LED Backlight "Deadspots"

[534n]

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

You would be surprised how many people do that to my posts

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?

Yes that makes sense actually, like pixel noise in a picture taken of something that is in reality uniform color, like if you take a picture of complete blackness and you get random flecks of distorted colors that are "near-blacks." So I guess the backlight is turning off in the places the image is trying to display truly black and just getting close elsewhere? It is odd since it should be truly black in a native (loading / booting) screen, but then again it could be hardware based in the pixel grid or just bad approximation - or even stranger: some type of 3D "pixel terrain" that could be modeled on a tri-axis which explains why the dark spots occur where they do due to some fault or limitation of the logic control in the display.

Electronics have minds of their own sometimes and it is fascinating.

 

[crackberrytraitor]

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.

It's still burn in, just not the the same kind of burn in that occurred on monochrome CRTs. Using an AMOLED display on max brightness over a period of time can result in static images on the display being permanently burned into the screen. The problem occurred with a great many Galaxy Nexus devices, and is a failing of AMOLED technology. It looks almost exactly like old school burn in, which a ghost image overlaying whatever is displayed.

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[534n]

It's still burn in, just not the the same kind of burn in that occurred on monochrome CRTs. Using an AMOLED display on max brightness over a period of time can result in static images on the display being permanently burned into the screen. The problem occurred with a great many Galaxy Nexus devices, and is a failing of AMOLED technology. It looks almost exactly like old school burn in, which a ghost image overlaying whatever is displayed.

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It also occurred on color CRTs. Oddly, not all AMOLED based displays suffer from it, and my Nexus was on max brightness for pretty much as long as I owned it and never had an issue.

The burn in of OLED is not the same as old school burn in because it is not image retention that is the issue, it is more pixel degradation, loss of brightness, and loss of color change speed/capability. The impression of a burned in images comes from the less bright or duller color from the pixels in the commonly displayed image pixel area.

Other things that can damage OLED screens are UV light, certain lasers, moisture, and decay.

 

[crackberrytraitor]

It also occurred on color CRTs. Oddly, not all AMOLED based displays suffer from it, and my Nexus was on max brightness for pretty much as long as I owned it and never had an issue.

The burn in of OLED is not the same as old school burn in because it is not image retention that is the issue, it is more pixel degradation, loss of brightness, and loss of color change speed/capability. The impression of a burned in images comes from the less bright or duller color from the pixels in the commonly displayed image pixel area.

Other things that can damage OLED screens are UV light, certain lasers, moisture, and decay.

Image retention most certainly is an issue. You can literally see all the burned in icons and text underneath. The mechanism causing burn in may be different, but the end result is the same.

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[534n]

Actually, those images quite accurately illustrate the difference that I am talking about. The CRT shows you detailed images of what was burned in, quite literally.

The OLED screen just shows dim/dark spots where the text/icons were. It is not a "burn in" so much as a "burn out."

And the words image retention mean that the display is retaining the images, not losing the capacity to display new ones. The CRT monitor has a retained image physically burned into a layer on the screen. The OLED display just lacks the brightness in those frequently updated pixel areas. There is no retained image there.

While an interesting divergence into a different topic, this is also not what I was originally describing seeing.

 

[crackberrytraitor]

Actually, those images quite accurately illustrate the difference that I am talking about. The CRT shows you detailed images of what was burned in, quite literally.

The OLED screen just shows dim/dark spots where the text/icons were. It is not a "burn in" so much as a "burn out."

And the words image retention mean that the display is retaining the images, not losing the capacity to display new ones. The CRT monitor has a retained image physically burned into a layer on the screen. The OLED display just lacks the brightness in those frequently updated pixel areas. There is no retained image there.

While an interesting divergence into a different topic, this is also not what I was originally describing seeing.

Look man, dark splotches in the exact shape of whatever was burned in=image retention. I can literally see which icons are what. As I said, the mechanism may be different, but it still ends up with burn in overlaying whatever you're looking at. Pretty sure most people with burn wouldn't feel at all comforted by knowing that it's not caused by phosphorus.

