printer

Abstract

To provide a printer which can suppress a difference in printing quality caused by a difference in rigidity of a medium.SOLUTION: A printer includes a platen roller 6, a substrate 71, a heating element 73, a heat sink 8, a first regulation member 3, and a second regulation member 9. The platen roller 6 conveys a medium. The substrate 71 faces to the platen roller 6. The heating element 73 is arranged on a front surface 511 of the substrate 71. The heat sink 8 is in contact with a rear surface 712 of the substrate 71. The first regulation member 3 is arranged on an upstream side in a conveyance direction from the substrate 71. The second regulation member 9 is arranged on the heat sink 8 on a downstream side in the conveyance direction from the substrate 71, and has a contact surface 94. The contact surface 94 extends from a second opposite direction to a first opposite direction as extending from the upstream side to the downstream side in the conveyance direction. An upstream end 942 of the contact surface 94 is positioned in the second opposite direction from the front surface 711. A downstream end 941 of the contact surface 94 is positioned in the first opposite direction from the front surface 711.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] The printer described in Patent Document 1 includes a platen roller and a thermal line head. The platen roller transports the medium and presses the medium against the thermal line head at the portion facing the thermal line head. The thermal line head prints on the medium pressed by the platen roller. The printer is provided with a guide member upstream of the portion facing the medium in the transport direction. The guide member is located closer to the platen roller than the thermal line head. The guide member forms an angle at which the medium approaches the portion facing the thermal line head. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-56703 Summary of the Invention [Problem to be solved by the invention]

[0004] Because the printer forms an approach angle, the position where the thermal line head contacts the medium may shift in the transport direction from the opposing part depending on the rigidity of the medium, which can result in differences in print quality depending on the rigidity of the medium.

[0005] An object of the present invention is to provide a printer that can suppress differences in print quality caused by differences in media stiffness. [Means for solving the problem]

[0006] A printer according to a first aspect of the present invention includes a platen roller that rotates about a rotation center extending in an axial direction to transport a medium in a transport direction that intersects the axial direction, a substrate having a front surface that faces the platen roller across a transport path of the medium in an opposing direction that intersects the axial direction and the transport direction, and a back surface that faces away from the front surface, a heating element that is provided on the front surface of the substrate and comes into contact with the medium pressed against the front surface by the platen roller to print on the medium, a heat sink that contacts the back surface of the substrate, and a defining portion that is provided upstream of the heating element in the transport direction and defines the transport path, the defining portion being located upstream of the heating element in the opposing direction and having a width greater than the front surface. and a first defining portion that contacts the medium at a position in a first opposing direction from the front surface toward the platen roller, the defining portion being provided on the heat sink downstream of the substrate in the transport direction and defining the transport path, the defining portion facing the first opposing direction and extending from a second opposing direction opposite the first opposing direction toward the first opposing direction as it moves from the upstream side to the downstream side in the transport direction, the second defining portion having a contact surface with which the medium comes into contact, the upstream end of the contact surface in the transport direction being located further in the second opposing direction than the front surface, and the downstream end of the contact surface in the transport direction being located further in the first opposing direction than the front surface.

[0007] According to the first aspect, the printer can prevent the position where the medium contacts the substrate from shifting in the transport direction by the second regulating unit, thereby preventing differences in print quality caused by differences in the rigidity of the medium.

[0008] In the printer according to the first aspect of the present invention, the downstream end of the contact surface in the transport direction may be located furthest downstream in the transport direction among the portions of the second defining portion that come into contact with the medium. In this case, the distance in the transport direction from the position where the medium comes into contact with the substrate to the downstream end of the contact surface in the transport direction is large. Therefore, the printer can suppress deviation of the position where the medium comes into contact with the substrate due to dimensional variations in the opposing direction of the second defining portion.

[0009] In the printer according to the first aspect of the present invention, the second determining portion may be provided on the heat sink as a separate body. In this case, the position where the medium contacts the substrate can be adjusted by changing the design of the second determining portion without changing the design of the heat sink. Therefore, even if different printer models support different types of media, the heat sink configuration can be standardized regardless of the model.

[0010] In the printer according to the first aspect of the present invention, the second determining portion may be integral with the heat sink and constitute a part of the heat sink, in which case the printer can suppress deviation of the position at which the medium contacts the substrate due to variations in the second determining portion and variations in the assembly position.

[0011] In the printer according to the first aspect of the present invention, the second defining portion may be provided with a protruding portion that protrudes from an upstream end of the second defining portion in the transport direction to the upstream side in the transport direction, or from a downstream end of the second defining portion in the transport direction to the downstream side in the transport direction. In this case, for example, when assembling the second defining portion to a heat sink, the protruding portion serves as a reference, making the assembling work easier.

[0012] A printer according to a first aspect of the present invention includes a support portion, a shaft extending in the axial direction and fixed to the heat sink, with one axial end rotatably supported by the support portion and the other axial end being a free end, and a plurality of springs aligned in the axial direction and pressing the heat sink in the first opposing direction, wherein the plurality of springs are configured such that the pressing load of a first spring is greater than the pressing load of a second spring positioned on one side of the first spring in the axial direction. In this case, the printer can reduce differences in the amount of deformation of the heat sink in the opposing direction at each axial position. Therefore, the printer can reduce differences in printing quality along the axial direction.

[0013] In a printer according to a first aspect of the present invention, a discharge angle of a virtual line passing through the front surface at an intersection of a virtual line passing through the rotation center and extending in the opposing direction with the front surface and a downstream end of the contact surface in the transport direction may be smaller than an approach angle of a virtual line passing through the intersection and the downstream end of the first defining portion in the transport direction with respect to the front surface, and the heating element may be located downstream of the intersection in the transport direction. In this case, by reducing the discharge angle, the printer can prevent the medium from curling downstream of the intersection in the transport direction. Because the heating element is located downstream of the intersection in the transport direction, the printer can tolerate a shift in the position where the medium contacts the substrate downstream in the transport direction. Therefore, the printer can prevent the medium from curling downstream of the intersection in the transport direction while preventing differences in print quality due to differences in media rigidity.

