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:
Aug. 19, 1998
Steven E Stark, Portland, OR (US);
Edmund D Passon, Eindhoven, NL;
In Focus Systems, Inc., Wilsonville, OR (US);
Abstract
A multimedia projector (30) employing a color wheel (42) in a frame sequential color display system includes a light sensor (68) positioned to receive light scattered from a point in an optical path (34) after the color wheel. The light sensor detects particular colors of light propagating through red, green, and blue filter segments (R, G, and B) on the color wheel and toward a display device (50). The light sensor provides, without any adjustments, an inherently accurate timing mark signal (78) to a display controller (56) to ensure that red, green, and blue image data are properly synchronized with the respective filter segments R, G, and B. In particular, the light sensor receives polychromatic light through a yellow optical filter (74) to illuminate an optoelectric detector (70) that is responsive to visible and near IR light wavelengths. The photodetector drives a timing mark signal generator (80) to detect a sudden increase in yellow (red plus green) light, which indicates to the display controller that filter segment R has just rotated into the optical path.