Slashdot Mirror
Video Projector on a Chip?
Stile 65 writes "Cornell researchers have made a 0.2mm-squared mirror mounted on carbon fibers that can oscillate at 2.5KHz, 'caus[ing] a laser beam to scan across a range of up to 180 degrees.' These can be mounted on a chip, and in combination with lasers, arrays of such mirrors on a chip can be made into a video projector. From the article: ''"It would be an incredibly cheap display," [Cornell grad student Shahyaan] Desai said. And the entire device would be small enough to build into a cell phone to project an image on a wall."' This display is made possible because of the innovative use of carbon fiber instead of silicon in MEMS. Unlike a standard DMD, this type of device would have one mirror per scanline, not one mirror per pixel, allowing the chip to be much smaller."
Finally, the resolution of a cellphone VDU on a screen the size of a bedsheet! Amazing!
Agreed! Although Light Blue Optics Ltd's devices aren't available on the market yet, and they claim to have no mirrors, prisms, or moving parts. I poked around in Feb when LBO announced their laser projector tech. I couldn't believe no one had tried to make a cheap laser/mirror scanning projector. I found some patents on the technology from the 70's that appear to be used by companies doing the "Pink Floyd laser light show" type devices. They just don't understand what they have could be used to kill off the multi-million dollar LCD projector market, home theater, and even win the LCD/Plasma/OLED/etc TV wars.
we could get the scan rate higher. The optics just hum drawing those lines (laser video isn't vector scanned like most entertainment laser applications). The beam from a laser big enough to do outdoor video might be 1/16th of an inch or bigger before it even leaves the projector head. So even a mirror just 1/8th wide is needed to scan the beam. And that mirror has to move stop and redraw thousands of times a second. One mirror rotating for horizontal refresh, one galvonmeter for vertical drawing (this is the part that gets really sticky on a big screen) and an AOM for the color changes (a custom grown crystal that will vibrate at different frequencies when in the presence of an RF signal, thus blanking the beam (turning it off and on) and diffracting it (picking the color).
Also, if we could get the color right. Solid state lasers are helping here quite a bit, though the blue lines could still use more brightness. But until the big solid state lasers come down in price, a lot of the pros (and I don't mean the guy who did the lasers at your rave) are still dependent on their ancient SpectraPhyscics 171. Three phase power, a fire hydrant's worth of water, a drain, two men to carry the exciter, two to carry the head, two to carry the projector, and thats just one laser. Our small shows had three (one for full color graphics, two for beams in the air). Mosat guys are now using sold state yags for their beam effects. The solid state full colors are pricey. I believe the laser show at Hershey Park is using a full color solid state laser, I don't know who else, its been a few years.
That being said, laser video is starting to show up in more and more places, and it is looking really good. Just don't expect to be putting one in your living room any time soon. Aside from the cost, lasers are heavily regulated in the US. One bright enough to replace your tv is going to require a whole host of permits from the CDRH (Center for Devices and Radiological Health) and your state, plus don't even think about doing your own laser display outside, the FAA's paperwork will make your head spin.
PS, apologies to all the laser jocks if I got something horribly wrong, its been a few years for me, its late, I have a screaming infant and I'm doing this all off the top of my head.