JP2001030569A - Thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer printer which can uniformly press a platen roller into contact with an entire face of a thermal head and can print images of a high quality. SOLUTION: In the thermal transfer printer, an ink ribbon drawn outside from a body part of a ribbon cassette is positioned between a thermal head 8 and a platen roller 4, and a ribbon guide part which is part of the body part is positioned between a head mount stage 9 and a top plate 1c of a frame. A movement of the head mount stage 9 when the platen roller 4 is pressed into contact with the thermal head 8 because of the rotation of the platen roller 4 is controlled by the top plate 1c of the frame via the ribbon guide part of the ribbon cassette.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer, and more particularly to a thermal transfer printer capable of uniformly applying a pressure of a platen roller to a thermal head without variation.

[0002]

2. Description of the Related Art A conventional thermal transfer printer is disclosed in
No. 3,149,952 is disclosed. Such a conventional thermal transfer printer has a thick plate-like printer base 3 on one side as shown in FIG.
The printer base 31 is provided with a paper feed unit 32 at the right end in the figure. On the upper side of one side of the printer base 31, a cassette mounting portion 33 having a thermal head 35 which can be moved up and down by being elastically urged by a head operation plate 34 is mounted in a cantilever manner. A platen support portion 37 having a platen roller 37a is provided below the cassette mounting portion 33.
1 and supported by a cantilever.

The cassette mounting portion 33 has an operation arm 36 attached to a free end thereof, and the operation arm 36 can be manually rotated in the directions of arrows A and B. The thermal head 35 elastically urged by the head operation plate 34 can be moved up and down by rotating the operation arm 36 in the directions of the arrows A and B. A rotatable platen roller 37 attached to a platen support portion 37 that is cantilevered by the printer base 31 is disposed below the thermal head 35. And
Thermal head 3 that can be moved up and down by operation of operation arm 36
5 can be moved toward and away from the platen roller 37.

A driving source (not shown) for driving a platen roller 37a and the like is provided on the platen support portion 37.
Is formed. A support portion 37c for supporting the end portion 36a of the operation arm 36 when rotated in the direction of arrow B is formed near the platen roller 37a on the free end side of the platen support portion 37. By rotating the operation arm 36 in the direction of arrow B, a part of the operation arm 36 moves the head operation plate 34 downward, and the thermal head 35 moves up and down to come into pressure contact with the platen roller 37a. ing. The paper feed unit 3
2, a roll supply shaft 32a is formed, and a roll paper 39 wound in a roll around the roll supply shaft 32a is detachable.

[0005] A ribbon cassette 40 is detachable from the cassette mounting portion 33. The ribbon cassette 40 has a supply shaft 40a on the right side in the figure and a take-up shaft 40a.
b and an ink ribbon 40c wound therearound is provided on the outer peripheral portion. In the ribbon cassette 40, a gap portion 40e is formed by the upper ribbon guide portion 40d and the lower ink ribbon 40c, and the gap portion 40e is inserted into the free end of the cantilever-supported cassette mounting portion 33. The ribbon cassette 40 is attached to and detached from the cassette mounting section 33. Further, the sheet feeding unit 32 and the cassette mounting unit 33
A guide plate 41 is disposed near the paper feed unit 32 between
The guide plate 41 guides the roll paper 39 fed from the paper feed unit 32 toward the platen roller 37a.

In the conventional thermal transfer printer having such a structure, the ink ribbon 40c and the roll paper 39 are sandwiched between the thermal head 35 and the platen roller 37.
With the rotation of the operation arm 36 in the direction of arrow B by manual operation,
A pressing portion (not shown) provided on a part of the operation arm 36 presses the head operation plate 34 to move it downward. By moving the head operation plate 34 downward, the thermal head 35 elastically urged by the head operation plate 34 causes the platen roller 37 to move.
Move to the side. Then, the thermal head 35 is connected to the platen roller 37 via the ink ribbon 40 c and the roll paper 39.
Is pressed against. At this time, as shown in FIG. 12, the end portion 36a of the operation arm 36 is connected to the engaging portion 3 of the platen support portion 37.
7c, the thermal head 35 and the platen roller 37 can be kept in pressure contact with each other. Further, by manually returning the operation arm 36 to the initial state in the direction of the arrow A, the pressure contact state between the thermal head 35 and the platen roller 37 can be released.

