Granted Patent B2

US 12,737,089 · App. 18/970,150 · Granted Sep 15, 2026

Inventors: Chunbo Liu (San Jose, CA); Mulka R. Reddy (San Jose, CA)

Assignee: Synaptics Incorporated

G06F3/0446G06F3/0412G06F3/04164

Abstract

Claims (40)

1 . A touch sensor comprising:

a plurality of sensor electrodes configured to transmit a periodic signal corresponding to a first waveform with varying frequencies and a second waveform with varying frequencies; and

a sensor circuit comprising:

a first charge pump configured to supply current to a first load comprising a plurality of first sensor electrodes of the plurality of sensor electrodes, the plurality of first sensor electrodes configured to be driven by the first waveform; and

a second charge pump configured to supply current to a second load comprising a plurality of second sensor electrodes of the plurality of sensor electrodes, the plurality of second sensor electrodes configured to be driven by the second waveform, wherein the second sensor electrodes are different from the first sensor electrodes.

2 . The touch sensor according to claim 1 , wherein the sensor circuit further comprises:

one or more first switches configured to connect the first sensor electrodes to the first charge pump; and

one or more second switches configured to connect the second sensor electrodes to the second charge pump.

3 . The touch sensor according to claim 1 , wherein an amplitude of the first waveform varies between a first pair of reference values, wherein an amplitude of the second waveform varies between a second pair of reference values, and wherein the first pair of reference values are different from the second pair of reference values.

4 . The touch sensor according to claim 3 , wherein the first charge pump is configured to output a first reference value that doubles a source reference value provided as input to the first charge pump, and wherein the second charge pump is configured to output a second reference value that inverts the source reference value provided as input to the second charge pump.

5 . The touch sensor according to claim 1 , wherein an amplitude of the first waveform varies between a first pair of reference values, wherein an amplitude of the second waveform varies between a second pair of reference values, and wherein the first pair of reference values and the second pair of reference values are identical.

6 . The touch sensor according to claim 1 , wherein the first sensor electrodes includes all rows of the plurality of sensor electrodes, and the second sensor electrodes includes all columns of the plurality of sensor electrodes.

7 . The touch sensor according to claim 1 , wherein the sensor circuit further comprises a third charge pump configured to supply current to a third load comprising a plurality of third sensor electrodes of the plurality of sensor electrodes, the plurality of third sensor electrodes configured to be driven by a third waveform, wherein the third waveform is predefined with a same amplitude and frequency as the first and second waveforms.

8 . The touch sensor according to claim 7 , wherein an amplitude of the first waveform corresponds to a first pair of reference values, an amplitude of the second waveform corresponds to a second pair of reference values, an amplitude of the third waveform corresponds to a third pair of reference values, and

wherein the third pair of reference values are identical to the first pair of reference values, the third pair of reference values are different from the second pair of reference values.

9 . The touch sensor according to claim 7 , wherein an amplitude of the first waveform corresponds to a first pair of reference values, an amplitude of the second waveform corresponds to a second pair of reference values, an amplitude of the third waveform corresponds to a third pair of reference values, and

wherein the first, second, and third pairs of reference values are different.

10 . The touch sensor according to claim 1 , wherein the first waveform and the second waveform are predefined with a same amplitude, and wherein the first waveform and the second waveform are synchronized in frequency.

11 . An input device comprising:

a display; and

a touch sensor comprising:

a plurality of sensor electrodes configured to transmit a periodic signal corresponding to a first waveform with varying frequencies and a second waveform with varying frequencies; and

a sensor circuit comprising:

a first charge pump configured to supply current to a first load comprising a plurality of first sensor electrodes of the plurality of sensor electrodes, the plurality of first sensor electrodes configured to be driven by the first waveform; and

a second charge pump configured to supply current to a second load comprising a plurality of second sensor electrodes of the plurality of sensor electrodes, the plurality of second sensor electrodes configured to be driven by the second waveform, wherein the second sensor electrodes are different from the first sensor electrodes.

12 . The input device according to claim 11 , wherein the sensor circuit further comprises:

one or more first switches configured to connect the first sensor electrodes to the first charge pump; and

one or more second switches configured to connect the second sensor electrodes to the second charge pump.

13 . The input device according to claim 11 , wherein an amplitude of the first waveform varies between a first pair of reference values, wherein an amplitude of the second waveform varies between a second pair of reference values, and wherein the first pair of reference values are different from the second pair of reference values.

14 . The input device according to claim 13 , wherein the first charge pump is configured to output a first reference value that doubles a source reference value provided as input to the first charge pump, and wherein the second charge pump is configured to output a second reference value that inverts the source reference value provided as input to the second charge pump.

15 . The input device according to claim 11 , wherein an amplitude of the first waveform varies between a first pair of reference values, wherein an amplitude of the second waveform varies between a second pair of reference values, and wherein the first pair of reference values and the second pair of reference values are identical.

16 . The input device according to claim 11 , wherein the first sensor electrodes includes all rows of the plurality of sensor electrodes, and the second sensor electrodes includes all columns of the plurality of sensor electrodes.

17 . The input device according to claim 11 , wherein the sensor circuit further comprises a third charge pump configured to supply current to a third load comprising a plurality of third sensor electrodes of the plurality of sensor electrodes, the plurality of third sensor electrodes configured to be driven by a third waveform, wherein the third waveform is predefined with a same amplitude and frequency as the first and second waveforms.

18 . The input device according to claim 17 , wherein an amplitude of the first waveform corresponds to a first pair of reference values, an amplitude of the second waveform corresponds to a second pair of reference values, an amplitude of the third waveform corresponds to a third pair of reference values, and

wherein the third pair of reference values are identical to the first pair of reference values, the third pair of reference values are different from the second pair of reference values, or wherein the first, second, and third pairs of reference values are different.

19 . The input device according to claim 11 , wherein the first waveform and the second waveform are predefined with a same amplitude and frequency.

20 . A method for transmitting a periodic signal, comprising:

driving a plurality of sensor electrodes based on a first waveform with varying frequencies and a second waveform with varying frequencies;

supplying, by a first charge pump, current to a first load comprising a plurality of first sensor electrodes of the plurality of sensor electrodes, the plurality of first sensor electrodes configured to be driven by the first waveform; and

supplying, by a second charge pump, current to a second load comprising a plurality of second sensor electrodes of the plurality of sensor electrodes, the plurality of second sensor electrodes configured to be driven by the second waveform, wherein the second sensor electrodes are different from the first sensor electrodes.

Assignments (1)

Continuity (1)

References Cited (10)