JP2012076880A - Sheet sorting apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet sorting apparatus effectively preventing the rear end of a sheet from being left behind whereby a stable stacking performance can be attained, and to provide an image forming apparatus provided with it.SOLUTION: The sheet sorting apparatus 120 for sorting the sheet P placed on a sheet discharging tray 91 from a sheet conveying part 30 by shift movement of the sheet conveying part 30 conveying the sheet P in a shift direction X is provided with a sheet-presser guide 300 for pressing the sheet P by coming into contact with the sheet P placed on the sheet discharging tray 91. The sheet-presser guide 300 is provided with a contact member 310 coming into contact with the sheet P discharged to the sheet discharging tray 91. The contact member 310 is configured in a manner that a friction force acting on the sheet P sliding down a slope of an inclined surface 91a toward the upstream side in the conveying direction Y1 is larger than a friction force acting on the sheet P upon movement of the sheet-presser guide 300 in the shift direction X.

Description

  The present invention relates to a sheet sorting apparatus that can be applied to an image forming apparatus such as a printer, a copier, or a multifunction peripheral, and an image forming apparatus including the sheet sorting apparatus.

  As a conventional sheet sorting apparatus, a sheet conveying unit that conveys a sheet such as recording paper is shifted in a shift direction along a sheet surface that intersects the sheet conveying direction, and is loaded from the sheet conveying unit onto a sheet discharge tray. There is known one that sorts the placed sheets (offset sorting) (see, for example, Patent Document 1).

  In such a sheet sorting apparatus, from the viewpoint of improving the stackability of sheets discharged to the sheet discharge tray, a sheet pressing guide for pressing the sheets in contact with the upper surface of the sheet placed on the sheet discharge tray The structure which provides a member is conventionally known (for example, patent document 2).

JP-A-3-42460 JP 2002-2111814 A JP 2006-89198 A

  In view of such a conventional technique, in a sheet sorting apparatus that sorts a sheet placed on a sheet discharge tray from the sheet conveyance unit by shifting a sheet conveyance unit that conveys the sheet in the shift direction, the sheet is placed on the sheet discharge tray. When a sheet pressing guide member for pressing the sheet in contact with the upper surface of the placed sheet is provided, there are the following disadvantages.

  That is, in such a sheet sorting apparatus, the sheet pressing guide member moves with the sheet conveying unit as the sheet conveying unit moves in the shift direction (specifically, the sheet pressing guide member is provided in the sheet conveying unit). When the sheet pressing guide member comes into contact with the upper surface of the sheet placed on the sheet discharge tray, the bundle of sheets stacked on the sheet discharge tray is moved when the sheet conveying unit shifts in the shift direction. This causes a situation in which the offset sorting of the bundle of sheets is disturbed by shifting in the shift direction.

  FIGS. 10 and 11 respectively show a configuration in which the sheet pressing guide member C1 is provided in the sheet conveying unit C2 and is in contact with the upper surface Pa of the sheet P placed on the sheet discharge tray C3 in the conventional sheet sorting apparatus. It is the schematic side view seen from the shift direction X and the conveyance direction Y1. FIG. 10A shows a state where the sheet P is not placed on the sheet discharge tray C3. FIG. 10B shows a state where the sheets P are stacked on the sheet discharge tray C3. FIG. 11A shows a state in which the sheet P is not placed on the sheet discharge tray C3. FIG. 11B shows a state in which the sheets P are stacked on the sheet discharge tray C3. In FIG. 11C, the sheet conveying unit C2 moves in the shift direction X, and the bundle of sheets P stacked on the sheet discharge tray C3 shifts in the shift direction X, and the offset sorting of the bundle of sheets P is disturbed. It shows the state being done.

  In the conventional sheet sorting apparatus shown in FIGS. 10 and 11, the sheet pressing guide member C3 is arranged in the shift direction X at the upper part of the discharge port C2a (see FIGS. 10A and 11A) of the sheet conveying unit C2. It is provided in the center. As a result, the sheet pressing guide member C1 moves together with the sheet conveying unit C2 as the sheet conveying unit C2 moves in the shift direction X. Specifically, the sheet pressing guide member C1 is provided so as to be rotatable about an axis along the shift direction X with respect to the sheet conveying portion C2, and the leading end side hangs down to the sheet discharge tray C3 side by its own weight. Yes. Further, the sheet discharge tray C3 has an inclined surface C3a that is lower on the upstream side than the downstream side in the transport direction Y1 on the placement surface C3x of the sheet P (see FIG. 10). The sheet pressing guide member C1 presses the sheet P in contact with the upper surface Pa of the sheet P placed on the sheet discharge tray C3.

  For this reason, as shown in FIG. 11C, when the sheet pressing guide member C1 moves together with the sheet conveying portion C2 as the sheet conveying portion C2 moves in the shift direction X, the sheet discharge tray C3 of the sheet pressing guide member C1. The sheet P stacked on the sheet discharge tray C3 is displaced in the shift direction X due to the contact with the upper surface Pa of the sheet P placed on the sheet P, and the offset sorting of the sheet P bundle is disturbed. Invite.

  From the viewpoint of suppressing the frictional force with the sheet as much as possible, the conventional sheet pressing guide member is a member having a small friction coefficient at least in contact with the sheet. In general, the sheet pressing guide member is often formed of a resin (specifically, a resin molded product). This causes the following inconvenience.

  FIG. 12 is an explanatory diagram for explaining inconveniences in the case where the contact portion C1a of at least the sheet P of the sheet pressing guide member C1 is formed of resin in the sheet sorting apparatus shown in FIGS.

  In the sheet sorting apparatus shown in FIG. 12, since at least the contact portion C1a of the sheet pressing guide member C1 with the sheet P is simply formed of resin, the direction of the frictional force generated at the contact portion C1a with the sheet P Regardless, the frictional force is almost the same. For this reason, even if the movement of the bundle of sheets P stacked on the sheet discharge tray C3 in the shift direction X can be reduced by the movement of the sheet pressing guide member C1 accompanying the movement of the sheet conveying unit C2 in the shift direction X. When the sheet P is discharged to the sheet discharge tray C3, when the upstream end (rear end P2) in the transport direction Y1 of the sheet P is not on the sheet discharge tray C3, the sheet discharge tray C3 is placed. Before contacting the inclined surface C3a on the surface C3x, or when the sheet P is on the sheet discharge tray C3, before contacting the sheet P on the inclined surface C3a, the downstream end (tip P1) side is the sheet discharge tray. It is impossible to prevent the slope of C3 from being inclined due to the inclined surface C3a, and this causes inconvenience (so-called rear end remaining) in which the rear end P2 side of the sheet P remains on the vertical wall C4.

  In this regard, Patent Document 3 discloses a configuration in which a contact member (specifically, a roller) is attached to the free end of the sheet pressing arm (see FIG. 1 of Patent Document 3).

  However, in Patent Document 3, the contact member is a member that contacts the sheet to such an extent that the sheet does not interfere with the progress when the sheet travels by receiving a conveying force from the paper discharge roller (paragraph of Patent Document 3). [0009]) is disclosed. In other words, in the configuration described in Patent Document 3, the contact member (roller) is merely a member that contacts the sheet to an extent that does not hinder the progress of the sheet. It does not contribute to prevention.

  In view of this, the present invention shifts a sheet conveying unit that conveys a sheet in a shift direction along a sheet surface that intersects the sheet conveying direction, so that the sheet placed on the sheet discharge tray is transferred from the sheet conveying unit. To provide a sheet sorting apparatus for sorting, which can effectively prevent the occurrence of the trailing edge remaining of the sheet, and thereby obtain a stable stackability, and an image forming apparatus including the same. Objective.

