JP2025033996A - Printer - Google Patents

Abstract

To provide a printer capable of suppressing the occurrence of mis-winding of a take-up roll caused by winding tightness of the take-up roll in a printer including a printing mechanism that prints on a long medium, a take-up roll holding part that holds the take-up roll, which is a medium after printing wound in a roll form, and a tension bar that contacts the medium after printing between the printing mechanism and the take-up roll holding part and imparts tension to the medium.SOLUTION: A printer 1 includes a guide roller 46 that is arranged in a moving path of a medium 2 between a tension bar 34 and a take-up roll holding part 8 and guides a medium 2 moving toward the take-up roll holding part 8, and a roller rotation control mechanism for controlling the rotation of the guide roller 46. The roller rotation control mechanism can switch between a braking state for applying a degree of brake to the guide roller 46 which makes the guide roller 46 rotatable and a fixed state in which the guide roller 46 is fixed so that the guide roller 46 does not rotate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printer for printing on long media.

Conventionally, printers (inkjet printers) for printing on long media are known (see, for example, Patent Document 1). The printer described in Patent Document 1 includes a printer body that prints on the media, a take-up roll holder that holds a take-up roll of the printed media wound into a roll, and a cylindrical tension bar that contacts the printed media and applies tension to the media. The take-up roll holder includes a winding core (rotating shaft) that is inserted into the inner periphery of the winding roll, and a drive mechanism that rotates the winding core.

JP 2019-195973 A

The inventors of the present application are developing a printer for printing on long media. The printer under development is equipped with a printing mechanism that prints on long media, a take-up roll holding section that holds a take-up roll of the printed media wound into a roll, and a tension bar that contacts the printed media between the printing mechanism and the take-up roll holding section to apply tension to the media. The take-up roll holding section has a winding core that is inserted into the inner circumference of the take-up roll.

In this printer under development, the inventors have found through their research that as printing on the medium progresses and the outer diameter of the winding roll increases, tightening of the medium that constitutes the winding roll occurs over time, in which a strong force acts on the winding core, depending on the type of medium and the printing conditions of the medium. When this tightening occurs, for example, as shown in Figure 5, a winding misalignment occurs in which the middle part of the winding roll 101 in the radial direction of the winding roll 101 is shifted in the axial direction of the winding roll 101, which can make handling of the winding roll 101 complicated after printing is completed.

The objective of the present invention is to provide a printer that is equipped with a printing mechanism that prints on long media, a take-up roll holding section that holds a take-up roll of the printed media wound into a roll, and a tension bar that contacts the printed media between the printing mechanism and the take-up roll holding section to apply tension to the media, and that can suppress the occurrence of misalignment of the take-up roll caused by tightening of the take-up roll.

In order to solve the above problems, the inventor of the present application conducted various studies. As a result, the inventor of the present application discovered that one of the causes of the occurrence of tightening is the fluctuation in the tension of the medium caused by the tension bar acting on the medium when it is wound on the winding roll. The inventor of the present application also discovered that it is possible to suppress the occurrence of tightening on the winding roll by suppressing the fluctuation in the tension of the medium caused by the tension bar acting on the medium when it is wound on the winding roll and suppressing the fluctuation in the tension of the medium when it is wound on the winding roll.

The present invention is based on this new finding, and the printer of the present invention comprises a printing mechanism that prints on a long medium, a take-up roll holding section that holds a take-up roll, which is the printed medium wound into a roll, a tension bar that contacts the printed medium between the printing mechanism and the take-up roll holding section to apply tension to the medium, a guide roller that is disposed between the tension bar and the take-up roll holding section on the medium's movement path and guides the medium moving toward the take-up roll holding section, and a roller rotation restriction mechanism for restricting the rotation of the guide roller, the take-up roll holding section has a winding core that is inserted into the inner circumference of the take-up roll, the guide roller is a driven roller that contacts the medium and can rotate as the medium moves, and the roller rotation restriction mechanism is switchable between a brake state in which a brake is applied to the guide roller to an extent that the guide roller can rotate, and a fixed state in which the guide roller is fixed so that it does not rotate.

The printer of the present invention includes a guide roller disposed between the tension bar and the winding roll holding section in the medium movement path, and a roller rotation restriction mechanism for restricting the rotation of the guide roller. Therefore, in the present invention, by restricting the rotation of the guide roller with the roller rotation restriction mechanism, it is possible to suppress the fluctuation in tension of the medium caused by the tension bar from acting on the medium when it is wound by the winding roll, and to suppress the fluctuation in tension of the medium when it is wound by the winding roll. Therefore, in the present invention, it is possible to suppress the occurrence of tightening of the winding roll, and as a result, it is possible to suppress the occurrence of winding misalignment of the winding roll caused by the tightening of the winding roll.

