# US 11,908,224 B2 · Fingerprint identification structure, driving method thereof and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,224 B2 - Document ID: US11908224B2 - Status: Granted - Kind: B2 - Application number: 17/781,066 - Filed: 2021-05-21 - Published: 2023-01-05 - Granted: 2024-02-20 - Earliest claimed: 2020-06-19 - Assignees: Boe Technology Group Co., Ltd. - Applicants: Boe Technology Group Co., Ltd. - Inventors: Yingming Liu; Xiaoliang Ding; Xiufeng Li; Lei Wang; Yingzi Wang - Web page: https://patentgrep.com/patent/US11908224B2 ## CPC - B06B 1/0629: {Square array} - G06V 40/1306: {non-optical, e.g. ultrasonic or capacitive sensing} - B06B 1/0207: {Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03)} - B06B 1/0692: {with a continuous electrode on one side and a plurality of electrodes on the other side} - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract Disclosed are a fingerprint identification structure, a driving method thereof and an electronic device. The fingerprint identification structure includes: a driving electrode layer; a piezoelectric material layer; a receiving electrode layer, which includes M receiving electrodes; an auxiliary driving electrode layer, which is located at the side of the piezoelectric material layer away from the receiving electrode layer, and is arranged in a layer different from the driving electrode layer; and a first insulating layer, the auxiliary driving electrode layer includes N auxiliary driving electrodes; the N driving electrodes and the N auxiliary driving electrodes are alternately arranged; and the orthographic projection, on the piezoelectric material layer, of an i-th auxiliary driving electrode overlaps with an interval between the orthographic projections, on the piezoelectric material layer, of an i-th driving electrode and an (i+1)-th driving electrode. ## Claims ### Claim 1 A fingerprint identification structure, comprising: a driving electrode layer, comprising N driving electrodes arranged at intervals; a piezoelectric material layer, located on a side of the driving electrode layer; a receiving electrode layer, located on a side of the piezoelectric material layer away from the driving electrode layer, and comprising M receiving electrodes; an auxiliary driving electrode layer, located on a side of the piezoelectric material layer away from the receiving electrode layer, and arranged in a different layer from the driving electrode layer; and a first insulating layer, located between the driving electrode layer and the auxiliary driving electrode layer, wherein the auxiliary driving electrode layer comprises N auxiliary driving electrodes, the N driving electrodes and the N auxiliary driving electrodes are alternately arranged, an orthographic projection of an i-th auxiliary driving electrode on the piezoelectric material layer is overlapped with an interval between an orthographic projection of an i-th driving electrode on the piezoelectric material layer and an orthographic projection of an (i+1)-th driving electrode on the piezoelectric material layer, M is a positive integer greater than or equal to 2, N is a positive integer greater than or equal to 2, and i is a positive integer greater than or equal to 1 and less than N. ### Claim 2 (depends on 1) The fingerprint identification structure according to claim 1, wherein the interval between the orthographic projection of the i-th driving electrode on the piezoelectric material layer and the orthographic projection of the (i+1)-th driving electrode on the piezoelectric material layer completely falls in the orthographic projection of the i-th auxiliary driving electrode on the piezoelectric material layer. ### Claim 3 (depends on 1) The fingerprint identification structure according to claim 1, wherein the i-th driving electrode and the i-th auxiliary driving electrode are configured to receive a same driving signal, and an N-th driving electrode and an N-th auxiliary driving electrode are configured to receive a same driving signal. ### Claim 4 (depends on 1) The fingerprint identification structure according to claim 1, wherein the fingerprint identification structure comprises a fingerprint identification area and a peripheral area surrounding the fingerprint identification area, the i-th driving electrode and the i-th auxiliary driving electrode are electrically connected in the peripheral area, and an N-th driving electrode and an N-th auxiliary driving electrode are electrically connected in the peripheral area. ### Claim 5 (depends on 1) The fingerprint identification structure according to claim 1, wherein an orthographic projection of an N-th auxiliary driving electrode on the piezoelectric material layer is located on a side of an orthographic projection of an N-th driving electrode on the piezoelectric material layer away from an (N−1)-th driving electrode. ### Claim 6 (depends on 1) The fingerprint identification structure according to claim 1, wherein the M receiving electrodes are arranged in an array along a first direction and a second direction, the second direction intersects with the first direction, each of the driving electrodes extends along the first direction, the N driving electrodes are arranged along the second direction, an orthographic projection of each of the N driving electrodes on the piezoelectric material layer is overlapped with at least a part of orthographic projections of the M receiving electrodes arranged along the first direction on the piezoelectric material layer. ### Claim 7 (depends on 6) The fingerprint identification structure according to claim 6, further comprising: a conductive auxiliary layer, located on a side of the piezoelectric material layer away from the driving electrode layer, and arranged in a different layer from the receiving electrode layer, wherein an orthographic projection of the conductive auxiliary layer on the piezoelectric material layer is overlapped with intervals among orthographic projections of the M receiving electrodes on the piezoelectric material layer. ### Claim 8 (depends on 7) The fingerprint identification structure according to claim 7, wherein the conductive auxiliary layer is a conductive mesh, and the conductive mesh is arranged around the M receiving electrodes. ### Claim 9 (depends on 8) The fingerprint identification structure according to claim 8, wherein an orthographic projection of the i-th auxiliary driving electrode on the piezoelectric material layer is overlapped with an orthographic projection of the conductive mesh on the piezoelectric material layer, and an orthographic projection of an N-th auxiliary driving electrode on the piezoelectric material layer is overlapped with the orthographic projection of the conductive mesh on the piezoelectric material layer. ### Claim 10 (depends on 7) The fingerprint identification structure according to claim 7, wherein the conductive auxiliary layer is configured to be connected to a fixed potential or ground. ### Claim 11 (depends on 7) The fingerprint identification structure according to claim 7, further comprising: a second insulating layer, located between the conductive auxiliary layer and the receiving electrode layer. ### Claim 12 (depends on 1) The fingerprint identification structure according to claim 1, wherein the auxiliary driving electrode layer is located on a side of the driving electrode layer away from the piezoelectric material layer. ### Claim 13 (depends on 1) The fingerprint identification structure according to claim 1, further comprising: an acoustic wave reflection layer, located on a side of the auxiliary driving electrode layer away from the piezoelectric material layer; and a third insulating layer, located between the acoustic wave reflection layer and the auxiliary driving electrode layer. ### Claim 14 (depends on 1) The fingerprint identification structure according to claim 1, wherein material of the piezoelectric material layer comprises polyvinylidene fluoride. ### Claim 15 (depends on 1) An electronic device, comprising the fingerprint identification structure according to claim 1. ### Claim 16 (depends on 15) The electronic device according to claim 15, further comprising: a driving circuit, wherein the driving circuit is electrically connected with the N driving electrodes and the N auxiliary driving electrodes respectively, and is configured to apply a same driving signal to the i-th driving electrode and the i-th auxiliary driving electrode, and is configured to apply a same driving signal to an N-th driving electrode and an N-th auxiliary driving electrode. ### Claim 17 (depends on 1) A driving method of a fingerprint identification structure according to claim 1, comprising: applying a driving voltage to the i-th driving electrode and the i-th auxiliary driving electrode to drive the piezoelectric material layer corresponding to the i-th driving electrode and the i-th auxiliary driving electrode to emit an ultrasonic wave; and using the piezoelectric material layer to receive the ultrasonic wave reflected by a fingerprint, and outputting a corresponding fingerprint electrical signal through at least a part of the M receiving electrodes.