Thermal head and thermal printer

Abstract

This thermal head comprises a substrate and a connector that fits to an end part of the substrate. The connector has a plurality of connector pins which are arranged to be spaced apart in a first direction of the substrate and which fit to the end part of the substrate, and a housing which houses the plurality of connector pins. The housing has a side wall that is positioned further outward in the first direction than the plurality of connector pins and that faces a lower surface of the substrate at an end face, and an arm part that rises up from an end surface of the side wall in a region other than a region facing the lower surface of the substrate, and that extends along an upper surface of the substrate in a second direction which intersects the first direction.

Description

Thermal heads and thermal printers

[0001] The disclosed embodiments relate to a thermal head and a thermal printer.

[0002] 2. Description of the Related Art Various thermal heads have been proposed for use in printing devices such as facsimiles and video printers. For example, a thermal head having a structure in which a connector is fitted into a substrate is known (see, for example, Patent Documents 1 and 2).

[0003] International Publication No. 2016 / 031740 Japanese Patent Application Laid-Open No. 2021-84426

[0004] A thermal head according to one aspect of the present invention includes a substrate and a connector that is fitted to an end of the substrate. The connector has a plurality of connector pins that are arranged at intervals in a first direction of the substrate and are fitted to the end of the substrate, and a housing that accommodates the plurality of connector pins. The housing is positioned outward in the first direction from the plurality of connector pins and has a sidewall that faces the underside of the substrate at its end surface, and an arm that rises from the end surface of the sidewall except for a region facing the underside of the substrate and extends along the upper surface of the substrate in a second direction that intersects the first direction.

[0005] FIG. 1 is a diagram schematically illustrating the configuration of a thermal head according to an embodiment. FIG. 2 is a plan view showing the schematic configuration of the thermal head shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a perspective view showing the schematic configuration of a connector that constitutes a thermal head according to an embodiment. FIG. 5 is a perspective view showing the schematic configuration of a portion of a connector that constitutes a thermal head according to an embodiment. FIG. 6 is a front view showing the schematic configuration of a connector that constitutes a thermal head according to an embodiment. FIG. 7 is a rear view showing the schematic configuration of a connector that constitutes a thermal head according to an embodiment. FIG. 8 is a partial cross-sectional view of a substrate end and arm portion according to an embodiment, viewed from the side. FIG. 9 is a schematic diagram showing a thermal printer according to an embodiment.

[0006] Hereinafter, a detailed description will be given of a thermal head and a thermal printer according to the present disclosure (hereinafter referred to as an "embodiment") with reference to the drawings. Note that the thermal head and the thermal printer according to the present disclosure are not limited to the embodiment.

[0007] Furthermore, in the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0008] <Configuration of Thermal Head> FIG. 1 is a diagram schematically illustrating the configuration of a thermal head according to an embodiment. In the following description, a left-handed XYZ Cartesian coordinate system is set, and the positional relationship of each part is sometimes described with reference to this XYZ Cartesian coordinate system. One direction within a horizontal plane is defined as the X-axis direction, a direction perpendicular to the X-axis direction within the horizontal plane is defined as the Y-axis direction, and a direction perpendicular to both the X-axis direction and the Y-axis direction is defined as the Z-axis direction. The XY plane including the X-axis and Y-axis is parallel to the horizontal plane. In the following description, the surface where the substrate 7 of the thermal head 1 is mated with the connector 31 may be parallel to the horizontal plane. The Z-axis direction, which is perpendicular to the XY plane, is the vertical direction. In the following description, the direction perpendicular to the surface where the substrate 7 of the thermal head 1 is mated with the connector 31 may be parallel to the Z-axis.

[0009] The thermal head 1 shown in FIG. 1 includes a head substrate 3 , a heat sink 90 , an adhesive member 14 , a connector 31 , and a sealing member 12 .

