Conveying device, printing device, and conveying control method

Abstract

To solve the problem that when an inertia when rotating a roll body becomes large, the inertia lowers the accuracy of a medium conveyance control using a driving force applied to a holding part.SOLUTION: A conveyance device includes: a holding part that rotatably holds a roll body on which a medium is wound, a conveyance part that conveys the medium pulled out from the roll body; a tension applying part that applies a tension to the medium by pressing the medium between the holding part and the conveyance part; a driving unit that applies a driving force to the tension applying part; a control unit that controls the conveyance part and the driving unit; and a detection unit that detects a load applied to the conveyance part. The control unit adjusts the tension applied to the medium by controlling the driving force applied by the driving unit and controls the driving force of the driving unit based on the load detected by the detection unit.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a conveying device, a printing device, and a conveying control method.

Background Art

[0002] There is known a conveying device that conveys a medium wound around a roll body. The conveying device of Patent Document 1 holds the roll body with a holding portion that can be rotated by a driving force. When the conveying device conveys the medium, it detects the tension applied to the medium. The conveying device controls the driving force applied to the holding portion based on the detection result of the tension.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the conveying device becomes larger, the diameter of the roll body installed in the holding portion becomes larger. When the diameter of the roll body becomes larger, the inertia when rotating the roll body becomes larger. Due to this inertia, the accuracy of the conveyance control of the medium using the driving force applied to the holding portion decreases.

Means for Solving the Problems

[0005] The conveying device of this disclosure comprises a holding unit for rotatably holding a roll body on which media is wound, a conveying unit for conveying the media drawn out from the roll body, a tensioning unit for applying tension to the media by pressing the media between the holding unit and the conveying unit, a drive unit for applying driving force to the tensioning unit, a control unit for controlling the conveying unit and the drive unit, and a detection unit for detecting the load applied to the conveying unit, wherein the control unit adjusts the tension applied to the media by controlling the driving force applied by the drive unit, and controls the driving force by the drive unit based on the load detected by the detection unit.

[0006] The conveying device of this disclosure comprises a conveying unit for conveying media in a conveying direction, a winding unit for winding up the media conveyed by the conveying unit, a tensioning unit for applying tension to the media by pressing it between the conveying unit and the winding unit, a drive unit for applying driving force to the tensioning unit, a control unit for controlling the conveying unit and the drive unit, and a detection unit for detecting the load applied to the conveying unit, wherein the control unit controls the driving force by the drive unit based on the load detected by the detection unit.

[0007] The printing apparatus of this disclosure comprises: a holding unit for rotatably holding a roll body on which media is wound; a transport unit for transporting the media drawn from the roll body; a printing unit for printing on the media transported by the transport unit; a tensioning unit for applying tension to the media by pressing it between the holding unit and the transport unit; a drive unit for applying driving force to the tensioning unit; a control unit for controlling the transport unit and the drive unit; and a detection unit for detecting the load applied to the transport unit, wherein the control unit controls the driving force by the drive unit based on the load detected by the detection unit.

[0008] The transport control method of this disclosure transports media wound around a roll body held by a holding unit by a transport unit, applies tension to the media by pressing it with a tensioning unit between the holding unit and the transport unit, detects the load applied to the transport unit, and controls a drive unit that applies driving force to the tensioning unit based on the detected load. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic cross-sectional diagram showing the configuration of the printer. [Figure 2] A diagram showing the configuration for driving the supply bar member. [Figure 3] A diagram showing the functional blocks of a printer. [Figure 4] A diagram illustrating the operation of the supply unit during media transport. [Figure 5] A diagram showing the position of the supply bar component. [Figure 6] A diagram showing the position of the supply bar component. [Figure 7] A diagram showing the position of the supply bar component. [Figure 8] A diagram illustrating the operation of the supply unit during media transport. [Figure 9] A diagram illustrating the operation of the winding unit during media transport. [Modes for carrying out the invention]

[0010] 1. Configuration of printer 10 Figure 1 is a schematic cross-sectional view showing the configuration of printer 10. Printer 10 is an inkjet printer that prints by ejecting ink onto a medium M. Printer 10 comprises a printing unit 20, a supply unit 30 for feeding out the medium M, and a winding unit 40. Printer 10 corresponds to an example of a printing device. Medium M corresponds to an example of a media.

[0011] Some of the figures, including Figure 1, show an XYZ coordinate system. The X, Y, and Z axes are orthogonal to each other. The X axis is parallel to the mounting surface of the printer 10 and corresponds to the width of the printer 10. The Y axis is parallel to the mounting surface of the printer 10 and corresponds to the depth of the printer 10. The Z axis is perpendicular to the mounting surface of the printer 10 and corresponds to the height of the printer 10.

[0012] Hereafter, when showing the XYZ coordinate system, the +X direction parallel to the X axis indicates the direction from the supply unit 30 to the winding unit 40. In Figure 1, the +X direction indicates the direction from the center of the figure to the left. The -X direction parallel to the X axis indicates the direction from the winding unit 40 to the supply unit 30. In Figure 1, the -X direction of the X axis indicates the direction from the center of the figure to the right. The +Y direction parallel to the Y axis indicates the direction from the back to the front of the printer 10 when the winding unit 40 is positioned to the left of the printing unit 20. In Figure 1, the +Y direction parallel to the Y axis indicates the direction towards the front of the figure. The -Y direction parallel to the Y axis indicates the direction from the front to the back of the printer 10 when the winding unit 40 is positioned to the left of the printing unit 20. In Figure 1, the -Y direction parallel to the Y axis indicates the direction towards the back of the figure. The +Z direction parallel to the Z axis indicates the direction upward from the mounting surface of the printer 10. In Figure 1, the +Z direction parallel to the Z-axis indicates the direction upward from the center of the figure. The -Z direction parallel to the Z-axis indicates the direction from the top of the printer 10 toward the mounting surface. In Figure 1, the -Z direction parallel to the Z-axis indicates the direction downward from the center of the figure.

[0013] The printing unit 20 includes a supply guide frame 21, a pair of transport rollers 24 having a first transport roller 22 and a second transport roller 23, a platen 25, a print head 26, a carriage 27, an ejection guide frame 29, a control unit 50, and a load detection sensor 80.

[0014] The supply guide frame 21 guides the medium M sent from the supply unit 30 to the pair of conveyance rollers 24. The supply guide frame 21 guides the medium M in a diagonal direction intersecting the +X direction and the +Z direction. The supply guide frame 21 may be composed of one member or a plurality of members.

[0015] The pair of conveyance rollers 24 has a first conveyance roller 22 and a second conveyance roller 23 and is capable of conveying the medium M. The pair of conveyance rollers 24 corresponds to an example of a conveyance unit. The first conveyance roller 22 is disposed at a position in the +Z direction with respect to the medium M. The second conveyance roller 23 is disposed at a position in the -Z direction with respect to the medium M. The first conveyance roller 22 or the second conveyance roller 23 is rotationally driven by a driving force from a conveyance roller driving mechanism 126 described later. The first conveyance roller 22 and the second conveyance roller 23 convey the medium M to the print head 26 in a state where the medium M is sandwiched by being pressed against each other.

[0016] The platen 25 is provided at a position in the -Z direction with respect to the print head 26. The platen 25 is a flat member that supports the medium M conveyed by the pair of conveyance rollers 24. When a suction fan is provided at a position in the -Z direction with respect to the platen 25, the platen 25 is provided with through holes for allowing the flow of air. By the airflow of the suction fan, the medium M is attracted to the platen 25.

[0017] The print head 26 can perform printing by discharging ink onto the medium M supported by the platen 25. The print head 26 is an inkjet head. The print head 26 forms an image on the medium M by discharging ink. The print head 26 corresponds to an example of a printing unit.

[0018] The carriage 27 supports the print head 26. The carriage 27 moves along an axis parallel to the Y axis. When the carriage 27 moves on the medium M along an axis parallel to the Y axis, the print head 26 forms an image on the medium M by discharging ink onto the medium M.

