JP6180266B2 - Sheet conveying apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet conveying apparatus capable of conveying a sheet and an image forming apparatus including the sheet conveying apparatus.

  Conventionally, a sheet feeding unit for feeding sheets is provided at the bottom, and an image is formed on the sheet fed from the sheet feeding unit by an image forming unit provided above the sheet feeding unit and provided at the top. There is known an image forming apparatus that discharges a sheet on which an image is formed on the sheet discharge unit. In this image forming apparatus, a sheet conveyance path for moving the sheet upward is provided along the side surface on one side of the apparatus main body, and an opening / closing door that can open the sheet conveyance path is provided to facilitate jamming and maintenance. I can do it.

  The open / close door is provided with a double-sided conveyance path for re-conveying the sheet to the image forming unit when an image is formed on both sides of the sheet. Thus, a part thereof is configured (see Patent Document 1).

JP 2010-117715 A

  Here, the swing guide described in Patent Document 1 is pivotally supported by the open / close door and is biased in a direction away from the open / close door (a direction in which the double-sided conveyance path is opened). As a result, the double-sided conveyance path is opened when the open / close door is opened, so that jamming and the like can be easily performed. Further, the swing guide is provided with a conveyance roller that is driven by a conveyance roller that conveys the sheet conveyed to the double-sided conveyance path, and the conveyance roller is in pressure contact with the conveyance roller supported by the opening and closing door. It is biased toward the open / close door.

  These urging forces need to increase the force acting in the direction of opening the double-sided conveyance path, but if this force is increased too much, the operability when opening and closing the door is lowered. Further, if this urging force is reduced, the pressure contact force of the transfer roller to the transfer roller is further reduced, which may cause a transfer failure. As described above, if these two urging forces are configured by different urging means, it is difficult to adjust the force relationship.

  Therefore, the present invention is a simple and inexpensive configuration, and a guide configured to easily open the second (double-sided) conveyance path while securing the conveyance force of the sheet conveyed to the second (double-sided) conveyance path. It is an object of the present invention to provide a sheet conveying apparatus having a unit and an image forming apparatus including the sheet conveying apparatus.

  The present invention relates to a sheet conveying apparatus, an apparatus main body, a first conveyance path provided in the apparatus main body for conveying a sheet, an opening / closing door pivotally supported by the apparatus main body, and the opening / closing door. A second conveyance path for re-conveying the sheet to the first conveyance path, a conveyance roller provided in the opening / closing door and capable of conveying the sheet conveyed to the second conveyance path, and the first Comprising a guide means that is pivotally supported by the open / close door so that the second transfer path is opened from the open / close door when the open / close door is opened from the apparatus main body. The guide means includes: a guide main body that is pivotally supported by the opening and closing door; a conveyance roller that is rotatably supported by the guide main body and capable of conveying a sheet in pressure contact with the conveyance roller; and the conveyance roller as the conveyance roller. The pressure roller and the conveying roller And biasing means for biasing the guide body in a direction to open the second conveying path by the reaction force, and having a.

  According to the present invention, a sheet conveying apparatus having guide means configured to be able to easily open the second conveying path while securing the conveying force of the sheet conveyed to the second conveying path with a simple and inexpensive configuration. And an image forming apparatus provided with the same can be provided.

1 is a cross-sectional view schematically showing a printer according to a first embodiment of the present invention. It is sectional drawing which shows the state which opened the opening-and-closing door of the printer shown in FIG. FIG. 3 is a block diagram illustrating a configuration of a control unit of the printer according to the first embodiment. It is a figure which shows the rocking | fluctuation guide in the state which closed the door. It is a figure which shows the rocking | fluctuation guide of the state which opened and closed the door. It is sectional drawing of the guide means which concerns on 1st Embodiment. It is sectional drawing which shows the guide means in the positioned state. It is sectional drawing of the guide means which concerns on 2nd Embodiment.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. An image forming apparatus according to an embodiment of the present invention is an image forming apparatus (sheet conveying apparatus) provided with an opening / closing door capable of opening a sheet conveying path inside a printer main body, such as a copying machine, a printer, a facsimile, and a composite device thereof. is there. The following embodiments will be described using an electrophotographic laser beam printer (hereinafter referred to as “printer”) 100 that forms toner images of four colors.

