Printing device

Abstract

To provide a printing device that is configured so that a printing medium can be easily conveyed along a U-shape conveyance path to pass through a gap between a thermal head and a platen roller even in a state where the thermal head retreats from the platen roller, which can be reduced in manufacturing cost.SOLUTION: The printing device is provided with: a supply part that supplies a printing medium in a lengthy shape; a platen roller; a thermal head; a conveyance path, formed in a U-shape along a peripheral surface of the platen roller, through which the printing medium is conveyed; a pinch roller that contacts the printing medium entering the conveyance path from the supply part side with the platen roller; a winding part that winds up the printing medium; and an operation part that moves the thermal head back and forth with respect to the peripheral surface of the platen roller, which when mounting a starting end of the printing medium pulled out from the supply part on the winding part, makes the printing medium pass through a gap between the thermal head and the platen roller, by making the platen roller convey the printing medium while making the pinch roller contact the printing medium entering the conveyance path from the supply part side with the platen roller, in a state where the operation part retreats the thermal head from the platen roller.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a printing device. [Background technology]

[0002] A known printing device includes a supply unit that supplies long print media, a platen roller that transports the print media supplied from the supply unit, a thermal head that prints on the print media sandwiched between the platen roller, and a winding unit that winds up the print media that has passed through the thermal head.

[0003] In some printing devices of this type, the transport path that transports the print medium pulled out from a supply roll supported by a supply unit is U-shaped along the circumferential surface of a platen roller, and the thermal head is located on the exit side where the print medium exits the transport path. The print medium pulled out from the supply roll in the supply unit enters the transport path from the supply roll side and is sent in a direction generally opposite to the direction in which it entered the transport path, passes between the thermal head and the platen roller, exits the transport path, and is taken up by the winding unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2-535 Summary of the Invention [Problem to be solved by the invention]

[0005] When loading a long print medium into a printing device having a U-shaped transport path as described above, the user inserts the leading end of the print medium pulled out from the supply roll into the entrance side of the transport path, pushes the print medium along the transport path, passes through the gap between the thermal head and the platen roller, and exits from the exit side of the transport path.The user then attaches the leading end of the print medium pulled out from the transport path to the winding unit, and the long print medium is stretched from the supply roller through the transport path to the winding unit.

[0006] In such printing devices, variations in the size of the gap between the thermal head and the platen roller occur due to the dimensional accuracy and assembly accuracy of various components. If this variation increases the gap between the thermal head and the platen roller, the rigidity of the print medium makes it difficult for the leading edge of the print medium pushed along the U-shaped transport path to come into contact with the circumferential surface of the platen roller, preventing the print medium from being smoothly fed by the rotating platen roller. As a result, the print medium does not pass smoothly through the gap between the thermal head and the platen roller and becomes clogged midway along the transport path, preventing the print medium from exiting the transport path. Therefore, precisely controlling the size of the gap between the thermal head and the platen roller increases the manufacturing costs of printing devices.

[0007] The disclosed technology has been made in consideration of the above, and aims to provide a printing device that allows the printing medium to be easily fed along a U-shaped transport path so that it passes between the thermal head and the platen roller even when the thermal head is retracted from the platen roller, thereby reducing the manufacturing costs of the printing device. [Means for solving the problem]

[0008] One aspect of the printing device disclosed in the present application comprises a supply unit having a supply roll on which a long print medium is wound, the supply unit supplying the print medium from below the supply roll with the inner peripheral side of the print medium facing upward, a platen roller transporting the print medium supplied from the supply unit, a thermal head printing on the print medium sandwiched between the platen roller and the supply unit, a transport path formed in a U shape along the circumferential surface of the platen roller and along which the print medium is transported, a pinch roller bringing the print medium that has entered the transport path from the supply unit side into contact with the platen roller, a transport guide unit guiding the print medium along the transport path, a winding unit winding up the print medium that has passed the thermal head, and an operation unit moving the thermal head forward and backward relative to the circumferential surface of the platen roller, a first guide surface extending obliquely upward facing the peripheral surface of the supply roll; a flat second guide surface extending horizontally from the first guide surface; Along the circumferential surface of the platen roller Extends upward Arc-shaped Third a guide surface; a rotation center of the supply roll is located below the second guide surface of the conveying guide portion; The peripheral surface of the pinch roller is Third The pinch roller is provided to protrude from the guide surface toward the circumferential surface of the platen roller, and when the starting end of the printing medium pulled out from the supply unit is attached to the winding unit, the thermal head is retracted from the platen roller by the operation unit, and the printing medium that has entered the transport path from the supply unit side is brought into contact with the platen roller by the pinch roller while being transported by the platen roller, thereby passing through the gap between the thermal head and the platen roller. [Effects of the Invention]