[0010] The head substrate 3 is formed in a substantially rectangular parallelepiped shape and is placed on a heat sink 90 via an adhesive member 14. The components that make up the thermal head 1 are provided on a substrate 7 of the head substrate 3. The head substrate 3 applies a voltage in accordance with an electrical signal supplied from the outside via a connector 31, causing the heating element 9 to heat up and print on the recording medium. The components that make up the thermal head 1 will be described later using Figures 2 and 3, and the recording medium will be described later using Figure 9.

[0011] The connector 31 is joined to the head base 3 by a sealing member 12, electrically connecting the head base 3 to the outside. An adhesive member 14 bonds the head base 3 to a heat sink 90. ​​The heat sink 90 has a rectangular parallelepiped shape and is provided to dissipate heat from the head base 3. The heat sink 90 is made of a metal material such as copper, iron, or aluminum, and has the function of dissipating heat generated in the heat-generating portion 9 of the head base 3 that does not contribute to printing.

[0012] Next, the components constituting the thermal head 1 will be further described with reference to Figures 2 and 3. Figure 2 is a plan view showing the schematic configuration of the thermal head 1 shown in Figure 1, and Figure 3 is a cross-sectional view taken along line III-III in Figure 2.

[0013] The thermal head 1 further includes a substrate 7, a heat storage layer 13, a resistive layer 15, a common electrode 17, an individual electrode 19, a first connection electrode 21, a ground electrode 4, a connection terminal 2, a second connection electrode 26, a driving IC 11, a hard coat 29, a protective layer 25, and a coating layer 27.

[0014] The substrate 7 has a rectangular shape in a plan view and includes a first long side 7a, a second long side 7b, a first short side 7c, a second short side 7d, a side surface 7e, a first surface 7f, and a second surface 7g. The substrate 7 is made of, for example, an electrically insulating material such as alumina ceramics or a semiconductor material such as single crystal silicon. Hereinafter, for convenience of explanation, the first surface 7f may be referred to as the "top surface" and the second surface 7g may be referred to as the "bottom surface." Similarly, with respect to the side surface 7e, the first surface 7f side may be referred to as the "top" or "upper" and the second surface 7g side may be referred to as the "bottom" or "lower."

[0015] A connector 31 is provided on the side surface 7e of the substrate 7. The connector 31 is fixed to the side surface 7e by connector pins 8, a bonding member 23, and a sealing member 12. The bonding member 23 is a conductive member and is disposed between the connection terminals 2 and the connector pins 8. Examples of the bonding member 23 include solder and anisotropic conductive paste. Note that a metal plating layer (pad layer) made of Ni, Au, or Pd may be located between the bonding member 23 and the connection terminals 2. Note that the bonding member 23 is not necessarily provided.

[0016] The connector 31 also has a plurality of connector pins 8 and a housing 10 that houses the plurality of connector pins 8. One of the two ends of the plurality of connector pins 8 is exposed to the outside of the housing 10, and the other of the two ends is housed inside the housing 10. The plurality of connector pins 8 are electrically connected to the connection terminals 2 of the head base 3, and are electrically connected to various electrodes of the head base 3.

[0017] The sealing member 12 is located on the first surface 7f side of the substrate 7. The sealing member 12 is located so as to seal the connector pins 8 and the various electrodes.

[0018] The sealing member 12 is positioned so as to prevent the connection terminals 2 and the connector pins 8 from being exposed to the outside. The sealing member 12 can be made of, for example, an epoxy-based thermosetting resin, an ultraviolet-curable resin, or a visible-light-curable resin.

[0019] The adhesive member 14 is disposed on the heat sink 90 and bonds the second surface 7g of the substrate 7 to the heat sink 90. ​​Examples of the adhesive member 14 include double-sided tape or a resin adhesive.

[0020] The heat storage layer 13 is a so-called glaze layer, and is located over the entire first surface 7f of the substrate 7. A portion of the heat storage layer 13 protrudes upward from the substrate 7, and has a substantially semi-elliptical cross section. It is practically preferable that the heat storage layer 13 be provided at a height from the substrate 7 of, for example, 15 to 90 μm.

