LCD Displays?
Hi list, i had this event yesterday. In office, a friend of mine spotted my Freerunner laying on the desk and said Hey, thats freakin cool display!. He shared his problem with me: its hard to find cheap LCD displays that may be used outdoors. And i replied that community that produced Freerunner might know the direction where to look at. Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? P.S. Im aware that this is little bit offtopic, but this is the only place i know that has knowledge in this matter. :) ~ Zoggie ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
On Thu, May 21, 2009 at 9:12 AM, zogg zoggif...@gmail.com wrote: Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? The OLPC has an LCD which is very easy to read in daylight. When backlit, it appears as a color LCD, but when frontlit (as from the sun), it appears greyscale. This is a function of the OLPC's very efficient backlight system (instead of using colored filters to block out 66% of the light from the white backlight for each pixel, they use a fresnel prism to split the backlight into it's component wavelengths on pixel boundaries. Thereby allowing nearly 100% of the light produced by the backlight through to your eyes, as opposed to less than 33% for typical LCDs. Light from the front of the LCD passes through the pixels, and is reflected by a silvered layer, back through the pixels to your eyes, never passing through the prism, so what would normally be colored sub-pixels appear as greyscale pixels. --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
What about protection film? Tim Schmidt wrote: On Thu, May 21, 2009 at 9:12 AM, zogg zoggif...@gmail.com wrote: Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? The OLPC has an LCD which is very easy to read in daylight. When backlit, it appears as a color LCD, but when frontlit (as from the sun), it appears greyscale. This is a function of the OLPC's very efficient backlight system (instead of using colored filters to block out 66% of the light from the white backlight for each pixel, they use a fresnel prism to split the backlight into it's component wavelengths on pixel boundaries. Thereby allowing nearly 100% of the light produced by the backlight through to your eyes, as opposed to less than 33% for typical LCDs. Light from the front of the LCD passes through the pixels, and is reflected by a silvered layer, back through the pixels to your eyes, never passing through the prism, so what would normally be colored sub-pixels appear as greyscale pixels. --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community -- View this message in context: http://n2.nabble.com/LCD-Displays--tp2950632p2950710.html Sent from the Openmoko Community mailing list archive at Nabble.com. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
Thats intresting. What could have stopped them from making it non-monochrome in daylight? Tim Schmidt wrote: On Thu, May 21, 2009 at 9:12 AM, zogg zoggif...@gmail.com wrote: Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? The OLPC has an LCD which is very easy to read in daylight. When backlit, it appears as a color LCD, but when frontlit (as from the sun), it appears greyscale. This is a function of the OLPC's very efficient backlight system (instead of using colored filters to block out 66% of the light from the white backlight for each pixel, they use a fresnel prism to split the backlight into it's component wavelengths on pixel boundaries. Thereby allowing nearly 100% of the light produced by the backlight through to your eyes, as opposed to less than 33% for typical LCDs. Light from the front of the LCD passes through the pixels, and is reflected by a silvered layer, back through the pixels to your eyes, never passing through the prism, so what would normally be colored sub-pixels appear as greyscale pixels. --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
Hi Zoggie, i had this event yesterday. In office, a friend of mine spotted my Freerunner laying on the desk and said Hey, thats freakin cool display!. He shared his problem with me: its hard to find cheap LCD displays that may be used outdoors. And i replied that community that produced Freerunner might know the direction where to look at. Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? Look for the word transflective displays when you look for lcd supplies. There are a number of manufacturers that produces transflective displays. KP ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
On Thursday 21 May 2009, zogg wrote: Thats intresting. What could have stopped them from making it non-monochrome in daylight? Probably cost and efficiency as these were major factors in OLPC. If PixelQi don't start producing screens that are colour in daylight then I guess there's a technical reason as well. Based on the explanation below I would have thought adding the coloured filters between the LCD and the reflective layer would drop backlight efficiency only a little since the prism has already split the light, but I'm no expert. The extra component requiring precision placement would add cost though. Tim Schmidt wrote: On Thu, May 21, 2009 at 9:12 AM, zogg zoggif...@gmail.com wrote: Looks like LCD for indoors are common, and for outdoors theres scarcity. So, do you know any manufacturers, or at least in what direction should i try and look at? The OLPC has an LCD which is very easy to read in daylight. When backlit, it appears as a color LCD, but when frontlit (as from the sun), it appears greyscale. This is a function of the OLPC's very efficient backlight system (instead of using colored filters to block out 66% of the light from the white backlight for each pixel, they use a fresnel prism to split the backlight into it's component wavelengths on pixel boundaries. Thereby allowing nearly 100% of the light produced by the backlight through to your eyes, as opposed to less than 33% for typical LCDs. Light from the front of the LCD passes through the pixels, and is reflected by a silvered layer, back through the pixels to your eyes, never passing through the prism, so what would normally be colored sub-pixels appear as greyscale pixels. --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
Tim Schmidt wrote: The OLPC has an LCD which is very easy to read in daylight. When backlit, it appears as a color LCD, but when frontlit (as from the sun), it appears greyscale. This display _very_ cool, I saw an OLPC in action a few weeks ago. It is not even limited to direct sunlight for the reflective display, it already works extremly well at normal room lighting. You just turn the backlight off and it then switches automatically to greyscale at increased resolution. This would be way cool to have as a phone/PDA display. :) -- Tobias PGP: http://9ac7e0bc.uguu.de ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
On Thu, May 21, 2009 at 10:01 AM, zogg zoggif...@gmail.com wrote: Thats intresting. What could have stopped them from making it non-monochrome in daylight? It's not possible, as light coming from the front of the LCD will have to pass through the prism in the wrong direction in order to be reflected back through the prism. The split light would then not line up with the pixel boundaries. --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: LCD Displays?
On Thu, May 21, 2009 at 12:37 PM, Al Johnson openm...@mazikeen.demon.co.uk wrote: On Thursday 21 May 2009, zogg wrote: Thats intresting. What could have stopped them from making it non-monochrome in daylight? Probably cost and efficiency as these were major factors in OLPC. If PixelQi don't start producing screens that are colour in daylight then I guess there's a technical reason as well. Based on the explanation below I would have thought adding the coloured filters between the LCD and the reflective layer would drop backlight efficiency only a little since the prism has already split the light, but I'm no expert. The extra component requiring precision placement would add cost though. That's a good idea actually, and might just work. (!) --tim ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