[0009] According to one aspect of the printing device disclosed in the present application, it is possible to easily feed the printing medium along a U-shaped transport path so that it passes between the thermal head and the platen roller even when the thermal head is retracted from the platen roller, thereby reducing the manufacturing costs of the printing device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view schematically showing a printing device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view schematically showing the main part of the printing device of the embodiment. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the main part of the printing device of the embodiment. [Figure 4] FIG. 4 is another vertical cross-sectional view showing the main part of the printing device of the embodiment. [Figure 5] FIG. 5 is a schematic diagram for explaining the positional relationship of the main parts of the printing device of the embodiment. [Figure 6] FIG. 6 is a flowchart for explaining the operation when loading roll paper into the printing device of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the printing device disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the printing device disclosed in the present application is not limited to the following embodiment. [Example]

[0012] (Printing device configuration) Fig. 1 is a side view showing a schematic diagram of a printing device according to an embodiment. Fig. 2 is a plan view showing a schematic diagram of a main part of the printing device according to an embodiment. In Fig. 1 and subsequent figures, the short side direction (width direction) of the printing device 1 is indicated as the X direction, the long side direction (depth direction) of the printing device 1 is indicated as the Y direction, and the height direction of the printing device 1 is indicated as the Z direction.

[0013] As shown in Figures 1 and 2, the printing device 1 of the embodiment includes a supply unit 11 that supplies roll paper 3 as a long printing medium, a platen roller 12 that transports the roll paper 3 supplied from the supply unit 11, a thermal head 13 that prints on the roll paper 3 sandwiched between the platen roller 12, and a transport path 15 that is formed in a U-shape along the peripheral surface 12a of the platen roller 12 and through which the roll paper 3 is transported.

[0014] In the embodiment, the U-shaped conveying path 15 refers to a path that continues along the peripheral surface 12a of the platen roller 12, for example, from the lower end to the upper end in the circumferential direction of the platen roller 12, and is formed so that the direction of travel of the roll paper 3 entering the entrance 15A of the conveying path 15 is roughly opposite to the direction of travel of the roll paper 3 exiting from the exit 15B of the conveying path 15.

[0015] The printing device 1 also includes a pinch roller 16 that brings the roll paper 3 that has entered the conveying path 15 from the supply section 11 side into contact with the platen roller 12, a winding section 17 that winds up the roll paper 3 that has passed through the thermal head 13, and an operating section 18 that moves the thermal head 13 forward and backward relative to the peripheral surface 12a of the platen roller 12.

[0016] The printing device 1 also includes an optical sensor 19 that detects the starting end 3a of the roll paper 3 entering the conveying path 15 from the supply unit 11 side, and a control unit 20 that controls the platen roller 12 to be driven based on the detection result of the optical sensor 19.

[0017] A feature of the printing device 1 of this embodiment is that when the beginning end 3a of the roll paper 3 pulled out from the supply section 11 is attached to the winding section 17, the thermal head 13 is retracted from the platen roller 12 by the operating section 18, and the roll paper 3 that has entered the transport path 15 from the supply section 11 side is brought into contact with the platen roller 12 by the pinch roller 16 while being transported by the platen roller 12, thereby passing through the gap between the thermal head 13 and the platen roller 12.

[0018] In other words, in the printing device 1, even if the gap between the thermal head 13 and the platen roller 12 becomes approximately 10 times larger than the thickness of the roll paper 3, the pinch roller 16 guides the roll paper 3 that has entered the U-shaped transport path 15 along the circumferential surface 12a of the platen roller 12, allowing the roll paper 3 to be transported properly by the platen roller 12, allowing it to pass smoothly through the gap between the thermal head 13 and the platen roller 12. As a result, the roll paper 3 that has entered the U-shaped transport path 15 is prevented from clogging along the transport path 15, and can pass smoothly through the gap between the platen roller 12 and the thermal head 13 that has retracted from the platen roller 12. This improves the part precision and assembly precision of the various parts of the printing device 1, eliminating the need for highly precise control of the dimensions of the gap between the thermal head 13 and the platen roller 12, and reduces the manufacturing costs of the printing device 1.

[0019] (Details of each part of the printer) As shown in Figure 1, the supply unit 11 of the printer 1 has a supply shaft 11a that supports a supply roll 4 around which roll paper 3 is wound. The supply shaft 11a is supported by a support portion 7b formed on a side plate 7a of a support frame 7 of the printer 1. The roll paper 3 is pulled out from below the outer periphery of the supply roll 4 supported by the supply shaft 11a and enters the conveying path 15.

[0020] Fig. 3 is a vertical cross-sectional view showing the main parts of the printing device 1 of the embodiment. Fig. 3 shows the cross-section AA in Fig. 2. Fig. 4 is another vertical cross-sectional view showing the main parts of the printing device 1 of the embodiment. Fig. 4 shows the cross-section BB in Fig. 2.