<First Embodiment>
A printer 100 according to a first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the printer according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a cross-sectional view schematically showing a printer 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a state where the opening / closing door 300 of the printer 100 shown in FIG. 1 is opened. FIG. 3 is a block diagram illustrating a configuration of the control unit 50 of the printer 100 according to the first embodiment.

  As shown in FIGS. 1 and 2, the printer 100 includes a printer main body (apparatus main body) 101, an image reading device 102 that can read an image of a document, and a control unit 50 that controls the printer 100. .

  The printer main body 101 includes a sheet feeding unit 10 that feeds the sheet S, an image forming unit 30 that can form an image on the sheet S, a discharge roller pair 40 that discharges the sheet S outside the apparatus, and a printer main body 101. And an opening / closing door 300 capable of opening the inside.

  The sheet feeding unit 10 is provided in the lower part of the printer main body 101, and separates the feeding sheet stacking unit 11 on which the sheets S are stacked and the sheet S stacked on the feeding sheet stacking unit 11 one by one. And a separate feeding means 12 for feeding while feeding. In the present embodiment, these are provided in four stages.

  The image forming unit 30 is provided above the sheet feeding unit 10. The image forming unit 30 includes four process cartridges 31Y to 31K that form four color images of yellow (Y), magenta (M), cyan (C), and black (K), and photosensitive drums 33Y to 33K described later. And an exposure device 32 for exposing the surface. Since the four process cartridges 31Y to 31K have the same configuration except that the colors of the images to be formed are different, the configuration of the process cartridge 31Y that forms a yellow (Y) image will be described to explain the process cartridge 31M. Description of ~ 31K is omitted. The process cartridge 31Y includes a photosensitive drum 33Y, a charging roller for charging the photosensitive drum 33Y, and a developing roller for developing an electrostatic latent image formed on the photosensitive drum 33Y, and is detachable from the printer main body 101. It is configured.

  Further, the image forming unit 30 includes an intermediate transfer belt 34 on which the toner images on the photosensitive drums 33Y to 33K are primarily transferred, and primary transfer rollers 35Y to 35K that primarily transfer the toner images to the intermediate transfer belt 34. Yes. Further, the image forming unit 30 includes a secondary transfer unit 36 that secondary-transfers the primary-transferred toner image, and a fixing unit 37 that heat-fixes the secondary-transferred toner image.

  The opening / closing door 300 is pivotally supported by the printer main body 101 on one side surface (the right side shown in FIG. 1) of the printer main body 101, and is opened upward from the sheet feeding unit 10 toward the discharge roller pair 40. The sheet conveying path (first conveying path) 107 extending in the direction is openable. In addition, when the image is formed on both surfaces (first surface and second surface) of the sheet S, the sheet S on which the image is formed on the first surface (front surface) is returned to the sheet conveyance path 107 on the opening / closing door 300. A double-sided conveyance path (second conveyance path) 106 for conveyance is provided. The opening / closing door 300 will be described in detail later.

  The image reading apparatus 102 is disposed above the printer main body 101, and is provided above the discharged sheet stacking unit 104 provided on the upper portion of the printer main body 101. Note that the sheet S discharged outside the apparatus by the discharge roller pair 40 is stacked on the discharge sheet stacking unit 104.

  As shown in FIG. 3, the control unit 50 includes a CPU 51 that drives and controls the sheet feeding unit 10, the image forming unit 30, the image reading device 102, and the like, and a memory 52 that stores various programs and various information. ing. The control unit 50 controls the sheet feeding unit 10, the image forming unit 30, the image reading device 102, and the like based on various programs, various information, and the like, and executes image reading of a document, image formation on a sheet S, and the like. .

