Patent Document ID: 20020067348
Application ID: 09728999
Patent Flag: 0

Claim One:
1. An infrared touch system having increased resolution for determining position of a touch on a touch screen, said infrared touch system comprising: a first plurality of infrared transmitters positioned along a first edge of the touch screen, each infrared transmitter of said first plurality of infrared transmitters controllably emitting a cone of infrared light; a first plurality of infrared receivers positioned along a second edge of the touch screen directly opposite from the first plurality of transmitters, whereby each receiver of said first plurality of infrared receivers is aligned on-axis with one infrared transmitter of the first plurality of transmitters and is off-axis to each of the other first plurality of transmitters; a second plurality of infrared transmitters positioned along a third edge of the touch screen, said third edge being approximately perpendicular to the first and second edge of the touch screen, each infrared transmitter of said second plurality of infrared transmitters controllably emitting a cone of infrared light; a second plurality of infrared receivers positioned along a fourth edge of the touch screen opposite from the second plurality of transmitters, whereby each receiver of said second plurality of infrared receivers is aligned on-axis with one infrared transmitter of the second plurality of transmitters and is off-axis to each of the other second plurality of transmitters; a processor to control activation of the first and second plurality of infrared transmitters and control activation of the first and second plurality of infrared receivers and for calculating the touch position on the touch screen using on-axis and off-axis activation of the infrared transmitters and receivers.