JP2005238662A - Thermal head and thermal printer using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high performance thermal head capable of being miniaturized and a thermal printer. <P>SOLUTION: This thermal head comprises a head substrate 1 having a plurality of heating elements 2 and a circuit conductor 3 electrically connected to the heating elements 2, and an FPC 4 having a plurality of wiring conductors 5, the one end side of the FPC 4 being provided along the edge of the head substrate 1. The one end side of the FPC 4 is folded and the wiring conductor 5 positioned on the folded section 13 is electrically connected to the circuit conductor 3 on the head substrate 1. <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. 8, the conventional thermal head includes a square head substrate 21 having a plurality of heat generating elements 22 and circuit conductors 23 connected to both ends of the heat generating elements 22 on the upper surface, and the head. A flexible wiring substrate 24 (hereinafter abbreviated as FPC) having a plurality of wiring conductors 25 electrically connected to the circuit conductor 23 of the substrate 21, and the head substrate 21 and the FPC 24 are bonded to each other through an adhesive 27. And a support member 30 supported by

  The FPC 24 is used to supply various print signals (driver IC control signals) from the printer main body and power from an external power source to the heating elements 22 and the driver IC 29, and between a plurality of flexible resin films. And a wiring conductor 25 made of copper foil or the like.

Note that the electrical connection between the head substrate 21 and the FPC 24 is, for example, by solder welding, in which a part of the wiring conductor 25 exposed at the tip portion on one end side of the FPC 24 is overlapped along the end portion of the head substrate 21. In addition, the wiring conductor and the circuit conductor 23 on the head substrate 21 are joined by soldering at this overlapping portion.
JP 2001-334696 A JP 2000-177159 A

  By the way, in recent thermal heads, with the miniaturization of printers, there is an increasing demand for miniaturization of thermal heads, and accordingly, miniaturization of the FPC 24, particularly the direction along the end of the head substrate 21. It is desired to reduce the size in a direction perpendicular to (a sub-scanning direction in the case of this prior art).

  On the other hand, with the recent increase in the density of heating elements, the pattern of the wiring conductor 25 of the FPC 24 tends to become complicated, and there is a problem that it is difficult to downsize the FPC 24 in the sub-scanning direction.

  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 downsizing the thermal head.

  The thermal head of the present invention has a head substrate having a plurality of heating elements and circuit conductors electrically connected to the heating elements, and a plurality of wiring conductors, and one end side is at the end of the head substrate. A flexible wiring board disposed along the wiring board, and the one end side of the flexible wiring board is folded back, and the wiring conductor located at the folded portion is electrically connected to the circuit conductor on the head board. It is characterized by.

  The thermal head of the present invention includes a head substrate having a plurality of heating elements and a circuit conductor electrically connected to the heating elements, and a plurality of wiring conductors, one end of which is an end portion of the head substrate. A flexible wiring board disposed along the wiring board, and electrically connecting the wiring conductor to the circuit conductor in a region inside the tip part on the one end side of the flexible wiring board, and the connection part Further, the flexible wiring board located on the one end side is folded back.

  Furthermore, in the thermal head of the present invention, in the above-described thermal head, a part of the wiring conductor is disposed between the connection portion of the wiring conductor connected to the circuit conductor and one end of the flexible wiring board. Features.

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

  According to the present invention, in a thermal head comprising a head substrate having a heating element and a circuit conductor, and a flexible wiring substrate having one end side disposed along an end of the head substrate, the thermal wiring of the flexible wiring substrate In the thermal head in which the wiring conductor is electrically connected to the circuit conductor on one end side, the one end side of the flexible wiring board is folded back, and the wiring conductor located at the folded portion is connected to the circuit conductor on the head substrate. It is electrically connected, or the wiring conductor is electrically connected to the circuit conductor in a region inside the tip on the one end side of the flexible wiring board, and is located on the one end side from the connection portion. Since the flexible wiring board is folded back, the flexible wiring board is folded over the head by the amount of the flexible wiring board folded back. It can be miniaturized in a direction perpendicular to the end portion of the plate, thereby contributing to the miniaturization of the thermal head and a thermal printer.

  Further, according to the present invention, by arranging a part of the wiring conductor between the connection portion of the wiring conductor connected to the circuit conductor and one end of the flexible wiring board, a surplus area in the folded portion can be provided. Effective use makes it possible to further reduce the size of the flexible wiring board. In this case, the area of the wiring conductor can be widened, and the voltage drop generated in the wiring conductor can be reduced to contribute to the reduction in power consumption of the thermal head.

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

  FIG. 1 is a plan view of a thermal head according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. The thermal heads shown in these drawings generally support the head substrate 1, the FPC 4 (flexible wiring substrate) connected to the head substrate 1, the connector 6 attached to the FPC 4, and the head substrate 1. It is comprised with the supporting member 10. FIG.

