Ultrasonic Fingerprint Sensor Same-Plane Structure
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Solution Overview
Problem
Existing fingerprint recognition technologies face challenges in achieving high accuracy and minimizing interference between signal transmission and reception, particularly in display devices where space and aperture ratio are concerns.
Innovation Solution
An ultrasonic fingerprint sensor is integrated into a display substrate with a driving structure and a receiving structure, both located in the same plane, utilizing piezoelectric materials and electrodes to transmit and receive ultrasonic signals for fingerprint recognition, allowing for improved touch accuracy and reduced interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the driving structure and receiving structure are arranged in different planes (vertical stacking), then the aperture ratio is improved, but signal interference occurs between transmission and reception
Solution Approach 1:
The patent transitions from vertical stacking (different planes) to horizontal arrangement (same plane) of the driving and receiving structures. This dimensional change in spatial configuration eliminates signal interference while maintaining effective ultrasonic wave transmission for fingerprint recognition.
2Object-generated harmful factors
If the driving structure and receiving structure are arranged in the same plane, then signal interference is avoided, but the aperture ratio decreases
Solution Approach 1:
The patent applies local quality by positioning the driving and receiving structures in non-adjacent areas within the same plane, specifically utilizing different regions of the black matrix. This localized spatial distribution maintains aperture ratio while preventing signal interference between the structures.
3Measurement precision
If the ultrasonic wave transmission distance is increased to ensure effective finger contact, then touch accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent merges the fingerprint sensing function with the display substrate by integrating the driving and receiving structures directly into the display panel structure. This combination eliminates the need for separate fingerprint sensor modules, reducing overall device complexity while maintaining effective ultrasonic wave transmission distance for accurate touch detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances touch accuracy by ensuring ultrasonic waves effectively reach the finger, while maintaining the display's aperture ratio and avoiding signal interference, allowing for clear recognition of fingerprint valleys and ridges.
Implementation Method 1
a first piezoelectric material layer... configured to transmit an ultrasonic signal
Implementation Method 2
a second piezoelectric material layer... configured to receive the ultrasonic signal reflected by a finger, and convert the ultrasonic signal into an electrical signal
Data Source
AI summary
The present disclosure provides an ultrasonic fingerprint sensor, a display substrate, a driving method thereof and a display device. The ultrasonic fingerprint sensor includes: a base substrate; a driving structure provided on the base substrate and configured to transmit an ultrasonic signal; a receiving structure provided on the base substrate and configured to receive the ultrasonic signal reflected by a finger, and convert the ultrasonic signal into an electrical signal for determining fingerprint information, the driving structure and the receiving structure are provided in a same plane. Since the driving structure and the receiving structure of the ultrasonic fingerprint sensor of the present disclosure are in a same plane, the driving structure can be closer to the touch body (for example, a finger), which is advantageous for the ultrasonic waves generated by the driving structure to reach the finger to improve the touch accuracy.