Data input device

• US 20080018608A1
• Filed: 07/18/2006
• Published: 01/24/2008
• Est. Priority Date: 07/18/2006
• Status: Active Grant

• Current Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Original Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Inventors: Schoos, Aloyse, Boyer, Philippe, Serban, Bogdan
• Granted Patent: US 8,063,886 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H03K 17/975 using a capacitive movable element

Abstract

A data input device is provided with a film-based pressure sensor build from a first carrier film, a second carrier film and a spacer arranged between the carrier films for keeping them at a distance from one another. The spacer has an opening delimiting an active zone, in which first and second electrodes are arranged in such a way that, in response to a compressive force acting on the active zone, an electrical contact is established between the first and second electrodes. A control circuit able to operate in at least a first and a second mode of operation is configured so as to measure, in the first mode of operation, a quantity indicative of electrical resistance between the first and second electrodes for detecting an amount or a position of a compressive force acting on the active zone and, in the second mode of operation, a quantity indicative of a capacitance for detecting a person or an object approaching thereto.

Claims

1. A data input device comprising

a film-based pressure sensor with an active zone, said pressure sensor comprising a first carrier film, a second carrier film and a spacer arranged between said first and second carrier films for keeping the first and second carrier films at a distance from one another, said spacer comprising an opening delimiting said active zone, said first carrier film having a first electrode applied thereon, said second carrier film having a second electrode applied thereon, said first and second electrodes facing each other in said active zone in such a way that, in response to a compressive force acting on the active zone, the first and second carrier films are pressed together and an electrical contact is established between the first and second electrodes;

and a control circuit able to operate in at least a first and a second mode of operation, said control circuit being configured so as to measure, in said first mode of operation, a quantity indicative of electrical resistance between said first and second electrodes for detecting an amount of compressive force acting on the active zone and, in said second mode of operation, a quantity indicative of a capacitance of said first electrode for detecting a person or an object approaching thereto.

2. A data input device according to claim 1, comprising a first module, dedicated to said first mode of operation, said first module comprising a current source operationally connected, in said first mode of operation, to said first and second electrodes so as to create a current through said first and second electrodes if an electrical contact is established between said first and second electrodes, and a voltage measurement circuit operationally connected, in said first mode of operation, to said first and second electrodes for measuring a voltage between them, said voltage being indicative of electrical resistance between said first and second electrodes.

3. A data input device according to claim 1, comprising a first module, dedicated to said first mode of operation, said first module comprising a voltage source operationally connected, in said first mode of operation, to said first and second electrodes for creating a voltage between them and a current measurement circuit operationally connected, in said first mode of operation, for measuring a current flowing through said first and second electrodes, said current being indicative of electrical resistance between said first and second electrodes.

4. A data input device according to claim 1, comprising a second module, dedicated to said second mode of operation, said second module including an AC voltage source operationally connected, in said second mode of operation, at least to said first electrode for applying an oscillating voltage to said first electrode and a current measurement circuit operationally connected, in said second mode of operation, for measuring an electrical current flowing into said first electrode, said electrical current flowing into said first electrode being indicative of a capacitance of said first electrode.

5. A data input device according to claim 4, wherein said AC voltage source is operationally connected to said first and second electrodes so as to apply voltages of substantially same phase and amplitude to said first and second electrodes, in said second mode of operation.

6. A data input device according to claim 1, wherein said control circuit comprises a first module, dedicated to said first mode of operation, a second module, dedicated to said second mode of operation, and a switching unit switching said control circuit between at least said first and second modes of operation.

7. A data input device as claimed in claim 1, wherein at least one of said first and second electrodes comprises a pressure sensitive layer arranged in facing relationship with the respective other one of said first and second electrodes in said active zone.

8. A data input device as claimed in claim 1, wherein said control circuit is configured so as to output a first output signal responsive to said quantity indicative of electrical resistance and a second output signal responsive to said quantity indicative of a capacitance of said first electrode.

9. A data input device as claimed in claim 8, wherein said control circuit comprises at least a first and a second output, said control circuit being configured so as to output said first output signal at said first output and said second output signal at said second output.

10. A data input device as claimed in claim 1, wherein said first electrode is subdivided into at least two electrode portions and wherein said at least two electrode portions are electrically separated at least in said second mode of operation, said quantity indicative of a capacitance of said first electrode being determined separately for each one of said at least two electrode portions.

