JP2007308283A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of improving jam handling performance. <P>SOLUTION: A sheet stacking member 4 is turnably provided at a sheet stacking part 14 stacking sheets P. The sheets P stacked on the sheet stacking member 4 are brought into pressure contact with a sheet feeding means 7, and a separating member 8 is brought into pressure contact with the sheet feeding means 7 downstream of the sheet P in a sheet feeding direction to separate the sheet P fed by the sheet feeding means 7. At least one of pressure contact between the sheet feeding means 7 and separating member 8 and pressure contact between the sheet feeding means 7 and the sheets P stacked on the sheet stacking member 4 can be released interlocked with the opening operation of a door member 3 provided in an openable/closable manner at a device body 1A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to a configuration for processing a jammed sheet.

  Conventionally, as an image forming apparatus such as a copying machine or a printer, a process cartridge having a photosensitive drum, a charging roller, a developing roller and the like integrally provided in the apparatus main body is detachably arranged, and an image forming unit is configured by the process cartridge. There is something to do.

  FIG. 12 is a view showing a schematic configuration of a laser beam printer as an example of a conventional image forming apparatus provided with such a process cartridge. In FIG. 12, G is a process cartridge. In addition to the image forming unit 105 configured by the process cartridge G, the laser beam printer includes a sheet feeding cassette 107 and a cassette feeding unit having a feeding roller 108 for feeding the sheet P stored in the sheet feeding cassette 107. A sending part C is provided.

  In addition, a multi-feed unit B having a manual feed tray 111 that can be opened and closed in the apparatus main body 120 and a multi-feed roller 112 that feeds sheets stacked on the manual feed tray 111 is provided.

  The manual feed tray 111 of the multi-feed unit B is loaded with sheets and is urged toward the multi-feed roller side by a biasing unit (not shown) so that the stacked sheets are pressed against the multi-feed roller 112. A moving intermediate plate 113 is provided so as to be rotatable in the vertical direction.

  The laser beam printer further includes a double-sided feeding unit D that feeds the sheet P having an image formed on one side thereof to the image forming unit 105 again.

  In FIG. 12, reference numeral 81 denotes a separation pad that presses against the multi-feed roller 112 to separate the sheets, and 116 denotes a skew of the sheet conveyed by the cassette feeding unit C, the multi-feed unit B, or the double-sided feeding unit D. It is a pair of registration rollers that are conveyed at a predetermined timing after correcting a row. Reference numeral 106 denotes a cartridge door that is opened and closed when the process cartridge G is attached or detached.

  In the laser beam printer having such a configuration, for example, when a sheet jam occurs, the cartridge door 106 is first opened as shown in FIG. 13, and then the process cartridge G is taken out from the apparatus main body 120. I am doing so. Then, by taking out the process cartridge G in this way, the sheet conveying surface is exposed and jam processing is performed.

  Further, when a jam occurs in the sheet conveyance path R for conveying the sheet P stored in the sheet feeding cassette 107 to the image forming unit 105, one roller 115a constituting the conveyance roller pair 115 shown in FIG. The provided transport unit 116a is pulled out. Then, by pulling out the conveyance unit 116a in this way, the sheet conveyance path R is opened and jam processing is performed.

  However, in the laser beam printer having the configuration shown in FIGS. 12 to 14, since the cassette feeding unit C, the multi feeding unit B, and the duplex feeding unit D are densely packed, the cartridge door 106 or the paper transport unit 116a is opened. Even then, only a part of the sheet conveying path R can be accessed.

  Therefore, the multi-feed section B is rotated integrally with the cartridge door 106 so that the almost entire area of the sheet transport path R from the cassette feeding section to the vicinity of the multi-feed section can be opened. Some are open (see, for example, Patent Document 1).

  For example, FIG. 15 shows a conventional laser beam printer configured as described above. By rotating the multi-feed unit B integrally with the cartridge door 106 as shown in FIG. The sheet conveyance path R can be opened. This improves the visibility of the jam sheet and simplifies the jam handling operation.

