Source Driving Circuit Charge Recycling for LCD Power Reduction
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Solution Overview
Problem
LCD devices using polarity inversion driving methods face high power consumption due to frequent changes in display signal voltages, especially when transitioning from positive to negative voltages, as existing charge sharing technologies do not fully utilize the charges generated during this transition.
Innovation Solution
A source driving circuit with multiple output channels, each equipped with a first and second switch element, a digital-to-analog converter, an amplifier, and a diode, where the switches control the output of display signals and recycling of charges when the voltage changes from positive to negative, allowing for the reuse of charges and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polarity inversion driving method is used to drive LCD pixels, then display quality is improved, but power consumption increases due to frequent voltage polarity changes
Solution Approach 1:
The patent converts the harmful effect of charge loss during polarity inversion into a beneficial resource by capturing and recycling the charges generated when transistors turn off. The charge recycling circuit captures these otherwise wasted charges and redistributes them to subsequent pixels, transforming the energy loss into a power-saving mechanism that maintains display quality while reducing power consumption.
2Use of energy by moving object
If charge sharing technology is used to reduce power consumption, then power consumption is reduced, but charges generated during voltage transition from positive to negative are not fully utilized
Solution Approach 1:
The patent implements a charge recycling mechanism that recovers charges from transistors when they turn off during polarity inversion. Instead of discarding these charges as conventional charge sharing does, the circuit captures and stores them in capacitors, then redistributes them to subsequent pixels. This recovering approach fully utilizes charges during voltage transitions, improving both power efficiency and charge utilization.
3Measurement precision
If voltage polarity changes frequently in dot inversion mode, then display signal accuracy is improved, but power consumption increases significantly
Solution Approach 1:
The patent maintains continuous useful action by ensuring that charges are continuously recycled and redistributed across pixel transitions. The charge recycling circuit operates throughout the entire scanning process, capturing charges from each transistor turn-off and immediately making them available for subsequent pixels. This continuous charge circulation maintains signal accuracy while eliminating the energy waste associated with frequent polarity changes.
Data Source
AI summary
The present invention provides a source driving circuit and an LCD device. The source driving circuit includes output channels, and each output channel includes a first switch element, a second switch element, a first output end, and a second output end. The first switch element and the second switch element are respectively connected to the first output end and the second output end. When the first switch element is turned on, the output channel outputs a display signal, and when the second switch element is turned on, the output channel provides recycled charges which are generated when the display signal is changed from a positive voltage to a negative voltage. The source driving circuit can recycle charges to make the most of charges generated when the display signals change from positive voltages to negative voltages and reduce power consumption of the LCD device.