OLED Scan Driver Alternating Odd Even Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic light emitting displays face challenges in maintaining uniform brightness due to varying loads on the power source, which can result in non-uniform image display as the voltage of the power source changes with the pattern and brightness of images.
Innovation Solution
The solution involves a scan driver that alternates the supply of scan signals to odd and even scan lines between frames, ensuring that pixels on odd and even horizontal lines emit light in alternate frames, thereby minimizing the load on the power source and maintaining consistent voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If all pixels emit light simultaneously in conventional organic light emitting displays, then the image display is complete, but the voltage of the power source changes significantly causing non-uniform brightness
Solution Approach 1:
The pixel array is divided into two groups based on the parity of their horizontal line numbers. Pixels on odd horizontal lines and pixels on even horizontal lines are driven in alternating frames, with each group emitting light in half of the frames. This segmentation reduces the simultaneous load on the power source, stabilizing voltage and ensuring uniform brightness across the display.
2Productivity
If pixels on all horizontal lines emit light in each frame, then the display updates completely, but the load on the power source varies causing voltage changes
Solution Approach 1:
The display operates in a periodic manner where pixels on odd horizontal lines emit light in one frame while pixels on even horizontal lines emit light in the next frame. This alternating periodic action ensures that the power source experiences reduced and more stable load variations, maintaining voltage stability while still achieving complete display updates over two frames.
3Productivity
If the scan driver supplies scan signals to all scan lines in each frame, then all pixels can be updated, but the emission control signals cause all pixels to emit light except during scanning
Solution Approach 1:
The scan driver is configured to supply scan signals alternately to odd scan lines and even scan lines in different frames. Correspondingly, emission control signals are supplied to odd emission control signal lines in one frame and to even emission control signal lines in the next frame. This segmented approach ensures uniform brightness while maintaining complete pixel update coverage.
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 reduces the change in voltage of the power sources, allowing for more uniform image display with improved brightness consistency by alternating the emission periods of pixels between frames.
Implementation Method 1
organic light emitting diodes (OLED), which generate light by re-combination of electrons and holes
Data Source
AI summary
An organic light emitting display including a scan driver for supplying scan signals to odd scan lines in an ith frame and for supplying scan signals to even scan lines in an (i+1)th frame, a data driver for supplying data signals corresponding to the scan signals, and an image display unit including a plurality of pixels coupled with the scan lines and the data lines. Pixels coupled with the odd scan lines do not emit light when the scan signals are supplied to the odd scan lines, and pixels coupled with the even scan lines do not emit light when the scan signals are supplied to the even scan lines.