JP2011251786A - Discharge device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detachability of a detection member that detects stacking height of recording media discharged to a discharge part and a pressing member that presses the recording media discharged to the discharge part, from a discharge device body.SOLUTION: The discharge device 20 includes: a discharge device body 20A that is provided in an image forming apparatus body 10A so as to discharge the recording medium P to the discharge part 84; an attaching member 88 that is detachably provided in the discharge device body 20A above the discharge part 84; the detection member 86 that is rotatably provided on the attaching member 88 and detects the stacking height of the recording media P, into contact with the recording media P stacked in the discharge part 84; and the pressing member 100 that is rotatably provided on the attaching member 88 and presses the recording media P, in contact with the recording media P stacked in the discharge part 84 by gravity.

Description

  The present invention relates to a discharge device and an image forming apparatus.

  2. Description of the Related Art A sheet stacking device including an actuator that detects the stacking height of sheets placed on a stacking tray, that is, the uppermost sheet and detects that the sheets are stacked to a predetermined height is conventionally known. (For example, refer to Patent Document 1). Further, a paper tray provided with a pressing member that presses the paper discharged onto the tray is also conventionally known (for example, see Patent Document 2).

JP 2006-225062 A JP-A-5-254709

  The present invention relates to a detection device for detecting the stacking height of a recording medium discharged to a discharge portion, and a discharge device capable of improving the detachability of the pressing member for pressing the recording medium discharged to the discharge portion from the discharge device main body. An object is to obtain an image forming apparatus.

  In order to achieve the above object, a discharge device according to a first aspect of the present invention includes a discharge device main body provided in the image forming apparatus main body so that the recording medium can be discharged to the discharge portion, and above the discharge portion. A mounting member that is detachably provided on the main body of the discharge device, and a detection member that is rotatably provided on the mounting member and detects the stacking height of the recording medium by contacting the recording medium stacked on the discharge portion. And a pressing member that is rotatably provided on the mounting member and that presses the recording medium by contacting the recording medium loaded on the discharge portion by its own weight.

  A discharge device according to a second aspect is the discharge device according to the first aspect, wherein the discharge device is rotatably provided on the mounting member, and is provided on a rotation shaft to which the detection member is fixed, and on the discharge device main body. And a detecting member that is fitted in such a manner that one end portion of the rotating shaft is detachable and relatively non-rotatable, and moves by rotation of the rotating shaft, thereby detecting a preset stacking height of the recording medium. It is characterized by having.

  Further, the discharge device according to claim 3 is the discharge device according to claim 1 or 2, wherein the discharge device is provided in the discharge device main body, the transfer means for transferring the recording medium to the discharge portion, and the attachment And a guide member that is provided on the member and guides the recording medium from above between the transport unit and the detection member.

  An image forming apparatus according to a fourth aspect of the present invention includes an image forming apparatus main body provided with the discharge device according to any one of the first to third aspects, and the image forming apparatus main body. And a discharge portion on which the recording medium discharged from the discharge device main body of the discharge device is stacked, and a post-treatment device can be connected to the discharge device main body from which the mounting member is removed It is characterized by being.

  According to the first aspect of the invention, the detection member for detecting the stacking height of the recording medium discharged to the discharge portion and the recording discharged to the discharge portion are attached to the attachment member detachably provided on the discharge device main body. Compared with a configuration in which a pressing member for pressing the medium is not provided, the detachability of the detection member and the pressing member from the discharge device main body can be improved.

  According to the second aspect of the present invention, the detection member for detecting the preset stacking height of the recording medium is configured such that one end of the rotating shaft to which the detection member is fixed is not detachably fitted. In comparison, the detachability of the rotary shaft from the discharge device body can be improved.

  According to the third aspect of the present invention, compared to a configuration in which the guide member that guides the recording medium from the upper side between the conveying means and the detection member is not provided on the attachment member, the discharge device main body of the guide member It is possible to improve the detachability from the.

  According to invention of Claim 4, compared with the structure in which the discharge apparatus of any one of Claims 1-3 is not provided, a post-processing apparatus can be connected easily.