  Next, the image forming operation (image forming control by the control unit 50) of the printer 100 will be specifically described. When image information is input from the image reading apparatus 102 or an external PC, the exposure device 32 irradiates the photosensitive drums 33Y to 33K with laser light based on the input image information. At this time, the photosensitive drums 33Y to 33K are charged in advance by a charging roller, and an electrostatic latent image is formed on the photosensitive drums 33Y to 33K when irradiated with laser light. Thereafter, the electrostatic latent image is developed by the developing roller, and toner images of yellow (Y), magenta (M), cyan (C) and black (K) are formed on the photosensitive drums 33Y to 33K. The toner images of the respective colors formed on the photosensitive drums 33Y to 33K are superimposed and transferred to the intermediate transfer belt 34 by the primary transfer rollers 35Y to 35K, and conveyed to the secondary transfer unit 36 by the intermediate transfer belt 34.

  In parallel with the above-described image forming operation, the separation sheet feeding unit 12 feeds the sheets S stacked on the feeding sheet stacking unit 11 one by one toward the registration roller pair 103. Then, the registration roller pair 103 conveys the toner image on the intermediate transfer belt 34 to the secondary transfer unit 36 at a predetermined conveyance timing. The sheet S on which the toner image has been transferred is fixed on the toner image by the fixing unit 37 and discharged to the outside by the discharge roller pair 40. The sheets S on which the images are fixed are sequentially stacked on the discharged sheet stacking unit 104.

  When images are formed on both sides of the sheet S, the sheet S on which the image is formed on the first side is conveyed to the double-sided conveyance path 106 by the reverse conveyance roller 105, and the image forming unit via the double-sided conveyance path 106. The sheet S is conveyed again to 30, and an image is formed on the second surface (back surface).

  Next, the door 300 described above will be specifically described with reference to FIGS. 4 to 7 in addition to FIG. FIG. 4 is a view showing the swing guide 306 in a state where the open / close door 300 is closed. FIG. 5 is a view showing the swing guide 306 with the opening / closing door 300 open. FIG. 6 is a sectional view of the guide means 304 according to the first embodiment. FIG. 7 is a sectional view showing the guide means 304 in a positioned state.

  First, a schematic configuration of the opening / closing door 300 will be described. As shown in FIG. 2, the opening / closing door 300 is pivotally supported on the printer main body 101 by a rotary shaft 301, and a hook 314 (see FIG. 4) is attached to an engaged portion (not shown) of the printer main body 101. Is fixed to the printer main body 101 by being engaged. Further, the open / close door 300 is provided with a manual feed unit 20, and the manual feed unit 20 can feed the sheets S stacked on the manual feed tray 21 that can be stored in the open / close door 300 to the printer main body 101. It is configured.

  Further, the open / close door 300 is provided with a double-sided conveyance path 106 through which the sheet S is conveyed when images are formed on both sides of the sheet S. A roller (conveyance roller) 124a and a double-sided lower roller 124b are provided. The double-sided upper roller 124a and the double-sided lower roller 124b are driven by a driving device (not shown).

  As shown in FIGS. 4 to 6, the upstream side of the double-sided conveyance path 106 includes a double-sided conveyance guide 305 and guide means 304.

  The double-sided conveyance guide 305 is fixed to the open / close door 300 and guides one side (outer side) of the sheet S conveyed toward the double-sided conveyance path 106 by the reverse conveyance roller 105 (see FIG. 2). . The double-sided conveyance guide 305 supports a double-sided upper roller 124a, and the double-sided upper roller 124a includes a roller shaft 307 and a plurality of roller main bodies 308 fixed to the roller shaft 307 at a predetermined interval. . Both ends of the roller shaft 307 are supported by the double-sided conveyance guide 305 via bearings 302. The roller shaft 307 has a roller gear (not shown) provided at one end connected to the driving device (not shown).

  The guide unit 304 is in pressure contact with a swinging guide (guide body) 306 that guides the other surface (inner surface) of the sheet S conveyed to the duplex conveying path 106 and the roller body 308 of the duplex upper roller 124a. A conveyance roller 309 capable of conveying the sheet S. The guide unit 304 includes a torsion coil spring (biasing unit) 310 that urges the conveyance roller 309 toward the double-sided upper roller 124a and urges the swing guide 306 in a direction to open the double-sided conveyance path 106. ing.