  In order to solve the above problems, the present invention shifts a sheet conveying unit that conveys a sheet from the sheet conveying unit to a sheet discharge tray by shifting the sheet conveying unit in a shift direction along a sheet surface that intersects the sheet conveying direction. A sheet sorting device that sorts the placed sheets, comprising a sheet pressing guide member that contacts the sheets placed on the sheet discharge tray and presses the sheets, and the sheet pressing guide member conveys the sheet The sheet discharge tray has an inclined surface whose upstream side is lower than the downstream side in the transport direction on the sheet placement surface. The sheet pressing guide member is provided with a contact member that contacts the sheet discharged to the sheet discharge tray. The contact member has a frictional force with the sheet that slides down the gradient due to the inclined surface of the sheet discharge tray to the upstream side in the transport direction, and the sheet pressing guide member moves with the sheet when the sheet pressing guide member moves in the shift direction. Provided is a sheet sorting apparatus characterized by being configured to be larger than a frictional force. The present invention also provides an image forming apparatus comprising the sheet sorting apparatus according to the present invention.

  According to the present invention, the frictional force with the sheet sliding down the gradient by the inclined surface of the sheet discharge tray toward the upstream side in the transport direction is different from the sheet when the sheet pressing guide member moves in the shift direction. When the contact member configured to be larger than the frictional force contacts the sheet, it is possible to delay the timing at which the downstream end side of the sheet slides down the gradient due to the inclined surface, and therefore the remaining rear end of the sheet. Can be effectively prevented, and stable loading performance can be obtained. This means that, in particular, the greater the distance that the sheet slides down the gradient due to the inclined surface, for example, the greater the step between the sheet discharge port of the sheet transport unit and the placement surface of the sheet discharge tray ( Specifically, the larger the maximum stacking capacity of the sheet discharge tray, the more effective.

  In the present invention, the sheet pressing guide member is configured such that the base end side is provided so as to be swingable in the vertical direction with respect to the sheet conveying unit, and the front end side is configured to hang down to the sheet discharge tray side by its own weight. it can.

  In this specific matter, the base end side of the sheet pressing guide member is provided to be swingable in the vertical direction with respect to the sheet conveying unit, and the leading end side of the sheet pressing guide member hangs down to the sheet discharge tray side by its own weight. Therefore, the contact between the contact member in the sheet pressing guide member and the sheet discharged to the sheet discharge tray can be realized with a simple configuration.

  In the present invention, the contact member maintains a contact area in the transport direction with the sheet regardless of a change in an angle between the sheet on the sheet discharge tray and the sheet pressing guide member that contacts the sheet. It is preferable that it is set as the structure which does.

  In this specific matter, the contact area of the contact direction of the sheet with the sheet is determined regardless of a change in an angle between the sheet on the sheet discharge tray and the sheet pressing guide member that contacts the sheet. Since it is configured to maintain, even if the stacking amount of the sheets stacked on the sheet discharge tray changes (increases) when the sheets are discharged, the effect of preventing the remaining trailing edge of the sheets is maintained. Is possible.

  As a specific aspect of this configuration, the contact member can be exemplified by an aspect in which the shape of the surface in the transport direction is a convex curved surface.

  In this specific matter, even if the stack amount of the sheet on the sheet discharge tray changes (increases) when the sheet is discharged, the convex curved surface shape of the surface of the contact member causes the contact member The contact area in the conveyance direction with the sheet can be maintained. In this case, examples of the shape of the contact member include a barrel shape, an egg shape, or a spherical shape in which the major axis direction is the rotation axis direction.

  The contact member may be supported so as to be rotatable about an axis along the shift direction with respect to the sheet pressing guide member.

  In this specific matter, the contact member is rotated about the axis along the shift direction as a fulcrum even when the stack amount of the sheet on the sheet discharge tray changes (increases) when the sheet is discharged. Thus, the contact area of the contact member with the sheet in the transport direction can be maintained.

  In the present invention, it is preferable that the sheet pressing guide member is provided with a guide member that guides the sheet from the sheet conveying unit downward of the contact member.

  In this specific matter, the guide member provided on the sheet pressing guide member can avoid catching with the joint portion of the sheet from the sheet conveying unit, thereby effectively reducing the stackability of the sheet. Can be prevented.

  In the present invention, the main body of the image forming apparatus provided with the sheet discharge tray or the sheet sorting apparatus is provided with a vertical wall facing the upstream end in the transport direction of the sheet placed on the placement surface. The vertical wall has a downstream end in the transport direction of the sheet transport section with the upstream end in the transport direction of the contact position between the contact member and the placement surface of the sheet discharge tray as a center point The aspect located outside the virtual arc which touches can be illustrated.

  In this specific matter, since the vertical wall is located outside the virtual arc, the placement surface on which the upstream end side of the sheet is placed when the sheet is discharged to the sheet discharge tray Can be secured.

  In the present invention, the contact member is provided at a front end of the sheet pressing guide member, and the sheet pressing guide member is moved in the shift direction by contact with the sheet on the sheet discharge tray. The aspect provided with the rolling member rotated about the axis line along a direction and the friction member provided in the surface of this rolling member can be illustrated.

  In this specific matter, the frictional force with the sheet sliding down the gradient due to the inclined surface to the upstream side in the conveying direction is larger than the frictional force with the sheet when the sheet pressing guide member moves in the shift direction. The contact member can be realized with a simple configuration in which the friction member is provided on the surface of the rolling member.

  In the present invention, examples of the friction member typically include a rubber member and suede. Any rubber member can be used as long as it has a frictional force larger than the frictional force generated by the rotation of the rolling member. Examples of the rubber member include, but are not limited to, materials such as urethane rubber, ethylene-propylene-diene (EPDM) rubber, and CR (chloroprene) rubber. The suede refers to tanned leather with the back of the leather raised in a bell bed shape with a sandpaper or other file.

  In the present invention, the contact member includes a brush member that is provided at a tip of the sheet pressing guide member and has brush hairs, and the brush member transports the brush hairs on the tip side of the brush hairs. The aspect which is a member flocked so that it may incline toward a direction can be illustrated.

  In this specific matter, the frictional force with the sheet sliding down the gradient due to the inclined surface to the upstream side in the conveying direction is larger than the frictional force with the sheet when the sheet pressing guide member moves in the shift direction. Thus, the contact member can be realized with a simple configuration using the brush member.

  A typical example of the brush member is a planar brush member having a friction direction that has a different frictional force depending on the direction, as used in a so-called etiquette brush (registered trademark).

  As described above, according to the present invention, when the sheet pressing guide member moves in the shift direction due to the frictional force with the sheet sliding down the gradient due to the inclined surface of the sheet discharge tray to the upstream side in the transport direction. When the contact member configured to be larger than the frictional force with the sheet contacts the sheet, it is possible to delay the timing at which the downstream end side of the sheet slides down the gradient due to the inclined surface. Occurrence of the trailing edge of the sheet can be effectively prevented, and stable stackability can be obtained.

