Printing apparatus

Abstract

The invention provides a printing apparatus. The subject of the invention is to worry about reduction of throughput when a plurality of media are continuously printed. A printing apparatus (1) includes: a feed roller (5) that conveys a medium (P) from a storage unit (2) to a feed path RF; an intermediate roller (8) provided downstream of the feed roller (5); a first motor (7); and a power transmission section (51) that transmits power from the first motor (7) to the feed roller (5) and the intermediate roller (8), the power transmission section (51) having a connection section on a transmission path TP in which the power of the first motor (7) is transmitted to the intermediate roller (8), the connection section (51) connecting the power of the first motor (7) to the intermediate roller (8) when an external force that rotates the intermediate roller (8) in a direction in which the medium (P) is conveyed downstream acts on the connection section (51). The connecting portion allows the intermediate roller (8) to rotate following an external force.

Description

Technical Field

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

[0002] A printing apparatus is disclosed in Patent Document 1. The printing apparatus includes a supply roller, an intermediate roller, a printing roller, a first motor, a second motor, a switching gear mechanism, and a control unit. The supply roller supplies a printing medium from a storage unit that stores the printing medium to a transport path. The intermediate roller is disposed on the transport path and transports the printing medium. The printing roller is disposed on a printing path that is downstream of the transport path and performs printing processing on the printing medium, and transports the printing medium. The first motor rotates the supply roller and the intermediate roller. The second motor rotates the printing roller. The switching gear mechanism switches whether to rotate the supply roller and the intermediate roller or to rotate the intermediate roller according to the rotation direction of the first motor. The control unit executes a first transport mode and a second transport mode. In the first transport mode, the supply and transport of the printing medium are performed by the rotation of the first motor in a predetermined direction. In the second transport mode, the transport of the printing medium is performed by the reverse rotation of the first motor in the predetermined direction.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-513

[0006] For example, in the printing apparatus of Patent Document 1, in order to supply the next printing medium during the printing process of the printing medium transported in the second transport mode, the control unit switches the transport mode from the second transport mode to the first transport mode. When switching the transport mode from the second transport mode to the first transport mode, there is an instant when the rotation of the intermediate roller stops. In this case, the transport of the printing medium during the printing process is hindered at the instant when the rotation of the intermediate roller stops, and it is easy to cause a decrease in printing quality and transport failure. Therefore, when supplying the next printing medium during the printing process, it is necessary to switch the transport mode from the second transport mode to the first transport mode after the transport of the printing medium by the intermediate roller during the printing process is completed. As a result, the timing of starting the paper feed of the next printing medium is delayed, and there is a possibility that the throughput when continuously printing a plurality of printing media is reduced. Summary of the Invention

[0007] The printing apparatus includes: a feed roller that conveys the medium from a storage unit that stores the medium, the feed roller being provided on a conveyance path that is downstream of the storage unit in the conveyance direction of the medium; an intermediate roller that is provided at a position downstream of the feed roller on the conveyance path and conveys the medium; a printing roller that is provided at a position downstream of the intermediate roller, the printing roller conveying the medium toward a medium support unit that performs printing on the medium; a first motor that rotates the feed roller and the intermediate roller via a power transmission unit; the power transmission unit that transmits the power of the first motor to the feed roller and the intermediate roller; and a second motor that rotates the printing roller, wherein the power transmission unit has a connection part on a power transmission path that transmits the power of the first motor to the intermediate roller, and when an external force that rotates the intermediate roller in the direction in which the medium is conveyed downstream acts, the connection part allows the intermediate roller to rotate following the external force. Description of the Drawings

[0008] Figure 1 It is a schematic side view showing an embodiment of the printing apparatus.

[0009] Figure 2 It is a perspective view showing the power transmission unit that transmits the power of the first motor.

[0010] Figure 3 It is a flowchart showing the processing performed by the control unit during the feeding process.

[0011] Figure 4 It is a schematic side view showing the medium conveyed along the conveyance path.

[0012] Figure 5 It is a schematic side view showing the medium conveyed along the conveyance path.

[0013] Figure 6 It is a schematic side view showing the medium conveyed along the conveyance path.

[0014] Figure 7 It is a schematic side view showing the medium conveyed along the conveyance path.

[0015] Symbol Description

[0016] 1. Printing device; 2. Accommodating section; 3. Pickup roller; 5. Feed roller; 6. Separation roller; 7. First motor; 8. Intermediate roller; 9, 10, 11. Clamping roller; 12. Supply tray; 13. Supply roller; 14. Separation roller; 15. Printing roller pair; 16. Printing roller; 17, 21. Driven roller; 18. Medium support section; 19. Rear feed roller pair; 20. Rear feed roller; 22, 24. Medium detection section; 23. Second motor; 25. Return roller pair; 26. Switching baffle; 27. Transfer roller pair; 28. Discharge roller pair; 29. Discharge tray; 40. Print head; 42a. Spray surface; 44. Nozzle; 51. Power transmission section; 52. Gear train; 53. Drive shaft; 54. One-way clutch; 80. Control section; S110, S120, S130, S140. Steps; P. Medium; Pn. Next medium; Pp. Previous medium; PE, PL. Positions; RD. Discharge path; RF. Feed path; RR. Return path; RS. Supply path; TP. Transfer path; TR. Conveyor path. Detailed implementation mode

[0017] Hereinafter, the present disclosure will be described based on the implementation modes. In each figure, the same reference numerals are assigned to the same components, and repeated descriptions are omitted. In addition, in this specification, "same", "identical", and "simultaneous" do not only refer to exactly the same situation. For example, in this specification, "same", "identical", and "simultaneous" include cases where they are the same considering measurement errors. For example, in this specification, "same", "identical", and "simultaneous" include cases where they are the same considering manufacturing deviations of components.

