As seen by the NoLED app over in the dev section, and in a few other places on the net, people are finding that when they display a black image on their amoled/samoled screens in a dark room there is still light emitted by the display. it is not truly black
I would like to know why!
One thing i hear is about image compression and signal noise causing the pixels to not display #000000 black and instead a variant of black/grey causing the pixel to become lit.
This problem is not an issue during the day, i can't tell the difference when my screen is displaying black or off. but what it does effect is battery life.
If the screen isn't powering down its pixels then it is not saving anywhere near as much power as it could do
Also
How happy are you with your display?
I knew about the pentile problem before buying, however i am not dissatisfied with the display at all. Infact if i did not read up about it i would not have realised there was anything different with the screen.
Text is clear and sharp, images are vibrant, and colours seem true with no issue of pink problems like the desire
looool, look at any lcd screen(tv whatsoever) and you don't have true black, because the backlight is on. Only the best LED LCD screens in TV world have FULL LED backlight that can dim the leds from parts of the screen that are fully black in the processed image.
take care
yup, if you take apart your LCD watch, phone, laptop or monitor
you'll see 2 layers, first layer the LCD/TFT/AMOLED/SAMOLED/etc whatever new technology screen you can think of name it here.
then the bottom layer is pretty much like a light bulb/white led/ccfl or whatever you want to call it to light up the first portion of the screen.
most devices you can control the 2 separate pieces separately via "screen" and "back light"
you'll noticed that usually on software options what specifically lets you control both indedpendly.
Eh.. Yes But the SGS hade OLED screen. So it should be able to turn pixels completly off. My guess is that each led has some very small current applied to it possibly to speed up response off screen.
But it come close to true blacks..
EDIT
OLED screen has NO backlight... Each pixel is an tiny led...
Sent from my GT-I9000 using XDA App
thanks for the heads up, that's good to know
i've yet to take apart a new SGS to figure out how the AMOLED displays works
You guys need educating on displays lol
oled screens have no backlight, thus no backlight bleed.
That means that this is a software issue, unless the screen not powering down completely is intentional
Software issue and nothing more.
Open up the calculator, drag down the numpad, hide the 2 stripes (status bar and numpad drag bar) in the top and bottom of the screen, and tell me if you see any lighting.
There's absolutely nothing.
there is still light emitted. cover up the top and bottom bar with your hands, go into a completely dark room then look into the center of the screen.
There is a uniform glow, just like when looking at a black image in the gallery or browser
It's actually more noticeable if you look AWAY. The peripheral area of your retina will be able to pick up a very feeble amount of light. Feeble, sure, but it's there nonetheless.
seriously, guys?
XQC said:
seriously, guys?
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The problem is that the way it is supposed to work is that if you display black, the screen shouldn't use any energy at all but it is and people can see it and so is using precious battery charge.
The issue is... that apps like noled which were going to display a red dot on the screen to let people know if they had mail waiting or whatever wouldnt use much power at all because they were displaying mainly a black screen but it isnt actually black and still using light so still chews through the power..
hope that made sense.. but that is why people are interested in it..
Ok, I missed the battery part, sorry If so, it is indeed an annoyance...
I thought people were seriously complaining about image quality.
I have the Samsung wave and it uses the same screen technology and I can tell that it does not have true blacks pixels are still lit, I can easily tell that its on and totally off there is a very faint trace amount of light produced..
Since I first got this device and turned it on I have been impressed with the display. I am kind of partial to AMOLED diplays and am, thus, a bit biased. What surprised me was that it "appeared" sharper than the display on the Nexus One. Considering it is slightly larger and at the same resolution I just assumed that it wasn't using the PenTile arrangement - yet it appears that it does in fact use the same subpixel arrangement as the screen on the Nexus One. My point is... now I've forgotten my point. Basically that I am more than satisfied with this display.
As far as the black issue is concerned I have no idea. There must be some reason considering that was one of the supposed strengths of this technology (i.e. true blacks and lower power consumption).
El Mono
wait so why would you display an image if you want to save battery?
really
How many of you have measured how much power is being used up when the display is displaying a true black image(measured with multimeter, or other measuring device)
How many of you have made sure that the glow is not caused by a residual charge in the display?
How many of you know how much time it takes for the "glow" to leave an OLED panel when power is not being applied?
just some food for thought
The thing is, amoled screens were advertised as having true blacks and having the pixels off when displaying black. this is clearly not the case
It's not an issue with the technology. The screen doesn't have a back lighting panel, so i think it's more of a problem of what shade is default defined as "black" in the system, or something with any current running through the screen.
Well considering the screen doesn't turn off when displaying a 100% black bitmap image, its safe to say that the say that the pixels NEVER turn themselves off during use when displaying black
Could be the screen isn't calibrated properly, or they lied to us about the tech(wouldn't be the first time).
While its not "true black" it is defenently beyond what any backlit screentype can do regarding blacks.
Except perhaps for the retina display forged by god himself
But I agree that if Samsung states True black then it should be able to do that.