[0021] The heat storage layer 13 is made of a material such as glass with low thermal conductivity, and has the function of temporarily storing a portion of the heat generated by the heat generating portion 9. Therefore, the heat storage layer 13 can shorten the time required to raise the temperature of the heat generating portion 9. As a result, it functions to improve the thermal response characteristics of the thermal head 1. The heat storage layer 13 is formed, for example, by applying a predetermined glass paste, obtained by mixing glass powder with an appropriate organic solvent, to the upper surface of the substrate 7 by screen printing or the like, and then firing the paste.

[0022] The resistive layer 15 is located on the substrate 7 and the heat storage layer 13. Various electrodes (common electrode 17, individual electrodes 19, ground electrode 4, first connection electrode 21, and second connection electrode 26) that constitute the head substrate 3 are located on the resistive layer 15. The resistive layer 15 is patterned to the same shapes as the various electrodes that constitute the head substrate 3. Between the common electrode 17 and the individual electrodes 19, there is an exposed area where the resistive layer 15 is exposed. These exposed areas constitute each element of the heat generating section 9. The multiple elements that constitute the heat generating section 9 are arranged on the heat storage layer 13 along the longitudinal direction of the substrate 7. Furthermore, the heat generating section 9 is arranged at a predetermined distance from the first short side 7c and the second short side 7d that are along the short direction of the first surface 7f of the substrate 7.

[0023] The heat generating section 9 generates heat in response to an externally supplied electrical signal, and has the function of thermally transferring ink from an ink sheet (not shown) to a recording medium (not shown). The multiple elements that make up the heat generating section 9 are arranged at a density of, for example, 100 dpi to 2400 dpi (dots per inch). The arrangement of the resistance layer 15 that makes up the heat generating section 9 is not limited to that shown in the figure, and it may be provided, for example, only between the common electrode 17 and the individual electrode 19.

[0024] The heat generating portion 9 is composed of a resistive layer 15 having a relatively high electrical resistance, such as a TaN-based, TaSiO-based, TaSiNO-based, TiSiO-based, TiSiCO-based, or NbSiO-based material, a common electrode 17 made of a metal such as Al or Cu, and individual electrodes 19. When a voltage is applied to the resistive layer 15 disposed between the common electrode 17 and the individual electrodes 19, the resistive layer 15 generates heat due to Joule heating.

[0025] The common electrode 17 includes main wiring portions 17a and 17d, a sub-wiring portion 17b, and a lead portion 17c. The common electrode 17 electrically connects the multiple elements that make up the heat generating portion 9 to the connector 31. The main wiring portion 17a extends along the first long side 7a of the substrate 7. The sub-wiring portion 17b extends along each of the first short side 7c and the second short side 7d of the substrate 7. The lead portions 17c extend individually from the main wiring portion 17a toward each of the multiple elements that make up the heat generating portion 9. The main wiring portion 17d extends along the second long side 7b of the substrate 7.

[0026] The individual electrodes 19 electrically connect the heat generating section 9 and the driving IC 11. Specifically, the elements constituting the heat generating section 9 are divided into a plurality of groups. The individual electrodes 19 electrically connect each element of the heat generating section 9 constituting each group to the driving IC 11 corresponding to each group. The driving IC 11 will be described later.

[0027] The first connection electrodes 21 electrically connect the driving ICs 11 and the connectors 31. A plurality of first connection electrodes 21 are connected to each driving IC 11, and each of these first connection electrodes 21 is composed of one or more wirings having different functions.

[0028] The ground electrode 4 is surrounded by the individual electrodes 19, the first connection electrode 21, and the main wiring portion 17d of the common electrode 17. The ground electrode 4 is maintained at a ground potential of 0 to 1V.

[0029] Furthermore, a metal plating layer (pad layer) for soldering the connector 31 to the substrate 7 (connection terminal 2) may be provided on the upper portion of each electrode layer of the common electrode 17, the individual electrodes 19, the first connection electrode 21, and the ground electrode 4. The metal plating layer (pad layer) is made of a metal material such as Au. The metal plating layer (pad layer) may be made of Ni or Pd in ​​addition to Au. The solder joint between the connector 31 and the substrate 7 (connection terminal 2) is covered with a sealing member 12.

