JP2005186345A - Thermal head and thermal printer using this thermal head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance thermal head capable of maintaining a sustained reliability of an electrical connection between FPC and a head board, and a thermal printer. <P>SOLUTION: The thermal head is equipped with the head board 1 having a plurality of heating elements 2 and a circuit conductor 3; the PFC 4 with a wiring conductor electrically connected with the circuit conductor 3; and a support member 10 which supports the FPC 4 through an adhesive and of such a construction that one end side of the FPC 4 is overlapped along a surface end part of the head substrate 1 and the circuit conductor 3 is joined with the wiring conductor through a conductive material at the overlapping part. In this thermal head, a part of the FPC 4 is curved in such a way that this part protrudes downward or upward to the main surface of the FPC 4 and the curved part serves as a cushioning part 14 for absorbing an external force applied to the FPC 4. Also, the thermal printer is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermal head that performs a recording operation using heat generated by a heating element, and a thermal printer using the same.

  Conventionally, a thermal head has been used as a printer mechanism such as a word processor. For example, as shown in FIG. 4, such a conventional thermal head is electrically connected to a rectangular head substrate 21 having a plurality of heating elements 22 and circuit conductors 23 formed on the upper surface, and to the circuit conductors 23 of the head substrate 21. A flexible wiring board 24 (hereinafter abbreviated as FPC) having a plurality of wiring conductors connected to the head, and a support member 30 that supports the head substrate 21 and the FPC 24 on the upper surface via an adhesive 27. Is done.

  The FPC 24 is for supplying power from the outside to the heating element 22 on the head substrate 21, and the power is supplied to the heating element 22 on the head substrate 21 through the FPC 24. Then, the heating element 22 generates Joule heat and forms a predetermined print on the recording medium.

  The electrical connection between the head substrate 21 and the FPC 24 is performed by superimposing one end of the FPC 24 along one end of the upper surface of the head substrate 21 and then using the overlapping portion on the wiring conductor and the head substrate 21. This is performed by joining the circuit conductor 23 via solder.

  Incidentally, a connector member 26 is attached to the other end of the FPC 24 so that an electric circuit and an electric signal from the outside can be supplied onto the head substrate 21 by connecting the electric circuit in the printer and the FPC 24. It is worn.

The connector member 26 has a structure in which a metal connector pin is supported by a housing, and an FPC 24 and an electric circuit in the printer are electrically connected by inserting an external connection member into the housing. Is done. The external connection member inserted into the connector member 26 may be removed from the housing of the connector member when the thermal head is replaced. At this time, a large external force is applied to the FPC 24.
JP-A-9-150540 Japanese Patent Laid-Open No. 11-8455

  However, since most of the FPC 24 is bonded to the support member 30 in the conventional thermal head described above, most of the external force applied to the FPC 24 when the external connection member is pulled out from the connector member 26 is obtained. There is a problem that it is difficult to improve the connection reliability between the FPC 24 and the head substrate 21 because it is transmitted to the connection portion between the FPC 24 and the head substrate 21.

  Such a problem is particularly likely to occur when an attempt is made to reduce the size of the thermal head by reducing the bonding area between the FPC 24 and the support member 30.

  The present invention has been devised in view of the above problems, and an object thereof is to provide a high-performance thermal head and a thermal printer capable of maintaining high reliability of electrical connection between an FPC and a head substrate. It is in.

  The thermal head of the present invention includes a head substrate on which a plurality of heating elements and circuit conductors are formed, a flexible wiring substrate having wiring conductors electrically connected to the circuit conductors, and the flexible wiring substrate using an adhesive. A support member that supports the circuit board, and superimposes one end side of the flexible wiring board along an end portion on the head substrate, and the circuit conductor and the wiring conductor are passed through the conductive material at the overlapping portion. In the thermal head formed by bonding, a part of the flexible wiring board located outside the overlapping part is bent so as to protrude downward or upward with respect to the main surface of the flexible wiring board, and the bending part is flexible wiring. A cushion portion for absorbing an external force applied to the substrate is used.

  In the thermal head of the present invention, a connector member into which an external connection member is inserted is attached to the other end side of the flexible wiring board, and the insertion direction of the external connection member and the protruding direction of the cushion portion are substantially orthogonal to each other. It was made to be characterized.

  Furthermore, the thermal head of the present invention is characterized in that the cushion portion of the flexible wiring board is not bonded to the support member.

  A thermal printer according to the present invention includes the above-described thermal head, a transport unit that transports a recording medium onto the thermal head, and a drive unit that drives the thermal head.

  According to the present invention, a part of the flexible wiring board is bent so as to protrude downward or upward with respect to the main surface of the flexible wiring board, and the bending portion absorbs an external force applied to the flexible wiring board. Even if a large external force is applied to the flexible wiring board when the external connection member is pulled out from the connector member attached to the flexible wiring board or when the external connection member is inserted into the connector member because it is a cushion part. The force is satisfactorily absorbed by the cushion portion, and the impact transmitted to the connection portion between the flexible wiring board and the head substrate can be reduced. Therefore, even when the bonding area between the flexible wiring board and the support member is reduced to reduce the size of the thermal head, the connection reliability between the flexible wiring board and the head substrate can be improved.