[0014] A printer according to a second aspect of the present invention is a printer including: a platen roller that rotates about a rotation center extending in an axial direction to transport a medium in a transport direction that intersects the axial direction; a substrate having a front surface that faces the platen roller across a transport path for the medium in an opposing direction that intersects the axial direction and the transport direction; a heating element that is provided on the front surface of the substrate and contacts the medium pressed against the front surface by the platen roller to print on the medium; and a first defining portion that is provided upstream of the heating element in the transport direction and that defines the transport path, the first defining portion being in contact with the medium at a position further upstream than the front surface in a first opposing direction from the front surface to the platen roller in the opposing direction; a second defining portion having a contact surface with which the medium comes into contact, the second defining portion facing the first opposing direction and extending from a second opposing direction opposite the first opposing direction toward the first opposing direction as it moves from the upstream side to the downstream side in the conveying direction, the second defining portion having a contact surface with which the medium comes into contact, the upstream end of the contact surface in the conveying direction being located further in the second opposing direction than the front surface, the downstream end of the contact surface in the conveying direction being located further in the first opposing direction than the front surface, the discharge angle of a virtual line passing through an intersection of a virtual line passing through the rotation center and extending in the opposing direction with the front surface and the downstream end of the contact surface in the conveying direction being smaller than an entrance angle of a virtual line passing through the intersection and the downstream end of the first defining portion in the conveying direction, with respect to the front surface,

[0015] According to the second aspect, by reducing the discharge angle, the printer can prevent the medium from curling downstream of the intersection in the transport direction. Because the heating element is located downstream of the intersection in the transport direction, the printer can tolerate the position where the medium contacts the substrate being shifted downstream in the transport direction. Therefore, the printer can prevent the medium from curling downstream of the intersection in the transport direction while also preventing differences in print quality due to differences in media rigidity. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a printer 1. [Figure 2] FIG. 2 is an exploded perspective view of the printer 1. [Figure 3] 4. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line III-III in FIG. 3. [Figure 5] FIG. 2 is a left side view of the head unit 4. [Figure 6] FIG. 2 is a right side view of the head unit 4. [Figure 7] FIG. 4 is an enlarged view of an area W shown in FIG. [Figure 8] FIG. 8 is a schematic diagram corresponding to FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0017] A printer 1 according to an embodiment of the present invention will be described with reference to the drawings. Hereinafter, the lower left, upper right, upper left, lower right, upper, and lower in Fig. 1 will be referred to as the front, rear, left, right, upper, and lower of the printer 1, respectively.

[0018] The printer 1 shown in FIG. 1 can print an image on a medium M based on print data. The medium M is not limited to a specific medium, but may be, for example, a sheet or tape, and in this embodiment is thermal cut paper. The printer 1 can print on multiple types of medium M with different rigidities. The rigidity of the medium M varies depending on, for example, the material of the medium M, and increases as the medium M becomes thicker.

[0019] The external configuration of the printer 1 will be described with reference to Figures 1 and 2. As shown in Figure 1, the printer 1 has a case 2. The case 2 is rectangular and is longer left to right than it is front to back and up to down. A battery 10, shown in Figure 2, is attached to the lower rear of the case 2. The battery 10 supplies power to the printer 1.

[0020] As shown in FIG. 2, the case 2 includes a lower cover 21, an upper cover 22, and an opening / closing cover 23. The lower cover 21 is plate-shaped and extends in the front-rear and left-right directions. The lower cover 21 forms the lower part of the case 2. The upper cover 22 opens downward and is attached to the upper side of the lower cover 21. An opening 221 is formed in the upper cover 22. The opening 221 extends from the center in the up-down direction to the upper end on the front surface of the upper cover 22. The opening 221 extends from the front end to the center in the front-rear direction on the top surface of the upper cover 22. The opening 221 extends from near the left end to near the right end of the upper cover 22. Hereinafter, the end of the upper cover 22 that defines the rear end of the opening 221 will be referred to as the "opening end 223," and the end of the upper cover 22 that defines the lower end of the opening 221 will be referred to as the "opening end 224."

[0021] The opening / closing cover 23 is plate-shaped and includes a first portion 231 and a second portion 232. The first portion 231 extends in the front-rear and left-right directions. The second portion 232 extends downward from the front end of the first portion 231 and also extends in the left-right direction. The opening / closing cover 23 fits into the opening 221. A rear end 233 of the first portion 231 is rotatably supported by the upper cover 22. Therefore, the opening / closing cover 23 can be opened and closed relative to the opening 221 by swinging about the rear end 233 of the first portion 231 as an axis.

[0022] 1, the following description will be based on the state in which the openable cover 23 is closed relative to the opening 221. In this case, the rear end 233 of the first portion 231 faces the opening edge 223 of the upper cover 22 with a gap in the front-to-rear direction. Furthermore, the lower end 234 of the second portion 232 faces the opening edge 224 of the upper cover 22 with a gap in the up-down direction.

[0023] An insertion slot 24 is formed in the top surface of the case 2. The insertion slot 24 is an opening defined by an opening edge 223 of the upper cover 22 and a rear end 233 of the opening / closing cover 23. The medium M is supplied into the case 2 through the insertion slot 24.

[0024] An outlet 25 is formed in the front surface of the case 2. The outlet 25 is an opening defined by an opening edge 224 of the upper cover 22 and a lower edge 234 of the opening / closing cover 23. After printing on the medium M inside the case 2, it is discharged from the case 2 through the outlet 25.

