JP4977639B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a secondary transfer device provided with a paper discharging / separating device for discharging the back surface of a transfer sheet after the secondary transfer to facilitate separation from the intermediate transfer body. .

  An image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine having at least two functions of these includes a secondary transfer device that secondarily transfers a toner image transferred to an intermediate transfer member by primary transfer onto a transfer sheet. The thing is well known. Also, it is already well known that a paper discharging / separating device as shown in Patent Documents 1 and 2 for removing the charge on the back surface of the transfer paper after the secondary transfer and facilitating separation from the intermediate transfer member is already known. .

  Further, in recent image forming apparatuses, it is required that a recovery operation in the event of a machine abnormality can be performed by only a front operation and by one action as much as possible. For this reason, it is proposed that a secondary transfer device including a secondary transfer roller is supported by a front plate that opens and closes, and when the front plate is opened, a transfer paper conveyance path from the paper feed outlet to the fixing device inlet appears. ing. The image forming apparatus configured as described above can easily perform processing such as removing jammed paper by opening the front plate during jam processing.

  However, in consideration of the operability of removing jammed paper, if the above-mentioned paper static elimination device is attached to the secondary transfer device in the image forming device in which the transfer paper conveyance path appears when the front plate is opened, the size of the device can be reduced. As a result, the paper discharging / separating device interferes with the fixing device. Therefore, if a paper static elimination device is attached to the secondary transfer device, the device for moving the fixing device upward cannot be enlarged. Therefore, the rotation accompanying the opening and closing of the front plate is abandoned and the secondary plate is opened after the front plate is opened. There is a problem that it is necessary to perform a two-action operation of moving the transfer device or to devise a method for opening and closing the front plate.

JP 2001-302011 A Japanese Patent Laid-Open No. 2002-156834

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of solving the above-described conventional problems and recovering a jam or the like by one action without increasing the size of the apparatus.

  In order to achieve the above object, the present invention provides at least one image carrier on which a toner image is formed, an intermediate transfer member to which a toner image formed on the image carrier is primarily transferred, and an intermediate transfer member on the intermediate transfer member. A secondary transfer device for secondary transfer of the toner image to the transfer paper, a paper static elimination device for facilitating the separation from the intermediate transfer member by removing the back surface of the transfer paper after the secondary transfer, A fixing device that fixes the toner transferred onto the transfer paper to the transfer paper, and the secondary transfer device is moved away from the intermediate transfer member by the rotation of the adjacent side plate and rotated along with the side plate. In the image forming apparatus, the paper discharging / separating device is provided on a guide member that guides a back surface side of the transfer paper, and the guide member is rotatably attached to the secondary transfer device, and when the side plate is opened and closed. When the guide member hits the fixing device The fixing device overcome by dynamic, proposes an image forming apparatus characterized by being rotated together with the second transfer device.

The present invention is effective when the rotation center of the guide member is the roller shaft of the secondary transfer roller when the secondary transfer device includes a secondary transfer roller.
Furthermore, the present invention is effective when the positioning of the guide member when the side plate is closed is performed against the inlet guide plate of the fixing device.

Furthermore, the present invention is effective when positioning when the side plate of the guide member is closed is performed against the casing of the secondary transfer device.
Furthermore, the present invention is effective when the surface of the fixing device that is rotated by the contact of the guide member is different when the side plate is opened and closed.

  According to the present invention, the secondary transfer device can be opened / closed together with the side plate even if a static elimination needle is attached to the secondary transfer device without increasing the size of the device, and recovery such as jamming in one action is possible. can do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic sectional view showing an example of an image forming apparatus. The image forming apparatus shown here is configured as a color printer for forming a full-color image.

  In FIG. 1, a developing device 12, an endless photosensitive belt 4 that is an example of an image carrier, and an endless intermediate transfer belt 15 are provided in a main body casing 50 of the image forming apparatus. . The photosensitive belt 5 is wound around the driving roller 1 and the driven rollers 2 and 3, and the intermediate transfer belt 15 is a cleaning facing roller 16, a primary transfer roller 17, a driving roller 18, a tension roller 19, and a secondary transfer facing roller 20. Are wound around a plurality of rollers.

  The developing device 12 is disposed so as to face the photosensitive belt portion between the driving roller 1 and the driven roller 2, and has four developing units, a yellow developing unit 12Y, a magenta developing unit 12M, a cyan developing unit 12C, and a black developing unit 12K. Has a vessel. The developing units 12Y to 12K respectively include developing cases 13Y, 13M, 13C, and 13K that contain yellow toner, magenta toner, cyan toner, and black toner, and developing rollers 14Y, 14M, and 14C that carry and carry the respective toners. , 14K. Each of the developing devices 12Y to 12K is supported by a driving device (not shown) so as to occupy a developing position that is close to the outer peripheral surface of the photosensitive belt 4 and a retracted position that is separated from the outer peripheral surface.