[0007]

However, in the conventional thermal transfer printer as described above, the cassette mounting portion 33 to which the thermal head 35 is mounted and the platen support portion 37 to which the platen roller 37a is mounted are each provided in the printer base 31. When the thermal head 35 is pressed against the platen roller 37 by operating the operation arm 36 attached to the free end side of the cassette mounting portion 33, the cassette mounting portion 33 and the platen support portion 37 Of the thermal head 35 cannot be uniformly pressed against the platen roller 37. Further, since the thermal head 35 is pressed against the platen roller 37a by manually operating the operation arm 36, the printing operation by the conventional thermal transfer printer is troublesome, and it takes time for printing.

The thermal transfer printer of the present invention has been made in view of the above-described problems, and provides a thermal transfer printer capable of uniformly pressing a platen roller over the entire surface of a thermal head and performing high-quality printing. It is intended to do so.

[0009]

As a first means for solving the above problems, a method of driving a motor according to the present invention comprises a ribbon cassette containing an ink ribbon in a main body, and a cassette to which the ribbon cassette can be attached and detached. A frame having a mounting portion, a platen roller rotatably supported on both side plates of the frame, and a thermal head supported at one side plate of the frame and cantilevered and arranged at a position facing the platen roller And a head mounting base to which the
The head mount is located within the cassette mounting portion formed to accommodate the ribbon cassette, and the free end is positioned at the entrance side of the cassette mounting portion, and the ribbon cassette is moved from the main body to the outside. The drawn-out ink ribbon is located between the thermal head and the platen roller, and a part of the main body is located between the head mount and the top plate of the frame, and the platen roller A rotation of the platen roller presses against the thermal head to restrict the movement of the head mount on the top plate of the frame via a part of the main body of the ribbon cassette. did.

As a second means for solving the above problems, the ribbon cassette has the main body for accommodating a supply roller for winding both ends of the ink ribbon and a winding roller, A ribbon guide portion, which is a part of the main body portion, is formed to extend from the main body portion to one side, and has a ribbon folded portion at a tip end portion of the ribbon guide portion, and the ink ribbon extends from the inside of the main body portion to the outside. Once the ink ribbon is pulled out and folded back at the ribbon folding portion, the ink ribbon is drawn back into the main body portion through the ribbon guide portion and can be wound up, and is drawn out of the main body portion to the outside. A gap is formed between the ribbon mounting portion and the ribbon guide portion so that the head mounting base can be inserted by the ribbon folded portion. And configured so as to releasably the ribbon cassette is positioned.

As a third means for solving the above-mentioned problems, the platen roller has a rotatable shaft supported at both ends by support members, and the support members are supported by both side plates of the frame. The platen roller is rotatable toward the thermal head via the support member by rotation of the shaft member.

As a fourth means for solving the above-mentioned problem, a twisted coil spring for applying a rotational load in a direction in which the platen roller is always separated from the thermal head is wound around the shaft member. A cam mechanism for moving the platen roller to the thermal head side against the spring force of the torsion coil spring is provided on one end side of the torsion coil spring. The operation of the cam mechanism corrects the rotation of the shaft member. The platen roller is rotated by reversing the rotation, so that the platen roller can be brought into contact with and separated from the thermal head.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal transfer printer according to the present invention will be described below with reference to FIGS. 1 is a front view of the thermal transfer printer of the present invention, FIG. 2 is a bottom view of FIG. 1, FIG. 3 is a left side view of FIG. 1, and FIG. 4 is a right side view of FIG. 5 is a schematic perspective view of the periphery of the platen roller according to the present invention, FIG. 6 is a schematic view illustrating the operation of the platen roller according to the present invention, and FIG. 7 is a top view of the ribbon cassette according to the present invention. 8 is a right side view of FIG. 7, FIG. 9 is a front view of FIG. 7, and FIG. 10 is a cross-sectional view of a main part explaining the operation of the thermal transfer printer of the present invention.

