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:
Apr. 05, 2005
Filed:
Apr. 29, 2003
Isaac Farr, Corvallis, OR (US);
Shane Shivji, Corvallis, OR (US);
Isaac Farr, Corvallis, OR (US);
Shane Shivji, Corvallis, OR (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
A printing device is provided, which is configured to print a printing fluid onto a printing medium. The printing device includes a printing fluid reservoir configured to hold a volume of the printing fluid, a print head assembly configured to transfer the printing fluid to the printing medium, a conduit fluidically connecting the printing fluid reservoir to the print head assembly, and a printing fluid detector associated with the conduit. The printing fluid detector includes a first electrode and a second electrode coupled with the conduit and configured to be in contact with printing fluid in the conduit, a power supply configured to apply an alternating supply signal to the first electrode, and detector circuitry configured to detect a measured impedance value related to the presence of printing fluid within the conduit by comparing the alternating supply signal with a detected signal that has been modified from the applied signal by an impedance characteristic of the printing fluid.