SHEET DISCHARGE DEVICE AND IMAGE FORMING APPARATUS

Abstract

A sheet discharge device includes a discharge tray that accommodates a discharged sheet with an end portion on an upstream side along a discharging direction of the sheet abutting against a wall surface and a plurality of exhaust passages that are provided in the wall surface of the discharge tray and that are inclined to extend outward of both end portions along a width direction intersecting the discharging direction of the sheet toward a lower side of the wall surface.

Claims

1. A sheet discharge device comprising: a discharge tray that accommodates a discharged sheet with an end portion on an upstream side along a discharging direction of the sheet abutting against a wall surface; and a plurality of exhaust passages that are provided in the wall surface of the discharge tray and that are inclined to extend outward of both end portions along a width direction intersecting the discharging direction of the sheet toward a lower side of the wall surface.

2. The sheet discharge device according to claim 1, wherein the plurality of exhaust passages are provided in a symmetrical shape with a reference position as a center.

3. The sheet discharge device according to claim 2, wherein the reference position is at a center in a direction intersecting the discharging direction of the sheet.

4. The sheet discharge device according to claim 2, wherein the plurality of exhaust passages are formed by protruding portions or slit portions provided in the wall surface of the discharge tray.

5. The sheet discharge device according to claim 1, wherein the discharge tray has an inclined surface that is formed such that the end portion on the upstream side along the discharging direction of the sheet is lowest.

6. The sheet discharge device according to claim 5, wherein the sheet is discharged along the inclined surface of the discharge tray due to a weight of the sheet in a state where the end portion on the upstream side along the discharging direction of the sheet has abutted against the wall surface.

7. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 1 is used as the sheet discharge section.

8. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 2 is used as the sheet discharge section.

9. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 3 is used as the sheet discharge section.

10. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 4 is used as the sheet discharge section.

11. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 5 is used as the sheet discharge section.

12. An image forming apparatus comprising: an image forming section that forms an image on a sheet; and a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, wherein the sheet discharge device according to claim 6 is used as the sheet discharge section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Exemplary embodiment(s) of the present invention will be described in detail based on the following figures, wherein:

[0012] FIG. 1 is an overall configuration view showing an image forming apparatus to which a sheet discharge device according to exemplary embodiment 1 of the invention is applied;

[0013] FIG. 2 is a configuration view showing a major portion of the image forming apparatus according to exemplary embodiment 1 of the invention;

[0014] FIG. 3 is a perspective configuration view showing the major portion of the image forming apparatus according to exemplary embodiment 1 of the invention;

[0015] FIGS. 4A and 4B are configuration views showing a sheet discharge device of the related art;

[0016] FIG. 5 is a perspective configuration view showing the sheet discharge device according to exemplary embodiment 1 of the invention;

[0017] FIG. 6 is a front configuration view showing a wall surface of the sheet discharge device;

[0018] FIG. 7 is a sectional arrow view taken along line VII-VII in FIG. 6;

[0019] FIG. 8 is a perspective configuration view showing operations of the sheet discharge device according to exemplary embodiment 1 of the invention;

[0020] FIG. 9 is a perspective configuration view showing a sheet discharge device according to exemplary embodiment 2 of the invention;

[0021] FIG. 10 is a front configuration view showing a wall surface of the sheet discharge device; and

[0022] FIG. 11 is a sectional arrow view taken along line XI-XI in FIG. 10.

DETAILED DESCRIPTION

[0023] Hereinafter, modes for carrying out the invention (hereinafter, referred to as exemplary embodiment) will be described with reference to the drawings.

Exemplary Embodiment 1

[0024] FIGS. 1 and 2 show an image forming apparatus to which a sheet discharge device according to exemplary embodiment 1 is applied. FIG. 1 shows an overall outline of the image forming apparatus, and FIG. 2 shows enlarged major portions (an image forming device and the like) of the image forming apparatus.

Overall Configuration of Image Forming Apparatus

[0025] An image forming apparatus 1 according to exemplary embodiment 1 is configured as, for example, a color printer. The image forming apparatus 1 includes, at an upper end of an apparatus body 1a, an image reading device 2 that reads an image of a document (not shown). The image forming apparatus 1 functions as a color printer or the like that records image information sent from a host computer (not shown) or the like, in addition to functioning to copy the image of the document read by the image reading device 2.

[0026] The image forming apparatus 1 includes, inside the apparatus body 1a, a plurality of image forming devices 10 that form a toner image developed with a toner configuring a developer 4, an intermediate transfer device 20 that holds each toner image formed by each image forming device 10 and that performs transportation to a secondary transfer position where the toner image is secondarily transferred to recording paper 5, which is an example of a sheet, ultimately, a feeding device 50 that accommodates and transports the required recording paper 5 to be supplied to the secondary transfer position of the intermediate transfer device 20, a fixing device 40 that fixes the toner image secondarily transferred to the recording paper 5 by the intermediate transfer device 20, and the like. The plurality of image forming devices 10 and the intermediate transfer device 20 configure an image forming section that forms an image on the recording paper 5. The apparatus body 1a of the image forming apparatus 1 is formed by a support structural member, an exterior cover, or the like.

