JP2012214028A - Thermal head array and thermal printer including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal head array capable of improving pitch accuracy of heat generating parts between adjacent thermal heads and having improved maintainability, and to provide a thermal printer including the same.SOLUTION: This thermal head array Y is obtained by arranging a plurality of thermal heads X1, X2 including a substrate 1 and a plurality of heat generating parts 3 arranged in one row. The plurality of heat generating parts 3 of the thermal heads X1, X2 are linearly provided. The substrate 1 includes one long side 1d, the other long side 1e, one short side 1a, and the other short side 1c. In the adjacent thermal heads X1, X2, the one short side 1a of the substrate 1 of the one thermal head X1 and the other short side 2c of a substrate 2 of the other thermal head X2 form different angles. The other short side 1c of the substrate 1 of the one thermal head X1 and one short side 2a of the substrate 2 of the other thermal head X2 form different angles.

Description

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

  Conventionally, various thermal heads have been proposed as printing devices such as facsimiles and video printers. For example, the thermal head described in Patent Document 1 includes a substrate and a plurality of heat generating portions provided on the substrate. The thermal head array is configured such that the rows of the heat generating portions of the pair of substrates are arranged on a straight line.

JP-A 62-77954

  In the thermal head array described in Patent Document 1, the entire short sides of the pair of substrates facing each other are bonded together. For this reason, for example, due to the state of the short side of the substrate, such as variations in processing accuracy, the pitch interval of the heat generating portions between adjacent thermal heads varies, and the pitch interval of the heat generating portions is within a predetermined range. There is a problem that it is difficult.

  In order to solve the above problems, when the short sides of the thermal head are processed so that the short sides of the opposing thermal heads do not contact each other, it is necessary to process the short sides according to the place to be arranged in the thermal head array. In other words, each thermal head has position dependency. For this reason, each time the thermal head is replaced, it is necessary to replace the thermal head array, which causes a problem that the maintainability is poor.

  The present invention has been made to solve the above-described problem, and can improve the pitch accuracy of the heat generating portion between adjacent thermal heads, and includes a thermal head array with improved maintainability. An object is to provide a thermal printer.

  A thermal head array according to an embodiment of the present invention is formed by arranging a plurality of thermal heads having a substantially rectangular substrate and a plurality of heat generating portions provided on the substrate in a row. The plurality of heat generating portions of the thermal head are linearly provided. Further, the substrate has one long side, the other long side, one short side connecting the one long side and the other long side, and the other short side connecting the one long side and the other long side. And have sides. In the adjacent thermal heads, one short side of the substrate of one thermal head and the other short side of the substrate of the other thermal head are at different angles with respect to the arrangement direction of the heat generating portions. In addition, the other short side of the substrate of one thermal head and the one short side of the substrate of the other thermal head form different angles with respect to the arrangement direction of the heat generating portions.

  In addition, a thermal printer according to an embodiment of the present invention includes the above-described thermal head array, a transport mechanism that transports a medium onto the heat generating portion, and a platen roller that presses the medium onto the heat generating portion.

The thermal head array of the present invention and the thermal printer including the thermal head array can improve the pitch accuracy of the heat generating portions between adjacent thermal heads, and have an effect that the maintainability is improved.

It is a top view which shows one Embodiment of the thermal head array of this invention. It is the elements on larger scale of the thermal head array of FIG. FIG. 3 is a sectional view taken along line III-III of the thermal head of FIG. 2. It is the elements on larger scale which show the grinding reference marker utilized when grinding the short side of a board | substrate. 1 is a schematic configuration diagram showing an embodiment of a thermal printer of the present invention. It is the elements on larger scale of the thermal head array of this invention. (A) is a figure which shows the resistance value of each conventional heat generating part, (b) is a figure which shows the resistance value of each heat generating part in the thermal head array shown in FIG.

Hereinafter, an embodiment of a thermal head array of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the thermal head array Y of this embodiment includes a radiator H, a plurality of thermal heads X <b> 1 and X <b> 2 arranged in a row on the radiator H, the radiator H and the thermal head. An adhesive layer S and a double-sided tape R interposed between X1 and X2 are provided. The thermal head array Y is composed of thermal heads X1 and X2. Hereinafter, the thermal head X1 may be described as “one thermal head X1” and the thermal head X2 as “the other thermal head X2”.

The heat radiating body H is formed of, for example, a metal material such as copper or aluminum, and a plurality of thermal heads X 1,
In addition to supporting X2, it has a function of radiating a part of heat that does not contribute to printing out of heat generated in the heat generating portion 3 of the thermal heads X1 and X2, as will be described later.

