Optical Material for Spectacle Lenses Blocking Blue Light
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Solution Overview
Problem
Existing optical materials fail to effectively block harmful ultraviolet rays and blue light in the 400-420 nm range while maintaining transparency and avoiding coloration, which is essential for eye protection and aesthetic appeal, particularly in applications like spectacle lenses.
Innovation Solution
A plastic spectacle lens composed of an optical material containing a phosphor with specific excitation and fluorescence wavelengths and an ultraviolet light absorber, where the ultraviolet light absorber is present in a proportion of two or more times the weight of the phosphor, ensuring high transmittance at 440 nm and low transmittance at 420 and 410 nm, thereby effectively blocking harmful light while maintaining transparency and colorlessness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If fullerenes are used as blue light-absorbing component, then blue light absorption is improved, but the optical article becomes colored
Solution Approach 1:
The patent changes the chemical composition parameters by replacing fullerene with a specific organic compound (7-diethylamino-4-methylcoumarin) that has tailored absorption characteristics. This compound absorbs blue light effectively while being transparent in the visible region, thus resolving the contradiction between blue light absorption and appearance.
Solution Approach 2:
The patent creates a composite optical material system combining the coumarin derivative with specific resins (polycarbonate, polymethyl methacrylate, or polyacrylonitrile). This composite approach allows the material to achieve both blue light absorption functionality and optical clarity through synergistic combination of components.
2Object-affected harmful factors
If an anti-glare optical element contains a pigment with specific absorption wavelength, then short-wavelength light absorption is improved, but the optical element becomes colored
Solution Approach 1:
The patent modifies the absorption spectrum parameters by selecting a coumarin derivative with maximum absorption at 420 nm and ensuring transparency above 440 nm. This parameter optimization allows effective short-wavelength light blocking while maintaining a colorless appearance in the visible spectrum.
3Object-affected harmful factors
If fine iron oxide particles are contained in the molded product, then light absorption at 420 nm is improved, but the molded product becomes colored
Solution Approach 1:
The patent changes from inorganic iron oxide particles to an organic coumarin derivative molecule, altering the absorption mechanism from particle-based scattering to molecular-level absorption. This enables precise control over absorption wavelength (420 nm) while maintaining transparency in the visible region, thus achieving both harmful light blocking and aesthetic appearance.
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 strong blocking effect against harmful ultraviolet rays and blue light, ensuring the optical material remains colorless and transparent, effectively reducing eye strain and improving appearance, making it suitable for use in plastic spectacle lenses and other optical applications.
Implementation Method 1
a phosphor which has an excitation wavelength in a range from 220 nm to 500 nm, a fluorescence wavelength in a range from 380 nm to 650 nm, a maximum excitation wavelength in a range from 350 nm to 400 nm, and a maximum fluorescence wavelength in a range from 400 nm to 500 nm
Implementation Method 2
an ultraviolet light absorber
Data Source
AI summary
An optical material of the present invention includes: a phosphor which has an excitation wavelength in a range from 220 nm to 500 nm, a fluorescence wavelength in a range from 380 nm to 650 nm, a maximum excitation wavelength in a range from 350 nm to 400 nm, and a maximum fluorescence wavelength in a range from 400 nm to 500 nm; and an ultraviolet light absorber, and the light transmittance thereof measured at a thickness of 2 mm satisfies the following features (1) to (3) : (1) The light transmittance at a wavelength of 440 nm is 80% or higher. (2) The light transmittance at a wavelength of 420 nm is 70% or lower. (3) The light transmittance at a wavelength of 410 nm is 5% or lower.