JP2006224625A - Thermal transfer printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer printing device which can make effective use of a recording medium by mending a print substandard part, even when a print reject is generated in a process to print an image to the recording medium by thermal transfer. <P>SOLUTION: This thermal transfer printing device prints a printing image to a card by thermal transfer and laminate-treats the surface of the card. In this device, the image of the card printed by thermal transfer is photographed, and thus the photographed image is acquired (step S302). Next, it is judged whether the printing image is a reject by comparing the printing image with the photographed image (step S304). In case it is judged that the printing image is a reject, a mended printing image which is the printing image of the print substandard part to be mended, is formed from the printing image and the photographed image. Further, the card judged as printed defectively is printed by thermal transfer from the mended printing image (step S307). <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.

  In general, a thermal transfer printing apparatus (thermal transfer printing apparatus) that performs thermal melting recording or thermal sublimation recording sublimates ink on an ink ribbon by a print head in a state where the ink ribbon is superimposed on a recording medium such as a card. Printing on the recording medium is performed by melting.

  For this reason, for example, when dust adheres between the ink ribbon and the recording medium, the color is not transferred to the recording medium only in that portion, and so-called transfer omission occurs.

  In view of this, the operator normally determines whether or not there is a printing defect such as a transfer omission with respect to a printed card by visual observation or the like. As a result, the card determined to have a printing defect such as a transfer omission was discarded after being punctured or the like.

  However, since conventional printing objects such as magnetic stripe cards made of PVC are inexpensive, even if the printing card is discarded when the printing is defective, it does not cause a big problem in terms of cost.

  On the other hand, recently, the demand for IC cards is increasing, and the objects to be printed are also becoming expensive. For this reason, if the printing failure occurs, if it is discarded easily, the manufacturing cost will increase.

Therefore, in order to eliminate printing defects due to transfer omission or the like as much as possible, for example, Patent Document 1 takes measures such as incorporating a cleaning roller for preventing dust adhesion. Japanese Patent Laid-Open No. 2004-228561 prevents the occurrence of transfer omission by providing a cleaner that cleans the printing screen before printing.
JP 11-291527 A JP-A-10-105798

  However, even if the measures disclosed in Patent Documents 1 and 2 are taken, it is difficult to completely remove fine dust, and transfer omission cannot be eliminated. For this reason, up to now, even if an IC card is to be printed, when the printing failure occurs, the IC card is discarded as in the case of a conventional inexpensive card. Invited to increase. Therefore, there is a demand for a thermal transfer printing apparatus that can repair and use an IC card in which a printing defect has occurred without discarding it.

  The present invention has been made in view of the above problems, and even when printing defects occur in printing on a recording medium by thermal transfer, the recording medium can be effectively used by repairing the defective printing portion. It is an object to provide a thermal transfer printing apparatus.

In order to achieve the above object, a thermal transfer printing apparatus according to the present invention has the following configuration. That is,
A thermal transfer printing apparatus for laminating the surface of a recording medium after printing a printed image on the recording medium by thermal transfer,
Image acquisition means for imaging the recording medium printed by thermal transfer and acquiring the captured image;
A determination unit that compares the print image with the captured image and determines whether there is a print defect;
When the determination unit determines that there is a print defect, a repair print image generation unit that generates a repair print image that is a print image for repairing a print defect portion based on the print image and the captured image And comprising
It is characterized in that printing is performed by thermal transfer on a recording medium determined to have the printing defect based on the repaired printing image.

  In addition, when the determination unit determines that there is no printing defect, the surface of the recording medium is laminated.

  Further, the repaired print image generating means normalizes the captured image, and then generates the repaired print image by taking a difference in density between the captured image and the print image.

  According to the present invention, even when a printing defect occurs in printing on a recording medium by thermal transfer, the recording medium can be effectively used by repairing the defective printing portion.

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

<Configuration of printing section of sublimation printer>
First, the configuration of a printing unit of a thermal transfer printing apparatus (sublimation printer) according to an embodiment of the present invention will be described.

  FIG. 1 is a diagram illustrating a configuration of a printing unit of a sublimation printer. A print head 101 presses a recording medium (IC card) 113 on which an ink ribbon 105 is superimposed with the platen roller 102 to sublimate the ink on the ink ribbon 105 to perform printing on the recording medium 113. A conveyance roller 108 conveys the recording medium 113. Reference numerals 103 and 104 denote a supply roller and a take-up roller, respectively, around which an ink ribbon 105 is wound. The ink ribbon 105 stretched between the supply roller 103 and the take-up roller 104 is transferred along the guide roller 106 by the take-up roller 104 taking up.

  Reference numeral 107 denotes a print image reading sensor (CCD line sensor) that captures an image of the surface of the printed card and transmits the captured image to the control unit 109.

