Optical Pattern Layer for Fingerprint Sensitivity
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Solution Overview
Problem
Existing electronic devices with fingerprint recognition functionality face challenges in achieving improved sensitivity due to limitations in the design and manufacturing of the sensing layers.
Innovation Solution
The electronic device incorporates a biometric information sensing layer under the display panel, paired with an optical pattern layer that includes a light blocking layer, an intermediate layer, and a metal layer, strategically patterned to control the incident angle of light and enhance fingerprint recognition sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional sensing layer is used for fingerprint recognition, then the device structure is simple, but the fingerprint recognition sensitivity is insufficient
Solution Approach 1:
The optical pattern layer is segmented into multiple functional layers: a light blocking layer with light blocking portions, an intermediate layer, and a transmissive layer with transmissive portions. This segmentation allows each layer to perform its specific function optimally, improving fingerprint recognition sensitivity while maintaining manageable structural complexity
Solution Approach 2:
The patent introduces a vertical stacking dimension by placing the optical pattern layer between the display panel and the biometric information sensing layer. This vertical arrangement creates multiple optical paths and incident angles for light reflected from the fingerprint, enhancing sensitivity without increasing the horizontal footprint of the device
2Measurement precision
If the optical pattern layer is added to improve light control, then the fingerprint recognition sensitivity is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The light blocking layer is formed first as a preliminary structure, followed by the intermediate layer and transmissive layer. This sequential formation with preliminary patterning simplifies the overall manufacturing process by establishing a foundation structure before adding more complex optical elements
Solution Approach 2:
The patent optimizes specific parameters such as the thickness of the light blocking layer (4-5 μm) and the ratio of light blocking layer thickness to transmissive portion width (2:1). These parameter specifications provide clear manufacturing targets, making the complex optical structure easier to manufacture with consistent quality
3Measurement precision
If the light blocking layer thickness is increased to control light better, then the incident angle control is improved, but the light transmission is reduced
Solution Approach 1:
The patent identifies and optimizes the thickness parameter of the light blocking layer to a specific range (4-5 μm) that achieves the desired incident angle control while maintaining sufficient light transmission. This parameter optimization resolves the trade-off between light control precision and light intensity
Solution Approach 2:
The optical pattern layer uses different materials with different optical properties in different regions: the light blocking layer uses non-transmissive materials for incident angle control, while the transmissive layer uses transmissive materials for light transmission. This local differentiation allows simultaneous achievement of both incident angle control and light transmission
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 significantly improves fingerprint recognition sensitivity by controlling the incident angle of light reflected by the fingerprint, thereby enhancing the accuracy and reliability of fingerprint recognition.
Implementation Method 1
controlling the incident angle of light reflected by the fingerprint
Data Source
AI summary
An electronic device includes a display panel, a biometric information sensing layer disposed under the display panel and including a sensor, and an optical pattern layer disposed between the display panel and the biometric information sensing layer and including a plurality of transmissive portions and a light blocking portion. The light blocking portion includes a light blocking layer disposed on the biometric information sensing layer, an intermediate layer disposed on the light blocking layer, and a metal layer disposed on the intermediate layer.