SENSOR ELECTRONICS IN A VEHICLE DOOR HANDLE

• US 20100271049A1
• Filed: 04/21/2010
• Published: 10/28/2010
• Est. Priority Date: 04/22/2009
• Status: Active Grant

• Current Assignee: Huf Hulsbeck & Furst GmbH & Co. KG
• Original Assignee: Huf Hulsbeck & Furst GmbH & Co. KG
• Inventors: Van Gastel, Peter, Lindic, Iko
• Granted Patent: US 8,482,303 B2
• Time in Patent Office: Days
• US Class Current: 324/679
• CPC Class Codes: E05B 81/77 comprising sensors detecting the presence of the hand of a user
• CPC Class Codes: E05B 81/78 as part of a hands-free locking or unlocking operation
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2217/960705 Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe
• CPC Class Codes: H05K 9/002 with localised screening

Abstract

A solution for sensor electronics provided in a door handle of a vehicle with a sensor control circuit (6) that is provided on a circuit board (1) and with a sensor electrode (11) of a capacitive sensor for detection of the approach of an object to the door handle connected to the sensor control circuit through which the sensitivity is improved, interference is decreased, and a compact structure is achieved. This task is solved by sensor electronics with a ground-metallization plane having a ground potential and a shielding electrode provided between the sensor electrode (11) and the ground-metallization plane, whereby the circuit board (1) has at least four metallization planes (7, 8. 9, 10) insulated from each other by insulating layers (13, 14, 15), whereby a first metallization plane (7) is provided on an upper side (5) of circuit board (1) including wiring connections between the components of the sensor control circuit (6), a second metallization plane (8) that is the ground-metallization plane, a third metallization plane (9) that includes the shielding electrode, and a fourth metallization plane (10) that includes the sensor electrode (11) so that the wiring connections of the components of the sensor control circuit (6) are provided on one side of the ground-metallization plane and the shielding electrode and the sensor electrode (11) on the other side of the ground-metallization plane.

Claims

1. Sensor electronics that are provided in a door handle of a vehicle, comprising

a sensor control circuit located on a circuit board that has a ground-metallization plane conducting a ground potential,

a sensor electrode of a capacitive sensor for detection of the approach of an object to the door handle connected to the sensor control circuit, and

a shielding electrode provided between the sensor electrode and the ground metallization plane of the circuit board and a shielding electrode control switch connected with the shielding electrode that tracks the potential of the shielding electrode with the potential of the sensor electrode,

whereby the circuit board is provided on the inside of the door handle and the components of the sensor control circuit are mounted on an upper side of the circuit board,

whereby the circuit board has at least four metallization planes insulated from each other by insulating layers, whereby

a first metallization plane provided on the upper side of the circuit board includes wiring connections between the components of the sensor control circuit,

a second metallization plane that is a ground-metallization plane,

a third metallization plane that includes the shielding electrode, and

a fourth metallization plane that includes the sensor electrode,

so that the connecting leads of the components of the sensor control circuit are provided on one side of the ground-metallization plane and the shielding electrode and the sensor electrode on the other side of the ground metallization plane.

2. Sensor electronics according to claim 1 characterized in that the sensor control circuit includes a transmitter coil of a circuit for communication with a transportable ID encoder.

3. Sensor electronics according to claim 1 or 2 characterized in that the shielding electrode control circuit is a constituent of the sensor control circuit.

4. Sensor electronics according to claim 1 characterized in that the voltage supply leads for the sensor control circuit are provided in the first metallization plane.

5. Sensor electronics according to claim 1 characterized in that between the first metallization plane and the ground-metallization plane at least a further metallization plane is provided, which has voltage supply leads and/or wiring connections between the components of the sensor control circuit.

6. Sensor electronics according to claim 1 characterized in that the circuit board has a total thickness of between 1 mm and 3 mm, advantageously approx. 1.5 mm.

7. Sensor electronics according to claim 6 characterized in that an insulating layer is provided between the second metallization layer and the third metallization layer with a thickness of 0.3 to 2 mm, advantageously about 0.5 mm.

8. Sensor electronics according to claim 1 characterized in that the shielding electrode extends beyond the sensor electrode on all sides by at least 0.3 mm, advantageously by about 0.3 to 0.6 mm.

9. Sensor electronics according to claim 1 characterized in that the metallization planes are formed of conducting layers, advantageously of copper layers, of 35 μ

m to 70 μ

m.

10. Sensor electronics according to claim 1 characterized in that the circuit board is provided adjacent to an outer wall of the door handle in such a way that the sensor electrode abuts to the outer wall.