JP2007316191A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which forms an image having high image quality by surely removing residual toner or the like without influencing a transfer means, an image carrier and an intermediate transfer body. <P>SOLUTION: In the image forming apparatus, a cleaning means for removing substance to be removed which adheres to the transfer means or a cleaning means for removing substance to be removed which adheres to the image carrier has: a first brush roller and a second brush roller whose rotating directions are reverse to each other, which remove toner while abutting on the transfer means or the image carrier and which can rotate; and a contact-sliding member which is arranged in parallel with the common tangential direction of the first brush roller and the second brush roller and slides in contact with the first brush roller and the second brush roller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multi-function machine having a plurality of these functions, and in particular, to clean an object to be cleaned such as toner, paper dust, talc, etc. The present invention relates to an image forming apparatus including a cleaning device.

  Generally, in an image forming apparatus using an electrophotographic process or the like, an electrostatic latent image corresponding to a document screen is formed on the surface of an image carrier charged to a predetermined potential, and a visible image (toner image) is formed by a developing device. It is formed. The toner image formed on the image carrier reaches the transfer means by the rotation of the image carrier and is transferred to the transfer material conveyed to the transfer means. After the toner image is transferred, residual toner on the image carrier is removed by a cleaning device arranged around the image carrier. Further, a cleaning object such as toner is removed by a cleaning unit arranged in the transfer unit. When a blade system is used as the cleaning unit disposed in the transfer unit, the transfer belt is worn by the blade pressed against the rotating transfer belt, and the life is shortened.

  In a color image forming apparatus, a toner image of each color formed on each image carrier by a plurality of image forming means is transferred onto an intermediate transfer member, and the superimposed image formed on the intermediate transfer member is recorded on a recording medium A batch transfer is performed on the top. In this intermediate transfer system, a cleaning means is required for removing residual toner on the intermediate transfer body after transfer to a recording medium. Further, a cleaning unit for removing the toner remaining on each image carrier of the plurality of image forming units is necessary. A blade method or a fur brush method is employed as the image carrier cleaning means.

  In the intermediate transfer body system, the cleaning means must be retracted from the intermediate transfer body while the multi-color toner images are superimposed on the intermediate transfer body. When the target load is large, the positions of the toner images of the respective colors are shifted. For this reason, as a means for cleaning the intermediate transfer member, a fur brush method with a smaller contact load than the blade method is suitable.

  The cleaning device of Patent Document 1 is provided with two cleaning rollers, and one conveying screw for conveying and discharging residual toner is provided in the middle of the two cleaning rollers.

In the cleaning device of Patent Document 2, two cleaning brushes are arranged, and one sliding contact member that is in sliding contact with both of the two cleaning brushes is provided in the middle of the two cleaning rollers.
JP 2001-337542 A JP 2001-305929 A

  The cleaning device described in Patent Document 1 requires a plurality of roller members for removing toner from a plurality of cleaning brushes, and an auxiliary member for guiding the toner to the conveying screw. Increase in size and size.

  In the cleaning device described in Patent Document 2, toner scraped off by one cleaning brush floats around the other cleaning brush and is not collected and overlaps with the next image to be produced, resulting in an image defect. Is produced.

  It is an object of the present invention to provide an image forming apparatus that reliably removes residual toner and the like and forms a high-quality image without affecting the transfer unit, the image carrier, and the intermediate transfer member.

  The above object is solved by the image forming apparatus described below of the present invention.

  1. In the image forming apparatus for cleaning, by a cleaning unit, an object to be cleaned attached to a transfer unit that transfers an image formed on an image carrier to a recording medium, the cleaning unit has rotational directions opposite to each other, and A rotatable first brush roller and a second brush roller that contact the transfer means to remove toner, and are arranged in parallel to a common tangential direction of the first brush roller and the second brush roller; An image forming apparatus comprising: a sliding contact member that is in sliding contact with the first brush roller and the second brush roller.

2. In an image forming apparatus for cleaning an object to be cleaned remaining on an image carrier by a cleaning unit, the cleaning units are rotatable in directions opposite to each other and remove toner by contacting the image carrier. A first brush roller and a second brush roller;
A sliding contact member arranged in parallel to a common tangential direction of the first brush roller and the second brush roller, and in sliding contact with the first brush roller and the second brush roller;
An image forming apparatus comprising:

  1. The cleaning means for cleaning the object to be cleaned such as residual toner attached to the transfer means by the cleaning means includes a first brush roller, a second brush roller, and a sliding contact member that are rotatable in directions opposite to each other. Due to the action, the object to be cleaned such as toner, paper dust, talc and the like removed from the transfer belt can be effectively stored in the storage means, and maintenance is not required for a long period of time, and good cleaning performance is maintained. The effect that you can do things. Furthermore, the following effects can be obtained.

