Fundus Imaging Optical Path Using Fixed Plane Mirror
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Solution Overview
Problem
Existing fundus imaging systems face challenges with increased size and maintenance difficulties due to the inclusion of a mechanically driven oscillating plane mirror between elliptical mirrors, which complicates the optical system and affects device compactness.
Innovation Solution
A fundus imaging system is designed with a scanning optical system that utilizes a two-dimensional scanning unit, elliptical reflection mirrors, and a plane reflection mirror, where the plane reflection mirror is strategically positioned to maintain consistent angular scanning and reduce device size by eliminating mechanically movable parts between the mirrors, using a configuration where the plane reflection mirror's normal bisects the angle between the focal lines of the elliptical mirrors, ensuring consistent angular changes and minimizing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an oscillating plane mirror is disposed between the first elliptical mirror and the second elliptical mirror to scan the retina, then the scanning function is achieved, but the device size increases and maintenance becomes difficult
Solution Approach 1:
The patent removes the oscillating plane mirror from the optical path between the first and second elliptical mirrors. Instead, it uses a fixed plane mirror positioned at the common focus of the two elliptical mirrors, eliminating the need for mechanical oscillation while maintaining the scanning function through the geometric properties of the elliptical mirrors.
Solution Approach 2:
The patent replaces the mechanical oscillating plane mirror system with a static optical configuration using fixed plane mirror and elliptical mirrors. The scanning function is achieved through the inherent geometric properties of the elliptical mirrors rather than mechanical motion, reducing device complexity and maintenance requirements.
2Ease of operation
If an oscillating plane mirror is used for scanning, then the retina can be scanned, but maintenance of the device becomes difficult
Solution Approach 1:
The oscillating plane mirror is removed from the system, eliminating the mechanical component that requires maintenance. The scanning function is maintained through the fixed optical configuration of elliptical mirrors and a stationary plane mirror.
Solution Approach 2:
The elliptical mirrors inherently provide the scanning function through their geometric properties without requiring additional mechanical components. The system uses the natural optical paths defined by the elliptical geometry to achieve retinal scanning, making the system more reliable and easier to maintain.
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 compact and simplified fundus imaging system that maintains consistent angular scanning, reduces distortion, and simplifies the optical path, enabling efficient two-dimensional scanning of the retina without mechanically movable parts, thereby enhancing the system's size reduction and maintenance ease.
Implementation Method 1
vertically scans the retina with a laser beam using a polygon mirror and concurrently causes the laser beam to be incident on a first elliptical mirror
Implementation Method 2
horizontally scans the retina with a light beam reflected off the first elliptical mirror using an oscillating plane mirror and concurrently causes the light beam to be incident on a second elliptical mirror
Data Source
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AI summary
A fundus imaging system comprises: a first reflection mirror that reflects a light beam passing through a first focus of the first reflection mirror to pass through a second focus; a two-dimensional scanning unit that is disposed at a position of the first focus and reflects a light beam incident on the two-dimensional scanning unit so as to scan the retina with the light beam in two-dimensional directions; and a second reflection mirror that reflects a light beam passing through a third focus so as to cause the light beam to pass through a fourth focus, the second reflection mirror being disposed so that a position of the third focus coincides with a position of the second focus, wherein a position of the pupil of the subject is disposed so as to coincide with a position of the fourth focus.