A large-active-area light-blocking based switch for people with disability

摘要: Abstract This paper proposes a force-free large-active-area light-blocking based switch structure. Our key approach is on combination of three basic optical concepts: beam shaping (S) that converts an incident into diverging sheet light across desired active area, floating (F) allows the float above area and blocking (B) for checking appearance obstruction in space over touching zone. By adding electronic filters post processing, unwanted noises can also be suppressed. SFB-based sensor prototype using two emitting diodes, plastic cylindrical lenses eight photoreceivers shows 27 mm × 29 mm with measured 23.5-dB electrical on/off ratio. A 100% achieved ≥9-mm diameter obstruction. In addition, our operated under typical 300 lx high illumination 2000 lx without malfunction, verifying it suitable indoor use. So far, 10 sets sensors have been deployed disabled students to comfortably turn computers more than 9 months showing failure.