The thermal transfer printer of the present invention is provided with a frame 1 made of a metal plate and formed in a box shape with a hollow inside. This frame 1 is formed by pressing or the like as shown in FIG.
As shown in the figure, a side plate 1a formed on the near side, one side plate 1b formed on the rear side opposite to the side plate 1a, a top plate 1c covering the upper part of the inside of the cavity, and an illustration of the inside of the cavity The lower plate 1d covers a part of the lower part on the left side. As shown in FIG. 1, an entrance 2a of the cassette mounting portion 2 is punched and formed in the side plate 1a of the frame 1, and a cassette mounting portion 2 to which a ribbon cassette 17 described later can be attached and detached is formed inside the cavity. ing.

The cassette mounting section 2 has a rotatable take-up bobbin 3 disposed on a side plate 1b on the side facing the supplementary 9a having an entrance 2a formed therein. Roll-up roller 2 of ribbon cassette 17
0 is positioned to enable engagement. In the vicinity of the winding bobbin 3, a positioning hole 1e for positioning a ribbon cassette 17 described later is formed. On the upper part of the frame 1, a top plate 1c is provided over almost the entire surface.
Is formed, the upper part of the cassette mounting portion 2 is covered with the top plate 1c. Also, frame 1
A rotatable platen roller 4 supported by support plates 5 and the like on both side plates 1a and 1b is disposed. The platen roller 4 has a configuration in which a rotary shaft 4a is covered with a rubber roller 4b.

As shown in FIG. 2, both ends of the rotating shaft 4b of the platen roller 4 are supported by a pair of supporting members 5 so as to be rotatable. The pair of support members 5 are made of a metal plate, and end portions of the platen roller 4 opposite to the side supporting the rotation shaft 4a are bent inward at substantially right angles to form bent portions 5a. I have. Such a pair of support members 5 are provided on both sides 1a, 1
It is rotatably attached to a shaft member 6 supported by b. The shaft member 6 has a pair of first projections projecting in the same direction.
And the second pins 6a and 6b are fixed to each other, and the bent portions 5a of the support member 5 come into contact with the first pins 5a and 5a near both ends.

Further, springs 6c, 6c are respectively wound around the shaft member 6 between the first and second pins 6a, 6b, and one end of the spring 6c is connected to a bent portion of the support member 5. 5
a, and the other end is in contact with the second pin 6b. Such a supporting member 5 and a shaft member 6
Means that the shaft member 6 shown in FIG. 1 is urged to rotate clockwise and the support member 5 is urged to rotate counterclockwise by the spring force of the spring 6c. It is unitized and assembled so that one pin 6a always contacts. Therefore, the platen roller 4 is assembled integrally with the shaft member 6 via the support member 5 by the action of the spring 6c, and when the shaft member 6 shown in FIG. When the shaft member 6 rotates in the direction of arrow C and rotates clockwise, the platen roller 4 rotates in the direction of arrow C.

A shaft member 6 pivotally supported on both side surfaces 1a and 1b of the frame 1 has a part of a cam mechanism at one end protruding outward from a lower side plate 1b of the frame 1 shown in FIG. The cam lever 7 is fixed. The cam lever 7 is made of a resin material. As shown in FIG. 6, a lever part 7a is formed so that a part of the outer peripheral part protrudes downward in the figure, and a position detecting part 7b protrudes from a part of the lever part 7a. Thus, the cam lever 7 is formed in a forked shape.
FIG. 5 is a partial perspective view for easy understanding of the relationship between the platen roller 4 and the shaft member 6.

