JP2014061978A - Paper discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper discharge device capable of suppressing reduction in performance of arranging discharged paper.SOLUTION: A paper discharge device 1 includes: a paper discharge table 3 on which discharged paper P is loaded; an end fence 7 suspended above the paper discharge table 3, for regulating a front end position of the paper P discharged onto the paper discharge table 3; an elevation drive part 4 for making the paper discharge table 3 move upward/downward; a top surface detection sensor 9 for detecting presence/absence of the paper P at a reference top surface position; and a control part 11 for, when the number of discharged paper in a state where the top surface detection sensor 9 is detecting the paper P reaches the predetermined number, during paper discharge operation, performing control so that operation for moving the paper discharge table 3 downward is carried out by the elevation drive part 4.

Description

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

  2. Description of the Related Art Conventionally, a paper discharge device that discharges a sheet printed by a printing device has a discharge table that can be moved up and down (see, for example, Patent Document 1).

  In such a paper discharge device, control is performed to maintain the height position of the top surface of the stacked paper by lowering the paper discharge table as the number of stacked paper on the paper discharge table increases. Specifically, in such a paper discharge device, when the upper surface detection sensor installed at the reference upper surface position detects the paper, it is determined that the paper is stacked beyond the reference upper surface position, and the paper discharge table is lowered. As a result, the paper discharge unit that drops the paper onto the paper discharge tray and the height relationship between the top surface of the stacked paper on the paper discharge tray and the top surface of the stacked paper are kept almost constant, achieving good paper discharge alignment performance. ing.

JP 62-60757 A

  In the paper discharge device as described above, the paper discharge table may not be lowered properly depending on the state of the discharged paper. For example, when the discharged paper is placed on the stacked paper on the paper discharge tray with the center part floating, the paper discharge tray is lowered until the upper surface detection sensor no longer detects the paper. In this case, the paper discharge table may be lowered too much.

  As a result, the height relationship between the paper discharge unit and the uppermost surface of the stacked paper on the paper discharge stand is not optimal, and the paper discharge alignment performance may deteriorate. Further, for example, a gap in the height direction may be generated between the lower end of the suspended end fence and the stacked sheets, and the position of the discharged sheets in the discharge direction may not be regulated.

  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 a decrease in paper discharge alignment performance.

  In order to achieve the above object, a first feature of a paper discharge device according to the present invention is that a paper discharge base on which discharged paper is stacked, and a paper discharge base suspended above the paper discharge base. An end fence that regulates the front end position of the paper ejected on the paper, a lift drive unit that raises and lowers the paper ejection table, and a reference for the height position of the uppermost surface of the paper stacked on the paper ejection table. A first detection unit that detects the presence or absence of a sheet at one reference position; and when the number of discharged sheets in a state in which the first detection unit is detecting a sheet during a sheet discharge operation reaches a specified number, And a control unit that controls to perform the lowering operation of the paper discharge table.

  A second feature of the paper discharge device according to the present invention is that the control unit determines the number of discharged sheets to the specified number after a lapse of a specified time from the time when the first detection unit has detected a sheet. It is to start counting.

  A third feature of the paper discharge device according to the present invention is that, when the first detection unit is in a state in which the first detection unit does not detect paper in the lowering operation of the paper discharge table, or the predetermined number of sheets The lowering of the sheet discharge table is stopped when the sheet discharge table is lowered by a specified lowering amount equal to or more than the total thickness of the sheets.

  A fourth feature of the paper discharge device according to the present invention is that the first reference position is higher than a lower end of the end fence, and the control unit is configured to release the paper discharge base from the start of the paper discharge operation. When the value obtained by subtracting the total sheet thickness for the number of discharged sheets is greater than the difference in height between the first reference position and the lower end of the end fence, the discharge operation is performed. It is to stop.

  A fifth feature of the paper discharge device according to the present invention is further provided with a second detection unit that detects the presence or absence of a sheet at a second reference position that is higher than the first reference position, and the control unit includes: The detection result of the second detection unit is used to determine the presence or absence of paper stacking failure.

