Thanks for that description. Could you tell me how large each dot would be and how much downward pressure would it have to resist? I am thinking that there may be other ways to do this. As an example, some alpha-numeric displays for outdoor use are electro-mechanical in that they swing a little colored disk around behind a black half disk to show on and off. This of course is not the same as raising a dot, but it would be interesting if there is already an actuator out there in some mass produced piece of equipment that could be used. Thanks, Nick On Tue, 22 Jul 2003 10:48, Tommy Craig wrote: > Hi, > > I don't know if I can give you very precise measurements but I'll try. > Braille cells are made using piezo-electric crystals. This is one of the > biggest cost. These crystals change their properties when current is > applied to them. These crystals are used to raise and lower pins that make > up the Braille cell. Braille displays use eight dot Braille instead of six > dot Braille. All of these parts have to be made with very high precission. > They then have to be assembled. Unlike most electronics which have no > moving parts, Braille cells have numerous moving parts. The visible part of > the cell is about 3/8 of an inch wide and about 1.25 inches long. The part > you don't see is about 4 inches long and stands about an inch high. These > cells plug into a circuit board and then all of them are held together by > some sort of rod that runs through the cells. This all takes a lot of > manual labor to assemble. > > Tommy > _______________________________________________ Blinux-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/blinux-list