Printing apparatus

Abstract

To provide a printing device that can improve user convenience. [Solution] The control unit performs a first printing operation to print on the first surface of the first medium, a first inversion operation to invert the first medium, a second printing operation to print on the second surface of the first medium, a third printing operation to print on the first surface of the second medium, a second inversion operation to invert the second medium, and a fourth printing operation to print on the second surface of the second medium. The control unit performs the first printing operation, the third printing operation, the second printing operation, and the fourth printing operation in that order. The start timing of the second inversion operation is after the end timing of the first printing operation and before the start timing of the second printing operation. The interval between the start timing of the third printing operation and the start timing of the fourth printing operation is shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation.

Description

[Technical Field]

[0001] The present invention relates to a printing apparatus. [Background Art]

[0002] For example, as disclosed in Patent Document 1, there is provided a printing apparatus that performs printing on both sides of a medium conveyed along a conveyance path and a reversing path. In such a printing apparatus, when performing printing on both sides of a plurality of media, printing is alternately performed on a first side and a second side of the plurality of media based on the same control pattern. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2011-158504 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in such a printing apparatus, there have been cases where the processing interval between consecutive media is increased. As such, it is desired to improve user convenience by further increasing throughput. [Means for Solving the Problem]

[0005] A printing apparatus that solves the above problems comprises a transport unit that transports a medium along a transport path, a printing unit that prints on the medium transported by the transport unit, and a control unit that controls the transport unit and the printing unit, wherein the transport unit inverts the medium by transporting it along an inversion path connected to the transport path, the control unit causes the transport unit and the printing unit to perform a first printing operation to print on the first surface of the first medium, the transport unit to perform a first inversion operation to invert the first medium printed on the first surface by the first printing operation, the transport unit and the printing unit to perform a second printing operation to print on the second surface of the first medium that has been inverted by the first inversion operation, and a third printing operation to print on the first surface of the second medium that is transported after the first medium. The transport unit and the printing unit are instructed to perform a second inversion operation, which inverts the second medium printed on the first surface by the third printing operation, and the transport unit and the printing unit are instructed to perform a fourth printing operation, which prints on the second surface of the second medium that has been inverted by the second inversion operation. The control unit is instructed to perform the first printing operation, the third printing operation, the second printing operation and the fourth printing operation in that order, and the start timing of the second inversion operation is later than the end timing of the first printing operation and earlier than the start timing of the second printing operation, and the interval between the start timing of the third printing operation and the start timing of the fourth printing operation is shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 2] Figure 2 is a block diagram showing the electrical configuration of the printing apparatus according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 4] Figure 4 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 5] Figure 5 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 6]Figure 6 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 7] Figure 7 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 8] Figure 8 is a schematic diagram showing a printing apparatus according to the first embodiment. [Figure 9] Figure 9 is a timing chart showing the control pattern of the first embodiment. [Figure 10] Figure 10 is a timing chart showing the control pattern of the second embodiment. [Figure 11] Figure 11 is a timing chart showing the control pattern of the third embodiment. [Modes for carrying out the invention]

[0007] [First Embodiment] An embodiment of the printing apparatus will be described below with reference to the drawings. In the drawings, the direction of gravity is indicated by the Z-axis, assuming the printing apparatus is placed on a horizontal plane, and the directions along the horizontal plane are indicated by the X-axis and Y-axis. The X-axis, Y-axis, and Z-axis intersect each other.

[0008] <Configuration of the printing device 11> As shown in Figure 1, the printing device 11 is configured to print an image onto a medium 99. The printing device 11 may be, for example, an inkjet printer that prints an image by ejecting ink, which is an example of a liquid, onto the medium 99.

[0009] The printing device 11 may include one or more media storage sections 12. The media storage section 12 is capable of storing multiple media 99 in a stacked state. The printing device 11 may also include a stacker 13. The stacker 13 receives the printed media 99. The printing device 11 may also include a feed tray 14. The feed tray 14 is separate from the media storage section 12 and is a tray capable of stacking multiple media 99.

[0010] A printing apparatus 11 comprises a conveying unit 15 and a printing unit 16. The conveying unit 15 is configured to convey a medium 99 along a conveying path 90. The conveying unit 15 is configured to reverse the medium 99 by conveying the medium 99 along a reversing path 95.

[0011] The printing apparatus 11 comprises a conveying path 90. The conveying path 90 is a path along which the medium 99 is conveyed. In the drawings, the conveying path 90 is indicated by an alternate long and short dash line. In the present embodiment, the direction in which the medium 99 is conveyed is also referred to as a conveying direction D1. The conveying direction D1 is a direction along the conveying path 90. In the present embodiment, "upstream" refers to upstream in the conveying direction D1, and "downstream" refers to downstream in the conveying direction D1.

[0012] The conveying path 90 comprises a first conveying path 91, a second conveying path 92, and a third conveying path 93. The conveying path 90 may further comprise a fourth conveying path 94. The first conveying path 91 is the path located most upstream in the conveying path 90. A medium accommodating portion 12 is provided at an upstream end of the first conveying path 91. The first conveying path 91 is a path for conveying the medium 99 before printing.

[0013] The second conveying path 92 is a path located downstream of the first conveying path 91 in the conveying path 90. The second conveying path 92 is a path for conveying the medium 99 on which the printing unit 16 performs printing.

[0014] The third conveying path 93 is a path located downstream of the second conveying path 92 in the conveying path 90. The third conveying path 93 is the path located most downstream in the conveying path 90. A stacker 13 receives the medium 99 discharged from a downstream end of the third conveying path 93.

[0015] The fourth conveying path 94 is a path that merges with the second conveying path 92 in the conveying path 90. A feed tray 14 is provided at an upstream end of the fourth conveying path 94. The fourth conveying path 94 is a path for conveying the medium 99 before printing.

[0016] The printing apparatus 11 includes a reversing path 95. In the drawing, the reversing path 95 is indicated by an alternate long and short dash line. The reversing path 95 is a path for reversing a medium 99. The reversing path 95 is connected to the conveyance path 90.

[0017] Specifically, an upstream end of the reversing path 95 is connected to a branch point 96 of the conveyance path 90. The branch point 96 is provided on the third conveyance path 93. A downstream end of the reversing path 95 is connected to a confluence point 97 of the conveyance path 90. The confluence point 97 is provided on the first conveyance path 91.

[0018] As described above, the reversing path 95 is a path connecting the third conveyance path 93 to the first conveyance path 91, but may be a path connecting the third conveyance path 93 to the second conveyance path 92. Accordingly, the medium 99 is reversed by being conveyed from the third conveyance path 93 to the first conveyance path 91 via the reversing path 95. A direction in which the medium 99 is conveyed in the reversing path 95 is denoted as a reversing direction D2.

