Wavelength Shift Correction Using Polynomial Modeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical characteristic measuring apparatuses face measurement errors due to wavelength shifts caused by changes in optical component positions over time, which cannot be accurately corrected using light sources with a small number of independent emission lines, such as the neon lamp, leading to large correction errors in shorter-wavelength ranges.
Innovation Solution
An optical characteristic measuring apparatus that includes a spectroscopic means to disperse incident light, a photoelectric conversion element to measure the light, and a calculating means to determine coefficients for a polynomial that represents the wavelength shift characteristics, allowing for accurate wavelength correction across the entire visible light range using a light source with a small number of emission lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a light source with a small number of emission lines (e.g., neon lamp) is used for wavelength calibration, then the device is compact, inexpensive, and safe for on-site use, but the measurement precision of wavelength correction deteriorates in shorter-wavelength ranges
Solution Approach 1:
The patent introduces a polynomial function as an intermediary mathematical model that relates the wavelength shift at the emission line to the wavelength shift across the entire measurement range. This polynomial acts as a mediator that translates the limited information from a single emission line measurement into comprehensive wavelength correction data for all wavelengths, thereby enabling accurate on-site calibration with limited light sources
Solution Approach 2:
The patent creates a mathematical copy (polynomial function) of the wavelength shift characteristics across the entire spectrum based on measurement at a single wavelength point. Instead of directly measuring all wavelengths, the system captures the shift characteristic at one emission line and copies this information through the polynomial model to correct the entire wavelength range, achieving comprehensive correction with minimal measurement data
2Measurement precision
If a mercury cadmium lamp is used for wavelength calibration, then the measurement precision across the entire visible light range is improved, but the device becomes dangerous due to ultraviolet radiation and requires factory calibration
Solution Approach 1:
The patent extracts only the necessary functional characteristic (emission line at a specific wavelength) from the complex mercury cadmium lamp spectrum, and uses a simplified light source (neon lamp) that provides just this extracted function. By taking out only the essential emission line feature needed for calibration and discarding the harmful ultraviolet components, the system achieves adequate calibration capability without the dangerous radiation
Solution Approach 2:
The patent replaces the expensive, hazardous, and complex mercury cadmium lamp with a simple, inexpensive, and safe neon lamp. The neon lamp, while having fewer emission lines, provides the essential calibration function through the polynomial correction method, offering a disposable-like simplicity and safety advantage over the permanent, hazardous factory calibration requirement
3Measurement precision
If wavelength calibration is performed at a factory or service base, then the measurement precision is maintained, but the productivity is reduced due to device unavailability during calibration
Solution Approach 1:
The patent enables the optical characteristic measuring apparatus to perform its own wavelength calibration using the built-in or externally connected neon lamp and the polynomial correction capability. The device serves itself by detecting the emission line, calculating the wavelength shift, and applying the correction through the polynomial function, eliminating the need for external factory or service base calibration and maintaining continuous operational availability
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 wavelength correction over the entire range of wavelengths dispersed by the spectroscopic section, even with a light source like the neon lamp, reducing measurement errors and allowing on-site correction without the need for factory calibration.
Implementation Method 1
a spectroscopic section to disperse incident light according to wavelengths
Implementation Method 2
a plurality of photoelectric conversion elements arranged in a dispersion direction to receive the dispersed light
Data Source
AI summary
A wavelength of incident light is measured based on signals from a plurality of pixels of a photoelectric conversion element that are arranged in a dispersion direction in which the incident light is dispersed by a spectroscopic section. In correction of a shift in wavelength, a measured amount of shift in wavelength that is a difference between a measured value obtained when an emission line wavelength of incident light from a light source for wavelength shift correction that emits light including an emission line at least one wavelength in a range of wavelengths into which light can be dispersed by the spectroscopic section is measured and an original emission line wavelength is calculated. A reference amount of shift in emission line wavelength is calculated by a polynomial in which a characteristic of a wavelength shift that occurs is represented by a linear or higher polynomial with a variable indicating the wavelength or a parameter relating to the wavelength. Each coefficient of the polynomial is determined based on the calculated measured amount of shift in emission line wavelength and the reference amount of shift in emission line wavelength, and the wavelength of the incident light is corrected based on the determined polynomial.