  A sixth feature of the paper discharge device according to the present invention is that a difference in height between the second reference position and the first reference position is a difference in height between the first reference position and a lower end of the end fence. It is in the following.

  According to the first feature of the paper discharge device according to the present invention, during the paper discharge operation, when the number of paper discharged in the state where the first detection unit detects the paper reaches a specified number, the paper discharge table is lowered. Execute. As a result, it is possible to prevent the discharge table from descending more than necessary by starting the lowering of the discharge table before the posture of the paper discharged onto the discharge table is not adjusted. As a result, it is possible to suppress a decrease in paper discharge alignment performance.

  According to the second feature of the paper discharge device according to the present invention, the counting of the number of discharged paper sheets to the specified number of sheets is started after a lapse of a specified time from when the first detection unit is in a state of detecting the sheet. Accordingly, it is possible to more reliably suppress the lowering of the paper discharge table before the posture of the paper discharged on the paper discharge table is not adjusted.

  According to the third feature of the paper discharge device according to the present invention, the lowering of the paper discharge table is performed when the first detection unit is in a state where it does not detect the paper or when the paper discharge table is lowered by a specified lowering amount. Stop. As a result, it is possible to prevent the discharge tray from being lowered more than necessary while securing the necessary lowering amount.

  According to the fourth feature of the paper discharge device according to the present invention, a value obtained by subtracting the total thickness of the paper for the number of paper discharges from the total amount of lowering of the paper discharge tray from the start of the paper discharge operation, When the height difference between the first reference position and the lower end of the end fence becomes larger, the paper discharge operation is stopped. Thereby, it is possible to reduce the paper slipping under the end fence.

  According to the fifth feature of the paper discharge device according to the present invention, it is possible to easily detect a stacking failure of sheets on the paper discharge tray by the second detection unit.

  According to the sixth feature of the paper discharge device according to the present invention, the height difference between the second reference position and the first reference position is equal to or less than the height difference between the first reference position and the lower end of the end fence. By doing so, it is possible to detect a stacking failure of the sheets by the second detection unit before the discharge table is lowered too much.

It is a perspective view of the paper discharge device concerning an embodiment. FIG. 2 is a side sectional view of the paper discharge device shown in FIG. 1. It is a front view of an end fence. It is a flowchart for demonstrating upper surface maintenance operation | movement. It is explanatory drawing of the leaning of a sheet | seat. It is a flowchart for demonstrating lean detection operation | movement. It is a timing chart for explaining an example of an upper surface maintenance operation and a leaning detection operation. FIG. 6 is a schematic diagram illustrating a state in which a sheet with a posture in which a central portion is lifted is discharged. FIG. 6 is a schematic diagram illustrating a state where a sheet in a curled posture is discharged.

  Hereinafter, embodiments of the present invention will be described 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 is to arrange the components and the like as follows. It is not something specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  FIG. 1 is a perspective view of a paper discharge device according to an embodiment of the present invention, and FIG. 2 is a side sectional view of the paper discharge device shown in FIG. In the following description, the front and rear in the paper discharge direction is the front and rear direction. 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 and 2, the paper discharge device 1 according to the present embodiment includes a paper discharge unit 2, a paper discharge stand 3, a lift drive unit 4, a pair of side fences 5 </ b> A and 5 </ b> B, Fence drive unit 6, end fence 7, end fence drive unit 8, top surface detection sensor (corresponding to the first detection unit in the claims) 9, leaning detection sensor (corresponding to the second detection unit in the claims) 10 And a control unit 11.

  The paper discharge unit 2 discharges the paper P printed by a printing apparatus (not shown) to the paper discharge table 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 discharges the paper P 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 pairs of paper discharge rollers 21.

  The paper discharge sensor 23 detects the paper P discharged from the paper discharge unit 2 to the paper discharge tray 3. 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 composed of, for example, 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 tray 3 includes a bottom plate portion 26 having a rectangular shape in plan view, a central member 27, and stiffness members 28 and 29.

