LED Backlight "Deadspots"

534n

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This is not really a problem but more of a curiosity. When the screen is on, but completely black/blank (i.e. app loading) there are several very dark spots distributed throughout the screen where the LED backlight appears to be off. This has absolutely no effect on images on the screen though and is not noticeable when the screen is displaying ANYTHING other than a solid black.

Does anyone else see this on their phone?

EDIT: Also only visible when on lowest brightness.
 
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johnnyshinta

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This is not really a problem but more of a curiosity. When the screen is on, but completely black/blank (i.e. app loading) there are several very dark spots distributed throughout the screen where the LED backlight appears to be off. This has absolutely no effect on images on the screen though and is not noticeable when the screen is displaying ANYTHING other than a solid black.

Does anyone else see this on their phone?

EDIT: Also only visible when on lowest brightness.

I see the exact same thing.
 

funkylogik

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for one the LCD screen has NO backlight, black=no light.
sounds like screen "burn in". do you both have brightness at full?
 

funkylogik

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yeah im "lucky" to live in west of scotland so brightness is usualy around 10% so doubt il suffer burn in but if i get a deep scratch il be leavin ma phone on full brightness with an apple logo on the screen n sendin for replacement
 
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s14tat

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Seems like its the blotches of black dots only when screen is black on bright ness. This is certainly not screen burn it. Its the nature of amoled screens. People on xda have pointed this out on new phones. I have never seen it on mine even when I try to look for it since I only run max brightness.
 

534n

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They are LED based screens and I use auto brightness and never really have it go up that high because I don't use the phone outside. It is definitely not burn-in and that does not commonly affect the LED (whatever variant) or LCD screens, and I have NEVER heard of screen burn in on a non CRT based screen. The term screen "burn in" refers to the layer of phosphorous being modified by the constant bombardment of electrons from the cannon in exactly the same spots continuously over time that it never has a chance to re-settle, thus burning a permanent "image" in the screen, which is really just areas of the phosphorous layer that have been worn in unevenly.

It is just a perfect circle near the lower left of center on the screen. And a few other small spots throughout. I think it is places that the driving voltage for the brightness is not enough to keep the LED lit and it goes dark, or just a distribution from the function of the logic controller. I am not sure what causes it but it just intrigued me the first time I noticed it. It literally has no effect other than being visible when the screen is at minimum brightness and fully blank.
 

funkylogik

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They are LED based screens and I use auto brightness and never really have it go up that high because I don't use the phone outside. It is definitely not burn-in and that does not commonly affect the LED (whatever variant) or LCD screens, and I have NEVER heard of screen burn in on a non CRT based screen. The term screen "burn in" refers to the layer of phosphorous being modified by the constant bombardment of electrons from the cannon in exactly the same spots continuously over time that it never has a chance to re-settle, thus burning a permanent "image" in the screen, which is really just areas of the phosphorous layer that have been worn in unevenly.

It is just a perfect circle near the lower left of center on the screen. And a few other small spots throughout. I think it is places that the driving voltage for the brightness is not enough to keep the LED lit and it goes dark, or just a distribution from the function of the logic controller. I am not sure what causes it but it just intrigued me the first time I noticed it. It literally has no effect other than being visible when the screen is at minimum brightness and fully blank.
cheers for the technical info m8, i love to learn. but aparently (think it was jerry jerry who quoted it) samsung have admitted to a problem with burn in on the s3 and recommend using low briitness (not much use to our friends in horrible sunny places lol) and dont know if its rumour but aparently theyl replace affected panels if it impaires normal use.
so would burn in only be visible with pixels at high R/G/B level and not visible with them at zero (true black)?
 

534n

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cheers for the technical info m8, i love to learn. but aparently (think it was jerry jerry who quoted it) samsung have admitted to a problem with burn in on the s3 and recommend using low briitness (not much use to our friends in horrible sunny places lol) and dont know if its rumour but aparently theyl replace affected panels if it impaires normal use.
so would burn in only be visible with pixels at high R/G/B level and not visible with them at zero (true black)?

Honestly, I think Samsung took something that was just people complaining about something they thought they saw and then hysteria made worse and made an "issue" out of nothing so people would keep quiet. The only way an LED can burn is if too much power is fed across it so people with root brightness changers may have turned the brightness up higher than it should have or something damaged the screen outside of normal conditions.

The people that had legitimate problems seemed to arise from having the brightness up all the way and leaving the screen on for a majority of the time. While several people said this did not affect their phones, the heat, power (based on the color/contrast of the image on the screen), and other factors may have caused the LED's "backlight" capability to become reduced, lowering the sharpness between pixels and reducing the brightness possible for those pixels, thus creating the image distortion they saw.