  The swing guide 306 can be rotated to the double-sided conveyance guide 305 around a rotation shaft 311 positioned downstream of the double-sided upper roller 124a in the sheet conveyance direction at a position facing the double-sided conveyance guide 305 at a predetermined distance. Is pivotally supported. As the swing guide 306 rotates about the rotation shaft 311, the upstream side of the double-sided conveyance path 106 is opened, and when a jam or the like occurs in the double-sided conveyance path 106, it is possible to easily perform jam processing. become. Further, the guide surface 306 b on the opposite side of the guide surface 306 a constituting the double-sided conveyance path 106 of the swing guide 306 guides the sheet S moving on the sheet conveyance path 107. That is, the guide surface 306 b of the swing guide 306 constitutes a part of the sheet conveyance path 107.

  The conveying roller 309 is supported by the elongated hole portion 306c of the swing guide 306 so as to be able to rotate and move in the pressure contact direction so as to be driven and rotated by pressing against the roller body 308 of the double-sided upper roller 124a. The long hole portion 306 c is formed to be long in the pressure contact direction of the transport roller 309. The conveying roller 309 is urged by the torsion coil spring 310 so as to be pressed against the roller main body 308 of the double-sided upper roller 124 a, and conveys the sheet S at the nip with the roller main body 308.

  In the torsion coil spring 310, a winding portion (coil portion) 310 a is rotatably supported by a fulcrum 312 provided on the swing guide 306, and the fulcrum 312 is opposite to the rotation shaft 311 with respect to the conveying roller 309. Is formed. The torsion coil spring 310 has one end engaged with the swing guide 306 and the other end engaged with the rotating shaft 309 a of the transport roller 309. By disposing the torsion coil spring 310 in this way, the reaction force of the urging force to the conveying roller 309 by the torsion coil spring 310 (reaction force from the double-sided upper roller 124a) acts on the swing guide 306, and the rotation shaft 311 is centered. This is a force that rotates the swing guide 306 in the direction of arrow A.

  Further, as shown in FIG. 7, the swing guide 306 comes into contact with a positioning portion 315 provided in the printer main body 101 when the opening / closing door 300 is positioned and fixed to the printer main body 101 by the hook 314. The positioning portion 315 is provided along the movement direction (horizontal direction) immediately before the opening / closing door 300 is closed with respect to the printer main body 101, and the abutting portion 316 of the swing guide 306 that abuts against the positioning portion 315 is also in the movement direction. It is provided along. As a result, the swing guide 306 is positioned in the height direction.

  Next, the operation of the swing guide 306 when the opening / closing door 300 is opened will be described. As shown in FIG. 7, in the swing guide 306, the abutting portion 316 abuts against the positioning portion 315 when the open / close door 300 is closed. At this time, the reaction force from the double-sided upper roller 124 a by urging the conveying roller 309 acts on the torsion coil spring 310 around the fulcrum 312. Therefore, the torsion coil spring 310 presses the swing guide 306 in the direction of arrow A, and the swing guide 306 is positioned and fixed.

  Next, when the opening / closing door 300 is opened, the swing guide 306 rotates relative to the opening / closing door 300 while the abutting portion 316 is in contact with the positioning portion 315. Thereby, the double-sided conveyance path 106 is opened. When the opening / closing door 300 is further opened, the end of the swing guide 306 in the vicinity of the rotation shaft 311 contacts the double-sided conveyance guide 305, so that the relative rotation of the swing guide 306 with respect to the open / close door 300 is stopped. The When the opening / closing door 300 is further opened from this state, the swing guide 306 rotates together with the opening / closing door 300 and the sheet conveying path 107 is opened.

