JP2016137692A - Thermal head and thermal printer comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal head in which heat efficiency is improved.SOLUTION: A thermal head X1 comprises: a substrate 7; a thick film electric resistance layer 15 which is provided in a belt-state in a main scanning direction D1, and having a first edge 15a, and a second edge 15b; a common electrode 17 having a first common electrode 17c1 and a second common electrode 17c2 disposed so as to cross the thick film electric resistance layer 15; an individual electrode 19 disposed so as to cross the thick film electric resistance layer 15; a first heating part 9a disposed between the first common electrode 17c1 and the individual electrode 19; and a second heating part 9b disposed between the second common electrode 17c2 and the individual electrode 19. The first heating part 9a is configured so that, length of the thick film electric resistance layer 15 on the first edge 15a is shorter than length of the thick film electric resistance layer 15 on the second edge 15b, and the second heating part 9b is configured so that, length of the thick film electric resistance layer 15 on the second edge 15b is shorter than length of the thick film electric resistance layer 15 on the first edge 15a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a thermal head and a thermal printer including the same.

  Conventionally, various thermal heads have been proposed as printing devices such as facsimiles and video printers. Such a thermal head is, for example, a substrate, a thick film electric resistance layer provided on the substrate, provided in a strip shape in the main scanning direction, and having a first edge and a second edge along the main scanning direction, A common electrode having a first common electrode and a second common electrode provided so as to intersect with the membrane electrical resistance layer; a first common electrode and a second common electrode provided so as to intersect with the thick film electrical resistance layer; Between the individual electrode disposed between the first common electrode and the individual electrode, and between the second common electrode and the individual electrode. And a second heat generating portion provided by a thick film electric resistance layer is known (see, for example, Patent Document 1).

JP-A-1-31656

  However, the above-described thermal head has a problem that the thermal efficiency is still low.

  A thermal head according to an embodiment of the present invention includes a substrate, a thick film electrical resistor provided on the substrate, provided in a strip shape in the main scanning direction, and having a first edge and a second edge along the main scanning direction. A common electrode having a first common electrode and a second common electrode provided to cross the thick film electric resistance layer, and the first common electrode provided to cross the thick film electric resistance layer An individual electrode disposed between an electrode and the second common electrode; a first heat generating portion provided between the first common electrode and the individual electrode and formed by the thick film electric resistance layer; A second heat generating portion provided between the second common electrode and the individual electrode and formed by the thick film electric resistance layer. Further, in the first heat generating portion, the length of the thick film electrical resistance layer located on the first edge is shorter than the length of the thick film electrical resistance layer located on the second edge. In the second heat generating portion, the length of the thick film electric resistance layer located on the second edge is shorter than the length of the thick film electric resistance layer located on the first edge.

  A thermal printer according to an embodiment of the present invention includes the thermal head described above, and a transport mechanism that transports a recording medium onto the thick film electrical resistance layer sandwiched between the common electrode and the individual electrode. And a platen roller for pressing a recording medium on the thick film electric resistance layer sandwiched between the common electrode and the individual electrode.

  According to the present invention, the thermal efficiency of the thermal head X1 can be improved.

It is a perspective view showing the outline of the thermal head concerning a 1st embodiment. It is a top view which shows the thermal head which concerns on 1st Embodiment. (A) is the II sectional view taken on the line shown in FIG. 2, (b) is the II-II sectional view taken on the line shown in FIG. (A) is a top view which expands and shows a part of thermal head shown in FIG. 1, (b) is the III-III sectional view taken on the line shown to Fig.4 (a). 1 is a diagram illustrating a schematic configuration of a thermal printer according to a first embodiment. It is a top view which shows the thermal head which concerns on 2nd Embodiment. (A) is a top view which expands and shows the site | part shown to E1 of FIG. 6, (b) is a top view which expands and shows the site | part shown to E2 of FIG. The thermal head which concerns on 3rd Embodiment is shown, (a) is a top view corresponding to FIG. 4, (b) is the IV-IV sectional view taken on the line shown to Fig.8 (a). The thermal head which concerns on 4th Embodiment is shown, (a) is a top view corresponding to FIG. 4, (b) is the VV sectional view taken on the line shown to Fig.9 (a). The thermal head which concerns on 5th Embodiment is shown, (a) is a top view corresponding to FIG. 4, (b) is VI-VI sectional view taken on the line shown to Fig.10 (a).

<First Embodiment>
Hereinafter, the thermal head X1 will be described with reference to FIGS. In FIG. 2, the protective layer 25, the coating layer 27, the flexible printed wiring board 5 (hereinafter referred to as FPC 5), and the connector 31 are indicated by alternate long and short dash lines. Further, the main scanning direction is indicated as D1, and the sub-scanning direction D2.

  As shown in FIG. 1, the thermal head X <b> 1 includes a heat radiating plate 1, a head base 3, an FPC 5, and a conductive member 23.

