Touch-sensing Device with a Touch Hold Function and a Corresponding Method

• US 20130057502A1
• Filed: 01/22/2010
• Published: 03/07/2013
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Aklil, Djamel
• Granted Patent: US 8,749,517 B2
• Time in Patent Office: Days
• 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.

2. A touch sensing device according to claim 1, further comprising:

a capacitance processing means configured to determine the touch hold and/or touch release based on a change of capacitance, in particular being larger than a predetermined threshold.

3. A touch sensing device according to claim 2,

wherein the processing means is configured to determine a hold action upon the detection of a touch by the touch location system.

4. A touch sensing device according to any of claims 1 to 3,

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.

5. A touch sensing device according to claim 4, wherein the processing means is further configured to provide information regarding the hold position on the basis of the plurality of measured capacitances.

6. A touch sensing device according to claim 5, wherein the processing means is configured to carry out a comparison of the touch position determined by the touch location system and the hold position determined by the capacitance processing means.

7. A touch sensing device according to any of claims 1 to 6, wherein the touch location system for determining a touch position comprises at least two transducers for acoustic waves.

8. A touch sensing device according to any of claims 1 to 7, wherein the first conductive electrode is a wire, in particular a steel wire, or a tape, in particular a copper plate.

9. A touch sensing device according to any of claims 1 to 8, wherein the second conductive electrode is a metallic plate, in particular a copper tape.

10. A touch sensing device according to one of claims 1 to 9, wherein the capacitance processing means is furthermore configured to carry out an auto-adaptation based on a change of the baseline of the measured capacitance.

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

a touch sensing device according to one of claims 1 to 10 and a screen with a metallic frame, wherein the metallic frame corresponds to the second electrode.

12. A method for determining a touch position and a touch hold and/or touch release action on a touch sensing device according to one of claims 1 to 11, 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.

13. The method according to claim 12,

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.

14. The method according to claim 12 or claim 13,

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