Title:
【発明の名称】容量性マトリックスを有する指紋感知装置及びこのような装置を組み込んだシステム
Document Type and Number:
Japanese Patent JP2001523349
Kind Code:
A
Abstract:
A fingerprint sensing device comprises an array of capacitive type sense elements (12) each having a sense electrode (14) for forming, together with an overlying fingerprint portion, a capacitance and a transistor (16) connected between the sense electrode and first and second associated address conductors (18, 20). The transistor is arranged with its gate connected to the sense electrode such that, due to the effect of the capacitance and parasitic capacitances in the transistor, a selection signal applied to the first conductor (18) causes the transistor to be turned on or to be held off in the presence of a fingerprint valley or ridge overlying the sense electrode. Fast sampling of the transistor on/off currents produced in the second conductor (20) is possible and improved noise rejection and high signal to noise ratio is obtained. A further transistor (17) may be included in the sense element which is operable to remove any unwanted charge on the gate of the first-mentioned transistor.
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Inventors:
Halkin Herald F
Application Number:
JP54445599A
Publication Date:
November 20, 2001
Filing Date:
March 04, 1999
Export Citation:
Assignee:
Konin Krekka Philips Electronics NV
International Classes:
G01B7/34; A61B5/117; G06K9/00; G06T1/00; (IPC1-7): G01B7/34; A61B5/117; G06T1/00
Attorney, Agent or Firm:
Akihide Sugimura (2 outside)