JP2009205018A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus into/from which an image carrier such as a photoreceptor drum can be inserted/removed without being damaged with an inexpensive and simple configuration and operation. <P>SOLUTION: The image forming apparatus includes a cleaning unit with a blade 22 recovering toner remaining on an image carrier 11 by coming into contact with the image carrier 11 after the toner on the image carrier 11 is transferred to the member to be transferred. In this case, a flange 13 is provided on both end section of the image carrier 11 for rotatably attaching the image carrier 11 to an image forming apparatus body. An outer periphery length of at least one flange 13 of the two flanges 13 is longer than the outer periphery length of the image carrier 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including an image carrier such as a photoconductor and an intermediate transfer member using an electrophotographic system.

  A conventional image forming apparatus is known in which an LED head, a developing device, a transfer roller, and a cleaning device are housed in a cartridge as a process unit and integrated on a photosensitive drum. In such a configuration, a member that contacts the photosensitive drum such as a blade as a cleaning device is also inserted into and removed from the photosensitive drum together with the photosensitive drum. There is no damage (see, for example, Patent Document 1).

  When the process unit is not housed in the cartridge, for example, a transfer guide that supports a transfer roller that contacts the photosensitive drum is provided so as to be tiltable in a direction in which the transfer roller and the photosensitive drum come into contact with and away from each other. It is known to provide an operation member that urges the transfer roller in a direction in which it is pressed against the photosensitive drum by an elastic member such as a spring and tilts the transfer guide from the front side of the apparatus against the urging force of the elastic member such as a spring. (For example, refer to Patent Document 2).

  By the way, in recent image forming apparatuses, there is an increasing demand for mass printing and cost reduction. For large-scale printing, in order to improve processing speed, increase process speed, reduce the stop time and frequency of image forming equipment, simplify consumable replacement operations, improve the life of consumables, etc. In response to the demand for cost reduction, reductions in the number of parts, the simplification of the configuration, etc., the reduction of the apparatus cost, and the reduction of the page cost by the improvement of the life of the consumables have come to be attempted.

  In the case of a conventional image forming apparatus, a member that contacts the photosensitive drum is housed in the process unit together with the photosensitive drum, and the photosensitive drum is not damaged when the photosensitive drum is inserted or removed. Etc. do not reach the end of the service life at the same time, and it is necessary to replace them in accordance with one of the short service lives. In this case, either one of the members before reaching the end of life is also replaced, so that the life cannot be improved, the frequency of stopping the image forming apparatus is increased, and the page cost is increased. . In addition, when the speed is increased, it is conceivable that the process unit is also increased in size, and it is extremely difficult to replace the process unit as a whole, and it takes a long time to replace the process unit, leading to an increase in the stop time of the image forming apparatus.

  Further, when the operation member is provided and the member that contacts the photoconductor drum is separated and the photoconductor drum is inserted and removed, the photoconductor drum is not similarly damaged, but the number of operations required before the photoconductor insertion and removal is increased. Therefore, the operation time is increased, which causes an increase in the stop time of the image forming apparatus. In addition, the number of parts is increased by installing the operation member, and a mechanism for performing this operation is required, resulting in an increase in apparatus cost.

JP 2006-56065 A JP 2006-30418 A

  An object of the present invention is to provide an image forming apparatus that can be inserted and removed without damaging an image carrier such as a photosensitive drum by an inexpensive and simple configuration and operation. .

In order to achieve the above object, the present invention comprises a cleaning device having a blade for transferring the toner on the image carrier to a member to be transferred and collecting the toner remaining on the image carrier by contacting the image carrier. In the image forming apparatus,
Flange for rotatably mounting the image carrier to the image forming apparatus main body is provided at both ends of the image carrier, and the outer circumference of at least one of the two flanges is longer than the outer circumference of the image carrier. It is also characterized by its long length.

  In the image forming apparatus of the present invention, it is not necessary to remove other parts that do not need to be replaced when replacing the image carrier, and it is possible to omit the operation and mechanism before insertion / extraction of the image carrier, without damaging the image carrier. The insertion / extraction operation of the image carrier can be realized.