  (1) The two belt rollers having opposite polarities can extend the life of the transfer belt while ensuring the cleaning performance.

  (2) Space saving is achieved by using a single sliding contact member that scrapes the object to be cleaned from the two brush rollers.

  (3) Since the sliding contact member functions as a partition wall of the two brush rollers, it is possible to prevent toner from returning to the transfer belt, toner scattering, and the like.

  (4) Since the sliding contact member is disposed in the center of the axis of the two brush rollers and the toner scraping direction (common tangential direction) is the same direction, the scraped toner is collected by the conveying screw. Cheap.

  (5) By making the bias polarity applied to the first brush roller and the second brush roller opposite, even if toners having different polarities remain on the transfer belt, all of them can be removed. .

  (6) The friction load on the transfer belt can be reduced by the first brush roller and the second brush roller, the wear of the transfer belt is reduced, and the life of the belt is extended.

  2. The cleaning means for cleaning the object to be cleaned remaining on the image carrier such as the photosensitive member and the intermediate transfer member by the cleaning means is rotatable so that the rotation directions are opposite to each other and the toner is removed by contacting the image carrier. By the action of the first brush roller, the second brush roller, and the sliding contact member, the object to be cleaned such as toner, paper dust, talc and the like removed from the image carrier can be effectively stored in the storing means. Good cleaning performance can be maintained without requiring maintenance for a long period of time.

  Further, by setting the bias polarity applied to the first brush roller and the second brush roller to opposite polarities, even if toners having different polarities remain on the transfer belt, all of them can be removed.

  Further, the friction load on the image carrier can be reduced by the first brush roller and the second brush roller, and the life of the cleaning means can be extended. For example, the cleaning blade is rubbed and worn on the photoconductor, and is replaced with a print of about 250,000 sheets. In the case of a brush roller, it is exchanged after printing 1 million sheets.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Image forming apparatus]
FIG. 1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body A, an image reading apparatus SC, and an automatic document feeder DF.

  The illustrated image forming apparatus main body A is an image comprising a photosensitive member (image carrier) 1, a charging unit 2, an image exposure unit 3, a developing unit 4, a transfer unit 5, a cleaning unit 6, a separation claw 7, a cleaning unit 8, and the like. The image forming apparatus includes a forming unit, a fixing device 9 and a paper transport system.

  The paper transport system includes a paper feed cassette 10, a first paper feed unit 11, a second paper feed unit 12, a paper discharge unit 14, a manual paper feed unit 15, a circulation refeed unit 16, and a reverse paper discharge unit 17. It is configured.

  The document d placed on the document table of the automatic document feeder DF is transported by the paper feeding means, and one or both side images of the document d are read by the optical system of the image reading device SC and read by the image sensor CCD. It is. The analog signal photoelectrically converted by the image sensor CCD is subjected to analog processing, A / D conversion, shading correction, image compression processing and the like in the image processing unit 20 and then sent to the image exposure apparatus 3.

  In the image forming unit, processes such as charging, exposure, development, transfer, separation, and cleaning are performed.

  In the image forming unit, a charge (negative charge in the present embodiment) is applied to the photosensitive member 1 by the charging unit 2, and an electrostatic latent image is formed by laser light irradiation from the image exposure device 3. The electrostatic latent image is visualized by 4 and becomes a toner image (negative charge in the present embodiment). Next, the sheet (recording medium) P stored in the sheet feeding cassette 10 is conveyed from the first sheet feeding unit 11. The sheet P is conveyed in synchronization with the toner image by the second sheet feeding means 12 made up of registration rollers, the traveling position of the leading edge of the sheet P is detected by a detection sensor (not shown), and the information is sent to the control means 100. Then, the entry timing to the transfer nip portion N1 is calculated. Thereafter, the sheet P is electrostatically attracted to the transfer belt 51 after the toner image is transferred at the transfer nip portion N1 formed by the transfer belt 51 of the transfer unit 5 and the photosensitive member 1, and the drive roller 52 The toner is separated from the transfer belt 51 by curvature separation and fixed at a fixing nip portion N2 formed by the fixing roller 91 and the pressure roller 92 of the fixing device 9. Details regarding the transfer according to the present invention will be described later.

  The paper P after fixing is discharged out of the apparatus by the paper discharge means 14. On the other hand, the transfer residual toner on the photoreceptor 1 is removed by the cleaning device 8 which is a cleaning means. In the case of double-sided copying, the paper P on which the image is formed on the first side is sent to the circulation refeed unit 16 and reversed, and after the image is formed again on the second side in the image forming unit, the paper discharge unit 14 is formed. Is discharged out of the apparatus. In the case of reverse paper discharge, the paper P branched from the normal paper discharge path is switched back by the reverse paper discharge means 17 and turned upside down, and then discharged from the apparatus by the paper discharge means 14.