  Reference numeral 109 denotes a control unit that is communicably connected to the PC 112 and controls the entire sublimation printer including the printing unit. In the present embodiment, in particular, the “inspection / determination and printing / restoration processing unit” 110 that inspects / determines whether or not there is a printing defect on the printed card in addition to the printing process, and performs a repairing process as necessary. (Details will be described later), and a transport control unit 111 that transports the card according to the printing / restoring process.

<Configuration of inspection / judgment and printing / restoration processing section>
FIG. 2 is a block diagram showing a detailed functional configuration of the inspection / determination and printing / restoration processing unit 110. In FIG. 1, reference numeral 201 denotes an image memory which receives a print image (image to be printed on a card) transmitted from a PC 112 connected so as to be communicable and temporarily stores the print image.

  A color conversion / gamma conversion processing unit 202 performs color conversion on a print image (R, G, B) stored in the image memory 201 to a print image (Y, M, C) and performs gamma correction. A head control unit 203 controls the print head 101 based on the print image (Y, M, C) output from the color conversion / gamma conversion processing unit 202. That is, normal printing processing is performed using the image memory 201, the color conversion / gamma conversion processing unit 202, and the head control unit 203.

  On the other hand, 206 is a captured image memory, which temporarily stores a captured image captured by the print image reading sensor 107. A histogram extraction unit 207 creates a histogram for each of the R, G, and B signals for the captured image. Similarly, 204 is a histogram extraction unit that reads a print image corresponding to the captured image from the image memory 201 and creates a histogram for each of the R, G, and B signals.

  Reference numeral 205 denotes a comparison / adjustment unit that compares the histograms created by the histogram extraction units 204 and 207, respectively. Here, the comparison between the histogram of the print image and the histogram of the captured image requires normalization of both images in advance in order to extract the difference between the two images in the recognition / difference processing unit 209 described later. Because. That is, since the captured image is an image obtained by capturing the surface of the card printed based on the printed image, it includes effects such as the printing characteristics of the print head 101 and the sensitivity characteristics of the printed image reading sensor. Yes. Therefore, the two images cannot be simply compared, and must be normalized in advance.

  An arithmetic processing unit 208 performs processing for normalizing the captured image based on the result of comparison of the histograms by the comparison adjustment unit 205.

  A recognition / difference processing unit 209 compares the print image with the normalized captured image, recognizes the difference between the two, and based on the print image, restores a print image (having a print defect) according to the difference. In addition, an image for printing performed in order to eliminate defective printing portions from the card is generated.

  A determination unit 210 determines whether or not the printed card has a printing defect based on the difference between both images in the recognition / difference processing unit 209, and whether or not the printing defect can be repaired. judge. If it is determined that there is no printing defect, the conveyance control unit 111 is instructed to send the card back to the printing position. The card that has returned to the printing position is then laminated. On the other hand, if it is determined that there is a print defect and it can be repaired, the recognition / difference processing unit is instructed to generate a repaired print image, and the transport control unit 111 is sent back to the print position of the card. Instruct. The card that has returned to the printing position is then subjected to a repair process.

  Reference numeral 211 denotes a repair print image memory, which temporarily stores the repair print image generated by the recognition / difference processing unit 209. The restored print image stored in the restored print image memory is transmitted to the head control unit 203 after color conversion and gamma correction are performed by the color conversion / gamma conversion processing unit 202 in the same manner as a normal print image. And used for printing by a print head.

<Operations during printing / restoration printing of the printing section of a sublimation printer>
Next, the operation at the time of printing / restoration printing of the printing section of the sublimation printer according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing the flow of the entire printing process.

  In step S <b> 301, the transport roller 108 rotates and the card 113 is inserted between the print head 101 and the platen roller 102. An ink ribbon 105 is inserted between the print head 101 and the platen roller 102, and printing on the card 113 is performed by sublimating the ink on the ink ribbon 105 by the print head 101 (step S302). In the case of color printing, the ink ribbon 105 includes yellow (Y), magenta (M), and cyan (C) ink layers and an overcoat layer (laminate) serving as a protective layer in a predetermined unit in the longitudinal direction. Repeatedly, it is configured such that printing of each color and laminating can be performed by reciprocating the card 113 by repeating forward and reverse rotation of the conveying roller 108. The used ink ribbon 113 is sequentially wound by a winding roller 104 that is rotated by a driving mechanism (not shown).

  When the printing process for each color (step S302) is completed, before the laminating process is performed, the transport roller 108 is driven to rotate forward, and the printed image reading sensor 107 images the surface of the printed card 113 (see FIG. Step S303). The captured image is transmitted to the control unit 109 and compared with the print image, and then the determination unit 210 determines whether there is a print defect.

  If the determination unit 210 determines that there is no printing defect (in the case of “YES” in step S304), the process proceeds to step S305. In step S305, the card 113 is sent back to the printing position, and the laminating process is performed at the position. When the laminating process is completed, the card 113 is ejected and the process ends.

