Sensor electronics in a vehicle door handle

• US 8,482,303 B2
• Filed: 04/21/2010
• Issued: 07/09/2013
• 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
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US12/764,875
• Publication Number:
  US 20100271049A1
• Time in Patent Office: 1,175 Days
• Field of Search: None
• 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. A sensor electronics in a door handle of a vehicle, comprising:

a capacitive sensor for detecting the approach of an object to the door handle, the capacitive sensor comprising;

a sensor electrode and

a shield electrode disposed between the sensor electrode and a ground metallization plane having a ground potential, the shield electrode connected to a shield electrode control circuit that tracks the potential of the shield electrode with the potential of the sensor electrode;

a sensor control circuit coupled to the sensor electrode for evaluation of and forwarding sensor output signals, the sensor control circuit having components; and

a circuit board being arranged in an internal space of the door handle, the components of the sensor control circuit being mounted on an upper side of the circuit board, the circuit board having at least four metallization planes insulated from each other by insulating layers, the metallization planes comprising;

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

a second metallization plane comprising the ground-metallization plane,

a third metallization plane including the shield electrode, and

a fourth metallization plane including the sensor electrode;

wherein the wiring connections between the components of the sensor control circuit are arranged on one side of the ground-metallization plane and the shield electrode and the sensor electrode are arranged on the other side of the ground-metallization plane.

2. The sensor electronics according to claim 1, wherein the sensor control circuit includes a transmitter coil of a circuit for communication with a transportable ID encoder.

3. The sensor electronics according to claim 1 or 2, wherein the shield electrode control circuit is a part of the sensor control circuit.

4. The sensor electronics according to claim 1, wherein the wiring connections in the first metallization plane comprise voltage supply leads for the sensor control circuit.

5. The sensor electronics according to claim 1, wherein the circuit board has a total thickness of between 1 mm and 3 mm, advantageously approx. 1.5 mm.

6. The sensor electronics according to claim 5, wherein 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.

7. The sensor electronics according to claim 1, wherein the shield electrode extends beyond the sensor electrode on all sides by at least 0.3 mm, advantageously by about 0.3 to 0.6 mm.

8. The sensor electronics according to claim 1, wherein the metallization planes are formed of conducting layers, advantageously of copper layers, of 35 mm to 70 mm.

9. The sensor electronics according to claim 1, wherein 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.