Optical Filter Density Gradient Reduces Light Diffraction
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Solution Overview
Problem
Optical filters, such as those used in liquid-crystal display devices, suffer from light diffraction and leakage at the boundaries between light-blocking and light-transmitting regions, which degrades filter performance.
Innovation Solution
An optical filter design featuring a light-blocking region with an optical density gradation in the normal direction from the contact point to the light-transmitting region, where the optical density is lowest at the contact point and increases in the in-plane direction, either continuously or discontinuously, to prevent diffraction phenomena.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light-blocking region and light-transmitting region are disposed adjacent to each other in a predetermined pattern, then the optical filter can transmit light of specific wavelengths while blocking other wavelengths, but light diffraction occurs at the boundary between regions causing filter performance degradation
Solution Approach 1:
The patent applies local quality by creating an optical density gradation within the light-blocking region, where the optical density varies from the contact point with the light-transmitting region toward the interior of the light-blocking region. This gradual change in optical density at the boundary area reduces light diffraction while maintaining the overall light-blocking function, thus improving filter performance without sacrificing the wavelength selection capability
Solution Approach 2:
The patent changes the optical density parameter of the light-blocking region by introducing a gradation structure. The optical density is designed to be lowest at the contact point with the light-transmitting region and increase toward the interior, creating a continuous or discontinuous gradient. This parameter change effectively reduces light diffraction at the boundary while preserving the light-blocking function
2Ease of manufacture
If the optical density of the light-blocking region is uniform, then the manufacturing process is simple, but light diffraction occurs at the boundary causing display performance degradation
Solution Approach 1:
The patent introduces local quality variation within the light-blocking region by creating an optical density gradation. The optical density is lowest at the contact point with the light-transmitting region and increases toward the interior, forming a gradient structure. This local variation reduces light diffraction and leakage at boundaries while maintaining relatively simple manufacturing processes
Solution Approach 2:
The patent adds a dimensional aspect to the optical density distribution by creating a gradient in the thickness direction of the light-blocking region. Instead of uniform optical density, the structure varies in the depth dimension, with thinner or less dense regions at the contact points and thicker or denser regions in the interior, effectively reducing light leakage
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 significantly reduces light leakage and improves filter performance by minimizing diffracted light intensity across the light-transmitting region, enhancing the overall display quality of liquid-crystal display devices.
Implementation Method 1
the light-blocking region has an optical density gradation relative to light in the normal direction, from the contact point to the light-transmitting region along an in-plane direction
Data Source
AI summary
Provided is an optical filter having a light-transmitting region of transmitting light having a predetermined wavelength and a light-blocking region disposed adjacent to the light-transmitting region to block out the light, wherein the light-blocking region has an optical density gradation relative to light in the normal direction, from the contact point to the light-transmitting region along an in-plane direction, and the optical density is the smallest at the contact point to the light-transmitting region.