.

  For this reason, there are many ideas that it is a good idea to leave the blades worn out and replace them with new ones as the wear progresses. Therefore, since no effective measure for suppressing the wear of the blade has been taken, there is a problem to be improved that the wear of the blade progresses rapidly and the durability is remarkably lowered.

  In order to solve the above problems, an intermediate transfer belt cleaning device according to the present invention is a cleaning device that removes waste toner remaining on an intermediate transfer belt, and includes a housing and the intermediate belt disposed in the housing. A cleaning blade that comes into contact with the surface of the intermediate transfer belt at a portion of the transfer belt that is stretched over the drive roller or driven roller, and the housing above the contact portion between the cleaning blade and the surface of the intermediate transfer belt. And a waste toner carrying pipe having a waste toner collection port in the body.

  In this intermediate transfer belt cleaning device, for example, the cleaning blade scrapes and removes the waste toner adhering to the surface of the intermediate transfer belt and removes the removed waste toner from the surface of the intermediate transfer belt. The waste toner carry-out pipe is accumulated in the housing above the contact portion of the cleaning blade with the surface of the intermediate transfer belt by the waste toner collection port. The waste toner is sequentially collected.

  According to the present invention, in the cleaning device for the intermediate transfer belt, the contact portion of the cleaning blade with the surface of the intermediate transfer belt is cleaned while being always buried in the waste toner accumulated in the housing of the cleaning device by cleaning. In addition, the lubricating function of the waste toner continuously acts on the cleaning blade, so that the wear of the cleaning blade is reduced. As a result, there is an effect that the life of the cleaning blade can be extended with a simple configuration.

FIG. 3 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (printer) including the intermediate transfer belt cleaning device according to the first exemplary embodiment of the present invention. 3 is an enlarged cross-sectional view showing details of an intermediate transfer belt cleaning device of the printer according to Embodiment 1 together with a part of the intermediate transfer belt. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a two-component developer composed of toner and carrier is used. In the following description, the two-component developer is simply referred to as toner.

  FIG. 1 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (hereinafter simply referred to as a printer) including an intermediate transfer belt cleaning device according to a first embodiment.

  A printer 1 shown in FIG. 1 is an electrophotographic secondary transfer tandem color image forming apparatus, and includes an image forming unit 2, a transfer belt unit 3, a toner supply unit 4, a paper feeding unit 5, and a belt type fixing device. It comprises a unit 6 and a transport unit 7 for duplex printing.

  The image forming unit 2 is in contact with the lower running unit surface 8a of the transfer belt 8 of the transfer belt unit 3 and multi-stages four developing devices 9 (9m, 9c, 9y, 9k) from right to left in FIG. It consists of a side-by-side configuration. The image forming unit 2 is held by a frame of the printer 1 main body so as to be movable up and down from a printing execution position shown in FIG. 1 to a maintenance position below it.

  Of the four developing devices 9, three developing devices 9m, 9c, and 9y on the downstream side (right side in the figure) are magenta (M), cyan (C), and yellow (Y), which are subtractive three primary colors, respectively. A mono-color image is formed with the color toner, and the developing device 9k forms a monochrome image mainly with black (K) toner used for characters and dark portions of the image.

  Each of the developing devices 9 has the same configuration except for the color of the toner that develops the image. Therefore, the configuration of the developing device 9k for black (K) toner will be described below as an example.

  The developing device 9 includes a photosensitive drum 10 at the top. The photosensitive drum 10 has a peripheral surface made of, for example, an organic photoconductive material. A cleaner 11, a charging roller 12, an optical writing head 13, and a developing roller 15 of the developing device 14 are disposed around the periphery of the photosensitive drum 10.

  The developing device 14 includes a housing 16 that covers the outside, a partition wall 17 provided inside, a developing roller 15, a first stirring and conveying screw 18, and a second stirring and conveying screw 19. Although not specifically shown, the first and second agitating and conveying screws 18 and 19 include a screw shaft and a fin that is integrally formed with the screw shaft and rotates.

  The developing unit 14 is supplied with toner from the toner supply unit 4, and in the drawing, any one of magenta (M), cyan (C), yellow (Y), and black (K) as indicated by M, C, Y, and K in FIG. Toner is supplied.

  The transfer belt unit 3 has an endless transfer belt 8 that extends in the shape of a flat loop in the left-right direction in the figure at approximately the center of the main unit, and the transfer belt 8 is stretched over the transfer belt 8. A driving roller 21 and a driven roller 22 are provided to circulate and move counterclockwise as indicated by an arrow a in the figure.