  The head base 3 is disposed on the heat sink 1 and is electrically connected to the FPC 5. The conductive member 23 electrically connects the head base 3 and the FPC 5. The head base 3 has a substrate 7, and a thick film electric resistance layer 15 is provided on the substrate 7. A region of the thick electrical resistance layer 15 that is sandwiched between the common electrode 17 (see FIG. 2) and the individual electrode 19 (see FIG. 2) is configured as a heat generating portion 9, and the heat generating portion 9 is in the main scanning. A plurality are provided in the direction D1.

  The heat generating unit 9 is electrically connected to the driving IC 11 by the individual electrode 19, and a voltage is applied to each heat generating unit 9 by the driving IC 11 to cause each heat generating unit 9 to generate heat, whereby the thermal head X1 performs printing. ing. A covering member 29 is provided on the driving IC 11 and the driving IC 11 is sealed.

  The heat sink 1 is formed in a plate shape and has a rectangular shape in plan view. The heat radiating plate 1 is made of, for example, a metal material such as copper, iron, or aluminum, and has a function of radiating heat that does not contribute to printing out of heat generated in the heat generating portion 9 of the head base 3. . A head substrate 3 is bonded to the upper surface of the heat radiating plate 1 by a double-sided tape or an adhesive (not shown).

  The head base 3 is formed in a plate shape in plan view, and each member constituting the thermal head X1 is provided on the substrate 7 of the head base 3. The head base 3 has a function of printing on a recording medium (not shown) in accordance with an electric signal supplied from the outside.

  The FPC 5 is an external substrate that is electrically connected to the head base 3 via the conductive member 23 and has a function of supplying a current and an electric signal to the head base 3. The FPC 5 has a wiring pattern (not shown) inside, and electrically connects the head base 3 to the outside via the wiring pattern. A reinforcing plate (not shown) made of a resin such as a phenol resin, a polyimide resin, or a glass epoxy resin may be provided between the FPC 5 and the heat radiating plate 1.

  In addition, although the example which used FPC5 as an external board | substrate was shown, you may use a hard wiring board instead of flexible FPC5. As a hard printed wiring board, the board | substrate formed with resin, such as a glass epoxy board | substrate or a polyimide board | substrate, can be illustrated.

  The conductive member 23 electrically connects the connection electrode 21 (see FIG. 2) of the head base 3 and the wiring pattern of the FPC 5. As the conductive member 23, for example, solder, anisotropic conductive film, or anisotropic conductive resin can be exemplified.

  Hereinafter, each member which comprises the head base | substrate 3 is demonstrated using FIGS.

  The substrate 7 is made of an electrically insulating material such as alumina ceramics or a semiconductor material such as single crystal silicon. The substrate 7 has a rectangular shape in plan view, and has one long side 7a, the other long side 7b, one short side 7c, and the other short side 7d.

  A heat storage layer 13 is formed over the entire surface of the substrate 7. The heat storage layer 13 is formed of glass having low thermal conductivity, and by temporarily storing a part of the heat generated in the heat generating part 9, the time required to raise the temperature of the heat generating part 9 is shortened. And functions to enhance the thermal response characteristics of the thermal head X1. The heat storage layer 13 is formed, for example, by applying a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent onto the upper surface of the substrate 7 by screen printing or the like known in the art, and baking it.

  On the heat storage layer 13, a common electrode 17, an individual electrode 19, and a connection electrode 21 are provided. The common electrode 17, the individual electrode 19, and the connection electrode 21 form a wiring pattern so as to electrically connect the heat generating portion 9 and the outside.

  The thick film electric resistance layer 15 is provided on the heat storage layer 13 provided with various electrodes, and is provided in a strip shape in the main scanning direction D1. The thick film electric resistance 15 is provided apart from one long side 7a of the substrate 7, and includes a first edge 15a along the main scanning direction D1 and a second edge 15b along the main scanning direction D1. Have. The first edge 15 a is provided on the one long side 7 a side of the substrate 7, and the second edge 15 b is provided on the other long side 7 b side of the substrate 7.

  Below the thick film electric resistance layer 15, common electrodes 17 and individual electrodes 19 are provided, and the common electrodes 17 and the individual electrodes 19 are alternately arranged in the main scanning direction D1. In the thick electrical resistance layer 15, a region sandwiched between the common electrode 17 and the individual electrode 19 is configured as the heat generating portion 9. A plurality of heat generating portions 9 are arranged in the main scanning direction D1, and the plurality of heat generating portions 9 are illustrated in a simplified manner in FIG. 1 for convenience of explanation, but for example, 100 dpi to 2400 dpi (dot per inch) or the like. Is arranged at a density of.

  The thick film electric resistance layer 15 is formed, for example, by printing and baking a thick film resistance paste containing ruthenium oxide as a conductive component. The width of the thick electrical resistance layer 15 can be set to, for example, 50 to 200 μm. The height of the thick film electric resistance layer 15 can be set to 5 to 50 μm, for example.

  The common electrode 17 includes a main wiring portion 17a, a sub wiring portion 17b, an extending portion 17c, and a thick electrode portion 17d.

