Posted by Bob Myers on 11/06/07 18:20

"Richard Crowley" <rcrowley@xp7rt.net> wrote in message
news:5pa3keFq6a9eU1@mid.individual.net...
>> 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.)

Sorry, no; the "ballast" for a cold-cathode fluorescent
of the type used in LCD backlighting is in the inverter,
which is a separate dedicated HV power supply
used solely to drive the CCFL tubes. You may replace
the inverter, but you don't replace a "ballast" per se.

>
> 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.

Sure, and that's where I figured Rita B. was going. But
concerns with fluorescent lighting for room illumination
purposes are irrelevant re the color performance of a display
using CCFL backlighting. The only issues there are what
primary chromaticities and white point you wind up with as
seen from the front of the LCD; what got you there is, from a
front-of-screen performance perspective, a "don't care."

Bob M.

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