1 is a schematic sectional view of an image forming apparatus provided with a sheet sorting apparatus according to an embodiment of the present invention as viewed from the front. It is a schematic sectional drawing which shows the discharge roller and its peripheral part in the sheet sorting apparatus which concerns on embodiment of this invention. It is the schematic side view which looked at the sorting structure in the sheet sorting apparatus concerning an embodiment of the invention from the conveyance direction of a sheet. FIG. 9 is an explanatory diagram for explaining a sorting operation by the sheet sorting apparatus according to the embodiment of the present invention, in which (a) shows a state in which a sheet is discharged at one shift end (moving end) in the shift direction. (B) is a schematic plan view showing a state in which the paper P is discharged at the shift end (moving end) on the other side in the shift direction, and (c) is a schematic view of the discharge roller shift unit. FIG. 7 is a schematic cross-sectional view of a paper discharge state when the shift end on one side or the shift end on the other side in the shift direction is viewed from the shift direction, and (d) is a sorting of the paper discharged to the discharge tray. It is a schematic plan view showing the positional relationship between the width and the discharge roller shift unit. In the sheet sorting apparatus according to the embodiment of the present invention, a schematic side view of a state in which a sheet placed on the discharge tray is pressed by a sheet pressing guide member provided in the discharge roller shift unit, as viewed from the shift direction. is there. It is the schematic which shows an example of the contact member in the pressing guide member, and its part, Comprising: (a) is the side view which looked at an example of this contact member from the direction opposite to a conveyance direction, (b) It is sectional drawing which looked at an example of the contact member from the shift direction. FIG. 6 is a schematic side view showing a state in which the sheet is not placed on the discharge tray in the sheet sorting apparatus shown in FIG. 5. It is the schematic which shows the other example of the contact member in a pressing guide member, and its peripheral part, (a) is the side view which looked at the other example of this contact member from the direction opposite to a conveyance direction, b) is a side view of another example of the contact member as viewed from the shift direction. FIG. 9 is a schematic diagram illustrating a configuration in which the sheet pressing guide member is rotatably supported around an axis along the shift direction in the example of the contact member illustrated in FIGS. 5 to 7 and the other example of the contact member illustrated in FIG. 8. In addition, (a) is a cross-sectional view showing an example of the contact member, and (b) is a side view showing another example of the contact member. In the conventional sheet sorting apparatus, a sheet pressing guide member is provided in the sheet conveying unit, and is a schematic view of a configuration in contact with an upper surface of a sheet placed on a sheet discharge tray, as viewed from the shift direction. FIG. 4B is a side view showing a state where no sheet is placed on the sheet discharge tray, and FIG. 5B is a side view showing a state where sheets are stacked on the sheet discharge tray. In the conventional sheet sorting apparatus, a sheet pressing guide member is provided in the sheet conveying section, and is a schematic view of the configuration in contact with the upper surface of the sheet placed on the sheet discharge tray, as viewed from the conveying direction. FIG. 4B is a side view showing a state in which no sheet is placed on the sheet discharge tray, FIG. 5B is a side view showing a state in which sheets are stacked on the sheet discharge tray, and FIG. FIG. 10 is a side view illustrating a state where the conveyance unit moves in the shift direction and the sheet bundle stacked on the sheet discharge tray is shifted in the shift direction and offset sorting of the sheet bundle is disturbed. In the sheet sorting apparatus shown in FIGS. 10 and 11, it is an explanatory diagram for explaining inconveniences when at least a contact portion of the sheet pressing guide member with the sheet is made of resin.

  Embodiments according to the present invention will be described below with reference to the drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

(Description of overall configuration of image forming apparatus)
FIG. 1 is a schematic sectional view of an image forming apparatus 100 provided with a sheet sorting apparatus 120 according to an embodiment of the present invention as viewed from the front.

  An image forming apparatus 100 shown in FIG. 1 is a color image forming apparatus that forms multicolor and single color images on a sheet P (hereinafter referred to as “paper”) P such as recording paper in accordance with image data transmitted from the outside. It is. The image forming apparatus 100 includes a document reading device 108 and an apparatus main body 110, and the apparatus main body 110 is provided with an image forming unit 102 and a sheet conveyance system 103.

  The image forming unit 102 includes an exposure unit 1, a plurality of developing units 2, a plurality of photosensitive drums 3, a plurality of cleaning units 4, a plurality of chargers 5, an intermediate transfer belt unit 6, a plurality Toner cartridge units 21... And a fixing unit 7.

  The sheet conveyance system 103 includes a paper feed tray 81, a manual paper feed tray 82, and a sheet discharge tray (hereinafter simply referred to as a discharge tray) 91.

  An upper part of the apparatus main body 110 is provided with an original placing table 92 made of transparent glass on which an original (sheet) is placed, and an optical unit 90 for reading the original is provided below the original placing base 92. . A document reading device 108 is provided above the document table 92. The document reading device 108 automatically conveys the document on the document placing table 92. Further, the document reading device 108 is attached to the apparatus main body 110 so as to be pivotable by opening the front side, and the document can be placed manually by opening the document placing table 92. .

  The document reading device 108 can read a document that is automatically conveyed or a document placed on the document placing table 92. The entire image of the original read by the original reading device 108 is sent as image data to the apparatus main body 110 of the image forming apparatus 100, and an image formed based on the image data in the apparatus main body 110 is recorded on the paper P.

  The image data handled in the image forming apparatus 100 corresponds to a color image using a plurality of colors (here, black (K), cyan (C), magenta (M), and yellow (Y)). Therefore, the developing unit 2,..., The photosensitive drum 3,..., The cleaning unit 4,. A plurality of (here, four are provided, each being black, cyan, magenta, and yellow) so as to be formed, and a plurality of (here, four) image stations are configured by these.

  The chargers 5,... Are charging means for uniformly charging the surface of the photosensitive drums 3,... To a predetermined potential. In addition to the charger type as shown in FIG. A type charger can be used.

  The exposure unit 1 is configured as a laser scanning unit (LSU) including a laser emitting unit and a reflection mirror. The exposure unit 1 is provided with a polygon mirror that scans a laser beam, and optical elements such as lenses and mirrors for guiding the laser beam reflected by the polygon mirror to the photosensitive drums 3. In addition to this, as the exposure unit 1, for example, a method using a writing head in which light emitting elements such as EL (electroluminescence) and LED (light emitting diode) are arranged in an array can be employed.

  The exposure unit 1 exposes the charged photoconductive drums 3... According to the input image data, so that an electrostatic latent image corresponding to the image data is displayed on the surface of each photoconductive drum 3. To form.

  The toner cartridge units 21,... Are units that contain toner, and are supplied to the developing tanks of the developing units 2,. In the apparatus main body 110 of the image forming apparatus 100, the toner supplied from the toner cartridge units 21,... To the developing tanks of the developing units 2,... Is controlled so that the toner concentration of the developer in the developing tank is constant. .

  The developing units 2... Visualize the electrostatic latent images formed on the respective photosensitive drums 3 with toners of four colors (Y, M, C, K). Further, the cleaning units 4... Remove and collect toner remaining on the surface of the photosensitive drums 3... After development and image transfer.

  The intermediate transfer belt unit 6 disposed above the photosensitive drums 3,... Has an intermediate transfer belt 61 that acts as an intermediate transfer member, an intermediate transfer belt drive roller 62, an intermediate transfer belt driven roller 63, and a plurality of intermediate transfer rollers. 64, and an intermediate transfer belt cleaning unit 65.

  Four intermediate transfer rollers 64,... Are provided corresponding to each color of Y, M, C, and K. The intermediate transfer belt drive roller 62 stretches the intermediate transfer belt 61 together with the intermediate transfer belt driven roller 63 and the intermediate transfer rollers 64, and is driven to rotate, whereby the intermediate transfer belt 61 moves in the direction of movement (arrow in FIG. 1). In the M direction, the driven roller 63 and the intermediate transfer rollers 64,.

  Each intermediate transfer roller 64,... Is applied with a transfer bias for transferring the toner image formed on the photosensitive drum 3,.

  The intermediate transfer belt 61 is provided so as to come into contact with the respective photosensitive drums 3. The intermediate transfer belt 61 forms a color toner image (multicolor toner image) on the surface by sequentially transferring the toner images of the respective colors formed on the photosensitive drums 3. The intermediate transfer belt 61 is, for example, endless using a film having a thickness of about 100 μm to 150 μm.

