JP6971870B2 - Thermal head and thermal printer - Google Patents

Description

The present invention relates to a thermal head and a thermal printer.

Conventionally, various thermal heads have been proposed as printing devices such as facsimiles and video printers. For example, a thermal head having a substrate and a heat generating portion and having a chamfered portion formed at an edge portion of the substrate in the vicinity of the heat generating portion is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2005-7286

The thermal head of the present disclosure includes a substrate, a heat storage layer, a heat generating portion, an electrode, and a protective layer. The heat storage layer is located on the substrate. The heat generating portion is located on the heat storage layer. At least a part of the electrode is located on the heat storage layer and is connected to the heat generating portion. The protective layer is located on the heat generating portion and the heat storage layer, and at least a part thereof is located on the substrate. The substrate has an inclined surface at at least one end in the main scanning direction. The heat storage layer has a convex portion between the inclined surface and the electrode in the main scanning direction, which protrudes in a direction away from the substrate.

The thermal printer of the present disclosure includes the above thermal head, a transfer mechanism, and a platen roller. The transport mechanism transports the recording medium so as to pass over the heat generating portion. The platen roller presses the recording medium.

FIG. 1 is a plan view showing an outline of the thermal head X1. FIG. 2 is a side view showing an outline of the thermal head X1. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4 is a plan view showing the vicinity of the convex portion of the thermal head X1 shown in FIG. FIG. 5 is a sectional view taken along line VV shown in FIG. FIG. 6 is a schematic view showing the configuration of the thermal printer Z1. FIG. 7 is a plan view showing the vicinity of the convex portion of the thermal head X2. FIG. 8 is a plan view showing the vicinity of the recess of the thermal head X3. FIG. 9 is a sectional view taken along line IX-IX shown in FIG.

As a conventional thermal head, a thermal head in which an end portion of a substrate in the main scanning direction is chamfered to form an inclined surface is known. By having such a configuration, it was possible to smooth out the wrinkles of the ink ribbon generated during printing.

However, if the film stress of the protective layer is low, there is a problem that the protective layer is peeled off when the substrate is chamfered. If the protective layer is peeled off, the sealed electrode or the heat generating portion may be corroded.

The thermal head of the present disclosure provides a thermal head with improved sealing performance by reducing peeling of the protective layer. Hereinafter, the thermal head of the present disclosure and a thermal printer using the same will be described in detail.

<First Embodiment>
Hereinafter, the thermal head X1 according to the first embodiment will be described with reference to the drawings. In FIG. 1, the FPC 5, the protective layer 25, and the covering layer 27 are not shown, and the region where the FPC 5, the protective layer 25, and the covering layer 27 are arranged is shown by a two-dot chain line. In FIG. 4, the protective layer 25 is not shown, and the same applies to FIGS. 7 and 9.

As shown in FIGS. 1 to 5, the thermal head X1 includes a heat radiating body 1, a head substrate 3, a flexible printed wiring board 5 (hereinafter referred to as FPC 5), and a connector 31. The head substrate 3 is arranged on the radiator body 1. The FPC 5 is electrically connected to the head substrate 3. The connector 31 is electrically connected to the FPC 5.

The heat radiating body 1 has a base portion 1a and a protrusion portion 1b. The base portion 1a is rectangular in a plan view, and the head substrate 3 is placed on the base portion 1a. The protrusion 1b is arranged on the pedestal 1a and extends along one long side of the pedestal 1a. The protrusion 1b is located adjacent to the head substrate 3. The radiator 1 is made of a metal material such as copper, iron, or aluminum. The heat radiating body 1 has a function of radiating a part of the heat generated in the heat generating portion 9 of the head substrate 3, which will be described later, that does not contribute to the printing.

The head substrate 3 is arranged on the base portion 1a, and the second end surface 7b is arranged so as to face the protrusion 1b of the radiator body 1. Further, the head substrate 3 and the upper surface of the base portion 1a are adhered to each other by a double-sided tape, an adhesive 33, or the like.

The FPC 5 has a function of supplying an electric current to the head substrate 3 from the outside, and includes an insulating resin layer 5a and a printed wiring 5b. As shown in FIG. 3, the head substrate 3 and the FPC 5 are electrically bonded by the conductive bonding material 23. Examples of the conductive bonding material 23 include an anisotropic conductive film (ACF) in which conductive particles are mixed in a conductive bonding material, a solder material, or an electrically insulating resin. A connector 31 is joined to the FPC 5, and each printed wiring 5b is electrically connected to an external power supply device and a control device (not shown) via the connector 31.

