PRESSURE-SENSITIVE CAPACITIVE MEASUREMENT DEVICE AND METHOD FOR TOUCH-SENSITIVE AND CONTACTLESS INTERFACES

• US 20140360854A1
• Filed: 12/18/2012
• Published: 12/11/2014
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Quickstep Technologies, LLC (Broadcom, Inc.)
• Original Assignee: Nanotec Corporation
• Inventors: Roziere, Didier
• Granted Patent: US 10,396,784 B2
• Time in Patent Office: Days
• US Class Current: 200/5.R
• CPC Class Codes: G01L 1/04 by measuring elastic deformation of gauges, e.g. of springs
• CPC Class Codes: G01L 1/14 by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9613 using two electrodes per touch switch
• CPC Class Codes: H03K 2217/0027 Measuring means of, e.g. currents through or voltages across the switch
• CPC Class Codes: H03K 2217/960765 Details of shielding arrangements
• CPC Class Codes: H03K 2217/96077 comprising an electrode which is floating

Abstract

A capacitive measurement device for control interfaces, includes: (i) a support plate (2) having elements for attachment (4) to a control interface (3), (ii) first electrodes (5) arranged on a first surface of the support plate (2) opposite the control interface (3) and including first active electrodes (5), (iii) electronic capacitive measurement elements capable of enabling the obtainment of proximity and/or contact information of objects of interest (1), and (iv) second electrodes (6, 7) arranged on a second surface of the support plate (2) facing the control interface (3) and including second active electrodes (6) connected to the electronic capacitive measurement elements such as to enable the obtainment of measurements of movement and/or deformation of the support plate (2). A method and apparatus implemented in the device are also described.

Claims

1. Capacitive measurement device for command interfaces, comprising:

a support plate (2) made from a dielectric material, with means for fixing (4) onto a command interface (3),

first electrodes (5) made from a substantially electrically conductive material, arranged on a first face of said support plate (2) opposite the command interface (3), and comprising first active electrodes (5),

electronic capacitive measurement means (17) suitable for allowing data on the approach and/or contact of object(s) of interest (1) to be obtained by measurements of capacitive coupling with said first active electrodes (5),

characterized in that it also comprises second electrodes (6, 7) made from a substantially electrically conductive material, arranged on a second face of said support plate (2) toward the command interface (3), and comprising second active electrodes (6) connected to said electronic capacitive measurement means (17) so as to allow measurements of the displacement and/or deformation of said support plate (2) to be obtained by measurement of capacitive coupling between said second active electrodes (6) and said command interface (3).

2. The device of claim 1, in which the first and second electrodes (5, 6, 7) moreover comprise respectively first and second guard electrodes excited at an alternating electric guard potential (11) substantially identical to that of the first and second active electrodes (5, 6), said first and second guard electrodes being arranged so as to electrically shield, respectively, on their face oriented toward the support plate (2), the second and first active electrodes (6, 5).

3. The device according to claim 2, also comprising switching means (10) making it possible to connect first and second electrodes (5, 6), either to the electronic capacitive measurement means (17) or to the guard potential (11).

4. The device of claim 1, also comprising electronic capacitive measurement means (17) configured so as to make it possible to obtain data on the approach and/or contact of (an) object(s) of interest by capacitance measurements between first active electrodes (5) and the object(s) of interest (1).

5. The device of claim 1, also comprising first active electrodes (5) with excitation electrodes and measurement electrodes capacitively coupled to said excitation electrodes, and electronic capacitive measurement means (17) configured so as to make it possible to obtain data on the approach and/or contact of (an) object(s) of interest (1) by measurements of the variation of coupling capacitance between said excitation and measurement electrodes.

6. The device of claim 1, also comprising electronic capacitive measurement means (17) configured so as to make it possible to obtain measurements of displacement and/or deformation of said support plate (2) by measurements of capacitance between said second active electrodes (6) and said command interface (3).

7. The device of claim 2, also comprising electronic capacitive measurement means (17) at least partially referenced to a reference electrical potential which is floating with respect to a ground potential (13).

8. The device of claim 7, in which the reference electrical potential is substantially equal to the guard potential (11).

14. Human-machine interface device comprising a command interface (3) and a capacitive measurement device according to claim 1.

15. The human-machine interface device according to claim 14 comprising a command interface (3) provided with a display screen, and a capacitive measurement device provided with a support plate (2) and electrodes (5, 6, 7) which are substantially transparent.

16. Device of one of the following types:

smartphone, tablet, display screen, computer, control pad for a machine or vehicle, comprising a human-machine interface device according to claim 14.

17. Device of one of the following types:

smartphone, tablet, display screen, computer, control pad for a machine or vehicle, comprising a human-machine interface device according to claim 15.

9. Capacitive measurement method for a command interface, utilizing (i) a support plate (2) made from a dielectric material with means for fixing (4) onto a command interface (3), (ii) first electrodes (5) made from a material that is substantially electrically conductive, arranged on a first face of said support plate (2) opposite the command interface (3), said first electrodes comprising first active electrodes (5), (iii) electronic capacitive measurement means (17), this method comprising a step of obtaining data on the approach and/or contact of (an) object(s) of interest (1) by measurement of capacitive coupling with said first active electrodes (5),characterized in that it also comprises a step of obtaining measurements of displacement and/or deformation of said support plate (2) by measurements of capacitive coupling between second active electrodes (6) and said command interface (3), said second active electrodes (i) belonging to a group of second electrodes (6, 7), made from a material that is substantially electrically conductive, arranged on a second face of said support plate (2) toward the command interface (3) and (ii) being connected to said electronic capacitive measurement means (17).

10. The method of claim 9, also comprising steps of:

connecting first electrodes (5) to the electronic capacitive measurement means (17), and second electrodes (6,7) to the guard potential (11) by switching means (10),

obtaining data on the approach and/or contact of (an) object(s) of interest.

11. The method of claim 9, also comprising steps of:

connecting second electrodes (6) to the electronic capacitive measurement means (17), and first electrodes (5) to the guard potential (11) by switching means (10),

obtaining data on displacement and/or deformation of the support plate (2).

12. The method of claim 9, also comprising steps of:

obtaining data on the approach and/or contact of (an) object(s) of interest (1),

when at least one object of interest (1) is at a distance less than a predetermined distance, or in contact with the first electrodes (5), obtaining data on displacement and/or deformation of the support plate (2).

13. The method of claim 9, also comprising a step of determining a pushing force and/or a pressure from data on displacement and/or deformation of the support plate (2).

18. The method of claim 10, also comprising steps of:

connecting first electrodes (5) to the electronic capacitive measurement means (17), and second electrodes (6,7) to the guard potential (11) by switching means (10),

obtaining data on the approach and/or contact of (an) object(s) of interest.