Under-screen Fingerprint Module Polarizer Noise Filtering
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Solution Overview
Problem
Current under-screen fingerprint modules in electronic devices face challenges with optical noise interference, affecting recognition accuracy and success rates, due to reflected and direct light noise from the screen.
Innovation Solution
Incorporating a first polarizer on the screen and a second polarizer in the under-screen fingerprint module, both with the same polarization direction, to filter out reflected and direct optical noise, thereby improving fingerprint image collection and recognition accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If an under-screen fingerprint module is used to enable full-screen display, then the display area is increased, but optical noise from reflected and direct light reduces fingerprint recognition accuracy
Solution Approach 1:
A polarizer is introduced as an intermediary component between the screen and the fingerprint sensor. The polarizer filters out reflected light (optical noise) while allowing direct light from the fingerprint to pass through, thereby resolving the contradiction between maintaining full-screen display and ensuring accurate fingerprint recognition.
Solution Approach 2:
The solution changes the optical parameters of the system by introducing polarized light filtering. By controlling the polarization state of light, the system can distinguish between reflected light (noise) and direct light (signal), thus improving recognition accuracy while maintaining the under-screen configuration.
2Length of stationary object
If the under-screen fingerprint module is positioned closer to the screen to reduce module thickness, then device thickness is reduced, but optical noise interference increases
Solution Approach 1:
The polarizer serves as a mediator that enables the fingerprint module to be positioned closer to the screen by effectively filtering optical noise. This allows the system to achieve thin module design without sacrificing recognition accuracy, as the polarizer compensates for the increased optical noise that would otherwise result from closer positioning.
3Measurement precision
If traditional fingerprint modules are used with physical buttons, then fingerprint recognition accuracy is maintained, but device design flexibility and screen utilization are reduced
Solution Approach 1:
The solution extracts the fingerprint sensing function from the traditional physical button location and integrates it into the under-screen area. By using the polarizer to filter optical noise, the system can perform fingerprint recognition within the display area, thereby freeing up physical buttons for other functions and increasing design flexibility.
Solution Approach 2:
The under-screen area, which previously served only for display, is made multi-functional by incorporating fingerprint sensing capability. The polarizer enables this area to simultaneously serve as both display and authentication zone, increasing the versatility of the device design.
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 effectively reduces optical noise interference, enhancing the accuracy and efficiency of fingerprint recognition by absorbing specific light vibrations, thus improving the overall performance of under-screen fingerprint modules.
Implementation Method 1
the screen being arranged with a first polarizer configured to filter a first optical noise
Implementation Method 2
a second polarizer arranged in the body; a polarization direction of the second polarize is configured to be the same as that of the first polarizer; the second polarizer is configured to filter the first optical noise; the second polarizer is further configured to filter a second optical noise
Data Source
AI summary
An under-screen fingerprint module for an electronic device is provided. The electronic device includes a screen defining a preset area and arranged with a first polarizer to filter first optical noise, and a back cover; the fingerprint module being arranged between the two. At least part of a vertical projection of the preset area on the back cover and that of the fingerprint module are overlapped. The fingerprint module includes a second polarizer to filter the first optical noise as reflected light of first light being part of emitted light of the screen and irradiated along a direction perpendicular to the screen and away from the back cover. A polarization direction of the second polarize and the first polarizer are same. The second polarizer is further configured to filter second optical noise as second light being part of the emitted light and irradiated along a direction towards the back cover.