[0027] The image forming devices 10 include four image forming devices 10Y, 10M, 10C, and 10K that exclusively form toner images of four colors including yellow (Y), magenta (M), cyan (C), and black (K), respectively. The four image forming devices 10 (Y, M, C, K) are disposed to be in a state of being arranged in one row in an inclined state in an internal space of the apparatus body 1a. Among the four image forming devices 10 (Y, M, C, K), the yellow (Y) image forming device 10Y is relatively high as the yellow (Y) image forming device 10Y is positioned high along a vertical direction Z, and the black (K) image forming device 10K is present at a relatively low position.

[0028] As shown in FIGS. 1 and 2, each of the yellow (Y), magenta (M), cyan (C), and black (K) image forming devices 10 (Y, M, C, K) includes a rotating photoconductor drum 11 which is an example of image holding means for holding an electrostatic latent image, and each device which is an example of the following toner image forming means is disposed in the vicinity of the photoconductor drum 11 as a major device. The major devices are a charging device 12 that charges a peripheral surface (image holding surface) of the photoconductor drum 11, on which an image can be formed, to a required potential, an exposure device 13 that irradiates the charged peripheral surface of the photoconductor drum 11 with light based on information (signal) of the image to form an electrostatic latent image (for each color) having a potential difference, a developing device 14 (Y, M, C, K) that develops the electrostatic latent image with a toner of the developer 4 of a corresponding color (Y, M, C, K) to form a toner image, a primary transfer device 15 (Y, M, C, K) that transfers each toner image to the intermediate transfer device 20, a drum cleaning device 16 (Y, M, C, K) that performs cleaning by removing an adhered object such as the toner remaining on and adhering to the image holding surface of the photoconductor drum 11 after primary transfer, and the like.

[0029] The photoconductor drum 11 forms an image holding surface that has a photoconductor layer (photosensitive layer) made of a photosensitive material on a peripheral surface of a cylindrical or columnar base material to be grounded. The photoconductor drum 11 is supported to rotate in a direction indicated by an arrow A as power is transmitted from a rotational drive device (not shown).

[0030] As shown in FIG. 2, the charging device 12 is configured by a contact-type charging roll 121 disposed in a state of being in contact with the photoconductor drum 11. A cleaning roll 122 that cleans a surface of the charging roll 121 is disposed on a back surface of the charging roll 121. A charging voltage is supplied to the charging roll 121 of the charging device 12. As the charging voltage, a voltage or a current having the same polarity as the charging polarity of a toner supplied from the developing device 14 is supplied in a case where the developing device 14 performs reversal development. A non-contact type charging device such as a scorotron disposed in a non-contact state with a surface of the photoconductor drum 11 may be used as the charging device 12.

[0031] The exposure device 13 irradiates the peripheral surface of the photoconductor drum 11 after charging with light configured according to information of an image input into the image forming apparatus 1 and forms an electrostatic latent image.

[0032] At a time of forming a latent image, information (signal) of an image input into the image forming apparatus 1 by any section is transmitted to the exposure device 13.

[0033] The exposure device 13 consists of an LED print head that irradiates the photoconductor drum 11 with light according to image information with a light emitting diode (LED), which is a plurality of light emitting elements arranged along an axial direction of the photoconductor drum 11, and that forms an electrostatic latent image. A device that performs deflection and scanning along the axial direction of the photoconductor drum 11 with laser light configured according to the image information may be used as the exposure device 13.

[0034] All of the developing devices 14 (Y, M, C, K) are configured such that a developing roll 141 that holds a developer to transport the developer to a developing region facing the photoconductor drum 11, an agitating and supplying member 142 consisting of a screw auger or the like that supplies the developer to pass through the developing roll 141 while agitating the developer, an agitating and transporting member 143 consisting of a screw auger or the like that transports the developer to the agitating and supplying member 142 while agitating the developer, a layer thickness regulating member 144 that regulates the amount (layer thickness) of the developer held by the developing roll 141, and the like are disposed inside a housing 140 in which an opening portion and an accommodation chamber for the developer are formed at positions facing the photoconductor drum 11. A developing voltage is supplied from a power supply device (not shown) to the developing device 14 between the developing roll 141 and the photoconductor drum 11.

[0035] For example, a two-component developer containing a non-magnetic toner and a magnetic carrier is used as developers of four colors.

[0036] The primary transfer device 15 (Y, M, C, K) is a contact-type transfer device including a primary transfer roll that rotates around the photoconductor drum 11 in contact therewith via an intermediate transfer belt 21 and that is supplied with a primary transfer voltage. As the primary transfer voltage, a direct current voltage indicating a polarity opposite to the charging polarity of a toner is supplied from the power supply device (not shown).

