Conveying device

Abstract

The invention provides a conveying device, which improves the conveying efficiency of the conveying device for conveying a medium in a conveying path including a circulation path. The conveyance device includes: a supply unit that supplies a medium; a transport unit that transports the medium on a transport path including a processing path that transports the medium to a processing unit that processes the medium, and a circulation path that reverses the medium that has passed through the processing unit and retransports the medium to the processing unit; and a control unit that adjusts, on the basis of the length of the medium in the conveyance direction, a conveyance condition including at least one of a supply start time at which the medium is supplied by the supply unit and a conveyance speed at which the medium is conveyed by the conveyance unit in the conveyance path. The control unit adjusts the conveyance condition on the basis of a longer length in the conveyance direction of a subsequent medium conveyed to the circulation path than a preceding medium conveyed to the circulation path, and maintains the conveyance condition of the preceding medium on the basis of a shorter length in the conveyance direction of the subsequent medium than the preceding medium.

Description

Technical Field

[0001] The present invention relates to a conveying device for conveying a medium in a conveying path including a circulation path. Background Art

[0002] In the past, an image forming apparatus is known that, when printing on both sides of a recording medium, supplies the recording medium at a timing where a predetermined interval is formed between the plurality of recording media in such a manner that a plurality of recording media can exist in a conveying path for conveying the recording medium (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 4893837 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In addition, when printing (processing) both sides of a paper (medium) as described above, the paper is turned over in the circulation path. Moreover, the conveying speed of the paper in the circulation path, the number of sheets of paper conveyed in the device, and the paper feeding time are different according to the length of the paper (the length in the conveying direction). Therefore, when a subsequent paper having a different length from the preceding paper is supplied, the conveying speed and the paper feeding time are set again, and the subsequent paper is supplied after all the preceding paper is discharged from the conveying path.

[0008] Therefore, in both the case of supplying subsequent paper longer than the preceding paper and the case of supplying subsequent paper shorter than the preceding paper, a waiting time is required until all the paper is discharged from the conveying path, and the conveying efficiency (productivity) decreases.

[0009] An object of the present invention is to improve the conveying efficiency of a conveying device that conveys a medium in a conveying path including a circulation path.

[0010] Solutions for solving problems

[0011] In one technical solution, a conveying device comprises: a supply unit that supplies a medium; a conveying unit that conveys the medium in a conveying path, the conveying path including a processing path for conveying the medium to a processing unit that processes the medium, and a circulation path for flipping the medium that has passed the processing unit and conveying it to the processing unit again; and a control unit that adjusts a conveying condition based on the length of the medium in a conveying direction, the conveying condition including at least one of a start time of supplying the medium by the supply unit and a conveying speed of the medium in the conveying path by the conveying unit, the control unit adjusting the conveying condition based on a length of the subsequent medium conveyed to the circulation path being longer in the conveying direction than the preceding medium conveyed to the circulation path, and maintaining the conveying condition of the preceding medium based on a length of the subsequent medium in the conveying direction being shorter in the conveying direction than the preceding medium.

[0012] Effects of the Invention

[0013] According to the above-described technical solution, it is possible to improve the conveying efficiency of the conveying device that conveys the medium in the conveying path including the circulation path. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing the internal structure of a printing device according to one embodiment.

[0015] Figure 2 This is a diagram showing a control structure of a printing device according to an embodiment.

[0016] Figure 3 This is a flowchart for explaining the paper feed reservation process according to one embodiment.

[0017] Figure 4 This is a flowchart for explaining a paper feeding process according to one embodiment.

[0018] Figure 5 This is a diagram for explaining the difference in the paper feed start timing between the comparative example (a) and the embodiment (b).

[0019] Figure 6 This is a diagram for explaining the timing of starting paper feeding according to one embodiment.

[0020] Description of Reference Numerals

[0021] 1. Printing device; 10. External paper supply unit; 20. Internal paper supply unit; 31. Positioning roller pair; 32. Accelerating conveying unit; 32a, 32b, 32c, Accelerating roller pair; 33. Constant speed conveying unit; 33a, 33b, 33c, Constant speed roller pair; 34. Reversing conveying unit (turning roller pair); 35. Re-feeding unit (re-feeding roller pair); 36. Paper discharge conveying unit (paper discharge roller pair); 37. Straight conveying unit (straight roller pair); 38, 39. Path switching unit; 40. Printing unit; 50. Printing conveying unit; 60. Paper discharge unit; 70. Conveying drive unit; 81. Control unit; 90. Discharging device; P. Paper; R. Conveying path; R1. Processing path; R2. Circulating path; R2a. Reversing path; R3. Paper discharge path; S. Paper detection sensor. DETAILED DESCRIPTION

[0022] Hereinafter, a mode in which a transport device according to an embodiment of the present invention is equipped in a printing device will be described with reference to the drawings as an example.

[0023] Figure 1 This is a diagram showing the internal structure of a printing device 1 according to an embodiment.

[0024] Figure 2 2 is a diagram showing a control structure of the printing device 1 .

