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got a question about turning pixels off on a screen. I can make a black image and show it full screen on my pc. Yet the screen looks black but the pixels aren't off. You can see the difference between an off screen and a black screen.

I am wordering if it would be possible to turn these pixels off via a program or is the best you can do: make them black?

I am looking for the delphi code to turn off the right half of my computer screen?

hope its clear!

thx

AakashM
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dave123
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  • What is it that you call an "off" pixel (since it's not a pixel displaying black)? – Pascal Cuoq Sep 27 '11 at 19:17
  • the difference between a screen with a entire black image and a screen that is off – dave123 Sep 27 '11 at 19:20
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    For most screen technologies, you can never reach the level of blackness that you have when the screen is off. Flat screens have backlighting and each pixel filters more or less of the light, but cannot filter it 100%. CRTs always have a few electrons starting off in the wrong direction, etc. – Pascal Cuoq Sep 27 '11 at 19:24
  • This is why "black level" sucks on most new TVs. With most flat panels, black is really "weird purple that glows around the edges". I think OLED is going to be the solution, probably in 10 years before 50" plus sets are affordable though. – Chris Thornton Sep 28 '11 at 12:00

3 Answers3

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You can't turn off individual pixels, or parts of the screen. Either the screen is on or it's off.

This works a bit differently depending on what kind of screen it is, but nowadays LCD screens is the most common kind. An LCD screen has a backlight behind an LCD display; the backlight is always on, and shine through the LCD display when the crystals are transparent. Pixels are made black by making the crystals non-transparent, however they still let a fraction of the back light through. To make pixels completely black you would have to turn the backlight off, and you can only to that for the entire screen.

Guffa
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If I get it right, you want to turn off the power from the half of your monitor, what is impossible. It would have to be supported by your graphic card as well as by your monitor driver.

TLama
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Turning off pixels can only work on new all-lead displays, except if you are switching off the computer, when all systems (including the screen) are off.

Alex Gauss
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