Research and development of a hand-held vision system for the visually impaired

The authors have proposed an artificial vision system for the visually impaired that compensates for their sight disabilities and enables them to walk without danger as much as possible. This system consists of a stereo distance-measuring system PRPS (passive range pattern sensor), MPU, a signal amplifier, and a tactile pin display. The system acquires multiple points of distance information (up to 3.0 meters away), converts and displays the information via a wired connection using amplitude intensities corresponding to each point in the distance. The distance information acquired via 24 windows in the image obtained from the PRPS was output from a PC. Using firmware in the RAM of the MPU, rectangular waveforms corresponding to the 24 points of distance information obtained from the PC are generated and output to each terminal of the specified ports. The signals (rectangular waveforms) from the MPU are amplified and output to /spl plusmn/90V. Piezoceramics corresponding to each terminal of the output ports specified by the processor are vibrated by the electric potential difference in the amplified rectangular waveforms.