Posted by Rita � Berkowitz on 11/06/07 11:55

Richard Crowley wrote:

>>> 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?

It's irrelevant. Stated MTBF of LCDs would have you believe the 50K-100K
hours. After 3-years it's Russian Rolette with 5 in the cylinder. Talk to
any one of your local asset recovery specialists and they will tell you of
the high rate of failures they get with the problems I listed, and this
doesn't even include bad pixels. CRTs have proven themselves as a reliable
technology that far exceeds that of LCD.

>> 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.)

Yep. No matter what you call it a HV power supply or electronic ballast it
is still the same.

> 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.

You got it.

> 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.

No, they are using basic "gel" type filters between the backlight and LCD.
No special technology here. Bust a few dead LCDs apart and you learn more
in 5-minutes than could be learned from most internet sites.





Rita

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