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:
Nov. 23, 1999
Filed:
Aug. 30, 1996
Norman E Pawlowski, Jr, Corvallis, OR (US);
Paul D Gast, Vancouver, WA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
In the preferred embodiment, an inkjet printer includes a replaceable print cartridge which is inserted into a scanning carriage. The print cartridge contains a regulator valve. An ink tube extends from the scanning carriage to a separate, disposable ink supply cartridge located within the printer. A second valve connected between the ink tube and the ink supply cartridge is automatically actuated when it is determined that the printer is not being used. The valve seal is more reliable than the inexpensive one-way valve seal in the disposable ink supply cartridge. The reliable valve seal prevents any air bubbles in the tube from expanding toward the ink supply cartridge, enabling the use of more flexible tubes which have less stringent air diffusion characteristics. In another embodiment, instead of a valve, a pressure source is connected to the ink tube to maintain the partial air pressure within the tube at approximately ambient pressure.