Display Panel Light Collimating Layer for Accurate Fingerprint Sensing
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Solution Overview
Problem
Optical touch technology experiences detection result errors due to diffuse reflection of light from various angles, which affects the accuracy of fingerprint identification in display panels.
Innovation Solution
A display panel manufacturing method involving a photosensitive element layer, a light collimating layer formed by a two-step oxidation method using a metal substrate, and an active light-emitting matrix layer, where the light collimating layer filters reflected light to allow only light within a certain angle range to reach the photosensitive element, improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional optical touch structure without light collimating layer is used, then the structure is simple and manufacturing is easy, but detection precision deteriorates due to reflected light from various directions entering the photosensitive element
Solution Approach 1:
A light collimating layer is introduced as an intermediary component between the photosensitive element layer and the active light-emitting matrix layer. This layer contains light-transmitting regions that guide reflected light from specific angles to the photosensitive elements, while blocking light from other directions, thereby improving detection precision without significantly complicating the overall structure
Solution Approach 2:
The light collimating layer is formed as a porous structure through anodization of aluminum substrate, creating a porous alumina layer with controlled pore size and distribution. This porous structure enables precise angular filtering of light while maintaining structural integrity and optical performance
2Measurement precision
If a light collimating layer is added to filter reflected light, then detection precision improves, but manufacturing complexity increases due to the two-step oxidation method
Solution Approach 1:
The manufacturing process utilizes controlled parameter changes during anodization, including voltage, current density, temperature, and electrolyte composition, to achieve the desired porous alumina structure with specific pore size and thickness. By optimizing these parameters, the process achieves high detection precision while maintaining reasonable manufacturing simplicity
Solution Approach 2:
The two-step oxidation method employs periodic alternation between anodization and etching cycles, where aluminum is oxidized to form alumina, then partially etched to create pores, and re-oxidized to enlarge and regularize the pore structure. This periodic process achieves complex porous morphology through repeated simple operations
3Manufacturing precision
If aluminum substrate is used directly without ultrasonic cleaning and annealing, then manufacturing steps are reduced, but light collimating layer quality deteriorates due to surface impurities and non-uniform oxidation
Solution Approach 1:
Ultrasonic cleaning is performed before anodization to remove surface impurities and oxides from the aluminum substrate, ensuring a clean surface for uniform oxide layer formation. Annealing is also performed preliminarily to relieve internal stresses and improve substrate uniformity, both preparing the substrate for high-quality light collimating layer formation
Solution Approach 2:
Ultrasonic cleaning replaces manual or mechanical cleaning methods by using acoustic cavitation in liquid to remove contaminants. The ultrasonic waves create micro-bubbles that collapse and generate localized high-energy impacts, effectively cleaning surface impurities without mechanical contact or damage
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 enhances the accuracy of light detection and fingerprint identification by filtering ineligible reflected light, resulting in a more precise and reliable optical fingerprint identification process.
Implementation Method 1
the light collimating layer filters some of the reflected light when the light passes through it, allowing only the light within a certain angle range passes
Implementation Method 2
the light collimating layer filters some of the reflected light when the light passes through it, allowing only the light within a certain angle range passes
Implementation Method 3
preparing a porous alumina as the light collimating layer by a two-step oxidation method
Implementation Method 4
putting the aluminum substrate into an electrolyte, and preparing a porous alumina as the light collimating layer by a two-step oxidation method
Data Source
AI summary
The present application discloses a display panel and a manufacturing method therefor, and the method includes steps of: forming a photosensitive element layer, forming a light collimating layer on the photosensitive element layer, and forming an active light-emitting matrix layer on the light collimating layer; where the step of forming the light collimating layer includes: providing a metal substrate, putting the metal substrate into an electrolyte, and preparing a porous oxidized metal as the light collimating layer by a two-step oxidation method.