JP2009234185A - Heat-transfer printer for film, and heat-transfer printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-transfer printer for a film in which the shift of printed images does not occur. <P>SOLUTION: For this heat-transfer printer for film, a sensor, and a compensation processing means are installed. In this case, the sensor is used for sensing an image which has been printed on a plastic film. The compensation processing means compares the image position concerning the image being sensed by the sensor with a reference position which has been stored in advance, and compensates the variation when the image position fluctuates from the reference position. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermal transfer printer that prints an image on a plastic film by a thermal transfer printing method, and a thermal transfer printing method.

  In recent years, as disclosed in Patent Document 1, it has a conveying means for conveying a plastic film along a predetermined path and a holding means for holding a plurality of ink ribbons. An ink ribbon moving mechanism for moving a selected ink ribbon to a printing position disposed on the predetermined path; a print head for heating the ink ribbon moved to the printing position to print on the plastic film; and a platen drum There is known a thermal transfer printer including

  In such a thermal transfer printer, the film is wound around the platen drum, the film is fixed, the printing position in the flow direction is defined by rotating the platen drum, the ink ribbon is heated by the thermal head at the printing position, The image is printed by transferring the ink on the ink ribbon to the film. According to such a thermal transfer printer, it is not necessary to prepare a new printing plate each time a printed image is changed or modified as in the screen printing method, and a desired image is continuously printed on a plastic film. Can do.

In addition, according to the thermal transfer printer, after the printing of the first image is completed, the platen drum is rotated, and the plastic film is moved again to the same printing position as the printing position of the first image. Images can be overlaid, and printing with a plurality of colors overlaid can be performed.
JP 2005-280198 A

  However, in the printing means in which a plastic film is wound around the platen drum and the printing position in the flow direction is defined by the rotation of the platen drum, the plastic film being printed is fixed on the platen drum, but when the platen drum rotates. The plastic film wound on the platen drum gradually shifts from the position fixed on the platen drum due to the influence of the tension on the plastic film, and when printing over multiple colors, the plastic film Due to misalignment, the overlay accuracy of printing decreases. Further, the displacement of the plastic film from the position fixed to the platen drum is random, and the amount of displacement is not constant.

  The present invention has been made paying attention to such a problem, and even when a plurality of colors are overlaid and printed, a thermal transfer printer for a film that can maintain the positional relationship between the images to be overlaid accurately, It is a main object to provide a thermal transfer printing method using the same.

  A first invention of the present application for solving the above-mentioned problems has a conveying means for conveying a plastic film along a predetermined path and a holding means for holding a plurality of ink ribbons. An ink ribbon moving mechanism for moving the selected ink ribbon to the printing position arranged on the predetermined path, a printing head for heating the ink ribbon moved to the printing position and printing on the plastic film, and For films equipped with a platen drum that is provided at a position facing the printing head and that can be rotated to accurately move the plastic film to the overlapping printing start position by winding a plastic film when performing overlapping printing A thermal transfer printer and a sensor for detecting an image printed on a plastic film And an image position of the image detected by the sensor and a pre-stored reference position, and if the image position varies from the reference position, a correction process for correcting the variation Means are provided.

  The second invention of the present application for solving the above-mentioned problems is a thermal transfer printing method for printing an image on a plastic film by the thermal transfer printer for film, wherein the image printed on the plastic film is detected by the sensor. The detection step and the image position of the image detected in the image detection step are compared with the reference position, and when the image position varies from the reference position, correction for correcting the variation A correction information processing step for determining information; and a platen drum control step for controlling rotation of the platen drum based on the correction information determined in the correction information processing step.

  The image detected in the image detection step according to the second invention of the present application may be a detection image printed in advance on the plastic film.

  Further, the image detected in the image detection step in the second invention of the present application may be an image printed at the time of the first printing on the plastic film.

  In the image detection step of the second invention of the present application, the sensor for detecting an image may detect an image printed on a plastic film fixed on the outer periphery of the platen drum.

