Capacitive Sensor System

• US 20080204047A1
• Filed: 09/13/2005
• Published: 08/28/2008
• Est. Priority Date: 09/17/2004
• Status: Active Grant

• Current Assignee: Electrolux Home Products Incorporated (AB Electrolux)
• Original Assignee: Electrolux Home Products Incorporated (AB Electrolux)
• Inventors: Johansson, Jan, Wern, Lars-Ake
• Granted Patent: US 8,049,518 B2
• Time in Patent Office: Days
• US Class Current: 324/661
• CPC Class Codes: E05F 15/46 responsive to changes in electrical capacitance
• CPC Class Codes: E05Y 2900/31 for refrigerators
• CPC Class Codes: F25D 23/028 Details
• CPC Class Codes: F25D 2700/02 Sensors detecting door opening
• CPC Class Codes: F25D 2700/04 Sensors detecting the presence of a person
• CPC Class Codes: F25D 29/00 Arrangement or mounting of control or safety devices
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/975 using a capacitive movable element

Abstract

The present invention relates to a capacitive sensor system provided for a moving object 21. The system comprises an antenna device with a first 26 and a second portion 39 which are movable in relation to each other, the two portions 26,39 being connected in parallel for capacitive influence from the surroundings. The first portion 26 constitutes in an electrical conductive part of said moving object 21 and the second section 39 constitutes in an electrical conductive device arranged at a rest position for the moving object 21.

Claims

1. Capacitive sensor system provided for a moving object (21) characterized in that it comprises an antenna device with a first (26) and a second portion (39) which are movable in relation to each other, the two portions (26,39) being connected in parallel for capacitive influence from the surroundings, whereby the first portion (26) constitutes in an electrical conductive part of said moving object (21) and the second section (39) constitutes in an electrical conductive device arranged at a rest position for the moving object (21).

2. Capacitive sensor system according to claim 1 characterized in that the moving object (21) is provided with an electrically operable unit (25) and in said rest position is arranged to close a passage, whereby the sensor system is provided with a operating device (46) arranged to operate the operable unit (25) and said electrical conductive device (39) being positioned at the periphery of the passage.

3. Capacitive sensor system according to claim 2 characterized in that said electrically operable unit (25) being arranged to move the moving unit (21), the operable unit (25) being operated depending on the influence of the surroundings through a capacitance formed between the antenna device and an earth plane for said antenna device, the antenna device being electrically insulated from the earth plane.

4. Capacitive sensor system according to claim 3 characterized in that said capacitive sensor system is integrated into the moving object (21) and has a signal input (59) connected to said earth plane and a signal ground (36) connected to the electrically conductive part (26), whereby all components connected to the sensor system will be a part of said antenna device.

5. Capacitive sensor system according to claim 4 characterized in that said electrically operable unit (25) is integrated into the moving object (21) and is arranged to be a part of the electrical conductive part (26), whereby the operable unit (25) will be an operational part of said first antenna.

6. Household appliance for instance a refrigerator or freezer characterized in that is comprises a capacitive sensor system according to any of the preceding claims.

7. Household appliance according to claim 6 characterized in that said moving object (21) is a door, lid or drawer being arranged to close at least one compartment opening of the appliance, the electrically conductive part (26) consisting the liner forming said door or lid.