Schematic diagram showing the overall configuration of the image forming apparatus according to the present embodiment Schematic diagram showing the configuration of the image forming unit The perspective view which shows the paper discharge apparatus to which the detection member was attached The perspective view which shows the attachment structure of the upper detection member and the pressing member The perspective view which shows the attachment structure of a lower detection member and a pressing member The perspective view which shows the guide member provided in a lower paper discharge part Side sectional view showing a configuration of a paper discharge unit provided with a guide member according to the present embodiment Schematic diagram showing a state where the lower detection member and the pressing member are removed and the post-processing apparatus is connected. Side sectional view which shows the structure of the paper discharge part provided with the guide member which concerns on a comparative example

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In FIG. 1, the arrow UP is the upward direction of the image forming apparatus 10, and the arrow RI is the right direction. The front side in the direction perpendicular to the paper surface shown in FIG. 1 is the front side of the image forming apparatus 10 and is the front. In this embodiment, recording paper P is employed as an example of the recording medium.

  As shown in FIG. 1, the image forming apparatus 10 is provided from the bottom side to the top side, the paper storage unit 12 that stores the recording paper P, and the paper storage unit 12. An image forming unit 14 that forms an image on the recording paper P to be printed, and a paper discharge device that is provided above the image forming unit 14 and that discharges (discharges) the recording paper P on which the image is formed. 20, a document reading unit 16 provided above the paper discharge device 20 for reading the document G, and a control unit 18 provided in the image forming unit 14 for controlling the operation of each unit of the image forming device 10. It consists of

  The sheet storage unit 12 includes a first storage unit 22, a second storage unit 24, a third storage unit 26, and a fourth storage unit 28. Each of the storage units 22, 24, 26, and 28 includes Recording sheets P of different sizes can be accommodated. Each of the storage units 22, 24, 26, 28 is provided with a delivery roll 32 that feeds the stored recording paper P to a transport path 30 provided in the image forming apparatus main body 10 </ b> A of the image forming apparatus 10. .

  A pair of transport rolls 34 and a transport roll 36 that transport the recording paper P one by one are provided downstream of the delivery roll 32 in the transport path 30. In addition, the recording paper P is temporarily stopped on the downstream side of the transport roll 36 in the transport direction of the recording paper P in the transport path 30 and the registration roll 38 is sent to a secondary transfer position T described later at a predetermined timing. Is provided.

  The transport path 30 is provided in a straight line from the fourth storage unit 28 to the alignment roll 38 in the upward direction when the image forming apparatus 10 is viewed from the front. Further, a fixing device 40 for fixing the toner image on the recording paper P on which the toner image is transferred is provided on the downstream side of the secondary transfer position T in the conveyance path 30.

  The fixing device 40 is provided in the image forming unit 14 and includes a heating roll 42 having a heat source that generates heat when energized, and a pressure roll 44 that contacts the heating roll 42 with a predetermined pressure. Yes. Then, on the downstream side of the fixing device 40 in the conveyance direction of the recording paper P in the conveyance path 30, the recording paper P on which the toner image is fixed is disposed on the lower paper discharge unit (first paper discharge unit) 80 or the upper paper discharge unit. A paper discharge device 20 for discharging paper to the (second paper discharge unit) 90 is provided. The paper discharge device 20 will be described in detail later.

  Further, on the left side of the paper discharge device 20, when an image is formed on the back surface of the recording paper P on which the image is formed on the front surface, the recording paper P is again transferred to the image forming unit 14 (on the downstream side of the transport roll 36, In addition, a reversing unit 46 is provided for transporting to the upstream side of the positioning roll 38. In other words, the reversing unit 46 is provided with a plurality of conveyance rollers 48 (three in the drawing) that convey the recording paper P toward the image forming unit 14.

  A manual paper feed unit 50 that can manually feed the recording paper P is provided below the reversing unit 46. That is, the manual sheet feeding unit 50 is provided with a delivery roll 32 that sends out to the conveyance path 30, a pair of conveyance rolls 34, and a conveyance roll 36, similarly to the storage units 22, 24, 26, and 28.

  A document reading unit 16 is provided above the paper discharge device 20. The document reading unit 16 includes a document transport device 52 that automatically transports the document G one by one, a platen glass 54 that is disposed below the document transport device 52 and on which one document G is placed, and the document transport device 52. And a document reading device 56 that reads the document G conveyed by the document G or the document G placed on the platen glass 54.

