JP2020015609A - Paper discharge device - Google Patents

Abstract

To increase efficiency in transporting paper bundles, in a paper discharge device having plural conveyance units.SOLUTION: A paper discharge device 1 includes: a first conveyor 10 (a first conveyance unit) for conveying a paper bundle PB consisting of multiple sheets of stacked paper P, in a conveyance direction D to a downstream side; a second conveyor 20 (a second conveyance unit) capable of conveying the paper bundle PB conveyed from the first conveyor 10, in the conveyance direction D to the downstream side and in the conveyance direction D to an upstream side; and a control unit 91 for controlling a first conveyor transport drive unit 40 and a second conveyor transport drive unit 50. The control unit 91 controls the second conveyor transport drive unit 50, so that the paper bundle PB stacked on the second conveyor 20 is conveyed in the conveyance direction D to the upstream side.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a sheet discharge device that conveys a stacked sheet bundle.

  2. Description of the Related Art Conventionally, as a paper discharge device disposed on a paper discharge side of a printing device, a paper discharge device including a belt conveyor on which paper discharged from the inside of the printing device is stacked, and conveying the paper by the belt conveyor is known. (For example, see Patent Document 1).

JP-A-9-301627

  By the way, the transport unit such as the above-described belt conveyor transports a sheet bundle including a plurality of sheets when sheets are sequentially stacked and a print job is completed or when the number of stacked sheets reaches a predetermined number. .

  Further, when a plurality of transport units are arranged in the paper discharge device and the plurality of transport units convey a sheet bundle while delivering the same, the lengths of the respective transport units in the transport direction are different from each other or the transport direction of each sheet bundle is different. May differ from each other, a useless space where the sheet bundle is not arranged on the upstream side in the transport direction in the transport unit may occur.

  When such a space occurs, it is impossible to pack a sheet bundle newly conveyed from the upstream side of the space into a sheet bundle conveyed in advance and convey the sheet bundle. For this reason, for example, the above-mentioned space may be generated in the transport unit capable of stacking a plurality of sheet bundles, so that the transport unit may not be able to receive the newly transported sheet bundle. As described above, if a useless space is generated on the upstream side in the transport direction in the transport unit, the transport efficiency of the sheet bundle is reduced.

  SUMMARY OF THE INVENTION It is an object of the present invention to increase the transport efficiency of a bundle of sheets in a sheet discharge device having a plurality of transport units.

  In one aspect, the paper discharge device includes a first transport unit configured to transport a plurality of stacked paper bundles to a downstream side in a transport direction, and a paper bundle transported from the first transport unit. A second transport unit capable of transporting downstream in the transport direction and upstream in the transport direction, a first transport drive unit that drives the first transport unit, a second transport drive unit that drives the second transport unit, A control unit that controls a first transport drive unit and the second transport drive unit, wherein the control unit transports the sheet bundle loaded on the second transport unit to an upstream side in the transport direction. The second transport driving unit is controlled.

  According to the above aspect, in the paper discharge device including the plurality of transport units, the transport efficiency of the paper bundle can be increased.

FIG. 1 is a configuration diagram illustrating a printing system including a sheet discharging device according to an embodiment. FIG. 3 is a diagram illustrating a control configuration of a sheet discharging device according to one embodiment. 5 is a flowchart for explaining an example of sheet bundle conveyance control according to one embodiment. FIGS. 4A to 4C are explanatory diagrams illustrating an example of conveyance control of a sheet bundle according to an embodiment. 9 is a table illustrating a relationship between stacked sheet information and intervals between sheet bundles.

  Hereinafter, a paper discharge device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram illustrating a printing system 100 including a paper discharge device 1 according to an embodiment.

  The printing system 100 illustrated in FIG. 1 includes a first printing device 110, a first intermediate device 120, a second printing device 130, a second intermediate device 140, and the sheet discharging device 1.

  In the printing system 100, when one-sided printing is performed on the paper P, the first printing device 110 or the second printing device 130 performs one-sided printing. When double-sided printing is performed on the paper P, for example, the first printing device 110 performs front side printing, and the second printing device 130 performs back side printing. In FIG. 1, the transport paths R1, R2-1, R2-2, R3, R4-1, and R4-2 of the sheet P are indicated by broken lines.

  The first printing device 110 includes a paper feed table 111, a scraper roller 112, a pickup roller 113, a registration roller pair 114, a printing unit 115, a suction conveyance unit 116, and a paper discharge roller pair 117.

Sheets P before printing are stacked on the sheet feeding table 111.
The scraper roller 112 is a feed roller that feeds and transports the uppermost sheet P among the sheets P stacked on the sheet feeding table 111.

  The pickup roller 113 conveys the sheet P fed by the scraper roller 112.

  The registration roller pair 114 conveys the sheet P after the sheet P is abutted for skew correction.

