Platen unit

Abstract

To provide a platen unit which can prevent occurrence of failure in printing even when various print media are used.SOLUTION: A platen unit 20 includes: a platen roller 21 which is disposed facing a thermal head configured to print information on a sleeve and transports the sleeve; and an induction guide part 22 which is located at the upstream side in a sleeve transport direction D1 relative to the platen roller 21 and guides the sleeve to the platen roller 21. The platen unit 20 is detachably attached to a device body 1 which houses the thermal head.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a platen unit. [Background technology]

[0002] Printing devices have been used for printing information such as letters and numbers on print media such as tubes and sleeves. The printing device prints predetermined letters, numbers, etc. on the print media by bringing the heating elements of the thermal head into close contact with the print media transported between a platen roller and a thermal head.

[0003] Patent Document 1 describes a platen roller equipped with a core having diameter portions of different diameters and an elastic member having thick and thin portions provided corresponding to each diameter portion of the core to enable printing on tubes of various diameters.Patent Document 2 describes a label printer equipped with a first label width regulation guide, etc., upstream of the platen roller to regulate the position of label paper in the width direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-245656 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-31488 Summary of the Invention [Problem to be solved by the invention]

[0005] Printing devices use a variety of print media, including sleeves, tubes, and tapes. Each print medium has different characteristics, thickness, hardness, and other properties. The frictional force with the transport path varies for each print medium, and the deformation shape when clamped between the platen roller and thermal head also varies. Therefore, if both the platen roller and the guide are not suitable for the print medium, misalignment of the print medium may occur during transport, resulting in poor printing. The prior art does not disclose how to consider the combination of the platen roller and the guide depending on the type of print medium.

[0006] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a platen unit that can prevent printing defects even when using various printing media. [Means for solving the problem]

[0007] The platen unit according to the present disclosure includes: a platen roller disposed opposite a thermal head that prints information on a print medium and that transports the print medium; a guide portion located upstream of the platen roller in a conveyance direction of the print medium, the guide portion guiding the print medium to the platen roller; Equipped with The thermal head is detachably attached to the printer body that houses the thermal head. [Effects of the Invention]

[0008] According to the present invention, a platen unit can be configured by combining a platen roller and a guide unit according to the characteristics of each print medium. Furthermore, according to the present invention, the platen unit can be replaced in the printer body according to the print medium being used. This prevents misalignment of the print medium during transport and suppresses the occurrence of print defects. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a perspective view of a printing device according to an embodiment of the present invention with a cover open to a main body portion. [Figure 2] 1 is a cross-sectional view of a printing device according to an embodiment of the present invention with a cover closed on a main body. [Figure 3A] FIG. 2 is a perspective view of a transport mechanism mounted in a case according to the embodiment. [Figure 3B] FIG. 2 is a perspective view showing a state in which a platen unit is removed from a transport mechanism mounted in a case according to the embodiment. [Figure 4A] FIG. 2 is a perspective view of a platen unit according to the embodiment. [Figure 4B] FIG. 2 is an exploded perspective view of the platen unit according to the embodiment. [Figure 5] FIG. 2 is a plan view of the platen unit according to the embodiment. [Figure 6] 7 is a cross-sectional view of the platen unit 20 according to the present embodiment taken along line AA shown in FIG. 6. [Figure 7] 7 is a cross-sectional view of the platen unit 20 according to the present embodiment taken along line BB shown in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0011] [Configuration example of printing device 100] Fig. 1 is a perspective view of a printing device 100 according to this embodiment with a cover 30 open to a main body 10. Fig. 2 is a cross-sectional view of the printing device 100 with the cover 30 closed to the main body 10. Fig. 3A is a perspective view of a transport mechanism 2 mounted in a case 11 according to this embodiment, and Fig. 3B is a perspective view showing the transport mechanism 2 mounted in the case 11 with the platen unit 20 removed.