But this is off topic since it's not likely what OP was describing.

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[534n]

Look man, dark splotches in the exact shape of whatever was burned in=image retention. I can literally see which icons are what. As I said, the mechanism may be different, but it still ends up with burn in overlaying whatever you're looking at. Pretty sure most people with burn wouldn't feel at all comforted by knowing that it's not caused by phosphorus.

But this is off topic since it's not likely what OP was describing.

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What happens when you put a bright, vivid image on that screen that is "burned in?" You get the proper picture with dull spots. What you are saying is just false. It is not the same mechanism. There is nothing functionally the same about the methods of how they are burned in or the effects that are present. The only time I see an "overlay" is on a blank screen. There is no physical change in the pixel color in a worn OLED display, hence the image is not "burned in" and referring to it that way is incorrect. With old screens, you can see one image on top of the other. With OLED you still see the proper image with dark spots or dull spots. Excluding dead/stuck pixels, there is no "overlay." If you look at phones with pictures or the screens having color on them, while you may see shapes and outlines (one person had his home screen clock on it) they are just dark spots. There is NO color or sharp detail. Another odd source of this phenomena was someone had a fake screen image over their phone in sunlight (display model) and it became burned into the screen by UV rays. That is the only actual "burn in" I could think of for these displays.

 

[crackberrytraitor]

What happens when you put a bright, vivid image on that screen that is "burned in?" You get the proper picture with dull spots. What you are saying is just false. It is not the same mechanism. There is nothing functionally the same about the methods of how they are burned in or the effects that are present. The only time I see an "overlay" is on a blank screen. There is no physical change in the pixel color in a worn OLED display, hence the image is not "burned in" and referring to it that way is incorrect. With old screens, you can see one image on top of the other. With OLED you still see the proper image with dark spots or dull spots. Excluding dead/stuck pixels, there is no "overlay." If you look at phones with pictures or the screens having color on them, while you may see shapes and outlines (one person had his home screen clock on it) they are just dark spots. There is NO color or sharp detail. Another odd source of this phenomena was someone had a fake screen image over their phone in sunlight (display model) and it became burned into the screen by UV rays. That is the only actual "burn in" I could think of for these displays.

Please read my posts. I've said like 3 times now, while the mechanism is different, the result is fairly similar and just as annoying.

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[Kevin OQuinn]

Please read my posts. I've said like 3 times now, while the mechanism is different, the result is fairly similar and just as annoying.

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And the point I was trying to make above is that most people will agree with you. While technically it might be accurate, it's close enough to them to be the same problem.


BUT, I have to agree with everything both of you have said.

 

[534n]

Just for closure on the topic, I never disagreed with you about the annoyance or end result. I just wanted to point out what was really happening and I don't care how people want to refer to it, but some of it is incorrect for anyone that wanted to learn about it. Lots of what the media says is from management and is aimed at the regular consumer, not from an engineering perspective. So in one hand, you're right.

This debate is a lot like the endless "light bleed" topics with ASUS tablets, some of which are comical, but I won't go any further with that or this.

 

[534n]

omg another intelectual ego rap battle by people i like want me to do the human geek-box

Lol, that's great

 

[funkylogik]

omg another intelectual ego rap battle by people i like want me to do the human geek-box

 

[crackberrytraitor]

Just for closure on the topic, I never disagreed with you about the annoyance or end result. I just wanted to point out what was really happening and I don't care how people want to refer to it, but some of it is incorrect for anyone that wanted to learn about it. Lots of what the media says is from management and is aimed at the regular consumer, not from an engineering perspective. So in one hand, you're right.

This debate is a lot like the endless "light bleed" topics with ASUS tablets, some of which are comical, but I won't go any further with that or this.

The difference being, if you have light bleed you'll know right away and get a replacement. If you have burn in, it generally occurs past the initial warranty period, and you're just screwed. I'd also point out that light bleed is a defect, while burn in is not and can occur on any AMOLED display.

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