[0019] The conveyance unit 15 includes a plurality of rollers. The conveyance unit 15 includes a feed roller 21 and a first separation roller pair 22. The feed roller 21 is provided at a position along the first conveyance path 91. The feed roller 21 is provided at the most upstream position of the first conveyance path 91. The feed roller 21 feeds the medium 99 stored in the medium storage portion 12 to the conveyance path 90.

[0020] The first separation roller pair 22 is provided at a position along the first conveyance path 91. The first separation roller pair 22 is provided downstream of the feed roller 21 in the conveyance path 90. The first separation roller pair 22 separates the media 99 fed out by the feed roller 21 one by one.

[0021] The conveyance unit 15 includes an intermediate roller pair 23. The intermediate roller pair 23 is provided at a position along the first conveyance path 91. The intermediate roller pair 23 is provided downstream of the first separation roller pair 22 in the conveyance path 90. The intermediate roller pair 23 may be composed of a plurality of rollers.

[0022] The transport unit 15 includes a second pair of separation rollers 24. The second pair of separation rollers 24 is positioned along the fourth transport path 94. The second pair of separation rollers 24 is located at the uppermost part of the fourth transport path 94. The second pair of separation rollers 24 is configured to feed the media 99 loaded on the feed tray 14 one sheet at a time to the transport path 90.

[0023] The transport unit 15 comprises a transport roller pair 25, a first discharge roller pair 26, and a second discharge roller pair 27. The transport roller pair 25 is positioned along the second transport path 92. The transport roller pair 25 is located downstream of the intermediate roller pair 23 in the transport path 90. The transport roller pair 25 is located downstream of the second separation roller pair 24 in the transport path 90. The transport roller pair 25 is located upstream of the printing unit 16 in the transport path 90.

[0024] The first discharge roller pair 26 is positioned along the second transport path 92. The first discharge roller pair 26 is located downstream of the transport roller pair 25 in the transport path 90. The first discharge roller pair 26 is located downstream of the printing section 16 in the transport path 90. The first discharge roller pair 26 is located upstream of the branching point 96 between the transport path 90 and the reversal path 95.

[0025] The second discharge roller pair 27 is located along the third transport path 93. The second discharge roller pair 27 is located downstream of the second discharge roller pair 27 in the transport path 90. The second discharge roller pair 27 is located downstream of the branching point 96.

[0026] The conveying unit 15 is equipped with a pair of reversing rollers 28. The pair of reversing rollers 28 is positioned along the reversing path 95. The pair of reversing rollers 28 is positioned downstream of the branching point 96 in the reversing path 95. The pair of reversing rollers 28 is positioned upstream of the confluence point 97 in the reversing path 95.

[0027] The printing unit 16 is configured to print on the medium 99 that is transported by the transport unit 15. The printing unit 16 is located along the transport path 90. More specifically, the printing unit 16 is located along the second transport path 92.

[0028] The printing unit 16 may include a dispensing unit 41 for dispensing liquid onto the medium 99. The dispensing unit 41 may include a plurality of nozzles 42 for dispensing liquid. The printing unit 16 may perform printing by dispensing liquid.

[0029] The discharge unit 41 is a line head, but it may also be a serial head. A line head is a head that extends in the Y-axis direction and is capable of simultaneously discharging liquid over the entire Y-axis direction of the medium 99. A serial head is a head that is capable of discharging liquid onto the medium 99 while moving in the Y-axis direction. Thus, the printing unit 16 is configured to extend along the Y-axis direction intersecting the transport direction D1, but is not limited to this. The Y-axis direction corresponds to an example of the width direction. In the printing unit 16, the transport direction D1 is along the X-axis direction.

[0030] <Electrical configuration of the printing device 11> As shown in Figure 2, the printing device 11 includes a control unit 19. The control unit 19 comprehensively controls the printing device 11. Specifically, the control unit 19 controls the transport unit 15. The control unit 19 also controls the printing unit 16.

[0031] The control unit 19 controls various operations performed by the printing device 11. The control unit 19 may be configured as a circuit including α: one or more processors that perform various processes according to a computer program, β: one or more dedicated hardware circuits that perform at least some of the various processes, or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform the processes. Memory, or computer-readable media, includes any readable media that can be accessed by a general-purpose or dedicated computer.

[0032] The transport unit 15 includes a first drive unit 31. The first drive unit 31 may be a motor. The first drive unit 31 is driven based on a drive signal from the control unit 19. The first drive unit 31 transports the media 99 along the first transport path 91. The first drive unit 31 is a drive source that transports the media 99 loaded in the media storage unit 12 one sheet at a time along the first transport path 91 by rotating the feed roller 21, the first separation roller pair 22, and the intermediate roller pair 23.

[0033] The first drive unit 31 transports the media 99 along the fourth transport path 94. The first drive unit 31 is a drive source that transports the media 99 loaded on the feed tray 14 one by one along the fourth transport path 94 by rotating the second separation roller pair 24.

[0034] The transport unit 15 includes a second drive unit 32. The second drive unit 32 may be a motor. The second drive unit 32 is driven based on a drive signal from the control unit 19. The second drive unit 32 transports the medium 99 along the second transport path 92. The second drive unit 32 is a drive source that transports the medium 99 along the second transport path 92 by rotating the transport roller pair 25 and the first discharge roller pair 26.

[0035] The transport unit 15 includes a third drive unit 33. The third drive unit 33 may be a motor. The third drive unit 33 is driven based on a drive signal from the control unit 19. The third drive unit 33 transports the medium 99 along the third transport path 93. The third drive unit 33 is a drive source that transports the medium 99 along the third transport path 93 by rotating the second discharge roller pair 27.

[0036] The third drive unit 33 transports the medium 99 along the reversal path 95. The third drive unit 33 is a drive source that transports the medium 99 along the reversal path 95 by rotating the reversal roller pair 28.

[0037] The transport unit 15 includes a switching unit 34. The switching unit 34 is configured to switch whether the second discharge roller pair 27 rotates in the forward direction or in the reverse direction. In other words, the switching unit 34 switches whether to transport the medium 99 along the third transport path 93 toward the stacker 13 or transport the medium 99 from the third transport path 93 toward the reversal path 95. The switching unit 34 may include a clutch. The switching unit 34 switches the rotation direction of the second discharge roller pair 27 based on a control signal from the control unit 19. The switching unit 34 does not need to switch the rotation direction of the reversal roller pair 28.

[0038] The control unit 19 controls the third drive unit 33 and the switching unit 34 to rotate the second discharge roller pair 27 in the forward direction. As a result, the medium 99 is transported along the third transport path 93 in the transport direction D1.