The main wiring portion 17a extends along one long side 7a of the substrate 7, and connects the plurality of extending portions 17c. The sub wiring portion 17b is provided so as to extend from the main wiring portion 17a along one short side 7c and the other short side 7d of the substrate 7, respectively.
It is pulled out to electrically connect a to the FPC 5. A plurality of extending portions 17 c are provided so as to individually extend from the main wiring portion 17 a toward the thick film electric resistance layer 15, and constitute the heat generating portion 9.

  The thick electrode portion 17 d is disposed along one long side 7 a of the substrate 7 and has a configuration that is thicker than other portions of the common electrode 17. Therefore, the thick electrode portion 17d has a low electric resistance, and the electrode function of the common electrode 17 can be enhanced. The thickness of the thick electrode portion 17d can be set to 0.7 to 20 μm, for example, and the thickness of the other part of the common electrode 17 can be set to 0.05 to 2.0 μm.

  A plurality of individual electrodes 19 are provided on the heat storage layer 13. The individual electrode 19 has an extending portion 19a, a connecting portion 19b, and a terminal portion 19c. The individual electrode 19 divides a plurality of heat generating portions 9 into a plurality of heat generating portion groups (not shown), and electrically connects the heat generating portions 9 of each heat generating portion group to a drive IC 11 provided corresponding to each heat generating portion group. Connected.

  The extending portion 19 a is provided below the thick film electric resistance layer 15 a, and the extending portion 17 c of the common electrode 17 constitutes the heat generating portion 9. The connecting portion 19b connects the extending portion 19a and the terminal portion 19c. The terminal portion 19 c is provided below a terminal (not shown) of the drive IC 11 and is electrically connected to the drive IC 11. Note that the extending portion 19a is disposed on the other long side 7b side of the substrate 7 with respect to the main wiring portion 17a, and below the thick film electrical resistance layer 15 and on the substrate 7 with respect to the thick film electrical resistance layer 15a. The part arrange | positioned at the one long side 7a side is shown.

  A plurality of connection electrodes 21 are provided on the heat storage layer 13 and electrically connect the drive IC 11 and the FPC 5. The plurality of connection electrodes 21 are composed of a plurality of wirings having different functions.

  The common electrode 17, the individual electrode 19, and the connection electrode 21 are formed of a conductive material, for example, any one of aluminum, gold, silver, and copper, or an alloy thereof. ing.

  As shown in FIG. 1, the drive IC 11 is disposed corresponding to each group of the plurality of heat generating portions 9 and is electrically connected to the terminal portions 19 b of the individual electrodes 19 and the connection electrodes 21. The drive IC 11 has a function of controlling the energization state of each heat generating unit 9. As the drive IC 11, a switching member having a plurality of switching elements inside may be used.

  The common electrode 17, the individual electrode 19, and the connection electrode 21 are formed by, for example, printing and baking the thick electrode portion 17 d, and then forming a material layer constituting each on the heat storage layer 13 by, for example, sputtering. It is formed by sequentially laminating by a conventionally well-known thin film forming technique and processing the laminated body into a predetermined pattern using a conventionally well-known photoetching or the like. Note that the thick electrode portion 17d is not necessarily provided. Moreover, the common electrode 17, the individual electrode 19, and the connection electrode 21 can be simultaneously formed by the same process.

  A protective layer 25 is formed on the thick film electric resistance layer 15 and the heat storage layer 13 to cover the heat generating portion 9, a part of the common electrode 17 and a part of the individual electrode 19. The protective layer 25 is provided on one long side 7 a side of the substrate 7. The protective layer 25 protects the area covered with the heat generating portion 9, the common electrode 17 and the individual electrode 19 from corrosion due to adhesion of moisture or the like contained in the atmosphere, or wear due to contact with the recording medium to be printed. belongs to.

The protective layer 25 can be formed using SiN, SiO ₂ , SiON, SiC, diamond-like carbon, or the like, and the protective layer 25 may be formed of a single layer or may be formed by stacking these layers. May be. Such a protective layer 25 can be produced using a thin film forming technique such as sputtering or a thick film forming technique such as screen printing.

  Further, a coating layer 27 that partially covers the common electrode 17, the individual electrode 19, and the connection electrode 21 is provided on the heat storage layer 13. The covering layer 27 is provided on the other long side 7 b side of the substrate 7.

  The covering layer 27 is for protecting the region covered with the common electrode 17, the individual electrode 19, and the connection electrode 21 from oxidation due to contact with the atmosphere or corrosion due to adhesion of moisture contained in the atmosphere. is there. The covering layer 27 can be formed of a resin material such as an epoxy resin or a polyimide resin by using a thick film forming technique such as a screen printing method.

  The coating layer 27 has openings (not shown) for exposing the terminal portions 19b of the individual electrodes 19 and the connection electrodes 21, and these wirings are connected to the drive IC 11 through the openings. . Further, the drive IC 11 is sealed by a covering member 29 made of a resin such as an epoxy resin or a silicone resin in order to protect the drive IC 11 in a state where it is connected to the individual electrode 19 and the connection electrode 21.

