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CN-115953811-B - Adaptive control method and device for ultrasonic sensor array

CN115953811BCN 115953811 BCN115953811 BCN 115953811BCN-115953811-B

Abstract

The embodiment of the application provides a self-adaptive control method of an ultrasonic sensor array, which is arranged below a screen protection film, and comprises the steps of acquiring pressing data of the ultrasonic sensor array under finger pressing and non-pressing data of the ultrasonic sensor array under finger lifting; and carrying out data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film is changed, and adaptively adjusting the configuration of the ultrasonic sensor array according to the change. The embodiment of the application can be used for automatically and adaptively adjusting the configuration of the ultrasonic sensor array by quickly determining whether the screen protection film is installed, removed or replaced.

Inventors

  • JIANG JIE

Assignees

  • 深圳市汇顶科技股份有限公司

Dates

Publication Date
20260508
Application Date
20221229

Claims (13)

  1. 1. An adaptive control method for an ultrasonic sensor array disposed below a screen protective film, comprising: Acquiring pressing data of the ultrasonic sensor array under finger pressing and non-pressing data of the ultrasonic sensor array when the finger is lifted; performing data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film changes or not; adaptively adjusting the configuration of the ultrasonic sensor array according to the change; The method for acquiring the pressing data of the ultrasonic sensor array under the pressing of the finger and the non-pressing data of the ultrasonic sensor array when the finger is lifted further comprises the following steps: Acquiring an Nth fingerprint signal of the ultrasonic sensor array under the pressing of an Nth finger and an Nth reference signal when the ultrasonic sensor array is lifted after the pressing of the Nth finger, wherein N is a positive integer; Acquiring an N-1 fingerprint signal of the ultrasonic sensor array under the N-1 finger pressing and an N-1 reference signal when the ultrasonic sensor array is lifted after the N-1 finger pressing; The step of performing data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film changes, and the method further comprises the following steps: Performing data processing according to the N-th fingerprint signal and the N-1-th reference signal to determine whether the state of the screen protection film is changed or not The method for acquiring the pressing data of the ultrasonic sensor array under the pressing of the finger and the non-pressing data of the ultrasonic sensor array when the finger is lifted further comprises the following steps: Acquiring an Nth fingerprint signal of the ultrasonic sensor array under the pressing of an Nth finger and an Nth reference signal when the ultrasonic sensor array is lifted after the pressing of the Nth finger, wherein N is a positive integer; Acquiring an N-1 fingerprint signal of the ultrasonic sensor array under the N-1 finger pressing and an N-1 reference signal when the ultrasonic sensor array is lifted after the N-1 finger pressing; The step of performing data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film changes, and the method further comprises the following steps: And carrying out data processing according to the Nth reference signal and the N-1 th reference signal to judge whether the state of the screen protection film is changed.
  2. 2. The adaptive control method of an ultrasonic sensor array according to claim 1, wherein said determining whether a screen saver state has changed by data processing based on said nth fingerprint signal and said N-1 th reference signal, further comprises: Judging whether the fingerprints are successfully matched according to the Nth fingerprint signal and the N-1 th reference signal; If the matching is successful, calculating fingerprint contrast according to the Nth fingerprint signal and the N-1 th reference signal; and if the ratio of the fingerprint contrast of the Nth fingerprint signal to the fingerprint contrast of the N-1 th reference signal is smaller than a first threshold value, judging that the state of the screen protection film is changed.
  3. 3. The adaptive control method of an ultrasonic sensor array according to claim 1, wherein said determining whether a screen saver state has changed based on data processing of said nth reference signal and said N-1 th reference signal, further comprises: calculating the spatial region inconsistency of the Nth reference signal and the N-1 th reference signal; If the ratio of the spatial region inconsistency of the nth reference signal to the spatial region inconsistency of the N-1 th reference signal is less than a second threshold; and judging that the screen protection film is changed.
  4. 4. The adaptive control method of an ultrasonic sensor array according to claim 3, further comprising: If the ratio of the spatial region inconsistency of the nth reference signal to the spatial region inconsistency of the nth-1 reference signal is not less than a second threshold; calculating the inconsistency of the space region according to the difference value of the N-th reference signal and the N-1-th reference signal; If the spatial region inconsistency of the difference values is greater than a third threshold; and judging that the screen protection film is changed.
  5. 5. The method for adaptive control of an ultrasonic sensor array according to claim 1, When N is 1, acquiring a1 st fingerprint signal of the ultrasonic sensor array under the 1 st finger pressing and a1 st reference signal when the ultrasonic sensor array is lifted after the 1 st finger pressing; acquiring an initial reference signal of the ultrasonic sensor array before the 1 st finger pressing and lifting operation; And respectively carrying out data processing according to the 1 st fingerprint signal and the 1 st reference signal and the initial reference signal to judge whether the state of the screen protection film is changed.
  6. 6. The method of any one of claims 1-5, wherein the change includes one of installation, removal, or replacement of a screen saver.
