Electrophoretic Display Driving Circuit Reset Signal Waveforms

Solution Overview

Problem

Electrophoretic displays experience unstable states and color mixing when resting in a non-horizontal position due to bi-stability effects, leading to dim and incorrectly colored images.

Innovation Solution

An electrophoretic display system with a driving circuit that provides sequential first and second reset signals with sub-balanced and sub-mixed signal waveforms to reset electrophoretic particles, ensuring their uniform distribution and maintaining display quality over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional driving method is used, then the electrophoretic display can operate normally during active display, but the display image becomes dim and mixed with wrong colors after resting in non-horizontal state

Engineering Contradiction:

Improvedisplay quality stabilityVSAvoidparticle distribution stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by implementing a reset stage before the display stage. During the reset stage, reset signals are applied to drive electrophoretic particles to predetermined positions (such as the center or uniform distribution), ensuring they are properly positioned before actual display operation begins. This preliminary particle positioning prevents the dim and color-mixed display issues that occur after non-horizontal resting, as particles are already in the correct distribution state before display content is rendered.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If simple reset signal is applied, then the driving circuit operation is simple, but the electrophoretic particles cannot be effectively reset to uniform distribution

Engineering Contradiction:

Improvedriving circuit complexityVSAvoidparticle distribution uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the reset signal into multiple sub-signals with different characteristics (first sub-reset signal, second sub-reset signal, etc.). Each sub-reset signal has specific voltage levels and time durations designed to address different aspects of particle redistribution. This segmented approach enables effective particle reset to uniform distribution while maintaining manageable driving circuit complexity, as each sub-signal performs a specific function in the overall resetting process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic action through the multi-stage reset signal sequence. The reset stage consists of multiple periodic signal cycles with different voltage levels and durations, creating a structured temporal pattern that systematically redistributes particles. This periodic multi-stage signaling ensures thorough particle resetting without requiring overly complex continuous control, achieving uniform particle distribution through rhythmic, phased signal application.

Inventive Principle:

Principle #19Periodic action

3Use of energy by moving object

If electrophoretic particles are allowed to settle naturally, then energy consumption is low, but the display image becomes biased and mixed with different colors

Engineering Contradiction:

Improveenergy consumptionVSAvoiddisplay image quality

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent applies preliminary action by implementing a reset stage before the display stage. During the reset stage, reset signals are applied to drive electrophoretic particles to predetermined positions (such as the center or uniform distribution), ensuring they are properly positioned before actual display operation begins. This preliminary particle positioning prevents the dim and color-mixed display issues that occur after non-horizontal resting, as particles are already in the correct distribution state before display content is rendered.

Inventive Principle:

Principle #10Preliminary action

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 system effectively resets and maintains the display quality of electrophoretic displays by ensuring the uniform distribution of particles, preventing color bias and maintaining clear images even after resting in a non-horizontal state.

Implementation Method 1

an electrophoretic display includes a display panel and a driving circuit. The display panel includes an electrophoretic unit... The electrophoretic unit includes a plurality of electrophoretic particles

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentUS11500261B2Electrophoretic display and driving method thereof

Publication Date: 2022.11.15 E INK HLDG INC

AI summary

An electrophoretic display and a driving method thereof are provided. The electrophoretic display includes a display panel and a driving circuit. The display panel includes an electrophoretic unit and a driving substrate. The electrophoretic unit includes a plurality of electrophoretic particles. The driving substrate is disposed below the electrophoretic unit. The driving circuit is coupled to the driving substrate. The driving circuit sequentially provides a first reset signal and a second reset signal to the driving substrate during a reset period to reset the plurality of electrophoretic particles. The first reset signal sequentially includes a first sub-balanced signal and a first sub-mixed signal. The second reset signal sequentially includes a second sub-balanced signal and a second sub-mixed signal.