Electrophoretic Display Pixel Group Management for Afterimage Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electrophoretic display systems suffer from persistent afterimages of erased characters, leading to a user-perceived feeling of incorrectness when characters are repeatedly inputted and erased, due to the display's structure causing afterimages to overlap and stand out in the character display region.

Innovation Solution

The method employs a display control system using pixel groups of predetermined shapes to display characters, where afterimages are formed and managed within these groups, allowing newly inputted characters to overlap and overwrite existing afterimages, and unused pixel groups are made inconspicuous to reduce the visibility of afterimages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electrophoretic display is used to display characters, then the display can show characters clearly, but afterimages of erased characters remain and stand out in the character display region

Engineering Contradiction:

Improvecharacter display clarityVSAvoidafterimage visibility

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The character display region is divided into multiple pixel groups, each responsible for displaying specific character portions. When a character is erased, only the corresponding pixel groups are affected, allowing selective management of afterimages through local refresh operations rather than entire screen updates.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different refresh strategies are applied to different regions: pixel groups displaying active characters receive full refresh to maintain clarity, while pixel groups containing only afterimages receive selective refresh or no refresh, optimizing the balance between character display quality and afterimage suppression.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If characters are repeatedly inputted and erased, then character input functionality is achieved, but multiple afterimages overlap and give users a feeling of wrongness

Engineering Contradiction:

Improvecharacter input capabilityVSAvoiddisplay accuracy perception

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system maintains a buffer that stores character input information before actual display update. This buffer is used to predict which pixel groups will contain afterimages after erasure operations, allowing the system to proactively refresh only those specific regions before the afterimages become problematic, thus preventing the feeling of wrongness before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the display buffer and compares it with the current display state to identify regions with afterimages. This feedback mechanism triggers selective refresh operations only in regions where afterimages would degrade display accuracy perception, maintaining reliability during repeated input-erase operations.

Inventive Principle:

Principle #23Feedback

3Object-affected harmful factors

If the entire display region is refreshed to remove afterimages, then afterimage visibility is reduced, but power consumption and processing load increase

Engineering Contradiction:

Improveafterimage visibilityVSAvoidpower consumption

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The display refresh operation is segmented into region-specific updates based on character position and erasure history. Only pixel groups corresponding to erased or newly inputted characters are refreshed, while other regions maintain their current state, dramatically reducing power consumption compared to full-screen refresh.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of refreshing the entire display region, the system applies partial refresh only to necessary pixel groups that contain afterimages or newly inputted characters. This partial action approach achieves sufficient afterimage suppression while minimizing energy expenditure and processing load.

Inventive Principle:

Principle #16Partial or excessive 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

This approach effectively minimizes the visibility of afterimages, alleviating the user's perception of incorrectness by ensuring that afterimages are either overwritten or appear with reduced density, enhancing the display's clarity and usability.

Implementation Method 1

A display using an electrophoretic method is known. The display includes a substrate with a common electrode formed thereon, another substrate with pixel electrodes formed for corresponding respective pixels, and microcapsules, each containing electrophoretic material liquid, arranged for the corresponding respective pixels disposed between the substrates

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentUS9076409B2Display control method, display control device and program

Publication Date: 2015.07.07 E INK CORP

AI summary

A display control method for controlling display of characters in a display section equipped with a plurality of pixels, includes: acquiring character data; and displaying a character according to the character data in a character display region of the display section. The character corresponding to the character data is displayed in the character display region by using a plurality of pixel groups each having a predetermined shape.