METHOD AND DEVICE FOR LOCATING AT LEAST ONE TOUCH ON A TOUCH-SENSITIVE SURFACE OF AN OBJECT

• US 20120120014A1
• Filed: 06/30/2010
• Published: 05/17/2012
• Est. Priority Date: 07/21/2009
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation), Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique, Commissariat A L'Energie Atomique et AUX Energies Alternatives
• Inventors: Hafez, Moustapha, Nikolovski, Jean-Pierre, Liu, Yuan, Mechbal, Nazih, Verge, Michel
• Granted Patent: US 8,913,039 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04808 Several contacts: gestures triggering a specific function, e.g. scrolling, zooming, right-click, when the user establishes several contacts with the surface simultaneously; e.g. using several fingers or a combination of fingers and pen
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

This method for locating at least one touch on a touch-sensitive surface of an object comprises the following steps:

• • monitoring (100) of at least one touch by propagating (102), in the touch-sensitive surface of the object, elastic mechanical waves from at least one transmitting point of the object, and by detecting (104) said elastic mechanical waves in at least one reception point of the object, in order to obtain at least one sensed signal, and
  • locating (200) at least one touch on the touch-sensitive surface of the object by comparing certain spectral characteristics of the sensed signal to a set of reference characteristics.

The monitoring step (100) comprises measuring (104, 106) the sensed signal during a time interval (t₃ ) starting during a transient phase of the propagation of the transmitted waves, for supplying, to said at least one reception point, information on radiation interfered with by said at least one touch.

Claims

1. A method for locating at least one touch on a touch-sensitive surface (24) of an object (10;

30), comprising the following steps;

monitoring (100) of at least one touch by propagating (102), in the touch-sensitive surface of the object, elastic mechanical waves from at least one transmitting point (E1, E2) of the object, and by detecting said elastic mechanical waves in at least one reception point (R1, R2) of the object, in order to obtain at least one sensed signal, and

locating (200) at least one touch on the touch-sensitive surface of the object by comparing certain spectral characteristics of the sensed signal to a set of reference characteristics,

characterized in that the monitoring step (100) comprises measuring (104, 106) the sensed signal during a time interval (t₃) starting during a transient phase of the propagation of the transmitted waves, for supplying, to said at least one reception point (R1, R2), information on radiation interfered with by said at least one touch.

2. A method for locating a least one touch on a touch-sensitive surface according to claim 1, in which the measurement (104, 106) of the sensed signal extends (t₄) beyond the establishment (t₁) of a stationary phase of the propagation of the transmitted waves, to provide illumination information to said at least one receiving point (R1, R2).

3. A method for locating at least one touch on a touch-sensitive surface according to claim 1 or 2, in which said reference characteristics correspond respectively to single or multiple touches in predetermined areas of the touch-sensitive surface.

4. A method for locating at least one touch on a touch-sensitive surface according to any one of claims 1 to 3, in which the transmitted waves comprise a plurality of predetermined frequency components that are all distinct from the vibratory natural frequencies of the object.

5. A method for locating at least one touch on a touch-sensitive surface according to claim 4, in which each frequency component of the transmitted waves is selected so as to be at a frequency distance that is twice the width of a resonance energy peak corresponding to any vibratory natural frequency of the object.

6. A method for locating at least one touch on a touch-sensitive surface according to claim 4 or 5, in which the characteristics of the sensed signal compared to the reference characteristics are spectral amplitudes of the sensed signal at said predetermined frequency components, forming a “

measured”

vector, and the set of reference characteristics comprises a set of reference vectors that are each associated with a single or multiple touch, this reference set being constructed during a preliminary training step, similar to the monitoring step, during which various single and multiple reference touches are measured.

7. A method for locating at least one touch on a touch-sensitive surface according to claim 6, in which, because the vectors are ordered in the reference set by the value of their norm, the location step (200) comprises the following substeps:

calculate the norm of the measured vector,

select a subset from the reference set that represents a range of norms in a predetermined vicinity of the norm of the measured vector, and

search for the closest reference vector to the measured vector in this subset using a predetermined distance function.

8. A device (10;

30) for locating at least one touch on a touch-sensitive surface (24) of an object (18;

30), comprising at least one transducer (E1, E2, R1, R2) designed to transmit and receive elastic mechanical waves propagated in the touch-sensitive surface of the object and one central processing unit (12, 32), connected to said at least one transducer, programmed;

to propagate elastic mechanical waves in the touch-sensitive surface of the object from said at least one transducer and to detect said elastic mechanical waves by said at least one transducer in order to obtain at least one sensed signal, and

to locate at least one touch on the touch-sensitive surface of the object by comparing certain spectral characteristics of the sensed signal to a set of reference characteristics,

characterized in that the central processing unit (12, 32) is further programmed to measure the sensed signal during a time interval starting during a transient phase of the propagation of the transmitted waves, for supplying, to said at least one reception point, information on radiation interfered with by said at least one touch.

9. A device for locating at least one touch on a touch-sensitive surface according to claim 8, further comprising the object (30), its touch-sensitive surface (24), and means (P) for holding the touch-sensitive surface onto the object, arranged in the vicinity of discontinuous convex areas on the periphery of the touch-sensitive surface.

10. A device for locating at least one touch on a touch-sensitive surface according to claim 8 or 9, in which the central processing unit (12, 32) is further designed to:

define at least one single or multiple tracing (26;

50, 52, 54, 56, 58, 60) from a plurality of touches successively located on the touch-sensitive surface (24),

interpret this single or multiple tracing (26;

50, 52, 54, 56, 58, 60) as a predetermined function to execute by comparing some of the characteristics of said tracing to a set of reference characteristics.