Ultrasonic image sensor and related electronic device
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Solution Overview
Problem
Current under-screen fingerprint recognition technologies suffer from issues related to resolution, sensitivity, and signal-to-noise ratio, necessitating improvements.
Innovation Solution
An ultrasonic image sensor is integrated with a sinusoidal pulse signal generating circuit, a piezoelectric layer, and a detection circuit array, which includes an operational amplifier, capacitor unit, and switch configurations to enhance resolution and sensitivity by generating and detecting ultrasonic waves through a cover plate for fingerprint recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional under-screen fingerprint recognition technology is used, then device integration is achieved, but resolution and sensitivity are insufficient
Solution Approach 1:
The patent replaces conventional optical or capacitive sensing mechanisms with ultrasonic wave-based sensing. The ultrasonic image sensor uses piezoelectric elements to generate and detect ultrasonic waves, enabling mechanical vibration-based fingerprint recognition that achieves higher resolution and signal-to-noise ratio compared to conventional methods
Solution Approach 2:
The patent changes the sensing parameter from optical/capacitive fields to ultrasonic mechanical vibrations. By using ultrasonic frequencies and piezoelectric transduction, the system achieves improved measurement precision and reliability in fingerprint recognition
2Measurement precision
If ultrasonic image sensor with detection circuit array is implemented, then resolution and sensitivity are improved, but device complexity increases
Solution Approach 1:
The patent merges the ultrasonic image sensor, detection circuit array, and signal processing circuits into an integrated structure beneath the cover plate. The sensor integrates multiple functional components including piezoelectric elements, detection circuits with operational amplifiers, and signal processing units into a unified system that achieves high resolution while managing complexity through integration
Solution Approach 2:
The ultrasonic image sensor serves multiple functions: generating ultrasonic waves, detecting reflected echoes, processing signals, and producing fingerprint images. This multi-functional integration reduces the need for separate components, managing device complexity while maintaining high measurement precision
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
The solution achieves high resolution and sensitivity, improving pixel size to 50 um and signal-to-noise ratio by 10 times, enhancing the accuracy and reliability of under-screen fingerprint recognition.
Implementation Method 1
the piezoelectric layer is excited to generate ultrasonic wave by means of the sinusoidal pulse signal generated by the sinusoidal pulse signal generating circuit
Implementation Method 2
a reflected echo is generated after the ultrasonic wave is transmitted along the cover plate to the object to be measured, and the reflected echo plate is transmitted back to the piezoelectric layer along the cover
Implementation Method 3
the reflected echo plate is transmitted back to the piezoelectric layer along the cover, so that the piezoelectric layer generates a receiving signal
Data Source
AI summary
The present application discloses an ultrasonic image sensor and a related electronic device. The ultrasonic image sensor is coupled to a sinusoidal pulse signal generating circuit. The ultrasonic image sensor and the sinusoidal pulse signal generating circuit are provided below a cover plate. The ultrasonic image sensor is used to sense a surface pattern of an object to be measured that makes contact with the cover plate from above the cover plate. The ultrasonic image sensor includes: an upper electrode; a lower electrode array; a piezoelectric layer, which is provided between the upper electrode and the lower electrode array, wherein the piezoelectric layer is excited by means of a sinusoidal pulse signal generated by the sinusoidal pulse signal generating circuit so as to generate an ultrasonic wave, the ultrasonic wave is transmitted along the cover plate to the object to be measured and then a reflected echo is generated.