Abstract: An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events on a surface. The optical touch-sensitive device includes multiple emitters and detectors. Each emitter produces optical beams which are received by the detectors. Touch events on the surface disturb the optical beams received by the detectors. Based on the disturbed beams, a map of the touch activity on the surface is generated. Touch characteristics and touch types for each touch event are determined from the map. By applying the touch characteristics and touch types to contextual information, a machine learned model, or a set of predefined rules, touches can be classified as wanted or unwanted touch events. Unwanted touch events may be ignored to improve user experience.

Abstract: A touch sensitive surface has emitters and detectors arranged around a periphery of the touch sensitive surface. The emitters produce optical beams that are received by the detectors. A stylus is configured to disturb one or more of the optical beams by a variable amount when in contact with the touch sensitive surface. The variable amount depends on an amount of force applied to the stylus towards the touch sensitive surface. A controller of the touch sensitive surface is configured to determine the touch strength of a touch event performed by the stylus based on disturbances of one or more of the optical beams. The touch strength provides a measure of the amount of force applied to the stylus.

Abstract: An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events on a surface. The optical touch-sensitive device includes multiple emitters and detectors. Each emitter produces optical beams which are received by the detectors. Touch events on the surface disturb the optical beams received by the detectors. Responsive to a touch event, the disturbed beams are identified and evaluated. Beams disturbed by two or more touches may be ignored. Alternatively, a beam response may be adjusted for a given touch event based on an estimated contribution of another touch event that also disturbs the beam. Additionally, touch events may be characterized as contamination touch events based on one or more past touch events.

Abstract: An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events on a surface. The optical touch-sensitive device includes multiple emitters and detectors. Each emitter produces optical beams which are received by the detectors. Touch events on the surface disturb the optical beams received by the detectors. Based on the disturbed beams, a map of the touch activity on the surface is generated. Touch characteristics and touch types for each touch event are determined from the map. By applying the touch characteristics and touch types to contextual information, a machine learned model, or a set of predefined rules, touches can be classified as wanted or unwanted touch events. Unwanted touch events may be ignored to improve user experience.

Abstract: A touch sensitive surface has emitters and detectors arranged around a periphery of the touch sensitive surface. The emitters produce optical beams that are received by the detectors. A stylus is configured to disturb one or more of the optical beams by a variable amount when in contact with the touch sensitive surface. The variable amount depends on an amount of force applied to the stylus towards the touch sensitive surface. A controller of the touch sensitive surface is configured to determine the touch strength of a touch event performed by the stylus based on disturbances of one or more of the optical beams. The touch strength provides a measure of the amount of force applied to the stylus.