A thermal head 8 is provided at a position facing the platen roller 4, and a head mount 9 to which the thermal head 8 is fixed with an adhesive or the like is screwed to one side plate 1b of the frame 1. Mounted with cantilever support. The head mounting base 9 is made of a material having good heat dissipation such as aluminum die casting, is cantilevered by the side plate 1b, is located in the cassette mounting portion 2, and has a free end 9a on the entrance 2a side of the cassette mounting portion 2. It is located at. Then, as shown in FIG. 2, the free end 9a slightly protrudes outward from the entrance 2a in the upper part of the drawing.

At one end of the shaft member 6 protruding outward from the side plate 1b, between the side plate 1b and the cam lever 7, a direction in which the platen roller 4 is always separated from the thermal head 8 (in a direction indicated by an arrow D in FIG. 6). ) Is wound with a torsion coil spring 10 for applying a rotational load. The torsion coil spring 10 has a cam lever 7 at one end and a frame 1 at the other end.
And constantly urges the shaft member 6 shown in FIG. 6 to rotate counterclockwise. At a position facing the lever portion 7a of the cam lever 7, a cam member 11 constituting a part of a cam mechanism is provided. The cam member 11 is made of a resin material, and as shown in FIG. 6, is formed by combining outer peripheral portions having different radii, that is, an outer peripheral portion having a large radius and an outer peripheral portion having a small radius, and has a fan-like shape. , Can be rotated by rotation of a drive source (not shown).

When the cam member 11 is rotated to bring the outer peripheral portion having a large radius into contact with the lever portion 7a, the shaft member 6 rotates clockwise in the forward direction, and resists the spring force of the torsion coil spring 10. By rotating the platen roller 4 in the direction of arrow C, the platen roller 4 can be moved to the thermal head 8 side. Further, when the cam member 11 is further rotated to bring the outer peripheral portion having a small radius into contact with the lever portion 7a, the shaft member 6 is rotated in reverse by the spring force of the torsion coil spring 10, and the platen roller 4 is moved in the direction of arrow D. By rotating, the platen roller 4 is separated from the thermal head 8. That is, the thermal transfer printer of the present invention rotates the platen roller 4 by rotating the shaft member 6 forward and reverse by the operation of the cam mechanism including the cam lever 7 and the cam member 11, thereby rotating the platen roller 4. Head 8
It can be separated from and connected to.

Further, in the thermal transfer printer of the present invention, a wall member 12 made of a resin material is disposed inside the cavity on the left end side of the frame 1 shown in FIG. A paper insertion port 12a as shown is formed.
On the right side of the platen roller 4 shown in FIG. 1, a paper feed roller 13 made of, for example, a metal bar, and a pressure roller 14 pressed against the paper feed roller 13 are provided with both side plates 1a and 1b.
It is rotatably attached to.

As shown in FIG. 2, the paper feed roller 13 is provided with a helical gear 15 having a rotating shaft 13a projecting outward from the side plate 1b and having a tooth ridge formed obliquely.
The rotation of a drive source (not shown) is transmitted to the paper feed roller 13 via a helical gear 15. Outside the side plate 1b, a plurality of gears for transmitting a driving force to various driving members such as the platen ten roller 4 as well as the helical gear 15 or a driving source such as a motor is attached. However, these are not particularly related to the present invention, so that illustration and description are omitted. The pressing roller 1
A substantially V-shaped leaf spring 16 is disposed between the top plate 4 and the top plate 1c of the frame 1 as shown in FIG.
, The pressing roller 14 is always pressed against the paper feed roller 13.

As shown in FIGS. 7 to 9, the ribbon cassette 17 which can be attached to and detached from the cassette
An ink ribbon 18 is housed in 7a, and the ink ribbon 18 is wound around a supply roller 19 and a take-up roller 20 whose both ends are housed in the main body 17a. Also,
The ribbon cassette 17 includes a ribbon guide portion 17b, which is a part of the main body portion 17a, and is formed to extend from the main body portion 17a to one side, and a ribbon folding portion in which a rotatable roller 17c is attached to a leading end of the ribbon guide portion 17b. 17d.

