EPD Reset Voltage Polarity Inversion for Afterimage Elimination
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Solution Overview
Problem
Electronic Paper Display (EPD) technology suffers from an afterimage phenomenon due to its bistable effect, where the reset system cannot completely reset black and white ink drops, leading to residual images.
Innovation Solution
An image display method is implemented using a display panel with micro liquid capsules, where a driving module applies a first driving voltage for image display and outputs a reset voltage with opposite polarity to reset the capsules after each frame, adjusting the polarity based on display data to effectively reset the capsules between frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reset system is used to reset black and white ink drops in EPD technology, then the display can be prepared for the next frame, but the bistable effect prevents complete reset, resulting in afterimage phenomenon
Solution Approach 1:
The patent applies preliminary anti-action by introducing a reset voltage with opposite polarity before displaying the next frame. This reset voltage actively counteracts the residual state of ink drops from the previous frame, preventing the afterimage phenomenon from occurring in the first place rather than trying to correct it afterward.
Solution Approach 2:
The patent uses inversion by applying a reset voltage with polarity opposite to the driving voltage. Instead of using the same polarity to attempt another reset, the system inverts the voltage polarity to forcefully reverse the state of ink drops, ensuring complete reset and eliminating the bistable effect's harmful influence.
2Device complexity
If the reset voltage has the same polarity as the driving voltage, then the reset system operates simply, but the ink drops cannot be completely reset due to the bistable effect
Solution Approach 1:
The patent implements inversion by reversing the polarity of the reset voltage relative to the driving voltage. This approach directly addresses the bistable effect by applying an opposite electrical field that can overcome the residual state of ink drops, ensuring complete reset functionality without significantly increasing system complexity.
3Use of energy by moving object
If the EPD technology uses ambient light reflection for display, then energy consumption is reduced, but the black and white particles require precise positioning to avoid afterimage
Solution Approach 1:
The patent applies preliminary anti-action by implementing a reset mechanism that actively returns ink drops to their initial positions before the next frame display. This preliminary action ensures precise particle positioning is restored, preventing afterimage phenomena while maintaining the energy-efficient reflective display characteristic of EPD technology.
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 method effectively avoids the afterimage phenomenon by ensuring complete reset of micro liquid capsules between frames, improving display reliability and image clarity.
Implementation Method 1
Each of the at least one micro liquid capsule displays a black-and-white grayscale under an action of an electric field
Implementation Method 2
black particles and white particles which are charged are encapsulated in a micro-capsule structure, and the black particles and the white particles with different charges are moved up and down under the control of an externally-applied electric field
Implementation Method 3
A reset voltage corresponding to the reset data provides an electric field for said each of the multiple pixel units to reset. The reset voltage has a polarity opposite to the first driving voltage
Data Source
AI summary
An image display method and a display device are provided. The driving module is coupled with multiple pixel units in the display panel and provides a driving voltage according to display data to define an electric field to display an image. For each of the multiple pixel units, an image is displayed under an electric field defined by a first driving voltage corresponding to first display data during a display period of a first frame image. Reset data is output by the driving module to said each of the multiple pixel units. A reset voltage corresponding to the reset data provides an electric field for said each of the multiple pixel units. An image is displayed under an electric field defined by a second driving voltage corresponding to second display data during a display period of a second frame image.