Touch sensing with touch down and lift off sensitivity
First Claim
Patent Images
1. A touch sensing device, comprising:
- a touch panel;
a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel and generate a bending wave signal responsive to the sensed bending waves;
a transducer coupled to the touch panel and configured to induce bending waves in the touch panel; and
a controller coupled to the plurality of sensors, the controller configured to identify an untouched condition signal responsive to the induced bending waves, compare the untouched condition signal to the bending wave signal, and detect a touch on the touch panel based on the comparison, wherein the transducer is configured to induce bending waves in the touch panel at a frequency greater than or equal to half the sampling frequency used by the controller.
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Abstract
A touch sensing device includes a plurality of sensors and an emitting transducer coupled to a touch panel. The transducer induces bending waves in the touch panel. The sensors sense bending waves in the touch panel and generate a bending wave signal responsive to the sensed bending waves. A controller identifies an untouched condition signal responsive to the induced bending waves. The controller compares the untouched condition signal to the bending wave signal, and detects a touch on the touch panel based on the comparison.
204 Citations
20 Claims
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1. A touch sensing device, comprising:
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a touch panel; a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel and generate a bending wave signal responsive to the sensed bending waves; a transducer coupled to the touch panel and configured to induce bending waves in the touch panel; and a controller coupled to the plurality of sensors, the controller configured to identify an untouched condition signal responsive to the induced bending waves, compare the untouched condition signal to the bending wave signal, and detect a touch on the touch panel based on the comparison, wherein the transducer is configured to induce bending waves in the touch panel at a frequency greater than or equal to half the sampling frequency used by the controller.
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2. A touch sensing device, comprising:
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a touch panel; a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel and generate a bending wave signal responsive to the sensed bending waves; a transducer coupled to the touch panel and configured to induce bending waves in the touch panel, the transducer configured to induce bending waves in the touch panel at a frequency associated with an aliased untouched condition signal; and a controller coupled to the plurality of sensors, the controller configured identify an untouched condition signal responsive to the induced bending waves, compare the untouched condition signal to the bending wave signal, and detect a touch on the touch panel based on the comparison. - View Dependent Claims (3, 4)
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5. A touch sensing device, comprising:
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a touch panel; a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel and generate a bending wave signal responsive to the sensed bending waves; a transducer coupled to the touch panel and configured to induce bending waves in the touch panel; and a controller coupled to the plurality of sensors, the controller configured to identify an untouched condition signal responsive to the induced bending waves, wherein the controller is configured to determine an amplitude of the untouched condition signal, compare the untouched condition signal amplitude to an amplitude of the bending wave signal, arid detect the touch based on the comparison. - View Dependent Claims (6)
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7. A touch sensing, device, comprising:
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a touch panel; a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel, and generate a bending wave signal responsive to the sensed bending waves; a transducer coupled to the touch panel and configured to induce bending waves in the touch panel; and a controller coupled to the plurality of sensors, the controller configured to identify an untouched condition signal responsive to the induced bending waves, wherein the controller is configured to determine a spectrum of the untouched condition signal, compare the untouched condition signal to a spectrum of the bending wave signal, and detect the touch based on the comparison.
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8. A touch sensing device, comprising:
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a touch panel; a plurality of sensors coupled to the touch panel, the plurality of sensors configured to sense bending waves in the touch panel and generate a bending wave signal, responsive to the sensed bending waves; a transducer coupled to the touch panel and configured to induce bending waves in the touch panel; and a controller coupled to the plurality of sensors, the controller configured to identify an untouched condition signal responsive to the induced bending waves, wherein the controller comprises an adaptive filter having a plurality of reference filter coefficients selected to cancel the untouched condition signal and the controller is configured to calculate the filter coefficients to cancel the bending wave signal, compare the calculated filter coefficients to the reference filter coefficients and detect a touch based on the comparison. - View Dependent Claims (9, 10, 11)
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12. A method for determining touch information, comprising:
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inducing bending waves in a touch panel using a driving signal associated with an aliased untouched condition signal; identifying an untouched condition signal responsive to the induced bending waves; generating a bending wave signal responsive to a touch on the touch panel; comparing the bending wave signal and the untouched condition signal; and detecting the touch on the touch panel based on the comparison.
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13. A method for determining touch information, comprising:
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inducing bending waves in a touch panel using a driving signal; identifying an untouched condition signal responsive to the induced bending waves; generating a bending wave signal responsive to a touch on the touch panel; comparing the bending wave signal and the untouched condition signal; detecting the touch on the touch panel based on the comparison; and updating the identified untouched condition signal based on non-touch related conditions. - View Dependent Claims (14, 15)
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16. A method for determining touch information, comprising:
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inducing bending waves in a touch panel using a driving signal; identifying an untouched condition signal by selecting a plurality of reference filter coefficients of an adaptive filter to cancel the untouched condition signal; generating a bending wave signal responsive to a touch on the touch panel;
calculating filter coefficients to cancel the bending wave signal and comparing the calculated filter coefficients to the reference filter coefficients; anddetecting the touch based on a difference between the calculated filter coefficients and the reference filter coefficients.
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17. A method for determining touch information, comprising:
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inducing the bending waves in the touch panel using a driving signal associated with an aliased untouched condition signal;
identifying an untouched condition signal responsive to the induced bending ways;generating a bending wave signal responsive to a touch on the touch panel; detecting a touch on the touch panel; comparing the bending wave signal and the untouched condition signal after the touch is detected; and detecting a touch lift off from the touch panel based on the comparison.
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18. A method for determining touch information, comprising:
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inducing bending waves in a touch panel using a driving signal; identifying the untouched condition signal responsive to the induced bending waves by selecting a plurality of reference filter coefficients of an adaptive filter to cancel the untouched condition signal; generating a bending wave signal responsive to a touch on the touch panel; detecting a touch on the touch panel; calculating filter coefficients to cancel the bending wave signal; comparing the calculated filter coefficients to the reference coefficient; and
detecting atouch lift off from the touch panel based on the comparison.
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19. A method for determining touch information, comprising:
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inducing bending waves in a touch panel using a driving signal; identifying an untouched condition signal responsive to the induced bending waves; generating a bending wave signal responsive to a touch on the touch panel; detecting a touch on the touch panel; comparing the bending wave signal and the untouched condition signal after the touch is detected; detecting a touch lift off from the touch panel based on the comparison; generating a wake on touch signal responsive to the touch; and energizing the emitting transducer if the wake on touch signal is generated.
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20. A system for determining touch lift off information, comprising:
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means for inducing bending waves in a touch panel using a driving signal; means for identifying an untouched condition signal responsive to the induced bending waves; means for generating a bending wave signal responsive to a touch on the touch panel; means for detecting the touch on the touch panel; means for comparing the bending wave signal and the untouched condition signal; means for detecting a touch lift off from the touch panel based on the comparison; means for generating a wake on touch signal responsive to the touch; and means for energizing the emitting transducer if the wake on touch signal is generated.
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Specification