Liquid Crystal Display Driver Circuit Power Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid crystal display devices face challenges in reducing power consumption and maintaining display quality due to complex driver circuit operations and temperature-induced luminance changes, leading to voltage fluctuations and image degradation.
Innovation Solution
Implementing a method that sets a moving image display mode and a still image display mode, where the image signal is rewritten to maintain the still image state, and the holding period is adjusted based on the display device's temperature, using a control circuit to manage the output of image signals and power supply voltage, and incorporating a temperature detection circuit to optimize the operation of the driver circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the driver circuit operation is stopped during break period to reduce power consumption, then power consumption is reduced, but the voltage applied to liquid crystal element fluctuates due to leakage current and parasitic capacitance
Solution Approach 1:
The patent implements periodic writing operations during the break period at optimized intervals. Instead of continuously writing image signals, the system performs periodic writes that refresh the liquid crystal element voltage before leakage current causes significant degradation, thereby maintaining voltage stability while allowing the driver circuit to remain in a low-power state for extended periods.
Solution Approach 2:
The patent optimizes the writing interval parameter during break period based on temperature conditions. By dynamically adjusting the timing of periodic write operations, the system adapts to temperature-dependent leakage current characteristics, ensuring voltage stability is maintained across different operating temperatures while minimizing unnecessary driver circuit activity.
2Loss of energy
If the writing interval is extended to reduce power consumption, then power consumption is reduced, but display quality degrades due to voltage decrease from leakage current
Solution Approach 1:
The system implements periodic image signal writing during break period with optimized intervals. This periodic refresh prevents voltage degradation from leakage current while minimizing the frequency of driver circuit operations, thereby maintaining display quality without requiring continuous high-power operation.
Solution Approach 2:
The patent maintains continuous display quality by ensuring that image signal writing operations occur at intervals that prevent voltage threshold degradation. The optimized writing schedule ensures the liquid crystal element voltage remains within the displayable range throughout the break period, providing continuous useful action without unnecessary interruptions.
3Reliability
If AC signals are applied to signal line and common electrode during break period to prevent voltage fluctuation, then voltage stability is improved, but driver circuit complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for complex break period signal generation circuits by optimizing the writing interval instead. Rather than adding AC signal generation hardware during break period, the system achieves voltage stability through carefully timed periodic writes, removing the need for additional driver circuit complexity.
Solution Approach 2:
The system uses the existing image signal writing mechanism to achieve voltage stabilization during break period, rather than introducing a separate AC signal generation system. By reusing the proven image signal writing circuitry with optimized timing, the patent avoids duplicating functionality and reducing circuit complexity.
4Loss of energy
If the refresh rate is reduced for still image display to reduce power consumption, then power consumption is reduced, but flicker perception may occur due to voltage fluctuation
Solution Approach 1:
The patent implements periodic image signal writing during break period with optimized intervals that prevent voltage degradation. This periodic refresh occurs at a frequency sufficient to prevent flicker perception while maintaining reduced power consumption compared to continuous high-rate refreshing, achieving the right balance between power savings and flicker avoidance.
Solution Approach 2:
The system optimizes the writing interval parameter based on temperature conditions to prevent both flicker and excessive power consumption. By adjusting the periodic write timing according to temperature-dependent leakage characteristics, the system maintains voltage stability that prevents flicker while keeping the refresh rate low enough for power savings.
Data Source
AI summary
The still image display mode includes a first period of writing the data of the image signal from the driver circuit portion into the pixel; after the first period, a second period of stopping supply of a signal or voltage for operating the driver circuit portion to the driver circuit portion; and after the second period, a third period of restarting the supply of a signal or voltage for operating the driver circuit portion to the driver circuit portion and writing the data of the image signal into the pixel from the driver circuit portion, so that the pixel keeps displaying a still image. A length of a period from the stop of the supply of the signal for operating the driver circuit portion to the driver circuit portion to the restart is set in accordance with a temperature of the display device.