JP6713366B2 - Sheet discharge device and image forming apparatus including the same - Google Patents

Description

The present invention relates to a sheet discharging device that discharges a sheet such as a recording sheet to a discharging tray, and an image forming apparatus such as a copying machine, a multifunction peripheral, a printer, and a facsimile device.

As a sheet discharging device that discharges a sheet such as a recording sheet to a discharge tray, a discharge roller that conveys a sheet in a predetermined conveying direction and discharges it to the discharge tray is shifted along the axial direction of the discharge roller. Conventionally, there is known one provided with a sheet sorting section for sorting sheets discharged by the discharging roller (for example, refer to Patent Document 1).

In the sheet discharging device including such a sheet sorting unit, the sheet is shifted in the axial direction by the sheet sorting unit and discharged while being transported in the transport direction by the discharging roller.

Further, as a sheet discharging device, there is a sheet discharging device provided with an upper member provided above the discharging tray with a space (see, for example, Patent Documents 2 and 3).

For example, Patent Document 2 discloses a configuration in which a paper discharge unit (upper member) is provided above a paper discharge tray (discharge tray) with a space therebetween. Patent Document 3 discloses a configuration in which an additional paper discharge tray (upper member) is provided above the in-body paper discharge unit (discharge tray) with a space.

JP, 2012-25545, A JP, 2005-75547, A JP 10-17195 A

When a sheet is discharged from the sheet discharge device, the sheet may be discharged in a skewed state instead of being discharged straight. Further, when the sheet is a thin paper, the leading edge of the sheet may be inclined with respect to the discharging direction even if the sheet is straight when passing through the discharging roller. In such a case, there is a problem that the sheet is easily caught on the bottom surface of the upper member.

The present invention has been made to solve the above problems, and provides a sheet discharge device and an image forming apparatus that can smoothly discharge a sheet that is discharged while being inclined, without being obstructed by an upper member. With the goal.

Further, in the sheet discharging device, when the sheet sorting unit and the upper member are provided, the sheet sorting unit shifts the sheet along the axial direction while discharging the sheet while transporting the sheet in the transport direction by the discharging roller. The bottom surface of the upper member, which faces the discharge tray, may be slidably contacted, which causes a problem that a sheet discharged while shifting in the axial direction while being transported in the transport direction is easily caught by the bottom surface of the upper member. is there. For example, when a protrusion (for example, a reinforcing rib) is provided on the bottom surface of the upper member, the downstream side end (front end) in the sheet conveying direction, the side end in the axial direction, and the corner between the front end and the side end. At least one of the portions (so-called ears) (particularly the corner portion between the tip and the side edge) is easily caught by the protrusion (for example, the reinforcing rib).

Therefore, in the present invention, the sheet discharged by the discharge roller is shifted by shifting the discharge roller that conveys the sheet in a predetermined conveyance direction and discharges it to the discharge tray along the axial direction of the discharge roller. A sheet discharge device including a sheet sorting section for sorting sheets and an upper member provided above the discharge tray with a space therebetween, and shifts the sheet along the axial direction while discharging the sheet in the transport direction and discharges the sheet. In doing so, even if the sheet is in sliding contact with the bottom surface of the upper member facing the discharge tray, the sheet discharging apparatus and the image forming apparatus including the sheet discharging apparatus can prevent the sheet from being easily caught by the bottom surface of the upper member. The purpose is to provide.

A sheet discharging device according to the present invention includes a discharging roller that conveys a sheet in a predetermined conveying direction and discharges the sheet to a discharge tray, and an upper member provided above the discharge tray with a space. In the sheet discharging device, a plurality of guide ribs extending along an oblique direction inclined with respect to the conveyance direction are provided on a bottom surface of the upper member facing the discharge tray, and the plurality of guide ribs are the discharging ribs. The roller has an inner rib and an outer rib in the axial direction of the roller, and the inner guide rib is shorter than the outer guide rib while leaving a downstream side in the transport direction, It is characterized in that it is inclined so as to gradually become higher with respect to the bottom surface of the upper member from the upstream side to the downstream side in the transport direction .

In the sheet discharging device according to the present invention, a sheet sorting section that sorts the discharged sheet by shifting the discharging roller by shifting along the axial direction of the discharging roller is provided, and the guide rib is provided by the discharging roller in the conveying direction. The sheet sorting unit may be configured to extend in the sheet diagonal movement direction or the substantially sheet diagonal movement direction of the sheet that shifts along the axial direction while being conveyed to.

In the sheet discharging device according to the present invention, a sheet sorting section that sorts the discharged sheet by shifting the discharging roller by shifting along the axial direction of the discharging roller is provided, and the guide rib is provided by the discharging roller in the conveying direction. The sheet sorting unit may be positioned inside a side end in the axial direction of the sheet that shifts along the axial direction by the sheet sorting unit.

In the sheet discharging device according to the present invention, the guide rib may be provided on at least one of the side end portions of the discharge roller in the axial direction on the bottom surface of the upper member. Good.

In the sheet discharging device according to the present invention, the guide rib may be configured so as to gradually increase in height from the upstream side to the downstream side with respect to the bottom surface of the upper member in the transport direction.

In the sheet ejection device according to the present invention, the inner guide rib has an inclination angle of an inclined surface facing the discharge tray with respect to the bottom surface of the upper member, and the inclination angle of the inclined surface of the outer guide rib with respect to the bottom surface of the upper member is the discharge tray. The configuration may be larger than the angle of the facing top surfaces.

In the sheet discharging device according to the present invention, the inner guide rib is composed of a plurality of inclined rib portions connected from the upstream side to the downstream side in the transport direction, and the inclination angle of the inclined rib portion on the upstream side is the downstream side. The angle may be larger than the inclination angle of the inclined rib portion.

In the sheet discharging device according to the present invention, a cross rib extending along a direction intersecting with the guide rib is provided on the bottom surface of the upper member, and the guide rib is higher than the height of the cross rib. It may be configured to have.

In the sheet discharging apparatus according to the present invention, the intersecting rib may extend along an edge portion of the bottom surface of the upper member at a downstream end in the transport direction.

In the sheet discharging device according to the present invention, the bottom surface of the upper member may be provided with an auxiliary rib extending in a direction inclined with respect to the transport direction and having an end portion connected to the guide rib.

In the sheet discharging device according to the present invention, the guide rib is such that a rib end portion which is a portion on the downstream side by a predetermined distance from the upstream side end in the conveyance direction is parallel or substantially parallel to the conveyance direction. It may be configured.

In the sheet discharging apparatus according to the present invention, the guide rib may be formed such that, when the sheet is slidably contacted, the top portion facing the discharging tray is in line contact or substantially line contact with the sheet.

An image forming apparatus according to the present invention includes the sheet discharging device according to the present invention.

According to the present invention, even if the sheet is in sliding contact with the bottom surface of the upper member, it is possible to make the sheet less likely to be caught by the bottom surface of the upper member.

FIG. 3 is a schematic cross-sectional view of the image forming apparatus according to the present embodiment as viewed from the front. FIG. 2 is a schematic cross-sectional view showing a discharge roller and its peripheral portion in the image forming apparatus shown in FIG. 1. FIG. 2 is a schematic side view of the sheet sorting unit in the image forming apparatus shown in FIG. 1 as viewed from the sheet conveying direction. FIG. 2 is a system block diagram of a control system of the image forming apparatus shown in FIG. 1. FIG. 6 is a schematic plan view of a state in which a sheet is discharged below an upper discharge tray in the sheet discharge device according to the present embodiment, as seen from a plane. It is the schematic perspective view which looked at the plane side of the upper discharge tray shown in FIG. 5 from diagonally right front. FIG. 6 is a schematic perspective view of the bottom surface side of the upper discharge tray shown in FIG. It is a front view in the schematic block diagram of the upper discharge tray shown in FIG. FIG. 6 is a left side view of the schematic configuration diagram of the upper discharge tray shown in FIG. 5. FIG. 6 is a bottom view of the schematic configuration diagram of the upper discharge tray shown in FIG. 5. FIG. 6 is an enlarged perspective view of a bottom surface side of a guide rib portion of the upper discharge tray shown in FIG. FIG. 6 is a schematic cross-sectional view showing an example (No. 1) of the cross-sectional shape of the guide rib in which the top portion is a flat surface or a curved surface when the guide rib is viewed from an oblique direction. FIG. 6 is a schematic cross-sectional view showing an example (No. 2) of the cross-sectional shape of the guide rib having a flat or curved top portion when the guide rib is viewed from an oblique direction. FIG. 7 is a schematic cross-sectional view showing an example (No. 3) of the cross-sectional shape of the guide rib in which the top portion is a flat surface or a curved surface when the guide rib is viewed from an oblique direction. FIG. 7 is a schematic cross-sectional view showing an example (No. 1) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 9 is a schematic cross-sectional view showing an example (No. 2) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 11 is a schematic cross-sectional view showing an example (No. 3) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 14 is a schematic cross-sectional view showing an example (No. 4) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 13 is a schematic cross-sectional view showing an example (No. 5) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 10 is a schematic cross-sectional view showing an example (No. 6) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. FIG. 9 is a schematic cross-sectional view showing an example (No. 7) of the cross-sectional shape of the guide rib having the inclined side surface in a state where the guide rib is viewed from an oblique direction. In the sheet ejection device according to the twelfth embodiment, it is a schematic plan view of a state in which a sheet is ejected below an upper ejection tray when seen from a plane. FIG. 14 is an enlarged bottom view showing the bottom surface of the upper discharge tray shown in FIG. 13 and the vicinity of the front guide rib in an enlarged manner. FIG. 15 is an enlarged cross-sectional view showing a cross section taken along arrow DD in FIG. 14.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Description of Overall Configuration of Image Forming Apparatus)
FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 according to this embodiment as viewed from the front.

The image forming apparatus 100 shown in FIG. 1 is a color image forming apparatus that forms a multicolor image and a single color image on a sheet P (recording sheet in this example) such as a recording sheet according to image data transmitted from the outside. Is. The image forming apparatus 100 includes a document reading device 108 and an image forming apparatus main body 110, and the image forming apparatus main body 110 is provided with an image forming unit 102 and a sheet conveying system 103. Specifically, the image forming apparatus 100 is a multi-function peripheral having a copy function, a printer function, and a facsimile function.

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

The sheet conveying system 103 also includes a paper feed tray 81, a manual paper feed tray 82, a discharge tray 14, and a sheet discharge device 400.