[0039] The control unit 19 controls the third drive unit 33 and the switching unit 34 to reverse the second discharge roller pair 27. As a result, the medium 99 is transported along the third transport path 93 in the direction opposite to the transport direction D1. At the branching point 96, the medium 99 is transported from the third transport path 93 to the reversal path 95.

[0040] The control unit 19 controls the third drive unit 33 to rotate the reversing roller pair 28 in the forward direction. As a result, the medium 99 is transported along the reversing direction D2 in the reversing path 95 by the rotation of the reversing roller pair 28.

[0041] The printing device 11 may include a display unit (not shown). The display unit is configured to display information. The printing device 11 may also include an input unit (not shown). The input unit allows user input of instructions. The input unit may also be an operation unit that can be operated by the user. The input unit may also be a communication unit that allows data input from a terminal device that can communicate with the printing device 11.

[0042] <Double-sided printing on medium 99> In this embodiment, the printing device 11 is capable of double-sided printing of the medium 99 based on user instructions. The printing device 11 prints on the back side of the medium 99 first, and then prints on the front side of the medium 99, although it may print on the front side first, and then print on the back side of the medium 99. The back side of the medium 99 corresponds to an example of the first side. The front side of the medium 99 corresponds to an example of the second side.

[0043] When performing double-sided printing on the medium 99, the control unit 19 controls the transport of the medium 99 and the printing on the medium 99 based on one of several control patterns for double-sided printing. The control patterns are patterns related to the control of the transport unit 15 and the printing unit 16. The multiple control patterns are stored in memory. The multiple control patterns are referenced by the control unit 19.

[0044] More specifically, the control unit 19 controls the transport of the media 99 and printing on the media 99 based on either the first control pattern or the second control pattern. The first control pattern is a control pattern for odd-numbered media 99. The second control pattern is a control pattern for even-numbered media 99. The control unit 19 performs double-sided printing on multiple media 99 by repeatedly performing operations based on the first control pattern and operations based on the second control pattern.

[0045] The control unit 19 prints the back side of the first medium 99 based on a first control pattern, and then controls the machine to print the back side of the second medium 99 based on a second control pattern. After that, the control unit 19 prints the front side of the first medium 99 based on a first control pattern, and then controls the machine to print the front side of the second medium 99 based on a second control pattern. After that, the control unit 19 prints the back side of the third medium 99 based on a first control pattern.

[0046] Here, with reference to Figures 3 to 8, a specific example of performing double-sided printing on media 99 loaded in the feed tray 14 will be explained. The first media 99 will be referred to as the first media 99A, and the second media 99 will be referred to as the second media 99B.

[0047] As shown in Figure 3, the first medium 99A, loaded on the feed tray 14, is transported along the fourth transport path 94 and then to the second transport path 92. This allows printing to be performed on the back side of the first medium 99A. The second medium 99B is loaded on the feed tray 14.

[0048] As shown in Figure 4, the first medium 99A, which has been printed on its reverse side, is transported along the second transport path 92 and the third transport path 93. The first medium 99A may be transported until its leading edge protrudes from the third transport path 93.

[0049] As shown in Figure 5, the first medium 99A is then transported along the third transport path 93 in the opposite direction to the transport direction D1. After being transported from the third transport path 93 to the reversal path 95, the first medium 99A stops in the reversal path 95.

[0050] The second medium 99B, loaded on the feed tray 14, is transported along the fourth transport path 94 and then to the second transport path 92. This allows printing to be performed on the back side of the second medium 99B.

[0051] As shown in Figure 6, the second medium 99B, which has been printed on its reverse side, is transported along the second transport path 92 and the third transport path 93. The second medium 99B may be transported until its leading edge protrudes from the third transport path 93.

[0052] When the second medium 99B is being transported in the transport direction D1 along the third transport path 93, the first medium 99A is transported in the reverse direction D2 along the reverse path 95. As a result, the first medium 99A is transported from the reverse path 95 to the first transport path 91.

[0053] As shown in Figure 7, the second medium 99B is then transported along the third transport path 93 in the opposite direction to the transport direction D1. After being transported from the third transport path 93 to the reversal path 95, the second medium 99B stops in the reversal path 95. The first medium 99A is transported along the first transport path 91 and then to the second transport path 92. This allows printing to be performed on the surface of the reversed first medium 99A.

[0054] As shown in Figure 8, the first medium 99A, which has been printed on both sides, is transported along the second transport path 92 and the third transport path 93. After that, the first medium 99A is discharged from the third transport path 93 to the stacker 13.

[0055] When the first medium 99A is being transported in the transport direction D1 along the third transport path 93, the second medium 99B is transported in the reverse direction D2 along the reverse path 95. As a result, the second medium 99B is transported from the reverse path 95 to the first transport path 91.

[0056] The second medium 99B is transported along the first transport path 91 and then along the second transport path 92. This allows printing to be performed on the inverted surface of the second medium 99B. The second medium 99B, which has been printed on both sides, is transported along the second transport path 92 and the third transport path 93. After that, the second medium 99B is discharged from the third transport path 93 to the stacker 13.

[0057] <Operation details> Next, referring to Figure 9, we will describe the operations controlled by the control unit 19 in a specific example of performing double-sided printing on media 99 loaded in the feed tray 14. The third media 99 is referred to as the third media 99C.

[0058] As shown in Figure 9, the control unit 19 controls the operation corresponding to the first medium 99A based on the first control pattern. Specifically, the control unit 19 causes the transport unit 15 and the printing unit 16 to sequentially execute the first feeding operation, the first printing operation, the first inversion operation, the second feeding operation, the second printing operation, and the first discharge operation based on the first control pattern. In the figure, each feeding operation, each printing operation, each inversion operation, and each discharge operation are simply referred to as feeding, printing, inversion, and discharge, respectively.

[0059] The first feeding operation is the operation of transporting the first medium 99A loaded on the feeding tray 14 along the fourth transport path 94. The first feeding operation is performed by the transport unit 15. More specifically, the first feeding operation is performed by the first drive unit 31.

[0060] The first printing operation involves transporting the first medium 99A along the second transport path 92 and printing on the first surface of the first medium 99A. The first printing operation is performed by the transport unit 15 and the printing unit 16. More specifically, the first printing operation is performed by the second drive unit 32 and the printing unit 16.

[0061] The first inversion operation is an operation to invert the first medium 99A that has been printed on the first surface by the first printing operation. The first inversion operation involves transporting the first medium 99A along the third transport path 93 in the transport direction D1, then transporting the first medium 99A along the third transport path 93 in the opposite direction to the transport direction D1, and finally transporting the first medium 99A along the inversion path 95. The first inversion operation is performed by the transport unit 15. More specifically, the first inversion operation is performed by the third drive unit 33.

