JP2004090451A - Recording sheet for laser marking and method for using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording sheet for laser marking with excellent counterfeit- and falsify-proof effect in which an adequate printing can not be performed without information (printing information) related to irradiation energy of a laser light corresponding to printing position of the recording sheet. <P>SOLUTION: A lower recording layer 30, an upper recording layer 20 and a covering layer 10 are successively overlaid on the surface of a sheet base material 40 and is printed. The lower recording layer 30 comprises a black ink layer 31 and a white ink layer 32 forming a printing such as letters and marks when they are exposed to the surface, and they are alternately and in parallel printed on the surface of the sheet base material 40. On the upper recording layer 20, a white ink layer 22 with a little narrower width than that of the black ink layer 31 is overlaid on the black ink layer 31 in such a way that it does not cover the end parts in the width direction of the black ink layer 31, and a black ink layer 21 is overlaid between them and is printed. Printing is performed by the laser light by selectively exposing the black ink layer 21 or the black ink layer 31. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording sheet for laser marking and a method for using the same, and more particularly, to a recording sheet for laser marking which has an excellent effect of preventing falsification of recorded contents by additional recording and a method for using the same.
[0002]
[Prior art]
Laser light is applied to the surface of a recording sheet with a solid ink layer on the substrate surface to remove the ink layer on the surface, and the difference in hue between the exposed underlying substrate surface and the background ink layer is used. Then, a laser marking method for displaying characters, symbols, and the like is known (for example, JP-A-11-70734).
[0003]
One of the features of the printing by the laser marking method is that the printing itself cannot be erased because the printing is formed by the concave portions obtained by removing the ink layer on the recording sheet surface. In this case, it is possible to remove the ink layer around the print or to print on the print with the same color ink as the solid print so that the print content cannot be determined, but in any case, the print sheet Traces associated with erasure of the print remain on the surface. Therefore, prevention of forgery and falsification of documents by a laser marking method utilizing such characteristics has been studied.
[0004]
[Problems to be solved by the invention]
However, in the case of the recording sheet as described above, additional writing on a completed document can be easily performed, and it is difficult to distinguish between characters and symbols printed from the beginning of the document and characters and symbols by additional writing, There is a problem that the effect of preventing counterfeiting and tampering with additional writing is small.
[0005]
The present invention has been made in view of such a situation, that is, the present invention is to prevent proper printing from being performed without information on the irradiation energy of laser light corresponding to the printing position of the recording sheet. Another object of the present invention is to provide a recording sheet for laser marking which has an excellent effect of preventing forgery and falsification, and a method of using the same.
[0006]
[Means for Solving the Problems]
The present invention is configured as follows in order to solve the above-mentioned technical problem. That is, the invention according to claim 1 includes a sheet base, a lower recording layer which is provided so as to be superposed on one surface of the sheet base, and is color-coded into a printing color portion and a background color portion, and superimposed on the lower recording layer. An upper recording layer color-coded into a printing color portion that at least completely covers the background color portion of the lower recording layer and a background color portion adjacent to the printing color portion, and a coating layer that covers the upper recording layer. Were laminated to form a recording sheet for laser marking.
[0007]
According to a second aspect of the present invention, there is provided the recording sheet for laser marking according to the first aspect of the present invention, wherein black ink is used for the printing color portion and white ink is used for the background color portion.
[0008]
According to a third aspect of the present invention, in the first or second aspect, the recording layer and the coating layer are selected from a printing method, a thermal transfer method, an electrophotographic method, an inkjet method, a coating method, a bonding method, and the like. A recording sheet for laser marking was formed by at least one method.
[0009]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the non-printing surface of the sheet substrate is provided with an adhesive layer and a release sheet covering the surface of the adhesive layer. To obtain a recording sheet for laser marking.
[0010]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, a print pitch detection mark for controlling a print start position, and information on laser beam irradiation energy corresponding to a print position of a recording sheet are input. The recording sheet for laser marking was provided with various symbols such as bar codes and two-dimensional codes.
[0011]
According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, a concealing layer is formed by depositing aluminum on any or all of the sheet base, the upper recording layer, and the lower recording layer. Was provided to form a recording sheet for laser marking.
