Excerpt from Performance of Partially Sighted With Randsight I Equipped With an X-Y Platform
The TV monitors were symmetrically placed on either side of the down - pointing camera and rested on shelves that were normally kept at a height of 11% in. Above the working surface. They could be pulled toward or pushed away from the viewer over a distance of about 8 in. (from about 4 in. To 16 in. Behind the front edge of the working sur face), and they could be raised or lowered slightly, although this was rarely done. Each monitor was equipped with circuitry and con trols that permitted it (1) to display an image with a normal or re versed gray scale, and (2) to vary the location and height of the electronic window on the monitor screen.
The TV camera could be moved up and down for focusing over a distance of 27 in. By means of a reversible motor and lead screw, and could also be rotated about its optical axis. The latter motion per mitred it to present an erect image of printed or handwritten material no matter what the orientation of that material was relative to the working surface.
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