JP2004058584A - Recording sheet for laser marking, and method for using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording sheet for laser marking, and a method for using the same, which disable the obtainment of an appropriate printing even if a user tries to add the printing to a printed recording sheet, which enable an easy discrimination between the presence or absence of the addition of the printing, and which make it extremely difficult to perform forgery and tampering. <P>SOLUTION: This recording sheet 1 for the laser marking is constituted in such a manner that a second recording layer 30, first recording layer 20 and a coating layer 10 are sequentially superposed for printing on the surface of a sheet substrate 60. The layer 30 is formed by alternately printing a black ink layer 31 and a white ink layer 32 on the sheet substrate 60 in parallel with each other. In the layer 20, the printing is performed not only by superposing a white ink layer 22 on the layer 31 but also by superposing a black ink layer 21 on the layer 32, so that the layer 20 can have color arrangement different from that of the layer 30, wherein white turns black and vice versa. The printing is performed by means of laser light in such a manner that the layer 21 or the layer 31 is exposed. <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 used for preventing falsification of recorded contents by additional recording and a method for using the same.
[0002]
[Prior art]
The recording sheet having a solid printed surface is irradiated with laser light to remove the ink layer on the irradiated portion, thereby exposing the base material surface on the recording sheet surface. The exposed base material surface and background solid color are exposed. There is known a laser marking method for displaying characters, symbols, and the like by using a difference in hue from printing (for example, Japanese Patent Application Laid-Open No. H11-70734).
[0003]
The feature of the printing by the laser marking method as described above is that the printing and the recording sheet are integrally inseparable, and it is difficult to erase only the printing without affecting the periphery of the printing. In other words, if you want to erase the print, there are methods such as removing the ink layer around the print to make the contents of the print unclear, or printing over the print with the same color ink as the solid print to erase the characters. Although it is conceivable, in any of the methods, some traces accompanying the erasure of the print remain on the surface of the sheet base material, and thus the erasure of the print by such a method can be easily determined. Therefore, a recording sheet using such a sheet substrate for preventing forgery or falsification is being studied.
[0004]
[Problems to be solved by the invention]
However, if the recording sheet has only a single layer of solid printing on the surface as described above, additional writing can be freely performed on the solid printing surface. Could not cope with forgery or tampering by appending the URL. Therefore, in order to use the recording sheet as described above for the purpose of preventing forgery or falsification, measures against such additional recording are indispensable.
From the above, forgery and falsification by additional writing as well as erasure of printing are difficult, and a recording sheet for laser marking that can be applied to important documents such as securities has been demanded.
[0005]
The present invention has been made in view of such a situation, that is, the present invention does not obtain an appropriate print even if additional printing is performed on a printed recording sheet for laser marking, and the additional writing It is an object of the present invention to provide a recording sheet for laser marking and a method of using the same, which can easily determine that the recording has been performed.
[0006]
[Means for Solving the Problems]
That is, the first invention is a recording sheet for laser marking that irradiates a laser beam to form a print such as a character, a symbol, and a picture on a print surface. A multi-layer recording layer in which the same color is not overlapped with a color-coded recording layer on at least one side of the sheet substrate, and a coating layer that covers the surface of the multi-layer recording layer and serves as the printing surface, A recording sheet for laser marking, comprising:
[0007]
According to a second aspect of the present invention, there is provided the recording sheet for laser marking according to the first aspect, wherein the plurality of recording layers include one set of the recording layers having the same pattern and different colors.
[0008]
The invention according to claim 3 is that the multilayer 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 ink jet method, a coating method, a bonding method, and the like. The recording sheet for laser marking according to claim 1, wherein the recording sheet is provided.
[0009]
The invention according to claim 4 is characterized in that 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. It is a recording sheet for laser marking described in 1. above.
[0010]
According to a fifth aspect of the present invention, there are provided a print pitch detection mark for controlling a print start position, and various symbols such as a barcode and a two-dimensional code for inputting various information necessary for printing. A recording sheet for laser marking according to any one of claims 1 to 4.
