DE9004042U1 - Receiver for a vehicle for remote control of the central locking system - Google Patents

Description

Ol Siemens Aktiengesellschaft TW *·· · " " GR 90 G 1199 DE

Receiver for a vehicle for remotely operating the central locking system

The invention relates to the receiving device specified in the preamble of the main claim for a motor vehicle for remotely controlling the central locking system using coded signals emitted by a transmitter or remotely effective key, e.g. by means of

IR-Qiier ultrasound signals, whose e*?de sslt help of a &ogr;&uacgr;&&idigr;

several special codes, which can be emitted , for example, by a transmitter or remote-operating key, are initially initialized and then re-initialized in order to determine the codes authorized to operate the device .

Such receivers are known in a wide variety of designs. There are even a large number of designs in which a complicated, electronically controlled analogue is used between the receiver and the transmitter for (re-)initialization. takes place.

One danger with such a receiver is the possibility that unauthorized persons can listen in on the special codes or record them electronically/magnetically in order to later use the now authorized code to apparently legitimately operate the central locking system, or to later secretly re-initialize the receiver and thus prepare for the theft of the vehicle or a break-in into the vehicle.

The object of the invention,

- to make it as impossible as possible for unauthorized persons to listen in during (re-)initialization in order to prevent unauthorized (re-)initialization of vehicles and/or

- to prevent unauthorized persons, such as thieves, from using the legitimately intercepted special code to apparently can legitimately enter the vehicle by unauthorized operation of the central locking system, e.g. to rob the vehicle or to steal the vehicle,

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WJ.1U UUiUM uxc j. in naufj iai ia;j J. uuii aiiycycurucii naui in iinci &igr;

Ol In the invention, the receiving device has at least two reception sensitivities. The first of these is intended for the current operations. The second of these is intended for the initialization or re-initialization, whereby the first sensitivity is higher than the second. This makes it very difficult for unauthorized persons to listen in during (re-)initialization; so that unauthorized access to the vehicle is made more difficult.

An unauthorized listener has particularly little chance if the % second sensitivity is so small that the receiving device, e.g. '{ the IR receiving diode input stage, of the receiving device to

The transmitting device must be less than 1 meter away from the transmission during (re-)irritation. The listener would then have to behave very conspicuously if he wanted to listen in.

f An unauthorized listener has particularly little chance if : the second sensitivity is so small that the receiving device

can only be (re-)initialized by a transmitter that is held inside the vehicle close to the receiver. If \ then in addition the authorized person closes the vehicle doors during (re-)initialization while holding the receiver inside (r^-)-

initialized, the protection against eavesdropping and thus against unauthorized operation of the central locking system is particularly high. 25

GI 199DE . ., ... ,.

Reference symbols/terms lists'

1 motor vehicle

2 Transmitter

3 Infrared transmission path

4 Receiver

El low sensitivity

E2 higher sensitivity

O Receiving diode

Claims (3)

Ol Protection claims '..'"..' ' ' ' """GR 90 G 1199 DE 1. Receiver for a motor vehicle for remotely controlling the central locking system using coded signals emitted by a transmitter or remote-operating key, e.g. using IR or ultrasonic signals, the code of which is initially initialized or occasionally reinitialized using one or more special codes that can be emitted by the transmitter or remote-operating key, for example, in order to determine the codes authorized for operation, characterized in that - the receiving device has at least two reception sensitivities, * the first of which is intended for the current activities, and * of which the second is intended for initialization or re-initialization, and - the first sensitivity is higher than the second. 2. Receiving device according to claim 1, characterized in that - the second sensitivity is so small that the receiving device, e.g. the IR receiving diode input stage, of the receiving device must be less than 1 meter away from the transmitting device during (re-)initialization. 3. Receiving device according to claim 2, characterized in that - the second sensitivity is so small that the receiving device can only be (re-)initialized by a transmitting device that is held close to the receiving device inside the vehicle.