  The document conveyance device 52 has an automatic conveyance path 55 in which a plurality of pairs of conveyance rolls 53 are arranged, and a part of the automatic conveyance path 55 is arranged so that the recording paper P passes over the platen glass 54. . That is, the document reading device 56 reads the document G transported by the document transport device 52 while being stationary at the left end of the platen glass 54, or reads the document G placed on the platen glass 54 while moving in the right direction. It is like that.

  The image forming apparatus 10 according to the present embodiment is a so-called tandem full-color printer, and the image forming unit 14 has four colors of cyan (C), magenta (M), yellow (Y), and black (K). An image is formed by a developer. The photoconductors 60C, 60M, 60Y, and 60K as image holding bodies that hold latent images are provided corresponding to the colors of cyan, magenta, yellow, and black. The photoreceptors 60C to 60K rotate in one direction (counterclockwise in FIG. 2).

  As shown in FIG. 2, an intermediate transfer belt 62 as an intermediate transfer member, a brush roll 64 as a cleaning member, in order along the rotation direction of the photosensitive members 60C to 60K, around each of the photosensitive members 60C to 60K. A charging roll 66 as a charging member, an LED array head 68 as an exposure device, and a developing device 70 are arranged. The intermediate transfer belt 62, the brush roll 64, and the charging roll 66 are in contact with the surfaces (circumferential surfaces) of the photoreceptors 60C to 60K, respectively.

  The intermediate transfer belt 62 is formed in an endless shape, and as illustrated in FIG. 2, a drive roll 72 disposed at the secondary transfer position T, and a downstream side in the rotation direction of the intermediate transfer belt 62 with respect to the drive roll 72 ( A driven roll 74 disposed on the right side opposite to the secondary transfer position T and an upstream side in the rotation direction of the intermediate transfer belt 62 with respect to the drive roll 72 (upstream of the conveyance path 30 with respect to the secondary transfer position T). It is wound around and supported by a transport roll 76 disposed on the side).

  As shown in FIG. 1, the primary transfer surface (outer peripheral surface) 62A of the intermediate transfer belt 62 on which the photoreceptors 60C to 60K are in contact with each other and the toner image is primarily transferred is from the diagonally lower left side to the diagonally upper right side. It is inclined and arranged. In addition, primary transfer rolls 78C, 78M, 78Y, and 78K are disposed on the opposite side of the photoreceptors 60C to 60K across the intermediate transfer belt 62, and the intermediate transfer belt 62 includes the primary transfer rolls 78C to 78K. Is pressed against each of the photoconductors 60C to 60K.

  Therefore, the toner image that is secondarily transferred to the recording paper P is primarily transferred to the intermediate transfer belt 62 as follows. That is, first, the surfaces of the photoreceptors 60 </ b> C to 60 </ b> K are uniformly charged by the charging roll 66. Each surface of each of the photoreceptors 60C to 60K is exposed by each LED array head 68, and an electrostatic latent image corresponding to image data is formed on each surface.

  The electrostatic latent images formed on the photoconductors 60C to 60K are developed by the developing devices 70C to 70K, and toner images are formed on the photoconductors 60C to 60K. Then, the toner images of the respective colors developed by the developing devices 70 </ b> C to 70 </ b> K are sequentially superimposed on the primary transfer surface 62 </ b> A of the intermediate transfer belt 62 while the intermediate transfer belt 62 makes one round. As a result, the toner image is primarily transferred onto the intermediate transfer belt 62.

  When the toner image is primarily transferred to the intermediate transfer belt 62, the primary-transferred toner image is secondarily transferred to the recording paper P at the secondary transfer position T. Here, a secondary transfer backup roll 58 is disposed on the opposite side of the drive roll 72 across the intermediate transfer belt 62. That is, the intermediate transfer belt 62 is sandwiched between the nip portion between the drive roll 72 and the secondary transfer backup roll 58.

  Therefore, when the recording paper P passes through the nip portion, the toner image primarily transferred to the intermediate transfer belt 62 is secondarily transferred to the recording paper P. The toner image secondarily transferred to the recording paper P is fixed to the recording paper P when the recording paper P is conveyed to the fixing device 40. Then, the recording paper P on which the toner image is fixed is discharged (discharged) to the lower discharge portion 80 or the upper discharge portion 90 by the discharge device 20.

  In the image forming apparatus 10 configured as described above, the paper discharge device 20 will be described in detail next. The paper discharge device 20 is provided downstream of the fixing device 40 in the conveyance path 30 of the image forming apparatus 10 (on the left side of the image forming apparatus 10). As shown in FIG. Is formed integrally with the image forming apparatus main body 10A.

