> Yikes! It sounds like halogen lighting is a death sentence to
> the display.
>
> Greg
Greg, your fears are completely unfounded.
Let us examine the halogen and fluorescent lighting.
Halogen:
So named because it has a small amount of Iodine or
Bromine (Halide) in the bulb. When the filament, which
is made of Tungsten, is heated to ~800 deg C, the atoms
'boil off' and would be deposited on the inside of the
glass if it weren't for the Halogen. At this temperature,
the Tungsten atoms spontaneously react with the halogen
and become a gas; albeit an unstable one. When the lamp
cools, the Halogen is released and the Tungsten is deposited
back on the filament. This is the Halogen cycle.
Apart from being brighter than a normal filament lamp,
they don't generate significant amounts of UV.
Fluorescent:
Works by passing a current through low pressure Mercury
vapor. This causes the vapor to emit UV light. In order
for it to be useful, the tube is coated with a phosphor.
The phosphor is excited by the UV light and re-emits it
in the visible region, the color depends on the particular
phosphor or combination of phosphors.
So, by definition, the Fluorescent lamp generates far more UV
than the Halogen - quite the reverse of the supporting
evidence from Pascal B. Kreil, Hagen/Germany (courtesy of DJ Schonfeld)
to condem Halogens as 'Backlight killers'!
I think that trying to ascertain any credible facts from a
misguided (though well meaning) and badly translated text
is fraught with danger.
Truth is, if you are operating in an environment where the
UV levels are high enough to have an effect, either the timer
is stuck on your sunbed or the Sun has just gone nova. ;}
Please don't worry folks!
The backlight will eventually wear out. It will exhibit a gradual
decline in brightness. This is normal.
In fact, you generally won't notice it unless you put it side by side
with a new one. Then it is really a subjective issue. Can you still
read the display? If so, does it really affect your interaction
with the machine?
Regards,
PCBman
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