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:
Mar. 05, 2002
Filed:
Mar. 04, 1997
Chris T. Armijo, San Diego, CA (US);
Gonzalo Gaston, Sant Cugat del Vallès, ES;
Javier Lagares, Sant Cugat del Vallès, ES;
Antoni Gil, Sant Cugat del Vallès, ES;
Francesc Subirada, Sant Cugat del Valles, ES;
Francisco Guerrero, Sant Cugat del Valles, ES;
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A nozzle detection test pattern has been developed which can be sensed by an optical sensor located on an inkjet printer carriage. By having the same nozzle print ink drops on multiple pixels to form a single thickened test line during multiple passes of the printhead, it is possible to thereafter scan across such test line and automatically determine by the light contrast ratios which nozzles are not firing properly. A green light LED is used to illuminate the magenta, cyan and black test patterns as they are being sensed, and a blue light LED is used to illuminate the yellow test pattern as it is being sensed. A separate test pattern is used for each printhead ink color. The test pattern constitutes six rows with forty test lines on each row for a printhead having 240 active nozzles.