  The printing unit 115 has, for example, a line head type inkjet head (not shown) for each color used for printing. The printing method of the printing unit 115 may be a printing method other than the inkjet printing method.

  The suction conveyance unit 116 is arranged to face the printing unit 115. The suction conveyance unit 116 conveys the sheet P by a belt while adsorbing the sheet P.

  The discharge roller pair 117 discharges the paper P from the first printing device 110 by transporting the paper P.

  The first intermediate device 120 includes a transport roller pair 121, a switchback roller pair 122, and a transport roller pair 123.

  The transport roller pair 121 transports the sheet P discharged from the first printing device 110 by the discharge roller pair 117 of the first printing device 110. The paper P transported by the transport roller pair 121 is fed from a straight transport path R1 continuing from the first printing device 110 to a reverse transport path R2-1 for reversing the sheet P or a straight transport without reversing the sheet P by a switching mechanism (not shown). The transport is switched to the route R2-2.

  The switchback roller pair 122 is rotatable in both forward and reverse directions, and switches back the paper P in the reverse transport path R2-1 and transports the paper P toward the transport roller pair 123.

  The transport roller pair 123 transports the sheet P transported from the reverse transport path R2-1 or the straight transport path R2-2 to the straight transport path R3 following the second printing device 130.

  The second printing device 130 includes a pair of registration rollers 131, a printing unit 132, a suction conveyance unit 133, and a pair of discharge rollers 134.

  The registration roller pair 131 conveys the sheet P after the sheet P is abutted for skew correction.

  The printing unit 132 has, for example, a line head type inkjet head (not shown) for each color used for printing. The printing method of the printing unit 132 may be a printing method other than the inkjet printing method.

  The suction conveyance section 133 is arranged to face the printing section 132. The suction conveyance unit 133 conveys the sheet P by a belt while adsorbing the sheet P.

  The paper discharge roller pair 134 discharges the paper P from the second printing device 130 by transporting the paper P.

  The second intermediate device 140 includes a transport roller pair 141, a switchback roller pair 142, and a transport roller pair 143.

  The transport roller pair 141 transports the sheet P discharged from the second printing device 130 by the discharge roller pair 134 of the second printing device 130. The sheet P conveyed by the pair of conveying rollers 141 has a straight conveying path R3 continuing from the second printing apparatus 130 and a reversing conveying path R4-1 for reversing the sheet P or a straight conveying method for not reversing the sheet P by a switching mechanism (not shown). The transport is switched to the route R4-2.

  The switchback roller pair 142 is rotatable in both forward and reverse directions, and switches back the paper P in the reverse transport path R4-1 and transports the sheet P to the transport roller pair 143.

  The transport roller pair 143 discharges the sheet P transported from the reverse transport path R4-1 or the straight transport path R4-2 from the second intermediate device 140.

FIG. 2 is a diagram illustrating a control configuration of the sheet discharging device 1.
As illustrated in FIG. 1, the paper discharge device 1 includes a first conveyor 10 as an example of a first transport unit, a second conveyor 20 as an example of a second transport unit, and a second conveyor 20 as an example of a third transport unit. 3 conveyor 30. As shown in FIG. 2, the paper discharge device 1 includes a first conveyor transport driving unit 40, a second conveyor transport driving unit 50, a third conveyor transport driving unit 60, and a first conveyor lifting driving unit 70. , A sensor 80, a control unit 91, a storage unit 92, and an interface unit 93.

  The sheet discharging device 1 is disposed in a printing system 100 including a first printing device 110 and a second printing device 130, which are examples of a plurality of printing devices. What is necessary is just to arrange | position to the apparatus which performs. Further, the paper discharge device 1 is disposed adjacent to the second intermediate device 140, but may be disposed adjacent to the second printing device 130 without passing through the second intermediate device 140. Further, the paper discharge device 1 may be a paper discharge device integrally including the second intermediate device 140.

  As shown in FIG. 1, the first conveyor 10 has a belt 11 and rollers 12 and 13.

  The belt 11 is stretched between the rollers 12 and 13. As described above, the sheet P discharged from the second intermediate device 140, that is, the printed sheet P is stacked on the belt 11. As described above, the sheets P discharged from the printing devices (the first printing device 110 and the second printing device 130) are sequentially stacked on the first conveyor 10 (belt 11). That is, the first conveyor 10 also functions as a paper discharge tray. However, the first transport unit (first conveyor 10) of the present embodiment may be a transport unit (conveyor) that receives a sheet bundle from a transport unit (conveyor) that functions as a sheet discharge table.

  The belt 11 (first conveyor 10) conveys a sheet bundle PB, which is a plurality of sheets P, to the downstream side in the conveyance direction D at a timing when the control unit 91, which will be described later, controls the first conveyor conveyance driving unit 40. I do.

