DocumentCode :
3248799
Title :
A pixel-level automatic calibration circuit scheme for sensing initialization of a capacitive fingerprint sensor LSI
Author :
Morimura, H. ; Shigematsu, S. ; Shimamura, T. ; Machida, K. ; Kyuragi, I.
Author_Institution :
Lifestyle & Environ. Technol. Lab., NTT, Kanagawa, Japan
fYear :
2001
fDate :
14-16 June 2001
Firstpage :
171
Lastpage :
174
Abstract :
We propose a pixel-level automatic calibration circuit scheme that initializes a capacitive fingerprint sensor LSI to eliminate the influence of the surface condition, which is degraded by dirt during practical use. The calibration is executed by adjusting the variable capacitance in each pixel to make the sensed signals of all pixels the same. A fingerprint sensor LSI using the 0.5-/spl mu/m CMOS process/sensor process demonstrates that clear fingerprint images are always obtained by the scheme though the surface condition degrades. The proposed scheme ensures consistent clear image capture during long-term usage.
Keywords :
CMOS image sensors; calibration; capacitive sensors; fingerprint identification; large scale integration; 0.5 micron; CMOS process; capacitive fingerprint sensor LSI; clear image capture; dirt degradation; fingerprint images; initialization sensing; long-term usage; pixel-level automatic calibration circuit; surface condition influence elimination; variable capacitance adjustment; CMOS image sensors; CMOS process; Calibration; Capacitance; Capacitive sensors; Circuits; Degradation; Fingerprint recognition; Image matching; Large scale integration;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
VLSI Circuits, 2001. Digest of Technical Papers. 2001 Symposium on
Conference_Location :
Kyoto, Japan
Print_ISBN :
4-89114-014-3
Type :
conf
DOI :
10.1109/VLSIC.2001.934229
Filename :
934229
Link To Document :
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