  Transfer of the toner image from the photosensitive drums 3 to the intermediate transfer belt 61 is performed by intermediate transfer rollers 64 that are in contact with the back side of the intermediate transfer belt 61. A high-voltage transfer bias (a high voltage having a polarity (+) opposite to the toner charging polarity (-)) is applied to the intermediate transfer rollers 64,... The intermediate transfer roller 64,... Is based on a metal (for example, stainless steel) shaft having a diameter of 8 mm to 10 mm, and the surface thereof is a conductive elastic material (for example, a resin material such as EPDM (ethylene-propylene-diene rubber) or urethane foam). It is the roller covered with. The intermediate transfer rollers 64,... Serve as transfer electrodes that uniformly apply a high voltage to the intermediate transfer belt 61 by the conductive elastic material. In this embodiment, a roller-shaped transfer electrode is used as the transfer electrode, but a transfer electrode such as a brush can be used in addition to this.

  As described above, the toner images visualized in accordance with the respective hues on the respective photosensitive drums 3 are stacked on the intermediate transfer belt 61. The toner images stacked on the intermediate transfer belt 61 are transferred to the sheet by the transfer roller 10 constituting the secondary transfer mechanism unit disposed at the contact position between the sheet P and the intermediate transfer belt 61 by the circumferential movement of the intermediate transfer belt 61. Transferred onto P. However, the configuration of the secondary transfer mechanism is not limited to the transfer roller, and a transfer configuration such as a corona charger or a transfer belt can be used.

  At this time, the transfer roller 10 has a transfer nip formed between the transfer roller 10 and a voltage for transferring the toner onto the paper P (a polarity (+) opposite to the toner charge polarity (−)). Is applied). A transfer nip is formed between the transfer roller 10 and the intermediate transfer belt 61 by the transfer roller 10 and the intermediate transfer belt driving roller 62 being pressed against each other. In order to obtain the transfer nip constantly, one of the transfer roller 10 and the intermediate transfer belt driving roller 62 is a hard roller made of a hard material (metal or the like), and the other is a soft material (elastic rubber or foam). The elastic roller is made of a resin material such as a functional resin.

  When the transfer roller 10 transfers the toner image from the intermediate transfer belt 61 onto the paper P, the toner may remain on the intermediate transfer belt 61 without being transferred onto the paper P. The toner remaining on the intermediate transfer belt 61 causes toner color mixing in the next step. For this reason, the toner remaining on the intermediate transfer belt 61 is removed and collected by the intermediate transfer belt cleaning unit 65. Specifically, the intermediate transfer belt cleaning unit 65 includes a cleaning member (for example, a cleaning blade) that contacts the intermediate transfer belt 61. The driven roller 63 supports the intermediate transfer belt 61 from the inner side (back side), and the cleaning member is in contact with the intermediate transfer belt 61 so as to be pressed toward the driven roller 63 from the outer side.

  The paper feed tray 81 is a tray that previously stores paper P on which image formation (printing) is performed, and is provided below the exposure unit 1 in the apparatus main body 110. Further, the paper P on which an image is formed (printed) is placed on the manual paper feed tray 82. The discharge tray 91 is provided above the image forming unit 102 in the apparatus main body 110 and stacks the sheets P on which image formation (printing) has been performed face-down. The discharge tray 91 has an inclined surface 91a that is lower on the upstream side than on the downstream side from the center to the upstream end in the transport direction (in the direction of arrow Y1 in FIG. 1) of the placement surface 91x on which the paper P is placed. Yes. The discharge tray 91 is provided with a vertical wall 91b facing the upstream end (hereinafter referred to as the rear end P2) in the transport direction Y1 of the paper P placed on the placement surface 91x. The vertical wall 91b may be provided in the apparatus main body 110.

  Further, the apparatus main body 110 is provided with a sheet transport path S for sending the paper P sent from the paper feed tray 81 and the manual paper feed tray 82 to the discharge tray 91 through the transfer roller 10 and the fixing unit 7. ing. In the vicinity of the sheet conveyance path S, pickup rollers 11a and 11b, a plurality of (here, first to fourth) conveyance rollers 12a to 12d, a registration roller 13, a transfer roller 10, a heat roller 71 in the fixing unit 7, and a pressure are applied. A roller 72 and a discharge roller 31 are disposed.

  The first to fourth transport rollers 12 a to 12 d are small rollers for promoting and assisting transport of the paper P, and are provided along the sheet transport path S. The pickup roller 11 a is provided in the vicinity of the paper supply side of the paper feed tray 81, picks up the paper P one by one from the paper feed tray 81, and supplies it to the sheet conveyance path S. Similarly, the pickup roller 11 b is provided near the paper supply side of the manual paper feed tray 82, picks up the paper P one by one from the manual paper feed tray 82, and supplies it to the sheet conveyance path S.

  The registration roller 13 temporarily holds the paper P that is being conveyed in the sheet conveyance path S. The registration roller 13 conveys the sheet P to the transfer roller 10 at a timing when the leading edge of the toner image on the photosensitive drums 3,... To do.

  The fixing unit 7 fixes an unfixed toner image on the paper P, and includes a heat roller 71 and a pressure roller 72 that act as a fixing roller. The heat roller 71 is driven to rotate so as to convey the paper P while sandwiching the paper P together with the pressure roller 72 that is driven to rotate. The heat roller 71 is heated by a heater 71a provided on the inner side, and is maintained at a predetermined fixing temperature based on a signal from the temperature detector 71b. The heat roller 71 heated by the heater 71a thermally bonds the multicolor toner image transferred onto the paper P together with the pressure roller 72 to the paper P, thereby melting, mixing, and pressing the multicolor toner image. Heat fix. The fixing unit 7 is provided with an external heating belt 73 for heating the heat roller 71 from the outside.

  In the image forming apparatus 100 configured as described above, when single-sided printing is requested for the paper P, the paper P supplied from the paper feed trays 81 and 82 is provided along the sheet conveyance path S. 1 is conveyed to the registration roller 13 by the conveying roller 12a, and is conveyed by the transfer roller 10 at a timing when the leading edge P1 of the paper P and the leading edge of the toner image on the intermediate transfer belt 61 are aligned, and the toner image is transferred onto the paper P. . Thereafter, the sheet P passes through the fixing unit 7, whereby unfixed toner on the sheet P is melted and fixed by heat, and is discharged onto the discharge tray 91 through the second conveyance roller 12 b and the discharge roller 31.

  When double-sided printing is requested for the paper P, the trailing edge P2 of the paper P that has passed through the fixing unit 7 after completion of the above-described single-sided printing is between the discharge roller 31 and the branch portion Sa of the sheet conveying path S. The paper P is guided to the third and fourth transport rollers 12c and 12d by the reverse rotation of the discharge roller 31 in a state of being positioned therebetween. Then, the paper P conveyed to the transfer nip via the registration roller 13 is printed on the back surface and then discharged to the discharge tray 91.

(About sheet sorting equipment)
The image forming apparatus 100 according to the present embodiment includes a sheet sorting device 120 that sorts the paper P discharged by the discharge roller 31 by shifting the discharge roller 31 along the axial direction of the discharge roller 31. .

  FIG. 2 is a schematic cross-sectional view showing the discharge roller 31 and its peripheral portion in the sheet sorting apparatus 120 according to the embodiment of the present invention. FIG. 3 is a schematic side view of the sorting configuration in the sheet sorting apparatus 120 according to the embodiment of the present invention as viewed from the conveyance direction Y1 of the paper P.

