Electrophoretic Display Pixel Electrode Segmentation for Leakage Current Reduction

Solution Overview

Problem

Electrophoretic display devices face issues with representing smooth contours and high power consumption due to inter-pixel leakage currents, which affect display quality and increase manufacturing costs.

Innovation Solution

The electrophoretic display device incorporates a configuration with multiple pixel electrodes and a switching circuit that allows for high impedance states, enabling naturalization and antialiasing processes without transmitting intermediate gray scale data, thereby reducing leakage currents and improving display quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If intermediate gray scale data is transmitted to perform anti-aliasing process, then smooth contour representation is improved, but current consumption increases and display completion time is lengthened

Engineering Contradiction:

Improvecontour smoothnessVSAvoiddriver current consumption

Core Design Contradiction:

ShapeVSUse of energy by moving object

Solution Approach 1:

The pixel electrode is divided into multiple sub-pixel electrodes (first pixel electrode and second pixel electrode). Each sub-pixel electrode can be independently controlled to different electric potentials, enabling anti-aliasing through spatial segmentation rather than requiring intermediate gray scale data transmission.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions within a pixel (different sub-pixel electrodes) are assigned different electric potentials locally. This creates local gray scale variations at pixel boundaries to achieve smooth contour representation without needing to transmit intermediate gray scale data for the entire display.

Inventive Principle:

Principle #3Local quality

2Shape

If intermediate gray scale data is transmitted to perform anti-aliasing process, then smooth contour representation is improved, but display completion time is lengthened

Engineering Contradiction:

Improvecontour smoothnessVSAvoiddisplay completion time

Core Design Contradiction:

ShapeVSLoss of time

Solution Approach 1:

The pixel electrode is divided into multiple sub-pixel electrodes (first pixel electrode and second pixel electrode). Each sub-pixel electrode can be independently controlled to different electric potentials, enabling anti-aliasing through spatial segmentation rather than requiring intermediate gray scale data transmission.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions within a pixel (different sub-pixel electrodes) are assigned different electric potentials locally. This creates local gray scale variations at pixel boundaries to achieve smooth contour representation without needing to transmit intermediate gray scale data for the entire display.

Inventive Principle:

Principle #3Local quality

3Illumination intensity

If pixel electrodes with high and low electric potentials are adjacent to each other, then display contrast is improved, but inter-pixel leakage currents increase

Engineering Contradiction:

Improvedisplay contrastVSAvoidpower consumption

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The pixel electrode is divided into multiple sub-pixel electrodes (first pixel electrode and second pixel electrode). This segmentation reduces the effective area of each electrode and creates more gradual potential transitions, thereby reducing inter-pixel leakage currents while maintaining display contrast.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple sub-pixel electrodes act as intermediaries between adjacent high and low potential regions. This creates a more gradual potential transition and reduces the direct electric field strength between adjacent pixels, thereby reducing leakage currents through the adhesive agent layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration allows for smooth contour representation and reduced power consumption, enhancing display quality and maintaining contrast during partial rewriting driving processes.

Implementation Method 1

an electrophoretic element (32) which moves, in accordance with an electric field, electrophoretic particles between two substrates so as to display an image

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentUS8390565B2Electrophoretic display device and electronic apparatus

Publication Date: 2013.03.05 E INK CORP

AI summary

An electrophoretic display device includes a first substrate and a second substrate that face each other, an electrophoretic element disposed between the first substrate and the second substrate, the electrophoretic element including electrophoretic particles, a display unit that has a plurality of pixels including the electrophoretic element, a common electrode that is formed on an electrophoretic element side of the second substrate, and a first control line and a second control line that are formed in either the first substrate or the second substrate. Each of the plurality of pixels includes a pixel switching element, a memory circuit that is connected to the pixel switching element, a switching circuit that is connected to the memory circuit, and a first pixel electrode and a second pixel electrode that are connected to the switching circuit and are disposed to face the common electrode. The switching circuit includes a first switch that controls a conductive state between the first control line and the first pixel electrode in accordance with an output signal of the memory circuit and a second switch that controls a conductive state between the second control line and the second pixel electrode in accordance with the output signal of the memory circuit.