  On the other hand, when the determination unit 210 determines that there is a printing defect (in the case of “NO” in step S304), the process proceeds to step S306, and the determination unit 210 determines whether or not restoration is possible. If it is determined in step S306 that the image cannot be repaired, the card 113 is ejected as a card with a printing defect (step S308), and the process ends.

  On the other hand, if it is determined in step S306 that restoration is possible, restoration printing processing is performed in step S307 (repair printing processing is performed based on the restoration printing image generated by the recognition / difference processing unit 209). ). After the repair printing, the process returns to step S303, and is again conveyed forward by the conveying roller 108 and picked up by the print image reading sensor 107. That is, for a recoverable card, the above process is repeated until the printing defect is resolved, and when the printing defect is resolved, the lamination process is performed and the card is discharged.

  In this way, only the ink ribbon is consumed in the restoration printing process, and it is cheaper than discarding the IC card, so that the manufacturing cost can be reduced.

<Example of restoration print>
Next, an example of the repair printing process will be described with reference to FIG. FIG. 4 is a conceptual diagram for explaining the repair printing process.

  In the figure, reference numeral 401 denotes an example of a card after the printing process. In the card 401, reference numeral 410 denotes a portion (printing defective portion) where transfer omission occurs due to adhesion of dust.

  Reference numerals 402 to 404 are normalized images (R, G, B) of the card 401, and the density of the image 406 at the position corresponding to the transfer defect 410 is lower than the peripheral density (this example). Shows a case where the density of the R signal is lowered due to transfer omission). Reference numerals 412 to 414 denote print images (R, G, B) corresponding to the captured image.

  Reference numeral 405 denotes a repair print image obtained by comparing the captured images 402 to 404 and 412 to 414. As described above, in this example, the density of the G signal and the B signal does not decrease due to omission of transfer, but only the density of the R signal decreases. Therefore, the position corresponding to the defective print portion 410 in the R signal (407). ), A repair print image 405 having a density corresponding to the density of the decrease (difference) is generated.

  Reference numeral 411 denotes a card after the repair printing process is performed using the repair printing image 405. As shown in the figure, the defective print portion 410 is repaired, and the defective card is eliminated.

  As is apparent from the above description, according to the sublimation type printer according to the present embodiment, even when a printing failure occurs in printing on a card by thermal transfer, the card is discarded by correcting the printing failure portion. It becomes unnecessary and can be used effectively.

  In this embodiment, the sublimation printer is described as an example of the thermal transfer printing apparatus. However, the present invention is not limited to this and may be a melt printer.

  In this embodiment, the ink ribbon is formed from the ink layers of three colors Y, M, and C. However, the present invention is not limited to this, and the four colors Y, M, C, and K are used. The ink layer may be a plurality of ink layers.

  Further, in the present embodiment, the image is picked up by the print image reading sensor after the print processing of each color of Y, M, and C is completed. However, the present invention is not limited to this, and one color print processing is performed. Each time it is completed, the image may be picked up by a print image reading sensor, and the presence or absence of a print defect may be determined and repaired.

  Furthermore, in this embodiment, the case where the printing process and the laminating process are performed at the same position has been described. However, even if the laminating process is performed as a separate unit, the restoration printing process is performed before the laminating process. Needless to say, this is applicable.

FIG. 2 is a diagram illustrating a configuration of a printing unit of a sublimation printer according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating a functional configuration of an inspection / determination and printing / restoration processing unit in a control unit configuring a sublimation printer. 6 is a flowchart showing a flow of processing during printing / restoration printing in a sublimation type printer. It is a conceptual diagram for demonstrating the process in a test | inspection / determination and a printing / restoration process part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Print head 102 Platen roller 103 Supply roller 104 Winding roller 105 Ink ribbon 106 Guide roller 107 Print image reading sensor (image acquisition means)
108 Conveying roller 109 Control unit 110 Inspection / judgment and printing / restoration processing unit 111 Conveying control unit 113 Recording medium (IC card)
209 Recognition / difference processing unit (restored print image generation means)
210 Judgment Unit (Judgment Means)
402, 403, 404 Captured image 405 Restoration print image 410 Print defect portion 412, 413, 414 Print image

Claims (3)

A thermal transfer printing apparatus for laminating the surface of a recording medium after printing a printed image on the recording medium by thermal transfer,
Image acquisition means for imaging the recording medium printed by thermal transfer and acquiring the captured image;
A determination unit that compares the print image with the captured image and determines whether there is a print defect;
When the determination unit determines that there is a print defect, a repair print image generation unit that generates a repair print image that is a print image for repairing a print defect portion based on the print image and the captured image And comprising
A thermal transfer printing apparatus that performs thermal printing on a recording medium that is determined to have the printing defect based on the repaired printed image. The thermal transfer printing apparatus according to claim 1, wherein when the determination unit determines that there is no printing defect, the surface of the recording medium is laminated. 2. The restoration print image generation unit, after normalizing the captured image, generates the repair print image by taking a difference in density between the captured image and the print image. Thermal transfer printing device.

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