JP4704114B2 - Thermal printer and method for assembling the same - Google Patents

Description

  The present invention relates to a thermal printer and an assembling method, and more particularly to a thermal printer capable of printing a desired image on a recording sheet by a thermal head and an assembling method thereof.

A conventional thermal printer will be described in Patent Document 1. As shown in FIG. 5, a conventional thermal printer 30 is configured to press and hold a recording sheet 33 between a first paper feed roller 31 and a pressure roller 32, and When the single paper feed roller 31 is rotated in the direction of arrow A, the recording paper 33 can be conveyed in the horizontal direction of arrow B.
A platen roller 34 and a thermal head 35 that can be pressed against the outer peripheral surface of the platen roller 34 are disposed on the downstream side of the first paper feed roller 31 in the conveyance direction indicated by the arrow B of the recording paper 33. .
As shown in FIG. 6, the thermal head 35 has a heat generating portion 35b formed on a convex portion 35a formed on one end side.

Further, the pressure contact position of the heat generating portion 35b of the thermal head 35 with respect to the platen roller 34 is a virtual connection between the position where the recording paper 33 conveyed in the horizontal direction of the arrow B and the platen roller 34 are in contact with the rotation center 34a of the platen roller 34. It is located downstream of the line 36 by an angle θ (5 to 30 degrees).
In this way, by positioning the heat generating portion 35b on the downstream side of the virtual line 36 by the angle θ, the recording head 33 is conveyed in the direction indicated by the arrow B with the pressure contact pressure that the thermal head 35 presses against the recording paper 33 during printing. Is bent downward in the angle θ and is conveyed in the direction of arrow C.
By curving the recording paper 33 being printed in the direction of arrow C with an angle θ with respect to the carrying direction of arrow B, it is possible to correct the upward bending of the recording paper 33 being printed. It has become.

A second paper feed roller 38 and a pressure roller 39 are disposed on the downstream side of the platen roller 34 in the conveyance direction indicated by the arrow C of the recording paper 33. The second paper feed roller 38 and the pressure roller 39 are arranged on the lower side of the angle θ from the platen roller 34, and press-clamp the recording paper 33 that is curved to the lower side of the angle θ during printing. Yes.
An ink ribbon 40 is drawn between the platen roller 34 and the thermal head 35.

In the conventional thermal printer 30 as described above, the angle of the heat generating portion 35b with respect to the recording paper 33 may be shifted by a predetermined angle, for example, β, as shown in FIG. .
If the angle of the heat generating portion 35b with respect to the recording paper 33 is shifted by a predetermined angle, the heat generated by the heat generating portion 35b cannot be sufficiently transmitted to the ink ribbon 40, and the image quality printed on the recording paper 33 may be deteriorated. there were.
As a countermeasure, the conventional thermal printer 30 moves the thermal head 35 in the horizontal direction indicated by the arrow D in accordance with the angle shift of the angle β, and the center of the heat generating portion 35b is recorded as shown in FIG. The adjustment was made so as to be positioned on the printing surface of the paper 33.
Japanese Patent Laid-Open No. 8-39840

However, the conventional thermal printer 30 as described above moves the thermal head 35 along arrow D or in the opposite direction, so was aligning centers of the heat generating portion 35b to the printing surface of the recording paper 33, There was a problem that fine adjustment was difficult and high-precision positioning was impossible.
In addition, as the thermal head 35 is moved in the direction of arrow D or in the opposite direction, the pressure contact position with respect to the recording paper 33 moves greatly corresponding to the angle deviation of the angle β. In addition, the amount of bending may vary.
The present invention has been made to solve the above-described problems, and it is easy to adjust the angle deviation of the heat generating part of the thermal head, and to prevent the pressure contact position of the heat generating part from moving greatly at the time of adjusting the angle deviation. It is an object of the present invention to provide a thermal printer that can perform high-quality image printing.