Japanese Patent Application Laid-Open No. 7-215531

  By the way, in the conventional image forming apparatus in which the multi-feed unit B is rotated integrally with the cartridge door 106 in this way, the sheet may jam in the multi-feed unit B.

  Such a sheet jam may occur between the sheet separation portion including the multi-feed roller 112 and the separation pad 113a and the nip portion on the conveyance path on the laser beam printer main body side, for example, the registration roller pair 116. is there. Further, there may occur between the pressure roller contact portion with the sheet on the intermediate plate 113 of the multi-feed roller 112 and the registration roller pair 116.

  Here, when the sheet jams so as to straddle such a position, that is, between the multi-feed unit B and the laser beam printer main body, the cartridge door 106 is to be opened integrally with the multi-feed unit B. The sheet is pulled by the laser beam printer body. As a result, the cartridge door 106 is difficult to open, and jam handling performance is reduced.

  Accordingly, the present invention has been made in view of such a current situation, and an object of the present invention is to provide an image forming apparatus capable of improving jam handling performance.

  The present invention provides an image forming apparatus including an image forming unit that forms an image on a sheet fed from a sheet feeding unit provided on a side surface of the apparatus main body, wherein the sheet feeding unit is a sheet on which sheets are stacked. A stacking unit; a sheet feeding unit that feeds the sheet; a sheet stacking member that is rotatably provided on the sheet stacking unit and presses the stacked sheet against the sheet feeding unit; and the sheet stacking member A separation member that presses against the sheet feeding unit downstream of the stacked sheets in the sheet feeding direction and separates the sheet fed by the sheet feeding unit, and is openable and closable to the apparatus main body. And a pressure contact between the sheet feeding means and the separating member and a pressure contact between the sheet feeding means and the sheets stacked on the sheet stacking member in conjunction with the opening operation of the door member. of Characterized in that so as to release the one even without.

  As in the present invention, at least one of the pressure contact between the sheet feeding means and the separation member and the pressure contact between the sheet feeding means and the sheets stacked on the sheet stacking member is released in conjunction with the opening operation of the door member. By doing so, the jam handling property can be improved.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a laser beam printer as an example of an image forming apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer, 1A denotes a laser beam printer main body (hereinafter referred to as a printer main body), and 1B denotes an image forming unit. A sheet feeding apparatus 1C is disposed below the image forming unit 1B. Yes. Further, a manual sheet feeder 1D constituting a sheet feeding unit is disposed on the side surface of the printer main body 1A.

  Here, the image forming unit 1B is detachably attached to the printer main body 1A, and includes a process cartridge G including a photosensitive drum 6, a charging roller 6a, a developing roller 3A, a cleaning unit 4a, and a toner storage unit 5. ing. The image forming unit 1B includes a laser scanner 12 that exposes the surface of the photosensitive drum 6 to form an electrostatic latent image on the photosensitive drum.

  The charging roller 6a is a charging unit that uniformly charges the surface of the photosensitive drum 6, and the developing roller 3A attaches toner to the electrostatic latent image formed by the laser scanner 12 and visualizes it as a toner image. Developing means. The cleaning unit 4a removes the toner remaining on the surface of the photosensitive drum 6 after the toner image is transferred.

  The sheet feeding apparatus 1C is provided below the printer main body 1A, and a paper feeding cassette 50 that is detachably attached to the printer main body 1A, and a feeding roller 7 that feeds the sheets P on the paper feeding cassette one by one. And.

  Here, the sheet feeding cassette 50 pushes up the intermediate plate 51 by a pressing means such as a spring (not shown), and presses the sheets P stacked on the intermediate plate 51 against the multi-feed roller 7 to cause friction between them. It is configured to generate force. In addition, the paper feed cassette 50 includes a separation pad 52 that is pressed by a pressing spring 53 and pressed against the multi-feed roller 7.

  The manual sheet feeding device 1D is a multi-tray 14 that is a sheet stacking unit that is rotatably attached to the side wall surface of the printer main body 1A and a sheet feeding member that sends out the sheets P stacked on the multi-tray 14. A multi-feed roller 7 and an intermediate plate 4 are provided.

