Providing intelligible markings

• US 5,093,147 A
• Filed: 09/12/1990
• Issued: 03/03/1992
• Est. Priority Date: 09/12/1990
• Status: Expired due to Term

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Andrus, Paul G., Dolash, Thomas M.
• Primary Examiner(s): BELL, JANYCE A
• Application Number:
  US07/581,835
• Time in Patent Office: 538 Days
• Field of Search: 427/160, 427/7, 427/64
• US Class Current: 427/7
• CPC Class Codes: B41M 3/06 Veined printings; Fluorescent printings; Stereoscopic images; Imitated patterns, e.g. tissues, textiles
• CPC Class Codes: B41M 3/144 using fluorescent, luminescent or iridescent effects
• CPC Class Codes: C09B 23/0008 substituted on the polymethine chain
• CPC Class Codes: C09B 23/0041 the substituent being bound through a nitrogen atom
• CPC Class Codes: C09B 23/0066 the polymethine chain being part of a carbocyclic ring,(e.g. benzene, naphtalene, cyclohexene, cyclobutenene-quadratic acid)
• CPC Class Codes: C09B 23/086 more than five >CH- groups
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26

Abstract

A method for providing intelligible markings that are virtually invisible to the unaided eye on the surface of an article, comprises: applying onto the surface, by a jet printing process, a marking medium comprising a compatible liquid or viscous substance containing an organic laser dye (typically IR-125 in a concentration of about 0.005 to 0.05 percent by weight of the medium) that is poorly absorptive of radiation in the visible range of about 400 to 700 nanometers, is highly absorptive of radiation in the near infrared range of at least about 750 nanometers in wavelength (typically about 750 to 900 nanometers), and fluoresces in response to radiation excitation in the said near infrared range to produce fluorescent radiation of wavelengths longer than the wavelength of the excitation (typically in the range of about 800 to 1100 nanometers). Other useful laser dyes may comprise DTTCI, DNTTCI, HDITCI, DDTTCI, IR-140, DDCI-4, or IR-132.

Claims

1. A method for providing intelligible markings that are virtually invisible to the unaided eye on the surface of an article, comprising:

applying, onto the surface, a marking medium comprising a compatible liquid or viscous substance containing an organic dye that is poorly absorptive of radiation in the visible range of about 400 to 700 nanometers, is highly absorptive of radiation in the near infrared range of at least about 750 nanometers in wavelength, and fluoresces in response to radiation excitation in the said near infrared range to produce fluorescent radiation of wavelengths longer than the wavelength of the excitation.

2. A method as in claim 1, wherein the dye is highly absorptive of radiation in the range of about 750 to 900 nanometers.

3. A method as in claim 2, wherein the fluorescent radiation is produced principally in the range of about 800 to 1100 nanometers.

4. A method as in claim 1, wherein the markings are applied by a jet printing process.

5. A method as in claim 1, wherein the dye comprises an organic laser dye.

6. A method as in claim 5, wherein the laser dye comprises IR-125.

7. A method as in claim 6, wherein the dye is present in a concentration of about 0.005 to 0.05 percent by weight of the medium.

8. A method as in claim 3, wherein the laser dye comprises DTTCI, DNTTCI, HDITCI, IR-125, DDTTCI, IR-140, DDCI-4, or IR-132.