The FPC 5 is adhered to the upper surface of the protrusion 1b of the heat radiating body 1 with an adhesive (not shown) such as double-sided tape or resin, and is fixed to the heat radiating body 1. It is not always necessary to fix it to the heat radiating body 1.

Next, each member constituting the head substrate 3 will be described with reference to FIGS. 1 to 5.

The substrate 7 has a function of holding each member constituting the head substrate 3, and has a substantially rectangular shape in a plan view. The substrate 7 has a first end surface 7a, a second end surface 7b, a first main surface 7c, a second main surface 7d, and an inclined surface 2.

The first end surface 7a is a surface adjacent to the first main surface 7c and the second main surface 7d. The second end surface 7b is a surface located on the opposite side of the first end surface 7a, and is positioned so as to face the protrusion 1b of the radiator body 1. The first main surface 7c is a surface adjacent to the first end surface 7a and the second end surface 7b. The second main surface 7d is a surface located on the opposite side of the first main surface 7c. The first end surface 7a has a curved surface shape that protrudes toward the side opposite to the second end surface 7b.

Inclined surfaces 2 are provided at both ends of the first end surface 7a in the main scanning direction. The inclined surface 2 is provided so as to intersect the main scanning direction.

The substrate 7 is formed of an electrically insulating material such as alumina ceramics or a semiconductor material such as single crystal silicon.

The heat storage layer 13 has a first portion 13a and a second portion 13b. The first portion 13a is formed over the entire first end surface 7a. The first end surface 7a of the substrate 7 has a convex curved surface shape when viewed in cross section. Therefore, the surface of the first portion 13a also has a curved surface shape.

The second portion 13b projects upward from the first portion 13a. The second portion 13b is located at the central portion in the sub-scanning direction when viewed from the first end surface 7a side. The second portion 13b is formed so as to extend in the main scanning direction.

Since the heat storage layer 13 has the first portion 13a and the second portion 13b, the recording medium P (see FIG. 5) to be printed is satisfactorily pressed against the protective layer 25 to be described later formed on the heat generating portion 9. It works to hit.

The heat storage layer 13 is formed of, for example, glass, and temporarily stores a part of the heat generated in the heat generating portion 9. Therefore, at the time of printing, the time required to raise the temperature of the heat generating portion 9 can be shortened, and the thermal response characteristics of the thermal head X1 can be improved.

An electric resistance layer 15 is provided on the first main surface 7c of the substrate 7, the heat storage layer 13, and the second main surface 7d of the substrate 7. The electric resistance layer 15 is interposed between the substrate 7 or the heat storage layer 13 and various electrodes described later.

The region of the electric resistance layer 15 located on the first main surface 7c of the substrate 7 is formed in the same shape as the common electrode 17, the individual electrode 19, and the connection electrode 21 in a plan view as shown in FIG. .. Further, the electric resistance layer 15 located on the second main surface 7d is provided over substantially the entire second main surface 7d.

As shown in FIG. 2, the region of the electric resistance layer 15 located on the heat storage layer 13 is a region formed in the same shape as the common electrode 17 and the individual electrode 19 and the common electrode 17 when viewed from the first end surface 7a. It has a plurality of exposed regions exposed from between the individual electrode 19 and the individual electrode 19. Each exposed region of the electric resistance layer 15 constitutes a heat generating portion 9.

As shown in FIG. 3, the plurality of heat generating portions 9 are arranged in a row on the second portion 13b of the heat storage layer 13. Therefore, the heat generating portion 9 is located at the central portion of the first end surface 7a in the sub-scanning direction. Although the plurality of heat generating portions 9 are shown in a simplified manner in FIG. 2, they are arranged at a density of, for example, 180 dpi to 2400 dpi (dot per inch).

The electric resistance layer 15 is formed of, for example, a material having a relatively high electric resistance such as TaN-based, TaSiO-based, TaSiNO-based, TiSiO-based, TiSiCO-based, or NbSiO-based. Therefore, when a voltage is applied between the common electrode 17 and the individual electrode 19, which will be described later, and a current is supplied to the heat generating portion 9, the heat generating portion 9 generates heat due to Joule heat generation. Utilizing this heat generation, the thermal head X1 prints on the recording medium P.

A common electrode 17, a plurality of individual electrodes 19, and a plurality of connection electrodes 21 are provided on the electric resistance layer 15.

