OPERATING DEVICE FOR AN ELECTRICAL APPLIANCE HAVING A CONTROL PANEL AND SUBADJACENT SENSOR ELEMENT AND METHOD OF OPERATING SUCH AN OPERATING DEVICE

• US 20070045281A1
• Filed: 08/01/2006
• Published: 03/01/2007
• Est. Priority Date: 02/02/2004
• Status: Active Grant

• Current Assignee: EGO Elektro-Gerã¤Tebau GmbH (EGO Blanc und Fischer & Company GmbH)
• Original Assignee: EGO Elektro-Gerã¤Tebau GmbH (EGO Blanc und Fischer & Company GmbH)
• Inventors: Baier, Martin
• Granted Patent: US 7,652,230 B2
• Time in Patent Office: Days
• US Class Current: 219/483
• CPC Class Codes: D06F 34/28 Arrangements for program selection, e.g. control panels therefor; Arrangements for indicating program parameters, e.g. the selected program or its progress
• CPC Class Codes: F24C 7/082 on ranges, e.g. control panels, illumination
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/036 Variable resistance
• CPC Class Codes: H01H 2231/012 Household appliance
• CPC Class Codes: H03K 17/9625 using a force resistance transducer
• CPC Class Codes: H05B 3/74 Non-metallic plates , e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits

Abstract

An operating device for a cooktop has a cover with a control panel with a plurality of operating areas. Below the panel, several FSR sensors are positioned. When a control panel is pushed down by a process of operation, the FSR sensor changes its electrical resistance resulting in change of a signals that can be detected and interpreted as operation of the appliance by a user.

Claims

1. An operating device for an electrical appliance, wherein said operating device comprises an operating field capable of deflection and a pressure-sensitive sensor element incorporating an FSR sensor arranged below said operating field, wherein a user pressing on said operating field results in deflection of said operating field causing the application of pressure on said FSR sensor, thereby altering the resistance of the FSR sensor and further altering an electrical signal passing through the FSR sensor, thereby signifying operation of the electrical appliance by the user.

2. The operating device according to claim 1, wherein said FSR sensor is constructed as having a variable, electrical resistance and wherein an increase of said pressure on said FSR sensor results in a decrease in said electrical resistance of said FSR sensor.

3. The operating device according to claim 1, wherein said operating field has a closed and interruption-free surface.

4. The operating device according to claim 3, wherein said operating field is part of a cover of said operating device.

5. The operating device according to claim 4, wherein said cover comprises a first area over said FSR sensor capable of said deflection more so than a second area surrounding the first area.

6. The operating device according to claim 1, comprising a plurality of operating fields are arranged in a juxtaposed form in an operating area and a one-piece, continuous cover comprising an operating area defining the plurality of operating fields.

7. The operating device according to claim 6, further comprising a plurality of pressure sensitive sensors incorporating a respective plurality of FSR sensors located beneath the plurality of operating fields.

8. The operating device according to claim 7, wherein the plurality of FSR sensors are separately electrically connected to a lead device and have a common connection area.

9. The operating device according to claim 8, wherein each said FSR sensor has a respective first lead device as a first electrical connection and second electrical connection as a common return line wherein the second electrical connection is common with each other FSR sensor.

10. The operating device according to claim 9 wherein the lead device comprises at least one film layer with at least one of said respective first electrical connection or said second electrical connection extends over said entire lead device.

11. The operating device according to claim 10, wherein the lead device comprises a first film layer and a second film layer with said respective first electrical connection and said second electrical connection line between said first and second film layers.

12. The operating device according to claim 1, wherein said operating field is electrically conductive throughout.

13. The operating device according to claim 12, wherein said operating field is made from a sheet metal.

14. The operating device according to claim 13, wherein said FSR sensor is insulated against said operating field.

15. The operating device according to claim 1, wherein said FSR sensor is connected by means of an elastic coupling element to said operating field.

16. The operating device according to claim 15, wherein said FSR sensor is connected to an underside of said operating field as a direct coupling.

17. The operating device according to claim 15, wherein an elasticity of said elastic coupling element is such that under an operating force of 2 Newtons or less, said elastic coupling element is largely uncompressed.

18. The operating device according to claim 15, wherein said elastic coupling element is an elastomer connected directly to said FSR sensor.

19. The operating device according to claim 1, wherein said operating device has a support below said operating field, wherein said FSR sensor is located on said support between said support and said operating field.

20. The operating device according to claim 19, wherein said support has a control circuit for said operating device.

21. The operating device according to claim 1, wherein an elastic deformation of said FSR sensor in the range of 1 μ

m to 100 μ

m alters an electrical signal signifying user operation of the appliance.

22. A method of operating a device comprising an operating field capable of deflection and a pressure-sensitive sensor element incorporating an FSR sensor arranged below said operating field comprising the steps of:

applying pressure by application of a user'"'"'s finger on said operating field resulting in deflecting the operating field;

detecting a change in a signal value as a result of a change in resistance of said FSR sensor;

detecting a second change in the signal value as a result in a second change in resistance of said FSR sensor; and

determining that the time duration between said first change and said second change is less than a threshold duration thereby defining a user operation.

23. The method according to claim 22, wherein said threshold duration is less than two seconds.

24. The method according to claim 22, wherein said FSR sensor is used as a variable resistance and is evaluated with a resistance measurement.

25. The method according to claim 24, wherein said FSR sensor is constructed in such a way that a deflection of the operating cover onto the FSR sensor of 10 μ

m causes the resistance to change by at least a factor of 10.