Media supply institution

Abstract

To provide a medium supply mechanism which includes a plurality of individual conveyance paths which is connected to a plurality of supply parts and has different path lengths, and of which control is simplified with a simple structure.SOLUTION: A medium supply mechanism includes a first individual conveyance path P1 connected to a first supply part 11, a second individual conveyance path P2 which is connected to a second supply part 12 and has a shorter path length than the first individual conveyance path P1, a joining conveyance path P3, and a control part 151 which makes the plurality of supply parts supply the medium M so that the medium M is arrived at a reference arrival position (for example, a resist sensor S10) of the joining conveyance path P3 in reference arrival time. The control part 151 controls the first supply part 11 so that supply start time t12 of the first supply part 11 is later than supply start time t21 of the second supply part 12 when a medium M (M3) supplied from the first supply part 11 after the medium M (M2) supplied from the second supply part 12 is arrived at the reference arrival position and when the supply start time t12 of the first supply part 11 is earlier than the supply start time t21 of the second supply part 12.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a media supply mechanism. [Background technology]

[0002] Conventionally, there has been proposed an image forming device that controls the timing of paper feed start to change during continuous printing in which the paper feed tray used for paper feeding is alternately selected from multiple paper feed trays for each page printed, so that paper fed later does not catch up with paper fed earlier (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-2685 Summary of the Invention [Problem to be solved by the invention]

[0004] Now, consider a media supply mechanism that supplies media such as paper to a destination device such as a printing device, and that includes a plurality of supply sections that supply media, a plurality of individual transport paths connected to these plurality of supply sections, and a merging transport section where these plurality of individual transport paths merge.

[0005] In such a medium supply mechanism, if the path lengths of the multiple individual transport paths are different, when switching the supply unit that supplies the media, it may be necessary to change the order of the supply start times of the media in the supply unit to an order different from the order (e.g., printing order) of the media arriving at a reference arrival position (e.g., a pair of registration rollers) in the merging transport path. This change in the order of the supply start times is more likely to occur the greater the difference in path lengths of the multiple individual transport paths is, or the shorter the media length, which is the length in the transport direction of the media, is.

[0006] If the order of the supply start times is changed to an order different from the order of the media arriving at the reference arrival position, not only does control of restarting operations in the event of a jam become complicated, but the control for changing the order in the first place becomes complicated.

[0007] In addition, when the path lengths of the multiple individual transport paths are different, it is possible to increase the transport speed in each individual transport path as the path length becomes longer so that the difference in transport time between the individual transport paths becomes shorter. However, in this case, the transport speed is increased as the difference in path length becomes larger, which requires a high-performance motor, resulting in increased costs and complicated control.

[0008] An object of the present invention is to simplify the control with a simple configuration in a medium supply mechanism having a plurality of individual transport paths with different path lengths connected to a plurality of supply units. [Means for solving the problem]

[0009] In one aspect, the medium supply mechanism includes a plurality of supply units that supply medium, a plurality of individual conveying paths having different path lengths connected to the plurality of supply units, a merging conveying path where the plurality of individual conveying paths join, and a control unit that causes the plurality of supply units to supply the medium so that the medium reaches a reference arrival position on the merging conveying path at a reference arrival time, the plurality of individual conveying paths including a first individual conveying path and a second individual conveying path having a path length shorter than that of the first individual conveying path, the plurality of medium supply units including a first supply unit that supplies the medium to the first individual conveying path and a second supply unit that supplies the medium to the second individual conveying path, and the control unit controls the first supply unit so that the supply start time of the first supply unit is later than the supply start time of the second supply unit when the medium supplied from the first supply unit is to reach the reference arrival position after the medium supplied from the second supply unit and when the supply start time of the first supply unit is earlier than the supply start time of the medium of the second supply unit. Effect of the Invention

[0010] According to the above aspect, in a medium supply mechanism including a plurality of individual transport paths connected to a plurality of supply units and having different path lengths, it is possible to simplify control with a simple configuration. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an internal configuration of a printing system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a control configuration of a medium supplying device and a printing device according to an embodiment. [Diagram 3] 13 is a diagram illustrating transport times of a medium supplied from a first supply unit and a second supply unit in a comparative example. FIG. [Figure 4] 10 is a diagram illustrating transport times for a medium supplied from a first supply unit and a second supply unit in an embodiment. FIG. [Diagram 5] 1 is a table illustrating arrival intervals and productivity for each media size according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A medium supply mechanism according to an embodiment of the present invention will now be described with reference to the drawings.

[0013] FIG. 1 is a diagram showing the internal configuration of a printing system 100. As shown in FIG.

[0014] FIG. 2 is a diagram showing the control configuration of the medium supplying device 1 and the printing device 101.

[0015] Note that the front-rear, up-down, and left-right directions shown in FIG. 1 are merely directions for convenience of explanation, but for example, the front-rear and left-right directions are horizontal directions, and the up-down direction is vertical directions.

[0016] 1 includes a medium supply device 1 and a printing device 101. Although details will be described later, the medium supply mechanism in this embodiment includes the medium supply device 1, a conveying path configuration to a registration roller pair 131 of the printing device 101 (receiving roller pair 132, registration sensor S10, and junction conveying path P3), and a control unit 151 of the printing device 101.