[0012] The printing device 100 shown in FIG. 1 and elsewhere can use a variety of printing media, including sleeves, inline markers, and marker plates. Sleeves, which are one type of printing medium, come in a variety of sizes, including an inner diameter (width) of 4.9 mm and an inner diameter of 5.4 mm. In this embodiment, a platen unit 20 is provided for each type of printing medium, and is configured by combining a platen roller 21 and an induction guide unit 22 selected in consideration of the width, thickness, hardness, and other characteristics of each printing medium. Below, an example will be described in which a sleeve C is used as the printing medium, and the width of the sleeve C will be referred to as width W.

[0013] As shown in Fig. 2, the printing device 100 is provided with an insertion opening 10i for inserting the sleeve C into the main body 10 and an ejection opening 10o for ejecting the sleeve C to the outside of the main body 10. In this embodiment, the insertion opening 10i side of the sleeve C is the rear side of the printing device 100, and the ejection opening 10o side of the sleeve C is the front side of the printing device 100. The left-right direction when the front-to-rear direction of the printing device 100 is used as the reference is the left-to-right direction of the printing device 100. The up-down direction when the printing device 100 is placed on a flat surface such as a horizontal surface is the up-down direction of the printing device 100.

[0014] As shown in Figures 1 and 2, the printing device 100 comprises a device main body 1 and a platen unit 20 that is detachably attached to the device main body 1. The device main body 1 comprises a main body section 10 and a cover 30 that is attached to the main body section 10 in an openable and closable manner. A setting section 50 for setting the type of print medium, printing information, pitch length, etc. is provided on the left side of the main body section 10. The setting section 50 is composed of, for example, a display section and an operation section that includes buttons, etc.

[0015] As shown in FIGS. 3A and 3B, the main body 10 has a case 11 that houses the conveyance mechanism 2, such as the platen unit 20. The case 11 is a box-like structure having a pair of side walls 11a and 11b extending from both left and right ends of a bottom wall (not shown) and a rear wall 11c extending from the rear end of the bottom wall. A bearing 12a for supporting the left end of the platen roller 21 is formed in the left side wall 11a. The bearing 12a is formed in a substantially U-shape corresponding to the circular cross-section of the left end of the platen roller 21. A bearing 12b for supporting the right end of the platen roller 21 is formed in the right side wall 11b. The bearing 12b is formed in a substantially U-shape corresponding to the circular cross-section of the right end of the platen roller 21.

[0016] As shown in FIGS. 1 and 2, a transport path P for transporting the sleeve C is provided on the transport mechanism 2. The transport path P extends in the front-rear direction from the insertion opening 10i toward the discharge opening 10o. In this embodiment, the direction from the insertion opening 10i toward the discharge opening 10o is defined as the transport direction D1 in which the print medium, such as the sleeve C, is transported. A first guide unit 13 is provided on the transport path P on the insertion opening 10i side. The first guide unit 13 is composed of, for example, a pair of guide walls that constitute the transport path P. The pair of guide walls are arranged with a gap therebetween that is the same as or approximately the same as the width of the sleeve C, and regulate the left-right position of the sleeve C during transport. The gap between the first guide units 13 can be adjusted depending on the print medium used.

[0017] A second guide section 14 is provided on the transport path P downstream of the first guide section 13 in the transport direction D1. Similar to the first guide section 13, the second guide section 14 is composed of a pair of guide walls that form the transport path P. The pair of guide walls are arranged with a gap that is the same as or approximately the same as the width of the sleeve C, and regulate the left-right position of the sleeve C during transport. The gap between the second guide sections 14 can be adjusted depending on the print medium used.

[0018] The platen unit 20 is disposed downstream of the second guide part 14 in the transport direction D1 and is detachably attached to the main body part 10. The platen unit 20 is disposed opposite the thermal head 31 that prints information on the sleeve C and includes a platen roller 21 that transports the sleeve C, and an induction guide part 22 that is positioned upstream of the platen roller 21 in the transport direction D1 of the sleeve C and serves as an example of a induction part that guides the sleeve C to the platen roller 21. Details of the platen unit 20 will be described later.