[0025] like Figure 1 and Figure 2 As shown in FIG. 1 , the printing device 1 includes an external paper supply unit 10, an internal paper supply unit 20, a printing unit 40, a printing conveying unit 50, a paper discharge unit 60, and a paper detection sensor S. Figure 1 As shown in FIG. 1 , the printing device 1 includes a registration roller pair 31, an accelerating conveying unit 32, a constant speed conveying unit 33, a reversing conveying unit 34, a re-feeding unit 35, a paper discharge conveying unit 36, a straight conveying unit 37, a path switching unit 38, and a path switching unit 39. Figure 2 As shown, the printing device 1 includes a transport driving unit 70 , a control unit 81 , a storage unit 82 , and an interface unit 83 .

[0026] The printing device 1 is an example of a processing device including a processing unit and a conveying device, and includes a printing unit 40 as a processing unit, and includes components of the printing device 1 other than the printing unit 40 as a conveying device. In addition, the processing unit may be an inspection unit that performs an image inspection of a medium, a pasting unit that pastes a seal on a medium, a drying unit that dries the medium, etc. For example, when the processing unit is an inspection unit, the processing device can be said to be an inspection device.

[0027] exist Figure 1In the figure, the solid line indicates the processing path (printing path) R1 of the paper P that continues from the external paper feed unit 10 or the internal paper feed unit 20, the double-dashed line indicates the path that continues from the circulation path R2 for double-sided printing located above the printing unit 40 to the paper discharge path R3, and the dotted line indicates the reversing path R2a of the circulation path R2. These processing path R1, circulation path R2, and paper discharge path R3 constitute the transport path R. In other words, the transport path R includes the processing path R1, the circulation path R2, and the paper discharge path R3.

[0028] Paper P is an example of a medium. In this specification, paper supply is an example of supply, and paper discharge is an example of discharge. Therefore, paper supply can be replaced by supply, and paper discharge can be replaced by discharge. The medium may be a sheet formed of a raw material other than paper, an article having a folded portion such as an envelope, etc.

[0029] The external paper supply unit 10 is configured to be exposed to the outside of the printing device 1. The external paper supply unit 10 includes: a paper supply tray 11, which is loaded with, for example, A3-sized paper P before printing; and a paper supply roller 12, which releases and conveys the topmost paper P among the multiple papers P loaded on the paper supply tray 11. Although not shown in the figure, the external paper supply unit 10 is also provided with an actuator such as a motor for driving the paper supply tray 11 and the paper supply roller 12. The paper supply roller 12 is an example of a conveyor, and a belt may be used instead of a roller. In addition, the external paper supply unit 10 is an example of a supply unit that supplies a medium (paper P) to a processing unit (printing unit 40).

[0030] The internal paper feed unit 20 includes a first paper feed unit 21, a second paper feed unit 22, and a third paper feed unit 23. The first paper feed unit 21, the second paper feed unit 22, and the third paper feed unit 23 are arranged in this order from the top inside the printing device 1. The first paper feed unit 21, the second paper feed unit 22, and the third paper feed unit 23 respectively include: paper feed trays 21a, 22a, and 23a, which are loaded with, for example, A4-sized paper P before printing; and paper feed rollers 21b, 22b, and 23b, which feed and convey the topmost paper P among the plurality of paper P loaded on the paper feed trays 21a, 22a, and 23a. Although not shown in the figure, an actuator such as a motor that drives the paper feed rollers 21b, 22b, and 23b is also arranged in the internal paper feed unit 20. The paper feed rollers 21b, 22b, and 23b are examples of conveyors, and belts may be used instead of rollers. The internal paper feed unit 20 is an example of a supply unit that supplies a medium (paper P) to a processing unit (printing unit 40 ), similarly to the external paper feed unit 10 .

[0031] The registration roller pair 31 is arranged on the upstream side of the conveying direction of the printing section 40 and the printing and conveying section 50 in the processing path R1 that continues from the external paper feeding section 10 or the internal paper feeding section 20. The paper P conveyed toward the printing section 40 hits the registration roller pair 31. Thus, the registration roller pair 31 corrects the skewness of the paper P and conveys the paper P while holding it. A paper detection sensor S is arranged on the downstream side of the registration roller pair 31 in the conveying direction and on the upstream side of the printing section 40.

[0032] The accelerating conveying section 32 can accelerate the paper P to the conveying speed of the constant speed conveying section 33 on the circulation path R2 and convey it. The accelerating conveying section 32 has accelerating roller pairs 32a, 32b, and 32c that convey the paper P while clamping it. The accelerating roller pairs 32a and 32b can also be called ascending conveying rollers because they convey the paper P upward. In addition, the accelerating roller pair 32c can also be called horizontal conveying rollers because it conveys the paper P horizontally.

[0033] The constant speed conveying unit 33 conveys the paper P at a variable constant speed at a position downstream of the accelerating conveying unit 32 in the circulation path R2 in the conveying direction. The constant speed conveying unit 33 includes constant speed roller pairs 33a, 33b, and 33c that convey the paper P while sandwiching it.

[0034] The reversing conveying section 34 is a pair of switchback rollers that reverses the front and back sides of the paper P while pinching the paper P in the reversing path R2a provided downstream of the constant speed conveying section 33 in the conveying direction.

[0035] The re-feeding unit 35 re-feeds the reversed paper P toward the printing unit 40 at a position downstream of the constant speed conveying unit 33 in the circulation path R2 in the conveying direction. The re-feeding unit 35 conveys the paper P at a reduced speed when the paper P hits the registration roller pair 31 .

