Multilayer Spectacle Lens Coating for Wide-Angle Reflection Control
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Solution Overview
Problem
Existing spectacle lenses do not effectively control reflection characteristics for light incident at wider angles, which can impair visibility and appearance.
Innovation Solution
A spectacle lens with a multilayer film that controls reflection characteristics by maintaining an average reflectance of 7.0% or less for light incident at 65° and 1.0% or less for light incident at 0° in the wavelength range of 400 to 700 nm, using high- and low-refractive index layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a multilayer film is provided on the lens substrate to control reflection characteristics, then the visibility and appearance of the spectacle lens are improved, but the manufacturing complexity and number of layers increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the refractive index values and thickness of each layer in the multilayer film. By adjusting parameters such as the refractive index of the low-refractive index layer (1.20-1.38) and high-refractive index layer (2.00-2.40), and optimizing layer thicknesses, the invention achieves superior reflection control (average reflectance ≤7.0% at 65° incidence) without unnecessarily increasing the number of layers
Solution Approach 2:
The invention uses composite materials by combining multiple layers with different refractive indices (low-refractive index materials with n=1.20-1.38 and high-refractive index materials with n=2.00-2.40) to create a multilayer film structure. This composite approach enables effective control of reflection characteristics across different incident angles and wavelengths, achieving both visibility improvement and appearance quality
2Illumination intensity
If the multilayer film uses more layers with specific refractive indices to control wide-angle reflection, then the visibility is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent defines specific parameter ranges for manufacturability: low-refractive index layers with n=1.20-1.38 and high-refractive index layers with n=2.00-2.40. These parameter specifications provide clear manufacturing targets that balance performance requirements with fabrication capabilities, enabling consistent production of wide-angle reflection control
3Illumination intensity
If the average reflectance at 65° is controlled to 7.0% or less to improve visibility, then reflected light perception is reduced, but the reflectance control across different wavelengths and angles becomes more difficult
Solution Approach 1:
The multilayer film design achieves universal reflection control by simultaneously addressing multiple requirements: controlling reflectance at 65° incidence (≤7.0%), controlling UV reflectance (≤7.0% at 280-380 nm), and maintaining low normal-incidence reflectance (≤1.0% at 0°). The same multilayer structure with carefully selected refractive index ranges and thicknesses accomplishes all these functions together, reducing reflected light perception across different conditions
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
Improves visibility and appearance by reducing perceived reflected light, making it less noticeable to the wearer and others, while maintaining optical clarity.
Implementation Method 1
a multilayer film located on at least one surface of the lens substrate... controlling the reflection characteristics with a multilayer film so that the average reflectance with respect to light incident at 65° in the wavelength range of 400 to 700 nm on the spectacle lens surface is 7.0% or less
Implementation Method 2
the multilayer film includes one or more high-refractive index layers and one or more low-refractive index layers, and one or more of the low-refractive index layers are layers having a refractive index of 1.20 or more and 1.38 or less
Data Source
AI summary
Provided is a spectacle lens including a lens substrate and a multilayer film located on at least one surface of the lens substrate, in which an average reflectance with respect to light incident at 65° in a wavelength range of 400 to 700 nm on the spectacle lens surface side having the multilayer film is 7.0% or less.