In the present invention, for example, the printer includes a second guide roller that is disposed between the tension bar and the winding roll holding section in the medium movement path and guides the medium moving toward the winding roll holding section, the second guide roller is a driven roller that contacts the medium and can rotate with the movement of the medium, and the guide roller is disposed closer to the winding roll holding section in the medium movement path than the second guide roller. According to the inventor's study, by restricting the rotation of the guide roller that is disposed closer to the winding roll holding section in the medium movement path, it is possible to effectively suppress the tension fluctuation of the medium caused by the tension bar from acting on the medium when it is wound by the winding roll. Therefore, in this case, it is possible to effectively suppress the tension fluctuation of the medium caused by the tension bar from acting on the medium when it is wound by the winding roll.

In the present invention, the guide roller comprises a cylindrical roller body that contacts the medium and a rotating shaft fixed to the inner periphery of the roller body, and the roller rotation restriction mechanism comprises a first restricting member that has a C-shape when viewed from the axial direction of the guide roller and is arranged on the outer periphery of the rotating shaft so as to surround the rotating shaft, a screw member that engages with the first restricting member and elastically deforms the first restricting member in a direction in which the inner diameter of the first restricting member changes, and a second restricting member that contacts the outer periphery of the first restricting member to restrict the rotation of the first restricting member in the circumferential direction of the guide roller, and it is preferable that when the screw member is tightened, the inner diameter of the first restricting member narrows and is fixed, and when the screw member is loosened, the inner diameter of the first restricting member widens and is braked. With this configuration, it is possible to restrict the rotation of the guide roller with a relatively simple configuration. Therefore, it is possible to reduce the cost of the roller rotation restriction mechanism.

In the present invention, the printer preferably includes a bearing that rotatably holds the guide roller, and the bearing is held by the second regulating member. With this configuration, the bearing is held by the second regulating member that regulates the rotation of the first regulating member, so that the printer configuration can be simplified compared to when a separate member for holding the bearing is provided.

In the present invention, it is preferable that the roller rotation restriction mechanism is disposed only on one side of the guide roller in the axial direction of the guide roller. In this configuration, it is possible to simplify the configuration of the printer compared to a case in which the roller rotation restriction mechanism is disposed on both sides of the guide roller in the axial direction of the guide roller.

In the present invention, for example, the guide roller is a brush roller. In this case, for example, by using a guide roller that is a brush roller, it is possible to suppress the occurrence of wrinkles in the media in the width direction of the media (the axial direction of the guide roller).

As described above, the present invention makes it possible to suppress the occurrence of misalignment of the winding roll caused by tightening of the winding roll in a printer equipped with a printing mechanism that prints on a long medium, a winding roll holding section that holds a winding roll which is the printed medium wound into a roll, and a tension bar that contacts the printed medium between the printing mechanism and the winding roll holding section to apply tension to the medium.

1 is a side view illustrating a configuration of a printer according to an embodiment of the present invention. FIG. 2 is a block diagram for explaining a configuration of the printer shown in FIG. 1 . 2 is a front view for explaining the configuration of a guide roller and a roller rotation restricting mechanism shown in FIG. 1 . 5 is a diagram for explaining the configuration of the roller rotation restricting mechanism as viewed from the E-E direction in FIG. 3. FIG. 1 is a diagram for explaining problems with the conventional technology.

The following describes an embodiment of the present invention with reference to the drawings.

(Overall printer configuration)
Fig. 1 is a side view for explaining the configuration of a printer 1 according to an embodiment of the present invention Fig. 2 is a block diagram for explaining the configuration of the printer 1 shown in Fig. 1 .

The printer 1 of this embodiment is, for example, an inkjet printer for commercial use. The printer 1 includes a printing mechanism 3 that prints on a long medium 2 (sheet-like medium 2) such as paper, a medium transport mechanism 4 that transports the medium 2, a pay-out roll holding section 6 that holds a pay-out roll 5 that is the medium 2 wound into a roll before printing, a take-up roll holding section 8 that holds a take-up roll 7 that is the medium 2 wound into a roll after printing, and a heater 9 that heats the medium 2 after printing. The medium 2 of this embodiment is, for example, transfer paper. The length of the medium 2 is, for example, 2000 (m).