[0036] The paper discharge conveying section 36 is a pair of paper discharge rollers that convey the paper P toward the paper discharge section 60 while sandwiching the paper P in the paper discharge path R3 that is connected to the circulation path R2 and located upstream in the conveying direction of the reversing path R2 a.

[0037] The straight conveying section 37 is disposed at the downstream end of the processing path R1 in the conveying direction, and is a straight roller pair that holds the paper P and conveys it toward a connected paper discharge section, conveying section, post-processing section, etc. (not shown) connected to the printing device 1 .

[0038] The registration roller pair 31, the accelerating conveying section 32, the constant speed conveying section 33, the reversing conveying section 34, the re-feeding section 35, the paper ejecting conveying section 36, and the straight conveying section 37 are examples of a conveying section that conveys the medium (paper P) on the conveying path R. The conveying section is an example of a conveyor, and a belt may be used instead of a roller.

[0039] The path switching unit 38 switches the path of the paper P in the processing path R1 printed by the printing unit 40 to a continuous path from the straight conveying unit 37 to the connecting paper discharge unit or the like and a circulating path R2. The path switching unit 38 is, for example, a flipper.

[0040] The path switching unit 39 switches the path of the paper P conveyed in the circulation path R2 to the reversing path R2a and the paper discharge path R3. The path switching unit 39 is, for example, a flipper.

[0041] The printing unit 40 includes, for example, a line-type inkjet head (not shown) used for printing and separated into various colors. The printing method of the printing unit 40 may be a printing method other than the inkjet printing method.

[0042] The printing conveying unit 50 is arranged to face the printing unit 40 and conveys the paper P. The printing conveying unit 50 includes: a plurality of pulleys 51; a belt 52 mounted on the pulleys 51; a suction fan 53 that sucks air through a plurality of holes provided in the belt 52 so that the paper P is adsorbed to the belt 52; a guide roller 54 that is arranged to face the pulley 51 at the upstream end of the printing conveying unit 50 in the conveying direction; and a guide roller 55 that is arranged to face the pulley 51 at the downstream end of the printing conveying unit 50 in the conveying direction. The printing conveying unit 50 is an example of a processing conveying unit and is not limited to a method of conveying the paper P while adsorbing it.

[0043] The paper discharge unit 60 is disposed so as to be exposed to the outside of the printing apparatus 1 . The paper discharge unit 60 includes a paper discharge tray 61 on which printed paper P is loaded, and a pair of paper discharge rollers 62 that convey the paper P toward the paper discharge tray 61 .

[0044] Figure 2The transport drive unit 70 shown has a positioning drive unit 71 for driving the positioning roller pair 31, an acceleration drive unit 72 for driving the acceleration transport unit 32, a constant speed drive unit 73 for driving the constant speed transport unit 33, a reversing drive unit 74 for driving the reversing transport unit 34, a re-feeding drive unit 75 for driving the re-feeding unit 35, a paper discharge drive unit 76 for driving the paper discharge transport unit 36, a straight drive unit 77 for driving the straight transport unit 37, and a switching drive unit 78 and a switching drive unit 79 for driving the path switching unit 38 and the path switching unit 39. Each drive unit includes one or more actuators such as motors. In addition, a single actuator may also take care of multiple drive units.

[0045] The control unit 81 has a processor (e.g., CPU: Central Processing Unit) that functions as a computing processing unit that controls the overall operation of the printing device 1. The control unit 81 adjusts the conveying conditions including the start time of the paper supply of the paper P supplied by the external paper supply unit 10 and the internal paper supply unit 20 and the conveying speed of the paper P conveyed by the conveying unit (especially the conveying speed of the circulation path R2), and the details are described later. In addition, the control unit 81 is configured as a device independent of the main body of the printing device 1 (e.g., the conveying unit such as the registration roller pair 31), and the supply unit (external paper supply unit 10 and internal paper supply unit 20) and the conveying unit can also be controlled wirelessly via the Internet. In this case, it can also be said that the conveying device, taking the printing device 1 as an example, includes a supply unit (external paper supply unit 10 and internal paper supply unit 20), a conveying unit, and a control unit 81.

[0046] The storage unit 82 includes, for example, a read-only semiconductor memory, i.e., a ROM (Read Only Memory), which pre-stores a predetermined control program, a semiconductor memory, i.e., a RAM (Random Access Memory), which can be read and written at any time and is used as a job storage area as needed when the processor executes various control programs, and a hard disk device.

[0047] The interface unit 83 exchanges various information with external devices. For example, the interface unit 83 receives a print job including image data from a user terminal.

[0048] Next, a normal printing operation of the printing device 1 will be described.

[0049] Figure 2 The control unit 81 shown in the figure performs paper feeding reservation processing and paper feeding processing of the paper P when a print job is input. In addition, the control unit 81 controls the conveying unit such as the registration roller pair 31 to convey the paper P. In addition, the control unit 81 controls the printing unit 40 to print the paper P after performing predetermined image processing on the image data included in the print job.

