Capacitive sensing using matrix electrodes driven by routing traces disposed in a source line layer

• US 9,542,023 B2
• Filed: 12/20/2013
• Issued: 01/10/2017
• 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
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Ritchie, Darlene M
• Application Number:
  US14/137,581
• Publication Number:
  US 20150042599A1
• Time in Patent Office: 1,117 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 wires 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 wires, 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 touch cycles.

Claims

1. An input device comprising:

a display device configured to sense input objects;

a plurality of sensor electrodes disposed in a first layer of a stack, wherein each of the plurality of sensor electrodes comprises at least one common electrode of the display device that is configured for display updating and capacitive sensing;

a plurality of sub-pixels corresponding to a display line of the display device;

a plurality of gate lines, wherein a first gate line of the plurality of gate lines is coupled to a first subset of the plurality of sub-pixels in the display line and a second gate line of the plurality of gate lines is coupled to a second subset of the plurality of sub-pixels in the display line;

a plurality of conductive routing traces disposed in a second layer of the stack, wherein each of the plurality of routing traces couples to only one of the plurality of sensor electrodes in the first layer;

a plurality of source lines disposed in the second layer of the stack, the plurality of source lines is coupled to the plurality of sub-pixels; and

a processing system coupled to the plurality of conductive routing traces, the processing system is configured to perform absolute capacitive sensing using the plurality of sensor electrodes, wherein a first sensor electrode of the plurality of sensor electrodes is coupled to a first conductive routing trace of the plurality of conductive routing traces, wherein the first conductive routing trace is selectively coupled to a driver module and a receiver module of the processing system.

2. The input device of claim 1, wherein each of the plurality of conductive routing traces is disposed in the second layer between two of the plurality of source lines.

3. The input device of claim 1, wherein the driver module is configured to drive the first sensor electrode with at least one of a transmitter signal, a guarding signal, and a shield signal.

4. The input device of claim 1, wherein the receiver module is configured to receive resulting signals with the first sensor electrode.

5. The input device of claim 1, wherein the plurality of sensor electrodes are disposed in a matrix on the first layer, wherein at least one of the plurality of sensor electrodes overlaps at least two of the plurality of conductive routing traces extending in the second layer of the stack.

6. The input device of claim 1, wherein a second sensor electrode of the plurality of sensor electrodes is coupled to a second conductive routing trace of the plurality of conductive routing traces, wherein the first conductive routing trace and the second conductive routing trace are coupled to the processing system via a selection mechanism.

7. The input device of claim 6, wherein the selection mechanism is configured to selectively couple the first sensor electrode and the second sensor electrode with the receiver module.

8. A processing system for a display device comprising a capacitive sensing device, the processing system comprising:

a sensor module comprising sensor circuitry configured to be coupled to a plurality of sensor electrodes via a plurality of conductive routing traces, wherein each of the plurality of sensor electrodes comprises at least one of a plurality of common electrodes configured for display updating and absolute capacitive sensing, wherein the plurality of sensor electrodes is disposed in a first layer of a stack and the plurality of conductive routing traces is disposed in a second layer of the stack, and wherein each of the plurality of routing traces couples to only one of the plurality of sensor electrodes,

wherein a plurality of source lines is disposed in the second layer of the stack, wherein the plurality of source lines is coupled to a plurality of sub-pixels corresponding to a display line of the display device, wherein a first subset of the plurality of sub-pixels in the display line is coupled to a first gate line and a second subset of the plurality of sub-pixels in the display line is coupled to a second gate line, wherein a first sensor electrode of the plurality of sensor electrodes is coupled to a first conductive routing trace of the plurality of conductive routing traces, wherein the first conductive routing trace is selectively coupled to a driver module and a receiver module of the processing system.

9. The processing system of claim 8, wherein each of the plurality of conductive routing traces is disposed in the second layer between two of the plurality of source lines.

10. The processing system of claim 8, wherein the driver module is configured to drive the first sensor electrode with at least one of a transmitter signal, a guarding signal, and a shield signal.

11. The processing system of claim 8, wherein the receiver module is configured to receive resulting signals with the first sensor electrode.

12. The processing system of claim 8, 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.

13. The processing system of claim 8, wherein a second sensor electrode of the plurality of sensor electrodes is coupled to a second conductive routing trace of the plurality of conductive routing traces, wherein the first conductive routing trace and the second conductive routing trace are coupled to the sensor module via a selection mechanism.

14. The processing system of claim 13, wherein the selection mechanism is configured to selectively couple the first sensor electrode and the second sensor electrode with the receiver module.

15. A matrix sensor comprising:

a first layer comprising a plurality of sensor electrodes arranged in a matrix on a common surface in the first layer, wherein the plurality of sensor electrodes is arranged to perform absolute capacitive sensing;

a second layer comprising a plurality of conductive routing traces and a plurality of source lines, wherein each of the plurality of conductive routing traces is coupled to a only one of the plurality of sensor electrodes on the first layer; and

a third layer comprising display materials of a plurality of sub-pixels corresponding to a display line of a display device, wherein a first gate line of a plurality of gate lines is coupled to a first subset of the plurality of sub-pixels in the display line and a second gate line of the plurality of gate lines is coupled to a second subset of the plurality of sub-pixels in the display line, and wherein the plurality of sources lines is coupled to the plurality of sub-pixels, wherein a first sensor electrode of the plurality of sensor electrodes is coupled to a first conductive routing trace of the plurality of conductive routing traces, wherein the first conductive routing trace is selectively coupled to a driver module and a receiver module.

16. The matrix sensor of claim 15, wherein each of the plurality of conductive routing traces is disposed in the second layer between two of the plurality of source lines.

17. The matrix sensor of claim 15, further comprising a fourth layer comprising a glass cover, wherein the first, second, and third layers are all disposed on a same side of the glass cover.

18. The matrix sensor of claim 15, wherein at least one of the plurality of sensor electrodes overlaps at least two of the plurality of conductive routing traces extending in the second layer.