Touch panel scan control
First Claim
1. A touch sensing display system comprising:
- a touch panel including;
a plurality of sensors arranged to form a plurality of capacitors,drive circuitry in data communication with a plurality of output terminals, each of the plurality of output terminals configured to apply voltage to one of the plurality of sensors when activated, andanalog front-end circuitry in data communication with a plurality of input terminals, each of the plurality of input terminals configured to sense electrical signals from one of the plurality of sensors;
a scan control system includinga passive scan module configured to monitor absolute capacitance of the plurality of sensors of the touch panel,a focused active scan module configured to drive sets of at least some of the plurality of sensors using mutual capacitance scanning at an active scan rate, anda hover module configured to determine whether data received from the plurality of sensors of the touch panel is consistent with hover touch data and, in response to determining that the data is consistent with the hover touch data, to output an indication to scan the touch panel using the passive scan module,the scan control system configured to at least generate instructions for a scan of the touch panel by adaptively selecting one of the passive scan module and the focused active scan module to perform the scan of the touch panel, and to generate instructions to scan a reduced subset of the plurality of sensors of the touch panel during at least a portion of the scan, wherein the reduced subset of the plurality of sensors are distributed in a spatially non-uniform density over an area of the touch panel, wherein the spatially non-uniform density includes a first region and a second region, the first region more frequently associated with touch event locations than the second region, the first region having a higher density of the reduced subset than the second region; and
a scanning engine configured to at least configure one or both of the drive circuitry and the analog front-end circuitry to perform the scan according to the instructions.
1 Assignment
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Accused Products
Abstract
Certain aspects relate to systems and techniques for scan control for scanning a touch panel. The scan control system can alternate adaptively between scanning the touch panel in a passive scan mode requiring minimal power and in a focused active scan mode that sequentially scans only a portion of the touch panel. The scan control system can monitor the absolute capacitance of some or all of the sensors of the touch panel in passive scan mode and can monitor the mutual capacitance of a portion of the touch panel in focused active scan mode. If the absolute capacitance of any sensor is greater than the baseline capacitance, then the scan control can use this absolute capacitance touch data to determine one or more sub-regions of the touch panel for scanning in focused active scan mode. The mutual capacitance touch data can be used for determining features of the touch event.
22 Citations
30 Claims
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1. A touch sensing display system comprising:
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a touch panel including; a plurality of sensors arranged to form a plurality of capacitors, drive circuitry in data communication with a plurality of output terminals, each of the plurality of output terminals configured to apply voltage to one of the plurality of sensors when activated, and analog front-end circuitry in data communication with a plurality of input terminals, each of the plurality of input terminals configured to sense electrical signals from one of the plurality of sensors; a scan control system including a passive scan module configured to monitor absolute capacitance of the plurality of sensors of the touch panel, a focused active scan module configured to drive sets of at least some of the plurality of sensors using mutual capacitance scanning at an active scan rate, and a hover module configured to determine whether data received from the plurality of sensors of the touch panel is consistent with hover touch data and, in response to determining that the data is consistent with the hover touch data, to output an indication to scan the touch panel using the passive scan module, the scan control system configured to at least generate instructions for a scan of the touch panel by adaptively selecting one of the passive scan module and the focused active scan module to perform the scan of the touch panel, and to generate instructions to scan a reduced subset of the plurality of sensors of the touch panel during at least a portion of the scan, wherein the reduced subset of the plurality of sensors are distributed in a spatially non-uniform density over an area of the touch panel, wherein the spatially non-uniform density includes a first region and a second region, the first region more frequently associated with touch event locations than the second region, the first region having a higher density of the reduced subset than the second region; and a scanning engine configured to at least configure one or both of the drive circuitry and the analog front-end circuitry to perform the scan according to the instructions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for detecting touch events on a touch panel, the method comprising:
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selecting a passive scan mode for a first scan of at least a portion of the touch panel; based on the selection of the passive scan mode, measuring absolute capacitance of at least one of a plurality of sensors of the touch panel to determine a measured absolute capacitance value; comparing the measured absolute capacitance to a baseline absolute capacitance value to generate a difference value; comparing the difference value to a threshold, wherein the difference value exceeding the threshold indicates a possibility of a touch event on the touch panel; in response to the difference value not exceeding the threshold;
selecting the passive scan mode to perform a second scan of the touch panel;in response to the difference value exceeding the threshold selecting a focused active scan mode to perform the second scan of at least a portion of the touch panel, analyzing data resultant from the second scan to determine whether the data is consistent with hover touch data, and in response to determining that the data is consistent with the hover touch data, outputting an indication to perform a third scan of the touch panel using the passive scan mode; and generating instructions to scan a reduced subset of the plurality of sensors of the touch panel during at least a portion of the first scan, the second scan, or the third scan, wherein the reduced subset of the plurality of sensors are distributed in a spatially non-uniform density over an area of the touch panel, wherein the spatially non-uniform density includes a first region and a second region, the first region more frequently associated with touch event locations than the second region, the first region having a higher density of the reduced subset than the second region. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. Non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more physical computing devices, cause operations comprising:
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measuring absolute capacitance of at least one of a plurality of sensors of the touch panel to determine a measured absolute capacitance value; comparing the measured absolute capacitance to a baseline absolute capacitance value to generate a difference value; comparing the difference value to a threshold, wherein the difference value exceeding the threshold indicates a possibility of a touch event on the touch panel; in response to the difference value not exceeding the threshold;
selecting a passive scan mode to perform a scan of the touch panel;in response to the difference value exceeding the threshold selecting a focused active scan mode to perform the scan of at least a portion of the touch panel, analyzing data resultant from the second scan to determine whether the data is consistent with hover touch data, and in response to determining that the data is consistent with the hover touch data, outputting an indication to perform an additional scan of the touch panel using the passive scan mode; and generating instructions to scan a reduced subset of the plurality of sensors of the touch panel during at least a portion of the scan or the additional scan, wherein the reduced subset of the plurality of sensors are distributed in a spatially non-uniform density over an area of the touch panel, wherein the spatially non-uniform density includes a first region and a second region, the first region more frequently associated with touch event locations than the second region, the first region having a higher density of the reduced subset than the second region. - View Dependent Claims (23, 24, 25, 26)
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27. A touch panel display apparatus comprising:
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means for measuring absolute capacitance of at least one of a plurality of sensors of a touch panel to determine a measured absolute capacitance value; means for comparing the measured absolute capacitance to a baseline absolute capacitance value to generate a difference value; means for comparing the difference value to a threshold, wherein the difference value exceeding the threshold indicates a possibility of a touch event on the touch panel; means for selecting, based at least partly on a result of comparing the difference value to the threshold, one of a focused active scan mode and a passive scan mode to perform a scan of at least a portion of the touch panel; means for determining whether data resultant from the scan is consistent with hover touch data, and, in response to determining that the data is consistent with the hover touch data, outputting an indication to perform an additional scan of the touch panel using the passive scan mode; and generating instructions to scan a reduced subset of the plurality of sensors of the touch panel during at least a portion of the scan or the additional scan, wherein the reduced subset of the plurality of sensors are distributed in a spatially non-uniform density over an area of the touch panel, wherein the spatially non-uniform density includes a first region and a second region, the first region more frequently associated with touch event locations than the second region, the first region having a higher density of the reduced subset than the second region. - View Dependent Claims (28, 29, 30)
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Specification