  According to the thermal transfer printer for film of the present invention, even when the printing position of the plastic film fluctuates from the reference position when printing a plurality of colors, the positional accuracy between the superimposed images is corrected by correcting the printing start position. Can be maintained with high accuracy, and high-precision printing becomes possible.

  Further, according to the thermal transfer printing method of the present invention, since the rotation of the platen drum is controlled based on the change between the image position detected by the sensor and the reference position, the print position changes from the reference position. Even so, the positional accuracy between the images to be superimposed can be maintained with high accuracy.

  FIG. 1 is a diagram illustrating a main part of a thermal transfer printer for film according to an embodiment of the present application.

  As shown in FIG. 1, a thermal transfer printer for film 1 includes a film supply roller 3 and a film winding roller 4 as conveying means for conveying a plastic film 2 along a predetermined path, and a plurality of ink ribbons R, R,. .. A holding means for holding the ink ribbon, and an ink ribbon movement that moves an ink ribbon R arbitrarily selected from the plurality of ink ribbons R, R... To a printing position arranged on the predetermined path. A rotary ink ribbon unit 5 that functions as a mechanism, and a thermal head 6 as a print head that heats the ink ribbon R moved to the printing position and prints it on the plastic film 2, and further includes the thermal head 6. The plastic film 2 is wrapped around the position opposite to the position at the time of overprinting, and the overprint start position is It has a platen drum 7 capable of rotation control for accurately moving the plastic film 2, and a pair of nip rolls 8 (supply side nip rolls), 9 (for fixing the plastic film 2 on the platen drum) Winding nip roll).

  The printer 1 of the present invention further stores in advance a sensor 10 for detecting an image printed on the plastic film 2 and an image position related to the image connected to the sensor 10 and detected by the sensor 10. A correction processing unit 11 is provided for correcting the fluctuation when the image position fluctuates from the reference position.

  In addition to the illustration, a plurality of guide rollers for guiding the plastic film 2 along the path, a motor for driving the film supply roller 3 and the film winding roller 4 are provided in the film transport path. It is provided as appropriate.

  The present invention compares the sensor 10 for detecting an image printed on a plastic film with the image position of the image detected by the sensor and a pre-stored reference position, and the detected image position is the reference. The main effect of the sensor 10, which is a feature of the present invention, relates to a thermal transfer printer for a film provided with a correction processing means for correcting the fluctuation when the position changes from the position. The main effect of the detection and correction processing means 11 is to compare the image position relating to the image detected by the sensor 10 with a pre-stored reference position, and to correct the fluctuation when a fluctuation occurs in the comparison. Even when multiple colors are printed in this way, the positional accuracy between the superimposed images can be kept at ± 0.1 μm or less and high-precision printing Therefore, there is no particular limitation on the other components constituting the thermal transfer printer for film, and conventionally known techniques can be appropriately selected and used.

  First, the sensor 10 that is a feature of the present invention will be described. As described above, the sensor 10 is provided for detecting an image printed on the plastic film 2, and the sensor 10 is not particularly limited as long as the above effect can be obtained. Can be appropriately selected and used. Examples of such a sensor 10 include a phototube sensor and an image sensor.

  The position where the sensor 10 is provided is not particularly limited as long as it can detect an image printed on the plastic film 2.

  However, the image processing position of the image detected by the sensor 10 is used to correct the fluctuation in the correction processing means 11 when the fluctuation is caused by comparison with the reference position stored in advance. Therefore, when the plastic film 2 is moved by the platen drum 7 after the sensor 10 detects an image, the plastic film 2 fixed on the platen drum 7 is affected by the tension applied to the plastic film 2 during the movement. The image position detected by the sensor 10 may fluctuate. If the detection position where the image is detected by the sensor 10 is too far from the print position, it is necessary to rotate the platen drum 7 and move the plastic film to the print position after detecting the image at the detection position. Yes, the image position detected by the sensor 10 at this time may vary. Considering the above, the position where the sensor 10 is provided is not a position away from the printing position of the plastic film 2, more specifically, an image printed on the plastic film 2 fixed on the outer periphery of the platen drum 7. It is preferable to be provided at a position where can be recognized.