The printer 1 also includes a tension applying mechanism 11 for applying tension to the medium 2 before printing, a tension applying mechanism 12 for applying tension to the medium 2 after printing, and a control unit 13 for controlling the printer 1. If the Y direction in FIG. 1, which is perpendicular to the up-down direction (vertical direction), is defined as the "left-right direction", the width direction of the medium 2 coincides with the left-right direction. In the following explanation, the X direction in FIG. 1, which is perpendicular to the up-down direction and left-right direction, is defined as the "front-to-back direction". Also, the X1 direction side in FIG. 1, which is one side of the front-to-back direction, is defined as the "front" side, and the X2 direction side in FIG. 1, which is the opposite side, is defined as the "rear" side.

The printing mechanism 3 includes an inkjet head 17 (hereafter referred to as "head 17") that ejects ink onto the medium 2, a carriage 18 on which the head 17 is mounted, a carriage drive mechanism that moves the carriage 18 back and forth in the main scanning direction (i.e., left and right direction) which is the width direction of the medium 2, and a support frame (Y bar) 19 that supports the carriage 18 so that it can move left and right. The head 17 ejects ink downward. A number of nozzles that eject ink are formed on the underside of the head 17. The head 17 includes a piezoelectric element for ejecting ink from the nozzles. The carriage drive mechanism includes, for example, a belt that is partially fixed to the carriage 18, a pulley around which the belt is stretched, and a motor for rotating the pulley.

The printing mechanism 3 also includes a platen 20 on which the medium 2 is placed during printing, and a suction mechanism for sucking and holding the medium 2 placed on the platen 20 to the platen 20. The platen 20 is disposed below the carriage 18. The platen 20 is formed in an elongated shape that is long in the left-right direction. The platen 20 is also formed in a hollow shape. The upper surface of the platen 20 is formed with a plurality of suction holes for sucking the medium 2 placed on the platen 20. A large number of these suction holes are formed over almost the entire area of the platen 20. The thickness direction of the medium 2 when printing is performed by the printing mechanism 3 coincides with the up-down direction. The upper surface of the medium 2 when placed on the platen 20 is the printing surface on which printing is performed by the printing mechanism 3.

The medium transport mechanism 4 transports the long medium 2 in the longitudinal direction of the medium 2. The medium transport mechanism 4 includes a transport roller 21 that contacts the medium 2 to transport the medium 2. The transport roller 21 is a rubber roller with a rubber surface. The transport roller 21 is connected to a drive mechanism that rotates the transport roller 21. The drive mechanism includes a motor as a drive source and a power transmission mechanism that transmits the power of the motor to the transport roller 21. The transport roller 21 is disposed behind the platen 20. The medium 2 before printing is transported from the rear side to the top surface of the platen 20. In addition, the medium 2 after printing is transported from the top surface of the platen 20 toward the front side and then toward the bottom side. In other words, the medium 2 printed by the printing mechanism 3 moves toward the front side and then toward the bottom side.

The pay-out roll holding unit 6 is disposed below the platen 20. The pay-out roll holding unit 6 is also disposed behind the printing mechanism 3. The pay-out roll 5 is disposed so that its axial direction coincides with the left-right direction. The pay-out roll holding unit 6 includes a rotating shaft 22 as a winding core that is inserted into the inner periphery of the pay-out roll 5, and a drive mechanism that rotates the rotating shaft 22. The drive mechanism includes a motor 23 as a drive source, and a power transmission mechanism that transmits the power of the motor 23 to the rotating shaft 22.

The motor 23 is PID controlled. A rotary encoder is attached to the motor 23 to detect the amount of rotation and the rotation speed of the motor 23. The rotary encoder is equipped with a disk-shaped rotary scale (slit plate) fixed to the rotating shaft of the motor 23, and a sensor 24 to detect the rotary scale. The sensor 24 is a transmission type optical sensor having a light emitting section and a light receiving section, and a part of the rotary scale is disposed between the light emitting section and the light receiving section. The sensor 24 is electrically connected to the control section 13.

The winding roll holding unit 8 is disposed, for example, below the unwinding roll holding unit 6 and behind the printing mechanism 3. The winding roll 7 is disposed so that the axial direction of the winding roll 7 coincides with the left-right direction. The winding roll holding unit 8 includes a rotating shaft 25 as a winding core that is inserted into the inner periphery of the winding roll 7, and a drive mechanism that rotates the rotating shaft 25. The drive mechanism includes a motor 26 as a drive source and a power transmission mechanism that transmits the power of the motor 26 to the rotating shaft 25.