  One of the rollers 12 and 13 is a driving roller to which power is transmitted from a first conveyor transport driving unit 40 described later, and the other is a driven roller.

The second conveyor 20 has a belt 21, rollers 22 and 23, and a mounting table 24.
The belt 21 is stretched between the rollers 22 and 23. Further, the belt 21 is disposed downstream of the belt 11 of the first conveyor 10 in the transport direction D. Then, the belt 21 (second conveyor 20) conveys the sheet bundle PB conveyed from the first conveyor 10 to the downstream side in the conveyance direction D. Although described in detail later, the second conveyor 20 can also transport the sheet bundle PB to the upstream side in the transport direction D.

  One of the rollers 22 and 23 is a driving roller to which power is transmitted from a second conveyor conveyance driving unit 50 described later, and the other is a driven roller.

  The installation table 24 is installed so that the height of the belt 21 is adjusted to the height of the belt 11 during transportation.

  The third conveyor 30 has a belt 31, rollers 32 and 33, and a mounting table 34, similarly to the second conveyor 20.

  The belt 31 is arranged downstream of the belt 11 of the second conveyor 20 in the transport direction D. The belt 31 (the third conveyor 30) conveys the sheet bundle PB conveyed from the second conveyor 10 to, for example, the center of the belt 31 in the conveyance direction D. Thereafter, the sheet bundle PB is received by the user. Note that a fourth conveyor may be arranged further downstream of the third conveyor 30 in the transport direction D. In this case, the third conveyor 30 conveys the sheet bundle PB to the fourth conveyor. Further, the third conveyor 30 may be a trolley or the like in which a conveying member such as a roller is arranged on the mounting surface of the sheet bundle PB. In this case, a third conveyor transport driving unit 60 described later is omitted. Further, in a case where the third conveyor 30 is disposed in a device different from the paper discharge device 1, the third conveyor 30 may be omitted in the paper discharge device 1.

  Here, since the first conveyor 10, the second conveyor 20, and the third conveyor 30 have the belts 11, 21, and 31, they can be said to be belt conveyors, but may be other conveyance units such as a roller conveyor. Also, in FIG. 1, the first conveyor 10 is accommodated in the housing and the second conveyor 20 and the third conveyor 30 are not accommodated in the housing, but the first conveyor 10 and the second conveyor 20 or all of the first conveyor 10, the second conveyor 20, and the third conveyor 30 may be housed in the housing, or not all may be housed in the housing.

  Further, a single sheet bundle PB is stacked on the first conveyor 10 and the third conveyor 30, while a plurality of sheet bundles PB can be stacked on the second conveyor 20. However, the second conveyor 20 may be capable of stacking only a single sheet bundle PB, or the first conveyor 10 and the third conveyor 30 may be capable of stacking a plurality of sheet bundles PB.

  The first conveyor transport drive unit 40 shown in FIG. 2 is an example of a first transport drive unit (actuator) that drives the first conveyor 10 (first transport unit). The second conveyor transport drive unit 50 is an example of a second transport drive unit (actuator) that drives the second conveyor 20 (second transport unit). The third conveyor transport drive unit 60 is an example of a third transport drive unit (actuator) that drives the third conveyor 30 (third transport unit). The first conveyor transport drive unit 40, the second conveyor transport drive unit 50, and the third conveyor transport drive unit 60 are, for example, motors.

  The first conveyor lifting drive unit 70 is an actuator for moving the first conveyor 10 between an upper end initial position and a lower end transfer position, and is, for example, a motor. Under the control of the control unit 91, the first conveyor elevating drive unit 70 lowers the first conveyor 10 as the sheets P are stacked on the first conveyor 10.

  The sensor 80 includes a sensor for detecting the height of the first conveyor 10, a sensor for detecting the position of the sheet bundle PB stacked on the first conveyor 10 in the transport direction D, and a sensor for detecting the position of the sheet bundle PB stacked on the second conveyor 20. It may include a sensor for detecting the position in the transport direction D, a sensor for detecting the position in the transport direction D of the sheet bundle PB stacked on the third conveyor 30, and the like. Further, the sensor 80 may include an airflow detection sensor that detects an airflow that is an example of environmental information of an environment in which the paper discharge device 1 is installed, a humidity detection sensor that detects a humidity that is another example of environmental information, and the like. . These airflow detection sensor and humidity detection sensor function as an example of an environment information detection unit that detects environment information. The environment information detected in this way is acquired by the control unit 91. Note that environmental information such as airflow and humidity may be detected by a sensor of a device other than the sheet discharging device 1 and acquired by the control unit 91 via the interface unit 93.

