Power usage of white screens on AMOLED displays?

[HaydenOscar]

Hello there! First post on here, been stalking the forums for a bit and been reading AnandTech for a lot longer than that.

My question comes in two parts.
First, does the colour of the screen affect the power consumption at all on LCD displays?
Secondly, is the power usage of white (or other colour) screens on AMOLED displays the same/similar or higher than that of an LCD display showing the same screen?

Just something that's been on my mind recently. Thanks for your answers!

 

[ponyo]

white uses the least power on LCD. But it uses the most on Amoled.

Black uses the most power on LCD. But it uses no power on Amoled.

I don't know about blue on LCD. I think on Amoled, blue takes up second most power besides white. I think that's what I read. That's why I was surprised when I learned ICS was blue based.

 

[HaydenOscar]

Is the power consumption differences between colours on LCD displays as tangible as they are on AMOLED, though?

 

[QuantumPion]

Is the power consumption differences between colours on LCD displays as tangible as they are on AMOLED, though?

No. OLED elements have different powers for different colors because the light emitting elements are not the same size and efficiency for red, green and blue. LCD transistors are the same for each subpixel, they just have a different color filter for each.

 

[HaydenOscar]

So if power consumption is similar across colours for LCDs, what sort of difference would there be compared to a white screen AMOLED display?

 

[runawayprisoner]

So if power consumption is similar across colours for LCDs, what sort of difference would there be compared to a white screen AMOLED display?

I don't have concrete numbers, but from what I can remember, white screen on AMOLED consumes a very significant amount of power. For some OLED displays, displaying white inflates the power consumption up 2x to 3x compared to average.

So if an LED LCD screen consumes about 2.5W on average, an OLED of similar size and resolution might consume about 4-5W with all white. But that's just my guestimation. Take it with a healthy grain of salt.

Also obviously power consumption of OLED heavily depends on size and resolution. For regular LED-backlit LCD, typically only size effects power consumption.

Some OLED displays are starting to incorporate a separate white LED complimenting the red, green, and blue LEDs so that it can save a bit on white backgrounds.

 

[Brian Stirling]

http://en.wikipedia.org/wiki/Oled


See reference to power use...


Brian