The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 1979
Filed:
Oct. 15, 1974
Paul-Henri Voisin, San Mateo, CA (US);
Michael F Mizianty, Sunnyvale, CA (US);
Xidex Corporation, Sunnyvale, CA (US);
Abstract
Photographic element designed to prevent duplication by contact copying with actinic light, formed from a synthetic organic polymer having a nitrogen gas permeability suitable for use as a vehicle in a vesicular film, and a light sensitive diazotype composition dispersed therein in which the diazotype composition includes a light decomposable diazonium salt and a coupler for forming a dye with said diazonium salt. Upon image-wise exposure and development, the light-struck areas are vesiculated and an azo dye is formed in the nonlight-struck areas. The image formed from the vesicules relative to the azo dye provide sufficient contrast for viewing by projected light but insufficient contrast for contact copying with UV light.