Recording device, control method, storage medium, and program

Abstract

To reduce an overlapping amount of a preceding recording medium and a subsequent recording medium, while slowing down the conveyance speed of the preceding recording medium.SOLUTION: A recording device includes: recording means for recording an image in a recording medium; first conveyance means for conveying the recording medium in a conveyance direction; second conveyance means for conveying the recording medium recorded by the recording means, on the downstream side in the conveyance direction of the first conveyance means; and control means capable of performing reduction control which reduces an overlapping amount of a preceding recording medium and a subsequent recording medium, from a state where the following subsequent recording medium overlaps with a rear end of the preceding medium which precedes it. The reduction control includes control which, in a state where the subsequent recording medium can be conveyed by the first conveyance means in the conveyance direction, stops the conveyance of the subsequent recording medium by the first conveyance means, and conveys the preceding recording medium by the second conveyance means.SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] The present invention relates to a recording apparatus.

Background Art

[0002] There is known a recording apparatus that transports a preceding recording medium and a succeeding recording medium while maintaining a stacked state in which the leading end portions thereof are overlapped, and performs recording on the succeeding recording medium. After the overlapping portion has passed through the recording head, it may be desirable to eliminate the stacked state or reduce the amount of overlap from the viewpoints of the dischargeability of the recording medium and prevention of jamming. Patent Document 1 discloses a recording apparatus that eliminates the stacked state by increasing the transport speed of the preceding recording medium. body

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the method of eliminating the stacked state by increasing the transport speed of the preceding recording medium, very high-speed transport may be required depending on the dimensions of the transport path of the recording medium, which is disadvantageous in terms of noise and power consumption. <000​​​​​​​​​​​​​​​​​​​ Downstream of the first transport means in the transport direction, a second transport means for transporting the recording medium recorded by the recording means, A control means capable of reducing the amount of overlap between a preceding recording medium and a succeeding recording medium, from a state where the succeeding recording medium overlaps the trailing end of a preceding recording medium, A recording device equipped with, The control means performs recording control that alternately performs the transport operation of the recording medium and the recording operation that performs recording by the recording means while moving the carriage. The aforementioned reduction control is This is performed during the recording control for the subsequent recording medium, The control includes stopping the transport of the subsequent recording medium by the first transport means and transporting the preceding recording medium by the second transport means when the subsequent recording medium is transportable by the first transport means in the transport direction, A recording device characterized by the above is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique that reduces the amount of overlap between the preceding recording medium and the succeeding recording medium at a lower transport speed for the preceding recording medium. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of a recording device according to one embodiment of the present invention. [Figure 2] Block diagram of the control unit of the recording device shown in Figure 1. [Figure 3] (A) and (B) are diagrams showing examples of recording conditions. [Figure 4] (A) and (B) are diagrams illustrating the operation of the recording device in Figure 1. [Figure 5] (A) and (B) are diagrams illustrating the operation of the recording device in Figure 1. [Figure 6] (A) and (B) are diagrams illustrating the operation of the recording device in Figure 1. [Figure 7] (A) and (B) are diagrams illustrating the operation of the recording device in Figure 1. [Figure 8] (A) and (B) are diagrams illustrating the operation of the recording device in Figure 1. [Figure 9](A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 10] (A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 11] (A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 12] (A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 13] (A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 14] (A) and (B) are operation explanatory diagrams of the recording apparatus in FIG. 1. [Figure 15] Flowchart showing an example of the processing of the control unit in FIG. 2. [Figure 16] Flowchart showing an example of the processing of the control unit in FIG. 2. [Figure 17] Flowchart showing an example of the processing of the control unit in FIG. 2. [Figure 18] (A) to (C) are explanatory diagrams of the reduction control. [Figure 19] (A) to (C) are explanatory diagrams of the reduction control. [Figure 20] Flowchart showing an example of the processing of the control unit in FIG. 2. [Figure 21] (A) and (B) are operation explanatory diagrams of the recording apparatus showing another example of the reduction control. [Figure 22] (A) and (B) are operation explanatory diagrams of the recording apparatus showing another example of the reduction control. [Figure 23] (A) and (B) are operation explanatory diagrams of the recording apparatus showing another example of the reduction control.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] <First Embodiment> <Outline of the recording device> Figure 1 is a schematic diagram of the recording device 1 in this embodiment. In this embodiment, the application of the present invention to a serial inkjet recording device is described, but the present invention is also applicable to other types of recording devices. In the figure, arrows X and Y indicate mutually orthogonal horizontal directions, and arrow Z indicates the vertical direction. Furthermore, the terms downstream and upstream refer to the transport direction of the recording medium.

[0011] Furthermore, "recording" includes not only cases where meaningful information such as characters and figures is formed, but also broadly cases where images, patterns, etc. are formed on a recording medium, or where the medium is processed, regardless of whether it is meaningful or not, and does not depend on whether or not it is manifested in a way that can be perceived visually by humans.In addition, in this embodiment, a sheet of paper is assumed as the "recording medium," but it may also be cloth, plastic film, etc.

[0012] The recording device 1 is a device that records data onto sheets SH, which are recording media, loaded onto a feeding tray (loading section) 2, and discharges them onto an output tray 17. A main transport path RT1 that guides the transport of the sheets SH is formed from the feeding tray 2 to the output tray 17, and the sheets SH on the feeding tray 2 are introduced one by one into the main transport path RT1 by a pickup roller 3. The pickup roller 3 is rotated by the driving force of the feeding motor 22. In each figure, although there is only one path between the feeding unit 4 and the transport unit 5 of the main transport path RT1 schematically shown, upper and lower paths are shown along the upper and lower transport guides.

[0013] The recording device 1 also has a secondary transport path RT2 that branches off from the main transport path RT1 at branching point BP. The secondary transport path RT2 is a path that inverts the front and back sides of the sheet SH and returns the sheet SH to the main transport path RT1, and is used when recording both sides of the sheet SH. Note that the recording device 1 may not have a double-sided recording function for the sheet SH, in which case the secondary transport path RT2 and related configurations are unnecessary.

[0014] The recording device 1 comprises a feeding unit 4 and a plurality of transport units 5 to 10. The feeding unit 4 and transport units 5 to 8 are arranged along the main transport path RT1. In the transport direction of the sheet SH along the main transport path RT1, they are arranged from upstream to downstream in the order of feeding unit 4, transport unit 5, transport unit 6, transport unit 7, and transport unit 8. Transport units 9 and 10 are arranged along the secondary transport path RT2, and in the transport direction of the sheet SH along the secondary transport path RT2, they are arranged from upstream to downstream in the order of transport unit 9, and transport unit 10.

[0015] In the following explanation, unless otherwise specified, "upstream" and "downstream" refer to the upstream and downstream sides in the transport direction of sheet SH along the main transport path RT1. Similarly, "leading end" and "rear end" of sheet SH refer to the downstream and upstream ends of sheet SH.

[0016] The feeding unit 4 feeds the sheets SH introduced into the main transport path RT1 by the pickup roller 3, or the sheets SH returned to the main transport path RT1 from the secondary transport path RT2, to the transport unit 5. The feeding unit 4 includes a feeding roller 4a and a driven roller 4b which is pressed against the feeding roller 4a by a spring or the like (not shown). The feeding roller 4a is a rotating body that rotates by the driving force of the feeding motor 23, and the driven roller 4b is a rotating body that rotates in accordance with the rotation of the feeding roller 4a.

[0017] The sheet SH is held between the drive roller 4a and the driven roller 4b at the nip section and conveyed by the rotation of the drive roller 4a and the driven roller 4b. The pickup roller 3 is a one-way roller, and once the sheet SH has been conveyed to a position beyond the nip section of the feeding unit 4, the feeding unit 4 can continue conveying the sheet SH even if the drive of the pickup roller 3 is stopped.

[0018] Although this embodiment includes a pickup roller 3 and a feed roller 4a, it may also be configured to include only a feed roller 4a that feeds the sheets SH loaded on the feed tray 2.

[0019] Sensor 31 is a sensor that detects the passage of the leading and trailing ends of sheet SH, and is, for example, an optical sensor. The detection position of sensor 31 is set to a position downstream of the nip portion of the feeding unit 4.

[0020] The transport unit 5 is located upstream of the recording head 12, and the feed unit 4 The sheet SH, which is fed by the conveyor, is transported to the recording head 12. The sheet SH is transported downstream by the conveyor unit 5 between the recording head 12 and the platen 15 facing the recording head 12. The conveyor unit 5 includes a conveyor roller 5a and a driven roller (pinch roller) 5b which is pressed against the conveyor roller 5a by a spring or the like (not shown). The conveyor roller 5a is a rotating body that rotates by the driving force of the conveyor motor 24, and the driven roller 5b is a rotating body that rotates in accordance with the rotation of the conveyor roller 5a. The sheet SH is held between the nip portion of the conveyor roller 5a and the driven roller 5b and is transported by the rotation of the conveyor roller 5a and the driven roller 5b.