[0030] The connection terminals 2 are provided on the second long side 7b of the substrate 7, and connect the common electrode 17, the individual electrodes 19, the first connection electrode 21, and the ground electrode 4 to the connector 31. The connection terminals 2 are provided to correspond to the connector pins 8, and when the connector 31 is connected, the connector pins 8 and the connection terminals 2 are connected to each other so as to be electrically independent of each other. A protective resin layer (not shown) is provided on the upper surface of the connection terminals 2 (the surface in contact with the connector pins 8).

[0031] The second connection electrodes 26 electrically connect adjacent driving ICs 11. The second connection electrodes 26 are provided to correspond to the first connection electrodes 21, respectively, and transmit various signals to the adjacent driving ICs 11.

[0032] The resistance layer 15 and the various electrodes can be formed, for example, as follows. The materials constituting each layer are sequentially stacked on the heat storage layer 13 using a thin-film forming technique such as sputtering. The stack is then processed into a predetermined pattern using conventional photoetching or the like. In this way, the various electrodes are electrically connected to the heat generating portion 9. The thickness of the various electrodes can be, for example, 0.1 to 1 μm.

[0033] The driving IC 11 is disposed, for example, on the first surface 7f side of the substrate 7. The multiple driving ICs 11 are disposed along the arrangement direction of the heat generating portion 9 so as to correspond to each element of the heat generating portion 9 assigned to each driving IC 11. The driving ICs 11 are connected to ends of the individual electrodes 19 and ends of the first connection electrodes 21, and supply power to the heat generating portion 9 to cause each element of the heat generating portion 9 to individually generate heat in accordance with an electrical signal supplied from the outside. The driving IC 11 can be, for example, a switching member having multiple switching elements therein.

[0034] The protective layer 25 is disposed on the heat storage layer 13 formed on the upper surface of the substrate 7, and is a member that covers the heat generating portion 9, the common electrode 17, and the individual electrodes 19. More specifically, the protective layer 25 is provided so as to cover the edges of the substrate 7, i.e., the first long side 7a, the first short side 7c, and the second short side 7d of the substrate 7, and a portion of the individual electrodes 19.

[0035] The protective layer 25 protects the areas covered by the heat generating portion 9, the common electrode 17, and the individual electrodes 19 from corrosion due to adhesion of moisture contained in the atmosphere, or from abrasion due to contact with the recording medium to be printed. ２ The protective layer 25 can be formed using SiON, SiC, diamond-like carbon, etc. The protective layer 25 may be configured as a single layer or multiple layers.

[0036] The covering layer 27 is provided on the substrate 7 so as to partially cover the common electrode 17, the individual electrodes 19, the first connection electrodes 21, and the protective layer 25. The covering layer 27 protects the covered area from oxidation due to contact with the atmosphere or corrosion due to the adhesion of moisture contained in the atmosphere. The covering layer 27 also tightly contacts the protective layer 25 and covers the edges of the protective layer 25, thereby reducing the occurrence of problems such as the protective layer 25 peeling off from the objects to be protected, such as the heat generating portion 9 or various electrodes. The covering layer 27 is made of a resin material such as an epoxy resin, a polyimide resin, or a silicone resin. All of these resin materials have fluidity before they are hardened to form the covering layer 27.

[0037] The covering layer 27 has openings (not shown) for exposing the individual electrodes 19 connected to the driving IC 11 and the first connection electrodes 21. These wirings are connected to the driving IC 11 through the openings. The driving IC 11 is also sealed with a hard coat 29 while connected to the individual electrodes 19 and the first connection electrodes 21. This protects the driving IC 11 and the connections between the driving IC 11 and these electrodes. The hard coat 29 is made of a resin such as epoxy resin or silicone resin.