The sheet discharge device 400 shifts the discharge roller 31 that conveys the sheet P in a predetermined conveyance direction Y1 and discharges it to the discharge tray 14 along the axial direction X (shift direction) of the discharge roller 31. A sheet sorting unit 300 that sorts the sheets P discharged by the discharge rollers 31 and an upper discharge tray 15 (an example of an upper member) provided above the discharge tray 14 with a space SP therebetween are provided. The sheet ejection device 400 may include the ejection tray 14.

An original placing table 92 made of transparent glass on which an original (not shown) is placed is provided above the image forming apparatus main body 110, and an optical unit 90 for reading the original is provided below the original placing table 92. Has been. A document reading device 108 is provided above the document placing table 92. The document reading device 108 automatically conveys the document onto the document table 92. Further, the document reading device 108 is rotatably attached to the image forming apparatus main body 110 with the front side opened, and the document can be placed by hand by opening the top of the document placing table 92. ing.

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

The image data handled by the image forming apparatus 100 corresponds to a color image using a plurality of colors (black (K), cyan (C), magenta (M), and yellow (Y) in this example). .. Therefore, the developing units 2 to 2, the photoconductor drums 3 to 3, the cleaning units 4 to 4 to 4, the chargers 5 to 5, and the toner cartridge units 21 to 21 have a plurality of types (four types in this example) according to each color. A plurality of (four in this example, respectively, black, cyan, magenta, and yellow) are set so as to form images, and a plurality of (four in this example) image stations are configured by these. There is.

The chargers 5 to 5 are charging means for uniformly charging the surfaces of the photoconductor drums 3 to 3 to a predetermined potential, and in addition to a charger type as shown in FIG. 1, a contact type roller type or brush. Any type of charger can be used.

The exposure unit 1 is configured as a laser scanning unit including a laser emitting section 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 that guide the laser light reflected by the polygon mirror to the photosensitive drums 3 to 3.

The exposure unit 1 exposes the charged photoconductor drums 3 to 3 in accordance with the input image data to form an electrostatic latent image corresponding to the image data on the surface of each photoconductor drum 3 to 3. To form.

The toner cartridge units 21 to 21 are units for containing toner, and are configured to supply toner to the developing tanks of the developing units 2 to 2. In the image forming apparatus main body 110, the toner supplied from the toner cartridge units 21 to 21 to the developing tanks of the developing units 2 to 2 is controlled so that the toner concentration of the developer in the developing tanks becomes constant.

The developing units 2 to 2 visualize the electrostatic latent images formed on the photoconductor drums 3 to 3 with toners of four colors (Y, M, C, K). Further, the cleaning units 4 to 4 remove and collect the toner remaining on the surfaces of the photoconductor drums 3 to 3 after development and image transfer.

The intermediate transfer belt unit 6 arranged above the photosensitive drums 3 to 3 includes an intermediate transfer belt 61 acting as an intermediate transfer member, an intermediate transfer belt driving roller 62, an intermediate transfer belt driven roller 63, and a plurality of intermediate transfer rollers. 64-64 and an intermediate transfer belt cleaning unit 65 are provided.

Four intermediate transfer rollers 64 to 64 are provided for each color of Y, M, C, and K. The intermediate transfer belt driving roller 62 stretches the intermediate transfer belt 61 along with the intermediate transfer belt driven roller 63 and the intermediate transfer rollers 64 to 64, and is driven to rotate, whereby the intermediate transfer belt 61 is moved in the moving direction M in a circular manner. Accordingly, the intermediate transfer belt driven roller 63 and the intermediate transfer rollers 64 to 64 are driven to rotate.

A transfer bias for transferring the toner images formed on the photoconductor drums 3 to 3 onto the intermediate transfer belt 61 is applied to the intermediate transfer rollers 64 to 64.

The intermediate transfer belt 61 is provided so as to contact the photoconductor drums 3 to 3. On the intermediate transfer belt 61, the color toner images (multicolor toner images) are formed on the surface by sequentially transferring the toner images of the respective colors formed on the photoconductor drums 3 to 3 in an overlapping manner.

The transfer of the toner image from the photosensitive drums 3 to 3 to the intermediate transfer belt 61 is performed by the intermediate transfer rollers 64 to 64 which 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 charging polarity (-) of the toner) is applied to the intermediate transfer rollers 64 to 64 in order to transfer the toner image.

As described above, the toner images visualized in accordance with the respective hues on the respective photosensitive drums 3 to 3 are stacked on the intermediate transfer belt 61. The toner images stacked on the intermediate transfer belt 61 are transferred onto the sheet by the transfer roller 10 which constitutes a secondary transfer mechanism portion arranged at the contact position between the sheet P and the intermediate transfer belt 61 by the circular movement of the intermediate transfer belt 61. Transcribed on P.

At this time, the transfer roller 10 has a voltage (a polarity (+) opposite to the toner charging polarity (−)) for transferring the toner to the sheet P in a state where a transfer nip is formed between the transfer roller 10 and the intermediate transfer belt 61. High voltage) is applied. When the transfer roller 10 and the intermediate transfer belt drive roller 62 are pressed against each other, a transfer nip is formed between the transfer roller 10 and the intermediate transfer belt 61. Here, when the transfer roller 10 transfers the toner image from the intermediate transfer belt 61 onto the sheet P, the toner remaining on the intermediate transfer belt 61 without being transferred onto the sheet P is removed by the intermediate transfer belt cleaning unit 65. Removed and recovered.

The paper feed tray 81 is a tray for preliminarily accommodating a sheet P on which an image is formed (printed), and is provided below the exposure unit 1 in the image forming apparatus main body 110. A sheet P on which an image is formed (printed) is placed on the manual feed tray 82.

The discharge tray 14 is provided above the image forming unit 102 in the image forming apparatus main body 110, and stacks the image-formed (printed) sheets P face down. The discharge tray 14 is configured such that the upstream side of the placement surface 14a on which the sheet P is placed in the transport direction Y1 of the sheet P is lower than the downstream side. The discharge tray 14 is not limited thereto, but in this example, a copy sheet P having an image formed (printed) by the copy function and a printer sheet P having an image formed (printed) by the printer function are discharged. .. Then, the sheet P for copying and the sheet P for printer are sorted by the sheet sorting unit 300 in the discharge tray 14.

Further, the upper discharge tray 15 is provided above the discharge tray 14 in the image forming unit 102 of the image forming apparatus main body 110 with a space SP in between, and stacks the image-formed (printed) sheets P face down. To do. Like the discharge tray 14, the upper discharge tray 15 is configured such that the upstream side of the placement surface 15a on which the sheet P is placed in the transport direction Y1 of the sheet P is lower than the downstream side. The upper discharge tray 15 is not limited thereto, but in this example, the sheet P for a facsimile on which an image is formed (printed) by the facsimile function is discharged.

Further, in the image forming apparatus main body 110, a sheet conveyance path S1 for guiding the sheet P sent from the paper feed tray 81 or the manual paper feed tray 82 to the discharge tray 14 via the transfer roller 10 and the fixing unit 7. An upper sheet conveyance path S2 is provided that branches upward from a branching portion S1a located between the fixing unit 7 and the discharge roller 31 of the sheet conveyance path S1 and guides it to the upper ejection tray 15. In the vicinity of the sheet conveying path S1, pickup rollers 11a and 11b, plural (two in this example) conveying rollers 12a and 12b, a registration roller 13, a transfer roller 10, a heat roller 71 and a pressure roller 72 in the fixing unit 7. A discharge roller 31 is provided.

The upper transport roller 12c and the upper discharge roller 36 are disposed near the upper sheet transport path S2. A branch claw G1 is provided near the branch portion S1a. The branch claw G1 guides the sheet P from the fixing unit 7 to the discharge roller 31 in the first switching posture (the posture shown by the solid line in FIG. 1) and the second guide posture to guide the sheet P from the fixing unit 7 to the upper sheet conveying path S2. The switching posture (the posture shown in the imaginary line in FIG. 1) is taken.

Further, the upper discharge roller 36 rotates in the forward direction so as to discharge the sheet P to the upper discharge tray 15, and in the reverse direction so as to convey the sheet P to the side opposite to the conveying direction Y1 (so-called switchback). It is designed to rotate. The image forming apparatus main body 110 is provided with a reversal sheet conveyance path S3 that guides the sheet P from the upper branch portion S2a in the middle of the upper sheet conveyance path S2 to the upstream side of the registration rollers 13 of the sheet conveyance path S1 so that the front and back of the sheet P are reversed. It is provided.

A plurality of (four in this example) reversal conveyance rollers 12d to 12g are arranged near the reversal sheet conveyance path S3. An upper branch claw G2 is provided near the upper branch S2a. The upper branch claw G2 reverses the sheet P that is switched back from the upper discharge roller 36 and the first switching posture (the posture shown by the solid line in FIG. 1) that guides the sheet P from the branch portion S1a to the upper discharge roller 36. The second switching posture (the posture shown in the imaginary line in FIG. 1) is introduced to the transport path S3.

The conveying rollers 12a and 12b, the upper conveying roller 12c, and the reversing conveying rollers 12d to 12g are small rollers for promoting and assisting the conveyance of the sheet P, and the sheet conveying path S1, the upper sheet conveying path S2, and the reversal, respectively. It is provided along the sheet conveying path S3.

The pickup roller 11a is provided in the vicinity of the sheet supply side of the paper feed tray 81, and picks up the sheets P one by one from the paper feed tray 81 and supplies them to the sheet conveyance path S1. Similarly, the pickup roller 11b is provided in the vicinity of the sheet supply side of the manual paper feed tray 82, and picks up the sheets P one by one from the manual paper feed tray 82 and supplies them to the sheet conveying path S1.

Further, the registration rollers 13 temporarily hold the sheet P conveyed to the sheet conveying path S1. Then, the registration roller 13 transfers the sheet P to the transfer roller 10 and the intermediate transfer belt 61 at the timing when the front ends of the toner images on the photosensitive drums 3 to 3 are aligned with the downstream end (front end P1) of the sheet P in the transport direction Y1. To the transfer nip between.

The fixing unit 7 fixes an unfixed toner image on the sheet P, and includes a heat roller 71 and a pressure roller 72 that function as a fixing roller. The heat roller 71 is rotatably driven, and conveys the sheet P while sandwiching the sheet P together with the pressure roller 72 that is driven to rotate. The heat roller 71 is heated by a heater 71a provided inside and is maintained at a predetermined fixing temperature based on a signal from a temperature detector 71b. The heat roller 71 heated by the heater 71a heats and press-bonds the multicolor toner image transferred onto the sheet P together with the pressure roller 72 to the sheet P, thereby melting, mixing, and pressure contacting the multicolor toner image. Heat fix against.

