JPH0199869A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To obtain a good printing, by providing a tension applying mechanism to apply an upstream direction tension to an ink ribbon during printing where a thermal head presses the ink ribbon against a paper to move the ribbon toward the upstream side. CONSTITUTION:With a thermal head 7 abutting against a paper on a platen 1 via an ink ribbon 8, a cam block 21 is stopped and a carriage 3 is moved upstream (in the left direction) to perform thermal transfer by means of the thermal head 7. A pinion 59 moves in rotation along a rack 58 to quickly rotate a pinch roller 9 via a friction engagement member such as a gear train and a felt by the moving speed to give a tension to the ink ribbon pinched by the pinch roller and a driven roller 10 and separate it from the paper. At the same time, a ribbon take-up motor is driven to rotate a bobbin 14 via a felt 75 which is the friction engagement member of a supply side gear 73 and give the ribbon a upstream direction tension. Thus, high-quality printing is assured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer printer that uses heat to roll ink formed on an ink ribbon onto paper.

[Conventional technology]

In general, this type of thermal transfer printer is often used as an output device for various information processing devices, and presses an ink ribbon onto paper using a thermal head equipped with a heat generating section in which a large number of heat generating elements are arranged in a row. Then, while moving the thermal head in a direction substantially perpendicular to the column direction of the heating elements, serial printing is performed by selectively generating heat in each heating element in accordance with a printing command. has been done.

[Problem that the invention seeks to solve]

In this thermal transfer printer, a thermal head presses the ink ribbon on the front side against the paper and platen and heats it, so that a heated ink layer is attached to the paper, and the attached ink layer remains on the paper. The thermal transfer is completed by peeling the ink ribbon from the paper, and printing is performed by continuing this operation. Further, when printing is performed, the ink ribbon is kept stationary so as to face the paper, and in this state, the thermal head is moved to perform thermal transfer.

However, in conventional thermal transfer printers, printing is performed by simply moving the thermal head while holding the ink ribbon in an immobile state, so the ink ribbon may sag, causing the ink ribbon and thermal head to become disconnected. There is a possibility that a deviation from the proper positional relationship may occur and proper printing may not be performed.

The present invention has been made in view of these points, and it reliably prevents the ink ribbon from sagging during printing, maintains the positional relationship between the ink ribbon and the thermal head in an appropriate state at all times, and creates a beautiful and high quality print. An object of the present invention is to provide a thermal transfer printer that can perform high-quality printing.

[Means for solving problems]

In the thermal transfer printer of the present invention, a thermal head is attached to a carriage that is movable in the carry-up/down direction, and a pair of ribbon winding bobbins are provided on the carry-up side and the carry-down side of the carriage for ribbon supply and ribbon winding, respectively. In a thermal transfer printer that is provided separately from the carriage, when printing when the thermal head is moving the ink ribbon to the carry side with the ink ribbon in contact with the paper, a digit is applied to the ink ribbon on the carry side from the thermal head. It is characterized by providing a tension applying mechanism that applies a predetermined tensile force in the upward direction.

[For production]

According to the thermal transfer printer of the present invention, the tension applying mechanism tensions the ink ribbon in the carry direction with a constant tension during printing, so that the ink ribbon used for printing is completely prevented from sagging. The ink ribbon and the thermal head are always maintained in a proper positional relationship without being misaligned, and good printing is performed.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 12.

FIG. 1 shows an entire embodiment of a thermal transfer printer of the present invention, in which a flat platen 1 whose upper surface is a bonding surface is disposed at the bottom of the printer body. A carriage 3 is supported by a guide rod 2 provided parallel to the longitudinal direction of the platen 1 so as to be movable in the longitudinal direction of the platen 1 . An endless drive belt 5 wound around a pair of pulleys 4, 4 is attached to the back side of the carriage 3, and the pulleys 4, 4 are rotated in both forward and reverse directions by a carriage drive motor 6. The carriage 3 is configured to move back and forth by being driven. Further, a thermal head 7 that presses an ink ribbon 8 toward the guide rod 2 to print on the paper S is mounted on the carriage 3 so as to face the platen 1.

Further, on the front side of the carriage 3, a pinch roller 9 and a driven pinch roller 10 opposite thereto are mounted below the digit of the thermal head 7 in order to guide the ink ribbon 8. A ribbon guide 11 is mounted on the raised side.

These thermal head 7, pinch roller 9, and ribbon guide 11 are operated by a state control wIm mechanism 13 (described later, not shown in FIG. 1) whose driving source is one state switching motor 12 mounted on the carriage 3. ), the relative position 4 with respect to the platen 1 can be changed, and the pinch roller 9 is also formed so as to be able to be changed between a rotatable state and a rotationally locked state. Further, ribbon winding bobbins 14 and 14 are respectively disposed at both ends of the guide rod 2 so as to be rotatable in forward and reverse directions. Both ribbon winding ribbins 14, 14 are each formed to be rotationally driven by a ribbon winding mechanism 16 (described later) whose driving source is one ribbon winding motor 15. Also,
Both ribbon winding bobbins 14 and 14 have a ribbon storage case 1 consisting of a case body 17A with a cutout at the bottom.
7 is installed. Winding lowers 18° 18 are built into both ends of the case body 17A so as to be attached to the respective ribbon winding bobbins 14° 14, and winding is performed on these winding cores 18° 18. The ink ribbon 8 is pulled out downward from the case body 17A,
It is wound around the lower outer peripheral surface of a pair of small-diameter stretching rollers 19, 19 (only one of which is shown in FIG. , the lower part of the thermal head 7 and both pinch rollers 9.
It is attached so that 10ffil passes through it.