[0019] The discharge guide frame 29 guides the medium M printed by the print head 26 to the take-up unit 40. The discharge guide frame 29 guides the medium M in a diagonal direction intersecting the +X direction and the -Z direction. The discharge guide frame 29 may be composed of one member or a plurality of members.

[0020] A drying unit (not shown) may be provided at a position facing the discharge guide frame 29. The drying unit includes, for example, a heater as a heat source. The drying unit heats the medium M on the discharge guide frame 29 and promotes the fixing of the ejected ink to the medium M.

[0021] The control unit 50 performs various controls such as conveyance control of the medium M and printing control on the medium M. The control unit 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a storage, etc. (not shown). The control unit 50 acquires detection results from various sensors and performs various controls. The control unit 50 may acquire print data and perform various controls based on the acquired print data. The control unit 50 may be composed of one or a plurality of units. The control unit 50 corresponds to an example of a control section.

[0022] The load detection sensor 80 detects the load applied to the conveyance roller pair 24. The load detection sensor 80 shown in FIG. 1 detects the conveyance current I when the conveyance roller pair 24 conveys the medium M. The detection data detected by the load detection sensor 80 is transmitted to the control unit 50. The load detection sensor 80 corresponds to an example of a detection section. The load detection sensor 80 is not limited to a device that measures the conveyance current I. For example, it may be a tension measuring device that measures the tension of the medium M conveyed from the supply unit 30 to the print unit 20.

[0023] The supply unit 30 comprises a media roll support shaft 31, a media roll drive mechanism 32, a supply guide member 33, a supply bar member 34, a supply bar support member 35, and a supply bar drive mechanism 36. The supply unit 30 is supplied with a media roll 60 in which the media M is wound in a roll shape. The media roll 60 corresponds to an example of a roll body.

[0024] The media roll support shaft 31 supports the media roll 60. The media roll support shaft 31 is rotatably supported by a frame (not shown) located at the +Y and -Y ends of the supply unit 30. As the media roll support shaft 31 rotates, the media roll 60 rotates. As the media roll 60 rotates, the media M is dispensed. The media roll support shaft 31 corresponds to an example of a holding part.

[0025] The media roll drive mechanism 32 rotates the media roll support shaft 31 based on the control of the control unit 50. The media roll drive mechanism 32 includes a drive source such as a motor (not shown), a transmission mechanism for transmitting the driving force from the drive source, and a control circuit for operating the drive source based on signals from the control unit 50.

[0026] The supply guide member 33 guides the medium M dispensed from the medium roll 60. The supply guide member 33 guides the medium M in diagonal directions intersecting the +X and -Z directions. The supply guide member 33 is, for example, a roll member. The roll member may be rotatably supported or non-rotatably supported. To improve the sliding properties of the medium M, it is desirable that the roll member be rotatably supported.

[0027] The supply bar member 34 is supported by the supply bar support member 35. The supply bar member 34 wraps around the medium M guided by the supply guide member 33 and applies tension to the medium M. The supply bar member 34 is positioned between the medium roll support shaft 31 and the transport roller pair 24 in the transport path through which the medium M is transported. The supply bar member 34 contacts the medium M directly or via a cover member (not shown). The cover member is, for example, a friction member for applying a predetermined frictional force to the medium M. That is, the supply bar member 34 can contact the medium M directly or indirectly. The supply bar member 34 guides the medium M to the transport roller pair 24 via the supply guide frame 21. The supply bar member 34 guides the medium M in approximately the +Z direction. When the supply bar drive mechanism 36, described later, is not operating, the supply bar member 34 applies tension to the medium M by its own weight. The supply bar member 34 can have any shape as long as it can apply tension to the medium M, but it is preferable that its shape be a cylinder or column extending in the direction along the Y axis. The supply bar member 34 can be an extruded member of a metal material such as aluminum or stainless steel, or a pipe processed member of a metal material such as aluminum or stainless steel. The supply bar member 34 corresponds to an example of a tension bar.

[0028] The supply bar support member 35 is positioned at a position in the +Y direction and a position in the -Y direction relative to the supply bar member 34, so as to sandwich the supply bar member 34. The supply bar support member 35 supports the supply bar member 34 so that it can move. The supply bar member 34 and the supply bar support member 35 correspond to an example of a tensioning section.

[0029] The supply bar drive mechanism 36 applies a driving force to the supply bar support member 35 based on the control of the control unit 50. The supply bar drive mechanism 36 has a supply bar drive source that generates the driving force, which will be described later. With the driving force applied, the supply bar support member 35 and the supply bar member 34 supported by the supply bar support member 35 oscillate as the medium M is transported. In the case of Figure 1, the supply bar drive mechanism 36 oscillates the supply bar support member 35 and the supply bar member 34 supported by the supply bar support member 35 around a hypothetical supply bar oscillation axis (not shown). That is, the supply bar drive mechanism 36 can adjust the biasing force that the supply bar member 34 exerts on the medium M. The supply bar oscillation axis does not coincide with the rotation axis (not shown) of the medium roll support shaft 31. The supply bar oscillation axis may coincide with the rotation axis of the medium roll support shaft 31. The supply bar drive mechanism 36 adjusts the tension applied to the medium M as the supply bar member 34 swings by adjusting the driving force applied to the supply bar support member 35. The supply bar drive mechanism 36 adjusts the tension acting on the portion of the medium M from the medium roll 60 to the conveyor roller pair 24. The supply bar drive mechanism 36 corresponds to an example of a drive unit. The supply bar drive mechanism 36 shown in Figure 1 swings the supply bar support member 35 and the supply bar member 34, but is not limited to this. The supply bar drive mechanism 36 may also translate the supply bar support member 35 and the supply bar member 34 along an axis parallel to the Z axis. The trajectory of the supply bar support member 35 and the supply bar member 34 when they translate is not limited to an axis parallel to the Z axis, but may be appropriately changed to match the path of the medium M. The supply bar member 34 applies tension to the medium M by wrapping it around it, but is not limited to this. For example, tension may be applied to the medium M by pressing it with a device that makes line contact or point contact with the medium M.

[0030] Figure 2 shows an example of a configuration for moving the supply bar member 34. Figure 2 shows an example of the supply bar member 34, the supply bar support member 35, and the supply bar drive mechanism 36. The supply bar member 34 has a supply bar shaft 34A.

[0031] The supply bar shaft 34A extends along an axis parallel to the Y-axis from one end to the other end of the supply bar member 34. The supply bar shaft 34A is supported by at least one supply bar support member 35. The supply bar shaft 34A constitutes part of the tension bar. The at least one supply bar support member 35 includes a first support member 35A and a second support member 35B. The first support member 35A supports the supply bar shaft 34A located at one end of the supply bar member 34. The second support member 35B supports the supply bar shaft 34A located at the other end of the supply bar member 34. The first support member 35A and the second support member 35B support the supply bar member 34 by supporting the supply bar shaft 34A. The first support member 35A and the second support member 35B may each support the supply bar shaft 34A via bearings (not shown). The first support member 35A and the second support member 35B support the supply bar shaft 34A via bearings, thereby rotatably supporting the supply bar member 34 on the supply bar support member 35. The supply bar support member 35 may support the supply bar member 34 in a non-rotatable manner. The first support member 35A corresponds to an example of a first arm. The second support member 35B corresponds to an example of a second arm. The supply bar shaft 34A may be omitted.

