JP6598717B2 - Thermal head and thermal printer - Google Patents

Description

  The disclosed embodiment 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 in which a wiring board having a connector for connecting to the outside is provided on a heat sink is known (for example, see Patent Document 1).

Japanese Utility Model Publication No. 2-27344

  However, the conventional thermal head has a concern that, for example, when an external force through the connector is repeatedly applied to the wiring board, the wiring board is deformed or damaged.

  One aspect of the embodiments has been made in view of the above, and provides a thermal head and a thermal printer that can reduce the occurrence of deformation and damage in the wiring board while ensuring the heat dissipation of the wiring board. With the goal.

  A thermal head according to an aspect of the embodiment includes a heat radiating plate, a head base, and a wiring board. The head base has a substrate provided on the heat dissipation plate. The wiring board is provided on the heat radiating plate so as to be adjacent to the head base. The wiring board is inclined with respect to the heat sink so that one of the one end close to the head base and the other end far from the head base is in contact with the heat sink and the other is separated from the heat sink. Arranged.

  According to the thermal head of one aspect of the embodiment, one end and the other end of the wiring board are inclined with respect to the heat sink so that one is in contact with the heat sink and the other is separated from the heat sink. By doing so, it is possible to reduce the occurrence of deformation and damage in the wiring board while ensuring the heat dissipation of the wiring board.

FIG. 1 is a perspective view of the thermal head according to the first embodiment. FIG. 2 is a plan view of the head substrate according to the first embodiment. FIG. 3 is a front view of the thermal head according to the first embodiment. FIG. 4 is a schematic diagram of the thermal printer according to the first embodiment. FIG. 5 is a front view of the thermal head according to the second embodiment. FIG. 6 is a front view of a thermal head according to the third embodiment. FIG. 7 is a front view of a thermal head according to the fourth embodiment.

  Embodiments of a thermal head and a thermal printer disclosed in the present application will be described below with reference to the accompanying drawings. In addition, this invention is not limited by each embodiment shown below.

<First Embodiment>
FIG. 1 is a perspective view showing a configuration of a thermal head 1 according to the first embodiment.

  As shown in FIG. 1, the thermal head 1 according to the first embodiment includes a head substrate 10, a wiring board 20, a heat radiating plate 50, and a covering member 24. The head base 10 includes a substrate 11, a heat generating part 12, a heat storage layer 13, a plurality of individual electrodes 14, and a common electrode 15.

  The head base 10 has a substantially rectangular parallelepiped shape that is wide in the arrangement direction of the heat generating portions 12, and each member constituting the thermal head 1 is provided on the front surface of the substrate 11. The head substrate 10 has a function of printing on a recording medium (not shown) in accordance with an electric signal supplied from the outside.

  The substrate 11 has a substantially rectangular parallelepiped shape and is made of an electrically insulating material such as alumina ceramics or a semiconductor material such as single crystal silicon.

  The heat storage layer 13 is disposed on the front surface of the substrate 11 along the longitudinal direction of the substrate 11. The heat storage layer 13 is made of a material such as glass having low thermal conductivity, and has a function of temporarily storing a part of heat generated in the heat generating portion 12. Therefore, the time required to raise the temperature of the heat generating portion 12 can be shortened, and the thermal response function of the thermal head 1 is enhanced. The heat storage layer 13 is formed by, for example, applying a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent to the front surface of the substrate 11 by screen printing or the like, and firing the same. Is done.

  The heat generating part 12 is disposed on the heat storage layer 13. The plurality of elements constituting the heat generating portion 12 are arranged along the longitudinal direction of the substrate 11. The heat generating unit 12 has a function of generating heat in accordance with an electric signal supplied from the outside and printing on a recording medium (not shown). The plurality of elements constituting the heat generating unit 12 are arranged with a density of, for example, 100 dpi to 2400 dpi (dots per inch).

  The heat generating part 12 has an electric resistance layer having a relatively high electric resistance such as TaN, TaSiO, TaSiNO, TiSiO, TiSiCO, or NbSiO. When a voltage is applied to the electric resistance layer disposed between the individual electrode 14 and the common electrode 15, the electric resistance layer generates heat due to Joule heating.