The tips of the pinch roller 9, the driven pinch roller 10, the ribbon guide 11, and both spreading rollers 19 and 19 are tapered conical portions 9a and 10a, respectively.

11a and 19a to facilitate the mounting operation of the ink ribbon 8. Further, the pinch roller 9 is formed so as to be in contact with the ink layer side on the lower surface side having a larger coefficient of friction among the ink ribbon 8 consisting of a base layer and an ink layer, and its outer peripheral surface is made of a rubber material having a larger coefficient of friction. It is manufactured by etc.

Next, the state control mechanism 13 will be explained with reference to FIGS. 2(a), 3, and 4.

FIG. 2(a) shows the thermal head 7, both pinch rollers 9 and 10, and the ribbon guide 11 for the ink ribbon 8.
shows a free state in which they are not in contact, and the left direction in the figure is the folding direction (the same in FIGS. 5, 6, 7, 11, and 12). The state control mechanism 13 transfers the driving force of the state switching motor 12 provided at the upper corner of the carriage 3 to the thermal head 7 using a cam, a link, etc.
, transmitted to the pinch roller 9 and the ribbon guide 11,
It is formed so that each state can be switched. That is, above the thermal head 7, a substantially cylindrical cam block 21 is rotatably mounted on a fixed center @20 fixed to the carriage 3. A driven gear 23 that meshes with a drive gear 22 fixed to the output shaft of the state switching motor 12 is formed on the back side of the cam block 21 .

A groove-shaped first switching cam 24 for switching the relative position of the thermal head 7 with respect to the platen 1 is carved on the surface of the cam block 21, and a pinch roller 9 and the platen of the ribbon guide 11 are carved on the back surface of the cam block 21. a grooved second switching cam 25 that switches the relative position with respect to 1;
is carved on the inner side of the radius of the driven gear 23, and a third switching cam 26 in the form of a side cam is formed on the outer periphery of the cam block 21 to enable or lock the pinch roller 9. There is. Further, on the front side of the cam block 21, a fixed shaft 27 fixed to the carriage 3 is provided.
A head drive lever 28 whose end in the carry direction is pivotally connected to
is provided so as to cross the cam block 21 from side to side, and a bin 29 protruding from the back side of the intermediate portion of the head drive lever 28 is connected to the first switching cam 2 of the cam block 21.
4. At the end of the head drive lever 28 in the lowering direction, a head pressing member 31 that presses the head mounting base 30 to which the thermal head 7 is fixed from the back side passes through a bearing portion 32 and is movable in the axial direction. It is provided. The head pressing member 31 is given elasticity to constantly press the head mount 30 toward the platen 1 by a pressure contact spring 33 interposed between its tip and the bearing 32 . The head mounting base 30 is pivotally attached to the carriage 3 at both ends thereof in the direction of raising and lowering the carriage 3 with horizontal axes 34 and 34 parallel to the guide rod 2, and as shown in FIG. The thermal head 7 is formed to move closer to the platen 1 by rotating around the center. For this head mount 30, the thermal head 7 has an end in the carry-up direction that is further away from the platen 1 than an end in the carry-down direction, and the part that comes into contact with the platen 1 is formed at the end in the carry-down direction. Only the heat generating part 7a is located on the thermal head 7 (see FIGS. 5 and 6).As shown in FIG. 30, so that the heat generating part 7a can be pressed well.Also, as shown in FIGS. The electrode group 7b extends in the carry-up direction where the thermal head 7 is far away from the platen 1, and furthermore, at the end of the thermal head 7 in the carry-up direction, the electrode group 7b and the flat elastic A flexible printed circuit (hereinafter referred to as FPC) 87, which is widely available, is welded.

Further, on the back side of the cam block 21, a pin and guide drive lever 36 for driving the pinch roller 9 and the ribbon guide 11 is attached to a fixed @35 fixed to the carriage 3.
is pivotally attached at its longitudinally intermediate portion, and the second switching cam 25 of the cam block 21 is connected to the second switching cam 25 of the cam block 21.
It is engaged inside. Further, a fixed shaft 38 is fixed to the back of the thermal head 7 of the carriage 3, and a ribbon guide drive lever 39, to which the ribbon guide 11- is rotatably attached to one end, is attached to the fixed shaft 38 in the longitudinal direction. The ribbon guide drive lever 39 has a pin 4 which is pivotally attached to the middle part of the ribbon guide drive lever 39 and protrudes from the surface side of the other end of the ribbon guide drive lever 39.
0 is engaged with a hole 41 provided on the carry side of the bin and guide drive lever 36. carriage 3
A pinch roller support lever 4 supporting the pinch roller 9 is positioned in the lowering direction position by the thermal head 7 at the lower end of the
2 is pivotally connected to a fixed shaft 43 fixed to the carriage "3," and the end of the pinch roller support lever 42 and the end of the bin and guide drive lever 36 in the lowering direction connect a connecting link 44 to a pivot shaft 45, respectively. .46. Therefore, by swinging the bin and guide drive lever 36 about the fixed shaft 35, the ribbon guide drive lever 39 and the pinch roller support lever 42 are connected to the fixed flit 38, respectively. .