[0032] The supply bar drive mechanism 36 has a supply bar drive source. In Figure 2, the supply bar drive source has a first supply bar drive source 36A and a second supply bar drive source 36B. The first supply bar drive source 36A and the second supply bar drive source 36B are, for example, motors. A supply bar drive current is applied to the first supply bar drive source 36A and the second supply bar drive source 36B under the control of a controller 150, which will be described later. The first supply bar drive source 36A and the second supply bar drive source 36B generate a driving force when the supply bar drive current is applied. The supply bar drive mechanism 36 also has a first drive shaft 36C and a second drive shaft 36D. The first drive shaft 36C is connected to the first supply bar drive source 36A and the first support member 35A. The first drive shaft 36C transmits the driving force generated by the first supply bar drive source 36A to the first support member 35A. The first support member 35A rotates around the first drive shaft 36C due to the transmitted driving force. The second drive shaft 36D is connected to the second supply bar drive source 36B and the second support member 35B. The second drive shaft 36D transmits the driving force generated by the second supply bar drive source 36B to the second support member 35B. The second support member 35B rotates around the second drive shaft 36D due to the transmitted driving force. The first supply bar drive source 36A and the second supply bar drive source 36B correspond to an example of a drive unit and a second drive unit, respectively. The driving force generated by the second supply bar drive source 36B corresponds to an example of a second driving force.

[0033] The supply bar drive mechanism 36 may consist of only one of the first supply bar drive source 36A or the second supply bar drive source 36B. However, it is preferable for the supply bar drive mechanism 36 to consist of both the first supply bar drive source 36A and the second supply bar drive source 36B. When the supply bar drive mechanism 36 includes both the first supply bar drive source 36A and the second supply bar drive source 36B, the controller 150 controls the first supply bar drive source 36A and the second supply bar drive source 36B. Specifically, the controller 150 controls the first supply bar drive source 36A and the second supply bar drive source 36B so that the driving force from the second supply bar drive source 36B is equal to the driving force from the first supply bar drive source 36A.

[0034] As described above, the conveying device includes a first supply bar drive source 36A that applies driving force to a first support member 35A, and a second supply bar drive source 36B that applies driving force to a second support member 35B. The supply bar support member 35 has a supply bar member 34 around which the medium M is wrapped, a first support member 35A that supports one end of the supply bar member 34, and a second support member 35B that supports the other end of the supply bar member 34. The control unit 50 controls the first supply bar drive source 36A and the second supply bar drive source 36B so that the driving force applied by the second supply bar drive source 36B is equal to the driving force applied by the first supply bar drive source 36A. The conveying device can perform conveyance while suppressing slanting and meandering when conveying a wide medium M. For example, the conveying device can perform conveyance while suppressing slanting and meandering caused by the twisting of the second support member 35B relative to the first support member 35A.

[0035] The winding unit 40 comprises a winding member 41, a winding member drive mechanism 42, a guide bar member 43, a winding guide member 44, a guide bar support member 46, and a guide bar drive mechanism 49. The winding unit 40 winds up the medium M printed by the printing unit 20.

[0036] The winding member 41 is capable of winding the printed medium M onto the roll core 71. The roll core 71 is installed on the winding member 41 and winds the medium M. The winding member 41 is located downstream of the transport roller pair 24 in the transport direction of the medium M. The winding member 41 is rotatable around a winding member rotation axis (not shown). The winding member 41 supports the printed medium roll 70, which has been wound with the medium M printed by the printing unit 20. The printed medium roll 70 in Figure 1 shows a hypothetical state when the medium M is wound. The winding member 41 is rotatably supported by a frame (not shown) located at the +Y end and the -Y end of the winding unit 40. The winding member 41 corresponds to an example of a winding section.

[0037] The winding member drive mechanism 42 rotates the winding member 41 based on the control of the control unit 50. The winding member drive mechanism 42 includes a drive source such as a motor (not shown), a transmission mechanism for transmitting the driving force from the drive source, and a control circuit for operating the drive source based on signals from the control unit 50. By rotating the winding member 41, the winding member drive mechanism 42 causes the medium M to be wound onto the winding member 41, forming a printing medium roll 70. By winding the medium M, the roll diameter of the printing medium roll 70 increases. Roll diameter refers to the diameter.

[0038] The guide bar member 43 wraps around the printed surface of the medium M printed by the print head 26. The guide bar member 43 is positioned between the transport roller pair 24 and the winding member 41 in the transport path through which the medium M is transported. The guide bar member 43 contacts the printed surface directly or via a cover member (not shown). The cover member is, for example, a friction member for applying a predetermined frictional force to the medium M. That is, the guide bar member 43 can contact the printed surface directly or indirectly. The guide bar member 43 applies tension to the medium M. The shape of the guide bar member 43 is not limited as long as it can apply tension to the medium M, but it is preferable that its shape be a cylinder or column extending in the direction along the Y axis. The guide bar member 43 is made of an extruded metal member such as aluminum or stainless steel, or a pipe processed metal member such as aluminum or stainless steel. The guide bar member 43 corresponds to an example of a tension bar.

[0039] The guide bar support members 46 are positioned at +Y and -Y directions relative to the guide bar member 43, so as to sandwich the guide bar member 43. The guide bar support members 46 movably support the guide bar member 43. The guide bar member 43 and the guide bar support members 46 correspond to an example of a tensioning section.

[0040] The guide bar drive mechanism 49 applies a driving force to the guide bar support member 46 based on the control of the control unit 50. The guide bar drive mechanism 49 has a guide bar drive source (not shown) that generates the driving force. With the driving force applied, the guide bar support member 46 and the guide bar member 43 supported by the guide bar support member 46 oscillate as the medium M is transported. In the case of Figure 1, the guide bar drive mechanism 49 oscillates the guide bar support member 46 and the guide bar member 43 supported by the guide bar support member 46 around a virtual guide bar oscillation axis (not shown). That is, the guide bar drive mechanism 49 can adjust the biasing force that the guide bar member 43 exerts on the medium M. The guide bar oscillation axis does not coincide with the rotation axis (not shown) of the winding member 41. The guide bar oscillation axis may coincide with the rotation axis of the winding member 41. The guide bar drive mechanism 49 adjusts the tension applied to the medium M as the supply bar member 34 swings by adjusting the driving force applied to the guide bar support member 46. The guide bar drive mechanism 49 adjusts the tension acting on the portion of the medium M from the transport roller pair 24 to the printing medium roll 70. The guide bar drive mechanism 49 corresponds to an example of a drive unit. The guide bar drive mechanism 49 shown in Figure 1 swings the guide bar support member 46 and the guide bar member 43, but is not limited to this. The guide bar drive mechanism 49 may also translate the guide bar support member 46 and the guide bar member 43 along an axis parallel to the Z axis. The trajectory of the translational movement of the guide bar support member 46 and the guide bar member 43 is not limited to an axis parallel to the Z axis, but may be appropriately changed to match the path of the medium M.

[0041] The printer 10 transports the media M unwound from the media roll 60 supported by the media roll support shaft 31 along the following transport path. The media M unwound from the media roll 60 is transported to the printing unit 20 via the supply guide member 33 and the supply bar member 34. The printing unit 20 transports the media M to the winding unit 40 using the supply guide frame 21, the transport roller pair 24, the platen 25, and the discharge guide frame 29. The winding unit 40 winds the media M, which has passed through the guide bar member 43 and the winding guide member 44, onto the printing media roll 70 supported by the winding member 41. The device including the media roll support shaft 31, the supply bar member 34, the supply bar support member 35, the supply bar drive mechanism 36, and the transport roller pair 24 corresponds to an example of a transport device. The device including the transport roller pair 24, the guide bar member 43, the guide bar support member 46, the guide bar drive mechanism 49, and the winding member 41 also corresponds to an example of a transport device.

[0042] Figure 3 shows the functional blocks of the printer 10. Figure 3 shows the functional unit related to drive control for operating the printer 10.

[0043] The printing unit 20 includes a control panel 122, a print head drive mechanism 124, a transport roller drive mechanism 126, and a load detection sensor 80. The control panel 122 receives input from the user. The control panel 122 corresponds to an example of a reception unit. The user uses the control panel 122 to input various settings related to printing. These settings include, for example, the size of the media M, the type of media M, the thickness of the media M, the print resolution, and the print mode. The size of the media M, the type of media M, and the thickness of the media M correspond to an example of a media type. The function unit that receives input from the user is not limited to the control panel 122. A communication interface that receives data from an external device such as a computer may also be the function unit that receives input from the user. The user sends the printing settings entered into the external device to the printer 10. The printer 10 receives the printing settings via the communication interface.

