JP2007219179A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which enhances sheet processability and making small a space in the upper part of an apparatus body. <P>SOLUTION: A multiple manual feeding device M is turnably provided in the apparatus body 51, and integrally provided on a path member 9 constituting a sheet conveying path Q conveying a sheet P fed from a sheet feeding part C to an image forming part 52. When attaching/detaching an image forming means G, the multiple manual feeding device M is made to retreat interlocked with the opening of a door 6 turnably provided in the apparatus body 51, and the sheet conveying path Q is opened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus (process cartridge) that is detachably provided.

  Conventionally, as an image forming apparatus such as a copying machine or a printer, a process cartridge, which is an image forming means integrally provided with a photosensitive drum, a charging roller, a developing roller, etc., is detachably arranged in the apparatus main body. Some image forming units are configured.

  FIG. 6 is a diagram showing a schematic configuration of a laser beam printer which is an example of a conventional image forming apparatus provided with such a process cartridge. In FIG. 6, 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 sheet feeding roller 108 that feeds the sheet P stored in the sheet feeding cassette 107. A sheet feeding device C is provided.

  Further, a multi-manual feeding device M having a multi-tray 111 arranged to be openable and closable on the apparatus main body 120 and a sheet feeding roller 112 for feeding the sheets P stacked on the multi-tray 111 is provided. Further, a double-sided feeding device D that re-feeds the sheet P fed from the paper discharge unit 121 by the double-sided conveyance roller 119 to the image forming unit 105 by the re-feed roller 123 is provided. In FIG. 6, reference numeral 106 denotes a cartridge door that is opened and closed when the process cartridge G is attached or detached.

  Here, in the laser beam printer having such a configuration, for example, the sheet P fed from the sheet feeding device C passes through the reverse conveyance path Q and is guided to the registration roller pair 113. Further, the sheet P fed from the multi-manual feeding device M is directly guided to the registration roller pair 113. Further, the sheet P conveyed from the duplex feeding device D passes through the reverse conveyance path R and is guided to the registration roller pair 113.

  The sheet P thus fed from any one of the sheet feeding device C, the multi-manual feeding device M, and the duplex feeding device D and guided to the registration roller pair 113 is thereafter registered to the registration roller pair 113. As a result, the skew is corrected. Further, after that, it is conveyed to the image forming unit 105 by the registration roller pair 113 at a predetermined timing, and an image is formed.

  By the way, in this laser beam printer, the jam processing mechanisms of the process cartridge G, the sheet feeding device C, and the duplex feeding device D are provided independently. That is, when a jam (paper jam) occurs in the process cartridge G and the registration roller pair 113, the cartridge door 106 is opened upward as shown in FIG. Then, after the process cartridge G is taken out from the opening J1 formed by opening the cartridge door 106 in this way, the jam processing is performed.

  Further, when a jam occurs in the reverse conveyance path Q and the refeed path R, the jam is caused from the opening J2 formed by removing the sheet feeding cassette 107 from the apparatus main body 120 and opening the sheet feeding apparatus C. The sheet is taken out.

  In addition, as a configuration for such a jam processing, there is another configuration in which the multi-manual feeding device M and the reversing guide 124 are integrally configured as a door unit. When a jam occurs, only the door unit is rotated to open a sheet reverse conveyance path so as to secure a jam processing space (for example, Patent Document 1 and Patent Document 2). reference).

Japanese Patent Application Laid-Open No. 7-215531 No. 2-15881

  By the way, in a conventional image forming apparatus such as a laser beam printer, the opening / closing of the cartridge door 106 and the operation of the sheet feeding device C and the multi-manual feeding device M can be performed from the same direction from the viewpoint of usability including installation space. It is desirable to make it.

  Here, when the cartridge door 106 is opened and closed in one direction, for example, from the side of the apparatus main body 120, the multi-manual feeding apparatus M is avoided when the process cartridge G is attached and detached as shown in FIG. The opening J1 needs to be formed in the upper part of the apparatus main body 120. However, when the opening J1 is formed in the upper part of the apparatus main body 120 in this way, the cartridge door 106 must be opened upward. In this case, a space for opening and closing the door is required above the apparatus main body 120.

  On the other hand, if a jam occurs in the process cartridge G and the registration roller pair 113, the cartridge door 106 is opened and the process cartridge G is removed as described above, and then the jammed sheet is removed from the upper opening J1. Like to do. Further, when a jam occurs in the reverse conveyance paths Q and R, the sheet feeding device C is opened, and the jam sheet is removed from the lower opening J2.

