Electrical System, Method, and Apparatus of Fingerprint Sensor Using Acoustic Impediography

• US 20120092026A1
• Filed: 10/19/2011
• Published: 04/19/2012
• Est. Priority Date: 10/19/2010
• Status: Abandoned Application

• Current Assignee: Sonavation, Inc.
• Original Assignee: Sonavation, Inc.
• Inventors: Liautaud, Christian, Schmitt, Rainer M.
• Application Number:
  US13/277,021
• Publication Number:
  US 20120092026A1
• Time in Patent Office: Days
• US Class Current: 324/649
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

Provided is a method of arranging a plurality of sensor elements to form a sensor array. The method includes arranging the plurality of elements to form two or more sub-rows along an axis. Elements in a first of the two or more sub-rows are positioned in a staggered arrangement with the elements in a second of the two or more sub-rows.

Claims

1. A fingerprint sensor, comprising:

mechanical oscillators, and an electrical system to measure the impedance and/or the electrical current through each mechanical oscillator.

2. The method of claim 1, wherein groups of mechanical oscillators form an array arranged in rows and columns.

3. The method of claim 1, wherein the mechanical oscillators are used to measure the acoustic impedance of the finger.

4. The method of claim 1, wherein the mechanical oscillators are excited with an electrical signal with a specific oscillation frequency to maximize the received signal quality and reduce signal to noise ratio.

5. The method of claim 1, wherein the electrical signal used to excite the mechanical oscillators is generated with one or multiple adjustable transmitters, where the transmitters have adjustable voltage amplitude and/or frequency controls.

6. The method of claim 1, wherein the fingerprint electrical system is comprised of:

current to voltage converters, noise filters, signal conditioning, adjustable gain and offset, analog to digital converters, data storage, and fingerprint data processing unit.

7. The method of claim 6, wherein one or more multiplexers are used to reduce the amount and complexity of the electrical circuit.

8. The method of claim 6, wherein electrical signal sample and hold circuits are used to reduce scan time and increase performance.