[Transfer means]
FIG. 2 is a cross-sectional view of the image forming unit.

  The transfer means 5 includes a transfer belt 51 stretched around rollers such as a drive roller 52 made of stainless steel, a driven roller 53 made of aluminum alloy, a backup roller 54 made of urethane foam rubber, a bias roller 55 made of stainless steel, and the like. . A voltage having a polarity opposite to that of the toner is applied to the bias roller 55.

[Cleaning means]
FIG. 3 is a sectional view of the cleaning means 6.

  The cleaning means 6 has a first brush roller 61 and a second brush roller 62 that are rotatable in reverse directions and are in contact with the transfer belt 51 of the transfer means 5 to remove the toner. A sliding contact member 63 disposed parallel to the common tangential direction of the first brush roller 61 and the second brush roller 62 and slidably contacting the first brush roller 61 and the second brush roller 62, and a conveying screw 64. Have.

  These members of the cleaning means 6 are accommodated in a cleaner housing 65.

  The first brush roller 61 and the second brush roller 62 are fur brushes that are arranged to have a predetermined distance from each other via a sliding contact member 63, and are made of conductive fibers having a high electric resistance value. . The bias polarity applied to the first brush roller 61 and the second brush roller 62 is opposite.

  The driving roller 52 facing the first brush roller 61 and the second brush roller 62 has conductivity and is grounded.

  One common sliding contact member 63 that scrapes off toner from the first brush roller 61 and the second brush roller 62 is formed of a non-conductive resin member. An arrow-shaped scraping portion 63 </ b> A formed at one end (upper part in the drawing) of the sliding contact member 63 connects the rotation shaft of the first brush roller 61 and the rotation shaft of the second brush roller 62. It is provided near the straight line. The other end (lower part in the drawing) of the sliding contact member 63 is extended in the vicinity of the outer diameter of the conveying screw 64 that conveys the object to be cleaned.

  The toner scraped off by the first brush roller 61 is isolated by the sliding contact member 63 and does not enter the second brush roller 62 and mix. Further, the toner scraped off by the second brush roller 62 is not returned to the first brush roller 61 and mixed therein.

  In the image forming apparatus main body A shown in FIG. 1, the cleaning device 8 has substantially the same configuration as the cleaning means 6 shown in FIG. In other words, the cleaning device 8 that cleans the toner remaining on the photosensitive member 1 has the first brush roller 81 and the rotatable first brush roller 81 that rotate in opposite directions and that contact the photosensitive member 1 and remove the toner. The second brush roller 82, the first brush roller 81, and the second brush roller 82 are arranged in parallel to the common tangential direction, and are in sliding contact with the first brush roller 81 and the second brush roller 82. Member 83.

  The toner scraped off by the first brush roller 81 and the second brush roller 82 is isolated by the sliding contact member 83 and is transported and stored by the transport screw 84.

[Color image forming apparatus]
FIG. 4 is a configuration diagram of a color image forming apparatus according to the present invention. In addition, about the code | symbol used in drawing, the same code | symbol is attached | subjected to the part which has the same function as FIG.

  The image forming apparatus main body A is called a tandem color image forming apparatus, and includes a plurality of sets of image forming portions AY, AM, AC, AK, a transfer material feeding / conveying means, and a fixing device 9.

  The image forming unit AY that forms a yellow (Y) image includes a charging unit 2Y, an image exposure device 3Y, a developing device 4Y, and a cleaning device 8Y arranged around the photosensitive member (first image carrier) 1Y. Have. The image forming unit AM that forms a magenta (M) color image includes a photoconductor (first image carrier) 1M, a charging unit 2M, an image exposure device 3M, a developing device 4M, and a cleaning device 8M. The image forming unit AC that forms a cyan (C) color image includes a photoreceptor (first image carrier) 1C, a charging unit 2C, an image exposure device 3C, a developing device 4C, and a cleaning device 8C. The image forming unit AK that forms a black (K) image includes a photoconductor (first image carrier) 1K, a charging unit 2K, an image exposure device 3K, a developing device 4K, and a cleaning device 8K.

  The charging means 2Y and the image exposure apparatus 3Y, the charging means 2M and the image exposure apparatus 3M, the charging means 2C and the image exposure apparatus 3C, and the charging means 2K and the image exposure apparatus 3K constitute a latent image forming means.

  4Y, 4M, 4C, and 4K are developing devices that contain a two-component developer composed of a small particle size toner of yellow (Y), magenta (M), cyan (C), and black (K) and a carrier.