43 as the center, the ribbon guide drive lever 39
The ribbon guide 11 attached to the ribbon guide 11 and the pinch roller 9 attached to the pinch roller support lever 42
The relative position with respect to the platen 1 can be changed. This pinch row 59 is connected to a gear 47 which is rotatably fitted loosely into a pivot shaft 46 attached to the pinch roller support lever 42.
They are arranged so that they can rotate integrally through a friction retaining member (not shown) such as felt. This gear 47 meshes with a gear 49 rotatably attached to the connecting link 44 with a center shaft 48, and the gear 49 meshes with a gear 50 rotatably attached to the pivot shaft 45. A small gear 51 is coaxially and integrally formed with this gear 50. Further, a fixed shaft 52 is fixed to the lower side of the cam block 21 at the upper end of the carriage 3, and to this fixed shaft 52, three levers 53a1 and 52 are attached.
3b and a third lever 53c integrally formed in a substantially radial manner, a drive lever group 53 is pivotally mounted. A roller 54 is attached to the tip of the second lever 53b of the drive lever group 53, and the elasticity of the tension spring 55 allows the roller 54 to freely move against the outer peripheral surface of the third switching cam 26 of the cam block 21. The cam 26 is brought into contact with the cam 26 and is formed to move along with the cam 26. The second lever 53b of the drive lever group 53 is provided with a stopper 56 that meshes with a gear 50 pivotally mounted on the pivot shaft 45 to lock the rotation of the gear 50, that is, the rotation of the pinch roller 9. Further, the fixed shaft 52 has a guide rail 5 for guiding the movement of the carriage 3.
A binion 59 meshing with a rack 58 formed at 7
is rotatably attached to the pinion 59, and a small pinion 60, which is coaxially and integrally formed with the pinion 59, is a gear rotatably attached to the tip of the third lever 53c of the drive lever group 53 with a pivot 61. It is meshed with 62. This gear 62 meshes with the small gear 51 integrated with the gear 50 and acts to transmit rotational force to the pinch roller 9. In addition, the pinch roller support lever 4 of the carriage 3
At a position above 2, a driven pinch roller support lever 64, which rotatably supports the driven pinch roller 10 at one end, is pivotally mounted with a fixed shaft 63. This driven pinch roller support lever 64 is given elasticity in the direction approaching the pinch roller 9 by a tension spring 65, and the bent piece 66a of the stopper lever 66 extending from the base end of the driven pinch roller support lever 64 is By bringing it into contact with the end surface of the carriage 3, it is stopped at the stop position shown in FIG. 2(a).

Further, a cam position detection sensor 67 is provided below the drive gear 22 fixed to the state switching motor 12. This cam position detection sensor 67 is connected to each cam 2 formed on the cam block 21 by contacting one protrusion 68 protruding from the cylindrical outer circumference of the cam block 21.
4.25.26.

Next, as shown in FIGS. 8 and 9, the ribbon winder 116
Explain.

The ribbon winding mechanism 16 of this embodiment uses one ribbon winding motor 15 to operate two ribbon winding bobbins 14.1.
Selectively rotate 4. A driving gear 70 is fixed to the output shaft 69 of the ribbon winding motor 15, and a swinging arm 71 is rotatably attached to the output shaft 69 of the ribbon winding motor 15. A Chitose wheel 72 is rotatably attached. This swinging arm 7
1 rotates in the same direction as the driving gear 70 rotates clockwise in FIG. 8, and is connected to the ribbon take-up bobbin 14 on the ribbon supply side provided on the carry side of the chitose wheel 72. It meshes with the supply side gear 73. On the other hand, swinging arm 7
1 is for driving! When the gear 70 rotates counterclockwise in the figure, it rotates in the same direction, and the swinging chitose wheel 72 is connected to the ribbon winding bobbin 14 on the ribbon winding side provided on the lower side. It meshes with the gear 74. As shown in FIG. 9, between the supply side gear 73 and the ribbon winding bobbin 14, there is an r! It is formed so that rotation can be transmitted via felt 75, which is a type of frictional engagement member. That is, the ribbon winding revolving bobbin 14 rotatably passes through the center of the supply gear 73 with the shaft 14a, and the felt 75 fixed to the 7 flange 14b formed at the rear end of the shaft 14a is attached to the supply gear 73. On the other hand, the supply side gear 73 and the head 14C formed at the tip of the shaft 14a are formed so as to come into elastic contact due to the elasticity of a compression spring 76 interposed therebetween.

A coaxial wheel 77 is connected to the other take-up side gear 74 via a friction engagement member (not shown) in the same manner as described above, and this wheel 77 and the ribbon take-up bobbin 14 on the take-up side are connected to each other via a friction engagement member (not shown). ``An endless transmission belt 79 is wound between the wheel 78 and the fixed wheel 78.

Further, as shown in FIG. 1, in this embodiment, a supply cassette 80 loaded with sheets S is removably installed at the upstream end of the printer main body. A feeding roller 81 is provided that feeds out the sheets S in the supply cassette 80 one by one from above. Furthermore, a pair of conveyance rollers 82 (only the lower side is shown in FIG. 1) are disposed at a position upstream from the platen 1 and are connected to each other from above and below. Similarly, a pair of paper ejection rollers 83 and 8 are connected to each other from above and below.
3 are arranged. This paper discharge roller 83 is formed to be rotationally driven by a paper conveyance motor 84. Further, the paper ejection roller 83 is connected to the transport roller 82 via a transmission belt 85, and the paper ejection roller 83 and the transport roller 82 are formed to be driven synchronously and at the same transport speed. . Further, an insertion 086 for manually feeding the sheets S one by one is formed on the upstream side of the conveyance roller 82 in the printer main body.