  The control unit 91 includes a processor (for example, a central processing unit (CPU)) that functions as an arithmetic processing unit that controls the operation of the entire sheet discharging device 1, and includes a first conveyor transport driving unit 40, a second conveyor transport driving unit 50, and the like. Controls the operation of each unit. The control unit 91 is not limited to a single control unit, and controls, for example, a control unit that controls the first conveyor transport driving unit 40 and the first conveyor elevating drive unit 70, and a second conveyor transport driving unit 50. The control unit and the control unit that controls the third conveyor transport driving unit 60 may be separately arranged.

  The storage unit 92 is, for example, a ROM (Read Only Memory) which is a read-only semiconductor memory in which a predetermined control program is recorded in advance, and a work storage area as necessary when the processor executes various control programs. A random access memory (RAM), which is a semiconductor memory that can be written and read as needed, is used.

  The interface unit 93 exchanges various information with an external device such as a control unit of the printing system 100. For example, the interface unit 93 receives, from the control unit of the printing system 100, information that printing of the print job has been completed. The first conveyor up / down drive unit 70 is controlled so as to lower the first conveyor 10 to the transport position at the lower end. Further, the control unit 91 controls the first conveyor transport driving unit 40 so that the first conveyor 10 transports the sheet bundle PB.

  Alternatively, when the number of sheets P stacked on the first conveyor 10 has reached a predetermined number (for example, the sensor that detects the height of the first When it is detected that the first conveyor 10 descends and is at the lower end conveyance position as the sheets P are stacked on the conveyor 10), the first conveyor 10 conveys the sheet bundle PB by the first conveyor 10. The transport drive unit 40 is controlled.

FIG. 3 is a flowchart for explaining an example of transport control of the sheet bundle PB.
FIGS. 4A to 4C are explanatory diagrams for explaining an example of transport control of the sheet bundle PB.

  Each process shown in FIG. 3 is performed by the control unit 91 shown in FIG. 2, and mainly relates to control of the second conveyor transport driving unit 50 that drives the second conveyor 20. The process illustrated in FIG. 3 is a process that is started, for example, when the sheet bundle PB4 on the first conveyor 10 illustrated in FIG.

  4A to 4C, “a” to “h” are all lengths in the transport direction D, “a” is the length of the second conveyor 20, and “b” is the length of the sheet bundle PB3. Length, “c” is the length of the sheet bundle PB2, “d” is the length of the sheet bundle PB1, “e” is the interval between the sheet bundle PB2 and the sheet bundle PB3, and “f” is the sheet bundle PB1 and the sheet bundle. The distance from PB2, “g” represents the length of the sheet bundle PB4, and “h” represents the distance between the sheet bundle PB3 and the sheet bundle PB4. Note that the sheet bundle PB1, the sheet bundle PB2, the sheet bundle PB3, and the sheet bundle PB4 are arranged in this order from the downstream side in the transport direction D.

  First, when the controller 91 conveys the sheet bundle PB4 stacked on the first conveyor 10 shown in FIG. 4A to the second conveyor 20, the controller 91 transfers the sheet bundle PB1 stacked on the second conveyor 20 to the third conveyor 30. (Step S1). Specifically, the control unit 91 determines whether “a− (b + c + d + e + f) ≦ g + h”.

  The left side of “a− (b + c + d + e + f) ≦ g + h” is the length of the space on the second conveyor 20 downstream of the sheet bundles PB1, PB2, and PB3 in the transport direction D, and the right side is the length of the sheet bundle PB4. And the assumed distance between the sheet bundle PB4 and the sheet bundle PB3.

  The controller 91 does not need to transport the sheet bundle PB1 loaded on the second conveyor 20 to the third conveyor 30 even if the sheet bundle PB4 loaded on the first conveyor 10 is transported to the second conveyor 20. (Ie, “a− (b + c + d + e + f)> g + h”) (step S1: NO), the first and second conveyor transport driving units 40 and 50 are controlled to control the sheet bundles PB1 and PB2. , PB3, and PB4 are driven to the downstream side in the transport direction D, and the first conveyor 10 and the second conveyor 20 are driven so as to be loaded on the second conveyor 20 (step S2). Then, the control unit 91 ends the processing illustrated in FIG.

  The control unit 91 determines that when the sheet bundle PB4 loaded on the first conveyor 10 is transported to the second conveyor 20, the sheet bundle PB1 loaded on the second conveyor 20 needs to be transported to the third conveyor 30. If it is (Step S1: YES), the first conveyor transport drive unit 40, the second conveyor transport drive unit 50, and the third conveyor transport drive unit 60 are controlled to move the sheet bundles PB1, PB2, PB3, and PB4 in the transport direction D. The normal rotation of the first conveyor 10, the second conveyor 20, and the third conveyor 30 is started so that the sheet bundle PB1 is conveyed to the downstream side and stacked on the third conveyor 30 (step S3).