[0017] The medium supplying device 1 supplies the medium M to a pair of registration rollers 131 of a printing device 101, which is an example of a supply destination of the medium M. The supply destination device of the medium M is not limited to the printing device 101, and may be other devices such as a conveying device or a post-processing device. The medium supplying device 1 may be provided integrally with a supply destination device such as the printing device 101. The medium M is, for example, paper (sheets), but may also be other sheet-like media such as film.

[0018] 1, the medium supplying device 1 includes a first supplying section 11, a second supplying section 12, a first individual transport path P1, a second individual transport path P2, a junction transport path P3, first to ninth transport roller pairs 21 to 29, first to fourth transport driving sections D1 to D4, a first inlet passage detection sensor S1, a first outlet passage detection sensor S2, a second inlet passage detection sensor S3, and a second outlet passage detection sensor S4. Also, as shown in FIG. 2, the medium supplying device 1 further includes a control section 31, a storage section 32, and an interface section 33.

[0019] The medium supply device 1 is divided into an upper level 1a and a lower level 1b, with the first supply unit 11 disposed in the upper level 1a and the second supply unit 12 disposed in the lower level 1b. In this manner, the first supply unit 11 and the second supply unit 12 are disposed side by side vertically. The first supply unit 11 and the second supply unit 12 are an example of a plurality of supply units that supply the medium M. The plurality of supply units may be three or more supply units. Furthermore, the direction in which the plurality of supply units are disposed may be the front-rear direction or the left-right direction, and is not particularly limited.

[0020] The first supply section 11 and the second supply section 12 each include a loading platform 11a, 12a and a suction transport section 11b, 12b.

[0021] A plurality of sheets of medium M are loaded on the loading tables 11a and 12a. Different types (sizes, materials, colors, etc.) of medium M may be loaded on the loading table 11a of the first supply unit 11 and the loading table 12a of the second supply unit 12. In this case, when the type of medium M to be printed is changed, the supply unit that supplies the medium M is switched between the first supply unit 11 and the second supply unit 12.

[0022] The suction conveying units 11b and 12b have, for example, two pulleys and a belt stretched around these pulleys, and pay out the media M that is attracted to the belt by air suction one by one. The suction conveying units 11b and 12b are an example of a pay-out unit that pays out the media M from the first supply unit 11 and the second supply unit 12 one by one.

[0023] Although not shown in the figure, the first supply unit 11 and the second supply unit 12 each have a loading platform lifting drive unit such as a motor (an example of an actuator) that moves the loading platforms 11a, 12a up and down, and a payout drive unit such as a motor (an example of an actuator) that rotates a drive pulley, which is one of the two pulleys of the suction conveying units 11b, 12b.

[0024] In addition, the first supply section 11 and the second supply section 12 may be provided with a floating air blowing mechanism that blows floating air to float multiple sheets of media M including the topmost medium M stacked on the stacking tables 11a, 12a, and a separation air blowing mechanism that blows separation air to separate the topmost medium M from the lower media M.

[0025] The first individual conveying path P1 is connected to the first supply unit 11. The second individual conveying path P2 is connected to the second supply unit 12. The junction conveying path P3 is a conveying path where the first individual conveying path P1 and the second individual conveying path P2 join together, and extends to the registration roller pair 131 of the printing device 101. The first individual conveying path P1 and the second individual conveying path P2 are examples of multiple individual conveying paths with different path lengths that are connected to multiple supply units.

[0026] Most of the first individual transport path P1 is disposed in the upper stage 1a of the medium supplying device 1, and the second individual transport path P2 is disposed in the lower stage 1b of the medium supplying device 1. The first individual transport path P1 merges with the second individual transport path P2 at a junction transport path P3 disposed in the lower stage 1b. The second individual transport path P2 has a path length (length in the transport path) shorter than that of the first individual transport path P1 (e.g., less than half).

[0027] Each of the first to ninth transport roller pairs 21 to 29 has a drive roller and a driven roller disposed opposite each other, and transports the medium M while nipping it.

[0028] The first to fifth transport roller pairs 21-25 transport the medium M on the first individual transport path P1 in the upper stage 1a of the medium supplying device 1. The sixth and seventh transport roller pairs 26, 27 transport the medium M on the second individual transport path P2 in the lower stage 1b of the medium supplying device 1. The eighth and ninth transport roller pairs 28, 29 transport the medium M on the junction transport path P3 in the lower stage 1b of the medium supplying device 1. In addition, a receiving roller pair 132 of the printing device 101, which will be described later, transports the medium M on the junction transport path P3 of the printing device 101. The first to fifth transport roller pairs 21-25 and the sixth and seventh transport roller pairs 26, 27 are an example of a plurality of individual transport sections that transport the medium M on the first individual transport path P1 and the second individual transport path P2 (a plurality of individual transport paths). The eighth and ninth conveying roller pairs 28, 29 and the receiving roller pair 132 are an example of a junction conveying section that conveys the medium M on the junction conveying path P3.

