Fingerprint Sensor Light-Blocking Layers for Ambient Noise Control
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Solution Overview
Problem
Ambient light and light generated by information products affect the accuracy of fingerprint recognition, necessitating improvements in signal to noise ratio for enhanced performance.
Innovation Solution
Incorporating a light blocking layer with specific openings to reduce light noise entering the sensor unit, thereby increasing the signal to noise ratio and improving fingerprint recognition accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ambient light blocking structures are added to reduce light noise, then signal to noise ratio improves, but device complexity increases
Solution Approach 1:
The patent implements nested light blocking layers where a first light blocking layer is disposed within a second light blocking layer. The first layer has a first opening and the second layer has a second opening, creating a nested structure that progressively filters ambient light from multiple angles while maintaining a compact form factor. This nested arrangement reduces light noise effectively without proportionally increasing device complexity.
Solution Approach 2:
The patent addresses light noise by introducing spatial dimensionality through multiple stacked layers with different opening patterns. Instead of simply increasing the size of a single blocking layer, the solution transitions to a multi-dimensional stacked architecture where each layer contributes to ambient light rejection from different angular perspectives, thereby improving signal to noise ratio without linearly increasing complexity.
2Object-affected harmful factors
If multiple light blocking layers with different opening widths are used, then ambient light interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by designing different light blocking layers with distinct opening characteristics. The first light blocking layer has a first opening with a specific width, while the second light blocking layer has a second opening with a different width. Each layer is optimized locally to block ambient light from specific angular ranges, creating a cumulative effect that reduces overall ambient light interference while maintaining manufacturability through standardized layer designs.
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 light blocking layer effectively reduces ambient light interference, enhancing the signal to noise ratio and improving the accuracy of fingerprint recognition.
Implementation Method 1
Since the electronic device includes a light blocking layer, the light noise entering a sensor unit can be reduced
Data Source
AI summary
An electronic device includes a first substrate, a second substrate overlapped with the first substrate and having a first side and a second side opposite to the first side, a sensor unit disposed between the first substrate and the second substrate, a first blocking layer disposed on the first side, and a second blocking layer disposed on the sensor unit. The second side is disposed between the sensor unit and the first side. The first blocking layer has a first opening, and the second blocking layer has a second opening. A width of the first opening is smaller than a width of the second opening.