Demultiplexer-Based Pixel Voltage Coupling Compensation
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Solution Overview
Problem
Voltage coupling during pixel scanning in OLED display devices leads to color deviation issues, as existing technologies fail to maintain consistent voltage levels across sub-pixels of the same color, affecting display quality.
Innovation Solution
The implementation of demultiplexers in the display device, controlled by a timing controller, selectively connects data signals to sub-pixels through a network of scan and data lines, ensuring consistent coupling effects across sub-pixels of the same color, thereby maintaining uniform voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pixels are scanned using conventional multiplexing, then the display device can operate with simpler circuitry, but voltage coupling causes color deviation between sub-pixels
Solution Approach 1:
The patent divides the pixel array into multiple blocks, with each block containing sub-pixels of the same color. Demultiplexers are assigned to each block to independently control voltage coupling characteristics. This segmentation allows different coupling compensation strategies to be applied to different color groups, resolving the color deviation issue while maintaining manageable circuit complexity through modular organization.
Solution Approach 2:
The patent introduces demultiplexers as intermediary components between the data lines and sub-pixels. These demultiplexers act as mediators that can selectively connect data signals to specific sub-pixels and compensate for voltage coupling effects. By placing these intermediary devices at the signal distribution stage, the system achieves color consistency without requiring complex per-pixel circuitry.
2Productivity
If data signals are provided through shared data lines, then the display device reduces the number of data lines, but voltage coupling causes inconsistent voltage levels across sub-pixels
Solution Approach 1:
The patent applies preliminary compensation actions through the demultiplexers before data signals are finally delivered to sub-pixels. The demultiplexers pre-adjust voltage levels to account for anticipated coupling effects, ensuring that despite shared data lines, each sub-pixel receives the correct voltage level. This preliminary correction maintains voltage consistency while preserving the efficiency of shared data line architecture.
Solution Approach 2:
The patent dynamically changes electrical parameters (voltage levels, connection states) through the demultiplexers based on the specific coupling characteristics of each data line and sub-pixel combination. By adjusting these parameters in real-time, the system compensates for coupling effects and maintains consistent voltage delivery across all sub-pixels using shared data lines.
Data Source
AI summary
A display device includes a display panel including a plurality of scan lines, a plurality of data lines, and a plurality of unit pixels. Each unit pixel includes a plurality of sub-pixels, each coupled to a respective data line. The plurality of sub-pixels includes a red sub-pixel, a first green sub-pixel, a blue sub-pixel, and a second green sub-pixel. The display device further includes a data driver configured to output data signals via output channels. The display device additionally includes a plurality of demultiplexers configured to selectively connect data signals output from the output channels to the plurality of sub-pixels in response to a plurality of select signals that are sequentially provided to the plurality of demultiplexers. The display device further includes a scan driver configured to provide scan signals to the unit pixels through the scan lines, and a timing controller.