JP4357333B2 - Thermal head - Google Patents

Description

  The present invention relates to a thermal head that is incorporated in a printing apparatus such as a thermal transfer printer and can perform image printing suitable for recording paper, and an assembling method thereof.

A conventional thermal head is described in Patent Document 1, and will be described with reference to FIG. 5. A horizontally long head substrate 31 having a predetermined thickness is disposed at the bottom of the figure. A plurality of heating elements 32 are aligned.
The head substrate 31 is attached to the lower surface of the heat radiating plate 35, and the heat radiating plate 35 is attached to the lower surface of the base 36. Accordingly, the conventional thermal head has a configuration in which the head substrate 31 is attached to the base 36 via the heat radiating plate 35.

The base 36 has a plurality of through holes 36a and screw holes 36b formed between the through holes 36a and the through holes 36a.
A first screw member 37 having a length longer than the thickness dimension of the base 36 is passed through the through hole 36a, and one end of the first screw member 37 on the lower side in the figure is attached to the heat radiating plate 35 with an adhesive. It is fixed with etc.
The other end of the first screw member 37 on the upper side in the figure protrudes upward from the upper surface of the base 36, and a nut member 38 is screwed to the protruding portion so that the heat radiating plate 35 and the base 36 are connected. It is integrated.

The first screw member 37 is configured such that the heat radiating plate 35 and the base 36 are in close contact with or separated from each other by rotating the nut member 38 at the other end with a tool such as a wrench.
Further, the second screw member 39 is screwed into the screw hole 36b of the base 36, and the tip thereof is in contact with the upper surface of the heat sink 5, and the second screw member 39 is rotated by a screwdriver or the like. By doing so, the front end presses the upper surface of the heat radiating plate 35, and the heat radiating plate 35 at the portion where the second screw member 39 is rotated is pushed down by a predetermined amount so as to be separated from the base 36.

  Such a conventional thermal head may warp when the head substrate 31 is manufactured. However, when the head substrate 31 has a warp, the nut member 38 is tightened or loosened, or the second screw member 39 is used. The heat sink 35 is partially separated from or closely adhered to the base 36 by tightening or loosening the head plate 31 to correct the warp of the head substrate 31 and make it flat.

In addition, when a conventional thermal head is used in a thermal transfer printer, a central portion in the longitudinal direction of the heat radiating plate 35 is unified by the nut member 38 and the second screw member 39 in order to stabilize the running of the ink ribbon during printing. The head substrate 31 was curved in a circular arc shape through the heat radiating plate 35 by adjusting to be convex.
A thermal head having a head substrate that is curved in an arc shape so that the central portion is most convex can stably meander the ink ribbon during printing. Occurrence can be prevented and image quality can be improved.
Japanese Patent Laid-Open No. 9-201991

However, in the conventional thermal head, the central portion in the longitudinal direction of the head substrate 31 can be made the most convex only by adjusting the nut member 38 and the second screw member 39 near the central portion of the base 36. The left and right end portions could not be curved in an arc shape.
Therefore, the nut member 38 and the second screw member 39 on the left and right end sides are also adjusted and the head substrate 31 is curved in an arc shape via the heat radiating plate 35, so that there is a problem that it takes time to assemble. .
Further, since the plurality of first and second screw members 37 and 39 and the nut member 38 are used, there is a problem that the number of parts increases and the cost increases.
As described above, the present invention solves the above-mentioned problem, and with a small number of parts, the central portion of the head substrate is curved in a circular arc shape that is most convex so that the ink ribbon travels stably and high-quality image printing is performed. It is an object of the present invention to provide a thermal head that can be performed and an assembly method thereof.

As a first means for solving the above problems, a thermal head of the present invention includes a long head substrate in which a plurality of heating elements are aligned, a first head mounting base on which the head substrate is mounted, A second head mounting base to which the first head mounting base is attached, and a facing surface is formed on the second head mounting base on the side facing the first head mounting base. with the central portion convex portion is formed, in the corners of the both longitudinal ends are formed cut-shaped inclined surface, prior Symbol first head mount, the inclined surface of the both longitudinal ends The portion nearest to the inner side of the position facing the head is inserted into a through hole formed in the second thermal head mounting base, and the tip of the screw hole formed on the surface of the first head mounting base facing the second head mounting base. Tighten by screw member By being kicked, and wherein the central portion of the convex portion and the abutting longitudinal direction set to be the most convex, and both ends of the longitudinal direction are formed by bending so as to follow the inclined surface To do.

Further, as a second means for solving the above-described problem, the convex portion at the center of the second head mounting base is made of a screw, and the amount of protrusion on the facing surface can be adjusted. To do.

In the thermal head of the present invention, the first head mounting base mounted to face the opposing surface of the second head mounting base has a convex portion at the center in the longitudinal direction that is the most convex, and both end portions in the longitudinal direction are since located on the inclined surface is curved so as to follow the second head mount of the inclined surface, even the head substrate is curved following the first head mount, the wrinkles or the like occurs in the ink ribbon Can be prevented.
Therefore, high quality image printing can be performed.

