JP2003103813A - Thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer printer in which staining of a sheet can be eliminated at the time of printing by equalizing the carrying speed of a recording medium and an ink ribbon when a thermal head is brought up and down while carrying the recording medium in order to enhance the throughput. SOLUTION: A pinch roller 9 has a friction mechanism (not shown) which slips to rotate when a tension of a specified level or above is applied to an ink ribbon 10. When a thermal head 5 is pressed against a carry roller 3 or separated therefrom by means of a rotary arm 7 while carrying a recording medium 1 by rotating the carry roller 3, rotational speed of the pinch roller 9 is controlled such that the carrying speeds of the recording medium 1 and the ink ribbon 10 are equalized.

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 printing a desired image or the like by transferring ink of an ink ribbon with a thermal head onto a recording medium being conveyed.

[0002]

2. Description of the Related Art A conventional thermal transfer printer has a thermal head in which a large number of heating elements are linearly arranged, and the thermal head is headed up from a platen roller and recording is performed between the thermal head and the platen roller. It is designed to position the paper, which is the medium, and the ink ribbon. Both ends of the ink ribbon are wound around a winding core and a supply core, respectively, and the ink ribbon supplied from the supply core is wound around the winding core by rotationally driving the winding core. It is designed to be used.

Then, in a head-down state in which the thermal head is pressed against the platen roller via the ink ribbon and the paper, the conveying roller is rotationally driven to convey the paper and the platen roller is rotationally driven to convey the ink ribbon. By selectively heating each heating element of the thermal head, the ink of the ink ribbon is thermally transferred onto the paper, and desired characters, images, etc. can be printed on the paper. In such a conventional thermal transfer printer, it is general to perform the up / down operation of the thermal head while the conveyance of the paper and the ink ribbon is stopped.

[0004]

However, if the conveyance of the paper and the ink ribbon is stopped each time the thermal head is moved up / down, the effective printing speed (throughput) on the paper becomes slow. there were. In order to solve this, it is attempted to improve the throughput by performing the up / down operation of the thermal head while conveying the paper, and when the head up / down operation is performed, the relative distance between the ink ribbon and the paper is increased. The speed creates and the ink ribbon rubs against the paper,
It was found that there is a problem that the ink of the ink ribbon adheres to the paper and stains the paper.

The present invention has been made in view of the above points, and when the thermal head is moved up / down while the recording medium is being conveyed in order to improve the throughput, the conveying speed of the recording medium and the ink ribbon. An object of the present invention is to provide a thermal transfer printer that can eliminate the paper stains that are generated during printing by making the conveyance speed of the same.

[0006]

As a first means for solving the above problems, a thermal transfer printer according to the present invention comprises a recording medium, an ink ribbon wound around a winding core and a supply core, and the ink. A thermal head capable of thermally transferring the ink of the ribbon onto the recording medium to print, a platen roller disposed so as to face the thermal head and capable of press-contacting the thermal head, and a thermal head disposed downstream of the thermal head. A pinch roller in which the surface of the ink ribbon opposite to the ink application surface is wound at a predetermined angle, a head drive member that drives the thermal head to press and separate from the platen roller, and the recording medium. And a pinch roller that slips when a tension of a predetermined value or more is applied to the ink ribbon. When the thermal head is pressed against the platen roller by the head driving member or separated from the platen roller while rotating the conveying roller to convey the recording medium. In addition, the rotational speed of the pinch roller is controlled so that the transport speed of the recording medium and the transport speed of the ink ribbon become equal.

As a second means for solving the above-mentioned problems, further, when the thermal head is completely in pressure contact with the platen roller, the conveyance speed of the ink ribbon is slightly lower than the conveyance speed of the recording medium. The rotational speed of the pinch roller is controlled so as to increase the speed.

As a third means for solving the above problems, the platen roller and the conveying roller are the same roller.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer printer of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic diagram for explaining the thermal transfer printer of the present invention, and FIG. 2 is a schematic diagram for explaining the operation of the present invention.

First, an embodiment of the thermal transfer printer of the present invention will be described with reference to FIGS. 1 and 2. At a predetermined position in a case (not shown), for example, plain paper wound in a roll shape or the like. A recording medium 1 composed of is stored. The recording medium 1 can be transported in the transport direction indicated by arrow A. Further, a rotatable guide roller 2 is arranged in the conveyance path of the recording medium 1, and the guide roller 2 guides the conveyance of the recording medium 1 to the downstream side.

Further, a rotatable conveying roller 3 composed of a platen roller is disposed on the downstream side of the guide roller 2 in the conveying direction indicated by arrow A, and the conveying roller 3 is provided on the outer peripheral portion of the conveying roller 3. A rotatable pressure contact roller 4 is disposed in pressure contact with the rotatable roller. The leading end of the recording medium 1 conveyed between the conveying roller 3 rotating in the direction of arrow B and the pressure contact roller 4 has the conveying roller 3 and the pressure contact roller 4.
It is pressed against and sandwiched by and so that it can be carried in the carrying direction of arrow A at a predetermined carrying speed. In addition, the arrow A of the recording medium 1
A sheet cutting device (not shown) is provided downstream of the conveyance roller 3 in the conveyance direction of (1) so that the recording medium 1 made of rolled paper after printing can be cut into a predetermined length.