  The common electrode 17, the individual electrode 19, and the heat generating portion 9 will be described in detail with reference to FIG. In FIG. 4A, illustration of the protective layer 25 (see FIG. 3) is omitted, and in FIG. 4B, the substrate 7, the heat storage layer 13, and the thick film electric circuit are shown for easy understanding. Only the resistance layer 15 is shown, and the same applies to FIGS.

  The common electrode 17 has a plurality of extending portions 17c, and the plurality of extending portions 17c each constitute a first heat generating portion 9a and a second common electrode forming a second heat generating portion 9b. Is functioning as Therefore, the extending portion 17c1 is referred to as the first common electrode 17c1, and the extending portion 17c2 is referred to as the second common electrode 17c2, which will be described below.

  The common electrode 17 includes a first common electrode 17c1 and a second common electrode 17c2. The first common electrode 17c1 is provided so as to extend along the sub-scanning direction D2 from the main wiring portion 17a. It arrange | positions on the thermal storage layer 13 by the side of the other long side 7b.

  The second common electrode 17c2 is disposed adjacent to the first common electrode 17c1 with the individual electrode 19 interposed therebetween. The second common electrode 17c2 is provided so as to extend from the main wiring portion 17a along the sub-scanning direction D2. It arrange | positions on the thermal storage layer 13 by the side of the other long side 7b.

  The individual electrode 19 has an extending portion 19a, and the extending portion 19a is disposed between the first common electrode 17c1 and the second common electrode 17c2. The extending portion 19a is provided so as to be inclined with respect to the sub-scanning direction D2 in plan view. That is, the extending portion 19a is provided to be inclined with respect to the first common electrode 17c1 and the second common electrode 17c2 in plan view. In addition, the extending portion 19 a is disposed on the heat storage layer 13 on the one long side 7 a side of the substrate 7 with respect to the thick film electrical resistance layer 15, with the distal end exceeding the thick film electrical resistance layer 15 from the connection portion 19 b. .

  The first heat generating portion 9a is formed by the first common electrode 17c1 and the extending portion 19a, and has a trapezoidal shape in plan view. The first heat generating portion 9a generates heat by applying a voltage from the first common electrode 17c1 to the extending portion 19a.

  The first heat generating portion 9a includes a first portion 9a1 provided on the first edge 15a of the thick film electric resistance layer 15, and a second portion 9a2 provided on the second edge 15b of the thick film electric resistance layer 15. have. In addition, the 1st site | part 9a1 is an area | region provided in the vicinity of the 1st edge 15a among the 1st heat generating parts 9a. The second portion 9a1 is a region provided in the vicinity of the first edge 15a in the first heat generating portion 9a.

  The first heat generating portion 9a has a configuration in which the length of the first portion 9a1 in the main scanning direction D1 is shorter than the length of the second portion 9a2 in the main scanning direction D1. Therefore, the electrical resistance value of the first part 9a1 is lower than the electrical resistance value of the second part 9a2.

  The second heat generating portion 9b is formed by the second common electrode 17c2 and the extending portion 19a, and has a trapezoidal shape in plan view. Further, the second heat generating part 9b is arranged adjacent to the first heat generating part 9a in the main scanning direction D1. The first heat generating portion 9a generates heat by applying a voltage from the second common electrode 17c2 to the extending portion 19a.

  The second heat generating portion 9b includes a first part 9b1 provided on the first edge 15a of the thick film electric resistance layer 15, and a second part 9b2 provided on the second edge 15b of the thick film electric resistance layer 15. have. In addition, the 1st site | part 9b1 is an area | region provided in the vicinity of the 1st edge 15a among the 2nd heat generating parts 9b. Moreover, the 2nd site | part 9b2 is an area | region provided in the vicinity of the 2nd edge 15b among the 2nd heat generating parts 9b.

  The second heat generating portion 9b has a configuration in which the length of the second part 9b2 in the main scanning direction D1 is shorter than the length of the first part 9b1 in the main scanning direction D1. For this reason, the electrical resistance value of the first part 9b1 is higher than the electrical resistance value of the second part 9b2.

  Here, when the first heat generating portion is formed by the thick film electric resistance layer, the thick film electric resistance layer has a shape in which the central portion in the sub-scanning direction protrudes most in the cross-sectional view, and the central portion in the sub-scanning direction is the first portion. It is formed higher than the part and the second part. Therefore, the recording medium (see FIG. 5) contacts the central portion in the sub-scanning direction and does not contact the first part and the second part, or even when it comes in contact with the platen roller 50 (see FIG. 5). It becomes a configuration that is difficult to apply a load. Therefore, the first part and the second part are configured not to contribute directly to printing even if heat is generated. Thereby, when the 1st part and the 2nd part generate heat, the thermal efficiency of a thermal head may deteriorate. In particular, in the case of a thermal head that performs high-speed printing, there is a possibility that the thermal configuration is inferior to a thin film head that forms the heat generating portion 9 with a thin film.