  The paper discharge device main body 20A (paper discharge device 20) has (two) upper and lower paper discharge ports for discharging the recording paper P on which the toner image is fixed. That is, the paper discharge apparatus main body 20A has a lower paper discharge port 82 formed on the lower side and an upper paper discharge port 92 formed on the upper side. The opening length (length in the front-rear direction of the image forming apparatus main body 10A) and the opening width (so that the maximum size recording paper P stored in any of the storage units 22, 24, 26, 28 can be discharged. The width in the vertical direction) is determined.

  In addition, a lower discharge tray 84 is formed in the image forming apparatus main body 10A below the lower discharge port 82. An upper discharge tray 94 is detachably cantilevered and supported by the discharge device main body 20A above the lower discharge port 82 and below the upper discharge port 92. 94 extends from the discharge device main body 20 </ b> A upward (to the right side) above the lower discharge tray 84.

  It should be noted that a lower discharge section 80 as a first discharge section is configured including at least a lower discharge opening 82 and a lower discharge tray 84, and includes at least an upper discharge opening 92 and an upper discharge tray 94. Thus, an upper sheet discharge unit 90 as a second sheet discharge unit is configured. In addition, a pair of paper discharge rollers 83 and 93 as an example of a conveyance unit are provided in the conveyance path 30 in the lower sheet discharge unit 80 and the upper sheet discharge unit 90, respectively.

  Further, as shown in FIG. 3, the lower discharge unit 80 and the upper discharge unit 90 are detection members 86 and 96 that detect the stacking height of the recording paper P on the lower discharge tray 84 and the upper discharge tray 94, respectively. And a pair of pressing members 100 that press the recording paper P discharged to the lower discharge tray 84 and the upper discharge tray 94 from above. The detection members 86 and 96 and the pressing member 100 can be rotated about the front and rear direction of the image forming apparatus main body 10A by the resin mounting members 88 and 98 configured to be detachable from the paper discharge apparatus main body 20A. (It can swing in the vertical direction).

  As shown in FIG. 3 to FIG. 5, each of the attachment members 88 and 98 is formed in a flat plate shape that is long in the front-rear direction of the image forming apparatus main body 10 </ b> A, ) And the other end (the front side of the image forming apparatus main body 10A), a pair of brackets 108 for supporting a support shaft (not shown), which will be described later, project in the discharge direction (right direction) of the recording paper P. ing.

  Further, on one end in the longitudinal direction of each attachment member 88, 98 and on the wall surface opposite to the bracket 108, an insertion portion 88A to be inserted into one attachment hole 21, 21 formed in the paper discharge device main body 20A, 98A is projected. Then, at the other end in the longitudinal direction of each of the mounting members 88 and 98, the outermost bracket 108 is inserted into the other mounting holes 23 and 23 formed in the paper discharge apparatus main body 20A and is locked by elastic force. Hook portions 88B and 98B are formed.

  The hook portions 88B and 98B are arranged on the outer side (the front side of the image forming apparatus main body 10A) from the end of the bracket 108, which is the discharge direction (right direction) of the recording paper P, and in the opposite direction (left). The claw 88C, 98C protruding toward the outer side (the front side of the image forming apparatus main body 10A) is integrally formed at the tip thereof. .

  Therefore, when the attachment members 88 and 98 are attached to the paper discharge apparatus main body 20A, first, the insertion portions 88A and 98A are inserted into the attachment holes 21 and 21, and then the hook portions 88B and 98B are moved inward in the longitudinal direction (image formation). The locking claws 88C and 98C are inserted into the mounting holes 23 and 23 while being pressed (elastically deformed) toward the rear side of the apparatus main body 10A.

  And if the latching claw 88C and 98C are inserted in the attachment holes 23 and 23, the press with respect to the hook parts 88B and 98B will be cancelled | released. Then, the hook portions 88B and 98B expand (restore) outward due to the elastic force (restoring force), and the locking claws 88C and 98C are locked to the peripheral portions of the mounting holes 23 and 23.

  When the attachment members 88 and 98 are removed from the paper discharge apparatus main body 20A, the hooks 88B and 98B are pressed toward the inner side in the longitudinal direction (elastically deformed), and the locking claws 88C and What is necessary is just to remove 98C. Accordingly, each of the attachment members 88 and 98 is detachably attached to the paper discharge apparatus main body 20A.