  The control section 91 performs this forward drive until the transport distance of the second conveyor 20 reaches “a− (b + c + d + e + f) + (d + f)” (step S4). That is, the control unit 91 transfers the sheet bundle PB1 to the third conveyor 30 as shown in FIG. 4B, and performs the forward rotation drive until the rear end of the sheet bundle PB1 is completely transferred to the third conveyor 30. Do.

  After the normal rotation drive ends (step S4: YES), that is, after the second conveyor 20 has passed the sheet bundle PB to the third conveyor 30, the control unit 91 performs the second rotation as shown in FIG. The control of the reverse rotation drive for transporting the second conveyor 20 in the reverse direction to the upstream in the transport direction D so as to narrow the space S on the upstream side in the transport direction D of the sheet bundles PB2, PB3, and PB4 stacked on the two conveyors 20 This is performed for the conveyor transport drive unit 50 (Step 5).

  The control unit 91 performs the above-described reverse rotation drive until the reverse transport distance of the second conveyor 20 reaches “a− (b + c + g + e + h)” (Step S6). Thereby, the sheet bundle PB4 on the upstream side in the transport direction D stacked on the second conveyor 20 is transported to the end on the upstream side in the transport direction D on the second conveyor 20.

  When the reverse rotation drive ends (step S6: YES), the control unit 91 ends the process illustrated in FIG.

  In the flowchart of FIG. 3, the reverse rotation drive process (step S5) of the second conveyor 20 is performed by setting the sheet bundle PB4 on the upstream side in the transport direction D loaded on the second conveyor 20 to the upstream side in the transport direction D on the second conveyor 20. , The length of the space S in the transport direction D becomes zero (the space S disappears). However, in the reverse rotation drive, the space S only needs to be slightly narrowed, and the sheet bundle PB4 loaded on the second conveyor 20 does not have to be transported to the upstream end in the transport direction D.

  In the flowchart of FIG. 3, the process illustrated in FIG. 3 ends after the process of step S2. In the state where the sheet bundles PB1, PB2, PB3, and PB4 are stacked on the second conveyor 20 in step S2, 4B, the second conveyor 20 transfers the sheet bundle PB1 to the third conveyor 30. Therefore, even after the second conveyer 20 transfers the sheet bundle PB1 to the third conveyer 30, similarly to the processing in step S5 described above, the control unit 91 continues the second conveyer 20 as shown in FIG. Control of reverse rotation driving the second conveyor 20 in the reverse direction to the upstream side in the transport direction D so as to reduce the space S on the upstream side in the transport direction D of the sheet bundles PB2, PB3, and PB4 stacked on the second conveyor. This may be performed on the driving unit 50.

  Further, the control unit 91 can load the sheet bundle PB4 loaded on the first conveyor 10 on the second conveyor 20 in step S1 before step S2 described above (“a− (b + c + d + e + f)> g + h”). ) (Step S1: NO). Therefore, the relation of “a− (b + c + d + e + f) = g + h” is not established. Therefore, after the sheet bundles PB1, PB2, PB3, and PB4 are conveyed downstream in the conveyance direction D so as to be stacked on the second conveyor 20 in step S2, the sheet bundles PB4 on the second conveyor 20 are further upstream in the conveyance direction D than the sheet bundle PB4. On the side, there is a space similar to the space S described above. Therefore, the control unit 91 may control the second conveyor transport driving unit 50 to control the reverse rotation similarly to the above-described step S5 so as to reduce the space. In this way, the control of the reverse rotation drive is not limited to after the second conveyor 20 has passed the sheet bundle PB to the third conveyor 30.

  Alternatively, the control unit 91 may perform the above-described reverse drive every time the second conveyor 20 transfers the sheet bundle PB to the third conveyor 30. The fact that the second conveyor 20 has passed the sheet bundle PB to the third conveyor 30 means that, for example, the sensor for detecting the position of the sheet bundle PB stacked on the second conveyor 20 in the transport direction D, the third conveyor 30 Can also be detected by a sensor or the like that detects the position in the transport direction D of the sheet bundle PB stacked on the sheet bundle PB.

  In the present embodiment, the control unit 91 reverses the second conveyor 20 in the transport direction D upstream in order to transport the sheet bundle PB stacked on the second conveyor 20 in the transport direction D upstream. The control of the reverse rotation drive for the conveyance is performed on the second conveyor conveyance drive unit 50. However, in order to transport the sheet bundle PB stacked on the second conveyor 20 to the upstream side in the transport direction D, the reverse rotation drive does not necessarily have to be performed. For example, the second conveyor 20 circulates (circulates) between a position where the sheet bundle PB is received from the first conveyor 10 and a position where the sheet bundle PB is transferred to the third conveyor 30, and is transferred by a transfer member (not shown) at the transfer position. When the delivery of the sheet bundle PB to the third conveyor 30 is performed, after the sheet bundle PB is delivered to the third conveyor 30 and the normal rotation drive is performed without performing the reverse rotation drive, the second conveyor may be also controlled. 20 can be transported upstream in the transport direction D.