  On the other hand, the first heat generating portion 9a has a configuration in which the length of the first portion 9a1 in the main scanning direction D1 is shorter than the length of the second portion 9a2 in the main scanning direction D1. The electrical resistance value of 9a1 is higher than the electrical resistance value of the second portion 9a2.

  Therefore, after forming the thick electrical resistance layer 15, trimming is performed to adjust the resistance value, and when a voltage is applied to the first heat generating portion 9 a, the first portion 9 a 1 having a low electrical resistance value is oxidized first. It will be. Therefore, the electrical resistance value of the first portion 9a1 can be further increased by performing trimming to apply a voltage.

  As a result, the first portion 9a1 has a configuration in which current does not easily flow even when the thermal head X1 is driven, and it is possible to reduce the possibility that unnecessary heat is generated in the first portion 9a1. Therefore, the thermal efficiency of the thermal head X1 can be improved.

Further, the second heat generating portion 9b has a configuration in which the length of the second part 9b2 in the main scanning direction D1 is shorter than the length of the first part 9b1 in the main scanning direction D1, and the electric power of the second part 9b2 The resistance value is lower than the electrical resistance value of the first portion 9b1.

  Therefore, similarly to the first heat generating portion 9a, when a voltage is applied and a voltage is applied to the second heat generating portion 9b during trimming, the second portion 9b2 having a high electrical resistance value is oxidized first. Therefore, the electrical resistance value of the second part 9b2 can be further increased by performing trimming.

  As a result, the second portion 9b2 has a configuration in which current does not easily flow even when the thermal head X1 is driven, and the possibility that unnecessary heat is generated in the second portion 9b2 can be reduced. Therefore, the thermal efficiency of the thermal head X1 can be improved.

  And since the 1st site | part 9a1 of the 1st heat generating part 9a becomes a structure which an electric current does not flow easily, the heat spot of the 1st heat generating part 9a is rather than the center part in the sub scanning direction D2 of the 1st heat generating part 9a. The second part 9a2 is shifted and arranged. Similarly, since the second portion 9b2 of the second heat generating portion 9b is configured so that current does not easily flow, the heat spot of the second heat generating portion 9b is more than the central portion in the sub-scanning direction D2 of the second heat generating portion 9b. Is also shifted to the first part 9b1 side.

  Therefore, in the adjacent first heat generating part 9a1 and second heat generating part 9b1, the heat spots are arranged to be alternately shifted. As a result, in the thermal head X1, the heat spots of the adjacent heat generating portions 9 are alternately shifted in the sub-scanning direction D2, and the possibility of sticking can be reduced.

  The first common electrode 17c1 and the second common electrode 17c2 are provided along the sub-scanning direction D2, and the extending portions 19a constituting the first heat generating portion 9a and the second heat generating portion 9b are viewed in plan view. It inclines with respect to the 1st common electrode 17c1 and the 2nd common electrode 17c2.

  Thereby, the electrical resistance value of the first part 9a1 of the first part 9a1 is reduced in the first part 9a2 by the simple configuration in which the extending part 19a is inclined with respect to the first common electrode 17c1 and the second common electrode 17c2. While making it lower than an electrical resistance value, in the 2nd heat generating part 9b, the electrical resistance value of 2nd site | part 9b2 can be made lower than the electrical resistance value of 1st site | part 9b1.

  The inclination angle θ of the extending portion 19a is preferably 3 to 20 °. Thereby, it is possible to reduce the possibility of current flowing through the first part 9a1 of the first heat generating part 9a and the second part 9b2 of the second heat generating part 9b.

  Next, a trimming method of the thermal head X1 will be described. The thermal head x1 performs energization overload trimming that adjusts the electric resistance value by self-generated Joule heat of the thick film electric resistance layer 15. In the energization overload trimming, the electric resistance value of each heat generating part 9 can be individually adjusted by applying a pulse voltage of 30 to 80 V for 100 μs to 10 ms individually for each heat generating part 9. The thermal head X1 can reduce variation in electric resistance value for each heat generating portion 9 by performing trimming.

  In addition, although the thick film electrical resistance layer 15 is oxidized and applied with a trimming to be oxidized, the electrical resistance value is increased. However, the present invention is not limited to this. That is, the present invention may be used for the thick-film electrical resistance layer 15 that is annealed to lower the electrical resistance value when trimming is performed by applying a voltage.

  Next, the thermal printer Z1 will be described with reference to FIG.

  As shown in FIG. 5, the thermal printer Z <b> 1 of the present embodiment includes the thermal head X <b> 1, the transport mechanism 40, the platen roller 50, the power supply device 60, and the control device 70. The thermal head X1 is attached to an attachment surface 80a of an attachment member 80 provided in a housing (not shown) of the thermal printer Z1. Note that S shown in FIG. 5 indicates the conveyance direction of the recording medium P.