The motor 26 is PID controlled. A rotary encoder is attached to the motor 26 for detecting the amount of rotation and the rotation speed of the motor 26. The rotary encoder includes a disk-shaped rotary scale fixed to the rotating shaft of the motor 26, and a sensor 27 for detecting the rotary scale. The sensor 27 is a transmission type optical sensor having a light emitting portion and a light receiving portion, and a part of the rotary scale is disposed between the light emitting portion and the light receiving portion. The sensor 27 is electrically connected to the control portion 13.

The tension applying mechanism 11 includes a tension bar 31 that contacts the medium 2 before printing between the printing mechanism 3 and the pay-out roll holding unit 6 to apply tension to the medium 2, and a guide unit that linearly guides the tension bar 31 in the vertical direction. The tension bar 31 is arranged so that its axial direction coincides with the left-right direction. The tension bar 31 is arranged between the printing mechanism 3 and the pay-out roll 5 in the front-rear direction. The tension bar 31 is also arranged below the printing mechanism 3 and the pay-out roll 5. The tension bar 31 contacts the medium 2 from above as it moves forward from the pay-out roll holding unit 6 toward the printing mechanism 3. The tension bar 31 applies tension to the medium 2 by gravity acting on the tension bar 31. When printing the medium 2, the tension bar 31 moves linearly in the vertical direction in accordance with the movement of the medium 2.

The tension applying mechanism 11 also includes a linear encoder for detecting the position of the tension bar 31. The linear encoder includes a linear scale that moves vertically together with the tension bar 31, and two sensors 32 and 33 for detecting the linear scale. The sensors 32 and 33 are arranged at a predetermined interval in the vertical direction. The sensors 32 and 33 are transmissive optical sensors having a light-emitting portion and a light-receiving portion, and a portion of the linear scale is arranged between the light-emitting portion and the light-receiving portion. The sensors 32 and 33 are electrically connected to the control unit 13.

The tension applying mechanism 12 is equipped with a tension bar 34 that contacts the printed medium 2 between the printing mechanism 3 and the winding roll holding unit 8 to apply tension to the medium 2. The tension bar 34 is arranged so that its axial direction coincides with the left-right direction. The tension bar 34 is arranged forward and below the printing mechanism 3. The tension bar 34 is capable of moving linearly in a downward forward direction, as shown by the arrow in FIG. 1. The tension applying mechanism 12 also includes a guide unit that guides the tension bar 34 linearly in the downward forward direction, and a tension coil spring that biases the tension bar 34 diagonally toward the upper rear.

The tension bar 34 contacts the printed medium 2 from the diagonally upper rear side as the medium 2 moves from the platen 20 toward the front and then toward the bottom. The tension bar 34 applies tension to the medium 2 by gravity acting on the tension bar 34. When printing on the medium 2, the tension bar 34 moves linearly in a downward direction toward the front in accordance with the movement of the medium 2. The inclination θ of the movement direction of the tension bar 34 relative to the front-to-back direction when viewed from the left-to-right direction (see Figure 1) is 30° to 60°. In this embodiment, the inclination θ is 45°.

The tension applying mechanism 12 also includes a linear encoder for detecting the position of the tension bar 34. The linear encoder includes a linear scale that moves vertically together with the tension bar 34, and two sensors 35, 36 for detecting the linear scale. The sensors 35, 36 are arranged at a predetermined interval in the longitudinal direction of the linear scale. The sensors 35, 36 are transmissive optical sensors having a light-emitting portion and a light-receiving portion, and a portion of the linear scale is arranged between the light-emitting portion and the light-receiving portion. The sensors 35, 36 are electrically connected to the control unit 13.

The heater 9 is disposed below the printing mechanism 3. The heater 9 is disposed below the tension bar 31. The heater 9 is also disposed below and to the rear of the tension bar 34. The heater 9 is also disposed below and in front of the pay-out roll 5 and the take-up roll 7. As described above, the medium 2 printed by the printing mechanism 3 moves toward the front and then moves toward the bottom. The medium 2 that moves toward the bottom passes the tension bar 34 and then moves toward the rear. The medium 2 that moves toward the rear passes above the heater 9.

The printer 1 is equipped with multiple guide rollers 40-46 for guiding the moving medium 2. The guide rollers 40-46 are driven rollers that come into contact with the medium 2 and can rotate as the medium 2 moves. In other words, the guide rollers 40-46 are not connected to a drive mechanism that has a drive source such as a motor. The guide rollers 40-46 are arranged so that the axial direction of the guide rollers 40-46 coincides with the left-right direction.