[0029] The first to fourth transport drive units D1 to D4 are motors (an example of an actuator) that rotate the drive rollers of the first to ninth transport roller pairs 21 to 29. The first transport drive unit D1 rotates the drive rollers of the first and second transport roller pairs 21, 22. The second transport drive unit D2 rotates the drive rollers of the third to fifth transport roller pairs 23 to 25. The third transport drive unit D3 rotates the drive rollers of the sixth and seventh transport roller pairs 26, 27. The fourth transport drive unit D4 rotates the drive rollers of the eighth and ninth transport roller pairs 28, 29. The first and second transport drive units D1, D2 and the third transport drive unit D3 are an example of individual transport drive units that drive a plurality of individual transport units (the first to seventh transport roller pairs 21 to 27). The transport drive unit (not shown) that drives the fourth transport drive unit D4 and the receiving roller pair 132 is an example of a junction transport drive unit that drives the junction transport unit (the eighth and ninth transport roller pairs 28, 29 and the receiving roller pair 132). Note that the transport speed of the medium M by the first to ninth transport roller pairs 21-29 is constant, for example. However, the transport speed may be different between the first individual transport path P1, the second individual transport path P2, and the junction transport path P3, or the transport speed may be different within at least one of the first individual transport path P1, the second individual transport path P2, and the junction transport path P3.

[0030] The first entrance passage detection sensor S1, the first exit passage detection sensor S2, the second entrance passage detection sensor S3, and the second exit passage detection sensor S4 are, for example, reflective or transmissive photoelectric sensors that detect the passage of the media M.

[0031] The first inlet passage detection sensor S1 is disposed adjacent to the first conveying roller pair 21 on the downstream side in the conveying direction of the first conveying roller pair 21. The first outlet passage detection sensor S2 is disposed adjacent to the fifth conveying roller pair 25 on the downstream side in the conveying direction of the fifth conveying roller pair 25. As a result, the first inlet passage detection sensor S1 detects the passage of the medium M near the inlet of the first individual conveying path P1, and the first outlet passage detection sensor S2 detects the passage of the medium M near the exit of the first individual conveying path P1.

[0032] The second inlet passage detection sensor S3 is disposed adjacent to the sixth conveying roller pair 26 on the downstream side in the conveying direction of the sixth conveying roller pair 26. The second outlet passage detection sensor S4 is disposed adjacent to the ninth conveying roller pair 29 on the downstream side in the conveying direction of the ninth conveying roller pair 29. As a result, the second inlet passage detection sensor S3 detects the passage of the medium M near the inlet of the second individual conveying path P2, and the second outlet passage detection sensor S4 detects the passage of the medium M near the outlet of the medium supply device 1 on the merging conveying path P3.

[0033] The first inlet passage detection sensor S1, the first outlet passage detection sensor S2, and the second inlet passage detection sensor S3 are an example of a plurality of passage detection sensors that are arranged on a plurality of individual transport paths (first individual transport path P1 and second individual transport path P2) and detect the passage of the medium M before it reaches the arrival detection sensor (a registration sensor S10 described later). The second inlet passage detection sensor S3 is also an example of an entry detection sensor that detects that the medium M supplied from the second supply unit 12 has entered the second individual transport path P2. This entry detection sensor may be the second outlet passage detection sensor S4 because there is no particular restriction on the detection position on the second individual transport path P2, but it is preferable that the entry detection sensor be arranged near the second supply unit 12 because it is used to determine whether or not empty transport is occurring for the medium M.

[0034] The control unit 31 shown in FIG. 2 has a processor (e.g., CPU: Central Processing Unit) that functions as an arithmetic processing device that controls the operation of the entire medium supplying device 1, and controls each unit of the medium supplying device 1. For example, the control unit 31 controls the first supplying unit 11, the second supplying unit 12, and the first to fourth transport driving units D1 to D4 based on a supply start signal for the medium M that an interface unit 33 described later receives from an interface unit 153 (control unit 151) of the printing device 101. Note that, when the control units disposed in the first supplying unit 11 and the second supplying unit 12 receive the supply start signal from the printing device 101, the control of the first supplying unit 11 and the second supplying unit 12 may be performed by these control units. Furthermore, when the medium supplying device 1 is provided integrally with a supply destination device such as the printing device 101, a control unit of the supply destination device (e.g., the control unit 151 of the printing device 101 described later) may function as the control unit 31.

[0035] Incidentally, the passing time of medium M through the first inlet passage detection sensor S1 or the second inlet passage detection sensor S3 may be delayed from the reference passing time, which is a predetermined theoretical value, due to a low conveyance rate caused by a large amount of slippage between medium M and the suction conveyance units 11b, 12b. In this case, in order to make up for the delay of medium M, the control unit 31 may control the first to fourth conveyance drive units D1 to D4 to convey medium M faster than expected between the first inlet passage detection sensor S1 and the first outlet passage detection sensor S2, or between the second inlet passage detection sensor S3 and the second outlet passage detection sensor S4.

[0036] On the other hand, there may be cases where the conveying rate is high due to less slippage between medium M and suction conveying units 11b, 12b, and the passing time of medium M through first inlet passage detection sensor S1 or second inlet passage detection sensor S3 is faster than the reference passing time. In this case, control unit 31 may control first to fourth conveying drive units D1 to D4 to convey medium M slower than planned between first inlet passage detection sensor S1 and first outlet passage detection sensor S2, or between second inlet passage detection sensor S3 and second outlet passage detection sensor S4.

[0037] The difference in the passing time of media M at the first inlet passage detection sensor S1 or the second inlet passage detection sensor S3 described above is not limited to when the topmost media M, which has been floated by floating air and separated from the lower media M by separation air, is adsorbed and transported by the suction transport sections 11b, 12b, but also occurs when the topmost media M and the lower media M are separated by a separation plate or the like, due to friction acting between the separation plate and media M.

