OLED Panel Signal Line Merging and Reverse Biasing
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Solution Overview
Problem
Organic Light Emitting Diode (OLED) displays face challenges with reduced aperture ratio and increased number of lines and elements required to drive pixels, leading to inefficiencies in light emission and panel space utilization.
Innovation Solution
The implementation of a light emitting display panel with a reduced number of signal lines and elements, utilizing a pixel driver that outputs a current for two light emitting elements, with time-divisional light emission controlled by separate light emission control signals, and the use of transistors to manage current flow and reverse biasing to extend OLED lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional OLED display uses separate data lines and source lines for each subpixel, then each subpixel can be independently driven, but the number of lines increases and the aperture ratio decreases
Solution Approach 1:
The patent merges the data line and source line functions into a single signal line per pixel. The pixel driver integrated circuit performs both data signal processing and source voltage generation, eliminating the need for separate data lines and source lines for each subpixel. This consolidation reduces the total number of lines while maintaining independent subpixel driving capability through time-divisional control.
Solution Approach 2:
The pixel driver is designed with multi-functionality to handle multiple tasks: it generates data signals, produces source voltages, and controls light emission timing. This universal pixel driver replaces multiple specialized components (separate data line drivers and source line drivers), reducing overall system complexity and line count while preserving full subpixel control.
2Measurement precision
If more signal lines are used to drive each pixel independently, then pixel control precision improves, but panel space utilization deteriorates
Solution Approach 1:
The patent combines multiple signal transmission functions into a single signal line by implementing time-divisional multiplexing. The same signal line carries both data signals and source voltage signals at different time intervals, eliminating the need for separate dedicated lines for each function while maintaining precise pixel control through temporal separation of signal types.
Solution Approach 2:
The pixel driver operates with periodic time-divisional control, alternating between data signal input phase and source voltage output phase. This periodic action allows a single signal line to serve multiple purposes sequentially, reducing spatial requirements while preserving control precision through structured temporal sequencing of operations.
3Duration of action of moving object
If continuous current is supplied to OLEDs, then light emission is maintained, but OLED lifetime decreases due to accumulated space charges
Solution Approach 1:
The patent implements periodic light emission control where the pixel driver alternates between light emission phases and space charge discharge phases. During emission, current flows to maintain light output; during discharge intervals, reverse bias is applied to remove accumulated space charges. This periodic cycling maintains continuous light emission over time while preventing degradation from charge accumulation.
Solution Approach 2:
The pixel driver performs preliminary space charge discharge actions before the next light emission cycle begins. By proactively removing accumulated charges during the off-phase, the system prevents harmful charge buildup that would otherwise occur during continuous operation, thereby extending OLED lifetime while maintaining emission continuity.
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 configuration increases the aperture ratio, effectively uses panel space, and extends the lifetime of light emitting elements by reducing the number of lines and elements while ensuring efficient light emission and appropriate current interruption.
Implementation Method 1
an Organic Light Emitting Diode (OLED) display using the electro-luminescence of an organic material
Implementation Method 2
the use of transistors to manage current flow and reverse biasing to extend OLED lifetime
Data Source
AI summary
A light emitting display increases the lifetime of a light emitting element by reverse biasing the light emitting element without using an additional power source and a power source line. The light emitting element is reverse biased without using the power source and the power source line for the reverse bias because a low level light emitting scan signal is used. The aperture ratio, contrast ratio, and lifetime of the light emitting display are increased.