Aspherical Endoscope Illumination Lens Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current illumination lenses for endoscopes face challenges in achieving wide-angle light distribution with consistent light quantity across the illumination field, particularly in medical applications where low-invasive light is required, and are sensitive to wavelength changes.
Innovation Solution
An illumination lens with an aspherical surface on the incident side, having specific refractive index and Abbe's number ranges, and a flat emission surface, designed to ensure wide-angle light distribution with reduced wavelength dependence and low-invasive illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the illumination lens uses a conventional spherical surface design, then the manufacturing is simpler, but the light distribution in the peripheral portion of the illumination field is insufficient
Solution Approach 1:
The patent applies an aspherical surface to the incident surface of the illumination lens instead of a conventional spherical surface. This aspherical design enables wide-angle light distribution while securing sufficient light quantity in the peripheral portion of the illumination field, directly resolving the contradiction between illumination uniformity and optical complexity.
2Illumination intensity
If the lens converges light to a focal point, then the illumination intensity at the center is improved, but high energy concentration causes light to invade the object to be observed
Solution Approach 1:
The aspherical surface design prevents light from converging to a sharp focal point, instead distributing light more evenly. This eliminates the high energy concentration that would cause light invasion to the observed object, while still providing sufficient illumination intensity.
Solution Approach 2:
The patent specifies particular parameter ranges for the aspherical surface (Conditional Expressions 1 and 2) to control the refraction of incident light. By adjusting these parameters, the lens achieves low-invasive illumination while maintaining adequate central brightness.
3Adaptability or versatility
If the lens system is designed for wide-angle illumination, then the observation angle is widened, but the wavelength dependence of the illumination system increases
Solution Approach 1:
The patent specifies particular parameter ranges for the aspherical surface (Conditional Expressions 1 and 2) to control the refraction of incident light across different wavelengths. This parameter optimization enables the lens to maintain wide-angle illumination while reducing wavelength dependence, ensuring reliable performance across 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
The lens provides secure light quantity in the peripheral illumination field, is less affected by wavelength changes, and achieves low-invasive illumination, enhancing the performance of endoscope illumination systems.
Implementation Method 1
An aspherical surface is formed on an incident surface on which light generated from a light source is to be incident
Implementation Method 2
converges a part of incidence rays inside the lens, and then emits the converged light as divergent light
Data Source
AI summary
An illumination lens is formed of one lens, and an aspherical surface is formed on an incident surface on which light generated from a light source is to be incident so that the incident surface has a convex shape in a paraxial region. In a case in which the amount of sag at each point on an aspherical surface corresponding to a height from an optical axis is expressed by a function of h, predetermined Conditional Expression, which is related to a height at which a second derivative of the function with respect to h is 0 and the maximum height of the aspherical surface, is satisfied. Predetermined Conditional Expression related to a refractive index of the illumination lens is satisfied.