[0025] The internal configuration of the printer 1 will be described with reference to Figures 2 to 7. As shown in Figures 2 to 4, the printer 1 is equipped with a head unit 4. The head unit 4 is housed in the case 2 and includes a support plate 5, a platen roller 6, a thermal head 7, and a heat sink 8. The support plate 5 includes a lower plate 51, a left plate 52, and a right plate 53. The lower plate 51 is rectangular in plan view and is longer in the left-right direction than in the front-to-back direction. The lower plate 51 is fixed to the upper surface of the lower cover 21. The left plate 52 extends upward from the left end of the lower plate 51 and also extends in the front-to-back direction. The right plate 53 extends upward from the right end of the lower plate 51 and also extends in the front-to-back direction. The left plate 52 and right plate 53 face each other in the left-to-right direction.

[0026] The platen roller 6 is located diagonally above the front of the case 2 (see FIG. 3) and extends in the left-right direction. The platen roller 6 has a cylindrical portion 61 and a shaft 62. The cylindrical portion 61 is an elastic body made of rubber or the like. The shaft 62 passes through the cylindrical portion 61 and is fixed to the cylindrical portion 61. As shown in FIGS. 4 and 5, a left end 621 of the shaft 62 is supported by the left plate 52. As shown in FIGS. 4 and 6, a right end 622 of the shaft 62 is supported by the right plate 53. The platen roller 6 can rotate around the shaft 62.

[0027] As shown in Fig. 2, the platen roller 6 is connected to a motor 69 via a gear 691 and the like. The motor 69 is fixed to the rear lower part on the right surface of the left plate 52. The gear 691 is supported by the left plate 52 on the left side of the left plate 52. Note that the gear 691 is not shown in Fig. 5. When the motor 69 is driven, it rotates the platen roller 6 via the gear 691.

[0028] As shown in Figures 3 and 4, the center of rotation C of the platen roller 6 passes through the center of the shaft 62 and extends in the left-right direction. As shown in Figure 3, the platen roller 6 rotates around the center of rotation C to transport the medium M in a transport direction. The transport direction is the direction in which the medium M is transported by the platen roller 6 and is perpendicular to the left-right direction. In this embodiment, the transport direction extends diagonally upward toward the rear and diagonally downward toward the front. Hereinafter, the diagonally upward toward the rear of the transport direction will be referred to as the upstream side, and the diagonally downward toward the front will be referred to as the downstream side. A direction perpendicular to the left-right direction and the transport direction will be referred to as the opposing direction. In this embodiment, the opposing direction extends diagonally upward toward the front and diagonally downward toward the rear. Of the opposing directions, the diagonally upward toward the front will be referred to as the first opposing direction, and the diagonally downward toward the rear will be referred to as the second opposing direction.

[0029] 7, the thermal head 7 is provided in the second opposing direction of the platen roller 6. The thermal head 7 is a line head and includes a substrate 71, a mold 72, a plurality of heating elements 73, and a driver IC 74. The substrate 71 extends in the left-right direction and the transport direction so as to be perpendicular to the opposing direction.

[0030] The substrate 71 has a front surface 711 and a back surface 712. The front surface 711 faces a first opposing direction and faces the platen roller 6 in the opposing direction with the transport path R therebetween. The back surface 712 faces the opposite side of the front surface 711 in the opposing direction, i.e., faces a second opposing direction. Note that in this embodiment, "a surface facing a specific direction" does not necessarily mean that the surface extends perpendicular to the specific direction, but rather that the surface extends so as to at least intersect with the specific direction. In this embodiment, the front surface 711 and the back surface 712 extend perpendicular to the opposing direction.

[0031] The mold 72 and the multiple heating elements 73 are provided on the front surface 711 of the substrate 71. The mold 72 protrudes upward from the front surface 711. The height of the mold 72 in the facing direction from the front surface 711 is smaller than the length of the mold 72 in the transport direction. As shown in FIG. 2, the mold 72 extends in the left-right direction from near the left end of the substrate 71 to near the right end. The mold 72 is a base for fixing the heating elements 73 to the substrate 71.

[0032] As shown in FIG. 7, the multiple heating elements 73 are fixed to vertices of the mold 72 in the first opposing direction and are aligned in the left-right direction. An imaginary line V1 passes through the rotation center C and extends in the opposing direction. The multiple heating elements 73 are located downstream in the transport direction of an intersection X between the imaginary line V1 and the front surface 711. The distance in the transport direction between the intersection X and the heating elements 73 is smaller than half the outer diameter of the cylindrical portion 61. The length of the heating elements 73 in the transport direction is smaller than the length of the mold 72 in the transport direction. The multiple heating elements 73 come into contact with the medium M pressed against the front surface 711 by the platen roller 6 and generate heat, thereby printing on the medium M.

[0033] The driver IC 74 protrudes in the first opposing direction from the upstream end of the front surface 711 in the transport direction to an extent that it does not come into contact with the platen roller 6. As shown in Figure 2, the driver IC 74 extends in the left-right direction. The driver IC 74 selectively causes the multiple heating elements 73 to generate heat based on print data.

[0034] As shown in FIGS. 3 and 7 , the heat sink 8 is provided in the second opposing direction of the thermal head 7 and is in contact with the back surface 712 of the substrate 71. In other words, the heat sink 8 supports the substrate 71. The heat sink 8 is plate-shaped and dissipates heat generated by the heat generated by the multiple heating elements 73. The heat sink 8 extends in the left-right direction and the transport direction perpendicular to the opposing direction. In this embodiment, the heat sink 8 extends from near the right side of the left plate 52 to near the left side of the right plate 53. The heat sink 8 extends from upstream of the rotation center C of the platen roller 6 in the transport direction to downstream of the rotation center C of the platen roller 6 in the transport direction. More specifically, the heat sink 8 extends in the transport direction from upstream of the outer circumferential surface of the cylindrical portion 61 in the transport direction to downstream of the outer circumferential surface of the cylindrical portion 61 in the transport direction.