[0021] As shown in Figures 3 and 4, the platen roller 12 is supported by a rotary shaft 22 and is rotated by a transport mechanism (not shown). The transport mechanism is controlled by the control unit 20. The outer diameter of the platen roller 12 is, for example, approximately 12 mm. Therefore, the radius of curvature of the transport path 15 formed along the circumferential surface 12a of the platen roller 12 is approximately 7 mm. With a transport path 15 having such a small radius of curvature, as mentioned in the Background Art section, the rigidity of the roll paper 3 may cause the roll paper 3 to separate from the circumferential surface 12a of the platen roller 12 within the transport path 15. To solve this problem, the printing device 1 of this embodiment uses a pinch roller 16 to bring the roll paper 3 that has entered the transport path 15 into contact with the circumferential surface 12a of the platen roller 12.

[0022] The thermal head 13 is disposed opposite the peripheral surface 12a of the platen roller 12 and is supported by a head lifting mechanism 23. The head lifting mechanism 23 has a head support plate 24 that supports the thermal head 13, a swing shaft 25 that swingably supports the head support plate 24 so that the head support plate 24 moves toward and away from the platen roller 12, and an operating shaft 36 that is operated by the operating unit 18.

[0023] The head lifting mechanism 23 moves the thermal head 13 forward and backward between a close position where the printing surface 13a of the thermal head 13 is brought close to the peripheral surface 12a of the platen roller 12 and a retracted position where the printing surface 13a of the thermal head 13 is retracted a predetermined distance from the peripheral surface 12a of the platen roller 12 by swinging the head support plate 24 around the swing axis 25.

[0024] In the proximity position of the thermal head 13, for example, the thermal head 13 and the platen roller 12 may be set to be in contact with each other, or a gap of about 0.1 mm may be set between the printing surface 13a of the thermal head 13 and the circumferential surface 12a of the platen roller 12. In the printing device 1, the thermal head 13 is moved to the proximity position when printing on the roll paper 3 with the thermal head 13. In the retracted position of the thermal head 13, the gap between the printing surface 13a of the thermal head 13 and the circumferential surface 12a of the platen roller 12 is set to 0.6 mm ± 0.5 mm (see FIG. 4).

[0025] The side of the conveyance path 15 facing the supply unit 11 is formed by a conveyance guide unit 28. The conveyance guide unit 28 has an arc-shaped guide surface 28a that guides the roll paper 3 along the conveyance path 15. The conveyance guide unit 28 is attached to a side plate 7a of the support frame 7 of the printing device 1.

[0026] Guide surface 28a of conveying guide portion 28 is formed continuously from a position facing the lower outer periphery of supply roll 4 supported by supply portion 11 to a position past pinch roller 16. Guide surface 28a includes a portion formed in an arc shape along peripheral surface 12a of platen roller 12, and this arc shape forms the entrance 15A side of U-shaped conveying path 15.

[0027] Furthermore, guide surface 28a is formed so that the distance between guide surface 28a and circumferential surface 12a of platen roller 12 in the radial direction of platen roller 12 gradually decreases from entrance 15A of conveyance path 15 toward the contact point between platen roller 12 and pinch roller 16. As a result, guide surface 28a smoothly guides starting end 3a of roll paper 3 entering conveyance path 15 toward the contact point between platen roller 12 and pinch roller 16.

[0028] The conveyance guide unit 28 is also provided with an optical sensor 19 that detects the beginning end 3a of the roll paper 3 entering the entrance 15A of the conveyance path 15 from the supply unit 11 side. The optical sensor 19 is located near the entrance 15A of the conveyance path 15, and can quickly detect the roll paper 3 inserted into the entrance 15A. In this embodiment, for example, a reflective optical sensor is used as the optical sensor 19, and the light-emitting unit and the light-receiving unit are provided on the guide surface 28a of the conveyance guide unit 28 on the entrance 15A side of the conveyance path 15, facing the platen roller 12.

[0029] In the optical sensor 19, detection light is emitted from a light-emitting unit toward the peripheral surface 12a of the platen roller 12, and the detection light reflected by the platen roller 12 is received by a light-receiving unit. The optical sensor 19 detects the roll paper 3 when the detection light is blocked by the starting end 3a of the roll paper 3 that has entered the transport path 15. Note that the sensor that detects the starting end 3a of the roll paper 3 entering the transport path 15 is not limited to a reflective optical sensor; other sensors such as a transmissive optical sensor or a contact sensor may also be used.

