Eraser for touch displays
First Claim
1. A touch sensing apparatus, comprising:
- a touch surface,a plurality of emitters, arranged around a periphery of the touch surface, configured to emit a plurality of light beams such that one or more objects touching the touch surface cause an attenuation of at least one of the plurality of light beams;
a plurality of detectors, arranged around the periphery of the touch surface, configured to receive light from the plurality of emitters on a plurality of light paths, wherein each detector in the plurality of detectors is arranged to receive light from more than one emitter of the plurality of emitters; and
a hardware processor configured to;
determine, based on output signals from the plurality of detectors, a plurality of transmission values, each of the plurality of transmission values corresponding to each of the plurality of light paths;
determine an object reference point on the touch surface where the light is attenuated or occluded by an object based on the plurality of transmission values;
determine one or more unaffected light paths from the plurality of light paths that are not affected by the object based on the plurality of transmission values;
determine, from the one or more unaffected light paths that are not affected by the object, one or more object boundary light paths in relation with the object reference point; and
determine one or more characteristics of the object based on the one or more object boundary light paths,wherein the one or more object boundary light paths comprise a closest boundary light path passing closest to the object reference point.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical IR touch sensing apparatus configured to determine, based on output signals of light detectors, a light energy value for each light path across a touch surface, and generate a transmission value for each light path based on the light energy value. A processor is then configured to process the transmission values to determine an object reference point on the touch surface where the light is attenuated or occluded by an object and determine, from a set of light paths unaffected by an object, a set of object boundary light paths comprising one or more light paths passing closest to the object reference point. The characteristics of the object may then be determined in dependence on the set of object boundary light paths.
592 Citations
13 Claims
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1. A touch sensing apparatus, comprising:
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a touch surface, a plurality of emitters, arranged around a periphery of the touch surface, configured to emit a plurality of light beams such that one or more objects touching the touch surface cause an attenuation of at least one of the plurality of light beams; a plurality of detectors, arranged around the periphery of the touch surface, configured to receive light from the plurality of emitters on a plurality of light paths, wherein each detector in the plurality of detectors is arranged to receive light from more than one emitter of the plurality of emitters; and a hardware processor configured to; determine, based on output signals from the plurality of detectors, a plurality of transmission values, each of the plurality of transmission values corresponding to each of the plurality of light paths; determine an object reference point on the touch surface where the light is attenuated or occluded by an object based on the plurality of transmission values; determine one or more unaffected light paths from the plurality of light paths that are not affected by the object based on the plurality of transmission values; determine, from the one or more unaffected light paths that are not affected by the object, one or more object boundary light paths in relation with the object reference point; and determine one or more characteristics of the object based on the one or more object boundary light paths, wherein the one or more object boundary light paths comprise a closest boundary light path passing closest to the object reference point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of determining characteristics of an object in contact with a touch surface of a touch sensing apparatus, said touch sensing apparatus comprising:
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a touch surface, a plurality of emitters arranged around a periphery of the touch surface, configured to emit a plurality of light beams such that one or more objects touching the touch surface cause an attenuation of at least one of the plurality of light beams; and a plurality of detectors, arranged around the periphery of the touch surface, configured to receive light from the plurality of emitters on a plurality of light paths, wherein each light detector in the plurality of detectors is arranged to receive light from more than one emitter of the plurality of emitters; said method comprising; determining, based on output signals from the plurality of detectors, a plurality of transmission values, each of the plurality of transmission values corresponding to each of the plurality of light paths; determine an object reference point on the touch surface where the light is attenuated or occluded by an object based on the plurality of transmission values; determining one or more unaffected light paths from the plurality of light paths that are not affected by the object based on the plurality of transmission values; determining, from the one or more unaffected light paths that are not affected by the object, one or more object boundary light paths in relation with the object reference point, and determining one or more characteristics of the object based on the one or more object boundary light paths, wherein the one or more object boundary light paths comprise a closest boundary light path passing closest to the object reference point.
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Specification