Sent from my GT-I9000 using XDA App
On LCD screens (as our hd2) white uses LESS power.
On AMOLED screens (omnia 7) white uses MORE power.
HD2's a white background is best for conserving and attaining maximum battery life.
http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-black-is
marek1 said:
On LCD screens (as our hd2) white uses LESS power.
On AMOLED screens (omnia 7) white uses MORE power.
HD2's a white background is best for conserving and attaining maximum battery life.
http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-black-is
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Thanks, this i checked just 2days before one day i kept backgroud light and dark which differs in battery backup of 2hours(more in white) , this i checked because while googling i came to know that dark colors accents best for battery ,so in that test this is a part, anyway i came to know the exact reason behind that . thanks
By switching your HD2 screen to completely white you would save about 3% of your battery. You can't change your HD2 screen to completely white as the live tiles cover about 2/3's of your screen. So by switching to a white background you would save only about 1% of your battery.
Too fast.....
mickfarr said:
By switching your HD2 screen to completely white you would save about 3% of your battery. You can't change your HD2 screen to completely white as the live tiles cover about 2/3's of your screen. So by switching to a white background you would save only about 1% of your battery.
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You're assuming different colours use the same amount of energy as black, just as most people assumed a black screen uses less than a white one. Tch Tch Tch.
Does anybody want to do a scientific comparison of the energy consumptions of differently coloured tiles on black and white screens respectively??
stepthehen said:
You're assuming different colours use the same amount of energy as black, just as most people assumed a black screen uses less than a white one. Tch Tch Tch.
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You're wrong in your assumption, you don't compare apples and oranges. I'm comparing two identical phones, the only difference is one is using a black background and the other is using a white background.
Also I said by switching your background from black to white, I didn't mention switch any themes or anything else.
did anybody catch the word "backlight" the screen its self, ie, what is displayed isnt really an issue, the backlight sits behind the LCD screen, much the same way as it does on a TV or a laptop, for that reason you may have noticed that it is impossible for an LCD screen to display a black screen, it cant because it has a light behind it and the mask from the LCD panel comes out gray or washed out black.
Anyhow, any difference in the power consumption will be either down to the brightness settings or how much activity is on the LCD screen. more changes would equal more power, black has a single consistant change white does not have any as such, but as pointed out, the tile page will always be covered in something and thus would never be completely white. there may well be a difference between different colours/black in terms of powerusage but compared to the VERY BRIGHT backlight it would be tiny amounts of difference
in short, turn the brightness down and save a meaningful amount of power. fiddle with the colours and you could probably count the number of min savd on your hands
Statement from the university of the bleeding obvious.
After a year of usage, through using the antutu test app for LCD I noticed that the pixels on top edge of the screen are brighter than the rest. It's probably because of the black notification bar.
Can other users with super amoled NS check this and see how their panel holded up? The best way to check it is with a plain gray or blue image.
Thanks
neXus S i9020T - AOSP+ - SG Kernel - 100/1320 MHz
I've the i9023 myself, but current (possibly future, too) OLED panels degrade unevenly. Whites and blues use the most power and lower the brightness after prolonged use more so than reds and blacks (with blacks effectively turning off the pixels and draining little to no power and don't effect brightness).
These kinds of effects are likely going to be more prevalent now that some years have passed since the first OLED displays have appeared. For comparison, LCDs use a backlight behind the screen which uses the same amount of power between white and black, though blacks look a little grey. As a result, there is even brightness fade.
For those unaware of it, on AMOLED displays, a black wallpaper will provide a boost to battery life because black pixels on AMOLED screens don't consume any power, because they aren't powered at all in the first place.
My question is, does this work with the display on the Nexus 7 even though it's a different type?
krion64 said:
For those unaware of it, on AMOLED displays, a black wallpaper will provide a boost to battery life because black pixels on AMOLED screens don't consume any power, because they aren't powered at all in the first place.
My question is, does this work with the display on the Nexus 7 even though it's a different type?
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I'm guessing it doesn't since its LCD technology, meaning ALL pixels on the display are powered and therefore draw power, no matter what color is present on the pixels. Black may draw less power than usual but it won't be as good as the AMOLED screens. The biggest power saver on LCD-screens is the brightness is my guess.
Please correct me if I'm wrong.
It doesn't save any power if the screen is colored black (besides it being off). The only way to save power on the n7 is to decrease the screen back light.
A lot of apps have a "dark theme" option (such as Tapatalk)... do the light colors (such as white) or the dark colors (such as black) drain the battery more? Just wondering because I always use the "dark theme" on every app that has that option. Thanks in advance!
In the case of an oled or amoled screen, white drains more power. Because the whole screen is in use. When it's black, those pixels in that part of the screen are actually turned off. Which uses less power. This is one reason why the moto x active display works as good as it does to save energy and gets much praise.
Looks like I'll be downloading that active notifications app then!
Sent from a Galaxy 4 Light Years away