JP5156712B2 - Paper discharge device and image forming apparatus - Google Patents

Description

  The present invention relates to a paper discharge device that discharges an image-formed paper and an image forming apparatus including the paper discharge device.

  In general, an image forming apparatus such as a copying machine, a facsimile machine, or a printer is provided with a paper discharge device for discharging and conveying a sheet on which an image has been formed onto a paper discharge tray. However, the paper on the paper discharge tray does not always maintain a flat state, and sometimes the rear end of the paper is curved upward. For example, the sheet fed from the fixing device may be in a curled state in which the trailing edge of the sheet is curved upward due to a heating action during fixing. When curled sheets are stacked on the paper discharge tray, the consistency of the sheets may deteriorate.

  Accordingly, a paper discharge device including a curl detection unit for detecting a curled sheet on the paper discharge tray is disclosed (for example, see Patent Document 1).

JP 2007-062928 A

  An actuator having a curl detection unit disclosed in Patent Document 1 is temporarily lifted to contact with the front end of the sheet when the sheet is discharged, and the position energy is converted into kinetic energy after the sheet is discharged, thereby discharging the sheet. It collides with the wall of the main body. At this time, there was a problem that abnormal noise was generated.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a paper discharge device that can reduce a collision sound generated when an actuator collides with a paper discharge device body.

  The paper discharge device of the present invention includes a paper discharge tray, an actuator, an actuator position detector, and a flexible sheet. The paper discharge tray is configured to stack paper discharged from the paper discharge port. The actuator is capable of swinging between a standby position for closing the paper discharge port and an open position positioned on the top surface of the paper discharged from the paper discharge port by being pushed by the leading edge of the paper discharged from the paper discharge port. An actuator supported by the discharge port, having a rear end curl detecting portion facing the rear end of the paper stacked on the paper discharge tray at the standby position, and the rear end of the uppermost paper on the paper discharge tray When the part is curled, the trailing edge curl detecting part comes into contact with the trailing edge part of the uppermost sheet on the sheet discharge tray and swings from the standby position to the open position side. The actuator position detection unit detects that the actuator is not located at the standby position. The flexible sheet is affixed in a state where a gap is provided in a portion of the wall surface formed below the paper discharge port that faces the actuator.

  In this configuration, a flexible sheet is provided that is attached in a state where a gap is provided in a portion of the wall surface formed below the paper discharge port that faces the actuator. By providing a gap in the flexible sheet, it is possible to prevent an impact upon collision between the flexible sheet and the actuator from being transmitted to the wall surface. Therefore, it is possible to reduce the collision sound that is generated when the actuator collides with the paper discharge device main body.

  The paper discharge device according to the present invention can reduce a collision sound generated when the actuator collides with the paper discharge device main body.

1 is a diagram illustrating a configuration of an image forming apparatus including a paper discharge device according to a first embodiment of the present invention. It is a figure which shows the paper discharge port in the paper discharge apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the shifter in the paper discharge apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the flexible sheet in the paper discharge apparatus which concerns on 1st Embodiment of this invention. FIG. 3 is a diagram illustrating a relationship between stacked paper and an actuator in the paper discharge device according to the first embodiment of the present invention. It is a figure which shows a mode that the actuator in the paper discharge apparatus which concerns on 1st Embodiment of this invention rock | fluctuates. It is a figure which shows the structure formed in the wall surface in the paper discharge apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the flexible sheet | seat in the paper discharge apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the actuator in the paper discharge apparatus which concerns on 4th Embodiment of this invention. FIG. 10 is a diagram illustrating a relationship between stacked paper and an actuator in a paper discharge device according to a fourth embodiment of the present invention.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

  First, a first embodiment of the present invention will be described.

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus 100 forms a multi-color or single-color image on a predetermined sheet (recording paper) in accordance with image data transmitted from the outside. The image forming apparatus 100 includes a document processing device 120, a paper feeding unit 80, an image forming unit 110, and a paper discharge device 90.

  The document processing device 120 includes a document placement table 121, a document transport device 122, and a document reading unit 123. The document placing table 121 is made of transparent glass and is configured to be able to place a document. The document transport device 122 transports the documents stacked on the document tray one by one. Further, the document conveying device 122 is configured to be rotatable in the direction of the arrow 124, and the document can be placed on the document placing table 121 by opening the document placing table 121. The document reading unit 123 reads a document being transported by the document transport device 121 or a document placed on the document placing table 122.