  As shown in FIGS. 2 and 3, the sheet sorting apparatus 120 includes a discharge roller shift unit 30 (an example of a sheet conveying unit) having a discharge roller 31, a rotation drive unit 40, a shift drive unit 50, and a discharge tray 91. And.

  The discharge roller shift unit 30 is provided to be reciprocally movable along the axial direction of the discharge roller 31 (the arrow X direction in FIG. 3, hereinafter referred to as the shift direction X) with respect to the apparatus main body 110. That is, the shift direction X is a direction along the sheet surface orthogonal to the conveyance direction Y1 of the sheet P. The discharge roller shift unit 30 is supported by the apparatus main body 110 via a sliding member (specifically, a slide rail) 30b (see FIG. 2) that can be reciprocated along the shift direction X. In addition, the sliding member 30b can be set as a conventionally well-known structure, and detailed description is abbreviate | omitted here.

  The main body frame 30a of the discharge roller shift unit 30 is provided with a detection piece 30c detected by the position detection switch SWp. The position detection switch SWp detects whether or not the discharge roller shift unit 30 is located at a reference position (specifically, a central position in the shift direction X (standard position where sorting is not performed)). Here, a transmission type optical sensor that detects a detection piece 30c (see FIGS. 2 and 3) provided on the main body frame 30a of the discharge roller shift unit 30 is used.

  The discharge roller 31 discharges the paper P to the discharge tray 91, and includes a discharge roller pair 34 including a discharge drive roller 32 and a discharge driven roller 33 here.

  Specifically, the drive discharge roller 32 includes a drive roller shaft 32a and a plurality (four in this case) of drive roller portions 32b that are coaxially fixed to the drive roller shaft 32a. The discharge driven roller 33 includes a driven roller shaft 33a and a plurality of driven roller portions 33b arranged coaxially with the driven roller shaft 33a and facing the driving roller portion 32b. The discharge roller 31 further includes an urging member (here, a winding spring) 35 that urges the driven roller portion 33b toward the drive roller portion 32b.

  The discharge roller pair 34 and the urging member 35 are provided on the main body frame 30 a of the discharge roller shift unit 30, and one end of the discharge drive roller 32 extends from the main body frame 30 a of the discharge roller shift unit 30 in the shift direction X. It protrudes outward.

  Here, the drive roller shaft 32 a of the discharge drive roller 32 is a single roller, and is provided so as to be rotatable about the axis with respect to the main body frame 30 a of the discharge roller shift unit 30.

  Here, a plurality of (here, two) driven roller shafts 33a of the discharge driven roller 33 are juxtaposed along the shift direction X, and a plurality of (here, two) driven roller portions 33b are fixedly arranged. Has been. The driven roller shaft 33a is rotatable about the axis relative to the main body frame 30a of the discharge roller shift unit 30 so that the driven roller portion 33b faces the corresponding drive roller portion 32b, and in the vertical direction (see FIG. It can be reciprocated along the middle arrow Z direction). The discharge roller 31 is transported while being held in a state where the paper P is pressed by the discharge driven roller 33 at the nip portion N between the discharge drive roller 32 and the discharge driven roller 33.

  Specifically, the urging member 35 urges the discharge driven roller 33 toward the discharge drive roller 32. Here, the driven roller shaft 33a and the main body frame 30a of the discharge roller shift unit 30 are provided. It is arranged between the position opposite to the discharge drive roller 32. The pressing force of the discharge driven roller 33 to the discharge drive roller 32 by the urging member 35 is a pressure at which the paper P is properly conveyed.

  The rotation drive unit 40 drives the discharge roller 31 to rotate, and includes a conveyance drive motor 41 (here, a stepping motor) and a drive transmission mechanism 42 that transmits the rotation drive from the conveyance drive motor 41 to the discharge roller 31. I have.

  The conveyance drive motor 41 is provided in the apparatus main body 110 so that the rotation shaft 41a is along the shift direction X.

  Here, the drive transmission mechanism 42 is configured by a gear train in which a plurality of gears are arranged, and here includes a drive gear 42a, a roller gear 42b, and an intermediate gear 42c.

  The drive gear 42 a is connected to the rotation shaft 41 a of the transport drive motor 41. The roller gear 42b is connected to the end of the driving roller shaft 32a that protrudes outward in the shift direction X from the main body frame 30a of the discharge roller shift unit 30. The intermediate gear 42c is rotatably supported by a rotating shaft 110a fixed to the apparatus main body 110, and meshes with the drive gear 42a and the roller gear 42b. Here, the gear teeth of the drive gear 42a, the roller gear 42b, and the intermediate gear 42c are formed in an uneven strip extending in the shift direction X, and the roller gear 42b is slid in the shift direction X in a state where the roller gear 42b is engaged with the intermediate gear 42c. It can be moved. The length of the intermediate gear 42c in the shift direction X is the length that allows the movement width of the discharge roller shift unit 30 in the shift direction X (the length obtained by adding the length corresponding to the shift amount to the meshing length of the gear). The length of the roller gear 42b does not separate from the intermediate gear 42c even when the discharge roller shift unit 30 reciprocates in the shift direction X.

  The shift drive unit 50 shifts and moves the discharge roller 31 (here, the discharge roller shift unit 30). The shift drive unit 50 shifts the shift drive motor 51 (here, a stepping motor) and the discharge roller shift unit 30. And a shift mechanism 52.

  The shift drive motor 51 is provided in the apparatus main body 110 so that the rotating shaft 51a is along a direction orthogonal to the shift direction X (here, the vertical direction Z).

  Here, the shift mechanism 52 is configured by a rack and pinion gear that converts the drive in the rotation direction into the drive in the linear direction, and includes a rack gear 52a extending along the shift direction X and a cylindrical pinion gear 52b. And.

  The end of the rack gear 52 a in the shift direction X is connected to the end of the discharge roller shift unit 30. The pinion gear 52b is connected to the rotation shaft 51a of the shift drive motor 51 and meshes with the rack gear 52a. Thereby, the discharge roller shift unit 30 can be reciprocated in the shift direction X by the rotation shaft 51a of the shift drive motor 51 rotating in one direction or the other direction.

  The conveyance drive motor 41 is electrically connected to the output system of the control unit so as to obtain a drive signal (ON signal) or a drive stop signal (OFF signal) from a control unit (not shown). A rotation instruction signal for instructing the direction is transmitted to the transport drive motor 41 to drive the transport drive motor 41, so that the first discharge rollers 31 are moved in one direction (transport direction Y1) or in the other direction (transport direction Y1). It can be rotated in the opposite direction. In the present embodiment, during double-sided printing, the conveyance drive motor 41 is also instructed to rotate in the direction opposite to the one direction A. The description is omitted because it is not directly related to the control of the sorting configuration.

  The shift drive motor 51 is electrically connected to the output system of the control unit so as to obtain a drive signal (ON signal) or a drive stop signal (OFF signal) from the control unit (not shown). Rotation for moving the roller shift unit 30 in one side of the shift direction X (left side direction X1 in FIG. 3) and the discharge roller shift unit 30 in the other side of the shift direction X (right side direction X2 in FIG. 3) A movement instruction signal for instructing rotation to be transmitted is transmitted to the shift drive motor 51 and the shift drive motor 51 is pulse-driven with reference to the reference position, so that the discharge roller shift unit 30 is moved in the direction X1 on one side and the other Shift drive in the side direction X2 is possible.

  In the present embodiment, the discharge tray 91 has a maximum stacking capacity of paper P of 500 sheets or more.