  The central member 27 is formed at the central portion in the left-right direction on the bottom plate portion 26 so as to extend in the front-rear direction. The upper surface 27a of the central member 27 is a substantially horizontal plane. The upper surface 27 a of the central member 27 constitutes a part of the sheet placement surface of the sheet discharge table 3.

  The stiffening members 28 and 29 are wedge-shaped members elongated in the left-right direction. A plurality of the stiffening members 28 and 29 are arranged at intervals in the front-rear direction. The stiffening member 28 is disposed on the left side of the central member 27 via a gap. The upper surface 28a of the crimping member 28 is inclined so as to gradually increase from the center side toward the left side. The stiffening member 29 is disposed on the right side of the central member 27 via a gap. The upper surface 29a of the stiffness enhancing member 29 is inclined so as to gradually increase from the central side toward the right side. The upper surfaces 28 a and 29 a of the crimping members 28 and 29 together with the upper surface 27 a of the central member 27 constitute a paper placement surface of the paper discharge tray 3. The sheet stacking surface has a substantially V shape in which both sides in the left-right direction are higher than the center when viewed from the front-rear direction. As a result, the paper P is stacked on the paper discharge tray 3 in a substantially U shape in which both sides in the paper width direction (left-right direction) are curved upward from the center. As a result, the paper P can be stiff and the alignment can be improved.

  The elevating drive unit 4 elevates and lowers the paper discharge table 3. The lift drive unit 4 includes a lift mechanism 31 and a lift motor 32.

  The elevating mechanism 31 has a rack and pinion mechanism, and raises and lowers the paper discharge tray 3 by the driving force of the elevating motor 32.

  The raising / lowering motor 32 generates a driving force for raising / lowering the sheet discharge tray 3 by the raising / lowering mechanism 31. The discharge table 3 is raised by the forward drive of the lifting motor 32, and the discharge table 3 is lowered by the reverse drive.

  The pair of side fences 5 </ b> A and 5 </ b> B regulates the positions of both ends in the width 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 33 and a side fence motor 34.

  The side fence moving mechanism 33 moves the pair of side fences 5 </ b> A and 5 </ b> B in a direction in which the pair of side fences 5 </ b> A and 5 </ b> B approach each other or in a direction in which the pair of side fences 5 </ b> B are separated from each other. The side fence moving mechanism 33 is provided above the pair of side fences 5A and 5B.

  The side fence motor 34 generates a driving force for moving the side fences 5A and 5B by the side fence moving mechanism 33. The side fences 5A and 5B approach each other by the forward rotation drive of the side fence motor 34, and the side fences 5A and 5B are separated from each other by the reverse rotation drive of the side fence motor 34.

  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.

  As shown in FIG. 3, the end fence 7 has protrusions 7 a and 7 b that protrude downward on the left and right sides. The protrusions 7a and 7b are arranged so as to enter a gap between the central member 27 of the paper discharge tray 3 and the crimping members 28 and 29. Further, the end fence 7 is provided with a window portion 7c through which light emitted from the light emitting portion 10a of the lean detection sensor 10 passes.

  The end fence driving unit 8 moves the end fence 7. The end fence driving unit 8 includes an end fence moving mechanism 35 and an end fence motor 36.

  The end fence moving mechanism 35 moves the end fence 7 in the front-rear direction by the driving force of the end fence motor 36. The end fence moving mechanism 35 is provided above the end fence 7.

  The end fence motor 36 generates a driving force for moving the end fence 7 by the end fence moving mechanism 35. The end fence 7 is moved forward by the forward drive of the end fence motor 36, and the end fence 7 is moved backward by the reverse drive of the end fence motor 36.