As a first means for solving the above problems, a thermal printer according to the present invention includes a cylindrical platen roller, a thermal head having a heat generating portion that can be pressed against the platen roller, and the thermal head supported on one end side. And a recording medium conveyed between the platen roller and the thermal head, the head support member rotating around the support shaft as a fulcrum. By moving, the thermal head can be brought into contact with and separated from the platen roller, and the head support member can adjust the angular deviation of the heat generating portion with respect to the printing surface of the conveyed recording paper. angle adjusting mechanism which is disposed, said angle adjusting mechanism is put in the length direction of the thermal head a the other end of the head supporting member A guide member disposed in the center and attached to the other end of the head support member; and a bearing member rotatably supported by the support shaft, wherein the guide member is the bearing member The guide member is slid with respect to the bearing member, and the other end portion side of the head support member is moved in a direction in which it is in contact with or away from the support shaft. Thus, the angular deviation of the heat generating portion of the thermal head can be adjusted .

Further, as a second means for solving the above-mentioned problem, the angle adjusting mechanism is provided with an adjusting screw capable of moving and adjusting the other end side of the head support member in a direction in which the head is moved away from the support shaft. It is provided.
Further, as a third means for solving the above-described problem, the adjustment screw has a thread portion and a flange portion formed on one side of the thread portion, and the thread portion is used as the head support member. The other end portion side is screwed to the bearing member, and the collar portion is supported by the bearing member so that the other end portion side contacts and separates from the support shaft by adjusting the adjustment screw.

Further, as a fourth means for solving the above-mentioned problem, the thermal printer assembling method of the present invention comprises the angle adjustment mechanism according to any one of claims 1 to 5, and the adjustment screw is adjusted in the adjustment step. When the rotation of the screw is adjusted, the other end side of the head support member moves in a direction in which the head support member comes in contact with or separates from the support shaft, and the angular deviation of the heat generating portion with respect to the printing surface of the recording paper is adjusted. .
Further, as a fifth means for solving the above-mentioned problem, the head support member is provided with a measuring instrument capable of measuring the amount of movement on the other end side that moves in the direction of contact with and away from the support shaft. The angle shift of the heat generating part is adjusted while observing the amount of movement on the other end side by the measuring device.
Further, as a sixth means for solving the above problem, after adjusting the angular deviation of the heat generating part, the positional deviation of the heat generating part with respect to the part where the outer peripheral surface of the platen roller and the conveyed recording paper are in contact with each other. If the positional deviation is found, the thermal head is moved in a direction parallel to the conveyance direction of the recording paper to adjust the positional deviation.

The head support member of the thermal printer of the present invention is rotated about the support shaft, so that the thermal head can be brought into contact with and separated from the platen roller. Since the angle adjustment mechanism that can adjust the angle deviation of the heat generating part with respect to the printing surface is arranged, when the heat generating part is angle shifted, this angle deviation can be easily adjusted with the angle adjustment mechanism, A thermal printer excellent in assemblability can be provided.
The angle adjustment mechanism is disposed on the other end side of the head support member, and the angle adjustment mechanism moves the other end side of the head support member in a direction in which the head support member is moved away from the support shaft. Since the angle deviation of the heat generating part of the head can be adjusted, the angle deviation can be easily adjusted and the assembly is excellent.
The angle adjustment mechanism includes a guide member attached to the other end side of the head support member and a bearing member rotatably supported on the support shaft, and the guide member slides on the bearing member. When the guide member is slid with respect to the bearing member, the other end side of the head support member moves in a direction to be in contact with or separated from the support shaft, so that the thermal head heat generating part can be easily displaced in the angle. Can be adjusted.

In addition, the angle adjustment mechanism is provided with an adjustment screw that can be moved and adjusted in a direction in which the other end portion of the head support member is moved away from the support shaft. Can be adjusted, and is easy to assemble.
The adjustment screw has a threaded portion and a flange formed on one side of the threaded portion. The threaded portion is screwed to the other end of the head support member, and the flange is a bearing member. Since the other end is brought into contact with and separated from the support shaft by adjusting the adjustment screw, the angle of the heat generating portion can be easily adjusted with a commercially available jig such as a screwdriver.