[0037] As shown in FIG. 2, the drum cleaning device 16 is configured by a container-shaped body 160 having a part opened, a cleaning plate 161 that is disposed to be in contact with the peripheral surface of the photoconductor drum 11 after primary transfer at a required pressure and that performs cleaning by removing an adhered object such as a remaining toner, a sending member 162 such as a screw auger that transports the adhered object such as the toner removed by the cleaning plate 161 to be sent out to a collection system (not shown), and the like. A plate-shaped member (for example, a blade) made of a material such as rubber is used as the cleaning plate 161.

[0038] As shown in FIG. 1, the intermediate transfer device 20 is disposed to be present at a position above each image forming device 10 (Y, M, C, K). The intermediate transfer device 20 is generally configured by the intermediate transfer belt 21 that rotates in a direction indicated by an arrow B while passing through a primary transfer position between the photoconductor drum 11 and the primary transfer device 15 (primary transfer roll), a plurality of belt support rolls 22 to 25 that hold the intermediate transfer belt 21 in an appropriate state from an inner surface thereof and that rotatably support the intermediate transfer belt 21, a secondary transfer device 30 that is an example of a secondary transfer member, which is disposed on an outer peripheral surface (image holding surface) side of the intermediate transfer belt 21 supported by the belt support roll 25 and which secondarily transfers a toner image on the intermediate transfer belt 21 to the recording paper 5, and a belt cleaning device 26 that performs cleaning by removing an adhered object such as a toner and paper dust which remain and are adhered to the outer peripheral surface of the intermediate transfer belt 21 after passing through the secondary transfer device 30.

[0039] For example, an endless belt made of a material, in which a resistance adjusting agent such as carbon black is dispersed in a synthetic resin such as a polyimide resin and a polyamide resin, is used as the intermediate transfer belt 21. In addition, the belt support roll 22 is configured as a drive roll that is rotationally driven by a drive device (not shown), the belt support roll 23 is configured as a surface roll that maintains a traveling position or the like of the intermediate transfer belt 21, the belt support roll 24 is configured as a tension applying roll that applies tension to the intermediate transfer belt 21, and the belt support roll 25 is configured as a backup roll for secondary transfer.

[0040] As shown in FIG. 1, the secondary transfer device 30 is a contact-type transfer device including a secondary transfer roll 31, which rotates while being in contact with the peripheral surface of the intermediate transfer belt 21 and to which a secondary transfer voltage is supplied, at the secondary transfer position which is an outer peripheral surface portion of the intermediate transfer belt 21 supported by the belt support roll 25 of the intermediate transfer device 20. In addition, a direct current voltage indicating an opposite polarity or the same polarity as the charging polarity of a toner is supplied as the secondary transfer voltage to the secondary transfer roll 31 or the belt support roll 25 of the intermediate transfer device 20.

[0041] As shown in FIG. 2, the belt cleaning device 26 is configured by a container-shaped body 260 having a part opened, a cleaning plate 261 that is disposed to be in contact with the peripheral surface of the intermediate transfer belt 21 after secondary transfer at a required pressure and that performs cleaning by removing an adhered object such as a remaining toner, a sending member 262 such as a screw auger that transports the adhered object such as the toner removed by the cleaning plate 261 to be sent out to the collection system (not shown), and the like. A plate-shaped member (for example, a blade) made of a material such as rubber is used as the cleaning plate 261.

[0042] The fixing device 40 is configured such that a heating rotating body 41 in a drum form or a belt form heated by a heating section so that a surface temperature is maintained at a required temperature, a pressurizing rotating body 42 in a drum form or a belt form rotating in contact with a predetermined pressure in a state substantially along an axial direction of the heating rotating body 41, and the like are disposed. An outlet roll 43 that transports the recording paper 5 on which fixing processing is performed is provided at an outlet portion of the fixing device 40. In the fixing device 40, a contact portion where the heating rotating body 41 and the pressurizing rotating body 42 are in contact with each other is a fixing processing portion in which required fixing processing (heating and pressurization) is performed.

[0043] The feeding device 50 is disposed to be present at a position on a lower side of the yellow (Y), magenta (M), cyan (C), and black (K) image forming devices 10 (Y, M, C, K). The feeding device 50 is generally configured by a plurality of (or a single) paper accommodating bodies 51 that accommodate the recording paper 5 of an appropriate size and type in a stacked state and sending devices 52 and 53 that send out the recording paper 5 one by one from the paper accommodating bodies 51. The paper accommodating body 51 is attached, for example, such that the paper accommodating body 51 can be pulled to a front surface (a side surface facing a user during operation) side of the apparatus body 1a or a front side of the page in the shown example.

[0044] Examples of the recording paper 5 include plain paper used in an electrophotographic copying machine or a printer, thin paper, an OHP sheet, and the like. In order to further improve smoothness of an image surface after fixing, for example, it is preferable that the surface of the recording paper 5 is also as smooth as possible, and for example, so-called thick paper having a relatively large basis weight, such as coated paper obtained by coating the surface of plain paper with a resin, printing art paper, or the like can also be used.