  By providing the sensor 10 at the above position, it is possible to effectively prevent fluctuations in the image position caused by the movement of the platen drum 7 after image detection.

  Next, the correction processing means 11 that is a feature of the present invention will be described.

  The correction processing means 11 compares the image position of the image detected by the sensor 10 with the reference position stored in advance as described above, and determines that the image position has changed from the reference position. It is provided to correct the fluctuation.

  The correction processing means 11 is not particularly limited as long as the above functions can be achieved, and conventionally known processing means can be appropriately selected and used. Examples of such processing means 11 include a personal computer 12 and a platen drum 7 connected to the personal computer 12 in the present embodiment. The personal computer 12 uses the image position and reference based on the image detected by the sensor 10. By comparing the positions, it is determined whether or not there is a variation between the two. When it is determined that the variation has occurred, a correction value based on the variation is calculated. The platen drum 7 connected to the personal computer 12 is based on the correction value. The plastic film 2 is moved to the printing start position where the fluctuation is corrected by rotating the plastic film in a wound state.

  In this embodiment, the plastic film 2 is moved by the platen drum 7 to control the start position. However, the personal computer 12 is connected to a servo motor (not shown) or the like, and the print start position is controlled by the servo motor or the like. Control may be performed.

  The operation of the printer 1 will be further described.

  FIG. 2 is a diagram showing a print preparation state of the thermal transfer printer for film according to the present embodiment.

  In the print preparation operation, as shown in FIG. 2, at the platen drum 7 origin position, the supply side nip roll 8 and the winding side nip roll 9 move in the direction of arrow A (platen drum side), and a plastic film is placed on the outer periphery of the platen drum 7. 2 is fixed (nip). By fixing the plastic film 2 on the outer periphery of the platen drum 7 in this way, it is possible to prevent a large printing shift during printing.

  The print preparation operation is completed by fixing the plastic film 2 on the outer periphery of the platen drum 7.

  Next, the print start moving operation of the thermal transfer printer for film will be described. FIG. 3 is a diagram showing the print start operation of the thermal transfer printer for film according to this embodiment.

  As shown in FIG. 3, first, the rotary ink ribbon unit 5 moves the ink ribbon R arbitrarily selected to the printing position. In parallel with this operation, by rotating the platen drum 7 from the origin position in the direction of arrow B, the printing start position along the predetermined path with the plastic film 2 fixed on the outer periphery of the platen drum 7. Move to.

  After moving the plastic film 2 to the printing start position, the sensor 10 detects the image printed on the plastic film 2 and transmits the detected image to the personal computer 12 constituting the correction processing means 11. When the personal computer 12 compares the image position of the image detected by the sensor 10 with a pre-stored reference position and determines that the image position has changed from the reference position, the personal computer 12 corrects the change. The correction information is determined, transmitted to the platen drum 7, and the platen drum 7 is rotated based on the correction information to move the plastic film 2 to the print start position where the variation from the reference position is corrected.

  Here, the image for the sensor 10 to detect is demonstrated.

  The image to be detected by the sensor 10 is not particularly limited as long as the image can be detected by the sensor 10, and the image shape, the image printing position, and the image printing method are not particularly limited. For example, FIG. ), The image detected by the sensor 10 may be a detection image X printed on the plastic film 2 in advance. By printing a detection image on the plastic film 2 in advance, the sensor 10 detects the detection image X, and the personal computer 12 compares and corrects the variation between the image position and the reference position for the detection image X. A correction value, which is information, is calculated, and the platen drum 7 is rotated based on the correction information to move the plastic film 2 to the corrected print start position, and the first image is printed in a print operation operation described later. . Further, in the case of printing with a plurality of colors overlaid, after the first image is printed, the sensor 10 detects the detection image X again, and the image position of the detected image changes from the reference position. Rotate the platen drum to move the plastic film 2 to the corrected printing start position, and the second and subsequent printings are performed. As described above, when the detection image X is printed on the plastic film 2 in advance, when printing a plurality of colors, it is possible to control the printing position based on the detection image from the first printing.

