Optical Sensor Signal Detection for Under-Display Fingerprint
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Solution Overview
Problem
Existing signal detection methods for under-screen fingerprint identification face challenges in accurately collecting signal variations due to signal coupling phenomena during the display process, leading to errors in fingerprint identification accuracy.
Innovation Solution
The method involves resetting optical sensors at specific time points before and after the pixel units perform display, collecting signals at these points to offset errors caused by signal coupling, and calculating difference values to determine accurate signal variation amounts, thereby improving fingerprint identification accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical sensors are used to detect light signals above the LCD screen for fingerprint identification, then fingerprint identification capability is enabled, but signal coupling phenomena occur during display causing measurement errors
Solution Approach 1:
The patent applies preliminary action by resetting the optical sensor at a first time point before the pixel unit performs display, and collecting signals at multiple predetermined time points before display occurs. This preliminary measurement approach captures the baseline signal state before display-induced signal coupling contaminates the measurement, thereby resolving the contradiction between enabling fingerprint identification and maintaining measurement precision.
Solution Approach 2:
The patent implements periodic action by collecting signals at multiple predetermined time points within each display cycle, including before and after the pixel unit performs display. This periodic sampling strategy allows the system to distinguish between genuine fingerprint-induced signal variations and display-induced signal coupling effects, thus maintaining measurement precision while enabling continuous fingerprint identification capability.
2Productivity
If signals are collected during the display process, then continuous monitoring is achieved, but signal coupling errors occur reducing detection accuracy
Solution Approach 1:
The patent resolves this contradiction by implementing periodic signal collection at multiple predetermined time points within each display cycle. By sampling signals both before and after the pixel unit performs display, the system achieves continuous monitoring capability while using the periodic pattern to identify and eliminate display-induced signal coupling errors, thereby maintaining high detection accuracy.
Solution Approach 2:
The patent applies feedback by comparing signals collected at different time points (before and after display) to identify and compensate for signal coupling effects. This feedback mechanism allows the system to continuously adjust and correct measurements, maintaining both continuous monitoring capability and high signal detection accuracy despite display-induced interference.
3Measurement precision
If multiple time points are used for signal collection, then measurement accuracy is improved, but system complexity increases
Solution Approach 1:
The patent reduces system complexity by applying preliminary action - establishing a baseline signal measurement at predetermined time points before display occurs. This preliminary measurement approach simplifies the overall process by providing a reference point that eliminates the need for complex real-time compensation algorithms, thereby improving measurement accuracy without proportionally increasing system complexity.
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 approach enhances the accuracy of signal detection and fingerprint identification by minimizing errors from signal coupling, ensuring precise signal variation measurement and improved safety in electronic devices.
Implementation Method 1
an under-screen fingerprint identification technology is currently proposed to perform fingerprint identification according to image information above a display screen, the image information being collected below the display screen by utilizing the characteristic that ultrasonic waves and light can penetrate through the display screen
Implementation Method 2
an optical sensor is provided below the LCD screen to detect a light signal above the LCD screen
Data Source
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AI summary
The present disclosure provides a signal detection method and an electronic device, which belongs to the field of electronic technology. The method includes: resetting (301, 901) each optical sensor (102, 1121, 1321) at a first time point; collecting (302, 902) a first signal, a second signal, a third signal and a fourth signal output by the optical sensor (102, 1121, 1321) at the first time point, a second time point, a third time point, and a fourth time point; obtaining (303, 905) a first difference value between the first signal and the second signal and a second difference value between the third signal and the fourth signal, and determining a sum of the first difference value and the second difference value as a signal variation amount in a current cycle.