[0045] A feeding transport path 56 configured by a plurality (or a single) of pairs of paper transport rollers 54 and 55 that transport the recording paper 5 sent out from the feeding device 50 to the secondary transfer position, a transport guide (not shown), and the like is provided between the feeding device 50 and the secondary transfer device 30. The pair of paper transport rolls 55 are configured as, for example, registration rolls that adjust the transport timing of the recording paper 5. In addition, a paper discharge transport unit 58 including first to fourth paper discharge transport paths 57a to 57d for discharging the recording paper 5 sent out from the outlet roll 43 of the fixing device 40 after fixing to a sheet discharge device 60 that is an example of a sheet discharge section provided at an upper portion of the apparatus body 1a is provided at an upper portion of the fixing device 40 along the vertical direction Z.

[0046] The sheet discharge device 60 includes so-called in-body discharge type first and second discharge trays 61 and 62 provided at the upper portion of the apparatus body 1a and a third discharge tray 63 provided at a side surface (a left surface in the drawing) of the paper discharge transport unit 58 toward the outside. Inside the paper discharge transport unit 58, the first paper discharge transport path 57a that branches from the second paper discharge transport path 57b and that includes a first pair of paper discharge rolls 64 for discharging the recording paper 5 to the first discharge tray 61, the third paper discharge transport path 57c that branches from the second paper discharge transport path 57b and that includes a second pair of paper discharge rolls 66 for discharging the recording paper 5 to the second discharge tray 62, and the fourth paper discharge transport path 57d that branches from the third paper discharge transport path 57c and that includes a third pair of paper discharge rolls 67 for discharging the recording paper 5 to the third discharge tray 63 are provided.

[0047] In FIG. 1, the reference symbol 68 indicates a pair of paper transport rolls provided in the middle of the second paper discharge transport path 57b, the reference symbol G1 indicates a first switching gate that branches the first paper discharge transport path 57a and the second paper discharge transport path 57b, and the reference symbol G2 indicates a second switching gate that branches the third paper discharge transport path 57c and the fourth paper discharge transport path 57d. The sheet discharge device 60 will be described in detail later.

[0048] In addition, inside the apparatus body 1a, as shown in FIG. 2, a double-sided transport path 70 including a pair of paper transport rolls 69 that reverse the front and back of the recording paper 5 by switching a rotation direction of the first pair of paper discharge rolls 64 from a forward rotation direction to a reverse rotation direction and that transport the recording paper 5 again to the pair of paper transport rolls 55 while the recording paper 5 having one side on which an image is formed is held by the first pair of paper discharge rolls 64 is provided.

[0049] In FIG. 1, the reference symbol 71 indicates a manual feeding tray provided openably and closably on a side surface (a left surface in FIG. 1) of the apparatus body 1a of the image forming apparatus 1. Between the manual feeding tray 71 and the pair of paper transport rolls 55, a sending device 72 that sends out the recording paper 5 accommodated in the manual feeding tray 71 one by one and a manual feeding transport path 74 configured by a pair of paper transport rolls 73, a transport guide (not shown), or the like are provided.

[0050] In addition, the reference symbol 145 (Y, M, C, K) in FIG. 1 indicates each of a plurality of toner cartridges that are arranged along a direction perpendicular to the page and that accommodate a developer containing at least a toner to be supplied to the corresponding developing device 14 (Y, M, C, K).

[0051] In addition, the reference symbol 100 in FIG. 1 indicates a control device that comprehensively controls an operation of the image forming apparatus 1. The control device 100 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a bus that connects the CPU, the ROM, and the like to each other, a communication interface, and the like (not shown).

Operation of Image Forming Apparatus

[0052] Hereinafter, a basic image forming operation by the image forming apparatus 1 will be described.

[0053] Herein, an operation of forming a full-color image configured by combining toner images of four colors (Y, M, C, K) using the four image forming devices 10 (Y, M, C, K) will be described.

[0054] In a case where the control device 100 receives command information requesting for an image forming operation (printing), the image forming apparatus 1 starts the four image forming devices 10 (Y, M, C, K), the intermediate transfer device 20, the secondary transfer device 30, the fixing device 40, and the like.

[0055] Then, in each image forming device 10 (Y, M, C, K), each photoconductor drum 11 first rotates in the direction indicated by the arrow A, and each charging device 12 charges the surface of each photoconductor drum 11 to each of a required polarity (a negative polarity in exemplary embodiment 1) and a required potential. Next, the exposure device 13 irradiates the surface of the photoconductor drum 11 after charging with light emitted based on a signal of an image obtained by converting information of an image input into the image forming apparatus 1 into each color component (Y, M, C, K), and each electrostatic latent image having each color component configured by a required potential difference is formed on the surface.