  As described above, the printer 100 according to the first embodiment has a simple and inexpensive configuration using only one torsion coil spring 310, and the pressure contact force of the conveying roller 309 and the vibration acting in the opposite direction to the pressure contact force. The urging force of the moving guide 306 can be generated at the same time. Therefore, when the opening / closing door 300 is opened, the swing guide 306 is opened by a moment acting on the torsion coil spring 310, and the visibility of a sheet jam (for example, a paper jam) portion can be improved. At this time, the conveying roller 309 is separated from the double-sided upper roller 124a, so that the sheet S can be easily removed. Thereby, the jam handling property can be improved.

  Further, in the printer 100 according to the present embodiment, when the opening / closing door 300 is closed, the abutting portion 316 abuts against the positioning portion 315 of the printer main body 101 so that the swing guide 306 is positioned. The positioning portion 315 of the printer main body 101 is provided along the moving direction (horizontal direction) immediately before the opening / closing door 300 is closed with respect to the printer main body 101. Therefore, the position of the swing guide 306 in the substantially vertical direction (height direction) is restricted by the positioning unit 315, but the position in the horizontal direction (for example, the depth direction) is not restricted. Thus, even when the opening / closing door 300 is closed due to various factors such as part tolerance and part rigidity, even if the closing position of the opening / closing door 300 varies with respect to the printer body 101, the swing guide 306 is The horizontal position with respect to the printer main body 101 can be maintained. As a result, the distance (gap) between the guides of the double-sided conveyance path 106 can be made constant while maintaining the urging force of the conveyance roller 309 constant.

Second Embodiment
Next, a printer according to the second embodiment will be described with reference to FIG. The printer according to the second embodiment is different from the first embodiment in the urging means for urging the swing guide 306 and the conveying roller 309. Therefore, in 2nd Embodiment, it demonstrates centering on an urging | biasing means, and about the other structure, the same code | symbol as 1st Embodiment is attached | subjected and the description is abbreviate | omitted. FIG. 8 is a cross-sectional view of the guide means 304 according to the second embodiment.

  As shown in FIG. 8, the biasing means includes a swing member 400 and a compression spring 410. The swing member 400 is swingably supported by the swing guide 306 around a fulcrum portion (fulcrum) 400a located on the opposite side of the swing shaft 311 of the swing guide 306 with respect to the transport roller 309. One end portion 400 c is engaged with the rotation shaft 309 a of the transport roller 309. Specifically, the swing member 400 is supported by the shaft portion 401 of the swing guide 306 so that the fulcrum portion 400a can rotate. One end of the compression spring 410 is fixed to the swing guide 306, and the other end biases the other end portion 400 b of the swing member 400 in a direction away from the opening / closing door 300 (a direction in which the double-sided conveyance path 106 is opened). ing.

  By arranging the swing member 400 and the compression spring 410 in this way, the reaction force of the urging force of the compression spring 410 to the conveying roller 309 acts on the swing guide 306 and swings around the rotation shaft 311. This is a force for rotating the moving guide 306 in the direction of arrow A.

  Next, the operation of the swing guide 306 when the opening / closing door 300 is opened will be described. In the swing guide 306, the abutting portion 316 abuts against the positioning portion 315 when the open / close door 300 is closed. At this time, the swinging guide 306 is pressed in the direction of arrow A by the reaction force from the double-sided upper roller 124a by the compression spring 410 urging the conveying roller 309, and the swinging guide 306 is positioned and fixed.

  Next, when the opening / closing door 300 is opened, the abutting portion 316 is rotated relative to the opening / closing door 300 with the abutting portion 316 abutting against the positioning portion 315. Thereby, the double-sided conveyance path 106 is opened. When the opening / closing door 300 is further opened, the end of the swing guide 306 in the vicinity of the rotation shaft 311 contacts the double-sided conveyance guide 305, so that the relative rotation of the swing guide 306 with respect to the open / close door 300 is stopped. The When the opening / closing door 300 is further opened from this state, the sheet conveying path 107 is opened.

