Endoscope Illumination Optics for Wide Field and Clear Imaging
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Solution Overview
Problem
Existing endoscopes face issues with poor light distribution at the periphery of the field of view, leading to a narrow actual viewing angle and potential image degradation due to body fluids adhering to emission side surfaces, causing color tinting and reduced clarity.
Innovation Solution
An endoscope design that includes a first positive lens to concentrate light onto an internal focus point located on the incidence side, using a rod lens and positive lenses to uniformly illuminate a wide area and maintain image clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a lens with strong refractive power is used to widen the field of view, then the viewing angle is improved, but light distribution at the periphery becomes poor and the actual viewing angle becomes narrow
Solution Approach 1:
The illumination optical system is divided into multiple lens groups with different functions: a first lens group for light collection, a second lens group for light distribution, and a third lens group for final illumination. This segmentation allows each group to be optimized for its specific function, resolving the contradiction between field of view and light distribution.
Solution Approach 2:
The patent introduces a multi-dimensional optical path structure with lens groups arranged at different positions and orientations. The first lens group collects light from the light source, the second lens group distributes it radially, and the third lens group ensures uniform illumination across the field of view, creating a three-dimensional illumination architecture that simultaneously achieves wide viewing angle and uniform light distribution.
2Illumination intensity
If the focus point is located on the emission side from the center of the lens, then light concentration is improved, but temperature of the emission end surface rises and body fluids adhere to the surface
Solution Approach 1:
Instead of placing the focus point on the emission side as in conventional designs, this patent inverts the approach by positioning the focus point on the incidence side from the center of the lens. This inversion reduces light concentration on the emission surface, preventing temperature rise and body fluid adhesion while maintaining effective illumination through the multi-lens group configuration.
Solution Approach 2:
The patent introduces intermediate lens groups and optical elements between the light source and the target area. The first lens group acts as an intermediary to collect and redirect light, the second lens group serves as a mediator for radial distribution, and the third lens group functions as an intermediary for uniform illumination, thereby preventing direct light concentration on the emission surface that would cause overheating and fluid adhesion.
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 endoscope achieves wide illumination and clear observed images by efficiently distributing light and preventing image degradation from body fluids.
Implementation Method 1
a first positive lens configured to concentrate light emitted from a light source onto an internal focus point and to emit the concentrated light to irradiate an object
Implementation Method 2
incident parallel light is concentrated at approximately the center of curvature of the spherical surface, diverged and then refracted at the plane on emission side of the lens
Data Source
AI summary
An endoscope including: a light guide to guide the light from a light source; a first positive lens to concentrate light from the light guide onto an internal focus point and emit the concentrated light to irradiate an object, a rod lens provided on an emission side of the light guide; and a second positive lens provided on an emission side of the rod lens and on an incidence side of the first positive lens. Wherein the internal focus point is in a position where a conjugate image of an emission surface of the light guide is formed; the internal focus point is closer to the light guide than an intermediate point between an incidence surface of the first positive lens and an emission surface of the first positive lens on an optical axis of the first positive lens; and the rod lens has an emission convex lens surface.