[0030] The optical sensor 19 is electrically connected to the control unit 20, and sends a detection signal to the control unit 20 when it detects the roll paper 3. The control unit 20 drives the platen roller 12 based on the detection signal from the optical sensor 19, so that when the user inserts the beginning end 3a of the roll paper 3 into the transport path 15, the platen roller 12 pulls the roll paper 3 into the transport path 15, making it possible to easily feed the roll paper 3 along the transport path 15. The control unit 20 may also control the platen roller 12 to rotate for a certain period of time and then stop after the optical sensor 19 detects the roll paper 3, so that the rotation of the platen roller 12 stops when the beginning end 3a of the roll paper 3 passes the thermal head 13, for example.

[0031] In addition, the printing device 1 of the embodiment is equipped with a metal plate 30 that eliminates static electricity carried by the roll paper 3. By eliminating static electricity from the roll paper 3, the stability of the feed operation of the roll paper 3 in the conveying path 15 is improved, and the stability of the printing quality of the roll paper 3 by the thermal head 13 is also improved.

[0032] Furthermore, since the metal plate 30 for discharging electricity is simply formed from a single component, it is possible to reduce manufacturing costs and improve the accuracy of the attachment position relative to the conveying path 15 compared to a structure in which, for example, a metal piece for discharging electricity is attached to the tip of a resin sheet.

[0033] The metal plate 30 is provided on the transport guide portion 28 and is disposed at one end 28b of a guide surface 28a extending toward the thermal head 13. A tip 30a of the metal plate 30 protrudes from the guide surface 28a in the circumferential direction of the platen roller 12. In the embodiment, the tip 30a of the metal plate 30 protrudes from the guide surface 28a toward the circumferential surface 12a of the platen roller 12, and the amount of protrusion from the guide surface 28a in the vertical direction (Z direction) is set to approximately 1.5 mm. In addition, the base end 30b side of the metal plate 30 is bent toward the tip 30a side, and the metal plate 30 is positioned and fixed to a fixing surface 28c (see FIG. 4) of the transport guide portion 28.

[0034] The inclination angle of the leading edge 30a of the metal plate 30 relative to the horizontal direction (Y direction) is set to approximately 50 degrees. By positioning the metal plate 30 in this position, the first distance D1 between the leading edge 30a of the metal plate 30 and the circumferential surface 12a of the platen roller 12 in the radial direction of the platen roller 12 is smaller than the second distance D2 between one end 28b of the guide surface 28a and the circumferential surface 12a of the platen roller 12. As a result, the leading edge 30a of the metal plate 30 can guide the starting edge 3a of the roll paper 3 that has passed the guide surface 28a along the conveyance path 15 so that it comes into contact with the circumferential surface 12a of the platen roller 12. In this embodiment, the first distance D1 is set to approximately 0.6 mm, and the second distance D2 is set to approximately 1.0 mm (see FIG. 4).

[0035] By positioning the leading edge 30a of the metal plate 30 with the above-described posture and protrusion amount, it guides the roll paper 3 as it passes over the guide surface 28a toward the circumferential surface 12a of the platen roller 12. As a result, the leading edge 30a of the metal plate 30 guides the roll paper 3 so that it comes into contact with the circumferential surface 12a of the platen roller 12, and the platen roller 12 feeds the roll paper 3 smoothly. This prevents the rigidity of the roll paper 3 from separating from the circumferential surface 12a of the platen roller 12 in the U-shaped transport path 15, which has a small radius of curvature. As a result, in the printing device 1, the platen roller 12 can feed the roll paper 3 along the U-shaped transport path 15 more stably.

[0036] If the leading edge 30a of the metal plate 30 protrudes only a little from the end 28b of the guide surface 28a, the metal plate 30 cannot smoothly guide the roll paper 3 so that the direction of travel of the roll paper 3 follows the circumferential surface 12a of the platen roller 12. On the other hand, if the protrusion is too great, the starting edge 3a of the roll paper 3 may collide with the circumferential surface 12a of the platen roller 12, or the leading edge 30a of the metal plate 30 may collide with the circumferential surface 12a of the platen roller 12, which is not appropriate.

[0037] In addition, the metal plate 30 is arranged across the width of the roller along the axial direction (X direction) of the rotation axis 22 of the platen roller 12, and is in contact with the paper surface of the roll paper 3 across the width direction (X direction) of the roll paper 3, which is perpendicular to the conveying direction of the conveying path 15.

[0038] The pinch roller 16 is rotatably supported by a rotary shaft 32, and rotates in response to the rotation of the platen roller 12. The pinch roller 16 is positioned so that its peripheral surface 16a contacts the peripheral surface 12a of the platen roller 12. Furthermore, a portion of the peripheral surface 16a of the pinch roller 16 protrudes from the guide surface 28a of the conveyance guide portion 28 toward the platen roller 12. This allows the peripheral surface 16a of the pinch roller 16 to feed the starting end 3a of the roll paper 3 that advances along the guide surface 28a so that it contacts the peripheral surface 12a of the platen roller 12.

