Dual Polarizer Fingerprint Sensor Noise Reduction
Solution Overview
Problem
Fingerprint recognition technologies face efficiency issues due to screen light interference with optical fingerprint identification modules, leading to reduced fingerprint collection efficiency.
Innovation Solution
Incorporating a first and second polarizer with the same polarization direction below the screen, where the first polarizer filters screen light noise directed towards the optical fingerprint identification module, and the second polarizer filters noise reflected away from the module, thereby reducing optical noise and improving image accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a single polarizer is used to filter screen light noise, then optical noise is reduced, but some fingerprint image light is also lost
Solution Approach 1:
The patent divides the polarizer into two separate polarizers (first polarizer and second polarizer) positioned at different locations. The first polarizer is positioned to receive light from the screen, and the second polarizer is positioned to receive light from the fingerprint. Each polarizer independently filters light in its specific path, allowing selective noise reduction without compromising fingerprint image light transmission.
2Object-affected harmful factors
If the polarizer is positioned to filter noise directed towards the optical fingerprint identification module, then noise is reduced, but the configuration complexity increases
Solution Approach 1:
The patent combines the noise filtering function with the existing screen structure by integrating the first polarizer into the screen assembly. This merging approach allows the polarizer to utilize the screen's light path without requiring separate complex filtering systems, thereby reducing overall device complexity while maintaining effective noise reduction.
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 effectively attenuates screen light noise, enhancing the accuracy and efficiency of fingerprint image collection by ensuring correct fingerprint image light is not lost, thus improving the overall fingerprint recognition process.
Implementation Method 1
A polarization direction of the first polarizer is the same with the polarization direction of the second polarizer. The first polarizer and the second polarizer are both configured to filter a first optical noise from a screen light of the screen
Data Source
AI summary
Provided is an electronic device. The electronic device includes a screen provided with a first polarizer, a second polarizer arranged below the screen, and an optical fingerprint identification module arranged below the second polarizer. The polarization direction of the first polarizer is the same with the polarization direction of the second polarizer. The first polarizer and the second polarizer are configured to filter a first optical noise. The second polarizer is configured to filter a second optical noise. The first optical noise is light from screen light of the screen and directing to the optical fingerprint recognition module. The second optical noise is light from the screen light, directing away from the optical fingerprint recognition module and reflected by a glass cover on an outer side of the screen.