JP2005306496A - Thermal transfer printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism for correcting camber of a recording medium at low cost in a thermal transfer printer for printing an image using the recording medium wound in a roll-like shape. <P>SOLUTION: The thermal transfer printer is provided with a pivotal support means for pivotally supporting a turnably inserted cylindrical core material; a conveying means (104) for turning the cylindrical core material by pulling a rolled paper RP wound on the cylindrical core material in the roll-like shape and conveying the rolled paper RP; and a printing means (107) for printing the image on the rolled paper RP conveyed by the conveying means (104) by thermally transferring an ink. The printer is provided with a correction roller (101) arranged such that the roll paper RP tensionaly laid between the conveying means (104) and the cylindrical core material is wound in a direction opposite to an winding direction in which it is wound on the cylindrical core material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer printing apparatus that performs thermal melting recording or thermal sublimation recording.

  A thermal transfer printing device (thermal transfer printing device) that performs thermal fusion recording or thermal sublimation recording uses a thermal head to sublimate ink ribbon ink while the ink ribbon is superimposed on a recording medium such as photographic paper. Alternatively, the image is printed on the recording medium by melting (see, for example, Patent Document 1).

  The photographic paper used as a recording medium for such a thermal transfer printing apparatus generally has a roll shape wound in a roll shape (hereinafter, the roll-shaped photographic paper is referred to as “roll paper”), and thermal transfer. It is used by being rotatably mounted on a bearing of a printing apparatus. The loaded roll paper is unwound while being rotated along with the conveyance by the conveyance roller, and is supplied to the printing position where the thermal head is arranged.

  FIG. 4 is a diagram showing a state in which roll paper RP is loaded and printed on a conventional thermal transfer printing apparatus. As shown in the figure, the roll paper RP is transported to the position where the thermal head 405 is disposed by the transport rollers 401 and 403 and the driven rollers 402 and 404 while the stamp screen (the surface indicated by the arrow 400) is up. Then, printing is performed at the printing position.

  Here, in a thermal transfer printing apparatus that uses a roll paper RP as a recording medium and performs printing after the roll state is released by rotation, conventionally, the printed paper (the printed roll paper RP is cut into a predetermined size). ) Has a problem of remaining warpage due to winding of roll paper.

  For this reason, in order to suppress the occurrence of such warpage as much as possible, for example, measures have been taken to minimize warpage by increasing the inner diameter of the roll paper and reducing the curvature of the roll.

Further, as another countermeasure, for example, in Patent Document 2, a warp correction mechanism is provided inside the apparatus to avoid the occurrence of warp. According to this document, in addition to the thermal head for printing, a new thermal head for warpage correction is arranged, and the roll paper is heated to correct the warpage.
JP 2002-20002 A JP 2000-318194 A

  However, when the inner diameter of the roll paper is increased, the outer diameter of the roll paper is increased accordingly, resulting in a problem that the apparatus is increased in size. Also, if the outer diameter of the roll paper is made constant regardless of the inner diameter to maintain the apparatus size, the length of the roll paper must be shortened, in which case the number of sheets that can be printed with one roll paper Will decrease.

  Furthermore, if a warp correction mechanism is provided inside the apparatus as shown in Patent Document 2, there is a problem that not only the apparatus is increased in size but also the cost is increased.

  The present invention has been made in view of the above problems, and provides a mechanism for correcting warping of a recording medium at a low cost in a thermal transfer printing apparatus that performs printing by thermal transfer onto a recording medium wound in a roll shape. With the goal.

In order to achieve the above object, a thermal transfer printing apparatus according to the present invention has the following configuration. That is,
A shaft support means for supporting a cylindrical core member rotatably supported by the shaft, and a recording medium wound in a roll shape around the cylindrical core member, thereby pulling the cylindrical core member. A thermal transfer printing apparatus comprising: a conveying unit that rotates and conveys the recording medium; and a printing unit that performs printing by thermally transferring ink to the recording medium conveyed by the conveying unit,
Straightening arranged so that the recording medium stretched between the conveying means and the cylindrical core is wound in a direction opposite to the winding direction wound around the cylindrical core. A roller is further provided.

  ADVANTAGE OF THE INVENTION According to this invention, in the thermal transfer printing apparatus which prints on the recording medium wound by roll shape by thermal transfer, it becomes possible to provide the mechanism which corrects the curvature of a recording medium at low cost.

  Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Configuration of sublimation printer>
FIG. 1 is a schematic diagram showing the configuration of a sublimation printer (100) according to an embodiment of the present invention. In the figure, RP is a roll paper, which is wound in a roll shape around a cylindrical core member that is pivotably pivoted with the stamp screen facing outward, and is provided with a shaft support means (not suitable for the sublimation printer 100). It is pivotally supported by the figure. In order to rotate the roll paper RP, it is necessary to apply a predetermined amount of torque, and the roll paper RP wound in a roll shape is supported by a shaft so that the rotation is started by being pulled with a predetermined tension. Means are configured.

