JP2007136978A - Thermal transfer printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer printer which can prevent an ink ribbon from obliquely moving by using an inexpensive ribbon separation means and prevent creases from occurring in the ink ribbon. <P>SOLUTION: The formation of a butting portion of a separation shaft 8 which butts against the ink ribbon to ensure that it becomes a symmetrical inclined shape so that it becomes most concave in the width direction center portion of the ink ribbon, as the width direction ends of the ink ribbon is made to be more strongly pulled than the center portion and the width direction both ends of the ink ribbon taken up by the ribbon take-up shaft to be pulled outwardly in taking up the ink ribbon by a ribbon take-up shaft, the oblique movement of the ink ribbon is prevented by using the separation shaft 8, and the occurrence of creases in the ink ribbon can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal transfer printer that performs printing by sandwiching and transporting a printing medium such as a label and an ink ribbon between a thermal head and a platen roller, and in particular, an ink ribbon that is in close contact with the printing medium after printing at a predetermined angle. The present invention relates to a thermal transfer printer having a ribbon peeling means that is peeled off at the same time.

  A general thermal transfer printer sandwiches and conveys a printing medium such as a label and an ink ribbon between a thermal head and a platen roller, and selectively heats a heating element of the thermal head, thereby printing the printing surface of the printing medium. Ink is transferred from the ink ribbon to perform printing, and the ink ribbon after printing is taken up by a ribbon take-up shaft through a ribbon peeling means such as a peeling roller.

  When the ink ribbon is wound around the ribbon take-up shaft, if the print area is different on the left and right in the width direction of the ink ribbon, the tension applied to the ink ribbon is not even on the left and right, so the ink ribbon is positioned relative to the peeling roller. There is a risk that the skew will occur and the ink ribbon will be wrinkled and the print quality will deteriorate. Therefore, an elastic member that elastically urges the ink ribbon in a direction perpendicular to the traveling direction of the ink ribbon is disposed on the peeling roller, and even if the skew occurs in the ink ribbon, the peeling roller elastically moves along the skew, There has been proposed a thermal transfer printer that can return to the neutral position and correct the skew (see, for example, Patent Document 1).

  However, in the prior art, the peeling roller, which is a ribbon peeling means, is elastically moved in a direction perpendicular to the traveling direction of the ink ribbon. However, if the peeling roller is inclined with respect to the traveling direction of the ink ribbon, Since wrinkles are generated in the ink ribbon, it is necessary to process the guide member that guides the peeling roller in a direction orthogonal to the traveling direction of the ink ribbon with high accuracy, and the work for assembling the peeling roller, the elastic member, and the guide member However, there is a problem that it becomes expensive.

JP 2001-293940 A

  The present invention has been made in view of such problems, and an object of the present invention is to use an inexpensive ribbon peeling means without the need for elastically moving the ribbon peeling means in a direction perpendicular to the running direction of the ink ribbon. Accordingly, it is an object to provide a thermal transfer printer that can prevent the ink ribbon from skewing and prevent the ink ribbon from wrinkling.

In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is a thermal transfer printer which performs printing by sandwiching and transporting a printing medium and an ink ribbon between a thermal head and a platen roller, and the ink which is in close contact with the printing medium after printing Ribbon peeling means for peeling the ribbon at a predetermined angle is provided, and the contact portion of the ribbon peeling means that comes into contact with the ink ribbon has a symmetric gradient shape that is the most concave at the center in the width direction of the ink ribbon. There exists a thermal transfer printer characterized by being.
According to a second aspect of the present invention, the ribbon peeling means is disposed downstream of the platen roller and the thermal head in the traveling direction of the ink ribbon and orthogonal to the traveling direction of the ink ribbon. 2. The thermal transfer printer according to claim 1, wherein the thermal transfer printer is a cylindrical peeling shaft that is fixed and has a diameter at the center smaller than that at both ends.

  The thermal transfer printer of the present invention is configured so that the abutting portion that abuts on the ink ribbon of the ribbon peeling unit is configured to have a symmetrical gradient shape that is the most concave at the center in the width direction of the ink ribbon. When winding the ink ribbon by the take-up shaft, both ends in the width direction of the ink ribbon are pulled stronger than the center portion, and both ends in the width direction of the ink ribbon taken up by the ribbon take-up shaft are pulled outward, Therefore, it is not necessary to elastically move the ribbon peeling means in the direction orthogonal to the running direction of the ink ribbon, and the inexpensive ribbon peeling means is used to prevent the ink ribbon from skewing and to prevent the ink ribbon from wrinkling. There is an effect that can be done.

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

(First embodiment)
FIG. 1 is a schematic side view showing the configuration of the first embodiment of the thermal transfer printer according to the present invention, and FIG. 2 is a side view showing the configuration of the peeling shaft 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 a ribbon supply shaft 5 and a ribbon take-up shaft 6 that takes up the ink ribbon 4. 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 to perform printing. Done. Further, the ink ribbon 4 after printing is turned at a predetermined angle in the direction of peeling from the printing medium 3 by the peeling shaft 8, and 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.

  The peeling shaft 8 is a ribbon peeling means for peeling the ink ribbon 4 that is in close contact with the printing medium 3 after printing at a predetermined angle, and on the downstream side of the platen roller 1 and the thermal head 2 in the traveling direction of the ink ribbon 4. It is fixed so as to be orthogonal to the traveling direction. 2, the shape of the peeling shaft 8 is a columnar shape in which the central portion CL, that is, the diameter A where the central portion in the width direction of the ink ribbon 4 is located is smaller than the diameter B at both ends. The abutting portion of the shaft 8 that abuts on the ink ribbon 4 has a symmetric gradient shape that is the most concave at the center portion CL in the width direction of the ink ribbon 4.