11. In a data input device according to claim 1, a method comprising measuring a quantity indicative of electrical resistance between said first and second electrodes for detecting an amount of compressive force acting on the active zone;

measuring a quantity indicative of a capacitance of said first electrode for detecting a person or an object approaching thereto.

12. A method as claimed in claim 11, wherein said measuring a quantity indicative of a capacitance of said first electrode includes applying an oscillating voltage to said first electrodes and measuring an electrical current flowing into said first electrode in response to said applied oscillating voltage.

13. A method as claimed in claim 11, wherein said measuring a quantity indicative of a capacitance of said first electrodes includes applying an oscillating voltage to said second electrode, the oscillating voltage applied to said second electrode having substantially same phase and amplitude as the oscillating voltage applied to said first electrode.

14. A data input device comprising

a film-based pressure sensor with an active zone, said pressure sensor comprising a first carrier film, a second carrier film and a spacer arranged between said first and second carrier films for keeping the first and second carrier films at a distance from one another, said spacer comprising an opening delimiting said active zone, said first carrier film having a first electrode and a second electrode applied thereon, said second carrier film having a third electrode applied thereon, said first and second electrodes facing said third electrode in said active zone in such a way that, in response to a compressive force acting on the active zone, the first and second carrier films are pressed together and an electrical contact is established between the first and second electrodes via said third electrode, and a control circuit able to operate in at least a first and a second mode of operation, said control circuit being configured so as to measure, in said first mode of operation, a quantity indicative of electrical resistance between said first and second electrodes for detecting an amount of compressive force acting on the active zone and, in said second mode of operation, a quantity indicative of a capacitance of at least one of said first, second and third electrodes for detecting a person or an object approaching thereto.

15. A data input device according to claim 14, comprising a first module, dedicated to said first mode of operation, said first module comprising a current source operationally connected, in said first mode of operation, to said first and second electrodes so as to create a current through said first and second electrodes if an electrical contact is established between said first and second electrodes via said third electrode, and a voltage measurement circuit operationally connected, in said first mode of operation, at said first and second electrodes for measuring a voltage between them, said voltage being indicative of electrical resistance between said first and second electrodes.

16. A data input device according to claim 14, comprising a first module, dedicated to said first mode of operation, said first module comprising a voltage source operationally connected, in said first mode of operation, at said first and second electrodes for creating a voltage between them and a current measurement circuit operationally connected, in said first mode of operation, for measuring a current flowing through said first and second electrodes, said current being indicative of electrical resistance between said first and second electrodes.

17. A data input device according to claim 14, comprising a second module, dedicated to said second mode of operation, said second module including an AC voltage source operationally connected, in said second mode of operation, at least to said at least one of said first, second and third electrodes for applying an oscillating voltage to said at least one of said first, second and third electrodes and a current measurement circuit operationally connected, in said second mode of operation, for measuring an electrical current flowing into said at least one of said first, second and third electrodes, said electrical current flowing into said at least one of said first, second and third electrodes being indicative of a capacitance of said at least one of said first, second and third electrodes.

18. A data input device according to claim 17, wherein said AC voltage source is operationally connected to said first, second and third electrodes so as to apply voltages of substantially same phase and amplitude to said first, second and third electrodes, in said second mode of operation.

19. A data input device according to claim 14, wherein said control circuit comprises a first module, dedicated to said first mode of operation, a second module, dedicated to said second mode of operation, and a switching unit switching said control circuit between at least said first and second modes of operation.

20. A data input device as claimed in claim 14, wherein at least one of said first, second and third electrodes comprises a pressure sensitive layer arranged in facing relationship with a respective other one or respective other ones of said first, second and third electrodes in said active zone.

21. A data input device as claimed in claim 14, wherein said control circuit is configured so as to output a first output signal responsive to said quantity indicative of electrical resistance and a second output signal responsive to said quantity indicative of a capacitance of said at least one of said first, second and third electrodes.

22. A data input device as claimed in claim 21, wherein said control circuit comprises at least a first and a second output, said control circuit being configured so as to output said first output signal at said first output and said second output signal at said second output.

23. A data input device as claimed in claim 14, wherein said at least one of said first, second and third electrodes is said first electrode.

24. A data input device as claimed in claim 14, wherein said at least one of said first, second and third electrodes is said first and second electrodes.

25. A data input device as claimed in claim 14, wherein said at least one of said first, second and third electrodes is said third electrode.

