Capacitive sensing using a matrix electrode pattern

• US 9,552,089 B2
• Filed: 12/20/2013
• Issued: 01/24/2017
• Est. Priority Date: 08/07/2013
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Lukanc, Jeffrey, Morein, Stephen L., Ludden, Christopher A., Semeraro, Greg P., Reynolds, Joseph Kurth, Shepelev, Petr, Mackin, Thomas
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Ritchie, Darlene M
• Application Number:
  US14/137,692
• Publication Number:
  US 20150042600A1
• Time in Patent Office: 1,131 Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

An electrode matrix that is used for capacitive sensing may be integrated into a display panel of an input device. In one embodiment, source drivers may be mounted on the display panel which drive the display signals and capacitive sensing signals into the display panel. In one embodiment, the capacitive sensing signals may be routed on traces or lines that are interleaved on the same layer as the source lines used for setting a voltage on the pixels in the display panel during display updating. Using the interleaved traces, the source drivers may drive the capacitive sensing signals in parallel to a plurality of the electrodes in the matrix in a predefined pattern that spans one or more sensing cycles.

Claims

1. An input device comprising:

a plurality of individual sensor electrodes disposed in a matrix format on a common plane of a first layer of a display panel; and

a processing system coupled to the plurality of sensor electrodes via a plurality of conductive routing traces in a second layer of the display panel, the processing system is configured to;

acquire a capacitive image frame with the plurality of sensor electrodes based on a pattern such that during a first time period of the pattern a first sensor electrode of the plurality of sensor electrodes is operated in a first mode and a second sensor electrode and a third sensor electrode of the plurality of sensor electrodes are operated in a second mode, and during a second time period of the pattern the first sensor electrode is operated in the second mode and the second sensor electrode is operated in the first mode, wherein the second sensor electrode is in a facing relationship with a first side of the first sensor electrode and the third sensor electrode is in a facing relationship with a second side of the first sensor electrode, and wherein the first and second sides are perpendicular,

wherein, when operated according to the first mode, the first and second sensor electrodes are driven with a transmitter signal, and, when operated according to the second mode, the first, second, and third sensor electrodes receive respective resulting signals.

2. The input device of claim 1, wherein the processing system is configured to, during the first time period, operate a fourth sensor electrode of the plurality of sensor electrodes according to the second mode, and during the second time period operate the fourth sensor electrode according to the first mode.

3. The input device of claim 1, wherein the first and second sensor electrodes are coupled to the processing system via a multiplexer for selectively driving the first and second sensor electrodes according to the first and second modes.

4. The input device of claim 1, wherein each of the sensor electrodes comprises at least one common electrode of a plurality of common electrodes configured for display updating and input sensing.

5. The input device of claim 1, wherein each of the plurality of sensor electrodes comprises a similar shape and size.

6. The input device of claim 1, wherein, during the first time period, the processing system is configured to drive the transmitter signal on a third sensor electrode of the plurality of sensor electrodes and, during the second time period, receive resulting signals with the third sensor electrode.

7. The input device of claim 1, wherein the plurality of individual sensor electrodes are arranged in rows and columns on the common plane and the first and second sensor electrodes are in directly adjacent rows or columns.

8. The input device of claim 1, wherein, during the second time period of the pattern the third sensor electrode is operated in the second mode.

9. An input device comprising:

a plurality of individual sensor electrodes disposed in a matrix format on a common plane of a first layer of a display panel; and

a processing system coupled to the plurality of sensor electrodes via a plurality of conductive routing traces in a second layer of the display panel, the processing system is configured to;

acquire a capacitive image frame with the plurality of sensor electrodes based on a pattern such that during a first time period of the pattern first and second sensor electrodes of the plurality of sensor electrodes are operated in a first mode and third and fourth sensor electrodes of the plurality of sensor electrodes are operated in a second mode, and during a second time period of the pattern the first and second sensor electrodes are operated in the second mode and the third sensor electrode is operated in the first mode, wherein the third sensor electrode is in a facing relationship with a first side of the first sensor electrode and the fourth sensor electrode is in a facing relationship with a second side of the first sensor electrode, wherein the first and second sides are perpendicular,

wherein, when operated according to the first mode, the first, second, and third sensor electrodes are driven with respective transmitter signals and, when operated according to the second mode, the first, second, third and fourth sensor electrodes receive respective resulting signals.

