Infrared touchscreen electronics

A touchscreen display comprising:

• a display screen on which information is displayed;
• and
• touchscreen electronics for detecting touches on the display screen, the touchscreen electronics comprising—
• a plurality of transmitters for transmitting beams across the display screen, each beam being switched on and off in a repeated pattern,
• a plurality of receivers configured to detect the beams from the transmitters, each receiver operable to generate an on value that corresponds to the beam being switched on and an off value that corresponds to the beam being switched off, and
• a controller in communication with the transmitters and the receivers and configured to:
• register an interrupted beam when the on value generated by one of the receivers transitions in a sequence from greater than a lower level to less than the lower level,
• register an uninterrupted beam when the on value generated by one of the receivers transitions in a sequence from less than a upper level to greater than the upper level, wherein the upper level is greater than the lower level, and
• determine that a touch event has occurred based on at least one of the registered interrupted beam and the registered uninterrupted beam.

An electronic device comprising:

• a processing element for performing logical functions;
• and
• a touchscreen display comprising—
• a display screen on which information is displayed, and
• touchscreen electronics for detecting touches on the display screen, the touchscreen electronics comprising—
• a plurality of transmitters positioned adjacent to opposing sides of the display screen for transmitting beams across the display screen, each beam being switched on and off in a repeated pattern,
• a plurality of receivers positioned adjacent to opposing sides of the display screen for detecting the beams from the transmitters, each receiver operable to generate an on value that corresponds to the beam being switched on and an off value that corresponds to the beam being switched off, and
• a controller in communication with the transmitters and the receivers and configured to:
• register an interrupted beam when the on value generated by one of the receivers transitions in a sequence from greater than a lower level to less than the lower level,
• register an uninterrupted beam when the on value generated by one of the receivers transitions in a sequence from less than an upper level to greater than the upper level, wherein the upper level is greater than the lower level, and
• determine that a touch event has occurred based on at least one of the registered interrupted beam and the registered uninterrupted beam.

A method for establishing operating parameters for a touchscreen display, the method comprising the steps of:

• a) transmitting a beam that is switched on and off between a plurality of transmitter and receiver pairs;
• b) recording an output of each receiver with the beam on to collect a plurality of beam on values;
• c) exposing the receivers to a source of infrared radiation;
• d) recording the output of each receiver with the beam off to collect a plurality of beam off values;
• e) setting an upper break band that is less than a lowest beam on value;
• and
• f) setting a lower break band that is greater than the largest beam off value.