As shown in FIGS. 1-3, each thermal head X1 and X2 is a substantially rectangular substrate 1 in plan view.
A plurality of heat generating parts 3 provided on the substrate 1 and arranged along the longitudinal direction of the substrate 1 in the vicinity of one long side 1d of the substrate 1, and on the substrate 1 along the arrangement direction of the heat generating parts 3 And a plurality of drive ICs 5 arranged side by side. For the sake of convenience of explanation, only the schematic arrangement position of the drive IC 5 is shown by broken lines in FIGS.

The plurality of thermal heads X1 and X2 arranged on the radiator H are arranged in a line so that the heat generating portions 3 of the thermal heads X1 and X2 are arranged on a straight line. Thus, by arranging the thermal heads X1 and X2 in a line, in the thermal head array Y of the present embodiment,
Printing on wide media is also possible.

  The substrate 1 constituting the thermal head X1 includes one long side 1d, the other long side 1e, one short side 1a connecting the one long side 1d and the other long side 1e, and one long side 1d. And the other short side 1c connecting the other long side 1e.

  Similarly, the substrate 2 constituting the thermal head X2 includes one long side 2d, the other long side 2e, one long side 2d and one short side 2a connecting the other long side 2e, It has a long side 2d and the other short side 2c connecting the other long side 2e.

In the thermal head X1, the angle formed by one short side 1a and the other long side 1e is θ1a, and the angle formed by the other short side 1c and the other long side 1e is θ1c. In the thermal head X2, the angle formed by one short side 2a and the other long side 2e is θ2a,
The angle formed by the other short side 2c and the other long side 2e is θ2c.

  One short side 1a of one thermal head X1 and the other short side 2c of the other thermal head X2 are provided to face each other, and one short side with respect to the arrangement direction of the heat generating portions 3 is provided. 1a and the other short side 2c form different angles.

  Further, as shown in FIG. 1, the other short side 1c of one thermal head X1 and the one short side 2a of the other thermal head X2 are provided at both ends of the thermal head array Y to generate heat. The other short side 1c and the one short side 2a are at different angles with respect to the arrangement direction of the portions 3.

  Each of the substrates 1 and 2 in the adjacent thermal heads X1 and X2 has an edge 1b on one long side 1d and 2d side of each of the substrates 1 and 2 when the plurality of thermal heads X1 and X2 are arranged in a line. It arrange | positions so that it may be faced | matched and contacted in 2b.

  Therefore, even if the substrates 1 and 2 constituting the thermal heads X1 and X2 facing each other are arranged in contact with each other at the edges 1b and 2b on the one long side 1d and 2d side, one short side 1a And the other short side 2c are not in contact with each other, and it is possible to reduce the possibility of variations in the pitch interval of the heat generating portions 3.

  Furthermore, one short side 1a of one thermal head X1 and the other short side 2c of the other thermal head X2 are at different angles. The other short side 1c of one thermal head X1 and the other thermal side Xc Since one short side 2a of the head X2 forms a different angle, it is possible to reduce the thermal heads X1 and X2 from having position dependency.

  That is, in the thermal head array Y, even if the arrangement of one thermal head X1 and the other thermal head X2 is reversed, the other short side 1c and the one short side 2a are arranged in the arrangement direction of the heat generating parts 3. On the other hand, since the other short side 1c and the one short side 2a have different angles, the possibility that the other short side 1c and the one short side 2a come into contact with each other can be reduced.

  That is, when configuring the thermal head array Y, it is not necessary to consider where the one thermal head X1 and the other thermal head X2 are arranged, so that the thermal head array Y can be easily manufactured.

  The thermal head array Y is provided such that one short side 1a and the other short side 2c facing each other are separated from each other as they go from one long side 1d, 2d to the other long side 1e, 2e. Yes. Therefore, the possibility that one short side 1a and the other short side 2c facing each other come into contact with each other can be reduced, and the possibility that the pitch intervals of the heat generating portions 9 may vary can be further reduced.

  Furthermore, the thermal head array Y includes an angle θ1a formed by one short side 1a of one thermal head X1 and the other long side 1e, the other short side 2c of the other thermal head X2, and the other long side 2e. Is substantially equal to the angle θ2c. Therefore, in a region surrounded by one short side 1a and the other short side 2c, which is a region where the thermal heads X1 and X2 are joined, the heat radiating body H is joined to one thermal head X1 and the other thermal head X2. The state can be made substantially the same. As a result, the pressing force by the medium generated in the thermal heads X1 and X2 can be made close to uniform in the central portion of the thermal head array Y to which the pressing force is most applied by the medium. From the above, it is possible to reduce the occurrence of uneven printing at the center of the thermal head array Y.