  Further, in the lower discharge section 80, as will be described later, the end 126A of the rotating shaft 126 to which the detection member 86 is fixed is detached from the cylindrical section 128A of the detection member 128 provided in the discharge apparatus body 20A. It is possible to fit in such a manner that the relative rotation is impossible.

  Each of the attachment members 88 and 98 supports a pair of elongated pressing members 100 configured to include an elastic body such as rubber so as to be rotatable about the front-rear direction of the image forming apparatus main body 10A. Since the pressing member 100 is a common member in the lower sheet discharge unit 80 and the upper sheet discharge unit 90, the upper sheet discharge unit 90 side will be described as an example here.

  Support shafts (not shown) are respectively supported by a pair of brackets 108 at both ends of the attachment member 98, and a support member 106 attached to the upper end portion of the pressing member 100 is rotatably attached to each support shaft. ing. The pressing member 100 is configured by attaching an elastic body 104 such as rubber to a resin film member 102, and an upper end portion of the film member 102 is fixed to a support member 106.

  The pressing members 100 are provided as a pair at predetermined intervals (at both ends of the mounting member 98). When the recording paper P is not stacked on the upper paper discharge tray 94, As shown in FIG. 3, it is a structure that hangs down by its own weight (the weight of the elastic body 104). When the recording paper P is discharged onto the upper paper discharge tray 94, the uppermost recording paper P is pressed by its own weight from above.

  Further, detection members (actuators) 86 and 96 for detecting the stacking height of the recording sheets P stacked on the lower discharge tray 84 and the upper discharge tray 94 are attached to the attachment members 88 and 98 between the pressing members 100. Is provided. As shown in FIG. 4, the detection member 96 provided in the upper sheet discharge unit 90 is fitted to a pair of C-shaped hook portions 110 formed on the attachment member 98, so that the rotation shaft 112 </ b> A is rotatably supported. It has the fulcrum member 112 provided with.

  Further, the fulcrum member 112 has a shielding portion (not shown) that blocks the light emitted from the light emitting portion of the optical sensor (not shown) provided in the paper discharge apparatus main body 20A so as not to be received by the light receiving portion. The contact member 114, which will be described later, is integrally projected on the opposite side. The function of the shielding unit is the same as that of the lower sheet discharge unit 80, and will be described together with the detection member 86 of the lower sheet discharge unit 80 described later.

  The detection member 96 has a contact member 114 that is discharged to the upper discharge tray 94 and is in contact with the uppermost recording paper P that is stacked while being pressed by the pressing member 100. The contact member 114 includes a main body 114B supported by the fulcrum member 112 and a flat contact portion 114A that actually contacts the recording paper P.

  The contact portion 114A is formed such that its tip end side is larger than the main body portion 114B side and larger than the shielding portion so that the contact member 114 rotates and moves downward by its own weight. The leading end side is formed in an arc shape in front view of the image forming apparatus main body 10A so as not to damage the recording paper P.

  A plurality of through holes 114C are formed in the contact portion 114A of the contact member 114, and the contact member 114 is reduced in weight. Thereby, the recording paper P is not further damaged. The detection member 96 has a tension coil spring 116 as an example of an elastic member for pressing the contact member 114 against the fulcrum member 112 side.

  That is, substantially one ring-shaped hook portions 116A and 116B (see FIGS. 6 and 7) are formed at one end and the other end of the coil spring 116, respectively, and the hook portion 116A on the one end side serves as a fulcrum member. 112, the hook member 116B on the other end side is locked to the hook portion 114D (see FIG. 7) of the contact member 114, so that the contact member 114 is coil coil 116. It is supported in a state where it is pressed against the fulcrum member 112 by the tensile elastic force.

  On the other hand, as shown in FIGS. 5 to 7, the detection member 86 provided in the lower-stage paper discharge unit 80 includes a fulcrum member 113 that protrudes integrally with a rotation shaft 126 that is rotatably supported by the attachment member 98. Have. The fulcrum member 113 protrudes in a direction perpendicular to the axial direction of the rotating shaft 126 and supports the contact member 114 in the same manner as the detection member 96.