[0038] <Configuration of Connector> The configuration of the connector 31 will be described using Figures 4 to 7. Figure 4 is a perspective view showing a schematic configuration of the connector 31 that constitutes the thermal head 1 according to the embodiment. Figure 5 is a perspective view showing a schematic configuration of a portion of the connector 31 that constitutes the thermal head 1 according to the embodiment. Figure 6 is a front view showing a schematic configuration of the connector 31 that constitutes the thermal head 1 according to the embodiment. Figure 7 is a rear view showing a schematic configuration of the connector 31 that constitutes the thermal head 1 according to the embodiment.

[0039] As shown in FIGS. 4 to 7, the connector 31 includes a plurality of connector pins 8 and a housing 10 that accommodates the plurality of connector pins 8.

[0040] The connector pins 8 are made of a conductive metal or alloy and include a movable pin 8a, a fixed pin 8b, a connecting pin 8c, and a pull-out pin 8d.

[0041] The connector pins 8 are configured such that a movable pin 8a and a fixed pin 8b are connected by a connecting pin 8c, and a pull-out pin 8d is pulled out from the end of the fixed pin 8b opposite the connecting pin 8c. The movable pin 8a, the fixed pin 8b, the connecting pin 8c, and the pull-out pin 8d are integrally formed, forming an S-shape as a whole. The multiple connector pins 8 are arranged at intervals in the longitudinal direction of the substrate 7 (first direction, here the X-axis direction). The connector pins 8 are spaced apart from each other by a predetermined distance. Adjacent connector pins 8 are electrically insulated. The longitudinal direction of the substrate 7 may be parallel to the main scanning direction, which is perpendicular to the transport direction S (see FIG. 9 ).

[0042] The movable pin 8a is located above the substrate 7 of the head base 3 and is arranged on the connection terminal 2. The fixed pin 8b is located below the substrate 7 of the head base 3, and the movable pin 8a and the fixed pin 8b sandwich the substrate 7. The fixed pin 8b is arranged to protrude further from the connecting pin 8c than the movable pin 8a.

[0043] The connecting pin 8c connects the movable pin 8a and the fixed pin 8b, and is positioned so as to extend in the thickness direction of the substrate 7. The pull-out pin 8d extends downward from the end of the fixed pin 8b opposite the connecting pin 8c, is bent and pulled out in a direction away from the head base 3, and is joined to the housing 10. The connector 31 and the head base 3 are joined electrically and mechanically by inserting the substrate 7 of the head base 3 between the movable pin 8a and the fixed pin 8b.

[0044] The housing 10 has a rod shape that extends in the longitudinal direction (e.g., the X-axis direction) of the substrate 7, and has the function of accommodating each of the connector pins 8 in an electrically independent state. An opening is formed on the back surface of the housing 10, and a socket connected to an external cable is inserted into this opening, and electricity (driving power, driving signals, etc.) is supplied to the head base 3 by attaching and detaching the external cable, etc.

[0045] The housing 10 includes a rod-shaped main body 10a, a sidewall 10b, and an arm 10c. The main body 10a has multiple grooves formed at intervals in the longitudinal direction of the board 7 (e.g., the X-axis direction), and multiple connector pins 8 are fixed to the multiple grooves. The main body 10a also has an opening on the side of the connector pin 8 where the lead pin 8d is located.

[0046] The side wall 10b is located further outward in the longitudinal direction (e.g., the X-axis direction) of the substrate 7 than the multiple connector pins 8. The upper end surface 10b1 of the side wall 10b faces the underside of the substrate 7. Here, "facing" means that the upper end surface 10b1 of the side wall 10b is in direct contact with the underside of the substrate 7 or is located away from the underside of the substrate 7.

[0047] The arm portion 10c rises from the upper end surface 10b1 of the side wall 10b other than the area facing the underside of the substrate 7, and extends along the upper surface of the substrate 7 in a second direction (e.g., the Y-axis direction) that intersects the longitudinal direction of the substrate 7.