  7. 7. The adaptive control method of an ultrasonic sensor array according to any one of claims 1 to 5, wherein the adaptively adjusting the configuration of an ultrasonic sensor array according to the variation further comprises: triggering a recalibration process after judging that the screen protection film changes; detecting a finger pressing and lifting operation; Collecting an Mth moment fingerprint signal and an Mth moment reference signal of a plurality of time interval windows, wherein M is a positive integer; Calculating the screen echo delay after the screen protection film state is changed according to the film thickness and the film sound velocity; judging whether the fingerprints are successfully matched according to the Mth moment fingerprint signal and the Mth-1 moment reference signal; If the matching is successful, calculating fingerprint contrast of the time interval windows; and selecting a time interval window with the maximum fingerprint contrast ratio, updating and configuring the screen echo delay.
  8. 8. The adaptive control method of an ultrasonic sensor array according to claim 7, wherein the calculating the screen echo delay after the screen saver state is changed according to the film thickness and the film sound velocity, further comprises: The screen echo delay after the screen protection film state is changed is equal to the screen echo delay before the screen protection film state is changed by adding and subtracting the echo time of different film thicknesses.
  9. 9. The method for adaptive control of an ultrasonic sensor array according to claim 8, Acquiring an Mth moment reference signal corresponding to a time interval window with the maximum fingerprint contrast; Judging the saturation of the screen echo signal according to the M time reference signal; Adjusting the integration times of the fingerprint signals according to the saturation of the screen echo signals; Updating and configuring the integration times in a time interval window with the maximum fingerprint contrast; and controlling the ultrasonic sensor array to be adjusted in a self-adaptive mode according to the screen echo delay and the integration times.
  10. 10. An ultrasonic sensor array self-adaptive control device, the ultrasonic sensor array is set up in screen protection film below, its characterized in that includes: the first data acquisition module is used for acquiring the pressing data of the ultrasonic sensor array under the pressing of the finger and the non-pressing data of the finger when the finger is lifted; the data processing module is used for carrying out data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film changes or not; the correction module is used for adaptively adjusting the configuration of the ultrasonic sensor array according to the change; the first data acquisition module is further configured to: Acquiring an Nth fingerprint signal of the ultrasonic sensor array under the pressing of an Nth finger and an Nth reference signal when the ultrasonic sensor array is lifted after the pressing of the Nth finger, wherein N is a positive integer; Acquiring the N-1 fingerprint signal of the ultrasonic sensor array under the N-1 finger pressing and the N-1 reference signal when the ultrasonic sensor array is lifted after the N-1 finger pressing, or The first data acquisition module is further configured to: Acquiring an Nth fingerprint signal of the ultrasonic sensor array under the pressing of an Nth finger and an Nth reference signal when the ultrasonic sensor array is lifted after the pressing of the Nth finger, wherein N is a positive integer; Acquiring an N-1 fingerprint signal of the ultrasonic sensor array under the N-1 finger pressing and an N-1 reference signal when the ultrasonic sensor array is lifted after the N-1 finger pressing; The step of performing data processing according to the pressing data and the non-pressing data to judge whether the state of the screen protection film changes, and the method further comprises the following steps: And carrying out data processing according to the Nth reference signal and the N-1 th reference signal to judge whether the state of the screen protection film is changed.
  11. 11. The ultrasonic sensor array adaptive control apparatus according to claim 10, further comprising: the fingerprint matching judging module is used for judging whether the fingerprint is successfully matched according to the Nth fingerprint signal and the N-1 th reference signal; The contrast calculating module is used for calculating fingerprint contrast according to the Nth fingerprint signal and the N-1 th reference signal if the fingerprint matching judging module judges that the fingerprint matching is successful; and the film state judging module is used for judging that the screen protection film state changes if the ratio of the fingerprint contrast of the Nth fingerprint signal to the N-1 th reference signal is smaller than a first threshold value.
  12. 12. The ultrasonic sensor array adaptive control apparatus according to claim 10 or 11, characterized by comprising: The triggering module is used for triggering the recalibration process after the screen protection film is judged to be changed; The detection module is also used for detecting the finger pressing and lifting operation; The second data acquisition module is used for acquiring an Mth moment fingerprint signal and an Mth moment reference signal of a plurality of time interval windows, wherein M is a positive integer; The correction parameter calculation module is used for calculating the screen echo delay after the screen protection film state is changed according to the film thickness and the film sound velocity; The fingerprint matching judging module is also used for judging whether the fingerprint is successfully matched or not according to the Mth moment fingerprint signal and the Mth-1 moment reference signal; The contrast calculating module is used for calculating fingerprint contrast of the time interval windows if the matching is successful; and the correction module is also used for selecting a time interval window with the maximum fingerprint contrast ratio to update and configure the screen echo delay.
  13. 13. The apparatus of claim 12, wherein the sensor array comprises a plurality of sensors, The second data acquisition module is also used for acquiring an M-th time reference signal corresponding to a time interval window with the maximum fingerprint contrast; The correction parameter calculation module is also used for judging the saturation of the screen echo signal according to the M-th time reference signal, and adjusting the integration times of the fingerprint signal according to the saturation of the screen echo signal; And the correction module is used for updating and configuring the integration times in a time interval window with the maximum fingerprint contrast ratio, and controlling the ultrasonic sensor array to adaptively adjust according to the screen echo delay and the integration times.