[0019] A cutting unit 18 is provided downstream of the platen unit 20 in the conveying direction D1. The cutting unit 18 has a cutter and half-cuts the long sleeve C at a predetermined pitch. Whether or not the cutting unit 18 performs half-cutting processing can be set using an operation unit, etc. The sleeve C that has passed through the cutting unit 18 is discharged to the outside from the discharge port 10o.

[0020] As shown in FIGS. 1 and 2, the cover 30 is attached to the main body 10 so as to be rotatable relative to the main body 10 on a hinge portion 16 (see FIG. 3A) provided at the upper rear end of the main body 10. This allows the interior of the main body 10 to be exposed when the cover 30 is opened, making it possible to replace the platen unit 20 and perform various maintenance tasks. A thermal head 31, a ribbon holding shaft 32, and a ribbon winding shaft 34 are provided inside the cover 30. Below, the components of the thermal head 31 and the like will be described, assuming that the cover 30 is closed on the main body 10 as shown in FIG. 2.

[0021] The thermal head 31 is disposed at a position facing the platen roller 21 of the main body 10. The thermal head 31 is, for example, a line-type thermal printer head, and prints predetermined information such as letters and numbers onto the sleeve C held between the thermal head 31 and the platen roller 21. Note that the printing method of the thermal head 31 may be any other known printing method.

[0022] The ribbon holding shaft 32 is disposed upstream of the thermal head 31 in the conveying direction D1. A supply reel 33, on which an unused ink ribbon 36 is wound in a roll, is removably attached to the ribbon holding shaft 32. The ribbon take-up shaft 34 is disposed downstream of the thermal head 31 in the conveying direction D1. A take-up reel 35, which takes up the used ink ribbon 36 in a roll, is removably attached to the ribbon take-up shaft 34. The ink ribbon 36 is pulled out from the supply reel 33, passes over the surface (underside) facing the platen roller 21 of the thermal head 31, and is wound in a tensioned state around the take-up reel 35. At least one of the ribbon holding shaft 32 and the ribbon take-up shaft 34 may be rotated in synchronization with a conveying motor that rotates the platen roller 21. The supply reel 33, the take-up reel 35, and the ink ribbon 36 may be cassette-type.

[0023] As shown in FIG. 1 , a hook portion 40 for locking the cover 30 to the main body 10 is provided on the inside of the cover 30. An attachment hole 10b is formed on the top surface of a protruding portion 10a that protrudes forward from the main body 10 at a position corresponding to the hook portion 40 of the cover 30. A lock portion 42 for locking the hook portion 40 is provided inside the protruding portion 10a and below the attachment hole 10b. An unlocking lever 43 for unlocking the hook portion 40 by the locking portion 42 is provided on the left wall of the main body 10. When the cover 30 is closed on the main body 10, the hook portion 40 of the cover 30 is inserted into the attachment hole 10b of the protruding portion 10a and engages with the locking portion 42 inside the protruding portion 10a. This locks the cover 30 to the main body 10 in the closed state. When the cover 30 is opened from the main body 10, the user releases the locking lever 43, thereby releasing the engagement of the hook portion 40 with the locking portion 42. This allows the cover 30 to be opened relative to the main body 10.

[0024] [Platen unit 20 configuration example] Next, an example of the configuration of the platen unit 20 according to this embodiment will be described. Fig. 4A is a perspective view of the platen unit 20 according to this embodiment, and Fig. 4B is an exploded perspective view of the platen unit 20. Fig. 5 is a plan view of the platen unit 20 according to this embodiment, Fig. 6 is a cross-sectional view of the platen unit 20 shown in Fig. 5 taken along line AA, and Fig. 7 is a cross-sectional view of the platen unit 20 shown in Fig. 5 taken along line BB.