[0044] The print head drive mechanism 124 controls the print head 26 and the carriage 27. The print head drive mechanism 124 ejects ink from the print head 26 under the control of the control unit 50. The print head drive mechanism 124 moves the carriage 27 under the control of the control unit 50.

[0045] The transport roller drive mechanism 126 operates the transport roller pair 24. The transport roller drive mechanism 126 drives at least one of the first transport roller 22 and the second transport roller 23 under the control of the control unit 50. The transport roller drive mechanism 126 causes the transport roller pair 24 to perform intermittent transport, which alternates between transport operation and stopping operation. The transport operation is the operation of transporting a predetermined amount of media M by the transport roller pair 24. The transport operation corresponds to an example of media transport operation. The stopping operation is the operation of stopping the transport of media M by stopping the transport roller pair 24. The stopping operation corresponds to an example of media stopping operation.

[0046] The supply unit 30 includes a media roll drive mechanism 32, a supply bar drive mechanism 36, and a supply bar detection mechanism 132. The supply bar detection mechanism 132 detects the position of the supply bar member 34. As shown in Figure 1, when the supply bar support member 35 that supports the supply bar member 34 swings about the supply bar support axis, the supply bar detection mechanism 132 detects the swing angle of the supply bar support member 35. By detecting the swing angle of the supply bar support member 35, the supply bar detection mechanism 132 can calculate the position of the supply bar member 34. The supply bar detection mechanism 132 is not limited to a mechanism that detects the swing angle of the supply bar support member 35. The supply bar detection mechanism 132 may be, for example, a sensor that directly detects the position of the supply bar member 34.

[0047] The winding unit 40 includes a winding member drive mechanism 42, a winding amount detection mechanism 142, a guide bar drive mechanism 49, and a guide bar detection mechanism 144.

[0048] The winding amount detection mechanism 142 detects the amount of media M wound onto the roll core 71. The winding amount of media M is related to the roll diameter of the printing media roll 70. The winding amount detection mechanism 142 is, for example, a sensor that detects the roll diameter of the printing media roll 70. The winding amount detection mechanism 142 may calculate the winding amount of media M based on the cumulative length of media M conveyed by the transport roller pair 24 and the rotation angle of the printing media roll 70. The rotation angle of the printing media roll 70 may be detected, for example, by a rotary encoder (not shown). The winding amount detected by the winding amount detection mechanism 142 is transmitted to the control unit 50. The control unit 50 controls the guide bar drive mechanism 49 based on the received winding amount to adjust the tension on the media M between the transport roller pair 24 and the winding member 41.

[0049] The guide bar detection mechanism 144 detects the position of the guide bar member 43. As shown in Figure 1, when the guide bar support member 46 that supports the guide bar member 43 swings about the guide bar swing axis, the guide bar detection mechanism 144 detects the swing angle of the guide bar support member 46. By detecting the swing angle of the guide bar support member 46, the guide bar detection mechanism 144 can calculate the position of the guide bar member 43. The guide bar detection mechanism 144 is not limited to a mechanism that detects the swing angle of the guide bar support member 46. The guide bar detection mechanism 144 may be, for example, a sensor that directly detects the position of the guide bar member 43.

[0050] The control unit 50 comprises a controller 150, a memory 152, and an interface 154. The controller 150 has a CPU (Central Processing Unit) and a processor. The controller 150 controls the driving of the print head drive mechanism 124, the transport roller drive mechanism 126, the media roll drive mechanism 32, the winding member drive mechanism 42, and the guide bar drive mechanism 49. The controller 150 outputs signals to control the driving. The controller 150 performs control based on various information transmitted from the load detection sensor 80, the supply bar detection mechanism 132, the winding amount detection mechanism 142, and the guide bar detection mechanism 144.

[0051] Memory 152 includes semiconductor memory such as ROM (Read Only Memory) and RAM (Random Access Memory), as well as storage such as HDD (Hard Disk Drive). Memory 152 stores various programs that run on the controller 150. Memory 152 also stores information transmitted from various detection mechanisms.

[0052] Interface 154 connects to various drive mechanisms and detection mechanisms. Interface 154 transmits the drive control signals output from the controller 150 to the drive mechanisms to be controlled. Interface 154 also transmits information received from various detection mechanisms to the controller 150.

[0053] 2. Supply and transport control of medium M First Embodiment Figure 4 shows the operation of the first embodiment when the printer 10 transports the medium M. Figure 4 shows the changes over time in transport speed, transport current, supply bar drive current, supply bar position, and roll peripheral speed. In Figure 4, the supply bar member 34 is represented as SB.

[0054] The transport speed V is the speed at which the medium M moves when the transport roller pair 24 transports the medium M. Figure 4 shows the transport speed when the medium M is stationary as 0. Figure 4 shows the transport speed when the transport roller pair 24 transports the medium M along the transport path from the supply unit 30 to the winding unit 40 as +V.

[0055] The transport current is the current applied to the drive source included in the transport roller drive mechanism 126 when the transport roller pair 24 transports the medium M. The transport current is detected by the load detection sensor 80. The transport current represents the transport load applied to the transport roller pair 24 when the printer 10 transports the medium M at a desired transport speed. The transport load applied to the transport roller pair 24 corresponds to an example of the load applied to the transport section. In Figure 4, the transport current when the transport roller pair 24 transports the medium M is represented as +I.

[0056] Figure 4 shows the target current Im. The target current Im is the target value of the transport current applied to the drive source included in the transport roller drive mechanism 126 when the transport roller pair 24 transports the medium M. The target current Im is predetermined for each type of medium M, such as the size of the medium M, the type of medium M, and the thickness of the medium M, and is stored in the memory 152. The controller 150 receives the transport current detected by the load detection sensor 80. The controller 150 compares the received transport current with the target current Im stored in the memory 152. When the received transport current is greater than the target current Im, the controller 150 determines that the load on the transport roller pair 24 due to the tension of the medium M is excessive. When the received transport current is less than the target current Im, the controller 150 determines that the load on the transport roller pair 24 due to the tension of the medium M is insufficient.

[0057] The supply bar drive current is the current applied to the drive source included in the supply bar drive mechanism 36 when the supply bar member 34 applies tension to the medium M. In Figure 4, the supply bar drive current applied to the supply bar drive source, described later, included in the supply bar drive mechanism 36, when the supply bar member 34 increases the tension on the medium M is represented as +It. In Figure 4, the supply bar drive current applied to the supply bar drive source when the supply bar member 34 decreases the tension on the medium M is represented as -It. The supply bar drive mechanism 36 adjusts the tension that the supply bar member 34 applies to the medium M by driving the supply bar support member 35. In this embodiment, the applied supply bar drive current is a negative current in order to compensate for excessive biasing force, i.e., tension, caused by the weight of the supply bar member 34. That is, the controller 150 can control the biasing force that the supply bar member 34 exerts on the medium M by adjusting the supply bar drive current It. Note that if the mass of the supply bar member 34 is light, the applied supply bar drive current may be a positive current.

[0058] The supply bar position represents the position of the supply bar member 34. The supply bar member 34 moves in the +Z and -Z directions due to the oscillation of the supply bar support member 35. Figure 4 shows the position of the supply bar member 34 when the supply bar support member 35 is at the oscillation center, which is represented as the oscillation center position P0. In this embodiment, when the supply bar support member 35 is in a position along an axis parallel to the X-axis, the supply bar member 34 is at the oscillation center position P0. Figure 4 shows the position when the supply bar member 34 is located in the +Z direction relative to the oscillation center position P0, which is represented as the +Z position. Figure 4 shows the position when the supply bar member 34 is located in the -Z direction relative to the oscillation center position P0, which is represented as the -Z position.