  As described above, the printer according to the second embodiment has a simple and inexpensive configuration using one compression spring 410 and the swinging member 400, and acts in the opposite direction to the pressure contact force of the transport roller 309 and the pressure contact force. The urging force of the swinging guide 306 can be generated at the same time. Therefore, when the open / close door 300 is opened, the swing guide 306 is opened by a moment acting on the swing member 400, and the visibility of a sheet jam (for example, a paper jam) can be improved. At this time, the conveying roller 309 is separated from the double-sided upper roller 124a, so that the sheet S can be easily removed. Thereby, the jam handling property can be improved.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. In addition, the effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

  For example, in the present embodiment, the configuration in which the positioning portion 315 of the swing guide 306 is arranged in a substantially horizontal direction is shown, but the present invention is not limited to this. The positioning portion 315 can be positioned in a direction in which the direction of the urging force (direction of arrow A) of the conveying roller 309 determined by the position of the rotation shaft 311 of the swing guide 306 and the arrangement of the torsion coil spring 310 is always kept constant. Any position may be used as long as it is configured.

  Further, in the present embodiment, the sheet conveyance path 107 is opened when the opening / closing door 300 is opened, and the guide surface 306b of the swing guide 306 is described using an aspect that forms part of the sheet conveyance path 107. Is not limited to this. A mode in which a part of the swing guide does not constitute a part of the sheet conveying path 107 may be employed.

  In this embodiment, the electrophotographic printer has been described. However, the present invention is not limited to this. For example, the present invention can also be used for an ink jet printer (image forming apparatus) that forms an image on a sheet by ejecting ink liquid from a nozzle.

30 Image forming unit 100 Printer (sheet conveying device, image forming device)
101 Printer body (device body)
106 Double-sided conveyance path (second conveyance path)
107 Sheet transport path (first transport path)
124a Double-sided upper roller (conveyance roller)
300 Opening / closing door 304 Guide means 306 Swing guide (guide body)
309 Transport roller 310 Torsion coil spring (biasing means)
310a Winding part (coil part)
310b Protruding part 310c Connecting part 311 Rotating shaft 315 Positioning part 316 Abutting part S sheet

Claims (9)

The device body;
A first conveyance path provided in the apparatus main body and conveying a sheet;
An opening / closing door pivotally supported by the apparatus body;
A second conveyance path provided at the opening and closing door for re-conveying the sheet to the first conveyance path;
A conveyance roller provided in the opening and closing door and capable of conveying the sheet conveyed to the second conveyance path;
And a guide means that is pivotally supported by the open / close door so that the second transfer path is opened from the open / close door when the open / close door is opened from the apparatus main body. ,
The guide means includes: a guide main body that is pivotally supported by the opening and closing door; a conveyance roller that is rotatably supported by the guide main body and that can convey a sheet in pressure contact with the conveyance roller; and And a biasing means for biasing the guide body in a direction to open the second transport path by a reaction force from the transport roller.
A sheet conveying apparatus. The pressing force by the biasing means that presses the transport roller against the transport roller and the biasing force that biases the guide body act by moments in opposite directions.
The sheet conveying apparatus according to claim 1. The moment acts around a fulcrum located on the opposite side of the rotation axis of the guide body with respect to the transport roller,
The sheet conveying apparatus according to claim 2. The urging means has one end engaged with the guide body and the other end of the conveyance roller centered on a coil portion supported on the opposite side of the rotation axis of the guide body with respect to the conveyance roller. A torsion coil spring engaged with
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. The biasing means is supported by the guide body so as to be swingable about a fulcrum located on the opposite side of the rotation axis of the guide body with respect to the conveyance roller, and has one end engaged with the conveyance roller. A swing member that urges the other end of the swing member in a direction away from the door,
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. The apparatus main body has a positioning portion that contacts the guide main body when closing the opening and closing door and positions the guide main body.
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. The positioning portion is disposed along a moving direction immediately before the opening / closing door is closed with respect to the apparatus main body,
Restricting the guide body along the moving direction;
The sheet conveying apparatus according to claim 6. The open / close door is configured to be able to open the first transport path,
The guide body constitutes the first conveyance path on one side and the second conveyance path on the other side.
The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus. A sheet conveying device according to any one of claims 1 to 8,
An image forming unit that is provided in the first conveyance path and forms an image on a sheet conveyed by the sheet conveyance device;
An image forming apparatus.

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