DE112006003856T5 - Safety system for a vehicle with a passive key fob and a presence detection system with a key fob reader - Google Patents

Abstract

Security system for a vehicle, comprising:
a key fob reader capable of receiving a key fob and having a key fob interrogator that receives from the fob a signal indicating a code and compares the received code with an expected code to authorize the operation of the vehicle, when a key fob is inserted into the key fob reader,
a key fob which houses a magnetic element and contains both a recognition code and a transmitter, and
a sensor for detecting the presence of the magnetic element on a key fob, the sensor activating the key fob reader which interrogates the fob when a magnetic element is detected.

Description

GENERAL PRIOR ART

modern Vehicles are equipped with key fobs, which allow access to the vehicle electronically. Such a kind of key chain is a so-called passive key chain, at which is merely an electronic element. Of the Key Chain will in a reader plugged. The reader look for the key chain a recognition code, and if it finds a matching code, it can for example via an ignition switch the operation of the vehicle too.

in the The prior art activates the insertion of another device as a key fob in a keychain reader the circuit and leads to interrogate the device in the reader. It is a mechanical switch and a contact mechanism has been used. These mechanical switches and contact mechanisms often fail after prolonged use. Of Further need the cumulative tolerances of all the different mechanical Components considered and closely monitored be to ensure the switch contact when a key chain in the reader is plugged becomes.

The required mechanical switches are special for each individual system been made, resulting in undesirable Costs leads. About that In addition, the required mechanical switches are relatively large and require space, what the possible Installation sites for the reader limits.

BRIEF SUMMARY OF THE INVENTION

at a disclosed embodiment This invention is the presence of a key fob in a keychain reader on electronic Determined ways. In this way, those in the prior art required mechanical switch eliminated. Furthermore, will be It also eliminates read errors that occur when instead of a key fob other item has been inserted. In a disclosed embodiment This invention is the key chain with equipped with a magnetic element. The magnetic element is from a Sensor, such as a reed switch or a Hall sensor, detected in the key fob reader. This sensor can be relatively small, and the elimination of the mechanical contact leads that the sensor compared to the prior art, a relative has a long life. Furthermore, the sensor wears out barely or not at all, and the detection and accuracy are changing during the life of the product hardly or not at all.

These and other features of the present invention will be best understood from the description below and from the drawings, which are briefly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic representation of a first embodiment.

2 is a schematic representation of a second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED Embodiment

In 1 is a first embodiment 20 with a key fob reader 22 pictured, which is a key chain 24 receives. A circuit board 26 As you know, it contains the electronics that make up the key fob 24 queries and a transmitter 27 operated, which transmits a code from the circuit board 26 should be read. If this code is the one from the circuit board 26 and corresponding control expected, the key fob is authorized. In this case, then an ignition switch 32 be pressed, with which the ignition of the car is triggered.

The present invention improves on the prior art by adding a magnet 30 to a key chain 24 , The presence of the magnet 30 is from a sensor 28 detected. At the sensor 28 it can be a reed switch or a barrier that detects the presence of the magnet 30 can capture. In the prior art, there was a magnetic contact when the key fob 24 was inserted. The present invention enables a in 1 shown in the dashed line detection area, the reduction of the space required for the key fob reader 22 makes possible.

Furthermore The removal of mechanical switches brings the above Advantages.

The key fob reader 22 and the key chain 24 are shown greatly enlarged compared to the vehicle. However, this is only for the clarity of the presentation.

2 shows a second embodiment 120 , In the second embodiment 120 will the key Chain 124 as in the first embodiment of a reader 122 with a circuit board 126 added. The sensor 128 is located here, however, and may be the presence of a matching key fob 124 as soon as it is in the vehicle.

It Although preferred embodiments of this Invention has been disclosed for One skilled in the art is likely to However, be aware that certain modifications in the scope of protection of this invention. For this reason, the subsequent claims should be checked if the actual Scope and content of this invention is to be determined.

Summary

One passive key fob reader, the one Pick up a keychain can and the operation of a vehicle is equipped with an activation system, which has a sensor, such as a reed switch or a Hall barrier, which can detect the presence of a magnet on the key fob. The key fob will preferably provided with a magnet, so that when he is in the Keyring reader plugged is activated, the sensor and ensures that the sensor Control operated, which queries the key fob and determines if it has a matching identification number. at a second embodiment the sensor is removed from the key fob reader.

Claims (14)

Security system for a vehicle, the following includes: a keychain reader that has a Pick up a keychain can and has a control for interrogating the key fob, the of the Key chain Signal is received, that indicates a code, and the received code with an expected one Code compares to the actuation to authorize the vehicle if a key fob is plugged into the key fob reader becomes, a key chain that a magnetic element receives and both a recognition code and contains a transmitter, and a sensor for detecting the presence of the magnetic element on a key chain, being the sensor activates the key fob reader, that asks the key fob, when a magnetic element is detected. A security system according to claim 1, wherein a circuit board recorded in the key fob reader which contains the control. Safety system according to claim 2, wherein the sensor belongs to the circuit board in the key fob reader. Safety system according to claim 2, wherein the sensor belongs to the key fob reader. Safety system according to claim 1, wherein the sensor removed from the key fob reader lies. A security system according to claim 1, wherein it is the sensor is a reed switch. A security system according to claim 1, wherein it is the sensor is a Hall sensor. Method for operating a security system for a A vehicle comprising: Providing a key fob reader that pick up a keychain can and has a controller, the controller interrogating the key fob, from the key chain Receiving signal, indicating a code and the received code with an expected code compares to the actuation to authorize the vehicle if a key fob is plugged into the key fob reader will provide a key fob that has a magnetic element and contains a recognition code, and To capture the presence of a magnetic element on a key fob and Activating the key fob reader, the interrogating the key fob, when a magnetic element is detected. The method of claim 8, wherein a printed circuit board recorded in the key fob reader which contains the control. The method of claim 8, wherein the sensor to belongs to the circuit board in the key fob reader. The method of claim 8, wherein the sensor to heard the key fob reader. The method of claim 8, wherein the sensor of away from the key fob reader. The method of claim 8, wherein a reed switch detects the magnetic element. The method of claim 8, wherein a Hall sensor detects the magnetic element.