3

I created an that shows black screen and installed it on Moto X (with AMOLED display). Put the phone in aeroplane mode. Then ran Trepn profiler app to measure power consumed. The total battery drain was 53.36 for 10 minutes. Then repeated the same experiment with the same app showing white screen. Battery drain was 58.05 for 10 minutes. The difference is very small and I wonder does AMOLED really save power consumed on showing black.

EDIT: I don't want to switch the screen off. It can be done. I want to switch individual pixel off (when black color is shown) in an AMOLED display. Thereby reducing power consumption.

Note: 1. The app acquires a wake lock to keep the screen on. 2. The app does not have anything in it. It is just a black screen or white screen.

prasannatsm
  • 900
  • 1
  • 11
  • 19
  • 1
    You are probably **showing a black color screen**. Which is different from **turning the screen off**. – Phantômaxx Mar 24 '16 at 12:06
  • 3
    The screen color is set to #000000. Is that wrong? There is no way to explicitly turn the screen off. Black color is supposed to switch off the pixel. – prasannatsm Mar 24 '16 at 12:15
  • I assume that won't work on AMOLED without reducing brightness. Since AMOLED display doesn't have backlight it probably manages brightness through the pixel which requires some power even if that is pitch black. – Endre Börcsök Mar 24 '16 at 12:38
  • `The screen color is set to #000000. Is that wrong?` **Yes**, it is. The screen is still **on**. – Phantômaxx Mar 24 '16 at 13:06
  • Is it possible to switch the *screen off* instead of setting it to #000000? – prasannatsm Mar 24 '16 at 13:19
  • See the link in the duplicate mark. – Phantômaxx Mar 25 '16 at 08:36
  • 2
    The question is not about switching off the screen completely. It's about switching individual pixels off selectively (instead of showing black color). I am talking about saving power in AMOLED display when black color is shown. Looks like the question was mistaken. – prasannatsm Mar 26 '16 at 07:41
  • Often "black" is not the same as "off". Producers of rendering technologies (e.g. displays and printers) try to make "black" as close to what we perceive as black as is possible. Often, this is not "off". For example, when I print only "black and white" on my color printer, I consume color ink. The designers of the printer are not trying to get me to buy color cartridges but are actually trying to produce a better "black". On your display, when "black" is next to a color, a non-off color may actually look "black"-er. – Taylor Kidd Apr 04 '16 at 21:01
  • I understand your question, and I see why these people are mistaken - they didn't really consider the announced property of AMOLED. But, still, your test doesn't show "AMOLED not save power in full black". If you really want to say so, could you provide more repeated tests (e.g. by averaging)? If you have already averaged the results, this clearly shows AMOLED saves battery - not that much, but still saves. – renyuneyun May 13 '18 at 10:47

0 Answers0