Fixed Pattern Noise Reduction and Linearity Improvement in Time-Mode CMOS Image Sensors
Miron Kłosowski, Yichuang Sun
Abstract
In the paper, a digital clock stopping technique for gain and offset correction in time-mode analog-to-digital converters (ADCs) has been proposed. The technique is dedicated to imagers with massively parallel image acquisition working in the time mode where compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. Fixed pattern noise (FPN) reduction has been experimentally validated using 128-pixel CMOS imager. The reduction of the PRNU to about 0.5 LSB has been achieved. Linearity improvement technique has also been proposed, which allows for integral nonlinearity (INL) reduction to about 0.5 LSB. Measurements confirm the proposed approach.
Topics & Concepts
LinearityFixed-pattern noiseCMOSLeast significant bitDifferential nonlinearityIntegral nonlinearityOffset (computer science)PixelImage sensorReduction (mathematics)Electronic engineeringComputer scienceNoise (video)ConvertersNoise reductionEngineeringArtificial intelligenceVoltageElectrical engineeringMathematicsImage (mathematics)Operating systemGeometryProgramming languageCCD and CMOS Imaging SensorsImage Processing Techniques and ApplicationsAdvanced Optical Sensing Technologies