Variable Aperture Stray Light Stop for Eye Ametropia Measurement
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Solution Overview
Problem
Existing apparatuses for determining ametropia of the eye face challenges in obtaining data with high confidence due to difficulties in evaluating detection signals and distinguishing actual ametropia from stray light interference.
Innovation Solution
The apparatus incorporates adjustable stray light stops with variable apertures and positions along the measurement beam path to effectively suppress stray light, ensuring that only measurement light reaches the detector, thereby improving the accuracy of ametropia data collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stray light stops with fixed apertures are used, then device complexity is reduced, but measurement precision deteriorates due to inability to adapt to different ametropia types
Solution Approach 1:
The patent implements adjustable stray light stops where the aperture diameter can be dynamically changed based on the type of ametropia being measured. This allows the optical system to adapt its stray light suppression characteristics to match different measurement conditions, thereby improving measurement precision without requiring a completely complex redesign of the entire optical assembly.
Solution Approach 2:
The patent changes the parameter of aperture diameter of the stray light stops to optimize measurement precision. By adjusting this physical parameter according to the specific ametropia type (myopia, hyperopia, astigmatism), the system achieves better stray light suppression and improved data accuracy while maintaining a relatively simple overall device structure.
2Measurement precision
If adjustable stray light stops are implemented, then measurement precision improves, but device complexity increases due to additional actuators and control mechanisms
Solution Approach 1:
The patent divides the stray light suppression function into multiple adjustable stops positioned at different locations in the optical path. Each stop can be independently adjusted, allowing precise control of stray light from different sources. This segmentation approach improves detection signal quality while distributing the complexity across multiple simple adjustable components rather than one complex mechanism.
Solution Approach 2:
The patent incorporates control mechanisms that can adjust the stray light stop apertures based on feedback from the measurement process. This feedback system optimizes the balance between stray light suppression and measurement precision automatically, reducing the need for manual adjustment and simplifying the overall control complexity while maintaining high measurement precision.
3Object-affected harmful factors
If aperture diameter is reduced to block stray light, then harmful factors are reduced, but measurement light intensity decreases
Solution Approach 1:
The patent applies different aperture diameters at different locations in the optical path by using multiple adjustable stray light stops. Each stop is optimized for its specific position to block stray light from particular sources while preserving measurement light. This local optimization allows effective stray light reduction without excessively reducing overall measurement light intensity.
Solution Approach 2:
The patent dynamically adjusts the aperture diameters of the stray light stops based on the measurement conditions and type of ametropia. This dynamic adjustment allows the system to optimize the balance between stray light blocking and measurement light transmission for each specific measurement scenario, preventing excessive loss of measurement light intensity while still effectively reducing stray light interference.
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 solution enhances the confidence in obtaining ametropia data by minimizing stray light interference, allowing for more precise determination of spherical and astigmatic visual defects, even in varying types of ametropia, thereby supporting better prescription and surgical planning.
Implementation Method 1
Some of this light is scattered or reflected at the retina such that the small illuminated spot on the retina serves as a point light source for measurement light
Implementation Method 2
Some of this light is scattered or reflected at the retina
Implementation Method 3
This measurement light emerges from the eye as a light beam which is formed by the optical components of the eye, such as the vitreous humor, the lens and the curved cornea
Implementation Method 4
The measurement beam path can pass through the aperture of the at least one stray light stop, wherein a diameter of the aperture of the at least one stray light stop is variable
Data Source
AI summary
An apparatus for determining ametropia of an eye includes an optical assembly with a light source, a detector, a plurality of optical elements and at least one stray light stop and a controller. An illumination beam path is provided between the light source and an optical interface in order to allow illumination light generated by the light source to emerge from the optical interface. A measurement beam path is provided between the optical interface and the detector in order to supply measurement light entering through the optical interface to the detector. The measurement beam path passes through an aperture of the at least one stray light stop. A diameter of this aperture is variable or a position of this aperture along the measurement beam path is variable in order to reduce stray light at the detector.