Mitigating noise in capacitive sensor

• US 10,198,123 B2
• Filed: 04/21/2014
• Issued: 02/05/2019
• Est. Priority Date: 04/21/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Cheng, Uttermann, Erik A., Gibbs, Kevin D., Agarwal, Manu, Grunthaner, Martin P.
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): Mathews, Crystal A
• Application Number:
  US15/306,054
• Publication Number:
  US 20170046008A1
• Time in Patent Office: 1,751 Days
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

The disclosed embodiments relate to forming an area on a touchscreen which electrically isolates a portion of the viewable area of the touchscreen from a capacitive sensor associated with the touchscreen.

Claims

1. A touchscreen comprising:

a liquid crystal display having an upper surface area and a lower surface area;

a capacitive array adjacent said lower surface area;

an optically transparent electrically conductive layer deposited between said lower surface area and said capacitive array, said layer including;

a first area electrically isolating said liquid crystal display and said capacitive array, said first area including less than said upper surface area, and a second area permitting electrical transmission between said upper surface area and said capacitive array.

2. The touchscreen of claim 1 wherein said optically transparent electrically conductive layer includes indium tin oxide.

3. The touchscreen of claim 1 wherein said optically transparent electrically conductive layer includes silver nanowire matrix.

4. The touchscreen of claim 1 wherein said optically transparent electrically conductive layer is deposited on a thin film transistor layer in said liquid crystal display.

5. The touchscreen of claim 1 wherein said optically transparent electrically conductive layer is deposited on a transparent substrate between said liquid crystal display and said capacitive array.

6. The touchscreen of claim 1 wherein said first area and said second area are separated by an interface area formed on said optically transparent electrically conductive layer.

7. The touchscreen of claim 1 wherein said second area is electromagnetically connected to a processor, thereby facilitating detection of an object adjacent the liquid crystal display and above the second area.

8. An electronic device comprising:

a housing;

a touchscreen in said housing, said touchscreen including;

a liquid crystal display having an upper surface area and a lower surface area;

a capacitive array beneath said lower surface area;

an optically transparent electrically conductive layer deposited between said lower surface area and said capacitive array, said layer including;

a first area less in size than said upper surface area, and a second area electrically isolated from the first area, the second area operative to capacitively sense an object adjacent the touchscreen.

9. The electronic device of claim 8 wherein said optically transparent electrically conductive layer includes one of indium tin oxide and silver nanowire.

10. The electronic device of claim 8 wherein said optically transparent electrically conductive layer is deposited on a thin film transistor layer in said liquid crystal display.

11. The electronic device of claim 8 wherein said optically transparent electrically conductive layer is deposited on a transparent substrate between said liquid crystal display and said capacitive array.

12. The electronic device of claim 8 wherein said first area is approximately centered within said second area.

13. The electronic device of claim 8 wherein said first area is offset within said second area.

14. The electronic device of claim 8 wherein said first area and said second area are separated by an interface area formed on said optically transparent electrically conductive layer.