[0056] Next, each image forming device 10 (Y, M, C, K) performs development by each supplying a toner of a corresponding color (Y, M, C, K) charged to the required polarity (negative polarity) from the developing roll 141 and electrostatically adhering the toner to the electrostatic latent image having each color component, which is formed on the photoconductor drum 11. With the development, the electrostatic latent image having each color component formed on each photoconductor drum 11 is visualized as each toner image of each of four colors (Y, M, C, K) developed with a toner of a corresponding color.

[0057] Next, in a case where the toner image of each color formed on the photoconductor drum 11 of each image forming device 10 (Y, M, C, K) is transported to the primary transfer position, each primary transfer device 15 (Y, M, C, K) primarily transfers the toner image of each color in a state of overlapping each other in turn to the intermediate transfer belt 21 of the intermediate transfer device 20, which rotates in the direction indicated by the arrow B.

[0058] In addition, in each image forming device 10 (Y, M, C, K) that has ended primary transfer, the drum cleaning device 16 cleans the surface of the photoconductor drum 11 by scraping off and removing an adhered object. Accordingly, each image forming device 10 (Y, M, C, K) is brought into a state where the next image formation operation can be performed.

[0059] Next, the intermediate transfer device 20 holds the toner image primarily transferred in response to the rotation of the intermediate transfer belt 21 and transports the toner image to the secondary transfer position. On the other hand, the feeding device 50 sends out the required recording paper 5 to the feeding transport path 56 in accordance with the image formation operation. In the feeding transport path 56, the pair of paper transport rolls 55, which are registration rolls, send out and supply the recording paper 5 to the secondary transfer position in accordance with a transfer timing.

[0060] At the secondary transfer position, the secondary transfer roll 31 of the secondary transfer device 30 collectively and secondarily transfers the toner image on the intermediate transfer belt 21 to the recording paper 5. In addition, in the intermediate transfer device 20 that has ended the secondary transfer, the belt cleaning device 26 performs cleaning by removing an adhered object such as a toner remaining on the surface of the intermediate transfer belt 21 after the secondary transfer.

[0061] Next, the recording paper 5 to which the toner image is secondarily transferred is transported to the fixing device 40 after being peeled off the intermediate transfer belt 21 and the secondary transfer roll 31. The fixing device 40 performs necessary fixing processing (heating and pressurization) and fixes an unfixed toner image to the recording paper 5 by causing the recording paper 5 after the secondary transfer to be introduced into and to pass through the contact portion between the rotating heating rotating body 41 and the pressurizing rotating body 42. Finally, in a case of an image forming operation of forming an image on one side only, the recording paper 5 after fixing has ended is discharged to any one of the first to third discharge trays 61 to 63 provided at the upper portion of the apparatus body 1a via the first to fourth paper discharge transport paths.

[0062] In addition, in a case of forming images on both sides of the recording paper 5, the rotation direction of the first pair of paper discharge rolls 64 is switched to the reverse rotation direction while the first pair of paper discharge rolls 64 hold a trailing end of the recording paper 5, without the first pair of paper discharge rolls 64 discharging the recording paper 5 having one side on which the image is formed to the first discharge tray 61. The recording paper 5 transported in a reverse direction by the first pair of paper discharge rolls 64 is transported to the double-sided transport path 70 including the pair of paper transport rolls 69 and the like and is transported to the pair of paper transport rolls 55 again in a state where the front and back are reversed. The pair of paper transport rolls 55 send out and supply the recording paper 5 to the secondary transfer position in accordance with a transfer timing, form an image on the back surface of the recording paper 5, and discharge the recording paper 5 having the back surface on which the image is fixed to any one of the first to third discharge trays 61 to 63 provided at the upper portion of the apparatus body 1a via any one of the first to fourth paper discharge transport paths 57a to 57d.

[0063] With the operation above, the recording paper 5 having one side or both sides on which a full-color image configured by combining the toner images of four colors is formed is output.

Configuration of Sheet Discharge Device

[0064] As shown in FIG. 2, the image forming apparatus 1 includes, at the upper portion of the apparatus body 1a, the sheet discharge device 60 that discharges the recording paper 5 which is an example of a sheet having one side or both sides on which an image is formed.

[0065] The sheet discharge device 60 according to exemplary embodiment 1 is configured as a so-called in-body discharge type sheet discharge device that discharges the recording paper 5 into a trunk, which is the upper portion of the apparatus body 1a of the image forming apparatus 1.

[0066] As shown in FIGS. 2 and 3, the sheet discharge device 60 includes the first to third discharge trays 61 to 63 that accommodate the recording paper 5 to which an image is fixed and which is discharged by the fixing device 40 as an end portion on an upstream side along a discharging direction thereof abuts against a wall surface and the first to third pairs of paper discharge rolls 64, 66, and 67 that discharge the recording paper 5 to which the image is fixed by the fixing device 40 to the first to third discharge trays 61 to 63.

