JP2015086060A - Paper discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress poor paper discharge alignment.SOLUTION: A paper discharge device 1 includes an ascendable/descendable paper discharge tray 3 loaded with discharged sheets, an end fence 7 which is suspended above the paper discharge tray 3 and regulates the front end position of a sheet discharged into the paper discharge tray 3, an upper-surface detection sensor 9 for detecting presence or absence of a sheet at the reference upper-surface position, paper discharge tray control means of controlling descent of the paper discharge tray 3 using results of the detection of sheets by the upper-surface detection sensor 9, swell detection means of detecting a swell of the central part in the paper discharging direction for sheets loaded on the paper discharge tray 3 and swell elimination means of eliminating the swell when a swell of loaded sheets is detected by the swell detection means.

Description

  The present invention relates to a paper discharge device that discharges printed paper.

  2. Description of the Related Art A paper discharge device is known that includes a paper discharge table that can be moved up and down, and a fence that is suspended above the paper discharge table and regulates the position of a sheet (for example, see Patent Document 1).

  In such a paper discharge device, control is performed to lower the paper discharge tray as the number of sheets on the paper discharge tray increases. Specifically, when the upper surface detection sensor detects that the sheets are stacked to the reference height, the sheet discharge device lowers the sheet discharge table to a position where the upper surface detection sensor no longer detects the sheets. By repeating this, the height position of the upper surface of the stacked sheets on the sheet discharge table is kept substantially constant.

JP 2010-189182 A

  By the way, when air accumulates between sheets stacked on the sheet discharge table, the central portion of the stacked sheets in the sheet discharge direction may swell (swell). In particular, such a bulge is likely to occur when light and light lightweight paper is discharged.

  In such a state where the bulge is generated, in the above-described lowering control of the discharge table, the discharge table is lowered to a position where the upper surface detection sensor does not detect the highest position of the bulge portion. For this reason, when the swelling increases, a gap in the height direction is generated between the lower end of the suspended end fence that regulates the front end position of the discharged paper and the stacked paper, and the paper may slip through. is there.

  When a plurality of sheets are discharged continuously, it is difficult to predict when the stacked sheets will swell. For this reason, it has been difficult to suppress the above-described defective sheet discharge alignment due to slipping of the paper even if processing for periodically removing the bulge is performed during the paper discharge operation.

  The present invention has been made in view of the above, and an object of the present invention is to provide a paper discharge device that can suppress paper discharge alignment defects.

  In order to achieve the above object, the first feature of the paper discharge device according to the present invention is that the paper discharge tray that can stack the discharged paper, and that is suspended above the paper discharge base, A restricting member for restricting the front end position of the paper discharged to the paper discharge tray, an upper surface detecting means for detecting the presence or absence of the paper at the reference height position, and a result of detecting the paper by the upper surface detecting means during the paper discharging operation The sheet discharge table control means for controlling the lowering of the sheet discharge table, the bulge detection means for detecting the bulge of the central portion in the sheet discharge direction of the stacked sheets on the sheet discharge table, and the bulge detection means for stacking It is provided with a bulge eliminating means for eliminating the bulge when the bulge of the paper is detected.

  A second feature of the paper discharge device according to the present invention is that the bulge detection means is disposed above the paper discharge stand and measures the distance in the height direction to the upper surface of the end in the paper discharge direction of the stacked paper. And a determination unit that determines whether or not the stacked sheets are swollen by using the distance measured by the distance measuring unit when the sheet is detected by the upper surface detection unit. is there.

  A third feature of the paper discharge device according to the present invention is that the bulge detection means includes a paper detection means for detecting the presence / absence of paper in a predetermined range at an end in the paper discharge direction of the stacked paper at the reference height position. And determining means for determining whether or not the bulging of the stacked sheets has occurred based on the presence or absence of the sheet detection by the sheet detection means when the sheet is detected by the upper surface detection means.

  A fourth feature of the paper discharge device according to the present invention is that the bulge eliminating means includes a restriction member moving means for moving the restriction member along the paper discharge direction, and a restriction for moving at least a part of the restriction member up and down. After the member is moved upward and downward by the member vertical movement means and the restriction member moving means, at least a part of the restriction member is lowered by the restriction member vertical movement means and loaded by the restriction member. It is provided with a sheet pressing control means for eliminating the bulge by pressing the sheet.

  A fifth feature of the paper discharge device according to the present invention is that the bulge eliminating means eliminates the bulge of the stacked sheets by vibrating the paper discharge table up and down.

  A sixth feature of the paper discharge device according to the present invention is that the bulge eliminating means presses the stacked paper with the paper presser member provided above the paper discharge table and capable of moving up and down, and with the paper presser member. It is provided with a sheet pressing control means for eliminating the swelling.

  According to the first feature of the paper discharge device according to the present invention, the swelling of the central portion in the paper discharge direction of the stacked paper on the paper discharge table is detected. When the bulge of the loaded paper is detected, the bulge is eliminated. Thereby, the bulge can be eliminated at the timing when the bulge of the loaded paper occurs. For this reason, the expansion of the bulge of the loaded paper can be suppressed. Accordingly, it is possible to prevent the sheet from slipping out due to a gap in the height direction between the lower end of the regulating member and the stacked sheets due to the lowering control of the sheet discharge table. As a result, it is possible to suppress defective sheet alignment.

