Alternating Dual Drivers for OLED Subpixel Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electroluminescence displays face issues with ghost images due to cumulative stress on driving elements, leading to degradation and uneven brightness, and high power consumption.
Innovation Solution
The implementation of a compensation circuit within each subpixel that alternately operates two driving elements connected to a single light-emitting element, allowing for real-time threshold voltage sampling and offsetting data voltages to reduce stress and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single driving element is used to control the light-emitting element, then the device complexity is reduced, but cumulative stress on the driving element causes ghost images and brightness uniformity degradation
Solution Approach 1:
The patent divides a single driving element into multiple driving elements (first driving element and second driving element) that operate alternately to control the light-emitting element. This segmentation reduces cumulative stress on each individual driving element, preventing threshold voltage shifts and ghost images while maintaining overall system functionality.
Solution Approach 2:
The patent implements periodic action by alternately operating the first and second driving elements in alternating frames. Each driving element is activated for one frame then replaced by the other, providing regular stress relief and recovery time. This periodic operation prevents cumulative stress degradation while maintaining continuous display functionality.
2Productivity
If driving elements operate continuously without alternation, then productivity is maximized, but cumulative stress increases power consumption and causes ghost images
Solution Approach 1:
The patent employs periodic action by alternating between first and second driving elements on a frame-by-frame basis. Each driving element operates for one frame then is replaced by the other, providing regular stress relief and recovery time. This periodic operation prevents cumulative stress degradation while maintaining continuous display functionality, thereby optimizing power consumption without sacrificing productivity.
Solution Approach 2:
The patent implements discarding and recovering by temporarily deactivating one driving element while the other operates, allowing the deactivated element to recover from cumulative stress. This recovery mechanism reduces power consumption associated with stress-induced leakage current and threshold voltage shifts, while the alternating operation ensures continuous display refresh.
3Reliability
If compensation circuits are added to each subpixel, then ghost images are prevented through threshold voltage sampling, but device complexity increases
Solution Approach 1:
The patent merges the compensation function into the existing dual driving element structure, using the alternation mechanism itself to provide compensation. The first and second driving elements serve both as operational elements and as compensation mechanisms for each other, eliminating the need for separate compensation circuits while still achieving threshold voltage sampling and ghost image prevention.
Solution Approach 2:
The patent implements multi-functionality where the first and second driving elements serve dual purposes: they alternately drive the light-emitting element for display operation, and simultaneously provide compensation for each other by taking turns being inactive. This allows the same components to perform both driving and compensation functions, reducing overall circuit complexity while maintaining ghost image prevention capabilities.
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 effectively prevents ghost images and reduces power consumption by minimizing cumulative stress on driving elements and optimizing the operation of the electroluminescence display.
Implementation Method 1
an organic light-emitting display comprises organic light-emitting diodes (hereinafter, 'OLED') which emit light themselves
Data Source
AI summary
An electroluminescence display is provided. The electroluminescence display comprises data lines and gate lines intersecting each other and pixels arranged in a matrix, wherein each of subpixels of each pixel comprises: a first driver configured to drive a light-emitting element by using a first EM switching element, which switches the current path between a power supply line to which a pixel driving voltage is applied and the light-emitting element in response to a first light-emission control signal, and a first driving element connected between the first EM switching element and the light-emitting element; and a second driver configured to drive the light-emitting element by using a second EM switching element, which switches the current path between the power supply line and the light-emitting element in response to a second light-emission control signal, and a second driving element connected between the second EM switching element and the light-emitting element.