[0035] A shaft 81 is fixed to the rear end of the heat sink 8. The shaft 81 is located upstream of the rotation center C of the platen roller 6 in the transport direction and on the second opposing side of the rotation center C of the platen roller 6. The shaft 81 extends in the left-right direction.

[0036] 5, a support hole 521 is formed in the left plate 52 at a position diagonally below and rearward of the shaft 62. The support hole 521 is rectangular in left side view. The left end 811 of the shaft 81 is disposed within the support hole 521. As a result, the left plate 52 rotatably supports the left end 811 of the shaft 81. This allows the heat sink 8 to swing around the shaft 81.

[0037] As shown in FIG. 6, a support hole 531 is formed in the right plate 53 at a position diagonally below and rearward of the shaft 62. The support hole 531 has an arc shape centered on the rotation center C of the platen roller 6 when viewed from the right side. The upper end of the support hole 531 is located at the same position as the upper end of the support hole 521 shown in FIG. 5. The lower end of the support hole 531 is located lower than the lower end of the support hole 521 shown in FIG. 5. The right end 812 of the shaft 81 is disposed within the support hole 531. Because the lower end of the support hole 531 is located lower than the lower end of the support hole 521, a gap is formed between the right end 812 of the shaft 81 and the lower end of the support hole 521. Therefore, the right end 812 of the shaft 81 is a free end.

[0038] As shown in FIG. 4 , compression coil springs 41, 42, and 43 are provided within the case 2. The compression coil springs 41, 42, and 43 are aligned at equal intervals in the left-right direction and extend in the up-down direction. The compression coil spring 41 is located midway between the center and the right end of the heat sink 8 in the left-right direction. The compression coil spring 42 is located at the center of the heat sink 8 in the left-right direction and to the left of the compression coil spring 41. The compression coil spring 43 is located midway between the center and the left end of the heat sink 8 in the left-right direction and to the left of the compression coil spring 42. The compression coil springs 41, 42, and 43 are attached to shafts 411, 421, and 431, respectively. The shafts 411, 421, and 431 extend upward from the bottom plate 51 to a position below the heat sink 8.

[0039] The compression coil springs 41, 42, and 43 are arranged at the same positions relative to one another in the front-to-rear direction. Therefore, of the compression coil springs 41, 42, and 43, only the compression coil spring 41 is shown in Figure 3. As shown in Figures 3 and 4, the upper ends of the compression coil springs 41, 42, and 43 contact the underside of the heat sink 8 at a location downstream in the transport direction from the rotation center C of the platen roller 6. Therefore, the compression coil springs 41, 42, and 43 bias the heat sink 8 so that the heat sink 8 swings clockwise about the shaft 81 as viewed from the right side.

[0040] According to the above configuration, when the openable cover 23 is opened relative to the opening 221, a cam mechanism (not shown) causes the heat sink 8 to swing counterclockwise around the shaft 81 in a right side view against the biasing forces of the compression coil springs 41, 42, and 43. This causes the thermal head 7 to move away from the platen roller 6 in the second opposing direction.

[0041] When the open-close cover 23 is closed relative to the opening 221, a cam mechanism (not shown) causes the heat sink 8 to swing clockwise around the shaft 81 as viewed from the right side. This causes the thermal head 7 to approach the outer circumferential surface of the cylindrical portion 61 of the platen roller 6. The platen roller 6 is pressed against the thermal head 7 by the biasing forces of the compression coil springs 41, 42, and 43.

[0042] 4, in this embodiment, the pressing load F2 of the compression coil spring 42 is greater than the pressing load F3 of the compression coil spring 43. The pressing load F1 of the compression coil spring 41 is greater than the pressing load F2 of the compression coil spring 42. That is, the multiple compression coil springs 41, 42, and 43 are configured so that the pressing load increases as their positions move further to the right from the left end 811 of the shaft 81 and closer to the right end 812.

[0043] 2, 3, and 7, the printer 1 includes a first defining member 3 and two second defining members 9. The first defining member 3 is provided upstream of the multiple heating elements 73 in the transport direction, and is located below the insertion opening 24 inside the case 2. The first defining member 3 is plate-shaped and extends in the left-right direction, and also extends diagonally downward and forward from the opening edge 223 of the upper cover 22. The first defining member 3 defines the transport path R upstream of the intersection X in the transport direction (see FIG. 7).

[0044] The first defining member 3 includes a contact surface 31. The contact surface 31 faces the first opposing direction. The contact surface 31 extends in the left-right direction so as to intersect with both the conveying direction and the opposing direction, and extends from the first opposing direction to the second opposing direction as it moves from the upstream side to the downstream side in the conveying direction. A downstream end 311 of the contact surface 31 in the conveying direction is located further in the first opposing direction than the driver IC 74 and upstream of the driver IC 74 in the conveying direction.

[0045] The two second defining members 9 are provided on the upper surface of the heat sink 8 downstream of the substrate 71 in the transport direction, and are located behind the discharge port 25 inside the case 2. The two second defining members 9 are the same member and are lined up in the left-right direction (see FIG. 2). The two second defining members 9 define the transport path R downstream of the intersection X in the transport direction (see FIG. 7).

