Touch Panel With Via-Hole Light Blocking For Fingerprint Accuracy
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Solution Overview
Problem
Current touch panels and display apparatuses lack effective fingerprint identification capabilities, as existing technologies struggle to accurately distinguish and capture fingerprint ridges and valleys due to interference from ambient light and inefficient light distribution.
Innovation Solution
A touch panel design featuring an array substrate with organic light emitting diodes and a fingerprint identification substrate, utilizing a light blocking layer with strategically placed via-holes that reflect light from a touch terminal's ridges and valleys onto fingerprint identification devices, ensuring precise light irradiation and analysis of fingerprint patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional touch panel without specialized light path control is used, then the structure is simple, but fingerprint identification accuracy is insufficient
Solution Approach 1:
The touch panel is segmented into distinct functional zones: pixel units for display, via-holes for light transmission, light blocking layer for optical isolation, and fingerprint identification devices for biometric detection. This segmentation allows each component to perform its specific function optimally while maintaining overall system accuracy.
Solution Approach 2:
The via-hole acts as an intermediary optical element that selectively transmits light from the organic light emitting diode through the light blocking layer to the fingerprint identification devices. This intermediary structure enables precise light path control without requiring complex mechanical or electronic systems.
2Measurement precision
If light from pixel units is allowed to reach fingerprint identification devices directly, then more light is available for identification, but signal crosstalk occurs reducing identification precision
Solution Approach 1:
The light blocking layer extracts and blocks unwanted light paths from the pixel units, allowing only the specific light paths that pass through the via-holes to reach the fingerprint identification devices. This extraction of harmful light paths eliminates signal crosstalk while preserving useful identification signals.
Solution Approach 2:
The light blocking layer is positioned selectively between pixel units and the fingerprint identification substrate, creating local optical isolation zones. This local quality control ensures that light from specific pixel units is blocked from reaching fingerprint identification devices that do not correspond to the touched area, preventing crosstalk.
3Illumination intensity
If the aperture of via-holes is made large to improve light transmission, then more light reaches fingerprint identification devices, but light blocking efficiency decreases allowing more crosstalk
Solution Approach 1:
The via-hole aperture is optimized to a specific range (1 μm to 100 μm) that balances light transmission efficiency and optical isolation performance. This parameter optimization ensures sufficient light reaches the fingerprint identification devices while maintaining effective blocking of crosstalk signals from adjacent pixel units.
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 design enhances fingerprint identification accuracy by isolating light reflected from the touch terminal's surface, reducing signal crosstalk and improving light distribution, resulting in more precise identification of fingerprint ridges and valleys.
Implementation Method 1
light emitted by the organic light emitting diode is reflected by a surface of a touch terminal to irradiate onto more than one of the fingerprint identification devices
Implementation Method 2
the via-hole meets a principle of pinhole imaging, so that light emitted by the organic light emitting diode is reflected by a surface of a touch terminal to irradiate onto more than one of the fingerprint identification devices
Implementation Method 3
light reflected by others except the surface of the touch terminal is blocked by the light blocking layer and cannot pass through the via-hole
Implementation Method 4
the ridges and the valleys may be identified by analyzing intensity of light received by the fingerprint identification devices
Data Source
AI summary
There is provided a touch panel comprising an array substrate and a fingerprint identification substrate. The array substrate comprises a first base and pixel units provided on the first base, each pixel unit comprises a thin film transistor and an organic light emitting diode, the fingerprint identification substrate comprises a second base and fingerprint identification devices provided on the second base, the fingerprint identification substrate is located at a side of the first base distal to the pixel units, the array substrate further comprises a light blocking layer and a via-hole, the via-hole is formed in the light blocking layer so that light emitted by the organic light emitting diode is reflected by a surface of a touch terminal, the surface of the touch terminal comprises ridges and valleys, light reflected by the ridges and the valleys passes through the via-hole to irradiate onto different fingerprint identification devices respectively.