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On Mon, 9 Feb 1998, Stuart Biggar wrote: > > > I also really welcome a screen that can be used in bright light. The 770 > > > is the first screen that can really be used in bright light successfully > > > (it is MUCH brighter than any previous TP screen). > > > > Still not good enough! Why don't manufacturers make the case backs out of > > clear plastic? Then the backlight can be supplemented by the ambient light, > > and I might finally be able to use a laptop sitting outside on my deck! > > > > - David R. > > I wonder if anyone experimented with one of those ThinkPads > that were made to be used with an overhead projector. Slide > a nice white diffuser in place of the backlight and take it > outside. Would probably work real nice if the diffuser were > facing the sun... While I haven't seen a CV machine, I did used to have an LCD TV with a similar arrangement - active LCD screen with a transparent rear. The cover for the rear (which also held a backlight for use at night) folded out and had a reflective diffusor screen for use in sunlight. The main problem is angle and glare. To direct sunlight through the LCD, you have to hold everything at certain angles. The diffusor screen must be a fold-out type since the sun is often far above the horizon, and most people don't like to work on their backs with the laptop screen above them. Even then you have to combat glare. Sunlight from above is hitting the screen and reflecting to your eyes (and black is never truly black). The light going through the screen is reflected, diffused, then goes through three layers of LCDs. So unless you can get the angles just right, most of the time the light reflecting off the screen is as bright as or brighter than the light going through the screen. If you could make some kind of hood for the screen which blocked light hitting it from the front, that would work too. But then, unless you need really long battery life, why even bother using sunlight as a backlight - juse use the built-in backlight. -- John H. Kim kim@mak.com