[0048] The connector 31 is configured such that the end of the movable pin 8a opposite the connecting pin 8c is not constrained, so that when the board 7 is fitted into the connector 31, for example, the movable pin 8a deforms upward (positive direction of the Z axis), thereby fitting the board 7 and the connector pin 8 together.

[0049] When the board 7 and the connector 31 are mated, rattles of the board 7 may occur in a direction perpendicular to the mating surface of the board 7 and the connector 31 (for example, a direction parallel to the Z-axis direction). If rattles of the board 7 occur, the stress applied from the board 7 to the connector pins 8 increases, which may cause damage to the connector 31.

[0050] In contrast, in the connector 31 according to the embodiment, the housing 10 has a sidewall 10b at its upper end surface 10b1 that faces the underside of the board 7, and an arm 10c that rises from the upper end surface 10b1 and extends in the second direction along the upper surface of the board 7. That is, the board 7 is sandwiched between the sidewall 10b and the arm 10c of the housing 10 in the thickness direction of the board 7. As a result, when the board 7 and the connector 31 are mated, the sidewall 10b or the arm 10c of the housing 10 abuts against the board 7, limiting the degree of rattle of the board 7. As a result, the stress applied from the board 7 to the connector pins 8 can be reduced, thereby reducing the possibility of damage to the connector 31.

[0051] 6, the arm 10c has a width along the longitudinal direction of the board 7 (e.g., the X-axis direction) greater than that of each of the connector pins 8. The spacing between the arms 10c arranged at both ends of the connector 31 is greater than the length of the arrangement of the connector pins 8. That is, the arm 10c is located outside the arrangement of the connector pins 8 in the longitudinal direction of the board 7. This allows the side wall 10b or arm 10c of the housing 10 to abut against the board 7 over a wider area when the board 7 and the connector 31 are mated, thereby more stably limiting the degree of wobble of the board 7. As a result, the possibility of damage to the connector 31 can be further reduced.

[0052] <Configuration of Board End and Arm> Next, the configuration of the board end that is fitted into the connector 31 and the arm 10c of the connector 31 will be described in more detail with reference to Fig. 8. Fig. 8 is a partial cross-sectional side view of the board end and the arm 10c according to the embodiment.

[0053] As shown in FIG. 8 , the arm 10c has a raised surface 10c1. The raised surface 10c1 is raised from a portion 10P extending in the second direction (e.g., the Y-axis direction) of the arm 10c toward the recording medium P (see FIG. 9 ) being transported above the portion 10P. The raised surface 10c1 is the portion of the surface of the arm 10c facing the recording medium P that is the shortest distance to the recording medium P. The raised surface 10c1 is rounded. This reduces the frictional resistance when the recording medium P comes into contact with the arm 10c compared to when the raised surface 10c1 is not rounded. This reduces the possibility of printing scratches on the recording medium P due to contact with the arm 10c.

[0054] The arm 10c also has a first inclined surface 10c2. The first inclined surface 10c2 is continuous with the raised surface 10c1 and decreases in height toward the tip of the portion 10P in the second direction (e.g., the Y-axis direction). This reduces frictional resistance when the recording medium P comes into contact with the arm 10c. This reduces the possibility of printing scratches on the recording medium P due to contact with the arm 10c.

[0055] The arm 10c also has a second inclined surface 10c3. The second inclined surface 10c3 is continuous with the raised surface 10c1 and decreases in height toward the side opposite the tip of the portion 10P in the second direction (e.g., the Y-axis direction). This reduces frictional resistance when the recording medium P comes into contact with the arm 10c. This reduces the possibility of printing scratches on the recording medium P due to contact with the arm 10c.

[0056] Furthermore, arm portion 10c may have a height from substrate 7 higher than the connection portions of the connector pins 8 with the electrodes (here, ground electrode 4) in a side view. That is, height h2 of a portion of arm portion 10c that overlaps with the connection portions of the connector pins 8 with the electrodes in a side view may be higher than height h1 of the connection portions of the connector pins 8 with the electrodes. This makes it possible to prevent sealing member 12 that seals the connection portions of the connector pins 8 with the electrodes from climbing up onto arm portion 10c.