[0059] The roll peripheral speed represents the peripheral speed of the media roll 60. The media roll drive mechanism 32 adjusts the peripheral speed of the media roll 60 under the control of the controller 150. The peripheral speed of the media roll 60 is related to the amount of media M conveyed from the media roll 60. The amount of media M conveyed from the media roll 60 is related to the tension of the media M between the media roll 60 and the conveying roller pair 24. Figure 4 represents a predetermined peripheral speed as the reference peripheral speed Vr0. The reference peripheral speed Vr0 is stored in memory 152 in advance. Figure 4 represents a peripheral speed faster than the reference peripheral speed Vr0 as +Vr. Figure 4 represents a peripheral speed slower than the reference peripheral speed Vr0 as -Vr.

[0060] At time t0, the controller 150 drives the transport roller pair 24 by controlling the transport roller drive mechanism 126. The transport roller drive mechanism 126 applies a transport current to the drive source included in the transport roller drive mechanism 126 so that the transport speed of the medium M by the transport roller pair 24 becomes the target transport speed V1. In Figure 4, the transport roller drive mechanism 126 applies a transport current I1 to the drive source.

[0061] The load detection sensor 80 detects the carrier current I1 applied to the drive source. The controller 150 receives the carrier current I1 detected by the load detection sensor 80.

[0062] At time t0, the controller 150 causes the print head 26 to perform printing by controlling the print head drive mechanism 124. The print head drive mechanism 124 performs printing by driving the print head 26 and the carriage 27.

[0063] Furthermore, at time t0, the controller 150 adjusts the tension that the supply bar member 34 applies to the medium M by controlling the supply bar drive mechanism 36. In Figure 4, the controller 150 causes the supply bar drive current It1 to be applied to the supply bar drive source included in the supply bar drive mechanism 36. For example, based on the deviation between the target current Im and the actual transport current during the transport operation prior to time t0, feedback control is performed so that the supply bar drive current It1 is applied to the supply bar drive source so that a biasing force is applied to the medium M to bring the transport current closer to the target current Im. In Figure 4, the graph related to the transport operation prior to time t0 is omitted. The supply bar drive source will be described later. The supply bar drive mechanism 36 reduces the tension that the supply bar member 34 applies to the medium M by applying the supply bar drive current It1. Alternatively, by measuring the eccentricity of the roll body in advance, an eccentricity profile can be created based on the eccentricity of the roll body, and feedforward control can be performed based on the eccentricity profile so that the supply bar drive current It is applied to the supply bar drive source so that a biasing force is applied to the medium M so that the transport current approaches the target current Im. In this case, the eccentricity profile is created based on the change in the transport current applied to the drive source included in the transport roller drive mechanism 126 in response to a change in the rotation angle of the roll body, under the condition that the driving force from the medium roll drive mechanism 32 is constant and the amount of medium M transported from the medium roll 60 for each transport operation is constant.

[0064] Figure 5 schematically shows the position of the supply bar member 34 at time t0. Figure 5 shows a horizontal line HL parallel to the X-axis passing through the supply bar pivot axis (not shown). In this embodiment, the supply bar support member 35 coincides with the horizontal line HL when it is located at the pivot center.

[0065] At time t0, the supply bar support member 35 is oscillating around the supply bar pivot axis at an angle θ-α. The supply bar member 34 is at the lower limit position Pm. The media roll 60 is rotating at a lower limit peripheral speed Vr2. Immediately before time t0, the transport roller pair 24 is not transporting the media M, so the controller 150 controls the media roll drive mechanism 32 to reduce the roll peripheral speed of the media roll 60. The amount of media M transported from the media roll 60 rotating at the lower limit peripheral speed Vr2 is less than the amount of media M transported when the printer 10 is printing.

[0066] After the transport roller drive mechanism 126 applies a transport current I1 to the drive source, the transport speed of the medium M increases to the target transport speed V1. After reaching the target transport speed V1, the transport roller pair 24 continues to transport the medium M at the target transport speed V1.

[0067] After the transport roller pair 24 begins transporting the medium M, the position of the supply bar member 34 moves in the +Z direction. As the transport roller pair 24 transports the medium M, the medium M moves the supply bar member 34 in the +Z direction. At this time, the supply bar member 34 reduces the tension applied to the medium M by the drive of the supply bar drive mechanism 36.

[0068] At time t1, the supply bar support member 35 is positioned at the pivot center. At time t1, the controller 150 continues to apply the transport current I1 to the drive source included in the transport roller drive mechanism 126. The controller 150 also continues to apply the supply bar drive current It1 to the supply bar drive source included in the supply bar drive mechanism 36. Figure 6 schematically shows the position of the supply bar member 34 at time t1.

[0069] At time t1, the supply bar support member 35 is positioned along the horizontal line HL. The oscillation angle of the supply bar support member 35 is 0°. The supply bar member 34 is positioned at the center position P0. The controller 150 controls the roll peripheral speed of the media roll 60 based on the position of the supply bar member 34. From time t0 to time t1, the position of the supply bar member 34 rises from the lower limit position Pm to the center position P0 due to the media M. When the position of the supply bar member 34 moves in the +Z direction, the controller 150 increases the roll peripheral speed of the media roll 60 by controlling the supply bar drive mechanism 36. At time t1, the roll peripheral speed of the media roll 60 is the reference peripheral speed Vr0.

[0070] At time t2, the controller 150 stops applying the transport current I1 to the drive source included in the transport roller drive mechanism 126. At this time, the controller 150 also stops applying the supply bar drive current It1 to the supply bar drive source included in the supply bar drive mechanism 36. Figure 7 schematically shows the position of the supply bar member 34 at time t2.

[0071] At time t2, the supply bar support member 35 is oscillating around the supply bar pivot axis at an angle θ+α. The supply bar member 34 is at the upper limit position P+m. From time t0 to time t2, the transport roller pair 24 continues to transport the medium M, reducing the amount of medium M in the transport path from the medium roll 60 to the transport roller pair 24. Due to the reduction in the amount of medium M in the transport path, the supply bar member 34 moves in the +Z direction. As the supply bar member 34 moves in the +Z direction, the transport path of the medium M from the medium roll 60 to the transport roller pair 24 is shortened. The controller 150 increases the roll peripheral speed of the medium roll 60 from time t0 to time t2 by controlling the medium roll drive mechanism 32. Specifically, the controller 150 controls the medium roll drive mechanism 32 so that the roll peripheral speed of the medium roll 60 becomes the lower limit peripheral speed Vr2 at time t0 and the upper limit peripheral speed Vr1 at time t2. The controller 150 prevents the supply bar member 34 from moving beyond the upper limit position P+m in the +Z direction by increasing the roll peripheral speed of the medium roll 60.

[0072] At time t2, the controller 150 stops applying the supply bar drive current It1 to the supply bar drive source included in the supply bar drive mechanism 36. By stopping the application of the supply bar drive current It1, the controller 150 increases the tension that the supply bar member 34 applies to the medium M. By stopping the application of the supply bar drive current It1, the supply bar member 34 applies tension to the medium M by its own weight.

[0073] At time t2, the controller 150 stops printing by the print head 26 by controlling the print head drive mechanism 124. The print head drive mechanism 124 moves the print head 26 to a maintenance unit (not shown) by driving the carriage 27.

[0074] Between time t2 and time t4, the transport roller pair 24 stops transporting the medium M. Meanwhile, the controller 150 continues the rotation of the medium roll 60 by controlling the medium roll drive mechanism 32. As the medium roll 60 continues to rotate, the medium M is fed out of the medium roll 60 into the transport path. As the medium M is fed into the transport path, the amount of medium M in the transport path between the medium roll 60 and the transport roller pair 24 increases. Due to the increase in the amount of medium M, the position of the supply bar member 34 moves in the -Z direction.

[0075] At time t3, the supply bar member 34 is located at the central position P0 shown in Figure 6. Based on the position of the supply bar member 34, the controller 150 controls the peripheral speed of the media roll 60 to the reference peripheral speed Vr0.