[0038] The storage unit 32 has, for example, a memory such as a ROM (Read Only Memory), which is a read-only semiconductor memory in which a predetermined control program is pre-recorded, or a RAM (Random Access Memory), which is a semiconductor memory that can be written and read at any time and is used as a working storage area as necessary when a processor executes various control programs. Note that in cases where the medium supplying device 1 is provided integrally with a destination device such as the printing device 101, a storage unit of the destination device (for example, a storage unit 152 of the printing device 101 described later) may function as the storage unit 32.

[0039] The interface unit 33 transmits and receives various information to and from external devices such as the printing device 101. For example, the interface unit 33 receives information such as a supply start signal for the medium M from the interface unit 153 of the printing device 101, and the control unit 31 controls the operation of each part of the medium supplying device 1 based on this information.

[0040] Next, the printing device 101 will be described.

[0041] 1 and 2, the printing device 101 includes a printing unit 110, a suction conveying unit 120, a conveying unit 130, a registration sensor S10, a destination conveying path P11, a circulating inverting conveying path P12, an inverting unit 140, a control unit 151, a storage unit 152, and an interface unit 153. In addition, in Fig. 1, the junction conveying path P3 and the destination conveying path P11 are indicated by solid lines, and the circulating inverting conveying path P12 is indicated by dashed lines.

[0042] The printing unit 110 has, for example, a line-head type inkjet head (not shown) for each color used for printing. The printing method of the printing unit 110 may be a printing method other than the inkjet printing method.

[0043] 1, the suction transport unit 120 is disposed so as to face the printing unit 110. The suction transport unit 120 transports the medium M by a transport belt while suctioning the medium M.

[0044] The conveying section 130 includes a pair of registration rollers 131 that corrects skew of the medium M by being struck by the medium M conveyed toward the printing section 110, a pair of receiving rollers 132 that conveys the medium M in the junction conveying path P3 continuing from the medium supply device 1, and a plurality of conveying roller pairs 133 that convey the medium M in the supply destination conveying path P11 or the circular inversion conveying path P12. The pair of registration rollers 131, the pair of receiving rollers 132, and the plurality of conveying roller pairs 133 convey the medium M while nipping it. The pair of registration rollers 131 is an example of a reference arrival position in the junction conveying path P3, and the medium M arrives at a reference arrival time at a predetermined interval, for example. This reference arrival time may be a time with a certain range. The reference arrival time may be set for each medium M based on, for example, the size of the medium M, the printing time of the printing section 110 corresponding to the print content, the gap between the media M conveyed continuously, and the like. The arrival of the medium M at the registration roller pair 131 later than the reference arrival time can be used to determine whether a jam has occurred, and can also cause delays in the start of printing by the printing unit 110 and variations in the accuracy of skew correction. The reference arrival position can also be set to any position other than the registration roller pair 131.

[0045] The registration sensor S10 is disposed near the registration roller pair 131 in the junction conveying path P3 on the upstream side in the conveying direction of the registration roller pair 131. The registration sensor S10 is disposed in the junction conveying path P3 and is an example of an arrival detection sensor that detects the arrival timing of the medium M. This arrival detection sensor may be the above-mentioned second exit passage detection sensor S4 disposed in the junction conveying path P3 of the medium supplying device 1. As described above, the medium supplying mechanism in this embodiment includes the medium supplying device 1, the configuration of the conveying path to the registration roller pair 131 of the printing device 101 (the receiving roller pair 132, the registration sensor S10, and the junction conveying path P3), and the control unit 151, so that the receiving roller pair 132 and the registration sensor S10 can be said to be part of the medium supplying mechanism.

[0046] The pair of registration rollers 131, which is an example of the reference arrival position described above, is not provided with a sensor that detects the medium M. Therefore, it is possible to determine whether or not the medium M has reached the pair of registration rollers 131 based on the detection result of the registration sensor S10.

[0047] The destination transport path P11 is connected to the junction transport path P3 continuing from the medium supply device 1, and extends downstream in the transport direction from the registration roller pair 131. In the printing system 100 shown in Fig. 1, when other printing devices or medium ejection devices are disposed downstream in the transport direction of the printing device 101, the destination transport path P11 is connected to the transport paths of these devices.

[0048] The medium M is transported along the circulatory reversal transport path P12 when, for example, the opposite side of the medium M that has been printed on one side by the printing unit 110 is to be printed on as well.

[0049] The reversing section 140 has a reversing path that reverses the front and back of the medium M transported to the circulatory reversing transport path P12, a pair of switchback rollers, and the like.

[0050] 2 has a processor (e.g., a CPU) that functions as an arithmetic processing device that controls the operation of the entire printing device 101, and controls each part of the printing device 101. As will be described in detail later, the control unit 151 causes the first supply unit 11 and the second supply unit 12 to supply the medium M by, for example, sending a supply start signal to the medium supply device 1 so that the medium M reaches the registration roller pair 131 at a reference arrival time.

[0051] The storage unit 152 has memories such as a ROM, which is a read-only semiconductor memory in which a specific control program is pre-recorded, and a RAM, which is a semiconductor memory that can be written and read at any time and is used as a working memory area as necessary when the processor executes various control programs.

[0052] The interface unit 153 transmits and receives various information between the medium supplying device 1 and an external device such as a user terminal that transmits print data. For example, the interface unit 153 transmits information such as a supply start signal for the medium M to the interface unit 33 of the medium supplying device 1, as described above.