[0021] The transport unit 6 is positioned downstream of the recording head 12 and transports the sheet SH, which is transported by the transport unit 5, downstream. The transport unit 6 includes a transport roller 6a and a spur 6b which is pressed against the transport roller 6a by a spring (not shown) or the like. The transport roller 6a is a rotating body that rotates by the driving force of the transport motor 24, and the spur 6b is a rotating body that rotates in accordance with the rotation of the transport roller 6a. In this embodiment, the transport unit 5 and the transport unit 6 share a drive source (motor 24).

[0022] The transport unit 7 is positioned downstream of the recording head 12 and the transport unit 6, and transports the sheet SH transported by the transport unit 6 downstream. The transport unit 7 includes a transport roller 7a and a driven roller 7b which is pressed against the transport roller 7a by a spring (not shown) or the like. The transport roller 7a is a rotating body that rotates by the driving force of the transport motor 25, and the driven roller 7b is a rotating body that rotates in accordance with the rotation of the transport roller 7a. The sheet SH is held between the nip portion of the transport roller 7a and the driven roller 7b and transported by the rotation of the transport roller 7a and the driven roller 7b.

[0023] The transport unit 8 is located downstream of the recording head 12 and transport units 6 and 7, and is an discharge unit that discharges the sheet SH transported by transport unit 7 to the discharge tray 17. The transport unit 8 includes a transport roller 8a and a driven roller 8b which is pressed against the transport roller 8a by a spring (not shown) or the like. The transport roller 8a is a rotating body that rotates by the driving force of the transport motor 25, and the driven roller 8b is a rotating body that rotates in accordance with the rotation of the transport roller 8a. The sheet SH is held between the nip portion of the transport roller 8a and the driven roller 8b and is transported by the rotation of the transport roller 8a and the driven roller 8b. In this embodiment, the transport unit 7 and the transport unit 8 share a drive source (motor 25).

[0024] A flapper 16 is positioned at the branching point BP. The flapper 16 switches the transport route for sheet SH between the main transport route RT1 and the secondary transport route RT2. At the position shown in Figure 1, the flapper 16 maintains the transport route for sheet SH as the main transport route RT1, and sheet SH is discharged to the discharge tray 17 via the transport unit 8. The flapper 16 is rotatably mounted and rotates to switch routes using an actuator 27 such as an electromagnetic solenoid.

[0025] The transport unit 9 is a reversing unit that transports the sheet SH that has entered the secondary transport path RT2 from the branching point BP. The secondary transport path RT2 has a reversing path RT21 that extends upward from the branching point BP through the branching point BP', and a return path RT22 that extends from the branching point BP' to the supply unit 4. The transport unit 9 is located on the reversing path RT21.

[0026] The transport unit 9 includes a transport roller 9a and a driven roller 9b which is pressed against the transport roller 9a by a spring or the like (not shown). The transport roller 9a is a rotating body that rotates by the driving force of the transport motor 26, and the driven roller 9b is a rotating body that rotates in accordance with the rotation of the transport roller 9a.

[0027] The sheet SH, having entered the secondary transport path RT2 from the branching point BP, moves along the reverse path RT21. The transport roller 9a rotates bidirectionally in the R1 direction and the opposite R2 direction. As the transport roller 9a rotates in the R1 direction, the sheet SH is transported in the direction of arrow F. When the rear end of the sheet SH passes the branching point BP', the rotation direction of the transport roller 9a is switched to the R2 direction. The sheet SH is then transported in the reverse direction. The sheet SH is then reversed and introduced from the branching point BP' into the return path RT22.

[0028] The transport unit 10 is an intermediate unit located in the return path RT22. The transport unit 10 includes a transport roller 10a and a driven roller 10b which is pressed against the transport roller 10a by a spring (not shown) or the like. The transport roller 10a is a rotating body that rotates by the driving force of the transport motor 26, and the driven roller 10b is a rotating body that rotates in accordance with the rotation of the transport roller 10a. The sheet SH is held between the transport roller 10a and the driven roller 10b at the nip portion and transported by the rotation of the transport roller 10a and the driven roller 10b. In this embodiment, the transport unit 9 and the transport unit 10 share a drive source (motor 26). The transport roller 10a is a one-way roller, and after the sheet SH has been transported to a position beyond the nip portion of the feeding unit 4, the feeding unit 4 can continue transporting even if the drive of the transport roller 10a is stopped.

[0029] The recording head 12 is located in the middle of the main transport path RT1. In this embodiment, the recording head 12 is located downstream of the transport unit 5 and upstream of the transport unit 6. The recording head 12 performs recording on the sheet SH. Near the recording head 12, the sheet SH is transported in the X direction. In this embodiment, the recording head 12 is an inkjet recording head that ejects ink to record on the recording medium. The recording head 12 is supported by the carriage 11.

[0030] The carriage 11 reciprocates by the drive unit 14 in a direction that traverses the sheet SH (a direction that intersects the transport direction of the sheet SH near the recording head 12). In this embodiment, the carriage 11 reciprocates in the Y direction guided by a guide shaft 13 that extends in the Y direction.

[0031] The drive unit 14 is a mechanism driven by the carriage motor 21, and is, for example, a belt drive mechanism comprising a drive pulley and a driven pulley spaced apart in the Y direction, and an endless belt wound around these pulleys. The carriage 11 is connected to the endless belt. When the carriage motor 21 rotates the drive pulley, the endless belt moves and the carriage 11 moves. Recording head 12 is carriage 11 It may be attached in a replaceable manner.

[0032] As described above, the recording device 1 of this embodiment is a serial type recording device in which a recording head 12 is mounted on a carriage 11. Recording control for the sheet SH is performed by alternately repeating an intermittent transport operation (intermittent transport operation) in which a predetermined amount of recording medium is transported by transport units 5 and / or 6, and a recording operation while transport by transport units 5 and / or 6 is stopped. The recording operation is the operation of ejecting ink from the recording head 12 while moving the carriage 11 on which the recording head 12 is mounted.

[0033] <Control Unit> Figure 2 is a block diagram of the control unit 40 of the recording device 1. The MPU 41 is a processor that controls the operation of the recording device 1 and processes data. The MPU 41 executes programs stored in the storage device 42 to control the entire recording device 1. The storage device 42 is composed of, for example, ROM or RAM. The storage device 42 stores various data necessary for processing, such as programs executed by the MPU 41 and data received from the host computer 100.

[0034] The MPU 41 controls the recording head 12 via driver 44a. The MPU 41 controls the carriage motor 21 via driver 44b. The MPU 41 also controls the feed motors 22 and 23, transport motors 24 to 26, and actuator 27 via drivers 44c to 44i.

[0035] The sensor group 30 includes, in addition to sensor 31, a sensor (not shown) that detects the position of the carriage 11 in the Y direction, and sensors (not shown) that detect the rotation amounts of the feed motors 22 and 23 and the transport motors 24-26. By detecting the rotation amount of each motor, the rotation amount of the corresponding feed roller and transport roller can be identified, and the amount of sheet SH to be transported can be calculated.

[0036] The host computer 100 is, for example, a personal computer or mobile device (such as a smartphone or tablet) used by the user. The host computer 100 has a printer driver 100a installed that enables communication between the host computer 100 and the recording device 1. The recording device 1 is equipped with an I / F (interface) unit 43, and communication between the host computer 100 and the MPU 41 is performed via the interface unit 43.

[0037] For example, when the user inputs a request to execute recording control to the host computer 100, the printer driver 100a collects the data of the image to be recorded and the recording conditions (various information such as the quality of the recorded image), generates a recording job, and sends it to the recording device 1.

[0038] <Control Example> An example of control performed by the MPU41 is described below. When a recording job is sent from the host computer 15 via the I / F unit 43, it is processed by the MPU41 and then expanded into the storage device 42. The MPU41 starts control based on the expanded data.

[0039] <Recording conditions> Figures 3(A) and 3(B) show examples of recording conditions related to the transport operation of the sheets SH, which are included in the recording job. The recording device 1 of this embodiment is capable of single-sided and double-sided recording. Figure 3(A) shows an example of recording conditions when performing double-sided recording on two sheets SH, and Figure 3(B) shows an example of recording conditions when performing single-sided recording on three sheets SH. The recording order is assumed to be a face-down method in which the immediately preceding recording surface is discharged into the discharge tray 17 facing downwards, but a face-up method may also be used.

[0040] "Recording Order N" indicates the number and order of recording control on a single-sided basis for sheet SH, where N is the variable. In the example in Figure 3(A), recording control is performed on 4 sides (4 times), and in the example in Figure 3(B), it is performed on 3 sides (3 times).

[0041] "Page number K" indicates which page of the final recording corresponds to the recording order N, and K is the variable for this. "Sheet M" indicates the target sheet SH of the recording order N, and M is the variable for this. In this embodiment, the sheets are numbered in the order they are fed from the feed tray 2. Sheet SH1 indicates the first sheet SH fed from the feed tray 2 in that recording job, sheet SH2 indicates the second sheet SH fed from the feed tray 2, and sheet SH3 indicates the third sheet SH fed from the feed tray 2.

