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. 06, 1986
Filed:
Apr. 14, 1983
Applicant:
Inventors:
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03G / ;
U.S. Cl.
CPC ...
355 / ; 355 / ; 355 77 ; 355133 ;
Abstract
A confidential document reproduction prevention method of preventing confidential documents from being reproduced. This method is carried out by applying a particular material as a confidential mark at least to one portion of the surface of a confidential document, which material, when exposed to illumination light, is capable of emitting light with a wavelength different from the wavelength of the illumination light; detecting the light emitted from the material by a detector in a reproduction machine when the document is exposed to the illumination light; and making the reproduction machine inoperative, upon detection of the light emitted from the material.