[0039] 2, in this embodiment, pinch rollers 16 are arranged on both sides of the rotation shaft 22 of the platen roller 12 in the axial direction. This brings the roll paper 3 into contact with each pinch roller 16 on both sides in the width direction (X direction), preventing the roll paper 3 from moving obliquely relative to the conveyance direction of the conveyance path 15. Each pinch roller 16 is arranged in a cutout 33 formed by cutting out the metal plate 30 from the leading edge 30a.

[0040] The rotating shaft 32 of the pinch roller 16 is formed from a coil spring, and also serves as a biasing member that biases the pinch roller 16 toward the platen roller 12. When the rotating shaft 32 flexes, the elastic force of the coil spring that forms the rotating shaft 32 biases the pinch roller 16 toward the platen roller 12 with a biasing force of about 0.5 [N]. Because the pinch roller 16 is biased with such a small biasing force, the roll paper 3 that enters the contact area between the platen roller 12 and pinch roller 16 is lightly pressed by the pinch roller 16 so that it comes into contact with the circumferential surface 12a of the platen roller 12.

[0041] By reducing the biasing force of the pinch roller 16, the user of the printer 1 can attach the roll paper 3 to the winding unit 17 while easily manually adjusting the direction in which the roll paper 3 is pulled out from the exit 15B side of the transport path 15, that is, the skew of the roll paper 3, after passing between the thermal head 13 and the platen roller 12. This ensures the proper print quality of the printer 1.

[0042] The winding unit 17 has a winding roll 5 around which the roll paper 3 that has passed the thermal head 13 is wound, and a winding shaft 17a that supports the winding roll 5. The winding shaft 17a is supported by a support portion 7b formed on a side plate 7a of the support frame 7 of the printing device 1. The winding roll 5 has a fixing groove (not shown) that fixes the starting end 3a of the roll paper 3. The roll paper 3 that has passed the thermal head 13 and been pulled out of the transport path 15 is wound from above the outer periphery of the winding roll 5 supported by the winding shaft 17a. The winding unit 17 winds the roll paper 3 onto the winding roll 5 by rotating the winding shaft 17a using a winding mechanism (not shown).

[0043] The operation unit 18 has an operation lever 35 rotatably supported on the side plate 7a of the support frame 7 of the printing device 1, and an operation shaft 36 provided on the operation lever 35. A cam surface 36a of the operation shaft 36 is provided so as to come into contact with the head support plate 24 of the head lifting mechanism 23.

[0044] In the operating unit 18, the cam surface 36a of the operating shaft 36 rotates as the operating lever 35 rotates, and the cam surface 36a moves the head support plate 24. As the operating shaft 36 moves, the head support plate 24 swings around the swing shaft 25, thereby moving the thermal head 13 back and forth between the close position and the retracted position described above. When the thermal head 13 is retracted to the retracted position as described above, the gap between the printing surface 13a of the thermal head 13 and the circumferential surface 12a of the platen roller 12 is 0.6 mm ±0.5 mm (maximum 1.1 mm to minimum 0.1 mm).

[0045] The printing device 1 also includes an exit guide 38 that guides the roll paper 3 as it exits the transport path 15. The exit guide 38 is located above the exit opening 15B side of the transport path 15, and has an inclined surface 38a that directs the starting end 3a of the roll paper 3 that has passed through the gap between the thermal head 13 and the platen roller 12 toward the circumferential surface 12a of the platen roller 12, i.e., downward. This ensures that the direction in which the roll paper 3 is fed after passing the thermal head 13 is guided along the inclined surface 38a, preventing the starting end 3a of the roll paper 3 from colliding with the periphery on the exit opening 15B side of the transport path 15, allowing the roll paper 3 to exit the transport path 15 smoothly. In this embodiment, the exit guide 38 is located adjacent to the thermal head 13, and the distance between the rear end of the thermal head 13 on the exit opening 15B side and the exit guide 38 is set to approximately 1.5 mm (see FIG. 4).

[0046] (Positional relationship of the main parts of the printing device) The positional relationship of the main parts of the printing device 1 will be described based on the position of the platen roller 12. Figure 5 is a schematic diagram for explaining the positional relationship of the main parts of the printing device 1 of the embodiment.