[0042] The variable M can sometimes be expressed as M(N) as a function of the recording order N. In the example in Figure 3(A), M(1) represents sheet SH1, M(2) represents sheet SH2, and M(3) represents sheet SH1. In the example in Figure 3(B), M(3) represents sheet SH3.

[0043] "Recording surface F" indicates which of the front and back sides (in other words, the first and second sides) of sheet SH is the recording surface, and is sometimes expressed as F(N) as a function of the recording order N. In the example in Figure 3(A), F(1) means that the back side of sheet SH1 is the recording surface, and F(3) means that the front side of sheet SH1 is the recording surface.

[0044] "Source Q" indicates whether the source of sheet SH is the supply tray 2 or the sub-transport route RT2, and may be expressed as Q(N) as a function of the recording order N. In this implementation configuration, for double-sided recording, after recording on the back side, sheet SH is reversed in the reversal route RT21 of the sub-transport route RT2, and sheet SH is returned to the supply unit 4 via the return route RT22. For double-sided recording, the supply tray 2 or the sub-transport route RT2 is the source. For single-sided recording, the supply tray 2 is always the source.

[0045] "Post-recording processing G" indicates whether the sheet SH is processed after recording by being discharged to the discharge tray 17 or reversed on the sub-transport path RT2, and may be expressed as G(N) as a function of the recording order N. In the case of single-sided recording, processing G is always discharge. In the case of double-sided recording, the post-recording processing G for the first side is reversed, and the post-recording processing G for the next side is discharge.

[0046] <Example of operation> An example of the operation of recording device 1 will be explained with reference to Figures 4(A) to 14(B). Here, an example of operation when performing double-sided recording on two sheets SH according to the recording conditions in Figure 3(A) will be explained.

[0047] Refer to Figure 4(A). Since the recording conditions in Figure 3(A) are double-sided recording, the flapper 16 is moved in advance to guide the sheet SH to the secondary transport path RT2. The feed motor 22 is driven at a low speed. As a result, the pickup roller 3 rotates at, for example, 7.6 inches / sec (the transport speed of the sheet SH; similar expressions below have the same meaning). When the pickup roller 3 rotates, the top sheet SH loaded on the feed tray 2 is picked up. This is referred to as sheet SH1.

[0048] The sheet SH1 picked up by the pickup roller 3 is transported along the main transport path RT1 by the feed roller 4a, which rotates in the same direction as the pickup roller 3. The feed roller 4a is driven by the feed motor 23 at the same speed as the pickup roller 3. When the pickup roller 3 has transported the sheet SH1 beyond the feed roller 4a, it stops so as not to pick up the next sheet SH. As described above, the pickup roller 3 is a one-way roller, and even if the pickup roller 3 is stopped, feeding by the feed roller 4a can continue.

[0049] When the leading edge of the sheet SH1 is detected by the sensor 31 located downstream of the feed roller 4a in the conveying direction, the feed motor 23 is switched to high-speed drive. The feed roller 4a rotates at, for example, 20 inches / sec.

[0050] Refer to Figure 4(B). When the feeding roller 4a continues to feed the sheet SH1, the leading edge of the sheet SH1 will be on the conveyor roller 5a and the pinch roller 5 b The sheet SH1 abuts against the nip formed by the sheet. At this time, the conveying roller 5a is stopped. By rotating the feeding roller 4a by a predetermined amount even after the leading edge of the sheet SH1 abuts against the nip, the entire width of the leading edge of the sheet SH1 abuts against the nip, and the skew of the sheet SH1 can be corrected (skew correction operation).

[0051] Once the sheet SH1's skew correction operation is complete, the transport motor 24 is driven, causing the transport roller 5a to start rotating. The transport roller 5a transports the sheet SH1 at, for example, 15 inches / sec. When the sheet SH1 is positioned to face the recording head 12, recording control can begin. As shown in Figure 3(A) under the condition N=1, the recording operation for the second page of data is started on the back (top) surface of the sheet SH1.

[0052] Furthermore, when the leading edge of the sheet SH1 abuts against the nip portion of the transport unit 5, the leading edge of the sheet SH1 is temporarily positioned at the location of the transport roller 5a. Using this position as a reference, the positions of the leading and trailing edges of the sheet SH1 can be calculated based on the amount of rotation of the transport roller 5a thereafter. During the initial setup, this position control ensures that the sheet SH1 is transported to a position facing the recording head 12.

[0053] As described above, the recording device 1 of this embodiment is a serial type recording device in which the recording head 12 is mounted on the carriage 11. Recording on the sheet SH1 is performed by repeating a transport operation in which the transport roller 5a intermittently transports the recording medium in predetermined amounts, and a recording operation in which ink is ejected from the recording head 12 while the carriage 11 moves. When the beginning of the sheet SH1 is brought forward, the feed motor 23 is switched to low-speed drive. That is, the feed roller 4a rotates at, for example, 7.6 inches / sec. When the transport roller 5a is intermittently transporting the sheet SH1 in predetermined amounts, the feed roller 4a is also driven intermittently by the feed motor 23. That is, when the transport roller 5a is rotating, the feed roller 4a also rotates, and when the transport roller 5a is stopped, the feed roller 4a also stops. The rotation speed of the feed roller 4a is small compared to the rotation speed of the transport roller 5a. Therefore, the sheet SH is taut between the transport roller 5a and the feed roller 4a. Furthermore, the feeding roller 4a is made to rotate along with the sheet SH1, which is transported by the conveying roller 5a.

[0054] As recording progresses on sheet SH1, the leading edge of sheet SH1 reaches the transport unit 6. The transport roller 6a shares the same drive source, the transport motor 24, as the transport roller 5a, and is therefore controlled synchronously. Figure 5(B) shows the stage when the leading edge of sheet SH1 has passed the transport roller 6a.

[0055] Next, feeding of sheet SH2 begins following sheet SH1. Here, due to factors such as the responsiveness of the sensor, a predetermined interval is required between consecutive sheets SH in order for sensor 31 to detect the edge of the sheet SH. Therefore, the pickup operation of sheet SH2 begins after sensor 16 detects the rear end of sheet SH1 and determines that it has passed sensor 16. Furthermore, the rotation of the pickup roller 3 during the feeding of sheet SH2 is controlled so that the distance between the rear end of sheet SH1 and the front end of sheet SH2 is greater than or equal to a predetermined distance. In this embodiment, the positions of the front and rear ends of the sheet SH are determined by calculation from the rotation amounts of various rollers, but they may also be calculated using a separate sensor.

[0056] Refer to Figure 5(B). The rear end of sheet SH1 passes through the paper feed roller 4a and hangs slightly downwards. Sheet SH2, picked up by the pickup roller 3, is transported by the feed roller 4a. At this time, recording control is being performed on sheet SH1 in parallel. When the leading edge of sheet SH2 is detected by sensor 31, the feed motor 23 is switched to high-speed drive. That is, the feed roller 4a rotates at, for example, 20 inches / sec.

[0057] Furthermore, when the conveyor rollers 5a and 6a are intermittently conveying a predetermined amount of sheet SH1, the conveyor rollers 7a and 9a are intermittently driven by the conveyor motors 25 and 26 in the same rotational direction and speed as the conveyor roller 5a.

[0058] In this embodiment, the formation of an overlapping state can be controlled. Refer to Figure 6(A). By feeding sheet SH2 at a high speed relative to the transport speed of sheet SH1, an overlapping state is formed where the leading edge of sheet SH2 overlaps the rear end of sheet SH1 in front of the transport roller 5a. Since sheet SH1 is controlled based on recorded data, sheet SH1 is transported intermittently by the transport roller 5a. On the other hand, after the rear end of sheet SH2 is detected by the sensor 31, the feed roller 4a can catch up with sheet SH1 by continuously rotating at 20 inches / sec. After that, sheet SH2 is transported until its leading edge reaches a predetermined position slightly before the nip portion of the transport unit 5. The position of the leading edge of sheet SH2 is calculated from the amount of rotation of the feed roller 4a since the leading edge of sheet SH2 was detected by the sensor 31, and control is performed based on this calculation result. Sheet SH1 enters the sub-transport path RT2 guided by the flapper 16.

[0059] Next, the sheet SH2 is straightened. When the transport roller 5a is stopped for the recording operation of sheet SH1, the leading edge of sheet SH2 is driven to abut the nip portion. In this embodiment, in order to minimize the impact on the recording quality of sheet SH1, the straightening operation of sheet SH2 is performed when the transport roller 5a is stopped for the recording operation of the last row of sheet SH1.

[0060] Refer to Figure 6(B). When the recording operation for the last row of sheet SH1 is completed, the transport roller 5a is rotated by a predetermined amount to maintain the state in which sheet SH2 is overlapping sheet SH1 and to allow the beginning of sheet SH2 to be brought out. The overlapping portion of sheet SH1 and sheet SH2 is held in place by the nip portion of the transport unit 5 and transported.