Further, the first head mount may be curved head substrate simply tightening the screw member for attachment to the second head mount at inner position than a position facing the inclined surface.

  Moreover, since the convex part of the center part of a 2nd head mounting base consists of a screw and height adjustment is possible, the height of a convex part can be adjusted and the favorable curved shape of a head board | substrate can be obtained.

  In the thermal head assembly method of the present invention, when both ends of the first head mounting base are fastened to the second head mounting base with screw members, the first head mounting base is formed by the convex portions formed on the second head mounting base. The center part in the longitudinal direction of the other surface is pressed, the both ends of the first head mounting base are positioned on the inclined surfaces formed on the both ends of the second head mounting base, and the first head mounting base is arcuate. Therefore, the head substrate can be assembled in an arc shape through the first head mounting base.

   Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a thermal head according to the present invention, FIG. 2 is a front view of a second head mounting base according to the present invention, and FIG. 3 shows a head substrate mounted on the first head mounting base according to the present invention. FIG. 4 is a schematic front view of a thermal transfer printer using the thermal head of the present invention.

First, a thermal head 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the lower part of the figure, a horizontally long head substrate 2 is formed in a predetermined thickness in the horizontal direction of the figure. It is arranged.
The head substrate 1 has a plurality of heat generating elements 2a arranged on the lower surface in the figure in the longitudinal direction on the left and right sides, and the upper surface in the figure is fixed to one surface 3a of the first head mount 3 with an adhesive or the like. It has become.
The first head mount 3 is made of a metal plate with good heat dissipation such as aluminum, and dissipates heat stored in the head substrate 2 during printing.

Further, in the first head mounting base 3, screw holes 3b having a predetermined effective diameter are formed at two positions on the left and right in the figure on the other surface 3b which is the upper surface shown in FIG.
A second head mounting base 4 made of a metal such as SUS or iron is disposed above the other surface 3 b of the first head mounting base 3.
On the opposing surface 4a of the lower surface in the figure facing the other surface 3b of the first head mounting base 3 of the second head mounting base 4, a convex part 4b protruding at a predetermined height is formed at the center in the longitudinal direction. At the same time, the corners on both ends in the longitudinal direction are cut by grinding or the like to form inclined surfaces 4c and 4c that are inclined at a predetermined angle. The projecting dimension of the convex portion 4b from the facing surface 4a is approximately 70 μm.

Further, the second head mounting base 4 is formed with a pair of through holes 4d at positions facing the pair of screw holes 3c of the first head mounting base 3 inside the inclined surfaces 4c and 4c. In addition, a pair of screw members 5 having a predetermined effective diameter that can be screwed are disposed in the screw holes 3 c of the first head mounting base 3.
The first head mounting base 3 can be attached to the second head mounting base 4 by inserting the pair of screw members 5 through the through holes 4d and 4d and screwing them into the screw holes 3c.

In the method of assembling the thermal head 1 of the present invention having such a configuration, the head substrate 2 on which the plurality of heating elements 2a are formed is fixed to one surface 3a of the first head substrate 3 with an adhesive or the like. Thereafter, the second head mounting base 4 is positioned with a positioning jig or the like so as to face the other surface 3 b of the first head mounting base 3, and the second head mounting base 4 is mounted on the first head mounting base 3. Put.
Then, the screw member 5 is inserted into the pair of through holes 4d of the second head mounting base 4 aligned with the pair of screw holes 3c of the first head mounting base 3 and tightened.

Then, the central part in the longitudinal direction of the other surface 3b of the first head mounting base 3 is pressed by the convex part 4b formed on the second head mounting base 4, and the central part of the first head mounting base 3 is the first. It becomes convex.
At the same time, both end portions of the first head mounting base 3 are positioned on the inclined surfaces 4 c formed on both end sides of the second head mounting base 4. As a result, the first head mounting base 3 is curved in an arc shape so that the central portion is the most convex. Therefore, the head substrate 2 is also curved in an arc shape following the first head mounting base 3.
In addition, since the convex part 4b of the center part of the 2nd head mounting base 4 is comprised with screws, such as a female screw, it can be adjusted to the height from which the suitable curved shape of the 1st head mounting base 3 is obtained with a screw. It is.
For this reason, the tension of the ink ribbon 16 to be described later can be made appropriate, and stable ribbon running can be obtained.

Such a thermal transfer printer 11 using the thermal head 1 that is curved in an arc shape by projecting the central portion in the longitudinal direction of the head substrate 2 will be described with reference to FIG. The roller 12 is formed in a columnar shape that is elongated in a direction perpendicular to the paper surface and is rotatably arranged.
Above the platen roller 12, the thermal head 1 of the present invention comprising a line head is disposed in parallel to the platen roller 12.
Then, the thermal head 1 is configured such that the second head mounting base 4 is supported on one end side of the rotating arm 14, and the rotating arm 14 rotates about the rotation support portion 14 a on the other end side as a fulcrum. Head up / down is possible by contacting and separating from the roller 12.

