From: Dave Stampe-Psy+Eng Subject: Re: TECH: Radiation Date: Sat, 28 Mar 1992 15:09:59 GMT Organization: University of Waterloo TOBIAS@bonnie.physik.uni-stuttgart.de writes: > >Hi out there ! >I've tried building up my own Display helmet. The problem for me in fact >was: what kind of Display ?? I tried LCD but the resolution was quite bad. >Then I bought a Sony Watchman. It seemed to be perfect. The picture is >perfect and the devices are very small. But after playing >a little bit with it I discovered a small label on it saying: >"Attention, X-Ray-Radiation." > Don't worry about. Monochrome television picture tubes use about 8000 volts on their second anode, as opposed to 35000 for color TV CRTs. This means that X-ray production is negligable. Also, in a HMD the brightness is quite low, so the beam current (and thus X-ray output) is even lower! Glad to see someone else is looking at CRTs for their "homebrew" HMDs. Myself, I'm using 3 1/2 inch CRTs from Citizen SportTVision TVs. The advantage over Watchmans is they are cheap ($50) and the tubes are much lighter. I have moved the circuitry back over the head, resulting in a lightweight, balanced display. And of course there's the other advantages to CRTs: price, good resolution (depending on what you use to drive them) and adjustable picture size. Only problem with mine: the cheap scanning circuis result in the picture being squashed at one side. But I'm working on it... -------------------------------------------------------------------------- | My life is Hardware, | | | my destiny is Software, | Dave Stampe | | my CPU is Wetware... | | | Anybody got a SDB I can borrow? | dstamp@watserv1.uwaterloo.ca | __________________________________________________________________________