[0067] Herein, in particular, the first discharge tray 61 including the first pair of paper discharge rolls 64 will be described as the sheet discharge device 60.

[0068] As described above, the first discharge tray 61 is configured as a so-called in-body discharge type discharge tray for discharging the recording paper 5 into the trunk of the apparatus body 1a of the image forming apparatus 1. As shown in FIGS. 2 and 3, the first discharge tray 61 includes an inclined portion 611 that is an example of an inclined surface inclined such that an end portion on the upstream side along the discharging direction is positioned inside the apparatus body 1a, a flat portion 612 that is disposed on a downstream side of the inclined portion 611 along the discharging direction and that is flatly formed along a horizontal direction X, and a wall surface 613 that is disposed at the end portion of the inclined portion 611 on the upstream side along the discharging direction, that consists of a surface slightly inclined such that a lower end portion along the vertical direction Z is positioned on the downstream side along the discharging direction, and that aligns the end portion on the upstream side along the discharging direction of the recording paper 5, which is discharged to the first discharge tray 61, by abutting thereagainst.

[0069] Both end portions of the inclined portion 611 of the first discharge tray 61 along a width direction (depth direction) Y intersecting the discharging direction of the recording paper 5 are closed by front and rear side surfaces 1b and 1c configuring the apparatus body 1a. In FIG. 2, the reference symbol 1d indicates a blower port opened in the side surface 1c of the apparatus body 1a.

[0070] As shown in FIGS. 2 and 3, at the end portion of the first discharge tray 61 on the upstream side along the discharging direction of the recording paper 5, the first pair of paper discharge rolls 64 that discharge the recording paper 5 obliquely upward onto the first discharge tray 61 are provided at a height substantially equivalent to the flat portion 612 of the first discharge tray 61.

[0071] As shown in FIGS. 4A and 4B, in the sheet discharge device 60 configured as described above, in a case where the recording paper 5 is discharged onto the first discharge tray 61 by the first pair of paper discharge rolls 64, air positioned below the recording paper 5 is collected in a spiral shape with the discharge (movement) of the recording paper 5 as an air sump 75 since both sides of the inclined portion 611 of the first discharge tray 61 along the width direction intersecting the discharging direction are closed by the side surfaces 1b and 1c of the apparatus body 1a.

[0072] FIGS. 4A and 4B schematically show an image taken in a state where a front cover (not shown) of the image forming apparatus 1 is opened in order to observe the posture of the recording paper 5 discharged onto the first discharge tray 61.

[0073] For this reason, the recording paper 5 discharged onto the first discharge tray 61 does not immediately fall onto the first discharge tray 61 due to the presence of the air sump 75 and temporarily floats in the air. Then, in the first discharge tray 61, as air configuring the air sump 75 present below the recording paper 5 moves around the first discharge tray 61, the recording paper 5 falls onto a surface of the inclined portion 611 of the first discharge tray 61 or the like due to the weight thereof.

[0074] As a result, in the related art, in the sheet discharge device 60 configured as described above, as shown in FIG. 4B, in a case where the recording paper 5 is discharged to the first discharge tray 61, the posture of the recording paper 5 becomes unstable and becomes disordered due to an effect of the air sump 75 present below the recording paper 5, and the end portion on the upstream side along the discharging direction of the recording paper 5 comes into contact with the middle of the wall surface 613 of the first discharge tray 61 and remains in a curved state. That is, there is a technical issue of occurrence of a so-called bank remaining.

[0075] In order for the sheet discharge device according to exemplary embodiment 1 to suppress disorder of the posture of a sheet discharged to the discharge tray in a case of discharging the sheet, the sheet discharge device is configured to include a plurality of exhaust passages that are provided in the wall surface of the discharge tray and that are inclined to extend outward of both end portions along the width direction intersecting the discharging direction of a sheet toward a lower side of the wall surface.

[0076] In addition, the sheet discharge device according to exemplary embodiment 1 is configured such that the plurality of exhaust passages are provided in a symmetrical shape with a reference position as a center and the reference position is at, for example, the center in a direction intersecting the discharging direction of the sheet.

[0077] That is, as shown in FIG. 5, the sheet discharge device 60 according to exemplary embodiment 1 is provided with a plurality of exhaust passages 80, 80, . . . in the wall surface 613 of the first discharge tray 61.

[0078] As shown in FIGS. 6 and 7, on the wall surface 613 of the first discharge tray 61, a plurality of ribs 81, 81 . . . that are linear protruding portions for forming the plurality of exhaust passages 80, 80, . . . are integrally formed to protrude from an inner side surface of the wall surface 613 toward the inside of the first discharge tray 61.

[0079] As shown in FIG. 6, the plurality of ribs 81, 81 . . . are provided in a bilaterally symmetrical shape with a reference position C as a center. The reference position for providing the ribs 81, 81 . . . is configured to be at, for example, the center in the width direction intersecting the discharging direction of the recording paper 5.