As shown in FIG. 8, the ribbon guide 17b has a ribbon running groove 17g having a predetermined gap between the upper plate 17e and the lower plate 17f. The ink ribbon 18 wound around the supply roller 19 and the take-up roller 20 can run in the running groove 17g. The ink ribbon 18 is rotated by the take-up roller 20 shown in FIG.
It is once pulled out from the inside of 7a to the outside, is drawn around in the direction of arrow F, and is folded upward at the ribbon folding portion 17d. From the state in which the ribbon is folded back by the ribbon folding section 17d, the ink ribbon 18 travels in the ribbon traveling groove 17g of the ribbon guide section 17b and is drawn into the main body section 17a again, so that the ink ribbon 18 can be wound around the winding roller 20. ing.

Further, the ink ribbon 18 drawn out of the main body 17a and the lower plate 17 of the ribbon guide 17b are provided.
A gap 21 into which the head mounting base 9 can be inserted is formed by the ribbon fold-back portion 17c between the space 21 and the front end f.
In the vicinity of the take-up roller 20 slightly protruding from the upper end surface of the ribbon cassette 17 shown in FIG.
7h is formed to protrude. Also, the main unit 1 shown in FIG.
A tongue-shaped ribbon pull-out portion 17j is formed to extend downward from the lower portion of 7a.

To attach and detach the ribbon cassette 17 to and from the cassette mounting section 2, first, the gap 21 is positioned at the free end 9 a of the head mount 9, and the ribbon cassette 17 is inserted into the cassette mounting section 2. By mounting the ribbon cassette 17, the positioning projection 17h is inserted into the positioning hole 1e of the side plate 1b, and the ribbon cassette 17 is positioned in the cassette mounting portion 2. At the same time when the positioning protrusion 17h is inserted into the positioning hole 1e of the side plate 1b, the winding roller 20 is engaged with the winding bobbin 3 of the side plate 1b. Then, in conjunction with the rotation of the winding bobbin 3, the winding roller 20
Rotates in the direction of arrow E, so that the ink ribbon 18 can be wound around the winding roller 20.

Further, in order to pull out the ribbon cassette 17 mounted on the cassette mounting section 2, the drawer section 17j projecting from the entrance 2a of the cassette mounting section 2 to the outside.
, The ribbon cassette 17 can be pulled out of the cassette mounting section 2. FIG.
A paper guide 22 made of a metal plate is provided below the inclined portion 2b of the cassette mounting portion 2 shown in FIG. As shown in FIG. 2, a plurality of rib grooves 22
a is formed so as to protrude toward the cassette mounting portion 2, as shown in FIG.
The frictional resistance with the recording paper 23 shown in FIG. The recording paper 23 can be used in either a roll shape or a cut paper shape, and is fed from a feeding unit (not shown).

As shown in FIG. 10, the recording paper 23 fed from the paper feeding unit (not shown) is inserted from the paper insertion opening 12a in the direction of arrow P, passes through the lower part of the ribbon cassette 17, and The paper is conveyed between the platen roller 4 and the ink ribbon 18 through the paper feed roller 22 and is sandwiched between the paper feed roller 13 and the pressure roller 14 to form a conveyance path.
The recording paper 23 can be transported in the transport path in one direction of arrow P. The recording paper 23 transported to the paper feed roller 13 is rotated downstream of the transport direction by the rotation of the paper feed roller 23. Can be transported outside the thermal transfer printer.

The operation of printing a desired image on the recording paper 23 in the thermal transfer printer of the present invention having such a configuration will be described. First, a driving source (not shown) is driven to move the platen roller 4 shown in FIG. By rotating the platen roller 4 in the direction D, the platen roller 4 is separated from the thermal head 8. next,
The gap 21 of the ribbon cassette 17 is positioned at the free end 9a of the head mount 9, and the ribbon cassette 17 is moved to the entrance 2a.
And is inserted into the cassette mounting section 2 and mounted. Then
In the ribbon cassette 17, an ink ribbon 18 pulled out from the main body 17a is located between the thermal head 8 and the platen roller 4, and a ribbon guide 17b, which is a part of the main body 17a, is mounted on a head mount. 9 and the top plate 1c of the frame 1. The positioning projection 17h of the ribbon cassette 17 fits into the positioning hole 1e of the frame 1, and the winding roller 20 engages with the winding bobbin 3 of the frame 1.

