MULTI-PHASE SCANNING

• US 20160188105A1
• Filed: 03/09/2016
• Published: 06/30/2016
• Est. Priority Date: 08/25/2010
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Parade Technologies, Ltd.
• Inventors: Kremin, Viktor, Ogirko, Roman
• Granted Patent: US 10,216,314 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch sensing apparatus includes a touch sensing surface having a plurality of TX electrodes and a plurality of RX electrodes. The touch sensing apparatus also includes capacitance sensing circuitry. The circuitry receives a plurality of drive signals. For each of a plurality of scanning stages, the circuitry applies a respective one of the plurality of drive signals to each of the plurality of TX electrodes substantially simultaneously according to a respective TX pattern. The respective TX pattern for each scanning stage is distinct. The circuitry receives sense signals from the plurality of RX electrodes. Each of the plurality of sense signals represents capacitance of a respective intersection of a respective TX electrode and a respective RX electrode. The circuitry then correlates the received sense signals for the plurality of scanning stages with the received drive signals to detect an object proximate to the touch panel.

Claims

1. A method of detecting objects proximate to a touch panel having a plurality of TX electrodes and a plurality of RX electrodes, comprising:

receiving a plurality of drive signals;

for each of a plurality of scanning stages;

applying a respective one of the plurality of drive signals to each of the plurality of TX electrodes substantially simultaneously according to a respective TX pattern, wherein the respective TX pattern for each scanning stage is distinct;

receiving sense signals from the plurality of RX electrodes, wherein each of the plurality of sense signals represents capacitance of a respective intersection of a respective TX electrode and a respective RX electrode;

correlating the received sense signals for the plurality of scanning stages with the received drive signals to detect an object proximate to the touch panel.

2. The method of claim 1, wherein the plurality of drive signals includes a carrier signal and a second signal created by inverting the carrier signal.

3. The method of claim 2, wherein the plurality of drive signals further includes a third signal representing a grounded state.

4. The method of claim 1, wherein the plurality of drive signals includes a carrier signal and a second signal that is phase shifted from the carrier signal.

5. The method of claim 1, wherein the plurality of drive signals includes a first drive signal and a second drive signal that has a different amplitude or frequency from the first drive signal.

6. The method of claim 1, wherein the TX pattern for the second scanning stage is specified as a rotation of the TX pattern for the first scanning stage.

7. The method of claim 1, wherein the plurality of drive signals comprises a first drive signal and a second drive signal, and one or more of the TX patterns specifies an alternating sequence of the first and second drive signals for the TX electrodes.

8. A touch sensing apparatus, comprising:

a touch sensing surface having a plurality of TX electrodes and a plurality of RX electrodes; and

capacitance sensing circuitry configured for;

receiving a plurality of drive signals;

for each of a plurality of scanning stages;

applying a respective one of the plurality of drive signals to each of the plurality of TX electrodes substantially simultaneously according to a respective TX pattern, wherein the respective TX pattern for each scanning stage is distinct;

receiving sense signals from the plurality of RX electrodes, wherein each of the plurality of sense signals represents capacitance of a respective intersection of a respective TX electrode and a respective RX electrode;

correlating the received sense signals for the plurality of scanning stages with the received drive signals to detect an object proximate to the touch panel.

9. The touch sensing apparatus of claim 8, wherein the plurality of drive signals includes a carrier signal and a second signal created by inverting the carrier signal.

10. The touch sensing apparatus of claim 9, wherein the plurality of drive signals further includes a third signal representing a grounded state.

11. The touch sensing apparatus of claim 8, wherein the plurality of drive signals includes a carrier signal and a second signal that is phase shifted from the carrier signal.

12. The touch sensing apparatus of claim 8, wherein the plurality of drive signals includes a first drive signal and a second drive signal that has a different amplitude or frequency from the first drive signal.

13. The touch sensing apparatus of claim 8, wherein the TX pattern for the second scanning stage is specified as a rotation of the TX pattern for the first scanning stage.

14. The touch sensing apparatus of claim 8, wherein the plurality of drive signals comprises a first drive signal and a second drive signal, and one or more of the TX patterns specifies an alternating sequence of the first and second drive signals for the TX electrodes.

15. A host device, comprising:

a display;

a capacitance sensing array having a plurality of TX electrodes and a plurality of RX electrodes; and

a touchscreen controller coupled to the capacitance sensing array, wherein the touch screen controller is configured for;

receiving a plurality of drive signals;

for each of a plurality of scanning stages;

applying a respective one of the plurality of drive signals to each of the plurality of TX electrodes substantially simultaneously according to a respective TX pattern, wherein the respective TX pattern for each scanning stage is distinct;

receiving sense signals from the plurality of RX electrodes, wherein each of the plurality of sense signals represents capacitance of a respective intersection of a respective TX electrode and a respective RX electrode;

correlating the received sense signals for the plurality of scanning stages with the received drive signals to detect an object proximate to the touch panel.

16. The host device of claim 15, wherein the plurality of drive signals includes a carrier signal and a second signal created by inverting the carrier signal.

17. The host device of claim 16, wherein the plurality of drive signals further includes a third signal representing a grounded state.

18. The host device of claim 15, wherein the plurality of drive signals includes a carrier signal and a second signal that is phase shifted from the carrier signal.

19. The host device of claim 15, wherein the plurality of drive signals includes a first drive signal and a second drive signal that has a different amplitude or frequency from the first drive signal.

20. The host device of claim 15, wherein the TX pattern for the second scanning stage is specified as a rotation of the TX pattern for the first scanning stage.