  However, when different operations are performed according to the place where the jam occurs, it takes time to find the jam sheet. Further, the jam processing from below has poor visibility, the jam processing work is troublesome, and the sheet processing performance is low.

  In the case of Patent Document 1 and Patent Document 2, the jammed sheet is removed by opening the door unit, but also in this case, a different operation is performed depending on the place where the jam occurs. Similarly, it takes time to find a jam sheet.

  Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide an image forming apparatus capable of improving sheet processability and reducing the space above the apparatus main body. It is what.

  The present invention includes an image forming unit having an image forming unit that is detachably attached to the apparatus main body, a first sheet feeding unit that supplies a sheet to the image forming unit, and the first sheet feeding unit. A sheet conveying path that guides the supplied sheet to the image forming unit, a second sheet feeding unit that joins the sheet conveying path and supplies the sheet to the image forming unit, and the second sheet feeding A path member constituting the sheet conveyance path, and adjacent to the second sheet feeding section and rotatably provided in the apparatus main body, and the image forming means is disposed in the apparatus main body. A door that is opened for attachment and detachment, and in conjunction with the opening of the door, the second sheet feeding unit is retracted to a position where the image forming unit can be attached and detached, and the passage member moves. To open the sheet conveying path. And wherein the door.

  According to the present invention, when the image forming unit is attached / detached, the second feeding portion is retracted to a position that does not interfere with the attachment / detachment of the image forming unit in conjunction with the opening of the door to be opened. Space can be reduced. Further, by rotating the passage member in conjunction with the opening of the door to open the sheet conveyance passage, it is possible to improve sheet processing performance such as jamming.

  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 50 denotes a laser beam printer, 51 denotes a laser beam printer main body (hereinafter referred to as a printer main body), and 52 denotes an image forming unit. A first sheet feeding unit is configured below the image forming unit 52. A sheet feeding device C is disposed. Further, a multi-manual feeding device M constituting a second feeding unit is disposed on the side surface of the printer main body 51.

  In the present embodiment, a multi-manual feeding device has been described in which a user sets a plurality of sheets as a manual feeding device and sequentially feeds from the uppermost sheet. However, the present invention is not limited to this. For example, it may be a single sheet feeding device that sets sheets one by one.

  Here, the image forming unit 52 is configured by a process cartridge G that is detachably attached to the printer main body 51 and includes the photosensitive drum 1, the charging roller 2, the developing roller 3, the cleaning unit 4, and the toner storage unit 5. Has been. The image forming unit 52 includes a laser scanner S that exposes the surface of the photosensitive drum 1 to form an electrostatic latent image on the photosensitive drum.

  The charging roller 2 is a charging unit that uniformly charges the surface of the photosensitive drum 1, and the developing roller 3 attaches toner to the electrostatic latent image formed by the laser scanner S and is visualized as a toner image. Developing means. The cleaning unit 4 removes toner remaining on the surface of the photosensitive drum 1 after the toner image is transferred.

  The sheet feeding device C constituting the first sheet feeding unit is provided at the lower part of the printer main body 51, and also includes a paper feeding cassette 7 that is detachably attached to the printer main body 51, and a sheet P on the paper feeding cassette. And a sheet feeding roller 8a for feeding one sheet at a time. Here, the sheet feeding cassette 7 pushes up the middle plate 7a by a pressing means such as a spring (not shown), and presses the sheets P stacked on the middle plate 7a against the feeding roller 8a, thereby causing frictional force therebetween. Is configured to occur. The paper feed cassette 7 includes a separation pad 8 that is pressed by a pressing spring 8b and is in pressure contact with the feeding roller 8a.

  The multi-manual feeding apparatus M that constitutes the second sheet feeding unit includes a multi-tray 11 that is a sheet stacking unit that is rotatably attached to the side wall surface of the printer main body 51 with the rotation shaft 6a as a fulcrum. Yes. Further, a sheet feeding roller 12a that is a sheet feeding member that feeds the sheets P stacked on the multi-tray 11 and an intermediate plate 12d are provided. The sheet feeding roller 12a is in pressure contact with a separation pad 12b held by a support arm 12c urged by a spring 12f. The multi-tray 11 is provided with an extension tray 22.

  The intermediate plate 12d is provided so as to be rotatable in the vertical direction, and is lifted by a cam (not shown) so that the sheets P stacked on the multi-tray 11 are brought into pressure contact with the sheet feeding roller 12a. When the sheet P starts to move due to the rotation of the sheet feeding roller 12a, the intermediate plate 12d is lowered to the original position, and the pressure contact of the sheet P with the sheet feeding roller 12a is released. As a result, the sheet P that has started moving is separated and sent out by the separation pad 12b only on the uppermost side.