  According to the second feature of the paper discharge device according to the present invention, the bulge detecting means has distance measuring means for measuring the distance in the height direction to the upper surface of the end in the paper discharge direction of the stacked paper. Then, using the distance measured by the distance measuring unit when the sheet is detected by the upper surface detection unit, it is determined whether or not the stacked sheets are swollen. Thereby, it is possible to detect the swollenness of the loaded paper with a simple structure in which the distance measuring means is added to the existing apparatus.

  According to a third feature of the paper discharge device according to the present invention, the bulge detection means includes paper detection means for detecting the presence or absence of paper in a predetermined range at the end in the paper discharge direction of the stacked paper at the reference height position. Have. Then, based on the presence or absence of the sheet detection by the sheet detection unit when the sheet is detected by the upper surface detection unit, it is determined whether or not the stacked sheets are swollen. Thereby, it is possible to detect the swelling of the stacked sheets with a simple structure in which the sheet detecting unit is added to the existing apparatus.

  According to the fourth feature of the paper discharge device according to the present invention, the swelling is eliminated by pressing the stacked paper using the restricting member. As a result, it is possible to eliminate the swelling of the stacked sheets while suppressing the complexity of the structure of the apparatus.

  According to the fifth feature of the paper discharge device according to the present invention, the paper discharge table is vibrated up and down to remove air between the sheets and eliminate the swelling of the stacked sheets. As a result, it is possible to eliminate the swelling of the stacked sheets while suppressing the complexity of the structure of the apparatus.

  According to the sixth feature of the paper discharge device according to the present invention, the bulge eliminating means has a paper pressing member which is provided above the paper discharge table and can move up and down. Then, the bulge is eliminated by pressing the stacked sheets with the sheet pressing member. Thus, the use of a dedicated paper pressing member can quickly and surely eliminate the swelling of the stacked paper.

1 is a perspective view of a paper discharge device according to a first embodiment. It is side surface sectional drawing of the paper discharge apparatus which concerns on 1st Embodiment. It is a control block diagram of the paper discharge device according to the first embodiment. It is a front view of an end fence. 6 is a flowchart for explaining discharge tray lowering control, bulge detection processing, and bulge elimination operation in the first embodiment. It is a figure for demonstrating the bulge detection process in 1st Embodiment. It is a figure for demonstrating the swelling elimination operation | movement in 1st Embodiment. It is a figure for demonstrating the swelling elimination operation | movement in 1st Embodiment. It is the schematic of the principal part of the paper discharge apparatus which concerns on the modification of 1st Embodiment. FIG. 6 is a control block diagram of a paper discharge device according to a modification of the first embodiment. It is a figure for demonstrating the bulge elimination operation | movement in the modification of 1st Embodiment. It is a figure for demonstrating the bulge elimination operation | movement in the modification of 1st Embodiment. It is side surface sectional drawing of the paper discharge apparatus which concerns on 2nd Embodiment. FIG. 6 is a control block diagram of a paper discharge device according to a second embodiment. 10 is a flowchart for explaining discharge tray lowering control, bulge detection processing, and bulge elimination operation in the second embodiment. It is a figure for demonstrating the bulge detection process in 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention includes the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

[First Embodiment]
FIG. 1 is a perspective view of a paper discharge device according to the first embodiment of the present invention. FIG. 2 is a side sectional view of the paper discharge device shown in FIG. FIG. 3 is a control block diagram of the paper discharge device according to the first embodiment. In the following description, as shown in FIG. 1, the front end side of the discharged paper P is assumed to be the front. In addition, when viewed from the front side, the upper, lower, left, and right directions are the upper, lower, left, and right directions.

  As shown in FIGS. 1 to 3, the paper discharge device 1 according to the first embodiment includes a paper discharge unit 2, a paper discharge stand 3, a lift drive unit 4, and a pair of side fences 5 </ b> A and 5 </ b> B. , A side fence drive unit 6, an end fence 7, an end fence drive unit 8, an upper surface detection sensor 9, a distance measuring sensor 10, and a control unit 11. The paper discharge device 1 is connected to the printing device 100.

  The paper discharge unit 2 discharges the paper P printed by the printing apparatus 100 to the paper discharge tray 3. The paper discharge unit 2 includes a plurality of paper discharge rollers 21, a paper discharge motor 22, and a paper discharge sensor 23.

  The paper discharge roller 21 conveys the paper P and discharges it to the paper discharge tray 3. The paper discharge roller 21 is disposed on the rear upper side with respect to the paper discharge tray 3.

  The paper discharge motor 22 drives a plurality of paper discharge rollers 21.

  The paper discharge sensor 23 detects the paper P discharged to the paper discharge tray 3 by the paper discharge roller 21. The paper discharge sensor 23 is disposed below the transport path of the paper P transported by the paper discharge roller 21. The paper discharge sensor 23 is a reflective optical sensor.

  The paper discharge tray 3 is for stacking the paper P discharged from the paper discharge unit 2. The paper discharge table 3 is configured to be moved up and down by a lift drive unit 4. The paper discharge table 3 includes a bottom plate portion 31 having a rectangular shape in plan view, a central member 32, and inclined members 33 and 34.