  Moreover, according to this invention, since the cushion part of a flexible wiring board is not adhere | attached with respect to the said supporting member, the absorption force of the external force in a cushion part can be raised more.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of a thermal head according to an embodiment of the present invention. The thermal head shown in the figure is roughly a head substrate 1, an FPC 4 (flexible wiring substrate) connected to the head substrate 1, and The connector member 6 is attached to the FPC 4 and a support member 10 that supports the head substrate 1.

  The head substrate 1 is made of various materials such as an insulating material such as alumina ceramics and a semiconductor material such as single crystal silicon having an insulating film formed on the surface, and a heating element 2 and a circuit conductor 3 are provided on the upper surface thereof. And functions as a support base material that supports them.

  When the head substrate 1 is made of alumina ceramics, for example, an appropriate organic solvent or solvent is added to and mixed with ceramic raw material powders such as alumina, silica, and magnesia to form a slurry, and this is made into a conventionally known doctor blade method or calendar. A ceramic green sheet is formed by adopting a roll method or the like, and thereafter, the ceramic green sheet is punched into a predetermined shape and fired at a high temperature.

  On the head substrate 1, a plurality of heating elements 2, a plurality of circuit conductors 3 and the like arranged in a straight line are respectively attached.

  The heating element 2 is made of an electric resistance material such as TaSiO, TiSiO, TaSiNO, TaN, and has a predetermined electric resistivity, so that electric power from an external power source is applied via the circuit conductor 3 etc. Then, Joule heat is generated, and the heat is generated at a predetermined temperature necessary for forming a printed image on the heat-sensitive recording medium, for example, 200 ° C. to 350 ° C.

  The heating element 2 and the circuit conductor 3 are deposited on the head substrate 1 in a predetermined pattern and thickness by employing a conventionally known sputtering method and photolithography technique.

  The head substrate 1 is connected to an FPC 4 for supplying various print signals from the printer main body and power from an external power source to the heating element 2 and a driver IC (not shown).

  The FPC 4 is formed by interposing a plurality of wiring conductors 5 electrically connected to the circuit conductor 3 on the head substrate 1 between a plurality of flexible resin films (made of polyimide resin). A connection part 11 connected to the circuit conductor 3 on the substrate 1 via a conductive material such as solder or an anisotropic conductive resin material, a connector part 12 for connecting an external connection member, and a support member 10 and an adhesive material. The cushion part 14 is bent in a convex shape substantially perpendicular to the longitudinal direction of the connection part 11 and is formed in parallel with the heating element row of the head substrate. The groove portion 15 of the member 10 accommodates a curved portion protruding in the convex shape, that is, the cushion portion 14.

  The cushion portion 14 is curved so as to protrude toward the support member in the vicinity of the connection portion 11. For example, in the present embodiment, the cushion portion 14 is bent by approximately 90 ° with respect to the lower surface of the FPC. And the groove part 15 on the support member 10 is formed in the dimension (for example, width 5mm, depth 10mm) of the grade which can ensure sufficient clearance after accommodating the cushion part 14. FIG. You may process C surface or R surface suitably so that the support member surface opening edge of the groove part 15 may not damage the surface of FPC4. Moreover, the groove part 15 can consider various shapes, such as a V-shaped groove instead of a U-shaped groove.

  On the other hand, a right angle type connector member 6 is fixed to the connector portion 12 of the FPC 4 by soldering, and the insertion direction of the external connection member 9 when the external connection member 9 is fitted to the connector member 6 is the cushion portion. The direction is substantially perpendicular to the 14 protruding directions.

  For this reason, even when a large external force is applied to the FPC 4 when the external connection member 9 is pulled out from the connector member 6 attached to the FPC 4, the force is absorbed well by the cushion portion 14, and the FPC 4 and the head substrate 1 The impact transmitted to the connecting portion 11 can be reduced, and the connection reliability between the FPC 4 and the head substrate 1 can be improved.

  Moreover, in this embodiment, since the cushion part 14 of FPC4 is not adhere | attached with respect to the supporting member 10, the absorption force of the external force in the cushion part 14 can be raised more.

  For example, when the FPC 4 is soldered to the head substrate 1, first, one end side thereof is overlapped along the end portion of the head substrate 1, and the wiring conductor 5 is connected to the circuit conductor 3 by soldering at the overlapping portion. Then, this is melted at a predetermined temperature using a heater bar, and the circuit conductor 3 and the wiring conductor 5 are soldered together to be electrically connected to the head substrate 1. After that, a part of the head substrate 1 and the bonding portion 13 of the FPC 4 are further bonded to the upper surface of the support member 10 made of a good heat conductive material such as aluminum via an adhesive 7 such as a double-sided tape or an adhesive. ing.