[0050] Here, in the case of single-sided printing, Figure 1 As shown, unprinted paper P is fed out sequentially from any one of the external paper feed unit 10, the first paper feed unit 21, the second paper feed unit 22, and the third paper feed unit 23, and the paper is fed sequentially at a timing when each paper P is fed at a predetermined paper interval in the printing conveying unit 50. The fed paper P is printed by the printing unit 40 while being fed at a predetermined feeding speed in the printing conveying unit 50. The printed paper P is discharged from the paper discharge unit 60 or the connected paper discharge unit.

[0051] When the paper discharge destination is the connected paper discharge section, the path of the printed paper P is set by the path switching section 38 to a path that directly passes through the straight conveying section 37. Then, the paper P is discharged to the connected paper discharge section by the straight conveying section 37. On the other hand, when the paper discharge destination is the paper discharge section 60, the path of the printed paper P is guided to the circulation path R2 by the path switching section 38, and is guided to the paper discharge path R3 by the path switching section 39. Then, the paper P is discharged to the paper discharge section 60 by the paper discharge conveying section 36.

[0052] In the case of double-sided printing, for example, unprinted paper P is sequentially supplied at a time when the time interval between the paper feeds of each paper P is doubled relative to the paper feed time in single-sided printing. The supplied paper P is printed by the printing unit 40 while being transported by the print transport unit 50 as in single-sided printing.

[0053] After single-sided printing, the paper P is guided to the circulation path R2 for double-sided printing by the path switching section 38 and conveyed by the accelerating conveying section 32 and the constant speed conveying section 33, and then conveyed to the reversing path R2a by the path switching section 39. The paper P that has reached the reversing conveying section 34 changes direction.

[0054] Next, the paper P is conveyed to the registration roller pair 31 by the paper re-feeding unit 35. Then, the paper P is re-fed to the printing unit 40 after the skew of the paper P is corrected by the registration roller pair 31 as described above.

[0055] As an example, the paper P after single-side printing is fed again at the timing of being fed to the printing unit 40 alternately with the unprinted paper P fed in sequence. In the above example, in double-sided printing, the time between the paper feeding timings of the individual papers P is doubled compared to the paper feeding timing in the case of single-sided printing. Therefore, the paper P after single-side printing can be inserted between the unprinted papers P, and the paper P after single-side printing can be fed again alternately with the feeding of the unprinted papers P.

[0056] The paper P after single-side printing is changed in direction by the reversing conveying unit 34 and then conveyed to the printing unit 40 with the unprinted side facing upward. The paper P after single-side printing is printed on the unprinted side by the printing unit 40 while being conveyed by the printing conveying unit 50. Then, the paper P after double-side printing is discharged to the paper discharge unit 60 or the connected paper discharge unit.

[0057] Below, refer to Figure 3 to Figure 6 The following describes adjustment of the conveyance conditions of the paper P. The preceding paper P and the following paper P are the paper P to be printed on both sides, and are conveyed to the circulation path R2.

[0058] Figure 3 2 is a flowchart for explaining the paper feed reservation process. Figure 3 The process shown is for example Figure 2 The interface unit 83 shown in FIG. 1 receives a print job including double-sided printing, which is performed by the control unit 81. Figure 5 In the example of FIG. 1 , the printing job is to perform double-sided printing of the first A4 size sheet, the second A4 size sheet, and the third A3 size sheet (the fourth A4 size sheet, the fifth A4 size sheet, and the sixth A3 size sheet), thereby performing paper feed reservation and paper feed of a total of 6 sheets of paper P. In addition, in the present embodiment, the A4 size paper P is transported in a horizontal direction in which the length direction is orthogonal to the transport direction, and the A3 size paper P is transported in a vertical direction in which the length direction is parallel to the transport direction.

[0059] like Figure 3 As shown, first, the control unit 81 determines whether the paper P to be reserved for paper feeding is the first sheet (step S1).

[0060] If the paper P is the first sheet to be reserved (step S1: yes), the control unit 81 sets the "double-sided conveying length" to the paper length (length in the conveying direction) of the first sheet of paper P (step S2). Then, the control unit 81 sets the corresponding prescribed conveying conditions in coordination with the double-sided conveying length (step S3) and performs paper feed reservation (step S4). In addition, the conveying conditions are, for example, the start time of paper feed of the external paper feed unit 10 or the internal paper feed unit 20 and the conveying speed of the constant speed conveying unit 33 (circulation path R2). In addition, the paper feed reservation is, for example, an internal process of the control unit 81, which can be said to be a predetermined process that pre-establishes the subsequent paper feed processing.

[0061] Next, the control unit 81 determines whether there is no reservation for the subsequent paper P (step S5). If there is no subsequent paper P (step S5: Yes), the process ends. Figure 3 On the other hand, if there is a subsequent sheet P (step S5: No), the process is repeated from the process of the above-mentioned step S1.

[0062] In the processing of the above-mentioned step S1, if the paper P of the paper supply reservation object is not the first reserved paper (step S1: No), the control unit 81 determines whether the paper length of the paper P of the paper supply reservation object (the Nth paper) is longer than the double-sided conveying length set as described above (the paper length of the previous paper P) (step S6).

[0063] When the paper length of the subsequent paper P is longer than the double-sided conveyance length (step S6 : Yes), the control unit 81 sets the double-sided conveyance length as the paper length of the subsequent (Nth) paper P (step S7 ).

