Light scattering-based high contrast optical touch sensor architectures in transmissive and reflective configurations

摘要: Transmissive and reflective optical touch switch architectures based on the use of light scattering are proposed. Key features include high ON/OFF switching ratio, tunable sensitivity, ease implementation, no leakage beam incident user. Experimental proof concept using a visible laser diode plastic Dove prism arranged in transmissive configuration shows 24.4 dB contrast ratio which is hundred times higher than obtained previous total internal reflection-based switch. In addition, response milliseconds also investigated for both lifting sliding fingertip out touching surface Our scattering-based supports multiple keystroke operation.