  By the way, when the first conveyor 10, the second conveyor 20, and the third conveyor 30 convey the sheet bundle PB, the conveyance speed of the sheet bundle PB at the time of constant speed conveyance, and the conveyance acceleration of the sheet bundle PB at the time of accelerated conveyance (Ie, a positive acceleration), and depending on the conveyance acceleration (ie, a negative acceleration) of the sheet bundle PB during decelerated conveyance, the stacked sheet information of the sheet bundle PB (for example, the type of the sheet P (the sheet type in FIG. 5), Depending on the size of the paper P (the paper size in FIG. 5), the direction of the paper P (the paper direction in FIG. 5), the number of stacked paper P (the number of stacked paper PB), etc., the likelihood of the paper bundle PB being broken is reduced. different. This paper collapse means, for example, a state in which the sheet P is shifted in the sheet bundle PB, or a state in which the sheet has dropped from the sheet bundle.

  Therefore, depending on the loading sheet conditions, some of the sheets P of the sheet bundle PB are shifted beyond the interval of the sheet bundle PB such as “e”, “f”, and “h”, and two adjacent sheets P The sheets P of the bundle PB may come into contact with each other. On the other hand, if the interval is too wide, the transport efficiency of the sheet bundle PB will be deteriorated accordingly. Therefore, the control unit 91 determines the interval between the sheet bundles PB based on the stacked sheet information of the sheet bundle PB, and based on the determined intervals, the first conveyor transport driving unit 40 and the second conveyor transport driving unit. The control unit 50 and the third conveyor transport driving unit 60 may be controlled.

  The control unit 91 controls the sheet bundle PB based on the above-described stacked sheet information only when the user sets the setting for performing the process of determining the interval of the sheet bundle PB based on the stacked sheet information. May be determined.

  Here, an example in which the control unit 91 determines the interval of the sheet bundle PB by referring to the table illustrated in FIG. 5 stored in the storage unit 92 will be described.

  FIG. 5 is a table showing the relationship between the stacking sheet information (parameters) and the interval of the sheet bundle PB.

  First, in the table shown in FIG. 5, four types of paper type, paper size, paper direction, and number of paper sheets are included as the loaded paper information, but the table shown in FIG. 5 may include at least one loaded paper information. . The stacking sheet information is acquired by the control unit 91 based on a print job, for example.

  The paper type is, for example, plain paper having a relatively large basis weight (weight per unit area), thin paper having a relatively small basis, or the like. Since thin paper has a smaller basis weight than plain paper, if the paper size is the same, the weight is reduced, and the frictional force against sliding is reduced. Therefore, it can be said that thin paper is more likely to collapse than plain paper.

  Note that the paper type may include thick paper having a larger basis weight than plain paper. Further, the paper type is not limited to the basis weight (thin paper or plain paper), and may be another paper type such as the material of the paper P. This is because the frictional force generated differs depending on the material of the paper P, and the likelihood of paper collapse also differs.

  The paper size is, for example, A3 (297 × 420 mm), A4 (210 × 297 mm), or the like. A4, which is smaller in size than A3, has a smaller contact area with the belts 11, 21, 31 of the first conveyor 10, the second conveyor 20, and the third conveyor 30 than A3, so that the frictional force becomes smaller. Therefore, it can be said that A4 is more likely to cause paper collapse than A3.

  The paper direction is a vertical direction in which the longitudinal direction of the paper P is parallel to the transport direction D, or a horizontal direction in which the longitudinal direction of the paper P is orthogonal to the transport direction D. In the horizontal direction, since the distance from the center of gravity to the overturning fulcrum is shorter than in the vertical direction, it can be said that paper collapse is more likely to occur in the horizontal direction.

  The number of sheets is, for example, 1 to 1000, 1001 to 2000, 2001 or more. The larger the number of stacked sheets, the higher the center of gravity. Therefore, 2001 or more sheets are most likely to be broken, and 1001 to 2000 sheets are most likely to be broken next, and 1 to 2000 sheets are most likely to be broken. It is unlikely to occur. In the table of FIG. 5, the number of sheets is divided into three ranges, but may be divided into four or more or two ranges.

  In the table of FIG. 5, intervals (G1 to G24 [mm]) corresponding to the above-described paper type, paper size, paper direction, and the number of paper sheets are defined. These intervals may be determined experimentally. For example, the intervals may be set to be wider as the loaded paper information includes information that easily causes paper collapse.

  For example, in the table of FIG. 5, paper collapse is most likely to occur when the paper type is “thin paper”, the paper size is “A4”, the paper direction is “landscape”, and the number of sheets is “2001 or more”. It is desirable that [mm] be the largest.