[0025] As shown in Figures 4A, 4B, 6, etc., the platen roller 21 has a core 210 having an elongated cylindrical shape, an elastic member 211 covering the outer circumferential surface of the core 210, and a guide groove 212 for guiding and transporting the sleeve C. The core 210 can be made of a material such as metal, such as SUS or steel, or resin, such as polycarbonate (PC). In this embodiment, the core 210 corresponds to the shaft portion. An expanded diameter portion 210a having a diameter larger than that of the core 210 is provided in the center of the core 210 in the axial direction (left-right direction).

[0026] The elastic member 211 may be made of, for example, nitrile rubber (NBR), ethylene propylene rubber (EPDM: Ethylene Propylene Methylene Linkage), chloroprene rubber (polychloroprene), silicone rubber, urethane rubber, etc. The elastic member 211 is made of, for example, a pair of annular members, and is attached along the circumferential direction of the expanded diameter portion 210a of the core metal 210 with a predetermined gap in the axial direction.

[0027] The gap between the elastic members 211, 211 forms a guide groove 212. The guide groove 212 is formed by the opposing side surfaces of each elastic member 211, 211 and the surface of the core metal 210, and is formed around the entire circumferential direction of the expanded diameter portion 210a. In this embodiment, the surface of the core metal 210 is the bottom surface 212a of the guide groove 212, and the guide groove 212 forms the conveying path P. As shown in FIG. 5, the width W1 of the guide groove 212 is the same as or approximately the same as the width W of the sleeve C. The bottom surface 212a of the guide groove 212 is subjected to an anti-slip treatment to prevent the sleeve C from shifting in the axial direction during conveyance. Examples of anti-slip treatment include unevenness treatment and other known techniques.

[0028] As shown in FIGS. 4A to 6, a cylindrical shaft bushing 23a is attached to the outer periphery of the core metal 210 to the left of the elastic member 211 so as to abut against the stepped portion with the expanded diameter portion 210a. A guide holder 24a, which is an elongated plate extending in the front-to-rear direction, is attached to the shaft bushing 23a through an axial hole 24a1 provided in the front portion of the shaft bushing 23a. The guide holder 24a is an example of a support portion, and rotatably supports the platen roller 21, and also supports the leading guide portion 22 at a predetermined distance from the platen roller 21. As shown in FIGS. 4A and 4B, a cylindrical guide stopper 25 is attached to the outer periphery of the shaft bushing 23a, outside the guide holder 24a. The guide stopper 25 is an example of an insertion portion, and rotatably inserts the core metal 210 of the platen roller 21 through the guide holder 24a. A protrusion 25a formed on the inner edge of the guide stopper 25 fits into a notch 24a3 formed on the periphery of the hole in the guide holder 24a. In this embodiment, the guide stopper 25 has two protrusions 25a that fit into two notches 24a3 in the guide holder 24a. This fixes the guide stopper 25 to the guide holder 24a. A bearing 26a is attached to the left end of the core metal 210 that is exposed from the shaft bushing 23a. A C-ring 27 is attached to the core metal 210 outside the bearing 26a to prevent the bearing 26a and other components from coming off.

[0029] A cylindrical shaft bushing 23b is attached to the outer periphery of the core metal 210 to the right of the elastic member 211 so as to abut against the stepped portion with the expanded diameter portion 210a. A thin, plate-like guide holder 24b extending in the front-rear direction is attached to the shaft bushing 23b through a shaft hole 24b1 provided in the front portion of the shaft bushing 23b. The guide holder 24b is an example of a support portion, and rotatably supports the platen roller 21 and supports the leading guide portion 22 at a predetermined distance from the platen roller 21. Furthermore, a shaft bushing 23c is attached to the outside of the shaft bushing 23b. A bearing 26b is attached to the right end of the core metal 210 exposed from the shaft bushing 23c. A gear 28 is fixed to the core metal 210 outside the bearing 26a. The gear 28 meshes with a gear 60 (see FIG. 3A) connected to a drive motor that rotates the platen roller 21, and transmits the driving force of the drive motor to the platen roller 21.