As for one bit of interesting information that I read, the status bar is usually the only part of the phone that is not burned in by people with bright screens and images on all the time. Since the status bar is mostly black, the rest of the screen with the vibrant images becomes worn, but the user assumes the smaller portion of the screen is the damaged portion.

It looks like no one knows for a fact what causes it or how to replicate it reliably. It may just be a property of the driving voltage, switching, and material of (AM)OLED based screens.
 

Forgetful

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This is not burn in. Burn in is a different problem.

What you're seeing is a semi common defect with Oled screens in general. On a black background in a dark room darker splotches can be seen. Just Google "black splotches Oled phone" to see examples and compare

Sent from my SCH-I535 using Tapatalk 2
 

funkylogik

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This is not burn in. Burn in is a different problem.

What you're seeing is a semi common defect with Oled screens in general. On a black background in a dark room darker splotches can be seen. Just Google "black splotches Oled phone" to see examples and compare

Sent from my SCH-I535 using Tapatalk 2

but surely on any light emitting diode screen, theres no blacker possible than the colour of the screen off?
couldnt it be that theres lighter parts making the normal parts look dark?
 

Forgetful

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There is leakage current always and it's not a true "far edge of space black" at that. When the screen is on and the led is black it actually is still "on" in the sense that current is flowing at a small level. It's a misconception that leds are completely off when displaying black, in theory they should be but real world it is impossible. The doping of SI is inconsistent and the properties of the substrate are not ideal.


To test this just turn your phone off in a dark room and look at the screen. Now turn it on and look while on a black screen.


Sent from my SCH-I535 using Tapatalk 2
 

Kevin OQuinn

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@534n: You do understand the difference between LED and OLED right? They do not function exactly the same. Yes, I do understand exactly what burn-in refers to on CRT type monitors/screens. Does the average person? Probably not. So they use the term that they know that is the closest match for what they're trying to describe. Image being permanently displayed all the time = burn in. What's probably happening with the OLED "burn-in" is that those particular areas are wearing out at a faster rate then the rest, which makes them look noticeably different than the rest. So whatever area that is appears to be burned in, when it reality it's just worn out faster. Same affect, different cause.

OLED screens of all kinds can suffer from this "blotchyness". GNEX owner's have complained about this quite a bit.
 

534n

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@534n: You do understand the difference between LED and OLED right? They do not function exactly the same. Yes, I do understand exactly what burn-in refers to on CRT type monitors/screens. Does the average person? Probably not. So they use the term that they know that is the closest match for what they're trying to describe. Image being permanently displayed all the time = burn in. What's probably happening with the OLED "burn-in" is that those particular areas are wearing out at a faster rate then the rest, which makes them look noticeably different than the rest. So whatever area that is appears to be burned in, when it reality it's just worn out faster. Same affect, different cause.

OLED screens of all kinds can suffer from this "blotchyness". GNEX owner's have complained about this quite a bit.

Is that not similar to what I said about the issue? I was just pointing out the differences between the three and that is what I said about the image changes with regard the (AM)OLED and the status bar.
 

534n

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There is leakage current always and it's not a true "far edge of space black" at that. When the screen is on and the led is black it actually is still "on" in the sense that current is flowing at a small level. It's a misconception that leds are completely off when displaying black, in theory they should be but real world it is impossible. The doping of SI is inconsistent and the properties of the substrate are not ideal.


To test this just turn your phone off in a dark room and look at the screen. Now turn it on and look while on a black screen.


Sent from my SCH-I535 using Tapatalk 2

Some dynamic displays actually do turn off the backlight/LED power completely for "deep" blacks when the display is capable of turning off parts of the screen lighting, but I believe that in the case of the dark spots on the screen, you may have something like what I had mentioned about the driving voltage differences.
 

Kevin OQuinn

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Is that not similar to what I said about the issue? I was just pointing out the differences between the three and that is what I said about the image changes with regard the (AM)OLED and the status bar.

Ooops yeah. Sorry. I guess that's what I get for skimming LOL.

Some dynamic displays actually do turn off the backlight/LED power completely for "deep" blacks when the display is capable of turning off parts of the screen lighting, but I believe that in the case of the dark spots on the screen, you may have something like what I had mentioned about the driving voltage differences.

Everything that's ever been said about OLED displays is that when it's displaying black the pixel is off. So yes, it does have local dimming. Pixel perfect local dimming. What I'm thinking is that maybe the source isn't a "true" black and it's confusing the device, causing some of the pixels to display a "near black". Does that make sense at all?
 

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