US 11,776,296 B2
Ultrasonic fingerprint recognition circuit, method for driving same, and display device
Bo Wang, Beijing (CN); and Fuqiang Li, Beijing (CN)
Assigned to BOE Technology Group Co., Ltd., Beijing (CN)
Filed by BOE Technology Group Co., Ltd., Beijing (CN)
Filed on Oct. 20, 2021, as Appl. No. 17/506,522.
Claims priority of application No. 202110225761.7 (CN), filed on Mar. 1, 2021.
Prior Publication US 2022/0277157 A1, Sep. 1, 2022
Int. Cl. G06V 40/13 (2022.01); H01L 25/18 (2023.01); H10K 59/65 (2023.01)
CPC G06V 40/1306 (2022.01) [H01L 25/18 (2013.01); H10K 59/65 (2023.02)] 19 Claims
OG exemplary drawing
 
1. 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.