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:
May. 16, 2006
Filed:
Sep. 20, 1999
Kimble Dong, Sunnyvale, CA (US);
Datong Chen, Fremont, CA (US);
Kimble Dong, Sunnyvale, CA (US);
Datong Chen, Fremont, CA (US);
OmniVision Technologies, Inc., Sunnyvale, CA (US);
Abstract
Auto black expansion circuitry with a simplified digital control system. According to the system, a count of the number of pixels that fall below desired black level and mid-level ranges are maintained. The pixel counts are obtained by comparators that receive the adjusted signals at one input and the desired comparator signal levels at the other input. At the end of a field, when the pixel counts are complete, adjustment to the auto black expansion may be made for the following field. Once the pixel count at the end of a given field indicates that the auto black expansion has achieved the desired level, the automatic gain control may be adjusted for the following field. The method uses single comparators and single counters to obtain the pixel counts. The digital controller outputs an 8-bit control signal to adjust the analog auto black expansion and automatic gain control circuits to precise levels.