Next, the operation of this embodiment will be explained.

First, when the power switch (not shown) of the printer is turned on, the state switching motor 12 rotates, and the cam block 21 rotates clockwise in FIG. 2(a), changing the cam position. When the detection sensor 67 is turned on by the protrusion 68, the position of the cam block 21 is detected, and the state switching motor 12 is stopped. At the same time, the carriage drive motor 6 is also energized, and the carriage 3 is returned to the home position (in this embodiment, the lowest digit position) and stopped.

Next, the ink ribbon 8 is attached. When the lid for inserting the ribbon storage case 17 of the printer main body is opened, a sensor (both not shown) detects this, the state switching motor 12 is rotated, and the cam block 21 is moved to the position shown in FIG.
It will stop when it reaches state a). As a result, the thermal head 7, the pinch roller 9, and the ribbon guide 11 are moved away from the horizontal position where the ink ribbon 8 is mounted by a large distance upward and downward, as shown in the figure. Hereinafter, the position of the thermal head 7 in this case will be referred to as the UP large position. Thereafter, the ink ribbon 8 wound around the winding core 18.18 is installed in the case body 17A of the ribbon storage case 17, and the ink ribbon 8 is pulled out downward from the case body 17A.
is passed through the lower outer circumferential surfaces of a pair of spreading rollers 19° 19 disposed at both ends of the platen 1, and passes through the lower pair of pinch rollers 9 and ribbon guide 11 and the upper thermal head 7 and driven pinch roller. Attach it by inserting it between the 10 sets.

At this time, since the thermal head 7, pinch roller 9, driven pinch roller 10, and ribbon guide 11 are located at a large distance from the ink ribbon 8, the ink ribbon 8
Installation is a simple one-touch operation, and is done quickly and reliably. The ink ribbon 8 is attached to a pinch roller 9, a driven pinch roller 10, and a ribbon guide 11.
and each end of the stretching roller 19 has a tapered conical portion 9a.
.

1Qa, 11a, and 19a, the ink ribbon 8 can be carried out extremely smoothly without getting caught on each tip. Further, even when trying to insert the sheet S from the front between the pinch roller 9 and the ribbon guide 11 and the platen 1, the sheet S can be inserted smoothly without getting caught. Also, a skeleton representation of the state in which the ink ribbon 8 is attached is shown in Fig. 2 (b).
) (5th factor (b), Figure 6 (b), Figure 7 (b)
, the same in FIGS. 11 and 12).

The ink ribbon 8 is then removed by reversing the above-described mounting operation.

Next, in this state, the feeding roller 81 is driven to rotate to introduce the uppermost sheet S in the supply cassette 80 into the printer main body. Then, the paper transport motor 84 drives the transport roller 82 to transport the paper S until a predetermined position of the paper S reaches the printing section, and then the transport roller 82 is stopped.

Next, the printing operation is started.

In other words, the paper S that has been carried to the printing position and has stopped.
If the paper is made of high-quality paper with a uniform thickness, the cam block 21 is rotated clockwise from the state shown in FIG. 2(a) by the state shown in FIG. The state is switched to the state shown in Figure (a). This figure 5 (a
), as shown in FIG. 7B, the paper S is pressed against the platen 1 by the thermal head 7, and when the ink ribbon 8 is lowered by the thermal head 7, the pinch roller 9 and the driven pinch roller 10 are pressed. The ribbon guide 11 lifts the ribbon upward from the thermal head 7 in the carrying direction.

To explain further, while the cam block 21 rotates by the center angle α, the head drive lever 28 moves so that its bin 29 is in the first position.
From the small radius portion 24a of the switching cam 24 to the large radius portion 2
4b, it rotates clockwise in FIG. 2(a) about the fixed shaft 27. As a result, the head pressing member 31 disposed at the tip of the head drive lever 28
descends, gradually lowering the head mounting base 30 around the horizontal axis 34, and finally the ink ribbon 8 is heated by the heat generating part 7a provided at the lowermost part of the thermal head 7.
from its back against the platen 1, and further press the pressure contact spring 33.
As the head drive lever 28 rotates slightly clockwise against the elastic force, the heat generating portion 7a of the thermal head 7 is pressed against the paper S with a predetermined elasticity. Hereinafter, the position of the thermal head 7 at this time will be referred to as the DOWN position.

At this time, the head pressing member 31 is formed to press the back of the heat generating part 7a of the thermal head 7 toward the paper S and the platen 1, as shown in FIG.
A uniform and large pressing force acts on the entire heat generating part 7a,
Beautiful, even printing is achieved.

On the other hand, when the cam block 21 rotates by the central angle α, the bin 37 protruding from the bin and guide drive lever 36 is located at an intermediate position between the small radius portion 25a and the large radius portion valve 25b, and is still in a pinch position. The roller 9 and the driven pinch roller 10 are spaced apart, and the ink ribbon 8 is in a free state. Therefore, the thermal head 7 moves from the UP large position to the DOWN position.
When moving to the position, at least the ink ribbon 8 on the lower side of the thermal head 7 is in a free state, and the contact position between the heat generating part 7a of the thermal head 7 and the ink ribbon 8 is not relatively shifted. Even at the moment when the ink ribbon 8 is brought into contact with the paper S by the heat generating part 7a, there is no relative positional shift between the ink ribbon 8 and the paper S, so that the paper S is not stained by the ink ribbon 8. It is assumed that there are no

Then, as the cam block 21 further rotates by the central angle β, the bin 3 of the bin and guide drive lever 36 is rotated.
7 reaches the large radius portion 25b of the second switching cam 25. During this time, bin and guide.