  That is, the hook portion 116A on one end side of the coil spring 116 is locked to the hook portion 113A of the fulcrum member 113, and the hook portion 116B on the other end side is locked to the hook portion 114D of the contact member 114. The contact member 114 is supported while being pressed against the fulcrum member 113 by the tensile elastic force of the coil spring 116. The coil spring 116 of the detection member 86 is provided with a resin cover body 118 formed in a cylindrical shape so that the leading end of the recording paper P discharged from the lower discharge port 82 is not caught. It has become so.

  The rotating shaft 126 is formed long toward the rear of the image forming apparatus main body 10A. As shown in FIG. 3, the end 126A is detachably fitted to the detection member 128 provided in the paper discharge apparatus main body 20A and is relatively non-rotatably fitted. That is, the end portion 126A is formed in a substantially semicircular arc shape in cross section, and the shape in the cylindrical portion 128A of the detection member 128 is also formed in a substantially semicircular arc shape in cross section. Thereby, relative rotation between the rotation shaft 126 and the detection member 128 is impossible.

  The detection member 128 includes a flat plate-shaped shielding portion (not shown) that rotates and moves around a cylindrical portion 128A in which the end portion 126A of the rotating shaft 126 is fitted, and a stopper portion 128B. For example, the shielding portion and the stopper portion 128B are integrally protruded on the outer peripheral surface of the cylindrical portion 128A so as to be approximately 180 degrees opposite to each other, and the stopper portion 128B is fixed to the fixing plate 127 (see FIG. 3)) from above, the downward rotation is restricted. The shielding unit shields the light emitted from the light emitting unit of an optical sensor (not shown) provided in the paper discharge apparatus main body 20A so that the light receiving unit does not receive the light.

  That is, as shown in FIG. 7, when the recording paper P is discharged from the lower paper discharge port 82, the contact member 114 is pushed by the recording paper P and rotates upward, thereby rotating the shielding portion downward. Then, the light emitted from the light emitting unit is received by the light receiving unit, but within a predetermined time, the contact member 114 returns to the original position by its own weight, and the shielding unit returns to the original position and light again. If the recording sheet P is blocked, the control unit 18 determines that the recording paper P discharged and stacked on the lower discharge tray 84 has not reached the preset stacking height.

  Then, the recording paper P discharged on the lower paper discharge tray 84 continues to be stacked, and the contact member 114 is gradually lifted by the recording paper P, so that the shielding portion gradually rotates downward, and from the light emitting portion. When the emitted light continues to be received by the light receiving unit beyond a predetermined time, the recording paper P discharged and stacked on the lower discharge tray 84 is preset. The control unit 18 determines that the stacking height has been reached.

  In addition, a resin guide member 130 is attached to the attachment member 88 of the lower sheet discharge unit 80. As shown in FIGS. 5 to 7, the guide member 130 is formed in a substantially “L” shape when viewed from the axial direction of the rotating shaft 126, and has a bifurcated sandwiching portion formed at the upper end portion thereof. 132 is inserted into the attachment member 88 from below, and is attached to the attachment member 88 by sandwiching the attachment member 88 in the left-right direction.

  Further, the guide member 130 is fixed to the paper discharge apparatus main body 20 </ b> A by fitting a fitting part 134 having an arc shape in front view formed at the lower end of the guide member 130 to the support shaft 83 </ b> A of the upper paper discharge roll 83. It has come to be. A fulcrum member 113 is inserted into a hole 136 formed in the guide member 130 and a detection member 86 is provided. The hole 136 is large enough to allow the detection member 86 to rotate in the vertical direction. Is formed.

  Further, the central portion (substantially “L” -shaped corner portion) of the guide member 130 is formed in a substantially arc shape when viewed from the front (viewed from the axial direction of the rotating shaft 126), and the lower surface thereof is a discharge roll. A guide surface 130A for guiding the recording paper P from above is provided between 83 and the detection member 86. That is, as shown in FIG. 7, the leading edge of the recording paper P hits the detection member 86 while being rubbed and guided on the guide surface 130A, and is conveyed while pushing up the detection member 86, and finally the lower discharge tray 84. The paper is discharged (discharged) upward.

  At this time, even if the leading end of the recording paper P is conveyed at an angle so as to contact the coil spring 116, the cover body 118 is attached to the coil spring 116, so that the leading end of the recording paper P contacts the coil spring 116. There will be no problems that may be caught.

