TRACE DESIGN FOR REDUCED VISIBILITY IN TOUCH SCREEN DEVICES

• US 20120242606A1
• Filed: 03/23/2012
• Published: 09/27/2012
• Est. Priority Date: 03/23/2011
• Status: Abandoned Application

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Mackey, Bob Lee
• Application Number:
  US13/428,773
• Publication Number:
  US 20120242606A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/0443 using a single layer of sensing electrodes
• 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

An input device having a plurality of low-visibility sensor electrodes and method for using the same are provided. In one embodiment, an input device includes a display device and a plurality of sensor electrodes disposed over the display device. The sensor electrodes are configured to sense objects in a sensing region of the input device. The sensor electrodes include a plurality of spaced apart conductive traces, each conductive trace having a diameter less than about 10 um. The conductive traces are disposed such that the conductive traces form a moiré pattern with the display device, wherein said moiré pattern comprises a spatial frequency greater than about 10 cycles per centimeter.

Claims

1. An input device comprising:

a display device; and

a plurality of sensor electrodes disposed over the display device and configured to sense objects in a sensing region of the input device, wherein the plurality of sensor electrodes comprise a plurality of spaced apart conductive traces, each conductive trace having a diameter less than about 10 um, the conductive traces disposed such that the conductive traces form a moiré

pattern with the display device, wherein said moiré

pattern comprises a spatial frequency greater than about 10 cycles per centimeter.

2. The input device of claim 1, wherein the conductive traces comprise an opaque material.

3. The input device of claim 1, wherein the conductive traces comprise one of a metal mesh and thin metal wires.

4. The input device of claim 1, wherein the conductive traces are disposed on at least one transparent substrate external to the display device.

5. The input device of claim 1, wherein the at least some of the conductive traces are disposed on a transparent substrate internal to the display device.

6. The input device of claim 1, wherein each of the plurality of sensor electrodes have a linear orientation.

7. The input device of claim 1, wherein the conductive traces comprising each of the plurality of sensor electrodes comprise an orientation such that each of the plurality of sensor electrodes is substantially invisible.

8. The input device of claim 7, wherein the spatial frequency corresponding to the orientation is at least 30% of its maximum value.

9. The input device of claim 7, wherein the orientation is within +/−

5 degrees of an angle that provides a maximized spatial frequency.

10. The input of claim 1, wherein a combined moiré

pattern of a first subset of the plurality of sensor electrodes and a second subset of the plurality of sensor electrodes has a high spatial frequency.

11. An input device comprising:

a display device; and

a sensing device having a plurality of first sensor electrodes and a plurality of second sensor electrodes and configured to sense objects in a sensing region adjacent the displace device, wherein at least one of the first sensor electrodes and the second sensor electrodes comprise conductive traces having a diameter less than about 10 um, the conductive traces disposed such that the conductive traces form a moiré

pattern with the display device, wherein said moiré

pattern comprises a spatial frequency greater than 10 cycles per centimeter.

12. The input device of claim 11, wherein the conductive traces comprises an opaque material.

13. The input device of claim 11, wherein the conductive traces comprises one of a metal mesh and thin metal wires.

14. The input device of claim 11, wherein the conductive traces are disposed on at least one transparent substrate external to the display device or are disposed on a transparent substrate internal to the display device.

15. The input device of claim 11, wherein the conductive traces comprising each of the plurality of sensor electrodes comprise an orientation such that each of the plurality of sensor electrodes is substantially invisible.

16. The input device of claim 15, wherein the spatial frequency corresponding to the orientation is at least 30% of its maximum value.

17. The input device of claim 15, wherein the orientation is an angle within at least +/−

5 degrees of an orientation that provides a maximized spatial frequency.

18. The input of claim 11, wherein a combined moiré

pattern of a first subset of the plurality of sensor electrodes and a second subset of the plurality of sensor electrodes has a high spatial frequency.

19. An input device comprising:

a display device comprising a plurality of pixels having a first orientation and second orientation orthogonal to the first orientation; and

a plurality of sensor electrodes disposed over the display device and configured to sense an object in a sensing region of the input device, wherein the plurality of sensor electrodes comprise a plurality of spaced apart conductive traces, each conductive trace having a diameter less than about 10 um, the conductive traces oriented relative to plurality of pixels form a moiré

pattern with the display device, wherein said moiré

pattern comprises a pitch in a direction parallel to the first orientation smaller than the pitch of 3 cycles of pixels.

20. The input device of claim 19 further comprising:

a processing system coupled to the plurality of sensor electrodes, wherein the plurality of sensor electrodes comprise a plurality of transmitter sensor electrodes a plurality of receive electrodes, the processing system configured to;

drive a transmitter signal on at least one of the plurality of transmitter sensor electrodes;

receive a resulting signal from at least one of the plurality of receiver sensor electrodes, the resulting signal comprising effects corresponding to the transmitter signal; and

determine positional information for an object in the sensing region of the input device.