[0011]
The invention according to claim 6, wherein the sheet base and a recording layer of a multilayer structure in which a recording layer color-coded so that the same color does not overlap at least in part when superimposed on each other is laminated on at least one surface of the sheet base. And a coating layer covering the surface of the multilayer recording layer and serving as a printing surface, comprising the steps of: A method for using a recording sheet for laser marking, characterized by selectively exposing the color-coded recording layer of a predetermined color from the recording layer to form a print of characters, symbols, pictures and the like.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a first embodiment of a recording sheet for laser marking according to the present invention will be described with reference to FIG. 1 to FIG. 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 perspective view showing the formed state, 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. FIG. 7 is a cross-sectional view taken along line YY of FIG. 7 when laser irradiation is performed with energy capable of removing the coating layer 10, and FIG. 8 is a case where laser irradiation is performed with energy that partially reaches the surface of the second recording layer. FIG. 9 is a sectional view taken along the line Z-Z.
[0013]
As shown in FIGS. 1 and 2, a recording sheet 1 of the present invention is obtained by printing a second recording layer 30, a first recording layer 20, and a coating layer 10 on a surface of a sheet substrate 60 in order by using a printing ink. It is. As the sheet base material 60, a paper base material used in a printer, printing, or the like is used. In addition, a base material formed of one or more materials including a plastic film, a metal foil, or the like as a constituent material is used. Used. The second recording layer 30 is composed of a black ink layer 31 and a white ink layer 32 that are exposed on the surface to form a print of characters, symbols, and the like. Are provided on the surface of the sheet base 60 alternately and parallel to each other. Further, the first recording layer 20 is printed on the surface of the second recording layer 30 so as to be superimposed on the surface of the second recording layer 30. The first recording layer 20 has the same pattern as the second recording layer 30 and has a black and white color difference. The white ink layer 22 is provided on the black ink layer 31, and the black ink layer 21 is provided on the white ink layer 32. The first recording layer 20 is provided with a sufficient color density and thickness to cover the second recording layer 30 so that the configuration of the second recording layer 30 cannot be seen. Further, a coating layer 10 is printed on the surface of the first recording layer 20 with white ink, and this coating layer 10 also covers the first recording layer 20 so that the configuration of the first recording layer 20 is not visible. Color density and thickness sufficient for Further, it is preferable that the coating layer 10 be provided so as to entirely cover the first recording layer 20, but the printing shape of the black ink layer 21 and the white ink layer 22 of the first recording layer 20 and the position between them cannot be specified. If it is formed as described above, it is not always necessary to completely cover the first recording layer 20.
[0014]
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 a symbol 6 such as a bar code or a two-dimensional code into which various information required for printing are input are printed on the back surface of the peeling backing 3. However, these print pitch detection marks 5 and symbols 6 may be formed on the print surface or the non-print surface of the recording sheet 1 as long as they can be seen from the outside. If the sheet substrate 30 is an RFID card, the information can be recorded on an IC chip.
[0015]
Here, various kinds of information necessary for printing include a print start position and a print end position, positions of the black ink layers 21 and 31 and white ink layers 22 and 32, a print thickness, a material, and energy required for removal. And the type of laser marking device that performs printing. If various kinds of information necessary for these printings are added to the recording sheet 1 as described above, when performing laser irradiation based on a method described later, printing can be performed without erroneous laser irradiation conditions. It is. In addition, after the printing, the various information necessary for the printing is erased from the recording sheet 1 by, for example, cutting off with the peeling backing sheet 3 or deleting by laser irradiation, etc., so that the information can be known. The lack of clues makes forgery and tampering even more difficult.
[0016]
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.
[0017]
Next, a method of forming a print by irradiating the recording sheet 1 with a laser will be described in detail. In the present embodiment, with respect to the five-digit number “12345”, each of the numbers “1”, “3”, and “5” is printed on the coating layer 10 in contact with the white ink layer 22, and “2”, The case where each numeral of “4” is printed on the coating layer 10 in contact with the black ink layer 21 is illustrated. Here, the irradiation energy required for printing differs depending on the laser irradiation position of the recording sheet 1. That is, when the laser irradiation position is above the coating layer 10 in contact with the white ink layer 22, both the coating layer 10 and the white ink layer 22 can be removed, and the laser irradiation position does not reach the sheet base layer 60. Printing is performed by irradiating the laser beam with the irradiation energy adjusted to the above. On the other hand, when the laser irradiation position is above the coating layer 10 in contact with the black ink layer 21, the laser of the irradiation energy adjusted so that the coating layer 10 is removable and does not reach the second recording layer 30. Printing is performed by irradiating light. In this way, the recording layers colored black are selectively exposed from the multiple recording layers provided at the printing position. The results are as shown in FIG. 4 and FIG. 5, and the print recording sheet 100 in which the black ink layers 21 and 31 are exposed on the surface of the recording sheet 1 and “12345” is displayed in black is obtained. The above printing is performed by extracting various information such as positional information of the white ink layers 22 and 32 and the black ink layers 21 and 31 required for printing from the base sheet 1 and inputting the information to the laser irradiation device. Is achieved in.
