Ophthalmic Optical Layout Using Concave Mirrors for Wide Fundus Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ophthalmic devices face challenges in achieving wide-angled imaging of the fundus with high resolution while maintaining a compact and cost-effective design, as large lenses and complex aberration correction complicate the optical system.
Innovation Solution
An ophthalmic optical system utilizing a reflection unit with a pair of concave mirrors and a lens unit, including an angle conversion lens, to convert wide-angled light to a smaller angle, combined with a scanning member and imaging section to acquire and combine images of the fundus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If large diameter lenses are used to secure working distance and achieve wide-angled imaging, then the field of view increases, but the device size and weight increase
Solution Approach 1:
The patent replaces the traditional mechanical lens-based wide-angled optical system with a reflection unit comprising a first concave mirror and a second concave mirror. This substitution eliminates the need for large diameter lenses, thereby reducing device weight and size while maintaining the wide field of view capability. The mirrors reflect light to achieve wide-angled imaging without requiring bulky optical elements.
2Area of stationary object
If large diameter lenses are used to achieve wide-angled imaging, then the field of view increases, but the device becomes bulky
Solution Approach 1:
The patent substitutes large diameter lenses with a compact reflection unit consisting of two concave mirrors. This replacement dramatically reduces the volume occupied by the optical system while preserving the wide field of view function. The mirrors are positioned to reflect light rays effectively, achieving wide-angled imaging in a compact configuration.
Solution Approach 2:
The patent employs a folded optical path using the reflection unit, where light rays are reflected multiple times between the two concave mirrors. This dimensional folding of the optical path allows the system to achieve wide-angled imaging without requiring a linearly extended device structure, thereby reducing overall device volume.
3Measurement precision
If large diameter lenses are used to obtain high resolution images with wide field of view, then image quality improves, but aberration correction becomes complicated
Solution Approach 1:
The patent replaces the complex lens-based aberration correction system with a mirror-based reflection unit. Concave mirrors inherently provide different aberration characteristics compared to lenses, and the opposing arrangement of the two mirrors simplifies the overall aberration correction requirements while maintaining high image resolution across the wide field of view.
4Area of stationary object
If large diameter lenses are used to achieve wide-angled imaging, then the field of view increases, but manufacturing cost increases
Solution Approach 1:
The patent substitutes expensive large diameter lenses with concave mirrors that can be manufactured more economically. Mirrors, particularly concave mirrors, can be produced using techniques such as spin casting or replication, which are generally more cost-effective than manufacturing large precision lenses. This substitution reduces manufacturing costs while maintaining the wide field of view capability.
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
Enables wide-angled imaging of the fundus with high resolution and a simple lens configuration, reducing device size and manufacturing costs while effectively correcting aberrations.
Implementation Method 1
light rays from the focal point of the first concave mirror are reflected by the first concave mirror and the second concave mirror so as to converge as light toward the focal point of the second concave mirror
Implementation Method 2
an angle conversion lens that is arranged at a position of the aperture of the first concave mirror which is furthest toward an examined eye side of the lens unit, and that converts an angle of wide-angled converging light from the reflection unit to a smaller angle
Data Source
AI summary
An optical system is capable observing a peripheral field away from a visual axis and includes a reflection mirror unit forming an image of an examined eye with two concave mirrors in an opposing arrangement facing each other at the examined eye side, this being the upstream side, of a first optical unit and a second optical unit. In the reflection unit there is a conjugate relationship between one focal point thereof and another focal point thereof. By forming an image of the examined eye using the reflection unit a distance can be secured between the examined eye and the optical system and a wide range of the examined eye can be observed.