[0018] For example, in this specification, "same", "identical", and "simultaneous" include cases where they are the same within a range that does not impair the function. Therefore, for example, "the sizes of both are the same" means that considering measurement errors and manufacturing deviations of components, the size difference between the two is within ±5% of the size of one party, and particularly preferably within ±3%.

[0019] 1. Embodiment 1

[0020] The printing device 1 is, for example, an inkjet printer that can perform printing on a single-sheet printing paper or the like as an example of the medium P.

[0021] In addition, in each figure, X, Y, and Z represent three mutually orthogonal spatial axes. In this specification, the directions along these axes are taken as the X-axis direction, the Y-axis direction, and the Z-axis direction. When specifying the orientation, the positive direction is set to "+", the negative direction is set to "-", and the positive and negative signs are used together in the direction markings. The direction toward the arrow in each figure is set as the + direction, and the opposite direction of the arrow is set as the - direction for description.

[0022] In addition, the Z-axis direction represents the direction of gravity, the +Z direction represents vertically upward, and the -Z direction represents vertically downward. In addition, the plane including the X-axis and the Y-axis is defined as the X-Y plane, the plane including the X-axis and the Z-axis is defined as the X-Z plane, and the plane including the Y-axis and the Z-axis is defined as the Y-Z plane. In addition, the X-Y plane is a horizontal plane. Moreover, regarding the three X, Y, and Z spatial axes for which the positive and negative directions are not defined, they are described as the X-axis, the Y-axis, and the Z-axis.

[0023] The X-axis direction is the width direction of the printing apparatus 1 and becomes the width direction of the medium P to be printed. When observed from an operator located on the front side of the printing apparatus 1, the +X direction becomes the right side and the -X direction becomes the left side.

[0024] The Y-axis direction is the depth direction of the printing apparatus 1 and is the direction along the conveyance direction of the medium P during printing. The +Y direction is the direction from the front to the back of the printing apparatus 1, and the -Y direction is the direction from the back to the front of the printing apparatus 1. In the present embodiment, the side in the -Y direction among the side surfaces constituting the periphery of the printing apparatus 1 is the front of the printing apparatus 1, and the side in the +Y direction is the back of the printing apparatus 1.

[0025] Hereinafter, the direction in which the medium P is conveyed downward is referred to as "downstream", and the opposite direction is referred to as "upstream".

[0026] Hereinafter, with reference to Figure 1 The constituent components included in the printing apparatus 1 will be described along the conveyance path TR provided in the printing apparatus 1. The conveyance path TR is composed of a feed path RF, a supply path RS, a discharge path RD, and a return path RR. The feed path RF, the supply path RS, the discharge path RD, and the return path RR are an example of the conveyance path TR.

[0027] As Figure 1 shown, the printing apparatus 1 includes a cassette-type housing portion 2 at the bottom of the apparatus. The medium P is housed in the housing portion 2. The housing portion 2 is provided so as to be detachable from the front side of the apparatus.

[0028] The printing apparatus 1 includes a pickup roller 3 driven by a first motor 7 via a power transmission portion 51 above the housing portion 2. The power transmission portion 51 will be described later. The pickup roller 3 can advance and retreat with respect to the medium P housed in the housing portion 2. The pickup roller 3 sends out the medium P from the housing portion 2 in the +Y direction by contacting and rotating with the medium P housed in the housing portion 2.

[0029] The printing apparatus 1 includes a feed roller 5 and a separation roller 6 that is given a rotational torque by a torque limiter (not shown) in a feed path RF downstream of the accommodation unit 2. The feed roller 5 is driven by a first motor 7 via a power transmission unit 51. The medium P sent out from the accommodation unit 2 is clamped and separated by the feed roller 5 and the separation roller 6, and is conveyed downstream of the feed roller 5 and the separation roller 6 in the feed path RF.

[0030] The printing apparatus 1 includes a medium detection unit 24 at a position downstream of the feed roller 5 and the separation roller 6 in the feed path RF. The medium detection unit 24 is provided at a position PE downstream of the feed roller 5 and the separation roller 6 in the feed path RF. The medium detection unit 24 can detect whether the medium P has passed through the position PE. The position PE is an example of a predetermined position.

[0031] As the medium detection unit 24, a reflection type photoelectric sensor, a transmission type photoelectric sensor, etc. configured to be able to emit light toward the position PE can be used. For example, the control unit 80 described later can determine the timing of conveying the medium P to the feed path RF based on the detection information of the medium detection unit 24.

[0032] The printing apparatus 1 includes an intermediate roller 8 at a position downstream of the feed roller 5, the separation roller 6, and the medium detection unit 24 in the feed path RF. The intermediate roller 8 is driven by the first motor 7 via the power transmission unit 51. Clamping rollers 9, 10, and 11 are provided around the intermediate roller 8. The clamping rollers 9 and 10 together with the intermediate roller 8 form a part of the feed path RF. The clamping roller 11 and the intermediate roller 8 together form a part of the return path RR.

[0033] In the feed path RF, the clamping roller 10 is located downstream of the clamping roller 9. The medium P is clamped by the intermediate roller 8 and the clamping roller 9, and further clamped by the intermediate roller 8 and the clamping roller 10, and is conveyed downstream. The medium P passes through the intermediate roller 8 and reverses the conveying direction from the +Y direction to the -Y direction, and is conveyed downstream.

