Display Data Driver Charge Sharing to Reduce Switching Power
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Solution Overview
Problem
Display devices experience increased power consumption due to the alternation of data voltages with high and low voltage levels in each horizontal period, leading to inefficient power usage in data drivers.
Innovation Solution
A display device design incorporating a common line, data switches, common switches, and a voltage sensor to share charges among channels, utilizing a voltage comparator to connect channels to the common line when the common voltage is between the data voltages, and capacitors to adjust the common voltage, thereby reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If channels alternately output data voltages with high and low voltage levels to data lines for each horizontal period, then the display device can achieve normal display function, but power consumption of the data driver increases
Solution Approach 1:
The patent merges multiple channels to a common voltage line instead of each channel independently driving its data line. By combining channels and using a shared common voltage line with capacitive coupling, the system reduces the number of independent voltage drivers needed, thereby lowering power consumption while maintaining display functionality.
Solution Approach 2:
The patent implements preliminary charging of the common voltage line using capacitors before data transmission. The capacitors pre-charge the common line to the required voltage level, so that when data signals need to be transmitted, the voltage is already prepared, reducing the energy required for voltage transitions and lowering overall power consumption.
2Use of energy by moving object
If a common voltage line is shared among multiple channels, then power consumption is reduced, but voltage control precision for each channel deteriorates
Solution Approach 1:
The patent applies local quality by providing individual capacitors for each channel connected to the common voltage line. Each capacitor can be independently controlled to adjust the voltage for its specific channel, allowing precise local voltage control while still benefiting from the power savings of a shared common voltage line architecture.
Solution Approach 2:
The patent introduces capacitors as intermediary elements between the common voltage line and each channel. These capacitors act as mediators that can store and release voltage as needed, enabling precise voltage control for each channel while maintaining the power-efficient shared common line structure. The capacitors buffer voltage variations and allow independent channel control.
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
The solution effectively reduces power consumption in data drivers by pre-charging data voltages through shared charges, minimizing variations and optimizing power usage.
Implementation Method 1
a voltage sensor which senses a common voltage of the common line
Implementation Method 2
a voltage comparator which compares the common voltage, the nth data voltage, and the (n+1)th data voltage with each other
Implementation Method 3
the data driver may further include a plurality of capacitors connected to a ground, and a plurality of capacitor switches, where each of the capacitor switches selectively connects a corresponding one of the capacitors to the common line
Data Source
AI summary
A display device includes a display panel including a plurality of pixels and a plurality of data lines connected to the pixels, and a data driver which provide a plurality of data voltages to the data lines. The data driver includes a plurality of channels, where each of the channels outputs an nth data voltage in an nth horizontal period, and outputs an (n+1)th data voltage in an (n+1)th horizontal period, where n is a natural number, a common line, a plurality of data switches, which selectively connect the channels to the data lines, respectively, a plurality of common switches, each of which selectively connects a corresponding one of the channels to the common line, and a voltage sensor which senses a common voltage of the common line.