In the image forming apparatus 100 configured as above, when the printing of the copy function or the printer function is requested, first, the branch claw G1 is set to the first posture, and when the printing of the facsimile function is requested, the branch claw G1 is changed. While taking the second posture, the upper branch claw G2 is put in the first posture. Next, the sheet P is supplied from the sheet feeding tray 81 or the manual sheet feeding tray 82, and the sheet P is conveyed to the registration roller 13 by the conveying roller 12a provided along the sheet conveying path S1. Next, the transfer roller 10 conveys the sheet P at the timing when the front end P1 of the sheet P and the front end of the toner image on the intermediate transfer belt 61 are aligned, and the toner image is transferred onto the sheet P. Thereafter, by passing the sheet P through the fixing unit 7, the unfixed toner on the sheet P is melted and fixed by heat, and when the printing of the copy function or the printer function is requested, the conveying roller 12b, the branching claw G1 and the discharge are performed. While the sheet P is discharged onto the discharge tray 14 via the roller 31, when printing of the facsimile function is requested, the sheet P is discharged onto the upper discharge tray 15 via the transport roller 12b, the branch claw G1, the upper branch claw G2 and the upper discharge roller 36. Then, the sheet P is discharged.

Further, when double-sided printing is requested for the sheet P, the branch claw G1 is temporarily set to the second posture while the upper branch claw G2 is set to the first posture. Next, after the sheet P is passed through the fixing unit 7 and single-sided printing is completed, the upstream side end (rear end P2) in the transport direction Y1 is located between the upper discharge roller 36 and the upper branch portion S2a of the upper sheet transport path S2. The sheet P is guided to the reverse conveyance rollers 12d to 12g by rotating the upper discharge roller 36 in the state of being located between them. Then, when the printing of the copy function or the printer function is requested, the branch claw G1 is set to the first posture, and when the printing of the facsimile function is requested, the branch claw G1 is set to the second posture while the upper branch claw G2 is set. Take the first posture. After that, the sheet P is conveyed to the transfer nip via the registration roller 13, the back surface of the sheet P is printed, and when the printing of the copy function or the printer function is requested, the sheet P is discharged onto the discharge tray 14, while the facsimile is performed. When the printing of the function is requested, the sheet P is discharged onto the upper discharge tray 15.

Next, the sheet sorting unit 300 will be described below with reference to FIGS. 2 and 3, but constituent elements having reference numerals not described in FIG. 1 will be described later.

(About sheet sorting section)
FIG. 2 is a schematic sectional view showing the discharge roller 31 and its peripheral portion in the image forming apparatus 100 shown in FIG. FIG. 3 is a schematic side view of the sheet sorting unit 300 in the image forming apparatus 100 shown in FIG. 1 viewed from the sheet P transport direction Y1.

As shown in FIGS. 2 and 3, the sheet sorting unit 300 includes a discharge roller shift unit 30 having a discharge roller 31, a rotation drive unit 40 (see FIG. 3), and a shift drive unit 50 (see FIG. 3). I have it.

The discharge roller shift unit 30 is provided so as to be reciprocally movable with respect to the image forming apparatus main body 110 along the axial direction X of the discharge roller 31. Specifically, the discharge roller shift unit 30 is attached to the image forming apparatus main body 110 via a sliding member 30b (specifically, a slide rail) (see FIG. 2) that is reciprocally movable in the axial direction X. It is supported. The sliding member 30b may have a conventionally known structure, and a detailed description thereof will be omitted here.

Further, a main body frame 30a of the discharge roller shift unit 30 is provided with a detected portion 30c (specifically, a detected piece) detected by a position detection switch SWp described later.

The discharge roller 31 discharges the sheet P to the discharge tray 14, and specifically includes a discharge roller pair 34 (see FIG. 3) including a discharge drive roller 32 and a discharge driven roller 33.

Specifically, the discharge drive roller 32 includes a drive roller shaft 32a (see FIG. 3) and a plurality of (four in this example) drive roller portions 32b to 32b fixedly arranged coaxially with the drive roller shaft 32a. ing. The discharge driven roller 33 includes a driven roller shaft 33a (see FIG. 3) and a plurality of (four in this example) driven roller portions 33b fixedly arranged coaxially with the driven roller shaft 33a so as to face the drive roller portion 32b. .About.33b. Further, the discharge roller 31 further includes a biasing member (a winding spring in this example) 35 (see FIG. 3) that biases the driven roller portion 33b toward the drive roller portion 32b.

The discharge roller pair 34 and the biasing member 35 are provided on the main body frame 30 a of the discharge roller shift unit 30. One end of the discharge driving roller 32 is provided so as to project from the main body frame 30a of the discharge roller shift unit 30 to the outside in the axial direction X.

Specifically, the drive roller shaft 32a of the discharge drive roller 32 is a single unit, and is provided rotatably around the axis with respect to the main body frame 30a of the discharge roller shift unit 30.

A plurality (two in this example) of driven roller shafts 33a of the discharge driven roller 33 are arranged side by side along the axial direction X, and a plurality (two in this example) of driven roller portions 33b and 33b are fixed to each. It is arranged. The driven roller shafts 33a and 33a are rotatable about the axis with respect to the main body frame 30a of the discharge roller shift unit 30 so that the driven roller portions 33b and 33b face the corresponding drive roller portions 32b and 32b. Further, it is provided so as to be capable of reciprocating along the vertical direction Z. The discharge roller 31 is configured to be conveyed while being pinched by the discharge driven roller 33 in the nip portion N between the discharge drive roller 32 and the discharge driven roller 33.

The biasing member 35 includes a plurality (two in this example) of biasing members 35, 35 corresponding to a plurality (two in this example) of the driven roller shafts 33a, 33a. The urging members 35, 35 urge the discharge driven roller 33 toward the discharge driving roller 32, and the driven roller shafts 33 a, 33 a and the discharge driving roller of the main body frame 30 a of the discharge roller shift unit 30. It is arranged between the position opposite to 32. The pressing force of the discharge driven roller 33 against the discharge drive roller 32 by the biasing members 35, 35 is such that the sheet P is appropriately conveyed.

The rotation driving unit 40 drives the discharge roller 31 to rotate, and transmits the transport drive motor 41 (stepping motor in this example) (see FIG. 3) and the rotary drive from the transport drive motor 41 to the discharge roller 31. And a drive transmission mechanism 42 (see FIG. 3).

The transport drive motor 41 is provided in the image forming apparatus main body 110 so that the rotation shaft 41a extends along the axial direction X.

In this example, the drive transmission mechanism 42 is configured by a gear train in which a plurality of gears are arranged in a row, and specifically includes a drive gear 42a, a roller gear 42b, and an intermediate gear 42c.

The drive gear 42a is connected to the rotary shaft 41a of the transport drive motor 41. The roller gear 42b is connected to an end portion of the drive roller shaft 32a protruding outward from the main body frame 30a of the discharge roller shift unit 30 in the axial direction X. The intermediate gear 42c is rotatably supported by a rotary shaft 110a fixed to the image forming 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 spur gears that are formed in a concave-convex line extending in the axial direction X, and the roller gear 42b meshes with the intermediate gear 42c. It can slide in the direction X. The length of the intermediate gear 42c in the axial direction X is a length that allows the movement width of the discharge roller shift unit 30 in the axial direction X (the length obtained by adding the length corresponding to the shift amount to the gear meshing length). That is, 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 axial direction X.

The shift driving unit 50 shifts the discharge roller 31 (in this example, the discharge roller shift unit 30) by shifting and shifts it, and includes a shift drive motor 51 (in this example, a stepping motor) (see FIG. 3) and a discharge roller. A shift mechanism 52 (see FIG. 3) for shifting the roller shift unit 30 is provided.

The shift drive motor 51 is provided in the image forming apparatus main body 110 so that the rotation shaft 51a extends along a direction orthogonal to the axial direction X (the vertical direction Z in this example).

The shift mechanism 52 is composed of a rack-and-pinion gear that converts rotational drive into linear drive, and includes a rack gear 52a extending along the axial direction X and a cylindrical pinion gear 52b. ing.

An end of the rack gear 52a in the axial direction X is connected to an end of the discharge roller shift unit 30. The pinion gear 52b is connected to the rotary shaft 51a of the shift drive motor 51 and meshes with the rack gear 52a. As a result, the rotation shaft 51a of the shift drive motor 51 rotates in one direction and the other direction, so that the discharge roller shift unit 30 can be reciprocated in one side X1 and the other side X2 in the axial direction X.

Next, the control unit 200 will be described below with reference to FIG. 4, but constituent elements with reference numerals not described in FIG. 2 will be described later.

(About control unit)
FIG. 4 is a system block diagram of a control system of the image forming apparatus 100 shown in FIG. The image forming apparatus 100 includes a control unit 200, a first detection switch SW1 (see FIGS. 2 and 4), a second detection switch SW2 (see FIGS. 2 and 4), and a position detection switch SWp (see FIGS. 2 to 4). 4)) and. The control unit 200 may be included in the sheet ejection device 400.

As illustrated in FIG. 4, the control unit 200 includes a processing device 210 such as a CPU, and a storage unit 220 including a ROM (Read Only Memory), a RAM (Random Access Memory), and a rewritable nonvolatile memory. .. The ROM can store a control program that is a procedure of processing executed by the processing device 210. RAM can provide a work area for work. The non-volatile memory can back up and hold data necessary for control, and can hold and rewrite various data (for example, control time of timing control described later).

The control unit 200 is configured to perform timing control on the rotation drive unit 40 and the shift drive unit 50 as timing control of the sheet sorting unit 300 of the image forming apparatus 100.

The first detection switch SW1 detects whether or not the sheet P passes through the discharge roller 31, and is specifically arranged near the upstream side of the discharge roller 31 in the transport direction Y1. The first detection switch SW1 is a sheet non-passing signal (OFF signal in this example) indicating that the sheet P is not passing through the discharge roller 31 or a sheet passing signal indicating that the sheet P is passing through the discharge roller 31. It is electrically connected to the input system of the control unit 200 so that (ON signal in this example) can be transmitted to the control unit 200.

The second detection switch SW2 detects whether or not the sheet P passes through the nearest roller (in this example, the carrying roller 12b) arranged at the closest position upstream of the discharge roller 31 in the carrying direction Y1. Specifically, it is arranged near the downstream side of the nearest roller (conveying roller 12b in this example) in the conveying direction Y1. The second detection switch SW2 is a sheet non-passage signal (OFF signal in this example) indicating that the sheet P has not passed the closest roller (transport roller 12b in this example) or the closest roller (transport roller 12b in this example). The sheet P is electrically connected to the input system of the control unit 200 so that a sheet passage signal (ON signal in this example) indicating that the sheet P is passing through is transmitted to the control unit 200.