  Here, the guide member 140 shown in the comparative example will be described. Note that parts other than the holding part 142 and the fitting part 144 of the guide member 140 that are the same as those in the above embodiment are given the same reference numerals, and detailed description thereof is omitted. As shown in FIG. 9, the guide member 140 according to the comparative example has an acute corner portion 148 that is inclined toward the lower-stage sheet discharge table 84 (downward), and the lower surface of the corner portion 148 is a sheet discharge portion. A guide surface 148A is provided between the roll 83 and the detection member 86 to guide the recording paper P from above.

  Therefore, in this guide member 140, the discharge (discharge) direction of the recording paper P conveyed by the discharge roll 83 is forcibly changed so that the guide surface 148A is directed to the lower discharge tray 84. Be made. For this reason, the recording paper P may be damaged when it is rubbed against the guide surface 148A.

  However, in the guide member 130 according to the present embodiment, the discharge (discharge) direction of the recording paper P conveyed by the discharge roll 83 is directed toward the lower discharge tray 84 by the guide surface 130A. It is not forced to change. Therefore, even if the recording paper P is rubbed against the guide surface 130A, there is no risk of being damaged.

  Further, since the guide member 130 has a hole 136 that allows the detection member 86 to rotate in the vertical direction, the conveyed recording paper P contacts the contact portion 114A of the detection member 86. However, there is no problem that the detection member 86 prevents the recording paper P from being discharged (discharged). Therefore, there is no problem that the recording paper P is scratched by the detection member 86 or a paper jam occurs.

  Note that the image forming apparatus 10 according to the present embodiment employs a so-called center register that positions the recording paper P in the center in the width direction of the conveyance path 30, and thus the detection members 86 and 96, the pressing member 100, and the guide member 130. Are arranged in the center in the longitudinal direction of each of the paper discharge outlets 82 and 92 (the center in the opening length). Thereby, even if the size of the recording paper P is different, the detection members 86 and 96, the pressing member 100, and the guide member 130 are configured to function.

  Next, the operation of the paper discharge device 20 configured as described above will be described. The recording paper P on which the toner image is fixed by the fixing device 40 is discharged by the paper discharge device 20 to the lower paper discharge tray 84 or the upper paper discharge tray 94.

  For example, when the recording paper P is discharged (discharged) from the lower paper discharge port 82, the pressing member 100 is pushed by the recording paper P and rotates upward about the support shaft, and the recording paper P is discharged to the lower paper discharge. When the paper is discharged onto the table 84, the recording paper P is pressed from above by its own weight. When the recording paper P is discharged and stacked on the lower output tray 84, the contact portion 114A of the contact member 114 of the detection member 86 is lifted upward while contacting the uppermost recording paper P.

  Then, the fulcrum member 113 rotates upward about the rotation shaft 126, and the shielding portion of the detection member 128 rotates downward about the rotation shaft 126, and is blocked by the shielding portion. The light emitted from the light emitting unit continues to be received by the light receiving unit over a predetermined time. As a result, it is detected that the recording paper P is further improperly stacked (has reached a preset stacking height), and based on the detection result, for example, the recording paper on the lower output tray 84 is recorded. The delivery of P is temporarily stopped.

  Incidentally, as shown in FIG. 8, a post-processing device 150 that sorts and staples the recording paper P discharged from the paper discharge device 20 is detachable from the image forming apparatus 10. . The post-processing device 150 includes a paper feeding unit 152 that can be disposed along the shape of the lower paper ejection tray 84, for example, and the paper feeding unit 152 is connected to the paper ejection device body 20A (paper feeding unit). 152 paper feed ports can be arranged opposite to the lower paper discharge port 82).

  Therefore, when connecting the processing apparatus 150 to the image forming apparatus 10 thereafter, it is necessary to remove at least the detection member 86 and the pressing member 100 from the sheet discharge apparatus main body 20A in the lower sheet discharge section 80. Since both the detection member 86 and the pressing member 100 are attached to the attachment member 88, the detection member 86 and the pressing member 100 can be easily detached from the paper discharge apparatus main body 20A.

  That is, when the attachment member 88 is removed from the paper discharge apparatus main body 20A, first, the fitting portion 134 of the guide member 130 fitted to the support shaft 83A of the upper discharge roll 83 is moved from the support shaft 83A by fingers. Remove. Since the guide member 130 is formed of a resin material, the fitting portion 134 of the guide member 130 can be easily detached from the support shaft 83A by elastic deformation of the fitting portion 134.