  The upper surface detection sensor 9 detects the presence or absence of the sheet P at the reference upper surface position (corresponding to the first reference position in the claims), which is the reference of the height position (upper surface position) of the uppermost surface of the stacked sheets on the paper discharge tray 3. Is to do. The reference upper surface position is set in advance as an optimum height position so that the sheets P dropped from the paper discharge unit 2 to the paper discharge tray 3 are stacked in an orderly manner. The upper surface detection sensor 9 is 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 left-right direction with the paper discharge table 3 and the end fence 7 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. As shown in FIG. 3, the reference upper surface position is higher than the lower end of the end fence 7 (the lower ends of the protrusions 7a and 7b). The light emitting unit 9a and the light receiving unit 9b are arranged at positions where the optical axis enters between the projections 7a and 7b of the end fence 7 in the left-right direction. The light receiving unit 9b receives the light from the light emitting unit 9a when there is no paper P between the light emitting unit 9a and does not receive the light from the light emitting unit 9a when blocked by the paper P. That is, the upper surface detection sensor 9 detects the paper P when the light receiving unit 9b does not receive the light from the light emitting unit 9a.

  The lean detection sensor 10 is for detecting the presence or absence of the paper P at the lean detection position (corresponding to a second reference position in claims). The leaning detection position is set in advance as a height position for detecting whether or not a stacking defect occurs in which the paper P leans on the wall 12 facing the end fence 7 or the end fence 7 across the paper discharge tray 3. It has been done. The lean detection sensor 10 includes a transmissive optical sensor similar to the upper surface detection sensor 9 and includes a light emitting unit 10a and a light receiving unit 10b.

  The light emitting unit 10a and the light receiving unit 10b are disposed opposite to each other in the left-right direction with the paper discharge tray 3 and the end fence 7 interposed therebetween. As shown in FIG. 3, the lean detection position is at a position higher than the reference upper surface position. The light emitting unit 10a and the light receiving unit 10b are arranged at a position where the optical axis passes through the window part 7c of the end fence 7, and the height position of the optical axis leans to coincide with the detection position. Here, if the height difference between the reference upper surface position and the lower end of the end fence 7 (the lower ends of the projections 7a and 7b) is H1, and the height difference between the lean detection position and the reference upper surface position is H2, H2 ≦ H1.

  The control unit 11 controls the overall operation of the paper discharge device 1. The control unit 11 includes a storage device such as a CPU, RAM, ROM, and HDD. During the paper discharge operation, the control unit 11 performs control for lowering the paper discharge table 3 by the lift drive unit 4 in order to maintain the upper surface position of the stacked paper on the paper discharge table 3. In this upper surface maintaining operation, the control unit 11 executes the lowering operation of the paper discharge tray 3 by the elevating drive unit 4 after the specified number of sheets P are discharged while the upper surface detection sensor 9 detects the paper. Control to do.

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

  When starting the paper discharge operation, the control unit 11 performs an upper surface positioning operation. Specifically, the control unit 11 starts the raising of the paper discharge tray 3 by the forward drive of the lifting motor 32. Note that before the discharge operation is started, the discharge table 3 is 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 forward drive of the lift motor 32 is started, the control unit 11 stops the lift of the discharge table 3 by stopping the lift motor 32.

  Thereafter, the control unit 11 starts the lowering of the paper discharge tray 3 by the reverse drive of the lifting motor 32. When the upper surface detection sensor 9 is turned off, the control unit 11 stops the lowering motor 32 to stop the lowering of the paper discharge tray 3. Thus, the upper surface positioning operation is completed. By the upper surface positioning operation, the upper surface 27a of the central member 27 of the paper discharge tray 3 is adjusted so as to be positioned at the reference upper surface position.

  Here, the state in which the upper surface detection sensor 9 is detecting the paper P (the light from the light emitting unit 9a is blocked by the paper P and the light receiving unit 9b is not receiving light) is ON, and the paper P is not detected. The state (the state in which the light receiving unit 9b receives light from the light emitting unit 9a) is set to OFF. When the light receiving unit 9b receives light from the light emitting unit 9a, the light receiving unit 9b outputs a signal, and the control unit 11 determines ON / OFF of the upper surface detection sensor 9 based on the output signal of the light receiving unit 9b.