  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 in the direction of arrow S in FIG. 5 and on the protective layer 25 positioned on the plurality of heat generating portions 9 of the thermal head X1. It is for carrying. The drive unit has a function of driving the transport rollers 43, 45, 47, and 49, and for example, a motor can be used. The transport rollers 43, 45, 47, and 49 are formed by, for example, covering cylindrical shaft bodies 43a, 45a, 47a, and 49a made of metal such as stainless steel with elastic members 43b, 45b, 47b, and 49b made of butadiene rubber or the like. Can be configured. Although not shown, when the recording medium P is an image receiving paper or the like that is transferred to ink, an ink film is transported together with the recording medium P between the recording medium P and the heat generating portion 9 of the thermal head X1.

  The platen roller 50 has a function of pressing the recording medium P onto the protective film 25 located on the heat generating portion 9 of the thermal head X1. The platen roller 50 is disposed so as to extend along a direction orthogonal to the main scanning direction D1 of the recording medium P, and both ends thereof are supported and fixed so as to be rotatable in a state where the recording medium P is pressed onto the heat generating portion 9. Has been. The platen roller 50 can be configured by, for example, covering a cylindrical shaft body 50a made of metal such as stainless steel with an elastic member 50b made of butadiene rubber or the like.

  The power supply device 60 has a function of supplying a current for generating heat from the heat generating portion 9 of the thermal head X1 and a current for operating the drive IC 11 as described above. The control device 70 has a function of supplying a control signal for controlling the operation of the drive IC 11 to the drive IC 11 in order to selectively heat the heat generating portion 9 of the thermal head X1 as described above.

  As shown in FIG. 5, the thermal printer Z1 presses the recording medium P onto the heat generating part 9 of the thermal head X1 by the platen roller 50, and conveys the recording medium P onto the heat generating part 9 by the conveying mechanism 40. The heat generating unit 9 is selectively heated by the power supply device 60 and the control device 70 to perform predetermined printing on the recording medium P. When the recording medium P is an image receiving paper or the like, printing is performed on the recording medium P by thermally transferring ink of an ink film (not shown) conveyed together with the recording medium P to the recording medium P.

<Second Embodiment>
The thermal head X2 will be described with reference to FIGS. The thermal head X2 is different from the thermal head X1 in the configuration of the heat generating portion 109, the common electrode 117, and the individual electrode 119, and the other points are the same. The same members as those of the thermal head X1 are given the same numbers.

  The common electrode 117 includes a main wiring portion 117a, a plurality of sub wiring portions 117b, and an extending portion 117c. The sub wiring part 117b is provided so as to extend from the main wiring part 117a in the sub scanning direction D2, and is arranged between both ends in the main scanning direction D1 and the drive ICs 11. Therefore, the same wiring pattern 116 is configured for each driving IC 11, and the thermal head X2 has three wiring patterns 116 arranged in the main scanning direction D1.

  In the thermal head X2, a wiring pattern 116 is constituted by a plurality of individual electrodes 119 connected to the same driving IC 11 and a common electrode 117. The extending portions 119a of the individual electrodes 119 constituting the wiring pattern 116 have different inclination angles with respect to the first common electrode 117c1 and the second common electrode 117c2 in plan view.

  Hereinafter, a single wiring pattern 116 will be described with reference to FIG.

  As shown in FIG. 7A, the extending portion 119a of the wiring pattern 116 located at one end portion in the main scanning direction D1 among the plurality of wiring patterns 116 is in relation to the first common electrode 117c1 and the second common electrode 117c2. Are inclined at an inclination angle θ1 (hereinafter referred to as an inclination angle θ1).

  Also, as shown in FIG. 7B, among the plurality of wiring patterns 116, the extending portion 119a of the wiring pattern 116 located at the central portion in the main scanning direction D1 has a first common electrode 117c1 and a second common electrode 117c2. Is inclined at an inclination angle θ2 (hereinafter referred to as an inclination angle θ2).

  The inclination angle θ1 is provided to be larger than the inclination angle θ2, and the extended portion wiring pattern 116 119a located at one end portion in the main scanning direction D1 is located in the central portion in the main scanning direction D1. The wiring pattern 116 is provided in an inclined state with respect to the extending portion 119a.

  Although not shown, the extending portion 119a of the wiring pattern 116 located at the other end portion in the main scanning direction D1 is inclined with respect to the first common electrode 117c1 and the second common electrode 117c2. (Referred to as an inclination angle θ1). That is, the extending portion 119a is provided to be inclined with respect to the first common electrode 117c1 and the second common electrode 117c2 in a line-symmetric state with the center in the main scanning direction D1 of the wiring pattern 116 as a boundary.

  In the thermal head X2, as shown in FIG. 6, the length in the main scanning direction D1 of the region where the heat generating portion 9 formed by the wiring pattern 116 is arranged is the region where the terminals 119b constituting the wiring pattern 116 are arranged. Is longer than the length in the main scanning direction D1. For this reason, the inclination of the connecting portion 119b with respect to the sub-scanning direction D2 increases toward the both ends of the wiring pattern 116.