[0062] The second feeding operation involves transporting the first medium 99A, which has been inverted by the first inversion operation, from the inversion path 95 to the first transport path 91, and then transporting it along the first transport path 91. The second feeding operation is performed by the transport unit 15. More specifically, the second feeding operation is performed by the first drive unit 31 and the third drive unit 33. The second feeding operation is performed after the first inversion operation is completed and the transport of the first medium 99A has been stopped for a first stop time t1.

[0063] The second printing operation involves transporting the first medium 99A, which has been inverted by the first inversion operation, along the second transport path 92, and printing on the second surface of the first medium 99A. The second printing operation is performed by the transport unit 15 and the printing unit 16. More specifically, the second printing operation is performed by the second drive unit 32 and the printing unit 16.

[0064] The first discharge operation is the operation to discharge the first medium 99A printed on the second side by the second printing operation. The first discharge operation is the operation to transport the first medium 99A along the third transport path 93 in the transport direction D1. The first discharge operation is performed by the transport unit 15. More specifically, the first discharge operation is performed by the third drive unit 33.

[0065] The control unit 19 performs control to cause the second medium 99B to perform operations based on the second control pattern. Specifically, the control unit 19 causes the transport unit 15 and the printing unit 16 to sequentially perform the third feeding operation, the third printing operation, the second inversion operation, the fourth feeding operation, the fourth printing operation, and the second discharge operation based on the second control pattern. The control unit 19 performs control based on the second control pattern in parallel with control based on the first control pattern.

[0066] The third feeding operation is the operation of transporting the second medium 99B loaded on the feeding tray 14 along the fourth transport path 94. The third feeding operation is performed by the transport unit 15. More specifically, the third feeding operation is performed by the first drive unit 31. The third feeding operation may be the same operation as the first feeding operation.

[0067] The third printing operation involves transporting the second medium 99B along the second transport path 92 and printing on the first surface of the second medium 99B. The third printing operation is performed by the transport unit 15 and the printing unit 16. More specifically, the third printing operation is performed by the second drive unit 32 and the printing unit 16. The third printing operation may be the same as the first printing operation.

[0068] The second inversion operation is an operation to invert the second medium 99B that has been printed on the first side by the third printing operation. The second inversion operation involves transporting the second medium 99B along the third transport path 93 in the transport direction D1, then transporting the second medium 99B along the third transport path 93 in the opposite direction to the transport direction D1, and finally transporting the second medium 99B along the inversion path 95. The second inversion operation is performed by the transport unit 15. More specifically, the second inversion operation is performed by the third drive unit 33. The second inversion operation may be the same operation as the first inversion operation.

[0069] The fourth feeding operation is the operation of transporting the second medium 99B, which has been inverted by the second inversion operation, from the inversion path 95 to the first transport path 91, and then transporting it along the first transport path 91. The fourth feeding operation is performed by the transport unit 15. Specifically, the second feeding operation is performed by the first drive unit 31 and the third drive unit 33. The fourth feeding operation may be the same operation as the second feeding operation. The fourth feeding operation is performed after the transport of the second medium 99B has been stopped for a second stop time t2 after the second inversion operation is completed. The second stop time t2 is shorter than the first stop time t1.

[0070] The fourth printing operation involves transporting the second medium 99B, which has been inverted by the second inversion operation, along the second transport path 92, and printing on the second surface of the second medium 99B. The fourth printing operation is performed by the transport unit 15 and the printing unit 16. More specifically, the fourth printing operation is performed by the second drive unit 32 and the printing unit 16. The fourth printing operation may be the same operation as the second printing operation.

[0071] The second discharge operation is the operation to discharge the second medium 99B printed on the second side by the fourth printing operation. The second discharge operation is the operation to transport the second medium 99B along the third transport path 93 in the transport direction D1. The second discharge operation is performed by the transport unit 15. More specifically, the second discharge operation is performed by the third drive unit 33. The second discharge operation may be the same operation as the first discharge operation.

[0072] The control unit 19 repeatedly starts control based on the first control pattern and then starts control based on the second control pattern. Therefore, based on the first control pattern, the control unit 19 performs control to cause the operation corresponding to the third medium 99C to be performed in the same way as the operation corresponding to the first medium 99A.

[0073] <Operation Timing> Next, the operation timing controlled by the control unit 19 will be described. At the timing indicated by the symbol T10, the control unit 19 controls the first drive unit 31 to execute the first feeding operation based on the first control pattern. At the timing indicated by the symbol T11, the control unit 19 controls the second drive unit 32 and the printing unit 16 to execute the first printing operation. As a result, printing is performed on the first surface of the first medium 99A.

[0074] At the timing indicated by the symbol T12, the control unit 19 controls the third drive unit 33 to perform the first reversal operation. More specifically, at the timing indicated by the symbol T12, the control unit 19 controls the third drive unit 33 to transport the first medium 99A along the third transport path 93 in the transport direction D1.

[0075] Subsequently, at the timing indicated by reference numeral T13, the control unit 19 controls the third drive unit 33 and the switching unit 34 to transport the first medium 99A along the third transport path 93 in the opposite direction to the transport direction D1. The control unit 19 controls the third drive unit 33 and the switching unit 34 to transport the first medium 99A along the reversal path 95 in the reversal direction D2.

[0076] At the timing indicated by symbol T14, the control unit 19 controls the third drive unit 33 to stop the transport of the first medium 99A for a first stop time t1. In other words, the control unit 19 stops the transport of the first medium 99A for a first stop time t1 between the first reversal operation and the second printing operation.

[0077] At the timing indicated by reference numeral T15, the control unit 19 controls the first drive unit 31 and the third drive unit 33 to execute the second feeding operation. At the timing indicated by reference numeral T16, the control unit 19 controls the second drive unit 32 and the printing unit 16 to execute the second printing operation. As a result, printing is performed on the second side of the first medium 99A.

[0078] At the timing indicated by the symbol T17, the control unit 19 controls the third drive unit 33 to execute the first ejection operation. As a result, at the timing indicated by the symbol T18, the first medium 99A, which has been printed on both sides, is ejected to the stacker 13.

[0079] When the third time t3 has elapsed from the timing indicated by symbol T10, at the timing indicated by symbol T20, the control unit 19 controls the first drive unit 31 to execute the third feeding operation based on the second control pattern. At the timing indicated by symbol T21, the control unit 19 controls the second drive unit 32 and the printing unit 16 to execute the third printing operation. As a result, printing is performed on the first surface of the second medium 99B.

[0080] At the timing indicated by the symbol T22, the control unit 19 controls the third drive unit 33 to perform the second reversal operation. More specifically, at the timing indicated by the symbol T22, the control unit 19 controls the third drive unit 33 to transport the second medium 99B along the third transport path 93 in the transport direction D1.