  In FIG. 1, reference numeral 14 a denotes a transfer portion. The transfer portion 14 a includes a photosensitive drum 1 and a transfer roller 14 that presses against the photosensitive drum 1 to form a transfer nip. Reference numeral 9 denotes a reversing guide constituting a reversing conveyance path Q which is a sheet conveying path for reversing and conveying the sheet P fed by the sheet feeding roller 8a, and 10a and 10b are an upper guide and a lower guide for guiding the conveyance of the sheet P. is there.

  Next, an image forming operation in the laser beam printer 50 configured as described above will be described.

  When the image forming operation is started, the photosensitive drum 1 first rotates in the direction of the arrow, and is uniformly charged to a predetermined polarity and a predetermined potential by a charging roller 2 fed from a high voltage power source (not shown). The photosensitive drum 1 whose surface has been charged is irradiated with laser light L reflected from the laser scanner S based on image information, 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 3 onto the photosensitive drum 1 and attached to the electrostatic latent image, and visualized as a toner image. Is done.

  On the other hand, in the sheet feeding device C in parallel with such a toner image forming operation, the sheet P is fed out by the sheet feeding roller 8a. In the multi-manual feeding apparatus M, the sheets S stacked on the multi-tray 11 are fed by the sheet feeding roller 12a.

  Here, when the sheets P stacked and stored in the sheet feeding cassette 7 are fed, the sheets P are separated one by one by the separation pad 8 that is pressed against the sheet feeding roller 12a. Thereafter, the pair of transport rollers 23 a and 23 b are transported on the reverse transport path Q formed between the reverse guide 9 and the lower guide 10 b and transported to the registration roller pair 13.

  In the multi-manual feeding apparatus M, when the sheets P stacked on the multi-tray 11 are fed, the sheets P are first separated by the separation pad 12b that is pressed against the sheet feeding roller 12a. Thereafter, the sheet is conveyed along a conveyance path formed between the upper guide 10 a and the lower guide 10 b and conveyed to the registration roller pair 13.

  Next, the sheet P conveyed from the sheet feeding device C or the multi-manual feeding device M to the registration roller pair 13 is corrected in skew in the registration roller pair 13. Thereafter, the pair of registration rollers 13 is transported to the transfer unit 14a with 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 1.

  Then, the toner image on the surface of the photosensitive drum 1 is transferred by the transfer roller 14 to the sheet P thus conveyed to the transfer unit 14a. The untransferred toner remaining on the photosensitive drum 1 without being transferred is stored in a waste toner container (not shown) by the cleaning unit 4. Then, the photosensitive drum 1 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 15, and heat and pressure are applied in the fixing device 15 to fix the toner image on the sheet P. Thereafter, the sheet P on which the toner image has been 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 15. The paper is discharged onto a paper discharge unit 18 provided at the top.

  By the way, the reversing guide 9 which is a passage member constituting a guide outside the reversing conveyance path Q is a sheet feeding roller 12a, a separation pad 12b, and a support arm 12c of the multi-manual feeding apparatus M located on the side of the process cartridge G. Also serves as a frame to hold. Further, it also serves as a frame for holding one of the pair of transport rollers 23a and 23b. The multi-manual feeding apparatus M provided with the reversing guide 9 is rotatably attached to the printer main body 51 around the rotation shaft 9a.

  In FIG. 1, reference numeral 6 denotes a CRG door which is a door for detachably mounting the process cartridge G to the printer main body 51. The CRG door 6 uses the rotary shaft 6 a of the multi-tray 11 as a fulcrum. It is attached to be able to rotate. The printer main body 51 is rotatably provided. When the process cartridge G is attached or detached, the opened CRG door 6 also serves as a front cover when the process cartridge G is closed.

  Here, the rotating shaft 6a of the CRG door 6 is provided separately from the rotating shaft 9a of the multi-manual feeding apparatus M, but the reversing guide 9 and the CRG door 6 are connected by a link (not shown). Thus, the reversing guide 9 is also opened and closed as the CRG door 6 is opened and closed.

  With this configuration, when the CRG door 6 and the printer main body 51 are disengaged by pulling the handle 6b of the CRG door 6 as shown in FIG. 2, the CRG door 6 moves the rotating shaft 6a. Rotate clockwise around the center. At this time, since the reversing guide 9 is connected to the CRG door 6 by a link (not shown), it moves in the direction of arrow b.

