Screen flickering issue at absolute low brightness

[Hamza Waseem]

I originally meant to discuss this weird issue of the screen of my Lumia 1520 flickering when it is set to absolute low brightness. I.e. In the "Display" settings, when you slide the "Low" bar to minimum. The screen visibly flickers. However, this doesn't appear to be a hardware issue at all, because upon reading the forums, almost every Lumia I think has this problem. Even a guy with a surface had it. So it can't be a general or device specific defect. It could be:

A. A software issue, in the brightness settings. Or a buggy driver.

B. A characteristic defect of LCDs. Cuz I dont think it happens in LED displays. If this is the case, I presume its the backlight, rather than the pixels, which are the problem.

What do you guys think?

 

[gpobernardo]

I originally meant to discuss this weird issue of the screen of my Lumia 1520 flickering when it is set to absolute low brightness. I.e. In the "Display" settings, when you slide the "Low" bar to minimum. The screen visibly flickers. However, this doesn't appear to be a hardware issue at all, because upon reading the forums, almost every Lumia I think has this problem. Even a guy with a surface had it. So it can't be a general or device specific defect. It could be:

A. A software issue, in the brightness settings. Or a buggy driver.

B. A characteristic defect of LCDs. Cuz I dont think it happens in LED displays. If this is the case, I presume its the backlight, rather than the pixels, which are the problem.

What do you guys think?

The flickering is the mechanism employed to regulate the brightness of the screen. This can also be observed in high-power CREE LED flashlights, where the brightness of the flashlight is regulated by making the diode flicker at varying rates - where the shorter the "on time" and the wider the gap ("off time") between "on times", the dimmer the light will become. While the L1520 has an LCD screen, the same mechanism may have been employed and is, as such, not really an issue. It's just that at dimmer settings the interval between "off times" become long while the duration of the "on time" of the screen become shorter, making the flicker noticeable.

Most light-emitting devices (such as TVs, fluorescent bulbs and digital screens) flicker, but at rates that are high enough (e.g. 60 Hz) such that an average human eye won't even notice it.