  The middle plate 4 serving as a sheet stacking means for stacking the sheets P is provided so as to be rotatable in the vertical direction, and is lifted by a feeding cam shown in FIG. 7 to be in pressure contact. Further, the multi-feed roller 7 is attached by a spring (not shown) on the downstream side in the sheet feed direction of a pressure contact portion (hereinafter referred to as a middle plate nip portion) with the sheet P on the middle plate 4 of the multi-feed roller 7. The separated separation pad 8 is in pressure contact.

  Further, the intermediate plate 4 is lowered to the original position when the sheet P is fed by the rotation of the multi-feed roller 7 as will be described later, so that the pressure contact of the sheet P to the multi-feed roller 7 is released. It has become. As a result, the sheet P that has started to be moved is separated and sent out by the separation pad 8 only on the uppermost side.

  In FIG. 1, reference numeral 5a denotes a transfer portion. The transfer portion 5a includes a photosensitive drum 6 and a transfer roller 5 that presses against the photosensitive drum 6 to form a transfer nip.

  Next, an image forming operation in the laser beam printer 1 configured as described above will be described.

  When the image forming operation is started, the photosensitive drum 6 first rotates in the direction of the arrow, and is uniformly charged to a predetermined polarity and a predetermined potential by a charging roller 6a fed from a high voltage power source (not shown). Then, the laser beam L reflected from the laser scanner 12 on the basis of the image information is irradiated to the photosensitive drum 6 whose surface has been charged, whereby an electrostatic latent image is formed on the photosensitive drum.

  Next, the electrostatic latent image is developed by supplying toner that has been appropriately charged with the rotation of the developing roller 3A onto the photosensitive drum 6 and attached to the electrostatic latent image, and visualized as a toner image. Is done.

  On the other hand, in parallel with such a toner image forming operation, in the sheet feeding unit 1C, the sheet P stored in the sheet feeding cassette 50 is fed by the feeding roller 7a. In the manual sheet feeder 1D, the sheets P stacked on the multi-tray 14 are fed by the multi-feed roller 7.

  Here, when the sheets P stacked and stored in the sheet feeding cassette 50 are fed, the sheets P are separated one by one by the separation pad 52 that is in pressure contact with the feeding roller 7, and thereafter the sheet conveyance path R. And then conveyed to the registration roller pair 20. In addition, when the sheet P stacked on the multi-tray 14 is fed in the manual sheet feeding device 1D, the sheet P is first separated by the separation pad 8 which is a separation member that is pressed against the multi-feed roller 7. Thereafter, the sheet is conveyed to the registration roller pair 20.

  Next, the sheet P conveyed from the sheet feeding unit 1 </ b> C or the manual sheet feeding device 1 </ b> D to the registration roller pair 20 is corrected for skew in the registration roller pair 20. Thereafter, the pair of registration rollers 20 is conveyed to the transfer unit 5a at a timing so that the leading edge of the sheet P coincides with the leading edge of the toner image formed on the surface of the photosensitive drum 6.

  Then, the toner image on the surface of the photosensitive drum 6 is transferred by the transfer roller 5 to the sheet P thus conveyed to the transfer unit 5a. The untransferred toner remaining on the photosensitive drum 6 without being transferred is stored in a waste toner container (not shown) by the cleaning unit 4a. Then, the photosensitive drum 6 whose surface has been cleaned repeatedly enters the next image forming process.

  Next, the sheet P to which the toner image has been transferred is conveyed to the fixing device 9 where heat and pressure are applied to fix the toner image on the sheet P. Thereafter, the sheet P on which the toner image is fixed is conveyed to the discharge roller pair 17 by the conveyance roller pair 16 disposed in the sheet conveyance downstream portion of the fixing device 9, and the discharge roller pair 17 of the printer main body 1 </ b> A. The paper is discharged onto a paper discharge unit 18 provided at the top.

  By the way, as shown in FIG. 3, the manual sheet feeding device 1 </ b> D is in contact with a middle plate 4 on which sheets are stacked and rotatable in the vertical direction, and a cam follower unit 41 provided integrally with the middle plate 4. A feeding cam 71 that rotates the middle plate 4 in the vertical direction is provided. FIG. 3 shows a state in which the intermediate plate 4 is held by the feeding cam 71 at a home position where the sheet P and the multi-feed roller 7 are separated from each other. At this time, the multi-feed roller 7 arranged coaxially with the feed cam 71 remains at the home position.