  Here, since the multi-manual feeding apparatus M rotates around a rotation shaft 9a different from the rotation shaft 6a of the CRG door 6, the sheet feeding roller 12a rotates downward, and the process cartridge G side is rotated. Retreat to a position where it can move in the direction. As the sheet feeding roller 12a rotates downward in this manner, the process cartridge G can be attached to and detached from the printer main body 51 side. In addition, the sheet feeding roller 12a thus pivots downward as described above, so that the space above the reverse conveying path Q can be widely opened, and sheet processing is facilitated.

  Further, the reverse conveyance path Q is opened when the reversing guide 9 provided integrally with the multi-manual feeding apparatus M is moved by the operation of the CRG door 6, so that the reversing conveyance path Q is opened to the CRG door 6. It becomes visible from the part J1. After that, by removing the process cartridge G, the transfer portion 14a and the fixing device 15 can also be seen from the opening J1 of the CRG door 6.

  That is, by opening the CRG door 6 or thereafter removing the process cartridge G, the reverse conveyance path Q, the transfer unit 14a, and the fixing device 15 can be seen from the opening J1 of the CRG door 6, and the jam sheet. Is easy to discover.

  Further, the reversing guide 9 is opened, so that the nip between the conveying roller pair 23a and 23b is opened, a space for jamming from the opening J1 of the CRG door 6 can be secured, and the paper feeding cassette 7 can be attached and detached. And jam handling work is possible. As described above, the jam handling work can be performed only by operating one CRG door 6.

  As described above, the space above the printer main body 51 is reduced by retracting the sheet feeding roller 12a to a position where the process cartridge G can be moved to the side in conjunction with the opening of the CRG door 6. it can. Further, by rotating the reversing guide 9 in conjunction with the opening of the CRG door 6 to open the reversing conveyance path Q, the sheet processability can be enhanced.

  That is, by simply opening the CRG door 6, the process cartridge G can be attached and detached and the reverse conveyance path Q can be opened at the same time, and the jam handling workability can be improved by specifying the jam location and improving the visibility of the sheet.

  Next, a second embodiment of the present invention will be described.

  FIG. 3 is a diagram showing a schematic configuration of a laser beam printer as an example of the image forming apparatus according to the present embodiment. The laser beam printer according to the present embodiment has a function capable of forming images on both sides of the sheet P. In FIG. 3, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  In FIG. 3, D is a double-sided feeding device that is a sheet re-conveying unit that again conveys a sheet with an image formed on one side to the image forming unit 52 in order to form images on both sides of the sheet P. In the laser beam printer provided with such a double-sided feeding device D, when images are formed on both sides of the sheet P, the sheet P fed from the paper feed cassette 7 or the multi-tray 11 is first registered with a registration roller. The pair 13 is conveyed to the transfer unit 14a.

  Next, when the sheet P passes through the transfer portion 14 a, the toner image on the surface of the photosensitive drum 1 is transferred, and thereafter, the sheet P is conveyed to the fixing device 15. When passing through the fixing device 15, heat and pressure are applied to fix the toner image.

  Next, the sheet P on which the toner image is fixed on the first surface as described above is conveyed by the forward rotation of the conveying roller pair 16 and the discharge roller pair 17. Thereafter, when the trailing edge of the sheet P passes through the fixing device 15, the sheet P is conveyed to the conveyance path 21 of the duplex feeding device D by reverse rotation of the conveyance roller pair 16 and the discharge roller pair 17 at a predetermined timing. Is done.

  Next, the sheet P is nipped by the double-sided conveyance roller pair 19 provided in the conveyance path 21, passes through the conveyance path 21, and is fed to a refeed path R that is a reconveyance path. At this time, the sheet P is reversed and the front and back sides are switched. The refeeding path R is formed by a reversing guide 9 that also serves as a reversing guide unit for the sheet P conveyed from the duplex feeding device D, a middle guide 10c, and a refeeding guide 10d. is there.

  Next, the sheet P reversed in the refeed path R is conveyed to the registration roller pair 13, and after the skew feeding is corrected in the registration roller pair 13, the sheet P is conveyed to the transfer unit 14 a by the registration roller pair 13. . Then, the toner image on the surface of the photosensitive drum 1 is transferred by the transfer roller 14 to the sheet P thus transported to the transfer unit 14 a, and then transported to the fixing device 15. Then, the toner image is fixed on the sheet P by applying pressure.

  Next, the sheet P on which the toner image is fixed in this way is conveyed to the paper discharge roller pair 17 by the conveyance roller pair 16 and is discharged onto the paper discharge unit 18 by the paper discharge roller pair 17.