  The plurality of individual electrodes 14 are arranged on one side of the heat generating portion 12 on the front surface side of the substrate 11. The plurality of individual electrodes 14 are individually connected to each element of the heat generating portion 12. The common electrode 15 is disposed on the front surface side of the substrate 11 so as to surround the remaining three sides of the heat generating portion 12. The common electrode 15 is connected in common to all the elements of the heat generating portion 12. The individual electrode 14 and the common electrode 15 are made of a metal such as Cu or Al, for example. Details of the individual electrode 14 and the common electrode 15 will be described later.

  The wiring board 20 has a wide plate shape in the arrangement direction of the heat generating portions 12. The wiring board 20 is disposed adjacent to the head substrate 10 on the side where the individual electrodes 14 of the head substrate 10 are disposed. The wiring board 20 is electrically connected to a drive IC (not shown), and is electrically connected to the outside via a connector (not shown). The wiring board 20 is a rigid printed wiring board with high rigidity, for example. Details of the drive IC and the connector will be described later.

  The heat sink 50 is disposed on the back side of the substrate 11 and the back side of the wiring board 20. The heat sink 50 is a metal plate made of, for example, Cu or Al. The heat radiating plate 50 has a function of radiating excessive heat generated on the substrate 11 and the wiring board 20 to the outside.

  The covering member 24 is disposed across the front surface of the head base 10 and the front surface of the wiring board 20 that are disposed on the heat sink 50 from the wiring board 20 to the substrate 11. The detailed configuration of the covering member 24 will be described later.

  Next, details of the individual electrode 14 and the common electrode 15 will be described. FIG. 2 is a plan view of the head base 10 according to the first embodiment. The plurality of individual electrodes 14 are arranged on the front surface side of the substrate 11 along the arrangement direction of the heat generating portions 12. One end of the individual electrode 14 is electrically connected to the element of the heat generating unit 12, and the other end is electrically connected to a drive IC (not shown) via a wiring member (not shown).

  The common electrode 15 electrically connects each element of the heat generating portion 12 and a connector (not shown). The common electrode 15 has a main wiring portion 15a, a sub wiring portion 15b, and a lead portion 15c. The main wiring portion 15 a extends along one long side 11 a of the substrate 11. The sub wiring portion 15b extends along one short side 11b and the other short side 11c of the substrate 11. The lead portion 15c individually extends from the main wiring portion 15a toward each element of the heat generating portion 12. The common electrode 15 is electrically connected to a connector (not shown) from the end 15d via a wiring member (not shown). The common electrode 15 is disposed so as to surround the remaining three sides of the heat generating portion 12 where the individual electrode 14 is not disposed.

  Next, a specific configuration of the thermal head 1 according to the first embodiment will be further described with reference to FIGS. 1 and 3. FIG. 3 is a front view of the thermal head 1 shown in FIG.

  In the thermal head 1, the wiring board 20 is disposed to be inclined with respect to the heat sink 50. More specifically, one end 20a1 close to the head base 10 is in contact with the wiring board 20 out of both longitudinal ends 20a of the wiring board 20 disposed on the heat sink 50, and the back surface 22 of the other end 20a2 is the heat sink. It arrange | positions so that it may space apart from the front surface 51 of 50.

  For example, in the wiring board 20 having a length of 5 to 30 mm from the one end 20a1 to the other end 20a2, the distance from the front surface 51 of the heat sink 50 to the back surface 22 of the wiring board 20 at the other end 20a2 is 300 to 800 μm. It arrange | positions with respect to the heat sink 50 so that it may become a grade. Since the distance from the front surface 51 to the back surface 22 is 300 μm or more, the wiring board 20 and the heat sink 50 are not easily in contact with each other. Further, since the distance from the front surface 51 to the back surface 22 is 800 μm or less, the member provided on the wiring board 20 does not easily come into contact with the recording medium.

  A connector 60 for electrical connection to the outside is disposed on the other end 20a2 side of the wiring board 20 that is separated from the heat sink 50. The connector 60 is disposed at the center of the long side far from the head base 10 among the long sides of the front surface 21 of the wiring board 20. The connector 60 is electrically connected to the wiring board 20 and is electrically connected to the outside. A flexible flat cable (not shown) that electrically connects the connector 60 and the wiring board 20 may be arranged between the connector 60 and the wiring board 20.

  Here, for example, a case where an external force via the connector 60 is applied downward, that is, in a direction approaching the heat sink 50 with respect to the other end 20a2 of the wiring board 20 will be considered. Since the back surface 22 on the other end 20 a 2 side of the wiring board 20 and the front surface 51 of the heat sink 50 are separated from each other, they are not easily in contact with each other even if the wiring board 20 is brought closer to the heat sink 50. Therefore, according to the thermal head 1 which concerns on 1st Embodiment, generation | occurrence | production of the deformation | transformation and damage in the wiring board 20 accompanying the contact of the heat sink 50 can be reduced.