The common electrode 17 includes a main wiring portion 17a, a sub wiring portion 17b, and a lead portion 17c. The common electrode 17 electrically connects the FPC 5 and the heat generating portion 9. Since the main wiring portion 17a is provided on the second main surface 7d of the substrate 7, the electric capacity of the common electrode 17 can be increased. The sub-wiring portion 17b is provided on the first main surface 7c, the first end surface 7a, and the second main surface 7d of the substrate 7, and is electrically connected to the outside via the FPC 5. The lead portion 17c is provided on the first end surface 7a and extends from the main wiring portion 17a toward each heat generating portion 9.

Therefore, the voltage supplied from the outside is supplied from the sub wiring portion 17b to the main wiring portion 17a. The voltage supplied to the main wiring unit 17a is supplied to each heat generating unit 9 via the lead unit 17c. In this way, a current is supplied to each heat generating portion 9.

The plurality of individual electrodes 19 connect each heat generating portion 9 to the drive IC 11. As shown in FIGS. 1 to 3, each individual electrode 19 has one end connected to the heat generating portion 9 and individually extends in a band shape from the first end surface 7a of the substrate 7 to the first main surface 7c of the substrate 7. ing.

The other end of each individual electrode 19 is electrically connected to the drive IC 11. More specifically, the individual electrode 19 divides the plurality of heat generating portions 9 into a plurality of groups, and electrically connects the heat generating portions 9 of each group to the drive IC 11 provided corresponding to each group.

The plurality of connection electrodes 21 connect the drive IC 11 and the FPC 5. Each connection electrode 21 extends in a band shape on the first main surface 7c of the substrate 7, one end of which is electrically connected to the drive IC 11 and the other end of which is electrically connected to the FPC 5.

As shown in FIG. 1, the drive IC 11 is arranged corresponding to each group of the plurality of heat generating portions 9. The drive IC 11 is connected to the other end of the individual electrode 19 and one end of the connection electrode 21. The drive IC 11 is for controlling the energized state of each heat generating unit 9, and controls the heat generation drive of each heat generating unit 9 by switching a plurality of switching elements (not shown) contained therein.

The drive IC 11 is covered and sealed with a coating member 29 made of a resin such as an epoxy resin or a silicone resin in a state of being connected to the individual electrode 19 and the connection electrode 21. Thereby, the drive IC 11 and the connection portion between the drive IC 11 and these wirings can be protected.

The method of forming the electric resistance layer 15, the common electrode 17, the individual electrode 19, and the connection electrode 21 will be illustrated. The material layers forming each of them are sequentially laminated on the substrate 7 provided with the heat storage layer 13 by a conventionally known thin film forming technique such as a sputtering method. Next, the laminate can be formed by processing it into a predetermined pattern using conventionally known photoetching or the like.

The thickness of the electric resistance layer 15 can be, for example, 0.01 μm to 0.2 μm, and the thickness of the common electrode 17, the individual electrode 19, and the connection electrode 21 can be, for example, 0.05 μm to 2.5 μm. .. The thickness of the main wiring portion 17a of the common electrode 17 may be different from the thickness of the sub-wiring portion b17b and the lead portion 17c of the common electrode 17, and the thickness may be different depending on the electrode portion.

The protective layer 25 is provided on the first end surface 7a of the substrate 7, a part on the first main surface 7c, and a part on the second main surface 7d. The protective layer 25 is provided so as to cover the heat generating portion 9, a part of the common electrode 17, and a part of the individual electrode 19.

Further, the protective layer 25 is provided so as to cover the region on the first end surface 7a side of the first main surface 7c of the substrate 7. The protective layer 25 is provided on the second main surface 7d of the substrate 7 so as to cover the region on the first end surface 7a side, similarly to the first main surface 7c of the substrate 7.

The protective layer 25 is a recording medium P that corrodes or prints the heat-generating portion 9, a part of the common electrode 17, and a part of the individual electrode 19 covered by the adhesion of moisture or the like contained in the atmosphere. It has a function to protect from wear due to contact. The protective layer 25 can be formed of, for example, a material such as SiC-based, SiC-based, SiO-based, and SiON-based. In addition, it may contain a small amount of other elements such as Al or Ti.

The protective layer 25 can be formed by using, for example, a conventionally known thin film forming technique such as a sputtering method or a vapor deposition method, or a thick film forming technique such as a screen printing method. The thickness of the protective layer 25 can be, for example, 3 to 12 μm. Further, the protective layer 25 may be formed by laminating a plurality of material layers.

A coating layer 27 that partially covers the individual electrodes 19 and the connection electrodes 21 is provided on the first main surface 7c of the substrate 7. As shown in FIG. 1, the covering layer 27 is provided in a region not covered by the protective layer 25 on the first main surface 7c of the substrate 7. Further, it is provided so as to cover the sub-wiring portion 17b of the common electrode 17. The covering layer 27 is also provided in a region not covered by the protective layer 25 on the second main surface 7d.