  The intermediate transfer member (second image carrier) 5B is wound around a plurality of rollers and is rotatably supported.

  Each color image formed by the image forming units AY, AM, AC, and AK is sequentially transferred onto the rotating intermediate transfer body 5B by the primary transfer means 5Y, 5M, 5C, and 5K, and a combined color image is formed. It is formed.

  The paper P accommodated in the paper feeding cassette 10 of the transfer material paper feeding / conveying means is fed by the first paper feeding means 11, passed through the second paper feeding means 12, and conveyed to the secondary transfer means 5 </ b> A. After the color image is transferred onto the paper P, the paper P on which the color image is transferred is sandwiched by the fixing device 9 and the toner image on the paper P is fixed by applying heat and pressure to the paper P. The sheet is fixed on P, pinched by the sheet discharge means 14, and discharged outside the apparatus.

  On the other hand, after the color image is transferred to the paper P by the secondary transfer means 5A, the residual toner is removed by the cleaning device 8Z from the intermediate transfer body 5B from which the paper P is separated by curvature.

  The cleaning devices 8Y, 8M, 8C, and 8K that clean the photoreceptors 1Y, 1M, 1C, and 1K have substantially the same configuration as the cleaning device 8 shown in FIG. The toner scraped off by the first brush roller 81 and the second brush roller 82 is isolated by the sliding contact member 83, transported by the transport screw 84, and discharged.

  A cleaning device 8Z for cleaning the intermediate transfer member 5B has substantially the same configuration as the cleaning device 8. The toner scraped off by the first brush roller 81 and the second brush roller 82 is isolated by the sliding contact member 83, transported by the transport screw 84, and discharged.

1 is an overall configuration diagram of an image forming apparatus including an image forming apparatus main body, an image reading apparatus, and an automatic document feeder. Sectional drawing of an image formation part. Sectional drawing of a cleaning means. 1 is a configuration diagram of a color image forming apparatus according to the present invention.

Explanation of symbols

1 Photoconductor (image carrier)
1Y, 1M, 1C, 1K photoconductor (first image carrier)
5 Transfer means 5B Intermediate transfer member (second image carrier)
5Y, 5M, 5C, 5K Primary transfer means 51 Transfer belt 52 Drive roller 53 Driven roller 54 Backup roller 55 Bias roller 6 Cleaning means 61 First brush roller 62 Second brush roller 63 Sliding member 63A Scraping portion 64 Conveyance Screw 65 Cleaner housing 8, 8Y, 8M, 8C, 8K, 8Z Cleaning device 81 First brush roller 82 Second brush roller 83 Sliding member 84 Conveying screw A Image forming apparatus main body

Claims (9)

In an image forming apparatus for cleaning an object to be cleaned attached to a transfer means for transferring an image formed on an image carrier to a recording medium by a cleaning means,
The cleaning means has a first brush roller and a second brush roller that are rotatable in directions opposite to each other and that contact the transfer means to remove toner, and
A sliding contact member arranged in parallel to a common tangential direction of the first brush roller and the second brush roller, and in sliding contact with the first brush roller and the second brush roller;
An image forming apparatus comprising: In an image forming apparatus for cleaning an object to be cleaned remaining on an image carrier by a cleaning unit,
The cleaning means includes a first brush roller and a second brush roller that are rotatable in directions opposite to each other and that contact the image carrier and remove toner, and
A sliding contact member disposed in parallel to a common tangential direction of the first brush roller and the second brush roller, and in sliding contact with the first brush roller and the second brush roller;
An image forming apparatus comprising: An arrow-shaped scraping portion formed at one end of the sliding contact member is provided in the vicinity of a straight line connecting the rotation shaft of the first brush roller and the rotation shaft of the second brush roller, 3. The image forming apparatus according to claim 1, wherein the other end of the sliding contact member is extended in the vicinity of an outer diameter of a conveying screw that conveys an object to be cleaned. 4. The image forming apparatus according to claim 1, wherein bias polarities applied to the first brush roller and the second brush roller are opposite polarities. 5. The image forming apparatus according to claim 1, wherein the sliding contact member is a non-conductive resin member. The image forming apparatus according to claim 1, wherein the first brush roller and the second brush roller are fur brushes made of conductive fibers. The image forming apparatus according to claim 2, wherein the image carrier is a photoconductor. The image forming apparatus according to claim 1, wherein the image carrier is an intermediate transfer member that secondarily transfers a primary transfer image formed on a photosensitive member to a recording medium. The image forming apparatus according to claim 8, wherein the intermediate transfer member is a transfer belt constituted by an endless belt.

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