  On the other hand, since one end 20a1 of the wiring board 20 is in contact with the heat sink 50, the heat dissipation of the wiring board 20 is ensured. That is, according to the thermal head 1 according to the first embodiment, it is possible to reduce the occurrence of deformation and damage in the wiring board 20 while ensuring the heat dissipation of the wiring board 20.

  The wiring board 20 has a rectangular shape having a long side and a short side in plan view, and is arranged so that the long side faces the head substrate 10. Specifically, the wiring board 20 is disposed such that one end 20 a 1 in the longitudinal direction of the wiring board 20 is in contact with the wiring board 20. Therefore, according to the thermal head 1 according to the first embodiment, it is difficult to bend in the longitudinal direction as compared with the case where the short side is arranged to face the head substrate 10, and deformation of the wiring board 20 is prevented. Generation can be further reduced.

  A driving IC 30 is disposed on the front surface 21 of the wiring board 20 at the end on the head base 10 side. The drive IC 30 is electrically connected to the individual electrode 14 on the head substrate 10 via the wiring member 41. The drive IC 30 generates electric power for selectively heating each element of the heat generating part 12 in accordance with an electric signal supplied from the outside via the wiring board 20 and the wiring member 42 electrically connected to the wiring board 20. To the unit 12.

  The elements of the heat generating portion 12 and the individual electrodes 14 connected thereto are divided into a plurality of groups, and are electrically connected to the drive ICs 30 provided corresponding to the groups. For this reason, a plurality of drive ICs 30 are provided corresponding to the elements of the heat generating portion 12 and the groups of individual electrodes 14 connected thereto. Each drive IC 30 is disposed adjacent to the corresponding group of individual electrodes 14, and the plurality of drive ICs 30 are disposed on the front surface 21 side of the wiring board 20 along the arrangement direction of the heat generating portions 12. Is done.

  The wiring member 41 electrically connects the driving IC 30 and the individual electrode 14 corresponding to the driving IC 30. The wiring member 42 electrically connects the driving IC 30 and terminals (not shown) provided on the front surface 21 of the wiring board 20. The wiring members 41 and 42 are bonding wires made of metal such as Cu, Au, and Al, for example. In FIG. 3, only one set of driving IC 30 and wiring members 41 and 42 are illustrated for easy understanding.

  The covering member 24 is included in the atmosphere by oxidation due to contact with the atmosphere or by sealing the plurality of drive ICs 30 and the wiring members 41 and 42 electrically connected to each of the drive ICs 30. Protects against corrosion caused by moisture.

  The covering member 24 has a characteristic that resistance to compressive stress is stronger than resistance to tensile stress. The covering member 24 having such characteristics has, for example, a curing / shrinking property that shrinks when cured, and is made of a thermosetting, ultraviolet curable, or visible light curable resin material. Specific examples of the covering member 24 include an epoxy resin and a silicone resin.

  Here, for example, a case where an external force received by the wiring board 20 via the connector 60 is applied to the other end 20a2 of the wiring board 20 upward, that is, in a direction further away from the heat sink 50 is considered. At this time, a compressive stress is generated in the covering member 24. Since the covering member 24 has a characteristic that it is stronger against the compressive stress than the tensile stress, the covering member 24 is hardly damaged. Therefore, according to the thermal head 1 according to the first embodiment, electrical continuity between the head base 10 and the wiring board 20 can be ensured.

  Next, the thermal printer according to the first embodiment will be described with reference to FIG. FIG. 4 is a schematic diagram of the thermal printer 100 according to the first embodiment.

  The thermal printer 100 according to the first embodiment includes a thermal head 1, a platen roller 2, and a transport mechanism. The thermal head 1 is attached to a housing (not shown) so that the arrangement direction of the heat generating portions 12 is along the main scanning direction which is a direction orthogonal to the conveyance direction of the recording paper 4 as a recording medium. Yes.

  The transport mechanism includes a drive unit (not shown) and transport rollers 3a to 3d. The transport mechanism is for transporting the recording paper 4 in the direction of the arrow in FIG. 4 and transporting it onto the heat generating portion 12 of the thermal head 1. The drive unit has a function of driving the transport rollers 3a to 3d, and for example, a motor can be used. The transport rollers 3a to 3d can be configured by, for example, covering a cylindrical shaft body made of metal such as stainless steel with an elastic member made of butadiene rubber or the like.