[0061] When sheet SH2 is brought forward, the feed motor 23 is switched to low-speed drive. That is, the feed roller 4a rotates at, for example, 7.6 inches / sec. When sheet SH2 is being intermittently transported by the transport roller 5a in predetermined amounts, the feed roller 4a is also intermittently driven by the feed motor 23. As shown in Figure 3(A) under the condition N=2, the recording operation for the fourth page of recorded data is started on the back (top) surface of sheet SH2. When sheet SH2 is being intermittently transported for the recording operation, sheet SH1 is also being transported intermittently.

[0062] In this embodiment, it is possible to control the amount of overlap. When the overlapping portions of sheets SH1 and SH2 pass through the branching point BP, there is a risk of paper jamming. For example, if sheets SH1 and SH2 are transported along different paths at the branching point BP, the relative positions of sheets SH1 and SH2 may cause sheet SH2 to interfere with sheet SH1, resulting in a paper jam. For example, this can occur when sheet SH1 passes through the branching point BP along the main transport path RT1, while the subsequent sheet SH2, which overlaps sheet SH1 on top of it, is transported to the secondary transport path RT2.

[0063] Therefore, a reduction control is performed to decrease the amount of overlap before the overlapping portion reaches the branching point BP (in other words, before sheet SH2 reaches the branching point BP). In this embodiment, the amount of overlap is set to 0. However, even if the amount of overlap is not 0, reducing it will have a certain effect.

[0064] Refer to Figure 7(A). Based on the amount of rotation of the transport roller 5a from the start of the sheet SH1's leading edge movement and the length of the sheet SH1, it is determined whether the rear end of the sheet SH1 has passed the transport roller 6a. As illustrated in Figure 7(A), when the rear end of the sheet SH1 has passed the transport roller 6a, the transport roller 7a can transport the preceding sheet SH1, and the transport rollers 5a and 6a can transport the following sheet SH2. At this timing, the transport rollers 5a and 6a do not affect the transport of sheet SH1, and the transport roller 7a does not affect the transport of sheet SH2. At this timing, the reduction control is started.

[0065] In the reduction control mode, the transport roller 7a is continuously rotated by the transport motor 25, independently of the transport rollers 5a and 6a. The transport roller 9a is also rotated by the transport motor 26 in the R1 direction (see Figure 1) at the same speed as the transport roller 7a.

[0066] The relative speed difference between sheet SH1 and sheet SH2 allows the rear end of sheet SH1 to be pulled away from sheet SH2, as shown in Figure 7(B). At this time, the speed of the conveyor roller 7a is controlled so that the reduction control is completed before the rear end of the leading sheet SH1 passes the conveyor roller 7a. An example of speed control will be described later.

[0067] This reduction control prevents paper jams by preventing the overlapping portion of sheets SH1 and SH2 from passing through the branching point BP. Since the reduction control is performed during the recording control of sheet SH2, it includes at least a control section in which the transport rollers 5a and 6a stop transporting the subsequent sheet SH2 and the transport roller 7a transports the preceding sheet SH1.

[0068] In other words, the transport of sheet SH2 is stopped during its recording operation. By continuously transporting sheet SH1 during this recording operation, the relative speed difference between sheet SH1 and sheet SH2 can be maximized, and the overlap amount can be efficiently reduced. Therefore, the speed of transport roller 7a does not necessarily need to be faster than that of transport roller 5a in order to reduce the overlap amount. The overlap amount of sheet SH1 and sheet SH2 can be reduced at a lower transport speed for sheet SH1. In other words, by performing reduction control during the recording operation, the transport speed can be reduced and deterioration of noise and power consumption can be suppressed compared to when reduction control is not performed during the recording operation. However, if the reduction control is not completed during the recording operation of sheet SH2, reduction control can also be performed during the transport operation of sheet SH2. In this case, it is effective to reduce the overlap amount when the speed of transport roller 7a is faster than that of transport roller 5a. Of course, it goes without saying that reduction control may also be performed when the reduction control is completed during the recording operation of sheet SH2.

[0069] Refer to Figure 8(A). The sheet SH1 is continuously transported by the transport roller 9a until its rear end passes the branching point BP'. When the rear end of the sheet SH1 passes the branching point BP', the transport motor 26 is reversed in the R2 direction (see Figure 1) and switched to high-speed drive. The front and rear ends of the sheet SH1 are swapped in terms of its transport direction. The transport rollers 9a and 10a are rotated, for example, at 18 inches / sec. The sheet SH1 enters the return path RT22 and is transported to the feed roller 4a as shown in Figure 8(B).

[0070] As the sheet SH1 is being transported, and its leading edge is detected by the sensor 31, the transport motor 26 and the feed motor 23 are driven at a low speed. As a result, the transport roller 10a and the feed roller 4a rotate at, for example, 7.6 inches / sec. The sheet SH1 is then transported from the return path RT22 to the main transport path RT1 by the transport roller 10a and the feed roller 4a.

[0071] Next, control is performed to form the overlapping state. Refer to Figure 9(A). Unlike in Figure 6(A), sheet SH2 is the leading sheet and sheet SH1 is the following sheet. Sheet SH2 is controlled to record based on recorded data. When the rear end of sheet SH2 is detected by sensor 31, the transport motor 26 and the feed motor 23 are switched to high-speed drive. That is, the transport roller 10a and the feed roller 4a rotate at, for example, 20 inches / sec. By moving sheet SH1 at high speed, an overlapping state is formed where the leading edge of sheet SH1 overlaps the rear end of sheet SH2. Since sheet SH2 is controlled to record based on recorded data, sheet SH2 is intermittently transported by the transport roller 5a. On the other hand, after the rear end of sheet SH1 is detected by sensor 31, the feed roller 4a can continuously rotate at 20 inches / sec to catch up with sheet SH2. After that, sheet SH1 is transported until its leading edge reaches a predetermined position slightly before the nip portion of the transport unit 5. The position of the leading edge of sheet SH1 is calculated from the amount of rotation of the feed roller 4a after the leading edge of sheet SH1 is detected by sensor 31, and control is performed based on this calculation result. Sheet SH2 enters the secondary transport path RT2 guided by flapper 16.

[0072] Next, the sheet SH1 is straightened. When the transport roller 5a is stopped for the recording operation of sheet SH2, the leading edge of sheet SH1 is brought into contact with the nip by driving the feed roller 4a. In this embodiment, in order to minimize the impact on the recording quality of sheet SH2, the straightening operation of sheet SH1 is performed when the transport roller 5a is stopped for the recording operation of the last row of sheet SH2.

[0073] Refer to Figure 9(B). When the recording operation for the last row of sheet SH2 is completed, the transport roller 5a is rotated by a predetermined amount to maintain the state in which sheet SH1 is overlapping sheet SH2 and to allow the beginning of sheet SH1 to be brought out. The overlapping portion of sheet SH1 and sheet SH2 is held in place by the nip portion of the transport unit 5 and transported.

[0074] When sheet SH1 is brought forward, the feed motor 23 is switched to low-speed drive. That is, the feed roller 4a rotates at, for example, 7.6 inches / sec. When sheet SH2 is being intermittently transported by the transport roller 5a in predetermined amounts, the feed roller 4a is also intermittently driven by the feed motor 23. Based on the recording data, the recording operation for the first page of recording data on the surface (top surface) of sheet SH1 is started by ejecting ink from the recording head 12. When sheet SH1 is being intermittently transported for the recording operation, sheet SH2 is also being transported intermittently.

[0075] Next, the amount of overlap is reduced. Sheet SH2 is introduced into the secondary transport path RT2, while sheet SH1 is discharged while maintaining transport on the main transport path RT1. Then, the reduction control is performed again.

[0076] Refer to Figure 10(A). Based on the amount of rotation of the transport roller 5a from the start of the sheet SH2's leading edge movement and the length of the sheet SH2, it is determined whether or not the rear end of the sheet SH2 has passed the transport roller 6a. As illustrated in Figure 10(A), when the rear end of the sheet SH1 passes the transport roller 6a, the transport roller 7a can transport the preceding sheet SH2, and the transport rollers 5a and 6a can transport the following sheet SH1. At this timing, the transport rollers 5a and 6a do not affect the transport of sheet SH2, and the transport roller 7a does not affect the transport of sheet SH1. At this timing, the reduction control is started.

[0077] In the reduction control mode, the transport roller 7a is continuously rotated by the transport motor 25, independently of the transport rollers 5a and 6a. The transport roller 9a is also rotated by the transport motor 26 in the R1 direction (see Figure 1) at the same speed as the transport roller 7a.

[0078] The relative speed difference between sheet SH2 and sheet SH1 allows the rear end of sheet SH2 to be pulled away from sheet SH1, as shown in Figure 10(B). At this time, the speed of the conveyor roller 7a is controlled so that the reduction control is completed before the rear end of the preceding sheet SH2 passes the conveyor roller 7a. An example of speed control will be described later.

[0079] Since the reduction control is performed during the recording control of sheet SH1, it includes at least a control section in which the transport of the subsequent sheet SH1 by transport rollers 5a and 6a is stopped, and the preceding sheet SH2 is transported by transport roller 7a.

