Ophthalmic Optical Path Coupling to Reduce Corneal Flare
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flare caused by corneal reflected light and scattered light in ophthalmic apparatuses due to pupil division using a pupil dividing member with transmission and reflective regions, leading to image quality degradation.
Innovation Solution
An optical path coupling member with a transparent member having a reflective region formed by evaporating a reflective film on a transmission region, positioned conjugate to the iris, to reflect illumination light and transmit returning light, reducing the thickness of the optical path and minimizing flare.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pupil dividing member with transmission and reflective regions is used to perform pupil division, then the optical path can be coupled, but flare is caused by reflected or scattered light from cornea or crystalline lens degrading image quality
Solution Approach 1:
The pupil dividing member is segmented into distinct transmission regions and reflective regions on its surface. This segmentation allows separate optical paths for illumination light (reflected) and returning light (transmitted), enabling optical path coupling while controlling light direction to minimize flare.
Solution Approach 2:
Different regions of the pupil dividing member surface are given different optical properties: some regions have high reflectivity for illuminating the fundus, while other regions have high transmissivity for capturing returning light. This local differentiation of optical quality enables the system to achieve both illumination and imaging functions while reducing flare.
2Object-affected harmful factors
If the optical path coupling member has a reflective film formed on transmission region, then the thickness of optical path is reduced and flare is minimized, but manufacturing complexity increases
Solution Approach 1:
The reflective film is formed by evaporating reflective material onto specific regions of the transparent member surface. This changes the optical parameter (reflectivity) of localized areas while maintaining the overall transparency of the member. The evaporation process allows precise control of film thickness and distribution to optimize flare reduction.
Solution Approach 2:
The optical path coupling member is constructed as a composite structure combining a transparent base material with a reflective film layer deposited on specific surface regions. This composite design integrates both transmission and reflection functions in a single component, reducing overall optical path thickness while minimizing flare.
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
Substantially eliminates flare by guiding illumination light and returning light through optimized paths, enhancing image quality and allowing for luminance gradient correction in acquired images.
Implementation Method 1
a reflective region formed by evaporating a reflective film onto a part of a transmission region of its surface... The illumination optical system and the imaging optical system are arranged so that the illumination light is reflected on the reflective region
Implementation Method 2
a transparent member with a reflective region formed by evaporating a reflective film onto a part of a transmission region of its surface... the returning light is transmitted through the transmission region
Implementation Method 3
a reflective region formed by evaporating a reflective film onto a part of a transmission region of its surface
Data Source
AI summary
An ophthalmic apparatus includes an objective lens, an illumination optical system, an imaging optical system, and an optical path coupling member. The illumination optical system may illuminate a subject's eye with illumination light via the objective lens. The imaging optical system may guide returning light of the illumination light from the subject's eye to an imaging device via the objective lens. The optical path coupling member has a transparent member with a reflective region formed by evaporating a reflective film onto a part of a transmission region of its surface, and is configured to couple an optical path of the illumination optical system with an optical path of the imaging optical system. The transmission region may be arranged substantially conjugate optically to a subject's iris. The illumination light is reflected on the reflective region and the returning light is transmitted through the transmission region.