Further, a thermal head 5 capable of being in pressure contact with the conveying roller 3 is disposed in the vicinity of the pressure contact roller 4 on the upstream side of the pressure contact roller 4 in the conveying direction of the arrow A of the recording medium 1. The thermal head 5 has a plurality of heating element portions (not shown) arranged in the width direction of the recording medium 1 on the front surface facing the transport roller 3. The thermal head 5 is fixed to a rotating arm 7 that is rotatable about the support shaft 6 as a fulcrum. As the rotating arm 7 rotates about the support shaft 6 as a fulcrum, as shown in FIG. The thermal head 5 is in a down state in which the thermal head 5 is in pressure contact with the transport roller 3, or, as shown in FIG. 2, the thermal head 5 is in an up state in which the thermal head 5 is separated from the transport roller 3. That is,
The thermal head 5 can be brought into and out of contact with the conveyance roller 3 by moving up / down.

A guide roller 8 is axially supported on the right side of the thermal head 5 in the drawing, and on the upstream side of the thermal head 5 in the conveyance direction of an ink ribbon 10 described later.
The guide roller 8 is rotatably supported by the rotating arm 7 via a friction mechanism (not shown), and a constant rotational load is always applied to the guide roller 8. Therefore, the ink ribbon 10 A certain amount of back tension is applied to the.

A drive source (not shown) such as a motor is provided on the left side of the thermal head 5 on the left side of the thermal head 5 in the conveying direction of the ink ribbon 10 which will be described later.
A pinch roller 9 that is connected to and can be driven to rotate is pivotally supported. The outer peripheral surface of the pinch roller 9 is coated with a material having a high friction coefficient with respect to the ink ribbon 10, such as rubber or elastomer, and the outer peripheral surface is coated with ink of the ink ribbon 10. The surface opposite to the surface is wound at a predetermined angle.

The pinch roller 9 is provided with a known friction mechanism between the pinch roller 9 and the driving source. When the ink ribbon 10 is tensioned by a predetermined amount due to the function of the friction mechanism, the pinch roller 9 is moved. The ink ribbon 10 is slip-rotated.

Between the thermal head 5 and the transport roller 3, ink ribbons having both ends wound around a winding core and a supply core are disposed. The thermal head 5 has a winding core. And is located between the supply core.
Then, the thermal head 5 shown in FIG.
In the head-up state in which the ink ribbon 10 is separated from, the ink ribbon 10 is pulled out from the supply core 12 and conveyed to the winding core 11 side by rotating the pinch roller 9 at a speed corresponding to the rotation speed of the pinch roller 9. The ink ribbon 10 conveyed to the winding core 11 side is the winding core 1
When 1 is rotationally driven, it is wound around this winding core 11.

The rotation speed of the winding core 11 is set to be slightly higher than the rotation speed of the pinch roller 9, but the winding core 11 also has a winding bobbin (not shown) having a friction mechanism. Is driven to rotate. Since the torque of the friction mechanism of the pinch roller 9 is set to be slightly larger than the torque of the friction mechanism of the winding bobbin, the rotation speed of the winding core 11 is set to be higher than the rotation speed of the pinch roller 9. Pinch roller 9 and winding core 1
It is configured such that the ink ribbon 10 between the two does not slacken and the ink ribbon 10 is not pulled out from the supply core 12 by the rotation of the winding core 11.

When the thermal head 7 is in the head-up state, the conveyance speed of the recording medium 1 is equal to the rotation speed of the conveyance roller 3, and the conveyance speed of the ink ribbon 10 is equal to the rotation speed of the pinch roller 9. By controlling the rotation speed of the motor which is the drive source of the above and the rotation speed of the motor which is the drive source of the pinch roller 9, the conveyance speed of the recording medium 1 and the conveyance speed of the ink ribbon 10 can be controlled.

Next, the printing operation of the thermal transfer printer of the present invention will be described. First, in the head-up state shown in FIG. 2, while rotating the conveying roller 5 to convey the recording medium 1 located between the thermal head 5 and the conveying roller 3, the rotating arm 7 is rotated clockwise in the drawing. To move.
The rotation operation of the rotation arm 7 is started, the motor is rotationally driven to rotationally drive the pinch roller 9, and the down operation of the thermal head 5 causes the ink ribbon 10 to contact the recording medium 1 before contact. The rotation speed of the pinch roller 9 is controlled so that the conveyance speed of the ribbon 10 becomes equal to the conveyance speed of the recording medium 1. And the recording medium 1
After the conveyance speed of 1 and the conveyance speed of the ink ribbon 10 become equal, the thermal head 5 is brought into a state of being pressed against the conveyance roller 3. Therefore, when the ink ribbon 10 is pressed against the recording medium 1, the ink ribbon 10 and the recording medium 1 have the same conveyance speed and no relative speed, so that the ink ribbon 10 is not rubbed against the recording medium 1 and recording is performed. There is no stain such that the ink of the ink ribbon 10 adheres to the medium 1.