[0030] Next, the guide stopper 25 that constitutes the platen unit 20 will be described. When mounting the platen unit 20 to the main body 10, as shown in Fig. 2, the platen unit 20 needs to be mounted to the main body 10 so that the leading guide portion 22 is located upstream of the platen roller 21 in the conveyance direction D1. However, because the cylindrical core metal 210 has the same shape in the circumferential direction, the platen unit 20 can be mounted to the main body 10 even when the leading guide portion 22 is located downstream of the platen roller 21 in the conveyance direction D1. Therefore, in this embodiment, the guide stopper 25 is configured so that the platen unit 20 can be mounted to the main body 10 only when the leading guide portion 22 is located upstream of the platen roller 21 in the conveyance direction D1.

[0031] Specifically, a portion of the guide stopper 25 is utilized so that the shape of the bearing 26a attached to the bearing portion 12a (see FIG. 3B) of the main body 10 is asymmetric in the up-down direction. As shown in FIGS. 4A, 4B, and 6, the guide stopper 25 has an extension portion 25b at a portion of its left end portion that extends so as to cover part of the periphery of the bearing 26a. When the bearing portion 12a of the side wall 11a of the main body 10 is substantially U-shaped, the extension portion 25b has a shape that cannot fit into the bearing portion 12a, such as a cube with corners. As a result, when the platen unit 20 is attached to the main body 10, if the leading guide portion 22 is located downstream of the platen roller 21 in the conveyance direction D1, the extension portion 25b of the guide stopper 25 is located below the bearing 26a of the platen roller 21. In this case, the extension 25b on the left end side of the platen roller 21 is not fitted into the bearing portion 12a of the main body 10, so that the platen unit 20 can be prevented from being attached to the main body 10 in the wrong orientation.

[0032] Next, the leading guide unit 22 will be described. As shown in Figures 4A, 4B, and 5, the leading guide unit 22 has a bottom wall 220 and a pair of side walls 221a, 221b that stand facing each other from both ends of the bottom wall 220 in the left-right direction. In this embodiment, the bottom wall 220 and the pair of side walls 221a, 221b form a conveying path P. The conveying path P includes an inlet 22a for the sleeve C and an outlet 22b for the sleeve C that is located downstream of the inlet 22a in the conveying direction D1.

[0033] In the lead-in guide unit 22, the width of the entrance 22a is wider than the width of the exit 22b downstream in the conveyance direction D1. In other words, as shown in FIG. 5 and other figures, the distance W2 between the side walls 221a and 221b of the lead-in guide unit 22 on the entrance 22a side is wider than the distance W3 between the side walls 221a and 221b of the lead-in guide unit 22 on the exit 22b side. The distance W2 is set to be wider than the width W of the sleeve C so that the sleeve C can be smoothly received within the lead-in guide unit 22. In contrast, the distance W3 is set to be the same or approximately the same as the width W of the sleeve C so that the sleeve C can be fed to the platen roller 21 while reliably preventing misalignment in the axial direction, such as twisting. As the distance W3 is set to be approximately the same, misalignment in the axial direction, such as twisting, can be prevented when the distance W3 is approximately 10% larger than the width W of the sleeve. Therefore, the gap W3 at the exit 22b of the leading / guiding section 22 is the same as or approximately the same as the width W1 of the guide groove 212 of the platen roller 21 on the downstream side in the conveying direction D1. Note that in this embodiment, the gap W2 is set only near the entrance 22a of the leading / guiding section 22, and the gap W2 is set from near the entrance 22a to the exit 22b, but this is not limiting. For example, the width of the conveying path P may be configured to gradually narrow from the entrance 22a to the exit 22b of the leading / guiding section 22, or may be configured to narrow in stages from the entrance 22a to the exit 22b.

[0034] 4A, 4B, and 7, the leading guide unit 22 has mounting portions 222a and 222b extending downward from both left and right ends of the bottom wall 220. The left mounting portion 222a is attached with a screw to the inside of a support portion 24a2 provided at the rear of the guide holder 24a. Similarly, the right mounting portion 222a is attached with a screw to the inside of a support portion 24b2 provided at the rear of the guide holder 24b. At this time, the leading guide unit 22 is supported by the guide holders 24a and 24b at a predetermined distance so as not to come into contact with the rotating platen roller 21.