[0081] Subsequently, at the timing indicated by reference numeral T23, the control unit 19 controls the third drive unit 33 and the switching unit 34 to transport the second medium 99B along the third transport path 93 in the opposite direction to the transport direction D1. The control unit 19 controls the third drive unit 33 and the switching unit 34 to transport the second medium 99B along the reversal path 95 in the reversal direction D2.

[0082] At the timing indicated by symbol T24, the control unit 19 controls the third drive unit 33 to stop the transport of the second medium 99B in the reversal path 95 for a second stop time t2. In other words, the control unit 19 stops the transport of the second medium 99B for a second stop time t2 between the second reversal operation and the fourth printing operation.

[0083] At the timing indicated by reference numeral T25, the control unit 19 controls the first drive unit 31 and the third drive unit 33 to execute the fourth feeding operation. At the timing indicated by reference numeral T26, the control unit 19 controls the second drive unit 32 and the printing unit 16 to execute the fourth printing operation. As a result, printing is performed on the second side of the second medium 99B.

[0084] At the timing indicated by the symbol T27, the control unit 19 controls the third drive unit 33 to execute the second discharge operation. As a result, at the timing indicated by the symbol T28, the second medium 99B, which has been printed on both sides, is discharged to the stacker 13.

[0085] When the fourth time t4 has elapsed from the timing indicated by symbol T20, at the timing indicated by symbol T30, the control unit 19 controls the first drive unit 31 to execute a feeding operation to feed the third medium 99C based on the first control pattern. At the timing indicated by symbol T31, the control unit 19 controls the second drive unit 32 and the printing unit 16 to execute a printing operation. As a result, printing is performed on the first surface of the third medium 99C. At the timing indicated by symbol T32, the control unit 19 controls the third drive unit 33 to execute an inversion operation to invert the third medium 99C. The operation of the third medium 99C will be omitted from this point onward.

[0086] In this way, when the operations based on the first control pattern and the operations based on the second control pattern are arranged in chronological order, the control unit 19 causes the transport unit 15 and the printing unit 16 to execute the first printing operation, the third printing operation, the second printing operation, and the fourth printing operation in that order.

[0087] Comparing the operation based on the first control pattern with the operation based on the second control pattern, the start timing of the second inversion operation, indicated by symbol T22, is later than the end timing of the first printing operation, indicated by symbol T12. The start timing of the second inversion operation, indicated by symbol T22, is earlier than the start timing of the second printing operation, indicated by symbol T16.

[0088] In addition, the second stop time t2 is shorter than the first stop time t1. Therefore, the interval between the start timing of the third printing operation indicated by symbol T21 and the start timing of the fourth printing operation indicated by symbol T26 is shorter than the interval between the start timing of the first printing operation indicated by symbol T11 and the start timing of the second printing operation indicated by symbol T16.

[0089] Thus, the second control pattern is a control pattern in which the interval between the start timing of the printing operations by the transport unit 15 and the printing unit 16 is shorter than that of the first control pattern. Between the third printing operation and the fourth printing operation, the control unit 19 does not perform the reversal operation of the third medium 99C, which is transported after the second medium 99B.

[0090] <Operation and Effects of the First Embodiment> The operation and effects of the first embodiment will now be described. (1-1) The control unit 19 executes the first printing operation, the third printing operation, the second printing operation, and the fourth printing operation in that order. The start timing of the second inversion operation is after the end timing of the first printing operation and before the start timing of the second printing operation. The interval between the start timing of the third printing operation and the start timing of the fourth printing operation is shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. With this configuration, the fourth printing operation on the second medium 99B can be accelerated. This further improves throughput. Therefore, user convenience can be improved.

[0091] (1-2) The control unit 19 does not perform the reversal operation of the third medium 99C, which is transported after the second medium 99B, between the third printing operation and the fourth printing operation. With this configuration, the interval between the start timing of the third printing operation and the start timing of the fourth printing operation can be made shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. As a result, the fourth printing operation on the second medium 99B can be advanced. This further improves throughput. Therefore, user convenience can be improved.

[0092] (1-3) The second stop time t2 for stopping the transport of the second medium 99B is shorter than the first stop time t1 for stopping the transport of the first medium 99A. With this configuration, the interval between the start timing of the third printing operation and the start timing of the fourth printing operation can be made shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. As a result, the fourth printing operation on the second medium 99B can be accelerated. This further improves throughput. Therefore, user convenience can be improved.

[0093] (1-4) The second control pattern is a control pattern in which the interval between the start timing of the printing operations by the transport unit 15 and the printing unit 16 is shorter than that of the first control pattern. The control unit 19 repeatedly starts control based on the second control pattern after starting control based on the first control pattern. With this configuration, the interval between the start timing of the third printing operation and the start timing of the fourth printing operation can be made shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. As a result, the fourth printing operation on the second medium 99B can be accelerated. This further improves throughput. Therefore, user convenience can be improved.

[0094] (1-5) The transport unit 15 comprises a first drive unit 31, a second drive unit 32, and a third drive unit 33. With this configuration, by effectively utilizing the first drive unit 31, the second drive unit 32, and the third drive unit 33, the medium 99 can be transported along the first transport path 91 and the fourth transport path 94, the second transport path 92, the third transport path 93, and the reversal path 95. In addition, by sharing the third drive unit 33, the medium 99 can be transported along both the third transport path 93 and the reversal path 95.

[0095] [Second Embodiment] Next, a second embodiment will be described. In the following description, redundant explanations of the same configuration as in the previously described embodiment will be omitted or simplified, and configurations that differ from those in the previously described embodiment will be described.

[0096] As shown in Figure 10, in the second embodiment, if the transport of the second medium 99B has not started even after a predetermined time has elapsed from the timing indicated by reference numeral T10, the control unit 19 may perform control to cause the operation corresponding to the second medium 99B to be performed based on the first control pattern. The predetermined time is longer than the third time t3, but may be the same as it.

[0097] The printing apparatus 11 may include detection units for detecting media 99 in the first transport path 91 and the fourth transport path 94. The control unit 19 may determine that the transport of the second media 99B has not started based on the detection signal from the detection unit. The control unit 19 may also determine that the transport of the second media 99B has not started by detecting the occurrence of an error. The control unit 19 may also determine that the transport of the second media 99B has not started when it determines that no media 99 is loaded in the media storage unit 12 and the feed tray 14.

[0098] If the transport of the second medium 99B has not started, the control unit 19 may, after a fifth time t5 has elapsed from the timing indicated by symbol T10, perform control to cause the operation corresponding to the second medium 99B based on the first control pattern. The fifth time t5 may be the sum of the third time t3 and the fourth time t4.

[0099] Thus, if the transport unit 15 does not start transporting the second medium 99B after the completion of the first printing operation, the control unit 19 performs control to perform the operation corresponding to the second medium 99B based on the first control pattern after the transport of the first medium 99A is completed. Subsequently, the control unit 19 performs control to perform the operation corresponding to the third medium 99C based on the second control pattern.