The drive lever 36 is centered around the fixed shaft 35 as shown in FIG. 2(a).
, the pinch roller support lever 42, which is connected to the bin and guide drive lever 36 via the connecting link 44, rotates counterclockwise about the fixed shaft 43. The ink ribbon 8 is held between the pinch roller 9 and the driven pinch roller 10, and the driven pinch roller support lever 64 is rotated slightly upward against the elasticity of the tension spring 65, so that the ink ribbon 8 is held between both pinch rollers. 9 and 10 to elastically hold it. At the same time, as the bin and guide drive lever 36 rotates, 1141 of the bin and guide drive lever 36
Ribbon guide drive lever 3 engaging bin 40 with
9 rotates clockwise around the fixed shaft 38, the ribbon guide 11 lifts the ink ribbon 8 upward, and the ink ribbon 8 is expanded along the lower surface of the thermal head 7. Also, at this time, the bin and guide drive lever 36
The small tooth amount 51 attached to the pivot shaft 45 connecting the connecting link 44 is the third lever 53c of the drive lever group 53.
It is made to mesh with a gear 62 attached to. When the cam block 21 rotates by the center angle α+β, the roller 54 attached to the third lever 53c of the drive lever group 53 remains in an immobile state while contacting the maximum radius portion 26a of the third switching cam 26. keeping.

Next, the cam block 21 is stopped in this state,
At the same time, the carriage drive motor 6 is energized to move the carriage 3 in the carry-up direction, and at the same time, F is applied to the thermal head 7.
By applying electricity through the PC 87, the ink ribbon 8
Printing is performed by thermally transferring the ink to the paper S.

In this case, as the carriage 3 moves in the carry direction (to the left in FIG. 5(a)), the drive lever group 53
A pinion 59 rotatably attached to a fixed shaft 52 to which the pinion 59 is pivoted rotates clockwise in the figure. The gear 47 is connected to this pinion 59 via the small pinion 60, gear 62, small gear 51, gears 50 and 49.
rotates clockwise in the figure. The pinch roller 9, which is coaxial with the gear 47 and connected via an sm engaging member (not shown) such as a felt, moves clockwise in the figure and has a circumferential speed higher than the moving speed of the carriage 3. and rotated. The pinch roller 9 and the driven pinch roller 10 pinch the ink ribbon 8 with the elasticity of the tension spring 65. As the pinch roller 9 rotates, the paper S is attached to the heat generating part 78 of the thermal head 7. The ink ribbon 8 immediately after printing is pulled with a certain tension to forcibly peel the ink ribbon 8 from the surface of the paper S.

In this embodiment, since the pinch roller 9 is frictionally engaged with the gear 47, the attractive force of the pinch roller 9 to peel off the ink ribbon 8 is the maximum frictional force between the pinch roller 9 and the gear 47. If it becomes larger, a slip will occur between the pinch row 59 and the gear 47, and excessive tensile force will not be applied to the ink ribbon 8.

Therefore, in this embodiment, the ink ribbon 8 after printing can be smoothly peeled off from the paper S by the pinch roller 9 without sagging.

Further, in this embodiment, the outer peripheral surface of the pinch roller 9 is made of a rubber member with a large coefficient of friction, and
In the ink ribbon 8, r! Since the pinch roller 9 is brought into contact with the ink layer side having a larger lta coefficient, the frictional force between the pinch roller 9 and the ink ribbon 8 is large, and the ink ribbon 8 can be reliably peeled off from the paper S.

In addition, in this embodiment, the ribbon winding motor 15 is energized to output @69 and the drive gear 7.
0 clockwise in FIG. 8, the ink ribbon 8 is pulled toward the supply side as shown in FIG. 5(b). That is, in FIG. 8, when the driving gear 70 rotates clockwise, the swinging chitose wheel 72 meshing with the driving gear 70 rotates clockwise in the drawing about the output shaft 69 together with the swinging arm 71. It moves and meshes with the supply side gear 73 that drives the ribbon winding bobbin 14, as shown by the solid line in the figure. This supply side m! As shown in FIG. 9, the clockwise rotation of I73 causes the ribbon winding bobbin 1 to pass through the felt 75, which is an example of a tension applying mechanism and is a type of frictional engagement member.
4, the ribbon winding bobbin 14 on the supply side is rotated in the direction of winding the ink ribbon 8 between the thermal head 7 and the ink ribbon 8 as shown in FIG. 5(b). Pull in the upward direction. Furi Chitose car 72
The rotational driving force of the supply side gear 73 due to
If it becomes larger than the maximum frictional force between the felt 75 and the felt 75,
The supply side gear 73 and the felt 75 slip, and a constant tensile force corresponding to this friction angle load is applied to the ink ribbon 8. In this embodiment, during printing, the ink ribbon 8 on the carry direction side of the thermal head 7 is pulled in the carry direction to prevent the ink ribbon 8 from sagging. The thermal head 7 and the ink ribbon 8 are moved to a predetermined position relative to the ink ribbon 8, thereby reliably preventing the occurrence of misalignment that would result in an inappropriate U relationship between the thermal head 7 and the ink ribbon 8, and ensuring beautiful, high-quality printing at all times. can be administered.