  Here, since the interval between the sheet bundles PB is the interval between two sheet bundles PB adjacent to each other, the sheet P of the sheet bundle PB that is transported earlier in the transport direction D downstream moves upstream in the transport direction D. The sheet P of the sheet bundle PB subsequently conveyed on the upstream side in the conveying direction D may be shifted on the downstream side in the conveying direction D. Therefore, when referring to the table in FIG. 5, the control unit 91 calculates a value obtained by adding the interval corresponding to one of the stacked sheet information of the two adjacent sheet bundles PB and the interval corresponding to the other stacked sheet information. May be determined as the interval of the sheet bundle PB.

  Note that, for the sheet bundle PB under the condition (for example, the sheet size B4) including the stacked sheet information that is not included in the table of FIG. 5, the interval of the sheet bundle PB may be determined based on the interval of the table of FIG. .

  For example, the paper size B4 (257 × 364 mm) is smaller than A3 (297 × 420 mm), but larger than A4 (210 × 297 mm), which is more likely to cause paper collapse than A3. Therefore, in such a case, the control unit 91 may determine the interval to be wider than the interval of A3 and narrower than the interval of A4, where other loaded sheet information such as the sheet type matches. For example, the control unit 91 may determine the interval of B4 so that other loaded paper information such as the paper type becomes an intermediate value between A3 and A4, or the area ratio of A3, A4, and B4. The interval of B4 may be determined such that the ratio of the intervals coincides with the interval.

  When the control unit 91 cannot acquire a part (for example, paper type) of the loaded paper information included in the table of FIG. 5 as the loaded paper information of the paper bundle PB, the paper type “plain paper” and other The interval corresponding to the acquired loading sheet information and the interval corresponding to the sheet type “thin paper” and the other acquired loading sheet information may be determined as the interval. That is, the control unit 91 may determine the interval of the sheet bundle PB based on a plurality of intervals corresponding to a part of the obtained stacked sheet information.

  In the above description, the example in which the control unit 91 determines the interval by referring to the table has been described. However, the control unit 91 performs the calculation based on the set value corresponding to the stacking sheet information to thereby determine the interval. May be determined. In this case, instead of determining and adding an interval for each single sheet bundle PB, a single operation may be performed using a set value corresponding to the stacked sheet information of two adjacent sheet bundles PB. Good.

  As an example, the reference interval (reference interval) is not changed in the case of the paper type “plain paper”, and the paper type “thin paper” which is more likely to cause paper collapse than “plain paper” is used. In this case, the interval is widened by multiplying the reference interval by a set value (a value greater than 1), or the interval is widened by adding the set value to the reference interval. The control unit 91 can determine the interval by performing such an operation for each piece of loaded sheet information.

  Note that the control unit 91 can also determine the interval by calculation without using the reference interval. For example, the interval can be determined by calculation by adding or multiplying the set values corresponding to each piece of loaded paper information.

  Further, the control unit 91 may determine the interval based on environmental information such as airflow and humidity of the environment in which the sheet discharging device 1 is installed, in addition to the above-described loaded sheet information.

  For example, it can be said that paper collapse is more likely to occur when the airflow is strong than when the airflow is weak. In addition, when the humidity is low, the weight of the paper P is smaller than when the humidity is high, so that it can be said that the paper P is likely to collapse. Therefore, the setting value corresponding to the environmental information may be set such that the interval becomes wider as the airflow becomes stronger or the humidity becomes lower.

  The control unit 91 can determine the interval by multiplying, adding, or subtracting the set value corresponding to the environment information to the interval obtained by referring to the table shown in FIG. 5, for example. it can. Further, as described above, when the control unit 91 performs the calculation using the set value corresponding to each piece of paper information without referring to the table, not only the set value corresponding to the paper sheet information but also the environment information The calculation may be performed using a set value corresponding to.

  In the present embodiment described above, the sheet discharge device 1 includes the first conveyor 10 which is an example of the first transport unit that transports the sheet bundle PB, which is the plurality of stacked sheets P, in the transport direction D downstream. The second conveyor 20, which is an example of a second conveyor capable of conveying the sheet bundle PB conveyed from the first conveyor 10 downstream in the conveyance direction D and upstream in the conveyance direction D, drives the first conveyor 10 A first conveyor driving unit 40, which is an example of a first conveyor driving unit, a second conveyor driving unit 50, which is an example of a second conveying driving unit that drives the second conveyor 20, and a first conveyor conveying driving unit 40 and a control unit 91 for controlling the second conveyor transport driving unit 50. The control unit 91 controls the second conveyor conveyance driving unit 50 so as to convey the sheet bundle PB stacked on the second conveyor 20 to the upstream side in the conveyance direction D.

