Contact Detection Mode Switching in a Touchscreen Device

• US 20170322649A1
• Filed: 10/13/2014
• Published: 11/09/2017
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Wang, Han, Ksondzyk, Petro, Chen, Chris
• Granted Patent: US 9,983,738 B2
• Time in Patent Office: Days
• 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 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• 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 3/041662 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
• 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

A method is disclosed for determining detecting a conductive object and determining the type of object and the type of contact that object has with a touch sensitive surface, the method comprising measuring capacitance on a plurality of mutual capacitance sensors, each mutual capacitance sensor corresponding to a unit cell in an array of unit cells. After mutual capacitance is measured a peak unit cell is identified based on the measured capacitances and a matrix sum of a plurality of unit cells surround the peak unit cell is calculated. The value of the peak unit cell and the matrix sum are then compared to a range and a contact type determined based on the comparison.

Claims

1. A method comprising:

measuring capacitance on a plurality of mutual capacitance sensors, each mutual capacitance sensor corresponding to a unit cell in an array of unit cells;

identifying a peak unit cell based on the measured capacitances;

calculating a matrix sum of a plurality of unit cells surrounding each identified peak unit cell;

identifying a range into which a value of the peak unit cell and the matrix sum may be placed; and

determining an contact type based on the identifying range.

2. The method of claim 1, wherein the range is one of a plurality of ranges corresponding a plurality of contact identification types on the array of unit cells.

3. The method of claim 2, wherein the plurality of contact identification types includes at least one of a bare finger, a gloved finger, a stylus, and a contact hovering above the array.

4. The method of claim 2, wherein identification of the identifying the ranges of the plurality of ranges causes a touchscreen controller to enter a second operational mode from a first operational mode.

5. The method of claim 4, wherein the first and second operational modes each have a defined range of the plurality of ranges.

6. The method claim 1, wherein at least one of ranges of the plurality of ranges may be changed based on an operational mode of a touchscreen controller configured to measure capacitance and determine contact identification types.

7. The method of claim 6, wherein the operation mode of the touchscreen controller may be configured as at least one of a bare finger detection mode, a stylus detection mode, or a gloved finger detection mode.

8. A user interface device comprising:

a first plurality capacitance sensing electrodes disposed along a first axis of an array of unit cells;

a second plurality of capacitance sensing electrodes disposed along a second axis of an array unit cells; and

a controller configured to;

measure capacitance on a plurality of mutual capacitance sensors, each mutual capacitance sensor associated with a unit cell in an array of unit cells;

identify a peak unit cell based on the measured capacitances;

calculate a matrix sum of a plurality of unit cells surrounding each identified peak unit cell;

identify a range into which a value of the peak unit cell and the matrix sum may be placed; and

determine an contact type based on the identifying range.

9. A user interface device of claim 8, wherein the range is one of a plurality of ranges corresponding a plurality of contact identification types on the array of unit cells.

11. A user interface device of claim 9, wherein identification of the identifying the ranges of the plurality of ranges causes a touchscreen controller to enter a second operational mode from a first operational mode.

12. A user interface device of claim 11, wherein the first and second operational modes each have a defined range of the plurality of ranges.

13. A user interface device claim 8, wherein at least one of ranges of the plurality of ranges may be changed based on an operational mode of a touchscreen controller configured to measure capacitance and determine contact identification types.

14. A user interface device of claim 13, wherein the operation mode of the touchscreen controller may be configured as at least one of a bare finger detection mode, a stylus detection mode, or a gloved finger detection mode.

16. A touchscreen controller of claim 14, wherein the range is one of a plurality of ranges corresponding a plurality of contact identification types on the array of unit cells.

17. A touchscreen controller of claim 16, wherein the plurality of contact identification types includes at least one of a bare finger, a gloved finger, a stylus, and a contact hovering above the array.

18. A touchscreen controller of claim 16, wherein identification of the identifying the ranges of the plurality of ranges causes a touchscreen controller to enter a second operational mode from a first operational mode.

19. A touchscreen controller of claim 18, wherein the first and second operational modes each have a defined range of the plurality of ranges.

10. A user interface device 9, wherein the plurality of contact identification types includes at least one of a bare finger, a gloved finger, a stylus, and a contact hovering above the array.

15. A touchscreen controller configured to:

measure capacitance on a plurality of mutual capacitance sensors, each mutual capacitance sensor represented as a unit cell in an array of unit cells;

identify a peak unit cell based on the measured capacitances;

calculate a matrix sum of a plurality of unit cells surrounding each identified peak unit cell;

identify a range into which a value of the peak unit cell and the matrix sum may be placed; and

determine an contact type based on the identifying range.

20. A touchscreen controller of claim 15, wherein at least one of ranges of the plurality of ranges may be changed based on an operational mode of a touchscreen controller configured to measure capacitance and determine contact identification types.