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Discussion Starter · #1 ·
Since LCDs are backlit doesn't a white screensaver make more sense for reducing power consumption and increasing lifespan?
 

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No. Think about it. BACKlit. The light is a usually at a constant power level. It's the crystals which determine the color (even black and white). In order to have white, the bulb must be on. For a black screen you either have the pixels switch that way (still leaving the bulb lit) or turn off the bulb itself.


So, for the most in power saving, the bulb needs turned off.
 

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Discussion Starter · #3 ·
If the LCD is on the backlight is on. Backlights don't vary their brightness according to content. The question is, does it take more voltage to drive a white/transparent pixel or a black pixel. Which is the inactive (or least active) state for a pixel, white or black? and would it promote the longevity of an LCD (other then just truning it off) to have a screensaver of this color. The reason I ask is I do alot of PCing on my display and it's sometimes on nearly all day.
 

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Discussion Starter · #4 ·
After a little web surfing I've read from multiple sources that black is full voltage and white is essentially no voltage therefore, it would seem white would be a more effective screensaver for LCD. A little counter intuitive but makes sense w/projected light when you think about it.
 

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By LCD do you mean the monitor itself, or the panel holding the crystals? I ask because my monitor can be "on" in powersave mode, yet the bulb is off (and so is the panel).


Starsky, don't confuse DISPLAYED black with "power save" black. Some LCD panels require power to the crystals to "hide" the light coming from the bulb. For some power is used to "open" all crystals show the white light is visable on the outside of the screen.


Also, there isn't really a white or black crystal. There's a set of crystals for each pixel and they rotate based on voltage to determine what color is let through to our eyes. So, some LCD panels would have lower power consumption "displaying" white, while others black.


The simple fact is that for the lowest usage of power, the bulb must be turned off. That's primarily what ALL power saving modes do. The position of the crystal is secondary at that point (no light, no white).
 

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Discussion Starter · #6 ·
I should have clarified, my display has no power saving mode. I have a X30SV-NagaIII and when there is no signal it displays solid blue. It's very annoying, in general it's a great display but it's lack luster firmware leaves alot to be desired.
 

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Screen savers are for old CRTs where burn-in is a risk. For any type of LCD, the best screen saver is turn it off or into standby mode. That's what most computer LCD monitors and laptop LCDs do. Unfortunately, most LCD TVs don't support such power saving feature. The difference between all white screen and all black screen is minimal compared to shut off backlighting altogether.
 

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Discussion Starter · #8 ·
Quote:
Originally Posted by Foxbat121
... The difference between all white screen and all black screen is minimal compared to shut off backlighting altogether.
O.K. it's a minimal difference compaired to the power consumed by the backlight itself, but why not? Say for example my screen saver runs 20% of the time and uses 20% less power with fullscreen white, that's a 4% decrease in power consumption and lifespan of the display. No big whoop, but since I have to run a screensaver anyway...


Besides, nothing says "turn me off" like a blazing white screen.
 

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hmmm... it also seems that a black screensaver would trap more heat in the panel box. Would that not derteroirate the backlight more rapidly? Ofcourse, who wants a 37" pure white panel sitting in their living room?
 

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Exactly. Blue or green screen is used by most TVs to inidicate 'No Signal'. It's not a screen saver. In old days, when a TV receives no signal, it usually display random noises. A blue or green screen is to replace that. And a blue or green screen is much more pleasant to look at. Also, LCD itself uses very little power compared to back light. Life span of the panel is determined by back light burb itself not the panel LCD.


The bottom line, it makes no sense to run screen saver on LCD screens. It does not save your screen in any practical way.
 
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