초록 ▼

A touch system using a plurality of infrared ("IR") transmitters and receivers, and a method of determining with increased resolution the location of a touch between the IR transmitters and receivers using on-axis and off-axis detection are disclosed. The inventive touch system and method use, in co

A touch system using a plurality of infrared ("IR") transmitters and receivers, and a method of determining with increased resolution the location of a touch between the IR transmitters and receivers using on-axis and off-axis detection are disclosed. The inventive touch system and method use, in conjunction with the on-axis and off-axis detection, a coarse and fine sweep of the transmitters and receivers to increase the resolution of identified touch location. The method of determining a touch location involves selection and activation of particular off-axis infrared transmitter and receiver pairs determined from a triangulation interdependence between the x and y coordinates. The increased resolution of the identified touch location is achievable using the inventive system and method without the need for an increased number of IR transmitters and receivers and without the need for higher speed processing capability.

대표청구항 ▼

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 infr

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, wherein in calculating the touch position on the touch screen using on-axis and off-axis activation of the infrared transmitters and receivers, the processor (a) estimates a coarse touch location based upon a sequential on-axis activation of each infrared transmitter and opposing receiver; (b) selects off-axis transmitter and receiver pairs based upon the coarse touch location estimate; and (c) refines the touch location based upon a sequential activation of the selected off-axis transmitter and receiver pairs.