  On the other hand, when a power supply (not shown) is turned on and a paper feed signal is sent, the solenoid 43 is turned on accordingly, and when the plunger 41a is sucked in the on direction, the stopper 41b locked to the toothless gear 44 is stopped. Comes off. As a result, the feeding cam 71, which receives the force in the direction of the arrow through the cam follower 41 by the biasing means 42, rotates in the direction of the arrow Y, and accordingly, the missing gear 44 arranged coaxially is not shown. It meshes with an idler gear 45 that transmits the driving force from the driving source. As a result, the driving force is transmitted to the toothless gear 44, the multi-feed roller 7 arranged on the same axis also rotates, and the sheet feeding operation is started.

  At this time, the cam 71 rotates integrally with the multi-feed roller 7 in the direction of the arrow Y, whereby the intermediate plate 4 is pushed up to the feed position where the sheet P contacts the multi-feed roller 7 by the urging means 42. . Then, after the intermediate plate 4 is pushed up to such a position, sheet feeding by the multi-feed roller 7 is started.

  The sheet P fed by the multi-feed roller 7 in this way is fed to the separation pad 8 and only one uppermost sheet is separated and fed, and the transfer composed of the transfer roller 5 and the photosensitive drum 6 is performed. It is sequentially conveyed to the part 5a. During this time, the solenoid 43 is turned off, the plunger 41a moves in the off direction, and the stopper 41b meshes with the missing gear 44, whereby the rotation operation of the multi-feed roller 7 stops. By such one-rotation control of the multi-feed roller 7, the sheet feeding operation is repeatedly performed.

  1 and 2, reference numeral 3 denotes a cartridge door that can be opened and closed to the printer main body 1A, and is a door member for attaching and detaching the process cartridge G. When a sheet jam occurs in the printer main body 1A, first, The cartridge door 3 is opened.

  Here, in this embodiment, when the cartridge door 3 is opened in this manner, the pressure contact of the separation pad 8 against the multi-feed roller 7 is released, and the urging force of the intermediate plate 4 in the direction of the paper feed roller is reduced. Is configured to do.

  Next, the pad pressure releasing means for releasing the pressure contact of the separation pad 8 will be described.

  FIG. 4 is a diagram showing the configuration of such pad pressure releasing means, and FIG. 5 is a perspective view showing the configuration of the pad pressure releasing means. 4 is a view of the manual sheet feeding device 1D viewed from the direction of arrow C in FIG.

  4 and 5, reference numeral 83 denotes a slide member that can move the separation pad 8 in a direction in which the separation pad 8 contacts and separates from the multi-feed roller 7, 82 denotes a lever that is pressure release means that can move in the axial direction, and 84 denotes the separation pad 8 Separating pad pressurizing means provided between the lever 82 and the lever 82. The separation pad 8 includes a separation pad rubber portion 8a and a separation pad rubber holding portion 8b.

  Reference numeral 13 denotes a side plate fixed to the printer main body 1 </ b> A. An inner wall surface 13 a of the side plate 13 is provided with a recess 13 b. In the present embodiment, the recess 13b is provided on the inner wall surface 13a, but a hole may be provided.

  Here, the slide member 83 is brought into pressure contact with the lever 82 movable in the axial direction, that is, in the directions of the arrows D1 and D2, and the first and second contact portions 82b1 which are first and second holding portions having steps are provided. , 82b2 are formed in the axial direction.

  FIG. 4 shows a state when the cartridge door 3 is closed. At this time, the lever 82 is in a state of moving in the direction D2. When the lever 82 moves in this manner, the bottom surface 83a of the slide member 83 comes into pressure contact with the first contact portion 82b1 that is one step higher than the second contact portion 82b2.

