JP4780420B2 - Sheet discharging apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet discharging apparatus and an image forming apparatus such as a printer, a copying machine, and a facsimile.

  This type of image forming apparatus includes a paper discharge unit that discharges a sheet on which an image is printed. Specifically, a pair of discharge rollers are provided in the paper discharge unit, and a sheet on which an image has been formed is discharged from the image forming apparatus main body by driving the discharge rollers.

  On the other hand, there is known means for preventing foreign matter from entering the discharge roller when the apparatus opening / closing part is opened or closed for sheet replenishment or jam processing. (Patent Documents 1 to 5).

JP2001-205896 JP2001-213522A JP2001-341903A Japanese Utility Model 06-060006 JP 08-006338 A

  Since the discharge roller is exposed to the outside in the paper discharge unit, foreign matter may enter the image forming apparatus as the discharge roller is driven. Therefore, it is necessary to prevent the foreign matter from entering.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet discharge device and an image forming apparatus that can prevent foreign matters from entering from a discharge portion of a main body of an image forming apparatus.

In order to achieve the above object, a first feature of the present invention includes a discharge roller that discharges a sheet and a cover that covers the discharge roller, and the cover faces the periphery of the discharge roller. And a rib that protrudes toward the discharge roller, and the rib is provided in a sheet discharge apparatus having a displacement restricting portion that extends to the vicinity of a lower portion of a rotation shaft that constitutes the discharge roller .

  Preferably, the rib protrudes toward the discharge roller so as to cover a part of the peripheral edge of the discharge roller.

  Therefore, according to this sheet discharge device, the rib provided on the cover fills the gap between the discharge roller and the cover, thereby preventing foreign matter from entering when the discharge roller is driven, and further occurring when entering. Since the downward displacement of the discharge roller is restricted, it is possible to further prevent entry.

  Preferably, the rib has a sheet guide portion on the upstream side in the sheet conveyance direction of the discharge roller and having a smooth curve toward an insertion port into which the sheet is inserted into the discharge roller.

  Therefore, according to this sheet discharging apparatus, it is possible to prevent sheet clogging inside the main body while preventing entry of foreign matter.

  Preferably, the cover is formed so as to protrude toward the sheet discharge direction of the discharge roller.

  Therefore, according to this sheet discharge device, it is possible to further prevent foreign matter from entering the discharge roller.

  The second feature of the present invention resides in an image forming apparatus having the sheet discharge device described above.

  According to the present invention, it is possible to prevent foreign matter from entering the discharge roller constituting the paper discharge unit.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12. A paper feeding device 14 is disposed below the image forming apparatus main body 12, and a paper discharge unit 16 is disposed above the image forming apparatus main body 12. Is formed.

  The sheet feeding device 14 includes a sheet tray 18, and a large number of sheets are stacked on the sheet tray 18. A feed roll 20 is disposed at one upper end of the sheet tray 18, and a separating roll 22 is provided to face the feed roll 20. The uppermost sheet on the sheet tray 18 is picked up by the feed roll 20, and after the sheet is rolled by the cooperation of the feed roll 20 and the rolling roll 22, the sheet is conveyed downstream in the conveyance path 64.

  The sheet conveyed from the sheet tray 18 is temporarily stopped by the registration roller 24, and is driven between the photosensitive unit 26 and the transfer unit 28 and through the fixing device 30 by a driving discharge roller 32 and a driven discharge roller 34 at a predetermined timing. The paper is discharged to the paper discharge unit 16.

  In the image forming apparatus main body 12, a photosensitive unit 26, a transfer unit 28, a power supply unit 36, and a control unit 38 are arranged. A photosensitive member 40 is rotatably supported by the photosensitive unit 26. Around each photoconductor 40, a charging device 42 as a charging means provided with a charging roll for uniformly charging the photoconductor 40, and a latent image written on each photoconductor 40 is developed with a developer (toner). A developing device 44 as a developing means, a static eliminating device 46 for neutralizing the photoreceptor 40 after transfer, and a cleaning device 48 as a developer removing means for removing the developer remaining on the photoreceptor 40 after the transfer. Is arranged. The photoconductor unit 26 includes four photoconductors 40, a charging device 42, a developing device 44, a charge removal device 46, and a cleaning device 48, and is detachable from the image forming apparatus main body 12.

  In FIG. 1, four toner boxes 50 are connected to the back side of the photosensitive unit 26. Each toner box 50 is for magenta, yellow, cyan, and black, and a toner supply unit 52 and a toner recovery unit 54 are integrated. The toner supply unit 52 is connected to the developing device 44 to supply each color toner to the developing device 44, and the toner recovery unit 54 is connected to the cleaning device 48 to collect each color toner.

  Each of the optical writing devices 56 is composed of a laser exposure device, is arranged on the back side of the photosensitive unit 26 and is located at a position corresponding to each photosensitive member 40, and irradiates the uniformly charged photosensitive member 40 with a laser. To form a latent image.