  The paper feed unit 80 is provided with a paper feed cassette 81, a manual paper feed cassette 82, a pickup roller 83, and a pickup roller 84. The paper feed cassette 81 is a tray for storing regular sheets. The manual paper feed cassette 82 is a tray on which an irregular sheet can be placed. The pickup roller 83 is provided near the end of the paper feed cassette 81, picks up sheets one by one from the paper feed cassette 81, and supplies them to the paper transport path 101. Similarly, the pickup roller 84 is provided in the vicinity of the end of the manual paper feed cassette 82, picks up sheets one by one from the manual paper feed cassette 82, and supplies them to the paper transport path 101.

  The image forming unit 110 includes image forming stations 31, 32, 33, 34, an exposure unit 30, an intermediate transfer belt unit 50, and a fixing unit 70. Each of the image forming stations 31, 32, 33, and 34 is provided with a photosensitive drum 10, a charger 20, a developing device 40, and a cleaner unit 60. Black (K), cyan (C), magenta (M), and magenta (M) are provided. This corresponds to a color image using each color of yellow (Y). In the present embodiment, the image forming station 31 will be described.

  The photoconductor drum 10 is rotated when an image is formed and carries a developer image. Around the photosensitive drum 10, the charger 20, the exposure unit 30, the developing device 40, the intermediate transfer belt unit 50, and the cleaner unit 60 are arranged in this order from the upstream in the rotation direction. The fixing unit 70 is positioned on the most downstream side of the image forming unit 110 on the conveyance path 101.

  The charger 20 is a charging means for uniformly charging the surface of the photosensitive drum 10 to a predetermined potential. In addition to the charger type as shown in FIG. 1, a contact type roller type or brush type charger is used. Sometimes used.

  The exposure unit 30 has a function of forming an electrostatic latent image corresponding to the image data on the surface thereof by exposing the charged photosensitive drum 10 according to the input image data. The exposure unit 30 is configured as a laser scanning unit (LSU) provided with a laser emitting portion, a reflection mirror, and the like. The exposure unit 30 includes a polygon mirror that scans the laser beam and optical elements such as a lens and a mirror that guide the laser beam reflected by the polygon mirror to the photosensitive drum 10. As the exposure unit 30, for example, a method using an EL or LED writing head in which other light emitting elements are arranged in an array can also be adopted.

  The developing device 40 visualizes the electrostatic latent image formed on the photosensitive drum 10 with toner.

  The intermediate transfer belt unit 50 includes an intermediate transfer belt 51, an intermediate transfer belt drive roller 52, an intermediate transfer belt driven roller 53, an intermediate transfer roller 54, and an intermediate transfer belt cleaning unit 55.

  The intermediate transfer belt driving roller 52, the intermediate transfer belt driven roller 53, and the intermediate transfer roller 54 are driven to rotate while the intermediate transfer belt 51 is stretched. Further, the intermediate transfer roller 54 gives a transfer bias for transferring the toner image on the photosensitive drum 10 onto the intermediate transfer belt 51.

  The intermediate transfer belt 51 is provided in contact with the photosensitive drum 10. The toner image formed on the photosensitive drum 10 is transferred to the intermediate transfer belt 51, thereby forming a toner image on the intermediate transfer belt 51. The intermediate transfer belt 51 is formed in an endless shape using, for example, a film having a thickness of about 100 μm to 150 μm.

  Transfer of the toner image from the photosensitive drum 10 to the intermediate transfer belt 51 is performed by an intermediate transfer roller 54 that is in contact with the back side of the intermediate transfer belt 51. A high voltage transfer bias (a high voltage having a polarity (+) opposite to the toner charging polarity (−)) is applied to the intermediate transfer roller 54 in order to transfer the toner image. The intermediate transfer roller 54 is a roller whose base is a metal (for example, stainless steel) shaft having a diameter of 8 mm to 10 mm, and whose surface is covered with a conductive elastic material (for example, EPDM, urethane foam, or the like). With this conductive elastic material, a high voltage can be uniformly applied to the intermediate transfer belt 51. In this embodiment, a roller shape is used as the transfer electrode, but a brush or the like can also be used.

  The electrostatic images visualized on the photosensitive drum 10 as described above are stacked on the intermediate transfer belt 51. Thus, the laminated image information is transferred onto the sheet by the transfer roller 56 disposed at the contact position between the sheet and the intermediate transfer belt 51 by the rotation of the intermediate transfer belt 51.