The covering layer 27 has a function of protecting the covered region of the individual electrode 19 and the connecting electrode 21 from oxidation due to contact with the atmosphere or corrosion due to adhesion of moisture or the like contained in the atmosphere. The coating layer 27 can be formed of, for example, a resin material such as an epoxy resin or a polyimide resin. Further, the coating layer 27 can be formed by using, for example, a thick film forming technique such as a screen printing method. The thickness of the coating layer 27 can be, for example, 20 to 60 μm.

The end of the connection electrode 21 and the end of the sub-wiring portion 17b are exposed from the covering layer 27, and the FPC 5 and the head substrate 3 are connected to each other at these exposed portions.

The coating layer 27 is formed with an opening for exposing the individual electrodes 19 connecting the drive IC 11 and the ends of the connection electrodes 21. The individual electrode 19 and the connection electrode 21 are connected to the drive IC 11 via an opening.

A plating layer (not shown) may be provided in a region of the common electrode 17, the individual electrode 19, and the connection electrode 21 connected to the drive IC 11 or the FPC 5. The plating layer can be formed of a metal or alloy, for example, by well-known electroless plating or electrolytic plating.

Further, as the plating layer, for example, a first coating layer made of nickel plating may be formed on the common electrode 17, and a second coating layer made of gold plating may be formed on the first coating layer. In this case, the thickness of the first coating layer can be set to, for example, 1.5 μm to 4 μm, and the thickness of the second coating layer can be set to, for example, 0.02 μm to 0.1 μm.

As shown in FIGS. 4 and 5, the inclined surface 2 is provided on the first end surface 7a of the substrate 7. The inclined surfaces 2 are provided at both ends of the first end surface 7a in the main scanning direction, and are provided so as to intersect the first end surface 7a.

The crossing angle between the first end surface 7a and the inclined surface 2 is preferably 5 to 70 °, and is preferably 10 to 4.
It is more preferably 5 °. When the crossing angle with the first end surface 7a side is in such a range, the possibility of scratches on the recording medium P can be reduced.

The central portion of the inclined surface 2 in the sub-scanning direction is longer in the main scanning direction than the end portion in the sub-scanning direction when viewed from the first end surface 7a. In other words, the inclined surface 2 has a shape in which the central portion in the sub-scanning direction protrudes toward the heat generating portion 9 when viewed from the first end surface 7a side. The inclined surface 2 is formed by the surface of the substrate 7, the surface of the first portion 13a of the heat storage layer 13, and the surface of the protective layer 25.

Since the thermal head X1 has the inclined surface 2 on the first end surface 7a, the possibility that the recording medium P is scratched by the thermal head X1 is reduced even when the recording medium P is strongly pressed against the thermal head X1. can do.

The inclined surface 2 can be formed by forming the head substrate 3 of the thermal head X1 and then polishing the thermal head X1 with a file, a diamond cutter, a diamond grindstone, or the like.

The heat storage layer 13 has a convex portion 4 between the inclined surface 2 and the sub-wiring portion 17b of the common electrode 17. The convex portion 4 projects from the first portion 13a in a direction away from the substrate 7, and extends along the main scanning direction.

The height of the convex portion 4 can be, for example, 0.5 to 3 μm. The width of the convex portion 4 can be, for example, 50 to 200 μm.

The heat storage layer 13 is produced, for example, by the following method. First, a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent is applied onto the first end surface 7a of the substrate 7 by a conventionally known screen printing or the like, and fired. Next, a resist is applied to the region forming the second portion 13b and the convex portion 4, and etching is performed. Then, by removing the resist, the first portion 13a, the second portion 13b, and the convex portion 4 can be formed on the heat storage layer 13.

The protective layer 25 is provided so as to cover the heat generating portion 9, and is located on the heat storage layer 13. More specifically, it is provided on the second portion 13b so as to cover the heat generating portion 9, and is also provided on the first portion 13a and also on the convex portion 4.

Here, when the film stress of the protective layer 25 is low, there is a problem that the protective layer 25 is peeled off when the substrate 7 is chamfered to form the inclined surface 2. If the protective layer 25 is peeled off, the various sealed electrodes or the heat generating portion 9 may be corroded.

On the other hand, in the thermal head X1, the heat storage layer 13 has a convex portion 4 between the inclined surface 2 and the sub-wiring portion 17b of the common electrode 17 in the main scanning direction, so that the heat storage layer 13 has heat storage. When the protective layer 25 is formed on the layer 13, the film stress of the portion of the protective layer 25 located on the convex portion 4 becomes high. As a result, in the protective layer 25, a portion having a high film stress is formed between the portion located on the inclined surface 2 and the portion located on the sub-wiring portion 17b.