  The above-described transfer belt 8 is directly transferred to the surface of the belt that circulates below by a primary transfer roller 20 that is integrated with the unit and pressed against the photosensitive drum 10 via the transfer belt 8 (primary transfer). Then, the toner image is conveyed to the secondary transfer unit 23 to the paper for further transfer (secondary transfer) to the paper.

  In the transfer belt unit 3, the cleaning blade 25 of the belt cleaner 24 is disposed in contact with the surface of the belt 21 that is stretched over the driving roller 21. A waste toner collecting container 26 is detachably disposed below the belt cleaner 24.

  In the belt cleaner 24, the cleaning blade 25 abuts on the surface of the transfer belt 8 to scrape and remove the waste toner, and the waste toner is sent to the lower waste toner collection container 26 by the conveying screw 26-1.

  The toner supply unit 4 includes four toner hoppers 27 (27m, 27c, 27y, and 27k) disposed above the upper running unit of the transfer belt 8. The four toner hoppers 27m, 27c, 27y, and 27k respectively store magenta (M), cyan (C), yellow (Y), and black (K) toners, and include toner supply units 28, respectively.

  The four developing devices 9 of the image forming unit 2 described above are densely arranged on the left and right without spatial margins, whereas the four toner hoppers 27 of the toner supply unit 4 have margins on the left and right spaces. Is arranged. Therefore, the degree of freedom in design is large with respect to the arrangement position and size of the toner hopper 27.

  Although not particularly shown, the toner supply unit 4 is held on the frame of the printer 1 main body so as to be able to be raised and lowered from the printing execution position shown in FIG. 1 to a maintenance position above it.

  Two electrical parts 30 are disposed on the left side of the toner supply unit 4 from the left side of the belt cleaner 24 to above the drive roller 21. The electrical unit 30 includes a circuit board on which a control device including a plurality of electronic components is mounted.

  Although the controller is not particularly shown, it comprises a controller unit and an engine unit. The controller unit is a CPU (Central Processing Unit), ROM (Read Only Memory), EEPROM (Rewritable Read Memory), Frame Memory, Image Data. A transfer circuit is provided to analyze print data input from a host computer or the like, create print data, and transfer the print data to the engine unit.

  The engine unit includes a CPU, a ROM, and the like. Data and command signals from the controller unit, temperature sensor output, paper detection sensor output, and the like are input to the input side, and a motor (not shown) is driven to the output side. A motor driver and a clutch driver that switches a drive system that transmits the drive of the motor to each unit are provided.

  Further, the engine unit applies a predetermined bias current to the print driver that drives the optical writing head 13 based on the print data, the charging roller 12, the developing roller 15, the primary transfer roller 20, the secondary transfer roller 35, and the like. A bias power supply driver to be supplied is connected.

  The engine unit drives and controls each unit based on data and command signals from the controller unit, the output of the temperature sensor, the output of the paper detection sensor, and the like.

  The paper feed unit 5 includes two paper feed cassettes 29 (29a, 29b) arranged in two upper and lower stages. A paper take-out roller 31, a feed roller 32, a separating roller 33, and a standby conveyance roller pair 34 are disposed in the vicinity of the paper feed opening (right side of the drawing) of the two paper feed cassettes 29, respectively.

  A secondary transfer roller 35 that is in pressure contact with the driven roller 22 via the transfer belt 8 is disposed in the paper transport direction (vertically upward in the drawing) of the standby transport roller pair 34, and the secondary transfer onto the paper described above. Part 23 is formed.

  A belt-type heat fixing unit 6 is disposed downstream (upward in the drawing) of the secondary transfer portion. On the further downstream side of the belt-type heat fixing unit 6, a pair of carry-out rollers 36 for carrying out the fixed paper from the belt-type heat fixing unit 6, and a paper discharge tray 37 formed on the upper surface of the apparatus. A paper discharge roller pair 38 for paper discharge is provided.

  The conveyance unit 7 for double-sided printing also serves as an opening / closing member whose outer surface (right outer surface in the drawing) opens or shields the inside of the printer 1 from the side surface to the outside.

  This duplex printing transport unit 7 has a start return path 39a that branches rightward in the figure from just before the paper discharge roller pair 38, an intermediate return path 39b that bends downward, and a left lateral direction opposite to the above. Thus, a return path 39 including a terminal return path 39c for finally inverting the return sheet is provided.

