NIR Lens Assembly Using Visible-Light-Absorbing Material
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Solution Overview
Problem
Existing NIR imaging lens assemblies face challenges in reducing interference from visible and infrared light wavelengths, leading to increased complexity and cost due to the need for complex filters that cut off both ends of the NIR spectrum, which also result in a longer total track length.
Innovation Solution
The use of a lens element with refractive power made of a visible-light-absorbable material, combined with a filter that cuts off infrared light, allows only specific NIR wavelengths to pass through, improving resolution and reducing the total track length and production cost by absorbing visible light and filtering out longer infrared wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filter is added to cut off light at both ends of the NIR spectrum, then interference from other wavelengths is reduced, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the filtering function with the lens element by making the lens material itself absorb visible light while maintaining NIR transmission. This merges the previously separate functions of visible light absorption and NIR transmission into a single integrated lens element, eliminating the need for complex multi-layer filters and reducing manufacturing complexity
2Object-affected harmful factors
If a filter is added to cut off light at both ends of the NIR spectrum, then interference from other wavelengths is reduced, but the total track length increases
Solution Approach 1:
By integrating the visible light absorption function directly into the lens material, the patent eliminates the need for separate filter components that would add to the optical path length. The lens element itself performs both focusing and spectral filtering, thereby reducing the total track length while maintaining effective wavelength selection
3Object-affected harmful factors
If a filter with greater thickness is used to cut off light at both ends, then wavelength selection is improved, but production cost increases
Solution Approach 1:
The patent changes the material parameters of the lens element by selecting materials with specific optical properties that inherently absorb visible light while transmitting NIR wavelengths. This material parameter change eliminates the need for thick, complex filters, thereby reducing production cost while maintaining effective wavelength selection
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 enhances the response of electronic photo sensors by minimizing interference from other wavelengths, resulting in improved imaging resolution and a more compact lens system.
Implementation Method 1
the lens element with refractive power made of a visible-light-absorbable material is used for absorbing light in the visible light wavelength range
Implementation Method 2
the filter is used for cutting off light which has a longer wavelength in the infrared wavelength range
Implementation Method 3
the lens element with refractive power made of a visible-light-absorbable material... is used directly for refracting light
Data Source
AI summary
This invention provides an NIR imaging lens assembly comprising a lens element with refractive power made of a visible-light-absorbable material, and a filter or a filter film formed on one lens element with refractive power for filtering out infrared light, wherein the number of lens elements with refractive power in the NIR imaging lens assembly is N, and wherein N≧2. The above lens arrangement allows light in a specific NIR wavelength range to pass through the lens assembly, thereby reducing interferences or influences from light in the other wavelength ranges. As a result, the resolution of the imaging lens assembly is improved, and its total track length is reduced effectively so that the entire lens system can be compact.