Fundus Imaging Apparatus Eccentric Aberration Correction
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Solution Overview
Problem
Existing fundus imaging devices face challenges in capturing wide-range images due to aberrations and light reflection issues, particularly when using lens systems, which affect image quality.
Innovation Solution
A fundus imaging device with a novel optical system that includes a scanning optical system and an objective optical system with a first and second mirror, where at least one of the mirrors has a free-form or odd-order aspherical surface, and a third mirror for correcting eccentric aberrations, allowing for a wider scanning range and improved image capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a lens system is used to widen the scanning angle, then the scanning range is expanded, but light reflection from the lens surface degrades image quality
Solution Approach 1:
The patent replaces the lens-based objective optical system with a mirror-based reflective optical system. The scanning optical system uses galvanometer mirrors to deflect light onto the fundus, and the objective optical system uses spherical mirrors to focus and collect reflected light, eliminating the refraction and surface reflection issues inherent in lens systems while maintaining wide scanning capability
Solution Approach 2:
The spherical mirrors in the objective optical system serve multiple functions: they focus incident light from different angles onto a common focal point, collect reflected light from the fundus, and direct it to the imaging sensor. This multi-functional design achieves wide-angle imaging without requiring multiple separate optical components
2Area of stationary object
If an objective optical system with lens is used to capture wide-range images, then the field of view is increased, but aberration differences between scan positions degrade image quality
Solution Approach 1:
The patent replaces the lens-based objective optical system with a mirror-based reflective optical system. The scanning optical system uses galvanometer mirrors to deflect light onto the fundus, and the objective optical system uses spherical mirrors to focus and collect reflected light, eliminating the refraction and surface reflection issues inherent in lens systems while maintaining wide scanning capability
Solution Approach 2:
The patent employs asymmetric optical paths with spherical mirrors positioned at specific angles and locations to compensate for aberration variations across the scanning field. The mirrors are arranged to create symmetric optical paths for asymmetric incident angles, ensuring consistent focal points and minimizing aberration differences between center and peripheral scan positions
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 device effectively captures high-quality wide-range images of the fundus with reduced aberrations and improved light handling, enhancing image clarity and accuracy.
Implementation Method 1
a first mirror configured to reflect the light from the optical scanner, and to form a first turning point around which the light turns
Implementation Method 2
a second mirror configured to further reflect the light reflected by the first mirror, and to form a second turning point around which the light emitted to the examinee's eye turns
Implementation Method 3
the fundus imaging device forms an image of the fundus based on fundus reflected light being the light reflected from the fundus
Data Source
AI summary
A fundus imaging device includes an objective optical system formed of a plurality of eccentrically disposed mirrors, and an SLO optical system and an OCT optical system which irradiate a fundus with light from a light source via the objective optical system and receive fundus reflected light. The fundus imaging device further includes a correction mirror as a part of the objective optical system, or between the objective optical system and the SLO optical system or the OCT optical system. The correction mirror corrects an eccentric aberration which occurs due to eccentric arrangement of the plurality of mirrors.