Touch-sensitive detector

• US 20030112226A1
• Filed: 11/12/2002
• Published: 06/19/2003
• Est. Priority Date: 11/13/2001
• Status: Active Grant

• Current Assignee: Stmicroelectronics France (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Inventors: Le-Pailleur, Laurent
• Granted Patent: US 7,064,747 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

A touch-sensitive detector includes a detection surface and a conducting element, and a first and second set of electrodes, each set of electrodes including at least one electrode extending parallel to the detection surface and where each electrode is electrically isolated. A first and second interaction capacitor is formed by the conducting element with the first and second set of electrodes, respectively. The second interaction capacitor has a lower capacitance than the first interaction capacitor. The touch-sensitive detection element further includes a first and second set of detectors arranged for detecting a signal emitted by at least one electrode of the first set of electrodes and the second set of electrodes, respectively, and transmitted through an external element located at the electrode emitting the signal. The external element contacts the detection surface. A touch sensitive detection method is also provided.

Claims

1. A touch-sensitive detection element, comprising:

a detection surface;

a conducting element;

a first set of electrodes including at least one electrode extending parallel to the detection surface, each electrode electrically isolated, the first set of electrodes forming a first interaction capacitor with the conducting element;

a second set of electrodes including at least one electrode extending parallel to the detection surface, each electrode electrically isolated, the second set of electrodes forming a second interaction capacitor with the conducting element, the second interaction capacitor having a lower capacitance than the first interaction capacitor;

a first set of detectors arranged for detecting a signal emitted by at least one electrode of the first set of electrodes and transmitted through an external element contacting the detection surface at the electrode emitting the signal and at a detector of the first set of detectors; and

a second set of detectors arranged for detecting a signal emitted by at least one electrode of the second set of electrodes and transmitted through an external element contacting the detection surface at the electrode emitting the signal and at a detector of the second set of detectors.

2. The touch-sensitive detection element of claim 1, wherein the portion of the detection surface corresponding to the second set of electrodes is smaller than the portion of the detection surface corresponding to the first set of electrodes.

3. The touch-sensitive detection element of claim 1, further comprising at least one detector belonging both to the first set of detectors and to the second set of detectors.

4. The touch-sensitive detection element of claim 1, further comprising:

an electrode controller having a first touch-sensitive detection mode wherein a signal is transmitted from at least one electrode through an external element contacting the detection surface to at least one detector of the first set of detectors, and having a second touch-sensitive detection mode wherein a signal is transmitted from at least one electrode of the second set of electrodes through an external element contacting the detection surface to at least one detector of the second set of detectors.

5. The touch-sensitive detection element of claim 4, wherein in the first touch-sensitive detection mode a first electrical connection is established between an electrode of the first set of electrodes to at least one other electrode.

6. The touch-sensitive detection element of claim 4, wherein the second set of electrodes comprises at least two electrodes, and wherein in the second touch-sensitive detection mode, a second electrical connection is established between the electrodes of the second set of electrodes.

7. The touch-sensitive detection element of claim 4, the electrode controller having a third touch-sensitive detection mode for detecting a contact of an external element with the detection surface at two electrodes by a change in an impedance between the two electrodes upon contact.

8. The touch-sensitive detection element of claim 7, comprising at least three electrodes, and wherein in the third touch-sensitive detection mode at least one electrical connection is established between two electrodes.

9. A touch-sensitive detection device, comprising:

a detection surface;

means for conducting;

a first plurality of electrode means including at least one electrode means extending parallel to the detection surface, each electrode means electrically isolated, the first plurality of electrode means forming a first interaction capacitor means with the means for conducting;

a second plurality of electrode means including at least one electrode means extending parallel to the detection surface, each electrode means electrically isolated, the second plurality of electrode means forming a second interaction capacitor means with the means for conducting, the second interaction capacitor means having a lower capacitance than the first interaction capacitor means;

a first set of detecting means arranged for detecting a signal emitted by at least one electrode means of the first set of electrode means and transmitted through an external element located at the electrode means emitting the signal, the external element contacting the detection surface; and

a second set of detecting means arranged for detecting a signal emitted by at least one electrode means of the second set of electrode means and transmitted through an external element located at the electrode means emitting the signal, the external element contacting the detection surface.

10. The touch-sensitive detection device of claim 9, wherein the portion of the detection surface corresponding to the second set of electrode means is smaller than the portion of the detection surface corresponding to the first set of electrode means.

11. The touch-sensitive detection device of claim 9, further comprising at least one detecting means belonging both to the first set of detecting means and to the second set of detecting means.

