Multicomponent Glass Plate for High Transmittance Light Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional glass light guide plates for large liquid crystal display devices suffer from insufficient internal transmittance, brightness non-uniformity, and color non-uniformity due to increased optical path length, which is exacerbated by heat resistance issues and light absorption in the visible region.
Innovation Solution
A multicomponent oxide glass plate with specific composition and thickness, optimized for effective optical path lengths of 25 to 200 cm, achieving an average internal transmittance of at least 80% and chromaticity Y of 90% in the visible region, with controlled iron and iron oxide content to minimize light absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a glass light guide plate is used to increase heat resistance, then heat resistance is improved, but internal transmittance and brightness uniformity deteriorate due to increased optical path length
Solution Approach 1:
The patent applies parameter changes by precisely controlling the iron content (Fe2O3) to 100 ppm or less and optimizing the glass composition ratios of SiO2, Al2O3, B2O3, and other components. This changes the optical parameters of the glass material to achieve both high heat resistance (Tg ≥ 530°C) and high internal transmittance (≥80%) even with long optical path lengths of 25-200 cm.
Solution Approach 2:
The patent uses composite glass materials with a specific multicomponent formulation combining SiO2 (40-70%), Al2O3 (5-20%), B2O3 (5-15%), and controlled amounts of Fe2O3 (≤0.01%). This composite composition achieves synergistic effects: SiO2 provides structural integrity and heat resistance, Al2O3 enhances chemical stability, B2O3 improves glass formation and lowers melting point, while controlled Fe2O3 minimizes light absorption.
2Area of stationary object
If the optical path length is increased to support larger display sizes, then display size capability is improved, but brightness uniformity and color uniformity deteriorate
Solution Approach 1:
The patent changes the optical parameters by controlling Fe2+ content (calculated as Fe2O3) to 30 ppm or less and Fe2O3 to 100 ppm or less. This parameter optimization reduces light absorption and scattering, maintaining brightness uniformity across large display areas with optical path lengths of 25-200 cm and achieving chromaticity Y ≥ 90%.
Solution Approach 2:
The patent applies local quality by ensuring uniform distribution of glass composition throughout the material, with specific control over Fe2+ and Fe2O3 concentrations. This creates consistent optical properties across the entire glass plate, eliminating local variations in brightness and color that would occur with longer optical path lengths.
3Stability of the object's composition
If iron content is increased to improve glass stability, then chemical stability is improved, but light absorption in the visible region increases
Solution Approach 1:
The patent applies parameter changes by optimizing the Fe2O3 content to 100 ppm or less and Fe2+ content to 30 ppm or less. This precise parameter control minimizes light absorption in the visible region (380-780 nm) while maintaining adequate chemical stability through the overall glass composition, particularly the high SiO2 (40-70%) and Al2O3 (5-20%) content.
Solution Approach 2:
The patent applies color changes by controlling the iron content to achieve a neutral, transparent appearance in the visible region. By limiting Fe2O3 to ≤100 ppm and Fe2+ to ≤30 ppm, the glass maintains high chromaticity Y ≥ 90% and avoids the yellowish or greenish tints that would result from higher iron content, while still providing sufficient chemical stability.
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 glass plate provides enhanced heat resistance and uniform light transmission, addressing the challenges of brightness and color uniformity while supporting larger display sizes with improved optical performance.
Implementation Method 1
a light guide plate 20 to transmit light from a light source (not shown) disposed on a side surface to the interior by total reflection and to emit the light flatly
Implementation Method 2
The light-scattering part 40 scatters light totally reflected in the interior and emits the light from the light-emitting surface
Data Source
AI summary
To provide a glass plate excellent in the internal transmittance of light rays in the visible region.A glass plate consisting of multicomponent oxide glass, which has an effective optical path length of from 25 to 200 cm, a thickness of from 0.5 to 10 mm, and an average internal transmittance in the visible region of at least 80% and a chromaticity Y of tristimulus values in the XYZ colorimetric system as defined in JIS Z8701 (Appendix) of at least 90%, under the effective optical path length.