Re: OLED power usage?
You are confusing OLED with LED. "LED"-screens are just regular (usually TFT-) LCD screens with LED backlights. Any OLED technology will actually have pixels lighting up and no backlight. In fact there are currenty OLED lamps actually being made.
You can see that when you look up the datasheet of any OLED display. Here's one example of one not claiming to be AMOLED.
http://cdn-reichelt.de/documents/datenblatt/A400/DS_OLED_EA.pdf
As you can see there's no
AMOLED essentially is just OLED with extra transistors. Apparently those are used (with capacitors) to actually store the image on the screen, and to control it by constant current instead of scanning it.