[0053] The operation of the medium supplying device 1 will be described below while omitting points that overlap with the above description as appropriate.

[0054] 1, based on a supply start signal for medium M from the printing device 101 (interface unit 153) received by the interface unit 33, controls the first supply unit 11 and the second supply unit 12 to switch between the medium M of the first supply unit 11 and the medium M of the second supply unit 12, or to supply the medium M only from the first supply unit 11 or the second supply unit 12. Alternatively, as described above, when the control units disposed in the first supply unit 11 and the second supply unit 12 receive a supply start signal from the printing device 101, the first supply unit 11 and the second supply unit 12 may be controlled by the control units of the first supply unit 11 and the second supply unit 12.

[0055] The control unit 31 controls the first to fifth transport roller pairs 21-25 using the first transport drive unit D1 and the second transport drive unit D2 to transport the medium M supplied from the first supply unit 11 along the first individual transport path P1. When the medium M is transported along the first individual transport path P1, its passage is detected by the first entrance passage detection sensor S1 and the first exit passage detection sensor S2.

[0056] The control unit 31 also controls the sixth and seventh conveying roller pairs 26, 27 using the third conveying drive unit D3 to convey the medium M supplied from the second supply unit 12 along the second individual conveying path P2. When the medium M is conveyed along the second individual conveying path P2, its passage is detected by the second inlet passage detection sensor S3.

[0057] The control unit 31 then controls the eighth and ninth conveying roller pairs 28, 29 using the fourth conveying drive unit D4 so as to convey the medium M conveyed from the first individual conveying path P1 or the second individual conveying path P2 to the merging conveying path P3. When the medium M is conveyed to the merging conveying path P3, its passage is detected by the second exit passage detection sensor S4.

[0058] As a result, the medium M is supplied to the junction conveying path P3 of the printing device 101 connected to the junction conveying path P3 of the medium supplying device 1, and after the medium M is abutted against the registration roller pair 131 to correct the skew, the medium M is printed by the printing unit 110. When the medium M is transported on the junction conveying path P3 of the printing device 101, the passage (arrival) of the medium M is detected by the registration sensor S10.

[0059] Next, the control of the first supply unit 11 and the second supply unit 12 by the control unit 151 of the printing device 101 using a supply start signal will be described.

[0060] FIG. 3 is a diagram showing the transport time of the medium M supplied from the first supply unit 11 and the second supply unit 12 in the comparative example.

[0061] FIG. 4 is a diagram showing the transport time of the medium M supplied from the first supply unit 11 and the second supply unit 12 in this embodiment.

[0062] 3, consider a case in which medium M (medium M1) supplied from first supply unit 11, medium M (medium M2) supplied from second supply unit 12, medium M (medium M3) supplied from first supply unit 11, and medium M (medium M4) supplied from second supply unit 12 arrive at registration roller pair 131 (the right end of the thick and thin lines in FIG. 3) at a predetermined arrival interval in (an example of a reference arrival time). As described above, the reference arrival time determined by this arrival interval in can vary for each sheet of medium M or for each supply unit (first supply unit 11 or second supply unit 12) depending on the size of medium M, the print content (printing time in printing unit 110), etc.

[0063] When the first to fourth media M1 to M4 are to arrive at the registration roller pair 131 at a predetermined arrival interval in, particularly when the path length of the first individual transport path P1 is, for example, more than twice as long as the path length of the second individual transport path P2, or when the length in the transport direction of the medium M (medium length) is short, the supply start time t21 of the second medium M2 may be later than the supply start time t12 of the third medium M3, as shown in Fig. 3. When there is such a difference between the arrival order and the supply start order, the control unit 151 of the printing device 101 needs to change the supply start order for sending the supply start signal to an order other than the arrival order.

[0064] In this regard, in the present embodiment, the control unit 151 controls the first supply unit 11 by sending a supply start signal to the medium supply device 1 so that the supply start time t12 of the third medium M3 is later than the supply start time t21 of the second medium, as shown in FIG. 4. This allows the control unit 151 to avoid changing the order of sending the supply start signal from the arrival order. Note that by delaying the supply start time t12 of the third medium M3, the arrival interval in between the second medium M2 and the third medium M3 at the registration roller pair 131 is extended to the extended arrival interval in-e, and the reference arrival time of the medium M (such as the fourth medium M4) supplied thereafter is delayed, but the arrival interval in between the third medium M3 and the fourth medium M4 and thereafter may be maintained.

[0065] In other words, if the transport time of the third medium M3 becomes longer than the sum of the transport time of the second medium M2 and the arrival interval in (between the second medium M and the third medium M), the arrival interval in can be changed to the extended arrival interval in-e so that the transport time of the third medium M3 becomes less than the sum of the transport time of the second medium M2 and the extended arrival interval in-e (between the second medium M and the third medium M).

[0066] Here, for example, even if the supply start time t12 of the third medium M3 is a moment later than the supply start time t21 of the second medium M2, if they are almost simultaneous, the medium supply device 1 may not be able to identify the supply start signal from the control unit 151 of the printing device 101, or the control unit 151 may not be able to send the supply start signal continuously. Such communication constraints are likely to occur when the supply start signals of the first supply unit 11 and the second supply unit 12 are sent over a single signal line connected to the printing device 101.

