# US 5,348,348 A · Data-written medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,348,348 A - Document ID: US5348348A - Status: Granted - Kind: A - Application number: 07/840,479 - Filed: 1992-02-24 - Granted: 1994-09-20 - Earliest claimed: 1989-09-26 - Assignees: Toyo Ink Manufacturing Co., Ltd. - Inventors: Koji Hanada; Makiko Hamuro; Takeshi Yoshikawa; Toru Ohmura; Motohiko Kashioka - Web page: https://patentgrep.com/patent/US5348348A ## CPC - G06K 7/12: using a selected wavelength, e.g. to sense red marks and ignore blue marks - G06K 19/14: the marking being sensed by radiation - Y10S 283/901: Concealed data - Y10S 283/904: Credit card - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A data-written medium in which the data is readable with a light source having a main wavelength of 600 to 700 nm, the medium comprising a substrate and an ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having absorption substantially at 600 to 700 nm and at least one other color dyestuff as the remainder. The ink layer is formed on the substrate so as to have a form constituting the data. Also provided is a data-written medium in which the data is readable with light sources having a main wavelength of 600 to 1,500 nm, the medium comprising a substrate, a first ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having substantial absorption at 600 to 700 nm and another dyestuff as the remainder, and a second ink layer containing a substance having substantial absorption in a near infrared region. Each of the two ink layers is formed so as to individually have a form constituting to two corresponding data. ## Claims ### Claim 1 A data-written medium in which the data is readable with a device having a light source emitting light in a wavelength of 600 to 700 nm, the medium comprising a substrate and an ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having absorption substantially at 600 to 700 nm and at least one other color dyestuff which does not have a main absorption in the wavelength of 600 to 700 nm, said ink layer being formed on said substrate and having a form constituting the data. ### Claim 2 (depends on 1) A medium according to claim 1, wherein the form constituting the data is a bar code. ### Claim 3 (depends on 1) A medium according to claim 1, wherein the form constituting the data is a numeric or alphabetic character. ### Claim 4 (depends on 1) A medium according to claim 1, wherein said at least one other color dyestuff is a warm color dyestuff and/or a white color dyestuff. ### Claim 5 (depends on 4) A medium according to claim 4, where said warm color dyestuff is at least one member selected from the group consisting of red, orange, yellow and purple dyestuffs. ### Claim 6 (depends on 1) A medium according to claim 1, wherein said color dyestuff is a dye or a pigment. ### Claim 7 (depends on 1) A medium according to claim 1, wherein said chromatic color dyestuff is contained in an amount of 0.005 g/m.sup.2 to 0.08 g/m.sup.2. ### Claim 8 (depends on 1) A medium according to claim 1, wherein said ink layer is a layer formed from a heat-melting ink by a thermal transfer method. ### Claim 9 (depends on 1) A medium according to claim 1, wherein said chromatic color dyestuff having a substantial absorptivity at 600 to 700 nm is a blue or green dyestuff. ### Claim 10 (depends on 1) A medium according to claim 1, wherein said chromatic color dyestuff having a substantial absorptivity at 600 to 700 nm is a halogenated copper phthalocyanine. ### Claim 11 (depends on 10) A medium according to claim 10, wherein said halogenated copper phthalocyanine is a brominated copper phthalocyanine. ### Claim 12 (depends on 1) A medium according to claim 1, which contains data which is readable with a light source having a main wavelength of 600 to 700 nm by measuring its reflection strength, transmission strength or absorption strength. ### Claim 13 (depends on 1) A medium according to claim 1, wherein said ink layer is formed by laminating a first ink layer containing said chromatic color dyestuff and a second ink layer containing said at least one other color dyestuff. ### Claim 14 A data-written medium in which the data is readable with a device having a light source emitting light having a main wavelength of 600 to 1,500 nm, the medium comprising a substrate, a first ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having substantial absorption at 600 to 700 nm and at least one other color dyestuff which does not have a main absorption at 600 to 700 nm, and a second ink layer containing a substance having substantial absorption in a near infrared region, each of said first and second ink layers being formed to individually have a form constituting a corresponding data. ### Claim 15 A data-written medium in which the data is readable with a device having a light source emitting light in a wavelength of 600 to 700 nm, the medium comprising a substrate, a first ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having absorption substantially at a wavelength of 600 to 700 nm and a second ink layer containing a warm color dyestuff which does not have a main absorption in the wavelength of 600 to 700 nm, said first and second ink layers being formed on the substrate and having a form which constitutes data. ### Claim 16 A data-written medium in which the data is readable with a device having a light source emitting light having a main wavelength of 600 to 1,500 nm, the medium comprising a substrate, a first ink layer containing not more than 0.1 g/m.sup.2 of a chromatic color dyestuff having substantial absorption at 600 to 700 nm, a second ink layer containing at least one other color dyestuff which does not have a main absorption at 600 to 700 nm, and a third ink layer containing a substance having substantial absorption in a near infrared region, each of said first and third ink layers being formed to individually have a form constituting a corresponding data.