INTRUSION DETECTION USING A CAPACITANCE SENSITIVE TOUCHPAD

• US 20080278355A1
• Filed: 05/08/2008
• Published: 11/13/2008
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Cirque Corporation
• Original Assignee: Cirque Corporation
• Inventors: Bytheway, Jared G., Taylor, David, Carter, Dale J., Moore, J. Douglas
• Granted Patent: US 9,507,466 B2
• Time in Patent Office: Days
• US Class Current: 341/33
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof
• CPC Class Codes: G06F 3/044 by capacitive means
• 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: H03K 2217/96058 Fail-safe touch switches, where switching takes place only after repeated touch

Abstract

A capacitance sensitive proximity and touch-sensitive detection device having an XY electrode grid sensor, wherein a compensation matrix is created when the capacitance sensitive touchpad is installed within a PIN Entry Device (PED), wherein the compensation matrix enables the capacitance sensitive touchpad to compensate and be balanced for the operating environment of the PED, and wherein physical keys of a keypad can be also be individually identified as an actuated key by using a unique “key profile” for each key, and wherein the insertion of a foreign conductive and/or dielectric material such as an intruding sensor in proximity of the XY electrode grid sensor of the touchpad will cause an imbalance in the electrodes on the capacitance sensitive proximity and touch-sensitive detection device, thereby alerting detection circuitry that tampering has occurred with the PED.

Claims

1. A method for detecting a change in the operating environment of a touch and proximity sensitive device, said method comprising the steps of:

1) providing a touch and proximity sensitive device that is capable of touch and proximity detection of conductive or dielectric objects;

2) calibrating the touch and proximity sensitive device within a given operating environment;

3) obtaining first calibration settings for the touch and proximity sensitive device;

4) performing an intrusion detection procedure by recalibrating the touch and proximity sensitive device and obtaining new calibration settings; and

5) comparing the first calibration settings and the new calibration settings to determine if the operating environment of the touch and proximity sensitive device has changed in a first intrusion detection system.

2. The method as defined in claim 1 wherein the method further comprises the steps of:

1) measuring imbalances in electrical charges on touchpad electrodes when no object is being detected;

2) compensating for the measured imbalances so that the touchpad can operate without being influenced by the measured imbalances; and

3) creating a compensation matrix to store the measured imbalances.

3. The method as defined in claim 2 wherein the method further comprises the step of disposing the touch and proximity sensitive device within a point-of-sale (POS) device that includes a Personal Identity Number (PIN) Entry Device (PED).

4. The method as defined in claim 3 wherein the method further comprises the step of using a capacitive sensing touch and proximity sensitive touchpad as the touch and proximity sensitive device.

5. The method as defined in claim 4 wherein the method further comprises the step of calibrating the touchpad by creating the compensation matrix when the touchpad is inserted into the PED during manufacturing.

6. The method as defined in claim 4 wherein the method further comprises the step of recreating the compensation matrix each time that power is applied to the PED.

7. The method as defined in claim 4 wherein the method further comprises the step of performing the intrusion detection procedure each time that power is applied to the PED.

8. The method as defined in claim 3 wherein the method further comprises the steps of:

1) providing an X and SENSE electrodes that are coupled to the touch and proximity sensitive device; and

2) disposing the X and SENSE electrodes at locations around the PED wherein tampering is likely to occur.

9. The method as defined in claim 8 wherein the method further comprises the step of disposing the X and SENSE electrodes around keys of a keypad.

10. The method as defined in claim 8 wherein the method further comprises the steps of:

1) constructing the X and SENSE electrodes from Indium-Tin Oxide (ITO) so that the X and SENSE electrodes are easily damaged; and

2) covering the X and SENSE electrodes using a cover template and adhesive such that an intruding sensor must be inserted into the PED by at least partially lifting the cover template and thereby damaging the X or the SENSE electrodes.

