Vision-Protecting Filter Lens with Neutral-Density and Multilayer Film
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Solution Overview
Problem
Conventional vision-protecting filters used in personal protection devices, such as those for welding, often exhibit undesirable color biases due to uneven transmission of visible light, particularly favoring green over red, which is problematic in meeting ANSI Z87.1-2010 standards without significantly reducing infrared radiation.
Innovation Solution
A combination of a neutral-density optical filter with a multilayer optical film is used, where the neutral-density filter ensures a flat transmission across the visible spectrum and the multilayer film preferentially reflects near-infrared radiation, minimizing green bias while maintaining appropriate red light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional vision-protecting filters are used to block infrared radiation, then infrared protection is improved, but visible light transmission becomes uneven with green bias
Solution Approach 1:
The filter is divided into two distinct functional layers: a neutral-density optical filter layer that provides uniform attenuation across the visible spectrum, and a multilayer optical film layer that selectively reflects near-infrared radiation. This segmentation allows each layer to independently address its specific function without compromising the other, solving the contradiction between infrared blocking and visible light uniformity.
Solution Approach 2:
The invention uses a composite structure combining different optical materials with complementary properties: the neutral-density filter material provides flat visible spectrum attenuation, while the multilayer optical film material (with alternating high and low refractive index layers) provides selective infrared reflection. The composite nature of this two-layer system enables simultaneous achievement of uniform visible light transmission and effective infrared radiation blocking.
2Object-affected harmful factors
If filters are designed to meet ANSI Z87.1-2010 shade requirements, then radiation protection is improved, but color accuracy deteriorates due to green coloration
Solution Approach 1:
The filter system segments the radiation protection function into two parts: the neutral-density layer handles visible light attenuation uniformly across all wavelengths to maintain color accuracy, while the multilayer optical film layer handles infrared radiation blocking. This segmentation ensures that the visible spectrum passes through with uniform attenuation (preserving color information) while infrared radiation is selectively reflected ( providing radiation protection).
Solution Approach 2:
The multilayer optical film layer exhibits local quality by having different optical properties at different wavelength ranges: it is highly reflective in the near-infrared region (blocking harmful radiation) while being relatively transparent in the visible region (allowing uniform light passage). This wavelength-dependent local quality enables the filter to provide radiation protection without compromising color accuracy in the visible spectrum.
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 configuration achieves a Shade Number of 3 to 7 while maintaining a balanced red-green transmission, meeting ANSI Z87.1-2010 requirements without the undesirable green coloration typically seen in prior art filters.
Implementation Method 1
a multilayer optical film that exhibits a left band edge in the range of from about 600 nm to about 900 nm
Implementation Method 2
a neutral-density optical filter
Data Source
AI summary
A vision-protecting filter lens, including a multilayer optical film and a neutral-density optical filter.