  An angle θ1a formed by one short side 1a of one thermal head X1 and the other long side 1e and an angle θ2c formed by the other short side 2c of the other thermal head X2 and the other long side 2e are: The phrase “substantially equal” is not limited to the fact that the formed angle θ1a and the formed angle θ2c are exactly the same. For example, the difference between the formed angle θ1a and the formed angle θ2c may be within ± 3 °.

  Also, an angle θ1a formed by one short side 1a of one thermal head X1 and the other long side 1e and an angle θ2c formed by the other short side 2c of the other thermal head X2 and the other long side 2e are: It is preferable that it is 90.1-93.5 degrees.

  Furthermore, the thermal head array Y includes an angle θ1a formed by one short side 1a of one thermal head X1 and the other long side 1e, the other short side 1c of one thermal head X1, and the other long side 1e. Is substantially equal to the angle θ1c. Further, an angle θ2a formed by one short side 2a of the other thermal head X2 and the other long side 2e and an angle θ2c formed by the other short side 2c of the other thermal head X2 and the other long side 2e are: Almost equal. That is, the thermal heads X1 and X2 have a trapezoidal shape in plan view.

  As described above, since the thermal heads X1 and X2 have a trapezoidal shape in plan view, no matter where the thermal heads X1 and X2 are arranged in the thermal head array Y, the adjacent thermal heads X1 and X2 are arranged. One short side 1a, 2a and the other short side 1c, 2c are separated from one long side 1d, 2d toward the other long side 1e, 2e. Therefore, it is possible to further reduce the possibility of variations in the pitch interval of the heat generating portions 9. Further, the position dependency of the thermal heads X1 and X2 can be further reduced.

  Furthermore, since the thermal heads X1 and X2 have a trapezoidal shape in plan view, the other short side 1c of one thermal head X1 has an obtuse angle with respect to the arrangement direction of the heat generating portions 9. Become. In addition, one short side 2a of the other thermal head X2 has an acute angle with respect to the arrangement direction of the heat generating portions 9. In other words, when the thermal head array Y is viewed in plan, both ends of the thermal heads X1 and X2 constituting the thermal head array Y are inclined toward the center.

  Here, the medium to be printed is printed by being conveyed on the thermal head array Y by a roller, and the medium is directed from one long side 1d, 2d to the other long side 1e, 2e. Be transported. That is, the medium transport direction is a direction from one long side 1d, 2d toward the other long side 1e, 2e.

  As described above, when the medium is transported, if the medium is longer than the length of the thermal head array, the medium may not peel from the thermal head array. However, the thermal head array Y is located at both ends of the thermal heads X1 and X2 constituting the thermal head array Y, the other short side 1c of one thermal head X1 and the one short side 2a of the other thermal head X2. Are inclined toward the center of the thermal head array Y as it goes in the transport direction. Therefore, the substrates 1 and 2 of the thermal heads X1 and X2 do not exist at both ends of the thermal head array Y on the downstream side in the transport direction, and a gap is generated between the medium and the heat radiator H. Thereby, the medium can be efficiently peeled from the thermal head array Y.

  Further, the thermal heads X1 and X2 constituting the thermal head array Y have substantially the same shape in plan view. In the example shown in FIG. 1, the thermal heads X1 and X2 are trapezoidal.

  As described above, since the thermal heads X1 and X2 constituting the thermal head array Y have substantially the same shape in plan view, the positional dependency of the thermal heads X1 and X2 on the thermal head array Y is improved. Can be made. Therefore, when only one of the thermal heads X1 constituting the thermal head array Y is damaged, the thermal head array Y can be produced again by replacing only the thermal head X1, and the maintainability can be improved. . Further, by making the thermal heads X1 and X2 in the same shape, the manufacturing process can be simplified as compared with the case where the thermal heads X1 and X2 are manufactured in different shapes.

  Although FIG. 1 shows an example in which the thermal heads X1 and X2 have a trapezoidal shape in plan view, the present invention is not limited to this. That is, it is only necessary that the thermal heads X1 and X2 have substantially the same shape.

  In the thermal head array Y, one thermal head X1 and the other thermal head X2 are joined at the edges 1b and 2b on the long sides 1d and 2d of the substrates 1 and 2, respectively. Thereby, the adjustment of the pitch interval of the heat generating portion 3 can be easily performed. Furthermore, since the heat generating part 3 is provided on one of the long sides 1d and 2d of the substrates 1 and 2 and is arranged away from the one long side 1d and 2d, Even if the other thermal head X2 is joined at the edges 1b and 2b on the one long side 1d and 2d side of the substrates 1 and 2, the possibility that the heat generating portion 3 is cracked or chipped can be reduced. it can. Furthermore, since the heat generating part 3 is provided on the one long side 1d, 2d side of the substrates 1 and 2, it is possible to reduce an increase in the pitch interval of the heat generating part 3.

