Dec 06, 2021
Everyone knows that last year the iPhone 12 "green screen incident" caused a lot of uproars:
Recently, some netizens reported that the iPhone 13 series has also started to have a green screen!
Interestingly, the two iPhone "green screen" problems occurred in the cold winter.
And the lower the temperature, the greener the screen, so I put my phone in my trouser pocket, but after taking it out, it’s not so green...
Fortunately, there are not so many issues with the green screen of the iPhone 13 than the iPhone 12 at the time.
How do you know if your iPhone screen is green or not? This basically needs to meet two conditions at the same time:
The first condition is low brightness. Because the red, blue, and green pixels emit stronger when the brightness is high, the mixed color is still more uniform white.
At low brightness, the color of the screen driving circuit seems less controllable under low voltage, and many problems also arise.
The second condition is the need to display a dark but not pure black interface or picture, because the OLED pixels hardly emit light in black.
Therefore, it is necessary to use non-pure black interface detection, especially the dark gray under low brightness.
The easiest way to meet the above two conditions at the same time is:
So the most critical question is, why does iPhone 12/13 easily turn green in low temperature conditions?
Is it a system bug? Is it a quality control problem? Or is the screen material itself defective?
Don't worry, let me explain it to everyone.
First of all, system bugs can be ruled out. The reason is simple:
If the system bug is really caused, it will not be particularly green in winter, and it will not be green once the temperature rises.
Could it be a "seasonal system bug"? Obviously not, it is basically a hardware problem.
According to the previous online situation, whether it is the first purchase or the current iPhone 12:
In cold weather, after turning on low brightness, dark mode, there is a high probability that a "green screen" will appear.
In other words, this probability has nothing to do with quality control, but is caused by the screen substrate.
After consulting multiple iPhone 12 series screen research materials on the Internet, it is basically certain:
The base materials (luminescent materials) of the iPhone 12/mini Samsung screen and LG screen are all E3 materials;
The base material of the iPhone 12 Pro/Max Samsung screen is M10 material.
Someone should be wondering: aren't these two materials? Why is it easy to turn green?
In fact, the E3 material is actually a weakened takeaway version of the M10. The main difference is that the M10 strengthens the difference in the Blu-ray part.
The performance of these two materials is quite similar, and only similar luminescent materials have such continuity.
Compared with the previous generation of luminescent materials, E3/M10 has many improvements, such as:
Contrast, blue light and power consumption are all done better, and it can also greatly alleviate user's eye fatigue.
But it also has certain shortcomings, that is, the stability is relatively poor, for example, affected by low temperature, it is easier to "green screen".
Now that the "green screen" of the iPhone 13 series is reappearing, there is a high probability that the screen material also continues the iPhone 12 series.
In fact, those Android phones that use E3/M10 luminescent materials also have the problem of green screens, such as Samsung S20/Note20.
In fact, adjusting the color parameters of the screen through software updates can also make the "green screen" appear less frequently to a certain extent.
For example, by forcing the minimum brightness of the screen to be increased, making the green screen more difficult to appear...
Because Apple officially believes that the green screen can solve the problem through subsequent OTA updates...