The guide rollers 40-42 are disposed between the payout roll holder 6 and the transport roller 21 on the path of movement of the medium 2 (the transport path of the medium 2), and guide the medium 2 moving toward the transport roller 21. The guide rollers 40, 41 are disposed on both sides of the tension bar 31 in the front-to-rear direction, and are disposed above the tension bar 31. The guide roller 43 is disposed between the printing mechanism 3 and the tension bar 34 on the path of movement of the medium 2, and guides the medium 2 moving toward the tension bar 34. The guide roller 43 is also disposed on the front side of the platen 20. The guide roller 43 serves to change the direction of movement of the medium 2 moving from the platen 20 toward the front side to a downward direction.

The guide rollers 44-46 are arranged between the tension bar 34 and the winding roll holding unit 8 on the movement path of the medium 2. That is, three guide rollers 44-46 are arranged on the movement path of the medium 2 between the tension bar 34 and the winding roll holding unit 8. The guide rollers 44-46 guide the medium 2 moving toward the winding roll holding unit 8. The guide roller 44 is arranged below the tension bar 34 and on the front side of the printer 1. The guide roller 44 serves the function of changing the movement direction of the medium 2 moving downward to a direction toward the rear.

The guide rollers 45 and 46 are positioned below the tension bar 34 and between the heater 9 and the winding roll 7 in the front-to-rear direction. The guide roller 45 is positioned forward of the guide roller 46. The guide rollers 44 to 46 are positioned in this order from the tension bar 34 toward the winding roll holding section 8 on the movement path of the medium 2. In other words, the guide roller 46 is positioned closer to the winding roll holding section 8 than the guide rollers 44 and 45 on the movement path of the medium 2. The guide rollers 44 and 45 in this embodiment are second guide rollers.

The printer 1 also includes a roller rotation restriction mechanism 47 for restricting the rotation of the guide roller 46 (see FIG. 3). The specific configurations of the guide roller 46 and the roller rotation restriction mechanism 47 are described below.

(Configuration of the guide roller and roller rotation restriction mechanism)
Fig. 3 is a front view for explaining the configuration of the guide roller 46 and the roller rotation restricting mechanism 47 shown in Fig. 1. Fig. 4 is a view for explaining the configuration of the roller rotation restricting mechanism 47 from the E-E direction in Fig. 3.

The guide roller 46 includes a cylindrical roller body 50 that contacts the medium 2 and a rotating shaft 51 that is fixed to the inner periphery of the roller body 50. As described above, the guide roller 46 is arranged so that the axial direction of the guide roller 46 coincides with the left-right direction. That is, the left-right direction (Y direction) is the axial direction of the guide roller 46. The length (left-right length) of the rotating shaft 51 is longer than the length (left-right length) of the roller body 50. Both left-right ends of the rotating shaft 51 protrude outward in the left-right direction beyond the roller body 50. One end of the rotating shaft 51 is rotatably held by a bearing 52. The other end of the rotating shaft 51 is rotatably held by a bearing 53. That is, the printer 1 includes bearings 52 and 53 that rotatably hold the guide roller 46.

The rotating shaft 51 is made of metal. The roller body 50 has a cylindrical base material and a large number of brush bristles extending radially outward from the base material. That is, the guide roller 46 in this embodiment is a brush roller. The brush bristles are inclined outward in the left-right direction. Specifically, the brush bristles arranged to the right of the center of the roller body 50 in the left-right direction extend diagonally from the base material to the right, and the brush bristles arranged to the left of the center of the roller body 50 in the left-right direction extend diagonally from the base material to the left. The guide roller 46, which rotates in conjunction with the movement of the medium 2, serves the function of smoothing out wrinkles in the medium 2 in the left-right direction.

The roller rotation restriction mechanism 47 is disposed on only one side of the guide roller 46 in the left-right direction. The roller rotation restriction mechanism 47 includes a first restriction member 54 that has a C-shape when viewed from the left-right direction. The first restriction member 54 is disposed on the outer periphery of the rotating shaft 51 so as to surround the rotating shaft 51 (specifically, so as to surround one end of the rotating shaft 51). The roller rotation restriction mechanism 47 also includes a screw member 55 that engages with the first restriction member 54, and a second restriction member 56 that contacts the outer periphery of the first restriction member 54 to restrict the rotation of the first restriction member 54 in the circumferential direction of the guide roller 46. The screw member 55 is a hexagon socket bolt consisting of a head and a shaft.