  The head substrate 1 can be formed of various materials such as an insulating material such as alumina ceramic or a semiconductor material such as single crystal silicon having an insulating film formed on the surface, and the heating element 2 and the circuit conductor 3 are provided on the upper surface thereof. It is provided 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 elements 2 are linearly arranged in the main scanning direction along one side of the head substrate 1 at a density of 300 dpi, for example, and are made of an electric resistance material such as TaSiO, TiSiO, TaSiNO, TaN, and the like. Therefore, when energized power from an external power source is applied through a circuit conductor 3 electrically connected to the heating element 2, Joule heat is generated, and a print image is printed on the thermal recording medium. It acts to generate heat at a predetermined temperature required for forming, for example, 200 ° C. to 350 ° C.

  The circuit conductor 3 connected to the heating element 2 includes, for example, a common electrode conductor 3a commonly connected to one end side of the heating element 2 and an individual electrode conductor 3b individually connected to the other end side of the heating element 2. And is composed of. The common electrode conductor 3a is formed in a U shape so that a part thereof is arranged substantially in parallel with the arrangement of the heating elements 2, and both ends thereof are set to a predetermined positive potential (for example, 20V) via the wiring conductor 5 of the FPC 4. Connected to the positive terminal of the external power source held at ~ 25V). Further, one end of the individual electrode conductor 3b is connected to the switching element and ground terminal of the driver IC 9 and the negative terminal of the external power source held at the ground potential (for example, 0V to 2V) via the wiring conductor 5 of the FPC 4. When the switching element of the driver IC 9 is turned on, a current flows from the common electrode conductor 3a to the individual electrode conductor 3b, and the heating element 2 generates heat at a predetermined temperature.

  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. On the heating element 2 and the circuit conductor 3, a protective film 8 for covering them is attached.

  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 the driver IC 9.

  On the other hand, the FPC 4 connected to the head substrate 1 is electrically connected to the circuit conductor 3 on the head substrate 1 between a plurality of flexible resin films (formed of a resin material such as polyimide resin). A plurality of wiring conductors 5 are interposed.

  The FPC 4 is folded at one end side to the lower surface side (substrate 1 side) and exposes the wiring conductor 5 located at the folded portion 13 (refers to a region from the tip end on the one end side of the FPC 4). The exposed portion is electrically connected to the circuit conductor 3 of the head substrate 1 via a conductive material such as solder or an anisotropic conductive resin material, and this connection region is a connection portion 11. On the other hand, a connector portion 12 into which a connector pin of the connector 6 is inserted is disposed on the other end side of the FPC 4.

  As described above, since one end side of the FPC 4 is folded to connect the wiring conductor 5 and the circuit conductor 3 on the head substrate 1, the FPC 4 can be reduced in size in the sub-scanning direction by the amount of the folded FPC 4. As a result, the thermal head can be miniaturized.

  In the present embodiment, a part of the wiring conductor 5 is also disposed in a region between the connection portion 11 and the tip on one end side of the FPC 4. Therefore, it is possible to effectively utilize the remaining area in the folded portion 13 of the FPC 4 and to further reduce the size of the FPC 4. In addition, by arranging the wiring conductor 5 in the region, the area of the wiring conductor 5 can be increased, and the voltage drop generated in the wiring conductor 5 can be reduced to contribute to the reduction in power consumption of the thermal head.

  The wiring conductor 5 disposed in the region between the connecting portion 11 of the FPC 4 and the tip on one end side of the FPC 4 is preferably a wiring conductor capable of connecting a plurality of wiring conductors in common. The reason why the wiring conductors that can be connected in common is preferable is that if the wiring conductors that can be connected in common are not connected to each other, current does not flow so much through the wiring conductors in this region, and therefore the significance of the presence of the wiring conductors in the region is small.

  As an example of the wiring conductor 5 disposed in the region between the connection portion 11 of the FPC 4 and the tip on one end side of the FPC 4, signals having similar contents are parallel to a plurality of driver ICs 9 mounted on the head substrate 1. A signal wiring conductor that supplies a signal input to the input terminal, for example, a clock signal, a latch signal, a strobe signal, or the like, or a ground wiring conductor connected to the ground terminals of the plurality of driver ICs 9 is preferable. This is because, for example, in the case of a signal wiring conductor that supplies a clock signal, the same signal is input in parallel to each driver IC 9, so that it is possible to connect the signal wiring conductors in the FPC 4 in common. It is. Further, even in the case of the ground wiring conductor connected to the ground terminal of the driver IC 9, the ground wiring conductors can be connected in common.

  The connector 6 connected to the other end side of the FPC 4 has a structure in which a part of the connector pin is accommodated in the housing, and when an external connection member (not shown) on the printer side is inserted into the housing, The thermal head is electrically connected to an electric circuit in the printer.

  The electrical connection between the connector 6 and the FPC 4 is made by inserting a connector pin into a land 15 with a hole provided in the FPC 4 and connecting the connector pin to the FPC 4 with a conductive material such as solder while the connector pin penetrates the FPC 4. It is fixed to the wiring conductor 5.