  The platen roller 2 has a function of pressing the recording paper 4 onto the heat generating portion 12 of the thermal head 1. The platen roller 2 is disposed so as to extend along a direction (main scanning direction) orthogonal to the conveyance direction of the recording paper 4, and has both end portions so as to be rotatable while the recording paper 4 is pressed onto the heat generating portion 12. Is supported and fixed. The platen roller 2 can be configured by, for example, covering a cylindrical shaft body made of a metal such as stainless steel with an elastic member made of butadiene rubber or the like.

  As shown in FIG. 4, the thermal printer 100 generates heat while the recording paper 4 is pressed onto the heat generating portion 12 of the thermal head 1 by the platen roller 2 and the recording paper 4 is transferred onto the heat generating portion 12 by the transport mechanism. Each element of the section 12 is selectively heated. Through such a series of operations, the thermal printer 100 performs predetermined printing on the recording paper 4.

<Second Embodiment>
Next, a thermal head according to a second embodiment will be described with reference to FIG. FIG. 5 is a front view of a thermal head 1A according to the second embodiment.

  The thermal head 1A shown in FIG. 5 has the same configuration as the thermal head 1 shown in FIG. 3 except that an adhesive member 70 is further provided between the wiring board 20 and the heat sink 50.

  As the adhesive member 70, a double-sided tape or a resin adhesive can be exemplified. A plurality of materials may be combined to form the adhesive member 70.

  Since the heat radiating plate 50 comes into contact with the entire surface of the wiring board 20 through the adhesive member 70, the heat radiating performance is higher than that of the thermal head 1 in which only one end 20 a 1 of the wiring board 20 is in contact with the heat radiating plate 50. improves.

  Further, since the adhesive member 70 provided between the wiring board 20 and the heat radiating plate 50 can serve as a spacer, for example, the wiring board 20 arranged to be inclined with respect to the heat radiating plate 50, Deformation due to its own weight can be suppressed. Further, for example, the adhesive member 70 made of double-sided tape is soft and can buffer the external force received by the wiring board 20, so that it is difficult to be damaged. Therefore, according to the thermal head 1A according to the second embodiment, it is possible to improve the heat dissipation of the wiring board 20 and further reduce the occurrence of deformation and damage in the wiring board 20.

<Third Embodiment>
Next, a thermal head according to a third embodiment will be described with reference to FIG. FIG. 6 is a front view of a thermal head 1B according to the third embodiment.

  The thermal head 1B shown in FIG. 6 has the same configuration as the thermal head 1A shown in FIG. 5 except that an adhesive member 72 is provided instead of the adhesive member 70. The adhesive member 72 is disposed so that the thickness close to the head substrate 10, that is, the one end 20 a 1 side of the wiring board 20 is smaller than the thickness h far from the head substrate 10, that is, the other end 20 a 2 side of the wiring board 20. Has been. For this reason, for example, the heat generated in the drive IC 30 moves to the heat sink 50 and the other end 20a2 side of the wiring board 20, and as a result, the heat generated on the one end 20a1 side of the highly heat-generating wiring board 20 is effectively used. Can dissipate heat.

  In the thermal head 1 </ b> B shown in FIG. 6, the other end 20 a 2 of the wiring board 20 is separated from the adhesive member 72. For this reason, the bending of the other end 20a2 of the wiring board 20 to the heat radiating plate 50 can be allowed to some extent, but the deformation beyond the state in contact with the adhesive member 72 is limited. Therefore, according to the thermal head 1B according to the third embodiment, the occurrence of excessive deformation in the wiring board 20 can be reduced. That is, the thermal head 1 </ b> B according to the present embodiment is particularly advantageous when the wiring board 20 that is required to have high heat dissipation properties and is allowed to be deformed to some extent. Here, the thickness h on the other end 20a2 side of the adhesive member 72 can be set to 300 to 500 μm, for example, but is not limited thereto, and can be changed according to the size of the wiring board 20 and the degree of deformation, for example. .

<Fourth Embodiment>
Next, a thermal head according to a fourth embodiment will be described with reference to FIG. FIG. 7 is a front view of a thermal head 1C according to the fourth embodiment.

