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:
Feb. 24, 2009
Filed:
Jul. 07, 2003
Donald Henry Willis, Indianapolis, IN (US);
Donald Henry Willis, Indianapolis, IN (US);
Thomson Licensing, Boulogne Billancourt, FR;
Abstract
A field sequential pulse width modulated display system comprises a digital micromirror device (DMD) having a plurality of micromirrors that each selectively pivot to reflect light onto a screen to illuminate a corresponding pixel. A driver circuit controls the DMD responsive to sequences of pulse width segments formed by a processor. The processor actuates at least one pulse in a first pulse width segment for a given color to increase pixel brightness with a range lying between first and second pixel brightness values. To further increase pixel brightness, the processor actuates at least one pulse within additional pulse width segments associated with the same given color to increase pixel brightness above the second brightness boundary. The pulses within the additional segments are actuated unequally so that the additional pulse width segments closest in time to the first segment (i.e., the segment first in brightness) have a greater total duration of actuated pulses for a given pixel brightness compared to the additional pulse width segments farther in time from the first segment. Actuating the pulses in this manner serves to: (a) limit the time dispersal of darker objects within a picture, (b) minimize the light redistribution between time segments for incremental brightness changes, and (c) taper up and down light intensity for the sequence of pulse width segments for a given picture, all to minimize motion artifacts.