Liquid Crystal Display Charge Sharing for Power Reduction
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Solution Overview
Problem
Liquid crystal displays using inversion driving methods experience increased power consumption due to continuous changes in data voltage polarity, which affects the longevity of the liquid crystal layer and overall efficiency.
Innovation Solution
The implementation of a liquid crystal display system that includes a signal controller and data driver capable of charge sharing between data lines with different and same polarities, utilizing first and second charge sharing operations to minimize power consumption by short-circuiting adjacent data lines and applying additional capacitors, thereby reducing voltage changes and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inversion driving is used to prevent liquid crystal layer deterioration, then reliability is improved, but power consumption increases
Solution Approach 1:
The data lines perform self-service by sharing charge with adjacent data lines through short-circuiting. During inversion driving, data lines with opposite polarities exchange charge to reach intermediate voltages automatically, reducing the energy burden on the data driver and overall power consumption while maintaining the inversion driving benefit for liquid crystal layer durability
Solution Approach 2:
Adjacent data lines are merged through short-circuiting during charge sharing periods. This merging allows data lines with opposite polarities to share their electrical charge, enabling them to reach intermediate voltages more efficiently and reducing the total power consumption while maintaining inversion driving for reliability
2Reliability
If continuous polarity changes are applied to data lines for inversion driving, then liquid crystal layer protection is improved, but voltage changes and power consumption increase
Solution Approach 1:
Charge sharing is performed preliminarily before data lines need to transition to their next voltage levels. By pre-exchanging charge between adjacent data lines and reaching intermediate voltages through short-circuiting, the system reduces the magnitude of subsequent voltage changes required, thereby reducing energy loss while maintaining inversion driving for liquid crystal layer protection
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 power consumption by allowing data lines to reach intermediate voltages without additional driving, maintaining efficient display performance while minimizing the strain on the liquid crystal layer.
Implementation Method 1
a first charge sharing by short-circuiting first and second data lines that are adjacent to each other, the first data line having a positive voltage and the second data line having a negative voltage
Implementation Method 2
a second charge sharing by short-circuiting third and fourth data lines having data voltages in the same polarity
Implementation Method 3
The liquid crystal display generates an electric field in the liquid crystal layer by applying a voltage to the field generating electrodes, and determines the direction of liquid crystal molecules of the liquid crystal layer by the generated electric field, thus controlling polarization of incident light
Data Source
AI summary
A liquid crystal display includes: a display panel; a signal controller configured to receive an input image signal and an input control signal, output an output image signal and an output control signal, and determine a charge sharing between two or more data lines having voltages in the same polarity; and a data driver configured to convert, based on the output control signal, the image signal into data voltages to be supplied to the data lines connected to the pixels, the data voltages having positive levels and negative levels. The data driver is further configured to perform a first charge sharing by short-circuiting first and second data lines that are adjacent to each other, and a second charge sharing by short-circuiting third and fourth data lines having data voltages in the same polarity, wherein the first charge sharing and the second charge sharing may not temporally overlap with each other.