[0067] Therefore, the control unit 151 may control the first supply unit 11 so that the supply start time t12 of the third medium M3 is later than the supply start time t21 of the second medium M2 by at least the switching time tc required to switch the supply unit that supplies the medium M from the second supply unit 12 to the first supply unit 11.

[0068] From the viewpoint of ensuring the above-mentioned switching time tc, it is advisable to delay the supply start time t12 of the third medium M3 not only when the supply start time t12 of the third medium M is earlier than the supply start time t21 of the second medium M as shown in FIG. 3, but also when the supply start time t12 of the third medium M3 is earlier than the time delayed by the switching time tc from the supply start time t21 of the second medium M2.

[0069] In terms of ensuring the above-mentioned switching time tc, when delaying the supply start time t12 of the third medium M3, the control unit 151 may control the first supply unit 11 to make the supply start time t12 of the third medium M3 later than the supply start time t21 of the second medium M2 by at least the switching time tc, as shown in Fig. 4. Note that, since the number of printed sheets (productivity) decreases as the control unit 151 delays the supply start time t12 of the third medium M3, it is preferable to make the supply start time t12 of the third medium M3 later than the supply start time t21 of the second medium M2 and closer to this supply start time t21 (for example, as soon as possible, such as immediately after the supply start time t21 delayed by a predetermined switching time tc) so that the extension arrival interval in-e becomes the minimum interval required.

[0070] In other words, if the sum of the transport time and switching time tc of the third medium M3 is longer than the sum of the transport time and arrival interval in (between the second medium M and the third medium M) of the second medium M2, the arrival interval in can be changed to the extended arrival interval in-e so that the sum of the transport time and switching time tc of the third medium M3 is less than (and preferably equal to) the sum of the transport time of the second medium M2 and the extended arrival interval in-e (between the second medium M and the third medium M).

[0071] Next, a change in productivity caused by delaying the supply start time t12 of the third medium M3 so that the arrival interval in becomes the extended arrival interval in-e will be described.

[0072] FIG. 5 is a table for explaining the arrival interval and productivity for each medium M size.

[0073] 5 shows an example in which the medium M supplied from the first supply unit 11 and the medium M supplied from the second supply unit 12 alternately arrive at the pair of registration rollers 131 at predetermined arrival intervals in1 to in5. Note that the case in which the longitudinal direction of the medium M coincides with the transport direction will be described as "vertical", and the case in which the longitudinal direction of the medium M is perpendicular to the transport direction will be described as "horizontal".

[0074] When the size of medium M is A3 (297 mm x 420 mm) vertical, the medium length is 420 mm, the arrival interval in is the arrival interval in5 [ms], and normally (when the arrival interval in is not changed to the extended arrival interval in-e as described above or the switching time tc is not secured), the productivity [ppm], which is the number of printed sheets per minute, is n5.

[0075] When the size of the medium M is A3 portrait, the size is large enough that there is no difference between the order in which the medium M arrives at the registration roller pair 131 and the order in which supply starts, and even if a switching time tc [ms] of, for example, 10 [ms] is secured between each supply start time, productivity will not change and normal productivity will be 100%.

[0076] When the size of medium M is Letter (216 mm x 280 mm) vertical, the medium length is 280 mm, the arrival interval in is arrival interval in4 [ms] which is shorter than arrival interval in5, and normal productivity [ppm] is n4 which is less than n5.

[0077] Even when the size of the medium M is LETTER vertical, the size is large enough that there is no difference between the order in which the medium M arrives at the registration roller pair 131 and the order in which supply starts, and even if a switching time tc [ms] is secured between each supply start time, productivity does not change and normal productivity is 100%.

[0078] Next, when the size of medium M is B5 (182 mm x 257 mm) vertical, the medium length is 257 mm, the arrival interval in is arrival interval in3 [ms] which is shorter than arrival interval in4, and normal productivity [ppm] is n3 which is less than n4.

[0079] When the size of medium M is B5 portrait, there is no difference between the order in which medium M arrives at the registration roller pair 131 and the order in which supply starts, but by ensuring a switching time tc [ms] between each supply start time, productivity decreases slightly, and normal productivity is 99.6%.

[0080] Next, when the size of the medium M is Letter landscape, the medium length is 216 mm, the arrival interval in is the arrival interval in2 [ms] which is shorter than the arrival interval in3, and the normal productivity [ppm] is n2 which is smaller than n3.

[0081] When the size of the medium M is letter-width, there is a difference between the order in which the medium M arrives at the registration roller pair 131 and the order in which supply starts. Therefore, by changing the arrival interval in to the extended arrival interval in-e as described above to match the arrival order and the supply start order, and by ensuring a switching time tc [ms] between each supply start time, productivity decreases slightly and the productivity compared to normal is 92.2%.

[0082] Next, when the size of medium M is A4 (210 mm x 297 mm) horizontal, the medium length is 210 mm, the arrival interval in is arrival interval in1 [ms] which is shorter than arrival interval in2, and normal productivity [ppm] is n1 which is less than n2.

[0083] Even when the size of the medium M is A4 landscape, there is a difference between the order in which the medium M arrives at the registration roller pair 131 and the order in which supply starts. Therefore, by changing the arrival interval in to the extended arrival interval in-e as described above to match the arrival order and the supply start order, and by ensuring a switching time tc [ms] between each supply start time, productivity decreases slightly and the productivity compared to normal is 91.1%.

