Full-Color OLED Blue Sub-Pixel Pulsing for Low-Power Luminance
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Solution Overview
Problem
Conventional OLEDs face challenges in achieving low power consumption and long operational lifetimes, particularly in blue sub-pixels, which are crucial for full-color displays with high luminance and color gamut requirements.
Innovation Solution
The implementation of a pulsed drive current with a duty cycle less than 100% and a tandem structure for blue sub-pixels, combined with a plasmonic PHOLED design and optimized layer configurations, reduces current density and enhances efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional OLEDs use continuous drive current at 100% duty cycle to achieve high luminance, then brightness performance is improved, but power consumption increases and operational lifetime decreases
Solution Approach 1:
The patent applies periodic pulsed drive current instead of continuous drive current. The blue sub-pixel is driven with pulsed current at a duty cycle of 10% or less, meaning the pixel is active only 10% of the time. This periodic activation maintains high luminance during the active period while significantly reducing average power consumption and extending operational lifetime by allowing the organic materials to rest and cool between pulses.
2Illumination intensity
If conventional OLEDs increase drive current to achieve high luminance above 1,000 cd/m2, then brightness performance is improved, but blue sub-pixel operational lifetime decreases
Solution Approach 1:
The patent uses pulsed drive current with duty cycle of 10% or less for the blue sub-pixel, allowing high luminance during active periods while extending operational lifetime through periodic rest periods. This resolves the contradiction by decoupling peak luminance capability from continuous operation requirements.
Solution Approach 2:
The patent implements dynamic drive strategies where the blue sub-pixel operates in a pulsed manner rather than continuously. The drive current is dynamically adjusted to be high during brief active periods to achieve high luminance, then reduced to zero during rest periods, optimizing both brightness performance and device longevity.
3Adaptability or versatility
If OLEDs use white light emission with color filters to produce saturated colors, then color gamut is improved, but power consumption increases
Solution Approach 1:
The patent segments the display into separate red, green, and blue sub-pixels, each emitting its primary color directly through organic emissive materials. This eliminates the need for white light emission and color filtering, as each sub-pixel is independently optimized to emit saturated primary colors. The segmentation approach improves color gamut while reducing power consumption by eliminating the inefficiencies of wavelength filtering.
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 achieves high luminance and color gamut performance with reduced power consumption, exceeding 1,000 cd/m2 at the D65 white point using less than 0.5 mA/cm2 drive current, while extending the operational lifetime of blue sub-pixels.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Implementation Method 2
plasmonic PHOLED design
Data Source
AI summary
Embodiments of the disclosed subject matter provide a device having a full-color organic light emitting device (OLED) display having a plurality of pixels, with each pixel having a plurality of sub-pixels and where no individual sub-pixel of the plurality of sub-pixels emits white light. The OLED display may be configured to operate with a luminance of at least 1,000 cd/m2 at the D65 or higher white point, and using not more than a 0.5 mA/cm2 drive current for a blue sub-pixel of the plurality of sub-pixels based on an overall active area of the full-color OLED display.