Detecting multitouch events in an optical touch-sensitive device by combining beam information
First Claim
1. A method for determining simultaneous touch events on a surface, the surface having a plurality of emitters and detectors arranged around its periphery, the emitters producing optical beams received by the detectors, the touch events disturbing the optical beam, the method comprising:
- receiving numerical metrics, indicating which beams have been disturbed by touch events, having at least one of an analog indication and a gradated measure of the beams disturbances;
for a candidate touch point, combining the numerical metrics for at least two beams that would be disturbed by the candidate touch point;
determining the touch events based on the combined metrics;
wherein combining the numerical metrics comprises taking a weighted average of the numerical metrics; and
wherein two beams are weighted less when the two beams are from the same emitter or to the same detector.
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Abstract
An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events. The optical touch-sensitive device includes multiple emitters and detectors. Each emitter produces optical beams which are received by the detectors. The optical beams preferably are multiplexed in a manner so that many optical beams can be received by a detector simultaneously. Touch events disturb the optical beams. To determine whether a candidate touch point is an actual touch event, multiple beams that would be affected are considered together.
86 Citations
23 Claims
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1. A method for determining simultaneous touch events on a surface, the surface having a plurality of emitters and detectors arranged around its periphery, the emitters producing optical beams received by the detectors, the touch events disturbing the optical beam, the method comprising:
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receiving numerical metrics, indicating which beams have been disturbed by touch events, having at least one of an analog indication and a gradated measure of the beams disturbances; for a candidate touch point, combining the numerical metrics for at least two beams that would be disturbed by the candidate touch point; determining the touch events based on the combined metrics; wherein combining the numerical metrics comprises taking a weighted average of the numerical metrics; and wherein two beams are weighted less when the two beams are from the same emitter or to the same detector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An optical touch-sensitive device comprising:
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a surface for which touch events are to be detected; a plurality of emitters and detectors arranged around a periphery of the surface, the emitters producing optical beams received by the detectors, the touch events disturbing the optical beam; and a touch event processor coupled, directly or indirectly, to the emitters and detectors, the touch event processor receiving numerical metrics indicating which beams have been disturbed by touch events; for a candidate touch point, combining the numerical metrics, having at least one of an analog indication and a gradated measure of the beams disturbances, for at least two beams that would be disturbed by the candidate touch point; and determining the touch events based on the combined metrics; wherein combining the numerical metrics comprises taking a weighted average of the numerical metrics; and wherein two beams are weighted less when the two beams are from the same emitter or to the same detector.
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Specification