[0080] To describe further, as shown in FIGS. 6 and 7, the plurality of ribs are provided parallel to each other on the wall surface 613 of the first discharge tray 61 in a state of being inclined by an angle with respect to the vertical direction Z to extend outward of both end portions along the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613, so that the plurality of ribs are in a bilaterally symmetrical shape with the reference position C, which is at the center in the width direction intersecting the discharging direction of the recording paper 5, as reference.

[0081] The plurality of ribs 81, 81 . . . are formed in an elongated protruding shape having a required width and a required height with respect to the wall surface 613 of the first discharge tray 61. Among the plurality of ribs 81, 81 . . . , between the ribs 81, 81 . . . adjacent to each other, the plurality of exhaust passages 80, 80, . . . are provided as spaces defined between the ribs 81, 81 . . . adjacent to each other.

[0082] Like the plurality of ribs 81, 81 . . . , the plurality of exhaust passages 80, 80, . . . are disposed in an inclined state to extend outward of both end portions along the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613 along the vertical direction Z.

[0083] The plurality of exhaust passages 80, 80, . . . are set such that each of sectional areas of the exhaust passages 80, 80 . . . increases as the heights of the plurality of ribs 81, 81 . . . increase and intervals between the plurality of ribs 81, 81 . . . increase. Conversely, the plurality of exhaust passages 80, 80, . . . are set such that each of the sectional areas of the exhaust passages 80, 80 . . . decreases as the heights of the plurality of ribs 81, 81 . . . decrease and the intervals between the plurality of ribs 81, 81 . . . decrease.

[0084] However, a total sectional area of the plurality of exhaust passages 80, 80, . . . is determined by the product of each of the sectional areas of the exhaust passages 80, 80 . . . and the total number of the exhaust passages 80, 80 . . . .

[0085] In the configuration above, it is possible for the sheet discharge device according to exemplary embodiment 1 to suppress that the posture of a sheet discharged to the discharge tray is disordered in a case of discharging the sheet, compared to a case of not including the plurality of exhaust passages that are provided in the wall surface of the discharge tray and that are inclined to extend outward of both end portions along the width direction intersecting the discharging direction of the sheet toward the lower side of the wall surface as follows.

[0086] That is, as shown in FIG. 1, the recording paper 5 having one side or both sides on which an image is formed is discharged to any one of the first to third discharge trays 61 to 63 in the sheet discharge device 60 according to exemplary embodiment 1.

[0087] In this case, as shown in FIG. 4A, in a case where the recording paper 5 having one side or both sides on which an image is formed is discharged to the first discharge tray 61 of the sheet discharge device 60, the recording paper 5 having one side or both sides on which the image is formed is discharged by the first pair of paper discharge rolls 64 substantially parallel to the flat portion 612 of the first discharge tray 61.

[0088] In this case, due to various factors such as fixing properties of the fixing device 40, absorption properties of the recording paper 5, or a state of an image formed on the recording paper 5, curves, such as a down curl that curves in a protruding shape toward a first discharge tray 61 side and an upper curl that curves in a recessed shape toward the first discharge tray 61 side, are generated in the recording paper 5 in some cases.

[0089] Immediately after the recording paper 5 is discharged onto the first discharge tray 61, the air sump 75 where air below the recording paper 5 remains is present in the sheet discharge device 60.

[0090] As shown in FIG. 5, the sheet discharge device 60 according to exemplary embodiment 1 is provided with the plurality of exhaust passages 80, 80, . . . in the wall surface 613 which is the end portion of the first discharge tray 61 on the upstream side along the discharging direction of the recording paper 5. In addition, the plurality of exhaust passages 80, 80, . . . are inclined to extend outward of both end portions in the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613 of the first discharge tray 61.

[0091] For this reason, in a case where the recording paper 5 is discharged onto the first discharge tray 61, as shown in FIG. 8, air configuring the air sump 75 present below the recording paper 5 can quickly escape toward the upper side of the first discharge tray 61 via the plurality of exhaust passages 80, 80, . . . provided in the end portion of the first discharge tray 61 on the upstream side along the discharging direction of the recording paper 5.

[0092] In this case, the plurality of exhaust passages 80, 80, . . . are provided in a state of being inclined to extend outward of both end portions in the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613 of the first discharge tray 61. For this reason, the recording paper 5 discharged onto the first discharge tray 61 has the end portion on the upstream side along the discharging direction thereof, which comes into contact with the surfaces of the plurality of ribs 81, 81 . . . , and is guided to extend outward of both end portions in the width direction intersecting the discharging direction along inclination of the plurality of ribs 81, 81 . . . .

[0093] As a result, even in a case where a curve, such as a down curl and an upper curl, is generated in the recording paper 5 discharged onto the first discharge tray 61, the recording paper 5 is discharged in a state where the curve is corrected since the recording paper 5 comes into contact with the plurality of ribs 81, 81 . . . to expand toward both end portions along the width direction.

