Panel mismatch compensation for touch enabled displays
First Claim
1. A controller for a touch sensor panel, the controller comprising:
- transmit circuitry configured to generates a plurality of drive signals;
a plurality of transmit channels configured to transmit the plurality of drive signals simultaneously to drive the touch sensor panel; and
a plurality of adjustable gain buffers coupled to the transmit circuitry, wherein the plurality of adjustable gain buffers are directly connected to a plurality of outputs of at least one digital-to-analog converter (DAC), wherein gain of one or more of the plurality of adjustable gain buffers is adjustable to adjust an amplitude of one or more of the plurality of drive signals, thereby compensating the plurality of drive signals from the transmit circuitry for differences in path lengths in the touch sensor panel.
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Accused Products
Abstract
A controller with mismatch compensation for a touch panel is disclosed. A multi-stimulus controller for a touch panel can be formed on a single integrated circuit (single-chip) that can include a transmit section that can generate a plurality of drive signals, a plurality of transmit channels that can transmit the drive signals simultaneously to drive the touch panel, a receive channel that can receive a sense signal resulting from the driving of the touch panel, and a demodulation section that can demodulate the received sense signal to obtain sensing results, the demodulation section including a demodulator and a vector operator. The transmit section can include a pair of adjustable gain buffers that can adjust the gain of stimulation signals to account for the signal path length mismatch of various transmit signal paths.
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Citations
22 Claims
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1. A controller for a touch sensor panel, the controller comprising:
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transmit circuitry configured to generates a plurality of drive signals; a plurality of transmit channels configured to transmit the plurality of drive signals simultaneously to drive the touch sensor panel; and a plurality of adjustable gain buffers coupled to the transmit circuitry, wherein the plurality of adjustable gain buffers are directly connected to a plurality of outputs of at least one digital-to-analog converter (DAC), wherein gain of one or more of the plurality of adjustable gain buffers is adjustable to adjust an amplitude of one or more of the plurality of drive signals, thereby compensating the plurality of drive signals from the transmit circuitry for differences in path lengths in the touch sensor panel. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A controller for a touch sensor panel, the controller comprising:
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transmit circuitry configured to generates a plurality of drive signals; a plurality of transmit channels that transmit the plurality of drive signals simultaneously to drive the touch sensor panel; and a plurality of adjustable gain buffers coupled to the transmit circuitry, wherein gain of one or more of the plurality of adjustable gain buffers is adjustable to adjust an amplitude of one or more of the plurality of drive signals, thereby compensating the plurality of drive signals from the transmit circuitry for differences in path lengths in the touch sensor panel, wherein at least one of the plurality of adjustable gain buffers amplifies at least one of the plurality of drive signals by at least one amplification factor, and wherein a magnitude of the at least one amplification factor for the at least one of the plurality of adjustable gain buffers is different from a magnitude of another amplification factor for at least another of the plurality of adjustable gain buffers. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method for generating stimulation signals for a touch sensor panel, the method comprising:
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generating a plurality of drive signals; and compensating the plurality of drive signals using a plurality of adjustable gain buffers, wherein gain of one or more of the plurality of adjustable gain buffers is adjustable to adjust an amplitude of one or more of the plurality of drive signals, wherein compensating the plurality of drive signals comprises configuring at least one of the plurality of adjustable gain buffers to amplify at least one of the plurality of drive signals by at least one amplification factor, wherein a magnitude of the at least one amplification factor for the at least one of the plurality of adjustable gain buffers is different from a magnitude of another amplification factor for at least another of the plurality of adjustable gain buffers. - View Dependent Claims (14, 15)
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16. A method for generating a plurality of amplification factors for a plurality of adjustable gain buffers in a touch sensor panel, the method comprising:
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generating a plurality of drive signals when no touch event occurs at the touch sensor panel; sensing at one or more receive channels a total charge at an input to one or more sense amplifiers coupled to the one or more receive channels; and selecting an amplification factor for gain of at least one of the plurality of adjustable gain buffers, wherein; the gain is adjustable to adjust an amplitude of at least one of the plurality of drive signals, the amplification factor corresponds to the gain resulting in a minimum total charge sensed on the one or more receive channels, and the amplification factor for the at least one of the plurality of adjustable gain buffers is different from another amplification factor for at least another of the plurality of adjustable gain buffers. - View Dependent Claims (17)
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18. A non-transitory computer readable storage medium having stored thereon a set of instructions for generating a plurality of amplification factors for a plurality of adjustable gain buffers in a touch sensor panel, that when executed by a processor causes the processor to:
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generate a plurality of drive signals when no touch event occurs at the touch sensor panel; sense at one or more receive channels a total charge at an input to one or more sense amplifiers coupled to the one or more receive channels; and select an amplification factor for gain of at least one of the plurality of adjustable gain buffers, wherein; the gain is adjustable to adjust an amplitude of at least one of the plurality of drive signals, the amplification factor corresponds to the gain resulting in a minimum total charge sensed on the one or more receive channels, and the amplification factor for the at least one of the plurality of adjustable gain buffers is different from another amplification factor for at least another of the plurality of adjustable gain buffers. - View Dependent Claims (19)
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20. A non-transitory computer readable storage medium having stored thereon a set of instructions for generating stimulation signals for a touch sensor panel, that when executed by a processor causes the processor to:
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generate a plurality of drive signals; and compensate the plurality of drive signals using a plurality of adjustable gain buffers, wherein gain of one or more of the plurality of adjustable gain buffers is adjustable to adjust an amplitude of one or more of plurality of drive signals; wherein the processor configures at least one of the plurality of adjustable gain buffers to amplify at least one of the plurality of drive signals by at least one amplification factor, wherein a magnitude of the at least one amplification factor for the at least one of the plurality of adjustable gain buffers is different from a magnitude of another amplification factor for at least another of the plurality of adjustable gain buffers. - View Dependent Claims (21, 22)
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Specification