  The substrates 1 and 2 of the thermal heads X1 and X2 are formed of an electrically insulating material such as alumina ceramics or a semiconductor material such as single crystal silicon.

  Hereinafter, each member constituting the thermal heads X1 and X2 will be described using the thermal head X1.

  A heat storage layer 7 is formed on the upper surface of the substrate 1. The heat storage layer 7 includes a base portion 7a formed on the entire upper surface of the substrate 1 and a ridge that extends in a strip shape along one long side 1d of the substrate 1 and has a substantially semi-elliptical cross section as shown in FIG. 7b. The raised portion 7b functions to favorably press the heat generating portion 3 against the medium to be printed. For convenience of explanation, FIG. 1 does not show the raised portion 7b, and FIG. 2 shows a region where the raised portion 7b is formed by a two-dot chain line.

  In addition, the heat storage layer 7 is made of, for example, glass having low thermal conductivity, and temporarily accumulates a part of heat generated in the heat generating part 3 to increase the temperature of the heat generating part 3. It functions to shorten the time required and improve the thermal response characteristics of the thermal head X1. The heat storage layer 7 is formed, for example, by applying a predetermined glass paste obtained by mixing a glass powder with an appropriate organic solvent to the upper surface of the substrate 1 by screen printing or the like, and baking it at a high temperature. The

  As shown in FIG. 3, an electrical resistance layer 9 is provided on the upper surface of the heat storage layer 7. The electrical resistance layer 9 is interposed between the heat storage layer 7 and a first electrode wiring 11 and a second electrode wiring 13 which will be described later, and these first electrode wirings in plan view as shown in FIGS. 11 and a region having the same shape as the second electrode wiring 13 (hereinafter referred to as an intervening region) and a plurality of regions exposed from between the first electrode wiring 11 and the second electrode wiring 13 (hereinafter referred to as an exposed region). Have. In FIG. 1, the intervening region of the electrical resistance layer 9 is hidden by the first electrode wiring 11 and the second electrode wiring 13.

Each exposed region of the electrical resistance layer 9 forms the heat generating portion 3 described above. In the present embodiment, the heat generating portion 3 that is each exposed region of the electric resistance layer 9 has a rectangular shape. And the heat-emitting part 3 is arrange | positioned along with the row shape on the protruding part 7b of the thermal storage layer 7. FIG. Thereby, the plurality of heat generating portions 3 are arranged along one long side 1 d of the substrate 1. The plurality of heat generating units 3 are illustrated in a simplified manner in FIGS. 1 and 2 for convenience of explanation, but are arranged with a density of 180 dpi to 2400 dpi (dot per inch), for example.

  The electric resistance layer 9 is made of a material having a relatively high electric resistance, such as TaN, TaSiO, TaSiNO, TiSiO, TiSiCO, or NbSiO. Therefore, when a voltage is applied between the individual wiring portion 11a and the common wiring portion 11b of the first electrode wiring 11 to be described later and a current is supplied to the heat generating portion 3, the heat generating portion 3 generates heat due to Joule heat generation.

  As shown in FIGS. 1 to 3, the first electrode wiring 11 and the second electrode wiring 13 are provided on the upper surface of the electric resistance layer 9. The 1st electrode wiring 11 and the 2nd electrode wiring 13 are formed with the material which has electroconductivity, for example, is formed with any one kind of metal of aluminum, gold | metal | money, silver, and copper, or these alloys. .

  As shown in FIG. 1, the first electrode wiring 11 extends between the heat generating portion 3 and the drive IC 5, and connects between them. More specifically, the first electrode wiring 11 divides a plurality of heat generating portions 3 into a plurality of groups, and electrically connects the heat generating portions 3 of each group to a drive IC 5 provided corresponding to each group. Yes.

  In addition, as shown in FIG. 2, the first electrode wiring 11 is connected to one end part of both the individual wiring part 11 a individually connected to one end part of the heat generating part 3 and two adjacent heat generating parts 3. It is comprised with the common wiring part 11b.

  More specifically, the individual wiring portion 11a and the common wiring portion 11b are regularly connected to each heat generating portion row 3A that is a set of four adjacent heat generating portions 3. That is, one end of the individual wiring part 11a is connected to the two heat generating parts 3 arranged at both ends of each heat generating part row 3A. One end portion of the common wiring portion 11b is connected to both of the two heat generating portions 3 arranged in the center of each heat generating portion row 3A.