When the thermal head 5 is brought into pressure contact with the conveying roller 3, the rotational speed of the motor is adjusted so that the rotational speed of the pinch roller 9 is slightly higher (105 to 120%) than the sheet conveying speed of the conveying roller 3. Make it faster This allows
A proper tension is applied to the ink ribbon 10 by the action of the pinch roller 10. However, as described above, since the pinch roller 9 is provided with the friction mechanism that causes slip rotation when the ink ribbon 10 is applied with a tension of a predetermined value or more, the tension applied to the ink ribbon 10 is a predetermined value or more. In this case, the slip rotation is performed and the tension above the predetermined value is not applied to the ink ribbon 10. In this state, each heating element of the thermal head 5 is selectively driven to perform printing. However, since the conveyance speed of the ink ribbon 10 and the recording medium 1 is determined by the rotation of the conveyance roller 3, the printing is performed at this time. In, the conveyance speeds of the recording medium 1 and the ink ribbon 10 are equal, and there is no relative speed. Then, the ink ribbon 1 transferred to the recording medium 1
The ink of 0 has a predetermined tension applied to the ink ribbon 10 by the rotational driving of the pinch roller 9, so that it is peeled off from the recording medium 1 and desired characters, images, etc. are printed on the paper. Then, the ink ribbon 10 used for printing
Is wound around the winding core 11.

When the printing of the desired area is completed,
Again, the rotation speed of the motor that is the drive source of the pinch roller 9 is controlled so that the conveyance speed of the ink ribbon 10 and the conveyance speed of the recording medium 1 become equal. Ink ribbon 10
When the sheet conveyance speed becomes equal to the sheet conveyance speed, the rotation arm 7 is rotated counterclockwise in the drawing to separate the thermal head 5 from the conveyance roller 3. By controlling the rotation speed of the pinch roller 9 in this manner, the conveyance speed of the recording medium 1 and the conveyance speed of the ink ribbon 10 become equal during the up operation of the thermal head 5. Therefore, since the relative speed is not generated between the recording medium 1 and the ink ribbon 10, the problem that the recording medium 1 is rubbed by the recording medium 1 and the recording medium 1 is soiled does not occur. And
When the ink ribbon 10 is separated from the recording medium 1 by the up operation of the thermal head 5, the rotational driving of the pinch roller 9 is stopped. When the printed area of the printed recording medium 1 has passed the sheet cutting device on the downstream side, the rotation drive of the conveying roller 3 is stopped and the printing operation is completed.

In the above-described embodiment of the present invention, the transfer roller 3 is a thermal transfer printer that also serves as a platen roller. However, the transfer roller 3 and the transfer roller are in pressure contact with each other and are rotatable in addition to the platen roller. It may be a thermal transfer printer provided with.

[0023]

As described above, in the thermal transfer printer of the present invention, when the thermal head is in pressure contact with the platen roller during the down / up operation of the thermal head, or
When the thermal head separates from the platen roller, the paper conveyance speed and the ink ribbon conveyance speed are controlled to be equal to each other, so that the ink ribbon rubs against the paper when the thermal head is down / up. Instead, the stains on the paper can be eliminated.

During the printing operation, the rotational speed of the pinch roller is controlled to be slightly higher than the paper conveying speed, so that the ink ribbon is given an appropriate tension.
Since the ink of the ink ribbon transferred onto the paper can be peeled off from the paper in a good state, a good printed image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a thermal transfer printer of the present invention.

FIG. 2 is a schematic diagram illustrating the operation of the present invention.

[Sharp sign]

1 recording medium 2 Guide roller 3 Conveyor rollers 4 Pressing roller 6 thermal head 7 rotating arm 8 guide rollers 9 pinch rollers 10 Ink ribbon 11 winding core 12 Supply core

Claims (3)

[Claims] 1. A recording medium, an ink ribbon wound around a winding core and a supply core, a thermal head capable of thermally transferring the ink of the ink ribbon onto the recording medium to print, and a thermal head facing the thermal head. A platen roller which is arranged so that the thermal head can be brought into pressure contact with it, and a pinch roller which is arranged downstream of the thermal head and whose surface opposite to the ink application surface of the ink ribbon is wound at a predetermined angle. A head driving member that drives the thermal head so as to press and separate the thermal head from the platen roller; and a conveying roller that can convey the recording medium, and the pinch roller has a predetermined value or more on the ink ribbon. Having a friction mechanism that causes slip rotation when tension is applied, while rotating the conveyance roller to convey the recording medium, When the thermal head is pressed against the platen roller by the head driving member or when the thermal head is separated from the platen roller, the pinch roller of the pinch roller is adjusted so that the conveyance speed of the recording medium becomes equal to the conveyance speed of the ink ribbon. A thermal transfer printer characterized by controlling the rotation speed. 2. The rotation speed of the pinch roller is controlled so that the conveyance speed of the ink ribbon is slightly higher than the conveyance speed of the recording medium when the thermal head is in complete contact with the platen roller. The thermal transfer printer according to claim 1, wherein: 3. The thermal transfer printer according to claim 1, wherein the platen roller and the conveying roller are the same roller.