Design of an infrared multi-touch surface for use as a computer keyboard

Abstract

A multi-touch surface was designed and constructed to detect a person's finger when pressed against the touch surface, with the objective of developing a prototype touch surface computer keyboard. The prototype developed was a nine-key multi-touch surface designed to utilize the FTIR touch screen method while also maintaining a low profile. To ensure a low profile, the final design utilizes infrared phototransistors to detect and interpret incoming infrared light reflected off a user's finger in contact with the touch screen. The device proved it was capable of accurately determining which key(s) a user wished to activate. The keyboard measures 0.92" high which was within a 1" maximum thickness functional requirement.