  Thus, the support member 10 supports the head substrate 1, the FPC 4, and the like on the upper surface, and absorbs a part of the heat in the head substrate 1 through the lower surface of the head substrate 1, so that the temperature of the head substrate 1 is excessive. It is designed to effectively prevent high temperatures.

  Such a support member 10 is manufactured, for example, by forming an ingot (lumb) such as aluminum into a predetermined shape by a conventionally known metal processing method.

  In the thermal printer in which the thermal head as described above is incorporated, as shown in FIG. 2, the driving means C for driving the thermal head T, the external connection member 9 described above, and the recording medium as a heating element of the thermal head T. 2, a platen roller 17 and a transport roller 18 are disposed as transport means for transporting the sheet 2 up.

  The driving means C includes a driver IC in which a shift register, a latch, a switching transistor, and the like are integrated at a high density, a control circuit that supplies a control signal such as a strobe signal and a latch signal to the driver IC, and the like. The heat generation of the heating element 2 is controlled by switching on and off the switching transistor in the driver IC based on the control signal.

  The external connection member 9 is for electrically connecting the thermal printer and the above-described thermal head. Normally, the external connection member 9 is a connector member 6 having a shape corresponding to the connector member 6 by a predetermined external force. External connector members made of the same material (for example, nylon) are preferably used, and both connectors are connected when the thermal head T is assembled in the thermal printer.

  At this time, even if a large force is applied to the connector member 6 in the insertion direction of the external connection member 9, a strong external force is directly applied to the connection portion 11 because of the cushion portion 14 having a groove in a direction orthogonal to the insertion direction. Therefore, the occurrence of problems such as the FPC 4 being bent or the connecting portion 11 of the FPC 4 being peeled off from the head substrate is effectively prevented, and the connection work between the thermal head T and the printer body is simplified. It becomes possible to improve the productivity of the thermal printer.

  On the other hand, the platen roller 17 as a conveying means is a cylindrical member in which butadiene rubber or the like is wound around the outer periphery of a shaft core made of a metal such as SUS to a thickness of about 3 mm to 15 mm, and the heating element 2 of the thermal head T. The recording medium is conveyed in a direction orthogonal to the arrangement of the heating elements 2 (in the direction of the arrow in the figure) while being rotatably supported above and pressing the recording medium against the heating elements 2.

  The outer periphery of the conveying roller 18 is formed of metal, rubber, or the like, and is arranged separately from the thermal head T on the upstream side and the downstream side in the recording medium conveying direction. The platen roller 17 supports the running of the recording medium.

  At the same time, a large number of heat generating elements 2 are selectively joule-heated as the driving means C is driven, and a predetermined print is formed by conducting these heats to the recording medium.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, in the above-described embodiment, the cushion portion 14 is protruded toward the support member. Instead, as shown in FIG. 3, the cushion portion 14 is opposite to the support member 10, that is, the recording medium. You may make it protrude in the side. In this case, since it is not necessary to form the groove part 15 in the support member 10, productivity improves.

  In the embodiment described above, the cushion portions 14 may be formed in a plurality of rows.

  Furthermore, in the above-described embodiment, the support member 10 directly supports the head substrate 1, but instead, another member may be interposed between the support member 10 and the head substrate 1.

It is sectional drawing of the thermal head concerning one Embodiment of this invention. FIG. 2 is a schematic side view of a thermal printer configured by incorporating the thermal head of FIG. 1. It is sectional drawing of the thermal head concerning other embodiment of this invention. It is sectional drawing of the conventional thermal head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Head substrate 2 ... Heating element 3 ... Circuit conductor 4 ... FPC
5 ... Wiring conductor 6 ... Connector member 7 ... Adhesive material 9 ... External connection member 10 ... Support member 11 ... Connection portion 12 ... Connector portion 13 ... Adhesion portion 14 ... Cushion part 15 ... Groove part 17 ... Platen roller 18 ... Conveying roller

Claims (4)

A head substrate on which a plurality of heating elements and circuit conductors are formed; a flexible wiring substrate having wiring conductors electrically connected to the circuit conductors; and a support member that supports the flexible wiring substrate via an adhesive. A thermal head formed by superimposing one end side of the flexible wiring substrate along an end portion on the head substrate, and joining the circuit conductor and the wiring conductor via a conductive material at the overlapping portion. ,
A part of the flexible wiring board located outside the overlapping part is bent so as to protrude downward or upward with respect to the main surface of the flexible wiring board, and the bending part absorbs an external force applied to the flexible wiring board. A thermal head characterized in that it is a cushion part for carrying out. A connector member into which an external connection member is inserted is attached to the other end side of the flexible wiring board, and the insertion direction of the external connection member and the protruding direction of the cushion portion are substantially orthogonal to each other. Item 2. The thermal head according to Item 1. The thermal head according to claim 1, wherein the cushion portion of the flexible wiring board is not bonded to the support member. A thermal head comprising: the thermal head according to any one of claims 1 to 3, a transport unit that transports a recording medium onto the thermal head, and a drive unit that drives the thermal head. Printer.

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