US 10,761,644 B2Granted

Touch sensor circuit with self and mutual touch detection

AssigneeSigmasense, LLC.

InventorPatrick Troy Gray

Life of this patent

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Abstract

A touch sensor circuit includes a plurality of drive/receive circuits and a drive signal generation circuit. The drive/receive circuits drive and receive signals from a multi-touch sensor. A drive/receive circuit includes an analog to digital conversion (ADC) circuit and a digital to analog conversion (DAC) circuit. The ADC circuit includes a first input to receive a sensor signal on an electrode of the multi-touch sensor. The sensor signal includes a drive signal component and a receive signal component. The ADC circuit includes a second input to receive an analog reference signal from the drive signal generation circuit. The ADC circuit generates a digital signal based on the analog reference signal and the sensor signal. The DAC circuit converts the digital signal into the drive signal component and the receive signal component is representative of an impedance on the electrode detected and is indicative of a touch proximal to the electrode.

Claims14

Dependent claims

A touch sensor circuit comprises:

a plurality of drive/receive circuits for driving and receiving signals from a multi-touch sensor, wherein a drive/receive circuit of the plurality of drive/receive circuits includes:
a first conversion circuit operable to convert a sensor signal on an electrode of the multi-touch sensor into a sensed signal based on an analog reference signal, wherein the sensor signal includes a drive signal component and a receive signal component;
and
a second conversion circuit operable to convert the sensed signal into the drive signal component, wherein the receive signal component is representative of an impedance on the electrode detected when the drive signal component is applied to the electrode, wherein a first impedance change of the impedance of the electrode is indicative of a self-touch proximal to the electrode and a second impedance change of the impedance of the electrode is indicative of a mutual-touch proximal to the electrode, wherein the drive signal component includes a first frequency signal component and a second frequency signal component, wherein the first frequency signal component is used to detect the first impedance change of the self-touch and the second frequency component is used to detect the second impedance change of the mutual-touch;
and
a drive signal generation circuit operable to generate the analog reference signal.

3 more elements

A drive/receive circuit for driving and receiving signals on a single node, wherein the drive/receive circuit comprises:

a first conversion circuit operable to convert a sensor signal on a node of a sensor into a sensed signal based on an analog reference signal, wherein the sensor signal includes a drive signal component and a receive signal component;
and
a second conversion circuit coupled to convert the sensed signal into the drive signal component, wherein the receive signal component is representative of an impedance of a circuit coupled to the node detected when the drive signal component is applied to the node, and wherein detection of changes in the receive signal correspond to changes in the impedance of the circuit, wherein the first conversion circuit is further operable to keep the sensor signal substantially constant by creating the sensed signal to correspond to changes in the receive signal component, which corresponds to changes in impedance of the node, and wherein the second conversion circuit is further operable to generate the drive signal component based on the sensed signal to substantially compensate for changes in the receive signal component such that the sensor signal remains substantially constant.

Dependencies are inferred from the claim text.

Facts

Application: 16/109,004Filed 22 Aug 2018 · continuation
Priority: 22 Jun 2015
Published: US 2018/0364859 A120 Dec 2018
Granted: 1 Sep 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G06F 3/04166
Control or interface arrangements specially adapted for digitisers: details of scanning methods, e.g. sampling time, grouping of sub areas or time…
G06F 3/03545
With detection of two-dimensional [2D] relative movements between the device, or an operating part thereof, and a plane or surface, e.g. 2D…
G06F 3/04162
Control or interface arrangements specially adapted for digitisers: for exchanging data with external devices, e.g. smart pens, via the digitiser…
G06F 3/041662
Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving: using alternate mutual and…

Family

Application62/183,062Us provisional application · filed 22 Jun 2015
PCT/US2016/038497Parent of this continuation · filed 21 Jun 2016
US 2018/0364859 A1Pre-grant publication · published 20 Dec 2018
Application15/506,097Parent of this continuation
US 10,120,498 B2Parent of this continuation
US 2017/0242534 A1Published application
US 10,761,644 B2This patent

From the US filing history. Foreign family members aren’t listed.