[0012]
Further, the invention according to claim 7 provides a sheet recording medium, a lower recording layer which is provided so as to be superposed on one surface of the sheet recording medium, and which is color-coded into a print color portion and a background color portion, and overlaps the lower recording layer. An upper recording layer that is provided in combination and is color-coded into a printing color portion that at least completely covers the background color portion of the lower recording layer and a background color portion that is adjacent to the printing color portion; and a coating layer that covers the upper recording layer. And, the printing color portion is selectively exposed from the upper recording layer and the lower recording layer provided at the printing position by irradiating a laser beam, to form characters, symbols, pictures and the like. This is how to use the recording sheet for laser marking.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a recording sheet for laser marking according to the present invention will be described with reference to FIGS. However, the following description is merely an exemplification of the present invention, and the technical scope of the present invention is not limited by the following description.
[0014]
FIG. 1 is an exploded perspective view showing the configuration of a recording sheet 1 for laser marking (hereinafter, referred to as a recording sheet), FIG. 2 is a cross-sectional view thereof, and FIG. FIG. 4 is a plan view showing a case where laser irradiation is performed so that the black ink layers 21 and 31 are exposed by the method of the present invention, FIG. 5 is a sectional view taken along line XX of FIG. FIG. 7 is a plan view of a case where laser irradiation is performed at a constant intensity of energy in which only the coating layer 10 is removed, FIG. 7 is a cross-sectional view taken along the line YY, and FIG. FIG. 9 is a plan view in the case where laser irradiation is performed with energy of a constant intensity, and FIG.
[0015]
As shown in FIGS. 1 and 2, the recording sheet 1 of the present invention is obtained by printing a lower recording layer 30, an upper recording layer 20, and a coating layer 10 on a surface of a sheet substrate 40 in order by using a printing ink. .
[0016]
As the sheet substrate 40, a paper substrate generally used in a printer, a printing machine, or the like is used. In addition, a substrate made of one or more materials composed of a plastic film, a metal foil, or the like can be used.
[0017]
The lower recording layer 30 is composed of a black ink layer 31 and a white ink layer 32 that form a print of characters and symbols when exposed on the surface, and these are alternately parallel printed on the surface of the sheet substrate 40. Thus, one layer is formed. Here, the printing width of the black ink layer 31 and the white ink layer 32 can be freely set without being limited to the size of the printing, but the minimum width is limited by the irradiation position accuracy of the laser irradiation device.
[0018]
The upper recording layer 20 is printed on the black ink layer 31 by overlaying a white ink layer 22 having a width slightly smaller than the black ink layer 31 so as not to cover the widthwise end of the black ink layer 31. The black ink layer 21 is overlapped and printed to form a single layer. Therefore, in the cross-sectional view of FIG. 2, the black ink layer 31 and the black ink layer 21 are partially overlapped at both ends. This overlap width can be set as needed as long as it is equal to or higher than the irradiation position accuracy of the laser irradiation device. The upper recording layer 20 is provided with a color density and a thickness sufficient to cover the lower recording layer 30 so that the configuration of the lower recording layer 30 serving as a base is not clear.
[0019]
Further, a coating layer 10 is printed on the surface of the upper recording layer 20 with white ink, and this coating layer 10 also conceals the upper recording layer 20 so that the configuration of the upper recording layer 20 serving as a base is not clarified. Color density and thickness sufficient to perform The coating layer 10 is preferably provided so as to entirely cover the upper recording layer 20. However, the printing shape and the position between the black ink layer 21 and the white ink layer 22 of the upper recording layer 20 cannot be specified. If formed, the upper recording layer 20 does not necessarily need to be entirely covered.
[0020]
As shown in FIG. 3, the recording sheet 1 having the above-described configuration is configured such that an adhesive 2 is applied to a non-printing surface on the back surface, and the adhesive sheet 2 is temporarily attached to a release sheet 3 via the adhesive 2 to be able to be fed out. It may be wound around the core 4 in this state. In this figure, a printing pitch detection mark 5 for determining a printing position of a laser marking device, and information on irradiation energy of laser light corresponding to a printing position of a recording sheet (hereinafter, referred to as printing information) are provided on the back surface of the peeling backing sheet 3. Are printed on the printing surface or non-printing surface of the recording sheet 1 if the printing pitch detection mark 5 or the symbol 6 is visible from the outside. It may be formed. Further, if the sheet substrate 40 is an RFID card, it is also possible to record various information necessary for the printing on the IC chip.
[0021]
Here, the printing information includes a printing start position and a printing end position, positions of the black ink layers 21 and 31 and white ink layers 22 and 32, a printing thickness, a material, energy required for printing, and a laser marking device for printing. And the like. If such print information is added to the recording sheet 1 as described above, when laser irradiation is performed based on a method described later, printing can be performed without erroneous laser irradiation conditions. In addition, if these print information is erased from the recording sheet 1 after printing, for example, by cutting off together with the peeling backing 3 or by irradiating with a laser beam, forgery or falsification becomes more difficult. .
