OLED Display Leakage Current Bypass Resistor
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Solution Overview
Problem
Organic light emitting diode (OLED) displays suffer from reduced luminance and contrast ratio due to leakage currents, which also shorten the lifespan of the organic light emitting elements, especially during the black mode operation.
Innovation Solution
Incorporating a resistor and a bypass wire in the OLED display configuration, where the resistor is connected to the anode of the organic light emitting element and the bypass wire is connected to the second end of the resistor, allowing for the diversion of leakage current and improving luminance characteristics by adjusting the driving current distribution based on luminance levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional OLED display structure is used, then the display can be implemented with high luminance and fast response time, but leakage current causes light emission in black mode which deteriorates contrast ratio
Solution Approach 1:
The patent extracts the harmful leakage current from the main current path by introducing a bypass wire that provides a separate path for leakage current to flow through a resistor to the second power wire, separating it from the driving current that controls light emission
Solution Approach 2:
The patent introduces a resistor as an intermediary component connected between the anode and the second power wire, which mediates the leakage current by providing a controlled path that prevents direct leakage while maintaining display performance
2Use of energy by moving object
If the driving thin film transistor is in turn-off state, then power consumption is reduced, but leakage current still flows through the organic light emitting element causing undesirable light emission
Solution Approach 1:
The patent converts the harmful leakage current into a beneficial effect by routing it through a dedicated bypass path with a resistor, where it can be controlled and dissipated without affecting the contrast ratio or causing unwanted light emission in black mode
3Duration of action of stationary object
If leakage current flows through the organic light emitting element, then the display can maintain operation, but the life-span of the organic light emitting element is reduced
Solution Approach 1:
The patent extracts the damaging leakage current from the organic light emitting element by providing an alternative path through the bypass wire and resistor, preventing the cumulative damage that would otherwise reduce the element's lifespan while maintaining operational 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
The solution effectively reduces the impact of leakage currents on contrast ratio and extends the lifespan of the OLED display by optimizing current distribution, enhancing luminance consistency and reducing mura (luminance variation) across different luminance regions.
Implementation Method 1
Electrons and holes are combined with each other in an organic emissive layer to thereby generate excitons. When the excitons shift from the excited state to the ground state, energy is generated so as to emit light
Implementation Method 2
a resistor having a first end connected with an anode of the organic light emitting element; and a bypass wire connected with a second end of the resistor
Data Source
AI summary
An organic light emitting diode (OLED) display according to an exemplary embodiment of the present invention includes: a switching transistor configured to perform a switching operation according to a scan signal; a driving transistor configured to supply a driving current according to a data signal transmitted according to the switching operation of the switching transistor; an organic light emitting element electrically connected with the driving transistor and configured to emit light according to the driving current; a resistor having a first end connected with an anode of the organic light emitting element; and a bypass wire connected with a second end of the resistor.