  The thermal head 1C shown in FIG. 7 has the same configuration as the thermal head 1 shown in FIG. 3 except that the wiring board 20 having a different shape is provided.

  The wiring board 20 shown in FIG. 7 has a chamfered portion 23 on the back surface 22 side. The chamfered portion 23 is provided so that the wiring board 20 and the heat radiating plate 50 are in contact with each other in a region R where the wiring board 20 has a predetermined inclination with respect to the heat radiating plate 50 and overlaps the driving IC 30 in plan view. It has been. For this reason, for example, heat dissipation is further improved as compared with the case where the adhesive member 70 or the adhesive member 72 is provided between the wiring board 20 and the heat sink 50.

  Note that the wiring board 20 and the heat sink 50 need only be in contact with each other in the region R overlapping the driving IC 30 in plan view, and the chamfered portion 23 is not necessarily provided on the wiring board 20. Further, it is only necessary that the wiring board 20 and the heat radiating plate 50 are in contact with each other in a part of the region R that overlaps with the drive IC 30 in a plan view. The plate 50 may not be in contact.

  As mentioned above, although each embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and various changes are possible without departing from the gist thereof. For example, although the thermal printer 100 including the thermal head 1 according to the first embodiment is shown, the present invention is not limited to this, and the thermal head 1A, 1B, or 1C according to another embodiment is used as the thermal printer 100. You may prepare. Moreover, you may combine the thermal heads 1-1C which are several embodiment.

  Also, the head base 10 has been described by exemplifying a flat head in which the heat generating portion 12 is provided on the front surface side of the substrate 11, but an end face head in which the heat generating portion 12 is provided on the end surface of the substrate 11 may be used. Good.

  Further, in each of the above-described embodiments, the one end 20 a 1 near the head base 10 is in contact with the heat sink 50, and the other end 20 a 2 far from the head base 10 is inclined with respect to the heat sink 50 so as to be separated from the heat sink 50. However, the present invention is not limited to this. For example, the wiring board 20 may be arranged such that the other end 20 a 2 is in contact with the heat sink 50 and the one end 20 a 1 is separated from the heat sink 50.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1, 1A, 1B, 1C Thermal head 10 Head base 11 Substrate 12 Heat generating part 13 Thermal storage layer 14 Individual electrode 15 Common electrode 20 Wiring board 22 Adhesive member 24 Cover member 30 Drive IC
41, 42 Wiring member 50 Heat sink 60 Connector 100 Thermal printer

Claims (8)

A heat sink,
A head substrate having a substrate provided on the heat sink;
A wiring board provided on the heat sink so as to be adjacent to the head base ;
An adhesive member positioned between the wiring board and the heat sink ;
The wiring board is inclined with respect to the heat sink so that one of the one end close to the head base and the other end far from the head base is in contact with the heat sink and the other is separated from the heat sink. Arranged ,
The thermal head according to claim 1, wherein the adhesive member has a smaller thickness on a side closer to the head base than on a side far from the head base . The thermal head according to claim 1 , wherein the wiring board has the other end portion separated from the adhesive member. A heat sink,
A head substrate having a substrate provided on the heat sink;
A wiring board provided on the heat sink so as to be adjacent to the head base ;
An adhesive member positioned between the wiring board and the heat sink ;
The wiring board is inclined with respect to the heat sink so that one of the one end close to the head base and the other end far from the head base is in contact with the heat sink and the other is separated from the heat sink. disposed, a thermal head in which the other end is characterized that you have apart from the adhesive member. It further comprises a connector provided on the other end side of the wiring board,
The said wiring board is arrange | positioned so that the said one end part may contact the said heat sink, and the said other end part may leave | separate from the said heat sink, The thermal as described in any one of Claims 1-3 characterized by the above-mentioned. head. A driving IC provided on the wiring board;
The thermal head according to claim 4 , further comprising: a covering member that is made of a resin material having curing shrinkage and covers the driving IC from the wiring board to the substrate. The thermal head according to claim 5 , wherein a region of the wiring board that overlaps the driving IC in plan view is in contact with the heat radiating plate. The wiring board has a rectangular shape having a long side and a short side in plan view,
The thermal head according to any one of claims 1 to 6 , wherein the long side is disposed so as to face the head substrate. The thermal head according to any one of claims 1 to 7 ,
A transport mechanism for transporting a recording medium onto a heat generating portion provided on the substrate;
A thermal printer comprising: a platen roller that presses the recording medium on the heat generating portion.

Images