[0018]
On the other hand, a case will be described in which printing is performed on the recording sheet 1 with a constant level of irradiation energy in a normal sense without having the above information. FIGS. 6 and 7 show the case where the five digits “12345” from the top of the coating layer 10 of the recording sheet 1 are laser-irradiated 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 the print recording sheet 200 in which the black ink layer 21 and the white ink layer 22 of the first recording layer 20 are exposed is obtained. In this case, the printed portions of “1”, “3”, and “5” above the white ink layer 22 have the same white color as the coating layer 10, so that although the concave portions of the print are slightly formed, black clear prints are formed. It does not become. On the other hand, “2” and “4” above the black ink layer 21 are printed clearly in black due to the exposure of the black ink layer 21. 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.
[0019]
Next, a case where printing is performed with a constant irradiation energy that is stronger than the above will be described. In this case, the removal of the first 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, and the depth of the ink layer removed by the materials differs even when a laser beam of constant energy is irradiated. 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. The black ink layer emits laser light. Since it is easy to absorb, deeper printing can be achieved by using the same irradiation energy. FIGS. 8 and 9 show a case where a five-digit number “12345” is printed with a constant irradiation energy having an intensity enough to completely remove the black ink layer 21 at the positions “2” and “4”. It is a thing. In this case, in the printing of “1”, “3”, and “5”, since the white ink layer 22 is removed only halfway, the printing depth is deeper than the printing recording sheet 100, but black clear printing is obtained. Absent. In the case of "2" and "4", since the black ink layer 21 is completely removed, the underlying white ink layer 32 is exposed, and black and clear printing cannot be obtained. However, in this case, if the angle is changed, the periphery of the print is framed by the black ink layer 21 as schematically shown by the print recording sheet 300 in FIG. In any case, the predetermined printing cannot be obtained, and it is obvious that the additional printing has been performed.
[0020]
Even when the irradiation energy higher than that described above is applied to completely remove the white ink layer 22 under the printing of "1", "3", and "5", the predetermined printing cannot be obtained (not shown). . In this case, the black ink layer 31 below “1”, “3”, and “5” is exposed, and the prints “1”, “3”, and “5” are displayed in black. On the other hand, the white ink layer 32 under the printing of “2” and “4” is further removed and the printing becomes deeper than in the case of FIG. 9, but when viewed from the surface of the recording sheet 1, the white ink layer 32 is removed. Are exposed, and clear black printing cannot be obtained. It is obvious that this was also added.
[0021]
As described above, it is apparent that proper printing cannot be obtained by printing on the recording sheet 1 with the laser beam having a constant irradiation energy.
[0022]
FIG. 10 shows a second embodiment of the recording sheet for laser marking according to the present invention. However, the same parts as those in FIG. 1 to FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. The recording sheet 400 of the present embodiment has a structure in which the reflective layer 50 and the third recording layer 40 are sequentially laminated between the base sheet 60 and the second recording layer 30 as viewed from the base sheet 60. Here, black ink layers 21, 31, 41, white ink layers 22, 32, 42, and red ink layers 23, 33, 43 are provided in different colors on each recording layer. The reflection layer 50 is provided so that the base sheet 60 is not damaged by laser irradiation, and is formed by printing mica, aluminum, silicon dioxide, titanium oxide, or the like into ink. When black printing is performed at the position of the black ink layer 21 using the recording sheet 400, a laser beam having irradiation energy adjusted so that the coating layer 10 can be removed and does not reach the second recording layer 30 is irradiated. This is achieved by performing printing. Further, black printing and red printing at other positions can be achieved by performing printing in the same manner as described above in detail. When the number of colors is further required, at least the number of colors may be provided between the cover layer and the sheet substrate between the cover layer and the sheet substrate. It is also possible to change the white ink layer to a desired color.