  When the image forming operation is started, the driving roller 1 is driven to rotate in the clockwise direction, so that the photosensitive belt 4 is driven to run in the direction of arrow A, and the intermediate transfer belt 15 in contact with the photosensitive belt 4 is also moved. Driven in the direction of arrow B. At this time, the photosensitive belt 4 is uniformly charged by the charging roller 8, and the charged surface is irradiated with the light-modulated laser light L emitted from the laser writing unit 11 which is an example of an exposure apparatus, and thereby the photosensitive belt 4 is exposed to light. An electrostatic latent image is formed on the body belt 4.

  The above-described electrostatic latent image is visualized as a toner image by the first developing unit that occupies the developing position, in this example, the yellow developing unit 12Y. At this time, the other developing devices 12M to 12K occupy the retracted position. The developing roller 14Y of the yellow developing device 12Y is in contact with the outer peripheral surface of the photoreceptor belt 4 or is opposed to the outer peripheral surface with a minute gap therebetween, and the developing roller 14Y is rotated, for example, counterclockwise. A predetermined developing bias is applied to the developing roller 14Y. As a result, the yellow toner carried and conveyed on the peripheral surface of the developing roller 14Y is electrostatically transferred to an electrostatic latent image, and the latent image is visualized as a yellow toner image. The yellow toner image formed on the photoconductor belt 4 is electrostatically primary transferred onto the surface of the intermediate transfer belt 15 in contact with the photoconductor belt 4 by the action of the transfer voltage applied to the primary transfer roller 17. The The transfer residual toner adhering to the outer peripheral surface of the photoreceptor belt 4 after the toner image transfer is scraped and removed by the cleaning member 22 of the cleaning device 25. The removed toner is conveyed to a waste toner container (not shown) through a pipe (not shown) and stored therein.

  Next, in the same manner as described above, a second electrostatic latent image is formed on the photosensitive belt 4, and this is visualized as a magenta toner image by the magenta developing device 12M that has occupied the developing position. The image is transferred onto the surface of the intermediate transfer belt 15 from above the yellow toner image. The surface of the photoreceptor belt after the toner image is transferred is cleaned by the cleaning device 25. In exactly the same manner, a cyan toner image and a black toner image are sequentially formed on the outer peripheral surface of the photosensitive belt 4 by the cyan developing device 12C and the black developing device 12K, and these toner images are formed on the surface of the intermediate transfer belt 15. It is transferred onto the previously transferred toner image.

  On the other hand, a sheet feeding cassette 24, a sheet feeding device 24 having a sheet feeding roller 26, and a manual sheet feeding device 27 are disposed in the lower part of the main body casing so as to face each other. In the paper feeding device 24, a transfer material made of, for example, transfer paper is loaded in the paper feeding cassette 24, and the paper feeding roller 26 rotates in contact with the upper surface of the uppermost transfer material, whereby the uppermost transfer material. Is sent in the direction of arrow C. The transfer material fed from either the paper feeding device 24 or the manual paper feeding device 27 is conveyed upward, and then the intermediate transfer belt 15 and the secondary transfer belt are rotated at a predetermined timing by the rotation of the registration roller pair 33. The sheet is fed between the transfer roller 28. At this time, a transfer voltage is applied to the secondary transfer roller 28, whereby the superimposed toner images on the intermediate transfer belt 15 are collectively transferred onto the surface of the transfer material P. The transfer material to which the toner image has been transferred is conveyed further upward from the transfer portion and passes through the fixing device 29. At this time, the toner image is fixed on the surface of the transfer material by the action of heat and pressure. Subsequently, the transfer material is discharged to the paper discharge unit 30 at the top of the main body housing as indicated by an arrow D.

  Transfer residual toner adhering to the surface of the intermediate transfer belt after the toner image transfer is removed by the cleaning member 32 of the cleaning device 31. When the toner image before transfer on the intermediate transfer belt 15 passes through the cleaning member 32, the cleaning member 32 is separated from the surface of the intermediate transfer belt, and abuts on the surface of the intermediate transfer belt only when the transfer residual toner is removed. Similarly, the secondary transfer roller 28 also contacts the surface of the intermediate transfer belt 15 via the transfer material when the toner image is transferred onto the transfer material, and from the surface of the intermediate transfer belt at other times. The separation is prevented, and the untransferred toner image on the intermediate transfer belt 15 is prevented from being disturbed.

