Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ncar!ames!amelia!eos!jbm
From: jbm@eos.UUCP (Jeffrey Mulligan)
Newsgroups: sci.electronics
Subject: Re: visible infrared?
Message-ID: <2250@eos.UUCP>
Date: 30 Dec 88 19:26:31 GMT
References: <743@optilink.UUCP>
Organization: NASA Ames Research Center, California
Lines: 18

From article <743@optilink.UUCP>, by brad@optilink.UUCP (Brad Yearwood):
 
> Which brings me to a question.  There is a second LED, presumably infrared
> emitting, in the Mouse System mouse, to the left of the red LED.  If you
> look carefully (particularly if you cover the red LED), the infrared LED
> appears to have a pale bluish-gray glow.

If you look even more carefully (particularly if you exclude all ambient
light), the infrared LED or whaterver it is is completely dark.
Presumably the blue-gray appearace is due to ambient light being
concentrated by the lens of the thing, which may have a bluish tint.


-- 

	Jeff Mulligan (jbm@aurora.arc.nasa.gov)
	NASA/Ames Research Ctr., Mail Stop 239-3, Moffet Field CA, 94035
	(415) 694-6290