Touch-sensing device with a touch hold function and a corresponding method

• US 8,749,517 B2
• Filed: 01/22/2010
• Issued: 06/10/2014
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Aklil, Djamel
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US13/146,191
• Publication Number:
  US 20130057502A1
• Time in Patent Office: 1,600 Days
• Field of Search: 345156-184, 178 1801- 1809, 178/18.11
• US Class Current: 345/174
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/043 using propagating acoustic waves

Abstract

The invention relates to a touch-sensing device comprising an interaction surface with a touch location system for determining a touch position based on an acoustic signal. Gaskets, forming a means for acoustically isolating the interaction surface from the underground on which it is placed, are provided with an upper electrode and a lower electrode. The gaskets are elastically compressible and have dielectric properties, so that the two electrodes and the gasket form a capacitor with a capacitance that varies with the force applied to the interaction surface. In addition to the touch position determined by the acoustic signal, the touch-sensing device detects a touch duration based on capacitance variations, so that touch events can be classified according to their duration. The invention also relates to the corresponding method.

Claims

1. A touch sensing device with a touch hold function, comprising:

an interaction surface, in particular a touch panel, with a touch location system for determining a touch position based on an acoustic signal,

an acoustic isolating means being elastically compressive and dielectric provided on one surface of the interaction surface;

a first conductive electrode provided between the interaction surface and the isolating means;

a second conductive electrode, the first conductive electrode and the second conductive electrode sandwiching the isolating means;

a means for determining the capacitance between the first conductive electrode and the second conductive electrode; and

a capacitance processing means configured to

determine a touch hold and/or touch release based on a change of capacitance between the first conductive electrode and the second conductive electrode,

determine a hold action upon the detection of a touch by the touch location system,

provide information regarding a hold position on the basis of a plurality of measured capacitances, and

and carry out a comparison of the touch position determined by the touch location system and the hold position.

2. A touch sensing device according to claim 1, wherein the capacitance processing means is configured to determine the touch hold and/or touch release based on a change of capacitance being larger than a predetermined threshold.

3. A touch sensing device according to claim 2,

wherein the isolating means comprises a plurality of isolating means, in particular placed along more than one edge of the touch panel,

each of the plurality of isolating means being sandwiched between a first conductive electrode and a second conductive electrode, and

a means for measuring the capacitance of each pair of first conductive electrode and second conductive electrode.

4. A touch sensing device according to claim 3, wherein the plurality of measured capacitances comprises measured capacitances of each pair of first and second conductive electrodes.

5. A touch sensing device according to claim 1, wherein the touch location system for determining a touch position comprises at least two transducers for acoustic waves.

6. A touch sensing device according to claim 1, wherein the first conductive electrode is a wire, in particular a steel wire, or a tape, in particular a copper plate.

7. A touch sensing device according to claim 1, wherein the second conductive electrode is a metallic plate, in particular a copper tape.

8. A touch sensing device according to claim 1, wherein the capacitance processing means is furthermore configured to carry out an auto-adaptation based on a change of a baseline of the measured capacitance.

9. A touch screen system with a hold and/or release function, comprising:

a touch sensing device according to claim 1 and a screen with a metallic frame, wherein the metallic frame corresponds to the second electrode.

10. A method for determining a touch position and a touch hold and/or touch release action on a touch sensing device according to claim 1, comprising:

determining a touch, in particular the location of the touch, based on an acoustic signal provided by an impact on the interaction surface;

monitoring the capacitance between the first conductive electrode and the second conductive electrode, in particular after detecting the touch;

deciding whether a touch-hold action or a touch-release action is detected on the basis of the monitored capacitance,

wherein a touch release action is established when a change in capacitance is larger than a predetermined threshold value.

11. The method according to claim 10,

wherein a touch hold action is established if a change in capacitance is within a predetermined range over a predetermined time duration after detecting the touch.