초록 ▼

A fingerprint sensor includes an array of fingerprint sensing elements and associated active circuits and an impedance matrix filter connected to the active circuits for filtering the signals. The impedance matrix filter preferably comprises a plurality of impedance elements with a respective impeda

A fingerprint sensor includes an array of fingerprint sensing elements and associated active circuits and an impedance matrix filter connected to the active circuits for filtering the signals. The impedance matrix filter preferably comprises a plurality of impedance elements with a respective impedance element connectable between each the active circuit for each fingerprint sensing element and at least one other active circuit for an adjacent fingerprint sensing element. The impedance matrix filter may also include a plurality of switches with a respective switch connected in series with each impedance element. In one embodiment, the switches may be selectively operated to determine ridge flow directions of the fingerprint image. In addition, the ridge flow directions may be used to determined a core location of the fingerprint image. The switches may also be selectively operated to convert a gray scale fingerprint image to a binarized fingerprint image. Accordingly, processing of the fingerprint image may be carried out at the sensor and thereby reduce additional downstream computational requirements. In addition, sets of active circuits may be sequentially powered while the corresponding impedance elements are also sequentially connected. Further, subsets of active circuits may read during the sequential powering.

대표청구항 ▼

[ That which is claimed is:] [1.] A fingerprint sensor comprising:an array of fingerprint sensing elements;a plurality of active circuits with each active circuit connected to a respective fingerprint sensing element;a plurality of impedance elements connected to said active circuits so that a respe

[ That which is claimed is:] [1.] A fingerprint sensor comprising:an array of fingerprint sensing elements;a plurality of active circuits with each active circuit connected to a respective fingerprint sensing element;a plurality of impedance elements connected to said active circuits so that a respective impedance element is selectably connectable between each active circuit for a respective fingerprint sensing element and at least one other active circuit for at least one other respective adjacent fingerprint sensing element to generate signals relating to a fingerprint; anda plurality of switches, with each switch connected in series with a respective impedance element.