Description

Adaptive control method and device for ultrasonic sensor array Technical Field The present application relates to an ultrasonic sensor array, and more particularly, to an adaptive control method and apparatus for an ultrasonic sensor array. Background The ultrasonic fingerprint recognition system acquires a fingerprint image through an ultrasonic sensor array. Unlike optical imaging, the piezoelectric transducer inside an ultrasonic sensor generates ultra-high frequency sound waves that penetrate the skin epidermis layer and form a fingerprint by measuring reflected wave energy The image is little affected by the minutiae of the fingerprint surface, and can be recognized even in a state of being stained with dirt or wet hands. Compared with the capacitor and optical fingerprint identification in the prior art, the method has more advantages in safety (anti-counterfeiting) and accuracy. If the surface of the screen of the device is covered with a screen protection film, the reflection intensity of the sound wave may be seriously affected, and the whole phase of the sound wave signal is shifted, so that details of a fingerprint image are not obvious, the resolution is reduced, and the fingerprint recognition rate is reduced. 5 Summary of the invention The embodiment of the application provides a self-adaptive control method and a self-adaptive control device for an ultrasonic sensor array, which can quickly determine whether the state of a screen protection film changes, namely one of installation, removal or replacement, and readjust the configuration of the ultrasonic sensor array, so that the influence of the screen protection film change on fingerprint images and fingerprint identification is reduced. A first aspect of the embodiment of the present application provides an adaptive control method for an ultrasonic sensor array disposed under a screen protective film, including acquiring pressing data of the ultrasonic sensor array under finger pressing The method comprises the steps of carrying out data processing according to the pressed data and the non-pressed data, judging whether the state of a screen protection film is changed or not, and adaptively adjusting the configuration of an ultrasonic sensor array according to the change. In some possible implementations, the acquiring the compression data and the compression data of the ultrasonic sensor array under finger compression The method comprises the steps of acquiring an N fingerprint signal of the ultrasonic sensor array under the pressing of an N finger and an N reference signal of the ultrasonic sensor array after the pressing of the N finger, wherein N is a positive integer, acquiring the ultrasonic sensor The device comprises an N-1 th fingerprint signal pressed by an N-1 th finger and an N-1 th reference signal lifted after the N-1 th finger is pressed by the array, wherein the device is used for judging whether the state of a screen protection film changes according to data processing of pressing data and non-pressing data, and the device also comprises a device for judging whether the state of the screen protection film changes according to the N-1 th fingerprint signal and the N-1 th reference signal. In some possible implementation manners, the step of performing data processing according to the nth fingerprint signal and the N-1 th reference signal to determine whether the state of the screen protection film is changed, further includes the steps of determining whether the fingerprint is successfully matched according to the nth fingerprint signal and the N-1 th reference signal, calculating fingerprint contrast according to the nth fingerprint signal and the N-1 th reference signal if the fingerprint is successfully matched, and determining that the state of the screen protection film is changed if the ratio of the fingerprint contrast of the nth fingerprint signal to the fingerprint contrast of the N-1 th reference signal is smaller than a first threshold value. In some possible implementation manners, the method for acquiring the pressing data of the ultrasonic sensor array under the pressing of the finger and the non-pressing data when the finger is lifted further comprises the steps of acquiring an nth fingerprint signal of the ultrasonic sensor array under the pressing of the nth finger and an nth reference signal when the ultrasonic sensor array is lifted after the pressing of the nth finger, wherein N is a positive integer, acquiring an nth-1 reference signal of the ultrasonic sensor array under the pressing of the nth-1 finger and the lifting of the nth-1 finger, and judging whether the state of the screen protection film is changed according to the pressing data and the non-pressing data through data processing, and judging whether the state of the screen protection film is changed according to the nth reference signal and the nth-1 reference signal through data processing. In some possible implementations, the determining whe