Patent · US Expired

Security document

US4763927A · kind A · utility

45Cited by
11References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 7, 1985
Grant dateAug 16, 1988
Priority date
Expiry dateJun 7, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/24942
  • WIPO fieldOther consumer goods
  • WIPO sectorOther fields

Abstract

In order to increase the protection against forgery of a security paper, a security inlay made of polymer material having piezoelectric and/or pyroelectric properties is embedded in the security paper. The presence of such an inlay can be tested by means of contacting and non-contacting measuring methods.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.