Lens Refractive Index Detection via Liquid Immersion
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Solution Overview
Problem
Current methods for refractive index detection of optical lenses are destructive, time-consuming, and unsuitable for irregular or finished lenses, as they require prism formation and angle detection, which is not applicable for online high-precision testing.
Innovation Solution
A lens refractive index detection device and method that uses a light source module, physical and optical thickness detection modules, and interference phenomena to calculate refractive index without prism formation or angle detection, suitable for irregular and finished lenses, employing collimated light beams, beam splitting, and movable reflection mirrors for non-destructive online detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the minimum deflection angle method is used to detect refractive index, then measurement precision is improved, but the optical element must be destroyed and prism formation is required
Solution Approach 1:
The patent extracts the refractive index measurement function from the prism formation requirement. By using a liquid immersion method where the lens is placed directly in a liquid medium of known refractive index, the complex prism fabrication process is eliminated while still enabling accurate refractive index measurement through optical power comparison in different media.
Solution Approach 2:
The patent introduces a liquid medium as an intermediary substance between the lens and the measurement system. This liquid medium with known refractive index serves as a reference that enables indirect measurement of the lens refractive index by comparing optical powers in air and in liquid, avoiding direct prism formation.
2Measurement precision
If the minimum deflection angle method is used, then direct detection is achieved, but detection time increases and efficiency decreases
Solution Approach 1:
The patent performs preliminary preparation by selecting a liquid medium with known refractive index before the measurement process. This pre-prepared reference medium eliminates the need for real-time prism fabrication and angle measurement setup, enabling faster detection while maintaining measurement accuracy through the established liquid immersion method.
3Measurement precision
If the minimum deflection angle method is used, then refractive index can be detected, but it is not applicable for irregular aspherical lenses and cylindrical lenses
Solution Approach 1:
The patent creates a universal measurement method that works for various lens types including spherical lenses, aspherical lenses, and cylindrical lenses. The liquid immersion technique combined with optical power measurement is applicable to any lens geometry, eliminating the limitation of the traditional minimum deflection angle method which requires regular prism-shaped samples.
4Ease of operation
If inverse calculation according to refractive power formula is used, then refractive index can be calculated, but operational complexity increases and measurement accuracy is difficult to guarantee
Solution Approach 1:
The patent employs an automated measurement system that self-performs the optical power measurements in air and in liquid medium. The system automatically calculates the refractive index from the measured optical powers using the established formula, eliminating manual calculation errors and reducing operational complexity while maintaining high measurement accuracy.
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 fast, non-destructive, and indirect detection of refractive index and dispersion coefficients at multiple wavelengths for irregular and finished lenses, reducing operational complexity and time, while maintaining accuracy and reliability.
Implementation Method 1
a beam splitting component, a partial reflection mirror, and a movable reflection mirror, wherein the second photodetection component, the partial reflection mirror, the beam splitting component, the focusing component and the first light combining component are arranged along a first optical axis direction from front to back
Implementation Method 2
the other beam is projected on the partial reflection mirror and returns by reflection of the movable reflection mirror, and further transmitted by the beam splitter to the first photodetection component
Implementation Method 3
the two returned beams enter the first photodetection component for detecting an interference phenomena
Data Source
AI summary
A lens refractive index detection device is disclosed which has a light source module, a lens center physical thickness detection module and a lens center optical thickness detection module. The light source module includes a first light source component and a second light source component for outputting a collimated light beam, a first light combining component, and a focusing component. The lens center physical thickness detection module includes a first imaging component and a second imaging component. The lens center optical thickness detection module includes a first photodetection component and a second photodetection component, a beam splitting component, a partial reflection mirror, and a movable reflection mirror. The lens refractive index detection device enables simple operation, fast and non-destructive on-line detection, and is also applicable to lenses with irregular surfaces, such as aspherical lenses, cylindrical lenses, and finished lenses. A lens refractive index detection method is also provided.