[0046] 2 and 7, the second defining member 9 is trapezoidal in side view and is composed of a fixing surface 91, a downstream surface 92, an upstream surface 93, and a contact surface 94. As shown in Fig. 7, the fixing surface 91 faces the second opposing direction. The fixing surface 91 extends in the left-right direction and the conveying direction so as to be perpendicular to the opposing direction. The fixing surface 91 is fixed to the upper surface of the heat sink 8 via double-sided adhesive tape 89.

[0047] The downstream surface 92 extends in the first opposing direction from the downstream end of the fixing surface 91 in the conveying direction to a position in the first opposing direction further than the front surface 711. The downstream surface 92 faces downstream in the conveying direction and extends in the opposite direction to the left and right direction so as to be perpendicular to the conveying direction.

[0048] The upstream surface 93 extends in the first opposing direction from the upstream end of the fixed surface 91 in the conveying direction to a position in the second opposing direction beyond the front surface 711. The upstream surface 93 faces upstream in the conveying direction and extends in the left-right direction and opposing directions so as to be perpendicular to the conveying direction.

[0049] The contact surface 94 extends from the end of the upstream surface 93 in the first opposing direction to the end of the downstream surface 92 in the first opposing direction. The contact surface 94 faces the first opposing direction. The contact surface 94 extends in the left-right direction so as to intersect both the conveyance direction and the opposing direction, and extends from the second opposing direction to the first opposing direction as it moves from the upstream side to the downstream side in the conveyance direction. An upstream end 942 of the contact surface 94 in the conveyance direction is located further in the second opposing direction than the front surface 711, and a downstream end 941 of the contact surface 94 in the conveyance direction is located further in the first opposing direction than the front surface 711. In this embodiment, the downstream end 941 of the contact surface 94 is located at the same position as the discharge port 25 in the opposing direction, that is, between the opening edge 224 of the upper cover 22 and the lower end 234 of the openable cover 23.

[0050] 2, the second defining member 9 is provided with a plurality of (four in this embodiment) protruding portions 99. The plurality of protruding portions 99 protrude from the downstream surface 92 to the downstream side in the transport direction and are arranged at equal intervals in the left-right direction. The downstream ends of the plurality of protruding portions 99 in the transport direction are located at the same positions as one another in the transport direction and are located upstream in the transport direction of the downstream end of the heat sink 8 in the transport direction.

[0051] The transport path R will be described with reference to FIGS. 3 and 7. As shown in FIG. 3, the transport path R extends diagonally downward and forward from the insertion opening 24 along the contact surface 31 of the first defining member 3. The transport path R extends from the downstream end 311 of the contact surface 31 of the first defining member 3 to between the platen roller 6 and the thermal head 7. The transport path R passes in the first opposing direction further than the driver IC 74. In other words, the first defining member 3 defines the transport path R so that the medium M does not come into contact with the driver IC 74 upstream of the intersection X in the transport direction.

[0052] 7, the transport path R extends from between the platen roller 6 and the thermal head 7 toward the downstream end 941 of the contact surface 94. In other words, the transport path R extends from between the platen roller 6 and the thermal head 7 from the second opposing direction toward the first opposing direction as it moves from the upstream side to the downstream side in the transport direction. The transport path R extends forward from the downstream end 941 of the contact surface 94 to the discharge port 25.

[0053] The approach angle θ1 and the discharge angle θ2 will be described with reference to Figure 7. Hereinafter, the imaginary line passing through the intersection X and the downstream end 311 of the contact surface 31 will be referred to as the "imaginary line V2," and the imaginary line passing through the intersection X and the downstream end 941 of the contact surface 94 will be referred to as the "imaginary line V3." The imaginary line V2 substantially coincides with the path of the conveying path R that is upstream of the intersection X in the conveying direction. The imaginary line V3 substantially coincides with the path of the conveying path R that is downstream of the intersection X in the conveying direction.

[0054] The approach angle θ1 is the angle of the imaginary line V2 with respect to the front surface 711 and is determined by the downstream end 311 of the contact surface 31. The approach angle θ1 is greater than 0° and less than 90°. The discharge angle θ2 is the angle of the imaginary line V3 with respect to the front surface 711 and is determined by the downstream end 941 of the contact surface 94. The discharge angle θ2 is greater than 0° and less than 90°. In this embodiment, the discharge angle θ2 is smaller than the approach angle θ1.

[0055] Hereinafter, when the approach angle θ1 is greater than 0°, it is referred to as "the approach angle θ1 is formed," and when the discharge angle θ2 is greater than 0°, it is referred to as "the discharge angle θ2 is formed." In other words, when the approach angle θ1 or the discharge angle θ2 is not formed, it means that the approach angle θ1 or the discharge angle θ2 is 0°, that is, the virtual line V2 or the virtual line V3 coincides with the front surface 711.

[0056] The printing operation of the printer 1 will be described with reference to Figures 3, 7, and 8. As shown in Figure 3, the user inserts the medium M into the case 2 through the insertion slot 24 along the transport path R. The downstream end of the medium M is positioned between the platen roller 6 and the thermal head 7 in the facing direction. The printer 1 drives the motor 69 shown in Figure 2 to rotate the platen roller 6 clockwise as viewed from the right side. This causes the medium M to be transported along the transport path R from the upstream side to the downstream side in the transport direction. In this case, as shown in Figure 7, the downstream end of the medium M is transported along the substrate 71 toward the downstream side in the transport direction, and then comes into contact with the contact surface 94 between the upstream end 942 and the downstream end 941 in the transport direction. The downstream end of the medium M is transported on the contact surface 94 toward the downstream end 941.

[0057] After passing the downstream end 941 of the contact surface 94, the downstream end of the medium M is discharged from the discharge port 25 along the transport path R. Because the downstream surface 92 extends perpendicular to the transport direction, the downstream end of the medium M does not come into contact with the downstream surface 92 even if it hangs down after passing the downstream end 941 of the contact surface 94. Therefore, the downstream end 941 of the contact surface 94 is located furthest downstream in the transport direction among the portions of the second defining member 9 that come into contact with the medium M.

