JPH03182378A - Line thermal printer - Google Patents

Abstract

PURPOSE:To facilitate disassembly and to enable components to be used for a general purpose as much as possible by a method wherein a line thermal printer is formed with division units, and regarding a component not influenced by the width dimensional specification of a recording sheet, the size and the shape thereof are specified, and a cover is mounted openably in linkage with a thermal head unit. CONSTITUTION:A side frame 2 has a specified outer shape regardless of the size of the width dimensional specification of as recording sheet, a U-shaped notch part is formed approximately at a central part, and the one end part of a platen toller shaft 5 is removably journaled by the notched part. A hole through which a side frame shaft 10 is extended is formed in a bend part 24 of a cover 11, and this constitution mounts the cover 11 rotatably around the side frame shaft 10. A thermal head unit 9 is removably journaled with respect to a side frame beam 10. A protrusion part 28 is formed on a bend part 27, and through engagement of the protrusion part with a staged part 25 of a bent part 24 of the cover 11, the thermal head unit 9 is rotatable in linkage with the cover 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line thermal printer, and particularly to a small line thermal printer that corresponds to a recording paper width standard of Bowm, 80 mm, or 112 mm.

[Conventional technology]

Conventionally, small line thermal printers have been used as measurement and analysis equipment, PO8 communication data terminal equipment, CRT hard copies, or output terminals for medical equipment. Conventional small line thermal printers are constructed by incorporating a number of parts such as a platen roller, thermal head, motor, train wheel mechanism, and head-up lever into a printer frame that is sized to meet recording paper width standards.

[Problems to be solved by the invention]

However, in conventional small line thermal printers, each component is assembled individually, which not only complicates the assembly process but also makes it difficult to disassemble. Therefore, there is a problem in that maintenance of the printer and replacement of parts requires a great deal of effort. Furthermore, since the dimensions and shapes of individual parts were set according to the width dimension standards of the recording paper, the parts were specialized for each model, resulting in a problem of poor mass production efficiency.

[Means for solving problems]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of conventional small line thermal printers, it is an object of the present invention to provide a small line thermal printer that is easy to assemble and disassemble and has a structure that allows parts to be made as versatile as possible.

In order to achieve the above object, a line thermal printer according to the present invention includes a pair of side frames that are arranged facing each other at a predetermined interval according to the width dimension standard of recording paper, and a recording paper guide that is sandwiched between the pair of side frames. It has a frame. A platen roller unit is disposed between a pair of side frames, and is rotatably supported by the side frames in a detachable manner. A thermal head unit is arranged to face the platen roller unit, and is removably locked to the pair of side frames. Further, a cover is disposed to cover the thermal head unit, and this cover is built into the side frame so as to be openable and closable. Furthermore, in order to drive the platen roller unit, a drive unit is separably mounted on the outside of one of the side frames.

Preferably, the thermal head unit is configured to be interlocked with its cover so that the heating element of the thermal head unit is exposed when the cover is opened.

More preferably, the pair of side frames have a constant shape and dimension regardless of the width size standard of the recording paper. The drive unit is composed of a motor, a wheel train for transmitting the power of the motor to the platen roller unit, and a motor frame on which the motor and wheel train are mounted. It has a certain shape and size.

[For production]

According to the present invention, the components of the line thermal printer are divided into blocks such as a platen roller unit, a thermal head unit, a drive unit, etc., and these units are removably or separably engaged with a pair of side frames. ing.

The side frames and the motor frame of the drive unit have constant shapes and dimensions regardless of the width standard of the recording paper, and are general-purpose parts.

[Embodiments] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a front view of a small line thermal printer according to the present invention. Line thermal printers have recording paper width standards (60 liters, 80 squares).

112 mm, etc.), a pair of side frames 1 and 2 are arranged opposite to each other in the width direction of the recording paper at a predetermined interval. A recording paper guide frame 3 is sandwiched between a pair of side frames 1 and 2. Recording paper guide frame 3
is made of an extruded product and is cut to a desired length according to the width dimension standard of the recording paper. A platen roller unit 4 is disposed across a pair of side frames 1 and 2, and these side frames 1 and 2
It is pivotably supported in a detachable manner. The platen roller unit 4 includes a platen roller shaft 5, a platen roller 6 formed around the platen roller shaft 5,
It consists of a head lever 7 slidably locked to one end of the platen roller shaft 5 and a drive gear 8 fixed to the other end of the platen roller shaft 5. As shown in the figure, both ends of the platen roller shaft 5 are removably supported by a pair of side frames 1 and 2.

