High-Refraction Optical Glass Composition for Chromatic Aberration Correction
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Solution Overview
Problem
The high cost and scarcity of tantalum and germanium, essential components in high-refractivity low-dispersion glasses, pose challenges in maintaining stable supply and glass stability, while existing glasses with poor coloring properties reduce transmitted light quantity in optical systems.
Innovation Solution
An optical glass composition with specific ranges of SiO2, B2O3, La2O3, Gd2O3, Y2O3, ZnO, TiO2, Nb2O5, and reduced Ta2O5 and GeO2 content, optimized to achieve refractive index of 1.89-2.0 and Abbe's number of 32-38, ensuring excellent glass stability and reduced coloring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of Ta2O5 is introduced to secure glass stability in the high refractivity region, then glass stability is improved, but the cost increases and supply stability deteriorates due to rarity and high price of tantalum
Solution Approach 1:
The patent changes the compositional parameters by reducing Ta2O5 content from traditional high amounts (5-25 mass%) to low amounts (0-5 mass%) while compensating with optimized ratios of other components (SiO2/B2O3 ratio and rare earth oxide composition) to maintain glass stability and achieve the desired refractive index of 1.85 or more
Solution Approach 2:
The patent creates a composite glass system combining multiple components in specific proportions: SiO2 (5-32%), B2O3 (5-32%), rare earth oxides (La2O3, Gd2O3, Y2O3) (45-65%), ZnO (0.5-10%), and TiO2/Nb2O5 (1-20%), where the synergistic interaction of these materials achieves high refractivity with low dispersion while reducing dependence on rare and expensive Ta2O5
2Temperature
If germanium is used to increase refractive index without impairing glass stability, then refractive index is improved, but cost increases due to germanium being more expensive than tantalum
Solution Approach 1:
The patent replaces expensive germanium (GeO2) with more cost-effective combinations of common materials (SiO2, B2O3, rare earth oxides, ZnO, TiO2, Nb2O5) that can achieve the same refractive index function, thereby reducing material cost while maintaining optical performance
Solution Approach 2:
The patent changes the compositional parameters by limiting GeO2 to 0-5 mass% and instead optimizing the ratios of SiO2/B2O3 (0.3-1.0) and rare earth oxides to achieve the desired refractive index of 1.85 or more without relying on expensive germanium
3Ease of manufacture
If glass with poor coloring properties is used, then manufacturing cost is reduced, but transmitted light quantity decreases in optical systems with large aperture and thickness
Solution Approach 1:
The patent optimizes compositional parameters (SiO2/B2O3 ratio, rare earth oxide composition, ZnO content, TiO2/Nb2O5 content) to achieve the optimal balance between coloring properties and light transmittance, resulting in glass with low dispersion and high refractive index that maintains excellent optical transmission even in thick lenses with large apertures
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 provides a stable and cost-effective supply of high-refractivity low-dispersion optical glass with improved glass stability and reduced coloring, enhancing the performance of optical systems by maintaining high light transmittance and correcting chromatic aberration.
Implementation Method 1
a lens formed of a high-refractivity low-dispersion glass ensures that an optical system can be downsized while correcting chromatic aberration
Data Source
AI summary
A high-refractivity low-dispersion optical glass that can be stably supplied and has excellent glass stability and that has coloring reduced, composed of in mass %, 5 to 32% of total of SiO2 and B2O2, 45 to 65% of total of La2O2, Gd2O2 and Y2O2, 0.5 to 10% of ZnO, 1 to 20% of total of TiO2 and Nb2O5, and optionally other components. The optical glass has a refractive index nd of 1.89 to 2.0, an Abbe's number νd of 32 to 38 and a coloring degree λ70 of 430 nm or less.