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:
Sep. 21, 2004
Filed:
Nov. 14, 2002
Applicant:
Inventors:
Yu-Chang Shen, Taipei, TW;
In-Shan Sir, Kaohsiung, TW;
Chia-Hsin Chien, Taoyuan, TW;
Yu-Ting Lin, Lujou, TW;
Assignee:
Benq Corporation, Taoyuan, TW;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09D 1/100 ; B44F 1/12 ; B42D 1/510 ;
U.S. Cl.
CPC ...
C09D 1/100 ; B44F 1/12 ; B42D 1/510 ;
Abstract
An invisible ink composition and a method to ensure document confidentiality. The invisible ink composition includes a carrier as a solvent; and at least one leuco dye evenly dispersing in the carrier. The invisible ink becomes visible while the leuco dye is combined with a weak acidic developer.