[0047] 5, when viewed from the axial direction (X direction) of the rotation shaft 22 of the platen roller 12, the conveyance path 15 is divided into four quadrants Q1, Q2, Q3, and Q4 in the horizontal direction (Y direction) and the vertical direction (Z direction) with the center O of the rotation shaft 22 as the reference. Of these, the entrance 15A of the conveyance path 15 through which the starting end 3a of the roll paper 3 enters is located in the fourth quadrant Q4, the pinch roller 16 is located in the third quadrant Q3, the thermal head 13 is located in the second quadrant Q2, and the conveyance path 15 extends from the fourth quadrant Q4 to the second quadrant Q2 along the circumferential surface 12a of the platen roller 12. The leading end 30a of the metal plate 30 is located in the second quadrant Q2.

[0048] In this way, even if the roll paper 3 is fed along the U-shaped transport path 15 after entering the entrance 15A of the transport path 15 and is configured in such a way that it is difficult for the roll paper 3 to pass through the gap between the thermal head 13, located on the exit 15B side, and the platen roller 12, the printing device 1 uses the pinch roller 16 to encourage contact between the roll paper 3 and the circumferential surface 12a of the platen roller 12, thereby allowing the roll paper 3 to be transported smoothly along the transport path 15. In addition, the printing device 1 uses the tip 30a of the metal plate 30 to encourage contact between the roll paper 3 and the circumferential surface 12a of the platen roller 12, allowing the roll paper 3 to be transported smoothly along the transport path 15.

[0049] (Printing media installation work) The following describes the operation when loading the roll paper 3 into the printer 1 configured as above. Figure 6 is a flowchart for explaining the operation when loading the roll paper 3 into the printer 1 of this embodiment.

[0050] 6, when loading the roll paper 3 into the printing device 1, the user rotates the operating lever 35 of the operating unit 18 to cause the head lifting mechanism 23 to retract the thermal head 13 from the platen roller 12 (step S1). Next, the user pulls out the roll paper 3 from the supply roll 4 attached to the supply unit 11, and inserts the starting end 3a of the roll paper 3 pulled out from the supply roll 4 into the entrance 15A of the transport path 15 (step S2).

[0051] In the printing device 1, when the beginning end 3a of the roll paper 3 is inserted into the entrance 15A of the transport path 15, the optical sensor 19 detects the roll paper 3 (step S3), and the control unit 20 drives the platen roller 12 (step S4). As the platen roller 12 is driven, the roll paper 3 is pulled into the transport path 15 from the entrance 15A. This causes the beginning end 3a of the roll paper 3 to enter the contact area between the platen roller 12 and the pinch roller 16 (step S5), and the pinch roller 16 lightly presses the roll paper 3 against the circumferential surface 12a of the platen roller 12. As a result, the roll paper 3 is fed along the circumferential surface 12a of the platen roller 12 within the transport path 15 (step S6).

[0052] Next, the roll paper 3 fed along the circumferential surface 12a of the platen roller 12 passes over the guide surface 28a of the transport guide section 28 and comes into contact with the leading edge 30a of the metal plate 30 (step S7). As the starting edge 3a of the roll paper 3 comes into contact with the leading edge 30a of the metal plate 30, the metal plate 30 guides the starting edge 3a of the roll paper 3 toward the circumferential surface 12a of the platen roller 12 (step S8). This allows the starting edge 3a of the roll paper 3 to be fed smoothly along the circumferential surface 12a of the platen roller 12 without moving around in the transport path 15.

[0053] By being fed along the circumferential surface 12a of the platen roller 12 in this manner, the starting end 3a of the roll paper 3 passes smoothly through the gap between the thermal head 13 and the platen roller 12, even when the thermal head 13 is in a retracted position away from the platen roller 12 (step S9). After passing between the thermal head 13 and the platen roller 12, the starting end 3a of the roll paper 3 exits through the exit port 15B of the transport path 15. If the starting end 3a of the roll paper 3 exits through the exit port 15B of the transport path 15 and comes into contact with the inclined surface 38a of the exit guide section 38, it is guided downward along the inclined surface 38a and is smoothly pulled out of the transport path 15. Finally, the user inserts the starting end 3a of the roll paper 3 pulled out of the transport path 15 into the fixing groove (not shown) of the winding roll 5 of the winding section 17 and secures it (step S10).

[0054] (Effects of the Example) As described above, the printing device 1 of this embodiment is equipped with a transport path 15 formed in a U-shape along the circumferential surface 12a of the platen roller 12, a pinch roller 16 that brings the roll paper 3 that has entered the transport path 15 from the supply unit 11 side into contact with the platen roller 12, and an operation unit 18 that moves the thermal head 13 forward and backward relative to the circumferential surface 12a of the platen roller 12. When attaching the starting end 3a of the roll paper 3 pulled out from the supply unit 11 to the winding unit 17, the printing device 1 uses the operation unit 18 to retract the thermal head 13 from the platen roller 12, and then the roll paper 3 that has entered the transport path 15 from the supply unit 11 side is brought into contact with the platen roller 12 by the pinch roller 16 while being transported by the platen roller 12, causing the roll paper 3 to pass through the gap between the thermal head 13 and the platen roller 12. In this way, by bringing the roll paper 3 into contact with the peripheral surface 12a of the platen roller 12 using the pinch roller 16, it becomes possible to easily feed the roll paper 3 along the U-shaped transport path 15 so that it passes through the gap between the thermal head 13 and the platen roller 12, even when the thermal head 13 is retracted from the platen roller 12. As a result, the cost required to precisely control the dimensions of the gap between the thermal head 13 and the platen roller 12 can be reduced, and the manufacturing cost of the printing device 1 can be reduced.