[0058] As shown in Figure 8, because the cylindrical portion 61 of the platen roller 6 is elastic, when the platen roller 6 is pressed against the thermal head 7 with the medium M therebetween, the pressed portion of the cylindrical portion 61 is deformed so as to be crushed in the first opposing direction. Therefore, the medium M does not come into point contact with the thermal head 7 in the transport direction, but rather comes into surface contact with the thermal head 7 over a width D. The width D indicates the contact range between the thermal head 7 and the medium M in the transport direction. While transporting the medium M along the transport path R, the printer 1 selectively heats the multiple heating elements 73 under control of the driver IC 74. In this way, printing on the medium M is performed.

[0059] Referring to FIG. 2, an example of a method for fixing the second defining member 9 to the heat sink 8 will be described. The worker places the head unit 4 on a jig (not shown). In this case, the pressing surface of the jig extends in the left-right direction at the downstream end position in the transport direction on the upper surface of the heat sink 8. The worker presses the tip of each of the multiple protrusions 99 against the pressing surface of the jig from the upstream side in the transport direction, with the fixing surface 91 facing the upper surface of the heat sink 8 in the facing direction. In this way, the worker fixes the second defining member 9 to the heat sink 8 using double-sided adhesive tape 89 shown in FIG. 7 while pressing the tip of each of the multiple protrusions 99 against the pressing surface of the jig. This allows the worker to fix the second defining member 9 to the heat sink 8 so that the second defining member 9 does not warp in the transport direction. Furthermore, the worker can fix the second defining member 9 to the heat sink 8 so that the second defining member 9 does not shift from its intended fixed position relative to the heat sink 8 in the transport direction.

[0060] As described above, in the above embodiment, the printer 1 forms the approach angle θ1 using the first defining member 3. Because the approach angle θ1 is formed, the printer 1 can prevent the medium M from contacting the convex shape of the substrate 71, such as the driver IC 74, upstream in the transport direction from the intersection X. Therefore, the printer 1 can prevent damage to the medium M or the driver IC 74 due to contact between the medium M and the driver IC 74.

[0061] When the approach angle θ1 is formed, the transport mode of the medium M is as follows. That is, the higher the rigidity of the medium M, the more the cylindrical portion 61 is crushed by the medium M near the upstream side of the intersection X in the transport direction. Therefore, near the upstream side of the intersection X in the transport direction, the higher the rigidity of the medium M, the more the medium M is positioned in a direction away from the substrate 71 in the first opposing direction, and the smaller the width D shown in FIG. 4 becomes. Therefore, if the printer 1 were not equipped with the second defining member 9, the discharge angle θ2 would not be formed, and the higher the rigidity of the medium M, the more likely it is that the position (width D) where the medium M contacts the thermal head 7 will be shifted downstream in the transport direction from the intersection X.

[0062] In the above embodiment, the printer 1 forms the discharge angle θ2 using the second defining member 9. Therefore, the cylindrical portion 61 is also crushed by the medium M near the downstream side of the intersection X in the transport direction. In this way, the cylindrical portion 61 is crushed by the medium M both near the upstream side and near the downstream side in the transport direction around the intersection X. Therefore, even if the rigidity of the medium M is high, the printer 1 can correct the position (width D) where the medium M contacts the thermal head 7 to the upstream side in the transport direction. Therefore, the printer 1 can prevent the position (width D) where the medium M contacts the thermal head 7 from shifting in the transport direction using the second defining member 9. Therefore, the printer 1 can prevent differences in print quality caused by differences in the rigidity of the medium M.

[0063] In the above embodiment, both the substrate 71 and the second determining member 9 are directly fixed to the heat sink 8. Therefore, the printer 1 can suppress variations in the discharge angle θ2 due to variations in the assembly of the second determining member 9.

[0064] In the above embodiment, the upstream end 942 of the contact surface 94 is located in the second opposing direction relative to the front surface 711. Therefore, the downstream end of the medium M is transported along the contact surface 94 without colliding with the upstream surface 93 of the second defining member 9. Therefore, the printer 1 can prevent jams from occurring when the medium M is transported.

[0065] In the above embodiment, the downstream end 941 of the contact surface 94 is located at the most downstream side in the transport direction among the portions of the second defining member 9 that come into contact with the medium M. Therefore, the distance in the transport direction from the position (width D) where the medium M comes into contact with the thermal head 7 to the downstream end 941 of the contact surface 94 is large. Therefore, the printer 1 can suppress deviation of the position (width D) where the medium M comes into contact with the thermal head 7 due to dimensional variations in the opposing direction of the second defining member 9.

[0066] The second determining member 9 is provided on the heat sink 8 as a separate member. Therefore, the printer 1 can adjust the position (width D) where the medium M contacts the thermal head 7 by changing the design of the second determining member 9 without changing the design of the heat sink 8. Therefore, even if the type of medium M supported by each printer 1 model differs, the configuration of the heat sink 8 can be made common regardless of the model.

[0067] In the above embodiment, the protrusions 99 are provided on the second defining member 9. Therefore, for example, when the second defining member 9 is assembled to the heat sink 8, the protrusions 99 serve as a reference, facilitating the assembly work. Furthermore, by pressing the multiple protrusions 99 against a jig to fix the second defining member 9 to the heat sink 8, the worker can suppress warping of the second defining member 9 in the transport direction.