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

  During the paper discharge operation, the control unit 11 performs the upper surface maintaining operation. The upper surface maintaining operation will be described with reference to the flowchart of FIG.

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

  When it is determined that the upper surface detection sensor 9 is not ON (step S1: NO), in step S2, 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 been discharged (step S2: YES), the control unit 11 ends the upper surface maintaining operation. If it is determined that the number of printed sheets has not been discharged (step S2: NO), the control unit 11 returns to step S1.

  When it is determined in step S1 that the upper surface detection sensor 9 has been turned on (step S1: YES), in step S3, the control unit 11 performs a specified time T (for example, 1 second) after the upper surface detection sensor 9 has been turned on. ) Or not. When it is determined that the specified time T has not elapsed since the upper surface detection sensor 9 is turned on (step S3: NO), the control unit 11 proceeds to step S2.

  When it is determined that the specified time T has elapsed since the upper surface detection sensor 9 was turned on (step S3: YES), in step S4, the control unit 11 counts the number of discharged sheets after the specified time T has elapsed. To start. The control unit 11 counts the number of discharged sheets based on ON / OFF of the discharge sensor 23.

  Next, in step S5, the control unit 11 determines whether or not the upper surface detection sensor 9 is ON. When it is determined that the upper surface detection sensor 9 is OFF (step S5: NO), the control unit 11 proceeds to step S2.

  When it is determined that the upper surface detection sensor 9 is ON (step S5: YES), in step S6, the control unit 11 sets the count number Cn1 of the number of discharged sheets after the start of counting in step S4 to the specified number N1. Judge whether or not. The specified number of sheets N1 is a reference number of discharged sheets for determining whether or not to start the lowering of the discharge table 3 when the upper surface detection sensor 9 continues to be ON after the lapse of the specified time T. is there.

  When it is determined that the count sheet number Cn1 is not equal to the specified sheet number N1 (step S6: NO), in step S7, the control unit 11 determines whether or not the discharge for the number of printed sheets has been completed. When it is determined that the number of printed sheets has been discharged (step S7: YES), the control unit 11 ends the upper surface maintaining operation. If it is determined that the number of printed sheets has not been discharged (step S7: NO), the control unit 11 returns to step S5.

  If it is determined in step S6 that the count sheet number Cn1 has reached the specified sheet number N1 (step S6: YES), the control unit 11 starts the lowering of the paper discharge tray 3 in step S8. Specifically, the control unit 11 starts reverse rotation driving of the lifting motor 32.

  Next, in step S9, the control unit 11 determines whether or not the upper surface detection sensor 9 is ON.

  When it is determined that the upper surface detection sensor 9 is ON (step S9: YES), in step S10, the control unit 11 sets the lowering amount of the paper discharge tray 3 after starting the lowering in step S8 to the specified lowering amount. Determine whether it has been reached. Here, the specified descending amount is set to a value equal to or greater than the total thickness of the specified number of sheets N1. Note that the control unit 11 can calculate the lowering amount of the paper discharge tray 3 based on an output pulse of an encoder (not shown) provided in the lifting motor 32.

  When it is determined that the lowering amount of the paper discharge tray 3 has reached the specified lowering amount from the start of the lowering (step S10: YES), the control unit 11 stops the lowering of the paper discharge tray 3 in step S11. Specifically, the control unit 11 stops the lifting motor 32. Thereafter, the control unit 11 proceeds to step S2.

  When it is determined that the lowering amount of the paper discharge tray 3 from the lowering start has not reached the specified lowering amount (step S10: NO), the control unit 11 returns to step S9.

  If it is determined in step S9 that the upper surface detection sensor 9 has been turned off (step S9: NO), the control unit 11 proceeds to step S11.

  In addition to the above-described upper surface maintenance operation, the control unit 11 performs a lean detection operation during the paper discharge operation. The lean detection operation detects and copes with a stacking failure due to the sheet P leaning on the wall 12 or the sheet P leaning on the end fence 7 as shown in FIG. The lean detection operation will be described with reference to the flowchart of FIG.