  As shown in FIG. 2, the second electrode wiring 13 has a substantially U shape in plan view. For each heat generating portion group 33 composed of two adjacent heat generating portions 3, two adjacent heat generating portions 3. It is comprised so that between the other end parts may be connected. More specifically, each heat generating portion row 3 </ b> A includes two heat generating portion groups 33. The second electrode wiring 13 is connected to both of the two heat generating parts 3 of the one heat generating part group 33 and both of the two heat generating parts 3 of the other heat generating part group 33 in each heat generating part row 3A. ing.

  As described above, since the first electrode wiring 11 and the second electrode wiring 13 are connected to each heat generating part 3, the individual wiring part 11a connected to each heat generating part group 33 and the common wiring part 11b are connected. When a voltage is applied, a current is supplied to the heat generating unit 3.

  For example, the electric resistance layer 9, the first electrode wiring 11 and the second electrode wiring 13 are sequentially laminated on the heat storage layer 7 by a conventionally known thin film forming technique such as sputtering, for example. Thereafter, the laminated body is formed by processing into a predetermined pattern using a conventionally known photolithography technique or etching technique.

As shown in FIG. 1, the driving IC 5 is disposed corresponding to each group of the plurality of heat generating units 3 and is connected to the other end of the individual wiring unit 11 a of the first electrode wiring 11. The drive IC 5 is
It is for controlling the energization state of each heat generating part 3 and has a plurality of switching elements inside. When each switching element is in an on state, it is energized, and when each switching element is in an off state. A well-known thing which becomes a non-energized state can be used.

  The other end of the individual wiring portion 11a of the first electrode wiring 11 is electrically connected to one of a plus side terminal and a minus side terminal of an external power supply device (not shown) via the drive IC 5. On the other hand, the other end portion of the common wiring portion 11b of the first electrode wiring 11 is not electrically connected to the other of the positive side terminal and the negative side terminal of the external power supply device (not shown) without passing through the driving IC 5. It has become. Thereby, when each switching element of the driving IC 5 is in the ON state, the individual wiring part 11a connected to each switching element, and the common wiring part 11b connected to the heat generating part group 33 connected to the individual wiring part 11a A voltage is applied between the two and a current is supplied to the heat generating portion 3 of the heat generating portion group 33, whereby the heat generating portion 3 generates heat.

  The drive IC 5 is electrically connected to a control device (not shown) that controls the drive IC 5. As a result, a control signal from the control device is transmitted to the drive IC 5, and the heating unit 3 can be selectively heated by controlling the on / off state of the switching element in the drive IC 5 by the control signal.

  As shown in FIG. 3, a protective film 15 that covers the heat generating portion 3, the first electrode wiring 11, and the second electrode wiring 13 is formed on the heat storage layer 7 formed on the upper surface of the substrate 1. 1 and 2, the protective film 15 is not shown for convenience of explanation, but the protective film 15 extends along the arrangement direction of the heat generating portions 3, and the heat storage layer 7 of FIGS. It is formed so as to cover the region on the right side of the upper surface of. The protective film 15 corrodes the area covered with the heat generating portion 3, the first electrode wiring 11 and the second electrode wiring 13 by adhesion of moisture contained in the atmosphere or contact with a recording medium to be printed. It is intended to protect against wear. The protective film 15 can be formed of, for example, a SiC-based material, a SiN-based material, a SiO-based material, or a SiON-based material. Further, the protective film 15 can be formed by using a conventionally well-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.

  As shown in FIG. 3, the adhesive layer S and the double-sided tape R are provided between the radiator H and the substrate 1 of each thermal head X1 as described above. More specifically, the adhesive layer S extends between the substrate 1 and the heat radiating body H so as to correspond to the row of the plurality of heat generating portions 3 arranged on the substrate 1 and adheres them. The adhesive layer S is formed of an adhesive made of a heat-dissipating resin, such as a silicone resin, an epoxy resin, a polyimide resin, an acrylic resin, a phenol resin, and a polyester resin containing a filler. It is formed of a thermosetting type, a room temperature curing type, or a chemical reaction curing type.

  The double-sided tape R is interposed in a region where the adhesive layer S between the substrate 1 and the heat dissipating body H is not present, and bonds them together. The double-sided tape 4 is formed using, for example, an acrylic adhesive as a base material.