[0034] The printing apparatus 1 includes a medium detection unit 22 at a position downstream of the intermediate roller 8 in the feed path RF. The medium detection unit 22 is provided at a position PL downstream of the intermediate roller 8 in the feed path RF. The medium detection unit 22 is configured to be able to detect whether the leading end of the medium P has reached the position PL.

[0035] As the medium detection unit 22, a reflection type photoelectric sensor, a transmission type photoelectric sensor, etc. configured to be able to emit light toward the position PL can be used. For example, the control unit 80 can position the leading end of the medium P relative to the print head 40 based on the detection information of the medium detection unit 22. Additionally, for example, the control unit 80 can position the medium P at the printing start position.

[0036] In addition to the feeding path RF starting from the storage section 2, the printing apparatus 1 further includes a supply path RS starting from the supply tray 12. The supply tray 12 that constitutes the supply path RS supports the medium P in an inclined posture. The printing apparatus 1 is provided with a supply roller 13 and a separating roller 14 on the supply path RS. The supply roller 13 is driven by a first motor 7 via a power transmission section 51. The driving of the supply roller 13 may also be performed by a supply motor (not shown).

[0037] A rotational torque is imparted to the separating roller 14 by a torque limiter (not shown). The medium P supported on the supply tray 12 is conveyed by the supply roller 13 and the separating roller 14 toward the downstream feeding path RF. At a position between the clamping section formed by the intermediate roller 8 and the clamping roller 10 and the medium detection section 22 in the feeding path RF, the supply path RS merges with the feeding path RF.

[0038] The printing apparatus 1 includes a printing roller pair 15. The printing roller pair 15 is provided downstream of the intermediate roller 8 and the medium detection section 22. The printing roller pair 15 includes a printing roller 16 and a driven roller 17 that can rotate in a driven manner. The printing roller 16 is driven by a second motor 23.

[0039] For example, it is assumed that printing is being performed on the medium P. At this time, as Figure 5 shown, when the second motor 23 is viewed from the +X direction side, the second motor 23 is rotationally driven in the direction in which the output shaft of the second motor 23 rotates in the clockwise direction. Thereby, when the printing roller 16 is viewed from the +X direction side, the printing roller 16 rotates in the counterclockwise direction, and thus the medium P is conveyed toward the medium support section 18 that is downstream of the printing roller pair 15.

[0040] The printing apparatus 1 is provided with a medium support section 18 at a position downstream of the printing roller pair 15. The medium support section 18 supports the medium P conveyed by the printing roller pair 15. The medium support section 18 defines a gap between the ejection surface 42a of a printing head 40 described later and the medium P by supporting the medium P. Hereinafter, the gap between the medium P and the ejection surface 42a may sometimes be referred to as a printing gap. Printing of the medium P by the printing head 40 described later is performed in the medium support section 18.

[0041] The printing apparatus 1 is provided with a printing head 40 at a position on the +Z direction side of the medium support section 18. The printing head 40 has an ejection surface 42a. The ejection surface 42a faces the surface of the medium support section 18 that supports the medium P. A plurality of nozzles 44 are formed on the ejection surface 42a. The printing head 40 performs printing by ejecting ink from the plurality of nozzles 44 onto the medium P supported by the medium support section 18. Ink is an example of a liquid.

[0042] The print head 40 is a so-called line head in which a plurality of nozzles 44 are arranged so as to cover the entire area in the medium width direction along the X-axis direction. The print head 40 is long in the medium width direction and is configured as a liquid ejection head that can perform printing over the entire area of the medium width without moving in the medium width direction.

[0043] The ejection surface 42a faces the medium P supported by the medium support portion 18. The ejection surface 42a may also be referred to as a liquid ejection surface or a nozzle surface. The printing apparatus 1 includes a liquid storage portion (not shown). The ink ejected from the print head 40 is supplied to the print head 40 from the liquid storage portion via a supply pipe (not shown).

[0044] The print head 40 is provided so as to be movable in the direction of adjusting the printing gap, which is the direction of advancing and retreating with respect to the medium support portion 18, by a gap adjusting mechanism (not shown). In the present embodiment, the direction of adjusting the printing gap is the direction along the Z-axis direction.

[0045] The printing apparatus 1 includes a pair of post-feed rollers 19. The pair of post-feed rollers 19 is provided at a position downstream of the medium support portion 18. The pair of post-feed rollers 19 includes a post-feed roller 20 driven by a post-feed motor (not shown) and a driven roller 21 that can rotate idly. The printed medium P is conveyed toward the discharge path RD, which is downstream of the pair of post-feed rollers 19, by driving the post-feed roller 20. The driving of the post-feed roller 20 may also be performed by a second motor 23 via a power transmission mechanism (not shown).

[0046] The printing apparatus 1 includes a switching shutter 26 on the discharge path RD. The switching shutter 26 is provided on the discharge path RD so as to be movable to Figure 1 the discharge position shown by the solid line and the return position shown by the double-dot chain line by driving an actuator (not shown).

[0047] The discharge position is the position when the medium P is conveyed to the downstream discharge path RD by the rotational driving of the post-feed roller 20. The return position is the position when the medium P conveyed to the discharge path RD is conveyed toward the return path RR. As the actuator for moving the switching shutter 26 to the discharge position and the return position, for example, an electromagnetic solenoid or the like can be employed.