  In the sheet sorting apparatus 120 described above, the driving force from the transport driving motor 41 is transmitted to the drive transmission mechanism 42 by driving the transport driving motor 41 in accordance with the rotation instruction signal from the control unit. 31 is rotationally driven in one direction A. Further, when the shift drive motor 51 is driven by the movement instruction signal from the control unit, the driving force from the shift drive motor 51 is transmitted to the shift mechanism 52, whereby the discharge roller shift unit 30 is moved in one direction. Shift shift in X1 or other direction X2.

  FIG. 4 is an explanatory diagram for explaining a sorting operation by the sheet sorting apparatus 120 according to the embodiment of the present invention. FIG. 4A is a schematic plan view illustrating a state in which the paper P is discharged at one shift end (moving end) in the shift direction X. FIG. FIG. 4B is a schematic plan view showing a state in which the paper P is discharged at the shift end (moving end) on the other side in the shift direction X. FIG. 4C is a schematic cross-section of the discharge state of the paper P when the discharge roller shift unit 30 reaches the shift end α on one side in the shift direction X or the shift end β on the other side, as viewed from the shift direction X. FIG. FIG. 4D is a schematic plan view showing the positional relationship between the sorting width Sb of the paper P discharged to the discharge tray 91 and the discharge roller shift unit 30.

  As shown in FIG. 4, when the paper P is sorted to one side (left side in the figure) or the other side (right side in the figure) in the shift direction X, a paper passage signal is sent from the first detection switch SW1 (see FIG. 2). After the input and recognizing that the discharge roller 31 is holding the paper P (see FIG. 4C), the discharge roller shift unit 30 is shifted to one side of the shift end X in the shift direction X (α in FIG. 4A). Or the other side shift end β (see β in FIG. 4B), and the discharge roller shift unit 30 moves to the one side shift end α or the other side shift end β in the shift direction X. After the shift movement is completed (stopped), the paper P is discharged. The first detection switch SW1 detects whether or not the paper P passes through the discharge roller 31, and is here disposed in the vicinity of the upstream side of the discharge roller 31 in the transport direction Y1.

  As described above, in the sorting operation by the sorting configuration shown in FIG. 3, the sorting width Sb (see FIG. 4D, specifically 30 mm) of the paper P discharged to the discharge tray 91 is shifted by the discharge roller shift unit 30. This is equal to the shift amount L in the direction X (see FIG. 4D, specifically 30 mm). The discharge roller shift unit 30 moves from the center position in the shift direction X (standard position where sorting is not performed) by L / 2 on one side, and shift amount L / 2 on one side and shift amount L / on the other side. 2, the shift amount is L as a whole.

(Sheet holding guide member)
As shown in FIG. 5, the sheet sorting apparatus 120 includes a sheet pressing guide member 300. In FIG. 1, the sheet pressing guide member 300 is not shown.

  FIG. 5 shows a state in which the sheet P placed on the discharge tray 91 is pressed by the sheet pressing guide member 300 provided in the discharge roller shift unit 30 in the sheet sorting apparatus 120 according to the embodiment of the present invention. 3 is a schematic side view seen from a shift direction X. FIG.

  The sheet pressing guide member 300 is configured to press the paper P in contact with the paper P placed on the discharge tray 91. The sheet pressing guide member 300 also has a function of stably dropping the paper P that has jumped out of the discharge roller shift unit 30 downward.

  The sheet pressing guide member 300 is provided at the center in the shift direction X at the upper part of the discharge port 30 c of the discharge roller shift unit 30. Thus, the sheet pressing guide member 300 moves together with the discharge roller shift unit 30 as the discharge roller shift unit 30 moves in the shift direction X.

  The sheet sorting apparatus 120 includes a contact member 310. The contact member 310 is in contact with the paper P discharged to the discharge tray 91 and is provided on the sheet pressing guide member 300.

  5, reference numerals 301 and 302 (first and second support plates), reference numeral 311 (roller), reference numeral 312 (friction member), reference numeral 330 (guide member), reference numeral R (contact portion), reference numeral θ (angle), Q1 (rotation axis), Y2 (downward tilt direction), and W (virtual tangent) will be described later.

  FIG. 6 is a schematic view showing an example of the contact member 310 in the holding guide member 300 and its peripheral portion. 6A shows a side view of an example of the contact member 310 viewed from the direction opposite to the conveyance direction Y1, and FIG. 6B is a cross-sectional view of the example of the contact member 310 viewed from the shift direction. Is shown.

  In the present embodiment, the contact member 310 is moved in the shift direction X of the bundle of sheets P stacked on the discharge tray 91 by the movement of the sheet pressing guide member 300 accompanying the movement of the discharge roller shift unit 30 in the shift direction X. It has a coefficient of friction that provides a frictional force that can reduce or eliminate movement of Further, the contact member 310 is in contact with the sheet P when the sheet pressing guide member 300 moves in the shift direction X due to frictional force with the sheet P sliding down the gradient of the inclined surface 91a on the placement surface 91x toward the upstream side in the transport direction Y1. It has a characteristic (hereinafter, simply referred to as a friction coefficient characteristic) having a friction coefficient larger than the friction force. That is, the contact member 310 shifts the friction coefficient in the transport direction Y1 (more specifically, the friction coefficient at least in the upstream direction of the transport direction Y1 (the lower inclined direction Y2 in FIGS. 5 and 6B)). The friction coefficient in the direction X is larger.

  By the way, when the sheet P is discharged to the discharge tray 91, the leading end P1 side is inclined surface 91a of the discharge tray 91 before the trailing edge P2 side of the sheet P contacts the inclined surface 91a of the discharge tray 91 or the sheet P on the inclined surface 91a. And the rear end P2 side of the paper P remains on the vertical wall 91b (so-called rear end remaining) is likely to occur. In this regard, according to the present embodiment, when the contact member 310 having the above-described coefficient of friction characteristics contacts the paper P, the timing at which the front end P1 side of the paper P slides down the gradient due to the inclined surface 91a can be delayed. Accordingly, it is possible to effectively prevent the trailing edge of the paper P from being generated, and thus it is possible to obtain stable stackability.

  The sheet pressing guide member 300 is provided such that the base end side thereof can swing in the vertical direction Z with respect to the discharge roller shift unit 30. Here, the sheet pressing guide member 300 is rotatable about an axis along the shift direction X (specifically, a rotation axis Q1 provided along the shift direction X on the discharge roller shift unit 30 (FIG. 5). It is provided so as to be rotatable with respect to (see). The sheet pressing guide member 300 is configured such that the leading end hangs down toward the discharge tray 91 due to its own weight and contacts the discharge tray 91 when there is no paper P (see FIG. 2). By doing so, the contact between the contact member 310 in the sheet pressing guide member 300 and the paper P discharged to the discharge tray 91 can be realized with a simple configuration.

  Specifically, the sheet pressing guide member 300 is an elongated plate-shaped or bar-shaped member (a plate-shaped member in the illustrated example), and the contact member 310 is provided at the tip of the sheet pressing guide member 300.

  In the present embodiment, the contact member 310 is a rolling member that rotates about an axis along the conveyance direction Y1 as the sheet pressing guide member 300 moves in the shift direction X by contact with the paper P on the discharge tray 91. (Specifically, a roller 311) and a friction member 312 provided on the surface of the roller 311.

  In the sheet sorting apparatus 120 having such a configuration, the contact member 310 having the friction coefficient characteristics described above can be realized with a simple configuration in which the friction member 312 is provided on the surface of the roller 311.

  Specifically, as shown in FIG. 6, the roller 311 includes first and second support shafts 321 and 322 that protrude outwardly at the end portions on the downstream side and the upstream side in the transport direction Y1. Further, the sheet pressing guide member 300 includes a first support member (specifically, a first support plate 301 along the shift direction X) erected downward at the front end, and a transport direction Y1 more than the first support plate 301. And a second support member (specifically, a second support plate 302 along the shift direction X) that is erected downward on the upstream side.