  At this time, the intermediate transfer belt 51 and the transfer roller 56 are pressed against each other at a predetermined nip, and a voltage for transferring the toner onto the paper is applied to the transfer roller 56 (the polarity opposite to the toner charging polarity (−)). (+) High voltage). Further, in order to obtain the nip constantly, the transfer roller 56 uses either the transfer roller 56 or the intermediate transfer belt drive roller 52 as a hard material (metal or the like) and the other as a soft material such as an elastic roller (elastic rubber roller). Or a foaming resin roller or the like.

  Further, as described above, the toner adhered to the intermediate transfer belt 51 by contacting the photosensitive drum 10 or the toner remaining on the intermediate transfer belt 51 without being transferred onto the sheet by the transfer roller 56 is transferred to the intermediate transfer belt 51. It is set to be removed and collected by the cleaning unit 55. The intermediate transfer belt cleaning unit 55 is provided with, for example, a cleaning blade that contacts the intermediate transfer belt 51 as a cleaning member. The intermediate transfer belt 51 that contacts the cleaning blade is supported by an intermediate transfer belt driven roller 53 from the back side. ing.

  The cleaner unit 60 removes and collects toner remaining on the surface of the photosensitive drum 10 after development and image transfer.

  The fixing unit 70 includes a heating roller 71 and a pressure roller 72, and the heating roller 71 and the pressure roller 72 rotate with the sheet interposed therebetween. The heating roller 71 is set so as to reach a predetermined fixing temperature by a control unit based on a signal from a temperature detector (not shown), and the toner is thermocompression bonded to the sheet together with the pressure roller 72. It has a function of fusing, mixing, and pressing the transferred toner image and thermally fixing the sheet. An external heating belt 73 is provided for heating the heating roller 71 from the outside.

  The paper discharge device 90 includes a paper discharge tray 91 and a paper discharge roller 92. The sheet that has passed through the fixing unit 70 is discharged to a discharge tray 91 via a discharge roller 92. The paper discharge tray 91 is a tray for collecting printed sheets.

  When a double-sided printing request is made, when the single-sided printing is completed and the trailing edge of the sheet that has passed through the fixing unit 70 is gripped by the paper discharging roller 92 as described above, the paper discharging roller 92 rotates in the reverse direction. The sheet is guided to the conveyance rollers 102 and 103. Then, after printing is performed on the back side of the sheet through the registration roller 104, the sheet is discharged to the discharge tray 91.

  The paper discharge device 90 is provided with a shifter 200 as shown in FIG. The shifter 200 corresponds to the paper discharge port of the present invention. For example, when the sheets are continuously discharged to the discharge tray 91, the shifter 200 selectively offsets the sheets. The shifter 200 is supported by the paper discharge device 90 so as to be capable of reciprocating in the paper width direction (see arrow 201 in FIG. 2) perpendicular to the paper transport direction.

  Next, a schematic configuration of the shifter 200 will be described with reference to FIGS. 3 (A) to 3 (C). As shown in the figure, the shifter 200 includes a main body 202 that can slide on a moving shaft 203 arranged along the paper width direction. The main body 202 faces the rear end of the paper stacked on the paper discharge tray 91 in a standby position for closing the shifter 200 for detecting the curl of the rear end of the paper stacked on the paper discharge tray 91. When the rear end curl detecting unit 211 has a curl at the rear end of the uppermost sheet on the paper discharge tray 91, the rear end curl detecting unit 211 has the rear end of the uppermost sheet on the discharge tray 91. The actuator 210 that abuts on the part and swings from the standby position to the open position is supported swingably.

  FIGS. 4A and 4B are views showing a state where the flexible seed 300 is attached to the wall surface 93 formed below the shifter 200. As shown in FIG. 4B, the flexible sheet 300 includes two types of sheets having different thicknesses. The total length of the thick sheets 311 and 312 is shorter than that of the thin sheet 320. The sheets 311 and 312 are affixed to the wall surface 93 with double-sided tape. The sheet 320 is affixed to the sheets 311 and 312 with double-sided tape. As a result, a gap is formed between the wall surface 93 and the sheet 320 as illustrated. Note that the member for attaching the sheet may be other than the double-sided tape (the same shall apply hereinafter).

