Path: utzoo!attcan!uunet!cs.utexas.edu!titan!heskett From: heskett@titan.tsd.arlut.utexas.edu (Donald Heskett) Newsgroups: sci.electronics Subject: Re: HeadsUp Display ( WAS Re: Big Screen Projector from tiny LCD TV ? ) Message-ID: Date: 16 Sep 90 23:12:25 GMT References: <2916@anasaz.UUCP> <15880016@hpfinote.HP.COM> Sender: news@titan.tsd.arlut.utexas.edu Organization: Applied Research Laboratories, University of Texas at Austin. Lines: 19 In-reply-to: maj@hpfinote.HP.COM's message of 24 Aug 90 18:52:17 GMT In article <15880016@hpfinote.HP.COM> maj@hpfinote.HP.COM (Mike Jassowski) writes: > speaking of removing the backing on LCDs and projecting light through > them. Has anybody tried to make a heads up display that way? Something > that could be fitted to a helmet or added to glasses. ---------- >> Heads up displays are useful because they are virtual images focused >> at infinity. You don't have to refocus your eyes when you look from a >> distant object to the display, and can therefore read the information >> faster. Having a LCD a few inches from your face will be difficult to >> even focus on, much less focus quickly. Putting the proper optics, properly focused, between the eyes and LCD screen would allow the image of the screen to be in focus and the screen to appear to be at infinity. The ordinary use of a simple magnifying glass works in almost this fashion; for the suggested application, of course, you would want to use high quality optics instead of a simple magnifying glass, but the principle is the same.