  Further, as shown in FIG. 3, on the upper surface of the radiator H, a groove Ha extending along the arrangement direction of the heat generating portions 3 is provided between the region where the adhesive layer S is provided and the region where the double-sided tape R is provided. Is formed. The groove Ha is formed to accommodate an adhesive that protrudes from the upper surface of the radiator H on which the adhesive layer S is provided when the thermal head X1 is joined to the radiator H.

  Hereinafter, a method of forming the substrates 1 and 2 of the thermal heads X1 and X2 will be described using the thermal head X1.

The other short side 1c of the substrate 1 of each thermal head X1 is formed on the substrate 1 after the heat storage layer 7, the electric resistance layer 9, the first electrode wiring 11, the second electrode wiring 13, and the protective film 15 are formed. Before being bonded onto the body H, it is cut. The cutting of the other short side 1c of the substrate 1 can be performed with reference to a grinding reference marker 35 shown in FIG. 4, for example.

  The grinding reference marker 35 is formed on the substrate 1 and has a first marker part 36, a second marker part 37, and a third marker part 38. The first marker portion 36, the second marker portion 37, and the third marker portion 38 constitute the same material layer that constitutes the electrical resistance layer 9, and the first electrode wiring 11 and the second electrode wiring 13. It is formed by the laminated body with the same material layer as it exists. As a result, the material layer constituting each of the electrical resistance layer 9, the first electrode wiring 11 and the second electrode wiring 13 is processed into a predetermined pattern using a conventionally known photolithography technique, etching technique or the like. Among these, the first marker part 36, the second marker part 37, and the third marker part 38 can also be processed into a predetermined pattern in parallel.

  The first marker portion 36 extends in a band shape along one long side 1d of the rectangular substrate 1 before cutting. In the first marker portion 36, a rectangular notch 36a is formed in the vicinity of the other short side 1c 'of the substrate 1 before cutting, and the edge 36b of the notch 36a is the other side of the substrate 1 before cutting. It is arranged at a position of a first distance L1 from the short side 1c ′.

  The second marker portion 37 is positioned in the vicinity of the other short side 1c 'of the substrate 1 before cutting, and extends in a strip shape in parallel to the other short side 1c'. The edge 37a on the other short side 1c ′ side of the substrate 1 before cutting in the second marker portion 37 is a second distance that is longer than the first distance L1 from the other short side 1c ′ of the substrate 1 before cutting. Are arranged at a distance L2.

  The third marker portion 38 is located on the other short side 1 c ′ side of the substrate 1 before cutting with respect to the second marker portion 37, and extends in a strip shape parallel to the second marker portion 38.

  The grinding reference marker 35 is formed as described above. For example, a straight line K connecting one end of the edge 36 b of the first marker portion 36 and one end of the edge 37 a of the second marker portion 37 is used as the other short side of the substrate 1. As a reference for grinding 1c obliquely, the substrate 1 can be ground. The other short side 1c of the substrate 1 can be ground using, for example, a grinder equipped with a diamond grindstone or the like.

  Further, for example, when the other short side 1c ′ before cutting of the substrate 1 is ground and the other short side 1c after cutting has a desired inclination angle, the edge 36b of the first marker portion 36 and the first The edge 37a of the first marker part 36, the edge 37a of the second marker part 37, the edge 37a of the second marker part 37, and the third marker in such a positional relationship that the edge 37a of the two marker part 37 remains completely and only the third marker part 38 disappears completely. If the part 38 is arranged, the grinding reference marker 35 can be used for confirming the finished state after grinding.

  Moreover, in FIG. 4, although the 2nd marker part 37 is formed in parallel with the other short side 1c 'of the board | substrate 1 before cutting, the 2nd marker part 37 is formed in the other short side of the board | substrate 1 after cutting. If it is made to incline according to the desired inclination angle of 1c, the finished state can be easily confirmed for the inclination angle of the other short side 1c after grinding.

  Next, an embodiment of the thermal printer of the present invention will be described with reference to FIG. FIG. 5 is a schematic configuration diagram of the thermal printer Z of the present embodiment.

As shown in FIG. 5, the thermal printer Z of this embodiment includes the above-described thermal head array Y, transport mechanism 40, platen roller 50, power supply device 60, and control device 70. The thermal head array Y is attached to an attachment surface 80a of an attachment member 80 provided in a casing (not shown) of the thermal printer Z. The thermal head array Y is mounted such that the arrangement direction of the heat generating sections 3 is along a direction (main scanning direction) perpendicular to the conveyance direction S of the medium P, which will be described later, that is, a direction perpendicular to the paper surface of FIG. It is attached to the member 80.

