Conductive multi-touch touch panel

Patent metadata

Field	Value
Publication number	US-9342202-B2
Application number	US-53564709-A
Country	US
Kind code	B2
Filing date	Aug 4, 2009
Priority date	Jan 23, 2009
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A conductive multi-touch touch-sensitive panel includes two intersecting but electrically isolated arrays of linear conductors which can be brought into electrical contact by touching the panel. A display element may be positioned beneath the two arrays of linear conductors to provide a touchscreen panel. A touch to a cover plate or member causes one or more linear conductors in one array to contact one or more linear conductors in the other array. The location of a touch to the panel can be detected by individually or sequentially applying an electrical signal, such as a voltage or current, to each linear conductor in one array while sensing voltage or current on each of the linear conductors in the other array.

First claim

We claim:

1. A mobile device comprising:
a multi-touch touch-sensitive panel, comprising:
a first array of linear conductors;
a second array of linear conductors, wherein the second array is positioned in close proximity to and oriented at a non-zero angle with respect to the first array;
a switch configured to sequentially couple each of the linear conductors within the first array to an applied electrical signal; and
an electrical sensor coupled to each of the linear conductors within the second array; and

a processor coupled to the multi-touch touch-sensitive panel, wherein the processor is configured with processor-executable instructions to perform operations comprising:
sequentially applying the electrical signal to each linear conductor within the first array;
obtaining, upon application of the electrical signal to each linear conductor within the first array, a corresponding output electrical value on each linear conductor within the second array using the electrical sensor;
determining whether more than two touches to the panel are indicated based upon the obtained output electrical values, wherein the more than two touches correspond to more than two locations on the panel; and
in response to determining that more than two touches to the panel are indicated:
identifying any erroneous touch location due to a secondary electrical path by:
identifying output electrical values that indicate touches on the touch-sensitive panel; and
for each linear conductor within the second array that is determined to have multiple corresponding identified output electrical values based on the electrical signals applied to each linear conductor within the first array, comparing each of the identified output electrical values corresponding to a respective linear conductor within the second array to the other identified output electrical value(s) corresponding to the respective linear conductor within the second array in order to distinguish at least one real touch indication on that linear conductor within the second array and to identify an erroneous touch location on that linear conductor; and
providing an output of corrected touch locations on the touch-sensitive panel based on any distinguished real touch indications.

2. The mobile device of claim 1 , further comprising:
a first transparent member coupled to the first array of linear conductors;
a second transparent member coupled to the second array of linear conductors; and
a display element positioned beneath the first array of linear conductors and the second array of linear conductors,
wherein the first and second transparent members are configured so that a touch on the multi-touch touch-sensitive panel causes at least one linear conductor within the first array of linear conductors to come into electrical contact with at least one linear conductor within the second array of linear conductors.

3. The mobile device of claim 1 , wherein the applied electrical signal is a voltage source.

4. The mobile device of claim 1 , wherein the applied electrical signal is ground.

5. The mobile device of claim 1 , wherein the applied electrical signal is a current source.

6. The mobile device of claim 1 , wherein the applied electrical signal is a current sink.

7. The mobile device of claim 1 , wherein the first array of linear conductors and the second array of linear conductors are configured so there is a gap between the first array of linear conductors and the second array of linear conductors when the multi-touch touch-sensitive panel is not touched.

8. The mobile device of claim 7 , further comprising a nonconductive material positioned within the gap.

9. The mobile device of claim 1 , wherein the electrical sensor comprises an analog-to-digital converter circuit configured to output a signal representing a voltage or current level of the at least one linear conductor within the second array of linear conductors.

10. The mobile device of claim 1 , wherein the switch comprises a multiplexor circuit coupled between the first array of linear conductors and the applied electrical signal.

11. The mobile device of claim 1 , wherein the multi-touch touch-sensitive panel further comprises a multiplexor circuit coupled between the second array of linear conductors and the electrical sensor.

12. The mobile device of claim 1 , wherein the switch comprises a plurality of transistors each respectively coupled between one linear conductor within the first array of linear conductors and the applied electrical signal, wherein the transistor is configured to connect the linear conductor to the applied electrical signal in response to an applied voltage signal.

13. The multi-touch touch-sensitive panel of claim 1 , wherein the first array of linear conductors and the second array of linear conductors have different pitch densities.

14. A method for detecting touches on a conductive multi-touch touch-sensitive panel including a first array of linear conductors and a second array of linear conductors, comprising:
sequentially applying an electrical signal to each linear conductor within the first array of linear conductors; and
obtaining, upon application of the electrical signal to each linear conductor within the first array, a corresponding output electrical value on each linear conductor within the second array;
determining whether more than two touches on the conductive multi-touch touch-sensitive panel are indicated based upon the obtained output electrical values, wherein the more than two touches correspond to more than two touch locations on the panel; and
in response to determining that more than two touches on the conductive multi-touch touch-sensitive panel are indicated:
identifying any erroneous touch location due to a secondary electrical path by:
identifying output electrical values that indicate touches on the touch-sensitive panel; and
for each linear conductor within the second array that is determined to have multiple corresponding identified output electrical values based on the electrical signals applied to each linear conductor within the first array, comparing each of the identified output electrical values corresponding to a respective linear conductor within the second array to the other identified output electrical value(s) corresponding to the respective linear conductor within the second array in order to distinguish at least one real touch indication on that linear conductor within the second array and to identify an erroneous touch location on that linear conductor; and
providing an output of corrected touch locations on the touch-sensitive panel based on any distinguished real touch indications.

15. The method of claim 14 , wherein the applied electrical signal is one of a voltage, a ground, a current source and a current sink.

16. The method of claim 14 , wherein obtaining a corresponding output electrical value on each linear conductor within the second array comprises comparing a sensed voltage or current on each linear conductor within the second array to a threshold value.

17. The method of claim 14 , wherein obtaining a corresponding output electrical value on each linear conductor within the second array comprises measuring a voltage on each linear conductor within the second array.

18. The method of claim 14 , wherein obtaining a corresponding output electrical value on each linear conductor within the second array comprises measuring a current on each linear conductor within the second array.

19. The method of claim 14 , wherein obtaining a cor

Assignees

• Keskin Mustafa
• Kun Cheong
• Oliveira Louis Dominic
• Qualcomm Inc

Inventors

• Keskin Mustafa
• Kun Cheong
• Oliveira Louis Dominic

Classifications

• G06F2203/04104

  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 title

• G06F3/045 Primary

  using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact · CPC title