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:
Aug. 14, 2001
Filed:
Feb. 02, 1998
Sudhir Muniswamy Gowda, Ossining, NY (US);
Hyun Jong Shin, Ridgefield, CT (US);
Hon-Sum Philip Wong, Chappaqua, NY (US);
Peter Hong Xiao, San Jose, CA (US);
Jungwook Yang, West Nyack, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention relates to an automatic gain control circuit in which the automatic gain control function is performed entirely in the digital domain. In an illustrative embodiment, the digital automatic gain control circuit for an image sensor having associated therewith an analog-to digital (A/D) converter for converting analog electrical signals from the image sensor to corresponding digital codes, includes a min/max detector for determining minimum and maximum electrical signal values from the digital codes of the A/D converter for each frame of image. A filter coupled to the min/max detector dampens instantaneous changes of the minimum and maximum values by filtering to provide filtered minimum and maximum values. A digital-to-analog (D/A) converter coupled to the filter generates minimum and maximum analog reference voltages corresponding to the respective minimum and maximum filtered values, the reference voltages being applied to the A/D converter to control associated amplitudes of the digital codes provided thereby.