According to another aspect of the present invention, there is provided a thermal printer assembling method comprising the angle adjusting mechanism according to any one of claims 1 to 3 , wherein when the adjusting screw is rotated in the adjusting screw adjusting step, the other end side of the head support member is moved. Since the angle shift of the heat generating portion relative to the printing surface of the recording paper is adjusted by moving in the direction away from the support shaft, the angle shift of the heat generating portion can be adjusted with high accuracy.
The head support member is provided with a measuring device capable of measuring the amount of movement on the other end side that moves in the direction of moving away from the support shaft, and the amount of movement on the other end side is observed by this measuring device. However, since the angle deviation of the heat generating part is adjusted, the angle deviation can be adjusted while looking at the numbers displayed on the measuring instrument, and linear and fine adjustment is possible. Therefore, the heat generating portion can be adjusted with high accuracy without angular deviation.
Also, after adjusting the angular deviation of the heat generating part, check the positional deviation of the heat generating part with respect to the part where the outer peripheral surface of the platen roller and the conveyed recording paper are in contact. Since the positional deviation is adjusted by moving in the direction parallel to the transport direction, even if the thermal head is misaligned by adjusting the angular deviation, it can be easily adjusted.

Embodiments of a thermal printer according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a head support member according to the present invention, FIG. 2 is a cross-sectional view of the main part of the head support member according to the present invention, and FIGS. 3 and 4 are enlarged main parts of the thermal head according to the present invention. FIG.
First, a thermal printer 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. A cylindrical and long platen roller 2 includes a frame-side side plate (not shown) and a rotating shaft 2 a. It is supported so that it can be rotated. The platen roller 2 rotates about a rotation center 2b.

Further, on the outer peripheral surface of the platen roller 2 shown in FIG. 2, the recording paper 3 made of thick paper such as photographic paper can be conveyed, and the upper surface side of the recording paper 3 becomes a glossy printing surface 3a. ing.
Further, a thermal head 4 is disposed above the platen roller 2, and the thermal head 4 is composed of a long line head and can be brought into and out of contact with the platen roller 2 (head up / down). ing.
The recording paper 3 can be reciprocated and conveyed downstream of the platen roller 2 (in the direction of arrow E) or upstream of the platen roller 2 (in the direction of arrow F) by a paper feed roller (not shown).

On the thermal head 4, a convex portion 4 a protruding at a predetermined height is formed along the longitudinal direction of the platen roller 2 on the side facing the platen roller 2 on the lower surface side of the figure, as shown in FIG. A plurality of heat generating parts 4b are formed in a line with a predetermined width on the top of the convex part 4a.
The thermal head 4 is attached to a head mounting base 5 made of a high thermal conductivity material with an adhesive or the like.

Further, the head mounting base 5 shown in FIG. 2 is attached to a head support member 6 made of a highly heat conductive material such as an aluminum plate disposed on the upper side with a small screw (not shown) or the like.
The head support member 6 is bent in a substantially crank shape, and a flat head mounting portion 6a is formed on one end side on the left side of the figure. A head mounting base 5 on which a thermal head 4 is mounted on the head mounting portion 6a. Is attached.

Further, as shown in FIG. 2, the head support member 6 extends from the head mounting portion 6a obliquely upward to the right and has a predetermined length to form a connecting portion 6b. From the connecting portion 6b, the other end portion in the right direction in the drawing is formed. The heat radiation part 6c with a large area is formed.
A plurality of heat sink portions 6d are cut and formed in the heat radiating portion 6c, and the heat of the thermal head 4 that generates heat during printing passes through the head mounting portion 6a of the head support member 6 by the heat sink portion 6d. Heat is released.

The head mounting portion 6a of the head support member 6 is fixed to one end portion 7a of the first rotation lever 7 made of an iron plate or the like with a small screw (not shown), and one end of the first rotation lever 7 is fixed. On the upper side facing the portion side 7a, one end portion side 8a of the second rotating lever 8 made of an iron plate or the like is disposed with a predetermined interval.
A plurality of coil springs 9 are disposed at predetermined intervals between the first ends 7a and 8a of the first and second rotary levers 7 and 8, respectively. One end side 7a, 8a of 8 is elastically biased in a direction away from each other.

