SparkFun Forums

[magician13134]

Hi everyone, I bought the E-Paper LCD and breakout board ( http://www.sparkfun.com/products/10150 and http://www.sparkfun.com/products/10304 ) and have been using it with my Arduino. At first, it worked really well, but the more I used it, the more I noticed an issue with it. Whenever I update the image, the entire screen turns a mid-range gray color (not quite on, not quite off). The same thing happens when I disconnect power from it. I know it's supposed to be able to hold an image, but when it loses power even just for a few seconds, the display gets unreadable.

With power:


A few seconds after losing power:


A few minutes after losing power:


Does anyone know anything about this? Any ideas or suggestions?

[Joeisi]

Umm....As quoted from Wikipedia:

"Electronic paper technologies have a very low refresh rate compared to other low-power display technologies, such as LCD. This prevents producers from implementing sophisticated interactive applications (using fast moving menus, mouse pointers or scrolling) like those which are possible on mobile devices. An example of this limit is that a document cannot be smoothly zoomed without either extreme blurring during the transition or a very slow zoom.


An e-ink screen showing the "ghost" of a prior image
Another limit is that a shadow of an image may be visible after refreshing parts of the screen. Such shadows are termed "ghost images", and the effect is termed "ghosting". This effect is reminiscent of screen burn-in but, unlike it, is solved after the screen is refreshed several times. Turning every pixel white, then black, then white, helps normalize the contrast of the pixels. This is why several devices with this technology "flash" the entire screen white and black when loading a new image.[citation needed]
Electronic paper is still a topic in the R&D community and remains under development for manufacturability, marketability, and reliability considerations.[citation needed]"

[magician13134]

Right, but that's not my issue. I was aware of that and I have tried flashing the display full on and full off many times and it doesn't help. As you can see from the pictures, it's not the part where the characters show up that's having issues, it's the entire screen. It happens regardless of whether I change the image or simply leave a static one on the display. But thanks for your response!

[Joeisi]

Well all I can think of is it is a bad screen. Sorry I can't help further.