Photometric Device Using Interference Filters and Rotating Disk
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Solution Overview
Problem
Photometric devices face challenges in measuring light from low luminance to high luminance with high accuracy in a short time, as existing methods either compromise on speed or accuracy, with techniques using X, Y, and Z filters offering fast but low accuracy, and transmissive wavelength variable filters resulting in low light transmission and unsuitable for measuring low luminance.
Innovation Solution
A photometric device incorporating interference filters corresponding to tristimulus values and a spectral portion, supported by a rotatable disk with a motor-driven actuator, allowing sequential scanning of these filters to enhance measurement accuracy and complement low-luminance measurements with high-luminance capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transmissive wavelength variable filter is used to scan spectral characteristics, then spectral measurement accuracy is improved, but light transmission is reduced making low luminance measurement impossible
Solution Approach 1:
The patent segments the spectral measurement function into two distinct components: a transmissive wavelength variable filter for high-accuracy spectral measurement, and multiple interference filters (X, Y, Z filters) for light transmission and luminance measurement. This segmentation allows each component to optimize its function without compromising the other.
Solution Approach 2:
The patent merges the transmissive wavelength variable filter with multiple interference filters in a single photometric device. The interference filters are positioned to receive light that has passed through the transmissive wavelength variable filter, combining spectral analysis capabilities with sufficient light transmission for low luminance measurement.
2Productivity
If X, Y, and Z filters are used for measurement, then measurement speed is improved, but measurement accuracy is reduced
Solution Approach 1:
The patent enables continuous operation by having the transmissive wavelength variable filter and interference filters work simultaneously in parallel. The transmissive wavelength variable filter continuously scans spectral characteristics while the interference filters continuously measure luminance, eliminating the need for sequential measurement and maintaining high measurement speed without sacrificing accuracy.
3Measurement precision
If transmissive wavelength variable filter splits light by plane split, then spectral separation is achieved, but light amount to photoreceptor becomes very small
Solution Approach 1:
The patent introduces interference filters as intermediary components that receive light after it passes through the transmissive wavelength variable filter. These interference filters act as mediators that can handle and transmit sufficient light amounts to the photoreceptor while the transmissive wavelength variable filter performs its spectral separation function, thus decoupling the light splitting function from the light transmission bottleneck.
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 accurate measurement of light across a wide luminance range in a short time by combining the accuracy of spectral data with the complementing capabilities of interference filters, improving measurement speed and precision.
Implementation Method 1
interference filters selectively transmitting a particular wavelength corresponding to a respective one of tristimulus values
Implementation Method 2
spectral portion separating and transmitting an incident light
Implementation Method 3
photoreceptor converting light passed through the interference filter and light passed through the spectral portion to an electrical signal
Data Source
AI summary
A photometric device (1) measuring light emitted from a measuring object such as a display (2) includes interference filters (20X, 20Y, and 20Z) selectively transmitting a particular wavelength corresponding to a respective one of tristimulus values, an LVF (21) separating and transmitting incident light, a disk (22) supporting the interference filters and the LVF, a motor (23) rotatably drive the disk to cause the light emitted from the measuring object to scan the interference filters and the LVF sequentially, a photoreceptor (13) converting light passed through the interference filters and light passed through the LVF to an electrical signal, and a photometric controller (14) outputting photometric information based on the electrical signal of the light passed through the interference filters and converted by the photoreceptor and the electrical signal of the light passed through the LVF and converted by the photoreceptor.