[0048] The printing apparatus 1 includes a pair of transfer rollers 27. The pair of transfer rollers 27 is provided on the discharge path RD at a position downstream of the switching shutter 26. The printing apparatus 1 includes a pair of discharge rollers 28. The pair of discharge rollers 28 is provided on the discharge path RD at a position downstream of the pair of transfer rollers 27. The pair of transfer rollers 27 and the pair of discharge rollers 28 are driven by a discharge motor (not shown). The pair of transfer rollers 27 and the pair of discharge rollers 28 can rotate in one direction when the medium P is conveyed in the discharge direction and in the other direction when the medium P is conveyed in the return direction.

[0049] When the transfer roller pair 27 and the discharge roller pair 28 rotate in one direction, the medium P located in the discharge path RD is conveyed in the discharge direction toward the discharge tray 29 provided downstream of the discharge path RD. The medium P that has been printed and conveyed in the discharge direction is discharged to the discharge tray 29 through the discharge roller pair 28 with the most recent printed surface being the lower surface in the -Z direction state.

[0050] When the transfer roller pair 27 and the discharge roller pair 28 rotate in the other direction, the medium P located in the discharge path RD is conveyed in the return direction toward the return path RR.

[0051] The return path RR is a path for conveying the medium P during double-sided printing on both sides of the medium P. The return path RR connects the transfer roller pair 27 and the clamping portion formed by the intermediate roller 8 and the clamping roller 9.

[0052] The printing apparatus 1 includes a return roller pair 25 in the return path RR. For example, when double-sided printing is performed on the medium P, the return roller pair 25 is driven by a return motor (not shown). The return roller pair 25 conveys the medium P transported from the discharge path RD to the return path RR toward the clamping portion formed by the clamping roller 11 and the intermediate roller 8 that constitutes the return path RR.

[0053] At this time, the medium P is conveyed by the return roller pair 25 with the previously printed surface being the upper surface in the +Z direction side state. In the return path RR, the medium P conveyed by the return roller pair 25 is clamped by the rotating intermediate roller 8 and the clamping roller 11. The medium P clamped by the intermediate roller 8 and the clamping roller 11 is conveyed toward the clamping portion formed by the intermediate roller 8 and the clamping roller 9 that becomes the downstream.

[0054] The medium P clamped by the rotating intermediate roller 8 and the clamping roller 9 is conveyed downstream of the clamping portion formed by the intermediate roller 8 and the clamping roller 9. The medium P that is conveyed to the conveyance path RF again is conveyed toward the medium support portion 18 through the intermediate roller 8, the clamping roller 10, and the printing roller pair 15. At this time, the medium P is conveyed toward the medium support portion 18 with the previously printed surface being the lower surface in the -Z direction side state.

[0055] The medium P that is conveyed to the medium support portion 18 with the previously printed surface being the lower surface is printed by the print head 40, thereby performing double-sided printing on the medium P. The medium P that has undergone double-sided printing passes through the post-feed roller pair 19 and the switching baffle 26 at the discharge position and is conveyed to the discharge path RD.

[0056] The medium P conveyed to the discharge path RD is conveyed in the discharge direction toward the discharge roller pair 28 by the transfer roller pair 27. The medium P that has undergone double-sided printing is discharged to the discharge tray 29 through the discharge roller pair 28 in a state where the most recent printed surface is the surface in the -Z direction, that is, the lower surface.

[0057] The printing apparatus 1 includes a power transmission unit 51. The power transmission unit 51 transmits the power of the first motor 7 to the intermediate roller 8, the feed roller 5, and the pickup roller 3. The power transmission unit 51 is arranged to be able to switch the transmission destination of the power of the first motor 7 corresponding to the rotation direction of the output shaft of the first motor 7. In the present embodiment, the power transmission unit 51 also transmits the power of the first motor 7 to the supply roller 13.

[0058] As Figure 5 shown, the conveyance of the medium P by the first motor 7 and the power transmission unit 51 when the output shaft of the first motor 7 rotates in the clockwise direction when observing the first motor 7 from the +X direction side is referred to as the conveyance mode. As Figure 4 shown, the conveyance of the medium P by the first motor 7 and the power transmission unit 51 when the output shaft of the first motor 7 rotates in the counterclockwise direction when observing the first motor 7 from the +X direction side is referred to as the feed mode.

[0059] In addition, in Figures 4 to 7 , the medium P being conveyed in the medium P is represented as the previous medium Pp. In Figure 7 , the medium P that is conveyed following the previous medium Pp in the medium P is represented as the next medium Pn. In Figures 4 to 7 , when the rotation direction of each roller is indicated by a blackened arrow, it means that the roller is being rotated passively due to an external force or the like acting thereon.

[0060] Hereafter, rotating the output shaft of the first motor 7 in the clockwise direction is referred to as "the first motor 7 rotates in the clockwise direction". Rotating the output shaft of the first motor 7 in the counterclockwise direction is referred to as "the first motor 7 rotates in the counterclockwise direction". In the rotation direction of the output shaft of the first motor 7, the clockwise direction is an example of one direction, and the counterclockwise direction is an example of the other direction.

[0061] As Figure 5 shown, in the conveyance mode where the first motor 7 rotates in the clockwise direction, the power transmission unit 51 transmits the power of the first motor 7 to the intermediate roller 8. As a result, the intermediate roller 8 and the pinch rollers 9, 10 rotate in the direction of the arrow, and thus the medium P located in the feed path RF is conveyed downstream in the direction of the arrow.

[0062] As Figure 4As shown, in the feeding mode where the first motor 7 rotates counterclockwise, the power transmission unit 51 transmits the power of the first motor 7 to the intermediate roller 8, the feeding roller 5, and the pickup roller 3. Thereby, the pickup roller 3, the feeding roller 5, and the separating roller 6 rotate in the direction of the arrow, and thus the medium P is conveyed from the accommodating portion 2 toward the downstream in the direction of the arrow.

