Method and system for transmitting data for a security system of a motor vehicle

• US 7,551,066 B1
• Filed: 12/17/1999
• Issued: 06/23/2009
• Est. Priority Date: 12/21/1998
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Mannesmann VDO AG (Continental AG)
• Inventors: Burger, Thorsten
• Primary Examiner(s): Beamer; Temica M.
• Application Number:
  US09/465,676
• Time in Patent Office: 3,476 Days
• Field of Search: 455/411, 455/124, 340/5.26, 340/5.72, 340/5.54, 340/426.36, 340/428, 340/426.28
• US Class Current: 340/426.36
• CPC Class Codes: B60R 25/04 operating on the propulsion system, e.g. engine or drive motor
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07777 the antenna being of the inductive type
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: G06K 19/07788 the antenna being of the capacitive type
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10326 the antenna being of the very-near field type, e.g. capacitive
• CPC Class Codes: G07C 2009/00373 whereby the wake-up circuit is situated in the lock
• CPC Class Codes: G07C 2009/00619 by using capacitive transmission
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: H04B 13/005 Transmission systems in which the medium consists of the human body

Abstract

A method for transmitting data for a security device, in particular for access authorization systems and/or driving authorization systems of a motor vehicle, in which data are transmitted over the air from a transmitter unit to a receiver unit.

In a method in which, despite contactless interrogation of the identification signal transmitter, an authorizing access information item cannot be obtained by a third party, the data are transmitted, after capacitive coupling of the transmitter unit and receiver unit, from the transmitter to the receiver using a signal which is generated by a capacitive alternating field.

Claims

1. A system for activating and/or deactivating a security device, in particular for access authorization systems and/or driving authorization systems of a motor vehicle, in which system an encoded information item is transmitted over air between a portable transmitter and a receiver, the receiver comparing the received information item with a predefined encoded information item, and outputting a drive signal to the security device when said two information items correspond, wherein the receiver (2) has a capacitive transmitter unit (10, 11) comprising a first capacitor and generates a start signal (16) by means of an alternating electric field at the first capacitor, a receiver unit (13) of the transmitter (1) comprises a second capacitor for reception of the start signal, and transmission of the start signal from the first capacitor to the second capacitor is accomplished by a capacitive coupling between the first and the second capacitors.

2. The system as claimed in claim 1, wherein, in the capacitive transmitter unit (10, 11) of the receiver (2), the first capacitor (10) is operated with an alternating current generator (11), and the second capacitor (13) receives the signal generated by the transmitter unit (10, 11) of the receiver (2) and passes it on to an evaluation device (4) of the transmitter (1).

3. The system as claimed in claim 2, wherein, after evaluation of the start signal (16), the evaluation device (4) generates the encoded information item (3) which is transmittable from a transmitter unit (5) of the transmitter (1) to a receiver unit (6) of the receiver (2) by means of inductive coupling or far-field coupling.

4. The system as claimed in claim 1, wherein the encoded information item (3) is modulated onto a high-frequency carrier frequency which is generated by an alternating current generator (11).

5. The system as claimed in claim 2, wherein the first capacitor (10) is formed between an outer shell (15) of an access device and an activation device (12) which is arranged on the outer shell of the access device.

6. The system as claimed in claim 2, wherein the first capacitor (10) is formed between bodywork of the vehicle and a control element which is arranged in the interior of the motor vehicle.

7. The system as claimed in claim 5, wherein, when the activation device (12) is touched by the user, the signal which is to be detected by the second capacitor (13) is amplified.

8. The system as claimed in claim 6, wherein, when the control element is touched by the user, the signal which is to be detected by the second capacitor (13) is amplified.