  The transfer unit 28 is on the front side of the photoconductor unit 26 and is arranged in the vertical direction facing the photoconductor unit 26. In the transfer unit 28, a conveyance belt 60 is hung on two support rolls 58 provided in the vertical direction. Further, a transfer roll 62 is provided so as to face each photoconductor 40 with the conveyance belt 60 interposed therebetween.

  Therefore, each photoconductor 40 is uniformly charged by the charging device 42, a latent image is formed by the optical writing device 56, and the latent image is visualized by toner by the developing device 44. The toner images formed on the respective photoconductors 40 are transferred onto the conveyed sheet by the transfer roll 62 of the transfer unit 28 in order from below, and are fixed on the sheet by the fixing device 30.

  The sheet on which the toner image is fixed by the fixing device 30 is conveyed to the paper discharge unit 16 through the conveyance path 64 and is discharged to the outside of the image forming apparatus main body by the drive discharge roller 32 and the driven discharge roller 34.

Next, embodiments of the present invention will be described with reference to the drawings. 2 to 4, a first embodiment of the present invention is shown.
The paper discharge unit 16 includes a drive discharge roller 32, a driven discharge roller 34, and a cover 66. The drive discharge roller 32 includes a first roll 32a, a second roll 32b, a third roll 32c, a fourth roll 32d, and a rotating shaft 32e on which these rolls are integrally attached. The sheet conveyed through the conveyance path 64 is rotated to the outside of the image forming apparatus main body by the rotation of the drive discharge roller 32 driven by the rotation of the rotation shaft 32e and the driven discharge roller 34 driven by the drive discharge roller 32. And discharged. A cover 66 is provided above the drive discharge roller 32 to prevent the drive discharge roller 32 and the driven discharge roller 34 from being exposed to the outside.

  The cover 66 has an L-shaped cross section and covers the upper part of the drive discharge roller 32 and the driven discharge roller 34 from one end to the other end in the axial direction. A plurality of ribs 68 are provided on the surface of the cover 66 facing the drive discharge roller 32 in a direction orthogonal to the axial direction of the drive discharge roller 32. Among the ribs 68, ribs 68a, 68b formed at positions facing the first roll 32a, the second roll 32b, the third roll 32c, and the fourth roll 32d constituting the drive discharge roller 32, respectively. 68c and 68d are formed to protrude in a curved shape so as to be along a part of the peripheral edge of the first roll 32a, the second roll 32b, the third roll 32c, and the fourth roll 32d. . Of the ribs 68a, 68b, 68c, and 68d that are formed to protrude, for example, the rib 68a is close to the peripheral edge of the first roll 32a, so that the first roll 32a and the rib 68a The gap is very narrow.

  Furthermore, the number of ribs 68a provided on the surface facing the first roll 32a is two in the present embodiment. Accordingly, the ribs 68a and 68a are provided so as to have a short distance from each other and cover the entire cover side of the roll peripheral surface.

  As described above, the ribs 68a, 68b, 68c, and 68d formed at positions facing the first roll 32a, the second roll 32b, the third roll 32c, and the fourth roll 32d, respectively, Since it is in the vicinity and has a shape along a part of the peripheral edge of the roller, the gap between the upper portion of the drive discharge roller 32 and the cover 66 is very small. When the drive discharge roller 32 is driven, Even if it contacts the drive discharge roller 32, it does not get caught in the rotation direction of the drive discharge roller 32 and enter the cover 66.

  In addition, since the distance between the ribs 68a and 68a is short and is provided so as to cover the entire cover facing surface of the peripheral edge of the roll, it is possible to prevent the relatively small one from entering the discharge roller. it can.

  Next, a second embodiment of the present invention will be described based on FIG. 3, FIG. 5, and FIG.

  Of the ribs 68, between the first roll 32a and the second roll 32b, between the second roll 32b and the third roll 32c, and between the third roll 32c and the fourth roll 32d. Are provided with the same type of ribs 68e, 68f and 68g, respectively. The ribs 68e, 68f, and 68g are respectively formed with displacement restricting portions 70 facing downward. The displacement restricting portion 70 has a shape in which the lower portion of the rib hangs down in an L shape so as to surround the rotation shaft 32e of the driving roller 32 from the side opposite to the side from which the sheet is discharged.

  Here, the displacement restricting portions 70 of the ribs 68e, 68f, and 68g are arranged so that the outer periphery of the rotary shaft 32e is not touched when the paper discharge unit 16 is operating normally. To support with a predetermined gap. Further, the bottom side of the displacement restricting portion 70 is formed so as to be positioned above the contact point between the driving discharge roller 32 and the driven discharge roller 34 so as not to touch the discharged sheet.

  By forming the ribs 68e, 68f, and 68g in this manner, when foreign matter is mixed between the cover 66 and the drive discharge roller 32, the foreign matter comes into contact with the drive discharge roller 32, so that the drive discharge roller 32 is Even in the case of bending downward, the displacement restricting portions 70 of the ribs 68e, 68f, and 68g come into contact with the rotating shaft 32e, thereby restricting the downward displacement of the rotating shaft 32e. The gap between 66 and the drive discharge roller 32 is prevented from further expanding due to the entry of foreign matter.