11. The method as defined in claim 8 wherein the method further comprises the steps of:

1) Disposing the X and SENSE electrodes on a substrate having at least one perforation therethrough; and

2) covering the X and SENSE electrodes using a cover template and adhesive such that an intruding sensor must be inserted into the PED by at least partially lifting the cover template and thereby tearing the perforated substrate and causing detectable damage.

12. The method as defined in claim 8 wherein the method further comprises the steps of:

1) providing an Interlock circuit in the PED;

2) detecting tampering;

3) sending a signal to the Interlock circuit that the PED should be shut down; and

4) removing power from the PED using the Interlock circuit.

13. The method as defined in claim 8 wherein the method further comprises the steps of:

1) disposing one of the X and SENSE electrodes inside the PED; and

2) disposing the other electrode of the X and SENSE electrodes on an outside surface of the PED.

14. The method as defined in claim 3 wherein the method further comprises the step of modifying sensitivity of the intrusion detection procedure to thereby improve performance of the intrusion detection system.

15. The method as defined in claim 4 wherein the method further comprises the step of operating a second intrusion detection system at the same time as the first intrusion detection system.

16. The method as defined in claim 15 wherein the method further comprises the steps of:

1) disposing a keypad having a plurality of keys over the touchpad;

2) profiling each key of the plurality of keys by pressing each key and then measuring a response of the touchpad; and

3) storing a key profile for each of the plurality of keys.

17. The method as defined in claim 16 wherein the method further comprises the step of modifying sensitivity of the second intrusion detection procedure to thereby improve performance of the intrusion detection system.

25. The method as defined in claim 15 wherein the method further comprises the steps of:

1) providing a touch and proximity sensitive device that is capable of touch and proximity detection of conductive or dielectric objects;

2) calibrating the touch and proximity sensitive device within a given operating environment;

3) obtaining first calibration settings for the touch and proximity sensitive device;

4) performing a second intrusion detection procedure by recalibrating the touch and proximity sensitive device and obtaining new calibration settings; and

5) comparing the first calibration settings and the new calibration settings to determine if the operating environment of the touch and proximity sensitive device has changed in a second intrusion detection system.

26. The method as defined in claim 25 wherein the method further comprises the steps of:

1) measuring imbalances in electrical charges on touchpad electrodes when no object is being detected;

2) compensating for the measured imbalances so that the touchpad can operate without being influenced by the measured imbalances; and

3) creating a compensation matrix to store the measured imbalances.

18. A method for detecting a change in the operating environment of a keypad, said method comprising the steps of:

1) providing a touch and proximity sensitive touchpad that is capable of touch and proximity detection of conductive or dielectric objects;

2) providing a keypad having a plurality of keys that is disposed over the touchpad;

3) profiling each key of the plurality of keys by pressing each key and then measuring a response of the touchpad; and

4) storing a key profile for each of the plurality of keys.

19. The method as defined in claim 18 wherein the method further comprises the steps of:

1) actuating one of the plurality of keys on the keypad;

2) measuring a response of the touchpad to the actuated key;

3) comparing the measured response of the touchpad to the key profile that is stored for the actuated key in an intrusion detection procedure; and

4) determining if the operating environment has changed based on the comparison of the measured response and the key profile as a first intrusion detection system.

20. The method as defined in claim 19 wherein the method further comprises the step of disposing the touchpad and the keypad within a point-of-sale (POS) device that includes a Personal Identity Number (PIN) Entry Device (PED).

21. The method as defined in claim 20 wherein the method further comprises the step of creating the key profiles when the touchpad and the keypad are inserted into the PED during manufacturing.

22. The method as defined in claim 20 wherein the method further comprises the step of performing the intrusion detection procedure each time one of the plurality of keys is actuated.

23. The method as defined in claim 20 wherein the method further comprises the step of modifying sensitivity of the touchpad to thereby improve performance of the first intrusion detection system.

24. The method as defined in claim 20 wherein the method further comprises the step of operating a second intrusion detection system at the same time as the first intrusion detection system.