In addition, in this embodiment, as shown in FIGS. 10(a) and 10(b), the thermal head 7 connects the electrode group 7b for energizing the heat generating part 7a of the thermal head 7 to the platen 1.
Since the electrode group 7b and the FPC 87 are welded to each other at the end of the thermal head 7 in the carry direction, the FPC 87 is always kept far away from the platen 1 and the paper S. Even if the paper S is flat-fed in the horizontal direction on the upper surface of the platen 1, the FPC 87 and the paper S do not come into contact with each other, and beautiful printing is always performed. Furthermore, since the lengths of the patterns of the electrode group 7b for each element of the heat generating part 7a in the thermal head 7 are equal, the resistance value is also uniform, and the heat generating part 7a has the same length.
Temperature control for each element of a can be easily performed.

In addition, if the paper S carried in is so-called rough paper with uneven thickness compared to high-quality paper, the state switching motor 12 moves the cam block 21 further to the center angle from the state shown in FIG. 5(a). γ to move the pin 29 of the head drive lever 28 to the maximum radius portion 24c of the first switching cam 24 as shown in FIG. 6(a), and further rotate the pin 29 clockwise to move the head By further elastically compressing the pressure contact spring 33 attached to the pressing member 31, the pressing force for pressing the paper S of the thermal head 7 is strengthened, and even if the paper S is rough paper, the heat generation of the thermal head 7 is suppressed. Part 7a
To perform high-quality printing by always bringing the paper S into proper contact with the paper S. Also in this case, the lever 5 of the drive lever group 53
The roller 54 attached to the third switching cam 26
remains engaged with the largest radius portion 26a of the.

The pressure force applied to the thermal head 7 by the head suppressing member 31 is adjusted not only according to changes in the paper thickness of the paper S as in the above embodiment, but also according to the characteristics of the ink ribbon 8, for example, for a single color of black. It is preferable to print with an appropriate pressing force depending on the ribbon, color printing, multi-ribbon, etc.

Next, the ribbon save operation will be explained.

While printing is progressing in the state shown in Fig. 5 or 6, there is a part that does not require printing, and the process of not using the ink ribbon 8 in that part is called ribbon save operation. .

In this case, first, the carriage 3 is stopped, and then the state switching motor 12 is energized to move the cam block 21 to the fifth position.
From the state in figure (a), the center angle γ + δ + ε is set clockwise in the figure.
From the state shown in FIG. 6(a), the state shown in FIG. 7(a) is changed to the state shown in FIG.

In this case, in this embodiment, when the cam block 21 rotates by the center angle δ from the state shown in FIG. 24b and when the thermal head 7 is pressing the ink ribbon 8 against the paper S and the platen 1, the bin 37 provided on the bin and guide drive lever 36 is engaged with the intermediate radius portion 25c of the second switching cam 25. is engaged with, rotates clockwise in the figure around the fixed shaft 35, and is connected to the bin and guide drive lever 36.
Since the pinch roller support lever 42 connected via the links 4 and 4 similarly rotates clockwise in the figure around the fixed shaft 43, the pinch roller 9 provided at the tip of the pinch roller support lever 42 rotates clockwise in the figure. is lowered and separated from the driven pinch roller 10, leaving the ink ribbon 8 in a free state. At this time, the ribbon guide 11 also descends to some extent.

Thereafter, when the cam block 21 further rotates by the central angle ε, while the one pinch roller 9 is away from the driven pinch roller 10, the pin 29 of the other head drive lever 28 is moved between the first switching cam 24 By reaching the radius portion 24d first, the head drive lever 28 moves to the fixed shaft 27.
The head pressing member 31 provided at the end of the head drive lever 28 in the downward direction moves upward, and the head mounting base 30 is raised by the elasticity of a return spring (not shown), and the thermal head 7 is slightly separated from the paper S and the platen 1 and stops in the state shown in FIG. 7(a). Hereinafter, the position of the thermal head 7 at this time will be referred to as the UP small position. Thereafter, the bin 37 of the bin and guide drive lever 36 reaches the large radius portion 25b of the second switching cam 25, and as shown in FIG.
), the pinch roller 9 and the driven pinch roller 1
0 to sandwich the ink ribbon 8 from above and below. Also,
Until the cam block 21 completes its rotation by the center angle ε, the roller 54 attached to the second lever 53b of the drive lever group 53 rotates at the maximum radius portion 2 of the third switching cam 26.
6a to the small radius portion 26b, and the drive lever group 53
The entire body rotates counterclockwise in FIG. 7 around a fixed shaft 52. Therefore, the pinch roller 9 is the driven pinch roller 1.
When holding the ink ribbon 8 again between the
One of the integral gears 50 and 51 which are rotatably attached to the second lever 53b meshes with a stopper 56 formed at the tip of the second lever 53b, making it unrotatable. The other small gear 51 is spaced apart from the gear 62. As a result, the pinch roller 9, which is connected to the 61-fold 50 through the gears 49 and 47, is also locked in rotation.