12. The touch-sensitive detection device of claim 9, further comprising:

means for controlling electrode means having a first touch-sensitive detection mode wherein a signal is transmitted from at least one electrode means through an external element contacting the detection surface to at least one detecting means of the first set of detecting means, and having a second touch-sensitive detection mode wherein a signal is transmitted from at least one electrode means of the second set of electrode means through an external element contacting the detection surface to at least one detecting means of the second set of detecting means.

13. The touch-sensitive detection device of claim 12, wherein in the first touch-sensitive detection mode a first electrically connecting means is established between an electrode means of the first set of electrode means to at least one other electrode means.

14. The touch-sensitive detection device of claim 12, wherein the second set of electrode means comprises at least two electrode means, and wherein in the second touch-sensitive detection mode, a second electrically connecting means is established between the electrode means of the second set of electrode means.

15. The touch-sensitive detection device of claim 12, the means for controlling electrode means having a third touch-sensitive detection mode for detecting a contact of an external element with the detection surface at two electrode means by a change in an impedance between the two electrode means upon contact.

16. The touch-sensitive detection device of claim 15, comprising at least three electrode means, and wherein in the third touch-sensitive detection mode, at least one electrically connecting means is established between two electrode means.

17. A touch-sensitive detection method employing a touch-sensitive detection element comprising a detection surface, a conducting part, a first and a second sets of detectors arranged at the detection surface, a first and a second sets of electrodes, each set of electrodes comprising at least one electrode extending parallel to the detection surface, all the electrodes being in themselves electrically isolated in pairs, the first and second sets of electrodes each forming, with the conducting part of the touch-sensitive detection element, a respective interaction capacitor, each detector of the first set of detectors being arranged to detect a signal emitted by at least one electrode of the first set of electrodes and transmitted from one of the emitting electrodes through an external element coming into contact with the detection surface at this detector and at this electrode, each detector of the second set of detectors being arranged to detect a signal emitted by at least one electrode of the second set of electrodes and transmitted from one of the emitting electrodes through an external element coming into contact with the detection surface at this detector and at this electrode, wherein, with the interaction capacitor of the second set of electrodes with the conducting part having a lower capacitance than the interaction capacitor of the first set of electrodes with the conducting part, the touch-sensitive detection method comprises:

in a first touch-sensitive detection mode, detectors of the first set of detectors detecting a signal emitted by at least one electrode and transmitted through the external element upon contact of this element with the detection surface; and

in at least one second touch-sensitive detection mode, detectors of the second set of detectors detecting a signal emitted by at least one electrode of the second set of electrodes and transmitted through the external element upon contact of the external element with the detection surface.

18. The touch-sensitive detection method according to claim 17, wherein the first touch-sensitive detection mode comprises establishing a first electrical connection connecting an electrode of the first set of electrodes to at least one other electrode of the touch-sensitive detection element.

19. The touch-sensitive detection method according to claim 17, wherein, the second set of electrodes comprising at least two electrodes, and wherein the second touch-sensitive detection mode comprising establishing a second electrical connection connecting the electrodes of the second set of electrodes together.

20. The touch-sensitive detection method according to claim 17, further comprising a third touch-sensitive detection mode in which a contact of an external element with the detection surface at two electrodes of the touch-sensitive detection element is detected by the change in an impedance between these two electrodes.

21. The touch-sensitive detection method according to claim 20, wherein the touch-sensitive detection element comprises at least three electrodes, and wherein the third touch-sensitive detection mode comprises establishing at least one electrical connection between two electrodes.

22. An electronic apparatus incorporating a touch-sensitive detection element comprising a detection surface, a conducting part, a first and a second sets of detectors arranged at the detection surface, a first and a second sets of electrodes, each set of electrodes comprising at least one electrode extending parallel to the detection surface, all the electrodes being in themselves electrically isolated in pairs, the first and second sets of electrodes each forming, with the conducting part of the touch-sensitive detection element, a respective interaction capacitor, each detector of the first set of detectors being arranged to detect a signal emitted by at least one electrode of the first set of electrodes and transmitted from one of the emitting electrodes through an external element coming into contact with the detection surface at this detector and at this electrode, each detector of the second set of detectors being arranged to detect a signal emitted by at least one electrode of the second set of electrodes and transmitted from one of the emitting electrodes through an external element coming into contact with the detection surface at this detector and at this electrode, wherein the interaction capacitor of the second set of electrodes with the conducting part has a lower capacitance than the interaction capacitor of the first set of electrodes with the conducting part.