[0084] As described above, productivity decreases when the size of medium M is B5 portrait, Letter landscape, and A4 landscape, but in all cases, productivity is maintained at 90% or more compared to normal, and no significant decrease in productivity is observed.

[0085] The switching time tc may include a planned entry time from when the second supply unit 12 starts supplying the medium M until the medium M is detected by the second inlet passage detection sensor S3. In this case, when empty transport occurs in the second supply unit 12, the control unit 151 can determine the empty transport based on the detection result of the second inlet passage detection sensor S3, and re-supply the empty-transported medium M before the first supply unit 11 starts supplying the next medium M. The planned entry time may be determined in advance based on the detection result of the second inlet passage detection sensor S3 for other media M, etc.

[0086] In the present embodiment described above, the medium supply mechanism includes a plurality of supply units that supply medium M, a plurality of individual transport paths with different path lengths connected to the plurality of supply units, a merged transport path P3 where the plurality of individual transport paths merge, and a control unit 151 that causes the plurality of supply units to supply medium M so that medium M reaches a reference arrival position (e.g., registration roller pair 131) on the merged transport path P3 at a reference arrival time (e.g., at each arrival interval in). The plurality of individual transport paths include a first individual transport path P1 and a second individual transport path P2 having a path length shorter than that of the first individual transport path P1. The plurality of medium supply units include a first supply unit 11 that supplies medium M to the first individual transport path P1, and a second supply unit 12 that supplies medium M to the second individual transport path P2. When the control unit 151 causes the medium M (medium M3) supplied from the first supply unit 11 to reach the reference arrival position after the medium M (medium M2 shown in Figure 3) supplied from the second supply unit 12, and when the supply start time t12 of the medium M3 from the first supply unit 11 is earlier than the supply start time of the medium M2 from the second supply unit 12, the control unit 151 controls the first supply unit 11 to make the supply start time t12 of the medium M (M3) from the first supply unit 11 later than the supply start time t21 of the medium M (M2) from the second supply unit 12, as shown in Figure 4.

[0087] This makes it possible to avoid the order of the supply start times being changed to an order different from the order of the medium M arriving at the reference arrival position (e.g., the printing order) when the supply unit that supplies the medium M is switched from the second supply unit 12 that supplies the medium M to the second individual transport path P2 to the first supply unit 11 that supplies the medium M to the first individual transport path P1, which has a shorter path length than the second individual transport path P2. This makes it possible to avoid the control of the restart operation in the event of a jam becoming complicated or the control for changing the order becoming complicated, which is caused by changing the order of the supply start times to an order different from the order of the medium M arriving at the reference arrival position. Here, when the path lengths of the multiple individual transport paths are different, it is possible to increase the conveying speed in each individual transport path as the path length becomes longer so that the order of the supply start times of the medium M becomes the arrival order. However, when the order of the supply start times is made to match the arrival order by only adjusting the conveying speed in this way, the conveying speed is increased as the difference in the path lengths becomes larger, which requires a high-performance motor, which leads to increased costs and complicated control. In this regard, in the present embodiment, since it is possible to avoid matching the order of the supply start times with the arrival order by only adjusting the transport speed, the configuration of the medium supply mechanism can be simplified. Therefore, according to the present embodiment, in a medium supply mechanism having a plurality of individual transport paths connected to a plurality of supply units and having different path lengths, it is possible to simplify the control with a simple configuration.

[0088] In addition, in this embodiment, when the medium M3 supplied from the first supply unit 11 reaches a reference arrival position (e.g., the pair of registration rollers 131) after the medium M (medium M2 shown in FIG. 3) supplied from the second supply unit 12, and the supply start time t12 of the first supply unit 11 is earlier than the time delayed from the supply start time t21 of the second supply unit 12 by the switching time tc for switching the supply unit supplying the medium M from the second supply unit 12 to the first supply unit 11, as shown in FIG. 4, the control unit 151 controls the first supply unit 11 to make the supply start time t12 of the first supply unit 11 later than the supply start time t21 of the second supply unit 12 by at least the switching time tc (more preferably, by the switching time tc).

[0089] By thus ensuring the switching time tc between the supply start times t21 and t12, it is possible to avoid, for example, a situation in which the medium supply device 1 is unable to identify continuous supply start signals from the control unit 151 of the printing device 101, or in which the control unit 151 is unable to send continuous supply start signals.

[0090] In addition, this embodiment further includes a second inlet passage detection sensor S3, which is an example of an entry detection sensor that detects that the medium M supplied from the second supply unit 12 has entered the second individual conveying path P2, and the switching time tc includes the expected entry time from when the second supply unit 12 starts supplying the medium M to when the medium M is detected by the second inlet passage detection sensor S3.

[0091] This makes it possible to determine that empty transport has occurred in the second supply section 12 based on the detection result of the second inlet passage detection sensor S3, so that the medium M supplied from the first supply section 11 reaches the reference arrival position before the medium M that has been empty is re-supplied, thereby avoiding a change in the arrival order.

[0092] In addition, in this embodiment, when the control unit 151 causes the medium M (medium M3) supplied from the first supply unit 11 to reach the reference arrival position after the medium M (medium M2 shown in Figure 3) supplied from the second supply unit 12, and when the supply start time t12 of the medium M3 of the first supply unit 11 is earlier than the supply start time of the medium M2 of the second supply unit 12, the control unit 151 controls the first supply unit 11 so that the supply start time t12 of the medium M (M3) of the first supply unit 11 is later than the supply start time t21 of the medium M (M2) of the second supply unit 12 and closer to the supply start time t12, as shown in Figure 4.