  Next, the hook portion 88B is pressed with a finger toward the inner side in the longitudinal direction of the attachment member 88 (the rear side of the image forming apparatus main body 10A). Then, since the attachment member 88 is formed of a resin material, the hook portion 88B is elastically deformed, and the locking claw 88C is detached from the peripheral edge portion of the attachment hole 23. Then, the hook portion 88B is removed from the attachment hole 23 as it is, and the insertion portion 88A is further removed from the attachment hole 21.

  Thereafter, the end portion 126 </ b> A of the rotating shaft 126 is pulled out from the cylindrical portion 128 </ b> A of the detection member 128. Since the end 126A of the rotation shaft 126 is merely fitted to the cylinder portion 128A of the detection member 128, the detection member can be easily obtained by pulling the rotation shaft 126 toward the front side (the front side of the image forming apparatus main body 10A). The end 126A can be removed from the 128 cylinders 128A.

  Through the above steps, the detection member 86, the pressing member 100, and the guide member 130 can be easily removed from the paper discharge apparatus main body 20A via the attachment member 88. Therefore, the detachability of the detection member 86 and the pressing member 100 from the paper discharge device main body 20A can be improved.

  The hook 88B cannot be taken out from the attachment hole 23 unless the hook 88B is pressed toward the inner side in the longitudinal direction of the attachment member 88 (the rear side of the image forming apparatus main body 10A). There is no problem that the mounting member 88 is inadvertently detached from the paper discharge apparatus main body 20A.

  Further, when the post-processing device 150 is connected to the lower discharge section 80, as shown in FIG. 8, the upper discharge tray 94 is also removed. This upper discharge tray 94 is a conventionally known means. This makes it easy to remove. At this time, the upper surface of the paper feeding unit 152 of the post-processing device 150 is the upper paper ejection tray 154.

  The paper discharge device 20 according to the present embodiment has been described based on the example shown in the drawings. However, the paper discharge device 20 according to the present embodiment is not limited to the illustrated example. For example, depending on the form of the post-processing device 150, the detection member 96 and the pressing member 100 in the upper paper discharge unit 90 may be removed. Also in this case, the attachment member 98 can be easily detached from the paper discharge apparatus main body 20A in the same manner as described above.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 10A Image forming apparatus main body 20 Paper discharge apparatus (an example of discharge apparatus)
20A paper discharge device main body (an example of a discharge device main body)
80 Lower discharge section 82 Lower discharge slot 84 Lower discharge tray (an example of discharge section)
86 Detection member 88 Mounting member 90 Upper discharge section 92 Upper discharge slot 94 Upper discharge tray (an example of discharge section)
96 detection member 98 mounting member 100 holding member 112 fulcrum member 114 contact member 116 coil spring (an example of an elastic member)
126 Rotating shaft 128 Detection member 130 Guide member 150 Post-processing device P Recording paper (an example of a recording medium)

Claims (4)

A discharge device main body provided in the image forming apparatus main body so that the recording medium can be discharged to the discharge unit;
A mounting member detachably provided on the discharge device main body above the discharge unit;
A detection member that is rotatably provided on the attachment member and detects a stacking height of the recording medium in contact with the recording medium stacked on the discharge unit;
A pressing member that is rotatably provided on the attachment member, and that presses the recording medium by contacting the recording medium loaded on the discharge portion by its own weight;
A discharge device characterized by comprising: A rotation shaft provided rotatably on the attachment member, and to which the detection member is fixed;
In addition to being provided in the discharge device main body, one end of the rotary shaft is detachably fitted so as not to be relatively rotatable, and is moved by rotation of the rotary shaft, so that a preset stacking height of the recording medium is set. A detection member to be detected;
The discharge device according to claim 1, wherein A conveying means provided in the discharge device main body, for conveying the recording medium to the discharge unit;
A guide member provided on the attachment member for guiding the recording medium from above between the transport means and the detection member;
The discharge apparatus according to claim 1, wherein the discharge apparatus is provided. An image forming apparatus main body provided with the discharge device according to any one of claims 1 to 3,
A discharge unit provided in the image forming apparatus main body, on which a recording medium discharged from the discharge apparatus main body of the discharge device is stacked;
Have
An image forming apparatus, wherein a post-treatment device is connectable to the discharge device main body from which the attachment member is removed.

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