[0080] In other words, the transport of sheet SH1 is stopped during its recording operation. By continuously transporting sheet SH2 during this recording operation, the relative speed difference between sheet SH2 and sheet SH1 can be maximized, and the amount of overlap can be efficiently reduced. The amount of overlap between sheet SH2 and sheet SH1 can be reduced by transporting sheet SH2 at a lower speed. If the reduction control is not completed during the recording operation of sheet SH2, it is also performed during the transport operation of sheet SH2. In this case, the speed of the transport roller 7a being faster than that of the transport roller 5a is effective in reducing the amount of overlap.

[0081] Refer to Figure 11(A). The conveyor roller 9a continuously conveys the sheet SH2 until its rear end passes the branching point BP'. When the rear end of sheet SH2 passes the flapper 16, the flapper 16 is rotated in accordance with the post-recording processing of sheet SH1, which will pass through the flapper 16 next. Since the post-recording processing of sheet SH1 is discharge, the flapper 16 moves to a position that maintains the conveying path of sheet SH1 on the main conveying path RT1. Whether the rear end of sheet SH2 has passed the flapper 16 can be determined from the amount of rotation of the various rollers, or by providing a separate sensor.

[0082] When the rear end of sheet SH2 passes the branching point BP', the transport motor 26 is reversed in the R2 direction (see Figure 1) and switched to high-speed drive. The front and rear ends of sheet SH2 are swapped in terms of its transport direction. Transport rollers 9a and 10a are rotated at, for example, 18 inches / sec. Sheet SH2 enters the return path RT22 and is transported to the feed roller 4a as shown in Figure 11(B).

[0083] As the sheet SH2 is being transported, and its leading edge is detected by the sensor 31, the transport motor 26 and the feed motor 23 are driven at a low speed. As a result, the transport roller 10a and the feed roller 4a rotate at, for example, 7.6 inches / sec. The sheet SH2 is then transported from the return path RT22 to the main transport path RT1 by the transport roller 10a and the feed roller 4a.

[0084] Next, control is performed to form the overlapping state. Refer to Figure 12(A). Once again, sheet SH1 becomes the leading sheet and sheet SH2 becomes the following sheet. Sheet SH1 is controlled to record based on recorded data. When the rear end of sheet SH1 is detected by sensor 31, the transport motor 26 and the feed motor 23 are switched to high-speed drive. That is, the transport roller 10a and the feed roller 4a rotate at, for example, 20 inches / sec. By moving sheet SH2 at high speed, an overlapping state is formed where the leading edge of sheet SH2 overlaps the rear end of sheet SH1. Since sheet SH1 is controlled to record based on recorded data, sheet SH1 is transported intermittently by the transport roller 5a. On the other hand, after the rear end of sheet SH2 is detected by sensor 31, the feed roller 4a can continuously rotate at 20 inches / sec to catch up with sheet SH2. After that, sheet SH2 is transported until its leading edge reaches a predetermined position slightly before the nip portion of the transport unit 5. The position of the leading edge of sheet SH2 is calculated from the amount of rotation of the feed roller 4a after the leading edge of sheet SH2 is detected by sensor 31, and control is performed based on this calculation result. The leading edge of sheet SH1 passes through branching point BP and heads towards the transport roller 8a.

[0085] Next, the sheet SH2 is straightened. When the transport roller 5a is stopped for the recording operation of sheet SH1, the leading edge of sheet SH2 is driven to abut the nip portion. In this embodiment, in order to minimize the impact on the recording quality of sheet SH1, the straightening operation of sheet SH2 is performed when the transport roller 5a is stopped for the recording operation of the last row of sheet SH1.

[0086] Refer to Figure 12(B). When the recording operation for the last row of sheet SH1 is completed, the transport roller 5a is rotated by a predetermined amount to maintain the state in which sheet SH2 is overlapping sheet SH1 and to allow the beginning of sheet SH2 to be brought out. The overlapping portion of sheet SH1 and sheet SH2 is held in place by the nip portion of the transport unit 5 and transported.

[0087] When sheet SH2 is brought forward, the feed motor 23 is switched to low-speed drive. That is, the feed roller 4a rotates at, for example, 7.6 inches / sec. When sheet SH2 is being intermittently transported by the transport roller 5a in predetermined amounts, the feed roller 4a is also intermittently driven by the feed motor 23. Based on the recorded data, the recording operation for the third page of recorded data on the surface (top surface) of sheet SH2 is started by ejecting ink from the recording head 12. When sheet SH2 is being intermittently transported for the recording operation, sheet SH1 is also being transported intermittently.

[0088] Next, control is performed to reduce the amount of overlap. If sheets SH1 and SH2 are ejected while significantly overlapping, the stacking order of sheets SH1 and SH2 on the output tray 25 may be reversed. Therefore, control is performed to reduce the amount of overlap. In this embodiment, the amount of overlap is set to 0. However, even if the amount of overlap is not 0, reducing it will have a certain effect.

[0089] Refer to Figure 13(A). Based on the amount of rotation of the transport roller 5a from the start of the sheet SH1's leading edge movement and the length of the sheet SH1, it is determined whether the rear end of the sheet SH1 has passed the transport roller 6a. As illustrated in Figure 13(A), when the rear end of the sheet SH1 has passed the transport roller 6a, the transport roller 7a can transport the preceding sheet SH1, and the transport rollers 5a and 6a can transport the following sheet SH2. At this timing, the transport rollers 5a and 6a do not affect the transport of sheet SH1, and the transport roller 7a does not affect the transport of sheet SH2. At this timing, the reduction control is started.

[0090] In the reduction control mode, the transport roller 7a is continuously rotated by the transport motor 25, independently of the transport rollers 5a and 6a. The transport roller 8a, which shares the transport motor 25, also rotates continuously.

[0091] The relative speed difference between sheet SH1 and sheet SH2 allows the rear end of sheet SH1 to be pulled away from sheet SH2, as shown in Figure 13(B). At this time, the speed of the conveyor roller 7a is controlled so that the reduction control is completed before the rear end of the leading sheet SH1 passes the conveyor roller 7a. An example of speed control will be described later.

[0092] This reduction control prevents sheets SH1 and SH2 from being discharged stacked on top of each other, thus preventing the stacking order on the discharge tray 17 from being reversed. Since the reduction control is performed during the recording control of sheet SH2, it includes at least a control section in which the transport rollers 5a and 6a stop transporting the subsequent sheet SH2 and the transport roller 7a transports the preceding sheet SH1.

[0093] In other words, sheet SH2 is stopped from being transported during its recording operation. By continuously transporting sheet SH1 during this recording operation, the relative speed difference between sheet SH1 and sheet SH2 can be maximized, and the overlap can be efficiently reduced. Therefore, the speed of transport roller 7a does not necessarily need to be faster than that of transport roller 5a in order to reduce the overlap. The overlap between sheet SH1 and sheet SH2 can be reduced at a lower transport speed for sheet SH1. In other words, by performing reduction control during the recording operation, the transport speed can be reduced and deterioration of noise and power consumption can be suppressed compared to when reduction control is not performed during the recording operation. However, if the reduction control is not completed during the recording operation of sheet SH2, it is also performed during the transport operation of sheet SH2. In this case, it is effective for the speed of transport roller 7a to be faster than that of transport roller 5a in reducing the overlap.

[0094] Refer to Figure 14(A). Since both sides of sheet SH1 have been recorded, it is discharged into the discharge tray 17. When the recording of the last row of sheet SH2 is completed, the recording of both sides of sheet SH2, the last sheet of this job, is also completed. By rotating the transport rollers 8a, 7a, 6a, and 5a in the same direction, sheet SH2 is discharged into the discharge tray 17 as shown in Figure 14(B).

[0095] With the above steps, the double-sided recording operation based on the recording conditions in Figure 3(A) is completed. In the case of single-sided recording based on the recording conditions in Figure 3(B), the operation is carried out similarly, except for the operation of introducing sheet SH into the sub-transport path RT2, and the control of overlap formation and the control of overlap reduction are performed sequentially between consecutive sheets.

[0096] <Example of control processing> An example of the processing of the MPU41 that realizes the operation of the recording device 1 described above will be explained with reference to Figure 15. In step S1, the recording order N is initialized by setting it to 1. In step S2, the maximum recording order Nmax is obtained from the recording conditions. Nmax is the maximum value of the recording order N, which is 4 in the example in Figure 3(A) and 3 in the example in Figure 3(B).

[0097] In step S3, the position of the flapper 16 is controlled to correspond to the process G(N) corresponding to the recording order N=1. In the example of Figure 3(A), the post-recording process G(1) is inversion, so the flapper 16 moves to the position in Figure 4(B). In the example of Figure 3(B), the post-recording process G(1) is discharge, so the flapper 16 moves to the position in Figure 1.