The first regulating member 54 is disposed between the roller body 50 and the bearing 52 in the left-right direction. The first regulating member 54 is formed, for example, by removing a portion in the circumferential direction of a thick cylindrical metal member, and a slit 54a is formed in the first regulating member 54, which runs from the outer peripheral surface to the inner peripheral surface of the first regulating member 54. The slit 54a is formed in the upper end of the first regulating member 54. When viewed from the left-right direction, the shape of the first regulating member 54 is a C-shape with the upper end separated. The first regulating member 54 is elastically deformable in a direction in which the width of the slit 54a in the circumferential direction of the first regulating member 54 changes. In other words, the first regulating member 54 is elastically deformable in a direction in which the inner diameter of the first regulating member 54 changes.

A screw hole 54b into which the tip end of the shaft of the screw member 55 screws is formed in a portion of the first restricting member 54 on one side of the slit 54a. A screw arrangement hole 54c into which the head and base end of the shaft of the screw member 55 are arranged is formed in a portion of the first restricting member 54 on the other side of the slit 54a. The screw hole 54b is recessed from one side of the slit 54a. The screw hole 54b is formed in a straight line perpendicular to one side of the slit 54a.

The screw arrangement hole 54c runs from the other side of the slit 54a to the outer circumferential surface of the first restricting member 54. The screw arrangement hole 54c is formed in a straight line perpendicular to the other side of the slit 54a. The screw arrangement hole 54c is a stepped hole, and a ring-shaped contact surface 54d is formed in the screw arrangement hole 54c with which the head of the screw member 55 comes into contact. The lower end of the first restricting member 54 is a flat surface 54e perpendicular to the up-down direction.

The tip side of the shaft of the screw member 55 is engaged with the screw hole 54b. The head and base end side of the shaft of the screw member 55 are arranged in the screw arrangement hole 54c. The screw member 55 enters the screw arrangement hole 54c from the outer periphery side of the first restricting member 54. In this embodiment, when the screw member 55 is rotated in the tightening direction, the first restricting member 54 elastically deforms in a direction in which the inner diameter of the first restricting member 54 narrows, and when the screw member 55 is rotated in the loosening direction, the first restricting member 54 elastically deforms in a direction in which the inner diameter of the first restricting member 54 widens. In other words, the screw member 55 elastically deforms the first restricting member 54 in a direction in which the inner diameter of the first restricting member 54 changes.

The second restricting member 56 includes a restricting portion 56a that restricts the rotation of the first restricting member 54, and a bearing holder 56b that holds the bearing 52. The upper surface of the restricting portion 56a is a flat surface perpendicular to the up-down direction. The flat surface 54e of the first restricting member 54 is in contact with the upper surface of the restricting portion 56a. The bearing holder 56b is formed, for example, in a flat plate shape perpendicular to the left-right direction. The bearing holder 56b rises upward from the outer end of the restricting portion 56a in the left-right direction. The bearing 52 is attached to the inner surface of the bearing holder 56b in the left-right direction and is held by the second restricting member 56. Note that the bearing holder 56b is not shown in FIG. 4.

The roller rotation restriction mechanism 47 is switchable between a brake state in which a brake is applied to the guide roller 46 to the extent that the guide roller 46 can rotate, and a fixed state 47B (state shown in FIG. 4(B)) in which the guide roller 46 is fixed so that the guide roller 46 does not rotate. In this embodiment, the roller rotation restriction mechanism 47 is also switchable to a rotatable state 47A (state shown in FIG. 4(A)) in which the guide roller 46 can rotate. In other words, the roller rotation restriction mechanism 47 is switchable between the rotatable state 47A, the brake state, and the fixed state 47B.

Specifically, when the screw member 55 is tightened, the inner diameter of the first restricting member 54 narrows, and the inner peripheral surface of the first restricting member 54 comes into contact with the outer peripheral surface of the rotating shaft 51 with a predetermined contact pressure, and the roller rotation restricting mechanism 47 enters the fixed state 47B. Also, when the screw member 55 is loosened to the extent that the inner peripheral surface of the first restricting member 54 lightly comes into contact with the outer peripheral surface of the rotating shaft 51, the roller rotation restricting mechanism 47 enters the brake state. That is, when the screw member 55 is loosened, the inner diameter of the first restricting member 54 widens, and the roller rotation restricting mechanism 47 enters the brake state. Also, when the screw member 55 is further loosened in the roller rotation restricting mechanism 47 in the brake state, the inner diameter of the first restricting member 54 widens, and a gap is formed between the inner peripheral surface of the first restricting member 54 and the outer peripheral surface of the rotating shaft 51, and the roller rotation restricting mechanism 47 enters the rotatable state 47A.