[0023]
The present invention is not limited to the embodiment described above, and various modifications and changes are possible. For example, the coating layer 10 and the recording layers 20, 30, and 40 are not limited to printing inks, but can also use thermal transfer ink (thermal transfer method), toner (electrophotographic method), inkjet ink (inkjet method), paint (coating method), and the like. It is. In addition, it may be formed by extruding a plastic such as PE (polyethylene), PP (polypropylene), PET (polyester), PVC (vinyl chloride), or by laminating a film. Needless to say, the color-coded patterns and colors of the recording layer are not limited to the above examples, and a desired pattern such as a company name logo can be formed in a desired color. If the pattern is changed for each product and each manufacturing time, it is more suitable for preventing forgery and tampering. In addition, if necessary, a material having a high laser light absorbing power or a material having a high concealing property may be appropriately combined with the binder of each layer, and a difference may be appropriately provided in the laser light energy absorbing power.
[0024]
【The invention's effect】
As described above, according to the recording sheet for laser marking according to the present invention, since the desired printing cannot be performed unless the printing energy is changed according to the color-coded pattern of the recording layer, counterfeiting and tampering by additional writing are prevented. it can. Further, if additional writing is performed, traces of the printing remain on the recording sheet for laser marking. Therefore, if the printing surface is confirmed, it can be easily determined that the additional writing has been attempted. Further, since the recording layer can be color-coded with a desired color, color printing of a desired color can be performed. Furthermore, according to the printing method of the present invention, it is possible to perform suitable printing on a recording sheet for laser marking in which it is possible to easily determine that additional writing has been performed. Therefore, it is possible to provide a printing method that has an excellent effect of preventing falsification and forgery. It becomes.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view illustrating a configuration of a recording sheet (recording sheet) 1 for laser marking according to a first 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 black inks 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 at an energy capable of removing 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 that partially reaches the surface of the second recording layer 31.
FIG. 9 is a sectional view taken along the line ZZ.
FIG. 10 is an exploded perspective view showing a configuration of a recording sheet 400 for laser marking according to a second embodiment of the present invention.
[Explanation of symbols]
1,400 Recording sheet for laser marking (recording sheet)
2 Adhesive 3 Release liner 4 Core core 5 Print pitch detection mark 6 Symbol such as bar code or two-dimensional code 10 Coating layer 20 First recording layers 21, 31, 41 Black ink layers 22, 32, 42 White ink layer 30 2 recording layer 40 3rd recording layer 50 reflective layer 60 sheet base material 100, 200, 300 print recording sheet

Claims (6)

In the recording sheet for laser marking which irradiates laser light to form characters, symbols, pictures, etc. on the printing surface,
A sheet substrate, a multi-layer recording layer in which at least one side of the sheet substrate is laminated with a color-coded recording layer such that the same color does not overlap at least in part when superimposed on each other, and recording of the multi-layer A coating layer covering the surface of the layer and serving as the printing surface. 2. The recording sheet for laser marking according to claim 1, wherein the plurality of recording layers include one set of the recording layers having the same pattern and different colors. 3. The multi-layer recording layer and the coating layer are characterized by being formed by at least one method selected from a printing method, a thermal transfer method, an electrophotographic method, an ink jet method, a coating method, a bonding method, and the like. The recording sheet for laser marking according to claim 1. The recording 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. Sheet. 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 in which various information necessary for printing are input are provided. The recording sheet for laser marking according to any one of the above. A sheet substrate, a multi-layer recording layer in which at least one side of the sheet substrate is laminated with a color-coded recording layer such that the same color does not overlap at least in part when superimposed on each other, and recording of the multi-layer A method of using a recording sheet for laser marking, comprising a coating layer covering the surface of the layer and serving as a printing surface,
Irradiating a laser beam to selectively expose the color-coded recording layer of a predetermined color from a plurality of recording layers provided at a printing position, thereby forming characters, symbols, pictures, and the like. How to use the recording sheet for laser marking.

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