[0100] As a result, the control of media 99 with an odd number of sheets changes from control based on the first control pattern to control based on the second control pattern. The control of media 99 with an even number of sheets changes from control based on the second control pattern to control based on the first control pattern.

[0101] If the transport of the second medium 99B is started within a predetermined time elapsed from the timing indicated by reference numeral T10, the control unit 19 performs control to cause the operation corresponding to the second medium 99B to be performed based on the second control pattern, in the same manner as in the first embodiment.

[0102] <Operation and Effects of the Second Embodiment> The operation and effects of the second embodiment will now be described. (2-1) If the transport of the second medium 99B is not started after the completion of the first printing operation, the control unit 19 performs control to perform the operation corresponding to the second medium 99B based on the first control pattern after the transport of the first medium 99A is completed. The control unit 19 also performs control to perform the operation corresponding to the third medium 99C based on the second control pattern. With this configuration, even if the transport of the second medium 99B is not started after the completion of the first printing operation, the transport unit 15 and the printing unit 16 can be controlled using the first control pattern and the second control pattern. Therefore, user convenience can be improved.

[0103] [Third Embodiment] Next, a third embodiment will be described. As shown in Figure 11, in the third embodiment, the control unit 19 may change the transport speed of the medium 99 between the first control pattern and the second control pattern. For example, in the second inversion operation based on the second control pattern, the control unit 19 may transport the medium 99 at a faster transport speed than in the first inversion operation based on the first control pattern.

[0104] Thus, the transport speed of the second medium 99B in the second inversion operation is faster than the transport speed of the first medium 99A in the first inversion operation. In other words, the transport speed of the second medium 99B between the start timing of the third printing operation and the start timing of the fourth printing operation is faster than the transport speed of the first medium 99A between the start timing of the first printing operation and the start timing of the second printing operation. For this reason, the interval between the start timing of the third printing operation, indicated by symbol T21, and the start timing of the fourth printing operation, indicated by symbol T26, is shorter than the interval between the start timing of the first printing operation, indicated by symbol T11, and the start timing of the second printing operation, indicated by symbol T16.

[0105] The control unit 19 does not need to stop the transport of the first medium 99A between the first reversal operation and the second printing operation. The control unit 19 does not need to stop the transport of the second medium 99B between the second reversal operation and the fourth printing operation.

[0106] <Operation and Effects of the Third Embodiment> The operation and effects of the third embodiment will now be described. (3-1) The transport speed of the second medium 99B between the start timing of the third printing operation and the start timing of the fourth printing operation is faster than the transport speed of the first medium 99A between the start timing of the first printing operation and the start timing of the second printing operation. With this configuration, the interval between the start timing of the third printing operation and the start timing of the fourth printing operation can be made shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. Therefore, the fourth printing operation on the second medium 99B can be accelerated. This further improves throughput. Consequently, user convenience can be improved.

[0107] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0108] In the first and second embodiments, there may be a period during which the transport unit 15 performs the first reversal operation and the second reversal operation in parallel. Even in such a case, the control unit 19 can rotate the reversal roller pair 28 in the forward direction during the first reversal operation, and then rotate the second discharge roller pair 27 in the forward direction during the second reversal operation by controlling the switching unit 34.

[0109] In the first and second embodiments, when stopping the medium 99 after the first and second reversal operations, it may be stopped on the first transport path 91 instead of the reversal path 95.

[0110] In the second embodiment, if the transport of the second medium 99B has not started, the control unit 19 may, after a predetermined time has elapsed from the timing indicated by reference numeral T10, perform control to cause the operation corresponding to the second medium 99B based on the first control pattern. The predetermined time may be shorter than the fifth time t5, or longer than the fifth time t5. If the transport of the second medium 99B has not started, the control unit 19 may, when the second medium 99B becomes ready for transport, perform control to cause the operation corresponding to the second medium 99B based on the first control pattern.

[0111] In the third embodiment, the control unit 19 may stop the transport of the first medium 99A for a first stop time t1 between the first reversal operation and the second printing operation. The control unit 19 may stop the transport of the second medium 99B for a second stop time t2 between the second reversal operation and the fourth printing operation. In this case, the second stop time t2 is shorter than the first stop time t1, but may be longer than the first stop time t1, or may be the same as the first stop time t1.

[0112] The control unit 19 may repeatedly control the transport unit 15 and the printing unit 16 based on a first control pattern and a second control pattern, treating three or more media 99 as a set. To give a specific example of controlling three media 99 as a set, the control unit 19 performs control to cause the operation corresponding to the first media 99 to be performed based on the first control pattern. The control unit 19 performs control to cause the operation corresponding to the second media 99 to be performed based on the first control pattern. The control unit 19 performs control to cause the operation corresponding to the third media 99 to be performed based on the second control pattern. In such a case, the second media 99 corresponds to an example of the first media 99A. The third media 99 corresponds to an example of the second media 99B. The fourth media 99 corresponds to an example of the third media 99C.

[0113] Thus, the control unit 19 may perform control based on the second control pattern to perform an operation corresponding to the medium 99 that is a multiple of a natural number N. The control unit 19 may also perform control based on the first control pattern to perform an operation corresponding to the medium 99 that is not a multiple of a natural number N.

[0114] The control unit 19 may control the transport unit 15 and the printing unit 16 based on three or more control patterns. The three or more control patterns may include a first control pattern and a second control pattern. The control unit 19 may also control the transport unit 15 and the printing unit 16 based on detection signals from various media detection units, without relying on control patterns.

[0115] The printing device 11 may include a switchback path. The printing device 11 uses the third transport path 93 to switch back the medium 99, but it may also use a separate switchback path to switch back the medium 99.

[0116] The upstream end of the reversal path 95 may be connected to the downstream end of the second transport path 92. The switchback path may be connected to the downstream end of the second transport path 92 and the upstream end of the reversal path 95. The downstream end of the reversal path 95 may be connected to the upstream end of the second transport path 92. The medium 99 may be transported from the second transport path 92 to the switchback path, and then from the switchback path to the reversal path 95. The medium 99 may be transported from the reversal path 95 to the second transport path 92 in a reversed state.

[0117] At least one of the first separation roller pair 22, intermediate roller pair 23, second separation roller pair 24, conveying roller pair 25, first discharge roller pair 26, second discharge roller pair 27, and reversing roller pair 28 may be composed of a drive roller and a driven roller.

[0118] At least one of the first separation roller pair 22, intermediate roller pair 23, second separation roller pair 24, conveying roller pair 25, first discharge roller pair 26, second discharge roller pair 27, and reversing roller pair 28 may be composed of a drive roller pair.

