brad@optilink.UUCP (Brad Yearwood) (12/30/88)
After the recent discussion of bright LEDs, I got some from the local
Radio Shack (their entire supply - 3 pieces), and was quite impressed.
The brightest LED I had previously seen was the visible red one in the
bottom of the Sun (Mouse Systems) mouse.
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. Is the LED actually emitting
some bluish light, or does the eye give false-color responses to some
frequencies of intense IR?
Brad Yearwood
Optilink Corp. {pyramid, tekbspa, pixar}!optilink!brad
Petaluma, CAhaldane@warwick.UUCP (Steve Sykes) (01/05/89)
Hi, In article <743@optilink.UUCP> brad@optilink.UUCP (Brad Yearwood) writes: > ... >The brightest LED I had previously seen was the visible red one in the >bottom of the Sun (Mouse Systems) mouse. > >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. Is the LED actually emitting >some bluish light, or does the eye give false-color responses to some >frequencies of intense IR? I can't see mine glowing, but the physical colour of the led would appear to be blue... Anyway, looking inside my mouse brings me to another (unrelated) question: The light detection devices they use are ordinary 8 pin dil packages that are made from transparant plastic - so why, I think to myself, could one not package other chips in the same way? It looks really neat. Ok, maybe light would affect them, but you could do different colours - blue for ttl, red for cmos etc - why not even colour code chips in stripes in the same way resistors are? Thinking it over, it ocurred to me that someone must have already thought of doing it, and so there must be a good physical reason for not doing it. But I'm not really sure what this might be - surely not just the price of the dye? Comments folks? (Sorry if this has been discussed before!) Hal UUCP: ...!mcvax!ukc!warwick!haldane | Have you hugged your JANET: haldane@uk.ac.warwick.cs | radio today? ARPA: haldane@cs.warwick.ac.uk |_____________________________ Steve Sykes, Computing Dept, Warwick University, Coventry CV4 7AL, England