[0076] Between time t2 and time t4, the controller 150 reduces the roll peripheral speed of the media roll 60 by controlling the media roll drive mechanism 32. Specifically, the controller 150 controls the media roll drive mechanism 32 so that the roll peripheral speed of the media roll 60 becomes the upper limit peripheral speed Vr1 at time t2 and the lower limit peripheral speed Vr2 at time t4. By reducing the roll peripheral speed, the controller 150 reduces the amount of media M supplied to the transport path between the media roll 60 and the transport roller pair 24. By reducing the amount of media M supplied, it is possible to suppress the supply bar member 34 from moving beyond the lower limit position Pm in the -Z direction.

[0077] Between time t2 and time t4, the controller 150 calculates the supply bar drive current. The controller 150 calculates the supply bar drive current based on the carrier current detected by the load detection sensor 80, i.e., the actual carrier current, and the target current Im stored in the memory 152. For example, between time t2 and time t4, feedback control is performed based on the deviation between the target current Im and the actual carrier current, so that the controller 150 calculates a value of supply bar drive current such that a biasing force is applied to the medium M to bring the carrier current from time t4 to time t6 closer to the target current Im. The supply bar drive current calculated between time t2 and time t4 is the supply bar drive current It2, which will be described later. The supply bar drive current may be calculated at any time between time t0 and time t2. For example, the detection of the transport current by the load detection sensor 80 may end at time t1, and the supply bar drive current may be calculated between time t1 and time t2.

[0078] For example, when the detected transport current is greater than the target current Im, the controller 150 determines that the load on the transport roller pair 24 is greater than expected. When the controller 150 determines that the load is greater than expected, it reduces the supply bar drive current. By reducing the supply bar drive current, the tension that the supply bar member 34 applies to the medium M decreases. As the tension applied to the medium M decreases, the load on the transport roller pair 24 decreases.

[0079] When the detected transport current is smaller than the target current Im, the controller 150 determines that the load on the transport roller pair 24 is smaller than expected. When the controller 150 determines that the load is smaller than expected, it increases the supply bar drive current. By increasing the supply bar drive current, the tension that the supply bar member 34 applies to the medium M increases. As the tension applied to the medium M increases, the load on the transport roller pair 24 increases.

[0080] The controller 150 may adjust the supply bar drive current according to the type of medium M, such as the size of the medium M, the type of medium M, and the thickness of the medium M. For example, when the medium M is thin paper, the controller 150 reduces the supply bar drive current compared to when the medium M is standard paper. When the supply bar drive current is reduced, the driving force generated by the supply bar drive source included in the supply bar drive mechanism 36 is reduced. When the driving force is reduced, the tension that the supply bar member 34 applies to the medium M is reduced, making the medium M less likely to be damaged.

[0081] The transport device includes a control panel 122 that receives input regarding the type of medium M. The control unit 50 corrects the driving force of the supply bar drive mechanism 36 according to the type of medium M received by the control panel 122. The conveying device can suppress the decrease in accuracy of conveyed volume due to the type of media M. The media compatibility of the conveying device is improved.

[0082] At time t4, the controller 150 drives the transport roller pair 24 by controlling the transport roller drive mechanism 126. The transport roller drive mechanism 126 applies a transport current to the drive source included in the transport roller drive mechanism 126 such that the transport speed of the medium M by the transport roller pair 24 becomes the target transport speed V1. The controller 150 also causes the supply bar drive source included in the supply bar drive mechanism 36 to apply a supply bar drive current It2. The supply bar drive current It2 is smaller than the supply bar drive current It1.

[0083] After the transport current and the supply bar drive current are applied, the load detection sensor 80 detects the transport current. In Figure 4, the applied transport current matches the target current Im. By adjusting the supply bar drive current, the controller 150 reduces the load on the transport roller pair 24, and the transport current matches the target current Im. By adjusting the tension load on the medium M by the supply bar member 34, the controller 150 enables the transport roller pair 24 to transport the medium M with high precision.

[0084] Between time t4 and time t6, the transport roller pair 24 transports the medium M. The print head 26 and carriage 27 are driven by the print head drive mechanism 124 to perform printing. At time t5, the supply bar member 34 rises from the lower limit position Pm shown in Figure 5 to the center position P0 shown in Figure 6. The roll peripheral speed of the medium roll 60 changes according to the position of the supply bar member 34. The roll peripheral speed of the medium roll 60 increases from the lower limit peripheral speed Vr2 to the reference peripheral speed Vr0.

[0085] At time t6, the controller 150 stops the transport of the medium M and printing by the print head 26. The transport current is switched from the target current Im to current 0. The supply bar drive current is switched from the supply bar drive current It2 to supply bar drive current 0. The supply bar member 34 is at the upper limit position P+m. The peripheral speed of the medium roll 60 is controlled to the upper limit peripheral speed Vr1.

[0086] Between time t6 and time t8, the controller 150 maintains a transport current of 0 and a supply bar drive current of 0. The supply bar member 34 descends from the upper limit position P+m to the lower limit position Pm. The peripheral speed of the media roll 60 decreases from the upper limit peripheral speed Vr1 to the lower limit peripheral speed Vr2. The controller 150 receives the transport current between time t4 and time t6 and compares the received transport current with the target current Im stored in the memory 152. Based on the comparison result, the controller 150 calculates the supply bar drive current to be applied to the supply bar drive source included in the supply bar drive mechanism 36 from time t8 onward.

[0087] At time t7, between time t6 and time t8, the supply bar member 34 is at the center position P0. The roll peripheral speed of the media roll 60 is controlled to the reference peripheral speed Vr0.

[0088] At time t8, the controller 150 drives the transport roller pair 24 by controlling the transport roller drive mechanism 126. The transport roller drive mechanism 126 applies a transport current to the drive source included in the transport roller drive mechanism 126 such that the transport speed of the medium M by the transport roller pair 24 becomes the target transport speed V1. The controller 150 also causes the supply bar drive source included in the supply bar drive mechanism 36 to apply a supply bar drive current It2.

[0089] As described above, the conveying device comprises a media roll support shaft 31 that rotatably holds a media roll 60 on which the media M is wound, a pair of conveying rollers 24 that convey the media M drawn from the media roll 60, a supply bar member 34 and a supply bar support member 35 that wrap the media M between the media roll support shaft 31 and the pair of conveying rollers 24 and apply tension to the media M, a supply bar drive mechanism 36 that applies driving force to the supply bar support member 35, a control unit 50 that controls the pair of conveying rollers 24 and the supply bar drive mechanism 36, and a load detection sensor 80 that detects the load applied to the pair of conveying rollers 24. The control unit 50 adjusts the tension applied to the media M by controlling the driving force applied by the supply bar drive mechanism 36. The control unit 50 controls the driving force by the supply bar drive mechanism 36 based on the load detected by the load detection sensor 80. The conveying device has a supply bar member 34 interposed between the media roll support shaft 31 and the conveying roller pair 24, making it easier to eliminate the influence of inertia on the conveying roller pair 24. The conveying device can perform control that reduces the influence of inertia on the media roll 60 by controlling the detected load with the supply bar drive mechanism 36. The conveying device can control the conveyance of the media M with high precision.

[0090] The printer 10 also includes a media roll support shaft 31 that rotatably holds a media roll 60 on which the media M is wound, a pair of transport rollers 24 that transport the media M pulled from the media roll 60, a print head 26 that prints on the media M transported by the pair of transport rollers 24, a supply bar member 34 and a supply bar support member 35 that wrap the media M around the media M between the media roll support shaft 31 and the pair of transport rollers 24 and apply tension to the media M, a supply bar drive mechanism 36 that applies driving force to the supply bar support member 35, a control unit 50 that controls the pair of transport rollers 24 and the supply bar drive mechanism 36, and a load detection sensor 80 that detects the load on the pair of transport rollers 24. The control unit 50 controls the driving force by the supply bar drive mechanism 36 based on the load detected by the load detection sensor 80. In the printer 10, the supply bar member 34 is interposed between the media roll support shaft 31 and the transport roller pair 24, making it easier to eliminate the influence of inertia on the transport roller pair 24. The printer 10 can perform control that reduces the influence of inertia on the media roll 60 by controlling the detected load with the supply bar drive mechanism 36. The printer 10 can control the transport of the media M with high precision.

