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. 26, 2002
Filed:
Sep. 28, 1998
John T. Eaton, Vancouver, WA (US);
Jason Quintana, Brush Prairie., WA (US);
Carl Eric Thomsen, Portland, OR (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
The present invention provides a method for compensating for the velocity variation in an ink-jet pen by dynamically varying the ink drop firing timing as a function of pen velocity. This makes it possible to print while the pen is accelerating or decelerating without affecting image quality. Scanning velocity change compensation is dynamically and continuously updated at a rate equal to or greater than an encoder edge rate. Further, the present invention provides a method for improving ink drop positioning accuracy across a print media scan by compensating for the change in ink-drop flight time as printhead-to-paper distance changes. Ink drop flight time error is dynamically compensated such that a fired droplet of ink hits its intended target pixel without any appreciable error.