10. The input device of claim 9, wherein the first, second, and third sensor electrodes are coupled to the processing system via a multiplexer for selectively operating the first, second, and third sensor electrodes in the first and second modes.

11. An input device comprising:

a plurality of individual sensor electrodes disposed in a matrix format on a common plane of a first layer of a display panel; and

a processing system coupled to the plurality of sensor electrodes via a plurality of conductive routing traces in a second layer of the display panel, the processing system is configured to;

acquire a capacitive image frame with the plurality of sensor electrodes based on a pattern such that during a first time period of the pattern a first sensor electrode of the plurality of sensor electrodes is operated in a first mode and a second sensor electrode and a third sensor electrode of the plurality of sensor electrodes are operated in a second mode, and during a second time period of the pattern the first sensor electrode and the third sensor electrode are operated in the second mode and the second sensor electrode is operated in the first mode,

wherein, when operated according to the first mode, the first and second sensor electrodes are driven with a modulated signal to perform absolute capacitive sensing and, when operated according to the second mode, the first, second, and third sensor electrodes are driven with a guarding signal, wherein the first sensor electrode and the second sensor electrode operate in the first and second modes, respectively, during an overlapping time period, and

wherein the second sensor electrode is in a facing relationship with a first side of the first sensor electrode and the third sensor electrode is in a facing relationship with a second side of the first sensor electrode, and wherein the first and second sides are perpendicular.

12. The input device of claim 11, wherein the processing system is configured to, during the first time period, operate a fourth sensor electrode of the plurality of sensor electrodes in the second mode, and during the second time period operate the fourth sensor electrode in the first mode.

13. The input device of claim 11, wherein the first and second sensor electrodes are coupled to the processing system via a multiplexer for selectively operating the first and second sensor electrodes in the first and second modes.

14. The input device of claim 11, wherein the guarding signal is modulated with a same frequency as the modulated signal used to perform absolute capacitive sensing.

15. A processing system comprising:

a sensor module configured to couple to a plurality of individual sensor electrodes disposed in a matrix format on a first layer in a display panel, wherein the sensor electrodes are coupled to the sensor module via a plurality of conductive routing traces on a second layer in the display panel,

the sensor module is configured to;

acquire a capacitive image frame with the plurality of sensor electrodes based on a pattern such that during a first time period of the pattern a first sensor electrode of the plurality of sensor electrodes is operated in a first mode and a second sensor electrode and a third sensor electrode of the plurality of sensor electrodes are operated in a second mode, and during a second time period of the pattern the first sensor electrode is operated in the second mode and the second sensor electrode is operated in the first mode, wherein the second sensor electrode is in a facing relationship with a first side of the first sensor electrode and the third sensor electrode is in a facing relationship with a second side of the first sensor electrode, and wherein the first and second sides are perpendicular,

wherein, when operated according to the first mode, the first and second sensor electrodes are driven with respective transmitter signals and, when operated according to the second mode, the first, second, and third sensor electrodes receive respective resulting signals.

16. The processing system of claim 15, wherein, during the first time period, the sensor module is configured to drive the transmitter signal on a fourth sensor electrode of the plurality of sensor electrodes and, during the second time period, receive a resulting signal with the fourth sensor electrode.

17. The processing system of claim 15, further comprising a display driver module configured to drive source lines for display updating.

18. The processing system of claim 15, further comprising a data processing module coupled to the sensor module, the data processing module configured to determine positional information for an input object based on signals received from the sensor module.

19. The processing system of claim 15, wherein each of the sensor electrodes comprises at least one common electrode of a plurality of common electrodes configured for display updating and input sensing.