[0119] The first separation roller pair 22, the intermediate roller pair 23, the second separation roller pair 24, the conveying roller pair 25, the first discharge roller pair 26, the second discharge roller pair 27, and the reversing roller pair 28 may consist of one or more roller pairs.

[0120] The control unit 19 may control the transport unit 15 and the printing unit 16 when the medium 99 is supplied from the medium storage unit 12, in the same way as when the medium 99 is supplied from the supply tray 14. In other words, the control unit 19 may control the transport unit 15 and the printing unit 16 based on a first control pattern and a second control pattern when the supply source is the same. The printing device 11 may be configured not to supply the medium 99 from the supply tray 14. The printing device 11 may include at least one of the medium storage unit 12 and the supply tray 14.

[0121] The conveying unit 15 may include a drive unit separate from the first drive unit 31, the second drive unit 32, and the third drive unit 33. For example, the conveying unit 15 may include a fourth drive unit separate from the third drive unit 33 that rotates the reversing roller pair 28. In this case, the third drive unit 33 rotates the second discharge roller pair 27 without rotating the reversing roller pair 28. For example, the conveying unit 15 may include a fifth drive unit separate from the first drive unit 31 that rotates the second separation roller pair 24. In this case, the first drive unit 31 rotates the feed roller 21, the first separation roller pair 22, and the intermediate roller pair 23 without rotating the second separation roller pair 24.

[0122] The transport unit 15 may also include a second switching unit separate from the switching unit 34 for switching whether or not to drive the reversing roller pair 28. The control unit 19 may selectively control the driving of the second discharge roller pair 27 and the driving of the reversing roller pair 28 by controlling the second switching unit.

[0123] The conveying unit 15 does not necessarily have to include a switching unit 34. In particular, if the driving source for the second discharge roller pair 27 and the driving source for the reversing roller pair 28 are separate, the conveying unit 15 does not need to include a switching unit 34 if it can reverse the second discharge roller pair 27.

[0124] The transport unit 15 does not necessarily have to include at least one of the first drive unit 31, the second drive unit 32, and the third drive unit 33. The transport unit 15 may share at least one combination of the first drive unit 31, the second drive unit 32, and the third drive unit 33.

[0125] The medium 99 may be paper, resin films or sheets, composite films of resin and metal, laminate films, textiles, nonwoven fabrics, metal foils, metal films, ceramic sheets, and clothing.

[0126] The liquid can be any liquid that can be applied to the medium 99 and used for printing on the medium 99. For example, ink may include functional material particles consisting of solids such as pigments and metal particles dissolved, dispersed, or mixed in a solvent, and shall encompass various compositions such as water-based inks, oil-based inks, gel inks, and hot-melt inks.

[0127] A lateral printer may be used as the printing device 11. A lateral printer is a printer in which the carriage can move in two directions, the X-axis direction and the Y-axis direction. The printing device 11 is not limited to an inkjet printer, but may also be a dot matrix printer. The printing device 11 may also be a laser printer.

[0128] As used herein, the expression "at least one of" means one or more of the desired options. For example, as used herein, if there are two options, the expression "at least one of" means either one option or both of the two options. As another example, as used herein, if there are three or more options, the expression "at least one of" means either one option or any combination of two or more options.

[0129] [Note] The following describes the technical concepts and their effects as understood from the embodiments and modifications described above. These technical concepts and their effects can be combined with each other to the extent that they do not contradict each other.

[0130] [1] The printing apparatus comprises a transport unit that transports a medium along a transport path, a printing unit that prints on the medium transported by the transport unit, and a control unit that controls the transport unit and the printing unit, wherein the transport unit inverts the medium by transporting it along an inversion path connected to the transport path, the control unit causes the transport unit and the printing unit to perform a first printing operation to print on the first surface of the first medium, the transport unit to perform a first inversion operation to invert the first medium printed on the first surface by the first printing operation, the transport unit and the printing unit to perform a second printing operation to print on the second surface of the first medium that has been inverted by the first inversion operation, and the transport unit to perform a third printing operation to print on the first surface of the second medium that is transported after the first medium The control unit causes the printing unit to perform a second inversion operation, which inverts the second medium printed on the first surface by the third printing operation, and the transport unit to perform a fourth printing operation, which prints on the second surface of the second medium that has been inverted by the second inversion operation. The control unit causes the first printing operation, the third printing operation, the second printing operation, and the fourth printing operation to be performed in that order. The start timing of the second inversion operation is later than the end timing of the first printing operation and earlier than the start timing of the second printing operation. The interval between the start timing of the third printing operation and the start timing of the fourth printing operation is shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation.

[0131] This configuration allows the interval between the start of the third printing operation and the start of the fourth printing operation to be shorter than the interval between the start of the first printing operation and the start of the second printing operation. Therefore, the fourth printing operation on the second medium can be accelerated, further improving throughput. Consequently, user convenience can be enhanced.

[0132] [2] In the above-described printing apparatus, the control unit does not need to perform an inversion operation of the medium that is transported after the second medium between the third printing operation and the fourth printing operation. This configuration prevents the reversal of the medium transported after the second medium between the third and fourth printing operations. This allows the interval between the start of the third and fourth printing operations to be shorter than the interval between the start of the first and second printing operations. Therefore, the fourth printing operation on the second medium can be accelerated, further improving throughput and thus enhancing user convenience.

[0133] [3] In the above-described printing apparatus, the control unit stops the transport of the first medium for a first stop time between the first reversal operation and the second printing operation, and stops the transport of the second medium for a second stop time between the second reversal operation and the fourth printing operation, wherein the second stop time may be shorter than the first stop time.

[0134] This configuration allows the second stop time, which stops the transport of the second medium between the second inversion operation and the fourth printing operation, to be shorter than the first stop time, which stops the transport of the first medium between the first inversion operation and the second printing operation. This makes the interval between the start timing of the third printing operation and the start timing of the fourth printing operation shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. As a result, the fourth printing operation on the second medium can be accelerated. This further improves throughput. Therefore, user convenience can be improved.

[0135] [4] In the above-described printing apparatus, the transport speed of the second medium between the start timing of the third printing operation and the start timing of the fourth printing operation may be faster than the transport speed of the first medium between the start timing of the first printing operation and the start timing of the second printing operation.

[0136] This configuration allows the transport speed of the second medium between the start of the third printing operation and the start of the fourth printing operation to be faster than the transport speed of the first medium between the start of the first printing operation and the start of the second printing operation. This makes the interval between the start of the third printing operation and the start of the fourth printing operation shorter than the interval between the start of the first printing operation and the start of the second printing operation. Therefore, the fourth printing operation on the second medium can be accelerated, further improving throughput and thus enhancing user convenience.

