Method for reading of invisible marking
First Claim
1. A method for reading of information, which comprises printing information on a metal substrate or a substrate capable of transmitting infrared rays of 2-10 μ
- m wavelength, with a marking ink containing a marking component selected from the group consisting of (1) tin oxide, (2) indium-tin mixed oxide, (3) a mixture of tin oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate, and (4) a mixture of indium-tin mixed oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate said marking component being infrared absorbable;
as necessary coating a clear coating or a coloring ink on at least the information-printed area of the substrate;
when the substrate is not the metal substrate, then placing a metal sheet at a side opposite to the information-printed side of the substrate; and
identifying the information by detecting, from the information-printed side of the substrate, infrared rays emitted from the information-printed area of the substrate by means of a CCD camera sensitive to infrared rays of 2-10 μ
m wavelength or an infrared detector.
1 Assignment
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Accused Products
Abstract
A method for reading of information, which comprises printing information on a metal substrate or a substrate capable of transmitting infrared rays of 2-10 μm wavelength, with a marking ink containing tin oxide, indium-tin mixed oxide or a mixture of tin oxide or indium-tin mixed oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate, as necessary coating a clear coating or a coloring ink on at least the information-printed area of the substrate, and identifying the information by the use of a CCD camera sensitive to infrared rays of 2-10 μm wavelength or an infrared detector. No noise is generated even when the reflectance of a light from the substrate surface is large, and the information can be identified (read) easily.
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Citations
15 Claims
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1. A method for reading of information, which comprises printing information on a metal substrate or a substrate capable of transmitting infrared rays of 2-10 μ
- m wavelength, with a marking ink containing a marking component selected from the group consisting of (1) tin oxide, (2) indium-tin mixed oxide, (3) a mixture of tin oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate, and (4) a mixture of indium-tin mixed oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate said marking component being infrared absorbable;
as necessary coating a clear coating or a coloring ink on at least the information-printed area of the substrate;
when the substrate is not the metal substrate, then placing a metal sheet at a side opposite to the information-printed side of the substrate; and
identifying the information by detecting, from the information-printed side of the substrate, infrared rays emitted from the information-printed area of the substrate by means of a CCD camera sensitive to infrared rays of 2-10 μ
m wavelength or an infrared detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- m wavelength, with a marking ink containing a marking component selected from the group consisting of (1) tin oxide, (2) indium-tin mixed oxide, (3) a mixture of tin oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate, and (4) a mixture of indium-tin mixed oxide and at least one compound selected from the group consisting of alumina, barium sulfate, silicon dioxide and calcium carbonate said marking component being infrared absorbable;
Specification