  An embodiment of the present invention will be described. In this embodiment, the photosensitive member will be described as an image carrier. However, any member can be used as long as it is a member carrying a toner image such as an intermediate transfer member and the surface is cleaned with a blade. is there. In this embodiment, a single-color image forming apparatus is described, but the present invention can also be applied to a color image forming apparatus.

  1A and 1B are schematic views around a photoconductor of an image forming apparatus according to an embodiment of the present invention. FIG. 1A is a schematic cross-sectional view, and FIG. 1B is a schematic cross-sectional view as viewed from the direction of an arrow z in FIG. .

  In FIG. 1, reference numeral 1 denotes a photoreceptor, and 2 denotes a cleaning device. The photoreceptor 1 has a photosensitive drum 11 and flanges 12 and 13 provided at both ends thereof. The flanges 12 and 13 are fixed to the photosensitive drum 11 by, for example, press-fitting or bonding, and the rotation center with respect to the image forming apparatus main body is positioned on the image forming apparatus main body (not shown), for example, in FIG. The flanges 12 and 13 are supported by the drum holding shaft 3 that is rotatably mounted in the clockwise direction at the time of actual printing, and is fitted to a gear or the like (not shown) attached to the drum holding shaft 3 at a portion 13a of the flange 13. And rotates together with the drum holding shaft 3. As shown in FIG. 1B, the flange 13 is tapered in the axial direction, and the maximum outer diameter D13 has a relationship of D13> D11 with the outer diameter D11 of the photosensitive drum 11, and the flange 13 Is longer than the outer peripheral length of the photosensitive drum 11.

  The cleaning device 2 includes a housing 21 fixed to the image forming apparatus main body, a blade 22 installed in the housing 21, a cleaning brush 23, a flicker bar 24, a collection auger 25, and the like. The blade 22 is formed of a cleaner blade 221 made of, for example, polyurethane rubber and a holder 222 obtained by bonding the cleaner blade 221. The blade 22 is attached to the blade holder 26. The blade holder 26 is installed to be rotatable about a fulcrum 261 and is connected to the housing 21 via a spring 27 so that the blade 22 can be cleaned with an appropriate pressing force capable of cleaning the toner on the photosensitive drum 11. Is pressed to clean the toner on the photosensitive drum 11.

  The cleaning brush 23 rotates counterclockwise, for example, to perform a pre-cleaning process for the toner on the photoreceptor 1 before entering the blade 22, and the toner adhering to the cleaning brush 23 is beaten off by the flicker bar 24. The toner cleaned and collected by the blade 22 and the cleaning brush 23 falls into the collection auger 25 and is collected.

  Next, the operation of inserting / removing the photoreceptor will be described with reference to FIGS. When exchanging the photosensitive member 1 used in the state of FIG. 1, the photosensitive member 1 is pulled out along the axial direction of the drum holding shaft 3. At this time, the blade holder 26 comes into contact with the tapered portion 13 b of the flange 13, and the blade 22 is lifted by rotating clockwise around the fulcrum 261 along the tapered portion 13 b, so that the blade 22 moves to the photosensitive drum 11. The pressing force is weakened and finally separated from the photosensitive drum 11 (FIGS. 2A and 2B).

  Further, when the photosensitive member 1 is pulled out, the photosensitive member 1 is pulled out with the blade 22 being separated from the photosensitive drum 11 while the blade holder 26 is in contact with the flange 13. Here, the blade holder 26 is made of, for example, a rigid material such as a sheet metal, and since both ends are supported by the fulcrum 261, the influence of deflection can be ignored, and the blade 22 is separated from the photosensitive drum 11 over the entire width direction. (FIGS. 2A, 2C, and 2D).

  When the photoreceptor 1 is finally removed from the drum holding shaft 3, the blade holder 26 is separated from the flange 13 and rotated counterclockwise around the fulcrum 261 by the tension force of the spring 27, so that the blade 22 is free. In this state, the photosensitive drum 1 is positioned inside the locus (two-dot chain line portion in FIG. 3A) where the photosensitive drum 1 is installed.