[0094] As described above, it is possible for the sheet discharge device 60 according to exemplary embodiment 1 to suppress that the posture of the recording paper 5 discharged to the first discharge tray 61 is disordered in a case of discharging the recording paper 5, compared to a case of not including the plurality of exhaust passages 80, 80, . . . that are provided in the wall surface 613 of the first discharge tray 61 and that are inclined to extend outward of both end portions along the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613.

Exemplary Embodiment 2

[0095] FIG. 9 is a perspective configuration view showing an image forming apparatus to which a sheet discharge device according to exemplary embodiment 2 of the invention is applied. Members corresponding to exemplary embodiment 1 above will be described with the identical reference symbols assigned.

[0096] That is, as shown in FIGS. 9 to 11, the sheet discharge device 60 according to exemplary embodiment 2 is configured such that the plurality of exhaust passages 80, 80, . . . are formed by slit portions directly opened in a shape corresponding to the plurality of exhaust passages 80, 80, . . . in the wall surface 613 of the first discharge tray 61, instead of being formed by protruding portions provided on the wall surface 613 of the first discharge tray 61.

[0097] The plurality of exhaust passages 80, 80, . . . consisting of slit portions inclined to extend outward of both end portions along the width direction intersecting the discharging direction of the recording paper 5 toward the lower side of the wall surface 613 in the vertical direction Z are provided in the wall surface 613 of the first discharge tray 61.

[0098] The plurality of exhaust passages 80, 80, . . . are formed through integral molding, for example, in a case where a member configuring the wall surface 613 of the first discharge tray 61 is molded.

[0099] A region of the wall surface 613 of the first discharge tray 61 present between the plurality of exhaust passages 80, 80, . . . may be configured by the identical flat surface as a surface of the wall surface 613, but may be in, for example, a rib shape that protrudes from the surface of the wall surface 613 as in exemplary embodiment 1 in order to reduce a contact resistance with the recording paper 5.

[0100] In a case where the recording paper 5 is discharged onto the first discharge tray 61 of the sheet discharge device 60 according to exemplary embodiment 2, air configuring the air sump 75 present below the recording paper 5 escapes into the apparatus body 1a via the plurality of exhaust passages 80, 80, . . . . For this reason, unlike exemplary embodiment 1, air flowing in the plurality of exhaust passages 80, 80, . . . does not flow from the lower side toward the upper side along the vertical direction Z along a longitudinal direction of the plurality of exhaust passages 80, 80, . . . , but flows from the surface toward the back surface (inner surface) of the wall surface 613 of the first discharge tray 61 via the plurality of exhaust passages 80, 80, . . . , and thereby it is possible to make the air configuring the air sump 75 present below the recording paper 5 quickly escape.

[0101] Since other components and operations are similar to the components and operations in exemplary embodiment 1 above, description thereof will be omitted.

[0102] Although the full-color image forming apparatus has been described in the exemplary embodiments, the sheet discharge device according to the exemplary embodiments of the present invention is not limited thereto. It is evident that the same can also be applied to a monochrome image forming apparatus, and it is evident that the same can also be applied to a finisher or the like which binds a sheet or which performs perforation processing or the like, in addition to the image forming apparatus.

Supplementary Note

(((1)))

[0103] A sheet discharge device comprising: [0104] a discharge tray that accommodates a discharged sheet with an end portion on an upstream side along a discharging direction of the sheet abutting against a wall surface; and [0105] a plurality of exhaust passages that are provided in the wall surface of the discharge tray and that are inclined to extend outward of both end portions along a width direction intersecting the discharging direction of the sheet toward a lower side of the wall surface.
(((2)))

[0106] The sheet discharge device according to (((1))), [0107] wherein the plurality of exhaust passages are provided in a symmetrical shape with a reference position as a center.
(((3)))

[0108] The sheet discharge device according to (((2))), [0109] wherein the reference position is at a center in a direction intersecting the discharging direction of the sheet.
(((4)))

[0110] The sheet discharge device according to (((2))), [0111] wherein the plurality of exhaust passages are formed by protruding portions or slit portions provided in the wall surface of the discharge tray.
((5))

[0112] The sheet discharge device according to (((1))), [0113] wherein the discharge tray has an inclined surface that is formed such that the end portion on the upstream side along the discharging direction of the sheet is lowest.
(((6)))

[0114] The sheet discharge device according to any one of (((1))) to ((5))), [0115] wherein the sheet is discharged along an inclined surface of the discharge tray due to a weight of the sheet in a state where the end portion on the upstream side along the discharging direction of the sheet has abutted against the wall surface.
(((7)))

[0116] An image forming apparatus comprising: [0117] an image forming section that forms an image on a sheet; and [0118] a sheet discharge section that discharges the sheet on which the image is formed by the image forming section, [0119] wherein the sheet discharge device according to any one of (((1))) to (((6))) is used as the sheet discharge section.

[0120] The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.