  Reference numeral 101 denotes a warp correction roller, which is disposed to face the driving roller 102. Of the two rollers, the warp correction roller is configured to be pressed against the printing screen side of the roll paper RP, and the driving roller 102 is configured to be pressed against the non-printing screen side of the roll paper RP. The details of the warp correction roller 101 will be described later.

  Reference numeral 103 denotes a pinch roller that conveys the roll paper RP between the grip roller 104 (conveying means). It should be noted that the pinch roller 103 is configured to press the roll paper RP on the printing screen side, and the grip roller 104 is configured to press the roll paper RP on the non-printing screen side.

  Reference numeral 105 denotes an ink ribbon supply roller around which the ink ribbon R is wound, and reference numeral 106 denotes an ink ribbon take-up roller. The ink ribbon R supplied from the ink ribbon supply roller 105 passes between the thermal head 107 and the platen roller 110 along the guide roller 113 and is wound up by the ink ribbon winding roller 106.

  Reference numeral 107 denotes a thermal head (printing means), which heat-presses the platen roller 110 while the ink ribbon R is superimposed on the roll paper RP, thereby sublimating the ink on the ink ribbon R, so that the roll paper RP Print. Reference numeral 108 denotes an arm that holds the thermal head, and is pivotally supported on the rotary shaft 109 so that the thermal head moves to the retracted position during non-printing.

  Reference numeral 111 denotes a guide plate, which guides the roll paper RP printed by the thermal head 107 to change direction after passing through the printing position (a position where heat is pressed by the thermal head 107) and toward the cutter 112. Reference numeral 112 denotes a cutter which cuts the printed roll paper RP into a predetermined size.

<Description of operation of sublimation printer>
The roll paper RP is conveyed by the rotation of the driving roller 102 and the grip roller 104 and is inserted between the seal head 107 and the platen roller 110. An ink ribbon R is inserted between the thermal head 107 and the platen roller 110 in advance, and printing on the roll paper RP is performed by the thermal head 107 being heated and sublimating the ink on the ink ribbon R.

  In the case of color printing, yellow (Y), magenta (M), cyan (C) ink layers and an overcoat layer serving as a protective layer are repeatedly applied to the ink ribbon R in predetermined units in the longitudinal direction. The roll paper RP is reciprocated by repeating forward and reverse rotations of the drive roller 102 and the grip roller 104, thereby printing and overcoating each color. The used ink ribbon R is sequentially wound up by the ink ribbon winding roller 106.

  The printed roll paper RP is guided by the guide plate 111 toward the cutter 112, and is cut into predetermined sizes. The above procedure is repeated to sequentially generate photographs and the like.

<Configuration for warping correction of roll paper RP>
FIG. 2 is a schematic view showing the loaded roll paper RP and the mechanism for correcting warpage arranged in the periphery of the sublimation printer 100. The roll paper RP wound in a roll shape is shown in FIG. It shows how it is transported.

  As shown in the figure, the conveyed roll paper RP is wound around the warp correction roller 101 by being pulled by the grip roller 104, and the roll paper RP has a force in the direction of arrow T2 on the upstream side of the warp correction roller 101. Works. On the other hand, a predetermined back tension acts on the downstream side of the warp correction roller 101 in the direction of the arrow T1.

  That is, the roll paper RP wound with the curvature radius r1 / 2 is pulled in the T1 and T2 directions with the curvature radius r2 / 2 in the direction opposite to the winding direction of the roll paper RP in the warp correction roller 101. Wrapping will cause the warp to be corrected. A detailed configuration for realizing the warp correction will be described below.

(1) Positional relationship between devices Whether or not the winding direction of the roll paper RP with respect to the warp correction roller 101 is opposite to the winding direction of the roll paper RP depends on whether the roll paper RP is loaded and the warp correction roller 101 and It depends on the positional relationship of the grip roller 104. This will be described with reference to FIG.

  FIG. 5 illustrates various positional relationships among the loaded roll paper RP, the warp correction roller 101 (and drive roller 102), and the grip roller 104 (and pinch roller 103). 5, 501 to 503 are sandwiched between a point (P 1) where the roll paper RP wound in a roll shape is unwound and separated from the warp correction roller 101 and the driving roller 102. Three cases where the point (P2) is at the same height are shown. Since the roll paper RP is wound with the marking screen facing outward, the warp correction roller 101 and the pinch roller 103 are arranged on the side to be crimped to the marking screen.

