Close touch detection and tracking
First Claim
Patent Images
1. A method, comprising:
- based on a first scan of a touch-sensing surface, detecting an initial location of a first contact and an initial location of a second contact at the touch-sensing surface;
during a second scan of the touch-sensing surface subsequent to the first scan, detecting a plurality of signal levels caused by the first contact and the second contact, wherein each signal level is associated with one of a plurality of unit cells of the touch-sensing surface;
identifying a first signal level of the plurality of signal levels as a local maximum; and
locating a lost touch based on one or more signal levels associated with one or more unit cells within a fixed distance from a first unit cell associated with the local maximum.
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Abstract
A method of tracking touches at a touch-sensing surface may include, detecting an initial location of a first contact and an initial location of a second contact at the touch-sensing surface based on a first scan of a touch-sensing surface, detecting a plurality of signal levels caused by the first contact and the second contact during a second scan of the touch-sensing surface, identifying a first signal level of the plurality of signal levels as a local maximum, and locating a lost touch based on one or more signal levels associated with one or more unit cells within a fixed distance from a first unit cell associated with the local maximum.
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Citations
20 Claims
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1. A method, comprising:
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based on a first scan of a touch-sensing surface, detecting an initial location of a first contact and an initial location of a second contact at the touch-sensing surface; during a second scan of the touch-sensing surface subsequent to the first scan, detecting a plurality of signal levels caused by the first contact and the second contact, wherein each signal level is associated with one of a plurality of unit cells of the touch-sensing surface; identifying a first signal level of the plurality of signal levels as a local maximum; and locating a lost touch based on one or more signal levels associated with one or more unit cells within a fixed distance from a first unit cell associated with the local maximum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of tracking touches at a touch-sensing surface, the method comprising:
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assign one of a plurality of touch IDs to a location of each of an initial number of local maxima detected from an initial scan of the touch-sensing surface; in response to detecting fewer than the initial number of local maxima from a subsequent scan of the touch-sensing surface, determining a location of a lost touch based on signal levels associated with a subset of unit cells surrounding a first unit cell corresponding to one of the local maxima; and assigning one of the plurality of touch IDs to the location of the lost touch. - View Dependent Claims (12, 13, 14, 15)
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16. A capacitance sensing system, comprising:
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a processor; and a memory coupled with the processor, wherein the memory is configured to store instructions that when executed by the processor, cause the processor to perform a method comprising; based on a first scan of a touch-sensing surface, detecting an initial location of a first contact and an initial location of a second contact at the touch-sensing surface, during a second scan of the touch-sensing surface subsequent to the first scan, detecting a plurality of signal levels caused by the first contact and the second contact, wherein each signal level is associated with one of a plurality of unit cells of the touch-sensing surface; identifying a first signal level of the plurality of signal levels as a local maximum, and locating a lost touch based on one or more signal levels associated with one or more unit cells within a fixed distance from a first unit cell associated with the local maximum. - View Dependent Claims (17, 18, 19, 20)
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Specification