The position detection switch SWp is for detecting whether or not the discharge roller shift unit 30 is located at a reference position (specifically, a central position in the axial direction X, that is, a standard position where sorting is not performed). Is a transmissive optical sensor that detects a detected portion 30c (see FIGS. 2 and 3) provided on the main body frame 30a of the discharge roller shift unit 30. The position detection switch SWp is a unit presence signal (OFF signal in this example) indicating that the discharge roller shift unit 30 is located at the reference position or a unit indicating that the discharge roller shift unit 30 is not located at the reference position. It is electrically connected to the input system of the control unit 200 so that a no signal (an ON signal in this example) can be transmitted to the control unit 200.

The transport drive motor 41 and the shift drive motor 51 are electrically connected to the output system of the control unit 200 so that the drive signal (ON signal) or the drive stop signal (OFF signal) from the control unit 200 can be obtained. ..

More specifically, the control unit 200 transmits a rotation instruction signal for instructing rotation in one direction B (the direction in which the sheet P is discharged) (see FIG. 2) to the transport drive motor 41 to drive the transport drive motor 41. As a result, the discharge roller 31 in the discharge roller shift unit 30 can be rotationally driven in the one direction B via the drive transmission mechanism 42.

Further, the control unit 200 rotates the discharge roller shift unit 30 to the one side X1 in the axial direction X (left side direction in the example shown in FIG. 3) based on the reference position, and controls the discharge roller shift unit 30. By transmitting a movement instruction signal for instructing rotation to move to the other side X2 in the axial direction X (rightward direction in the example shown in FIG. 3) to the shift driving motor 51 to pulse-drive the shift driving motor 51, the shift mechanism The discharge roller shift unit 30 can be shifted and driven to the one side X1 and the other side X2 via 52.

In the sheet sorting unit 300 described above, the conveyance drive motor 41 is driven by the rotation instruction signal from the control unit 200, and the driving force from the conveyance drive motor 41 is transmitted to the drive transmission mechanism 42, whereby the discharge rollers are ejected. 31 is rotationally driven in one direction B. Then, when the sorting operation is not performed, the discharge roller shift unit 30 is positioned at the reference position, while when the sorting operation is performed, the discharge roller shift unit 30 is positioned at the reference position by the discharge roller 31. After the sheet P is conveyed only in the conveying direction Y1 by a predetermined distance, the shift driving motor 51 is driven by the movement instruction signal from the control unit 200, and the driving force from the shift driving motor 51 is applied to the shift mechanism 52. This is transmitted, whereby the discharge roller shift unit 30 shifts to one side X1 or the other side X2. Thus, in the sheet discharging device 400 including the sheet sorting unit 300, the sheet sorting unit 300 transports the sheet P in the transport direction Y1 while the sheet sorting unit 300 transports the sheet P in the axial direction X on one side X1 and/or the other side X2 (in this example Then, the sheet is shifted along the axial direction X along one side X1 and the other side X2) and discharged to the discharge tray 14. In the sheet sorting unit 300, the discharge roller shift unit 30 may be shifted to the one side X1 or the other side X2 without transporting the sheet P only in the transport direction Y1.

Next, the guide ribs 150 (see FIGS. 1 and 2) provided on the upper discharge tray 15 shown in FIGS. 1 and 2 will be described below.

[About this Embodiment]
By the way, when the sheet discharge device 400 includes the sheet sorting unit 300 and the upper discharge tray 15 (an example of the upper member) as in the present embodiment, the sheet P is conveyed by the discharge rollers 31 in the conveying direction Y1. Meanwhile, the sheet sorting unit 300 shifts the sheet along the axial direction X and discharges the sheet. Therefore, the sheet P faces the discharge tray 14 of the upper discharge tray 15 (see FIGS. 1 and 2 ). If the sheet P is slidably contacted to the bottom surface 15b of the upper discharge tray 15, the sheet P discharged while shifting in the axial direction X while being transported in the transport direction Y1 is likely to be caught.

FIG. 5 is a schematic plan view of a state in which the sheet P is discharged below the upper discharge tray 15 in the sheet discharge device 400 according to the present embodiment, as seen from a plan view. FIG. 6 is a schematic perspective view of the plane side of the upper discharge tray 15 shown in FIG. FIG. 7 is a schematic perspective view of the bottom surface side of the upper discharge tray 15 shown in FIG. FIG. 8A is a front view of the schematic configuration diagram of the upper discharge tray shown in FIG. 5. FIG. 8B is a left side view in the schematic configuration diagram of the upper discharge tray shown in FIG. 5. FIG. 8C is a bottom view of the schematic configuration diagram of the upper discharge tray shown in FIG. 5. Further, FIG. 9 is an enlarged perspective view of the bottom surface side of the guide rib 150 in the upper discharge tray 15 shown in FIG.

In the present embodiment, the bottom surface 15b of the upper discharge tray 15 (see FIGS. 7, 8C and 9) is provided with the guide rib 150 extending along the diagonal direction inclined to the shift movement side with respect to the transport direction Y1. ing. More specifically, the bottom surface 15b of the upper discharge tray 15 has a conveyance direction in and/or within a predetermined sliding contact area α (see FIG. 5) with which the sheet P can slidably contact. A guide rib 150 is provided, which extends in a diagonal direction in which the downstream side is inclined to the shift movement side with respect to Y1.

Here, with the sliding contact area α, there is a possibility that the sheet P that is shifted by the sheet sorting unit 300 along the axial direction X while being transported in the transport direction Y1 by the discharge roller 31 is in sliding contact with the bottom surface 15b of the upper discharge tray 15. In a certain area, the discharge angle and the discharge speed at which the sheet P is discharged from the discharge roller 31, the distance between the discharge roller 31 and the bottom surface 15b of the upper discharge tray 15 in the vertical direction Z, the size of the sheet P (for example, according to the standard). Is a region that can be set in advance by parameters such as the maximum size of the sheet P, the waist of the sheet P (for example, the maximum thickness according to the standard), and the distance that the sheet sorting unit 300 shifts the sheet P.

Specifically, the guide ribs 150 are in the axial direction X (conveying direction of the sheet P conveyed in the conveying direction Y1) of the sheet P (before sorting or not sorted) conveyed in the conveying direction Y1 (see FIG. 5). On the basis of the center in the width direction along the sheet P surface orthogonal to Y1), that is, at one side with a virtual boundary line β (see FIG. 5 and FIG. 8C) along the transport direction Y1 at the center in the axial direction X being separated. On the other side, it extends in an oblique direction from the upstream side to the downstream side in the transport direction Y1 toward the outside. In other words, the guide ribs 150 (151 to 153 in this example) are guide ribs that are angles on the downstream side with respect to the transport direction Y1 on the one side X1 and/or the other side X2 in the axial direction X with the virtual boundary line β in between. The angle θ (θ1 to θ3 in this example) (see FIG. 5) extends in an oblique direction at an acute angle. The guide rib 150 is integrally formed on the bottom surface 15b of the upper discharge tray 15.

According to the present embodiment, since the guide rib 150 provided on the bottom surface 15b of the upper discharge tray 15 extends along the diagonal direction inclined to the shift movement side with respect to the transport direction Y1, the sheet P is discharged from the discharge roller 31. When the sheet sorting unit 300 shifts the sheet P along the axial direction X and discharges the sheet P while conveying the sheet P in the conveying direction Y1, even if the sheet P slidably contacts the bottom surface 15b of the upper discharge tray 15, the sheet P is guided by the guide ribs. The sheet can be discharged to the discharge tray 14 while being in sliding contact with the guide rib 150 in a state in which the contact area with the sheet 150 is suppressed, and thus the sheet is shifted and moved along the axial direction X while being conveyed in the conveying direction Y1. It is possible to prevent P from being caught on the bottom surface 15b of the upper discharge tray 15.

(First embodiment)
In the first embodiment, the guide rib 150 shifts the sheet P along the axial direction X by the sheet sorting unit 300 while being conveyed in the conveying direction Y1 by the discharge roller 31, and the sheet diagonal movement direction W (see FIG. 5) or substantially. It extends in the diagonal direction W of the seat.

Specifically, the sheet diagonal movement direction W can be a vector direction in which a vector of the conveyance speed Vc of the sheet P in the conveyance direction Y1 and a vector of the movement speed Vm of the sheet P in the axial direction X are combined.

That is, the guide rib angle θ can be calculated by the formula of θ=cos ⁻¹ (Vc/√(Vm ² +Vc ² )) or θ=sin ⁻¹ (Vm/√(Vm ² +Vc ² )).

According to the first embodiment, the guide ribs 150 extend in the sheet diagonal movement direction W or the substantially sheet diagonal movement direction W, so that the sheet P is shifted in the axial direction X while being conveyed in the conveyance direction Y1. In discharging, even if the sheet P is slidably contacted with the bottom surface 15b of the upper discharge tray 15, the sheet P is slidably contacted with the guide rib 150 and further discharged to the discharge tray 14 in a state in which the contact area with the guide rib 150 is further reduced. Accordingly, the sheet P that is shifted in the axial direction X and is discharged while being conveyed in the conveying direction Y1 can be more difficult to be caught by the bottom surface 15b of the upper discharge tray 15.

(Second embodiment)
By the way, the guide rib 150 shifts along the axial direction X (the other side X2 in the example shown in FIG. 5) by the sheet sorting unit 300 while being transported by the discharge roller 31 in the transport direction Y1. When the sheet P is located outside the side end Ps (the side end Ps2 on the other side in the example shown in FIG. 5) in the conveyance direction Y1, the sheet P is conveyed in the conveyance direction Y1 in the axial direction X (in the example shown in FIG. 5). In other words, when the sheet P shifts along the other side X2) and is discharged, the sheet P may not come into contact with the guide rib 150 when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15. In particular, when the guide rib 150 includes a plurality of guide ribs 151 to 153 and has an inner rib and an outer rib in the axial direction X, the innermost guide rib 153 of the plurality of guide ribs 151 to 153 is the conveyance direction Y1. When the sheet P is positioned outside the side end Ps in the axial direction X of the sheet P that is shifted in the axial direction X while being conveyed to the sheet P, the sheet P is shifted in the axial direction X while being conveyed in the transport direction Y1. When the sheet P is moved and discharged, the sheet P does not come into contact with the guide ribs 150 when the sheet P comes into sliding contact with the bottom surface 15b of the upper discharge tray 15. Therefore, it is desirable that the sheet P be surely brought into contact with the guide rib 150 when the sheet P slides on the bottom surface 15b of the upper discharge tray 15.