  In the middle of the return path 39, five pairs of return rollers 41 (41a, 41b, 41c, 41d, 41e) are arranged. The exit of the end return path 41e joins the conveyance path to the standby conveyance roller pair 34 corresponding to the sheet feeding cassette 29b below the sheet feeding section 5.

Next, the belt cleaner 24 will be described.
FIG. 2 is an enlarged sectional view showing details of the cleaning device 24 for the intermediate transfer belt 8 of the printer 1 together with a part of the intermediate transfer belt 8.

  As shown in FIG. 2, the cleaning device 24 is stretched over a housing 42 and a driving roller or a driven roller (the driving roller 21 in the illustrated example) of the intermediate transfer belt 8 disposed in the housing 42. The cleaning blade 25 shown in FIG. 1 that abuts against the surface of the intermediate transfer belt 8 is provided.

  Further, the cleaning device 24 includes a waste toner discharge pipe 45 having a waste toner collection port 44 in the housing 42 above the contact portion 43 of the cleaning blade 25 with the surface of the intermediate transfer belt 8.

  In this configuration, the cleaning blade 25 scrapes and removes the waste toner 46 adhering to the surface of the intermediate transfer belt 8, and removes the removed waste toner 46 from the contact portion 43 with the surface of the intermediate transfer belt 8. Is also deposited to the top.

  The waste toner delivery pipe 45 sequentially collects the waste toner 46 accumulated in the housing 42 above the contact portion 43 of the cleaning blade 25 with the surface of the intermediate transfer belt 8 through the waste toner collection port 44.

  As described above, in the cleaning device 24 for the intermediate transfer belt 8, the cleaning blade 25 is in a state where the contact portion 43 with the surface of the intermediate transfer belt 8 is always buried in the waste toner 46 accumulated in the housing 42. The intermediate transfer belt 8 is configured to be cleaned.

  Accordingly, the lubrication function by the waste toner 46 continuously acts on the contact portion 43 of the cleaning blade 25, and wear at the contact portion 43 of the cleaning blade 25 is reduced. Thus, according to the present embodiment, it is possible to extend the life of the cleaning blade 25 with a simple configuration.

  The present invention can be used in an intermediate transfer belt cleaning device that achieves a long service life of a cleaning blade with a simple configuration.

1 Full-color image forming device (printer)
DESCRIPTION OF SYMBOLS 2 Image formation part 3 Transfer belt unit 4 Toner supply part 5 Paper feed part 6 Belt type fixing unit 7 Conveyance unit for double-sided printing 8 Transfer belt 8a Lower running part surface 9 (9m, 9c, 9y, 9k) Developing device 10 Photoconductor Drum 11 Cleaner 12 Charging roller 13 Optical writing head 14 Developer 15 Developing roller 16 Housing 17 Bulkhead 15 Developing roller 18 First agitating and conveying screw 19 Second agitating and conveying screw 20 Primary transfer roller 21 Drive roller 22 Driven roller 23 Secondary transfer section 24 Belt cleaner 25 Cleaning blade 26 Waste toner collection container 26-1 Conveying screw 27 (27m, 27c, 27y, 27k) Toner hopper 28 Toner supply section 29 (29a, 29b) Paper feed cassette 30 Electrical section 31 Paper Extraction roller 32 Feeding roller 33 Rolling roller 34 Standby conveyance roller pair 35 Secondary transfer roller 36 Unloading roller pair 37 Paper discharge tray 38 Paper discharge roller pair 39 Return path 39a Start return path 39b Intermediate return path 39c End return path 41 (41a, 41b, 41c, 41d) 41e) Return roller pair 42 Housing 43 Contact portion 44 Waste toner recovery port 45 Waste toner carry-out pipe 46 Waste toner

Claims (2)

A cleaning device for removing waste toner remaining on the intermediate transfer belt,
A housing,
A cleaning blade that is disposed in the housing and is in contact with the surface of the intermediate transfer belt at a portion of the intermediate transfer belt that is stretched over the driving roller or the driven roller;
A waste toner carry-out pipe having a waste toner collection port in the housing above the contact portion of the cleaning blade with the surface of the intermediate transfer belt;
An intermediate transfer belt cleaning device comprising: The cleaning blade scrapes and removes the waste toner adhering to the surface of the intermediate transfer belt and deposits the removed waste toner to a position above the contact portion with the surface of the intermediate transfer belt,
The waste toner carry-out pipe sequentially collects the waste toner accumulated in the casing above the contact portion of the cleaning blade with the surface of the intermediate transfer belt by the waste toner collection port.
The intermediate transfer belt cleaning device according to claim 1.