What is backlight bleeding?

[OVERKILL]

?

 

[ChuckHsiao]

LCDs consist of several layers. The bottom layer consists of a backlight, which is what generates the light that you see (it's several fluorescent tubes along with light diffusers to make the lighting even). The LCD layer just controls how much of that light gets through. Then there are other layers that do other things (like the color filter layer to produce the different colors). The entire thing is aligned and sealed, but if that process doesn't happen properly, then the LCD layer can't eliminate all that light that it's supposed to. This is most prevalent at the sides and the corners, it doesn't happen very much in the middle of the screen. So backlight bleeding refers to just how much of that light gets through when (for example) you're using a black screen -- basically the quality and evenness of the monitor with respect to its brightness. One with a lot of backlight bleeding means you can definitely notice that the sides are lighter than the middle. One without means the shades of color are pretty even no matter where it is on the screen.

 

[klah]

Dell 2005fpw example

http://www.hotboatpics.com/pics/data/500/1039DSC00167small.jpg

 

[hootpie]

Another example:

http://www.unfinite.com/backlight.JPG

 

[ty1er]

What is backlight bleeding?

i was wondering the same thing

thanks klah, and hootpie for the examples.

 

[ShadowBlade]

Originally posted by: hootpie
Another example:

http://www.unfinite.com/backlight.JPG

thats horrible
what monitor is that?

 

[hootpie]

Originally posted by: ShadowBlade

Originally posted by: hootpie
Another example:

http://www.unfinite.com/backlight.JPG

thats horrible
what monitor is that?

It's a bit exaggerated due to the night mode on my cameraphone, but it's still noticable. That's a Rev A02 2005fpw :

I've already had it replaced once, but the replacement wasn't much better

 

[midnight growler]

Does backlighting occur randomly (like dead pixels) or is it just by poor quality (cheap brand A monitor will have more than decent brand B monitor)?

 

[ChuckHsiao]

Backlight bleeding is a fault of the manufacturing process, so yes it is somewhat random like dead pixels. However, unlike dead pixels (which all panels have in more or less equal amounts), it's more preventable through quality control, so some panels have more and others have less on average. The Dell has been getting lots of attention for backlight bleeding lately, but that may simply be because Dell's the biggest vendor of LCDs. Or maybe the panels Dell buys really do have problems with it.

 

[jevans64]

That picture is a good example of backlight bleeding. Man. My Dell 2405FPW looks A HECK of a lot BETTER than that 2005FPW. :lol

 

[extnct]

I just got a 2005FPW a few days ago, and it has a problem with both backlight bleeding and stuck pixels:

http://img353.imageshack.us/img353/7233/img11879yv.jpg
http://img353.imageshack.us/img353/3757/pixels1zc.jpg

Do you guys think there's any chance Dell will replace it?

 

[ChuckHsiao]

Call them and find out. Especially if it's within 21 days, since they're reputed to be really good about returns for any reason during that time frame.

 

[BigfootKevin]

I think all 2005fpw's are plagued with the backlight issue, mine does it as well.

 

[ssvegeta1010]

Now I think that my laptop has some slight backlight bleeding issues.

 

[extnct]

Alright, I called and they said the replacement is on its way. Thanks guys

 

[MX2]

I have heard that if you let the LCD heat up during normal use for about an hour then unplug it, immediately dismount from base and lay flat (LCD side down) on a solid surface, that some of the bleed might correct itself from the adhesive/seal being weighted down to form a better and more even seal.

Dont know if its true, but it certainly couldnt hurt to try it

 

[dev0lution]

Originally posted by: hootpie
Another example:

http://www.unfinite.com/backlight.JPG

Damn...and I thought the bleed on my 2001FP was bad