A new sensing and digital-conversion scheme with adaptive image-quality adjustment for a fingerprint sensor chip

Author

Shigematsu, Satoshi ; Morimura, Hiroki ; Machida, Katsuyuki

Author_Institution

NTT Lifestyle & Environ. Technol. Labs., Kanagawa, Japan

fYear

2001

fDate

6/23/1905 12:00:00 AM

Firstpage

396

Lastpage

400

Abstract

A new fingerprint sensing and digital-conversion scheme is proposed. In this scheme, transforming the sensed signal to a time axis widens the dynamic range of the signal, and the transformed signal is converted to the digital signal with variable range and offset. These features make it possible to sense various fingerprints clearly. We also propose a flow that adjusts the quality of the fingerprint image adaptively. The effectiveness of the scheme on sensing fingerprints clearly was confirmed by a test chip fabricated using 0.5-μm CMOS/sensor process. This scheme assists in precise user identification for a safe and comfortable networked world

Keywords

CMOS integrated circuits; analogue-digital conversion; capacitive sensors; fingerprint identification; 0.5 micron; CMOS/sensor process; digital-conversion scheme; dynamic range; fingerprint sensing; time axis; transformed signal; user identification; CMOS image sensors; CMOS process; Capacitance; Circuits; Dynamic range; Fingerprint recognition; Fingers; Image converters; Image matching; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC/SOC Conference, 2001. Proceedings. 14th Annual IEEE International

Conference_Location

Arlington, VA

Print_ISBN

0-7803-6741-3

Type

conf

DOI

10.1109/ASIC.2001.954734

Filename

954734