[0055] The printing device 1 of this embodiment also includes an optical sensor 19 that detects the roll paper 3 entering the transport path 15 from the supply unit 11, and a control unit 20 that controls the platen roller 12 to operate based on the detection results of the optical sensor 19. As a result, when the user inserts the starting end 3a of the roll paper 3 into the transport path 15, the platen roller 12 pulls the roll paper 3 into the transport path 15, making it possible to easily feed the roll paper 3 along the transport path 15.

[0056] Furthermore, when viewed from the axial direction of the rotation shaft 22 of the platen roller 12, the printing device 1 of the embodiment is divided into four quadrants Q1, Q2, Q3, and Q4 in the horizontal direction (Y direction) and the vertical direction (Z direction) based on the center O of the rotation shaft 22. Of these, the entrance 15A of the conveying path 15 through which the roll paper 3 enters is located in the fourth quadrant Q4, the pinch roller 16 is located in the third quadrant Q3, the thermal head 13 is located in the second quadrant Q2, and the conveying path 15 extends from the fourth quadrant Q4 to the second quadrant Q2. In this way, even if the roll paper 3 that has entered the conveying path 15 is sent along the conveying path 15 and the structure makes it difficult for the roll paper 3 to pass through the gap between the thermal head 13 and the platen roller 12, which are located on the exit 15B side of the conveying path 15, the printing device 1 can smoothly convey the roll paper 3 along the conveying path 15 by using the pinch roller 16 to encourage contact between the roll paper 3 and the peripheral surface 12a of the platen roller 12.

[0057] The printing device 1 of this embodiment also includes a metal plate 30 that is placed in contact with the roll paper 3 as it is fed along the transport path 15 and that neutralizes static electricity carried by the roll paper 3. By neutralizing the roll paper 3, this not only increases the stability of the roll paper 3's feeding operation along the transport path 15, but also improves the stability of the print quality of the roll paper 3 produced by the thermal head 13. Additionally, because the metal plate 30 for neutralization is simply formed from a single component, it reduces manufacturing costs and improves the accuracy of its attachment position relative to the transport path 15 compared to, for example, a structure in which a metal piece for neutralization is attached to the leading edge of a resin sheet.

[0058] The printing device 1 of this embodiment also has a transport guide section 28 with an arc-shaped guide surface 28a that guides the roll paper 3 along the transport path 15, with a metal plate 30 located at one end 28b of the guide surface 28a, and a tip 30a of the metal plate 30 protruding from the guide surface 28a in the circumferential direction of the platen roller 12. This allows the roll paper 3 that has passed over the guide surface 28a to be guided in the circumferential direction of the platen roller 12.

[0059] Furthermore, in the printing device 1 of this embodiment, in the radial direction of the platen roller 12, the first distance D1 between the leading edge 30a of the metal plate 30 and the circumferential surface 12a of the platen roller 12 is smaller than the second distance D2 between one end 28b of the guide surface 28a and the circumferential surface 12a of the platen roller 12. As a result, the leading edge 30a of the metal plate 30 can guide the starting edge 3a of the roll paper 3 passing over the guide surface 28a along the conveyance path 15 so that it comes into contact with the circumferential surface 12a of the platen roller 12.

[0060] The printer 1 of this embodiment also has a rotating shaft 32 formed by a coil spring that biases the pinch roller 16 toward the platen roller 12, and the rotating shaft 32 biases the pinch roller 12 with a force of 0.5 N. This lightly presses the roll paper 3 along the circumferential surface 12a of the platen roller 12. This allows the user of the printer 1 to easily manually adjust the direction in which the roll paper 3 is pulled out from the exit 15B side of the transport path 15, i.e., the skew of the roll paper 3, while attaching the roll paper 3 to the winding unit 17. This ensures that the print quality of the printer 1 is adequately maintained.

[0061] Additionally, in the conveyance path 15 of the printing device 1 of this embodiment, pinch rollers 16 are provided on both sides in the axial direction (X direction) of the rotation shaft 22 of the platen roller 12. This allows the roll paper 3 to contact each pinch roller 16 on both sides in the width direction (X direction), preventing the roll paper 3 from skewing.