As described above, in this embodiment, when the thermal head 7 moves from the DOWN position to the UP small position, the pinch roller 9 separates from the driven pinch roller 10 and leaves the ink ribbon 8 in a free state. No unreasonable tension is applied to the ink ribbon 8, the ink ribbon 8 is not unnecessarily rubbed against the paper S when the thermal head 7 is separated from the ink ribbon 8, and the paper S is prevented from being stained. This figure 7(a)
While maintaining this state, the carriage drive motor 6 is energized to move the carriage 3 in the carry direction, and at the same time, the ribbon winding motor 15 is energized to move the output shaft 69 and drive gear 70 as shown in FIG. Rotate clockwise. As a result, the ink ribbon 8 is held between the rotation-locked pinch roller 9 and the driven pinch roller 10, so that it is conveyed in the carrying direction with the movement of the sharp edge 3, and is also conveyed on the right side in FIG. The ribbon is unwound from the take-up core 18 attached to the ribbon take-up bobbin 14 on the take-up side, and wound by the slack amount onto the take-up core 18 attached to the ribbon take-up bobbin 14 on the supply side on the left side of the figure. It will be taken away. The ribbon winding bobbin 14 on the supply side is connected to the supply side gear 73 via a felt 75.
Moreover, since the winding speed of the ribbon winding bobbin 14 is set higher than the moving speed of the carriage 3,
The ribbon winding bobbin 14 rotates while slipping on the felt 75, and reliably winds up the ink ribbon 8.

When such a ribbon saving operation progresses and the heat generating part 7a of the thermal head 7 faces the printing position again, the carriage driving motor 6 and the ribbon winding motor 1
5 is stopped, and then the state switching motor 12 is energized, the state switching motor 12 rotates in the reverse direction, and the cam block 21 changes from the state shown in FIG. 7(a) to the state shown in FIG. 6(a) or the state shown in FIG. 5 The printing state is returned to that shown in FIG. 5(a). In this case, first, after the pinch roller 9 separates from the driven pinch roller 10, the thermal head 7 moves from the UP small position to the DOWN position, and then the pinch roller 9 moves back to the driven pinch roller 10.
The ink ribbon 8 is sandwiched between the ink ribbon 8 and the ink ribbon 8 to prevent the ink ribbon 8 from staining the paper S.

When printing is performed on the paper S up to the most significant digit in this state, the carriage drive motor 6 and the ribbon winding motor 15 are stopped, and then the carriage 3 is returned.

That is, the state switching motor 12 is energized and the cam block 21 is rotated clockwise in FIGS. 5(a) and 6(a), resulting in the state shown in FIG. 7(a). Next, the ribbon winding motor 15 is energized to rotate the output shaft 69 and the drive gear 70 counterclockwise in FIG. 8, and at the same time, the carriage drive motor 6 is energized to move the carriage 3 in the lowering direction. be moved to (
Figure 11). When the output shaft 69 and the drive gear 70 rotate counterclockwise in FIG. 8, the swinging chitose wheel 72 rotates counterclockwise in the same figure together with the swinging arm 71, and the swinging chitose wheel 72 rotates counterclockwise in the figure as shown by the chain line in the figure. It meshes with the gear 74. The rotation of the winding side gear 74 is transmitted to the wheel 77 via an rIl friction engagement member (not shown), and further transmitted to the wheel 78 via the transmission belt 79, and the ribbon winding ribbin 14 on the winding side takes up the winding. The carriage 3 is rotated at a speed greater than the moving speed of the carriage 3. As a result, the ink ribbon 8 sandwiched between the rotationally locked pinch roller 9 and the driven pinch roller 10 moves in the downward direction as the carriage 3 moves. As a result, the ink ribbon 8 is moved from the winding lower 18 attached to the ribbon winding bobbin 14 on one supply side.
The unused portion of the winding core 1 is fed out in the lowering direction, and the winding core 1 is attached to the ribbon winding ribbin 14 on the other winding side.
At step 8, the used portion of the ink ribbon 8 is reliably wound up in the same manner as described above.

As this return operation progresses and the heat generating part 7a of the thermal head 7 reaches the lowest digit as shown in FIG.
5 is stopped. Hereinafter, the state shown in FIG. 12 will be referred to as an initial state.

Further, when the ink ribbon 8 is of a single color, for example, black, during the return operation, the paper conveyance motor 84 is energized to rotate the conveyance roller 82 and the paper ejection roller 83 to move the paper S by one line. Improve printing efficiency by feeding paper at the same time. Also, for the same reason, the carriage 3 is stopped to prevent staining of the paper S at the moment when the thermal head 7 contacts or separates from the ink ribbon 8, the paper S, and the platen 1, but the thermal head 7 The carriage 3 is moved simultaneously during the DOWN operation before contact and during the UP operation after separation.

In addition, in this embodiment, when saving glue in Fig. 7,
The thermal head 7 is positioned at the small UP position during the return shown in FIG. 11 and in the initial state shown in FIG. 12, thereby shortening the time required for UP-DOWN of the thermal head 7 and improving printing efficiency. ing. Therefore, the distance between the small UP position of the thermal head 7 and the platen 1 is set to the minimum necessary size to prevent the ink ribbon 8 from staining the paper S.