[0063] As Figure 2 shown, the power transmission unit 51 has a transmission path TP for transmitting the power of the first motor 7 to the intermediate roller 8. The transmission path TP is constituted by a gear train 52 including a plurality of gears, a drive shaft 53, a one-way clutch 54, and the like.

[0064] The drive shaft 53 is provided so as to be rotatable about the axis center along the X axis. The intermediate roller 8 is provided at the end portion on the +X direction side of the drive shaft 53. By transmitting the power of the first motor 7 from the gear train 52, the drive shaft 53 and the intermediate roller 8 rotate about the axis center.

[0065] The one-way clutch 54 may be provided in the transmission path TP, for example, on the gear train 52, but the one-way clutch 54 of the present embodiment is provided between the intermediate roller 8 and the drive shaft 53.

[0066] When an external force that rotates the intermediate roller 8 in the direction in which the medium P is conveyed downstream (refer to Figure 6 ) acts, the one-way clutch 54 allows the intermediate roller 8 to rotate following the external force. At this time, the intermediate roller 8 rotates relative to the drive shaft 53 with the drive shaft 53 as the rotation axis according to the external force. The one-way clutch 54 is an example of a connection portion that the power transmission unit 51 has in the transmission path TP.

[0067] The one-way clutch 54 of the present embodiment is provided between the intermediate roller 8 having an outer diameter larger than the outer diameter of the gears constituting the gear train 52 and the drive shaft 53. Thereby, it is easy to dispose the one-way clutch 54 inside the intermediate roller 8 between the intermediate roller 8 and the drive shaft 53. Therefore, by providing the power transmission unit 51 with the one-way clutch 54 in the transmission path TP, it is easy to suppress the enlargement of the printing apparatus 1.

[0068] The one-way clutch 54 of the present embodiment can employ, for example, a roller type one-way clutch having a cylindrical outer shape (refer to Figure 1 ). In this case, the one-way clutch 54 is composed of an outer ring and an inner ring forming a cylindrical shape, a plurality of rollers provided between a cam surface formed on the inner diameter surface of the outer ring and the inner ring, and a spring. The outer ring of the one-way clutch 54 is fixed to the center of the intermediate roller 8, and the inner ring is fixed to the drive shaft 53, so that the intermediate roller 8 is mounted on the drive shaft 53.

[0069] The one-way clutch 54 may also be a planetary gear type that has planetary gears instead of rollers and springs of the roller type. In this case, teeth for causing the drive shaft 53 to function as a sun gear may also be provided on the circumferential surface of the drive shaft 53 on which the one-way clutch 54 is mounted.

[0070] As Figure 1 shown, the printing apparatus 1 includes a control unit 80. The control unit 80 controls the entirety of the printing apparatus 1. The control unit 80 may include a processor that executes various processes according to a program, a dedicated hardware circuit such as an application-specific integrated circuit that executes at least a part of the various processes, or a combination thereof.

[0071] The processor includes a CPU and memories such as a RAM and a ROM, and the memories store program codes or instructions configured to cause the CPU to execute processes. The memories, i.e., computer-readable media, include all readable media that can be accessed by a general-purpose or dedicated computer.

[0072] The control unit 80 drives and controls the first motor 7 to rotate it counterclockwise, thereby transmitting the power of the first motor 7 to the feed roller 5, the intermediate roller 8, and the pickup roller 3 via the power transmission unit 51. Thereby, the control unit 80 conveys the medium P downstream from the storage unit 2 by setting the conveyance of the medium P to the feed mode.

[0073] The control unit 80 drives and controls the first motor 7 to rotate it clockwise, thereby transmitting the power of the first motor 7 to the intermediate roller 8 via the power transmission unit 51. Thereby, the control unit 80 conveys the medium P located in the feed path RF downstream by setting the conveyance of the medium P to the conveyance mode.

[0074] The control unit 80 drives and controls the first motor 7 to transmit the power of the first motor 7 to the supply roller 13 via the power transmission unit 51. Thereby, the control unit 80 conveys the medium P from the supply tray 12 toward the feed path RF.

[0075] The control unit 80 drives and controls the second motor 23 to rotate the printing roller pair 15. Thereby, the control unit 80 conveys the medium P toward the medium support unit 18 located downstream of the printing roller pair 15.

[0076] The control unit 80 drives and controls the gap adjustment mechanism to adjust the printing gap. The control unit 80 drives and controls the print head 40 to eject ink from the nozzles 44 onto the medium P supported by the medium support unit 18. Thereby, the control unit 80 performs printing on the medium P.

[0077] The control unit 80 rotates the post-feed roller pair 19 by driving and controlling the post-feed motor. Thereby, the control unit 80 conveys the medium P toward the discharge path RD that is downstream of the post-feed roller pair 19.

[0078] The control unit 80 moves the switching shutter 26 to the discharge position by driving and controlling the actuator. The control unit 80 rotates the transfer roller pair 27 and the discharge roller pair 28 in one direction by driving and controlling the discharge motor. Thereby, the control unit 80 discharges the medium P with the latest printed surface as the lower surface to the discharge tray 29.

[0079] When double-sided printing is performed on the medium P, the control unit 80 moves the switching shutter 26 to the return position by driving and controlling the actuator. The control unit 80 rotates the transfer roller pair 27 and the discharge roller pair 28 in the other direction by driving and controlling the discharge motor. Thereby, the control unit 80 conveys the medium P printed on one surface from the discharge path RD toward the return path RR.