  As a result, the slide member 83 moves to the multi-feed roller side indicated by the arrow E2 while being urged by the separation pad pressurizing means 84, and the separation pad 8 (the separation pad rubber portion 8a) moves along with the movement of the slide member 83. The multi-feed roller 7 is pressed against and a separation nip is formed. When the separation pad 8 is pressed against the multi-feed roller 7 as described above and a jam occurs in the separation nip, the jammed sheet is sandwiched in the separation nip.

  In FIG. 4, reference numeral 85 denotes urging means, and the lever 82 is urged toward the side plate 13 by the urging means 85. When the lever 82 is moved in the D2 direction, that is, when the cartridge door 3 is closed, the lever 82 always receives the applied pressure in the D1 direction by the urging means 85. Thereby, the front-end | tip 82a is press-contacted to positions other than the recessed part 13b of the side plate 13 which is a contact part.

  On the other hand, for example, when the manual sheet feeder 1D is opened as shown in FIG. 1 and a jam occurs in the manual sheet feeder 1D with sheets P stacked on the multi-tray 14, the cartridge door 3 is opened for processing. Is done.

  Here, when the cartridge door 3 is thus opened, the manual sheet feeder 1D is pushed downward by a link member (not shown), and as a result, the multi-feed roller 7 (and the lever 82) as shown in FIG. ) Also moves downward. When the lever 82 moves downward in this way, the tip 82a of the lever 82 moves in the direction of the recess 13b along the side plate 13 shown in FIG. 4, and eventually enters the recess 13b by the pressure applied by the biasing means 85. .

  Here, when the tip 82a of the lever 82 enters the recess 13b in this way, the lever 82 moves in the D1 direction. As a result, the second contact portion 82b2 that has been in contact with the bottom surface 83a of the slide member 83 and has been held at the position where the separation pad 8 is pressed against the multi-feed roller 7 is moved.

  Accordingly, the slide member 83 moves in the direction indicated by the arrow E1 shown in FIG. 5 while being urged by the separation pad pressurizing means 84, and slides to the second contact portion 82b2 that is one step lower than the first contact portion 82b1. The bottom surface 83a of the member 83 abuts.

  As the slide member 83 moves in this manner, the separation pad 8 is held at a position where the pressure contact with the multi-feed roller 7 is released. As a result, the pressure applied to the separation pad 8 by the separation pad pressurizing means 84 is reduced by the level difference between the first and second contact portions 82b1 and 82b2, and the separation nip pressure is reduced. Alternatively, the separation pad 8 is separated from the multi-feed roller 7 and the separation nip is opened by Δ1 shown in FIG.

  As described above, when the cartridge door 3 is opened, the separation nip pressure is reduced or the separation nip is opened, so that the sheet generated in the separation nip portion can be easily pulled out. Jam handling is improved.

  Next, biasing force reducing means for reducing the biasing force of the intermediate plate 4 in the direction of the paper feed roller will be described.

  In FIGS. 1 and 2, reference numeral 31 denotes an arm which is a pressing member for releasing the pressure contact between the sheet P stacked on the middle plate 4 of the multi-feed unit 1 </ b> D and the multi-feed roller 7 when the cartridge door 3 is opened and closed. This arm portion 31 is provided integrally with the cartridge door 3. Here, by providing the arm portion 31 integrally with the cartridge door 3 as described above, when the cartridge door 3 is opened with the sheets stacked on the middle plate 4 as shown in FIG. 4 is pressed from above.

  Then, by pressing the intermediate plate 4 from above, the applied pressure of the intermediate plate 4 is gradually released. As a result, the sheet P stacked on the intermediate plate 4 is separated from the multi-feed roller 7 by Δ2. To do. That is, when the cartridge door 3 is opened, the middle plate nip portion is opened, and the multi-feed roller 7 can be separated from the sheets P stacked on the middle plate 4.

  As described above, when the cartridge door 3 is opened, the multi-feed roller 7 is separated and the middle plate nip portion is opened so that the sheet generated at the middle plate nip portion can be easily pulled out. Thus, the jam handling property is improved.

