Light Modulation Layer for Wider-Gamut Wearable Displays
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Solution Overview
Problem
Display devices, particularly those for wearable devices, often present dark gray or dark black colors and suffer from color deviation issues, failing to meet the requirement for brilliant and diverse color displays.
Innovation Solution
A display substrate with a light-emitting unit layer and a light modulation layer that includes alternately stacked sub-layers with different refractive indices, configured to selectively transmit and reflect specific wavelength ranges of light, enhancing color gamut and reducing color deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional display device is used, then the display can show basic colors, but the color gamut is limited and color deviation occurs
Solution Approach 1:
The light modulation layer is designed with spatially varying properties - different regions reflect different wavelength ranges. The first wavelength range (500-600nm) is reflected to enhance red/green colors, while the second wavelength range (600-760nm) is transmitted to maintain blue colors. This local differentiation of optical properties enables simultaneous expansion of color gamut and maintenance of color accuracy across different spectral regions.
Solution Approach 2:
The patent changes the optical parameters of the display device by introducing a light modulation layer with specific refractive index characteristics. The layer has a first refractive index in the range of 1.6 to 2.5 and a second refractive index in the range of 1.3 to 1.5, creating a refractive index difference that enables selective reflection and transmission of specific wavelength ranges, thereby expanding color gamut while maintaining color accuracy.
2Illumination intensity
If the display device presents dark gray or dark black colors, then the basic display function is achieved, but the color vibrancy and diversity are insufficient
Solution Approach 1:
The light modulation layer induces color changes by selectively reflecting specific wavelength ranges. When light passes through the layer, wavelengths in the first range (500-600nm) are reflected, while wavelengths in the second range (600-760nm) are transmitted. This selective wavelength processing enhances the vibrancy of displayed colors and enables the display to present diverse colors including red, yellow, green, and other colors, moving beyond the limited dark gray or dark black presentation of conventional devices.
3Adaptability or versatility
If a light modulation layer with high reflectivity for all wavelengths is used, then the color gamut can be expanded, but the light transmission and color accuracy would be compromised
Solution Approach 1:
The light modulation layer is designed with spatially varying optical properties - different regions reflect different wavelength ranges. The first wavelength range (500-600nm) is reflected to enhance red/green colors, while the second wavelength range (600-760nm) is transmitted to maintain blue colors. This local differentiation of optical properties enables simultaneous expansion of color gamut and maintenance of color accuracy across different spectral regions.
Solution Approach 2:
The patent changes the optical parameters of the display device by introducing a light modulation layer with specific refractive index characteristics. The layer has a first refractive index in the range of 1.6 to 2.5 and a second refractive index in the range of 1.3 to 1.5, creating a refractive index difference that enables selective reflection and transmission of specific wavelength ranges, thereby expanding color gamut while maintaining color accuracy.
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
The display substrate achieves a broader color gamut by selectively reflecting and transmitting light, providing a more vibrant and accurate color display, effectively addressing color deviation issues.
Implementation Method 1
the light modulation layer is configured to transmit a part of the light emitted from the plurality of light-emitting units and reflect the other part of the light emitted from the plurality of light-emitting units; wherein the light modulation layer is configured such that a reflectivity of the light modulation layer to light in a first wavelength range is greater than that of the light modulation layer to light outside the first wavelength range
Implementation Method 2
the light modulation layer is configured to transmit a part of the light emitted from the plurality of light-emitting units and reflect the other part of the light emitted from the plurality of light-emitting units
Implementation Method 3
the light modulation layer includes an odd number of sub-layers arranged in stack, and the odd number is 3 or more; and the odd number of sub-layers include a first sub-layer having a first refractive index and a second sub-layer having a second refractive index, the first sub-layer and the second sub-layer are alternately arranged, and the first refractive index is greater than the second refractive index
Data Source
AI summary
A display substrate is provided. The display substrate includes: a base substrate; a light-emitting unit layer arranged on the base substrate, wherein the light-emitting unit layer includes a plurality of light-emitting units respectively emitting light of a plurality of colors; and a light modulation layer located on a side of the light-emitting unit layer away from the base substrate, and configured to transmit a part of the light emitted from the plurality of light-emitting units and reflect the other part of the light emitted from the plurality of light-emitting units; wherein the light modulation layer is configured such that a reflectivity of the light modulation layer to light in a first wavelength range is greater than that of the light modulation layer to light outside the first wavelength range, and the first wavelength range is within a wavelength range of visible light and is 500 nm or more.