As a result, the stress generated during chamfering is hindered by the portion of the protective layer 25 located on the convex portion 4, and the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to peel off. .. Therefore, the sealing property of the protective layer 25 can be improved.

Further, since the convex portion 4 is formed by the heat storage layer 13, the heat generated in the heat generating portion 9 is stored in the convex portion 4, and it becomes difficult for the heat to be dissipated to the inclined surface 2. Therefore, the thermal responsiveness of the thermal head X1 can be improved.

Further, in the present embodiment, the central portion of the inclined surface 2 in the sub-scanning direction has a longer length in the main scanning direction than the end portion in the sub-scanning direction, and the inclined surface 2 is centered in the sub-scanning direction. The distance between the portion and the convex portion 4 may be smaller than the distance between the end portion and the convex portion 4 in the sub-scanning direction of the inclined surface 2.

With such a configuration, the distance between the protective layer 25 located on the inclined surface 2 and the portion of the protective layer 25 located on the convex portion 4 can be reduced, and the stress generated during chamfering can be reduced. However, the portion of the protective layer 25 located on the convex portion 4 immediately hinders the progress, and the stress becomes difficult to progress. As a result, the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to be peeled off, and the sealing performance of the protective layer 25 can be further improved.

The relationship between the recording medium P and the thermal head X1 will be described with reference to FIG. 5 by using the ink ribbon R and the card C as the recording medium P. The recording medium P is a concept including the ink ribbon R and the card C as an example, and is a concept including a thermal paper that does not require the ink ribbon R.

The thermal head X1 prints on the card C using the ink ribbon R. The card C is pressed against the thermal head X1 by a platen roller 50, which will be described later, in a state where the ink ribbon R is interposed between the card C and the thermal head X1.

In FIG. 5, the platen roller 50 presses the card C downward, so that the platen roller 50 is deformed into a convex shape upward. The platen roller 50 conveys the card C and the ink ribbon R while being in contact with the card C and being supported by the protective layer 25 located on the convex portion 4. A gap 10 is formed between the thermal head X1 and the platen roller 50.

Further, in the present embodiment, the heat storage layer 13 has a first portion 13a located on the substrate 7 and a second portion 13b protruding from the first portion 13a in a direction away from the substrate. The heat generating portion 9 is provided on the second portion 13b, and the convex portion 4 protrudes from the first portion 13a in a state of being separated from the second portion 13b, and the second portion 13b and the convex portion 4 A sub-wiring portion 17b may be arranged between them.

With such a configuration, the card C is less likely to come into contact with the portion of the protective layer 25 located on the sub-wiring portion 17b. Therefore, the pressing force from the card C is less likely to occur in the portion of the protective layer 25 located on the sub-wiring portion 17b, and the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to be peeled off. As a result, the sealing property of the protective layer 25 can be improved.

Further, in the present embodiment, a gap 10 is formed between the platen roller 50 and the thermal head X1, and the ink ribbon R may be accommodated in the gap 10.

With such a configuration, even when the ink ribbon R is thermally expanded due to the heat of the heat generating portion 9, the expanded portion due to the thermal expansion of the ink ribbon R can be stored in the gap 10. As a result, the possibility of wrinkles on the ink ribbon R can be reduced.

Further, in the present embodiment, the ink ribbon R may be conveyed while being in contact with a portion of the protective layer 25 located on the convex portion 4. In other words, the platen roller 50 may be in contact with the protective layer 25 located on the convex portion 4 via the ink ribbon R.

With such a configuration, the print on the card C is less likely to be blurred. That is, the platen roller 50 presses the card C against the protective layer 25 on the heat generating portion 9 by pressing both ends of the shaft body 50a, which will be described later, toward the thermal head X1. Therefore, the platen roller 50 is deformed into a convex shape in which the central portion protrudes upward, the pressing force of the card C on the heat generating portion 9 becomes small, and the printing may be blurred.

However, in the thermal head X1, the platen roller 50 is also supported by a portion of the protective layer 25 located on the convex portion 4, and the platen roller 50 is less likely to be deformed into a convex shape. As a result, the print is less likely to be blurred.

In the thermal head X1, an example in which only one convex portion 4 is provided is shown, but the present invention is not limited to this. A plurality of may be provided between the inclined surface 2 and the sub-wiring portion 17b. In this case, a plurality of portions of the protective layer 25 having high film stress can be provided between the inclined surface 2 and the sub-wiring portion 17b, and the progress of stress can be further hindered.