The thermal head unit 9 is connected to the platen roller unit 4
The side frames 1 and 2 are arranged opposite to each other and are removably locked to the pair of side frames 1 and 2. In this embodiment, the thermal head unit 9 includes a side frame beam 10 fixed between a pair of side frames 1 and 2.
It is removably locked to. The thermal head unit 9 is swingable about the side frame shaft 10 and is urged against the platen roller unit 4. The thermal head unit 9 is moved between a pressure contact position and a non-pressure contact position with respect to the platen roller unit 4 by operating the held lever 7. A cover 11 is disposed to cover the thermal head unit 9 and is built into the pair of side frames 1 and 2 so as to be openable and closable. In this embodiment, the cover 11 is rotatably incorporated into the side frame shaft IO.

In normal use, that is, when the cover 11 is in the closed state, the cover 11 is fixed to the pair of side frames 1 and 2 by screws 12 and 13. When opening the cover 11, it is sufficient to remove the screws 12 and 13 and rotate it in the opening direction around the side frame beam IO.

A drive unit 14 is separably mounted on the outside of the first side frame 1 in order to rotationally drive the platen roller unit 4. The drive unit 14 is a motor 15
, a wheel train IB for transmitting the power of the motor 15 to the platen roller unit 4, and a motor frame 17 on which the motor 15 and the wheel train IB are mounted. Gear train 16
The gear at the final stage is separably engaged with the drive gear 8 fixed to the platen roller unit 4, and the gear at the final stage of the motor 1
5 drives the platen roller unit 4 and feeds the recording paper. One end of the motor frame I7 is removably positioned and fixed to the first side frame 1, and the other end of the motor frame 17 is fixed with a screw 1.
8 is fixed to the first side frame 1.

As is clear from FIG. 1, the recording paper guide frame 3, platen roller unit 4
, the length dimensions of the thermal head unit 9, etc. must be set. However, since the pair of side frames 1 and 2 and the motor frame 17 are not affected by the width dimension standard of the recording paper, they can have constant shapes and dimensions regardless of the size of the standard, and parts can be shared.

FIG. 2 is a right side view of the line thermal printer shown in FIG. 1. As shown in the figure, in normal use, the thermal head unit 9 is pressed against the platen roller 6 by operating the head lever 7. A cover 11 covering the thermal head unit 9 is also in a closed state and is secured to the second side frame 2 by screws 13.

Next, during maintenance, the screws 13 are removed from the second side frame 2, and the cover 11 is rotated around the side frame beam IO as shown by the dashed line and opened.

At this time, the thermal head unit 9 is interlocked with the cover 11 and rotates in the same direction around the side frame shaft IO. As a result, the heating element 18 of the thermal head unit 9, which was in pressure contact with the platen roller 6, becomes exposed. In this state, the surface of the heating element 18 is cleaned, making maintenance work easier.

FIG. 3 is a sectional view of the line thermal printer taken along line A--A in FIG. 1. The assembly structure and assembly method of the line thermal printer according to the present invention will be explained in detail based on FIG. As shown in the figure, the second side frame 2 has a constant external shape regardless of the width size standard of the recording paper. Two guide pins 20 and 21 are installed on the inner surface of the second side frame 2. Further, guide grooves are formed in the recording paper guide frame 3 in correspondence with the guide pins 20 and 21, so that one end of the recording paper guide frame 3 is positioned and fixed with respect to the second side frame 2. Although not shown, the other end of the recording paper guide frame 3 is similarly positioned and fixed to the first side frame 1.

The recording paper guide frame 3 defines a first recording paper insertion slot connected to a curl path (indicated by arrow C) of the recording paper on the rear side with respect to the platen roller 6, and defines a straight path (indicated by arrow C) of the recording paper on the front side with respect to the platen roller 6. A second recording paper insertion slot connected to the arrow S) is defined. A guide beam 22 is connected to a pair of side frames 1 to prevent the recording paper from floating up and down in the second insertion slot.
and 2. That is, the clearance between the guide surface portion of the recording paper guide frame 3 and the guide beam 22 prevents the recording paper from becoming loose.

In addition, the inner surfaces of the pair of side frames 1 and 2 prevent the recording paper from shifting in the width direction.

A U-shaped notch is formed approximately in the center of the side frame 2, and a platen roller shaft 5 is inserted into this notch.
One end is removably supported. Similarly, the other end of the platen roller shaft 5 is attached to the other side frame 1.
It is removably pivoted in a U-shaped notch provided in the center of the body.

That is, in the present invention, the platen roller unit 4 can be easily assembled by simply fitting it into the notches provided in the pair of side frames 1 and 2.

