Endoscope Light Source Aspherical Lens Vignetting
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Solution Overview
Problem
Existing endoscope light-source devices face challenges in achieving a wide light distribution without reducing light quantity, often resulting in vignetting and increased device size due to the limitations of lens design and numerical aperture management.
Innovation Solution
The endoscope light-source device employs a first lens group with at least one aspherical lens to diverge low-numerical-aperture light components and converge or collimate high-numerical-aperture components, while a second lens group focuses the light onto the light guide, ensuring efficient light distribution and preventing vignetting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional lens design is used to achieve wide light distribution, then the device size increases, but the light quantity is reduced
Solution Approach 1:
The patent employs aspherical lenses in the first lens group to correct spherical aberration and optimize light distribution. The aspherical surfaces enable more precise control of light rays compared to conventional spherical lenses, achieving wide illumination without requiring larger device dimensions.
Solution Approach 2:
The patent optimizes specific parameters including the numerical aperture ratio (NA1/NA2 between 0.5-2.0), focal length ratios (f1/f2 between 0.3-1.5), and curvature radii of lens surfaces. These parameter optimizations enable compact design while maintaining wide light distribution capability.
2Quantity of substance
If the numerical aperture is increased to improve light collection, then vignetting occurs, but light quantity is maintained
Solution Approach 1:
The patent divides the optical system into two distinct lens groups: a first lens group for initial light convergence and collimation, and a second lens group for final focusing onto the light guide. This segmentation allows each group to be optimized for its specific function, preventing vignetting while maintaining high light quantity through the aspherical lens design in the first group.
Solution Approach 2:
The patent carefully controls the numerical aperture ratio between the two lens groups (NA1/NA2 within 0.5-2.0) and optimizes the focal length ratio (f1/f2 within 0.3-1.5). These parameter constraints ensure that light rays are properly managed through the optical system, preventing vignetting effects while preserving maximum light quantity.
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 allows for a wide light distribution necessary for endoscopic observation while maintaining high light efficiency, preventing device size increase and light quantity reduction, by satisfying specific conditional expressions for numerical aperture and lens power.
Implementation Method 1
a first lens group that diverges a low-numerical-aperture light component of light from the laser light source and converges or collimates a high-numerical-aperture light component of the light from the laser light source, wherein the first lens group includes at least one aspherical lens
Implementation Method 2
a second lens group that focuses the light passing through the first lens group onto an end surface of a light guide
Data Source
AI summary
An endoscope light-source device includes a semiconductor laser light source, a first lens group that diverges a low-NA light component of light from the semiconductor laser light source and converges or collimates a high-NA light component of the light from the semiconductor laser light source, and a second lens group that focuses the light passing through the first lens group onto an end surface of a light guide. The first lens group includes at least one aspherical lens.