Multi-Touch Detection Panel with Disambiguation of Touch Coordinates

• US 20090267903A1
• Filed: 04/23/2008
• Published: 10/29/2009
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ishikawa, Tomohiro, Polak, Robert D., Cady, Andrew N.
• Granted Patent: US 8,519,965 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• 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

An multi-touch detection system (100) separately determines each of the coordinates of multiple touches and is able to correctly pair the coordinates, the touch panel includes multiple (e.g., two or four) separate sections (104, 106, 404, 406, 504, 506, 508, 510) to detect touches in different areas. The system (100) is able to operate at high refresh rates allowing speed sensitive applications to be supported.

Claims

1. A multi-touch detection system comprising:

a touch panel comprising a first section and a second section;

a first sensing subsystem for separately detecting a first coordinate of a pair of coordinates and a second coordinate of said pair of coordinates for a first touch of said first section; and

a second sensing subsystem for separately detecting said first coordinate of said pair of coordinates and said second coordinate of said pair of coordinates for a first touch of said second section,

wherein said first touch of said first section and said first touch of said second section are contemporaneous.

2. The multi-touch detection system according to claim 1 wherein said first section and said second section are rectangular in shape and said first coordinate and said second coordinate are Cartesian coordinates.

3. The multi-touch detection system according to claim 2 further comprising:

a third section and a fourth section;

a third sensing subsystem for separately detecting said first coordinate of said pair of coordinates for each touch of said third section and separately detecting said second coordinate of said pair of coordinates for each touch of said third section; and

a fourth sensing subsystem for separately detecting said first coordinate of said pair of coordinates of each touch of said fourth section and separately detecting said second coordinate of said pair of coordinates for each touch of said fourth section.

4. The multi-touch detection system according to claim 3 wherein said first section and said second section are arranged side-by-side and said third section and said fourth section are arranged side-by-side;

and wherein said first section and said second section are arranged above said third section and said fourth section respectively.

5. The multi-touch detection system according to claim 1 wherein said first sensing subsystem comprises:

a first plurality of electrodes;

and said second sensing subsystem comprises;

a second plurality of electrodes, and

wherein said first plurality of electrodes and said second plurality of electrodes are coupled to at least one electrical circuit that is adapted to measure changes in electrical impedance of said electrodes induced by touches.

6. The multi-touch detection system according to claim 5 wherein said at least one electrical circuit comprises at least one microcontroller.

7. The multi-touch detection system according to claim 6 wherein said at least one microcontroller comprises:

a first microcontroller and a second microcontroller, wherein said first microcontroller is coupled to said first plurality of electrodes and said second microcontroller is coupled to said second plurality of electrodes.

8. The multi-touch detection system according to claim 5 wherein said at least one electrical circuit is adapted to measure changes in capacitance.

9. The multi-touch detection system according to claim 5 wherein said first plurality of electrodes and said second plurality of electrodes are transparent.

10. The multi-touch detection system according to claim 9 further comprising a display.

11. The multi-touch detection system according to claim 1 further comprising a display.

12. A method of detecting multiple touches comprising:

during a first time period using a first sensing sub-system to detect coordinates of a first touch in a first part of a touch panel;

during said first time period using a second sensing sub-system to detect coordinates of a second touch in a second part of said touch panel;

during a second time period using the first sensing sub-system to detect new coordinates of the first touch in the first part of said touch panel; and

during the second time period using the second sensing sub-system to detect new coordinates of the second touch in the second part of said touch panel.

13. A user interface comprising:

a display; and

a multi-touch detection system, said multi-touch detection system comprising;

a touch panel overlying said display said touch panel comprising;

a first section and a second section;

a first sensing subsystem for separately detecting a first coordinate of a pair of coordinates for each touch of said first section and separately detecting a second coordinate of said pair of coordinates for each touch of said first section; and

a second sensing subsystem for separately detecting said first coordinate of said pair of coordinates of each touch of said second section and separately detecting said second coordinate of said pair of coordinates for each touch of said second section.