  As described above, according to the present embodiment, when the cartridge door 3 is opened, the separation nip can be opened (or the separation nip pressure is reduced), and the intermediate plate nip portion can be opened. As a result, it is possible to open the sheet conveyance path R in a wider range than before, and it is possible to easily pull out the sheets generated in the separation nip portion and the middle plate nip portion, thereby improving the jam handling performance.

  Further, even when a jam occurs between the manual sheet feeding device 1D and the printer main body, the middle plate nip portion and the separation nip portion can be opened, so that a jammed sheet remains on the printer main body side. The cartridge door 3 can be opened. Thereby, opening of the door 3 becomes easy and jam handling property can be improved.

  Further, with this configuration, even when the jam processing is performed while the sheet P is set in the manual sheet feeding device 1D, the unpleasant feeling of applying extra force to pull out the jammed sheet is reduced. be able to. Further, it is possible to prevent the sheet from being damaged and remaining in the printer main body caused by applying an excessive force.

  In the above description, the case where the pressure contact of both the separation nip and the middle plate nip portion is released in conjunction with the opening operation of the cartridge door 3 has been described. However, when one of the separation nip and the middle plate nip portion has a nip pressure that does not hinder the opening of the cartridge door 3, the pressure contact of at least the other nip portion may be released. That is, the pressure contact of one of the separation nip portion and the intermediate plate nip portion may be released in conjunction with the opening operation of the cartridge door 3.

  Next, the second and third embodiments of the present invention in which one pressure contact of the separation nip portion and the intermediate plate nip portion is released will be described.

  FIG. 7 is a view of the state in which the cartridge door 3 of the laser beam printer as an example of the image forming apparatus according to the second embodiment of the present invention is opened, as viewed from the direction of arrow C in FIG. FIG. 8 is a perspective view showing the configuration of the pad pressure releasing means.

  7 and 8, reference numeral 182 denotes a lever movable in the axial direction, and the lever 182 is movable in the axial direction, that is, in the directions of arrows D1 and D2. The slide member 83 is pressed against the lever 182 and first and second contact portions 182b1 and 182b2 having steps are formed in the axial direction.

  Here, when the cartridge door 3 is in a closed state, the lever 182 moves in the D2 direction so that the bottom surface 83a of the slide member 83 is in pressure contact with the first contact portion 82b1 that is one step higher than the second contact portion 82b2. It has become. Then, when the bottom surface 83a of the slide member 83 is in pressure contact with the first contact portion 182b1, the separation pad 8 (the separation pad rubber portion 8a) is in pressure contact with the multi-feed roller 7 to form a separation nip.

  In FIG. 7, reference numeral 185 denotes urging means, and the urging means 185 urges the lever 182 to the D1 side. When the cartridge door 3 is in a closed state, the tip 182a of the lever 182 urged to the D1 side by the urging means 185 is a contact provided on the printer main body 1A side as shown by a broken line in FIG. The contact member 23 is in pressure contact. Then, the tip 182 a of the lever 182 is in pressure contact with the contact member 23 in this way, so that the lever 182 is held at a position where the separation pad 8 is in pressure contact with the multi-feed roller 7.

  On the other hand, when the cartridge door 3 is opened, the manual sheet feeder 1D is pushed downward by a link member (not shown), and the multi-feed roller 7 and the lever 182 are also moved downward. When the lever 182 moves downward in this way, the tip 182a of the lever 182 moves along the contact member 23 and eventually comes off the contact member 23 as shown by the solid line.

  Here, when the lever 182 is released from the contact member 23 in this way, the lever 182 moves in the D1 direction, thereby contacting the bottom surface 83a of the slide member 83 and pressing the separation pad 8 against the multi-feed roller 7 until then. The second contact portion 182b2 held at the position moves. As a result, the bottom surface 83a of the slide member 83 contacts the second contact portion 182b2 that is one step lower than the first contact portion 182b1.

  As the slide member 83 moves in this manner, the separation pad 8 is held at a position where the pressure contact with the multi-feed roller 7 is released. As a result, the pressure applied to the separation pad 8 by the separation pad pressurizing means 84 is reduced by the level difference between the first and second contact portions 182b1 and 182b2, and the separation nip pressure is reduced. Alternatively, the separation pad 8 is separated from the multi-feed roller 7 and the separation nip is opened by Δ1 shown in FIG.

