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. 02, 1997
Filed:
Nov. 13, 1995
Richard G Crystal, Los Altos, CA (US);
Graphic Utilities, Inc., Concord, MA (US);
Abstract
This invention is directed to improved aqueous pigment-based ink compositions for use in ink jets and methods of enhancing and/or controlling the optical density and print sharpness of both pigment-based and dye-based inks. The improved ink compositions include a class or organic quaternary ammonium compounds which improve the optical density and print sharpness of the inks. Other improvements include the use of a polyalkylene oxide to impedence match the ink with the drop formation rate to provide drop formation rates as high as 8,000 drops per second. These high drop rates permit higher writing speeds and enhanced printer resolution. Yet another improvement to ink jet ink composition is the addition of urea, urea derivatives and thiol compounds. These compounds prevent the ink jet from accumulating dried ink thus preventing clogging of the ink jet.