Title :
A self-calibrating single-chip CMOS camera with logarithmic response
Author :
Loose, Markus ; Meier, Karlheinz ; Schemmel, Johannes
Author_Institution :
Rockwell Sci. Center, Thousand Oaks, CA, USA
fDate :
4/1/2001 12:00:00 AM
Abstract :
A high-dynamic-range CMOS image sensor consisting of nonintegrating, continuously working photoreceptors with logarithmic response is presented. The nonuniformity problem caused by the device-to-device variations is greatly reduced by an implemented analog self-calibration. After performing this calibration, the remaining fixed pattern noise amounts to 3.8% (RMS) of an intensity decade at a uniform illumination of 1 W/m2. The sensor provides a resolution of 384×288 pixels and a dynamic range of 6 decades in the intensity region from 3 mW/m2 to 3 kW/m2. It contains all components required for operating as a camera-on-a-chip. The image data can be read out either via a single analog line (video standard) or via a digital interface after undergoing an analog-to-digital conversion on the chip. Additional features like automatic exposure control, averaging of adjacent pixels, and digital zoom have been implemented, making the sensor suitable for a wide field of applications
Keywords :
CMOS image sensors; calibration; cameras; integrated circuit noise; 288 pixel; 384 pixel; CMOS image sensor; active pixel sensor; adjacent pixel averaging; analog line; analog-to-digital conversion; automatic exposure control; digital interface; digital zoom; dynamic range; fixed pattern noise; logarithmic response; photoreceptor; resolution; self-calibration; single-chip camera; CMOS image sensors; Calibration; Cameras; Circuits; Dynamic range; Lighting; Photodiodes; Photoreceptors; Pixel; Sensor arrays;
Journal_Title :
Solid-State Circuits, IEEE Journal of