[0080] The control unit 80 rotates the return roller pair 25 by driving and controlling the return motor. Thereby, the control unit 80 conveys the medium P to the clamping portion formed by the clamping rollers 11 and the intermediate roller 8. The control unit 80 conveys the medium P to the feed path RF again by conveying the medium P based on the conveyance mode.

[0081] The control unit 80 conveys the medium P that has been conveyed again to the feed path RF downstream. The control unit 80 rotates the printing roller pair 15 by driving and controlling the second motor 23. Thereby, the control unit 80 conveys the medium P toward the medium support portion 18.

[0082] The control unit 80 performs printing on the medium P that has been conveyed to the medium support portion 18 in a state where the previously printed printed surface is the lower surface by driving and controlling the print head 40. Thereby, double-sided printing is performed on the medium P.

[0083] The control unit 80 rotates the post-feed roller pair 19 by driving and controlling the post-feed motor. Thereby, the control unit 80 conveys the medium P on which double-sided printing has been performed toward the discharge path RD.

[0084] The control unit 80 moves the switching shutter 26 to the discharge position by driving and controlling the actuator. The control unit 80 rotates the transfer roller pair 27 and the discharge roller pair 28 in one direction by driving and controlling the discharge motor. Thereby, the control unit 80 discharges the medium P on which double-sided printing has been performed with the latest printed surface as the lower surface to the discharge tray 29.

[0085] Next, refer to Figure 3The flowchart shown below explains the processing performed by the control unit 80 during the feeding process of transporting the medium P from the storage unit 2 to the transport path TR. In the feeding process of the present embodiment, the flow of the processing performed by the control unit 80 corresponds to the control method of the printing apparatus 1.

[0086] In step S110, the control unit 80 confirms whether there is a medium P in the feeding path RF. As Figure 5 shown, the feeding process of transporting the medium P from the storage unit 2 to the transport path TR may be performed while printing is being performed on the previous medium Pp. Alternatively, the feeding process may be performed when there is a previous medium Pp in the feeding path RF.

[0087] Therefore, during the feeding process, the control unit 80 confirms whether there is a medium Pp in the feeding path RF. As Figure 5 shown, if there is a medium Pp in the feeding path RF, step S110 is "Yes", and the control unit 80 transfers the processing to step S120. As Figure 1 shown, if there is no medium Pp in the feeding path RF, step S110 is "No", and the control unit 80 transfers the processing to step S130.

[0088] In addition, when step S110 is "Yes", the first motor 7 is being driven to rotate in the clockwise direction as one direction. Therefore, the previous medium Pp located in the feeding path RF is conveyed downstream by the intermediate roller 8. As Figure 5 shown, when printing is being performed on the previous medium Pp, by driving the second motor 23, the previous medium Pp is conveyed downstream by the printing roller pair 15. When step S110 is "No", the first motor 7 is not driven.

[0089] In step S130, the control unit 80 drives the first motor 7 to rotate in the counterclockwise direction as the other direction. Thereby, the control unit 80 sets the conveyance of the medium P to the feeding mode. As Figure 4 shown, in the feeding mode, the power transmission unit 51 transmits the power of the first motor 7 to the intermediate roller 8, the feeding roller 5, and the pickup roller 3.

[0090] Thereby, the pickup roller 3, the feeding roller 5, and the separating roller 6 rotate in the direction of the arrow, and thus the medium P is conveyed downstream from the storage unit 2 in the direction of the arrow. When the processing of step S130 is completed, the control unit 80 ends the feeding process.

[0091] In step S120, the control unit 80 confirms whether the medium Pp has passed a predetermined position. That is, the control unit 80 confirms whether the previous medium Pp has passed the position PE. Specifically, after the medium detection unit 24 changes from the detection state of detecting the medium P to the non-detection state of not detecting the medium P, the control unit 80 determines that the rear end of the previous medium Pp has passed the position PE. As Figure 5 shown, if the detection state of the medium detection unit 24 is the detection state of detecting the medium P, the control unit 80 determines that the previous medium Pp has not passed the position PE.

[0092] When the control unit 80 determines that the rear end of the previous medium Pp has passed the position PE, step S120 is "Yes", and the control unit 80 transfers the process to step S140. When the control unit 80 determines that the previous medium Pp has not passed the position PE, step S120 is "No", and the control unit 80 continues the detection of the medium Pp by the medium detection unit 24 in step S120.

[0093] In step S140, the control unit 80 switches the rotation direction of the first motor 7 from the clockwise direction as one direction to the counterclockwise direction as the other direction. Thereby, the control unit 80 changes the conveyance of the medium P from the conveyance mode to the feeding mode. As Figure 7 shown, in the feeding mode, the power transmission unit 51 transmits the power of the first motor 7 to the intermediate roller 8, the feeding roller 5, and the pickup roller 3.

[0094] Thereby, the pickup roller 3, the feeding roller 5, and the separating roller 6 rotate in the direction of the arrow, so that the next medium Pn is conveyed from the storage unit 2 toward the downstream in the direction of the arrow. When the process of step S140 is completed, the control unit 80 ends the feeding process.

[0095] When the feeding process of the next medium Pn is completed, the control unit 80 switches the rotation direction of the first motor 7 from the counterclockwise direction to the clockwise direction. Thereby, the control unit 80 changes the conveyance of the medium P from the feeding mode to the conveyance mode.

[0096] In addition, in step S140, when switching the rotation direction of the first motor 7 from the clockwise direction to the counterclockwise direction, as Figure 6 shown, there is a moment when the rotation of the first motor 7 stops. At this time, the previous medium Pp is clamped by the intermediate roller 8 and the clamping rollers 9 and 10. In addition, at this time, printing is performed on the previous medium Pp by the print head 40.

