Spectacle Lens Coating Cure Using Filtered Light Spectra
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for curing liquid coating compositions on spectacle lenses using intense light sources face issues such as crazing, yellowing, or darkening due to high-energy ultraviolet radiation, leading to incomplete or inhomogeneous curing and potential damage to the lens.
Innovation Solution
The method involves excluding specific wavelength ranges of optical radiation emitted by the intense light source, selected based on the emission and absorptance spectra of the spectacle lens, to prevent ultraviolet radiation from causing undesirable effects while ensuring sufficient radiant energy for complete thermal curing within 1 ms to 3 min.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-spectrum optical radiation from an intense light source is used for curing, then curing speed is improved and curing time is reduced, but crazing, yellowing, and darkening occur due to high-energy ultraviolet radiation
Solution Approach 1:
The patent extracts and removes the harmful ultraviolet wavelength range (below 280 nm) from the optical radiation spectrum emitted by the intense light source. This is achieved by selecting a light source with appropriate optical filters or by choosing a light source that naturally emits minimal UV radiation below 280 nm, thereby eliminating the harmful effects while preserving the beneficial curing radiation in the visible and infrared ranges.
Solution Approach 2:
The patent applies different spectral characteristics to different parts of the radiation spectrum. The harmful UV component (below 280 nm) is excluded, while the beneficial visible and infrared components are retained for curing. This creates a differentiated radiation profile where only specific wavelength ranges are present, allowing fast curing without the harmful ultraviolet effects.
2Reliability
If conventional oven curing is used, then lens damage is avoided, but curing time is excessively long
Solution Approach 1:
The patent replaces the conventional thermal convection oven curing system with an intense light source system that uses optical radiation (visible and infrared) for curing. This substitution enables volumetric heating through direct photon absorption by the coating material and lens, achieving rapid curing (within seconds) without the prolonged exposure times required by conventional oven methods, while avoiding lens damage by excluding harmful UV radiation.
3Productivity
If intense light source is used for rapid curing, then productivity is improved, but the light source undergoes solarization and its life is reduced
Solution Approach 1:
The patent extracts and eliminates the harmful ultraviolet wavelength component (below 280 nm) from the light source output. By removing this solarization-causing radiation, the intense light source is protected from degradation, thereby extending its operational life while maintaining high-speed curing capabilities through the retained visible and infrared radiation.
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
This approach allows for full curing of the coating material without damaging the lens, maintaining its optical and mechanical properties, and extending the life of the intense light source by preventing solarization, while reducing curing time compared to conventional oven methods.
Implementation Method 1
The absorption spectrum of the spectacle lens shows a significant overlap with the emission spectrum of the light source, ensuring efficient energy transfer for curing
Implementation Method 2
curing, within a curing time ranging from 1 ms to 3 min, the coating material on the surface of a spectacle lens using optical radiation emitted by an intense light source
Data Source
Figure 1
AI summary
The application relates to a method for manufacturing a spectacle lens, the method comprising the step of: - curing a coating material on a surface of a spectacle lens using optical radiation emitted by an intense light source, said coating material resulting in a coating on said surface of said spectacle lens, the method is characterized in that a wavelength range of said optical radiation emitted by said intense light source is limited by at least one of i) a wavelength at a) an intersection point of an emission spectrum of said intense light source and an absorptance spectrum of the spectacle lens and b) a maximum wavelength of optical radiation emitted by said intense light source, ii) a wavelength larger than a wavelength at a) an intersection point of an emission spectrum of said intense light source and an absorptance spectrum of the spectacle lens and b) a maximum wavelength of optical radiation emitted by said intense light source, iii) a wavelength smaller than a wavelength at a) an intersection point of an emission spectrum of said intense light source and an absorptance spectrum of the spectacle lens and b) a maximum wavelength of optical radiation emitted by said intense light source.