LCD Monitor Image Retention

[Jerry G.]

This question has come up from time to time about LCD monitor and TV
technology.

LCD displays cannot be burned in like with CRT and Plasma type
displays. LCD displays can however, retain a ghost effect of the images
that have been affixed on to the display for a long period of time. The
effect of the image retension is from an accumulation of charge
retained by the pixels.

If the monitor is left running with a screen saver, or some type of
moving image, after a period of time it should clear itself.

There are a number of methods of clearing the retention problems. Using
a screen saver will prevent the retention effect, and will allow it to
clear itself. Having the monitor sit with a blank screen, but be
powered up is another way that is said to clear the retention effect.
Leaving the monitor powerd off for a long period of time, may also
clear the retention effect.

LCD retention can take a number of weeks or a few months to be cleared.
This type of effect is not permanent.

With CRT and Plasma screens, image retention is actualy a screen burn.
This is where the phosphors have been burnt. There is no possible fix
other than replacing the display device. The cost of this type of
repair is usually too expensive in relation to the replacement cost of
the monitor.

A Reference About LCD Retension:
http://service.dell.com/dell/kb/tech_support/view_article/1,,6073+5818+5828+19153,00.html

Some Myths And Facts:
http://hometheater.consumerelectronicsnet.com/articles/viewarticle.jsp?id=25018

Jerry G.

[dkuh...@locl.net]

So what you are saying is that all these LCD monitors that have been in
service with the same image for a few years and then move to another
location with a completely different screen display for a couple more
years should have had the first image retention go away? So far it has
not happened here, the image that was permanently affixed to the LCD
screen from the first couple of years use is still there even after a
couple of years with a completely different image and screen saver.

[Jerry G.]

You should read the links to have a better understanding. LCD monitors can
have retention just from a number of hours. Years are not necessary. The
advantage is that they are recoverable, because they do not burn in like
other types of displays.

--

Jerry G.
=====

<dkuh...@locl.net> wrote in message
news:1141046188....@z34g2000cwc.googlegroups.com...

[dkuh...@locl.net]

I did read the links. So what I am seeing does not appear to be image
retention but some kind of image 'burn' on the lcd panels as it does
appear to be very permanent.

The image is even visible with the monitor turned off. So it does
appear to be some kind of permanent 'burned in' pattern.

Yes, these are LCD monitors exhibiting this problem.

[Jerry G.]

Try the recommendations from the web pages. Have you contacted the monitor
manufacture about this?

Some model types will tend to have the retention problem worse than others.
But, an LCD cannot be burned in, because they do not have a beam current.
They work on the principle of twisting crystals to shift the polarization of
light.

The activation current levels in the LCD panel is very low, and thus the
load resistance is extremely high. This makes for a high degree of
sensitivity.

--

Jerry G.
======

<dkuh...@locl.net> wrote in message
news:1141077020.5...@i39g2000cwa.googlegroups.com...

[dkuh...@locl.net]

Yes, we have contacted NEC about this problem. The recommendation of
putting up a random screen saver pattern failed to resolve the issue.

According to NEC the problem is in fact UV burn of the color filters
that are part of the screen.

So the answer is, yes, LCD monitors can and do suffer from a type of
image burn problem.
The image burn generally takes the exact same image in the same spot
over months and months, but once the color filters have been
discolored, there is no repair but to replace the lcd panel.

[carneyke]

To prevent this should the intensity be kept down as you would with a
CRT ?

[James Sweet]

Jerry G. wrote:
> Try the recommendations from the web pages. Have you contacted the monitor
> manufacture about this?
>
> Some model types will tend to have the retention problem worse than others.
> But, an LCD cannot be burned in, because they do not have a beam current.
> They work on the principle of twisting crystals to shift the polarization of
> light.
>
> The activation current levels in the LCD panel is very low, and thus the
> load resistance is extremely high. This makes for a high degree of
> sensitivity.
>

I have seen LCD panels that have a form of screen "burn", which as far
as I know is actually electrolysis which has occurred due to an
asymmetrical drive waveform.

[Sjouke Burry]

I have made lcd shutters once, and the main problem
is pollution,any trace of cleaner/chemical/dust is
reacting/decomposing when you put a voltage on.
So its a kind of chemical burnin,and will be less
of a problem with LCDs of better quality.