Field Recalibration of Color Measurement Instruments
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Solution Overview
Problem
Color measurement instruments, such as colorimeters, are often factory-calibrated for specific display types and cannot accurately measure new display types or categories without being recalibrated, requiring return to the factory for updates, which is inefficient and causes equipment downtime.
Innovation Solution
A method to recalibrate color measurement instruments in the field by assembling a new calibration matrix using measurements from both the instrument and a spectroradiometer, allowing for remote recalibration without removing the instrument from service, using a combination of data generated in the factory and in the field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If color measurement instruments are factory-calibrated for specific display types, then measurement accuracy for those display types is ensured, but the instrument cannot measure new display types without returning to the factory for recalibration
Solution Approach 1:
The patent uses a spectroradiometer as an intermediary device to capture reference spectral data from new display types. This reference data is then combined with the colorimeter's existing calibration data to generate updated calibration coefficients without requiring the colorimeter to leave the field, thus resolving the contradiction between adaptability and downtime.
Solution Approach 2:
The patent performs preliminary spectral measurements using a spectroradiometer to capture reference data from new display types before recalibrating the colorimeter. This preliminary data collection enables the subsequent calculation of new calibration coefficients to be done quickly and accurately without extended equipment downtime.
2Measurement precision
If color measurement instruments are factory-calibrated, then initial measurement accuracy is achieved, but recalibration requires returning to the factory which is inefficient
Solution Approach 1:
The patent enables the colorimeter to perform self-recalibration in the field by combining its existing calibration data with new spectral reference data from a spectroradiometer. The system automatically calculates updated calibration coefficients and stores them locally, eliminating the need for factory recalibration and improving ease of operation while maintaining measurement precision.
Solution Approach 2:
The patent segments the recalibration process into two independent parts: spectral reference data collection (performed by spectroradiometer) and calibration coefficient calculation (performed by colorimeter). This segmentation allows the colorimeter to remain in the field while only the necessary recalibration computations are performed, improving convenience without sacrificing accuracy.
3Adaptability or versatility
If factory calibration is performed for specific display types, then calibration accuracy for those types is ensured, but the calibration matrix cannot be updated for new display types
Solution Approach 1:
The patent changes the calibration parameters by combining spectral reference data from new display types with existing colorimeter calibration data. This parameter transformation allows the calibration matrix to be updated for new display types while maintaining the mathematical relationships that ensure calibration accuracy through the use of CIE color space transformations.
Data Source
AI summary
A method includes determining a fielded color measurement instrument is not calibrated to measure light emitted by a fielded light emitting device, assembling a calibration matrix, such that a product of the calibration matrix multiplied by a response of the fielded color measurement instrument to the light emitted by the fielded light emitting device is a triplet that corresponds to a Commission Internationale de L'éclairage XYZ color space, wherein the calibration matrix contains measurements made by the fielded color measurement instrument of a first plurality of lights emitted by the fielded light emitting device and measurements made by a spectroradiometer of a second plurality of lights emitted by a reference light emitting device of a same make and model as the fielded light emitting device, wherein the spectroradiometer is located remotely from the fielded color measurement instrument, and storing the calibration matrix on the fielded color measurement instrument.