Flickering Displays With LED Backlighting

I made some posts about this over in the TabletPCReview forum but wanted to get some feedback here as well. I have a an X200 Tablet with an LED backlit display. I have been getting a lot of eye strain and headaches when using my laptop particularly when its unplugged (running on batteries). Using my cell phone camera, I was able to see that my LCD panel was indeed flickering. Because of the slow refresh rate of the cell phone camera, it interferes with the flicker rate of an LED backlit display causing a horizontal or vertical banding pattern on your cell phone's display.

Can anyone else confirm flicker on your LED backlit laptop using your cell phone? Just point your cell phone camera at your laptop screen and see if you can see a horizontal or vertical banding pattern that moves across the screen (when viewed through your cell phone display). Try this at various brightness levels plugged and unplugged. Does the flicker bother anyone, i.e. eye strain/headaches?

I have detectable flicker 100% of the time when unplugged (regardless of brightness level). When I'm plugged in, I get detectable flicker on all brightness levels except at the highest level. This is sad because I love the convenience of not being plugged in. To get a flicker free display I not only have to be plugged in but the brightness has to be set all the way up. In most situations (unless I'm outdoors or next to a window) this is way too bright.

 

Some one around here said before that to dim the new LED screens, they dont actually turn down the brightness. What they do is to lower the number of times which the back light flickers so it seems dimmer to the user. Which seems to be the case here...

And it just seems you eyes might be more sensitive than others. I don't own a LED screen might I have a similar (not same cause) problem with CRT screens.

 

I hooked-up my my Asus G50vt, w/ LED screen, via VGA to my Viewsonic monitor and placed them right next to each other. The Viewsonic now displays a moving white line that scrolls from top to bottom of screen. Not sure if it's a bad connection or something related to your problem. Will move the laptop screen further away from the monitor to see if problem disappears.

 

I was the one who raised the issue of LED screens and headaches earlier.

My concern was due to the nature of LED lights (they just flat-out hurt my eyes no matter what), and I ended up getting a non-LED T400. Here is a link to that thread.

In my research, I ended up on an apple forum of people complaining about eye strain on their Macbook Pro LED laptops. Here is that link.

On the apple forum, they were discussing how apparently LED screens can only be dimmed by reducing the voltage, which can cause flicker. However, this has been disputed and I'm not an expert by any means: I don't know if that's really how it is.

That said, I see that you only have problems when you're on battery or on AC using less than 100% brightness, and that might be consistent with the voltage reduction issue. On my non-LED T400, I notice that 100% brightness on AC power is minutely (but noticeably) brighter than 100% brightness on battery. When I unplug it, it gets dimmer even though it stays at "100%." Has anyone else noticed this?

Anyway, I hope those links are helpful. There have undoubtedly been newer discussions about this issue, as I last looked into it a few months ago.

 

i5aac, thanks for your input. I have come across those links while doing my internet research. But I wish I saw them before I bought my X200 Tablet. I would definitely have avoided the LED model.

I think this is normal. If I recall, there should be a setting in your BIOS where you can turn on full brightness on battery. I don't have my laptop handy so I can't check for you. But try perusing your BIOS options - you should see something related to this.

 

I noticed this flickering also on low brightness settings of my Sony SZ, but I noticed when I got my X300 that either it flickers a whole lot faster, or doesn't flicker at all, because I can't detect it (and it feels more comfortable to view than my SZ so I'm happy). I did set the BIOS "full brightness on battery" option though before even using battery, because I heard this limits your maximum brightness when on battery.

 

ac500,

Funny, I never noticed it at low brightness levels on my SZ680. Maybe different panel than the SZ7's? But my SZ6 also flickers when viewed by a camera phone. At 100% brightness there is no flicker. I also had a Dell E6500 and the LED panel (LG Panel) on that screen did have noticeable (to the eye) flicker at lower brightness levels.

 

I think it's just a matter of what you're sensitive to. I look at my x200 Tablet's LED display for several hours a day (almost always with reduced brightness) and I don't suffer any eye fatigue.

 

I'm with jon on this one - I tried to get flickering on mine - turned the display as dim as I could, turned room lights off, and worked on it for a couple hours - nothing... must be an individual sensitivity thing. The old 60 hz crt monitors used to drive me nuts! But on this - nothing.

 

Thanks for your input guys. I just found out that if you fiddle with the power savings setting in the intel graphics properties, you can get the screen to go flicker free at full brightness even when on batteries. I get less battery life, but at least my eyes feel better.

 

Hi everybody.

I also have flickering in my T400 with led backlight. It disappears when at maximum brighness and it's barely visible when I dim the display, although I can see it if the screen displays a black or dark grey image.

Here comes the important: my laptop has two graphic cards (intel and ati) and this only happens with the intel one. I've recorded a video at 30 fps showing the BIOS environment with both graphic cards activated, and the flickering is far more visible with the intel.

I have this problem since 4 or 5 days and I had noticed no flickering before. But the problem didn't come alone: the laptop has difficulties when detecting/connecting to encrypted wireless networks, which didn't have before. I've tried it with different Linux distros and also with live cd's to discard a software problem. I've also tried another laptop to discard a router problem. So I think it must be hardware problem, but I don't know how are the Intel graphics card and wifi card related.

Finally, sorry for my bad english.