Capacitive touch screen including a first sensor pattern for mutual sensing and a second sensor pattern for self sensing

• US 9,626,049 B2
• Filed: 05/05/2014
• Issued: 04/18/2017
• Est. Priority Date: 05/05/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: Chandran, Praveesh, Ng, Chee Yu
• Primary Examiner(s): ABDULSELAM, ABBAS I
• Application Number:
  US14/269,295
• Publication Number:
  US 20150317008A1
• Time in Patent Office: 1,079 Days
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• 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 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

A capacitive touch panel includes a first sensor pattern and second sensor pattern. The first sensor pattern supports mutual-capacitance detection and the second sensor pattern supports self-capacitance detection. The first sensor pattern includes row conductors and column conductors which intersect each other at mutual-capacitance sensing locations. The second sensor pattern includes island conductors. The island conductors are grouped in clusters of conductors, each cluster providing a self-capacitance sensing location. Control circuitry coupled to the first and second sensor patterns functions to make touch/hover position detections by sensing changes in capacitance at the mutual-capacitance and self-capacitance nodes. The row and column conductors include openings, and the island conductors are positioned in vertical alignment with corresponding openings in the conductors.

Claims

1. An apparatus, comprising:

a capacitive touch panel including;

a first sensor pattern configured to solely operate in a mutual-capacitance detection mode of operation, the first sensor pattern comprising;

a plurality of rows of electrically connected sensor nodes; and

a plurality of columns of electrically connected sensor nodes;

wherein each sensor node in the rows and columns has a ring shape with a central open region; and

a second sensor pattern configured to solely operate in a self-capacitance detection mode of operation;

wherein said first and second sensor patterns are supported by a support substrate one pattern on top of the other pattern;

wherein the second sensor pattern comprises a plurality of conductive islands, each conductive island positioned in vertical alignment perpendicular to the support substrate with the central open region of the sensor node; and

wherein the plurality of conductive islands are divided into a plurality of clusters, each cluster including two or more conductive islands which are electrically connected to each other by one or more conductive lines.

2. The apparatus of claim 1, further comprising:

a control circuit coupled to the capacitive touch panel and including;

a mutual-capacitance sensing circuit electrically coupled to the first sensor pattern; and

a self-capacitance sensing circuit electrically coupled to the second sensor pattern.

3. The apparatus of claim 1, wherein the ring shape of each sensor node has a square shape, and each central opening has a square shape and each island has a square shape.

4. An apparatus, comprising:

a capacitive touch panel including;

a first sensor pattern configured to operate in a mutual-capacitance detection mode of operation; and

a second sensor pattern configured to operate in a self-capacitance detection mode of operation;

wherein said first and second sensor patterns are supported by a support substrate one pattern on top of the other pattern;

wherein the first sensor pattern comprises;

a plurality of row conductors; and

a plurality of column conductors; and

wherein the second sensor pattern comprises;

a plurality of conductive islands; and

wherein the plurality of conductive islands are divided into a plurality of clusters, each cluster including two or more conductive islands which are electrically connected to each other by one or more conductive lines.

5. The apparatus of claim 4, wherein each cluster of electrically connected conductive islands is electrically isolated from other clusters.

6. The apparatus of claim 5, wherein each row and column conductor includes a plurality of openings, and wherein each conductive island is positioned in vertical alignment with a corresponding one of the openings.

7. The apparatus of claim 4, further comprising:

a control circuit coupled to the capacitive touch panel and including;

a mutual-capacitance sensing circuit including a first set of traces electrically coupled to the plurality of row conductors and a second set of traces electrically coupled to the plurality of column conductors; and

a self-capacitance sensing circuit including a third set of traces electrically coupled to the plurality of clusters.

8. The apparatus of claim 4, wherein each cluster includes a same number of electrically connected conductive islands.

9. The apparatus of claim 4, wherein the clusters comprise:

first clusters each having a first number of electrically connected conductive islands; and

second clusters each having a second number of electrically connected conductive islands different from the first number.

10. A capacitive touch panel apparatus, comprising:

a first layer of patterned conductive material forming a plurality of rows of electrically connected sensor nodes;

a second layer of patterned conductive material forming a plurality of columns of electrically connected sensor nodes;

a third layer of pattered conductive material forming a plurality of conductive islands;

wherein each sensor node includes a central opening; and

wherein each conductive island is positioned in vertical alignment with the central open region of a corresponding sensor node.

11. The apparatus of claim 10, wherein the rows of electrically connected sensor nodes and columns of electrically connected sensor nodes form a first sensor pattern configured to operate in a mutual-capacitance detection mode of operation.

12. The apparatus of claim 10, wherein the plurality of conductive islands are divided into a plurality of clusters, each cluster including two or more conductive islands which are electrically connected to each other by one or more conductive lines.

13. The apparatus of claim 12, wherein the plurality of clusters form a second sensor pattern configured to operate in a self-capacitance detection mode of operation.

14. The apparatus of claim 10, wherein the first, second and third layers of patterned conductive material are supported by a support substrate with the layers configured on top of each other.

15. The apparatus of claim 10, further comprising:

a control circuit including;

a mutual-capacitance sensing circuit electrically coupled to the rows of electrically connected sensor nodes and columns of electrically connected sensor nodes which form a mutual-capacitance sensor pattern; and

a self-capacitance sensing circuit electrically coupled to the plurality of conductive islands which form a self-capacitance sensor pattern.

16. An apparatus, comprising:

a capacitive touch panel including;

a mutual-capacitance sensor pattern including a plurality of row conductors and a plurality of column conductors; and

a self-capacitance sensor pattern including a plurality of clusters of conductive islands, each cluster including two or more conductive islands electrically connected by one or more conductor lines;

wherein said mutual-capacitance and self-capacitance sensor patterns are supported by a support substrate one pattern on top of the other pattern;

wherein each row conductor and each column conductor of the mutual-capacitance sensor pattern includes a plurality of openings; and

wherein each conductive island is positioned in vertical alignment perpendicular to the support substrate with a corresponding opening in the row and column conductors.

17. An apparatus, comprising:

a capacitive touch panel including;

a mutual-capacitance sensor pattern including a plurality of row conductors and a plurality of column conductors;

a self-capacitance sensor pattern including a plurality of clusters of conductive islands, each cluster including two or more conductive islands electrically connected by one or more conductor lines;

wherein said mutual-capacitance and self-capacitance sensor patterns are supported by a support substrate one pattern on top of the other pattern; and

a control circuit including;

a mutual-capacitance sensing circuit electrically coupled to the row and column conductors which form the mutual-capacitance sensor pattern; and

a self-capacitance sensing circuit electrically coupled to the clusters of conductive islands which form the self-capacitance sensor pattern.