JP4589784B2 - Thermal transfer printer - Google Patents

Description

  The present invention relates to a thermal transfer printer that performs printing using an ink ribbon on a printing medium such as a label, and more particularly to a thermal transfer printer that winds a transferred ink ribbon around a ribbon take-up shaft.

  In a thermal transfer printer that performs printing using an ink ribbon on a printing medium such as a label, an ink ribbon wound in a roll is mounted on a ribbon supply shaft, and the ink ribbon is connected to a thermal head, a platen roller, and a ribbon supply shaft. The ink ribbon is also nipped and conveyed in synchronization with the print medium by the thermal head and the platen roller, and the ink ribbon after printing is taken up by the ribbon take-up shaft.

  As a method of winding an ink ribbon, a method of driving a ribbon winding shaft by a motor is generally used. However, in order to prevent slack in the ink ribbon, the ink ribbon travels when the printing medium travels and the ink ribbon travels. The difference between the winding length of the ink ribbon and the traveling speed of the printing medium is determined by the slip mechanism on the ribbon winding shaft. A certain torque limiter is provided for absorption.

  A torque limiter that absorbs the difference between the winding length of the ink ribbon and the running speed of the printing medium is attached to the drive part of the ribbon winding shaft, so the torque that causes the slip is constant, but the ink ribbon The tension of the ink ribbon varies depending on the amount of ink ribbon wound around the ribbon winding shaft, that is, the winding diameter of the ink ribbon, and starts to wind strongly and weakens at the end. As the tension of the ink ribbon changes in this way, the ink ribbon may expand and contract, and wrinkles may occur.

  Therefore, the ink ribbon is spread from the center to the outside in the width direction across the running direction by the guide roller having spiral grooves formed on the outer peripheral surface in the opposite directions from the center toward both ends. A technique for preventing such wrinkles has been proposed (see, for example, Patent Document 1).

However, in the prior art, the guide roller that spreads the ink ribbon from the center to the outside in the width direction across the running direction is a driven roller that rotates by the pressure contact of the ink ribbon, and the guide roller is used for running the ink ribbon. Since the load is applied, the ink ribbon is stretched, and there is a problem that the generation of wrinkles cannot be effectively prevented.
JP 2004-338108 A

  The present invention has been made in view of such problems, and an object of the present invention is to draw up the ink ribbon by stretching the ink ribbon in the width direction without imposing a load on the running of the ink ribbon. The present invention is to provide a thermal transfer printer that can suppress the expansion and contraction of the ink ribbon even if the temperature changes, and can prevent the generation of wrinkles.

In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is that printing is performed by transferring the ink from the ink ribbon onto the printing surface of the printing medium by sandwiching and conveying the printing medium and the ink ribbon by the platen roller and the thermal head. together, a thermal transfer printer for taking up the transfer already the ink ribbon to the ribbon take-up shaft, the path of the ink ribbon after printing, provided with a tensile means, the tensile means, opposite to each other on the outer peripheral surface A pair of tension rollers each formed with a spiral groove and disposed substantially parallel to the running direction of the ink ribbon, and a pressing disposed at a position facing the pair of tension rollers across the ink ribbon. Each of which is arranged near each end of the ink ribbon in a state where the ink ribbon is sandwiched between a pair of the tension roller and the pressing plate. By rotating the pair of tension rollers in opposite directions to each other, a stress that conveys the ink ribbon in the running direction is applied, and a stress that stretches the ink ribbon in the width direction is applied. the tension resides roller in the thermal transfer printer, wherein a movable der Rukoto the width direction of the ink ribbon.
According to a second aspect of the present invention, there is provided a running speed detecting means for detecting an actual running speed of the ink ribbon, and the tension means is an actual ink ribbon detected by the running speed detecting means. the running speed lies in the thermal transfer printer according to claim 1 Symbol mounting, characterized in that the action of stress that conveys the ink ribbon in the direction of travel.
According to a third aspect of the present invention, the travel speed detecting means determines an actual travel speed of the ink ribbon based on an output of an encoder provided on a rotary shaft of a driven roller that rotates by pressure contact of the ink ribbon. 3. The thermal transfer printer according to claim 2 , wherein the thermal transfer printer detects the thermal transfer printer .