  The center member 32 is formed in the center part of the left-right direction on the baseplate part 31 so that it may extend in the front-back direction. The upper surface 32a of the central member 32 is a substantially horizontal plane. The upper surface 32 a of the central member 32 constitutes a part of the sheet placement surface of the sheet discharge table 3.

  The inclined members 33 and 34 are wedge-shaped members elongated in the left-right direction. A plurality of the inclined members 33 and 34 are arranged on the bottom plate portion 31 at intervals in the front-rear direction. The inclined member 33 is disposed on the left side of the central member 32 via a gap. The upper surface 33a of the inclined member 33 is inclined so as to gradually increase from the right side to the left side. The inclined member 34 is disposed on the right side of the central member 32 via a gap. The upper surface 34a of the inclined member 34 is inclined so as to gradually increase from the left side toward the right side. The upper surfaces 33 a and 34 a of the inclined members 33 and 34 together with the upper surface 32 a of the central member 32 constitute a sheet placement surface of the sheet discharge table 3. The sheet stacking surface has a substantially V shape formed so that both sides are higher than the central portion in the sheet width direction (left-right direction) when viewed from the paper discharge direction (front-rear direction). Thereby, the paper P is stacked on the paper discharge tray 3 in a shape curved in a substantially U shape.

  The elevating drive unit 4 elevates and lowers the paper discharge table 3. The lift drive unit 4 includes a lift mechanism 36 and a lift motor 37.

  The elevating mechanism 36 has a rack and pinion mechanism, and raises and lowers the paper discharge tray 3 by the driving force of the elevating motor 37.

  The raising / lowering motor 37 generates a driving force for raising / lowering the paper discharge tray 3 by the raising / lowering mechanism 36.

  The side fences 5 </ b> A and 5 </ b> B regulate the positions of both ends in the paper width direction (left-right direction) of the paper P discharged onto the paper discharge tray 3. The side fences 5 </ b> A and 5 </ b> B are provided in a state of being suspended above the paper discharge table 3 and are separated from the paper discharge table 3. The side fences 5A and 5B are arranged side by side in the left-right direction.

  The side fence drive unit 6 moves the pair of side fences 5A and 5B. The side fence drive unit 6 includes a side fence moving mechanism 38 and a side fence motor 39.

  The side fence moving mechanism 38 moves the pair of side fences 5A and 5B in a direction toward and away from each other by the driving force of the side fence motor 39. The side fence moving mechanism 38 is provided above the pair of side fences 5A and 5B.

  The side fence motor 39 generates a driving force for moving the side fences 5A and 5B by the side fence moving mechanism 38.

  The end fence 7 regulates the front end position of the paper P discharged to the paper discharge tray 3. The end fence 7 is provided in a state of being suspended above the paper discharge tray 3 and is separated from the paper discharge tray 3. The end fence 7 corresponds to a restricting member in claims.

  FIG. 4 is a front view of the end fence 7. As shown in FIGS. 4 and 3, the end fence 7 includes a main body 41, a pair of protrusions 42A and 42B, a slide plate 43, and a solenoid 44 (not shown in FIG. 4).

  The main body 41 receives the paper P discharged from the paper discharge unit 2 to the paper discharge tray 3. The main body 41 is formed in a plate shape having a plane perpendicular to the paper discharge direction (front-rear direction).

  The protrusions 42 </ b> A and 42 </ b> B can adjust the height position of the lower end of the end fence 7. Further, as will be described later, the protrusions 42A and 42B play a role of pressing the upper surface of the stacked paper in order to eliminate the swelling of the stacked paper. The protrusions 42A and 42B are configured to be movable up and down. When the projecting portions 42A and 42B are pulled upward, the lower ends of the projecting portions 42A and 42B reach above a reference upper surface position described later.

  The slide plate 43 is for moving the pair of protrusions 42A and 42B up and down. Protrusions 42 A and 42 B are attached to the slide plate 43. The slide plate 43 is installed in the main body 41 so as to be movable up and down.

  The solenoid 44 is for moving the protrusions 42A and 42B up and down. When the solenoid 44 is turned on, the protrusions 42A and 42B are pulled upward together with the slide plate 43, and when the solenoid 44 is turned off, the protrusions 42A and 42B are lowered together with the slide plate 43 by its own weight. The solenoid 44 corresponds to a regulating member up-and-down moving means in the claims.

  The end fence drive unit 8 moves the end fence 7 along the paper discharge direction (front-rear direction). The end fence drive unit 8 corresponds to a restricting member moving unit in the claims. The end fence driving unit 8 includes an end fence moving mechanism 46 and an end fence motor 47.

  The end fence moving mechanism 46 moves the end fence 7 along the front-rear direction by the driving force of the end fence motor 47. The end fence moving mechanism 46 is provided above the end fence 7.

  The end fence motor 47 generates a driving force for moving the end fence 7 by the end fence moving mechanism 46.

  The upper surface detection sensor 9 detects the presence or absence of the paper P at the reference upper surface position (corresponding to the reference height position in the claims). The reference upper surface position is a position serving as a reference for the height position (upper surface position) of the upper surface (upper surface of the uppermost sheet P) of the stacked sheets on the paper discharge tray 3. The reference upper surface position is below the paper discharge roller 21. The upper surface detection sensor 9 corresponds to the upper surface detection means in the claims. The upper surface detection sensor 9 is formed of a transmissive optical sensor, and includes a light emitting unit 9a and a light receiving unit 9b.

