METHOD OF READING PATTERN CONTAINING A MATERIAL CAPABLE OF RADIATING INFRARED LIGHT

• US 20010001472A1
• Filed: 07/01/1999
• Published: 05/24/2001
• Est. Priority Date: 02/08/1996
• Status: Abandoned Application

• Current Assignee: Hideyuki Nishizawa, Kenji Sano, Kenji Todori, Mitsunaga Saito, Taeko I. Urano
• Original Assignee: Hideyuki Nishizawa, Kenji Sano, Kenji Todori, Mitsunaga Saito, Taeko I. Urano
• Inventors: SANO, KENJI, TODORI, KENJI, NISHIZAWA, HIDEYUKI, SAITO, MITSUNAGA, URANO, TAEKO I.
• Application Number:
  US09/346,170
• Publication Number:
  US 20010001472A1
• Time in Patent Office: Days
• US Class Current: 235/462.01
• CPC Class Codes: G06K 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks

Abstract

Disclosed is a method of reading a pattern comprising steps of heating or irradiating with infrared light a substrate on which a transparent pattern is formed, the pattern containing a material capable of absorbing infrared light of specific wavelength such as polyacrylonitrile, and detecting infrared light which is radiated or reflected from the pattern.

Claims

1. A method of reading a pattern comprising steps of:

heating or irradiating with infrared light a substrate on which a transparent pattern is formed, said pattern containing a material capable of absorbing infrared light of specific wavelength; and

detecting infrared light from said pattern.

2. The method according to

claim 1

, wherein said pattern constitutes a symbol.

3. The method according to

claim 1

, wherein said material capable of absorbing infrared light of specific wavelength is a polymer or a low molecular-weight compound having a cyano group.

4. The method according to

claim 3

, wherein said polymer having cyano groups is polyacrylonitrile or a acrylonitrile-based copolymer.

5. The method according to

claim 1

, wherein said substrate is made of cloth, and said pattern is formed by sewing a thread made of fibers of polyacrylonitrile or a acrylonitrile-based copolymer.

6. The method according to

claim 1

, wherein said material constituting said pattern has a higher thermal conductivity than that of said substrate.

7. The method according to

claim 1

, wherein a colored mark is formed in the vicinity of the pattern region on said substrate.

8. The method according to

claim 1

, wherein a mark comprising a fluorescent material capable of emitting visible light upon absorption of ultraviolet light is formed in the vicinity of the pattern region on said substrate.

9. An optical signal reader comprising:

a means for conveying a substrate on which a transparent pattern is formed, said pattern containing a material capable of absorbing infrared light of specific wavelength;

a means for heating or irradiating with infrared light a region of said pattern formed on said substrate; and

a means for detecting infrared light from said pattern.

10. The optical signal reader according to

claim 9

, wherein at least either one of said means for irradiating with infrared light and said means for detecting infrared light is provided with a filter capable of selecting infrared light of specific wavelength.

11. A method of preventing counterfeiting of a certification document on which visible information for certification is formed comprising steps of:

forming a transparent pattern corresponding to said visible information on said document, said pattern containing a material capable of absorbing infrared light of specific wavelength;

heating or irradiating with infrared light a region of said pattern on said substrate;

detecting infrared light from said pattern; and

comparing information detected from said pattern with said visible information.

12. The method according to

claim 11

, wherein said pattern region is covered with a transparent film.

13. A method of preventing counterfeiting of a prepaid card in which magnetic information is recorded comprising steps of:

forming a plurality of transparent patterns corresponding to remaining sums on said prepaid card;

punching a hole in one of said patterns corresponding to a remaining sum available for use at the time when said prepaid card is used;

heating or irradiating infrared light a region of said patterns on said prepaid card;

detecting infrared light from said patterns; and

comparing information detected from said patterns with the magnetic information recorded in said prepaid card.