  In the thermal transfer printer of the present invention, an ink ribbon is provided by applying a stress for conveying the ink ribbon in the running direction to the path of the ink ribbon after printing and by applying a stress for stretching the ink ribbon in the width direction. By stretching the ink ribbon in the width direction without imposing a load on the running of the ink ribbon, the expansion and contraction of the ink ribbon can be suppressed even when the winding diameter of the ink ribbon changes, and the generation of wrinkles can be prevented. There is an effect.

  Furthermore, the thermal transfer printer according to the present invention is configured to detect the actual traveling speed of the ink ribbon and to apply a stress that conveys the ink ribbon in the traveling direction at the detected actual traveling speed of the ink ribbon. The ink ribbon can be stretched in the width direction in a state in which the load on the running of the ribbon is completely eliminated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic side view showing a configuration of an embodiment of a thermal transfer printer according to the present invention, FIG. 2 is an explanatory view of the tension portion shown in FIG. 1 viewed from the direction of arrow A, and FIG. 2 is an explanatory view of the guide plate shown in FIG. 2 as viewed from the direction of arrow B, and FIG. 4 is a block diagram for explaining drive control of the tension roller shown in FIG.

  In this embodiment, referring to FIG. 1, a platen roller 1 and a thermal head 2 having a heating element formed on a surface facing the platen roller 1, a printing medium 3 such as a label, and an ink ribbon 4 is sandwiched between the platen roller 1 and the thermal head 2 and the heating element of the thermal head 2 is selectively heated to transfer the ink from the ink ribbon 4 to the printing surface of the medium 3 to be printed. Desired characters, barcodes and the like are printed.

  The ink ribbon 4 is bridged between the ribbon supply shaft 5 and the ribbon take-up shaft 6. The ink ribbon 4 held in a state of being wound around the ribbon supply shaft 5 is supplied between the platen roller 1 and the thermal head 2 via a guide roller 7 that is rotatably provided. The ink ribbon 4 reaches the ribbon take-up shaft 6 via a turning roller 8 provided rotatably, and is taken up by the ribbon take-up shaft 6.

  The traveling speed of the ink ribbon 4 wound on the ribbon winding shaft 6 is set to exceed the traveling speed of the printing medium 3 conveyed by the platen roller 1 so as not to loosen the ink ribbon 4. The difference in travel speed between the ink ribbon 4 and the printing medium 3 is configured to be absorbed by providing the ribbon take-up shaft 6 with a torque limiter 9 as a slip mechanism.

  In the travel path of the ink ribbon 4 between the turning roller 8 and the ribbon take-up shaft 6, a tension portion 10 is provided that stretches the ink ribbon 4 from both sides in the width direction, that is, the direction orthogonal to the travel direction. .

  Referring to FIG. 2, the tension portion 10 is disposed at a position facing the tension rollers 11 a and 11 b with the pair of left and right tension rollers 11 a and 11 b disposed in parallel with the traveling direction of the ink ribbon 4 and the ink ribbon 4 interposed therebetween. The pair of tension rollers 11a and 11b are respectively rotated in opposite directions, that is, as shown by arrows in FIG. Each is configured to rotate in a direction away from each other. Accordingly, in a state where the ink ribbon 4 is held between the tension rollers 11a and 11b and the pressing plate 12, the tension roller 11a pulls the ink ribbon 4 held between the pressing plate 12 to the left side in FIG. At the same time, the pulling roller 11b pulls the ink ribbon 4 sandwiched between the pressing plate 12 to the right side in FIG. 2 and a pair of pulling rollers 11a disposed near the respective end portions of the ink ribbon 4. , 11b, the ink ribbon 4 is stretched in the width direction. The outer peripheral surfaces of the pulling rollers 11 a and 11 b are made of a material such as rubber that generates friction with the ink ribbon 4.

  The rotating shafts 111a and 111b of the pair of pulling rollers 11a and 11b are rotatably supported by the opposing guide plates 13, and bevel gears 113a and 113b are respectively provided at one end portions of the rotating shafts 111a and 111b. It is attached.

  Referring to FIG. 3, the guide plate 13 has an opening 131 for rotatably supporting the rotation shaft 111a of the tension roller 11a and openings 132a to 132c for rotatably supporting the rotation shaft 111b of the tension roller 11b. Is formed. The openings 132a to 132c are connected by a guide groove 133, and the tension roller 11b is moved in the width direction of the ink ribbon 4, and the tension roller 11b (the rotation shaft 111b of the tension roller 11b) is disposed at the position of the openings 132a to 132c. Be able to. The movement of the pulling roller 11b in the width direction makes the distance from the pulling roller 11a variable, and pulls the ink ribbon 4 at an appropriate position according to the ribbon width, that is, near each end of the ink ribbon 4. In order to arrange the rollers 11a and 11b, the tension roller 11b (the rotation shaft 111b of the tension roller 11b) can be disposed at any position of the openings 132a to 132c.