  In the contact portion of the peeling shaft 8 that contacts the ink ribbon 4, the center portion CL is lower by (BA) / 2 than both end portions, and the difference in height between the center portion CL and both end portions, that is, ( The value of B−A) / 2 can be set as appropriate, but it is considered that the range is appropriate to 0.1 to 0.2% of the length C of the peeling shaft 8.

  The abutting portion of the peeling shaft 8 that abuts on the ink ribbon 4 has a symmetrical gradient shape that is the most concave at the center portion CL in the width direction of the ink ribbon 4. When the ink ribbon 4 is wound, both end sides in the width direction of the ink ribbon 4 are pulled more strongly than the center portion, and both end portions in the width direction of the ink ribbon 4 wound by the ribbon take-up shaft 6 are pulled outward. Wrinkles can be prevented from occurring on the ribbon 4.

  In the first embodiment, the peeling shaft 8 is fixed. However, the peeling shaft 8 may be used as a peeling roller by rotatably supporting the peeling shaft 8.

(Second Embodiment)
FIG. 3 is a schematic side view showing the configuration of the second embodiment of the thermal transfer printer according to the present invention, and FIG. 4 is a cross-sectional view showing the configuration of the peeling plate shown in FIG.

  In the second embodiment, referring to FIG. 3, a peeling plate 81 is used as a ribbon peeling means for peeling the ink ribbon 4 that is in close contact with the print medium 3 after printing at a predetermined angle.

  FIG. 4 is a cross-sectional view of the peeling plate 81 cut in a direction orthogonal to the traveling direction of the ink ribbon 4, and in the drawing, the upper surface side is a contact portion that contacts the ink ribbon 4. Referring to FIG. 4, the peeling plate 81 is curved symmetrically, and the abutting portion that abuts on the ink ribbon 4 of the peeling plate 81 is the left and right most concave at the center portion CL in the width direction of the ink ribbon 4. It has a symmetrical gradient shape.

  In the abutting portion of the peeling plate 81 that abuts on the ink ribbon 4, the center portion CL is lower than the both end portions by D, and the height difference between the center portion CL and both end portions, that is, the value of D is appropriately set. However, it is considered that the range is appropriate to 0.1 to 0.2% of the width E of the peeling plate 81.

  Since the contact portion of the peeling plate 81 that contacts the ink ribbon 4 has a symmetric gradient shape that is the most concave at the center portion CL in the width direction of the ink ribbon 4, the ink ribbon 4 is driven by the ribbon take-up shaft 6. When the ink ribbon 4 is wound, both end sides in the width direction of the ink ribbon 4 are pulled more strongly than the center portion, and both end portions in the width direction of the ink ribbon 4 wound by the ribbon take-up shaft 6 are pulled outward. Wrinkles can be prevented from occurring on the ribbon 4.

  As described above, according to the present embodiment, the abutting portion that abuts on the ink ribbon 4 of the peeling shaft 8 is formed to have a symmetrical gradient shape that is the most concave at the center in the width direction of the ink ribbon 4. With this configuration, when the ink ribbon 4 is taken up by the ribbon take-up shaft 6, both end sides in the width direction of the ink ribbon 4 are pulled more strongly than the center portion, and the ink ribbon 4 taken up by the ribbon take-up shaft 6 is used. Therefore, it is not necessary to elastically move the peeling shaft 8 in a direction perpendicular to the traveling direction of the ink ribbon 4, and the inexpensive ribbon shaft 8 is used to remove the ink ribbon 4. It is possible to prevent the skew and prevent the ink ribbon 4 from being wrinkled.

  Furthermore, according to the present embodiment, the peeling shaft 8 is fixed to the downstream side of the platen roller 1 and the thermal head 2 in the traveling direction of the ink ribbon 4 so as to be orthogonal to the traveling direction, and the peeling shaft. 8 is configured in a columnar shape in which the diameter A of the central portion CL is smaller than the diameter B of both ends, so that when the peeling shaft 8 is attached so as to be orthogonal to the running direction of the ink ribbon 4, the peeling shaft No matter which part of the peripheral surface of 8 is an abutting part that abuts against the ink ribbon 4, it has the same gradient shape, so it can be attached without having to consider positioning around the axis of the peeling shaft 8, There is an effect that efficiency is improved.

  It should be noted that the present invention is not limited to the above-described embodiments, and it is obvious that each embodiment 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 suitable number, position, shape, and the like in practicing 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 a first embodiment of a thermal transfer printer according to the present invention. It is a side view which shows the structure of the peeling shaft shown in FIG. It is a schematic side view which shows the structure of 2nd Embodiment of the thermal transfer printer which concerns on this invention. It is sectional drawing which shows the structure of the peeling plate 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 Peeling shaft 9 Torque limiter 81 Peeling plate

Claims (2)

A thermal transfer printer that performs printing by sandwiching and conveying a printing medium and an ink ribbon between a thermal head and a platen roller,
Ribbon peeling means for peeling the ink ribbon that is in close contact with the printing medium after printing at a predetermined angle;
The thermal transfer printer according to claim 1, wherein the abutting portion of the ribbon peeling unit that abuts on the ink ribbon has a symmetric gradient shape that is the most concave at the center in the width direction of the ink ribbon. The ribbon peeling means is fixed to the downstream side of the platen roller and the thermal head in the traveling direction of the ink ribbon and to be orthogonal to the traveling direction of the ink ribbon, and the diameter of the central portion is at both end portions. The thermal transfer printer according to claim 1, wherein the thermal transfer printer is a cylindrical peeling shaft smaller than the diameter of the cylindrical peeling shaft.

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