  Each of the first and second support plates 301 and 302 is provided with a bottomed hole or a through hole (here, the through holes 301a and 302a) along the transport direction Y1. The through holes 301a and 302a support the first and second support shafts 321 and 322 of the roller 311 so as to be rotatable about the axis. By providing such a configuration, the contact member 310 is configured such that the roller 311 is rotatable around an axis along the transport direction Y1. Here, the frictional force at the first and second support shafts 321 and 322 with respect to the first and second support plates 301 and 302 of the roller 311 is generated on the discharge tray 91 by the movement of the sheet pressing guide member 300 in the shift direction X. The frictional force is such that the movement of the paper P in the shift direction X can be reduced or eliminated.

  In the present embodiment, in the first and second support plates 301 and 302, the lower sides of the first and second support shafts 321 and 322 are opened with a width smaller than the diameter of the support shafts 321 and 322 (see FIG. 6 (a)), the first and second support shafts 321 and 322 are detachably fitted in the vertical direction.

  In the present embodiment, the sheet pressing guide member 300 and the first and second support plates 301 and 302 are made of resin, and the sheet pressing guide member 300 and the first and second support plates 301 and 302 Are integrally formed.

  In the present embodiment, a sheet-like rubber member (for example, CR rubber) is attached to the surface of the roller 311 as an friction member 312 with an adhesive (not shown). A suede may be used instead of the rubber member.

  By the way, when the load amount of the paper P stacked on the discharge tray 91 changes (increases) when the paper P is discharged, the upper surface of the paper P at the contact portion R with the contact member 310 of the paper P on the discharge tray 91. Since the angle θ (see FIG. 5) between the virtual tangent W (see FIG. 5) with the contact surface (see FIG. 5) and the sheet pressing guide member 300 that holds the paper P may change, the paper P of the contact member 310 and May change, and the contact area with the paper P in the transport direction Y1 may decrease. As a result, the frictional force of the contact member 310 with the sheet P sliding down the gradient by the inclined surface 91a in the lower inclined direction Y2 upstream in the transport direction Y1 is reduced, and the effect of preventing the remaining rear end of the sheet P is reduced accordingly. End up.

  From this point of view, in the present embodiment, the contact member 310 is configured to maintain the contact area in the conveyance direction Y1 with the paper P regardless of the change in the angle θ. By doing so, it is possible to maintain the effect of preventing the remaining trailing edge of the paper P even if the amount of the paper P stacked on the discharge tray 91 changes (increases) when the paper P is discharged.

  Specifically, the contact member 310 has a curved surface shape with a convex shape in the transport direction Y1 on the surface. In such a configuration, in addition to maintaining the effect of preventing the trailing edge of the paper P from being maintained, the contact area of the contact member 310 with the paper P can be reduced, whereby the sheet pressing guide member 300 moves in the shift direction X. The frictional force of the contact member 310 with the paper P can be reduced, and the movement of the paper P on the discharge tray 91 in the shift direction X can be suppressed accordingly. Specifically, the shape of the contact member 310 is a barrel shape whose major axis direction is the rotation axis direction.

  Further, the sheet P from the discharge roller shift unit 30 is moved to the outside from the joint portion between the sheet pressing guide member 300 and the contact member 310 (specifically, the second support plate 302 or the through hole 302a of the second support plate 302). The protruding second support shaft 322) is easily caught. As a result, the stackability of the paper P is lowered.

  From this point of view, in the present embodiment, the sheet sorting apparatus 120 includes a guide member 330. The guide member 330 guides the paper P from the discharge roller shift unit 30 to the lower side of the contact member 310, and is provided on the upstream side of the contact member 310 in the sheet pressing guide member 300. In this way, the guide member 330 provided on the sheet pressing guide member 300 can prevent the paper P from contacting the contact portion R of the paper P from the discharge roller shift unit 30, thereby reducing the stacking property of the paper P. It can be effectively prevented. 3 and 4, the guide member 330 is not shown.

  Specifically, the guide member 330 moves toward the contact portion V (see FIG. 2) of the contact member 310 with the placement surface 91x of the discharge tray 91 in a state where the paper P is not discharged to the discharge tray 91, or In the state in which the paper P is discharged to the discharge tray 91, the contact portion R (see FIG. 5) with the paper P on the placement surface 91x (for example, the second support plate 302 or the second support shaft). It is set as the structure guided (lower than 322). Specifically, the guide member 330 has a curved shape that branches in the middle of the front end side of the sheet pressing guide member 300 and extends slightly downward toward the downstream side of the second support plate 302. ing. Further, the guide member 330 is not in contact with the placement surface 91x of the discharge tray 91 or the paper P on the placement surface 91x. Here, the guide member 330 is made of resin, and the sheet pressing guide member 300 and the guide member 330 are integrally formed.

  Further, in the present embodiment, the vertical wall 91b is formed from the viewpoint of securing a placement area of the placement surface 91x on which the rear end P2 side of the paper P is placed when the paper P is discharged to the discharge tray 91. It is located outside a virtual arc T shown in FIG.

  FIG. 7 is a schematic side view showing a state where the sheet P is not placed on the discharge tray 91 in the sheet sorting apparatus 120 shown in FIG.

  As shown in FIG. 7, the virtual arc T is downstream in the transport direction Y1 of the discharge roller shift unit 30 around the upstream end Va of the transport direction Y1 of the contact position V between the contact member 310 and the mounting surface 91x of the discharge tray. The arc is in contact with the side end 30d. Thus, since the vertical wall 91b is located outside the virtual arc T, when the paper P is discharged to the discharge tray 91, the rear end P2 end side of the paper P is placed on the placement surface 91x. A placement area can be secured.

  In the present embodiment, the contact member 310 may be configured to include a brush member 340 having brush hairs 341 (see FIG. 8 to be described later) instead of the configuration including the roller 311 and the friction member 312.

  FIG. 8 is a schematic view showing another example of the contact member 310 in the pressing guide member 300 and its peripheral portion. FIG. 8A shows a side view of another example of the contact member 310 viewed from the direction opposite to the transport direction Y1, and FIG. 8B shows another example of the contact member 310 from the shift direction. A side view is shown.

  In the configuration shown in FIG. 8, the same reference numerals are given to substantially the same configurations as those shown in FIGS. 5 to 7, and descriptions thereof are omitted.

  As shown in FIG. 8, the brush member 340 is a member in which the bristle 341 is flocked to the substrate 342 so that the front end side of the bristle 341 is inclined toward the transport direction Y1 side. By doing so, the contact member 310 having the friction coefficient characteristics described above can be realized with a simple configuration in which the brush member 340 is used.

  Specifically, the contact member 310 includes a support portion 350 that supports the brush member 340. The support portion 350 is provided at the tip of the pressing guide member 300. Here, the support portion 350 is made of resin, and the sheet pressing guide member 300 and the support portion 350 are integrally formed.

  The brush member 340 is a planar brush member having a friction directionality in which the frictional force varies depending on the direction of the paper P in contact. In the present embodiment, support portion 350 has a curved surface shape with a convex shape in the transport direction Y1 on the surface, and brush member 340 is attached to the surface of support portion 350 with an adhesive (not shown). It has been. Here, the frictional force in the shift direction X of the brush member 340 can reduce or eliminate the movement of the sheet P on the discharge tray 91 in the shift direction X due to the movement of the sheet pressing guide member 300 in the shift direction X. It is said that the frictional force is about.

  In the present embodiment shown in FIGS. 5 to 8, the contact member 310 has a convex curved surface shape in the transport direction Y1 on the surface, but in addition to or instead of such a configuration, The sheet pressing guide member 300 may be supported so as to be rotatable about an axis along the shift direction X.