The first and second rotating levers 7 and 8 have stopper portions (not shown) for preventing the one end sides 7a and 8a from being opened apart from each other by a biasing force of the coil spring 9. ) Is formed. Therefore, when the second rotation lever 8 is rotated downward, the one end portion side 7a of the first rotation lever 7 is elastically biased toward the lower platen roller 2 by the biasing force of the coil spring 9. Yes.
Further, a plurality of head pressing screws 10 are screwed to one end portion side 7 a of the first rotation lever 7 along the longitudinal direction of the thermal head 4 with a predetermined pitch dimension.

By adjusting the head pressing screw 10, the thermal head 4 can be uniformly pressed against the platen roller 2 via the head mounting base 5.
Further, as shown in FIG. 1, the head support member 6 has a pair of mounting legs 6e facing each other at both ends in the width direction of the arrow G on the other end side on the right end side of the heat radiating portion 6c. Is formed.
Elliptical holes 6f are formed in the mounting legs 6e, and support shafts 11 that support both ends of the side plates on the frame (not shown) side are inserted into the elliptical holes 6f. The other end side is supported.

In addition, the other end portions (not shown) of the first and second rotating levers 7 and 8 are supported on both end portions of the support shaft 11 protruding outward from the elliptical hole 6f, so that the second rotation is performed. By rotating the lever 8, the first rotating member 7 elastically biased by the coil spring 9 is also rotated.
Further, the head support member 6 having the head mounting portion 6a attached to the one end side 7a of the first rotation lever 7 is also rotated about the support shaft 11 with the second rotation lever 8 being driven to rotate. It has become.

When the head support member 6 and the first and second rotation levers 7 and 8 rotate with the support shaft 11 as a fulcrum, the thermal head 4 attached to the head attachment portion 6a of the head support member 6 is attached to the platen roller 2. On the other hand, it is possible to contact / separate (head up / down).
When the second rotation lever 8 is further rotated downward even after the heat generating portion 4b of the thermal head is brought into contact with the platen roller 2 by the rotation drive of the second rotation lever 8, the coil spring 9 The elastic force is transmitted to the thermal head 4 through the one end side 7 a of the first rotating lever 7 and the head mounting portion 6 a of the head support member 6, and the heat generating portion 4 b of the thermal head 4 is applied to the outer peripheral portion of the platen roller 2. It comes to be pressed.

An angle adjustment mechanism 12 is attached to the other end portion of the head support member 6 supported by the support shaft 11 at a substantially central portion in the width direction of the arrow G.
The angle adjustment mechanism 12 can adjust the movement of the head support member 6 in the direction in which the other end side of the head support member 6 contacts and separates from the support shaft 11.
As shown in FIG. 3, the angle adjustment mechanism 12 can adjust the angle deviation (angle α) of the heat generating portion 4 b with respect to the printing surface 3 a of the recording paper 3 being conveyed. The angle deviation of the heat generating part 4b is due to variations in the manufacturing of the thermal head 4, etc., with respect to a virtual line 13 connecting the position where the outer peripheral surface of the platen roller 2 and the recording paper 3 are in contact with the rotation center 2b of the platen roller 2. Thus, the heat generating portion 4b may be displaced by a predetermined angle (for example, the angle α), and this angle deviation can be adjusted by the angle adjusting mechanism 12.

The angle deviation of the heat generating portion 4b is adjusted by the angle adjusting mechanism 12 so that the center of the heat generating portion 4b is positioned on the printing surface 3a of the recording paper 3 as shown in FIG. 2) can be thermally transferred onto the recording paper 3 with high accuracy to perform high-quality image printing.
The angle adjusting mechanism 12 includes a bearing member 14 that is rotatably supported by the support shaft 11 and a guide member 15 that is attached to the other end of the head support member 6. It is supported by the bearing member 14 so as to be slidable in a direction (an arrow H direction or a J direction) that is in contact with or away from the support shaft 11.
In other words, the guide member 15 is supported by the bearing member 14 and is movable in a direction in which the guide member 15 is in contact with and away from the support shaft 11.
An adjustment screw 16 is screwed to the other end portion side of the head support member 6 where the angle adjustment mechanism 12 is attached.