[0022]
Next, a method of using the recording sheet 1 having the above configuration will be described.
First, the recording sheet 1 is mounted on a paper mounting device of a laser marking device (not shown). The laser marking device used here is capable of controlling the irradiation energy and spot diameter of the laser beam, and the irradiation head moves the irradiation surface precisely by means of a paper transport device or a driving device of the irradiation head, so that the laser irradiation can be performed. It is possible to do.
[0023]
Next, a method of forming a print by irradiating the recording sheet 1 with laser light will be described in detail. This embodiment exemplifies a case where an arrow “↑” is printed. Here, the irradiation energy required to print the arrow “↑” differs depending on the laser irradiation position of the recording sheet 1. That is, when the laser irradiation position for performing printing is at a position in contact with the white ink layer 22 of the coating layer 10, both the coating layer 10 and the white ink layer 22 are removed, and the black ink layer 31 is exposed. Printing is performed by irradiating the laser beam with the irradiation energy adjusted as described above. On the other hand, when the laser irradiation position is at a position in contact with the black ink layer 21 of the coating layer 10, the coating layer 10 is removed and a laser beam of irradiation energy adjusted so that the black ink layer 21 is exposed is irradiated. By doing so, printing is performed. In this manner, the black ink layers 21 and 31 are selectively exposed from the recording layers 20 and 30 provided below the printing position.
The results are as shown in FIGS. 4 and 5, and a print recording sheet 100 is obtained in which the black ink layers 21 and 31 are exposed on the surface of the recording sheet 1 and the arrow “↑” is displayed in black. The above printing is achieved by extracting print information from the symbol 6 provided on the recording sheet 1 and inputting the information to a laser irradiation device.
[0024]
On the other hand, a case in which printing is performed on the recording sheet 1 without having the above-described print information and without changing the irradiation energy will be described. FIGS. 6 and 7 show a case where laser light is irradiated from above the coating layer 10 of the recording sheet 1 in the shape of an arrow “↑” with a certain level of irradiation energy capable of removing only the coating layer 10. That is, the coating layer 10 of the recording sheet 1 is removed by the laser beam, and a print recording sheet 200 in which the black ink layer 21 and the white ink layer 22 of the upper recording layer 20 are exposed is obtained. It becomes a striped pattern, and the printing is not proper. If the additional recording is performed in such a state, it is obvious at a glance that the additional recording is performed only by looking at the print.
[0025]
Next, a case in which printing is performed with a stronger and constant irradiation energy than in the above case will be described. In this case, the removal of the upper recording layer 20 in addition to the coating layer 10 also proceeds. In general, different materials used for the recording sheet 1 have different energy absorbing powers. Therefore, even if a laser beam of a constant energy is irradiated, the depth of the ink layer removed differs depending on the material used for the ink. Normally, the black ink layers 21 and 31 contain a black pigment such as carbon black, and the white ink layers 22 and 32 contain a white pigment such as titanium oxide. Are more easily absorbed by the black ink layers 21 and 31 containing, so that printing with the same irradiation energy results in deeper printing. FIGS. 8 and 9 show the print recording sheet 300 when the arrow “矢 印” is printed with the irradiation energy at which the black ink layer 21 is completely removed. In this case, since the white ink layer 22 having a smaller energy absorbing power than the black ink is removed only halfway, a print in which only a part of the black ink layer 31 is exposed in black is obtained. As a result, it is clear that the additional information has been added.
[0026]
Although not shown, even when an irradiation energy higher than that described above is applied, the whole is not black-printed, and it is obvious that the additional writing has been performed.
[0027]
As described above, when printing is performed on the recording sheet 1 with the laser beam having a constant irradiation energy, it is apparent that proper printing cannot be obtained even by accident. To perform proper printing, the positional information of the black ink layers 21 and 31 and the white ink layers 22 and 32 is indispensable, but the print patterns of the upper recording layer 20 and the lower recording layer 30 cannot be seen from the covering layer 10. Therefore, it is difficult to estimate the positions of the printing unit 21 and the background forming layer 22 provided on the upper recording layer 20 only by looking at the recording sheet 1 for laser marking.
[0028]
As described above, according to the recording sheet 1 for laser marking of the present invention and the method of using the same, it is possible to prevent not only falsification due to erasure of printing but also falsification due to addition of printing. In particular, if the print patterns of the black ink layers 21 and 31 and the white ink layers 22 and 32 are changed for each product lot, forgery and falsification are almost impossible. The printing pattern is not limited to this. For example, a company name logo or the like can be selected.