  The transport mechanism 40 is for transporting a medium P such as thermal paper or image receiving paper onto which ink is transferred in the direction of arrow S in FIG. And conveying rollers 43, 45, 47, and 49. The transport rollers 43, 45, 47, and 49 are formed by, for example, covering cylindrical shaft bodies 43a, 45a, 47a, and 49a made of metal such as stainless steel with elastic members 43b, 45b, 47b, and 49b made of butadiene rubber or the like. Can be configured. Although not shown, when the medium P is an image receiving paper or the like onto which ink is transferred, an ink film is transported together with the medium P between the medium P and the heat generating portion 3 of the thermal head array Y. .

  The platen roller 50 is for pressing the medium P onto the heat generating portion 3 of the thermal head array Y, and is arranged so as to extend along a direction orthogonal to the conveyance direction S of the medium P. Both end portions are supported so as to be rotatable in a state of being pressed upward. The platen roller 50 can be configured by, for example, covering a cylindrical shaft body 50a made of metal such as stainless steel with an elastic member 50b made of butadiene rubber or the like.

  The power supply device 60 is for applying a voltage for generating heat from the heat generating section 3 of the thermal head array Y and a voltage for operating the drive IC 11 as described above. The control device 70 is for supplying a control signal for controlling the operation of the drive IC 11 to the drive IC 11 in order to selectively generate heat in the heat generating section 3 of the thermal head array Y as described above.

  As shown in FIG. 5, the thermal printer Z of the present embodiment conveys the medium P onto the heat generating unit 3 by the conveyance mechanism 40 while pressing the medium P onto the heat generating unit 3 of the thermal head array Y by the platen roller 50. However, it is possible to perform predetermined printing on the medium P by selectively causing the heat generating unit 3 to generate heat by the power supply device 60 and the control device 70. When the medium P is an image receiving paper or the like, printing on the medium P can be performed by thermally transferring ink of an ink film (not shown) conveyed together with the medium P to the medium P.

  The correction related to the resistance value of the heat generating portion 3 constituting the thermal heads X1 and X2 will be described with reference to FIGS. The resistance value is a value indicating electrical resistance, and is hereinafter referred to as a resistance value.

  As shown in FIG. 6, one thermal head X1 has a plurality of heat generating portions 3Aa to 3Ah, and these heat generating portions 3Aa to 3Ah constitute a heat generating portion row 3A. Similarly, the other thermal head X2 has a plurality of heat generating portions 3Ba to 3Bh, and these heat generating portions 3Ba to 3Bh constitute a heat generating portion row 3B.

  In the thermal heads X1 and X2, the heat generating portions 3Aa to 3Ah and 3Ba to 3Bh are subjected to so-called trimming correction for correcting the resistance value within a predetermined range. Therefore, as shown in FIGS. 7A and 7B, the resistance values of the heat generating portions 3Aa to 3Ah and 3Ba to 3Bh are corrected to values within a predetermined range.

However, as shown in FIG. 7A, the resistance values of the heat generating portions 3Aa to 3Ah of one thermal head X1 and the resistance values of the heat generating portions 3Ba to 3Bh of the other thermal head X2 increase from 3Ba to 3Bh. In such a case, the resistance value is greatly different between the adjacent heat generating part 3Ah and the heat generating part 3Ba. As a result, there is a possibility that uneven printing occurs due to a difference in resistance value between the adjacent thermal heads X1 and X2.

  On the other hand, as shown in FIG. 7B, the thermal head array Y includes the resistance value of the heat generating portion 3Ah provided adjacent to one short side 1a of one thermal head X1 and the other thermal head X1. The resistance value of 3Ba provided adjacent to the other short side 2c of the head X2 is substantially equal. Thereby, the difference in resistance value between the adjacent thermal heads X1 and X2 can be reduced, and the possibility of uneven printing can be reduced.

  In the thermal head array Y, the resistance values of the heat generating portions 3Aa, 3Ah, 3Ba, 3Bh arranged on the outermost sides of the thermal heads X1, X2 are set to predetermined values. Therefore, it is possible to reduce the difference in resistance value between the adjacent thermal heads X1 and X2, and it is possible to reduce the position dependency of the thermal heads X1 and X2. That is, regardless of the position of the thermal head array Y in which the thermal heads X1 and X2 are arranged, it is possible to reduce an increase in the difference in resistance value between the adjacent heat generating sections 3. Therefore, maintainability of the thermal head array Y can be improved.

  In addition, it is not limited that the resistance value of the adjacent heat generating part 3 is the same as the resistance value of the adjacent heat generating part 3 being substantially equal. For example, the resistance value of the adjacent heat generating portions 3 may include a predetermined value to a width of ± 3 to 5%. In other words, the upper limit value of the predetermined value may be 105% of the predetermined value, and the lower limit value of the predetermined value may be 95% of the predetermined value. The predetermined value may be appropriately changed depending on the configuration of the thermal head array Y.