  Further, when the photosensitive member 1 is inserted, it is inserted in the reverse order as described above, the blade holder comes into contact with the tapered portion 13c of the flange 13, and the blade holder 26 is rotated clockwise around the fulcrum 261 along the tapered portion 13c. The blade 22 is inserted while being separated from the photosensitive drum 11. In this manner, the photosensitive member 1 can be inserted and removed without damaging the photosensitive drum 11 by the blade 22.

  Next, the printing operation of the image forming apparatus using this embodiment will be described with reference to FIG. The image forming unit 100 includes a photoconductor 101, a charger 102, an exposure device 103, a developing device 104, a transfer device 105, and a cleaning device 106.

  The photosensitive member 101 starts rotating based on a printing operation start signal from a controller (not shown), rotates at a speed corresponding to the printing speed of the image forming apparatus, and continues rotating until the printing operation is completed. When the photosensitive member 101 starts to rotate, a high voltage is applied to the charger 102, and for example, positive charges are uniformly charged on the surface of the photosensitive member 101. When character data or graphic data converted into a dot image is sent from the controller (not shown) to the image forming apparatus as an on / off signal of the exposure apparatus 103, the exposure apparatus 103 irradiates the surface of the photoconductor 101 with laser light or the like. A portion and a portion that is not irradiated are formed.

  When the portion where the charge on the photoconductor 101 disappears due to the irradiation of the laser beam or the like from the exposure device 103 reaches a position facing the developing device 104, the toner charged to the positive charge is attracted by static electricity and is absorbed onto the photoconductor 101. A toner image is formed. The toner image formed on the photoconductor 101 is sucked onto the paper 107 by the action of the transfer unit 105 that applies a charge having a polarity opposite to that of the toner image on the back side of the paper 107. The photosensitive member 101 that has passed through the transfer device 105 is cleaned by the cleaning device 106, and the residual toner on the photosensitive member 101 is collected in a collecting unit (not shown) to prepare for the next printing operation.

  Thereafter, the sheet 107 is conveyed to the fixing unit 108, and the sheet 107 that has reached the fixing unit 108 is heated and pressurized by a nip formed by a pair of fixing rolls 108a and 108b, at least one of which is a heating roll. The image is melted and fixed on the sheet 107. By repeating the printing operation as described above, an image is formed on the sheet 107. As the printing operation is repeated, the photosensitive member 101 reaches the use limit and needs to be replaced.

  In the image forming apparatus of the present invention, it is not necessary to remove other parts that are not necessary for replacement other than the photosensitive member, and it is possible to omit the operation and mechanism before insertion / extraction of the photosensitive member. It is possible to enable insertion and removal of the photoreceptor without damaging the body.

1 is a schematic view around a photoconductor of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a schematic view of the image forming apparatus during insertion / extraction of a photoreceptor. FIG. 2 is a schematic view after the photoreceptor is inserted and extracted from the image forming apparatus. 1 is an overall schematic view of an image forming apparatus using the present invention.

Explanation of symbols

  1 is a photosensitive member, 2 is a cleaning device, 11 is a photosensitive drum, 13 is a flange, 13b and 13c are tapered portions, 22 is a blade, and 26 is a blade holder.

Claims (4)

In an image forming apparatus provided with a cleaning device having a blade for transferring toner on an image carrier to a member to be transferred and collecting the toner remaining on the image carrier in contact with the image carrier.
Flange for rotatably mounting the image carrier to the image forming apparatus main body is provided at both ends of the image carrier, and the outer circumference of at least one of the two flanges is longer than the outer circumference of the image carrier. An image forming apparatus characterized by being long.   The image forming apparatus according to claim 1, wherein the at least one flange is provided with a taper along an axial direction so that an outer peripheral length changes.   The image forming apparatus according to claim 2, wherein the taper is provided at both axial ends of the at least one flange.   The image forming apparatus according to claim 1, wherein a part of the holder that holds the blade is in a positional relationship in contact with the at least one flange when the image carrier is inserted into and removed from the image forming apparatus main body. .

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