  The support member 10 on which the head substrate 1 is placed supports the head substrate 1 and the FPC 4 on the upper surface thereof, and absorbs part of the heat in the head substrate 1 through the lower surface of the head substrate 1. This effectively prevents the temperature of the head substrate 1 from becoming excessively high.

  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 order to complete the head assembly by bonding the FPC 4 to the head substrate 1 with a conductive material (for example, solder bonding) and placing the FPC 4 on the support member 10, a method through the following steps is adopted (see FIG. 3). ).

  Step 1: With the head substrate 1 mounted on the base, the wiring conductor 5 of the FPC 4 to which the connector 6 is attached is electrically connected to the circuit conductor on the head substrate 1 via a conductive material such as solder ( FIG. 3 (a)).

  Step 2: The FPC 4 is bent to the upper surface side starting from a region inside the connecting portion between the FPC 4 and the head substrate 1 (FIG. 3B).

  Step 3: After the base is removed, the joined body of the head substrate 1 and the FPC 4 is bonded to the upper surface of the support member 10 made of a heat-conductive material such as aluminum via an adhesive 7 such as a double-sided tape or an adhesive. (FIG. 3C).

  Thus, the thermal head described above selectively heats each heat generating element 2 based on the driving of the driver IC 9 while conveying the recording medium onto the plurality of heat generating elements 2 and uses the heat to the recording medium. Transmit a predetermined image.

  In a thermal printer in which the above-described thermal head is incorporated, as shown in FIG. 4, the driving means C for driving the thermal head T, the external connection member (not shown), and the recording medium generate heat from the thermal head T. A platen roller 17, a transport roller 18, and the like are disposed as transport means for transporting onto the element 2.

  The external connection member is for electrically connecting the thermal printer and the above-described thermal head, and is usually made of the same material as the connector 6 having a shape corresponding to the connector member 6 by a predetermined external force ( An external connector (for example, made of nylon) is 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 6 in the insertion direction of the external connection member, the protruding portion 13 of the FPC 4 is overlapped in the attachment region of the connector 6, so that the FPC 4 is relatively at the overlapping portion. Becomes difficult to bend. Therefore, the connection work between the thermal head T and the printer body is simplified, and the productivity of the thermal printer can be improved.

  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 plurality 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 head substrate 1 and the FPC 4 are electrically connected by soldering or the like. Instead, as shown in FIG. 5, the head substrate 1 and the FPC 4 are bonded by bonding wires or the like. In this case, the same effect as described above can be obtained.

  In the above-described embodiment, one end side of the FPC 4 is folded and the wiring conductor 5 positioned at the folded portion is electrically connected to the circuit conductor 3 on the head substrate 1. As shown in FIG. 6, the wiring conductor 5 is electrically connected to the circuit conductor 3 in the region inside the tip on one end side of the FPC 4, and the FPC 4 located on one end side of the connecting portion is folded back. In this case, the same effect as described above can be obtained. Further, in this case, as shown in FIG. 7, the folded portion of the FPC 4 is extended to the attachment region of the connector 6, and the connector 6 of the connector 6 is penetrated and fixed by the extended portion. Since it is stably held with respect to the FPC 4, workability when the external connection member on the printer side is attached to and detached from the connector 6 is improved.

It is a top view of the thermal head concerning one Embodiment of this invention. It is sectional drawing of the thermal head of FIG. 1 (a supporting member not shown). (A)-(c) is a figure for demonstrating the assembly process of the thermal head of FIG. 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 thermal head concerning other embodiment of this invention. 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 3a ... Common electrode conductor 3b ... Individual electrode conductor 4 ... FPC
5 ... Wiring conductor 6 ... Connector 7 ... Adhesive 8 ... Protective film 9 ... Driver IC
DESCRIPTION OF SYMBOLS 10 ... Support member 11 ... Connection part 12 of FPC ... Connector part 17 of FPC ... Platen roller 18 ... Conveyance roller

Claims (4)

A head substrate having a plurality of heating elements and a circuit conductor electrically connected to the heating elements, and a flexible wiring board having a plurality of wiring conductors, one end of which is disposed along the end of the head substrate And a wiring board, wherein the one end side of the flexible wiring board is folded back, and the wiring conductor located at the folded portion is electrically connected to the circuit conductor on the head board. A head substrate having a plurality of heating elements and a circuit conductor electrically connected to the heating elements, and a flexible wiring board having a plurality of wiring conductors, one end of which is disposed along the end of the head substrate A flexible wiring board, and electrically connecting the wiring conductor to the circuit conductor in a region inside the tip of the one end side of the flexible wiring board, and being positioned closer to the one end side than the connection portion A thermal head characterized by folding the wiring board. The thermal conductor according to claim 1 or 2, wherein a part of the wiring conductor is disposed between a connection portion of the wiring conductor connected to the circuit conductor and one end of the flexible wiring board. head. A thermal printer comprising: the thermal head according to any one of claims 1 to 3; and a transport unit that transports a recording medium onto the thermal head.

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