Double Metal Layer Ultrasonic Touch Sensor for Thick Panel Penetration
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Solution Overview
Problem
Ultrasonic fingerprint recognition devices face energy attenuation issues due to the thickness of panels, leading to incorrect identification results, as the initial ultrasonic wave energy is not sufficiently maintained after reflection.
Innovation Solution
A touch recognition device with double metal layers is used to enhance the signal energy by generating resonance in the piezoelectric material layer, where the first metal layer surrounds transparent electrodes and the second metal layer is isolated from the transparent conductive layer by a dielectric layer, allowing for higher voltage input and maintaining energy in the reflected ultrasonic wave.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single metal layer is used with piezoelectric material, then the device structure is simple, but the ultrasonic wave energy is insufficient to penetrate thick panels
Solution Approach 1:
The patent combines two metal layers (first metal layer and second metal layer) with piezoelectric material layers to form an integrated ultrasonic generation structure. This merging of multiple functional layers creates a synergistic effect that generates stronger ultrasonic waves capable of penetrating thick panels, while the layers are integrated in a compact arrangement that manages structural complexity.
Solution Approach 2:
The patent uses composite material structures consisting of alternating metal layers and piezoelectric material layers. This composite construction allows the device to leverage the electrical conductivity of metals and the piezoelectric properties of the ceramic materials, creating a unified structure that generates high-energy ultrasonic waves for thick panel penetration.
2Strength
If the panel thickness is increased for protection, then the device durability is improved, but the ultrasonic wave energy attenuation increases leading to incorrect identification
Solution Approach 1:
The patent employs piezoelectric materials that convert electrical signals into mechanical vibrations at ultrasonic frequencies. These high-frequency vibrations generate ultrasonic waves with sufficient energy to penetrate thick protective panels and return reflected signals strong enough to ensure accurate fingerprint identification, thus maintaining reliability despite increased panel thickness.
3Use of energy by moving object
If the initial ultrasonic wave energy is increased, then the reflected wave energy is sufficient for accurate identification, but the device requires more complex electrical signal generation
Solution Approach 1:
The patent uses periodic electrical signals applied to the piezoelectric material layers to generate corresponding periodic mechanical vibrations. This periodic action at ultrasonic frequencies creates sustained ultrasonic waves that maintain energy throughout transmission through thick panels and upon reflection, ensuring sufficient energy returns for accurate fingerprint sensing.
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 double metal layer configuration increases the energy of the ultrasonic wave to penetrate thicker glass cover plates, ensuring accurate fingerprint recognition by maintaining sufficient energy in the reflected wave, thus improving identification results.
Implementation Method 1
the piezoelectric material layer is disposed on the transparent conductive layer and the first metal layer... generate resonance to enhance the signal of the identification element
Implementation Method 2
the characteristics of ultrasonic reflection are used to calculate the fingerprint pattern by receiving the ultrasonic reflection transmitted back from fingerprint ridges and fingerprint grooves
Implementation Method 3
uses double metal layers to provide electrical signals, and generate resonance to enhance the signal of the identification element
Data Source
AI summary
The disclosure provides a touch recognition device, including a display device and manufacturing method thereof. The touch recognition device includes a substrate, a thin film transistor layer, a transparent conductive layer, a first metal layer, a piezoelectric material layer and a second metal layer. The transparent conductive layer is disposed on an end of the thin film transistor layer, and the transparent conductive layer includes a plurality of transparent electrodes. The first metal layer is adjacent to the plurality of transparent electrodes. The piezoelectric material layer is disposed on the transparent conductive layer and the first metal layer. The second metal layer is disposed on the piezoelectric material layer to achieve the effect of increasing voltage of signals and power of ultrasound.