Next, an embodiment of the thermal printer of the present invention will be described with reference to FIG. FIG. 6 is a schematic configuration diagram of the thermal printer Z of the present embodiment.

As shown in FIG. 6, the thermal printer Z of the present embodiment includes the above-mentioned thermal head X1, transfer mechanism 40, platen roller 50, power supply device 60, and control device 70. The thermal head X1 is attached to the attachment surface 80a of the attachment member 80 provided in the housing of the thermal printer Z. The thermal head X1 is attached to the mounting member 80 so that the arrangement direction of the heat generating portions 9 is along the main scanning direction which is the direction orthogonal to the transport direction S of the recording medium P. Therefore, in the thermal head X1, the first main surface 7c side of the substrate 7 is the upstream side in the transport direction of the recording medium P, and the second main surface 7d side of the substrate 7 is the downstream side in the transport direction of the recording medium P.

The transport mechanism 40 is for transporting the recording medium P such as the thermal paper, the image receiving paper, the card C, and the ink ribbon R in the direction of the arrow S in FIG. 6 and transporting the recording medium P onto the plurality of heat generating portions 9 of the thermal head X1. It has transfer rollers 43, 45, 47, 49. In the transport rollers 43, 45, 47, 49, for example, a columnar shaft body 43a, 45a, 47a, 49a made of a metal such as stainless steel is covered with elastic members 43b, 45b, 47b, 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 a card, the ink film is conveyed between the recording medium P and the heat generating portion 9 of the thermal head X1 together with the recording medium P.

The platen roller 50 has a function of pressing the recording medium P onto the heat generating portion 9 of the thermal head X1. The platen roller 50 is arranged so as to extend along a direction orthogonal to the transport direction S of the recording medium P, and both ends thereof are supported so as to be rotatable while the recording medium P is pressed onto the heat generating portion 9. Has been done. The platen roller 50 can be configured by, for example, covering a columnar shaft body 50a made of a metal such as stainless steel with an elastic member 50b made of butadiene rubber or the like.

As described above, the power supply device 60 has a function of supplying a voltage for heating the heat generating portion 9 of the thermal head X1 and a voltage for operating the drive IC 11. 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 generate heat of the heat generation unit 9 of the thermal head X1 as described above.

In the thermal printer Z of the present embodiment, the recording medium P is conveyed onto the heat generating portion 9 of the thermal head X1 by the conveying mechanism 40, and the heat generating portion 9 is selectively generated by the power supply device 60 and the control device 70. Thereby, a predetermined printing can be performed on the recording medium P.

<Second embodiment>
The thermal head X2 will be described with reference to FIG. 7. The same members as those of the thermal head X1 are assigned the same numbers, and the same applies hereinafter.

The thermal head X2 has a plurality of protrusions 204. The convex portion 204 is provided between the inclined surface 2 and the sub-wiring portion 17b. The convex portion 204 is along the inclined surface 2 when viewed from the first end surface 7a. More specifically, the convex portion 204 is along the ridge line 25a where the inclined surface 2 and the upper surface of the protective layer 25 intersect with each other when viewed from the first end surface 7a.

The convex portion 204 has an end portion 204a and a central portion 204b. The end portion 204a is located at the end portion of the convex portion 204 in the sub-scanning direction. The central portion 204b is located in the central portion of the convex portion 204 in the sub-scanning direction. The central portion 204b of the convex portion 204 is located closer to the heat generating portion 9 than the end portion 204a when viewed from the first end surface 7a.

In the thermal head X1 of the present embodiment, the convex portion 204 is located along the inclined surface 2 when viewed from the first end surface 7a.

In the case of such a configuration, the distance between the convex portion 204 and the inclined surface 2 can be made constant. Therefore, the stress generated when the substrate 7 is chamfered to form the inclined surface 2 is easily transmitted uniformly to the protective layer 25, and it is difficult to form a portion where the stress is concentrated on the protective layer 25. As a result, the protective layer 25 is less likely to be peeled off, and the sealing property of the protective layer 25 can be improved.

<Third embodiment>
The thermal head X3 will be described with reference to FIG. The thermal head X3 has a concave portion 306 instead of the convex portion 4 of the thermal head X1.

The heat storage layer 313 has a first portion 313a, a second portion 313b, a convex portion 304, and a concave portion 306. Since the first part 313a and the second part 313b are the same as the first part 13a and the second part 13b of the thermal head X1, the description thereof will be omitted.