[0093] As a result, even if the arrival interval in at which the medium M reaches the reference arrival position is extended to the extended arrival interval in-e by delaying the supply start time t12 of the first supply unit 11 from the supply start time t21 of the second supply unit 12, this extended arrival interval in-e can be set to the minimum necessary interval. Therefore, it is possible to suppress a decrease in the number of printed sheets (productivity) caused by delaying the supply start time t12 of the first supply unit 11.

[0094] The present invention is not limited to the above-described embodiment as it is, and the components can be modified and embodied without departing from the gist of the invention in the implementation stage. In addition, various inventions can be formed by appropriate combinations of the multiple components disclosed in the above-described embodiment. For example, all the components shown in the embodiment may be appropriately combined. Of course, various modifications and applications are possible without departing from the spirit of the invention. The invention described in the claims at the time of filing of this application is appended below.

[0095] [Appendix 1] A plurality of supply units for supplying media; A plurality of individual transport paths having different path lengths connected to the plurality of supply units; a junction conveying path where the plurality of individual conveying paths join together; a control unit that controls the plurality of supply units to supply the medium so that the medium reaches a reference arrival position on the junction conveying path within a reference arrival time; the plurality of individual transport paths include a first individual transport path and a second individual transport path having a path length shorter than that of the first individual transport path; the plurality of medium supply units include a first supply unit that supplies the medium to the first individual transport path and a second supply unit that supplies the medium to the second individual transport path; When the medium supplied from the first supply unit is caused to reach the reference arrival position after the medium supplied from the second supply unit, and when a supply start time of the first supply unit is earlier than a supply start time of the medium from the second supply unit, the control unit controls the first supply unit to make the supply start time of the first supply unit later than the supply start time of the second supply unit. A media supply mechanism comprising:

[0096] [Appendix 2] When the medium supplied from the first supply unit is caused to reach the reference arrival position after the medium supplied from the second supply unit, and the supply start time of the first supply unit is earlier than a time delayed from the supply start time of the second supply unit by a switching time for switching the supply unit that supplies the medium from the second supply unit to the first supply unit, the control unit controls the first supply unit to delay the supply start time of the first supply unit by at least the switching time. 2. The medium supply mechanism of claim 1.

[0097] [Appendix 3] further comprising an entry detection sensor that detects that the medium supplied from the second supply unit has entered the second individual transport path; The switching time includes a predicted entry time from when the second supply unit starts supplying the medium to when the entry detection sensor detects the medium. 3. The medium supply mechanism according to claim 2.

[0098] [Appendix 4] When the medium supplied from the first supply unit is caused to reach the reference arrival position after the medium supplied from the second supply unit, and when the supply start time of the first supply unit is earlier than the supply start time of the second supply unit, the control unit controls the first supply unit so that the supply start time of the first supply unit is later than the supply start time of the second supply unit and closer to the supply start time of the second supply unit. 2. The medium supply mechanism of claim 1. [Explanation of symbols]

[0099] 1 Media supply device 1a Upper 1b Lower 11 1st supply section 11a Loading platform 11b Suction transport section 12 2nd supply section 12a Loading platform 12b Suction transport section 21-29 1st to 9th conveyor roller pairs 31 Control Unit 32 Storage section 33 Interface section 100 Printing System 101 Printing device 110 Printing Department 120 Suction conveying section 130 Conveyor 131 Registration roller pair 132 Reception Roller 133 Transport roller pair 140 Inversion section 151 Control section 152 Storage section 153 Interface section D1 to D4 First to fourth conveyor drive units in arrival interval in-e extended arrival interval M medium P1 First individual transport path P2 Second individual transport path P3 Converging transport route P11 Destination transport route P12 Circulation reversing conveyor S1 First entrance passage detection sensor S2 First exit passage detection sensor S3 Second entrance passage detection sensor S4 2nd exit passage detection sensor S10 Resist Sensor t11,t12,t21,t22 Supply start time tc Switching time

Claims

1. A plurality of supply units for supplying media; A plurality of individual transport paths having different path lengths connected to the plurality of supply units; a junction conveying path where the plurality of individual conveying paths join together; a control unit that controls the plurality of supply units to supply the medium so that the medium reaches a reference arrival position on the junction conveying path within a reference arrival time; the plurality of individual transport paths include a first individual transport path and a second individual transport path having a path length shorter than that of the first individual transport path, the plurality of supply units include a first supply unit that supplies the medium to the first individual transport path and a second supply unit that supplies the medium to the second individual transport path; When the medium supplied from the first supply unit is caused to reach the reference arrival position after the medium supplied from the second supply unit, and when the supply start time of the first supply unit is earlier than a time delayed from the supply start time of the second supply unit by a switching time for switching the supply unit that supplies the medium from the second supply unit to the first supply unit, the control unit controls the first supply unit to delay the supply start time of the first supply unit by at least the switching time. A media supply mechanism comprising:

2. an entry detection sensor that detects that the medium supplied from the second supply unit has entered the second individual transport path; The switching time includes a predicted entry time from when the second supply unit starts supplying the medium to when the entry detection sensor detects the medium.

2. The media supply mechanism of claim 1.

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