The cover 11 has an opening 23 connected to a recording paper ejection bus (indicated by an arrow) and a bent portion 24 . A hole penetrated by the side frame shaft 10 is formed in the bent portion 24, so that the cover 11 is rotatably attached around the side frame shaft 10. Further, a stepped portion 25 is formed at the tip of the bent portion 24.

The thermal head unit 9 is composed of a thermal head main body and a head mounting plate 26 for detachably mounting the main body. A bent portion 27 is also formed on the head mounting plate 26. A U-shaped notch is formed in this bent portion 27, and the thermal head unit 9 is thereby pivotally supported on the side frame beam 10 in a detachable manner. A protrusion 28 is formed on the bent portion 27, and by engaging with the stepped portion 25 of the bent portion 24 of the cover 11,
The thermal head unit 9 can rotate in conjunction with the cover IT. A spring 29 is interposed between the guide bar 11 and the head mounting plate 26 to bias the thermal head unit 9 against the platen roller 6.

Finally, the operation of the line thermal printer according to the present invention will be explained with reference to FIGS. 1 to 3.

First, normal printing operation will be explained. Prior to printing,
The head lever 7 is operated to bring the thermal head unit 9 into a non-pressing state with respect to the platen roller unit 4. In this state, the recording paper is fed into the printer through a curl path or a straight path as desired. When the supplied recording paper reaches the gap between the platen roller unit 4 and the thermal head unit 9, the head lever 7 is operated to bring the thermal head unit 9 into pressure contact with the platen roller unit 4, applying pressure to the recording paper. In this embodiment, thermal paper is used as the recording paper, but plain paper can also be used by using an ink ribbon. Next, the thermal head unit 9 is energized and the platen roller unit 4 is turned on.
to perform line printing and paper feeding. The printed recording paper is discharged to the outside through a discharge bus.

In the maintenance/inspection operation, first remove the screws (2 and 13), rotate the cover 11 around the side frame shaft IO, and open the cover 1i.At this time, the thermal head unit 9 also rotates in conjunction with the cover, and the heating element 18 In this state, the heating element 18 is cleaned, and the platen roller unit 4 and thermal head unit 9 are replaced as necessary.

〔Effect of the invention〕

As described above, according to the present invention, a line thermal printer is constructed from divided units, and has the advantage that disassembly and assembly are extremely easier than in the past. Furthermore, by keeping the dimensions and shapes of parts that are not affected by the width dimension standards of recording paper constant, there is an effect that parts can be more commonly used than in the past. Furthermore, since the cover is attached to the thermal head unit so that it can be opened and closed, maintenance, inspection, and replacement of parts is easier than in the past.

[Brief explanation of drawings]

FIG. 1 is a front view of a line thermal printer according to the present invention, FIG. 2 is a side view of the line thermal printer, and FIG. 3 is a cross section of the line thermal printer taken along line A-A shown in FIG. It is a diagram. 1... First side frame 2... Second side frame 3... Recording paper guide frame 4... Platen roller unit 9... Thermal head unit 10... Side frame shaft 11...・Cover 14... Drive unit applicant Seiko Electronics Co., Ltd. agent

Claims (1)

[Scope of Claims] 1. A pair of side frames arranged opposite each other at a predetermined interval in accordance with the recording paper width dimension standard, a recording paper guide frame held between the pair of side frames, and a pair of side frames between the pair of side frames. a platen roller unit disposed across the side frames and removably pivoted to the side frames; a thermal head unit disposed facing the platen roller unit and detachably locked to the pair of side frames; and a thermal head. A line thermal system consisting of a cover placed to cover the unit and built into the side frame so that it can be opened and closed, and a drive unit that is detachably mounted on the outside of one side frame to drive the platen roller unit. printer. 2. The line thermal printer according to claim 1, wherein the pair of side frames have a constant shape and dimension regardless of the width size standard of the recording paper. 3. The line thermal printer according to claim 1, wherein the thermal head unit is interlocked with its cover, and the heating element of the thermal head unit is exposed when the cover is open. 4. The recording paper guide frame defines a first insertion opening connected to the curl path of the recording paper on the rear side with respect to the platen roller unit, and a second insertion opening connected to the straight path of the recording paper on the front side with respect to the platen roller unit. 2. A line thermal printer according to claim 1. 5. The line thermal printer according to claim 4, wherein the guide shaft is disposed across the pair of side frames to prevent the recording paper from floating up and down in the second insertion slot. 6. The drive unit is composed of a motor, a wheel train for transmitting the power of the motor to the platen roller unit, and a motor frame on which the motor and the wheel train are mounted. The line thermal printer according to claim 1, wherein the line thermal printer has a constant shape and size.