  When the lean detection operation is started by starting the paper discharge operation, in step S21 in FIG. 6, the control unit 11 determines whether the lean detection sensor 10 is turned on.

  When it is determined that the lean detection sensor 10 is not ON (step S21: NO), in step S22, the control unit 11 determines whether or not the discharge for the number of printed sheets has been completed. If it is determined that the number of printed sheets has been discharged (step S22: YES), the control unit 11 ends the lean detection operation. If it is determined that the number of printed sheets has not been discharged (step S22: NO), the control unit 11 returns to step S21.

  If it is determined in step S21 that the lean detection sensor 10 is turned on (step S21: YES), in step S23, the control unit 11 starts counting the number of discharged sheets after the lean detection sensor 10 is turned on. To do.

  Next, in step S24, the control unit 11 determines whether the lean detection sensor 10 is ON. When it is determined that the lean detection sensor 10 is OFF (step S24: NO), the control unit 11 proceeds to step S22.

  When it is determined that the lean detection sensor 10 is ON (step S24: YES), in step S25, the control unit 11 sets the count number Cn2 of the number of discharged sheets after the start of counting in step S23 to the specified number N2. Judge whether or not. The specified number N2 is a reference number of discharged sheets for determining whether or not a stacking failure due to the leaning of the sheets P occurs when the leaning detection sensor 10 is continuously ON.

  When it is determined that the count number Cn2 is not equal to the specified number N2 (step S25: NO), in step S26, the control unit 11 determines whether or not the discharge for the number of printed sheets has been completed. If it is determined that the number of printed sheets has been discharged (step S26: YES), the control unit 11 ends the lean detection operation. If it is determined that the number of printed sheets has not been discharged (step S26: NO), the control unit 11 returns to step S24.

  If it is determined in step S25 that the counted number Cn2 has reached the specified number N2 (step S25: YES), in step S27, the control unit 11 determines that a stacking defect due to the leaning of the sheets P has occurred, and the jogger Start operation. Specifically, the control unit 11 controls the side fence driving unit 6 to finely open and close the side fences 5A and 5B. Moreover, the control part 11 controls the end fence drive part 8, and makes the end fence 7 reciprocate back and forth finely. Further, the control unit 11 controls the elevation driving unit 4 to move the paper discharge table 3 finely up and down.

  Next, in step S28, the control unit 11 determines whether or not the lean detection sensor 10 is ON. When it is determined that the lean detection sensor 10 is OFF (step S28: NO), the control unit 11 determines that the leaning of the paper P has been eliminated by the jogger operation, and proceeds to step S22.

  When it is determined that the lean detection sensor 10 is ON (step S28: YES), the control unit 11 determines that the slack of the paper P has not been eliminated by the jogger operation, and in step S29, the entire paper discharge device 1 is determined. Stop operation. As a result, the lean detection operation also ends.

  Next, an example of the upper surface maintaining operation of the flowchart of FIG. 4 and the lean detection operation of the flowchart of FIG. 6 will be described with reference to the timing chart of FIG.

  In FIG. 7, the uppermost row shows the ON / OFF state of the paper discharge sensor 23. The second row from the top indicates the ON / OFF state of the lean detection sensor 10. The third level from the top shows the ON / OFF state of the upper surface detection sensor 9. The lowermost row shows a state where the sheet discharge table is lowered / stopped.

  As shown in FIG. 7, if the upper surface detection sensor 9 is ON at time t2 after the specified time T has elapsed after the upper surface detection sensor 9 is turned ON at time t1, "YES" is set in step S3 of FIG. Is determined, and counting of the number of discharged sheets is started in step S4.

  Here, the specified number N1 = 3. Therefore, if three sheets are detected from time t2 with the upper surface detection sensor 9 being ON as shown in FIG. 7, “YES” is determined in the step S6 in FIG. In step S8, the discharge table 3 starts to descend (time t3).

  After that, when the upper surface detection sensor 9 is turned off, “NO” is determined in step S9 in FIG. 4, and the lowering of the paper discharge tray 3 is stopped in step S11 (time t4).

