Posted by Richard Crowley on 11/06/07 02:59

"Bob Myers" wrote ...
> "Rita � Berkowitz" wrote ...
>>> The "less environmental impact" statement is correct; however,
>>> LCDs are neither cheaper to manufacture than comparable-sized
>>> CRTs, nor do they have lower longevity.
>>
>> Wrong! The average life expectancy of an LCD monitor is 3-years before
>> one
>> has to have the power supply, ballast, backlight (if replaceable)
>> replaced.
>
> And you think the MTBF of a CRT monitor is...what?
>
> BTW, I'm not sure what you mean by the "ballast" of an LCD
> monitor. Are you referring to the inverter?

LCD displays don't work without backlights.
The most popular backlight so far has been
small-form fluouescent tubes (which require
ballasts, just like their big brothers.)

Apparently LEDs are now becoming more popular
as backlights for LCD displays. But they bring their
own peculiar "spikiness" to the fray. Some interesting
discussions of LEDs used for lighting sources over
in news:rec.arts.theatre.stagecraft


>> Don't know about the "spikey" nonsense, as this is a term thrown around
>> by
>> one of our resident idiots. I'll say that even the best fluorescent
>> lighting has problems that change with ambient temperature and can't be
>> corrected with the built in filters.
>
> Such as?

The spectrum of even "full-spectrum" fluorescents is rather
a significant compromise over reference sources such as
tungsten lamps. Traditional fluorescent tubes have a giant
green spike (or two). We used to use magenta-color plastic
tubes over the fluorescent lamps to try to knock down the green
to allow us to shoot film or video. Some professional video
cameras (particularly those used by news videographers)
have special settings to compensate for fluorescent illumination.

Perhaps higher-quality LCD manufacturers use fluorescent
tubes with custom-designed phosphors which match the red,
green, and blue filter colors of the LCD. And I'm sure they are
trying to stretch those three points out as far as possible into
the corners of the color gamut.
http://www.w3.org/Graphics/PNG/platform2.html
http://en.wikipedia.org/wiki/Chromaticity
http://en.wikipedia.org/wiki/CIE_1931
http://commons.wikimedia.org/wiki/Image:Fluorescent_lighting_spectrum_peaks_labelled.gif

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