  As described above, after the toner image on the intermediate transfer belt 15 is transferred to the transfer material, the toner remaining on the belt is removed by the cleaning device 31, but the removed toner is not shown. The toner is conveyed to the waste toner tank 5 by the toner conveying device and stored therein. The waste toner tank 5 is disposed in the inner space of the intermediate transfer belt 15. As described above, by storing the waste toner tank 5 in the space inside the intermediate transfer belt 15 that has conventionally been a dead space, the space in the main body housing 50 can be effectively used, and the image forming apparatus can be downsized. Can be achieved.

  Further, the image forming apparatus of the present embodiment includes a reversing unit 34 so that an image can be formed on both sides of the transfer material. A switching claw 35 for selectively switching between discharging to the paper discharge unit 30 indicated by D and feeding to the reversing unit 34 is provided. The reversing unit 34 includes a reversing path 36 that is fed when reversing by the reversing roller 36 and a return path 37 that re-feeds the reversed transfer material.

  By the way, it is impossible to completely prevent the transfer material from causing trouble such as jam in the image forming apparatus. If a jam occurs, it is necessary to take a measure such as removal. In general, the jam processing is basically performed by the user, and therefore various ideas for facilitating the jam processing have been proposed.

  Also in the image forming apparatus described above, the side plate 51 of the apparatus housing 50 to which the reversing unit 34 is attached is opened in the direction of arrow E as shown in FIG. As the side plate 51 is opened, the reversing unit 34 is rotated, and the paper conveyance path 52 from the outlet of the paper feeding device 24 to the fixing device 29 is opened. By opening the paper transport path 52, the jammed transfer material can be found immediately, and the jammed state can be recognized, so that the processing can be easily performed without error.

  The secondary transfer device 60 including the secondary transfer roller 28 includes a guide member 70 that guides the transfer material after transfer, and a static elimination needle 71 that is provided on the guide member 70 and neutralizes the transfer material after transfer. There is something. When the static elimination needle 71 is provided in the secondary transfer device 60, if the secondary transfer device 60 is rotated together with the opening of the side plate 51, the guide member 70 and the fixing member are fixed by downsizing the image forming apparatus. As the device 29 approaches, the guide member 70 comes into contact with the casing 52 of the fixing device 29, as is apparent from the rotation locus 74. At this time, moving the fixing device 29 upward to widen the gap between the guide member 70 and the fixing device 29 increases the size. Therefore, the one-action rotation accompanying the opening of the side plate 51 of the secondary transfer device 60 is abandoned. As described above, it is necessary to perform a two-action operation of moving the secondary transfer device 60 after the side plate 51 is opened or to devise a method for opening and closing the side plate 51.

The present invention solves this problem, and first, the secondary transfer device 60 of the present embodiment will be described in detail.
FIG. 3 is a perspective view showing the overall configuration of the secondary transfer device 60. In the secondary transfer device 60, both ends of the roller shaft 28 </ b> A of the secondary transfer roller 28 are rotatably supported by the unit side plate 61 via bearing members 63. As shown in FIG. 4, the bearing member 63 includes a cylindrical bearing portion 64 and a thick plate-like support portion 65. The support portion 65 has two leg portions 66 provided at the lower portion, and both side portions. A guide protrusion 67 is provided. On the other hand, the unit side plate 61 is formed with a guide concave portion 62 into which the guide convex portion 67 is fitted, and a pressing spring 68 is disposed between the unit side plate 61 and the bearing member 63 and is interposed via the bearing member 63. The secondary transfer roller 28 is urged to contact the intermediate transfer belt 15. The secondary transfer device 60 itself is rotatably attached to the side plate 51 via a shaft 68.

  5 and 6, the guide member 70 that supports the static elimination needle 71 is provided with arm portions 72 at both ends in the width direction (only one side is shown in FIGS. 5 and 6). The fitting part 73 is formed in the. When the fitting portion 73 is rotatably fitted to the bearing portion 64 of the bearing member 63, the guide member 70 is mounted so as to be rotatable about the roller 28A of the secondary transfer roller 28. Since the fitting portion 73 of the guide member 70 is rotatably fitted on the outer side of the bearing portion 64 of the bearing member 63, the static elimination needle 71 is configured not to receive vibration due to the rotation of the secondary transfer roller 28. Yes.

  The secondary transfer device 60 configured as described above is rotated together with the side plate 51 when the side plate 51 is opened and closed, and when the side plate 51 is opened, the guide member 70 is the first member of the fixing device 29 as shown in FIG. 1 surface 29-1. Then, the guide member 70 rotates counterclockwise in FIG. 7 about the shaft 28A of the secondary transfer roller 28, and can open the secondary transfer device 60 together with the side plate 51 by passing over the fixing device 29. it can. Conversely, when the side plate 51 is closed, the guide member 70 comes into contact with the second surface 29-2 of the fixing device 29 and is rotated clockwise around the shaft 28A of the secondary transfer roller 28 so that it can be passed over the fixing device 29. Therefore, the secondary transfer device 60 is closed together with the side plate 51, and the image forming apparatus can be operated.

