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:
Jan. 29, 2002
Filed:
Apr. 28, 1998
Joseph E. Scheffelin, San Diego, CA (US);
Mark E. Young, Escondido, CA (US);
Elizabeth Zapata, San Diego, CA (US);
Kenneth J. Courian, San Diego, CA (US);
George T. Kaplinsky, San Diego, CA (US);
David W. Swanson, Escondido, CA (US);
James E. Clark, Albany, OR (US);
Tofigh Khodapanah, San Diego, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A closed ink replenishment system for replenishing the supply of ink in negative pressure spring-bag reservoirs in a printer/plotter. A tube runs between each cartridge reservoir and an auxiliary reservoir mounted to the printer/plotter frame to form the closed ink system. As ink is depleted from the spring-bag reservoir during printing operation, the negative pressure in the cartridge increases, drawing ink through the tube from the auxiliary reservoir into the cartridge until the negative pressure decreases to an equilibrium point. As a result, the volume of ink within the spring-bag reservoir remains substantially constant so long as there is ink remaining within the auxiliary reservoir. This maintains the print quality. The auxiliary reservoir is a flat bag mounted on a spring-biased platform, which acts as a height regulating system. As ink is depleted from the auxiliary bag, the height of the platform and bag increases to maintain a constant pressure and elevation head at the spring-bag reservoir.