The adjustment screw 16 has a screw thread portion 16a that is screwed to the other end portion side of the head support member 6, and a flange portion 16b formed on one side of the screw thread portion 16a on the lower side in the drawing.
Further, the adjustment screw 16 has a flange portion 16b supported by the bearing member 14 so as to prevent the adjustment screw 16 from rotating. A screw thread portion 16a protruding from the other end side of the head support member 6 is rotated in a desired direction. Slides in the direction of arrow H or arrow J with respect to the bearing member 14 so that the other end of the head support member 6 moves in a direction in which the head support member 11 contacts and separates from the support shaft 11.

Then, the other end portion side of the head support member 6 moves in a direction in which the head support member 6 contacts and separates from the support shaft 11, so that the head support member 6 is attached to the head attachment portion 6 a on the one end portion side via the head attachment base 5. The center of the heat generating portion 4 b of the thermal head 4 is positioned on the printing surface 3 a of the recording paper 3.
Therefore, when the thermal head 4 is lowered and the plurality of heat generating portions 4b are selectively heated based on the printing information, the ink of the ink ribbon (not shown) is selectively applied to the printing surface 3 of the recording paper 4. Thus, a high-quality image can be printed on the recording paper 3.

Further, the support shaft 11 is provided with an elastic member 17 for preventing the head support member 6 from rattling in the lateral direction of the arrow G. The elastic member 17 always causes the head support member 6 to be elastic in the lateral direction. It is energized.
For this reason, it is possible to eliminate the play in the lateral direction of the thermal head 4 supported by the head support member 6 and to prevent the image to be printed on the recording paper 3 from shifting in the lateral direction.

In the method of assembling the thermal printer of the present invention having such a configuration, the head mounting base 5 to which the thermal head 4 is fixed is mounted on the head mounting portion 6a, and the angle adjusting mechanism 12 is mounted on the other end side of the head support member 6. .
The first rotation lever in a state where the other end portions of the first and second rotation levers 7 and 8 are fitted and supported on the support shaft 11 and the coil spring 9 is assembled between the one end portions 7a and 8a. 7 is attached to the head mounting portion 6a of the head support member 6.

Next, when the heat generating part 4b of the thermal head 4 enlarged and projected on the monitor screen is shifted by an angle α as shown in FIG. 3, for example, as shown in FIG. When the adjustment screw 16 of the mechanism 12 is rotationally adjusted, the other end side of the head support member 6 moves in a direction away from the support shaft 11.
As a result, the head support member 6 is inclined so that the right side of the head mounting portion 6a is raised, and the angle between the thermal head 4 and the recording paper 3 is α as shown in FIG. The angle deviation of the angle α of the heat generating portion 4b with respect to the printing surface 3a of the recording paper 3 being conveyed is adjusted and eliminated.

Further, on the other end side of the head support member 6, a measuring instrument (such as a dial gauge) capable of measuring the amount of movement on the other end side that moves in the direction of moving away from the support shaft 11 by adjusting the rotation of the adjustment screw 16 ( (Not shown) is provided.
With the measuring instrument, the adjustment screw 16 can be adjusted while looking at the number of movements on the other end side of the head support member 6 such as a dial gauge, and the angular deviation of the heat generating part 4b can be adjusted linearly and finely. Accurate adjustment is possible.

Further, after adjusting the angle deviation of the heat generating portion 4b by the adjusting screw 16, the heat generating portion 4b has a portion where the outer peripheral surface of the platen roller 2 and the conveyed recording paper 3 are in contact (the portion where the virtual line 13 shown in FIG. 4 intersects). Check the misalignment on the monitor screen.
And when the heat generating part 4b after the angular deviation adjustment is misaligned, the thermal head 4 attached to the head attaching part 6a of the head support member 6 is moved in the conveyance direction (arrow E, F direction) of the recording paper 3. The position shift is adjusted by moving in the parallel direction.
The thermal printer 1 of the present invention assembled by such an assembling method is free from the angular deviation and the positional deviation of the heat generating portion 4b, and can reliably transfer the ink of the ink ribbon onto the recording paper 3. Therefore, high quality image printing can be performed.

