Xajel
Joined: Jun 18, 2004
Posts: > 500
From: Bahrain
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black is good for CRT, but for LCD you can't do it
in CRT, when you choose the black color ( i mean totally black ), the screen will basicly will not any energy to the phosfor in the inside the CRT, this will give no light at all, and this is the black...
in LCD, the pixels them self don't produce colors, they are just on/off keys for light with three colors
the natural of Liquid Crystal in these display is they are shrouded every side when there's no electricity current, but if there's, they will all stands in the way of the current...
so to make a white color, the crystals will stand all to make the light that come from the backlight goes directly to front, if lets say we need a red color, then only the red sub pixel will let the light go a head, the blue and green will stand in 90 degrees to stop the light completly
as I said before, without any current they crystals will be shrouded every where and not directing some where, thats why they have some grayesh color when the screen is off, as some of them will let the light go and some will not and some will just reflect it any where...
so the back light is always on, if you turned it off you will save power, but the screen will be hard to view as it will depend on reflecting the light it recieves, but as there's always crystals, there will very little light to be there...
so there's two way to save power with LCD screen...
1- turn off the back light, and just make your eye being tired all the time to see what's there
2- lower the brigtness of the backlight, lowering the brighness will use a phenomal known to every one, the eye can't catch light change in very short time, the way the LCD will lower the light is the same, in Phones or Computer LCD's, they will normally use a high freq. ( normally it's 240Hz in Computer LCD's ) then from these 240 cycles they will not give the backlight power in some of these cycles and will give in others.. for example they from each 10 cycles they will cut the power in two, and leave the power on in eight, this mean the power will drop to 80% and the light power will drop to about 80% too... because of the fast natural of this cut and go, the eye will not catch it, and even the light it self will not have any time to go completly off, so it will have less light....
but this will reduce the power
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Posted: 2007-10-16 23:23