[0057] Furthermore, the sealing member 12 may have a portion 12a that fills a gap between the upper surface of the substrate 7 and the arm portion 10c, the gap being spaced apart in a direction perpendicular to the mating direction d (e.g., the Y-axis direction) when the substrate 7 and the multiple connector pins 8 are mated. That is, the portion 12a of the sealing member 12 may fill a space formed in a direction perpendicular to the mating surface of the substrate 7 and the connector 31 (e.g., a direction parallel to the Z-axis direction). This bonds the arm portion 10c to the substrate 7 via the sealing member 12, further limiting the degree of wobble of the substrate 7. As a result, stress applied to the connector pins 8 from the substrate 7 can be dispersed to the arm portion 10c, further reducing the possibility of damage to the connector 31.

[0058] The sealing member 12 may also be lower in height than the arm portion 10c. That is, the sealing member 12 may be lower in height than the top of the raised surface 10c1 of the surface of the arm portion 10c facing the recording medium P, which is the portion of the surface that faces the recording medium P and has the shortest distance to the recording medium P. In this case, the sealing member 12 may be lower in height than the first inclined surface 10c2. The sealing member 12 may also be lower in height than the second inclined surface 10c3. This reduces the possibility that the sealing member 12 and the recording medium P will come into contact with each other, causing stress to be applied to the connector pins 8 from the recording medium P via the sealing member 12. As a result, the possibility of damage to the connector 31 can be further reduced.

[0059] <Thermal Printer> Next, a thermal printer according to an embodiment will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing a thermal printer 100 according to an embodiment.

[0060] 9 includes the thermal head 1, a transport mechanism 40, a platen roller 50, a power supply unit 60, and a control unit 70. The thermal head 1 is attached to a mounting surface 80a of a mounting member 80 provided on a housing (not shown) of the thermal printer 100. The thermal head 1 is attached to the mounting member 80 so as to be aligned along the main scanning direction perpendicular to the transport direction S of the recording medium P.

[0061] The transport mechanism 40 includes a drive unit (not shown) and transport rollers 43, 45, 47, and 49. The transport mechanism 40 transports a recording medium P, such as thermal paper or image receiving paper onto which ink is transferred, along the transport direction S indicated by the arrow, onto the protective layer 25 disposed on the heat generating portion 9 of the thermal head 1. The drive unit has a function of driving the transport rollers 43, 45, 47, and 49, and may be, for example, a motor. The transport rollers 43, 45, 47, and 49 may each have a cylindrical shaft 43a, 45a, 47a, or 49a made of a metal such as stainless steel, covered with an elastic member 43b, 45b, 47b, or 49b made of butadiene rubber or the like. When the recording medium P is, for example, image receiving paper onto which ink is transferred, an ink film (not shown) may be transported between the recording medium P and the heat generating portion 9 of the thermal head 1 together with the recording medium P.

[0062] The platen roller 50 has the function of pressing the recording medium P onto the protective layer 25 located above the heat generating portion 9 of the thermal head 1. The platen roller 50 is arranged to extend along the main scanning direction, and both ends are supported and fixed so that it can rotate while pressing the recording medium P onto the heat generating portion 9. The platen roller 50 can be, for example, a cylindrical shaft 50a made of a metal such as stainless steel, covered with an elastic member 50b made of butadiene rubber or the like.

[0063] As described above, the power supply device 60 has a function of supplying a current for generating heat in the heat generating portion 9 of the thermal head 1 and a current for operating the driving IC 11. The control device 70 has a function of supplying a control signal to the driving IC 11 for controlling the operation of the driving IC 11 in order to selectively generate heat in the heat generating portion 9 of the thermal head 1.

