US 10,896,311 B2Granted

Acoustic fingerprint representation acquisition technique

AssigneeFingerprint Cards AB

InventorRoy Hansen

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Abstract

An acoustic biometric imaging system for acquiring a fingerprint representation, comprising: a device member; a transmitter transducer having a first fundamental mode resonance frequency, coupled to the device member; drive circuitry; a receiver transducer having a second fundamental mode resonance frequency, coupled to the device member; receiver circuitry; and processing circuitry configured to: control the drive circuitry to provide an electrical excitation signal to the transmit transducer resulting in fundamental mode oscillation of the transmit transducer with a frequency spectrum having a peak frequency being higher than the first fundamental mode resonance frequency and the second fundamental mode resonance frequency; receive, from the receiver circuitry, an electrical sensing signal indicative of an acoustic reflection signal; and determine the fingerprint representation based on the sensing signal received from the receiver circuitry.

Claims15

Dependent claims

An acoustic biometric imaging system for acquiring a fingerprint representation of a finger surface, the acoustic biometric imaging system comprising:

a device member having a finger touch region for receiving a finger touch of the finger surface;
a piezoelectric slab type ultrasound transmitter transducer having a first fundamental mode resonance frequency and being acoustically coupled to the device member in a transducer region of the device member, the transducer region being laterally spaced apart from the finger touch region of the device member;
drive circuitry connected to the transmitter transducer;
a piezoelectric slab type ultrasound receiver transducer having a second fundamental mode resonance frequency and being acoustically coupled to the device member in the transducer region of the device member;
receiver circuitry connected to the receiver transducer;
and
processing circuitry connected to the drive circuitry and the receiver circuitry, the processing circuitry being configured to:
control the drive circuitry to provide an electrical excitation signal to the transmit transducer resulting in fundamental mode oscillation of the transmit transducer with a frequency spectrum having a peak frequency being higher than the first fundamental mode resonance frequency of the transmit transducer and the second fundamental mode resonance frequency of the receiver transducer, the oscillation of the transmit transducer resulting in an acoustic transmit signal being conducted by the device member from the transducer region to the finger touch region;
receive, from the receiver circuitry, an electrical sensing signal indicative of an acoustic reflection signal, resulting from reflection of the acoustic transmit signal at an interface between the finger surface and the device member, being conducted by the device member from the finger touch region;
and
determine the fingerprint representation based on the sensing signal received from the receiver circuitry.

8 more elements

A method of acquiring a fingerprint representation of a finger surface touching a finger touch region of a device member, using an acoustic biometric imaging system including:

a piezoelectric slab type ultrasound transmitter transducer having a first fundamental mode resonance frequency and being acoustically coupled to the device member in a transducer region of the device member, the transducer region being laterally spaced apart from the finger touch region of the device member;
drive circuitry connected to the transmitter transducer;
a piezoelectric slab type ultrasound receiver transducer having a second fundamental mode resonance frequency and being acoustically coupled to the device member in the transducer region of the device member;
receiver circuitry connected to the receiver transducer;
and
processing circuitry connected to the driver circuitry and the receiver circuitry,
the method comprising the steps of:
controlling the drive circuitry to provide an electrical excitation signal to the transmit transducer resulting in fundamental mode oscillation of the transmit transducer with a frequency spectrum having a peak frequency being higher than the first fundamental mode resonance frequency of the transmit transducer and the second fundamental mode resonance frequency of the receiver transducer, the oscillation of the transmit transducer resulting in an acoustic transmit signal being conducted by the device member from the transducer region to the finger touch region;
receiving, from the receiver circuitry, an electrical sensing signal indicative of an acoustic reflection signal, resulting from reflection of the acoustic transmit signal at an interface between the finger surface and the device member, being conducted by the device member from the finger touch region;
and
determining the fingerprint representation based on the sensing signal received from the receiver circuitry.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/716,591Filed 17 Dec 2019
Priority: SE 19501396 Feb 2019
Published: US 2020/0250392 A16 Aug 2020
Granted: 19 Jan 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G06V 40/1306
Sensors therefor: non-optical, e.g. ultrasonic or capacitive sensing
B06B 1/06
Making use of electrical energy: operating with piezoelectric effect or with electrostriction
G06F 3/043
Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means: using propagating acoustic waves
G06F 21/32
User authentication: using biometric data, e.g. fingerprints, iris scans or voiceprints