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US 11,776,296 B2Granted
Ultrasonic fingerprint recognition circuit, method for driving same, and display device
AssigneeBoe Technology Group Co., Ltd.
InventorsBo Wang, Fuqiang Li
Life of this patent
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Abstract
Disclosed is an ultrasonic fingerprint recognition circuit. In the ultrasonic fingerprint recognition circuit, an ultrasonic sensor generates an AC echo signal based on an echo signal upon the fingerprint detection, and a signal converting unit converts the AC echo signal to a DC signal and transmit the DC signal to the signal output unit to generate a fingerprint recognition signal by a signal output unit.
Claims19
An ultrasonic fingerprint recognition circuit, comprising:
- an ultrasonic sensor, wherein the ultrasonic sensor is configured to generate an ultrasonic signal for fingerprint detection based on an input signal, and generate an AC echo signal based on an echo signal formed by reflection of the ultrasonic signal by a fingerprint;
- a signal converting unit, wherein one end of the signal converting unit is connected to the ultrasonic sensor, and the signal converting unit is configured to receive the AC echo signal and convert the AC echo signal to a DC signal;
- and
- a signal output unit, wherein the signal output unit is connected to the other end of the signal converting unit, and the signal output unit is configured to receive the DC signal and generate a fingerprint recognition signal based on the DC signal,
- wherein the signal converting unit comprises:
- an inverter;
- wherein the inverter is connected to a first voltage signal terminal and a second voltage signal terminal, and the inverter is configured to convert a positive voltage signal and a negative voltage signal in the AC echo signal to the DC signal based on a first voltage signal input by the first voltage signal terminal and a second voltage signal input by the second voltage signal terminal, and wherein the first voltage signal and the second voltage signal are configured to adjust magnitude of the DC signal.
4 more elements
A method for driving an ultrasonic fingerprint recognition circuit, applicable to the ultrasonic fingerprint recognition circuit, wherein the ultrasonic fingerprint recognition circuit comprises:
- an ultrasonic sensor, a signal converting unit, and a signal output unit, one end of the signal converting unit being connected to the ultrasonic sensor, and the signal output unit being connected to the other end of the signal converting unit;
- the method comprising:
- in a transmission phase, generating an ultrasonic signal for fingerprint detection by the ultrasonic sensor based on an input signal;
- and
- in a reception phase, receiving an echo signal formed by the reflection of a fingerprint on the ultrasonic signal by the ultrasonic sensor, and generating an AC echo signal based on the echo signal;
- receiving the AC echo signal by the signal converting unit and converting the AC echo signal to a DC signal;
- and receiving the DC signal by the signal output unit, and generating a fingerprint recognition signal based on the DC signal,
- wherein the signal converting unit comprises:
- an inverter;
- wherein the inverter is connected to a first voltage signal terminal and a second voltage signal terminal, and the inverter is configured to convert a positive voltage signal and a negative voltage signal in the AC echo signal to the DC signal based on a first voltage signal input by the first voltage signal terminal and a second voltage signal input by the second voltage signal terminal, and wherein the first voltage signal and the second voltage signal are configured to adjust magnitude of the DC signal.
7 more elements
A display device, comprising:
- a display module and a fingerprint recognition unit, wherein the fingerprint recognition unit is attached to either a light emitting surface or a backlight surface of the display module;
- wherein the fingerprint recognition unit comprises:
- an ultrasonic fingerprint recognition circuit;
- the ultrasonic fingerprint recognition circuit comprising:
- an ultrasonic sensor, wherein the ultrasonic sensor is configured to generate an ultrasonic signal for fingerprint detection based on an input signal, and generate an AC echo signal based on an echo signal formed by reflection of the ultrasonic signal by a fingerprint;
- a signal converting unit, wherein one end of the signal converting unit is connected to the ultrasonic sensor, and the signal converting unit is configured to receive the AC echo signal and convert the AC echo signal to a DC signal;
- and
- a signal output unit, wherein the signal output unit is connected to the other end of the signal converting unit, and the signal output unit is configured to receive the DC signal and generate a fingerprint recognition signal based on the DC signal,
- wherein the signal converting unit comprises:
- an inverter;
- wherein the inverter is connected to a first voltage signal terminal and a second voltage signal terminal, and the inverter is configured to convert a positive voltage signal and a negative voltage signal in the AC echo signal to the DC signal based on a first voltage signal input by the first voltage signal terminal and a second voltage signal input by the second voltage signal terminal, and wherein the first voltage signal and the second voltage signal are configured to adjust magnitude of the DC signal.
8 more elements
Dependencies are inferred from the claim text.