Endoscope Prism Assembly for Visible and Fluorescence Focus Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Endoscopes face challenges in compensating for chromatic aberration across the entire spectrum from deep blue to infrared, particularly when using fluorescing agents, due to the dispersive properties of optical materials and varying endoscope models, leading to complex and costly solutions that often introduce unwanted lateral chromatic aberration.
Innovation Solution
A chromatic adjustment assembly using a beamsplitter and prism system is positioned within the endoscope's optical path to separate and recombine light with different spectral content, compensating for chromatic aberration by focusing both visible and infrared light onto the same image plane, thereby correcting longitudinal chromatic aberration without affecting lateral aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional optical materials and long glass paths are used in endoscopes, then the endoscope can transmit light from deep blue to infrared, but chromatic aberration occurs causing different spectral bands to focus at different planes
Solution Approach 1:
A telecentric lens assembly is introduced as an intermediary optical element between the endoscope's rod lens and the image sensor. This telecentric lens specifically corrects lateral chromatic aberration by redirecting oblique light rays to converge at the same focal point for all wavelengths, while a chromatic adjustment assembly corrects longitudinal chromatic aberration. The telecentric lens acts as a mediator that compensates for the dispersive properties of the endoscope's optical materials without requiring changes to the endoscope itself.
2Manufacturing precision
If multiple image sensors are used to compensate for chromatic focal differences, then each spectral band can be detected at its appropriate focal plane, but device complexity and cost increase
Solution Approach 1:
The patent employs a single multi-functional image sensor that can detect both visible and infrared wavelengths. The telecentric lens assembly and chromatic adjustment assembly work together to bring all spectral bands (from deep blue to infrared) to a common focal plane, allowing one sensor to perform multiple spectral detection functions simultaneously. This eliminates the need for multiple specialized sensors while maintaining the ability to capture different spectral bands with appropriate focus.
3Manufacturing precision
If lenses or prisms are used to correct longitudinal chromatic aberration, then focal plane alignment improves, but unwanted lateral chromatic aberration is introduced
Solution Approach 1:
The patent segments the chromatic aberration correction into two distinct functional components: a chromatic adjustment assembly that corrects longitudinal chromatic aberration (focal plane alignment) and a telecentric lens assembly that corrects lateral chromatic aberration (oblique ray convergence). By separating these two correction functions into distinct optical elements, each component can be optimized for its specific purpose without introducing the harmful side effects that would occur if a single element attempted to correct both types of aberration simultaneously.
4Manufacturing precision
If autofocus mechanisms or complex optical elements are added to correct chromatic aberration, then imaging quality across spectrum improves, but cost and device complexity increase
Solution Approach 1:
The telecentric lens assembly and chromatic adjustment assembly serve as intermediary optical elements that can be added to existing endoscopes without requiring complex autofocus mechanisms. These passive optical components correct chromatic aberrations through their fixed optical design, eliminating the need for active focusing mechanisms while providing comprehensive chromatic correction across the spectrum from deep blue to infrared.
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 solution provides improved chromatic correction across the entire spectrum, allowing for clear imaging from deep blue to infrared wavelengths, enhancing the usability of existing endoscopes for fluorescence imaging without the need for expensive autofocus mechanisms or complex optical elements.
Implementation Method 1
compensating for chromatic aberration of the endoscope multiple lenses such that the first portion of light and the second portion of light are focused onto substantially the same image plane
Implementation Method 2
A chromatic adjustment assembly, typically implemented with prisms, compensates for a chromatic focal difference between the white light image and the fluoresced light image caused by the dispersive properties of the optical materials
Implementation Method 3
an objective lens group forming an image at the distal end
Implementation Method 4
multiple rod lenses which relay the image formed at the distal end to the proximal end
Data Source
AI summary
Improved fluoresced imaging (FI) endoscope devices and systems are provided to enhance use of endoscopes with FI and visible light capabilities. An endoscope device is provided for endoscopy imaging in a white light and a fluoresced light mode. A chromatic adjustment assembly, typically implemented with prisms, compensates for a chromatic focal difference between the white light image and the fluoresced light image caused by the dispersive properties of the optical materials or optical design employed in the construction of the optical channel. The assembly is placed optically between the most proximal rod lens of the endoscope and the focusing optics, typically at an internal telecentric image space, to improve the chromatic correction. The prism assembly directs incoming light with different spectral content along separate paths which compensate for chromatic aberration.