Title :
A Wide-Dynamic-Range CMOS Image Sensor Based on Multiple Short Exposure-Time Readout With Multiple-Resolution Column-Parallel ADC
Author :
Sasaki, Masaaki ; Mase, Mitsuhito ; Kawahito, Shoji ; Tadokoro, Yoshiaki
Author_Institution :
Dept. of Inf. & Commun. Eng., Sendai Nat. Coll. of Technol.
Abstract :
A wide-dynamic-range CMOS image sensor based on synthesis of one long and multiple short exposure-time signals is proposed. A high-speed, high-resolution column-parallel integration type analog-to-digital converter (ADC) with a nonlinear slope is crucial for this purpose. A prototype wide-dynamic-range CMOS image sensor that captures one long and three short exposure-time signals has been developed using 0.25-mum 1-poly 4-metal CMOS image sensor technology. The dynamic range of the prototype sensor is expanded by a factor of 121.5, compared with the case of a single long exposure time. The maximum DNL of the ADC is 0.3 least significant bits (LSB) for the single-resolution mode and 0.7 LSB for the multiresolution mode
Keywords :
CMOS image sensors; analogue-digital conversion; readout electronics; 0.25 micron; CMOS image sensor; analog-to-digital converter; exposure-time signals; least significant bits; multiple short exposure-time readout; Analog-digital conversion; CMOS image sensors; Cameras; Dynamic range; Image converters; Pixel; Prototypes; Signal resolution; Signal synthesis; Time measurement; CMOS image sensor; multiple-exposure; multiresolution analog-to-digital converter (ADC); wide dynamic range;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2006.888058