[0064] Then, the control unit 81 waits until all the paper sheets P in the conveying path R are discharged (step S8). Figure 5 Comparative Example (a) and Figure 5 In the present embodiment (b), the paper feed reservation of the third A3-size paper P (A3(3)) whose length is longer than the second A4-size paper P (A4(2)) is not immediately performed at the stage of the downward dotted arrow, but is performed after all the papers P in the conveying path R are ejected (downward solid arrow). In addition, as to whether all the papers P are ejected, a paper detection sensor (not shown) near the ejection conveying unit 36 ​​or near the straight conveying unit 37 can be used to detect whether all the papers P are ejected.

[0065] Then, the control unit 81 sets the conveyance conditions according to the double-sided conveyance length (step S9) and performs paper feed reservation (step S10). Thereafter, the control unit 81 performs the above-mentioned process of step S5, that is, the process of determining that there is no reservation for the following paper P.

[0066] In the above-mentioned processing of step S6, when the paper length of the following paper P is not longer than the double-sided conveying length (step S6: No), that is, when the paper length of the following paper P is shorter than or equal to the paper length of the preceding paper P, the control unit 81 performs paper feed reservation while maintaining the conveying conditions (step S11). Thereafter, the control unit 81 performs the above-mentioned processing of step S5, that is, the determination processing of whether there is no reservation for the following paper P.

[0067] Thus, even when the paper length of the subsequent paper P is shorter than the paper length of the preceding paper P, the conveying condition is maintained, thereby Figure 5 As in the example of the present embodiment (b), the fourth A4-sized paper P (A4(4)) whose length is shorter than the third A3-sized paper P (A3(3)) is fed while maintaining the A3-sized paper feed interval (upward solid arrow).

[0068] On the other hand, if Figure 5As in the comparative example (a), before making a paper feed reservation for the fourth A4-size paper P (A4(4)) whose length is shorter than the third A3-size paper P (A3(3)), the paper feed is slowed down accordingly after all the papers P inside the conveying path R are ejected and the paper feed interval is changed to A4 size.

[0069] And, in Figure 5 In the comparative example (a), before making a paper feed reservation for the sixth A3-size paper P (A3(6)) which is longer than the fifth A4-size paper P (A4(5)), the paper feed interval is changed to A3 size after all the papers P in the conveying path R are discharged. Figure 5 In the present embodiment (b), even when paper feeding reservation is made for the sixth sheet of A3 size paper P (A3(6)) which is longer than the fifth sheet of A4 size paper P (A4(5)), the paper feeding interval of the fourth and fifth sheets of A4 size paper P (A4(4), A4(5)) becomes the paper feeding interval of A3 size paper. Therefore, even when paper feeding reservation is made for the sixth sheet of A3 size paper P (A3(6)), the process of waiting until all the sheets of paper P inside the conveying path R are discharged can be avoided.

[0070] Thus, in this embodiment, the sixth A3-size paper P (A3 (6)) fed last is fed earlier than in the comparative example, and the printing (processing) completion time can be shortened. In other words, productivity (transport efficiency) is improved.

[0071] Next, refer to Figure 4 The flowchart of FIG. 1 illustrates a paper feeding process performed by the control unit 81 when the paper P is actually fed from the external paper feeding unit 10 or the internal paper feeding unit 20 .

[0072] like Figure 4 As shown, first, the control unit 81 determines whether the paper length of the paper P to be fed (Nth sheet) is shorter than the double-sided conveyance length (step S21).

[0073] When the length of the subsequent paper P is longer than or equal to the double-sided conveying length (step S21: No), the control unit 81 controls the external paper feed unit 10 or the internal paper feed unit 20 so that Figure 3 The paper P is fed under the feeding conditions determined in the paper feeding reservation process (step S28), and the process ends. Figure 4 Processing shown.

[0074] On the other hand, when the paper length of the subsequent paper P is shorter than the double-sided conveying length (step S21: Yes), the control unit 81 calculates the productivity A when a plurality of subsequent paper P are conveyed continuously at the paper feeding interval of the current double-sided conveying length (step S22). As the productivity A, at least the paper feeding start time when a plurality of subsequent paper P are conveyed, for example, the paper feeding start time of the last paper P for which paper feeding reservation has been completed can be calculated. The earlier the paper feeding start time is, the higher the productivity can be determined to be.

[0075] In addition, the control unit 81 calculates the productivity B (step S23) when the double-sided conveying length is switched to the shorter length of the subsequent paper P after all the papers P in the conveying path R are discharged. The productivity B may be calculated as the start time of paper feeding when at least a plurality of subsequent papers P are conveyed, similarly to the productivity A, for example, the start time of paper feeding of the last paper P for which paper feeding reservation has been completed.

[0076] Then, the control unit 81 compares the productivity A and the productivity B to determine whether the productivity B is higher than the productivity A (step S24). For example, the control unit 81 determines which of the start paper feeding times of the last paper P whose paper feeding reservations have been completed is earlier, and determines that the productivity of the one that starts first is higher.

[0077] When the productivity B is not higher than the productivity A (step S24: No), the control unit 81 controls the external paper feed unit 10 or the internal paper feed unit 20 so that Figure 3 The paper P is fed under the feeding conditions determined in the paper feeding reservation process (step S28), and the process ends. Figure 4 Processing shown.