[0097] In the present embodiment, a one-way clutch 54 is provided on the transfer path TP. Thereby, an increase in the load acting on the printing roller 16 can be suppressed, and at the same time, the intermediate roller 8 can be rotated passively by the rotation of the printing roller 16 caused by the driving of the second motor 23. Therefore, it is possible to suppress poor conveyance of the medium Pp caused by switching the rotation direction of the first motor 7 during the conveyance of the previous medium Pp. Therefore, it is possible to suppress a decrease in printing quality caused by switching the rotation direction of the first motor 7 during the printing of the previous medium Pp.

[0098] When printing on the medium P, sometimes due to a main cause different from the switching of the rotation direction of the first motor 7, a change in the rotation speed of the first motor 7 or a decrease in the rotation speed of the first motor 7 may occur. In this case as well, the one-way clutch 54 can be utilized to passively rotate the intermediate roller 8 by the rotation of the printing roller 16 caused by the driving of the second motor 23. Thereby, a change in the load acting on the printing roller 16 can be suppressed. Therefore, it is possible to suppress a decrease in printing quality due to a change in the rotation speed of the first motor 7, a decrease in the rotation speed of the first motor 7, etc. during the printing of the previous medium Pp.

[0099] As described above, according to the printing apparatus 1 according to Embodiment 1, the following effects can be obtained.

[0100] The printing apparatus 1 includes a feed roller 5 that conveys the medium P from the storage unit 2 that stores the medium P and is provided on a feed path RF that is downstream of the storage unit 2 in the conveyance direction of the medium P. The printing apparatus 1 includes an intermediate roller 8 that is provided at a position downstream of the feed roller 5 on the feed path RF and conveys the medium P. The printing apparatus 1 includes a printing roller 16 that is provided at a position downstream of the intermediate roller 8 and conveys the medium P toward a medium support unit 18 that performs printing on the medium P. The printing apparatus 1 includes a first motor 7 that rotates the feed roller 5 and the intermediate roller 8 via a power transmission unit 51. The printing apparatus 1 includes a power transmission unit 51 that transmits the power of the first motor 7 to the feed roller 5 and the intermediate roller 8. The power transmission unit 51 has a connection portion on a transfer path TP that transmits the power of the first motor 7 to the intermediate roller 8. When an external force that rotates the intermediate roller 8 in the direction in which the medium P is conveyed downstream acts, the connection portion allows the intermediate roller 8 to rotate following the external force.

[0101] Thereby, during the printing of the medium P conveyed by the printing roller 16 and the intermediate roller 8, the medium P can be conveyed from the storage unit 2 by the feed roller 5. Therefore, it is possible to suppress a decrease in throughput when continuously printing a plurality of sheets of the medium P.

[0102] The power transmission unit 51 has a drive shaft 53 provided on the transmission path TP in such a manner that the intermediate roller 8 can rotate, and a connection portion is provided between the intermediate roller 8 and the drive shaft 53.

[0103] Accordingly, compared with the case where the connection portion is provided at other positions on the transmission path TP, the intermediate roller 8 can rotate in the direction in which the medium P is conveyed downstream with a smaller external force. In addition, accordingly, the connection portion can be arranged inside the intermediate roller 8 between the intermediate roller 8 and the drive shaft 53. Therefore, by providing the connection portion on the transmission path TP in the power transmission unit 51, it is possible to easily suppress the enlargement of the printing apparatus 1.

[0104] The connection portion is a one-way clutch 54 that allows the intermediate roller 8 to rotate in the direction in which the medium P is conveyed downstream when an external force acts on the intermediate roller 8. Accordingly, the connection portion can be arranged on the transmission path TP with a simple structure.

[0105] When the first motor 7 rotates in the clockwise direction, the power of the first motor 7 is transmitted to the intermediate roller 8 via the power transmission unit 51, and thus the medium P is conveyed downstream. When the first motor 7 rotates in the counterclockwise direction, the power of the first motor 7 is transmitted to the feed roller 5 and the intermediate roller 8 via the power transmission unit 51, and thus the medium P is conveyed downstream from the storage unit 2.

[0106] Accordingly, by changing the rotation direction of the first motor 7, it is possible to switch between the conveyance of the medium P downstream in the feed path RF and the conveyance of the medium P downstream from the storage unit 2.

[0107] The printing apparatus 1 further includes a control unit 80. Assume that the previous medium Pp conveyed downstream has passed through the position PE between the feed roller 5 and the intermediate roller 8 in the feed path RF by rotating the printing roller 16 and the intermediate roller 8. In this case, the control unit 80 conveys the next medium Pn downstream from the storage unit 2 by switching the rotation direction of the first motor 7 from the clockwise direction to the counterclockwise direction.

[0108] Accordingly, during the printing of the previous medium Pp, it is possible to convey the next medium Pn from the storage unit 2 while ensuring the interval between the previous medium Pp and the next medium Pn.

[0109] The printing apparatus 1 also includes a medium detection unit 24 at the position PE. After the medium detection unit 24 changes from the detection state of detecting the medium P to the non-detection state of not detecting the medium P, the control unit 80 determines that the medium P has passed through the position PE. Accordingly, it is possible to easily determine that the medium P has passed through the position PE with a simple structure.

[0110] Although the printing apparatus 1 according to the above-described embodiment of the present disclosure is based on having the above-described structure, of course, partial structural changes, omissions, etc. can be made without departing from the gist of the present disclosure. In addition, the above-described embodiment and other embodiments described below can be implemented in combination with each other within a range where there is no technical contradiction. Hereinafter, other embodiments will be described.