  The light emitting unit 9a and the light receiving unit 9b are arranged opposite to each other in the front-rear direction with the paper discharge table 3 interposed therebetween. The light emitting unit 9a emits light toward the light receiving unit 9b. The light emitting unit 9a and the light receiving unit 9b are arranged such that the height position of the optical axis coincides with the reference upper surface position. The light emitting unit 9 a and the light receiving unit 9 b are arranged so that the optical axis passes through the range where the central member 32 of the paper discharge tray 3 exists in the left-right direction. In addition, the light emitting unit 9 a and the light receiving unit 9 b are arranged at positions where the optical axis passes between the protrusions 42 </ b> A and 42 </ b> B below the main body 41 of the end fence 7.

  The distance measuring sensor 10 measures the distance in the height direction to the upper surface of the front end in the paper discharge direction (front-rear direction) of the stacked sheets on the paper discharge tray 3. The distance measuring sensor 10 is disposed above the paper discharge tray 3 in the vicinity of the end fence 7. The distance measuring sensor 10 is connected to the end fence 7 and can move in the front-rear direction together with the end fence 7. The position of the distance measuring sensor 10 in the left-right direction is the same position as the upper surface detection sensor 9.

  The control unit 11 controls the overall operation of the paper discharge device 1. Further, the control unit 11 transmits and receives signals to and from the printing apparatus 100. The control unit 11 includes a CPU, a RAM, a ROM, and the like.

  As will be described later, the control unit 11 controls the lowering of the paper discharge table 3 using the detection result of the paper P by the upper surface detection sensor 9 during the paper discharge operation. In other words, the control unit 11 constitutes the discharge table control means in the claims.

  Further, as will be described later, the control unit 11 uses the distance measured by the distance measuring sensor 10 when the paper P is detected by the upper surface detection sensor 9 to the stacked paper on the paper discharge tray 3 in the paper discharge direction. It is determined whether or not a central bulge has occurred. That is, the control part 11 comprises the determination means of a claim. Further, the distance measuring sensor 10 and the control unit 11 constitute a bulge detecting means in claims.

  Further, when the bulge of the loaded paper is detected, the control unit 11 controls the solenoid 44 of the end fence 7 and the end fence driving unit 8 to cancel the bulge by pressing the loaded paper with the end fence 7. Specifically, the control unit 11 turns on the solenoid 44 and raises the projections 42A and 42B of the end fence 7 upward, and the end fence drive unit 8 moves the end fence 7 at the center of the stacked sheets. Move upward. Thereafter, the controller 11 turns off the solenoid 44 to lower the protrusions 42A and 42B. Thereby, the protrusions 42A and 42B hold the stacked sheets. In other words, the control unit 11 constitutes a sheet press control unit. Moreover, the end fence drive part 8, the solenoid 44, and the control part 11 comprise the swelling removal means of a claim.

  Next, the operation of the paper discharge device 1 will be described.

  The paper discharge device 1 performs a paper discharge operation in response to the printing device 100 performing a printing operation based on a print job.

  When starting the paper discharge operation, the control unit 11 performs an upper surface positioning operation. Specifically, the control unit 11 causes the lifting motor 37 to start raising the paper discharge tray 3. In addition, before the start of the upper surface positioning operation, the paper discharge table 3 is in a state of being lowered to a predetermined position. Further, the paper P is removed from the paper discharge tray 3, and there is no paper P on the paper discharge tray 3. When the upper surface detection sensor 9 is turned on after the discharge table 3 starts to rise, the control unit 11 stops the raising / lowering motor 37 to stop the discharge table 3 from rising.

  Here, the detection state in the upper surface detection sensor 9 (the state where the light from the light emitting unit 9a is blocked in the middle and the light receiving unit 9b is not receiving light) is turned on, and the non-detected state (the light from the light emitting unit 9a receives the light receiving unit 9b). Is off). The control unit 11 determines whether the upper surface detection sensor 9 is on or off based on the amount of light received by the light receiving unit 9b.

  Thereafter, the control unit 11 causes the lifting motor 37 to start lowering the discharge table 3. When the upper surface detection sensor 9 is turned off, the control unit 11 stops the lifting motor 37 to stop the lowering of the sheet discharge table 3. Thereby, the upper surface 32a of the central member 32 of the paper discharge tray 3 is adjusted so as to substantially coincide with the reference upper surface position. Thus, the upper surface positioning operation is completed.

  In addition, the control unit 11 controls the side fence driving unit 6 and the end fence driving unit 8 to adjust the side fences 5A and 5B and the end fence 7 to positions corresponding to the size of the paper P to be discharged.

  After completion of the upper surface positioning operation and the position adjustment of the side fences 5A and 5B and the end fence 7, the control unit 11 starts the paper discharge operation and discharges the paper P sent from the printing apparatus 100 from the paper discharge unit 2. The paper is discharged onto the paper base 3.

  During the paper discharge operation, the control unit 11 controls the paper discharge table 3 as the number of the paper P on the paper discharge table 3 increases in order to maintain the height position of the upper surface of the stacked paper on the paper discharge table 3 almost constant. The paper tray lowering control is performed.

