Green Display Spectrum Tuning for Rec. 2020 and M-Cone Perception
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Solution Overview
Problem
Display devices struggle to emit green light that meets the Rec. 2020 standard for ultra-high-definition while providing high perception to human M size cone cells, as designs with narrower green light spectra compromise on color gamut and perception.
Innovation Solution
A display device with a specific output spectrum profile, where the ratio of intensity integrals from 380 nm to 493 nm and from 576 nm to 780 nm is greater than 0.0% and less than or equal to 37.0%, and the ratio of secondary to primary intensity peaks is between 1.0% and 15.0%, ensuring high Rec. 2020 coverage ratio and improved perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the output spectrum of green light is designed with higher peak and smaller FWHM to meet Rec. 2020 standard, then the color gamut is improved, but the perception of M size cone cells is decreased
Solution Approach 1:
The patent applies parameter changes by optimizing the spectral distribution parameters of green light output. Specifically, it controls the FWHM to be between 30-50nm and sets the intensity ratio between 480-530nm and 531-560nm ranges to achieve both Rec. 2020 compliance and M cone cell stimulation. This precise parameter optimization resolves the contradiction between color gamut and perception.
Solution Approach 2:
The patent uses partial action by selectively enhancing specific wavelength components within the green spectrum. Instead of uniformly narrowing the spectrum, it maintains enhanced intensity in the 480-530nm range (which stimulates M cones) while still achieving narrow FWHM for color accuracy. This partial enhancement approach satisfies both requirements.
2Manufacturing precision
If the green light spectrum is narrowed to provide pure green light, then the Rec. 2020 coverage is improved, but the stimulation of M size cone cells is reduced
Solution Approach 1:
The patent applies local quality by creating non-uniform spectral distribution within the green light. It concentrates intensity in specific wavelength regions (480-530nm) that correspond to M cone cell sensitivity, while maintaining narrow overall bandwidth for color accuracy. This localized intensity enhancement resolves the contradiction between color purity and biological perception.
3Manufacturing precision
If the FWHM of green light is reduced to increase color purity, then the ultra-high-definition standard is met, but the perception quality deteriorates
Solution Approach 1:
The patent resolves this contradiction through precise parameter control: FWHM is set to 30-50nm for color purity, while the intensity ratio between 480-530nm and 531-560nm is optimized to ensure M cone cell stimulation. This dual parameter optimization achieves both ultra-high-definition color accuracy and high perception quality.
Data Source
AI summary
A display device includes a display unit emitting an output light that has an output spectrum corresponding to a highest gray level of the display device. A maximum peak of the output spectrum between 380 nm and 493 nm is defined as a first intensity peak. A secondary peak of the output spectrum between 380 nm and 493 nm is defined as a second intensity peak. A first sub-peak ratio of the second intensity peak to the first intensity peak is in a range from 7.0% to 75.0%.