[0035] As shown in FIGS. 5 and 7 , the leading / guiding unit 22 is located below the conveying path P and has a protrusion 220a that fits into the guide groove 212 of the platen roller 21. The protrusion 220a protrudes from the front end of the bottom wall 220 into the gap between the platen roller 21 and the leading / guiding unit 22, filling the gap between the platen roller 21 and the leading / guiding unit 22 that is located below the conveying path P. This prevents the sleeve C that is conveyed out from the exit 22b of the leading / guiding unit 22 from getting below the platen roller 21. Furthermore, by configuring the protrusion 220a to fit into the guide groove 212, a substantially continuous conveying path P can be formed by the bottom wall 220 of the leading / guiding unit 22 and the bottom surface 212a of the guide groove 212 of the platen roller 21. The distance between the protrusion 220a and the platen roller 21 is set to be smaller than twice the thickness of the sleeve C. The convex portion 220a is positioned at the same height as the central axis of the rotation shaft of the platen roller 21 or above the central axis.

[0036] Here, in the leading guide part 22, when the sleeve C is being transported, a rotational moment is generated due to friction between the sleeve C and the leading guide part 22. For example, as shown in FIG. 2, a force in a rotational direction D2, which includes a direction opposite to the transport direction D1, acts as a rotational moment below the transport path P of the leading guide part 22. This causes the leading guide part 22 to tilt forward, and the transport path P of the leading guide part 22 to be misaligned with the guide groove 212 of the platen roller 21, which may prevent the sleeve C from being smoothly fed into the guide groove 212.

[0037] Therefore, in this embodiment, the restricting portion 19 is provided on the main body 10 side, and contact portions 28a, 28b are provided on the lead guide portion 22 side, which contact the restricting portion 19 of the main body 10 from the direction opposite to the conveyance direction D1. As shown in FIGS. 2 and 4A , the restricting portion 19 of the main body 10 is erected downstream of the contact portions 28a, 28b in the rotation direction D2 of the rotational moment generated in the platen unit 20, and is fixed to a part of the case 11 with screws or the like. The front surface 19a of the restricting portion 19 receives the contact portions 28a, 28b of the lead guide portion 22 that attempts to rotate in the rotation direction D2, thereby restricting the movement of the lead guide portion 22 in the rotation direction D2. As shown in FIGS. 2 and 4A , the contact portions 28a, 28b extend from lower ends of the mounting portions 222a, 222b of the lead guide portion 22 toward the restricting portion 19 and are configured to be able to contact the restricting portion 19 of the main body 10.

[0038] [Example of use of the printing device 100] Next, an example of how the printing device 100 is used when printing information such as characters on a sleeve C will be described. When printing information on a sleeve C, a platen unit 20 customized for the sleeve C to be used is prepared. Next, the prepared platen unit 20 is attached to the main body 10 with the leading guide portion 22 positioned downstream of the platen roller 21 in the conveyance direction D1 and with the extension portion 25b of the guide stopper 25 facing upward. This allows both ends of the platen roller 21 to fit into the bearing portions 12a and 12b of the main body 10, respectively.

[0039] After setting the platen unit 20 and other components, the user starts the printing process by selecting "Start Printing" using the operation buttons on the main body 10. The operation to start the printing process may be performed using an information terminal such as a personal computer. When the printing process starts, the motor is driven, and the platen roller 21 rotates via gears 60 and other components, transporting the sleeve C along the transport path P. In this embodiment, the leading guide unit 22 and the guide groove 212 of the platen roller 21 are each configured with a width, thickness, etc. appropriate for the sleeve C being used, so the sleeve C can be transported to the printing position without misalignment such as twisting. The thermal head 31 prints predetermined information on the sleeve C transported to the printing position. The sleeve C with the printed information is half-cut by the cutting unit 18 and discharged to the outside through the discharge port 10o.