  In addition, the control unit 11 performs a bulge detection process for detecting a bulge at the center in the paper discharge direction of the stacked sheets on the paper discharge tray 3. The state where the central portion in the discharge direction of the stacked sheets on the discharge table 3 is in a state where the upper surface of the stacked sheets has a convex shape when viewed from the left and right. The swelling of the stacked sheets is caused by the accumulation of air between the sheets. This is likely to occur when light and light weight paper is discharged.

  When the bulge of the loaded paper is detected, the control unit 11 executes a bulge eliminating operation for eliminating the bulge using the end fence 7.

  The above-described discharge table lowering control, bulge detection processing, and bulge elimination operation will be described with reference to the flowchart of FIG.

  When the paper discharge operation is started, in step S1 of FIG. 5, the control unit 11 determines whether or not the upper surface detection sensor 9 is turned on.

  Here, as described above, the upper surface detection sensor 9 is turned off at the end of the upper surface positioning operation before the start of the paper discharge operation. When the sheets P to be sequentially discharged are stacked on the sheet discharge tray 3 and the height of the stacked sheets reaches the reference upper surface position, the upper surface detection sensor 9 is turned on. When it is determined that the upper surface detection sensor 9 is off (step S1: NO), the control unit 11 proceeds to step S13 described later.

  When it is determined that the upper surface detection sensor 9 is turned on (step S1: YES), in step S2, the control unit 11 starts counting the number of discharged sheets. The control unit 11 counts the number of discharged sheets based on whether the sheet discharge sensor 23 is on / off.

  Next, in step S <b> 3, the control unit 11 determines whether the count value C of the number of discharged sheets after the upper surface detection sensor 9 is turned on has reached a specified number N. The specified number N is a value for determining whether or not to start the lowering of the paper discharge tray 3. The condition that the upper surface detection sensor 9 remains on while N sheets are discharged after the upper surface detection sensor 9 is turned on is a condition for starting the lowering of the paper discharge tray 3. For example, the prescribed number N = 3.

  When it is determined that the count value C has not reached the specified number N (step S3: NO), in step S4, the control unit 11 determines whether or not the upper surface detection sensor 9 is off. When it is determined that the upper surface detection sensor 9 is off (step S4: YES), the control unit 11 proceeds to step S13 described later. When it is determined that the upper surface detection sensor 9 is on (step S4: NO), the control unit 11 returns to step S3.

  If it is determined in step S3 that the count value C has reached the specified number N (step S3: YES), the control unit 11 determines that the conditions for starting the lowering of the paper discharge tray 3 are satisfied, and in step S5, The raising / lowering motor 37 starts the lowering of the sheet discharge table 3. Further, the control unit 11 starts distance measurement by the distance measuring sensor 10. As shown in FIG. 6, the distance H measured by the distance measuring sensor 10 is a distance in the height direction to the upper surface of the front end portion in the paper discharge direction (front-rear direction) of the stacked sheets on the paper discharge tray 3.

  Next, in step S6 of FIG. 5, the control unit 11 determines whether or not the upper surface detection sensor 9 is turned off. When it is determined that the upper surface detection sensor 9 is on (step S6: NO), the control unit 11 repeats step S6.

  When it is determined that the upper surface detection sensor 9 is turned off (step S6: YES), in step S7, the control unit 11 stops the lowering of the discharge table 3 by stopping the lifting motor 37. In addition, the control unit 11 ends the distance measurement by the distance measuring sensor 10.

  Next, in step S <b> 8, the control unit 11 determines whether or not the maximum value Hmax of the distance H measured by the distance measuring sensor 10 during the lowering operation of the paper discharge tray 3 is greater than the threshold value Hth.

  The threshold value Hth is a value set in advance as a threshold value for determining whether or not the central portion of the stacked sheets on the sheet discharge tray 3 in the sheet discharge direction is bulged. The threshold value Hth is a value equal to or greater than the distance Hk in the height direction from the distance measuring sensor 10 to the reference upper surface position. As the threshold value Hth, for example, a value obtained experimentally is set. Hth = Hk may be sufficient.

  If there is no swelling at the center in the paper discharge direction of the stacked sheets on the paper discharge tray 3, the distance H measured by the distance measuring sensor 10 when the upper surface detection sensor 9 is on is equal to or less than Hk. During the above-described lowering operation of the paper discharge tray 3, the upper surface detection sensor 9 is on. Therefore, when the stacked sheets on the paper discharge tray 3 are not swollen, the maximum value Hmax of the distance H measured by the distance measuring sensor 10 during the lowering operation of the paper discharge tray 3 is Hk. For this reason, when the maximum value Hmax of the distance H measured by the distance measuring sensor 10 during the lowering operation of the paper discharge tray 3 is larger than the threshold Hth equal to or higher than Hk, the stacked sheets on the paper discharge tray 3 in the paper discharge direction. It can be judged that the central part is swollen.

  Therefore, when it is determined that the maximum value Hmax of the distance H measured by the distance measuring sensor 10 is larger than the threshold value Hth (step S8: YES), the control unit 11 determines that the stacked sheets are swollen, and the step In S9, the paper discharge operation is stopped. Specifically, the control unit 11 outputs an instruction to the printing apparatus 100 to stop the printing operation and stop the paper discharge unit 2.