  As shown in FIG. 4A, the flexible sheet 300 is attached in a state where a gap is provided in a portion of the wall surface 93 facing the actuator 210. The movable sheet 300 has a width that can cover the movable range of the shifter 200. Therefore, the flexible sheet 300 can cover all portions of the wall surface 93 that face the actuator 210. By disposing the flexible sheet 300 on the wall surface 93 in this way, the swinging actuator 210 does not directly collide with the wall surface 93, and the impact at the time of the collision is absorbed by the gap. Therefore, it is possible to reduce a collision sound generated when the actuator 210 collides with the main body of the paper discharge device 90. Further, by providing the flexible sheet 300, it is not necessary to strictly design the shape and the movable region of the actuator 210 in order to avoid the collision between the wall surface 93 and the actuator 210.

  In addition, as a material of the sheets 311, 312, and 320, it is preferable to use an inexpensive material having a low friction coefficient. An example of a material that satisfies this condition is PET. By using PET as the material of the sheets 311, 312, 320, it is possible to prevent the trailing edge of the sheet from being caught by the flexible sheet 300 when the sheet is discharged from the sheet discharge port, and to reduce the manufacturing cost. it can.

  As shown in FIGS. 3A to 3C and FIG. 4A, the actuator 210 includes a trailing edge curl detecting unit 211 in which the trailing edge of the sheet stacked on the sheet discharge tray 91 at the standby position. Are supported by the main body 202 so as to face each other. When a certain amount of paper is stacked on the paper discharge tray 91, as shown in FIG. 5, when the rear end of the uppermost paper 97 on the paper discharge tray 91 is curled, the actuator 210 The rear end curl detection unit 211 contacts the paper 97 and is displaced in a direction away from the wall surface 93. That is, the actuator 210 reaches the rear end curl detection position.

  The position of the actuator 210 is detected by a photo sensor. The photosensor corresponds to the actuator position detector of the present invention. When the actuator 210 reaches the rear end curl detection position, the photo sensor is shielded from light by the light shielding unit and outputs a signal. When the actuator 210 is continuously located at the trailing edge curl detection position for a predetermined time or more, that is, when a signal is continuously output from the photosensor, the control unit of the image forming apparatus 100 performs the operation on the discharge tray 91. It is detected that the rear end of the upper sheet 95 is curled. And this detection result is notified to a user via a display part etc.

  FIG. 6A to FIG. 6C are diagrams illustrating a mechanism in which the actuator 210 swings when the paper is discharged from the shifter 200. The actuator 210 swings in a direction away from the wall surface 93 when pressed by the leading end of the paper 94 discharged from the shifter 200, and the actuator 210 is placed on the upper surface of the paper 94 as shown in FIG. Located in the open position.

  Thereafter, as shown in FIG. 6B, as the paper 94 falls to the paper discharge tray 91, the potential energy held on the paper 94 is released and converted into kinetic energy. Then, as illustrated in FIG. 6C, the actuator 210 collides with the flexible sheet 300. In this case, since the actuator 210 is not continuously located at the rear end curl detection position for a predetermined time or more, no signal is continuously output from the photo sensor.

  When the flexible sheet 300 is not provided on the scale, a large collision sound is generated when it collides with the wall surface 93. Therefore, a large collision sound is generated every time the sheet is discharged. However, in the present embodiment, since the flexible sheet 300 is attached in a state where a gap is provided in a portion of the wall surface 93 that faces the actuator 210, a large collision sound is generated each time the sheet is discharged. There is no.

  6A to 6C show the case where the sheet passes through the shifter 200 and is accommodated in the sheet discharge tray 91. However, the image forming apparatus 100 according to the present embodiment also has a switchback function. For this reason, there is a case where the paper is switched back and conveyed immediately after the actuator 210 is pushed. In FIG. 6B, the paper 94 is falling toward the paper discharge tray 91 while holding the actuator 210. However, when the paper is switched back, the paper holding the free fall movement of the actuator 210. Therefore, the kinetic energy of the actuator 210 becomes larger than when the paper falls on the paper discharge tray 91. Therefore, although the collision force with respect to the wall surface 93 of the actuator 210 becomes large, since a space | gap absorbs a collision sound by sticking the flexible sheet 300 like this embodiment, a big collision sound does not generate | occur | produce.

  Next, a second embodiment of the present invention will be described.

  7A and 7B, ribs 94 and 95 are provided on the wall surface 93. FIG. The ribs 94 and 95 protrude from the wall surface 93. Further, the ribs 94 and 95 are arranged at positions that come into contact with the rear end of the paper that is offset and discharged by the shifter 200. Therefore, when the rear end of the sheet 96 discharged from the shifter 200 comes into contact with the ribs 94 and 95 when falling onto the discharge tray 91, the contact area is reduced as compared with the case where the rear end of the sheet contacts the wall surface 93. The paper 96 can be smoothly dropped onto the paper discharge tray 91.