In this respect, in the second embodiment, the guide rib 150 is shifted by the sheet sorting unit 300 along the axial direction X (the other side X2 in the example shown in FIG. 5) while being conveyed in the conveying direction Y1 by the discharge roller 31. It is located inside (for example, near the inside) of the side end Ps of P in the axial direction X (the side end Ps2 on the other side in the example shown in FIG. 5). Here, the position in the vicinity of the inner side can be exemplified by a position on the inner side from the side end Ps in the axial direction X of the sheet P by a predetermined distance. In particular, when the guide rib 150 includes a plurality of guide ribs 151 to 153 and has an inner rib and an outer rib in the axial direction X, the outermost guide rib 151 of the plurality of guide ribs 151 to 153 is the discharge roller. It is preferable that the sheet P is located inside the side end Ps in the axial direction X of the maximum size sheet P that is shifted in the axial direction X by the sheet sorting unit 300 while being transported in the transport direction Y1 by 31.

According to the second embodiment, the guide rib 150 is located inside the side end Ps in the axial direction X of the sheet P that is shifted by the sheet sorting unit 300 along the axial direction X while being conveyed by the discharge roller 31 in the conveying direction Y1. By being located, when the sheet P is shifted in the axial direction X while being transported in the transport direction Y1 and is discharged, even if the sheet P is in sliding contact with the bottom surface 15b of the upper discharge tray 15. The sheet P can be easily brought into contact with the guide rib 150. As a result, when the sheet P makes sliding contact with the bottom surface 15b of the upper discharge tray 15, the sheet P can be reliably brought into contact with the guide ribs 150.

(Third Embodiment)
By the way, when the guide rib 150 is provided from the position of the upstream end 15c (see FIGS. 5 to 7 and 8C) of the bottom surface 15b of the upper discharge tray 15 in the transport direction Y1 toward the downstream side, the sheet P Although it is possible to reduce or eliminate the possibility that the tip P1 of the guide rib 150 is caught on the guide rib 150 as much as possible, a large amount of material for forming the guide rib 150 is required. Therefore, from the viewpoint of reducing the material forming the guide ribs 150, when the guide ribs 150 are provided from the position downstream of the position of the upstream end 15c on the bottom surface 15b of the upper discharge tray 15 toward the downstream side. The tip P1 of the sheet P is easily caught by the guide rib. Therefore, even if the guide ribs 150 are provided from the position downstream of the position of the upstream end 15c on the bottom surface 15b of the upper discharge tray 15 toward the downstream side, the sheet P is on the bottom surface 15b of the upper discharge tray 15. It is desired to prevent the leading edge P1 of the sheet P from being caught by the guide rib 150 when slidingly contacting.

In this regard, in the third embodiment, the guide rib 150 is inclined so as to gradually become higher with respect to the bottom surface 15b of the upper discharge tray 15 from the upstream side to the downstream side in the sheet P transport direction Y1 (FIG. 8A, 8B and 9).

Specifically, the guide rib 150 is inclined with the bottom surface 15b of the upper discharge tray 15 as a starting point. However, the present invention is not limited to this, and the guide rib 150 may be inclined from a position higher than the bottom surface 15b of the upper discharge tray 15 as a starting point. Further, the guide rib 150 has a top surface 150g (in this example, inclined surfaces 151g, 152g, 153g) (see FIG. 9) formed linearly. However, the present invention is not limited to this, and the top surface 150g of the guide rib 150 may be formed in an upward convex curved shape or a downward convex curved shape.

According to the third embodiment, the guide ribs 150 are inclined from the upstream side to the downstream side with respect to the bottom surface 15b of the upper discharge tray 15 in the conveyance direction Y1 of the sheet P so that the guide ribs 150 gradually increase. The height of the upstream end (rear end 150b) (rear ends 151b, 152b, 153b in this example) of 150 (see FIG. 9) can be reduced or eliminated, and therefore the front end P1 of the sheet P is caught by the guide rib 150. In addition to suppressing the possibility, when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15, the sheet P can slide smoothly in the top surface 150g of the guide rib 150. Even when 150 is provided from the position downstream of the upstream end 15c on the bottom surface 15b of the upper discharge tray 15 toward the downstream side, the sheet when the sheet P is in sliding contact with the bottom surface 15b of the upper discharge tray 15 It is possible to suppress the tip P1 from being caught by the guide rib 150.

(Fourth Embodiment)
In the fourth embodiment, the guide rib 150 includes a plurality of (three in this example) guide ribs 151 to 153.

Specifically, the plurality of guide ribs 151 to 153 have inner ribs and outer ribs in the axial direction X. The plurality of guide ribs 151 to 153 are arranged side by side in the axial direction X. The plurality of guide ribs 151 to 153 are parallel or substantially parallel to each other. When the plurality of guide ribs 151 to 153 are inclined so as to gradually become higher from the upstream side toward the downstream side in the sheet P transport direction Y1 as in the third embodiment, the bottom surface 15b of the upper discharge tray 15 is formed. The inclination angles φ1 to φ3 (see FIG. 9) with respect to each other may be equal to or substantially equal to each other, or at least two may be different from each other. The plurality of guide ribs 151 to 153 may have the same or substantially the same guide rib angle θ (θ1 to θ3) and/or the length, or the guide rib angles θ (θ1 to θ3) and/or the length. At least two of may be different from each other. In this example, the guide rib angles θ1 to θ3 are equal or substantially equal to each other, and the lengths of the guide ribs 151 and 152 are equal or substantially equal to each other.

According to the fourth embodiment, the guide rib 150 includes the plurality of guide ribs 151 to 153, so that the plurality of guide ribs 151 to 153 are provided according to the size of the sheet P (specifically, the size in the axial direction X). This allows the sheets P of each size to be shifted along the axial direction X and discharged while being transported in the transport direction Y1, even if the sheets P of each size are placed on the bottom surface 15b of the upper discharge tray 15. Even if the sheets P are in sliding contact with each other, it is possible to prevent the sheets P of each size from being easily caught on the bottom surface 15b of the upper discharge tray 15.

For example, of the plurality of guide ribs 151 to 153, the outermost guide rib 151 has an axis line of the maximum size sheet P that shifts along the axial direction X by the sheet sorting unit 300 while being conveyed by the discharge roller 31 in the conveyance direction Y1. It is located on the inner side (for example, near the inner side) of the side end Ps in the direction X (in the example shown in FIG. 5, the other side end Ps2), and is on the inside of the n-th outermost guide rib 151 (n is an integer of 1 or more). The n-th guide ribs 152 and 153 (n=1, 2 in this example) are located at the maximum size that shifts along the axial direction X by the sheet sorting unit 300 while being transported by the discharge roller 31 in the transport direction Y1. It is possible to exemplify a mode in which the sheet P of the n-th smallest size is located inside (for example, in the vicinity of the inside) of the side end Ps (the other side end Ps2 in the example shown in FIG. 5) in the axial direction X. By doing so, when the sheets P of each size are shifted and moved along the axial direction X while being transported in the transport direction Y1, the sheets P of each size are slidably in contact with the bottom surface 15b of the upper ejection tray 15. Even if it does, it is possible to effectively prevent not only the maximum size but also the sheet P of the size nth smaller than the maximum size from being caught on the bottom surface 15b of the upper discharge tray 15. Here, the position in the vicinity of the inner side can be exemplified by a position on the inner side from the side end Ps in the axial direction X of the sheet P by a predetermined distance.

(Fifth Embodiment)
By the way, when the guide rib 150 is composed of a plurality of guide ribs 151 to 153 and has an inner rib and an outer rib in the axial direction X, a predetermined predetermined one of the plurality of guide ribs 151 to 153 is provided. The guide ribs (guide ribs 153 in this example) inside the reference guide ribs (guide ribs 152 in this example) that are guide ribs are auxiliary to the outer guide ribs (151, 152 in this example) including the reference guide ribs (guide ribs 152 in this example). It may function as a general guide member. In this case, if the inner guide ribs 153 have the same or substantially the same length as the outer guide ribs 151, 152, the amount of material used to form the inner guide ribs 153 increases, which in turn increases the weight of the upper discharge tray 15. The cost is high. Therefore, it is desirable to reduce the amount of material used to form the inner guide ribs 153, and thereby to realize weight reduction and cost reduction of the upper discharge tray 15.

In this respect, in the fifth embodiment, among the plurality of guide ribs 151 to 153, the inner guide rib 153 is shorter than the outer guide ribs 151 and 152 with the downstream side in the transport direction Y1 left, and the sheet In the transport direction Y1 of P, it is inclined from the upstream side to the downstream side so as to be gradually higher than the bottom surface 15b of the upper discharge tray 15.

Specifically, the inner guide rib 153 is missing (not provided) on the upstream side, leaving a predetermined distance d (see FIG. 8C) from the downstream end (tip 153a).

According to the fifth embodiment, among the plurality of guide ribs 151 to 153, the inner guide rib 153 is shorter than the outer guide ribs 151 and 152 with the downstream side in the transport direction Y1 left, which is only that much. The amount of material used to form the inner guide ribs 153 can be reduced, and thus the weight and cost of the upper discharge tray 15 can be reduced. Moreover, if the inner guide rib 153 is shorter than the outer guide ribs 151, 152 with the downstream side in the transport direction Y1 remaining, the leading end P1 of the sheet P when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15. Is easily caught by the inner guide rib 153, the inner guide rib 153 is inclined so as to gradually become higher with respect to the bottom surface 15b of the upper discharge tray 15 from the upstream side to the downstream side in the transport direction Y1 of the sheet P. Thus, when the sheet P is shifted in the axial direction X while being transported in the transport direction Y1 and is discharged, even if the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15, the guide rib 150 is removed. The sheet P can be smoothly slidably contacted with the inclined surface 153g (150g) of the inner guide rib 153 in a state where the amount of material to be formed is small, whereby the weight and cost of the upper discharge tray 15 can be reduced. At the same time, when the sheet P is in sliding contact with the bottom surface 15b of the upper discharge tray 15, it is possible to prevent the leading edge P1 of the sheet P from being caught by the inner guide rib 153.

