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:
Mar. 04, 2014
Filed:
May. 08, 2008
John Richardson, Newbury Park, CA (US);
John Wallner, Calabasas, CA (US);
John Richardson, Newbury Park, CA (US);
John Wallner, Calabasas, CA (US);
AltaSens, Inc., Westlake Village, CA (US);
Abstract
A method for correcting column Fixed Pattern Noise (FPN) in an image sensor offers a compromise between speed and precision for calculating column FPN offsets. The present correction technique is digital, and is applied after the pixel signal voltages have been digitized by an ADC. A first Optical Black (OB) pixel is sampled and compared to a target level. An offset is stored, and an appropriate push-size is determined. Additional OB pixels are sampled and the offset is applied. The push-size is increased or decreased depending upon whether the pixel signal with the applied offset is above or below a target value. This new offset value is written to memory, and the push-size is reduced, and the process is repeated until the last OB pixel has been processed. The resulting offset is applied to the signal pixels in a column. The primary advantage of this approach is that within a single frame, a good estimate of the column offset is made which is not as affected by outlier pixels (such as 'hot' or 'flashing' pixels).