Optical Measuring Device for Aperiodic Flicker via Digital Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical measuring devices struggle to accurately measure flicker in displays with complex and aperiodic light emission waveforms, such as those with variable refresh rates, due to waveform distortion and synchronization issues in digital Fourier transform methods, leading to measurement errors and lack of reproducibility.
Innovation Solution
An optical measuring device that includes a stimulus value acquirer, a response characteristic acquirer, and a digital filter processor to generate data with suppressed waveform distortion by superimposing a luminous stimulus response, using impulse response characteristics to process continuous data and derive flicker indices without digital Fourier transform.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If digital Fourier transform method is used to measure flicker, then measurement can be performed on displays with simple light emission waveforms, but waveform distortion occurs and measurement precision deteriorates for displays with complex and aperiodic light emission waveforms
Solution Approach 1:
The patent changes the fundamental measurement parameter from frequency-domain analysis (Fourier transform) to time-domain analysis (direct temporal processing of stimulus values). This allows accurate measurement of both periodic and aperiodic waveforms by processing the light emission waveform directly in the time domain, avoiding the synchronization requirements and waveform distortion issues inherent in Fourier transform methods
Solution Approach 2:
Instead of transforming the waveform to frequency domain and back (conventional approach), the patent inverts the approach by directly processing the time-domain stimulus values through convolution with the temporal contrast sensitivity function. This reversal eliminates the need for Fourier transform and its associated synchronization requirements, enabling accurate measurement of aperiodic waveforms
2Adaptability or versatility
If measurement time does not match cycle of light emission waveform, then measurement can be performed on aperiodic waveforms, but false frequency components are generated and measurement precision deteriorates
Solution Approach 1:
The patent eliminates the measurement time parameter constraint by changing from frequency-domain analysis to time-domain analysis. In the time domain, there is no requirement for the measurement window to match waveform cycles, allowing accurate measurement of aperiodic waveforms without generating false frequency components
Solution Approach 2:
The patent extracts and removes the Fourier transform step from the measurement process, eliminating the source of false frequency components. By directly convolving the time-domain stimulus values with the temporal contrast sensitivity function, the method avoids the frequency spectrum analysis that generates spurious frequency components when measurement time doesn't match waveform cycles
3Measurement precision
If leading end and trailing end data are deleted to ensure synchronization, then waveform distortion is reduced, but measurement time increases and productivity decreases
Solution Approach 1:
The patent changes from frequency-domain processing requiring synchronization to time-domain processing that does not require data deletion. By directly processing the complete stimulus value data in the time domain through convolution, the method maintains waveform accuracy without sacrificing measurement speed
Solution Approach 2:
Instead of deleting data to achieve synchronization (conventional approach), the patent inverts the approach by using all available data without deletion and processing it directly in the time domain. This reversal eliminates the need for synchronization adjustments while maintaining measurement accuracy and preserving measurement speed
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 and reproducible flicker measurement in displays with aperiodic light emission waveforms by suppressing waveform distortion and allowing for flexible measurement conditions, without the need for data deletion or synchronization adjustments.
Implementation Method 1
an optical sensor 21 and an output unit 22, which forms a stimulus value acquisition unit 20 that receives light from a measurement target 100 and continuously acquires intensity corresponding to a stimulus value
Data Source
AI summary
An optical measuring device includes: a stimulus value acquirer that receives light from a measurement target and continuously acquires intensity corresponding to a stimulus value at a regular time interval; a response characteristic acquirer that acquires an impulse response characteristic from a storage that stores the impulse response characteristic corresponding to a luminous stimulus response; and a hardware processor that performs digital filter processing on continuous data of stimulus value intensity acquired by the stimulus value acquirer by the impulse response characteristic acquired by the response characteristic acquirer to generate data on which the luminous stimulus response is superimposed.