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:
Oct. 19, 1999
Filed:
Apr. 20, 1995
Paul R Erickson, Prior Lake, MN (US);
David H Bennefeld, Ramsey, MN (US);
John P Novotny, Burnsville, MN (US);
Colorspan Corporation, Eden Prairie, MN (US);
Abstract
An ink on demand type ink jet head energization system is provided to drive ink out of a nozzle in the head. The head contains at least one nozzle for discharging ink. The power applied to the nozzle is modified to include a noise component. By providing a driving voltage which varies between firings, the head produces ink droplets which differ in size between firings. Preferably, the voltage is randomly or pseudo-randomly varied over a range of from 50 to 100% of maximum voltage, and a new voltage is provided for each successive firing of the head. This variation of drive voltage produces ink dots which randomly vary in size at a rate too dense to be perceived by a viewer, and successfully reduces perceived artifacts in the printed output.