  Further, in the printing operation described later, as shown in FIG. 4B, a desired image Z and an image Y for detection by the sensor 10 at the time of the first printing may be printed. By printing an image Y to be detected by the sensor 10 at the time of the first printing, the sensor 10 detects the detection image Y when the print start position is moved for the second and subsequent times when a plurality of colors are overlaid. When the image position of the image that has been changed fluctuates from the reference position, the plastic film 2 is moved to the corrected printing start position by rotating the platen drum 7 and is printed over the image Z. In this way, by printing the detection image Y at the time of the first printing, it is possible to accurately overlay the first image without providing a detection image in advance on the film. Note that the image Y1 and the image Z1 indicate the first print image at the end of the overlap print.

  As shown in FIG. 4C, the image Z itself printed at the time of the first printing may be used as the detection image. In this way, when the image Z itself printed at the time of the first printing is used as the detection image, the image position can be determined by detecting the edge of the image shown in the S part of the image Z. There is no need to provide it, which is preferable in terms of process simplification. Note that the image Z1 indicates the first print image at the end of the overlap print.

  In the print start moving operation, after the plastic film 2 is moved to the print start position, the sensor 10 detects an image printed on the plastic film 2, and the correction processing means 11 converts the image detected by the personal computer 12 to the image detected by the sensor 10. The image position is compared with a pre-stored reference position, and if there is a change in both, a correction value that is correction information for correcting the change is determined, and based on the correction value When the platen drum 7 is rotated, the plastic film 2 is moved to the print start position in which the fluctuation is corrected, and the process is terminated.

  In this embodiment, the sensor 10 constitutes an image detection process, the personal computer 12 constitutes a correction information processing process, and the platen drum 7 constitutes a platen drum control process.

  Next, the printing operation of the thermal transfer printer for film will be described. FIG. 5 is a diagram showing the printing operation of the thermal transfer printer for film according to the embodiment of the present application.

  As shown in FIG. 5, the thermal head 6 heats an arbitrarily selected ink ribbon R while pressing it against the plastic film 2 at the printing start position, thereby transferring the ink on the ink ribbon R to the plastic film 2. The platen drum 7 located at the position facing the thermal head 6 supports the ink ribbon R and the plastic film 2 at the time of ink transfer, and rotates the platen drum 7 at a predetermined speed in the direction of arrow C, whereby an image is formed on the plastic film 2. Is printed.

  In addition, the sensor 10 detects an image during the printing operation, and the correction processing unit 11 compares the image position of the image detected by the sensor 10 with the reference position during the printing operation, and fluctuations occur in both. If it is determined that the position is corrected, the correction information for correcting the variation may be processed to rotate the platen drum 7 based on the correction information so that the position correction is performed at any time. By adopting such a configuration, it is possible to more effectively prevent a shift in printing when a plurality of colors are overlaid.

  Further, as shown in FIGS. 4B and 4C, a detection image for detection by the sensor 10 may be formed during the first printing operation.

  When the platen drum 7 is rotated and the plastic film 2 is moved to the end position of the first printing range, the first printing operation is completed.

  Next, the print end operation will be described. FIG. 6 is a diagram illustrating an image printing end operation of the thermal transfer printer for film according to the embodiment of the present application.

  As shown in FIG. 6, when the platen drum 7 finishes the printing operation in the first printing range, it rotates in the direction of arrow B (the direction opposite to the printing direction) to return to the origin.