[0029]
The combination of the colors of the black ink layers 21 and 31 and the white ink layers 22 and 32 is not particularly limited, and various color combinations can be selected as long as they can be distinguished from each other. Furthermore, it is also possible to mix a material having a high laser light absorbing power or a material having a high concealing property into the black ink layers 21 and 31 and the white ink layers 22 and 32 to adjust the laser light absorbing power. Of course, the coating layer 10, the upper recording layer 20, and the lower recording layer 30 are not limited to the printing ink illustrated in the present embodiment, and may be formed of a thermal transfer ink, a toner, or the like. It may be formed. Further, in order to enhance the concealing property, a vapor deposition layer of aluminum or the like may be provided on any or all of the layers of the coating layer 10, the upper recording layer 20, and the lower recording layer 30.
[0030]
【The invention's effect】
As described above, the recording sheet for laser marking according to the present invention is configured such that proper printing cannot be performed unless the irradiation energy of the laser irradiation light is adjusted according to the printing position. It is difficult for a person to falsify or falsify documents. Also, improper printing leaves traces, so that it is easy to determine that forgery or tampering has been attempted. Further, according to the method of using the recording sheet for laser marking according to the present invention, the printing is performed by adjusting the irradiation energy of the laser irradiation light so that the black ink layer is exposed in accordance with the printing position. Appropriate printing can be performed on the recording sheet for laser marking of the invention.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a configuration of a recording sheet 1 for laser marking according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view thereof.
FIG. 3 is a perspective view showing a state in which an adhesive processing is performed, and the adhesive is temporarily attached to a release liner 3 and formed into a roll shape.
FIG. 4 is a plan view when laser irradiation is performed so that the black ink layers 21 and 31 are exposed by the method of the present invention.
FIG. 5 is a sectional view taken along line XX of FIG.
FIG. 6 is a plan view in a case where laser irradiation is performed with energy of a constant intensity that removes only the coating layer 10;
FIG. 7 is a sectional view taken along the line YY.
FIG. 8 is a plan view in the case where laser irradiation is performed with energy of a constant intensity for removing the black ink layer 21 of the upper recording layer.
FIG. 9 is a sectional view taken along the line ZZ.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Recording sheet for laser marking 2 Adhesive 3 Peeling backing sheet 4 Core core 5 Print pitch detection mark 6 Symbol 10 Coating layer 20 Upper recording layer 21, 31 Black ink layer 22, 32 White ink layer 30 Lower recording layer 40 Sheet substrate 100 , 200, 300 Printing record sheet

Claims (7)

Sheet base material,
A lower recording layer which is provided so as to be superimposed on one side of the sheet base material and is color-coded into a print color portion and a background color portion,
An upper recording layer which is provided so as to be superimposed on the lower recording layer, and which is color-coded into a printing color portion that at least completely covers the background color portion of the lower recording layer and a background color portion adjacent to the printing color portion,
A recording sheet for laser marking, comprising: a coating layer that covers the upper recording layer. The recording sheet for laser marking according to claim 1, wherein black ink is used for the printing color portion and white ink is used for the background color portion. The laser marking according to claim 1, wherein the recording layer and the coating layer are formed by at least one method selected from a printing method, a thermal transfer method, an electrophotographic method, an inkjet method, a coating method, a bonding method, and the like. For recording sheet. The recording sheet for laser marking according to any one of claims 1 to 3, further comprising an adhesive layer on a non-printing surface of the sheet substrate, and a release liner covering the surface of the adhesive layer. 5. A printing pitch detection mark for controlling a printing start position, and various symbols such as a bar code or a two-dimensional code for inputting information on irradiation energy of laser light corresponding to the printing position of the recording sheet. A recording sheet for laser marking according to the above item. The recording sheet for laser marking according to any one of claims 1 to 5, wherein a concealing layer formed by vapor deposition of aluminum is provided on any or all of the sheet base, the upper recording layer, and the lower recording layer. Sheet base material,
A lower recording layer which is provided so as to be superimposed on one side of the sheet base material and is color-coded into a print color portion and a background color portion,
An upper recording layer which is provided so as to be superimposed on the lower recording layer, and which is color-coded into a printing color portion that at least completely covers the background color portion of the lower recording layer and a background color portion adjacent to the printing color portion,
A coating layer covering the upper recording layer,
Laser marking characterized by irradiating a laser beam to selectively expose a printing color portion from the upper recording layer and the lower recording layer provided at a printing position to form characters, symbols, pictures and the like. How to use the recording sheet for the.

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