  On the other hand, when it is determined that the maximum value Hmax of the distance H measured by the distance measuring sensor 10 is equal to or less than the threshold value Hth (step S8: NO), the control unit 11 returns to step S1.

  When the paper discharge operation is stopped in step S9, in step S10, the control unit 11 executes a bulge eliminating operation.

  Specifically, first, the control unit 11 turns on the solenoid 44 to raise the protrusions 42A and 42B of the end fence 7 upward. Next, as shown in FIG. 7, the control unit 11 causes the end fence driving unit 8 to move the end fence 7 above the central portion in the sheet discharge direction of the stacked sheets.

  Next, the controller 11 turns off the solenoid 44 to lower the protrusions 42A and 42B. Thereby, as shown in FIG. 8, the protrusions 42A and 42B press the stacked sheets from above. As a result, the air between the sheets escapes and the swelling is eliminated.

  Thereafter, the control unit 11 turns on the solenoid 44 to raise the protrusions 42A and 42B of the end fence 7 upward. Next, the control unit 11 moves the end fence 7 forward by the end fence driving unit 8 and stops it at the home position on the front side of the front end of the paper discharge table 3. The home position of the end fence 7 is detected by an end fence HP (home position) sensor (not shown). Then, the control unit 11 turns off the solenoid 44 to lower the protrusions 42A and 42B. Thus, the bulge eliminating operation is completed.

  Returning to FIG. 5, after the bulge eliminating operation (step S <b> 10), in step S <b> 11, the control unit 11 performs an upper surface positioning operation. Here, after the side fence drive unit 6 moves the side fences 5A and 5B to the home position, the control unit 11 performs an upper surface positioning operation. The home positions of the side fences 5A and 5B are detected by a side fence HP sensor (not shown).

  The procedure of the upper surface positioning operation is as described above. Here, since the paper P is stacked on the paper discharge tray 3, the upper surface positioning operation is performed so that the upper surface of the stacked paper on the paper discharge tray 3 is substantially coincident with the reference upper surface position.

  Next, in step S12, the control unit 11 restarts the paper discharge operation. Specifically, the control unit 11 controls the side fence driving unit 6 and the end fence driving unit 8 so that the side fences 5A and 5B and the end fence 7 are positioned according to the size of the paper P to be discharged. adjust. Then, the control unit 11 outputs an instruction to the printing apparatus 100 to restart the printing operation and restarts the driving of the paper discharge unit 2. Thereafter, the control unit 11 returns to step S1.

  In step S13, the control unit 11 determines whether or not the discharge of the number of printed sheets has been completed. If it is determined that the number of printed sheets has not been discharged (step S13: NO), the control unit 11 returns to step S1. If it is determined that the number of printed sheets has been discharged (step S13: YES), the control unit 11 ends the series of processes.

  As described above, in the paper discharge device 1, during the paper discharge operation, the paper discharge platform lowering control is performed and the bulge detection process is performed. When the bulge of the loaded paper is detected, the paper discharge device 1 executes a bulge eliminating operation. Thereby, the paper discharge device 1 can eliminate the bulge at the timing when the bulge of the loaded paper occurs. For this reason, the expansion of the bulge of the loaded paper can be suppressed. Accordingly, it is possible to prevent a sheet from slipping out due to a gap in the height direction between the lower end of the end fence 7 and the stacked sheets due to the discharge table lowering control. As a result, it is possible to suppress defective sheet alignment.

  Further, in the paper discharge device 1, the control unit 11 determines whether or not the stacked paper is swollen by using the distance measured by the distance measuring sensor 10 when the upper surface detection sensor 9 detects the paper P. doing. Specifically, when the maximum value Hmax of the distance H measured by the distance measuring sensor 10 during the lowering operation of the paper discharge tray 3 in which the upper surface detection sensor 9 is on is larger than the threshold value Hth, the control unit 11 It is determined that the loaded paper is swollen. Thereby, it is possible to detect the swollenness of the loaded paper with a simple structure in which the distance measuring sensor 10 is added to the existing apparatus.

  Further, in the paper discharge device 1, the end fence 7 is used to press the stacked paper to eliminate the swelling. As a result, it is possible to eliminate the swelling of the stacked sheets while suppressing the complexity of the structure of the apparatus.

  In the paper discharge device 1 described above, the distance measuring sensor 10 is arranged so as to measure the distance in the height direction to the upper surface of the front end in the paper discharge direction of the stacked paper on the paper discharge tray 3. You may arrange | position so that the distance of the height direction to the upper surface of the rear-end part of a paper may be measured.

  In the paper discharge device 1 described above, the protrusions 42A and 42B, which are a part of the end fence 7, are configured to move up and down. However, the end fence may be moved up and down as a whole. It is sufficient that at least a part of the end fence can move up and down.

  Further, in the paper discharge device 1 described above, the bulge elimination operation using the end fence 7 is performed. However, as the bulge elimination operation, an operation of vibrating the paper ejection tray 3 up and down may be performed. In this case, the control unit 11 controls the elevating drive unit 4 to vibrate the discharge table 3 up and down. As a result, air accumulated between the sheets of the stacked sheets on the sheet discharge tray 3 is released, and the swelling is eliminated. Even in this case, it is possible to eliminate the swelling of the stacked sheets while suppressing the complexity of the structure of the apparatus. In this case, the elevating drive unit 4 and the control unit 11 constitute a bulge eliminating means.