26. A data input device as claimed in claim 14, wherein said at least one of said first, second and third electrodes is subdivided into at least two electrode portions and wherein said at least two electrode portions are electrically separated at least in said second mode of operation, said quantity indicative of a capacitance of at least one of said first, second and third electrodes being determined separately for each one of said at least two electrode portions.

27. In a data input device according to claim 14, a method comprising measuring a quantity indicative of electrical resistance between said first and second electrodes for detecting an amount of compressive force acting on the active zone;

measuring a quantity indicative of a capacitance of said at least one of said first, second and third electrodes for detecting a person or an object approaching thereto.

28. A method as claimed in claim 27, wherein said measuring a quantity indicative of a capacitance of said at least one of said first, second and third electrodes includes applying an oscillating voltage to said at least one of said first, second and third electrodes and measuring an electrical current flowing into said at least one of said first, second and third electrodes in response to said applied oscillating voltage.

29. A method as claimed in claim 27, wherein said measuring a quantity indicative of a capacitance of said at least one of said first, second and third electrodes includes applying an oscillating voltage to the other one or other ones of said at least one of said first, second and third electrodes, the oscillating voltage applied to said other one or other ones of said at least one of said first, second and third electrodes having same phase and amplitude as the oscillating voltage applied to said at least one of said first, second and third electrodes.

30. A data input device comprising

a film-based position sensor with an active zone, said position sensor comprising a first carrier film, a second carrier film and a spacer arranged between said first and second carrier films for keeping the first and second carrier films at a distance from one another, said spacer comprising an opening delimiting said active zone, said first carrier film having a first electrode and a second electrode applied thereon, said second carrier film having a third electrode applied thereon, said first electrode including a series of resistively connected first conductors, said third electrode facing said first electrode and said second electrode in said active zone in such a way that, in response to a compressive force acting on the active zone, the first and second carrier films are pressed together and an electrical contact is established between one or more of said first conductors and said second electrode via said third electrode;

and a control circuit able to operate in at least a first and a second mode of operation, said control circuit being configured so as to measure, in said first mode of operation, a quantity indicative of a position of resistive coupling between said first electrode and said second electrode for detecting a position of a compressive force acting on the active zone and, in said second mode of operation, a quantity indicative of a position of capacitive coupling between said first electrode and said second electrode for detecting a position of a person or an object approaching to said data input device.

31. A data input device as claimed in claim 30, wherein said second electrode comprises a series of conductively connected second conductors, said first and second conductors being arranged so as to interdigitate.

32. A data input device comprising

a film-based position sensor with a plurality of active zones, said position sensor comprising a first carrier film, a second carrier film and a spacer arranged between said first and second carrier films for keeping the first and second carrier films at a distance from one another, said spacer comprising at least one opening delimiting said active zones, said first carrier film having a first electrode and a second electrode applied thereon in each one of said active zones, said second carrier film having a third electrode applied thereon in each one of said active zones, each first electrode including a series of resistively connected first conductors, each third electrode facing a respective first electrode and a respective second electrode in a respective active zone in such a way that, in response to a compressive force acting on at least one of said active zones, the first and second carrier films are pressed together and an electrical contact is established between one or more of the first conductors of the first electrode of the at least one of said active zones on which the compressive force acts and a respective second electrode via a respective third electrode;

and a control circuit able to operate in at least a first and a second mode of operation, said control circuit being configured so as to measure, in said first mode of operation, a quantity indicative of a position in two dimensions of resistive coupling between said first electrode and said second electrode for detecting a position in two dimensions of a compressive force acting on at least one of the active zones and, in said second mode of operation, a quantity indicative of a position of capacitive coupling between said first electrode and said second electrode for detecting a position of a person or an object approaching to said data input device.

33. A data input device including

a film-based pressure sensor, the pressure sensor comprising an active zone, a first carrier film, a second carrier film and a spacer arranged between the carrier films for keeping them at a distance from one another, the spacer having an opening delimiting said active zone, in which a first and a second electrodes are arranged in such a way that, in response to a compressive force acting on the active zone, an electrical contact is established between the first and second electrodes,

control circuit able to operate in at least a first and a second mode of operation, said control circuit being configured so as to measure, in the first mode of operation, a quantity indicative of electrical resistance between the first and second electrodes for detecting an amount or a position of a compressive force acting on the active zone and, in the second mode of operation, a quantity indicative of a capacitance for detecting a person or an object approaching thereto.