Thereafter, as shown in FIG.
3 is inserted through the paper insertion slot 12a, the recording paper 23 is transported in the above-described transport path, and the leading end of the recording paper 23 is pressed and held by the paper feed roller 13 and the pressure roller 14. Next, the shaft member 6 is rotated by a predetermined angle by the cam lever 7 and the cam member 11 as a cam mechanism, so that the ink ribbon 18 and the recording paper 23 are rotated by the rotation of the platen roller 4 in the direction of arrow C. , Between the thermal head 8 and the platen roller 4.

Then, a dot-shaped heat generating portion (not shown) of the thermal head 8 is intermittently heated based on the recording information, and the recording paper 23 is transported at a predetermined speed while rotating the paper feed roller 20. The ink on the ink ribbon 18 can be transferred to the recording paper 23 so that a desired image can be printed on the recording paper 23.

In such a thermal transfer printer of the present invention, even if the platen roller 4 is pressed against the thermal head 8 of the head mounting base 9 cantilevered on the frame 1, the head mounting base 9 and the top plate of the frame 1 are pressed. 1c, the ribbon guide portion 17b, which is a part of the main body portion 17a of the ribbon cassette 17, is positioned. Therefore, when the platen roller 4 is rotated, the head is mounted when the platen roller 4 comes into pressure contact with the thermal head 8. The movement of the table 9 toward the top plate 1c is controlled by the ribbon cassette 18
Can be stopped by the top plate 1c of the frame 1 via the ribbon guide 17b which is a part of the main body 17a.

Further, the movement of the head mounting base 9 toward the top plate 1c when the platen roller 4 is pressed against the thermal head 8 is restricted, so that the vertical position of the thermal head 8 and the paper feed roller 20 is suppressed. The relationship can be kept constant without variation.

In the embodiment of the present invention, the recording paper 23 is transported in the paper transport path after the ribbon cassette 17 is mounted on the cassette mounting section 2.
Before the ribbon cassette 17 is mounted on the cassette mounting section 2, the recording paper 23 can be transported to the paper transport path.

[0036]

As described above, according to the thermal transfer printer of the present invention, the ink ribbon drawn out from the main body of the ribbon cassette is located between the thermal head and the platen roller, and the main body of the ribbon cassette is moved. Part of the ribbon cassette is positioned between the head mount and the top plate of the frame, and the movement of the head mount when the platen roller is pressed against the thermal head by the rotation of the platen roller. The platen roller can be uniformly pressed against the thermal head of the head mounting base that is cantilevered on the frame because the platen roller is stopped by the top plate of the frame via the portion. Therefore, a thermal transfer printer capable of performing high-quality printing on recording paper can be provided. In addition, since the movement of the head mount can be suppressed, the positional relationship between the thermal head and the paper feed roller in the height direction becomes constant, so that the recording paper can be transported without variation, and higher quality printing is performed. be able to.

Further, the ribbon cassette has a ribbon guide portion, which is a part of the main body portion, formed so as to extend to one side from the main body portion, and has a ribbon folded portion at a leading end portion of the ribbon guide portion. Once pulled out of the main body to the outside and folded at the ribbon fold, it travels along the ribbon guide and is drawn back into the main body so that it can be wound up and pulled out from the main body. A gap is formed between the ink ribbon and the ribbon guide so that the head mounting base can be inserted by the ribbon folding part, and the gap is positioned at the free end of the head mounting base to mount and remove the ribbon cassette. Therefore, the ribbon guide section of the ribbon cassette can be guided between the head mount and the top plate of the frame, and the ribbon cassette can be attached to and detached from the cassette mounting section. Set of detachable operation can provide easy thermal transfer printer.

Both ends of the platen roller are supported by a support member, and the support member is mounted on a rotatable shaft member that is supported by both side plates of the frame. Since the platen roller is rotatable toward the thermal head via the member, the platen roller can be reliably rotated toward the thermal head by rotating the shaft member. A thermal transfer printer having a pressing mechanism can be provided.