(Sixth Embodiment)
By the way, when the inner guide rib 153 is shortened in comparison with the outer guide ribs 151 and 152 while leaving the downstream side in the transport direction Y1, the inner guide rib 153 faces the discharge tray 14 with respect to the bottom surface 15b of the upper discharge tray 15. The inclination angle φ3 of the inclined surface 153g (150g) is the inclination of the top surface (in this example, the inclined surfaces 151g, 152g (150g)) facing the discharge tray 14 with respect to the bottom surface 15b of the upper discharge tray 15 of the outer guide ribs 151, 152. If the angles are the same as or substantially the same as or smaller than the angles φ1 and φ2, the leading end P1 of the sheet P is likely to be caught by the upstream end (rear end 153b) of the inner guide rib 153 in the transport direction Y1. Therefore, it is desired that the front end P1 of the sheet P is less likely to be caught by the rear end 153b of the inner guide rib 153.

In this regard, in the sixth embodiment, the inner guide rib 153 has an inclination angle φ3 of the inclined surface 153g (150g) with respect to the bottom surface 15b of the upper discharge tray 15, and the inclination angle φ3 of the outer guide rib 151, 152 is the top of the bottom surface 15b of the upper discharge tray 15. It is larger than the angles (inclination angles φ1 and φ2 in this example) of the surfaces (inclination surfaces 151g and 152g (150g) in this example).

Specifically, the plurality of guide ribs 151, 152, 153 have their downstream ends (tips 150a) (tips 151a, 152a, 153a in this example) (see FIG. 9) aligned in the axial direction X in the transport direction Y1. Further, the downstream ends (tips 150a) (tips 151a, 152a, 153a in this example) have the same or substantially the same height.

According to the sixth embodiment, the inner guide rib 153 has an inclination angle φ3 of the inclined surface 153g (150g) with respect to the bottom surface 15b of the upper discharge tray 15, and the inclination angle φ3 of the outer guide ribs 151, 152 is a top surface with respect to the bottom surface 15b of the upper discharge tray 15 ( In this example, the angle of the inclined surfaces 151g and 152g (150g) is larger than the angle (inclination angles φ1 and φ2 in this example) so that the inner guide rib 153 does not protrude more than the outer guide ribs 151 and 152. This allows the sheet P to be shifted along the axial direction X while being conveyed in the conveying direction Y1 and ejected, even if the sheet P is slidably contacted with the bottom surface 15b of the upper ejection tray 15. It is possible to reduce or eliminate the catch on the rear end 153b in the guide rib 153 inside the front end P1.

(Seventh embodiment)
By simply inclining the inner guide ribs 153, the inclination angle φ3 increases as the inner guide ribs 153 are shortened, and accordingly, when the sheet P slides on the bottom surface 15b of the upper discharge tray 15, The tip P1 is more likely to be caught by the inclined surface 153g (150g) of the inner guide rib 153. Therefore, even if the inner guide rib 153 is shortened, the inclination angle φ3 can be suppressed to be small, and when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15, the leading end P1 of the sheet P is guided by the inner guide rib 153. It is desired to reduce the possibility of being caught by the inclined surface 153g (150g).

In this regard, in the seventh embodiment, the inner guide rib 153 is composed of a plurality of (two in this example) inclined rib portions (1531, 1532 in this example) connected from the upstream side to the downstream side in the transport direction Y1. The inclination angle (φ31 in this example) of the upstream inclined rib portion (1531 in this example) is larger than the inclination angle (φ32 in this example) of the downstream inclined rib portion (1532 in this example). ..

Specifically, the inner guide rib 153 includes a first inclined rib portion 1531 (see FIG. 9) and a second inclined rib portion 1532 (see FIG. 9) located on the upstream side and the downstream side in the transport direction Y1, respectively. The inclination angle φ31 (φ3) of the first inclined rib portion 1531 is larger than the inclination angle φ32 (φ3) of the second inclined rib portion 1532 on the downstream side. The inner guide rib 153 is formed by connecting the downstream end of the first inclined rib portion 1531 and the upstream end of the second inclined rib portion 1532. The inner guide rib 153 is integrally formed with a plurality of inclined rib portions (the first inclined rib portion 1531 and the second inclined rib portion 1532 in this example). The inclined surfaces 153g (150g) of the plurality of inclined rib portions (the first inclined rib portion 1531 and the second inclined rib portion 1532 in this example) are linearly formed. However, the present invention is not limited to this, and in the plurality of inclined rib portions (the first inclined rib portion 1531 and the second inclined rib portion 1532 in this example), the inclined surface 153g (150g) is curved upward or downward. It may be formed in a convex curved shape.

According to the seventh embodiment, the inner guide rib 153 is composed of a plurality of inclined rib parts (1531, 1532 in this example) connected from the upstream side to the downstream side in the transport direction Y1, and the inclined rib part on the upstream side (this The inclination angle (1531 in the example) (φ31 in this example) is larger than the inclination angle (φ32 in this example) of the inclined rib portion (1532 in this example) on the downstream side. Even if it is slidably in contact with the bottom surface 15b of each of the plurality of inclined rib portions (the first inclined rib portion 1531 and the second inclined rib portion 1532 in this example), a multi-step inclination angle φ3 (in this example, two-step inclination angle φ31 , Φ32), in other words, the plurality of inclined rib portions (the first inclined rib portion 1531 and the second inclined rib portion 1532 in this example) from the upstream side to the downstream side in the transport direction Y1. The sheet P can be slidably contacted with the inner guide rib 153 that is inclined so that the inclination angle φ3 (in this example, φ31, φ32) gradually decreases. Even if the length is shortened, the inclination angle φ3 can be suppressed to be small, and when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15, the leading end P1 of the sheet P becomes the inclined surface 153g (150g) of the inner guide rib 153. The possibility of being caught can be reduced.

(Eighth Embodiment)
By the way, on the bottom surface 15b of the upper discharge tray 15, there are intersecting ribs 160 extending in a direction intersecting with the guide ribs 150 (for example, the axial direction X or the transport direction Y1) (see FIGS. 7, 8B, 8C and 9). May be provided. For example, since the space SP is provided on the bottom surface 15b of the upper discharge tray 15 and the places where the upper discharge tray 15 is supported are limited, cross ribs are provided to ensure the strength of the upper discharge tray 15. As 160, a reinforcing rib for reinforcing the upper discharge tray 15 is often provided. In this case, at least one of the leading edge P1 of the sheet P, the side edges Ps1 and Ps2 (Ps2 in this example) in the axial direction X, and the corner portions (so-called ears) between the leading edge P1 and the side edges Ps1 and Ps2 (particularly, ears) The corner portion between the tip P1 and the side ends Ps1 and Ps2) is easily caught by the intersecting rib 160 (for example, a reinforcing rib). Therefore, at least one of the leading edge P1 of the sheet P, the side edges Ps1 and Ps2 (Ps2 in this example) in the axial direction X, and the corner portion between the leading edge P1 and the side edges Ps1 and Ps2 (particularly the leading edge P1 and the side edges). It is desired that the corner portions (Ps1 and Ps2) are less likely to be caught by the intersecting rib 160. This means that the intersecting ribs 160 are formed along the edge of the downstream end 15d (see FIGS. 5, 6, 7, 8B, 8C, and 9) in the transport direction Y1 on the bottom surface 15b of the upper discharge tray 15. It becomes particularly noticeable when it extends.

In this regard, in the eighth embodiment, a cross rib 160 extending along a direction intersecting with the guide rib 150 is provided on the bottom surface 15b of the upper discharge tray 15, and the guide rib 150 is higher than the height of the cross rib 160. It's getting higher.

Specifically, the intersecting rib 160 is parallel or substantially parallel to the transport direction Y1 with the first intersecting rib 161 (see FIGS. 7, 8B, 8C and 9) extending in the direction parallel or substantially parallel to the axial direction X. A second cross rib 162 (see FIGS. 7, 8C and 9) extending in any direction. The first intersecting rib 161 is provided at the edge of the downstream end 15d in the transport direction Y1 on the bottom surface 15b of the upper discharge tray 15. A plurality of second intersecting ribs 162 are provided at predetermined intervals in the axial direction X. The cross rib 160 is integrally formed on the bottom surface 15b of the upper discharge tray 15.

Further, the intersecting rib 160 may be provided so as to intersect with the guide rib 150, or may be provided so as not to intersect with the guide rib 150. When the intersecting rib 160 is provided so as to intersect with the guide rib 150, it may be connected (specifically, integrally formed) with the guide rib 150 or may be missing at the intersecting portion (near the intersecting portion) (provided). Not required). When the guide rib 150 includes a plurality of guide ribs 151 to 153, the intersecting rib 160 may be connected (specifically, integrally formed) to at least two of the plurality of guide ribs 151 to 153. By doing so, at least two of the plurality of guide ribs 151 to 153 can be strongly reinforced.

In this example, the inner surface 161a (see FIG. 9) of the first intersecting rib 161 is connected (specifically, integrally formed) to the tips 151a, 152a, 153a of the plurality of guide ribs 151 to 153. One second intersecting rib 162 of the plurality of second intersecting ribs 162 to 162 is connected (specifically, integrally formed) so as to connect the plurality of guide ribs 151 to 153 to each other. The cross rib 160 further includes a third cross rib 163 (see FIG. 9) that reinforces the plurality of guide ribs 151 to 153. As shown in FIG. 9, the third intersecting rib 163 has a connecting portion 163a, a first end portion 163b, and a second end portion 163c. The connecting portion 163a extends in a direction parallel or substantially parallel to the axial direction X (parallel or substantially parallel to the first intersecting rib 161) to connect the plurality of guide ribs 151 to 153 (specifically, an integral body). Has been formed). The first end 163b includes an outermost guide rib 151 of the plurality of guide ribs 151 to 153 and a main rib 170 (see FIG. 9) provided at the other end X2 in the axial direction X and the downstream end in the transport direction Y1. They are connected (specifically, integrally formed) so as to be connected. The second end portion 163c is connected (specifically, integrally formed) so as to connect the innermost guide rib 153 of the plurality of guide ribs 151 to 153 and the first intersecting rib 161. By doing so, the plurality of guide ribs 151 to 153 can be reinforced more strongly.

According to the eighth embodiment, a cross rib 160 extending along a direction intersecting with the guide rib 150 is provided on the bottom surface 15b of the upper discharge tray 15, and the guide rib 150 is higher than the height of the cross rib 160. Thus, when the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15, the guide ribs 150 can effectively prevent the sheet P from coming into contact with the crossing ribs 160, whereby the sheet P is conveyed in the transport direction. When the sheet P is shifted in the axial direction X and discharged while being conveyed to Y1, even if the sheet P is in sliding contact with the bottom surface 15b of the upper discharge tray 15, the front end P1 of the sheet P and the side end in the axial direction X are conveyed. Ps1 and Ps2 (Ps2 in this example) and at least one of the corner portions between the tip P1 and the side ends Ps1 and Ps2 (particularly the corner portion between the tip P1 and the side ends Ps1 and Ps2) are caught by the cross rib 160. Can be difficult. This is particularly effective when extending along the edge of the downstream end 15d in the transport direction Y1 on the bottom surface 15b of the upper discharge tray 15 like the first intersecting rib 161.