[0078] When the productivity B is higher than the productivity A (step S24: Yes), the control unit 81 sets the double-sided conveying length to the length of the Nth sheet (step S25). Then, the control unit 81 waits until all the sheets P in the conveying path R are discharged (step S26), and sets the conveying conditions in accordance with the double-sided conveying length (step S27). After that, the control unit 81 controls the external paper supply unit 10 or the internal paper supply unit 20 to supply the sheets P (step S28), and ends. Figure 4 Processing shown.

[0079] Figure 6 An example is Figure 5 An example of double-sided printing of 6 sheets of paper P followed by 7th to 11th sheets of A4-sized paper P (A4(7) to A4(11)) whose length is shorter than the 6th sheet of A3-sized paper P (A3(6)). Figure 6In the example, the paper feeding reservation of the 7th sheet of paper P (A4(7)) is immediately performed at the stage of the downward dotted arrow, and compared with the case where paper is fed at an A3 size paper feeding interval (productivity A), when the 7th to 11th sheets of A4 size paper P (A4(7) to A4(11)) are fed at an A4 size paper feeding interval after all the sheets of paper P inside the conveying path R are discharged (productivity B), the start time of paper feeding of the last sheet of paper P, i.e. the 11th sheet of paper P (A4(11)), becomes earlier.

[0080] In addition, Figure 5 and Figure 6 In the example of , the case where all the sheets of paper P are printed on both sides is described. However, for example, in the case where the sheets of paper P printed (processed) only on one side (an example of a single-sided processed medium) are mixed with the plurality of sheets of paper P (an example of a double-sided processed medium) from the 7th to the 11th sheets of paper P printed (processed) on both sides (for example, only the 9th sheet of paper P is printed on one side), after the double-sided printing of the preceding 8th sheet of paper P printed on both sides is completed, the subsequent 9th sheet of paper P may be conveyed in the processing path R1 in a manner that the conveying speed in the conveying path R is maintained and the sheet of paper P is not conveyed to the circulation path R2. In this case, if the start of paper feeding of the 9th sheet of paper P is at the time when the single-sided printing of the 9th sheet of paper P is performed after the back side printing of the 8th sheet of paper P is performed, it may be before the 8th sheet of paper P is discharged from the conveying path R. In addition, for example, in the case of the 10th sheet of paper P printed on both sides, the sheet of paper P may be fed at the paper feeding interval in the case of single-sided printing after the 9th sheet of paper P is fed.

[0081] In addition, in the present embodiment, the conveying condition of the adjustment object includes both the start time of paper feeding of the external paper feeding unit 10 or the internal paper feeding unit 20 and the conveying speed of the conveying path R (circulation path R2 of the constant speed conveying unit 33, etc.), but the conveying condition of the adjustment object only needs to include at least one of the start time of paper feeding and the conveying speed. For example, whether the conveying speed is adjusted with a constant paper feeding interval or the paper feeding interval is adjusted with a constant conveying speed, it can be said that the conveying condition is adjusted. In addition, the conveying condition can also be adjusted according to, for example, the remaining amount of the rear end of the paper P protruding from the reversing path R2a when the reversing conveying unit 34 changes direction, the stop time of the paper P when changing direction, the deflection amount of the paper P when it hits the registration roller pair 31, the low speed of the contact speed, the period of maintaining the contact speed, etc.

[0082] In addition, in this embodiment, Figure 3 Flowchart of paper feed reservation processing and Figure 4 The paper feed process flowchart is described as a separate process, but it can also be Figure 3 The paper feed reservation process is performed at the stage Figure 4 For example, instead of Figure 3 The process of step S11 is performed Figure 4 The processing of steps S21 to S27 is Figure 4 If the judgment is negative in step S21 or step S24, Figure 3 The conveying conditions may be maintained as in step S11.

[0083] In addition, in the present embodiment, an example is described in which the length of the following paper P is shorter than the double-sided conveyance length (for example, the length of the preceding paper P). Figure 4 In steps S22 and S23, at least as the start paper feed time when a plurality of subsequent papers P are conveyed, the start paper feed time of, for example, the last paper P for which paper feed reservation has been completed is calculated, and the productivity A and B are compared. However, not only the comparison result of the start paper feed time, but also, for example, a slow conveying speed and less noise may be considered as one of the conditions for high productivity. In addition, in the case where a plurality of papers P for which paper feed reservation has been completed again include a paper P with a longer paper length, it is necessary to change the conveying conditions to the conveying conditions suitable for the paper P with a shorter paper length again after changing to the conveying conditions suitable for the paper P with a shorter paper length, so the waiting time for all the previous papers P to be discharged from the conveying path R may be considered as the amount of two times. In addition, based on the conditions of predetermined paper types and the number of sheets of paper, such as the determination that the productivity B is higher than the productivity A (step S24: Yes), the conveying conditions may be reset (step S27) without calculating the productivity A and B every time.

