power consumption for black & white?


New member
Sorry for the newbie question, but I can't find the info online. Does an LCD use more power showing a white screen than a black one? Or does it just leave the bulb on all the time, and which pixels are open or closed doesn't affect power use?

Also, I thought that an incandescent bulb could burn at varying power and brightness, but a flourescent bulb had to just be on or off. Is that true? If so, why does an LCD use more power at higher brightness?

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CF Tech

The LCD uses the same amount of power showing black or white. The LC material acts as a "shutter", blocking the light on dark pixels.

The CCFL bulbs are not "easy" to dim (the way an incandescent bulb is), but they can be dimmed with specially designed inverters.