Optical Lens Assembly with Visible Light Absorbing Elements
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Solution Overview
Problem
Conventional optical lens assemblies for near-infrared imaging struggle with low transmittance, particularly in reducing the length of the lens assembly while maintaining image quality and preventing reduction in photographic effects.
Innovation Solution
The optical lens assembly incorporates a plurality of lens elements with materials that absorb visible light, a filter with low transmittance for wavelengths greater than 1050 nm, and layer stacks composed of high and low index material layers to achieve high transmittance for the near-infrared band, specifically greater than 95% for wavelengths from 800 nm to 1000 nm through thin-film interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filter is added to block stray light in near-infrared optical lens assembly, then visible light blocking is improved, but transmittance for near-infrared band decreases
Solution Approach 1:
The patent applies local quality by designing different lens elements with specific material properties - at least one lens element uses material that absorbs visible light while maintaining near-infrared transmittance. This localized material selection allows the filter to block visible stray light without compromising near-infrared transmittance, resolving the contradiction between stray light blocking and infrared transmittance
Solution Approach 2:
The patent employs composite materials by combining lens elements with different optical properties - some elements use visible light absorbing materials while others maintain high near-infrared transmittance. This composite approach creates a multi-functional optical system that simultaneously achieves stray light rejection and near-infrared transmission, solving the contradiction between filtering visible light and transmitting infrared light
2Length of moving object
If the length of the optical lens assembly is reduced, then device size is improved, but optical performance deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive indices and thicknesses of individual lens elements to achieve high near-infrared transmittance (>95% for 800-1000 nm band) in a compact configuration. By carefully controlling optical parameters such as material composition and element geometry, the system maintains excellent optical performance despite reduced overall length
Solution Approach 2:
The patent uses segmentation by dividing the optical system into multiple lens elements with specific functions - some elements focus on visible light absorption while others optimize near-infrared transmission. This segmented approach allows each element to be optimized for its specific function, achieving high performance in a compact overall structure
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 transmittance of the optical lens assembly for near-infrared light, enabling high-performance night vision or infrared imaging while maintaining reduced system length and improved optical performance.
Implementation Method 1
layer stacks composed of high and low index material layers to achieve high transmittance for the near-infrared band, specifically greater than 95% for wavelengths from 800 nm to 1000 nm through thin-film interference
Implementation Method 2
At least one of the lens elements has a material capable of absorbing visible light and has transmittance being less than 2% for visible light
Implementation Method 3
The filter is disposed between the lens elements and the image side and has transmittance less than 1% for light having a wavelength band greater than 1050 nm
Implementation Method 4
Each of the lens elements includes an object-side surface facing the object side and allowing imaging rays to pass through and an image-side surface facing the image side and allowing the imaging rays to pass through
Data Source
AI summary
An optical lens assembly includes a plurality of lens elements, a filter, and a plurality of layer stacks. The lens elements are arranged in sequence from an object side to an image side along an optical of the optical lens assembly. Each of the lens elements includes an object-side surface and an image-side surface. At least one of the lens elements has a material capable of absorbing visible light. The filter is disposed between the lens elements and the image side and has transmittance less than 1% for light having a wavelength band greater than 1050 nm. The layer stacks are respectively stacked on the object-side surfaces and the image-side surfaces of the lens elements, so that transmittance of the optical lens assembly is greater than 95% for light having a wavelength band from 800 nm to 1000 nm.