  The tension rollers 11a and 11b are rotationally driven by a tension roller drive motor 14 which is the same drive source. Referring to FIG. 2, the rotation drive shaft 141 of the tension roller drive motor 14 is disposed in a direction orthogonal to the traveling direction of the ink ribbon 4, and the rotation drive shaft 141 meshes with the bevel gear 113a of the tension roller 11a. A bevel gear 142a is attached, and bevel gears 142b to 142d that mesh with the bevel gear 113b of the tension roller 11b are attached in the opposite direction to the bevel gear 142a.

  The bevel gear 142b meshes with the bevel gear 113b of the tension roller 11b when the tension roller 11b is disposed in the opening 132a, and the bevel gear 142c is the tension roller 11b when the tension roller 11b is disposed in the opening 132b. The bevel gear 113b meshes with the bevel gear 113b, and the bevel gear 142d meshes with the bevel gear 113b of the tension roller 11b when the tension roller 11b is disposed in the opening 132c.

  The tension roller 11b is provided so as to be movable in the axial direction, and is attached in a direction in which the bevel gear 113b meshes with the bevel gears 142b to 142d of the rotation drive shaft 141 by a coil spring 112 provided on the rotation shaft 111b of the tension roller 11b. It is energized. Accordingly, when the tension roller 11b is moved in the axial direction against the urging force of the coil spring 112, the meshing between the bevel gear 113b of the tension roller 11b and the bevel gears 142b to 142d of the rotary drive shaft 141 is released, and the guide The tension roller 11b can be moved in the width direction of the ink ribbon 4 along the guide groove 133 of the plate 13.

  As shown in FIG. 2, spiral grooves 114a and 114b opposite to each other are formed on the outer peripheral surfaces of the tension rollers 11a and 11b, respectively. The spiral grooves 114a and 114b are formed so as to face the traveling direction of the ink ribbon 4 along the rotation directions of the tension rollers 11a and 11b, respectively. The rotation of the tension rollers 11a and 11b causes the ink ribbon 4 to move. When the ink ribbon 4 is stretched in the width direction, a stress that conveys the ink ribbon 4 in the running direction acts. The traveling speed of the ink ribbon 4 due to the rotation of the tension rollers 11a and 11b is determined by the rotation speed of the tension rollers 11a and 11b and the angle of the spiral grooves 114a and 114b. In the present embodiment, the tension rollers 11a and 11b. Is controlled so that the actual traveling speed of the ink ribbon 4 by the ribbon take-up shaft 6 is the same as the traveling speed of the ink ribbon 4 by the rotation of the tension rollers 11a and 11b.

  Referring to FIG. 4, rotation control of the tension rollers 11 a and 11 b is performed on the rotation shaft 81 of the turning roller 8 that is a driven roller that rotates according to the actual traveling speed of the ink ribbon 4, that is, rotates by pressure contact of the ink ribbon 4. An encoder 15 which is provided and outputs a pulse corresponding to the rotational speed of the turning roller 8; a travel speed detector 16 which detects an actual travel speed of the ink ribbon 4 based on the pulse output from the encoder 15; Based on the actual traveling speed of the ink ribbon 4 detected by the detection unit 16, the actual traveling speed of the ink ribbon 4 and the traveling speed of the ink ribbon 4 due to the rotation of the tension rollers 11a and 11b are the same. The tension controller 17 drives the tension roller drive motor 14.

  Referring to FIG. 1, the pressing plate 12 and the pulling rollers 11 a and 11 b that are opposed to each other with the ink ribbon 4 interposed therebetween are located on the discharge direction side of the print medium 3, and FIG. Referring to, the pressing plate 12 is attached to the side wall or the like by a hinge (not shown), and is configured to be retractable from a position facing the tension rollers 11a and 11b. Since the working space can be secured by retracting the pressing plate 12, the setting of the ink ribbon 4 and the movement of the tension roller 11b to a position corresponding to the set ink ribbon 4 can be easily performed. .