The convex portion 304 is located between the inclined surface 2 and the sub-wiring portion 17b. Further, it is located away from the second portion 304b. The convex portion 304 has a height equivalent to that of the second portion 313b.

The concave portion 306 is formed in the convex portion 304. The depth of the concave portion 306 is substantially the same as the height of the convex portion 304.

The heat storage layer 13 is produced, for example, by the following method. First, a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent is applied onto the first end surface 7a of the substrate 7 by a conventionally known screen printing or the like, and fired. Next, a resist is applied to the region forming the second portion 313b and the convex portion 304, and etching is performed. At this time, no resist is provided in the region of the recess 306. Then, by removing the resist, the first portion 313a, the second portion 313b, the convex portion 304 and the concave portion 306 can be formed on the heat storage layer 13.

In the thermal head X3 of the present embodiment, since the heat storage layer 313 has a recess 306 between the inclined surface 2 and the sub-wiring portion 17b in the main scanning direction, the protective layer 25 is placed on the heat storage layer 13. When the film is formed, the film stress of the portion of the protective layer 25 located on the recess 306 increases. As a result, in the protective layer 25, a portion having a high film stress is formed between the portion located on the inclined surface 2 and the portion located on the sub-wiring portion 17b.

As a result, the stress generated during chamfering is hindered by the portion of the protective layer 25 located on the recess 306, and the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to peel off. Therefore, the sealing property of the protective layer 25 can be improved.

Further, in the present embodiment, the central portion of the inclined surface 2 in the sub-scanning direction has a longer length in the main scanning direction than the end portion in the sub-scanning direction, and the central portion of the inclined surface 2 in the sub-scanning direction. The distance between the portion and the recess 306 may be smaller than the distance between the end portion of the inclined surface 2 in the sub-scanning direction and the recess 306.

With such a configuration, the distance between the protective layer 25 located on the inclined surface 2 and the protective layer 25 located on the recess 306 in the sub-scanning direction can be reduced, and the stress generated during chamfering can be reduced. However, the protective layer 25 located on the recess 306 immediately hinders the progress, and the stress is less likely to progress. As a result, the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to be peeled off, and the sealing performance of the protective layer 25 can be further improved.

Further, in the present embodiment, the heat storage layer 313 has a first portion 313a located on the substrate 7 and a second portion 13b protruding from the first portion 313a in a direction away from the substrate. The heat generating portion 9 is provided on the second portion 13b, and the convex portion 304 protrudes from the first portion 313a in a state of being separated from the second portion 313b, and the second portion 313b and the convex portion 304 A sub-wiring portion 17b may be arranged between them, and a concave portion 306 may be provided in the convex portion 304.

With such a configuration, the card C is less likely to come into contact with the portion of the protective layer 25 located on the sub-wiring portion 17b. Therefore, the pressing force from the card C is less likely to occur in the portion of the protective layer 25 located on the sub-wiring portion 17b, and the portion of the protective layer 25 located on the sub-wiring portion 17b is less likely to be peeled off. As a result, the sealing property of the protective layer 25 can be improved.

Further, in the present embodiment, the ink ribbon R may be conveyed while being in contact with the protective layer 25 located on the convex portion 304 located around the concave portion 306. In other words, the platen roller 50 may be in contact with the protective layer 25 located on the convex portion 304 via the ink ribbon R.

With such a configuration, the print on the card C is less likely to be blurred. That is, the platen roller 50 presses the card C against the protective layer 25 on the heat generating portion 9 by pressing both ends of the shaft body 50a, which will be described later, toward the thermal head X1. Therefore, the platen roller 50 is deformed into a convex shape in which the central portion protrudes upward, the pressing force of the card C on the heat generating portion 9 becomes small, and the printing may be blurred.

However, in the thermal head X3, the platen roller 50 is also supported by the protective layer 25 located on the 313c, and the platen roller 50 is less likely to be deformed into a convex shape. As a result, the print is less likely to be blurred.

Although an example in which the concave portion 306 is provided in the convex portion 304 is shown, the present invention is not limited to this. For example, the recess 306 may be formed in the first portion 313a. Even in that case, the film stress of the portion of the protective layer 25 located on the recess 306 becomes high, and the sealing property of the protective layer 25 can be improved.

Although the plurality of embodiments have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the thermal printer Z using the thermal head X1 according to the first embodiment is shown, but the present invention is not limited to this, and the thermal heads X2 to X3 may be used for the thermal printer Z. Further, the thermal heads X1 to X3 may be appropriately combined.

