Light Measuring Apparatus Spectral Sensor Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light measuring apparatuses face challenges in achieving high precision for color luminance values of monochromatic lights due to limitations in half power band width and wavelength pitch of light receiving sensors, leading to decreased approximation precision and errors in measurements.
Innovation Solution
A light measuring apparatus with photoelectrical converters having a half power band width (A) and center wavelength interval (B) optimized to satisfy conditions B≧5 nm and A/B=1.5 to 4.0, using a spectral fitting method to calculate composite spectral responsivities approximate to specified color matching functions, thereby enhancing measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a spectral luminance meter uses a narrow half power band width to obtain spectral data at minute wavelength intervals, then the spectral responsitivities can precisely coincide with color matching functions, but a bright optical system with high resolving power is necessary, resulting in a relatively large size
Solution Approach 1:
The spectral measurement function is segmented across multiple light receiving sensors with different spectral responsitivities. Each sensor captures a portion of the spectrum, and the results are combined through spectral fitting to achieve high precision without requiring a single complex optical system.
Solution Approach 2:
The invention optimizes the parameters of light receiving sensors (half power band width A and center wavelength interval B) to satisfy specific relationships (A/B=1.5 to 4.0, B≥5 nm). By adjusting these parameters, the system achieves high spectral responsitivity approximation while using a compact optical system.
2Measurement precision
If the half power band width and wavelength pitch of light receiving sensors are not optimized, then the approximation precision of composite spectral responsitivities decreases, but using optimized parameters increases measurement precision for monochromatic lights
Solution Approach 1:
The invention systematically optimizes the parameters A (half power band width) and B (center wavelength interval) of light receiving sensors. By establishing specific relationships between these parameters (A/B=1.5 to 4.0, B≥5 nm), the system achieves both high approximation precision of spectral responsitivities and high measurement precision for monochromatic lights.
Solution Approach 2:
The spectral fitting method uses calculated weight coefficients based on the spectral responsitivities of individual sensors to combine their outputs. This feedback mechanism adjusts the contribution of each sensor to maximize the approximation precision of the composite spectral responsitivity, thereby improving measurement accuracy.
3Volume of moving object
If a color luminance meter combines multiple optical filters to build filter characteristics approximate to color matching functions, then the light measuring apparatus is compacted, but it is difficult to meet required approximation precision due to restrictions on usable filters and variations in their characteristics
Solution Approach 1:
The invention replaces the mechanical/optical filter combination approach with a spectral fitting method using multiple light receiving sensors with known spectral responsitivities. This substitution allows for more precise control of spectral characteristics while maintaining a compact form factor, as the spectral response is defined by sensor characteristics rather than physical filter geometries.
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 approach allows for highly precise measurements of color luminance values and chromaticity by maximizing error suppression in narrow band measurements, particularly for monochromatic lights from displays and LEDs.
Implementation Method 1
a spectral device for dispersing measurement light at each of specified wavelengths
Implementation Method 2
a predetermined number of photoelectrical converters for receiving the dispersed measurement light and outputting light reception signals corresponding to the predetermined number of wavelengths
Data Source
AI summary
A color luminance meter 1 is provided with a polychrometer 4 as a spectral optical system including a light receiving sensor array 43, a signal processing circuit 5 and an operation control unit 6. The operation control unit 6 carries out calculations to obtain characteristics of a measurement light based on a specified spectral responsitivity, using light reception signals and specified weighting coefficients. The spectral responsitivities of light receiving sensors constructing the light receiving sensor array 43 are selected such that B≧5 nm and A/B lies within a range of 1.5 to 4.0 when A, B denote the half power band width of the spectral responsitivities and a center wavelength interval of the spectral responsitivities. Accordingly, there can be provided a light measuring apparatus capable of maximally suppressing errors to highly precisely measure color luminance values and the like even in a measurement of a light lying in a narrow band such as a monochromatic light.