[0084] In the present embodiment described above, the printing device 1 having a conveying device includes an external paper supply unit 10 and an internal paper supply unit 20 (an example of a supply unit), a conveying unit (for example, a registration roller pair 31, an accelerating conveying unit 32, a constant speed conveying unit 33, a reversing conveying unit 34, a re-feeding unit 35, a paper ejection conveying unit 36, and a straight conveying unit 37), and a control unit 81. The external paper supply unit 10 and the internal paper supply unit 20 supply paper P (an example of a medium). The conveying unit conveys the paper P in a conveying path R, and the conveying path R includes a processing path R1 for conveying the paper P to a printing unit 40 (an example of a processing unit) for printing (an example of a processing) on ​​the paper P, and a circulation path R2 for reversing the paper P that has passed through the printing unit 40 and conveying it again to the printing unit 40. The control unit 81 adjusts the conveying conditions including at least one of the start time of supplying the paper P by the external paper supply unit 10 or the internal paper supply unit 20 and the conveying speed of the paper P conveyed by the conveying unit in the conveying path R, based on the length of the paper P in the conveying direction. In addition, the control unit 81 adjusts the conveying condition based on the fact that the length of the subsequent paper P (e.g., the third A3-sized paper P (A3(3))) conveyed to the circulation path R2 is longer in the conveying direction than the preceding paper P (e.g., the second A4-sized paper P (A4(2))) conveyed to the circulation path R2, and maintains the conveying condition of the preceding paper P based on the fact that the length of the subsequent paper P (e.g., the fourth A4-sized paper P (A4(4))) in the conveying direction is shorter than the preceding paper P (e.g., the third A3-sized paper P (A3(3))).

[0085] In addition, in the past, when printing is performed on both sides of the paper P, the paper P is turned over in the circulation path R2, and the paper P printed on one side and the paper P not printed are alternately sent to the printing unit 40. Therefore, according to the paper length (length in the conveying direction) of the paper P, the paper feeding timing of the external paper feeding unit 10 and the internal paper feeding unit 20, the conveying speed of the paper P in the circulation path R2, the number of sheets of paper P conveyed inside the printing device 1, etc. are changed accordingly. Therefore, in the past, when a paper P having a different paper length from the preceding paper P is fed, the conveying condition is set again, and the subsequent paper P is fed after the preceding paper P is completely discharged from the conveying path R. In contrast, in the present embodiment, when the length of the subsequent paper P (for example, the fourth A4-sized paper P (A4(4))) in the conveying direction becomes shorter than that of the preceding paper P (for example, the third A3-sized paper P (A3(3))), the conveying condition of the preceding paper P is maintained and the paper is fed. Therefore, when the length of the following paper P becomes shorter, it is possible to avoid waiting for the preceding paper P to be completely discharged from the conveying path R. Therefore, according to the present embodiment, it is possible to improve the conveying efficiency of the conveying device that conveys the paper P in the conveying path R including the circulation path R2. Figure 5 The process (b) performs double-sided printing on 5 A4-sized sheets of paper P and 1 A3-sized sheet of paper P in 5 copies, a total of 30 sheets, and starts with the 6th A3-sized sheet of paper P and performs double-sided printing on all the remaining sheets of paper P at the A3-sized paper feed interval (transportation condition). As a result, 43 sheets of paper are printed every 1 minute. Figure 5 As in the comparative example (a), the discharge standby of the preceding paper P from the conveyance path R and the reset of the paper feed interval are performed at all times when the paper length changes. As a result, only 30 sheets are printed per minute.

[0086] In addition, in the present embodiment, the control unit 81 maintains the conveying condition of the preceding paper P based on the result that the length of the subsequent paper P in the conveying direction becomes shorter than that of the preceding paper P, and a comparison result between the start supply time when a plurality of subsequent papers P are conveyed under the conveying condition of the preceding paper P and the start supply time when a plurality of subsequent papers P are conveyed under the conveying condition of the subsequent paper P.

[0087] Therefore, even when the length of the subsequent paper P (e.g., the seventh A4-size paper P (A4(7))) in the conveying direction is shorter than that of the preceding paper P (e.g., the sixth A3-size paper P (A3(6))), the subsequent paper P with a constant length can be continuously fed. If the paper feeding interval of the preceding paper P with a longer length is maintained, the conveying conditions can be reset when the paper feeding start time (feed start time) is late. Therefore, the conveying efficiency can be further improved.

[0088] In addition, in the present embodiment, when paper P printed on one side, i.e., single-sided processing media, is mixed with a plurality of paper P printed on both sides, i.e., double-sided processing media, the control unit 81 conveys the subsequent single-sided processing medium in the processing path R1 in a manner that maintains the conveying speed and does not convey it to the circulation path R2 after the processing of both sides of the previous double-sided processing medium is completed.

[0089] Thus, when single-sided processed media are mixed with double-sided processed media, it is possible to avoid changing the conveying speed in accordance with the single-sided processed media. Therefore, it is possible to avoid waiting for all single-sided processed media to be discharged from the conveying path R, thereby further improving the conveying efficiency.

[0090] In addition, the present invention is not limited to the above-mentioned embodiments as it is, and the structural elements can be deformed and concretized in the implementation stage without departing from the scope of its main purpose. In addition, various technical solutions can be formed by appropriately combining the multiple structural elements disclosed in the above-mentioned embodiments. For example, all the structural elements shown in the embodiments can also be appropriately combined. Of course, various deformations and applications can be made within the scope of such a scope without departing from the main purpose of the invention. Below, a part of the technical solutions recorded in the specification and drawings of this application are attached.