[0091] The transport control method for the transport device involves transporting the medium M wound on a medium roll 60 held by a medium roll support shaft 31 using a transport roller pair 24, winding the medium M onto a supply bar member 34 between the medium roll support shaft 31 and the transport roller pair 24, applying tension to the medium M by the rotation of a supply bar support member 35 that supports the supply bar member 34, detecting the load on the transport roller pair 24, and controlling a supply bar drive mechanism 36 that applies driving force to the supply bar support member 35 based on the detected load. The conveying device has a supply bar member 34 interposed between the media roll support shaft 31 and the conveying roller pair 24, making it easier to eliminate the influence of inertia on the conveying roller pair 24. The conveying device can perform control that reduces the influence of inertia on the media roll 60 by controlling the detected load with the supply bar drive mechanism 36. The conveying device can control the conveyance of the media M with high precision.

[0092] Second Embodiment Figure 8 shows the operation of the second embodiment when the printer 10 transports the medium M. Figure 8 shows the changes over time in transport speed, transport current, supply bar drive current, supply bar position, and roll peripheral speed. In Figure 8, as in Figure 4, the supply bar is represented as SB.

[0093] In the second embodiment, the timing for applying the supply bar drive current differs from the timing shown in the first embodiment. Other than the timing for applying the supply bar drive current, the operation in the second embodiment is the same as in the first embodiment.

[0094] In the second embodiment, the application time t3b for applying the supply bar drive current is between time t3 and time t4. The application time t3b is earlier than time t4 by a difference time Δt. By setting the application time t3b to the time at which the controller 150 applies the supply bar drive current, the tension applied by the supply bar member 34 to the medium M changes at time t4. In Figure 8, at time t4, the medium M is subjected to a reduced tension due to the application of the supply bar drive current. The tension applied to the medium M by the supply bar member 34 before transport by the transport roller pair 24 is reduced. The printer 10 can reduce the load on the transport roller pair 24 at the start of transport of the medium M, which is caused by the inertia of the supply bar member 34. The value of the supply bar drive current between application time t3b and time t4 may be a value that fluctuates due to feedback control, or it may be a constant value regardless of feedback control.

[0095] As shown in the second embodiment, the control unit 50 controls the transport roller pair 24 to alternately perform a media transport operation that transports a predetermined amount of media M and a media stop operation that stops the transport of media M. When the media M is stopped, the supply bar drive mechanism 36 is controlled to reduce the tension applied to the media M, and the transport operation of media M is restarted with the tension reduced. The conveying device can suppress a sudden increase in load on the conveying roller pair 24 when the conveying operation of the medium M begins. The conveying device can accurately control the amount of medium M conveyed when the conveying operation begins.

[0096] 3. Winding and transport control of medium M Figure 9 shows the transport operation when the printer 10 winds the medium M onto the winding member 41. Figure 9 shows the changes over time in transport speed, transport current, guide bar drive current, guide bar position, and WR peripheral speed. In Figure 9, the guide bar is represented as GB. The transport speed and transport current are the same as those shown in Figure 4.

[0097] The guide bar drive current is the current applied to a guide bar drive source (not shown) included in the guide bar drive mechanism 49 when the guide bar member 43 applies tension to the medium M. In Figure 9, the guide bar drive current applied to the guide bar drive source when the guide bar member 43 increases the tension on the medium M is represented as +Ig. In Figure 9, the guide bar drive current applied to the guide bar drive source when the guide bar member 43 decreases the tension on the medium M is represented as -Ig. The guide bar drive mechanism 49 adjusts the tension that the guide bar member 43 applies to the medium M by driving the guide bar support member 46. In this embodiment, the applied guide bar drive current is a negative current.

[0098] The guide bar position represents the position of the guide bar member 43. The guide bar member 43 moves in the +Z direction and the -Z direction due to the oscillation of the guide bar support member 46. Figure 9 shows the position of the guide bar support member 46 when it is at the oscillation center, which is represented as the guide bar oscillation center position GP0. In this embodiment, when the guide bar support member 46 is in a position along an axis parallel to the X-axis, the guide bar member 43 is at the guide bar oscillation center position GP0. Figure 9 shows the position when the guide bar member 43 is located in the +Z direction relative to the guide bar oscillation center position GP0, which is represented as the +Z position. Figure 9 shows the position when the guide bar member 43 is located in the -Z direction relative to the guide bar oscillation center position GP0, which is represented as the -Z position.

[0099] The WR peripheral speed represents the peripheral speed of the printing medium roll 70. The winding member drive mechanism 42 adjusts the peripheral speed of the printing medium roll 70 under the control of the controller 150. The peripheral speed of the printing medium roll 70 is related to the amount of medium M wound onto the printing medium roll 70. The amount of medium M wound onto the printing medium roll 70 is related to the tension of the medium M between the printing medium roll 70 and the transport roller pair 24. Figure 9 shows a predetermined peripheral speed as the reference peripheral speed Vg0. The reference peripheral speed Vg0 is stored in the memory 152 in advance. Figure 9 shows a peripheral speed faster than the reference peripheral speed Vg0 as +Vg. Figure 9 shows a peripheral speed slower than the reference peripheral speed Vg0 as -Vg.

[0100] As shown in Figures 4 and 9, the operation of the supply bar drive current and the guide bar drive current are the same. The change over time of the guide bar position and the peripheral speed of the printing medium roll 70 is the same as the change over time of the supply bar position and the roll peripheral speed of the medium roll 60. The controller 150 can control the supply bar drive current in the same way as the guide bar drive current. The printer 10 can adjust the tension on the medium M between the transport roller pair 24 and the printing medium roll 70 by controlling the guide bar drive current based on the load on the transport roller pair 24. The guide bar member 43 applies tension to the medium M by wrapping it around it, but is not limited to this. For example, tension may be applied to the medium M by pressing it with a line contact or point contact.

[0101] As described above, the conveying device comprises a pair of conveying rollers 24 that conveys the medium M in the conveying direction, a winding member 41 that winds up the medium M conveyed by the pair of conveying rollers 24, a guide bar member 43 that winds the medium M between the pair of conveying rollers 24 and the winding member 41 and applies tension to the medium M, a guide bar drive mechanism 49 that applies driving force to a guide bar support member 46 that supports the guide bar member 43, a control unit 50 that controls the pair of conveying rollers 24 and the guide bar drive mechanism 49, and a load detection sensor 80 that detects the load applied to the pair of conveying rollers 24. The control unit 50 controls the driving force by the guide bar drive mechanism 49 based on the load detected by the load detection sensor 80. The conveying device can control the tension of the media M between the conveying roller pair 24 and the printing media roll 70 within a predetermined range by controlling the detected load. The conveying device can accurately control the conveyance of the media M.

[0102] The following describes the conclusions drawn from the embodiment.

[0103] The conveying device comprises a holding unit that rotatably holds a roll body on which media is wound, a conveying unit that conveys the media drawn out from the roll body, a tensioning unit that presses the media between the holding unit and the conveying unit to apply tension to the media, a drive unit that applies driving force to the tensioning unit, a control unit that controls the conveying unit and the drive unit, and a detection unit that detects the load applied to the conveying unit. The control unit adjusts the tension applied to the media by controlling the driving force applied by the drive unit, and controls the driving force by the drive unit based on the load detected by the detection unit.

[0104] With this configuration, the conveying device has a tensioning unit interposed between the holding unit and the conveying unit, making it easier to eliminate the influence of inertia on the conveying unit. The conveying device can perform control that reduces the influence of the roll's inertia by controlling the detected load with the drive unit. The conveying device can control the conveyance of the media with high precision.

