Apparatus for detecting a security thread embedded in a paper-like material

Patent 4524276 Issued on June 18, 1985. Estimated Expiration Date:

April 4, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Apparatus for and method of detecting release tape sandwiched between layers of a carpeting strip
Patent #: 4239562
Issued on: 12/16/1980
Inventor: McLean

Method of measuring the amount of substance associated with a material in the presence of a contaminant Patent #: 4306151
Issued on: 12/15/1981
Inventor: Chase

Inventor

Ohtombe, Ko

Assignee

Tokyo Shibaura Denki Kabushiki Kaisha

Application

No. 06/481944 filed on 04/04/1983

US Classes:

250/338.1, Infrared responsive250/339.06, With radiation source250/341.1, With irradiation or heating of object or material356/71DOCUMENT PATTERN ANALYSIS OR VERIFICATION

Examiners

Primary: Smith, Alfred E.
Assistant: Hannaher, Constantine

Attorney, Agent or Firm

Cushman, Darby & Cushman

International Classes

G07D 7/00 (20060101)
G07D 7/12 (20060101)

Foreign Application Priority Data

1982-04-06 JP

Abstract

An apparatus for optically detecting a security thread embedded in a paper-like material, e.g., a paper currency. The paper-like material is carried through a detection region defined by an infrared radiation source and two infrared radiation detectors. Two optical filters are mounted on the detectors, respectively. Those filters have different infrared transmission characteristics. Therefore, one detector can detect infrared rays having wavelengths only within a specific range determined by that one filter, and the other detector can detect infrared rays having wavelengths only within another specific range determined by the other filter. When the infrared radiation source projects infrared rays to the paper-like material, the detectors deliver the respective detection signals. A processor processes these detection signals to determine whether or not a security thread is embedded in the paper-like material and also what a detected security material is made of.