In this embodiment, when tightening of the take-up roll 7 is likely to occur due to the type of medium 2, printing conditions, etc., the roller rotation restriction mechanism 47 is set to the fixed state 47B to fix the guide roller 46, or the roller rotation restriction mechanism 47 is set to the brake state to apply a brake to the guide roller 46 to the extent that the guide roller 46 can rotate. On the other hand, when tightening of the take-up roll 7 is unlikely to occur, the roller rotation restriction mechanism 47 is set to the rotatable state 47A to allow the guide roller 46 to rotate.

(Medium Payout Control and Medium Take-Up Control)
In the pay-out roll holding unit 6, the medium 2 is paid out based on the detection results of the sensors 32 and 33. That is, the control unit 13 controls the motor 23 based on the detection results of the sensors 32 and 33. Specifically, the control unit 13 controls the motor 23 based on the detection results of the sensors 32 and 33 so that the tension bar 31, which has moved in association with the transport of the medium 2 by the medium transport mechanism 4, returns to its original position. The control unit 13 also calculates the outer diameter of the pay-out roll 5 based on the detection results of the sensors 32 and 33 and the detection result of the sensor 24 (specifically, based on the movement amount of the tension bar 31 and the rotation amount of the motor 23), and controls the motor 23 based on the calculation result of the outer diameter of the pay-out roll 5. Specifically, when a certain amount of the medium 2 is paid out, the control unit 13 increases the rotation amount of the motor 23 as the outer diameter of the pay-out roll 5 becomes smaller.

In the winding roll holding unit 8, the medium 2 is wound based on the detection results of the sensors 35 and 36. That is, the control unit 13 controls the motor 26 based on the detection results of the sensors 35 and 36. Specifically, the control unit 13 controls the motor 26 based on the detection results of the sensors 35 and 36 so that the tension bar 34, which has moved with the transport of the medium 2 by the medium transport mechanism 4, returns to its original position. In addition, the control unit 13 calculates the outer diameter of the winding roll 7 based on the detection results of the sensors 35 and 36 and the detection results of the sensor 27 (specifically, based on the amount of movement of the tension bar 34 and the amount of rotation of the motor 26), and controls the motor 26 based on the calculation result of the outer diameter of the winding roll 7. Specifically, when winding up a certain amount of the medium 2, the control unit 13 reduces the amount of rotation of the motor 26 as the outer diameter of the winding roll 7 increases.

(Main effects of this embodiment)
As described above, in this embodiment, when the winding tension of the winding roll 7 is likely to occur, the roller rotation restricting mechanism 47 is set to the fixed state 47B to fix the guide roller 46 arranged in the movement path of the medium 2 between the tension bar 34 and the winding roll holding unit 8, or the roller rotation restricting mechanism 47 is set to the brake state to apply a brake to the guide roller 46 to an extent that allows the guide roller 46 to rotate. Therefore, in this embodiment, it is possible to suppress the fluctuation in the tension of the medium 2 caused by the tension bar 34 from acting on the medium 2 when it is wound by the winding roll 7, and to suppress the fluctuation in the tension of the medium 2 when it is wound by the winding roll 7. Therefore, in this embodiment, it is possible to suppress the occurrence of the winding tension of the winding roll 7, and as a result, it is possible to suppress the occurrence of the winding misalignment of the winding roll 7 caused by the winding tension of the winding roll 7.

In addition, in this embodiment, when the winding roll 7 is likely to become tight, the guide roller 46, which is located closest to the winding roll holding unit 8 among the guide rollers 44-46 arranged between the tension bar 34 and the winding roll holding unit 8, is fixed, or a brake is applied to the guide roller 46 to the extent that it allows the guide roller 46 to rotate. Therefore, according to the study of the present inventors, this embodiment makes it possible to effectively suppress the fluctuation in tension of the medium 2 caused by the tension bar 34 from acting on the medium 2 when it is being wound by the winding roll 7.

In this embodiment, the roller rotation restricting mechanism 47 includes a first restricting member 54, a screw member 55, and a second restricting member 56. In this embodiment, when the screw member 55 is tightened, the inner diameter of the first restricting member 54 narrows and the roller rotation restricting mechanism 47 enters a fixed state 47B, and when the screw member 55 is loosened, the inner diameter of the first restricting member 54 widens and enters a brake state. Therefore, in this embodiment, it is possible to restrict the rotation of the guide roller 46 with a relatively simple configuration. Therefore, in this embodiment, it is possible to reduce the cost of the roller rotation restricting mechanism 47.