(Modification of the first embodiment)
FIG. 9 is a schematic diagram of a main part of a paper discharge device according to a modification of the first embodiment. FIG. 10 is a control block diagram of the paper discharge device according to this modification.

  As shown in FIGS. 9 and 10, the paper discharge device 1 </ b> A according to this modification is different from the paper discharge device 1 according to the first embodiment described above in that a paper pressing member 51, a paper pressing drive unit 52, and the like. It is the structure which added.

  The paper pressing member 51 presses the stacked paper in order to eliminate the swelling of the stacked paper on the paper discharge tray 3. The sheet pressing member 51 is disposed above the sheet discharge table 3. The sheet pressing member 51 is disposed at the center of the sheet discharge table 3 in the left-right direction. The sheet pressing member 51 is configured to be movable up and down. Further, the sheet pressing member 51 is configured to be movable along the front-rear direction.

  The paper pressing drive unit 52 moves the paper pressing member 51 up and down. Further, the sheet pressing drive unit 52 moves the sheet pressing member 51 along the front-rear direction. The paper press drive unit 52 includes a paper press vertical movement motor 53, a paper press movement motor 54, a paper press vertical movement mechanism (not shown), and a paper press movement mechanism (not shown).

  The paper presser vertical movement motor 53 generates a driving force for moving the paper presser member 51 up and down by a paper presser vertical movement mechanism.

  The sheet pressing movement motor 54 generates a driving force for moving the sheet pressing member 51 in the front-rear direction by the sheet pressing movement mechanism.

  In the paper discharge device 1 </ b> A, the control unit 11 performs a bulge eliminating operation using the paper pressing member 51. Other operations in the paper discharge device 1A are the same as those in the paper discharge device 1 according to the first embodiment.

  A bulge eliminating operation in the paper discharge device 1A will be described.

  When the bulge of the stacked sheets on the sheet discharge tray 3 as shown in FIG. 11 is detected and the sheet discharge operation is stopped, the control unit 11 lowers the sheet pressing member 51 above the stacked sheets by the sheet pressing drive unit 52. . Here, the control unit 11 adjusts the position in advance when starting the paper discharge operation so that the paper pressing member 51 is positioned above the central portion in the paper discharge direction of the stacked paper.

  By lowering the sheet pressing member 51, the sheet pressing member 51 presses the stacked sheets from above as shown in FIG. As a result, the air between the sheets escapes and the swelling is eliminated. Thereafter, the control unit 11 moves the sheet pressing member 51 up by the sheet pressing drive unit 52 and retracts it. This completes the bulge eliminating operation.

  As is apparent from the above description, in the present modification, the control unit 11 constitutes the sheet press control means of the claims. Further, the sheet pressing member 51 and the control unit 11 constitute a bulge eliminating unit in the claims.

  As described above, in the paper discharge device 1A, the bulge is eliminated by pressing the stacked sheets with the dedicated sheet pressing member 51. Thereby, it is possible to quickly and surely eliminate the swelling of the loaded paper.

[Second Embodiment]
FIG. 13 is a side cross-sectional view of the paper discharge device according to the second embodiment. FIG. 14 is a control block diagram of the paper discharge device according to the second embodiment.

  As shown in FIGS. 13 and 14, the paper discharge device 1B according to the second embodiment omits the distance measuring sensor 10 from the paper discharge device 1 according to the first embodiment described above, and In this configuration, a distance sensor 61 is added.

  The short distance sensor 61 detects the presence or absence of the sheet P in a predetermined range at the rear end in the sheet discharge direction of the stacked sheets on the sheet discharge table 3 at the reference upper surface position. The short distance sensor 61 is a reflection type optical sensor whose detection range is limited to a short distance. The short distance sensor 61 is disposed in the vicinity of the light receiving portion 9 b of the upper surface detection sensor 9 and at the same height as the upper surface detection sensor 9. The short distance sensor 61 corresponds to the sheet detection means in the claims.

  As will be described later, the control unit 11 controls the center of the stacked sheets on the sheet discharge tray 3 in the sheet discharge direction based on the presence or absence of the sheet detection by the short distance sensor 61 when the sheet P is detected by the upper surface detection sensor 9. It is determined whether or not the part is swollen. In the second embodiment, the short-range sensor 61 and the control unit 11 constitute a bulge detection unit in the claims.

  The discharge tray lowering control, the bulge detection process, and the bulge eliminating operation in the paper discharge device 1B will be described with reference to the flowchart of FIG. In FIG. 15, steps similar to those in the flowchart of FIG. 5 described in the first embodiment are denoted by the same step numbers, and description thereof is omitted.

  If it is determined in step S3 that the count value C has reached the specified number N (step S3: YES), the control unit 11 starts the lowering of the paper discharge tray 3 by the lifting motor 37 in step S21.

  Next, in step S22, the control unit 11 determines whether or not the upper surface detection sensor 9 has been turned off.

  When it is determined that the upper surface detection sensor 9 is on (step S22: NO), in step S23, the control unit 11 determines whether or not the short-range sensor 61 is off.

