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View Full Version : Original Brightscreen patent, 1982



Kevin M Bourque
27-Mar-2010, 07:57
Hi All -

I didn't know if this had ever been posted here before. My apologies if its a repeat.

Apparently screen brightness is improved by the application of a thin layer of epoxy.

The other thing that good screens have is very fine pitch Fresnel lenses (about 300 grooves per inch). I searched around a good bit one day at all the likely places (Edmund and various others) and was never able to find a source. Anyone got a dealer? Do we have to get them from a shady character on the street corner ;-)

http://www.patentstorm.us/patents/4339188/fulltext.html

Bob Salomon
27-Mar-2010, 11:20
Way back when, before epoxy for instance, we applied a coating of lacquer to the grain side of the gg to brighten it. Of course, over time, it would crack and yellow but it was easy to remove and reapply.
Also why look at Edmund? They don't make fresnels. Try http://www.reflexite.com/ they do and they are the parent of Fresnel Optics and Beattie.

bvstaples
28-Mar-2010, 15:30
If you want a really bright screen, you could always grind it yourself. It's not that hard (of course I've ground telescope mirrors, so flat glass seems easy). There are numerous references on line on how to do this and it ends up being cheaper than buying a GG. Once ground you can rule to your desire with a light pencil.

Brian