[0068] In the above embodiment, the pressure load F2 of the compression coil spring 42 is greater than the pressure load F3 of the compression coil spring 43, and the pressure load F1 of the compression coil spring 41 is greater than the pressure load F2 of the compression coil spring 42. Therefore, the printer 1 can reduce the difference in the amount of deformation of the heat sink 8 in the opposing direction at each position in the left-right direction. Therefore, the printer 1 can reduce the difference in print quality in the left-right direction. Furthermore, the printer 1 does not need to increase the pressure load of the entire compression coil springs 41, 42, and 43 to reduce the difference in the amount of deformation. Therefore, the driving force of the motor 69 can be reduced, allowing the motor 69 to be made smaller. As a result, the printer 1 can be made smaller overall.

[0069] The larger the discharge angle θ2, the more likely the medium M is to curl downstream of the intersection point X in the transport direction. In the above embodiment, the discharge angle θ2 is smaller than the entry angle θ1. In this way, by reducing the discharge angle θ2, the printer 1 can prevent the medium M from curling downstream of the intersection point X in the transport direction. Furthermore, in the above embodiment, the heating element 73 is located downstream of the intersection point X in the transport direction. Therefore, the printer 1 can tolerate the position (width D) where the medium M contacts the thermal head 7 being shifted downstream of the intersection point X in the transport direction. Therefore, the printer 1 can prevent the medium M from curling downstream of the intersection point X in the transport direction, while also preventing differences in print quality due to differences in the rigidity of the medium M.

[0070] In the above embodiment, the left-right direction of the printer 1 corresponds to the "axial direction" of the present invention. The center of rotation C corresponds to the "center of rotation" of the present invention. The medium M corresponds to the "medium" of the present invention. The platen roller 6 corresponds to the "platen roller" of the present invention. The front surface 711 corresponds to the "front surface" of the present invention. The back surface 712 corresponds to the "back surface" of the present invention. The substrate 71 corresponds to the "substrate" of the present invention. The heating element 73 corresponds to the "heating element" of the present invention. The heat sink 8 corresponds to the "heat sink" of the present invention. The contact surface 31 corresponds to the "first determining portion" of the present invention. The contact surface 94 corresponds to the "contact surface" of the present invention. The second determining member 9 corresponds to the "second determining portion" of the present invention. The protruding portion 99 corresponds to the "protruding portion" of the present invention. The left plate 52 corresponds to the "support portion" of the present invention. The shaft 81 corresponds to the "shaft" of the present invention. The multiple compression coil springs 41, 42, and 43 correspond to the "multiple springs" of the present invention. The discharge angle θ2 corresponds to the "discharge angle" of the present invention. The approach angle θ1 corresponds to the "approach angle" of the present invention.

[0071] The present invention can be modified from the above embodiment. For example, the second defining member 9 may be integrated with the heat sink 8 and form part of the heat sink 8. In other words, the second defining member 9 may be molded integrally with the heat sink 8. In this case, the printer 1 can suppress deviations in the position (width D) where the medium M contacts the thermal head 7 due to variations in the second defining member 9 components and their assembly positions.

[0072] The second defining member 9 may be provided on a member other than the heat sink 8. For example, the second defining member 9 may be provided on the case 2. Specifically, the second defining member 9 may be fixed to the inner surface of the upper cover 22 below the exhaust port 25, or may be configured integrally with the upper cover 22. The second defining member 9 may extend from the left plate 52 to the right plate 53 and be fixed to the left plate 52 and the right plate 53. The second defining member 9 may be fixed to the lower plate 51 and extend upward from the lower plate 51. The second defining member 9 may be configured integrally with the support plate 5.

[0073] The printer 1 may include one or two of the compression coil springs 41, 42, and 43. The printer 1 may also include one or more compression coil springs in addition to the compression coil springs 41, 42, and 43. For example, one of the multiple compression coil springs may be referred to as the "first spring," and the compression coil spring located to the left of the first spring may be referred to as the "second spring." In this case, it is preferable that the multiple compression coil springs are configured so that the compression load of the first spring is greater than the compression load of the second spring. The multiple compression coil springs may also be configured so that the compression load of the first spring is greater than the compression load of the second spring in the relationship between the compression loads of any pair of compression coil springs. For example, when the pressing load F2 of the compression coil spring 42 is greater than the pressing load F3 of the compression coil spring 43, the pressing load F1 of the compression coil spring 41 may be equal to or less than the pressing load F2 of the compression coil spring 42. The compression loads of the multiple compression coil springs may all be the same, or may all be configured such that the pressing load of the second spring is greater than the pressing load of the first spring.

[0074] The printer 1 may include a spring such as a tension coil spring, a leaf spring, or a disc spring instead of the compression coil springs 41, 42, and 43. For example, the tension coil spring may be provided in the first opposing direction with respect to the heat sink 8. The printer 1 may also use an elastic body such as sponge or rubber instead of the compression coil springs 41, 42, and 43 to press the heat sink 8 in the first opposing direction.

[0075] The printer 1 may omit the first defining member 3. In this case, the insertion port 24 may function as the first defining member 3. In other words, the insertion port 24 may define a portion of the conveying path R upstream of the intersection point X in the conveying direction.

[0076] The printer 1 may include one second defining member 9. The printer 1 may include three or more second defining members 9. The multiple second defining members 9 may be arranged at predetermined intervals in the left-right direction.

[0077] The number of protruding portions 99 in the second defining member 9 may be one or two, or may be four or more. The protruding portion 99 may protrude from the upstream surface 93 of the second defining member 9 to the upstream side in the transport direction. In this case, for example, an operator can fix the second defining member 9 to the upper surface of the heat sink 8 while pressing the protruding portion 99 against the downstream end of the substrate 71 in the transport direction from the downstream side in the transport direction.