For example, when performing color printing using the ink ribbon 8 on which three colors of ink, cyan, yellow, and magenta, are sequentially and repeatedly applied in the length of one line each, the printing range is one line. Sometimes it doesn't fill the entire line. At this time, it is necessary to wind up the unused portion. In this embodiment, after the return operation shown in FIG. 11 is completed and the initial state shown in FIG. 12 is reached, the state switching motor 12 is energized to move the cam block 21 as shown in FIG.
From the state shown in FIG. 2, it is further rotated clockwise by a center angle ζ to obtain the state shown in FIG. 2(a). In this way, the ink ribbon 8 is transferred to the thermal head 7, the pinch roller 9, and the driven pinch roller 1.
0 and the ribbon guide 11, and the unused part is the ink part of the color used in the previous printing and remains in the carry direction position from the thermal head 7. As shown in FIG. 2(b), the ribbon winding bobbin 14 on the winding side is rotated to wind the ribbon, and is stopped with the predetermined position of the ink portion of the next new color facing the lowest digit. Thereafter, printing is performed using ink of a new color in the same manner as described above. By performing this operation for three colors, beautiful color printing is achieved. and. At the time of return shown in FIG. 11 after printing of the final color is completed, the paper S is simultaneously fed by one line.

In addition, in this embodiment, the rotational driving direction of the cam block 21 by the state switching motor 12 is as shown in FIGS. 2(a), 5(a), 6(a), and 7(a). Either a clockwise direction or a counterclockwise direction may be used, but it is preferable to select a direction that can shorten printing time.

Note that the present invention is not limited to the above embodiments,
It can be changed as necessary.

(Effects of the Invention) As described above, in the thermal transfer printer of the present invention, a thermal head is attached to a carriage that is movable in the carry up/down direction, and the carry up side and the carry down side of the carriage are used for ribbon supply and ribbon winding, respectively. In a thermal transfer printer in which a pair of ribbon winding bobbins are provided separately from a carriage, when the thermal head is moving the ink ribbon to the carry side with the ink ribbon in contact with the paper, during printing, Since the ink ribbon on the carry side is equipped with a tension applying mechanism that applies a predetermined tensile force in the carry direction, it is possible to reliably prevent the ink ribbon from sagging during printing, and the ink ribbon and thermal head are This has the advantage of being able to always maintain a proper positional relationship with the printer, thereby making it possible to perform beautiful, high-quality printing.

[Brief explanation of the drawing]

The drawings show one embodiment of the thermal transfer printer of the present invention.
The figure is a perspective view showing the overall configuration, and FIG. 2(a) is a front view of the carriage section showing the state of the thermal head in the large UP position.
Fig. 2(b) is a skeleton diagram showing the relationship between the constituent parts in Fig. 2(a), Fig. 3 is a plan view of Fig. 2(a) showing the main parts of the S-shaped control mechanism, and Fig. 4 is a A cross-sectional view showing the positional relationship between a thermal head and a head pressing member that presses the thermal head,
FIGS. 5(a) and (b) are views similar to FIGS. 2(a) and (b) showing the state in which printing is performed on high-quality paper, respectively;
FIGS. 6(a) and (b) are views similar to FIGS. 2(a) and (b) showing a state in which printing is performed on rough paper, respectively;
7(a) and 7(b) are views similar to FIGS. 2(a) and 2(b) showing the state of the thermal head in the UP small position, respectively, and FIG. 8 is a front view showing the ribbon winding mechanism; Figure 9 is an enlarged sectional view taken along line IX-IX in Figure 8, and Figure 10 (a
) and (b) are respectively a front view and a plan view showing the connection relationship between the thermal head and the FPC, FIG. 11 is the same as FIG. 2(b) showing the return state, and FIG. 12 is the initial state. FIG. 2(b) is a diagram similar to that shown in FIG. DESCRIPTION OF SYMBOLS 1... Platen, 3... Carriage, 7... Thermal head, 7a... Heat generating part, 7b... Electrode group, 8
... Ink ribbon, 9... Pinch roller, 10...
・Followed pinch roller, 11... Ribbon guide, 12.
... State switching motor, 13 ... State control tIII structure, 14 ... Ribbon winding ribbin, 15 ... Ribbon winding motor, 16 ... Ribbon winding mechanism, 18 ...
- Winding core, 21... cam block, 24... first switching cam, 25... second switching cam, 26... third
Switching cam, 28... Head drive lever, 31... Head pressing member, 36... Bin and guide drive lever, 39... Ribbon guide drive bar, 42... Pinch roller support lever, 53...・・Drive lever group, 54・
... Roller, 58 ... Rack, 64 ... Driven pinch roller support lever, 70 ... Drive gear, 71 ... Swing arm, 73 ... Supply side gear, 74 ... Winding side gear ,
75...Felt, 76...Compression spring, 87...
F.P.C. Applicant's agent Shunsuke Nakao Figure 3 Figure 4 Figure 8 Figure 9 Figure 10 (a) (b) Figure 11

Claims (1)

[Claims] 1) A thermal head is attached to a carriage that is movable in the direction of raising and lowering the carriage, and a pair of ribbon winding devices are provided on the raising side and the lowering side of the carriage, for supplying ribbon and winding the ribbon, respectively. In a thermal transfer printer in which a bobbin is provided separately from a carriage, when printing when the thermal head brings the ink ribbon into contact with the paper and moves to the carry side, the thermal head moves the ink ribbon on the carry side. A thermal transfer printer characterized by being provided with a tension applying mechanism that applies a predetermined tensile force in a carry direction. 2) Claims characterized in that the tension applying mechanism is formed by connecting a ribbon winding bobbin for ribbon supply with a rotational drive source so as to apply a predetermined tensile force to the ink ribbon in the carrying direction. The thermal transfer printer according to item 1.