  Therefore, by transporting the sheet bundle PB loaded on the second conveyor 20 to the upstream side in the transport direction D so as to narrow the space S on the upstream side in the transport direction D of the sheet bundle PB in the second conveyor 20, the first conveyor The sheet bundle PB newly conveyed from 10 can be conveyed while being packed into the sheet bundle PB conveyed in advance. Thus, for example, it is possible to prevent the second conveyer 20 from receiving the above-mentioned newly conveyed sheet bundle PB. Therefore, according to the present embodiment, the transport efficiency of the sheet bundle PB can be improved.

  Further, in the present embodiment, the control unit 91 determines the intervals between the plurality of sheet bundles PB (for example, “e”, “f”, and “f” shown in FIG. "H") is determined. Therefore, if the stacked sheet information of the stacked sheet bundle PB is a condition in which the sheet collapse is likely to occur, by increasing the interval as compared with the condition in which the sheet collapse is unlikely to occur, the two sheet bundles PB adjacent to each other are increased. It is possible to prevent the paper P from contacting between them. Further, it is possible to prevent the transport efficiency of the sheet bundle PB from being reduced as compared with the case where the interval is uniformly widened.

  In the present embodiment, the sheets P discharged from the printing apparatus are sequentially stacked on the first conveyor 10. As described above, in the present embodiment, by narrowing the space S on the upstream side in the transport direction D with respect to the sheet bundle PB on the second conveyor 20, the sheet bundle PB newly conveyed from the first conveyor 10 It is possible to prevent the two-conveyor 20 from being unable to receive. Therefore, it is easy to transfer the sheet bundle PB from the first conveyor 10 to the second conveyor 20. Therefore, it is possible to suppress the sheet bundle PB from staying on the first conveyor 10, and to suppress the printing apparatus from being unable to discharge the sheet P to cause a problem such as printing stop.

  In the present embodiment, the second conveyor 20 can stack a plurality of sheet bundles PB. This makes it easier for the second conveyor 20 to receive the sheet bundle PB from the first conveyor 10. Further, since the second conveyer 20 can stack a plurality of sheet bundles PB, the space S described above is easily widened, but the wide space can be narrowed as described above, so that the transport efficiency is further improved. be able to.

  It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the invention at the stage of implementation. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, all components described in the embodiments may be appropriately combined. Of course, various modifications and applications are possible without departing from the spirit of the invention. Hereinafter, the inventions described in the claims at the time of filing the application of the present application are additionally described.

[Appendix 1]
A first transport unit that transports a bundle of sheets as a plurality of stacked paper sheets to a downstream side in the transport direction;
A second transport unit capable of transporting the sheet bundle transported from the first transport unit downstream in the transport direction and upstream in the transport direction;
A first transport drive unit that drives the first transport unit;
A second transport drive unit that drives the second transport unit;
A control unit that controls the first transport drive unit and the second transport drive unit,
The sheet discharge device, wherein the control unit controls the second conveyance driving unit so as to convey the sheet bundle stacked on the second conveyance unit upstream in the conveyance direction.

[Appendix 2]
The sheet discharge device according to claim 1, wherein the control unit determines an interval between the plurality of sheet bundles based on the stacked sheet information of the sheet bundle.

[Appendix 3]
The sheet discharge device according to claim 1 or 2, wherein the sheets discharged from a printing device are sequentially stacked on the first transport unit.

REFERENCE SIGNS LIST 1 paper discharger 10 first conveyor 11 belts 12 and 13 rollers 20 second conveyor 21 belts 22 and 23 rollers 24 installation table 30 third conveyor 31 belt 32 and 33 rollers 34 installation table 40 first conveyor transport drive unit 50 second Conveyor conveyance drive unit 60 Second conveyor conveyance drive unit 70 First conveyor elevation drive unit 80 Sensor 91 Control unit 92 Storage unit 93 Interface unit 100 Printing system 110 First printing device 120 First intermediate device 130 Second printing device 140 Second Intermediate device P paper PB paper bundle S space

Claims (3)

A first transport unit that transports a bundle of sheets as a plurality of stacked paper sheets to a downstream side in the transport direction;
A second transport unit capable of transporting the sheet bundle transported from the first transport unit downstream in the transport direction and upstream in the transport direction;
A first transport drive unit that drives the first transport unit;
A second transport drive unit that drives the second transport unit;
A control unit that controls the first transport drive unit and the second transport drive unit,
The paper discharge device, wherein the control unit controls the second transport drive unit to transport the sheet bundle stacked on the second transport unit to an upstream side in the transport direction. The sheet discharge device according to claim 1, wherein the control unit determines an interval between the plurality of sheet bundles based on stacked sheet information of the sheet bundle. The paper discharge device according to claim 1, wherein the paper discharged from a printing device is sequentially stacked on the first transport unit.

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