On Fri, 1 Jul 2005, Bradley Ferguson wrote: > On 7/1/05, Peter wrote: >> On Thu, 30 Jun 2005, Don Taylor wrote: >>> Avoid the brightness drawback, turn the pointers around, paint directly on >>> the retina. >>> >>> You did ask for twisted. >> You could sell these as a kit. Alas the box would have to be large >> enough to hold the supplied white cane and opaque blind man's >> 'sunglasses' needed for completion. > > They make fold up canes, so the box wouldn't have to be that big. > > But on a serious note, I do recall reading that this was/is the > display of the future. A small laser (power limited, obviously) along > with a small, possibly MEMS, mirror structure would individually > activate the rods and cones of the eye to provide you with 36"(?) They are called 'retinal projection' displays and they use very high quality very low power lasers afair. A laser pointer is about 10 times too powerful and has a bad beam shape. The reason they use lasers is, to have very good beam shape and thus resolution. Based on this, it should be possible to experiment with a retinal projection device starting with a small propeller clock and some lenses. The required power will be *very* low. The eye is very sensitive even in daylight. The light from a single led should be more than enough to provide a viewable image. This is on my to-do list and has been for a while now. Alas, time ? What time ? Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist