🚀 go-pugleaf

marula31@hootmail.com (---) wrote:

>On Wed, 3 Apr 2002 08:14:31 +0100, John Chapple <jc@ch-w.demon.co.uk>
>wrote:
>
>>How can an Liquid Crystal Display type be low radation, or even high
>>radiation? Radiation applies only to Cathode Ray Tube types
>
>They can still radiate nasties. If not electromagnetic radiation,
>then some sort of ionisation.
>
>Apple is having problems in this respect, or so I'm told.
>
>The last one I bought has a 'TCO 99' sticker, which is
>supposed to guarantee the thing against throwing out nasties.

Firstly, it's worth pointing out that visible light *IS*
electromagnetic radiation.

Secondly, LCD displays get their brightness by means of illumination
with miniature cold cathode fluorescent light tubes placed at the
sides of the LCD panel.  The fluorescent light is diffused across the
screen by inclusion of a diffusion screen behind the LCD panel.  The
LCD panel itself emits nothing, although some LCD technologies use a
very small magnetic field within the panel.  It's just a mechanism for
filtering the transmission of light.

The stories about "nasties" with LCD's seems to relate to the fact
that some people don't seem to get on too well with fluorescent light.
This problem isn't specific to LCD displays; some people claim to get
headaches when working under fluorescent lights.  The reason why isn't
clear although there has been some surmise that it might be due to the
fact that fluorescent lights flicker at a rate of 100 hertz.  However,
the problem may be more to do with bad workplace design rather than
with the type of lighting.

I wouldn't mind betting that the story about Apple displays is just
marketing FUD created by one of Apple's competitors.  It's also very
easy to get TCO 99 certification for a device which doesn't emit any
radiation at wavelengths that are usually considered harmful (eg
X-rays, UVC and microwaves).  I rather suspect that you would be very
hard pressed to find an LCD PC display which hasn't been certified to
TCO 99.
-- 
Mike Humberston
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