[0098] In step S4, the feeding of the M(N)th sheet SH from the paper source Q(N) begins. If the paper source Q(N) is the feeding tray 2, the feeding motor 22 is initially driven at a low speed. This causes the pickup roller 3 to rotate at, for example, 7.6 inches / sec. When the pickup roller 3 rotates, the top sheet SH loaded on the feeding tray 2 is picked up. The sheet SH picked up by the pickup roller 3 is transported by the feeding roller 4a, which rotates in the same direction as the pickup roller 3. The feeding roller 4a is driven by the feeding motor 23 at the same speed as the pickup roller 3. After the pickup roller 3 has rotated a predetermined amount to transport the sheet SH to a position beyond the feeding roller 4a, it stops so as not to pick up the next transport medium. The pickup roller 3 is a one-way roller, so even if the pickup roller 3 is stopped, transport by the feeding roller 4a can continue.

[0099] When the paper source Q(N) is the secondary transport path RT2, the transport motor 26 and the feed motor 23 are driven at a low speed. As a result, the transport roller 10a and the feed roller 4a rotate at, for example, 7.6 inches / sec. The sheet SH is then transported by the transport roller 10a and the feed roller 4a from the return path RT22 through the main transport path RT1 towards the transport roller 5a.

[0100] In step S5, the tip of the M(N)th sheet SH is the sensor 31 Whether or not it was detected (the tip is the sensor) 31It is determined whether or not the sheet has passed the threshold. If it is determined that the sheet has passed the threshold, step S6 is executed. In step S6, the feeding speed of the M(N)th sheet SH is switched to high speed (for example, 20 inches / sec). By switching the feeding motor 23 to high speed drive, the feeding roller 4a rotates at 20 inches / sec. If there is a preceding M(N-1)th sheet SH, the operation to allow the following sheet SH to catch up with the preceding sheet SH is initiated.

[0101] In step S7, it is determined whether N=1. If it is determined that N=1, there is no preceding sheet SH to overlap with, so the process proceeds to step S9. On the other hand, if it is determined that N=1, there is a possibility that the preceding sheet SH and the following sheet SH will be transported overlapping, so the overlapping state formation control in step S8 is executed.

[0102] Figure 16 is a flowchart of the control for forming the stacked state. In step S21, the transport of the sheets SH is stopped so that the leading edge of the M(N)th sheet SH is positioned at a predetermined location in front of the transport roller 5a. If the rear end of the preceding sheet SH is located upstream of the transport roller 5a, an stacked state is formed where the leading edge of the following sheet SH overlaps the rear end of the preceding sheet SH. The position of the leading edge of the M(N)th sheet SH is calculated from the amount of rotation of the feed roller 4a since the leading edge of the M(N)th sheet SH was detected by the sensor 31, and control is performed based on this calculation result.

[0103] Step S22 determines whether the predetermined overlapping conditions are met. The overlapping conditions determine whether it is possible to overlap the rear end of the preceding sheet SH and the front end of the following sheet SH during transport. For example, if the preceding sheet SH has already passed the transport roller 5a, the result is negative. Also, for example, if the overlap amount is less than a predetermined amount, the result is negative. Furthermore, for example, if the overlap amount is greater than the transport distance between the transport roller 6a and the transport roller 7a, the result is negative because it will be difficult to separate the sheets in the reduction control described later. Also, for example, if the reduction control described later sets a target distance as the separation distance between the sheets and executes the control, the result is negative if the overlap amount exceeds the target separation distance.

[0104] If it is determined that the conditions for overlapping execution are met, step S23 is executed. In step S23, it is determined whether the recording operation for the last row of the M(N-1) preceding sheet SH has started. If it is determined that it has not started (step S23: NO), the system waits for the recording operation to start. If it is determined that it has started (step S23: YES), the process of step S9 in Figure 15 (skew correction) is executed.

[0105] If it is determined in step S22 that the overlapping conditions are not met, a process to resolve the overlapping state is performed in step S24. Here, for example, the process is to wait for the M(N)th subsequent sheet SH to pass the transport roller 5a before transporting the M(N)th preceding sheet SH. After that, the process in step S9 of Figure 15 (skew correction) is executed.

[0106] Returning to Figure 15, in step S9, the skew correction of the M(N)th sheet SH is performed. When the transport roller 5a is stopped, the feed roller 4a is driven to bring the leading edge of the M(N)th sheet SH against the nip of the transport unit 5, thereby performing the skew correction operation of the M(N)th sheet SH. If it was determined in step S7 that N=1, or if it was determined in S22 that the overlapping conditions were not met, the M(N)th sheet SH will be skew corrected without overlapping with the preceding sheet SH. On the other hand, if it was determined in step S22 that the overlapping conditions were met, the M(N)th sheet SH will be skew corrected while overlapping with the M(N-1)th preceding sheet SH.

[0107] In step S10, the head of the M(N)th sheet SH is brought forward. The head of the M(N)th sheet SH can be brought forward by rotating the conveyor roller 5a by a predetermined amount. At this time, if the M(N)th sheet SH was corrected for skew in step S9 while overlapping with the M(N-1)th sheet SH, the head will be brought forward while maintaining the overlapping state.

[0108] In step S11, the feeding speed of the M(N)th sheet SH is switched to a low speed (e.g., 7.6 inches / sec). By switching the feeding motor 23 to low-speed drive, the feeding roller 4a rotates at 7.6 inches / sec.

[0109] In step S12, the recording operation for page number K(N) of the M(N) sheet SH is started on the recording surface F(N). While the transport roller 5a intermittently transports the sheets SH in predetermined amounts, the feed roller 4a is also intermittently driven by the feed motor 23. When the M(N) sheet SH is intermittently transported for the recording operation, the M(N-1) sheet SH is also transported intermittently.

[0110] In step S13, it is determined whether N=1. If it is determined that N=1, step S16 is executed; otherwise, step S14 is executed. In step S14, it is determined whether an overlapping state is formed between the M(N)th sheet SH and the M(N-1)th sheet SH. If it is determined that an overlapping state is formed, the reduction control in S15 is executed. Details of the reduction control will be described later.

[0111] In step S16, inversion / discharge control is performed. Figure 20 is a flowchart showing an example of this process. In step S41, it is determined whether the post-recording process G(N-1) is inversion. If it is determined to be inversion, step S42 is executed, and the M(N-1)th sheet SH is transported to the sub-transport path RT2 by rotating the transport roller 7a. At this time, the position of the flapper 16 has been moved in advance by other processes to a position that guides the sheet SH to the sub-transport path RT2.

[0112] In step S43, it is determined whether the trailing edge of the M(N-1)th sheet SH has passed the flapper 16. This determination may be made based on the rotation amount of various rollers, or by using a separate sensor. If it is determined that the trailing edge has passed the flapper 16, step S44 is executed. In step S44, the flapper 16 is moved to correspond to the post-recording process G(N) of the subsequent sheet SH.

[0113] In step S45, it is determined whether the trailing edge of the M(N-1) sheet SH has passed the branching point BP'. If it is determined that it has passed, step S46 is executed. In step S46, the M(N-1) sheet SH is transported towards the return path RT22. By switching the transport motor 26 to high-speed drive in reverse (direction R2 in Figure 1), the transport rollers 9a and 10a are rotated at, for example, 18 inches / sec. The leading and trailing edges of the M(N-1) sheet SH are swapped as the transport direction is switched. Then, in step S47, the M(N-1) sheet SH is stopped when the leading edge of the sheet SH reaches a predetermined position just before the main transport path RT1. This position is also calculated from the amount of rotation of each roller since the start of the leading-out operation and the length of the paper. Then, step S17 in Figure 15 is executed.

[0114] In step S41, if it is determined that the post-recording process G(N-1) is not inversion, step S48 is executed, and the M(N-1)th sheet SH is discharged to the discharge tray 17 by the rotation of the transport rollers 8a and 7a. In step S49, it is determined whether the rear end of the M(N-1)th sheet SH has passed the flapper 16. If it is determined that the rear end has passed the flapper 16, step S50 is executed. In step S50, the flapper 16 is moved to correspond to the post-recording process G(N) of the subsequent sheet SH.

[0115] Returning to Figure 15, in step S17, the recording order is incremented by one. In step S18, it is determined whether the recording order N after incrementing is less than or equal to the maximum recording order Nmax. If it is determined to be less than or equal to the maximum recording order Nmax, step S19 is executed. In step S19, the rear end of the M(N-1) sheet SH is the sensor 31 It determines whether or not it has passed through. The rear end is a sensor. 31 If it is determined that the condition has been passed, the process returns to step S4 and the feeding operation begins, and the control is then executed in the same manner thereafter.

[0116] In step S18, if it is determined that the recording order N is not less than or equal to the maximum recording order Nmax, it is determined that recording is complete and step S20 is executed. In step S20, the M(N-1)th sheet SH is discharged. By rotating the transport rollers 8a, 7a, 6a, and 5a in the same direction, the sheet SH can be discharged into the discharge tray 17. This completes the process.

[0117] <Decrease control> Figure 17 is a flowchart showing an example of the S15 reduction control process. Figures 18(A) to 19(C) are explanatory diagrams of the reduction control.

[0118] Refer to Figure 18(A). The reduction control uses at least two transport units. Here, transport unit 6 and transport unit 7 are used. In the transport direction of sheet SH, transport unit 6 is located upstream of transport unit 7. Here, we will describe the case where the amount of overlap between the preceding sheet SH1 and the following sheet SH2 is reduced.