  The thermal head X2 is configured such that the inclination angle θ1 is larger than the inclination angle θ2. Accordingly, the inclination of the extending portion 119a can be increased in accordance with the increase in the inclination of the connection portion 119b with respect to the sub-scanning direction D2. As a result, the inclination angles θ1 and θ2 can be made closer to the inclination angle of the connection portion 119b of the individual electrode 119, and the possibility that a portion that is largely bent is formed in the individual electrode 119 can be reduced. Therefore, it is possible to reduce the possibility of disconnection in the individual electrode 119.

  In addition, the inclination angle of the extending portion 119a with respect to the first common electrode 117c1 and the second common electrode 117c2 is preferably provided so as to gradually increase toward both end portions of the heat generating portion group 9. Accordingly, the inclination angles θ1 and θ2 can be made closer to the inclination of the connection portion 119b of the individual electrode 119, and the possibility of disconnection in the individual electrode 119 can be further reduced.

<Third Embodiment>
The thermal head X3 will be described with reference to FIG. The thermal head X3 is a heating unit 2
09, the common electrode 217, and the individual electrode 219 are different from the thermal head X1, and the other points are the same. The same members as those of the thermal head X1 are given the same numbers.

  The extending portion 219a is provided so as to extend in the sub-scanning direction D2. Further, it is bent in the main scanning direction D <b> 1 below the thick film electrical resistance layer 15, and the tip is disposed on the one long side 7 a side of the substrate 7 with respect to the thick film electrical resistance layer 15. Therefore, the extending portion 219a is provided so as to extend from the connection portion 219b in the sub-scanning direction D2, and is bent in the main scanning direction D1 below the thick film electric resistance layer 15, and after being bent, the sub-scanning direction. It is provided to extend to D2.

  Therefore, the first heat generating portion 209a has a configuration in which the length of the first portion 209a1 in the main scanning direction D1 is shorter than the length of the second portion 209a2 in the main scanning direction D1. Therefore, the electrical resistance value of the first part 209a1 is lower than the electrical resistance value of the second part 209a2.

  The second heat generating portion 209b has a configuration in which the length of the second part 209b2 in the main scanning direction D1 is shorter than the length of the first part 209b1 in the main scanning direction D1. Therefore, the electrical resistance value of the second part 209b2 is lower than the electrical resistance value of the first part 209b1.

  Therefore, when trimming is performed, the first part 209a1 of the first heat generating part 209a and the second part 209b2 of the second heat generating part 209b can be oxidized, and the first part 209a1 of the first heat generating part 209a, and The electrical resistance value of the second portion 209b2 of the second heat generating part 209b can be increased.

  As a result, the first part 209a1 of the first heat generating part 209a and the second part 209b2 of the second heat generating part 209b are configured such that current does not easily flow even when the thermal head X3 is driven, and the first part of the first heat generating part 209a. It is possible to reduce the possibility that heat is generated at a location not used for printing in the second portion 209b2 of the second heat generating portion 209b. Therefore, the thermal efficiency of the thermal head X3 can be improved.

  In addition, although the example in which the extending portion 219a is bent below the thick film electric resistance layer 15 is shown, the extending portion 219a may be bent below the thick film electric resistance layer 15. Even in that case, the same effect can be obtained.

<Fourth Embodiment>
The thermal head X4 will be described with reference to FIG. The thermal head X4 is different from the thermal head X1 in the configuration of the heat generating portion 309, the common electrode 317, and the individual electrode 319, and the other points are the same. The same members as those of the thermal head X1 are given the same numbers.

  The tip of the first common electrode 317c1 is disposed below the thick film electrical resistance layer 15, and is not disposed on the other long side 7b side of the substrate 7 relative to the thick film electrical resistance layer 15. The tip of the second common electrode 317c2 is disposed below the thick film electrical resistance layer 15, and is not disposed on the other long side 7b side of the substrate 7 relative to the thick film electrical resistance layer 15. The leading end of the extending portion 319a is disposed below the thick film electrical resistance layer 15, and is not disposed on the one long side 7a side of the substrate 7 relative to the thick film electrical resistance layer 15.

That is, the thermal head X4 includes the first common electrode 317c1 and the second common electrode 317c2.
And the front-end | tip of the extending | stretching part 319a has a structure arrange | positioned under the thick film electrical resistance layer 15. FIG.

  Thereby, it is possible to suppress the distance between the first common electrode 317c1 and the distal end of the extending portion 319a and the distance between the second common electrode 317c1 and the rear end of the extending portion 319a from being too close. Accordingly, it is possible to reduce the possibility of discharge due to static electricity at the front ends of the first common electrode 317c1 and the extending portion 319a and the rear ends of the second common electrode 317c1 and the extending portion 319a, and the thermal head X4 is damaged. The possibility of doing so can be reduced.

<Fifth Embodiment>
The thermal head X5 will be described with reference to FIG. The thermal head X5 is different from the thermal head X1 in the configuration of the heat generating portion 409, the common electrode 417, and the individual electrode 419, and the other points are the same. The same members as those of the thermal head X1 are given the same numbers.