  Among the positional relationships indicated by 501 to 503 in FIG. 5, when the positional relationship indicated by 501 is present, the roll paper RP does not wrap around the warp correction roller 101, so that the warpage is not corrected. In the case of the positional relationship of 503, the roll paper RP is wound around the warp correction roller 101. However, since the winding direction is the same as the winding direction of the roll paper RP, the warp is not corrected. On the other hand, when the positional relationship is 502, the roll paper RP is wound around the warp correction roller 101 and the winding direction is opposite to the winding direction of the roll paper RP. Become.

  That is, even when the loading position of the roll paper RP and the warp correction roller 101 are in the same positional relationship, the warp correction roller 101 may or may not be warped depending on the position of the grip roller 104. Yes, the arrangement of the grip roller 104 is important.

  This is the same even when the positional relationship between the loading position of the roll paper RP and the warp correction roller 101 is changed. 511 to 513 in FIG. 5 are different from the positions 501 to 503 in the loading position of the roll paper RP and the arrangement of the warp correction roller 101 (from the point (P1) where the wound roll paper RP is unwound and separated. Also, three cases where the point (P2) where the roll paper RP is sandwiched between the warp correction roller 101 and the drive roller 102 are higher are shown).

  As is clear from 511 to 513 in FIG. 5, even in this case, the warp correction roller 101 may or may not exhibit the warp correction function by changing the arrangement of the grip roller 104. That is, in the case of the positional relationship of 511 and 513, the roll paper RP is not wound around the warp correction roller 101, or even if it is wound, the winding direction is the same as the winding direction of the roll paper RP. Is not corrected. On the other hand, when the positional relationship is 512, the roll paper RP is wound around the warp correction roller 101 and the winding direction is opposite to the winding direction of the roll paper RP. It will be.

  Further, this is the same even when the loading direction of the roll paper RP is changed. 5 are the same even when the loading direction of the roll paper RP is changed (501 to 503 and 511 to 513 are the roll paper by rotating the roll paper RP clockwise on the paper surface). RP is sent out, but the roll paper RP is sent out by rotating the roll paper RP counterclockwise in 521 to 523 and 531 to 533).

  That is, when the positional relationship is 521, 523, 531, 533, the warp correction roller 101 does not exhibit the warp correction function, but when the positional relationship is 522, 532, the warp correction roller 101 corrects the warp. Can be done.

  Thus, in order for the winding direction of the roll paper RP to the warp correction roller 101 to be opposite to the winding direction of the roll paper RP, the loading position of the roll paper RP, the warp correction roller 101, the grip roller 104, Determined by the positional relationship. The positional relationship for satisfying such conditions will be described in more detail with reference to FIG.

  FIG. 6 is a diagram showing the transport direction of the roll paper RP sent to the warp correction roller 101 and the transport direction of the roll paper RP sent out by the warp correction roller 101 (as described above, these are all rolls). It depends on the loading position of the paper RP and the positional relationship between the warp correction roller 101 and the grip roller 104).

  Now, the angle (hereinafter referred to as “incident angle”) formed with the conveyance direction of the roll paper RP sent to the warp correction roller 101 when the horizontal direction is a reference angle is θ1, and the warp correction roller 101 sends out the angle. An angle (hereinafter referred to as “output angle”) formed with the transport direction of the roll paper RP to be rotated is θ2 (counterclockwise is a positive direction). In this case, in order to wind around the warp correction roller 101 and the winding direction is opposite to the winding direction of the roll RP, it is necessary to satisfy the relationship of θ1> θ2. That is, it is necessary to maintain the positional relationship between the roll paper RP loading position and the warp correction roller 101 and the grip roller 103 so as to satisfy the relationship θ1> θ2.

(2) Strength of Warp Correction Next, the strength of warp correction by the warp correction roller 101 will be described. In order for the warp correction roller 101 to exhibit the warp correction function as described above, the loading position of the roll paper RP and the installation positions of the warp correction roller 101 and the grip roller 104 are determined so as to satisfy the relationship θ1> θ2. Although it is necessary, even when such a requirement is satisfied, the warp correction force varies depending on other parameters.

Specifically, the warping correction power is
i) Tensile force when the roll paper RP passes through the warp correction roller 101,
ii) radius of curvature of the warp correction roller 101;
iii) It is determined by the winding angle (α in FIG. 2) with respect to the warp correction roller 101 when the roll paper RP passes through the warp correction roller 101.

  Here, the tensile force (the above i) when the roll paper RP passes through the warp correction roller 101 is determined by the load when the roll paper RP rotates. That is, it is determined by the magnitude of the back tension in the conveyance direction of the roll paper RP, and the warp correction force increases as the back tension increases. The curvature radius of the warp correction roller 101 (ii) is greater, the warp correction force decreases as the radius increases, and the warp correction force increases as the radius decreases.

