Wavy Prism Sheet for LCD Moiré Fringe Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LCD devices, the uniform spacing of lenses in the prism sheet and the black matrix can create optical gratings that lead to the formation of Moiré fringes, degrading display characteristics.
Innovation Solution
A prism sheet with a wavy surface where lenses of the same shape are positioned on the upper surface, breaking the uniform spacing condition and preventing the formation of Moiré fringes, and optionally incorporating micro cavities in the base to diffuse light and eliminate the need for a second diffuser.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lenses are uniformly spaced on the prism sheet, then the manufacturing is simple and consistent, but optical gratings form causing Moiré fringes that deteriorate display characteristics
Solution Approach 1:
The patent applies asymmetry by making the spacing between adjacent lenses non-uniform on the prism sheet. Specifically, the distance between neighboring lenses varies, creating an asymmetric pattern that disrupts the formation of optical gratings. This non-uniform spacing prevents the periodic interference patterns that cause Moiré fringes, thereby improving display characteristics while maintaining manufacturing feasibility through injection molding processes.
2Illumination intensity
If a second diffuser is added to homogenize light beams, then light diffusion is improved, but the device complexity and number of components increase
Solution Approach 1:
The patent merges the functions of the prism sheet and the second diffuser into a single integrated component. The prism sheet itself is designed with both light-concentrating prism structures and light-diffusing micro-cavity structures. This combination allows the single component to perform both light concentration and homogenization functions, eliminating the need for a separate second diffuser and reducing overall device complexity.
Solution Approach 2:
The prism sheet is designed with multi-functionality by incorporating both concentrating and diffusing capabilities. The upper surface contains prism structures for light concentration while simultaneously containing micro-cavity structures for light diffusion. This universal design allows one component to fulfill multiple optical functions that would traditionally require separate elements.
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 wavy surface design improves display characteristics by eliminating Moiré fringes and potentially enhances light diffusion, thereby improving the overall brightness and clarity of the LCD device.
Implementation Method 1
The first and second diffuser 194, 196 are used to homogenize the planar light beams converted by the LGP 193
Implementation Method 2
The prism sheet 195 is used to convert scattered planar light beams into concentrated planar light beams for promoting a brightness of the planar light beams
Data Source
AI summary
An exemplary prism sheet includes a base including an upper surface and a plurality of lenses disposed on the upper surface. The upper surface is a wavy surface. A liquid crystal display device using the prism sheet is also provided.