Optical Measurement Apparatus Chromatic Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measurement apparatuses using low coherence interferometry struggle to accurately determine the condensing position on test surfaces due to wavelength differences between index light and test light, leading to inaccurate control and increased costs with infrared cameras.
Innovation Solution
A measurement apparatus employing a first light source, image sensor, interferometer with a second light source of different wavelength, and correction unit to adjust and correct condensing position deviations, allowing for accurate optical path length acquisition and distance measurement between test surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If infrared wavelength light source is used for low coherence interferometry measurement, then measurement precision is improved, but device cost increases due to requirement of infrared cameras
Solution Approach 1:
The patent changes the wavelength parameter of the light source from infrared to visible light range, enabling the use of cheaper visible cameras instead of expensive infrared cameras while maintaining measurement functionality through chromatic aberration correction
Solution Approach 2:
The patent uses visible light as a substitute (copy) for infrared light in the measurement process, achieving similar measurement objectives with more cost-effective equipment by correcting the wavelength-related deviations
2Ease of manufacture
If visible wavelength light source is used instead of infrared, then device cost is reduced by using visible cameras, but measurement precision deteriorates due to condensing position deviation caused by wavelength difference
Solution Approach 1:
The patent replaces the physical alignment mechanism with an optical correction mechanism using chromatic aberration correction lenses, substituting mechanical position adjustment with optical path correction to eliminate condensing position deviation
Solution Approach 2:
The patent introduces chromatic aberration correction lenses as intermediary optical elements between the visible light source and the tested optical system, mediating the wavelength difference effects to achieve accurate condensing position
3Ease of manufacture
If index light and test light have different wavelengths, then visible cameras can be used reducing cost, but condensing position control accuracy deteriorates due to wavelength difference between lights
Solution Approach 1:
The patent changes the optical parameters of the measurement system by introducing chromatic aberration correction lenses specifically designed to compensate for the wavelength difference between visible index light and infrared test light, maintaining condensing position accuracy
Solution Approach 2:
The patent implements a feedback mechanism where the condensing position is monitored and the chromatic aberration correction is adjusted based on the detected position deviation, ensuring accurate alignment despite wavelength differences
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 precise distance measurement between test surfaces by correcting condensing position deviations, reducing costs by using visible cameras and improving accuracy, even in cases of significant wavelength differences.
Implementation Method 1
acquire an interference signal by causing interference between the reference light and the test light
Implementation Method 2
measurement optical system configured to make first light emitted from the chart enter a tested optical system
Implementation Method 3
correction unit configured to correct a condensing position deviation between the first light and the test light caused by a wavelength difference between the first light and the test light
Data Source
AI summary
A measurement apparatus includes a measurement optical system configured to make first light emitted from a chart enter a tested optical system, an image sensor configured to receive the first light, an adjusting unit configured to adjust relative positions of the measurement optical system and the tested optical system, an interferometer configured to acquire an interference signal by causing interference between reference light and test light, a correction unit configured to correct a condensing position deviation between the first light and the test light, and an acquiring unit configured to acquire an optical path length from the first point to the plurality of test surfaces based on the interference signal, and a distance between adjacent test surfaces among the plurality of test surfaces based on the optical path length.