Path: utzoo!attcan!uunet!ginosko!ctrsol!emory!att!cbnewsc!psfales From: psfales@cbnewsc.ATT.COM (Peter Fales) Newsgroups: sci.electronics Subject: Re: consumer electronics question Message-ID: <3403@cbnewsc.ATT.COM> Date: 23 Sep 89 18:55:55 GMT References:Distribution: sci Organization: AT&T Bell Laboratories Lines: 24 In article , pausch@ra.cs.Virginia.EDU (Randy Pausch) writes: > > A student is interested in looking at variable-intensity L.E.D displays for > consumer electronics (i.e. your clock radio knows how bright to make itself, > based on the ambient light in the room). Does anyone know if > > a) this is already marketed in a commercial project? My clock radio has a day/night switch that reduces the intensity of the display. It does not sense the room light automatically, but this seems like a logical next step. > b) any R&D work has been done in this area? I don't think there is anything particularly difficult about building variable intensity LEDs. Reducing the current (i.e. greater series resistance) should do it. Pulsing the display and varying the duty cycle is another alternative that might lend itself better to a digital implementation. -- Peter Fales AT&T, Room 5B-420 2000 N. Naperville Rd. UUCP: ...att!peter.fales Naperville, IL 60566 Domain: peter.fales@att.com work: (312) 979-8031