PRS-950 Another ghosting question.

[Noobien]

I know ghosting is normal in e-Ink devices, but I'm not sure just how much ghosting is acceptable. It also seems to change depending on where I navigate from. For example, when going from page to page (text), there is almost no ghosting at all and you really have to struggle to see any at all and even then I need to place the reader under a light. However, when going from text to screensaver (specifically the snow road one), It's a bit easier to see the ghosting. Still I would imagine that it would be light enough to be acceptable. The worst is when I go from a menu to a cover image:







If anyone else has a 950, would you please be able to see if you get this level of ghosting when going from the main menu to a cover page?

I REALLY don't want to have to send this back to Borders in the US since I live in Australia.

[duncann]

You've pretty much described and shown exactly what my 950 looks like as far as ghosting.

[Noobien]

Ah, thats a relief
Must just be an e-Ink thing then. Does ghosting decrease over time?

[taosaur]

All I know is it can get you thrown out of a pottery class.

[Vesper]

I think it's a feature. To avoid ghosting you have to do a full refresh of the screen (ie black flash) and apparently it's done only while reading. If you exit the text and go to the menu/cover you get only partial refresh with ghosting.
It's probably done to extend number of pages you can read per charging cycle.

DrS

[duncann]

Originally Posted by Noobien

Ah, thats a relief
Must just be an e-Ink thing then. Does ghosting decrease over time?

I've had mine for somewhere between 2 and 3 months and haven't noticed any decrease in the ghosting.

[Noobien]

Originally Posted by duncann

I've had mine for somewhere between 2 and 3 months and haven't noticed any decrease in the ghosting.

Ah well. I'm fine with the reader as long as it's not faulty.

[vxf]

Mine is exactly the same. Has been since day 1, still is.

[simulacrum]

Australian 950 owner here.. I get the same level of ghosting. I notice it most going from text to screensaver as you mentioned.

[delphin]

I think that one reason that a few folks have reported that their ghosting issues got better with time, is that the problem is somewhat more pronounced when the reader is subjected to sudden large changes in temperature, such as might occur during the extremes of winter or summer.

For example, if you purchased your eInk device during the depths of a cold winter, you could quite conceivably notice an improvement in ghosting a few months later when the whether becomes more moderate.

This is because, with thermostats set to energy conserving settings these days, even when stored and used indoors, the device has to deal with greater temperature shifts during winter and summer months than it will in spring and fall when temperature swings are more moderate.

By the same token, I would guess that those who have reported more consistent levels of ghosting over time, are simply using their devices under more consistent conditions.

If this seems strange (since most electronic devices take fairly wide temperature shifts in stride) remember that the electrophoric eInk screens used in the Sony, Nook, and Kindle are not pure electronic devices, but rather employ a very sophisticated nano-technology scale electro-mechanical process that involves actually physically moving around microscopic pigment particles though a viscous medium to change screen pixels from light to dark.

This movement must be very accurately controlled to get gray scale image shading to work, and this is a little tricky because the sensitivity and speed of movement of the eInk pigments changes with temperature. Think of how a viscous liquid like honey pours on a cold winter morning vs. a hot summer day.

To deal with this effect, the controller chips used to drive the eInk screens include a temperature sensor so that the drive signals can be adjusted to compensate for temperature, but this compensation can't be perfect, and is most difficult to accomplish when the temperature is shifting quickly.

For example, the simple act of picking up the reader off a cold desk in the winter, and starting to read while holding it in your hand will warm the device quickly. Even this small change in temperature, because it happens fairly rapidly, is tricky for the temperature compensation circuits to deal with, and at these times you may notice more of a chance of ghosting.

Same thing goes if you leave the device in a hot car, then bring it inside to start reading.

Once you understand this, you will understand that occasional slight random ghosting is perfectly normal, and not something to be concerned about unless your reader is showing much more of a ghosting issue than another identical device under the same conditions.