[0062] The printing device 1 of this embodiment also includes an exit guide section 38 with an inclined surface 38a that directs the start end 3a of the roll paper 3 that has passed through the gap between the thermal head 13 and the platen roller 12 toward the circumferential surface 12a of the platen roller 12. This ensures that the direction in which the roll paper 3 is fed after passing the thermal head 13 is guided along the inclined surface 38a, preventing the start end 3a of the roll paper 3 from colliding with the periphery on the exit opening 15B side of the transport path 15, allowing the roll paper 3 to exit the transport path 15 smoothly. [Explanation of symbols]

[0063] 1 Printing device 3. Roll paper (long print media) 3a Starting point 4 Supply Rolls 11 Supply section 12 Platen roller 12a Circumferential surface 13 Thermal head 13a Printed surface 15 Transport path 15A entrance 15B Exit 16 Pinch roller 17 Winding section 18 Control section 19 Optical sensor (sensor) 20 Control Unit 22 Rotation axis 28 Transport guide section 28a Guide surface 28b one end 30 metal plate 30a tip 35 Operating lever 38 Exit Guide 38a Slope D1 First distance D2 2nd distance O center

Claims

1. a supply unit having a supply roll on which a long print medium is wound, the supply unit supplying the print medium from below the supply roll with the inner circumferential side of the print medium facing upward; a platen roller that conveys the print medium supplied from the supply unit; a thermal head that prints on the print medium sandwiched between the thermal head and the platen roller; a conveyance path formed in a U-shape along the circumferential surface of the platen roller, through which the print medium is conveyed; a pinch roller that brings the print medium that has entered the conveyance path from the supply unit side into contact with the platen roller; a conveyance guide portion that guides the print medium along the conveyance path; a winding section that winds up the print medium that has passed through the thermal head; an operation unit that moves the thermal head forward and backward relative to the circumferential surface of the platen roller, the transport guide portion has a first guide surface that faces the circumferential surface of the supply roll and extends obliquely upward, a flat second guide surface that extends horizontally from the first guide surface, and an arc-shaped third guide surface that extends upward from the second guide surface along the circumferential surface of the platen roller, a rotation center of the supply roll is located below the second guide surface of the conveying guide portion; the pinch roller has a peripheral surface that protrudes from the third guide surface toward the peripheral surface of the platen roller, a printing device in which, when attaching a starting end of the printing medium pulled out from the supply unit to the take-up unit, the thermal head is retracted from the platen roller by the operation unit, and the printing medium that has entered the transport path from the supply unit side is brought into contact with the platen roller by the pinch roller while being transported by the platen roller, thereby passing through a gap between the thermal head and the platen roller.

2. the third guide surface is formed so that the distance between the peripheral surface of the platen roller and the third guide surface in the radial direction of the platen roller gradually decreases from an entrance side of a conveyance path through which the print medium enters toward a contact portion between the platen roller and the pinch roller. The printing device according to claim 1 .

3. When viewed from the axial direction of the rotation shaft of the platen roller, of four quadrants divided horizontally and vertically with the center of the rotation shaft as a reference, an entrance of the transport path through which the print medium enters is located in the fourth quadrant, the pinch roller is located in the third quadrant, the thermal head is located in the second quadrant, and the transport path extends from the fourth quadrant to the second quadrant, the third guide surface of the transport guide portion is formed over the entire third quadrant, The printing device according to claim 2 .

4. a sensor that detects the print medium entering the conveyance path from the supply unit side; a control unit that controls the platen roller to be driven based on the detection result of the sensor, The printing device according to claim 1 .

5. The printing apparatus further includes a metal plate that is provided so as to come into contact with the print medium fed along the transport path and that removes static electricity from the print medium.

5. The printing device according to claim 1.

6. the metal plate is disposed at one end of the third guide surface, and a tip of the metal plate protrudes from the third guide surface in the circumferential direction of the platen roller. The printing device according to claim 5.

7. a first distance between the tip of the metal plate and the circumferential surface of the platen roller in the radial direction of the platen roller is smaller than a second distance between one end of the third guide surface and the circumferential surface of the platen roller; The printing device according to claim 6.

8. The pinch roller is further provided with a biasing member that biases the pinch roller toward the platen roller, The pinch roller is biased by the biasing member with a force of 0.5 [N].

5. The printing device according to claim 1.

9. the pinch rollers are provided on both sides of the platen roller in the axial direction of the rotation shaft in the conveying path, 5. The printing device according to claim 1.

10. a retraction guide portion having an inclined surface that directs a leading end of the print medium that has passed through the gap between the thermal head and the platen roller toward the circumferential surface of the platen roller; 5. The printing device according to claim 1.

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