  Further, as shown in FIG. 7B, the end portions of the ribs 94 and 95 on the shifter 200 side form rounds. Therefore, the rear end of the sheet 96 discharged from the shifter 200 can be prevented from being caught by the ribs 94 and 95.

  Furthermore, the flexible sheet 300 is provided so as not to protrude from the ribs 94 and 95 as shown in FIG. With this configuration, it is possible to prevent the trailing edge of the paper 96 falling on the paper discharge tray 91 from being caught by the flexible seed 300.

  Next, a third embodiment of the present invention will be described.

  In the present embodiment, as shown in FIGS. 8A and 8B, a flexible sheet 300 having a shape different from that of the other embodiments is employed. That is, the flexible sheet 300 forms an inclined surface where the gap gradually decreases toward the shifter 200 as shown in FIG.

  As shown in FIG. 8B, the flexible sheet 300 according to this embodiment includes a thick sheet 331 and a thin sheet 340. The sheet 331 is shorter than the sheet 340. The sheet 331 is attached to the wall surface 93 via a double-sided tape. The sheet 340 is affixed to the wall surface 93 and the sheet 331 via a double-sided tape.

  In the present embodiment, the thickness of the sheet 331 is 0.3 mm, and the thickness of the sheet 340 is 0.15 mm. When the thickness of the double-sided tape is 0.1 mm, a thickness of 0.25 mm (double-sided tape + sheet 340) is formed at the tip of the flexible sheet 300 on the shifter 200 side. A thickness of 0.65 mm (two sheets of double-sided tape + sheet 331 + sheet 340) is formed at the tip portion on the 91 side.

  As in the present embodiment, the rear surface of the sheet is prevented from being caught by the flexible sheet 300 by configuring the inclined surface so that the gap gradually decreases toward the shifter 200 in the flexible sheet 300. be able to.

  Next, a fourth embodiment of the present invention will be described.

  As shown in FIGS. 9A to 9C, an actuator 220 can be used instead of the actuator 210. The actuator 220 is swingably supported by the main body 202 of the shifter 200 via a support portion 228 provided at one end of the arm portion 226. A triangular plate-like member 225 is attached to the other end side of the arm portion 226. A fullness detection portion 224 in which the vicinity of the apex of the plate-like member 225 contacts the uppermost sheet on the paper discharge tray 91 is provided. Configure.

  Further, a rear end curl detection unit 222 is provided in the vicinity of the apex of one side of the plate-like member 225. Furthermore, as shown in FIG. 9C, the actuator 220 has a shape that tapers as it goes from the support portion 228 toward the full detection portion 224. The reason for adopting such a shape is to prevent the weight of the actuator 220 from becoming heavier than that of the actuator 210 by arranging the plate-like member 225 for forming the rear end curl detection unit 222.

  Subsequently, the operation of the actuator 220 will be briefly described with reference to FIGS. 10 (A) to 10 (C). 10A to 10C, a virtual line 410 indicates the position of the fullness detection unit 224 of the actuator 220 disposed at the standby position, and the virtual line 420 is stacked on the paper discharge tray 91. The position of the fullness detection unit 224 of the actuator 220 disposed at the fullness detection position for detecting that the sheet is full is shown.

  As shown in FIG. 10A, when the uppermost sheet 400 stacked on the paper discharge tray 91 is below the position indicated by the imaginary line 410, FIG. 6A to FIG. As described above, the actuator 220 swings and collides with the flexible sheet 300.

  When the uppermost sheet 400 stacked on the paper discharge tray 91 reaches the position indicated by the imaginary line 410, the actuator 220 is lifted upward by the uppermost sheet 400. At this time, the actuator 220 is displaced upward as the number of sheets on the paper discharge tray 91 increases.

  Then, as shown in FIG. 10B, when the uppermost sheet 400 reaches the position indicated by the imaginary line 420, the actuator 220 reaches the full detection position. The position of the actuator 220 is detected by a photo sensor. When the actuator 220 reaches the full detection position, the photo sensor is shielded from light by the light shielding unit and outputs a signal. When the actuator 220 is continuously located at the full detection position for a predetermined time, that is, when a signal is continuously output from the photosensor, the control unit of the image forming apparatus 100 is in a state where the paper on the paper discharge tray 91 is full. It is detected that And this detection result is notified to a user via a display part etc.