(9th Embodiment)
By the way, when the entire guide rib 150 is linearly formed along the oblique direction, when the sheet P slides in contact with the guide rib 150, the sheet P in the sliding contact area α on the bottom surface 15b of the upper discharge tray 15 is in contact with the sheet P. When there is a transport direction sliding contact area α1 (see FIG. 5) that makes sliding contact when the sheet is moving only in the transport direction Y1 in the initial sliding contact, contact with the guide rib 150 of the sheet P in the transport direction sliding contact area α1. The area becomes large. Therefore, when the sheet P slides in contact with the guide ribs 150, the contact area of the sheet P with the guide ribs 150 in the transport direction sliding contact area α1 is suppressed and the sheet P slides in contact with the bottom surface 15b of the upper discharge tray 15. It is desired to prevent the guide rib 150 from being caught.

In this respect, in the ninth embodiment, the guide rib 150 is a rib end portion 150c which is a portion on the downstream side by a predetermined distance from the upstream end 15c in the transport direction Y1 (see FIGS. 5, 8C and 9). Are parallel or substantially parallel to the transport direction Y1.

Specifically, the rib end portion 150c is provided in all or a part of the transport direction sliding contact area α1 with which the sheet P slides when the sheet P moves only in the transport direction Y1 at the initial stage of sliding contact. At least one of the plurality of guide ribs 151 to 153 (the outer guide ribs 151 and 152 in this example) is provided with rib end portions 151c and 152c (see FIGS. 5, 8C, and 9).

According to the ninth embodiment, in the guide rib 150, the rib end portion 150c (151c, 152c in this example), which is the downstream side portion by the predetermined distance from the upstream end 15c in the transport direction Y1, is in the transport direction Y1. By being parallel or substantially parallel, when the sheet P slides in contact with the guide rib 150, when the sheet P of the guide rib 150 moves only in the transport direction Y1 at the initial stage of slide contact, Even if there is a transport direction sliding contact area α1 that is in sliding contact with the sheet P, the contact area of the sheet P with the guide rib 150 can be made as small as possible in the transport direction sliding contact area α1. When the sheet P is in sliding contact with the guide rib 150, the contact area of the sheet P with the guide rib 150 in the conveying direction sliding contact area α1 is suppressed, and the sheet P is caught by the guide rib 150 when slidingly contacting the bottom surface 15b of the upper discharge tray 15. Can be suppressed.

(10th Embodiment)
By the way, in the case where the discharge roller 31 is configured to shift to both the one side X1 and the other side X2 in the axial direction X, the guide ribs 150 may be provided on both sides to shift the discharge roller 31. In this case, there are the following inconveniences.

That is, the one side X1 and the other side X2 (one side in this example) of the bottom surface 15b of the upper discharge tray 15 (separated by the virtual boundary line β) at the center in the axial direction X of the sheet P conveyed in the conveying direction Y1. X1), a point of providing a constricted portion 15e (see FIGS. 5 to 7, 8C, and 9) that is constricted toward the inner side in the axial direction X of the upper discharge tray 15 in order to facilitate taking of the discharged sheet P. From the viewpoint of space saving, or/or further, the area of the entire one side X1 of the bottom surface 15b (more specifically, the area of the one side X1 downstream from the center in the transport direction Y1) and/or the other side X2 entirely. Area (more specifically, the area of the other side X2 on the downstream side of the center in the transport direction Y1) becomes smaller, and the area of the sliding contact area α of the bottom surface 15b becomes smaller, and the sheet P is caught by the bottom surface 15b. There may be little or no effect. If the guide ribs 150 are provided with little or no influence of being caught on the bottom surface 15b of the sheet P, the material forming the guide ribs 150 is wasted to that extent. Therefore, it is desired to reduce the waste of the material forming the guide rib 150.

In this regard, in the tenth embodiment, the discharge roller 31 is configured to shift and move to both the one side X1 and the other side X2 in the axial direction X, and the guide rib 150 is provided for the sheet P conveyed in the conveying direction Y1. Of the one side X1 and the other side X2 of the bottom surface 15b of the upper discharge tray 15 (separated by the virtual boundary line β) at the center in the axial direction X, the area of the sliding contact area α is larger than a predetermined reference area. Is also provided on the larger side (in this example, the side opposite to the operating side, the upper side in FIG. 5). That is, on the bottom surface 15b, when the area of the sliding contact area α on the one side X1 is larger than the reference area on the basis of the center in the axial direction X, the guide rib 150 is provided on the one side X1 and the guide rib 150 on the other side X2. When the area of the sliding contact area α is larger than the reference area, the guide rib 150 is provided on the other side X2, and the areas of the sliding contact area α on both the one side X1 and the other side X2 are larger than the reference area. In this case, the guide ribs 150 are provided on both the one side X1 and the other side X2.

In other words, the guide rib 150 is provided on the side of the one side X1 and the other side X2 of the bottom surface 15b where the area of the sliding contact area α is equal to or smaller than the reference area (in this example, the operating side, the lower side in FIG. 5). Has not been done.

Here, the reference area is an area that can be considered to have little or no influence of being caught on the bottom surface 15b of the sheet P.

According to the tenth embodiment, the discharge roller 31 is configured to shift to both the one side X1 and the other side X2 in the axial direction X, and the guide ribs 150 are arranged in the axial direction of the sheet P conveyed in the conveying direction Y1. Of the one side X1 and the other side X2 of the bottom surface 15b of the upper discharge tray 15 at the center reference in X, the side where the area of the sliding contact area α is larger than a predetermined reference area (the other side in the example shown in FIG. 5). Since the guide ribs are provided on the side X2), the guide ribs can be provided only in the necessary portions on the bottom surface 15b of the upper discharge tray 15, and thus the waste of the material forming the guide ribs 150 can be reduced.

(Eleventh embodiment)
10A to 12C are schematic cross-sectional views showing the cross-sectional shape of the guide rib 150 when viewed from an oblique direction. 10A to 10C show examples of the cross-sectional shape of the guide rib 150 in which the top portion 150d is a flat surface or a curved surface. 11A to 11D and FIGS. 12A to 12C show examples of the cross-sectional shape of the guide rib 150 having the inclined side surface 150e.

As shown in FIGS. 10A to 10C, the guide rib 150 has a vertical side or a substantially vertical side when viewed in cross section, and a top 150d (top 150g) facing the discharge tray 14 is a plane (see FIGS. 10A and 10B). Alternatively, it is a curved surface (see FIG. 10C).

As a cross-sectional shape of the plane, a horizontal or substantially horizontal surface (see FIG. 10A), or an orthogonal direction inclined surface orthogonal to the direction (oblique direction) in which the guide rib 150 extends (or an orthogonal direction) (see FIG. 10B). Can be illustrated. The orthogonal direction inclined surface (see FIG. 10B) may be inclined to one side or the other side in the orthogonal direction or the substantially orthogonal direction of the guide rib 150. Further, as the curved surface (see FIG. 10C), an upwardly convex curved surface (specifically, an arcuate curved surface) can be exemplified. The curved surface may be a semi-spherical spherical surface or a semi-elliptical spherical surface.

Further, as shown in FIGS. 11A to 12C, the guide rib 150 has an inclined side surface 150e that is inclined so that the width (dimension in the orthogonal direction) becomes smaller as it goes from the base end portion to the top portion 150d in a sectional view. ..

The cross-sectional shape of the guide rib 150 having the inclined side surface 150e is polygonal, specifically, an isosceles triangle or a substantially isosceles triangle (see FIG. 11A), a right triangle or a substantially right triangle (see FIG. 11B), and a right angle. An isosceles triangle or a substantially right-angled isosceles triangle (see FIG. 11C), a triangular shape such as an acute triangle (see FIG. 11D), and an upper base (top surface 150g side) is smaller than a lower base (base end 150f side). In addition, angles δ1 and δ2 between the lower bottom (on the side of the proximal end 150f) and both legs are 90 degrees or less or about 90 degrees or less (see FIG. 12A), and the sides are vertical or substantially vertical. Moreover, a hexagon or a substantially hexagonal shape whose upper side is horizontal or substantially horizontal (see FIG. 12B) and a pentagon or a substantially pentagonal shape whose side edge is vertical or substantially vertical (see FIG. 12C) can be exemplified.

When the tip is sharpened like the guide rib 150 shown in FIGS. 10B, 11A to 11D, and 12C, the tip may be chamfered (for example, flat or arc-shaped).

Here, as shown in FIGS. 10B, 10C, 11A to 11D, and 12C, the guide rib 150 allows the top portion 150d to come into line contact or substantially line contact with the sheet P when the sheet P slides. It is preferably formed.

In this way, the guide rib 150 is formed so that the top portion 150d makes line contact or substantially line contact with the sheet P when the sheet P slides, so that the sheet P slides on the bottom surface 15b of the upper discharge tray 15. At the time of contact, the sheet P can be discharged to the discharge tray 14 while being in sliding contact with the guide rib 150 in a state where the contact area with the guide rib 150 is further suppressed, whereby the sheet P is conveyed along the axial direction X while being conveyed in the conveying direction Y1. The sheet P that is shifted and moved and discharged can be made more difficult to be caught by the bottom surface 15b of the upper discharge tray 15.

(Twelfth Embodiment)
Next, a sheet ejection device according to a twelfth embodiment of the present invention will be described with reference to the drawings. Note that the twelfth embodiment is different from the above-described embodiments only in the structure of the upper discharge tray 15, and therefore shows the drawings of the main parts and omits the other drawings.

FIG. 13 is a schematic plan view of a state in which a sheet is discharged below an upper discharge tray in a sheet discharge device according to the twelfth embodiment, as viewed from above. FIG. 14 is an enlarged bottom view of the bottom surface of the upper discharge tray shown in FIG. 13, which is an enlarged view of the vicinity of the front guide rib.

In the upper discharge tray 15 shown in FIG. 5, the guide rib 150 is provided on the bottom end 15b of the upper discharge tray 15 at the side end on the other side X2 of the discharge roller 31 in the axial direction X. On the other hand, the twelfth embodiment is different in that the guide ribs are provided on both side ends of the bottom surface 15b of the upper discharge tray 15 in the axial direction X of the discharge roller 31. In the following, in order to distinguish the guide ribs, the guide rib 150 provided at the side end on the other side X2 (upper side in FIG. 13) is referred to as the back side guide rib 150, and the one side X1 (lower side in FIG. 13). The guide ribs provided on the side ends may be referred to as front guide ribs 170. Further, the inner guide rib 150 has the same structure as that shown in FIG.