[0078] The discharge angle θ2 may be the same as the approach angle θ1, or may be greater than the approach angle θ1. By setting the discharge angle θ2 to the same magnitude as the approach angle θ1, the printer 1 can align the center of the conveyance direction of the position (width D) where the medium M contacts the thermal head 7 with the intersection point X or move it closer to the intersection point X. Therefore, the printer 1 can further reduce differences in print quality caused by differences in the rigidity of the medium M.

[0079] The number of heating elements 73 may be one. Multiple heating elements 73 may be disposed at the same position as intersection X in the transport direction, or may be disposed upstream of intersection X in the transport direction. The multiple heating elements 73 only need to be disposed near intersection X in the left-right direction so as to be able to come into contact with medium M when medium M is pressed against the thermal head 7 by the platen roller 6.

[0080] The method of fixing the second defining member 9 to the heat sink 8 is not limited to the above embodiment. For example, a jig does not have to be used. The second defining member 9 may be fixed to the heat sink 8 via an adhesive, or may be fixed to the heat sink 8 with screws or the like.

[0081] The downstream end 311 of the contact surface 31 may be located downstream in the transport direction from the driver IC 74, as long as it is located upstream in the transport direction from the plurality of heating elements 73. In this case, the printer 1 can further prevent the medium M from contacting the driver IC 74.

[0082] The shape of the second defining member 9 in a side view is not limited to a trapezoidal shape and may be other polygonal shapes, such as a quadrilateral or a triangle. For example, when the second defining member 9 is triangular in a side view, the upstream surface 93 may be omitted. In this case, the upstream end 942 of the contact surface 94 may be connected to the upstream end of the fixing surface 91 in the conveying direction. The downstream surface 92 may extend downstream in the conveying direction from the downstream end 941 of the contact surface 94 toward the second opposing direction. In this case, if the downstream end of the medium M sags after passing the downstream end 941 of the contact surface 94, it contacts the downstream surface 92. In this case, the downstream end of the downstream surface 92 in the conveying direction is located at the portion of the second defining member 9 with which the medium M comes into contact, that is, the most downstream of the contact surface 94 and the downstream surface 92 in the conveying direction. The downstream surface 92 may extend upstream in the conveying direction from the downstream end 941 of the contact surface 94 toward the second opposing direction. The contact surface 94 may be curved to be concave or convex in a side view. The downstream end 941 of the contact surface 94 may be located in the first opposing direction relative to the discharge port 25, or may be located in the second opposing direction. [Explanation of symbols]

[0083] 1. Printer 3. First prescribed member 6 Platen roller 8 Heatsink 9 Second prescribed member 31 Contact surface 41, 42, 43 Compression coil spring 52 Left board 71 PCB 73 Heating element 81 axes 94 Contact surface 99 Protrusion 711 Front 712 Back side θ1 Approach angle θ2 Discharge angle F1, F2, F3 pressing load

Claims

1. a platen roller that rotates about a rotation center extending in an axial direction to transport a medium in a transport direction that intersects with the axial direction; a substrate having a front surface facing the platen roller across a medium transport path in an opposing direction intersecting the axial direction and the transport direction, and a back surface facing the opposite side to the front surface; a heating element provided on the front surface of the substrate, in contact with the medium pressed against the front surface by the platen roller, and performing printing on the medium; a heat sink in contact with the rear surface of the substrate; a first defining portion that is provided upstream of the heat generating element in the transport direction and defines the transport path, the first defining portion being in contact with the medium at a position in a first opposing direction from the front surface toward the platen roller in the opposing direction, the first defining portion being located upstream of the heat generating element in the transport direction and defining the transport path, the first defining portion being in contact with the medium at a position in a first opposing direction from the front surface toward the platen roller in the opposing direction, the first defining portion being located upstream of the heat generating element in the transport direction and A printer comprising: a second defining portion that is provided on the heat sink downstream of the substrate in the transport direction and defines the transport path, the second defining portion facing the first opposing direction and extending from a second opposing direction opposite to the first opposing direction as it moves from the upstream side to the downstream side in the transport direction, the second defining portion having a contact surface with which the medium comes into contact; an upstream end of the contact surface in the conveying direction is located in the second opposing direction relative to the front surface; a downstream end of the contact surface in the conveying direction is located in the first opposing direction relative to the front surface, The second defining portion is a member provided on the heat sink as a separate member from the heat sink; And, it is fixed directly to the heat sink. A printer characterized by:

2. a downstream end of the contact surface in the transport direction is located on the most downstream side in the transport direction among the portions of the second defining portion that come into contact with the medium; 2. The printer according to claim 1, wherein:

3. The second defining portion is provided with a protruding portion that protrudes from an upstream end of the second defining portion in the conveying direction to the upstream side in the conveying direction, or from a downstream end of the second defining portion in the conveying direction to the downstream side in the conveying direction.

3. The printer according to claim 1 or 2, wherein:

4. A support part; a shaft extending in the axial direction and fixed to the heat sink, one end of the shaft in the axial direction being rotatably supported by the support portion and the other end of the shaft in the axial direction being a free end; a plurality of springs arranged in the axial direction and pressing the heat sink in the first opposing direction; Equipped with The plurality of springs are all configured such that the pressing load of a first spring is greater than the pressing load of a second spring located on one side of the first spring in the axial direction.

4. The printer according to claim 1, wherein:

5. a discharge angle, with respect to the front surface, of a virtual line passing through an intersection point between a virtual line passing through the rotation center and extending in the opposing direction and the front surface, and a downstream end of the contact surface in the conveying direction, is smaller than an approach angle, with respect to the front surface, of a virtual line passing through the intersection point and the downstream end of the first defining portion in the conveying direction, The heat generating element is located downstream of the intersection in the transport direction.

5. The printer according to claim 1, wherein:

Images