[0091] [Note 1]

[0092] A conveying device, characterized in that

[0093] The conveying device has:

[0094] a supply unit that supplies a medium;

[0095] a conveying section that conveys the medium in a conveying path, the conveying path including a processing path for conveying the medium to a processing section that processes the medium, and a circulation path for reversing the medium that has passed through the processing section and conveying it to the processing section again; and

[0096] a control unit that adjusts a conveying condition based on a length of the medium in a conveying direction, the conveying condition including at least one of a start time of supplying the medium by the supply unit and a conveying speed of the medium by the conveying unit in the conveying path,

[0097] The control unit adjusts the conveying condition based on the fact that the length of the subsequent medium conveyed to the circulation path is longer in the conveying direction than the previous medium conveyed to the circulation path, and maintains the conveying condition of the previous medium based on the fact that the length of the subsequent medium in the conveying direction is shorter than the previous medium.

[0098] [Note 2]

[0099] The conveying device according to Note 1 is characterized in that the control unit maintains the conveying condition of the preceding medium based on the fact that the length of the subsequent medium in the conveying direction is shortened compared with the preceding medium, and a comparison result of the start supply time when a plurality of subsequent media are conveyed under the conveying condition of the preceding medium and the start supply time when the plurality of subsequent media are conveyed under the conveying condition of the subsequent medium.

[0100] [Note 3]

[0101] The conveying device according to Note 1 or 2 is characterized in that, when media processed on one side, i.e. single-sided processing media, are mixed with a plurality of media processed on both sides, i.e. double-sided processing media, the control unit conveys the subsequent single-sided processing media in the processing path in a manner maintaining the conveying speed and not conveying it to the circulation path after the processing of both sides of the preceding double-sided processing media is completed.

[0102] [Note 4]

[0103] A processing device, characterized in that

[0104] The processing device has:

[0105] a supply unit that supplies a medium;

[0106] a processing unit for processing the medium;

[0107] a conveying section that conveys the medium in a conveying path, the conveying path including a processing path for conveying the medium to the processing section and a circulation path for reversing the medium that has passed through the processing section and conveying it to the processing section again; and

[0108] a control unit that adjusts a conveying condition based on a length of the medium in a conveying direction, the conveying condition including at least one of a start time of supplying the medium by the supply unit and a conveying speed of the medium by the conveying unit in the conveying path,

[0109] The control unit adjusts the conveying condition based on the fact that the length of the subsequent medium conveyed to the circulation path is longer in the conveying direction than the previous medium conveyed to the circulation path, and maintains the conveying condition of the previous medium based on the fact that the length of the subsequent medium in the conveying direction is shorter than the previous medium.

[0110] [Note 5]

[0111] A printing device, characterized in that

[0112] The printing device has:

[0113] a supply unit that supplies a medium;

[0114] a printing unit for printing on the medium;

[0115] a conveying unit that conveys the medium in a conveying path, the conveying path including a printing path for conveying the medium to the printing unit and a circulation path for reversing the medium that has passed through the printing unit and conveying it to the printing unit again; and

[0116] a control unit that adjusts a conveying condition based on a length of the medium in a conveying direction, the conveying condition including at least one of a start time of supplying the medium by the supply unit and a conveying speed of the medium by the conveying unit in the conveying path,

[0117] The control unit adjusts the conveying condition based on the fact that the length of the subsequent medium conveyed to the circulation path is longer in the conveying direction than the previous medium conveyed to the circulation path, and maintains the conveying condition of the previous medium based on the fact that the length of the subsequent medium in the conveying direction is shorter than the previous medium.

Claims

1. A conveying device, It is characterized in that The conveying device has: a supply unit that supplies a medium; a conveying section that conveys the medium in a conveying path, the conveying path including a processing path for conveying the medium to a processing section that processes the medium, and a circulation path for reversing the medium that has passed through the processing section and conveying it to the processing section again; as well as a control unit that adjusts a conveying condition based on a length of the medium in a conveying direction, the conveying condition including at least one of a start time of supplying the medium by the supply unit and a conveying speed of the medium by the conveying unit in the conveying path, The control unit adjusts the conveying condition based on the fact that the length of the subsequent medium conveyed to the circulation path is longer in the conveying direction than the previous medium conveyed to the circulation path, and maintains the conveying condition of the previous medium based on the fact that the length of the subsequent medium in the conveying direction is shorter than the previous medium.

2. The conveying device according to claim 1, It is characterized in that The control unit maintains the conveying condition of the preceding medium based on the fact that the length of the subsequent medium in the conveying direction is shortened compared to the preceding medium, and a comparison result between the start supply time when a plurality of subsequent media are conveyed under the conveying condition of the preceding medium and the start supply time when the plurality of subsequent media are conveyed under the conveying condition of the subsequent medium.

3. The conveying device according to claim 1 or 2, It is characterized in that In the case where media that have been processed on one side, i.e., single-sided processed media, are mixed with a plurality of media that have been processed on both sides, i.e., double-sided processed media, the control unit conveys the subsequent single-sided processed media in the processing path in a manner that maintains the conveying speed and does not convey the media to the circulation path after the processing of both sides of the preceding double-sided processed media is completed.

Images