Further, a recording paper 15 made of photographic paper or the like that can be transported in the transport direction of the arrow B is fed between the thermal head 1 and the platen roller 12, and one of the recording papers 15 is disposed above the recording paper 15. An ink ribbon 16 coated with ink of a desired color is supplied to the lower surface in the figure, which is a surface.
Further, on the downstream side (the left side in the drawing) of the recording paper 15 in the conveyance direction indicated by the arrow B, a paper feed roller 17 and a pressure roller 18 that can be driven and rotated by pressing against the paper feed roller 17 are arranged. It is installed.

  The paper feed roller 17 can be driven to rotate by a drive source such as a motor (not shown). The recording paper 15 fed between the platen roller 12 and the thermal head 13 is nipped between the paper feed roller 17 and the pressure roller 18 so that the paper feed roller 17 rotates counterclockwise. It can be conveyed in the direction of arrow B by rotation. Further, the recording paper 15 sandwiched between the paper feed roller 17 and the pressure roller 18 can be back-fed in the direction opposite to the arrow B by reversing the paper feed roller 17 in the clockwise direction. Yes.

The ink ribbon 16 is formed in a width dimension corresponding to the print range in the row direction of the recording paper 15 and is accommodated in the cartridge 19.
The ink ribbon 16 has one end wound around a winding core 19a and the other end wound around a supply core 19b. The ink ribbon 16 is wound around the supply core 19b by rotating the winding core 19a. The take-up core 19a can be wound up.
Then, the cartridge 19 can be mounted on the printer main body 11a by rotating the rotating arm 14 upward to largely separate the thermal head 1 from the platen roller 12.

  In the printing operation of the thermal transfer printer 11 using the thermal head 1 of the present invention, first, when the cartridge 19 is mounted on the printer main body 11a, the ink ribbon 16 is interposed between the platen roller 12 in the head-up state and the thermal head 1. Is located. Thereafter, when the recording paper 15 is fed between the ink ribbon 16 and the platen roller 12 in the direction of the arrow B, the recording paper 15 is sandwiched between the paper feed roller 17 and the pressure roller 18 so that the head is positioned. Done.

  After cueing the recording paper 15, the thermal head 1 is lowered to press the ink ribbon 16 against the recording paper 15. Then, the plurality of heating elements 2a of the thermal head 1 are selectively heated based on the print information, and the paper feed roller 17 is rotated to convey the recording paper 15 in the direction of arrow B. The ink is selectively thermally transferred, and a desired image can be printed on the recording paper 15.

In the image printed by the thermal transfer printer 11 using the thermal head 1 of the present invention, since the head substrate 2 is curved in a circular arc shape with the central portion in the longitudinal direction being the most convex, the ink being wound up The tension applied to the ribbon 16 can maximize the central portion in the width direction.
For this reason, it is possible to prevent problems such as meandering in the ink ribbon 16 during printing. Further, since the tension applied to the central portion of the ink ribbon 16 becomes the largest, it is possible to prevent the ink ribbon 16 from being wrinkled.

It is a front view of the thermal head regarding this invention. It is a front view of the 2nd head mounting base concerning this invention. It is the front view which attached the head board | substrate to the 1st head mounting base concerning this invention. 1 is a schematic front view of a thermal transfer printer using a thermal head of the present invention. It is principal part sectional drawing explaining the conventional thermal head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal head 2 Head substrate 3 1st head mounting base 3a One surface 3b The other surface 4 The 2nd head mounting base 4a Opposing surface 4b Convex part 4c Inclined surface 4d Through-hole 5 Screw member 11 Thermal transfer printer 12 Platen roller 14 Rotating arm 14a Rotating support 15 Recording paper 16 Ink ribbon 17 Paper feed roller 18 Pressure roller 19 Cartridge 19a Winding core 19b Supply core

Claims (2)

A long head substrate in which a plurality of heating elements are aligned, a first head mounting base to which the head substrate is mounted, and a second head mounting base to which the first head mounting base is mounted,
In the second head mounting base, a facing surface is formed on the side facing the first head mounting base, and a convex portion is formed at the center portion in the longitudinal direction of the facing surface, and on both end sides in the longitudinal direction. the corner cutting shape of the inclined surface is formed, the first head mount before SL, the inclined surfaces facing the inner most recent portion of the position in the longitudinal direction of the both end side, the second thermal head mount When the screw is inserted into the through hole formed on the surface of the first head mounting base and is screwed into a screw hole formed on the surface of the first head mounting base facing the second head mounting base, The thermal head is characterized in that a central portion in the longitudinal direction that comes into contact is most convex, and both end portions in the longitudinal direction are curved so as to follow the inclined surface . 2. The thermal head according to claim 1, wherein the convex portion at the center of the second head mounting base is made of a screw, and the amount of protrusion on the facing surface can be adjusted.

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