Scanning Laser Ophthalmoscope Objective Lens Unit Reflection Reduction
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Solution Overview
Problem
Existing scanning laser ophthalmoscopes face challenges in reducing reflected light from the objective lens, which increases noise and degrades image quality.
Innovation Solution
The scanning laser ophthalmoscope incorporates an objective lens unit with a first and second objective lens inclined at opposing angles, which refracts and disperses lens reflection light away from the light detector, maintaining the measurement light path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single objective lens is used in the optical system, then the device structure is simple, but lens reflection light enters the light detector causing noise and degraded image quality
Solution Approach 1:
The single objective lens is divided into multiple objective lenses (first objective lens and second objective lens) arranged in sequence. Each lens has a specific function: the first objective lens focuses measurement light while the second objective lens prevents reflection light from entering the light detector. This segmentation resolves the contradiction by maintaining structural simplicity while eliminating harmful reflection light through functional division.
2Object-affected harmful factors
If noise removal structures such as hole mirrors or pinholes are used, then lens reflection light is suppressed, but the conjugation position changes causing further noise increase
Solution Approach 1:
The harmful reflection light is extracted and separated from the measurement light path by positioning the second objective lens to reflect measurement light toward the retina while directing reflection light away from the light detector. This extraction method eliminates noise without requiring additional noise removal structures that would alter conjugation positions, thereby maintaining measurement precision.
3Reliability
If multiple lenses are used to transmit measurement light to the retina, then the measurement light path is maintained, but reflection light from the lenses enters the light detector increasing noise
Solution Approach 1:
Different parts of the optical system are assigned different functions: the first objective lens is optimized for focusing measurement light to maintain reliable transmission to the retina, while the second objective lens is specifically designed to prevent reflection light from entering the light detector. This local quality differentiation resolves the contradiction by ensuring each lens performs its specific function optimally without interfering with the other.
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 effectively reduces lens reflection light, suppressing noise and improving image quality by maintaining the integrity of the measurement light path.
Implementation Method 1
an objective lens unit (30) configured to focus the measurement light reflected from the scanner (16) to form the focus of the measurement light on the retina
Data Source
Figure 1~2
Figure 3~4
Figure 5(A)~5(D)
AI summary
A scanning laser ophthalmoscope capable of reducing reflected light generated from the objective lens is disclosed. The scanning laser ophthalmoscope may include: a light source (10) configured to irradiate measurement light; a scanner (16) configured to sequentially irradiate the measurement light to a desired position of the eye to be examined (5) by adjusting the reflection angle of the measurement light; an objective lens unit (30) configured to focus the measurement light reflected from the scanner (16) to form the focus of the measurement light on the retina of the eye to be examined (5); and a light detector 20 configured to detect retinal reflection light formed by the measurement light being reflected from the retina of the eye to be examined (5), wherein the objective lens unit (30) may include a first objective lens (32) positioned to be inclined at a first angle (a) with the vertical direction of the traveling path of the measurement light, a second objective lens (34) positioned to be inclined at a second angle (b) therewith, and a third objective lens (36) positioned in the vertical direction of the traveling path of the measurement light, and the inclination angle (a) of the first objective lens (32) and the inclination angle (b) of the second objective lens (34) may be formed to be inclined in opposite directions with respect to the vertical direction of the traveling path of the measurement light.