  FIG. 9 is supported by the sheet pressing guide member 300 so as to be rotatable about an axis along the shift direction X in the example of the contact member 310 shown in FIGS. 5 to 7 and the other example of the contact member 310 shown in FIG. It is the schematic which shows the structure performed. FIG. 9A shows an example of the contact member 310. FIG. 9B shows another example of the contact member 310. 9A, the same reference numerals are given to substantially the same configurations as those shown in FIGS. 5 to 7, and in FIG. 9B, the same configurations as those shown in FIG. A description thereof will be omitted.

  In the example shown in FIG. 9, the contact member 310 has a straight shape in the transport direction Y1 on the surface.

  In the example of the contact member 310 shown in FIG. 9A, one of the first and second support shafts 321 and 322 (here, 1321) is movable up and down with respect to the sheet pressing guide member 300. It is supported. Specifically, the through hole 301 a provided in the first support plate 301 is a long hole extending in the vertical direction Z. The through hole 302a provided in the second support plate 302 has a diameter in the vertical direction Z that increases from the upstream side to the downstream side in the transport direction Y1. With this configuration, the contact member 310 is rotatable around the axis 322a along the shift direction. Here, the frictional force at the first and second support shafts 321 and 322 with respect to the first and second support plates 301 and 302 of the roller 311 is generated on the discharge tray 91 by the movement of the sheet pressing guide member 300 in the shift direction X. The frictional force is such that the movement of the paper P in the shift direction X can be reduced or eliminated.

  In another example of the contact member 310 shown in FIG. 9B, the support portion 350 includes a pair of support shafts 351 and 351 that protrude outward on both sides in the shift direction X. In FIG. 9B, only the front support shaft 351 is shown. Further, the sheet pressing guide member 300 has a pair of support members (specifically, a pair of support plates 303 and 303 along the conveyance direction Y1) standing downward at the front end with a gap in the shift direction X. is doing. In FIG. 9B, only the front support plate 303 is shown.

  Each of the pair of support plates 303 and 303 is provided with a bottomed hole or a through hole (here, the through holes 303a and 303a) along the shift direction X. The through holes 303a and 303a support the support shafts 351 and 351 of the support portion 350 so as to be rotatable about the axis. By providing such a configuration, the contact member 310 is rotatable about an axis line (support shaft 351) along the shift direction X. Here, the frictional force in the shift direction X of the brush member 340 can reduce or eliminate the movement of the sheet P on the discharge tray 91 in the shift direction X due to the movement of the sheet pressing guide member 300 in the shift direction X. It is said that the frictional force is about.

  In this example, in the pair of support plates 303 and 303, the lower sides of the support shafts 351 and 351 are opened with a width smaller than the diameter of the support shafts 351 and 351, and the support shafts 351 and 351 can be attached and detached in the vertical direction. It is supposed to be fitted to the.

  In this example, the pair of support plates 303 and 303 are made of resin, and the sheet pressing guide member 300 and the pair of support plates 303 and 303 are integrally formed.

  In the configuration shown in FIG. 9, even when the stacking amount of the paper P on the discharge tray 91 changes (increases) when the paper P is discharged, the contact member 310 is rotated about the axis along the shift direction X as a fulcrum. Accordingly, the contact area of the contact member 310 with the paper P in the transport direction Y1 can be maintained.

30 discharge roller shift unit (an example of a sheet conveying unit)
30d The downstream end 91 in the transport direction Y1 of the discharge roller shift unit 30 The discharge tray (an example of a sheet discharge tray)
91a Inclined surface 91x Placement surface 91b Vertical wall 100 Image forming apparatus 110 Apparatus main body 120 Sheet sorting apparatus 300 Sheet pressing guide member 310 Contact member 311 Roller (an example of a rolling member)
312 Friction member 330 Guide member 340 Brush member 341 Brush bristle 342 Base P Paper (an example of sheet)
P1 Front end P2 Rear end T Virtual arc V Contact position Va Transport direction Y1 of contact position V Upstream end X Shift direction Y1 Transport direction Y2 Lower tilt direction θ Angle

Claims (12)

A sheet sorting apparatus that sorts a sheet placed on a sheet discharge tray from the sheet transport unit by shifting a sheet transport unit that transports a sheet in a shift direction along a sheet surface that intersects the sheet transport direction. And
A sheet pressing guide member for pressing the sheet in contact with the sheet placed on the sheet discharge tray;
The sheet pressing guide member is configured to move together with the sheet conveying unit as the sheet conveying unit moves in the shift direction.
The sheet discharge tray has an inclined surface whose upstream side is lower than the downstream side in the transport direction on the sheet mounting surface,
The sheet pressing guide member is provided with a contact member that contacts the sheet discharged to the sheet discharge tray.
The contact member has a frictional force with the sheet when the sheet pressing guide member moves in the shift direction due to frictional force with the sheet sliding down the gradient due to the inclined surface of the sheet discharge tray to the upstream side in the transport direction. A sheet sorting apparatus characterized by having a configuration larger than the force. The sheet sorting apparatus according to claim 1,
The sheet pressing guide member is configured such that a base end side thereof is swingable in a vertical direction with respect to the sheet conveying unit, and a leading end side is configured to hang down to the sheet discharge tray side by its own weight. apparatus. The sheet sorting apparatus according to claim 2,
The contact member is configured to maintain a contact area in the conveyance direction with the sheet regardless of a change in an angle between the sheet on the sheet discharge tray and the sheet pressing guide member that contacts the sheet. A sheet sorting apparatus characterized by that. The sheet sorting apparatus according to claim 3,
The sheet sorting apparatus according to claim 1, wherein the contact member has a convex curved surface shape in the transport direction. The sheet sorting apparatus according to claim 3 or 4,
The sheet sorting apparatus according to claim 1, wherein the contact member is supported by the sheet pressing guide member so as to be rotatable about an axis along the shift direction. The sheet sorting apparatus according to any one of claims 2 to 5,
The sheet sorting apparatus according to claim 1, wherein the sheet pressing guide member is provided with a guide member that guides the sheet from the sheet conveying unit to the lower side of the contact member. A sheet sorting apparatus according to any one of claims 2 to 6,
The main body of the image forming apparatus provided with the sheet discharge tray or the sheet sorting apparatus is provided with a vertical wall facing the upstream end in the transport direction of the sheet placed on the placement surface,
The vertical wall is a virtual arc in contact with the downstream end in the transport direction of the sheet transport unit with the upstream end in the transport direction of the contact position between the contact member and the placement surface of the sheet discharge tray as a center point The sheet sorting apparatus is characterized by being located outside. A sheet sorting apparatus according to any one of claims 2 to 7,
The contact member is provided at a front end of the sheet pressing guide member, and along the transport direction as the sheet pressing guide member moves in the shift direction by contact with the sheet on the sheet discharge tray. A sheet sorting apparatus comprising: a rolling member that rotates about an axis; and a friction member provided on a surface of the rolling member. The sheet sorting apparatus according to claim 8, wherein
The sheet sorting apparatus according to claim 1, wherein the friction member is a rubber member. The sheet sorting apparatus according to claim 8, wherein
The sheet sorting apparatus according to claim 1, wherein the friction member is a suede. A sheet sorting apparatus according to any one of claims 2 to 7,
The contact member is provided at a tip of the sheet pressing guide member, and includes a brush member having brush hairs,
The sheet sorting apparatus according to claim 1, wherein the brush member is a member in which the brush bristles are planted so that a front end side of the bristles is inclined in the conveying direction.   An image forming apparatus comprising the sheet sorting apparatus according to any one of claims 1 to 11.

Images