Liquid Crystal Display Light Control Member for Halo Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices with direct type backlights suffer from halo effects due to brightness differences, leading to blurred outlines of bright areas where black is intended, and require improved display quality.
Innovation Solution
Incorporating a light control member with specific optical properties, including a first optically anisotropic layer, a light absorption anisotropic layer with a dichroic substance, and a louver layer, between the polarizers and the direct type backlight, while ensuring specific ratios of brightness at different angles to control transmitted light profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a direct type backlight is used in a liquid crystal display device, then the device structure is simplified and manufacturing cost is reduced, but halo effects occur causing blurred outlines of bright areas where black is intended
Solution Approach 1:
A light control member is introduced as an intermediary component between the direct type backlight and the liquid crystal display panel. This member includes a first optically anisotropic layer and a light absorption anisotropic layer that work together to control light transmission, preventing light from leaking into black display areas while maintaining the simplicity of the direct type backlight structure.
Solution Approach 2:
The light control member is constructed using composite optical materials with specific properties: a first optically anisotropic layer with specific retardation values and a light absorption anisotropic layer with dichroic substances. These composite materials enable selective light control to eliminate halo effects while preserving the advantages of direct type backlighting.
2Object-affected harmful factors
If a light control member is added to suppress halo effects, then display quality is improved, but device structure becomes more complex
Solution Approach 1:
The light control function is extracted as a separate, dedicated component (light control member) with specific optical properties. By isolating this function into a specialized layer structure, the complexity is contained and managed within a defined module rather than being distributed throughout the entire display structure.
Solution Approach 2:
The light control member utilizes precise parameter control of optical properties, including specific retardation ranges (Re and Rth values) and light absorption characteristics. By optimizing these parameters within defined ranges, effective halo suppression is achieved with a relatively simple two-layer structure rather than requiring multiple complex layers.
3Illumination intensity
If the light control member uses specific optically anisotropic layers with controlled retardation, then brightness uniformity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies optimal parameter ranges for the optically anisotropic layers (Re: 50-300 nm, Rth: -500 to 50 nm) that balance brightness uniformity performance with manufacturing feasibility. These parameter ranges are engineered to provide sufficient performance margin while remaining achievable with conventional manufacturing tolerances.
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 effectively suppresses halo occurrences and enhances display quality by optimizing light transmission and absorption, achieving better brightness uniformity and image clarity across various viewing angles.
Implementation Method 1
a first optically anisotropic layer
Implementation Method 2
a first polarizer, a liquid crystal cell, a second polarizer
Implementation Method 3
a light absorption anisotropic layer containing a dichroic substance
Implementation Method 4
a light absorption anisotropic layer containing a dichroic substance
Implementation Method 5
a louver layer in which light transmission bands and light shielding bands are alternately and repeatedly disposed
Implementation Method 6
the transmittance of a liquid crystal changes in accordance with a change in an applied voltage
Data Source
AI summary
The present invention provides a liquid crystal display device having excellent display quality and suppressed occurrence of halo. The liquid crystal display device of the present invention is a liquid crystal display device including, in the following order, a first polarizer, a liquid crystal cell, a second polarizer, and a direct type backlight that uses a point light source, in which a light control member is further provided between the second polarizer and the direct type backlight, and the liquid crystal display device satisfies relationships of the following Expression (1) 70%≤(I20/I0)×100≤90%, Expression (2) 10%≤(I40/I0)×100≤35%, and Expression (3) 1%≤(I60/I0)×100≤20%.