The shaft member is wound with a torsion coil spring for applying a rotational load in a direction in which the platen roller is always separated from the thermal head. One end of the shaft member is opposed to the spring force of the torsion coil spring. A cam mechanism for moving the platen roller to the thermal head side is provided, and by rotating the shaft member forward and reverse by the operation of the cam mechanism, the platen roller is rotated to move the platen roller to the thermal head. Since the contact can be made detachable, the platen roller can be automatically brought into pressure contact with the thermal head by driving a drive source such as a motor, so that a thermal transfer printer with good operability can be provided. In addition, the cam mechanism can control the pressure of the platen roller against the thermal head in accordance with the smoothness of the recording paper, so that even if the recording paper is rough paper, the ink of the ink ribbon is transferred and printed with high quality. be able to.

[Brief description of the drawings]

FIG. 1 is a front view of a thermal transfer printer of the present invention.

FIG. 2 is a bottom view of FIG.

FIG. 3 is a left side view of FIG.

FIG. 4 is a right side view of FIG. 1;

FIG. 5 is a schematic perspective view illustrating a platen roller according to the present invention.

FIG. 6 is a schematic diagram illustrating the operation of a platen roller according to the present invention.

FIG. 7 is a top view of the ribbon cassette according to the present invention.

FIG. 8 is a right side view of FIG. 7;

FIG. 9 is a front view of FIG. 7;

FIG. 10 is a cross-sectional view of a principal part explaining the operation of the thermal transfer printer of the present invention.

FIG. 11 is a perspective view of a conventional thermal transfer printer.

FIG. 12 is a perspective view illustrating the operation of a conventional thermal transfer printer.

Claims (4)

[Claims] A ribbon cassette accommodating an ink ribbon in a main body, a frame having a cassette mounting portion to which the ribbon cassette can be attached and detached, a platen roller rotatably supported on both side plates of the frame, A head mount fixedly supported by one side plate of the frame and having a thermal head disposed at a position facing the platen roller, the head mount being formed to accommodate the ribbon cassette. And the free end side is positioned at the entrance side of the cassette mounting portion, and the ink ribbon pulled out of the main body portion is the thermal head, the platen roller, And between
Movement of the head mount when a part of the main body is positioned between the head mount and the top plate of the frame, and the platen roller is pressed against the thermal head by rotation of the platen roller. A heat transfer printer which is stopped by the top plate of the frame via a part of the main body of the ribbon cassette. 2. The ribbon cassette according to claim 1, further comprising: a main body for accommodating a supply roller and a take-up roller for winding both ends of the ink ribbon. Extending from the body to one side,
A ribbon folding section is provided at the tip of the ribbon guide section,
The ink ribbon is pulled out from the main body portion to the outside at one time, from the state folded back by the ribbon fold portion, travels along the ribbon guide portion, is drawn back into the main body portion and can be wound up, A gap is formed between the ink ribbon drawn out of the main body and the ribbon guide and the ribbon guide so as to allow the head mount to be inserted by the ribbon fold, and is formed at a free end of the head mount. 2. The thermal transfer printer according to claim 1, wherein the ribbon cassette is attached and detached with the gap positioned. 3. The platen roller has both ends supported by a support member, and the support member is attached to a rotatable shaft member supported by both side plates of the frame. 3. The thermal transfer printer according to claim 1, wherein the platen roller is rotatable toward the thermal head via the support member. 4. A torsion coil spring, which applies a rotational load in a direction in which the platen roller is always separated from the thermal head, is wound around the shaft member, and a spring force of the torsion coil spring is applied to one end of the shaft member. A cam mechanism is provided to move the platen roller toward the thermal head, and the operation of the cam mechanism causes the rotation of the shaft member to rotate forward and reverse, thereby rotating the platen roller. 4. A thermal transfer printer according to claim 3, wherein said platen roller can be brought into contact with and separated from said thermal head.