As described above, the discharge roller 31 is configured to shift and move in both the axial directions X, and FIG. 13 shows the sheet P that is shifted and moved to the one side X1. The sheet P is discharged in the front movement direction C inclined to the one side X1 with respect to the transport direction Y1 by shifting the discharge roller 31. The present embodiment is not limited to this, and the sheet P can be discharged in the above-described sheet diagonal movement direction W by shifting the discharging roller 31 to the other side X2.

The front guide rib 170 extends in the front movement direction C or the substantially front movement direction C. The specific direction of the front side movement direction C can be obtained in substantially the same manner as the diagonal seat movement direction W. In the present embodiment, two front side guide ribs 170 are provided, and one closer to the side end of the one side X1 of the upper discharge tray 15 is called a first front side guide rib 171 and the far side is a second side guide rib 171. This is called the front guide rib 172.

The front side guide rib 170 is provided at a position symmetrical with the back side guide rib 150 about the virtual boundary line β in the axial direction X, and the first front side guide rib 171 corresponds to the outer side guide rib 152 and the second guide rib 152. The front guide rib 172 corresponds to the inner guide rib 153. Note that the present invention is not limited to this, and when the upper discharge tray 15 is expanded to the one side X1, a front guide rib 170 corresponding to the outer guide rib 151 may be provided.

The front-side guide rib 170 has substantially the same configuration as the back-side guide rib 150, and gradually becomes higher than the bottom surface 15b of the upper discharge tray 15 from the upstream side toward the downstream side in the sheet P transport direction Y1. Is so inclined. That is, the upstream end (rear end 171b, 172b) of the front guide rib 170 has substantially the same height as the bottom surface 15b, and becomes higher as it goes away from the bottom surface 15b toward the downstream end (tip 171a, 172a). ..

The rib end portions 171c and 172c near the upstream end of the front guide rib 170 are substantially parallel to the transport direction Y1, and the downstream side of the rib end portions 171c and 172c extends in the front moving direction C. .. The guide rib angle θ (θ4) in which the first front side guide rib 171 is inclined with respect to the transport direction Y1 and the guide rib angle θ (θ5) in which the second front side guide rib 172 is inclined with respect to the transport direction Y1 are the back side guide rib 150. The guide rib angles θ (θ1 to θ3) are substantially the same.

A constricted portion 15e is provided on the front side of the upper discharge tray 15 (the lower side of the upper discharge tray 15 in FIG. 13). That is, the side of the upper discharge tray 15 on one side X1 is recessed on the other side X2. The portion of the constricted portion 15e facing the front guide rib 170 (the tray diagonal portion 15f) is a side parallel to the front movement direction C. That is, by providing the tray diagonal portion 15f parallel to the front guide rib 170, the side of the upper discharge tray 15 functions similarly to the front guide rib 170.

The bottom surface 15b of the upper discharge tray 15 is provided with an auxiliary rib 180 extending in a direction inclined with respect to the transport direction Y1 and having an end connected to the front guide rib 170. Specifically, as the auxiliary rib 180, a first auxiliary rib 181 connected to the first front side guide rib 171 and a second auxiliary rib 182 connected to the second front side guide rib 172 are provided. In the present embodiment, the auxiliary rib 180 extends in the axial direction X.

FIG. 15 is an enlarged cross-sectional view showing a cross section taken along arrow DD in FIG.

The top surface (auxiliary top surface 181a) of the first auxiliary rib 181 goes from one end (separation end 181b) separated from the first front guide rib 171 to the other end (connection end 181c) connected to the first front guide rib 171. Accordingly, the bottom surface 15b of the upper discharge tray 15 is inclined so as to be gradually higher. The separation end 181b is located on the one side X1 with respect to the rib end 151c, and the connecting end 181c is located lower than the top surface 171g of the first front guide rib 171. That is, the first front side guide rib 171 projects more from the bottom surface 15b than the first auxiliary rib 181. Since the second auxiliary rib 182 has a structure similar to that of the first auxiliary rib 181, the description thereof will be omitted. As described above, by providing the auxiliary rib 180 connected to the side surface of the guide rib, it is possible to prevent the sheet P from being caught on the side surface of the guide rib.

(Other embodiments)
In this example, the upper member is the upper discharge tray 15, but any member may be used as long as it covers the upper part of the discharge tray 14, and for example, without limitation, a transport unit or a housing may be used. It may be a constituent member or a cover member.

In addition, in this example, the discharge roller 31 is configured to shift and move to both the one side X1 and the other side X2 in the axial direction X, but the discharge roller 31 is either one of the one side X1 and the other side X2 in the axial direction X. It may be configured to shift to one side.

The present invention is not limited to the embodiments described above, but can be implemented in various other forms. Therefore, the embodiment is merely an example in all respects and should not be limitedly interpreted. The scope of the present invention is shown by the claims and is not bound by the text of the specification. Furthermore, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

14 discharge tray 14a mounting surface 15 upper discharge tray (an example of upper member)
15a Mounting surface 15b Bottom surface 15c Upstream end 15d Downstream end 15e Constriction part 30 Discharge roller shift unit 31 Discharge roller 32 Discharge drive roller 33 Discharge driven roller 34 Discharge roller pair 35 Energizing member 36 Upper discharge roller 40 Rotation drive part 41 Transport drive motor 42 Drive transmission mechanism 50 Shift drive section 51 Shift drive motor 52 Shift mechanism 100 Image forming apparatus 150 Guide rib 150a Tip (downstream side edge)
150b rear end (upstream end)
150c Rib end 150d Top 150e Sloping side surface 150f Base end 150g Top surface 151 Outer guide rib 151a Tip (downstream end)
151b Rear end (upstream end)
151c Rib end portion 152 Outer guide rib 152a Tip (downstream end)
152b Rear end (upstream end)
152c Rib end 153 Inner guide rib 1531 First inclined rib 1532 Second inclined rib 153a Tip (downstream end)
153b Rear end (upstream end)
160 Cross rib 161 First cross rib 162 Second cross rib 163 Third cross rib 170 Front side guide rib (an example of guide rib)
180 Auxiliary rib 300 Sheet sorting section 400 Sheet discharging device P Sheet P1 Tip (downstream side edge)
P2 rear end (upstream end)
Ps side edge Ps1 one side edge Ps2 other side edge S1 sheet transport path S2 upper sheet transport path S3 reverse sheet transport path SP space SW1 first detection switch SW2 second detection switch SWp position detection switch W sheet diagonal movement direction X axis direction X1 One side X2 Other side Y1 Transport direction Z Vertical direction d Distance α Sliding contact area α1 Transport direction sliding contact area β Virtual boundary line θ Guide rib angle φ1 Inclination angle φ3 Inclination angle φ31 Inclination angle φ32 Inclination angle

Claims (13)

A sheet discharge device comprising a discharge roller that conveys a sheet in a predetermined conveyance direction and discharges the sheet to a discharge tray, and an upper member that is provided above the discharge tray with a space therebetween.
On the bottom surface of the upper member facing the discharge tray, a plurality of guide ribs extending along an oblique direction inclined with respect to the transport direction are provided .
The plurality of guide ribs have inner ribs and outer ribs in the axial direction of the discharge roller, and the inner guide ribs are shorter than the outer guide ribs while leaving the downstream side in the transport direction. In the sheet conveying direction, the sheet discharging device is inclined so as to be gradually higher from the upstream side to the downstream side with respect to the bottom surface of the upper member . The sheet ejection device according to claim 1,
A sheet sorting unit that sorts the sheets to be discharged by shifting the discharging roller along the axial direction of the discharging roller,
The guide rib extends in the sheet diagonal movement direction or the sheet diagonal movement direction of the sheet that shifts along the axial direction by the sheet sorting unit while being conveyed in the conveyance direction by the discharge roller. Sheet ejection device. The sheet discharging device according to claim 1 or 2, wherein
A sheet sorting unit that sorts the discharged sheet by shifting the discharging roller along the axial direction of the discharging roller is provided, and the guide rib is conveyed by the discharging roller in the conveying direction while the sheet sorting unit is used. A sheet discharging device, which is located inside a side end of the sheet that shifts along the axial direction in the axial direction. The sheet discharging device according to any one of claims 1 to 3,
The sheet ejection device, wherein the guide rib is provided on at least one side end portion of both side end portions in the axial direction of the ejection roller on the bottom surface of the upper member. The sheet discharging device according to any one of claims 1 to 4,
The sheet ejection device according to claim 1, wherein the guide rib is inclined so as to be gradually higher with respect to the bottom surface of the upper member from the upstream side to the downstream side in the transport direction. The sheet ejection device according to claim 1 ,
In the inner guide rib, the inclination angle of the inclined surface facing the discharge tray with respect to the bottom surface of the upper member is larger than the angle of the top surface of the outer guide rib facing the discharge tray with respect to the bottom surface of the upper member. A sheet ejection device characterized by the above. The sheet discharging device according to claim 6 ,
The inner guide rib is composed of a plurality of inclined rib portions connected from the upstream side to the downstream side in the transport direction, and the inclination angle of the inclined rib portion on the upstream side is the inclination angle of the inclined rib portion on the downstream side. Sheet ejection device characterized by being larger than The sheet discharging device according to any one of claims 1 to 7 ,
On the bottom surface of the upper member, a crossing rib extending along a direction intersecting with the guide rib is provided,
The sheet discharging device, wherein the guide rib is higher than the height of the intersecting rib. The sheet discharging device according to claim 8 ,
The sheet discharging device, wherein the intersecting rib extends along an edge of a downstream end of the bottom surface of the upper member in the transport direction. The sheet discharging device according to any one of claims 1 to 9 ,
The sheet discharging device, wherein the bottom surface of the upper member is provided with an auxiliary rib extending in a direction inclined with respect to the transport direction and having an end portion connected to the guide rib. The sheet discharging device according to any one of claims 1 to 10 ,
The sheet discharging device according to claim 1, wherein the guide rib has a rib end portion that is a portion downstream of the upstream end in the transport direction by a predetermined distance from the upstream end in parallel or substantially parallel to the transport direction. The sheet discharging device according to any one of claims 1 to 11 ,
The sheet discharging apparatus, wherein the guide rib is formed so that the top portion facing the discharge tray makes a line contact or a substantially line contact with the sheet when the sheet is in sliding contact. An image forming apparatus comprising the sheet discharging device according to claim 1 .

Images