  After that, when the cartridge door 3 is closed, the manual sheet feeder 1D is rotated in the direction opposite to the arrow direction in FIG. 9 by a link member (not shown). Accordingly, the lever end 182a abuts on the protrusion 23 and is then pushed in the direction of the arrow D1, and the lever 182 stops at a position in contact with the inner wall surface 23a of the protrusion 23.

  Thus, by opening the cartridge door 3, the separation nip pressure can be reduced, or the separation nip portion can be opened. As a result, when the nip pressure at the intermediate plate nip portion is such that the opening of the cartridge door 3 is not hindered, the user can easily pull out the sheet generated at the separation nip portion, and the jam handling performance is improved. . Further, the cartridge door 3 can be easily opened even when the sheet is jammed between the manual sheet feeding device 1D and the printer main body 1A.

  FIG. 10 is a diagram showing a schematic configuration of a laser beam printer which is an example of an image forming apparatus according to the third embodiment of the present invention. 10, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  In FIG. 10, 104 is an intermediate plate, 104a is an arm portion that is a pressing member for opening the intermediate plate nip of the multi-feed portion 1D in accordance with opening and closing of the cartridge door 3, and this arm portion 104a is connected to the intermediate plate 104. They are arranged in one piece.

  Then, by providing the arm portion 104a integrally with the intermediate plate 104 in this way, when the cartridge door 3 is opened in a state where the sheet P is stacked on the intermediate plate 104, the arm portion 104a is pressed by the cartridge door 3 and is Rotate to. Thereby, the pressurizing force of the intermediate plate is gradually released.

  As a result, the sheet P stacked on the intermediate plate 4 is separated from the multi-feed roller 7 by Δ2. That is, when the cartridge door 3 is opened, the middle plate nip portion is opened, and the multi-feed roller 7 can be separated from the sheets P stacked on the middle plate 4.

  As described above, when the cartridge door 3 is opened, the multi-feed roller 7 is separated and the middle plate nip portion is opened so that the sheet generated at the middle plate nip portion can be easily pulled out. Thus, the jam handling property is improved. Further, the cartridge door 3 can be easily opened even when the sheet is jammed between the manual sheet feeding device 1D and the printer main body 1A.

  In the above description, the configuration for reducing the separation pad pressure or the like based on the opening of the cartridge door 3 has been extended, but the present invention is not limited to this. The separation pad pressure or the like may be reduced based on the opening of a door provided for purposes other than the attachment / detachment of the process cartridge G.

1 is a diagram showing a schematic configuration of a laser beam printer as an example of an image forming apparatus according to a first embodiment of the present invention. The figure which shows a state when not using the multi feeding part of the said laser beam printer. The figure explaining the drive mechanism of the said multi feeding part. The 1st figure which shows the structure of the pad pressure release means of the said multi feeding part. The 2nd figure which shows the structure of the pad pressure release means of the said multi feeding part. The figure which shows a state when the cartridge door of the said laser beam printer is open | released. The principal part enlarged view which shows the state when the cartridge door of the laser beam printer which is an example of the image forming apparatus which concerns on the 2nd Embodiment of this invention is open | released. The 1st figure which shows the structure of the pad pressure release means of the said multi feeding part. The 2nd figure which shows the structure of the pad pressure cancellation | release means of the said multi feeding part. FIG. 6 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus according to a third embodiment of the present invention. The figure which shows a state when the cartridge door of the said laser beam printer is open | released. 1 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of a conventional image forming apparatus. FIG. 6 is a first diagram illustrating a jam processing method of the conventional laser beam printer. FIG. 6 is a second diagram for explaining a jam processing method of the conventional laser beam printer. The figure which shows a state when the cartridge door of the said other conventional laser beam printer is open | released.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 1A Printer main body 1B Image formation part 1D Manual paper feeder 3 Cartridge door 4 Middle board 7 Multi feed roller 8 Separation pad 13 Side board 13b Recess 14 Multi tray 23 Contact member 31 Arm part 82 Lever 84 Separation pad addition Pressure means 82b1 First contact portion 82b2 Second contact portion 104 Middle plate 104a Arm portion 182 Lever 182b1 First contact portion 182b2 Second contact portion G Process cartridge P Sheet R Sheet conveyance path