  Thus, when the secondary transfer device 60 is opened and closed by the side plate 51, it is rotated together with the side plate 51. At this time, even if the guide member 70 hits the fixing device 29, the secondary transfer device 60 rotates and gets over the fixing device 29. The transfer paper conveyance path including the secondary transfer device 60 can be opened with one action. The secondary transfer device 60 is supported by the side plate 51 so as to be rotatable about a shaft 68. When the side plate 51 is closed, the intermediate transfer belt 15 is moved by a pressure spring 69 shown in FIGS. It is held at a normal position sandwiched between and pressed against the secondary transfer counter roller 20.

  By the way, the static elimination needle 71 is required to have a strong directivity in order to maintain its performance. However, if the secondary transfer device 60 can be opened and closed together with the side plate 51 as described above, when the side plate 51 is closed, not only the secondary transfer device 60 but also the guide member 70 is reliably returned to the normal position. I have to. That is, when the side plate 51 is closed, the position of the guide member 70 must be determined so that the guide member 70 is also in the normal position.

  Therefore, in this embodiment, as shown in FIG. 8, when the guide plate 70 is closed by the side plate 51, the guide member 70 is pressed against the inlet guide 29 </ b> A provided in the fixing device 29 by the pressing spring 75 and positioned. At this time, the pressing spring 75 presses the guide member 70 against the inlet guide 29 </ b> A via a small piece 76 protruding from the side surface of the guide member 70.

Further, the positioning of the guide member 70 when closed by the side plate 51 may be performed by the secondary transfer device 60.
As mentioned above, although preferable embodiment of this invention was described, this invention should not be limited only to the said embodiment. For example, the side plate of the above embodiment is preferably the front plate of the apparatus because the apparatus can be recovered by front operation. That is, it is preferable that the side plate that opens and closes at the time of jam when the front face of the device is specified by its operation panel or the like is constituted by the front plate.

  The image forming apparatus is not limited to the one shown in FIG. 1, and may be a device having a secondary transfer apparatus, for example, a tandem type color image forming apparatus.

1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus to which the present invention is applied. It is explanatory drawing which shows the relationship between the side plate which opens and closes, and a secondary transfer apparatus. It is a perspective view which shows the whole structure of a secondary transfer apparatus. It is a perspective view which shows the bearing member of a secondary transfer roller. It is a perspective view which shows the support part to the secondary transfer roller of a guide member. It is a perspective view which shows the guide member which attached the support part to the secondary transfer roller. It is explanatory drawing which shows the relationship between the guide member at the time of side plate opening and closing, and a fixing device. It is explanatory drawing which shows the positioning method of the guide member at the time of a side plate closing.

Explanation of symbols

4 Photosensitive belt 15 Intermediate transfer belt 28 Secondary transfer roller 29 Fixing device 51 Side plate 60 Secondary transfer device 70 Guide member 71 Static elimination needle

Claims (5)

At least one image carrier on which a toner image is formed, an intermediate transfer member on which the toner image formed on the image carrier is primarily transferred, and a toner image on the intermediate transfer member are secondarily transferred onto transfer paper A secondary transfer device, a paper discharge separation device for facilitating the separation from the intermediate transfer body by removing the back surface of the transfer paper after the secondary transfer, and the toner transferred to the transfer paper And a fixing device for fixing to
The secondary transfer device is an image forming apparatus that is separated from the intermediate transfer member by the rotation of an adjacent side plate and is rotated along with the side plate.
The paper discharging / separating device is provided on a guide member that guides the back side of the transfer paper, and the guide member is rotatably attached to the secondary transfer device, and the guide member is fixed to the fixing member when the side plate is opened and closed. An image forming apparatus, wherein the image forming apparatus is rotated together with the secondary transfer device by overcoming the fixing device by rotating on the apparatus.   The image forming apparatus according to claim 1, wherein the rotation center of the guide member is a roller shaft of the secondary transfer roller when the secondary transfer device includes a secondary transfer roller. Forming equipment.   3. The image forming apparatus according to claim 1, wherein positioning of the guide member when the side plate is closed is performed by abutting against an inlet guide plate of the fixing device.   3. The image forming apparatus according to claim 1, wherein the guide member is positioned by abutting against a casing of the secondary transfer device when the side plate of the guide member is closed. 4.   5. The image forming apparatus according to claim 1, wherein a surface of the fixing device to which the guide member hits and rotates is a surface different between when the side plate is opened and when the side plate is closed. Image forming apparatus.

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