[0137] [5] In the above-described printing apparatus, the control unit performs control to cause an operation corresponding to a first medium based on a first control pattern, and performs control to cause an operation corresponding to a second medium based on a second control pattern, wherein the second control pattern is a control pattern in which the interval between the start timing of printing operations by the transport unit and the printing unit is shorter than that of the first control pattern, and the control unit may repeatedly start control based on the second control pattern after starting control based on the first control pattern.

[0138] In this configuration, after starting control based on the first control pattern, control based on the second control pattern, which has a shorter interval between the start timings of the printing operations than the first control pattern, is repeatedly started. This makes the interval between the start timing of the third printing operation and the start timing of the fourth printing operation shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. Therefore, the fourth printing operation on the second medium can be accelerated. This further improves throughput. Consequently, user convenience can be improved.

[0139] [6] In the above-described printing apparatus, if the transport unit does not start transporting the second medium after the completion of the first printing operation, the control unit may, after the transport of the first medium is completed, perform control to cause an operation corresponding to the second medium based on the first control pattern, and perform control to cause an operation corresponding to a third medium that is transported by the transport unit after the second medium based on the second control pattern.

[0140] With this configuration, if the transport of the second medium does not start after the completion of the first printing operation, control can be performed to perform an operation corresponding to the second medium based on the first control pattern. Subsequently, control can be performed to perform an operation corresponding to the third medium based on the second control pattern. As a result, even if the transport of the second medium does not start after the completion of the first printing operation, the transport unit and the printing unit can be controlled using the first control pattern and the second control pattern. Therefore, user convenience can be improved.

[0141] [7] The printing apparatus described above, wherein the transport path includes a first transport path, a second transport path downstream of the first transport path, and a third transport path downstream of the second transport path, the printing unit is located along the second transport path, the reversal path is a path connected from the third transport path to the first transport path or the second transport path, and the transport unit may include a first drive unit for transporting a medium along the first transport path, a second drive unit for transporting a medium along the second transport path, and a third drive unit for transporting a medium along the third transport path and the reversal path.

[0142] With this configuration, by using the first drive unit, the second drive unit, and the third drive unit, the medium can be transported along the first transport path, the second transport path, the third transport path, and the reversal path. In addition, by sharing the third drive unit, the medium can be transported along both the third transport path and the reversal path. [Explanation of symbols]

[0143] 11…Printing device, 12…Media storage unit, 13…Stacker, 14…Feed tray, 15…Conveying unit, 16…Printing unit, 19…Control unit, 21…Feeding roller, 22…First separation roller pair, 23…Intermediate roller pair, 24…Second separation roller pair, 25…Conveying roller pair, 26…First discharge roller pair, 27…Second discharge roller pair, 28…Reversing roller pair, 31…First drive unit, 32…Second drive unit, 33…Third drive unit, 34… Switching section, 41…Discharge section, 42…Nozzle, 90…Conveying path, 91…First conveying path, 92…Second conveying path, 93…Third conveying path, 94…Fourth conveying path, 95…Reversal path, 96…Branching point, 97…Merging point, 99…Media, 99A…First media, 99B…Second media, 99C…Third media, D1…Conveying direction, D2…Reversal direction, t1…First stop time, t2…Second stop time, t3…Third time, t4…Fourth time, t5…Fifth time.

Claims

1. A transport unit that transports the medium along the transport path, A printing unit that prints on the medium transported by the transport unit, A control unit that controls the transport unit and the printing unit, Equipped with, The transport unit inverts the medium by transporting it along the inversion path connected to the transport path. The control unit, The transport unit and the printing unit are instructed to perform a first printing operation, which prints on the first surface of the first medium. The transport unit is instructed to perform a first inversion operation to invert the first medium printed on the first surface by the first printing operation. The transport unit and the printing unit are instructed to perform a second printing operation, which prints on the second side of the first medium that has been inverted by the first inversion operation. The transport unit and the printing unit are instructed to perform a third printing operation, which prints on the first surface of a second medium that is transported after the first medium. The transport unit is then instructed to perform a second inversion operation, which inverts the second medium printed on the first surface by the third printing operation. The transport unit and the printing unit are instructed to perform a fourth printing operation, which prints on the second surface of the second medium that has been inverted by the second inversion operation. The control unit causes the first printing operation, the third printing operation, the second printing operation, and the fourth printing operation to be executed in that order. The start timing of the second inversion operation is after the end timing of the first printing operation and before the start timing of the second printing operation. The interval between the start timing of the third printing operation and the start timing of the fourth printing operation is shorter than the interval between the start timing of the first printing operation and the start timing of the second printing operation. A printing apparatus characterized by the following features.

2. A printing apparatus according to claim 1, The control unit prevents the inversion operation of the medium transported after the second medium from being performed between the third printing operation and the fourth printing operation. A printing apparatus characterized by the following features.

3. A printing apparatus according to claim 1, The control unit, Between the first reversal operation and the second printing operation, the transport of the first medium is stopped for a first stop time. Between the second reversal operation and the fourth printing operation, the transport of the second medium is stopped for a second stop time. The second stop time is shorter than the first stop time. A printing apparatus characterized by the following features.

4. A printing apparatus according to claim 1, The transport speed of the second medium between the start timing of the third printing operation and the start timing of the fourth printing operation is faster than the transport speed of the first medium between the start timing of the first printing operation and the start timing of the second printing operation. A printing apparatus characterized by the following features.

5. A printing apparatus according to claim 1, The control unit, Based on the first control pattern, control is performed to cause the system to perform an action corresponding to the first medium. Based on the second control pattern, control is performed to cause the second medium to perform an action corresponding to that medium. The second control pattern is a control pattern in which the interval between the start timings of the printing operations by the transport unit and the printing unit is shorter than that of the first control pattern. The control unit repeatedly starts control based on the second control pattern after starting control based on the first control pattern. A printing apparatus characterized by the following features.

6. A printing apparatus according to claim 5, If the transport unit does not start transporting the second medium after the completion of the first printing operation, the control unit, after the transport of the first medium is completed, performs control to cause the operation corresponding to the second medium to be performed based on the first control pattern. Based on the second control pattern, control is performed to cause the transport unit to perform an operation corresponding to the third medium that is transported after the second medium. A printing apparatus characterized by the following features.

7. A printing apparatus according to any one of claims 1 to 6, The transport path includes a first transport path, a second transport path downstream of the first transport path, and a third transport path downstream of the second transport path. The printing unit is provided at a position along the second transport path, The inversion path is a path that connects from the third transport path to the first transport path or the second transport path, The aforementioned transport unit is A first drive unit that transports the medium along the first transport path, A second drive unit for transporting the medium along the second transport path, A third drive unit that transports the medium along the third transport path and the inversion path, Having, A printing apparatus characterized by the following features.

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