EPDs benefit from partial update functionality

The driving waveforms used for these partial updates have been optimised to deliver superior image quality, outperforming what other EPD vendors are able to achieve.

In most EPD application scenarios, like electronic retail shelf labelling, a conventional global update will prove to be sufficient. Here every pixel on the EPD is refreshed, as there are no time pressures and this can be done when the EPD is not being viewed by anyone (such as when the store is closed). There are, however, certain applications that require rendered information to be refreshed at a quicker rate, while still being viewed – and this is why a partial update capability has major appeal.

Using partial updates, rather than refreshing every pixel, the rendered information in a smaller section of the EPD can be refreshed. Changes can be implemented within a shorter time frame and there is even potential for simple animations to be displayed. Until now, the drawback of this has been that partial updates can often result in ghosting, where traces of the previous image remain present on the new image. This impacts on image quality and is clearly detrimental to the user experience. It may also reduce the EPD’s working lifespan.

Using Pervasive Displays’ advanced driving technology, the waveforms generated for partial updates are much more effective. Partial updates can take as little as 0.5 seconds to complete which is around a quarter of the time needed for a global update. However, ghosting issues are avoided and the EPD’s long-term operation is maintained.

“Thanks to the proprietary driver technology incorporated into our EPDs, we now have a game-changing differentiator to bring to the market,” stated Charming Su, Senior VP at Pervasive Displays. “The partial update performance we can attain is far better than that of competing solutions, without the appearance of ghosting. As a result, our customers are always certain of getting exceptional user experiences.”