Multiplexer for a piezo ceramic identification device

• US 20070126315A1
• Filed: 06/27/2006
• Published: 06/07/2007
• Est. Priority Date: 03/23/2000
• Status: Active Grant

• Current Assignee: Sonavation, Inc.
• Original Assignee: Cross Match Technologies Incorporated (Assa Abloy AB)
• Inventors: Scott, Walter
• Granted Patent: US 7,514,842 B2
• Time in Patent Office: Days
• US Class Current: 310/318
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

Provided is a multiplexer for a biometric apparatus. The multiplexer includes a plurality of first conductors coupled to the first ends of piezo ceramic elements in corresponding rows and a plurality of first switches each of which is coupled to a respective one of the first conductors and a plurality of second conductors coupled to the second ends of piezo ceramic elements in corresponding columns. The multiplexer also includes a plurality of second switches each of which is coupled to a respective one of the second conductors. The first conductors are approximately orthogonal to the second conductors, and the first switches are controlled to couple a signal output from an output port of the signal generator to a particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements. The second switches are controlled to couple a signal associated with the particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements to an input port of the processor.

Claims

1. A multiplexer for a biometric apparatus including a sensor coupled to a processor, the sensor having at least twenty five thousand piezo ceramic elements arranged in a two-dimensional array and spaced at a pitch equal to or less than approximately one hundred microns, each of the piezo ceramic elements having a first end and a second end, the multiplexer comprising:

a plurality of first conductors coupled to the first ends of piezo ceramic elements in corresponding rows;

a plurality of first switches each of which is coupled to a respective one of the first conductors;

a plurality of second conductors coupled to the second ends of piezo ceramic elements in corresponding columns; and

a plurality of second switches each of which is coupled to a respective one of the second conductors,

wherein the first conductors are approximately orthogonal to the second conductors, and

wherein the first switches are controlled to couple a signal output from an output port of the signal generator to a particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements, and

wherein the second switches are controlled to couple a signal associated with the particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements to an input port of the processor.