AMOLED Emission Control Across Luminance Boundaries to Reduce Flicker
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Solution Overview
Problem
Organic light emitting display devices experience a flicker phenomenon when the AMOLED impulsive driving (AID) method is applied in low luminance areas due to rapid changes in the number of cycles of the emission control signal.
Innovation Solution
Implementing a display device with distinct luminance ranges and a boundary area where the off-duty number of the emission control signal is gradually increased, maintaining a constant reference luminance and adjusting the off-duty ratio to minimize flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the AID method is applied with a low number of cycles in low luminance area, then power consumption is reduced, but a flicker phenomenon becomes visible
Solution Approach 1:
The patent applies different off-duty numbers for different luminance areas. Specifically, a first off-duty number is used for a first luminance area and a second off-duty number (different from the first) is used for a second luminance area. This local differentiation allows the low luminance area to use a higher off-duty number to reduce flicker while other areas maintain lower off-duty numbers for power efficiency.
Solution Approach 2:
The patent changes the parameter of off-duty number based on luminance area characteristics. By adjusting this parameter locally rather than uniformly across the entire display, the system optimizes both power consumption and flicker reduction for different viewing conditions and luminance levels.
2Object-affected harmful factors
If the off-duty number is increased to reduce flicker, then the flicker phenomenon is reduced, but luminance discontinuity occurs at the boundary area between different luminance ranges
Solution Approach 1:
The patent introduces a boundary area between the first luminance area and the second luminance area. This boundary area acts as an intermediary transition zone where the off-duty number gradually changes from the first off-duty number to the second off-duty number, preventing abrupt luminance discontinuities while still reducing flicker in the low luminance region.
Solution Approach 2:
The off-duty number is made dynamic and adaptive rather than fixed. The system dynamically adjusts the off-duty number based on the luminance area being displayed, allowing smooth transitions and maintaining luminance continuity while adapting to different viewing conditions and reducing flicker where necessary.
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 solution effectively reduces flicker phenomena by smoothing luminance transitions through controlled changes in the off-duty number and ratio of the emission control signal, enhancing display performance in low luminance areas.
Implementation Method 1
an organic light emitting display device displays an image using an organic light emitting diode that generates light by recombination of an electron and a hole
Data Source
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AI summary
A display device includes at least a first luminance range and a second luminance range which includes a luminance different from the first luminance range. In a boundary area of a second dimming range corresponding to the second luminance range and which is adjacent to a first dimming range corresponding to the first luminance range, a reference luminance emitted from a pixel is maintained as a first constant luminance value, and an off-duty number, which is the number of periods in which the pixel is turned off during one frame, is gradually increased by an emission control signal.