Stacked OLED Blue Sub-Pixel for Low Blue Light and High Gamut
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Solution Overview
Problem
Current OLED display technology struggles to reduce blue light emission while maintaining a high color gamut, as the light emitting wavelength of OLED devices is determined by the bandgap of the light emitting material, making it difficult to adjust and control blue light content effectively.
Innovation Solution
An OLED display panel with a stacked blue light emitting device structure, comprising a substrate layer, anode layer, first and second electroluminescent layers, and a charge generating layer, where the first electroluminescent layer has a peak wavelength of 450-465 nm and the second has a peak wavelength of 435-450 nm, allowing for adjustable blue light emission by varying the current applied to these layers based on image saturation thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the content of short-wave blue light is reduced in OLED display, then the damage to human eyes is reduced, but the gamut of the overall panel is affected
Solution Approach 1:
The blue light emitting device is divided into two separate electroluminescent layers: a first electroluminescent layer emitting long-wave blue light (450-465nm) and a second electroluminescent layer emitting short-wave blue light (435-450nm). This segmentation allows independent control of each layer's emission, enabling reduction of short-wave blue light content while preserving long-wave blue light contribution to color gamut.
Solution Approach 2:
The patent changes the emission wavelength parameter by using two distinct electroluminescent layers with different peak wavelengths. By adjusting the current applied to each layer independently, the system can control the spectral composition of blue light output, reducing harmful short-wave content while maintaining overall color performance.
2Object-affected harmful factors
If the light emitting wavelength of OLED is adjusted to reduce blue light, then blue light content is reduced, but the display cannot maintain true color representation
Solution Approach 1:
By segmenting the blue light emission into two distinct layers with different wavelength characteristics, the system can independently manage the spectral contribution of each layer. The first layer maintains color accuracy while the second layer's emission can be controlled to reduce overall blue light content.
Solution Approach 2:
The patent implements dynamic control by independently adjusting the current applied to each electroluminescent layer based on image content characteristics. When blue light reduction is needed, the system dynamically modifies the driving current to the second layer while compensating in the first layer to maintain color fidelity.
3Object-affected harmful factors
If a stacked blue light emitting device structure is used, then low blue light display is achieved, but the device structure becomes more complex
Solution Approach 1:
The patent merges two electroluminescent layers into a single integrated blue light emitting device structure, sharing common electrodes (anode and cathode) and encapsulation layers. This combining approach reduces the number of discrete components compared to using separate devices, while still achieving the dual-wavelength emission capability for blue light control.
Solution Approach 2:
The stacked structure serves multiple functions: the first electroluminescent layer provides long-wave blue light for color gamut and accuracy, the second electroluminescent layer provides short-wave blue light that can be controlled for blue light reduction, and together they enable dynamic blue light management while maintaining a unified device architecture.
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 enables low blue light display while maintaining high gamut by selectively driving the electroluminescent layers with appropriate currents, ensuring normal light emission and true color representation.
Implementation Method 1
the first electroluminescent layer has a first blue light peak wavelength, the second electroluminescent layer has a second blue light peak wavelength
Data Source
AI summary
An embodiment of the present invention discloses an OLED display panel, including a plurality of pixel structures arranged in an array, each pixel structure including a red sub-pixel, a green sub-pixel and blue sub-pixels, wherein the blue sub-pixel is a stacked device structure sequentially including a substrate layer, an anode layer, a first electroluminescent layer, a charge generating layer, a second electroluminescent layer and a cathode layer, wherein the first electroluminescent layer has a first blue light peak wavelength, the second electroluminescent layer has a second blue light peak wavelength, and the first blue light peak wavelength is greater than the second blue light peak wavelength. The invention also provides a corresponding driving method and driving device. By implementing the embodiments of the present invention, it is possible to reduce the content of the blue wavelength of the short wavelength in the display device.