[0119] Figure 18(A) shows the state in which the subsequent sheet SH2 is being straightened. When the transport roller 5a is stopped to perform the recording operation for the last row of sheet SH1, the leading edge of sheet SH2 is brought against the nip of the transport unit 5 to straighten the sheet SH2. At this time, the rear end of sheet SH1 and the leading edge of sheet SH2 overlap by an overlap amount W in the transport direction. As a prerequisite for reduction control, the overlap W is smaller than the distance between transport roller 6a and transport roller 7a.

[0120] In Figure 18(A), Dn is the distance of the nozzle area of ​​the recording head 12, which is the distance from the upstream to the downstream end of the discharge nozzle of the recording head 12, i.e., the maximum recording width in the transport direction. Therefore, if Ds is the recording width in one recording operation, then Ds ≤ Dn. The recording width Ds may differ for each recording operation. IM1 is an image already recorded on sheet SH1.

[0121] When the recording operation for the last row of sheet SH1 is completed, the transport roller 5a is rotated by a predetermined amount to maintain the state in which sheet SH2 is overlapping sheet SH1 by an overlap amount W, and the head of sheet SH2 can be brought forward. Figure 18(B) shows the state after the head has been brought forward, and the downstream end of the recording area of ​​sheet SH2 coincides with the position of the downstream discharge nozzle of the discharge nozzle equipped on the recording head 12. The speed during intermittent transport of sheet SH1 and sheet SH2 is shown as V1.

[0122] Refer to Figure 18(C). The reduction control starts after the rear end of the preceding sheet SH1 has passed the upstream transport roller 6a used for reduction control. Note that the start timing is not limited to immediately after passing, but can be anytime after passing. IM2 is an image recorded on sheet SH2.

[0123] The reduction control is performed so that it ends before the trailing edge of the preceding sheet SH1 passes an arbitrary position T. In the illustrated example, position T is set in front of the conveyor roller 7a. However, it may coincide with the conveyor roller 7a. In other words, the reduction control is performed so that it ends before the trailing edge of the preceding sheet SH1 passes the conveyor roller 7a. Also, depending on the setting of position T, the reduction control is performed so that it ends before the leading edge of the subsequent sheet SH2 reaches the conveyor roller 7a.

[0124] The area from the transport roller 6a to position T is defined as the separation area, and its distance is L. Furthermore, Dp is defined as the distance between the rear end of the preceding sheet SH1 and the front end of the following sheet SH2 after the reduction control. At this time, the distance (LW-Dp) is defined as the scan determination distance and is referenced in calculating the number of scans S when recording on the following sheet SH2. The number of scans can also be defined as the number of movements of the carriage 11.

[0125] Refer to the flowchart in Figure 17. In step S31, the transport speed V2 of the preceding sheet SH1 is calculated. Here, the stacking amount W is obtained by the MPU41. Also, from the recorded data recorded on the following sheet SH2, the number of scans S is calculated while the leading edge of the following sheet SH2 travels the scan determination distance (LW-Dp). In addition, the separation time Tmax is calculated.

[0126] From the stacking amount W, the number of scans S, the time required for one scan Ts, the distance of the separation area L, the paper spacing Dp after reduction control, and the transport speed V1 of the subsequent sheet SH2, Tmax can be calculated as Tmax = (LW - Dp) / V1 + S·Ts.

[0127] In this embodiment, the transport speed V1 of the subsequent sheet SH2 is the transport speed of the transport roller 6a. The time required for one scan Ts is t2-t3 hours or t4-t5 hours in Figure 19(C). The t4-t5 hours include the waiting time before and after recording. If the time required Ts differs for each recording operation, the average value of each time can be used.

[0128] The speed V2 of seat SH1 is calculated from the separation time Tmax and the distance L of the separation region, given by V2 = L / Tmax.

[0129] In step S32, it is determined whether the rear end of the preceding sheet SH1 has passed the conveyor roller 6a. In this embodiment, it is determined whether it has passed the conveyor roller 6a. If it is determined that it has passed, the process proceeds to step S33.

[0130] In step S33, the transport roller 7a on the downstream side in the transport direction, which is used for separation, is rotated at a speed of V2 or higher. Figure 18(C) shows the state in which the transport roller 7a has started to rotate at a speed of V2 or higher. As a result of this operation, as shown in Figure 19(A), the preceding sheet SH1 is separated from the following sheet SH2, and the stacking amount W decreases to W'. In Figure 18(C), the transport rollers 5a and 6a are stopped, while in Figure 19(A) they are rotating at a speed of V1.

[0131] As shown in Figure 19(B), it becomes possible to create a sheet spacing of Dp or more before the rear end of sheet SH1 passes position T, thereby eliminating the overlapping state.

[0132] In step S34, it is determined whether the distance between the rear end of the preceding seat SH1 and the front end of the following seat SH2 is greater than or equal to Dp. If it is determined that the distance is greater than or equal to Dp, the reduction control is terminated.

[0133] Figure 19(C) illustrates the change in recording operation and transport speed of the subsequent sheet SH2 and the transport speed of the preceding sheet SH1 after the start of deceleration control. Deceleration control starts at time t1, and the preceding sheet SH1 is transported at speed V2 (>V1) by the continuous rotation of the transport roller 7a. The subsequent sheet SH2 is transported intermittently, and transport stops while the recording operation is being performed. In the intervals of time t2-t3 and time t4-t5, the relative speed difference between the preceding sheet SH1 and the following sheet SH2 is maximized, promoting a reduction in the amount of overlap. The amount of overlap between the preceding sheet SH1 and the following sheet SH2 can be reduced at a lower transport speed for the preceding sheet SH1. Moreover, deceleration control does not have any effect such as delaying the recording control of the following sheet SH2.

[0134] In this embodiment, the spacing Dp is set to Dp≧0, which eliminates the overlapping state. However, it is also possible to set Dp<0. In this case, the overlapping state is not completely eliminated, but the amount of overlapping can be reduced. Dp may be set by experimentally obtaining in advance an amount of overlap that does not cause a paper jam at the branching point BP, or an amount of overlap that does not change the stacking order of multiple sheets SH on the discharge tray 17.

[0135] Furthermore, if reduction control is not performed during the recording operation, the release time Tmax' is: T'max = (LW - Dp) / V1. Therefore, in this case, the speed V2' of the leading sheet SH1 during the decrease control is: V2'=L / Tmax' This results in Tmax > Tmax’. Therefore, V2 < V2’. That is, by performing the reduction control during the recording operation in which the conveyance of the subsequent sheet SH2 has stopped, it is possible to reduce the conveyance speed and suppress deterioration such as noise and power as compared with the case where the reduction control is not performed during the recording operation.

[0136] When the time S·Ts required for the S scanning operations is large, V2 can be made smaller. Also, a standby time unrelated to the scanning operation may be provided separately. In this case, the conveyance speed can be further reduced and deterioration such as noise and power can be suppressed. Note that V2 in the reduction control may be faster than V1, but since there is a conveyance stop period for the subsequent sheet SH2, it is not always necessary to be fast depending on the calculation result of V2, and it may be the same or slower. The conveyance roller 7a that continuously conveys the preceding sheet SH1 does not necessarily have to be continuously driven at a constant speed of V2 or more. For example, it may be controlled so that the average speed including stops and acceleration / deceleration is V2 or more.

[0137] In the determination of the end of the deceleration control (step S34), another end condition may be provided. For example, it may be ended when the rear end of the preceding sheet SH1 reaches the conveyance roller 7a. At this time, if the reduction control is performed at a speed higher than V2, the sheet interval can be further widened.

[0138] <Second Embodiment> In the first embodiment, the conveyance rollers 6a and 7a were used during the reduction control, but the selection of the rollers used for the reduction control is not limited to this. For example, although limited to the conveyance of the sheet SH in the main conveyance path RT1, the rollers used for the reduction control may be the conveyance roller 6a and the conveyance roller 8a.

[0139] Since the conveyance rollers 7a and 8a are driven by the same conveyance motor 25, it is necessary for the reduction control to be completed before the leading end of the subsequent sheet SH reaches the conveyance roller 7a. The position T in Fig. 18(A) is set, for example, at a position Dp downstream in the conveyance direction from the conveyance roller 7a. The distance L of the separation area is the distance from the conveyance roller 6a to the position T that has advanced Dp downstream in the conveyance direction from the conveyance roller 7a.

[0140] Figure 21(A) shows an example of the timing for initiating the reduction control in this embodiment. The rear end of the leading sheet SH1 is passing the conveyor roller 6a. The conveyor motor 25 rotates the conveyor rollers 8a and 7a at a speed V2. Figure 21(B) shows the point when the reduction control is completed, and the rear end of the leading sheet SH1 and the front end of the following sheet SH2 are separated by the conveyor roller 7a.

[0141] Even with this control method, the overlapping state between the preceding sheet SH1 and the following sheet SH2 can be resolved.

