Electrophoretic Display Driving Method for Image Deformation Control
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Solution Overview
Problem
Existing electrophoretic display technologies face issues with image deformation and uneven gradation changes during image rewriting due to unintended voltage differences across the display area, leading to poor image quality and increased power consumption.
Innovation Solution
A driving method for electrophoretic displays that involves supplying specific voltages to pixel electrodes based on corrected image data to reduce the area displaying one gradation and expand the area displaying another, preventing voltage differences and thus minimizing image deformation and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a voltage difference is supplied to rewrite an image in a display area, then the new image can be displayed, but a voltage difference occurs in unintended areas due to electric field spread, causing image deformation
Solution Approach 1:
The patent applies preliminary anti-action by erasing the displayed image before rewriting it. The erasing process supplies a common voltage to the common electrode and specific voltages to pixel electrodes to create a uniform intermediate state, preventing unintended voltage differences and electric field spread during the subsequent rewriting process. This preliminary action eliminates the technical contradiction by preparing the display area in a controlled state before the new image is written.
2Reliability
If the whole display area is erased before rewriting, then errors in rewriting are reduced, but power consumption increases due to voltage supply across the entire area
Solution Approach 1:
The patent applies local quality by performing erasing and rewriting operations only in necessary areas rather than uniformly across the entire display. The controller identifies specific pixel regions that require rewriting and applies voltage differences only to those areas. This localized approach maintains rewriting accuracy by ensuring proper erasure where needed while significantly reducing power consumption by avoiding unnecessary voltage supply to other areas.
3Use of energy by moving object
If partial rewriting is performed to reduce power consumption, then energy use decreases, but image unevenness occurs due to continuous writing of the same gradation
Solution Approach 1:
The patent applies preliminary action by performing a complete erasing operation before partial rewriting. The erasing process resets the display area to a uniform intermediate state, eliminating accumulated gradation effects from previous writings. After erasing, only the necessary areas are rewritten with new image data. This sequence of preliminary erasing followed by selective rewriting maintains display uniformity while achieving power consumption reduction through localized operations.
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 prevents image deformation and reduces power consumption by ensuring accurate gradation changes and maintaining image quality during image rewriting, using corrected image data to account for electric field spread effects.
Implementation Method 1
movement of the electrophoretic particles caused by supplying a voltage difference between the pixel electrodes and the common electrodes allows displaying of an image
Data Source
AI summary
A driving method for driving an electrophoretic display apparatus, which has a display section including a plurality of pixels each having a pixel electrode and a common electrode opposing each other and an electrophoretic element interposed therebetween which includes electrophoretic particles, includes erasing a first image displayed on the display section, during a process of rewriting the first image into a second image. The driving method includes displaying the second image on the display section, during the process of rewriting the first image into the second image, wherein the corrected image data is image data obtained by correcting image data associated with the second image so as to reduce an area displaying the one gradation and expand an area displaying the other gradation in the second image.