  A conventionally known method can be used as a trimming method for the heat generating portions 3Aa to 3Ah and 3Ba to 3Bh. The thermal head array Y is an area between the thermal heads X1 and X2 by bringing the resistance values of the heat generating portions 3Aa, 3Ah, 3Ba, and 3Bh located at both ends of the thermal heads X1 and X2 constituting the thermal head array Y close to each other. Printing unevenness can be reduced, the thermal heads X1 and X2 can be easily replaced, and the maintainability can be improved.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning.

  For example, in the thermal head array Y of the above-described embodiment, the two thermal heads X are arranged on the heat radiating body H. However, the present invention is not limited to this, and an arbitrary number of three or more thermal heads X can be provided. You may arrange in a line.

  In the thermal head X of the above embodiment, as shown in FIG. 3, the heat storage layer 7 is interposed between the substrate 1 and the electric resistance layer 9, but the present invention is not limited to this. For example, although not shown, the electric storage layer 7 may be formed directly on the upper surface of the substrate 1 without forming the heat storage layer 7 between the substrate 1 and the electric resistance layer 9. Further, the base portion 7 a of the heat storage layer 7 may not be formed, and only the raised portion 7 b may be interposed between the substrate 1 and the electric resistance layer 9.

  Further, in the thermal head array Y of the above embodiment, as shown in FIGS. 1 and 2, the one short side 1 a and the other short side 3 c of each of the substrates 1 and 2 in the adjacent thermal heads X 1 and X 2 are opposed to each other. Although the edges 1b and 2b on the one long side 1d and 2d side are abutted and come into contact with each other, the present invention is not limited to this. The edges 1b and 2b of the substrates 1 and 2 may not be in contact with each other.

X1 One thermal head X2 The other thermal head Y Thermal head array Z Thermal printer 1 One thermal head substrate 1a One short side (after cutting)
1a 'One short side (before cutting)
1b Edge 1c Other short side 1d One long side 1e One short side 2 Substrate of the other thermal head 2a One short side (after cutting)
2a 'One short side (before cutting)
2b Edge 2c Other short side 2d One long side 2e One short side 3 Heat generating part 9 Electrical resistance layer 11 First electrode wiring 13 Second electrode wiring 15 Protective film 35 Grinding reference marker 36 First marker part 37 Second marker Part 38 Third marker part

Claims (9)

A thermal head array in which a plurality of thermal heads having a substantially rectangular substrate and a plurality of heat generating portions provided on the substrate are arranged in a row,
The plurality of heat generating portions of the plurality of thermal heads are linearly provided,
The substrate connects one long side, the other long side, the one long side connecting the one long side and the other long side, and the one long side and the other long side. The other short side,
In the adjacent thermal head,
The one short side of the substrate of one of the thermal heads and the other short side of the substrate of the other thermal head are at different angles with respect to the arrangement direction of the heat generating parts,
The other short side of the substrate of one of the thermal heads and the one short side of the substrate of the other thermal head are at different angles with respect to the arrangement direction of the heat generating portions. Characteristic thermal head array.   As the one short side of the substrate of one of the thermal heads and the other short side of the substrate of the other thermal head are directed from the one long side of the substrate to the other long side, The thermal head array according to claim 1, wherein the thermal head array is provided so as to be separated from each other.   The angle formed by the one short side of the one thermal head and the other long side is substantially equal to the angle formed by the other short side and the other long side of the other thermal head. Item 3. The thermal head array according to Item 1 or 2.   The angle formed by the one short side of the one thermal head and the other long side is substantially equal to the angle formed by the other short side of the one thermal head and the other long side. Item 4. The thermal head array according to Item 3.   The thermal head array according to any one of claims 1 to 4, wherein the thermal heads have substantially the same shape in plan view.   6. The thermal head array according to claim 1, wherein one of the thermal heads and the other thermal head are connected at the one long side of the substrate.   The thermal unit according to any one of claims 1 to 6, wherein the plurality of heat generating portions are provided on the one long side of the substrate and are arranged apart from the one long side. Head array.   The resistance value of the heat generating part provided adjacent to the one short side of one thermal head and the resistance value of the heat generating part provided adjacent to the other short side of the other thermal head The thermal head array according to claim 1, wherein the thermal head array is substantially equal to. The thermal head array according to any one of claims 1 to 8,
A transport mechanism for transporting a medium onto the plurality of heat generating units;
A thermal printer comprising: a platen roller that presses a medium onto the plurality of heat generating portions.

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