[0142] <Third Embodiment> The rollers used for reduction control may be transport roller 5a and transport roller 8a. However, in this case, transport roller 8a is driven independently of transport roller 7a by a separate dedicated motor not shared with transport roller 7a. Transport rollers 6a and 7a are one-way rollers and are assumed to be able to rotate freely in the transport direction. Position T in Figure 18(A) is assumed to coincide with transport roller 8a. The distance L of the separation region is the distance from transport roller 5a to transport roller 8a.

[0143] Figure 22(A) shows an example of the timing for initiating the reduction control in this embodiment. The rear end of the leading sheet SH1 has passed the conveyor roller 5a, but is upstream of the conveyor roller 6a. The conveyor roller 8a is rotated at a speed V2 by a dedicated motor. Since the conveyor rollers 6a and 7a are one-way rollers, the leading sheet SH1 can be conveyed without receiving a large load from these rollers. Figure 22(B) shows the point at which the reduction control is completed, and the rear end of the leading sheet SH1 and the leading edge of the following sheet SH2 are separated.

[0144] Even with this control method, the overlapping state between the preceding sheet SH1 and the following sheet SH2 can be resolved.

[0145] <Fourth Embodiment> Although limited to the transport of sheet SH1 on the secondary transport path RT2, the rollers used for reduction control may be transport roller 5a and transport roller 9a. Transport roller 6a and transport roller 7a are one-way rollers and are assumed to be able to rotate freely in the transport direction. Position T in Figure 18(A) is assumed to coincide with the branching point BP. The distance L of the separation region is the distance from transport roller 5a to branching point BP.

[0146] Figure 23(A) shows an example of the timing for initiating the reduction control in this embodiment. The rear end of the leading sheet SH1 has passed the conveyor roller 5a, but is upstream of the conveyor roller 6a. The conveyor roller 9a rotates at a speed V2. Since the conveyor rollers 6a and 7a are one-way rollers, the leading sheet SH1 can be conveyed without receiving a large load from these rollers. Figure 23(B) shows the point at which the reduction control is completed, and the rear end of the leading sheet SH1 and the leading edge of the following sheet SH2 are separated.

[0147] Even with this control method, the overlapping state between the preceding sheet SH1 and the following sheet SH2 can be resolved.

[0148] <Fifth Embodiment> Before performing the skew correction described in step S9 of Figure 15, an overlap adjustment operation may be performed to reduce the amount of overlap. In this case, by reducing the amount of overlap, the speed V2 during the reduction control can be set to a lower speed. The overlap adjustment operation may involve, for example, not performing skew correction on the following sheet SH when recording the last row of the preceding sheet SH, but performing skew correction after recording the last row and transporting a certain amount of the preceding sheet SH. This reduces the amount of overlap.

[0149] <Other Embodiments> In the reduction control, the speed of the conveyor rollers that transport the subsequent sheet SH may be controlled to be slower than usual.

[0150] Furthermore, the present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0151] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0152] 1 recording device, 4 feed units, 5-10 transport units, 12 recording heads, 40 control units

Claims

1. A recording means for recording images on a recording medium, A carriage on which the recording means is mounted and moves in a direction traversing the recording medium, A first transport means is arranged along the transport path of the recording medium and transports the recording medium in the transport direction, Downstream of the first transport means in the transport direction, a second transport means for transporting the recording medium recorded by the recording means, A control means capable of reducing the amount of overlap between a preceding recording medium and a succeeding recording medium, from a state where the succeeding recording medium overlaps the trailing end of a preceding recording medium, A recording device equipped with, The control means performs recording control that alternately performs the transport operation of the recording medium and the recording operation that performs recording by the recording means while moving the carriage. The reduction control is performed during the recording control relating to the subsequent recording medium and includes control to stop the transport of the subsequent recording medium by the first transport means and transport the preceding recording medium by the second transport means when the subsequent recording medium is transportable by the first transport means in the transport direction. A recording device characterized by the following features.

2. A recording device according to Claim 1, Equipped with a feeding means for feeding recording media, The first transport means transports the recording medium that has been fed by the feeding means. A recording device characterized by the following features.

3. A recording device according to claim 1, The aforementioned reduction control is The control includes transporting the subsequent recording medium by the first transport means and transporting the preceding recording medium faster than the subsequent recording medium by the second transport means, A recording device characterized by the following features.

4. A recording device according to any one of claims 1 to 3, The control means is It is possible to perform a formation control that creates an overlapping state in which the leading edge of the successor recording medium overlaps the preceding recording medium before the successor recording medium reaches the recording means. In the formation control, the amount of overlap between the preceding recording medium and the succeeding recording medium is less than the transport distance between the first transport means and the second transport means. A recording device characterized by the following features.

5. A recording device according to claim 3 or claim 4, In the aforementioned reduction control, the overlap amount between the preceding recording medium and the succeeding recording medium is set to zero. A recording device characterized by the following features.

6. A recording device according to any one of claims 3 to 5, The aforementioned transport path is The first route and This includes a second path that branches off from the first path at a branching point, The recording means is located along the first path, upstream of the branching point in the transport direction, The reduction control is performed before the subsequent recording medium reaches the branching point. A recording device characterized by the following features.

7. A recording device according to claim 4, The first conveying means is positioned downstream of the recording means in the conveying direction. The control means executes the reduction control when the preceding recording medium has passed the first transport means and the succeeding recording medium has not passed the first transport means. A recording device characterized by the following features.

8. A recording device according to claim 1, The first transport means is positioned upstream of the recording means in the transport direction. The control means executes the reduction control when the preceding recording medium has passed the first transport means and the succeeding recording medium has not passed the first transport means. A recording device characterized by the following features.

9. A recording device according to claim 1, The control means terminates the reduction control after the start of the reduction control until the rear end of the preceding recording medium reaches a predetermined position. A recording device characterized by the following features.

10. A recording device according to claim 1, The control means terminates the reduction control after the start of the reduction control until the rear end of the leading recording medium reaches the second transport means. A recording device characterized by the following features.

11. A recording device according to claim 1, The aforementioned transport path is The first route and This includes a second path that branches off from the first path at a branching point, The recording means is located along the first path, upstream of the branching point in the transport direction, The control means terminates the reduction control after the start of the reduction control until the rear end of the leading recording medium reaches the branching point. A recording device characterized by the following features.

12. A recording device according to claim 1, The control means terminates the reduction control after the start of the reduction control until the subsequent recording medium reaches the second transport means. A recording device characterized by the following features.

13. A recording device according to claim 1, The first transport means is positioned upstream of the recording means in the transport direction. The second conveying means is positioned downstream of the recording means in the conveying direction. A recording device characterized by the following features.

14. A recording device according to claim 1, The second transport means is an discharge means for transporting the preceding recording medium to the discharge tray. A recording device characterized by the following features.

15. A recording means for recording an image on a recording medium, A feeding means for feeding a recording medium, A first transport means is arranged along the transport path of the recording medium and transports the recording medium supplied by the feeding means in the transport direction, Downstream of the first transport means in the transport direction, a second transport means for transporting the recording medium recorded by the recording means, A recording device comprising: control means capable of reducing the amount of overlap between a preceding recording medium and a succeeding recording medium, from an overlapping state in which a succeeding recording medium overlaps the trailing end of a preceding recording medium; The reduction control includes, when the subsequent recording medium is in a state where it can be transported by the first transport means in the transport direction, control to stop the transport of the subsequent recording medium by the first transport means and transport the preceding recording medium by the second transport means, The aforementioned transport path is The first route and This includes a second path that branches off from the first path at a branching point, The recording means is located along the first path, upstream of the branching point in the transport direction, The second path is a path for transporting the preceding recording medium to the feeding means by reversing its front and back sides. The second transport means is located in the second path, A recording device characterized by the following features.

16. A recording device according to claim 6 or claim 15, The aforementioned branching point is provided with a flapper that switches the transport route for the preceding recording medium. A recording device characterized by the following features.

17. A recording device according to claim 1, In the aforementioned reduction control, The transport speed of the second transport means is set based on the amount of overlap between the preceding recording medium and the succeeding recording medium in the stacked state. A recording device characterized by the following features.

18. A recording means for recording images on a recording medium, A carriage on which the recording means is mounted and moves in a direction traversing the recording medium, A first transport means is arranged along the transport path of the recording medium and transports the recording medium in the transport direction, Downstream of the first transport means in the transport direction, a second transport means for transporting the recording medium recorded by the recording means, A control method for a recording device equipped with, A recording control step which alternates between transporting the recording medium and recording using the recording means while moving the carriage, The system includes a reduction control step that reduces the amount of overlap between the preceding recording medium and the succeeding recording medium, from an overlapping state where the succeeding recording medium overlaps the trailing end of the preceding recording medium. The reduction control step is performed during the recording control step relating to the subsequent recording medium and includes control to stop the transport of the subsequent recording medium by the first transport means and transport the preceding recording medium by the second transport means when the subsequent recording medium is transportable by the first transport means in the transport direction. A control method characterized by the following:

19. A storage medium storing a program that causes a computer to execute the control method described in claim 18.

20. A program that causes a computer to execute the control method described in claim 18.

Images