[0105] The above-described transport device is configured such that the control unit controls the transport unit to alternately perform a media transport operation, which transports a predetermined amount of media, and a media stop operation, which stops the transport of the media. During the media stop operation, the control unit controls the drive unit to reduce the tension applied to the media, and the media transport operation is performed with the tension reduced.

[0106] With this configuration, the conveying device can suppress a sudden increase in load on the conveying section when the media conveying operation starts. The conveying device can accurately control the amount of media conveyed when the media conveying operation starts.

[0107] The above-described transport device includes a receiving unit that receives input regarding the type of media, and the control unit corrects the driving force by the drive unit according to the type of media received by the receiving unit.

[0108] This configuration allows the conveying device to minimize the decrease in conveying accuracy due to the type of media. It also improves the media compatibility of the conveying device.

[0109] The above-described conveying device includes a second drive unit that applies a second driving force to the tensioning unit, the tensioning unit having a tension bar around which the media is wrapped, a first arm supporting one end of the tension bar, and a second arm supporting the other end of the tension bar, the drive unit applying the driving force to the first arm, the second drive unit applying the second driving force to the second arm, and the control unit controlling the drive unit and the second drive unit so that the second driving force is equal to the first driving force.

[0110] With this configuration, the conveying device can perform conveyance while suppressing slanting and meandering when conveying wide media. For example, the conveying device can perform conveyance while suppressing slanting and meandering caused by the twisting of the second arm relative to the first arm.

[0111] The conveying device comprises a conveying unit that conveys media in the conveying direction, a winding unit that winds up the media conveyed by the conveying unit, a tensioning unit that presses the media between the conveying unit and the winding unit to apply tension to the media, a drive unit that applies driving force to the tensioning unit, a control unit that controls the conveying unit and the drive unit, and a detection unit that detects the load applied to the conveying unit, wherein the control unit controls the driving force by the drive unit based on the load detected by the detection unit.

[0112] With this configuration, the conveying device can control the tension of the media between the conveying section and the winding section within a predetermined range by controlling the detected load. The conveying device can control the conveyance of the media with high precision.

[0113] The printing apparatus comprises a holding unit that rotatably holds a roll body on which media is wound; a transport unit that transports the media drawn from the roll body; a printing unit that prints on the media transported by the transport unit; a tensioning unit that presses the media between the holding unit and the transport unit to apply tension to the media; a drive unit that applies driving force to the tensioning unit; a control unit that controls the transport unit and the drive unit; and a detection unit that detects the load applied to the transport unit. The control unit controls the driving force provided by the drive unit based on the load detected by the detection unit.

[0114] With this configuration, the printing device has a tensioning unit interposed between the holding unit and the transport unit, making it easier to eliminate the influence of inertia on the transport unit. The printing device can perform control that reduces the influence of the roll's inertia by controlling the detected load with the drive unit. The printing device can control the transport of the media with high precision.

[0115] The transport control method transports media wound around a roll body held by a holding unit in a transport unit, applies tension to the media by pressing it with a tensioning unit between the holding unit and the transport unit, detects the load applied to the transport unit, and controls a drive unit that applies driving force to the tensioning unit based on the detected load.

[0116] With this configuration, the conveying device has a tensioning unit interposed between the holding unit and the conveying unit, making it easier to eliminate the influence of inertia on the conveying unit. The conveying device can perform control that reduces the influence of the roll's inertia by controlling the detected load with the drive unit. The conveying device can control the conveyance of the media with high precision. [Explanation of Symbols]

[0117] 10…Printer, 20…Printing unit, 21…Supply guide frame, 22…First transport roller, 23…Second transport roller, 24…Pair of transport rollers, 25…Platen, 26…Print head, 27…Carriage, 29…Discharge guide frame, 30…Supply unit, 31…Media roll support shaft, 32…Media roll drive mechanism, 33…Supply guide member, 34…Supply bar member, 34A…Supply bar shaft, 35…Supply bar support member, 35A…First support member, 35B…Second support member, 36…Supply bar drive mechanism, 36A…First supply bar drive source, 36B…Second supply bar drive source, 36C…First drive shaft, 36D…Second drive shaft, 40…Winding unit, 41…Winding member, 42…Winding member drive mechanism, 43…Guide bar section Material, 44...winding guide member, 46...guide bar support member, 49...guide bar drive mechanism, 50...control unit, 60...media roll, 70...printing media roll, 71...roll core, 80...load detection sensor, 122...control panel, 124...print head drive mechanism, 126...conveyor roller drive mechanism, 132...supply bar detection mechanism, 142...winding amount detection mechanism, 144...guide bar detection mechanism, 150...controller, 152...memory, 154...interface, Im...target current, HL...horizontal line, P0...center position, P+m...upper limit position, Pm...lower limit position, V1...target conveying speed, Vr0...reference peripheral speed, Vr1...upper limit peripheral speed, Vr2...lower limit peripheral speed, GP0...guide bar oscillation center position, M...media.

Claims

1. A holding part that rotatably holds a roll body on which media is wound, A transport unit for transporting the media drawn out from the roll body, A tension-applying unit presses the media between the holding unit and the transport unit to apply tension to the media, A drive unit that applies driving force to the tension-applying unit, A control unit that controls the transport unit and the drive unit, The transport section includes a detection unit for detecting the load applied to the transport section, The control unit, By controlling the driving force applied by the drive unit, the tension applied to the media is adjusted. Based on the load detected by the detection unit, the driving force by the drive unit is controlled. By controlling the transport unit, a media transport operation that transports a predetermined amount of media and a media stop operation that stops transporting the media are performed alternately. During the media stopping operation, the tension applied to the media is reduced by controlling the drive unit. The media transport operation is performed while the tension is reduced. Conveying device.

2. The system includes a reception unit that accepts input regarding the type of media, The control unit corrects the driving force by the drive unit according to the type of media received by the reception unit. The conveying device according to claim 1.

3. The tension-applying section is further equipped with a second drive unit that applies a second drive force, The tension-applying unit is, A tension bar around which the aforementioned media is wrapped, A first arm supporting one end of the tension bar, It has a second arm that supports the other end of the tension bar, The drive unit applies the driving force to the first arm, The second drive unit applies the second drive force to the second arm, The control unit controls the drive unit and the second drive unit so that the second drive force becomes equal to the drive force. The conveying device according to claim 1 or 2.

4. A winding unit that winds up the media conveyed by the transport unit, A second tension-applying unit presses the media between the transport unit and the winding unit to apply tension to the media, The device comprises a third drive unit that applies a third drive force to the second tension-applying unit, The control unit controls the third driving force by the third drive unit based on the load detected by the detection unit. The conveying device according to any one of claims 1 to 3.

5. A holding part that rotatably holds a roll body on which media is wound, A transport unit for transporting the media drawn out from the roll body, A printing unit that prints on the media transported by the transport unit, A tension-applying unit presses the media between the holding unit and the transport unit to apply tension to the media, A drive unit that applies driving force to the tension-applying unit, A control unit that controls the transport unit and the drive unit, The transport section includes a detection unit for detecting the load applied to the transport section, The control unit controls the driving force by the drive unit based on the load detected by the detection unit. By controlling the transport unit, a media transport operation that transports a predetermined amount of media and a media stop operation that stops transporting the media are performed alternately. During the media stopping operation, the tension applied to the media is reduced by controlling the drive unit. The media transport operation is performed while the tension is reduced. Printing device.

6. The media wound on the roll held in the holding section is transported in the transport section. The media is pressed by the tension-applying section between the holding section and the transport section, thereby applying tension to the media. The load applied to the transport section is detected, Based on the detected load, the drive unit that applies driving force to the tensioning unit is controlled. By controlling the transport unit, a media transport operation that transports a predetermined amount of media and a media stop operation that stops transporting the media are performed alternately. During the media stopping operation, the tension applied to the media is reduced by controlling the drive unit. The media transport operation is performed while the tension is reduced. A method for controlling transport.

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