  Furthermore, as a third embodiment of the present invention, as shown in FIG. 6, the ribs 68e, 68f, and 68g are inserted into the sheet between the drive discharge roller 32 and the driven discharge roller 34 from the upstream side of the sheet conveyance path. A sheet guide 72 is formed in a gentle slope toward the mouth.

  By forming such a sheet guide portion 72, the discharged sheet is smoothly fed to the drive discharge roller 32 and the driven discharge roller 34, and is a rib having a function of preventing entry of foreign matters, but is discharged at the same time. Prevents jamming of the used sheet.

  Furthermore, as a fourth embodiment of the present invention, as shown in FIGS. 7 and 8, the entire end portion of the cover 66 on the sheet discharge side is formed to project like a bowl. The cover 74 protruding like a bowl is formed in a length that prevents foreign matter from entering the drive discharge roller 32 and the driven discharge roller 34.

  Since the rib 68 provided on the cover 66 is formed so as to cover the upper peripheral edge of the drive discharge roller 32 as described above, the gap between the cover 66 and the drive discharge roller becomes very narrow. Intrusion of foreign matter during rotation can be prevented.

  In addition, since a part of the rib extends below the rotation shaft and the displacement restricting portion 70 is provided, it is possible to prevent the drive discharge roller 32 from being displaced downward due to foreign matter coming into contact with the drive discharge roller 32. Therefore, further entry of foreign matter can be prevented.

  In addition, by providing a sheet guide portion that guides the sheet conveyed toward the paper discharge portion, it is possible to provide a sheet discharge device that is capable of preventing foreign matter from entering and that is less likely to cause jamming. .

  Furthermore, by providing the cover 74 with the cover 66, it is possible to further prevent foreign matter from entering.

  In this embodiment, the number of ribs provided at the position facing the roll is two, but is not limited to this, and the number of ribs may be increased or decreased according to the length of the roll. By doing so, entry of foreign matter can be prevented more appropriately.

  Further, the rib 68 and the displacement restricting portion 70 are not limited to the present embodiment, and may be applied to the driven discharge roller 34. Alternatively, the drive discharge roller 32 and the driven discharge roller 34 may be combined.

  Further, the shape of the displacement restricting portion 70 is not limited to the present embodiment, and may be any other shape as long as it has a function of restricting the downward displacement of the drive roller 32. Further, the ribs 68f, 68g, and 68h may be configured to have a function for preventing the discharged sheet from being rounded.

1 is an overall view of an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view of a sheet discharge device according to a first embodiment of the present invention. It is a front view of the sheet discharging apparatus according to the first and second embodiments of the present invention. 1 is a side cross-sectional view of a sheet discharge device according to a first embodiment of the present invention. It is side surface sectional drawing of the sheet discharge apparatus which concerns on the 2nd Embodiment of this invention. It is side surface sectional drawing of the sheet discharge apparatus which concerns on the 2nd and 3rd embodiment of this invention. It is a perspective view of the sheet discharge apparatus which concerns on the 4th Embodiment of this invention. It is side surface sectional drawing of the sheet discharge apparatus which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 14 Paper feeder 16 Paper discharge part 18 Paper tray 20 Feed roll 22 Rolling roll 24 Registration roller 26 Photosensitive unit 28 Transfer unit 30 Fixing apparatus 32 Drive discharge roller 32a First roll 32b First 2nd roll 32c 3rd roll 32d 4th roll 32e Rotating shaft 34 Followed discharge roller 36 Power supply unit 38 Control unit 40 Photoconductor 42 Charging device 44 Developing device 46 Static eliminating device 48 Cleaning device 50 Toner box 52 Toner supply unit 54 Toner Collection unit 56 Optical writing device 58 Support roll 60 Conveying belt 62 Transfer roll 64 Conveying path 66 Covers 68a to 68d Rib 70 Displacement restricting units 68e to 68g Rib 72 Sheet guide unit 74 Covering unit

Claims (5)

A discharge roller for discharging the sheet;
A cover covering the discharge roller;
Have
The cover is provided with a rib protruding toward the discharge roller toward the periphery of the discharge roller ,
The rib is a sheet discharge device having a displacement restricting portion extending to the vicinity of a lower portion of a rotation shaft constituting the discharge roller .   The sheet discharge device according to claim 1, wherein the rib protrudes toward the discharge roller so as to cover a part of a peripheral edge of the discharge roller. 3. The sheet discharge according to claim 1, wherein the rib has a sheet guide portion on the upstream side in the sheet conveyance direction of the discharge roller and having a smooth curve toward an insertion port into which the sheet is inserted into the discharge roller. apparatus. The cover sheet discharging device according to any one of claims 1 to 3, characterized in that it is formed to protrude toward the sheet discharge direction of the discharge roller. An image forming apparatus having a sheet discharging apparatus in accordance with claim 1 to 4.

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