Claims (9)

In an image forming apparatus including an image forming unit that forms an image on a sheet fed from a sheet feeding unit provided on a side surface of the apparatus main body,
The sheet feeding unit is provided with a sheet stacking unit for stacking sheets, a sheet feeding unit for feeding sheets, and a rotatable sheet on the sheet stacking unit, and the stacked sheets are used as the sheet feeding unit. A sheet stacking member to be brought into pressure contact, and a separation member that presses the sheet feeding unit downstream of the sheets stacked on the sheet stacking member and separates the sheets fed by the sheet feeding unit And having
A door member provided on the apparatus main body so as to be freely opened and closed,
In conjunction with the opening operation of the door member, at least one of the pressure contact between the sheet feeding means and the separation member and the pressure contact between the sheet feeding means and the sheets stacked on the sheet stacking member is released. An image forming apparatus. Means for releasing the pressure contact between the sheet feeding means and the separating member in conjunction with the opening operation of the door member;
Provided in the sheet feeding section, moved to a position where the pressure contact of the separation member with the sheet feeding means is released in conjunction with the opening operation of the door member, and in conjunction with the closing operation of the door member A pressure contact release means for moving the separation member to a position for pressure contact with the sheet feeding means;
Provided in the apparatus main body, and when the door member is closed, holds the pressure contact releasing means in contact with the pressure release means, and holds the separation member in pressure contact with the sheet feeding means. The image forming apparatus according to claim 1, wherein when released, the pressure contact release unit is configured to include a contact member that moves the separation member to a position for releasing the pressure contact with the sheet feeding unit. apparatus. The pressure release unit is formed with a first holding unit that holds the separation member at a position where the separation member is pressed against the sheet feeding unit, and a step with respect to the first holding unit. A second holding unit that holds the pressure contact with the sheet feeding unit at a position where the pressure contact is released,
The abutting member holds the pressure release means at a position where the first holding portion faces the separating member when the door member is closed, and the second holding portion when the door member is opened. The image forming apparatus according to claim 2, wherein the image forming apparatus is configured to be movable to a position facing the separating member.   The pressure contact releasing means is a shaft member in which the first holding portion and the second holding portion are formed in the axial direction, and the contact member is configured to disengage the pressure contact releasing means when the door member is closed. A contact portion that contacts the pressure contact release means so that the first holding portion is held at a position facing the separation member, and the pressure contact release means when the door member is opened, the second holding portion. The image forming apparatus according to claim 3, further comprising a recess for moving to a position facing the separating member.   The pressure contact releasing means is a shaft member in which the first holding portion and the second holding portion are formed in the axial direction, and the contact member is configured to disengage the pressure contact releasing means when the door member is closed. An abutting portion that abuts against the pressure release means so that the first holding portion is held at a position facing the separating member, and is in non-contact with the pressure release means when the door member is opened. The image forming apparatus according to claim 3, wherein the pressure release unit is moved to a position where the second holding unit faces the separation member.   The means for releasing the pressure contact between the sheet feeding means and the sheets stacked on the sheet stacking member in conjunction with the opening operation of the door member is provided on the door member, and the door member is opened. 6. The pressing member according to claim 1, wherein the pressing member is pressed against the sheet stacking member and rotates the sheet stacking member in a direction away from the sheet feeding unit. Image forming apparatus.   Means for releasing the pressure contact between the sheet feeding means and the sheets stacked on the sheet stacking member in conjunction with the opening operation of the door member is provided on the sheet stacking member, and the door member is opened. The pressing member according to any one of claims 1 to 5, wherein the pressing member is pressed by the door member and rotates the sheet stacking member in a direction away from the sheet feeding unit. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the sheet feeding unit is provided on a side surface of the apparatus main body so as to be rotatable in the vertical direction. The image forming apparatus according to claim 1, wherein the door member is opened and closed when a process cartridge provided in the image forming unit is attached and detached.

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