[0111] In the above-described embodiment, if a gap can be ensured between the previous medium Pp and the next medium Pn, the position PE may not be the position between the feed roller 5 and the intermediate roller 8 in the feed path RF. For example, the position PE may be the position of the clamping portion formed by the feed roller 5 and the separation roller 6. Alternatively, the position PE may be the position between the pickup roller 3 and the feed roller 5.

[0112] In the above-described embodiment, the printing apparatus 1 may not include the medium detection unit 24. In this case, it may also be determined whether the medium P has passed through the position PE based on the conveyance amount of the medium P conveyed downstream from the time when the medium P is detected by the medium detection unit 22 and the size of the conveyance direction of the medium P. In this case, the position PL is an example of a preset reference position. Alternatively, it may be determined whether the medium P has passed through the position PE based on the conveyance amount of the medium P conveyed downstream from the start of the conveyance of the medium P from the storage unit 2 and the size of the conveyance direction of the medium P. In this case, the position of the front end of the medium P when housed in the storage unit 2 is an example of a preset reference position.

[0113] Alternatively, it may be determined whether the medium P has passed through the position PE based on the conveyance amount of the medium P conveyed downstream from the time when the rear end of the medium P passes through the position between the front end and the rear end of the medium P housed in the storage unit 2 in the Y-axis direction. In this case, the position between the front end and the rear end of the medium P housed in the storage unit 2 in the Y-axis direction is an example of a preset reference position. In this case, a sensor may also be provided at the reference position so as to be able to detect the medium P.

[0114] Alternatively, it may be determined whether the medium P has passed through the position PE based on the conveyance amount of the medium P conveyed downstream from the start of the conveyance of the medium P from the storage unit 2. In this case, the position of the rear end of the medium P when housed in the storage unit 2 is an example of a preset reference position. In this case, a sensor may also be provided at the reference position so as to be able to detect the medium P.

[0115] According to the printing apparatus 1 according to these embodiments, the following effects can be obtained. The control unit 80 determines whether the medium P has passed through the position PE based on the conveyance amount of the medium P conveyed downstream from a preset reference position. Thereby, the control unit 80 can easily determine whether the medium P has passed through the position PE.

[0116] In the above-described embodiment, the power transmission unit 51 may not include the one-way clutch 54 on the transmission path TP. For example, the power transmission unit 51 may include an electromagnetic clutch on the transmission path TP instead of the one-way clutch 54. The electromagnetic clutch is provided on the transmission path TP in such a manner that it can switch between a connected state generated by energizing the electromagnetic clutch and a non-connected state generated by cutting off the energization of the electromagnetic clutch. In the connected state, the intermediate roller 8 is connected to the drive shaft 53. In the non-connected state, the intermediate roller 8 can rotate relative to the drive shaft 53. The control unit 80 may set the conveyance of the medium P to the conveyance mode by setting the electromagnetic clutch to the connected state, and set the conveyance of the medium P to the feeding mode by setting the electromagnetic clutch to the non-connected state. In this case, the electromagnetic clutch is an example of the connecting portion.

Claims

1. A printing device, characterized in that: have: a feed roller for conveying the medium from a storage portion for accommodating the medium, the feed roller being disposed in a conveying path downstream of the storage portion in a conveying direction for conveying the medium; an intermediate roller provided on the conveying path at a position downstream of the feed roller and conveying the medium; a printing roller disposed at a position downstream of the intermediate roller, the printing roller conveying the medium toward a medium support portion for performing printing on the medium; a first motor that rotates the feed roller and the intermediate roller via a power transmission portion; the power transmission part transmitting the power of the first motor to the feed roller and the intermediate roller; and a second motor, which rotates the printing roller, The power transmission unit has a connection portion on a transmission path for transmitting the power of the first motor to the intermediate roller. When an external force acts on the intermediate roller to rotate in a direction in which the medium is conveyed downstream, the connecting portion allows the intermediate roller to rotate in accordance with the external force.

2. The printing device according to claim 1, characterized in that The power transmission unit includes a drive shaft provided on the transmission path so that the intermediate roller can rotate. The connection portion is provided between the intermediate roller and the driving shaft.

3. The printing device according to claim 1, characterized in that The connection portion is a one-way clutch that allows the intermediate roller to rotate in a direction in which the medium is conveyed toward the downstream when the external force acts on the intermediate roller.

4. The printing device according to any one of claims 1 to 3, characterized in that: When the first motor rotates in one direction, the power of the first motor is transmitted to the intermediate roller via the power transmission unit, so that the medium is transported toward the downstream. When the first motor rotates in the other direction, the power of the first motor is transmitted to the feed roller and the intermediate roller via the power transmission portion, so that the medium is conveyed from the storage portion toward the downstream.

5. The printing device according to claim 4, characterized in that It also has a control unit. After the medium previously transported to the downstream by rotating the printing roller and the intermediate roller passes through a predetermined position between the feed roller and the intermediate roller in the transport path, The control unit switches the rotation direction of the first motor from the one direction to the other direction to convey the next medium from the storage unit toward the downstream.

6. The printing device according to claim 5, characterized in that A medium detection unit is also provided at the predetermined position. The control unit determines that the medium has passed the predetermined position after the medium detection unit changes from a detection state in which the medium is detected to a non-detection state in which the medium is not detected.

7. The printing device according to claim 5, characterized in that The control unit determines whether the medium has passed the predetermined position based on a conveyance amount of the medium conveyed from a preset reference position toward the downstream.

Images