  Further, the winding angle (α) with respect to the warp correction roller 101 when the roll paper RP passes through the warp correction roller 101 ((iii) above) is determined by the positional relationship among the roll paper RP, the warp correction roller 101, and the grip roller 104. . For example, the winding angle increases as the distance between the outer peripheral surface of the roll paper RP and the outer peripheral surface of the warp correction roller 101 decreases. Similarly, the winding angle increases as the distance between the outer peripheral surface of the warp correction roller 101 and the outer peripheral surface of the grip roller 104 decreases. Further, the winding angle increases as the rotation center of the grip roller 104 is positioned in the clockwise direction with respect to the straight line connecting the rotation center of the roll paper RP and the rotation center of the warp correction roller 101. That is, the greater the difference between the incident angle θ1 and the output angle θ2, the greater the winding angle.

<Example of configuration for correcting warpage of roll paper RP>
Various dimensions (an example) of the sublimation printer according to the present embodiment relating to various parameters affecting the warp correction force described above are shown below in correspondence with FIGS. 2 shows an example when the outer diameter of the roll paper RP is maximum (r1 = 102 mm), and FIG. 3 shows an example when the outer diameter of the roll paper RP is minimum (r1 ′ = 60 mm).
-Outer diameter of warpage correction roller 101: 20 mm
The distance between the outer peripheral surface of the roll paper RP and the outer peripheral surface of the warp correction roller 101: 9 mm (FIG. 2), 30 mm (FIG. 3)
Difference between incident angle θ1 and output angle θ2: 71.53 degrees (FIG. 2), 65.53 degrees (FIG. 3)
As a result, in the sublimation printer 100 according to the present embodiment, the roll paper RP has a maximum winding angle α = 71.53 degrees (FIG. 2) and a minimum winding with respect to the warp correction roller 101 having a curvature radius of 10 mm. Wrapping was performed at an angle α ′ = 65.53 degrees (FIG. 3), thereby correcting the warp.

  Needless to say, various parameters that affect the warping correction force are not limited to the above specifications, and may be appropriately changed depending on the material of the roll paper RP, the diameter of the roll paper RP, and the like.

  As is clear from the above description, according to the present embodiment, when the roll paper RP is disposed and the roll paper RP is conveyed, the roll paper RP is wound in the direction opposite to the winding direction of the roll paper RP. Therefore, it becomes possible to correct the warp. Thus, warp correction can be realized at low cost by using a simple mechanism. Moreover, according to this embodiment, the roll paper which has the same core diameter and paper length as the conventional one can be used, which is excellent from the viewpoint of convenience.

It is a figure which shows the structure of the thermal transfer printing apparatus (sublimation printer) concerning one Embodiment of this invention. FIG. 2 is a schematic diagram illustrating a loaded roll paper RP and a warp correction mechanism disposed in the periphery of the sublimation printer 100. FIG. 2 is a schematic diagram illustrating a loaded roll paper RP and a warp correction mechanism disposed in the periphery of the sublimation printer 100. It is the figure which showed a mode that roll paper RP was loaded and printed in the conventional thermal transfer printing apparatus. FIG. 4 is a diagram illustrating various positional relationships among a loaded roll paper RP, a warp correction roller 101, and a grip roller 104. 2 is a diagram illustrating a conveyance direction of roll paper RP sent to the warp correction roller 101 and a conveyance direction of roll paper sent out by the warp correction roller 101. FIG.

Explanation of symbols

RP roll paper R ink ribbon 100 sublimation printer 101 warpage correction roller 102 drive roller 103 pinch roller 104 grip roller 105 ink ribbon supply roller 106 ink ribbon take-up roller 107 thermal head 110 platen roller

Claims (2)

A shaft supporting means for supporting a cylindrical core member that is pivotally supported and a recording medium wound in a roll shape around the cylindrical core member to pull the cylindrical core member. A thermal transfer printing apparatus comprising: a conveying unit that rotates and conveys the recording medium; and a printing unit that performs printing by thermally transferring ink to the recording medium conveyed by the conveying unit,
Straightening arranged so that the recording medium stretched between the conveying means and the cylindrical core is wound in a direction opposite to the winding direction wound around the cylindrical core. A thermal transfer printing apparatus, further comprising a roller. The angle formed by the conveyance direction of the recording medium fed from the cylindrical core material to the correction roller is a predetermined reference plane, and the incident direction is the angle of incidence, and the conveyance direction of the recording medium that has passed through the correction roller is the predetermined direction. The shaft support means, the correction roller, and the conveying means are arranged so that the incident angle> the output angle when the angle formed with the reference surface is an output angle. The thermal transfer printing apparatus as described.

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