Glass Light Guide with Nickel Oxide for Uniform Transmittance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Glass plates used as light guides in planar light-emitting devices, such as liquid crystal televisions, experience significant light absorption in the visible light region, leading to reduced brightness and in-plane unevenness of color due to iron ions, making it challenging to maintain a flat internal transmittance spectrum as screen size increases.
Innovation Solution
A glass article with controlled levels of total iron oxide (1-80 mass ppm) and nickel oxide (0.01-4.0 mass ppm) is developed, where the redox of iron is optimized between 0-50%, ensuring a high internal transmittance spectrum flatness (A value ≥ 0.83) by minimizing iron's divalent form and utilizing nickel to prevent sulfur component interaction, thereby reducing light absorption and maintaining color consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a glass plate is used as a light guide for larger screen sizes, then the optical path length increases, but light absorption in the visible light region becomes significant, leading to reduced brightness and color uniformity
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the glass, specifically limiting total iron oxide to 1-80 mass ppm and nickel oxide to 0.01-4.0 mass ppm, while controlling iron redox ratio to 0-50%. These parameter adjustments optimize the glass optical properties to reduce light absorption and maintain brightness uniformity across larger screen areas.
Solution Approach 2:
The patent uses nickel oxide as an intermediary element that prevents sulfur components from interacting with iron ions. This intermediary action stabilizes the iron oxidation state and reduces unwanted light absorption effects, thereby improving overall light transmission uniformity across the glass plate.
2Area of stationary object
If the optical path length is increased for larger screens, then the coverage area increases, but light absorption by iron ions becomes more significant, causing in-plane unevenness of color
Solution Approach 1:
The patent employs parameter changes by establishing specific compositional limits: total iron oxide (1-80 mass ppm), nickel oxide (0.01-4.0 mass ppm), and iron redox ratio (0-50%). These controlled parameters ensure consistent optical properties across the entire light guide area, maintaining color uniformity even with increased optical path length for larger screens.
Solution Approach 2:
Nickel oxide serves as an intermediary that stabilizes the chemical environment for iron ions, preventing sulfur-induced color variations. This intermediary effect ensures uniform color characteristics across the expanded light guide area.
3Reliability
If acrylic plates are replaced by glass plates, then heat resistance and water resistance improve, but light absorption in the visible region increases due to iron content
Solution Approach 1:
The patent applies parameter changes by reducing total iron oxide content to 1-80 mass ppm and controlling nickel oxide at 0.01-4.0 mass ppm with iron redox ratio of 0-50%. These compositional parameters minimize light absorption while preserving the inherent heat and water resistance advantages of glass material.
Solution Approach 2:
The patent converts the typically harmful effect of iron ions (light absorption) into a controllable parameter. By precisely limiting iron content and using nickel as a stabilizer, the harmful light absorption is minimized while retaining the beneficial mechanical and chemical properties of glass.
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 article achieves a high and uniform transmittance in the visible light region, minimizing brightness reduction and color unevenness, while providing improved heat resistance and water resistance compared to acrylic plates, making it suitable for larger screen sizes in liquid crystal display devices.
Implementation Method 1
light absorption inside the glass plate in the visible light region (wavelength of from 380 to 780 nm) tends to be not negligible
Implementation Method 2
has a redox of iron of from 0% to 50%
Data Source
AI summary
To provide a highly transmissive glass and a light guide that allow high internal transmittance of plate glass to be maintained and the internal transmittance spectrum of the plate to be flattened without lowering the redox of iron to a value equal to or more than a certain value. This glass article comprises a glass which includes 1 to 80 mass ppm of total iron oxide (t-Fe2O3) in terms of Fe2O3, has a redox of iron of 0 to 50% and includes 0.01 to 4.0 mass ppm of NiO. The glass article and the light guide comprising the glass article are characterized in that an A value of the internal transmittance spectrum flatness is 0.83 or more.