For example, the thermal head X1 may be combined with the thermal head X3 so that the heat storage layer 13 has the convex portion 4 and the concave portion 306. Even in such a case, since the film stress of the protective layer 25 located on the convex portion 4 and the protective layer 25 located on the concave portion 306 becomes large, the possibility of stress traveling from the inclined surface 2 can be reduced. can.

Further, in the thermal head X1, as shown in FIG. 3, an example in which the first end surface 7a of the substrate 7 has a convex curved surface shape is shown, but the surface shape and the inclination angle of the first end surface 7a of the substrate 7 are different. It is not particularly limited and can take any form.

Furthermore, an example is shown in which the heat generating portion 9 is provided on the first end surface 7a of the substrate 7, but the present invention is not limited to this. The present invention can also be applied to a flat head in which the heat generating portion 9 is provided on the first main surface 7c. It can also be applied to a thick film type thermal head in which the electric resistance layer 15 is formed by printing.

X1 to X3 Thermal head Z1 Thermal printer 1 Heat radiator 2 Inclined surface 3 Head substrate 4,204,304 Convex part 204a End part 204b Central part 5 Flexible printed wiring board (FPC)
306 Recessed 7 Board 9 Heat generating part 11 Drive IC
13, Heat storage layer 13a, 313a 1st part 13b, 313b 2nd part 17 Common electrode 17a Main wiring part 17b Sub wiring part 17c Lead part 25 Protective layer 27 Coating layer 29 Coating member 31 Connector 50 Platen roller 70 Control device

Claims (11)

With the board
The heat storage layer located on the substrate and
The heat generating part located on the heat storage layer and
An electrode that is at least partly located on the heat storage layer and is connected to the heat generating portion.
A protective layer located on the heat generating portion and the heat storage layer and at least a part thereof located on the substrate is provided.
The substrate has an inclined surface at at least one end in the main scanning direction.
The heat storage layer is a portion located below the protective layer, and has a convex portion protruding in a direction away from the substrate between the inclined surface and the electrode in the main scanning direction. In a plan view from a direction perpendicular to the plane including the main scanning direction and the sub-scanning direction.
The inclined surface has a longer central portion in the sub-scanning direction than an end portion in the sub-scanning direction in the main scanning direction.
The thermal head according to claim 1, wherein the distance between the central portion and the convex portion is smaller than the distance between the end portion and the convex portion. In a plan view from a direction perpendicular to the plane including the main scanning direction and the sub-scanning direction.
The thermal head according to claim 1, wherein the convex portion is located along the inclined surface. The heat storage layer has a first portion located on the substrate and a second portion protruding from the first portion in a direction away from the substrate.
The heat generating portion is located on the second portion, and the heat generating portion is located on the second portion.
The convex portion protrudes from the first portion in a state of being separated from the second portion.
The thermal head according to any one of claims 1 to 3, wherein the electrode is arranged between the second portion and the convex portion. The thermal head according to claim 4, wherein the convex portion is provided with a concave portion recessed in a direction approaching the substrate. With the board
The heat storage layer located on the substrate and
The heat generating part located on the heat storage layer and
An electrode that is at least partly located on the heat storage layer and is connected to the heat generating portion.
A protective layer located on the heat generating portion and the heat storage layer and at least a part thereof located on the substrate is provided.
The substrate has an inclined surface at at least one end in the main scanning direction.
The electrode is located away from the inclined surface and is located away from the inclined surface.
The heat storage layer is a thermal head having a recess recessed in a direction approaching the substrate between the inclined surface and the electrode located closest to the inclined surface in the main scanning direction. In a plan view from a direction perpendicular to the plane including the main scanning direction and the sub-scanning direction.
The inclined surface has a longer central portion in the sub-scanning direction than an end portion in the sub-scanning direction in the main scanning direction.
The thermal head according to claim 6, wherein the distance between the central portion and the concave portion is smaller than the distance between the end portion and the concave portion. In a plan view from a direction perpendicular to the plane including the main scanning direction and the sub-scanning direction.
The thermal head according to claim 6, wherein the recess is located along the inclined surface. The thermal head according to any one of claims 1 to 5.
A transport mechanism that transports the recording medium so that it passes over the heat generating portion.
A thermal printer comprising a platen roller for pressing the recording medium. The thermal printer according to claim 9, wherein the recording medium is conveyed while being in contact with a protective layer located on the convex portion. The thermal head according to any one of claims 6 to 8 and the thermal head.
A transport mechanism that transports the recording medium so that it passes over the heat generating portion.
A platen roller for pressing the recording medium is provided.
A thermal printer in which the recording medium is conveyed while being in contact with a protective layer located on the heat storage layer located around the recess.

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