[0064] In the thermal printer 100, the platen roller 50 presses the recording medium P onto the heat generating portion 9 of the thermal head 1, while the conveying mechanism 40 conveys the recording medium P onto the heat generating portion 9 along the conveying direction S. Then, while conveying the recording medium P so that it passes over the heat generating portion 9, the power supply unit 60 and the control unit 70 selectively cause the heat generating portion 9 to generate heat, thereby performing a predetermined print on the recording medium P. Note that if the recording medium P is image receiving paper or the like, printing on the recording medium P is performed by thermally transferring ink from an ink film (not shown) conveyed together with the recording medium P onto the recording medium P.

[0065] <Modifications> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0066] For example, in the above embodiment, an example has been described in which, when the board 7 and the multiple connector pins 8 are mated, a gap is formed between the upper surface of the board 7 and the arm 10c in a direction perpendicular to the mating direction d (e.g., the Y-axis direction) (see FIG. 8, etc.). However, the disclosed technology is not limited to this, and the arm 10c may be in direct contact with the upper surface of the board 7. In this case, the arm 10c may sandwich the board 7 between itself and the upper end surface 10b1 of the side wall 10b.

[0067] Further advantages and alternative embodiments may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0068] REFERENCE SIGNS LIST 1 thermal head 2 connection terminal 3 head base 4 ground electrode 7 substrate 8 connector pin 9 heat generating portion 10 housing 10a main body 10b side wall 10b1 upper end surface 10c arm portion 10c1 raised surface 10c2 first inclined surface 10c3 second inclined surface 10P portion 12 sealing member 12a section 13 heat storage layer 14 adhesive member 15 resistance layer 17 common electrode 19 individual electrode 21 first connection electrode 23 joining member 25 protective layer 26 second connection electrode 27 covering layer 29 hard coat 31 connector 40 transport mechanism 50 platen roller 60 power supply device 70 control device 80 mounting member 90 heat sink 100 thermal printer P recording medium

Claims

1. A thermal head comprising: a substrate; and a connector that is fitted to an end of the substrate, wherein the connector has a plurality of connector pins that are arranged at intervals in a first direction of the substrate and that are fitted to the end of the substrate; and a housing that accommodates the plurality of connector pins, wherein the housing is positioned outward in the first direction from the plurality of connector pins and has a side wall that faces the underside of the substrate at its end surface, and an arm portion that rises from the end surface of the side wall other than the area that faces the underside of the substrate and extends along the upper surface of the substrate in a second direction that intersects the first direction.

2. A thermal head according to claim 1, wherein the arm portion has a width along the first direction greater than that of each of the plurality of connector pins.

3. A thermal head as described in claim 1 or 2, wherein the arm portion has a raised surface that rises from the portion extending in the second direction above said portion toward the recording medium being transported, and the raised surface is rounded.

4. A thermal head as described in claim 3, wherein the arm portion has a first inclined surface that is continuous with the raised surface and decreases in height toward the tip of the portion in the second direction.

5. A thermal head as described in claim 3, wherein the arm portion has a second inclined surface that is continuous with the raised surface and decreases in height toward the opposite side from the tip of the portion in the second direction.

6. A thermal head as described in any one of claims 1 to 5, further comprising: electrodes located on the substrate and electrically connected to the plurality of connector pins; and a sealing member that seals the connection portions of the plurality of connector pins with the electrodes, wherein the arm portion is higher from the substrate in side view than the connection portions of the plurality of connector pins with the electrodes.

7. A thermal head as described in any one of claims 1 to 5, further comprising: electrodes located on the substrate and electrically connected to the plurality of connector pins; and a sealing member for sealing the connection portions of the plurality of connector pins with the electrodes, wherein the sealing member has a portion that fills the gap between the upper surface of the substrate and the arm portion, which are positioned at an interval in a direction perpendicular to the mating direction, when the substrate and the plurality of connector pins are mated.

8. A thermal head as described in any one of claims 1 to 5, further comprising: electrodes located on the substrate and electrically connected to the plurality of connector pins; and a sealing member that seals the connection portions of the plurality of connector pins with the electrodes, the sealing member being shorter in height than the arm portions.

9. A thermal printer equipped with the thermal head according to any one of claims 1 to 8.

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