[0040] As described above, in this embodiment, the platen unit 20 is constructed by combining the platen roller 21 and the leading guide section 22 according to the characteristics of each print medium, such as width, thickness, and hardness. Specifically, the platen roller 21 and the leading guide section 22, in which the width of the guide groove 212 of the platen roller 21 and the width of the leading guide section 22 are the same or approximately the same, are combined into a unit. This allows the print medium, such as the sleeve C, to be transported from the leading guide section 22 to the platen roller 21 without being displaced, such as twisted.

[0041] Furthermore, according to this embodiment, the platen roller 21 and the leading guide section 22 are unitized, eliminating the need to select the optimum combination of the platen roller 21 and the leading guide section 22 for each print medium to be used. Furthermore, according to this embodiment, the platen roller 21 and the leading guide section 22 are combined to form the platen unit 20, and this platen unit 20 is configured to be detachable from the main body 10, so the platen unit 20 can be replaced with a simple installation operation. These features make it possible to improve the efficiency of the printing process.

[0042] Furthermore, according to this embodiment, even if a rotational moment is generated in the platen unit 20 when the print medium is being transported, the abutment portions 28a, 28b of the leading / leading guide portion 22 abut against the regulating portion 19 of the main body 10, thereby restricting the movement of the leading / leading guide portion 22 in the rotational direction D2. This prevents the leading / leading guide portion 22 from shifting position, and allows the sleeve C to be smoothly transported into the guide groove 212 of the platen roller 21.

[0043] Furthermore, according to this embodiment, the width W1 of the guide groove 212 of the platen roller 21 is set to be equal to or approximately equal to the interval W3 of the outlets 22b of the leading-guide section 22, so that a nearly continuous conveying path P can be formed from the leading-guide section 22 to the platen roller 21. This allows the print medium such as the sleeve C to be conveyed without being misaligned, preventing the occurrence of printing defects.

[0044] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. A person skilled in the art of the present disclosure will understand that various modifications and improvements made within the scope of the technical ideas set forth in the claims are naturally within the technical scope of the present disclosure. [Explanation of symbols]

[0045] 1. Device main body (printing device main body) 10 Main body 20 Platen unit 21 Platen roller 22 Guidance guide section (guidance section) 22a entrance 22b exit 24a, 24b Guide holder (support part) 25 Guide stopper (insertion part) 28a,28b Contact part 31 Thermal head 100 Printing device 210 Core (shaft) 212 Guide groove 220a Convex part C Sleeve (printing media) D1 Conveying direction P transport path

Claims

1. a platen roller disposed opposite a thermal head that prints information on a print medium and that transports the print medium; a guide portion located upstream of the platen roller in a conveyance direction of the print medium, the guide portion guiding the print medium to the platen roller; Equipped with The thermal head is detachably attached to a printer body that houses the thermal head. Platen unit.

2. the guide unit has a transport path along which the print medium is transported, the transport path includes an inlet for the print medium and an outlet for the print medium located downstream of the inlet in the transport direction, The width of the inlet is wider than the width of the outlet. The platen unit according to claim 1 .

3. the platen roller has a guide groove in a circumferential direction for guiding and transporting the print medium, The width of the outlet is equal to or approximately equal to the width of the guide groove. The platen unit according to claim 2 .

4. The guide portion has a contact portion that contacts the printing device body from the direction opposite to the conveyance direction. The platen unit according to claim 3 .

5. The contact portion is located below the conveying path. The platen unit according to claim 4 .

6. The guide portion is located below the transport path and has a protrusion that fits into the guide groove. The platen unit according to claim 5 .

7. a support portion that rotatably supports the platen roller and supports the guide portion at a predetermined distance from the platen roller; The platen unit according to claim 6 .

8. the printing apparatus body is detachably attached to the printing apparatus body, and includes an insertion portion through which a shaft portion of the platen roller is rotatably inserted, The insertion portion is fixed to the support portion. The platen unit according to claim 7 .

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