  The extending portion 419a has a configuration in which the width of the extending portion 419a located on the drive IC 11 (see FIG. 3) side is larger than the width of the extending portion 419a located on the opposite side to the drive IC 11.

  Thereby, without increasing the distance between the first heat generating part 419a and the second heat generating part 9b, the electricity between the first part 409a1 of the first heat generating part 409a and the second part 409b2 of the second heat generating part 409b. The resistance value can be increased by trimming, and it is possible to make it difficult for current to flow through the first portion 409a1 of the first heat generating portion 409a and the second portion 409b2 of the second heat generating portion 409b. Thereby, the thermal efficiency of the thermal head X5 can be improved.

  Further, the heat of the heat generating part 409 is easily transferred to the extending part 419a located on the drive IC 11 side, and the heat of the heat generating part 409 is transferred to the drive IC 11 side upstream of the recording medium P (see FIG. 5). Can be made. As a result, the recording medium P can be preheated and the thermal efficiency of the thermal head X5 can be further improved.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, although the thermal printer Z1 using the thermal head X1 according to the first embodiment is shown, the present invention is not limited to this, and the thermal heads X2 to X5 may be used for the thermal printer Z1.

  In addition, although the example which provided the common electrode 17 and the individual electrode 19 on the thick film electrical resistance layer 15 was shown, it is not limited to this. After forming the common electrode 17 and the individual electrode 19, the thick film electric resistance layer 15 may be provided. Even in that case, the same effect can be obtained.

  Moreover, although the example which formed the heat generating part 9 on the main surface of the board | substrate 7 was shown, this invention can be implemented also in the end surface type thermal head which forms the heat generating part 9 in the end surface of the board | substrate 7. FIG.

  Further, the connector 31 may be directly electrically connected to the head base 3 without providing the FPC 5. In that case, a connector pin (not shown) of the connector 31 and the connection electrode 21 of the head base 3 may be electrically connected via the conductive bonding material 23.

X1 to X5 Thermal Head Z1 Thermal Printer 1 Heat Dissipator 3 Head Base 5 Flexible Printed Circuit Board 7 Substrate 9 Heating Part 9a First Heating Part 9a1 First Part 9a2 Second Part 9b Second Heating Part 9b1 First Part 9b2 Second Part 11 Drive IC
DESCRIPTION OF SYMBOLS 13 Heat storage layer 15 Thick film electric resistance layer 15a 1st edge 15b 2nd edge 17 Common electrode 17c1 1st common electrode 17c2 2nd common electrode 19 Individual electrode 19a Extension part 19b Connection part 19c Terminal 21 Connection electrode 23 Bonding material 25 Protective layer 27 Coating layer 29 Coating member

Claims (7)

A substrate,
A thick film electric resistance layer provided on the substrate, provided in a strip shape in the main scanning direction, and having a first edge and a second edge along the main scanning direction;
A common electrode having a first common electrode and a second common electrode provided to intersect the thick film electric resistance layer;
An individual electrode provided to intersect the thick film electrical resistance layer and disposed between the first common electrode and the second common electrode;
A first heat generating portion provided between the first common electrode and the individual electrode and formed by the thick film electric resistance layer;
A second heat generating part provided between the second common electrode and the individual electrode and formed by the thick film electric resistance layer,
In the first heat generating portion, the length of the thick film electric resistance layer located on the first edge is shorter than the length of the thick film electric resistance layer located on the second edge,
The second heat generating portion is characterized in that a length of the thick film electric resistance layer located on the second edge is shorter than a length of the thick film electric resistance layer located on the first edge. Thermal head. The common electrode extends along the sub-scanning direction;
2. The thermal head according to claim 1, wherein the individual electrode is inclined with respect to the first common electrode and the second common electrode in a plan view. The common electrode includes a main wiring portion extending in the main scanning direction, a sub wiring portion extending in the sub scanning direction from both ends of the main wiring portion, and a plurality extending from the main wiring portion toward the thick film electric resistance layer. An extending portion of
A plurality of the individual electrodes are provided between the extending portions adjacent to each other, and are arranged in the main scanning direction,
The thermal head according to claim 2, wherein an inclination angle of the individual electrode located at both ends with respect to the common electrode is larger than an inclination angle of the individual electrode located at a central part with respect to the common electrode. The common electrode extends along the sub-scanning direction;
The thermal head according to claim 1, wherein the individual electrode is bent or curved on the thick film electric resistance layer.   The thermal head according to any one of claims 1 to 4, wherein a distal end of the common electrode and a distal end of the individual electrode are disposed on the thick film electric resistance layer. The individual electrodes are connected to a driving IC,
The thermal head according to any one of claims 1 to 5, wherein a width of the individual electrode located on the drive IC side is larger than a width of the individual electrode located on the opposite side to the drive IC. The thermal head according to any one of claims 1 to 6,
A transport mechanism for transporting a recording medium onto a heat generating portion formed by the thick film electric resistance layer located between the extending portion of the common electrode and the one end portion of the individual electrode;
A thermal printer comprising a platen roller for pressing a recording medium on the heat generating portion.

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