The recording paper 3 may be conveyed while being wound around the platen roller 2 by 0 to 10 degrees.
In the embodiment of the present invention, the head support member 6 is supported by the first and second rotating levers 7 and 8 and the second rotating lever 8 is driven to rotate, whereby the thermal head 4 is moved to the head. As described above, the head support member 6 may be directly driven to rotate.
The angle adjusting mechanism 12 has been described as rotating the adjustment screw 16 so that the other end side of the head support member 6 is brought into contact with and separated from the support shaft 11. Instead, a cam (not shown) is disposed between the other end side of the head support member 6 and the bearing member 14, and the other end side of the head support member 6 is supported with respect to the support shaft 11 by this cam. It may be one that touches and separates.
Further, although the thermal printer 1 of the present invention has been described with respect to a thermal transfer printer using an ink ribbon (not shown), it may be one using thermal paper without using an ink ribbon.

It is a perspective view of the head support member concerning the present invention. It is principal part sectional drawing of the head support member concerning this invention. It is a principal part enlarged view of the thermal head concerning this invention. It is a principal part enlarged view of the thermal head concerning this invention. It is the schematic explaining the principal part of the conventional thermal printer. It is a principal part enlarged view of the conventional thermal head. It is a principal part enlarged view of the conventional thermal head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal printer 2 Platen roller 3 Recording paper 4 Thermal head 4a Convex part 4b Heat generating part 5 Head mounting base 6 Head support member 6a Head mounting part 6b Connection part 6c Heat radiation part 6d Heat sink part 6e Mounting leg 6f Elliptical hole 7 1 rotation lever 8 second rotation lever 9 coil spring 10 head pressing screw 11 support shaft 12 angle adjustment mechanism 13 virtual line 14 bearing member 15 guide member 16 adjustment screw 16a screw thread portion 16b collar portion 17 elastic member

Claims (6)

A cylindrical platen roller, a thermal head having a heat generating portion that can be pressed against the platen roller, a head support member that supports the thermal head on one end side and is supported on a support shaft on the other end side, and the platen A recording sheet conveyed between a roller and the thermal head,
The head support member is rotated about the support shaft, so that the thermal head can be brought into contact with and separated from the platen roller. An angle adjustment mechanism capable of adjusting the angle deviation of the heat generating portion with respect to the printing surface is disposed ,
The angle adjustment mechanism is disposed on the other end portion side of the head support member and at a central portion in the length direction of the thermal head, and is attached to the other end portion side of the head support member. And a bearing member rotatably supported on the support shaft,
The guide member is slidably supported with respect to the bearing member,
By sliding the guide member with respect to the bearing member and moving the other end portion side of the head support member in a direction to be in contact with and away from the support shaft, the angle of the heat generating portion of the thermal head is increased. A thermal printer characterized in that the displacement can be adjusted . Wherein the angle adjustment mechanism, thermal according to claim 1, wherein the moving adjustable adjusting screw is disposed to the other end of the head support member toward or away from the said support shaft Printer. The adjustment screw has a thread portion and a flange portion formed on one side of the thread portion, and the screw portion is screwed to the other end portion side of the head support member. The thermal printer according to claim 2 , wherein the bearing member is supported so as not to come off, and the other end side contacts and separates from the support shaft by adjustment of the adjustment screw. 4. The angle adjustment mechanism according to claim 1 , wherein when the adjustment screw is rotated and adjusted in the adjustment screw adjustment step, the other end portion side of the head support member is brought into contact with or separated from the support shaft. An assembly method for a thermal printer, wherein the thermal printer is moved to adjust an angle shift of the heat generating portion with respect to a printing surface of the recording paper. The head support member is provided with a measuring device capable of measuring the amount of movement on the other end side that moves in the direction of moving away from the support shaft, and the amount of movement on the other end side by the measuring device. The thermal printer assembling method according to claim 4, wherein an angle shift of the heat generating portion is adjusted while observing the temperature. After adjusting the angular deviation of the heat generating part, the positional deviation of the heat generating part with respect to the part where the outer peripheral surface of the platen roller and the conveyed recording paper are in contact is confirmed. claim 4 or 5 assembling method for a thermal printer according to characterized in that so as to adjust the positional deviation by moving in the direction parallel to the conveying direction of the recording paper to.

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