  If the specified number N2 = 5, as shown in FIG. 7, after the lean detection sensor 10 is turned on at time t5, five sheets are detected while the lean detection sensor 10 is on. Then, “YES” is determined in the step S25 in FIG. Thus, it is determined that a stacking failure due to the leaning of the paper P has occurred, and a jogger operation is performed in step S27.

  In addition, when the leaning of the paper P occurs and the leaning detection sensor 10 continues to be in the ON state, the upper surface detection sensor 9 is also in the ON state. For this reason, the discharge table 3 is lowered (time t6).

  As described above, in the paper discharge device 1 of the present embodiment, when the specified time T elapses with the upper surface detection sensor 9 being ON, and the subsequent number of discharged sheets reaches the specified number N1, the discharge is performed. The descending operation of the paper table 3 is executed. Accordingly, it is possible to prevent the discharge table 3 from starting to descend before the posture of the paper P discharged onto the discharge table 3 is adjusted, and to prevent the discharge table 3 from dropping more than necessary.

  Unlike the present embodiment, when the upper surface detection sensor 9 is turned on, the discharge table 3 starts to descend, and the upper surface detection sensor 9 is lowered until the upper surface detection sensor 9 is turned off. Depending on the posture of the paper P discharged onto the paper base 3, the paper discharge base 3 may be lowered too much.

  For example, it is assumed that the paper P is placed on the stacked paper on the paper discharge tray 3 in a posture in which the central portion is floated. With this posture, as shown in FIG. 8, when the paper discharge tray 3 is lowered until the upper surface detection sensor 9 is turned off, the paper discharge tray 3 is lowered more than necessary. As a result, the uppermost surface of the stacked sheets becomes lower than the reference upper surface position, and the height relationship between the paper discharge unit 2 and the uppermost surface of the stacked sheets is not optimal. In addition, as shown in FIG. 8, there may be a gap in the height direction between the stacked sheets and the lower end of the end fence 7 (lower ends of the protrusions 7a and 7b). If such a gap is generated, the paper P may slip through the gap. As a result, the paper discharge alignment performance decreases.

  For example, as shown in FIG. 9, the same problem occurs when the paper P is placed on the stacked paper on the paper discharge tray 3 in a curled posture.

  On the other hand, in the paper discharge device 1 according to the present embodiment, as described above, it is possible to prevent the paper discharge table 3 from being lowered more than necessary, and thus it is possible to suppress a decrease in paper discharge alignment performance.

  Further, in the paper discharge device 1, since the lowering of the paper discharge table 3 is stopped when the upper surface detection sensor 9 is turned off or when the paper discharge table 3 is lowered by a specified lowering amount, a necessary lowering amount is secured. However, it is possible to avoid the discharge table 3 from being lowered more than necessary.

  In the paper discharge device 1, a lean detection sensor 10 is installed, and using the detection result, it is determined whether there is a stacking failure due to the lean of the paper P. Thereby, in the paper discharge device 1, it is possible to easily detect a stacking failure due to the leaning of the paper P on the paper discharge tray 3.

  In the paper discharge device 1, a lean detection sensor 10 is disposed so as to satisfy H2 ≦ H1. As a result, without the lean detection sensor 10 detecting the lean of the paper P, the paper discharge table 3 is lowered until a height gap is generated between the stacked paper on the paper discharge table 3 and the lower end of the end fence 7. Can be prevented.

  When the sheet P is leaned, the upper surface detection sensor 9 is turned on, and the lowering operation of the sheet discharge table 3 is performed. If H2> H1, even if the sheet P is leaned, the leaning detection sensor 10 does not detect it, but the sheet discharge table 3 is lowered, and the stacked sheets and the end fence 7 on the sheet discharge table 3 are moved. There is a risk that the paper discharge tray 3 will be lowered until a gap in the height direction is formed between the lower end of the paper discharge tray 3 and the lower end. By setting H2 ≦ H1, it is possible to detect a stacking failure due to the leaning of the paper P before the paper discharge tray 3 is lowered too much as described above.