  Here, when the central portion in the paper discharge direction of the stacked sheets on the paper discharge tray 3 is swollen, the swollen portion is detected by the upper surface detection sensor 9 as shown in FIG. There is no sheet P in the range. For this reason, when the short distance sensor 61 is off when the upper surface detection sensor 9 is on, it can be determined that the central portion of the stacked sheets on the paper ejection tray 3 in the paper ejection direction is swollen.

  Therefore, when it is determined that the short distance sensor 61 is off (step S23: YES), the control unit 11 determines that the stacked sheets are swollen, and stops the lowering of the sheet discharge tray 3 in step S24. And the paper discharge operation is stopped. Thereafter, the control unit 11 proceeds to step S10.

  On the other hand, when it is determined in step S23 that the short-range sensor 61 is on (step S23: NO), the control unit 11 returns to step S22.

  If it is determined in step S22 that the upper surface detection sensor 9 is off (step S22: YES), the control unit 11 stops the lowering of the paper discharge tray 3 in step S25. If “YES” is determined in the step S22, the short-range sensor 61 is also turned on when the upper surface detection sensor 9 is turned on. In this case, the stacked paper does not bulge. After step S25, the control unit 11 returns to step S1.

  As described above, in the paper discharge device 1B, it is determined whether the bulging of the stacked paper has occurred based on the presence or absence of the paper detection by the short distance sensor 61 when the paper P is detected by the upper surface detection sensor 9. doing. Specifically, the control unit 11 determines that the bulging of the stacked sheets has occurred when the short distance sensor 61 is off when the upper surface detection sensor 9 is on. Thereby, it is possible to detect the swollenness of the loaded paper with a simple structure in which the short-range sensor 61 is added to the existing apparatus.

  In the paper discharge device 1B described above, the short distance sensor 61 is arranged so as to detect the presence or absence of the paper P in a predetermined range at the rear end in the paper discharge direction of the stacked paper on the paper discharge tray 3. It may be arranged so as to detect the presence or absence of the paper P in a predetermined range of the front end. That is, in the paper discharge device 1B described above, the short distance sensor 61 is disposed on the light receiving unit 9b side of the upper surface detection sensor 9, but the short distance sensor 61 may be disposed on the light emitting unit 9a side.

  Further, in the paper discharge device 1B according to the second embodiment, as in the paper discharge device 1 according to the first embodiment, an operation of vibrating the paper discharge table 3 up and down may be performed as a bulge eliminating operation. .

  Further, a sheet pressing member 51 and a sheet pressing drive unit 52 in the sheet discharging apparatus 1A of the modification of the first embodiment are added to the sheet discharging apparatus 1B of the second embodiment, and the sheet pressing member You may make it perform the bulge removal operation | movement using 51. FIG.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1,1A, 1B Paper discharge apparatus 2 Paper discharge part 3 Paper discharge stand 4 Lift drive part 5A, 5B Side fence 6 Side fence drive part 7 End fence 8 End fence drive part 9 Upper surface detection sensor 10 Distance sensor 11 Control part 41 Main body 42A, 42B Protrusion 43 Slide plate 44 Solenoid 51 Paper pressing member 52 Paper pressing drive 61 Short distance sensor

Claims (6)

A paper tray that can be raised and lowered to stack the ejected paper;
A regulating member that hangs above the paper ejection tray and regulates the front end position of the paper ejected to the paper ejection tray;
Upper surface detection means for detecting the presence or absence of paper at a reference height position;
During the paper discharge operation, using the detection result of the paper by the upper surface detection means, the paper discharge table control means for controlling the lowering of the paper discharge table;
A bulge detecting means for detecting a bulge at the center in the paper discharge direction of the stacked paper on the paper discharge table;
A paper discharge device comprising: a bulge eliminating unit that eliminates the bulge when the bulge of the loaded paper is detected by the bulge detection unit. The bulge detecting means includes
Ranging means that is disposed above the paper discharge table and measures the distance in the height direction to the upper surface of the end in the paper discharge direction of the stacked paper;
2. A determination unit that determines whether or not a bulge of a stacked sheet has occurred using a distance measured by the distance measurement unit when the sheet is detected by the upper surface detection unit. The paper discharge device described in 1. The bulge detecting means includes
Paper detection means for detecting the presence or absence of paper in a predetermined range at the end in the paper discharge direction of the stacked paper at the reference height position;
And a determination unit configured to determine whether or not the bulging of the stacked sheets has occurred based on whether or not the sheet detection unit detects the sheet when the sheet is detected by the upper surface detection unit. The paper discharge device according to 1. The bulge eliminating means is
Restriction member moving means for moving the restriction member along the paper discharge direction;
Restriction member vertical movement means for moving up and down at least a part of the restriction member;
After the restriction member is moved above the stacked paper by the restriction member moving means, at least a part of the restriction member is lowered by the restriction member up-and-down moving means, and the loaded paper is pressed by the restriction member to swell. The paper discharge device according to any one of claims 1 to 3, further comprising: a sheet pressing control unit that eliminates the problem.   The paper discharge device according to any one of claims 1 to 3, wherein the bulge eliminating unit eliminates the bulge of the loaded paper by vibrating the paper discharge table up and down. The bulge eliminating means is
A sheet pressing member which is provided above the sheet discharge table and is movable up and down;
The paper discharge device according to any one of claims 1 to 3, further comprising: a paper pressing control unit that cancels the swelling by pressing the stacked paper by the paper pressing member.