  Further, as a result of providing the trailing edge curl detection unit 222 in the actuator 220, when the trailing edge of the sheet is curled upward as shown in FIG. The actuator 220 is lifted to the rear end curl detection position even if the position indicated by is not reached. For this reason, when the trailing edge curl has occurred in the paper stacked on the paper discharge tray 91, it is possible to prevent a problem that the alignment of the paper on the paper discharge tray 91 is deteriorated.

  The rear end curl detection unit 222 is formed to extend in a direction away from the paper placement surface of the paper discharge tray 91 as it goes from the full detection unit 224 in the opposite direction to the paper conveyance direction at the standby position. As the inclination angle of the rear end curl detection unit 222 approaches the sheet placement surface of the paper discharge tray 91 in parallel, the actuator 220 is lifted through the rear end curl detection unit 222 even by a smaller curl. For this reason, the inclination angle of the trailing edge curl detection unit 222 with respect to the sheet placement surface may be set in accordance with how much curl is allowed.

  For example, in the present embodiment, when a sheet with a trailing edge curled is disposed on the sheet discharge tray 91, the trailing edge is detected so that about 100 sheets are fully filled as compared with the case where the actuator 210 is used. The shape of the curl detection unit 222 and the arrangement of the actuator 220 are designed. Actually, it is preferable that the rear end curl detection unit 222 is inclined by about 1 to 15 degrees with respect to the sheet placement surface of the sheet discharge tray 91.

  In addition, since the actuator 220 is swingably supported by the main body 202 of the shifter 200, the trailing edge curl detection unit 222 approaches parallel to the placement surface of the paper discharge tray 91 as the number of sheets stacked approaches. . Therefore, the curl tolerance is large when the number of sheets is small, while the curl tolerance is small when the number of sheets is large. For this reason, when the number of sheets is almost full, full detection is performed even if the trailing edge of the sheet is curled upward.

  According to the present embodiment, it is possible to prevent the occurrence of a problem that the consistency of the paper stacked on the paper discharge tray 91 is deteriorated due to the paper curled at the rear end stacked on the paper discharge tray 91. Further, by using only one actuator 220, both the full state and the curl state of the paper on the paper discharge tray 91 can be easily detected. In particular, by replacing the actuator 210 with the actuator 220, it is possible to detect both the full state and the curl state of the paper on the paper discharge tray 91, so that the configuration to be newly added can be minimized. become.

  Although the first embodiment to the fourth embodiment have been described separately, the configurations of the first embodiment to the fourth embodiment can be arbitrarily combined.

  Finally, the description of the above-described embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

90-paper discharge device 91-paper discharge tray 93-wall surface 94-rib 95-rib 100-image forming device 110-image forming unit 200-shifter 210-actuator 211-rear end curl detection unit 220-actuator 222-rear end curl Detection unit 224-Full detection unit 300-Flexible sheet

Claims (5)

A paper discharge tray configured to stack paper discharged from the paper discharge port;
It is swingable between a standby position for closing the paper discharge port and an open position positioned on the upper surface of the paper discharged from the paper discharge port by being pushed by the leading edge of the paper discharged from the paper discharge port. An actuator supported by a paper discharge port, and having a rear end curl detecting portion facing a rear end portion of the paper stacked on the paper discharge tray at the standby position; An actuator that swings from the standby position to the open position when the trailing edge curl portion is curled and the trailing edge curl detecting portion abuts against the trailing edge of the uppermost sheet on the paper discharge tray;
An actuator position detector for detecting that the actuator is not located at the standby position;
A flexible sheet attached in a state where a gap is provided in a portion facing the actuator of a wall surface formed below the paper discharge port;
A paper discharge device. The actuator further includes a full detection unit that is disposed at a tip portion of the actuator and configured to abut on the uppermost sheet on the discharge tray,
2. The rear end curl detection unit according to claim 1, wherein the rear end curl detection unit is formed to extend in a direction away from a placement surface of the paper discharge tray as it goes in a direction opposite to a sheet conveyance direction from the full detection unit at the standby position. Paper discharge device. A rib protruding from the wall surface;
The paper discharge device according to claim 1, wherein the flexible sheet is provided so as not to protrude from the rib.   The paper discharge device according to claim 1, wherein the flexible sheet forms an inclined surface in which the gap gradually decreases toward the paper discharge port. An image forming unit that performs image forming processing on paper fed from a paper feeding device;
The paper discharge device according to claim 1, wherein the paper conveyed from the image forming unit is discharged.
An image forming apparatus comprising:

Images