  Further, when the paper discharge device 1 determines that a stacking failure due to the leaning of the paper P has occurred, the jogger operation of the side fences 5A and 5B, the end fence 7 and the paper discharge table 3 is executed. Thereby, the stacking failure of the paper P on the paper discharge tray 3 can be solved.

  Further, step S3 in FIG. 4 may be omitted. That is, the counting of the number of discharged sheets is started from the time when the upper surface detection sensor 9 is turned on, and when the counted number Cn1 becomes the specified number N1 while the upper surface detection sensor 9 is turned on, the lowering operation of the paper discharge table 3 is performed. May be executed. Even in this case, it is possible to prevent the discharge tray 3 from starting to descend before the posture of the paper P discharged onto the discharge tray 3 is adjusted, and to lower the discharge tray 3 more than necessary. However, by providing the specified time T, it is possible to more reliably suppress the lowering of the paper discharge table 3 before the posture of the paper P discharged onto the paper discharge table 3 is not adjusted.

  Further, the control unit 11 determines that a value H3 obtained by subtracting the total thickness of the paper P corresponding to the number of discharged paper sheets from the total amount of lowering of the paper discharge tray 3 from the start of the paper discharge operation is the reference upper surface position and the end fence. 7 may be stopped when the height difference H1 from the lower end of 7 is larger. H3 is larger than H1 when the discharge tray 3 is lowered more than necessary and a gap in the height direction is generated between the stacked sheets on the discharge tray 3 and the lower end of the end fence 7. It means that there is. In this case, the control unit 11 stops the paper discharge operation, so that the paper P can be prevented from slipping under the end fence 7.

  Moreover, in the said embodiment, although the jogger operation | movement of the side fences 5A and 5B, the end fence 7, and the paper discharge stand 3 was performed, you may abbreviate | omit any one or two of these.

  In the above embodiment, the number of discharged sheets is counted based on ON / OFF of the discharge sensor 23. However, the number of discharged sheets may be determined based on the time corresponding to the sheet size.

  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.

DESCRIPTION OF SYMBOLS 1 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 Leak detection sensor 11 Control part

Claims (6)

A paper discharge tray on which the discharged paper is stacked;
An end fence that is suspended above the paper discharge tray and regulates the front end position of the paper discharged to the paper discharge tray;
An elevating drive unit for elevating and lowering the discharge table;
A first detection unit that detects the presence or absence of a sheet at a first reference position, which is a reference of the height position of the uppermost surface of the sheets stacked on the sheet discharge table;
A control unit that controls the lowering drive unit to perform the lowering operation of the discharge table when the number of discharged sheets reaches a specified number in a state in which the first detection unit detects a sheet during the paper discharge operation; A paper discharge device comprising:   2. The control unit according to claim 1, wherein the control unit starts counting the number of discharged sheets to the specified number after a lapse of a specified time from when the first detection unit is in a state of detecting a sheet. Paper discharge device.   The control unit discharges the sheet when the first detection unit is in a state in which the sheet is not detected in the lowering operation of the sheet discharge table or by a specified lowering amount that is equal to or greater than the total thickness of the specified number of sheets. The paper discharge device according to claim 1 or 2, wherein the lowering of the paper discharge table is stopped when the table is lowered. The first reference position is higher than the lower end of the end fence;
The control unit obtains a value obtained by subtracting the total thickness of the sheet for the number of discharged sheets from the total amount of lowering of the discharge table from the start of the discharge operation. The paper discharge device according to any one of claims 1 to 3, wherein the paper discharge operation is stopped when a difference in height from the lower end becomes larger. A second detector for detecting the presence or absence of paper at a second reference position that is higher than the first reference position;
5. The paper discharge apparatus according to claim 1, wherein the control unit determines whether or not there is a stacking failure of sheets using a detection result of the second detection unit.   The height difference between the second reference position and the first reference position is equal to or less than a height difference between the first reference position and a lower end of the end fence. Paper discharge device.