  Next, jam processing of the laser beam printer 50 having such a configuration will be described.

  When a jam occurs in the printer main body 51, first, the handle 6b of the CRG door 6 shown in FIG. 3 is pulled to disengage the CRG door 6 from the printer main body 51. As a result, the CRG door 6 rotates clockwise about the rotation shaft 6a as shown in FIG. At this time, since the multi-manual feeding apparatus M is connected to the CRG door 6 by a link (not shown), it moves in the direction of arrow b shown in FIG.

  Here, since the multi-manual feeding apparatus M rotates around a rotation shaft 9a different from the rotation shaft 6a of the CRG door 6, the sheet feeding roller 12a is indicated by an arrow c as shown in FIG. Thus, the process cartridge G is rotated downward to a position where the process cartridge G can be moved to the side. As the sheet feeding roller 12a rotates downward as described above, the process cartridge G can be attached to and detached from the printer main body 51 side as indicated by an arrow d.

  Further, when the multi-manual feeding apparatus M is moved by operating the CRG door 6, the reversing guide 9 is rotated and the both sides of the reversing conveyance path Q from the sheet feeding cassette 7 are rotated as shown in FIG. 4. The refeed path R from the feeding device D is also opened. As a result, the reverse conveyance path Q and the refeed path R can be seen from the opening J1 of the CRG door 6. After that, by removing the process cartridge G, the transfer portion 14a and the fixing device 15 can also be seen from the opening J1 of the CRG door 6.

  That is, the reversing conveyance path Q, the refeed path R, the transfer unit 14a, and the fixing device 15 are opened from the opening J1 of the CRG door 6 simply by opening the CRG door 6 or removing the process cartridge G thereafter. This makes it possible to visually check the jam sheet.

  Further, the reversing guide 9 is opened, so that the nip between the conveying roller pair 23a and 23b is opened, a space for jamming from the opening J1 of the CRG door 6 can be secured, and the paper feeding cassette 7 can be attached and detached. And jam handling work is possible.

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 the CRG door of the said laser beam printer is open | released. FIG. 5 is a diagram illustrating a schematic configuration of a laser beam printer as an example of an image forming apparatus according to a second embodiment of the present invention. The figure which shows a state when the CRG door of the said laser beam printer is open | released. The figure which shows the state when removing a process cartridge after opening the CRG door of the said laser beam printer. 1 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of a conventional image forming apparatus. The figure which shows a state when removing the process cartridge of the conventional laser beam printer.

Explanation of symbols

6 CRG door 6a Rotating shaft 9 Reverse guide 9a Rotating shaft 11 Multi tray 12a Sheet feeding roller 50 Laser beam printer 51 Laser beam printer main body 52 Image forming unit C Sheet feeding device D Double-sided feeding device G Process cartridge M Multi Manual feeding device P Sheet Q Reverse conveyance path R Refeed path

Claims (4)

An image forming unit having image forming means detachably attached to the apparatus main body;
A first sheet feeding unit that supplies a sheet to the image forming unit;
A sheet conveyance path for guiding the sheet supplied from the first sheet feeding unit to the image forming unit;
A second sheet feeding unit that joins the sheet conveyance path and supplies the sheet to the image forming unit;
A path member provided integrally with the second sheet feeding unit and constituting the sheet conveyance path;
A door that is rotatably provided in the apparatus main body adjacent to the second sheet feeding unit and is opened to attach and detach the image forming means to and from the apparatus main body;
With
In conjunction with the opening of the door, the second sheet feeding unit is retracted to a position where the image forming unit can be attached and detached, and the passage member moves to open the sheet conveyance passage. Image forming apparatus. A sheet re-conveying unit that conveys the image-formed sheet to the image forming unit again;
The passage member constitutes a re-conveyance passage that conveys the sheet from the sheet re-conveyance unit to the image forming unit again, and the second sheet feeding unit is retracted in conjunction with opening of the door. The image forming apparatus according to claim 1, wherein the re-conveying passage is opened. The second sheet feeding unit is disposed on a side surface of the apparatus main body so as to be rotatable, and is positioned on a side of the image forming unit, and feeds the sheets stacked on the sheet stacking unit. A manual sheet feeding unit having sheet feeding means for feeding,
3. The image forming apparatus according to claim 1, wherein the door is rotatably provided coaxially with the sheet stacking unit, and rotates integrally with the sheet stacking unit. 4. The image forming apparatus according to claim 1, wherein one of a pair of conveyance rollers disposed in the sheet conveyance path is provided in the path member. 5.

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