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:
Jul. 06, 1999
Filed:
Aug. 05, 1997
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
Disclosed is an image sensor having A/D conversion circuitry coupled to column data lines of an image sensor array. The A/D conversion circuitry digitizes analog signals on the column data lines, each representing intensity of light incident upon an active imager cell. Higher resolution is provided for darker light levels than for bright light levels, such that a high resolution image is obtained with less storage data than would otherwise be required. In one embodiment, the A/D conversion circuitry includes a plurality of comparators, each having a first input coupled to one or more column data lines and a second input coupled to receive a time-varying reference signal, and a plurality of n-bit counters coupled to the comparator outputs. An n-bit to m-bit converter nonlinearly maps n-bit codes to m-bit codes and provides the m-bit codes to an m-bit D/A converter which produces the time-varying reference signal. In another embodiment, the A/D conversion circuitry is comprised of a non-uniform successive approximation A/D converter.