Ultrasonic fingerprint authentication based on beam forming
First Claim
Patent Images
1. A method of generating a three-dimensional representation of a fingerprint using ultrasound, the method comprising:
- scanning, by a device, a first region of a fingertip with a first directed series of ultrasonic pulses to determine a first location in a first dimension and a second dimension of a first ridge of a plurality of ridges, the ultrasonic pulses of the first directed series having a first ultrasonic frequency;
scanning, by the device, a second region of the fingertip with second directed series of ultrasonic pulses to determine a second location in the first dimension and the second dimension of a second ridge of the plurality of ridges, the ultrasonic pulses of the second directed series having a second ultrasonic frequency that is different from the first ultrasonic frequency, wherein the scanning of the first region overlaps in time with the scanning of the second region;
emitting, by the device, diffuse ultrasound at a third ultrasonic frequency having a first wavelength toward the fingertip;
determining, by the device, a third location in the first dimension and the second dimension where a first peak magnitude of first reflections occurs at a fourth ultrasonic frequency corresponding to a second wavelength, wherein the second wavelength is equal to the first wavelength or a harmonic of the first wavelength;
determining that a first depth in a third dimension of a first valley at the third location is equal to the second wavelength;
emitting, by the device, diffuse ultrasound at a fifth ultrasonic frequency having a third wavelength toward the fingertip;
determining, by the device, a fourth location in the first dimension and the second dimension where a second peak magnitude of second reflections occurs at a sixth ultrasonic frequency corresponding to a fourth wavelength, wherein the fourth wavelength is equal to the third wavelength or a harmonic of the third wavelength; and
determining that a second depth in the third dimension of a second valley at the fourth location is equal to the fourth wavelength;
combining the first location of the first ridge and the second location of the second ridge to generate a two-dimensional representation of locations of the plurality of ridges of the fingerprint; and
overlaying the two-dimensional representation of the locations of the plurality of ridges on the first depth of the first valley at the third location and the second depth of the second valley at the fourth location to generate the three-dimensional representation of the fingerprint.
1 Assignment
0 Petitions
Accused Products
Abstract
An ultrasonic finger print authentication system that generates a three-dimensional representation of a fingerprint. High frequency sound waves are used as a medium for imaging finer details of the patterns on a fingertip, including the ridge and valley formations. Multiple frequencies and beam-forming are used to quickly map the ridges. Acoustic resonance is used to determine the depths of the intervening valleys.
-
Citations
20 Claims
-
1. A method of generating a three-dimensional representation of a fingerprint using ultrasound, the method comprising:
-
scanning, by a device, a first region of a fingertip with a first directed series of ultrasonic pulses to determine a first location in a first dimension and a second dimension of a first ridge of a plurality of ridges, the ultrasonic pulses of the first directed series having a first ultrasonic frequency; scanning, by the device, a second region of the fingertip with second directed series of ultrasonic pulses to determine a second location in the first dimension and the second dimension of a second ridge of the plurality of ridges, the ultrasonic pulses of the second directed series having a second ultrasonic frequency that is different from the first ultrasonic frequency, wherein the scanning of the first region overlaps in time with the scanning of the second region; emitting, by the device, diffuse ultrasound at a third ultrasonic frequency having a first wavelength toward the fingertip; determining, by the device, a third location in the first dimension and the second dimension where a first peak magnitude of first reflections occurs at a fourth ultrasonic frequency corresponding to a second wavelength, wherein the second wavelength is equal to the first wavelength or a harmonic of the first wavelength; determining that a first depth in a third dimension of a first valley at the third location is equal to the second wavelength; emitting, by the device, diffuse ultrasound at a fifth ultrasonic frequency having a third wavelength toward the fingertip; determining, by the device, a fourth location in the first dimension and the second dimension where a second peak magnitude of second reflections occurs at a sixth ultrasonic frequency corresponding to a fourth wavelength, wherein the fourth wavelength is equal to the third wavelength or a harmonic of the third wavelength; and determining that a second depth in the third dimension of a second valley at the fourth location is equal to the fourth wavelength; combining the first location of the first ridge and the second location of the second ridge to generate a two-dimensional representation of locations of the plurality of ridges of the fingerprint; and overlaying the two-dimensional representation of the locations of the plurality of ridges on the first depth of the first valley at the third location and the second depth of the second valley at the fourth location to generate the three-dimensional representation of the fingerprint. - View Dependent Claims (2, 3, 4)
-
-
5. A computing device comprising:
-
an array of microphones arranged in a first dimension and a second dimension; an array of speakers interspersed among microphones of the array of microphones; a processor; a memory including instruction operable to be executed by the processor to perform a set of actions to configure the processor to; scan regions of a fingertip using a first directed ultrasonic pulse emitted by a first group of speakers of the array of speakers and a second directed ultrasonic pulse emitted by a second group of speakers, to determine locations of ridges of the fingertip relative to the first dimension and the second dimension; emit, from the array of speakers, first diffuse ultrasound having a first wavelength; receive first signal data from the array of microphones, the first signal data including first reflections of the first diffuse ultrasound from the fingertip; determine a first resonance location in the first dimension and the second dimension where the first diffuse ultrasound produces resonance based on a first peak magnitude of the first reflections included in first signal data; determine a first depth of a first valley of the fingertip in a third dimension orthogonal to the first and second dimensions based on the first wavelength or a harmonic of the first wavelength, the first valley coinciding with the first resonance location; emit, from the array of speakers, second diffuse ultrasound having a second wavelength; receive second signal data from the array of microphones, the second signal data including second reflections of the second diffuse ultrasound from the fingertip; determine a second resonance location in the first dimension and the second dimension where the second diffuse ultrasound produces resonance based on a second peak magnitude of second reflections included in the second signal data; determine a second depth of a second valley of the fingertip in the third dimension orthogonal to the first and second dimensions based on the second wavelength or a harmonic of the second wavelength, the second valley coinciding with the second resonance location; and generate a three-dimensional representation of a fingerprint of the fingertip including the locations of the ridges, the first depth of the first valley, and the second depth of the second valley. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
-
-
13. A non-transitory computer-readable storage medium storing processor-executable instructions for controlling a computing device, comprising program code to configure the computing device to:
-
scan regions of a fingertip using a first directed ultrasonic pulse emitted by a first group of speakers of an array of speakers and a second directed ultrasonic pulse emitted by a second group of speakers, to determine locations of ridges of the fingertip relative to the first dimension and the second dimension; emit, from the array of speakers, first diffuse ultrasound having a first wavelength; receive first signal data from an array of microphones, the first signal data including first reflections of the first diffuse ultrasound from the fingertip; determine a first resonance location in the first dimension and the second dimension where the first diffuse ultrasound produces resonance based on a first peak magnitude of the first reflections included in first signal data; determine a first depth of a first valley of the fingertip in a third dimension orthogonal to the first and second dimensions based on the first wavelength or a harmonic of the first wavelength, the first valley coinciding with the first resonance location; emit, from the array of speakers, second diffuse ultrasound having a second wavelength; receive second signal data from the array of microphones, the second signal data including second reflections of the second diffuse ultrasound from the fingertip; determine a second resonance location in the first dimension and the second dimension where the second diffuse ultrasound produces resonance based on a second peak magnitude of second reflections included in the second signal data; determine a second depth of a second valley of the fingertip in the third dimension orthogonal to the first and second dimensions based on the second wavelength or a harmonic of the second wavelength, the second valley coinciding with the second resonance location; and generate a three-dimensional representation of a fingerprint of the fingertip including the locations of the ridges, the first depth of the first valley, and the second depth of the second valley. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
Specification