Source Driver Noise Masking for Display Power Stability
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Solution Overview
Problem
Conventional liquid crystal display apparatuses experience errors in image data detection due to power noise, which affects the CEDS scheme's ability to synchronize clock and data signals, leading to operational issues.
Innovation Solution
A source driver with a clock data extraction circuit, cut-off switch, lock detection circuit, source driver control circuit, and noise masking circuit that forcibly maintains a normal operation state during power noise periods by generating noise period start and end signals to manage power noise, ensuring stable image voltage output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If CEDS scheme is employed for high speed image data transmission, then image data transmission speed is improved, but the source driver becomes sensitive to power noise causing operational errors
Solution Approach 1:
The source driver control circuit generates a noise mask signal in advance before the power noise generation period begins. This preliminary action allows the system to prepare for and prevent the harmful effects of power noise before they occur, maintaining reliable operation during high-speed CEDS transmission
Solution Approach 2:
The noise mask signal acts as a preliminary countermeasure against power noise. By establishing this protective signal before noise occurs, the source driver prevents power noise from disrupting the clock and data signal recognition, thus maintaining operational reliability during high-speed transmission
2Device complexity
If the source driver generates clock signal internally based on CED, then device complexity is reduced, but the source driver becomes vulnerable to power noise affecting clock and data signal detection
Solution Approach 1:
The noise mask signal serves as an intermediary protective element between the power noise environment and the clock data extraction circuit. This mediator prevents power noise from directly affecting the internal clock signal generation and data detection, maintaining reliability without adding external clock input complexity
Solution Approach 2:
The noise mask signal provides beforehand cushioning protection to the internal clock generation mechanism. By establishing this protective barrier in advance, the system cushions against power noise effects, allowing the simplified internal clock generation structure to remain reliable
3Productivity
If the source driver operates during power noise generation period, then productivity is maintained, but image data detection errors occur due to lock signal fluctuations
Solution Approach 1:
The harmful lock signal fluctuations during power noise periods are extracted and isolated from the normal operation flow. The noise mask signal separates the noise-affected lock signal from the clock data extraction process, allowing continuous operation while preventing detection errors
Solution Approach 2:
The power noise period, which would normally cause detection errors, is converted into a managed condition through the noise mask signal. The system uses the known timing of power noise generation to create protective intervals, transforming a harmful period into one where continuous operation can safely proceed
Data Source
AI summary
The present invention relates to a source driver of a display apparatus, and relates to a source driver for display apparatus insensitive to power noise, which forcibly decides an internal operation state as normality in a specific period including a power noise generation period and operates insensitively to the power noise. Accordingly, the display apparatus can normally output an image voltage even though power noise occurs.