In this embodiment, the bearing 52 is held by a second regulating member 56 for regulating the rotation of the first regulating member 54. Therefore, in this embodiment, it is possible to simplify the configuration of the printer 1 compared to a case where a separate member for holding the bearing 52 is provided. Also, in this embodiment, the roller rotation regulating mechanism 47 is disposed only on one side of the guide roller 46 in the left-right direction, so it is possible to simplify the configuration of the printer 1 compared to a case where the roller rotation regulating mechanism 47 is disposed on both sides of the guide roller 46 in the left-right direction.

Other Embodiments
The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made without departing from the spirit and scope of the present invention.

In the above-described embodiment, the roller rotation restriction mechanism 47 may be in a brake state when the winding roll 7 is unlikely to become tight. Also, in the above-described embodiment, the roller rotation restriction mechanism 47 does not have to be switchable to the rotatable state 47A. In other words, the roller rotation restriction mechanism 47 may be switchable between only two states, the brake state and the fixed state 47B.

In the above-mentioned embodiment, the roller rotation restriction mechanism 47 may be disposed on both sides of the guide roller 46 in the left-right direction. Also, in the above-mentioned embodiment, the roller rotation restriction mechanism 47 may be, for example, a powder brake having magnetic powder. Also, the roller rotation restriction mechanism 47 may be a disk brake. Furthermore, in the above-mentioned embodiment, the roller rotation restriction mechanism 47 may restrict the rotation of the guide roller 45 instead of restricting the rotation of the guide roller 46.

In the above-mentioned embodiment, in addition to the second restricting member 56, a member for holding the bearing 52 may be provided separately. Also, in the above-mentioned embodiment, the guide roller 45 may not be arranged in the movement path of the medium 2 between the tension bar 34 and the winding roll holding unit 8. That is, two guide rollers 44, 46 may be arranged in the movement path of the medium 2 between the tension bar 34 and the winding roll holding unit 8. Furthermore, in the above-mentioned embodiment, four or more guide rollers may be arranged in the movement path of the medium 2 between the tension bar 34 and the winding roll holding unit 8. Also, in the above-mentioned embodiment, the guide roller 46 does not have to be a brush roller.

REFERENCE SIGNS LIST 1 Printer 2 Medium 3 Printing mechanism 7 Winding roll 8 Winding roll holding section 25 Rotating shaft (winding core)
34 Tension bar 44, 45 Guide roller (second guide roller)
46 Guide roller 47 Roller rotation restriction mechanism 47B Fixed state 50 Roller body 51 Rotation shaft 52 Bearing 54 First restriction member 55 Screw member 56 Second restriction member Y Axial direction of guide roller

Claims (6)

the medium moving path being disposed between the tension bar and the winding roll holding part and configured to guide the medium as it moves toward the winding roll holding part; and a roller rotation restriction mechanism for restricting rotation of the guide roller.
the winding roll holding section includes a winding core that is inserted into the inner circumferential side of the winding roll,
the guide roller is a driven roller that is in contact with the medium and is rotatable in association with the movement of the medium,
The printer is characterized in that the roller rotation regulating mechanism is switchable between a brake state in which a brake is applied to the guide roller to a degree that allows the guide roller to rotate, and a fixed state in which the guide roller is fixed so that it does not rotate. a second guide roller that is disposed between the tension bar and the take-up roll holding part in a movement path of the medium and guides the medium moving toward the take-up roll holding part;
the second guide roller is a driven roller that is in contact with the medium and is rotatable in association with the movement of the medium;
2. The printer according to claim 1, wherein the guide roller is disposed closer to the take-up roll holder than the second guide roller is to the movement path of the medium. The guide roller includes a cylindrical roller body that contacts the medium and a rotation shaft that is fixed to an inner peripheral side of the roller body,
The roller rotation restricting mechanism comprises a first restricting member that has a C-shape when viewed from the axial direction of the guide roller and is arranged on the outer periphery of the rotating shaft so as to surround the rotating shaft, a screw member that engages with the first restricting member and elastically deforms the first restricting member in a direction that changes the inner diameter of the first restricting member, and a second restricting member that contacts the outer periphery of the first restricting member and restricts rotation of the first restricting member in the circumferential direction of the guide roller, and the printer described in claim 1 or 2 is characterized in that when the screw member is tightened, the inner diameter of the first restricting member narrows to enter the fixed state, and when the screw member is loosened, the inner diameter of the first restricting member widens to enter the brake state. A bearing is provided to rotatably hold the guide roller,
4. The printer according to claim 3, wherein the bearing is held by the second regulating member. The printer according to claim 1 or 2, characterized in that the roller rotation restriction mechanism is disposed on only one side of the guide roller in the axial direction of the guide roller. The printer according to claim 1 or 2, characterized in that the guide roller is a brush roller.

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