  For example, when the ink is transferred a plurality of times to the same printing range, such as when printing an image in color, the platen drum 7 rotates in the direction of arrow B after the first printing to the first printing range is completed. After returning to the origin, the plastic film 2 is conveyed to the printing start position shown in FIG. At this time, the sensor 10 detects an image printed on the plastic film 2, compares the image position of the image detected by the correction processing means 11 with a reference position stored in advance, and the image position is the reference position. When it is determined that the fluctuation has occurred, a correction value, which is correction information for correcting the fluctuation, is calculated, and the printing start position platen drum 7 that has corrected the fluctuation is rotated based on the correction information to thereby rotate the plastic. The film 2 is moved. Along with this operation, the ink ribbon unit 5 moves an ink ribbon R different from the ink ribbon R used in the first printing to the printing position. Thereafter, the ink can be transferred to the same print range a plurality of times by sequentially performing the processes in FIGS. 2 to 5 until the desired print is completed.

  According to the thermal transfer printer for film 1 in the embodiment of the present application described above, the sensor 10 detects an image printed on the plastic film 2, and the personal computer 12 in the correction processing unit 11 applies to the image detected by the sensor 10. The image position is compared with a pre-stored reference position, and when a change occurs in both, a correction value, which is correction information for correcting the change, is calculated. Based on the correction information, the platen drum 7 The plastic film 2 is moved to the printing start position in which the fluctuation is corrected by rotating. Therefore, even when the plastic film 2 is displaced due to the movement of the plastic film 2 and the image position detected by the sensor 10 varies from the reference position, the variation is corrected by rotating the platen drum 7. Since the plastic film 2 can be moved to the printing start position, it is possible to completely prevent printing displacement that occurs when printing with a plurality of colors superimposed.

It is a figure which shows the principal part of the thermal transfer printer for films which concerns on embodiment of this application. It is a figure which shows the print preparation operation | movement of the thermal transfer printer for films which concerns on embodiment of this application. It is a figure which shows the printing start movement operation | movement of the thermal transfer printer for films which concerns on embodiment of this application. It is a figure which shows the image for a detection printed on the plastic film which concerns on embodiment of this application. It is a figure which shows the printing operation | movement operation | movement of the thermal transfer printer for films which concerns on embodiment of this application. It is a figure which shows the printing end operation | movement of the thermal transfer printer for films which concerns on embodiment of this application.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thermal transfer printer for films 2 ... Plastic film 3 ... Supply roller 4 ... Hoisting roller 5 ... Rotary ink ribbon unit 6 ... Thermal head 7 ... Platen drum 8. ..Supply side nip roll 9 ... Upper side nip roll 10 ... Sensor 11 ... Correction processing means 12 ... PC

Claims (5)

A conveying unit configured to convey the plastic film along a predetermined path; and a holding unit configured to hold a plurality of ink ribbons, and an ink ribbon arbitrarily selected from the plurality of ink ribbons is disposed on the predetermined path. An ink ribbon moving mechanism for moving the ink ribbon to the print position, a print head for heating the ink ribbon moved to the print position to print on the plastic film, and a position facing the print head, and performing overprinting A thermal transfer printer for a film, comprising: a platen drum capable of rotating control for accurately moving the plastic film to a superimposed print start position by winding the plastic film.
The thermal transfer printer for film further includes a sensor for detecting an image printed on a plastic film,
A correction processing unit that compares an image position of the image detected by the sensor with a pre-stored reference position, and corrects the change when the image position changes from the reference position; ,
A thermal transfer printer for film, comprising: A thermal transfer printing method for printing an image on a plastic film by the thermal transfer printer for film according to claim 1,
In the thermal transfer printing method,
An image detection step of detecting an image printed on the plastic film by the sensor;
Comparing the image position of the image detected in the image detection step with a pre-stored reference position, and correcting the change when the image position has changed from the reference position A correction information processing step for determining information;
A platen drum control step for controlling the rotation of the platen drum based on the correction information determined in the correction information processing step;
A thermal transfer printing method comprising:   The thermal transfer printing method according to claim 2, wherein the image detected in the image detection step is a detection image preliminarily printed on the plastic film.   3. The thermal transfer printing method according to claim 2, wherein the image detected in the image detection step is an image printed at the first printing on the plastic film.   The sensor for detecting an image in the image detection step detects an image printed on a plastic film fixed on the outer periphery of the platen drum. The thermal transfer printing method as described.

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