Backlight Bleeding

Fr0dders · 22 Feb 2006 at 10:26

what causes it ?

some people seem to think its associated with particular panels types

others seem to thing its down to poor build quality on the manufacturers part.

which is right ?

Cal_G · 22 Feb 2006 at 14:46

Its not the panel

fish99 · 22 Feb 2006 at 14:57

I always assumed you could see the backlight through TFTs simply because they used bulbs for the backlight, so where there's a bulb right behind the panel, you see the light shining through more in that region. When I had a SM913B, the backlight shone through in a very definite pattern - one bright blob in each corner and one in the dead centre - so I assumed there were bulbs in those spots, in a sort of X formation.

I'd like to know if that's the case.

djohn · 22 Feb 2006 at 14:58

I think its down to build quality allowing the light to show through more in some parts than others. If it was poor design or placing of the tube/s then surely they would have rectified this and it shows up on some monitors more than others, whereas it would be the same for each model if it was poor positioning.

Baddass · 22 Feb 2006 at 18:53

it's down to build quality. Most TFT's will show some uneveness of panel lighting uniformity due to the way they are constructed. Proper backlight bleed is where it becomes very apparent and some models have been plagued by issues, most notably the Dell 2005FPW. Nothing to do with panel type really, more to do with the manufacturing process

Mud · 22 Feb 2006 at 19:53

What happened to the LED backlit TFTs that were on the horizon a while back? I think at least 1 went to production and cost about an extra £100-150 over the standard backlit model from memory.

Magic Man · 22 Feb 2006 at 20:05

It's down to the quality and functionality of the diffuser plate and how well masked the raw light source is.

fish99 · 22 Feb 2006 at 21:10

Anyone know how many backlights TFTs use and what they look like? Is it a long horizontal tube, or several smaller bulbs or something? I'm just curious about how they work.

edit:Ok, I found out via google - they're cold cathode tubes, the same ones people use in case modding. I'm guessing they mostly just have one at the bottom of the screen.

Baddass · 22 Feb 2006 at 22:54

there's normally 4 CCFL backlights in a TFT, that's pretty standard, with some manufacturers using more to boost brightness.