Electrophoretic Display Driving Method for Power Reduction
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Solution Overview
Problem
Existing electrophoretic display apparatuses face high power consumption due to the periodic alternation of potentials in both segment and common electrodes, even when only a part of the display state is rewritten, leading to increased current consumption and inefficient energy use.
Innovation Solution
A method of driving electrophoretic display apparatuses where the pixel electrode corresponding to a static display state is set to the same potential as the common electrode, reducing power consumption by eliminating the need for periodic potential changes in unchanged pixels, and allowing for selective pulse driving based on the ratio of updated pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pulse periodically alternating between low and high levels is input to the common electrode in common shake driving, then the display color can be maintained without changing the display state, but the potentials of the wiring and electrodes are forcibly charged/discharged leading to increased current consumption
Solution Approach 1:
The patent divides the electrode system into two independent groups: pixel electrodes that receive periodic pulses for display state maintenance, and segment electrodes that receive constant potentials when display states are not changed. This segmentation allows selective power consumption only where necessary (pixel electrodes) while eliminating unnecessary power consumption in segment electrodes, resolving the contradiction between reliable display state maintenance and reduced power consumption.
2Use of energy by moving object
If constant potential is input to both segment electrode and common electrode when display state is not changed, then power consumption is reduced, but the display apparatus cannot maintain proper electrophoretic particle positioning
Solution Approach 1:
The patent applies different potential conditions to different electrode types based on their specific functions: pixel electrodes receive periodic alternating pulses to maintain electrophoretic particle positioning and display state, while segment electrodes receive constant potentials when display states are not changed. This local differentiation allows the system to optimize power consumption in segment electrodes without compromising the electrophoretic particle positioning maintained by pixel electrodes, thus resolving the contradiction between power reduction and reliable particle positioning.
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 significantly reduces power consumption by minimizing power usage in pixels with unchanged display states and optimizing energy efficiency, especially when most pixels are updated, while maintaining display quality.
Implementation Method 1
A phenomenon in which electrophoretic particles migrate due to the Coulomb force when an electric field is applied to a dispersion liquid obtained by dispersing electrophoretic particles in a solution (so called electrophoresis) is known in the art.
Implementation Method 2
A phenomenon in which electrophoretic particles migrate due to the Coulomb force when an electric field is applied to a dispersion liquid obtained by dispersing electrophoretic particles in a solution (so called electrophoresis) is known in the art.
Data Source
AI summary
A method of driving an electrophoretic display apparatus, wherein during displaying an image on the display unit, executing a pixel electrode pulse driving in which a pulse periodically alternating between first and second potentials is input to the pixel electrode corresponding to the pixel of which a display state is changed, the first or second potential is input to the pixel electrode corresponding to the pixel of which a display state is not to be changed, and a potential equal to that of the pixel electrode corresponding to the pixel of which a display state is not to be changed is input to the common electrode.