  As described above, according to the present embodiment, the stress that conveys the ink ribbon 4 in the running direction and the stress that stretches the ink ribbon 4 in the width direction act on the path of the ink ribbon 4 after printing. By providing the pulling portion 10 to be stretched, the ink ribbon 4 is stretched in the width direction without imposing a load on the travel of the ink ribbon 4, so that the ink ribbon 4 can be expanded or contracted even if the winding diameter of the ink ribbon 4 changes. It is possible to suppress the occurrence of wrinkles.

  Furthermore, according to the present embodiment, the actual traveling speed of the ink ribbon 4 is detected, and the stress that transports the ink ribbon 4 in the traveling direction is applied at the detected actual traveling speed of the ink ribbon 4. Thus, there is an effect that the ink ribbon 4 can be stretched in the width direction in a state where the load on the running of the ink ribbon 4 is completely eliminated.

  In the present embodiment, only one tension roller 11b is configured to be movable in the width direction of the ink ribbon 4. However, in the case of a center-aligned printer or the like, both tension rollers 11a and 11b are connected to the ink ribbon 4. It may be configured to be movable in the width direction.

  In the present embodiment, the tension rollers 11a and 11b are arranged in parallel to the traveling direction of the ink ribbon 4, but the tension rollers 11a and 11b are slightly inclined with respect to the traveling direction of the ink ribbon 4. The upstream side in the traveling direction of the ink ribbon 4 in the tension rollers 11a and 11b may be slightly lifted from the pressing plate 12. By arranging the tension rollers 11 a and 11 b in this way, the traveling ink ribbon 4 is smoothly supplied between the tension rollers 11 a and 11 b and the pressing plate 12.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a number, position, shape, and the like that are suitable for implementing the present invention. In each figure, the same numerals are given to the same component.

1 is a schematic side view showing a configuration of an embodiment of a thermal transfer printer according to the present invention. It is explanatory drawing which looked at the tension | pulling part shown in FIG. FIG. 3 is an explanatory view of the guide plate shown in FIG. It is a block diagram for demonstrating drive control of the tension | pulling roller shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Platen roller 2 Thermal head 3 Medium to be printed 4 Ink ribbon 5 Ribbon supply shaft 6 Ribbon take-up shaft 7 Guide roller 8 Turning roller 9 Torque limiter 10 Tension part (tensioning means)
11a, 11b Tension roller 12 Pressing plate 13 Guide plate 14 Tension roller drive motor 15 Encoder 16 Travel speed detection unit 17 Tension control unit 81 Rotating shaft 111a, 111b Rotating shaft 112 Coil springs 113a, 113b Bevel gears 114a, 114b Helical groove 131 Opening 132a, 132b, 132c Opening 133 Guide groove 141 Rotation drive shaft 142a, 142b, 142c, 142d Bevel gear

Claims (3)

The printing medium and the ink ribbon are nipped and conveyed by the platen roller and the thermal head to transfer the ink from the ink ribbon onto the printing surface of the printing medium and print, and the transferred ink ribbon is used as a ribbon. A thermal transfer printer that winds on a winding shaft,
The path of the ink ribbon after printing, provided with a tensile means,
The tension means includes a pair of tension rollers formed with spiral grooves in opposite directions on the outer peripheral surface, and disposed substantially parallel to the running direction of the ink ribbon,
A pressing plate disposed at a position facing the pair of pulling rollers across the ink ribbon,
In a state where the ink ribbon is sandwiched between the pair of pulling rollers and the pressing plate, the pair of pulling rollers respectively disposed near the end portions of the ink ribbon are rotated in opposite directions, respectively. While acting the stress that conveys the ink ribbon in the running direction, and acting the stress that stretches the ink ribbon in the width direction,
Any thermal transfer printer, wherein a movable der Rukoto one of the tension rollers in the width direction of the ink ribbon. Comprising a running speed detecting means for detecting the actual running speed of the ink ribbon;
The tension means according to claim 1 Symbol placement of the thermal transfer printer, characterized in that the action of stress that conveys the ink ribbon at the actual traveling speed of the ink ribbon detected by said running speed detecting means in the direction of travel. The running speed detecting means, according to claim 2, wherein the detecting the actual traveling speed of the ink ribbon based on the output of the encoder provided on the rotation shaft of the driven roller rotated by pressing the ink ribbon Thermal transfer printer.

Images