If you are willing to look goofy there are some decent HMDs available http://wearcam.org/head-mounted-displays.html
The color ones are pretty low-res, but they certainly solve the glare problem. -- Daniel << When truth is outlawed; only outlaws will tell the truth. >> - RLiegh On Thu, 3 Jul 2003, Rolan wrote: ]Here are 2 other ways to use LCD's in the sun: ] ]http://www.steves-digicams.com/hoodman_e2000.html ]http://www.compushade.com/laptop.htm ] ]Yes, they are ugly and people will look at you funny, but ]at least he screen will be visible :P ] ]~Rolan ] ] ]Daniel Thor Kristjansson wrote: ] ]>This isn't really the right forum for this Q&A but I'll try to explain ]>this a little better. Kevin is right in most respects, LCD's work by ]>having two polarized filters one oriented and one variable, by turning ]>the variable one you control how much of the light from the flouresent ]>bulb in the back gets through to the viewer. ]> ]>But the principle behind anti-glare filters is to eliminate glare ]>by polarizing the external sources of light and then blocking them after ]>they reflect off the screen. One easy way to do this is to just stick a ]>linear polarizer and a quarter wave plane in front of the screen ]>(usually bonded into one sheet, called a circular polarizer)*. But this ]>doesn't work with LCD's because you need to exactly align the external ]>linear polarizer with the oriented linear polarizer in the LCD screen ]>itself, if you don't you get all sorts of artifacts. ]> ]>*the circular polarization flips on reflection. Light that enters the ]>space between the filter and screen reflects once off the glass and then ]>either gets reflected or absorbed on it's attempt to exit, since it is ]>now in exactly the wrong orientation to get through the filter. The ]>light that is reflected off the back of the anti-glare filter hits the ]>screen again, but this is an odd number of reflections again so it ]>can't get out now either, repeat... ]> ]>To really get an anti-glare filter to work you would need to build it ]>into the screen and precisely align it, read expensive. Instead LCD's ]>are built with matted screens which diffuse the light hitting your ]>screen and usually work for small to moderate levels of glare. Because ]>they are built with these matted screens even a preciesely aligned ]>filter would not work. The LCD screen being made out of a ]>lightweight plastic also helps.. they are out of a similar material as ]>the antiglare filters themselves, but you are still restricted more in ]>your material than in the material for an anti-glare filter. ]> ]>Anti-glare filters work well with monitors because they emit unpolarized ]>light (though this means the filter cuts your brigtness/contrast to less ]>than half, which it wouldn't with an LCD), and because the screens have ]>a highly specular, read smooth, screen. If you have one of those ]>perfectly flat CRT monitors with a good anti-glare filter you could sit ]>in the desert all day and never notice any glare. (the filter itself can ]>glare, but this is something you control for when you pick the material ]>for your filter, it does not need the material strength of the tube ]>material (dense glass)) ]> ]>OLED and plasma displays could work with anti-glare filters, but here ]>you cut the light in half which would nearly double the battery ]>consumption so you won't see this on any future laptops, near-term ]>anyway. However, this might mean you can put the flat-screen HDTV of ]>the future in a sunlit room. ]> ]>I think maybe we'll get anti-glare filters built into LCD screens ]>someday, but probably not until battery and heat dissipation ]>technologies allow a much brighter lightbulb behind the LCD. ]>As Kevin points out, most screens will be pretty washed out in the ]>sunlight anyway because the backlight is so comparatively weak. The ]>advantage of an anti-glare filter with LCD over say OLEDs is that you ]>wouldn't get the additional 50% light loss because the light is already ]>polarized, the alignment issue could be overcome with a sturdy ]>metal frame, some cross supports and that same alignment technology that ]>allows us to make microchips at all. There would be extra weight but ]>maybe with lightweight alloy... it's not an insurmountable engineering ]>problem, but trying it at home is probably a waste of time... ]> ]>My solution for computing out in the sun is to sit under a tree. My ]>solution in the office is to close the blinds. Healthy skin has a ]>slightly greenish hue. ;) ]> ]>-- Daniel ]> ]>On Thu, 3 Jul 2003, Kevin Arima wrote: ]> ]>]On Wed, 2 Jul 2003, Jon Baer wrote: ]>] ]>]> can anyone make a good recommendation for an anti glare for a laptop? ]>]> ]>]> i thought id be able to buy some film (vs. attachment) but not the case and ]>]> id like it to fit my thinkpad snug and not flimsy ... something like ... ]>]> ]>] ]>]Err, might I ask *why* you need it? ]>] ]>]What anti-glare filters do is to polarize light that passes through the ]>]filter. Since CRTs are emissive, you do not lose as much "light" that is ]>]generated by the CRT (unpolarized->polarized), but cuts down on glare ]>]considerably (outside source->polarized->bounce off CRT glass->filtered by ]>]anti-glare). ]>] ]>]Since LCDs are non-emissive, it work by polarizing and twisting a source ]>]of light (backlight->first polarizing film->color film->crystal->second ]>]polarizing film). The crystal determines how much "light" will pass ]>]through by "twisting" the light so it either passes through or gets ]>]filtered by the second polarizing film. ]>] ]>]If you are having trouble reading the screen outdoor, that is because the ]>]ambient light is overpowering what the LCD provides, similar to how a ]>]flashlight is less effective at daylight than it is at night. Reading an ]>]LCD is like having a piece of paper that has print on the "back side" of ]>]the page and you need to shine a light through in order to read it. ]>]"Your" light has to be stronger than the ambient light. Anti-glare will ]>]NOT fix that. Either turn up the brightness, or read below for a "cheat". ]>] ]>]If you have glare "indoors" (true glare - ie, what you would experience ]>]with CRT), then the only thing I can recommend is reorient the laptop, or ]>]change the angle of the screen. But I have a feeling this isn't what you ]>]were referring to. ]>] ]>]Now, for the cheat. Forget filters. You can improve the readability of ]>]your screen with ~$2 or less of parts, and it doesn't have to look ]>]half-bad. Get yourself some black heavy-duty construction paper. You ]>]need to create an overhang, similar to this: ]>] ]>]http://www.necmitsubishi.com/products/home/ProductDetail.cfm?product_id=254 ]>] ]>]This will cut down the side light, and give you more angle where the ]>]screen is "viewable" outdoors. ]>] ]>]Kevin "Starfox" Arima ]>]-- ]>]NYCwireless - http://www.nycwireless.net/ ]>]Un/Subscribe: http://lists.nycwireless.net/mailman/listinfo/nycwireless/ ]>]Archives: http://lists.nycwireless.net/pipermail/nycwireless/ ]>] ]> ]> ]> ] ]-- ]NYCwireless - http://www.nycwireless.net/ ]Un/Subscribe: http://lists.nycwireless.net/mailman/listinfo/nycwireless/ ]Archives: http://lists.nycwireless.net/pipermail/nycwireless/ ] -- NYCwireless - http://www.nycwireless.net/ Un/Subscribe: http://lists.nycwireless.net/mailman/listinfo/nycwireless/ Archives: http://lists.nycwireless.net/pipermail/nycwireless/
