DE102007002167A1 - Information sending method for e.g. car, involves sending information using window defogger of motor vehicle, where defogger is utilized as antenna, and information is sent in form of electromagnetic field having frequency - Google Patents

Abstract

The method involves sending information using a window defogger (2) of a motor vehicle (5) e.g. car, where the defogger is utilized as an antenna. The information is sent in the form of an electromagnetic field having a frequency ranging from 18 kilo hertz (kHz) to 300 kHz. The information is received and processed from an identity sensor (3) for a keyless entry system of the motor vehicle by the electromagnetic field. An alternating current is fed into a heating wire of the defogger, where the information is sent by modulation of the current. Independent claims are also included for the following: (1) a device for sending information in form of an electromagnetic field for a motor vehicle (2) a keyless entry system for a motor vehicle.

Description

The The present invention relates to a method for emitting a Information in the form of an electromagnetic field for a motor vehicle and a correspondingly configured device and a corresponding Keyless entry system.

To The prior art are appropriately designed LF antennas (Low frequency, i.e. 18 to 300 kHz) used in a motor vehicle, for a sufficiently strong LF field z. B. for the communication of a Keyless entry ID transmitters (remote key) with a keyless entry system in the Allow motor vehicle. For certain Areas of the motor vehicle, in particular a rear area of the Motor vehicle, are doing usually additional Antennas installed in the motor vehicle sufficient to these areas strongly illuminate, d. H. there a sufficiently strong electromagnetic Field to generate. For the rear of the vehicle used antennas are doing usually designed in the form of ferrite antennas, but can also be designed with a conductor loop design being between a loop antenna or loop antenna, in which both ends of a cable are routed to a control unit, or a bulk antenna with a single-sided ground connection.

Therefore is disadvantageous in the prior art due to the additionally required LF antenna for illuminating certain areas of the motor vehicle with a sufficiently strong LF field a corresponding space needed in the vehicle.

It is therefore the object of the present invention, all areas of the motor vehicle with a sufficiently strong LF field and illuminate in addition to the state of the art the space required for this purpose to reduce.

According to the invention this Task by a method according to claim 1, a device according to Claim 9 and a keyless entry system according to claim 14 solved. The dependent claims define preferred and advantageous embodiments of the invention.

in the Within the scope of the present invention is a method for emitting information in the form of an electromagnetic field for a motor vehicle provided, this information by means of a disk heater of the motor vehicle is emitted, the disk heater here is used as an antenna.

By doing the window heating of the motor vehicle is used as an antenna, will not be additional Space in the motor vehicle for an antenna is needed, as in the prior art, for example, for the rear area of the motor vehicle usual is. Therefore, according to the invention less Space for illuminating certain areas, in particular the rear area, needed with a sufficiently strong electromagnetic field.

there in particular, the electromagnetic field is constructed in such a way that it has a frequency of 18 kHz to 300 kHz, ie in the LF frequency band lies. This LF frequency band is used in particular for keyless entry systems used to address an ID transmitter, which z. B. subsequently, after he was approached, his ID or identity to the keyless entry system sent in the vehicle.

The Information emitted in the form of an electromagnetic field can be advantageously received and processed by the ID transmitter.

Around to generate the electromagnetic field by means of the disk heater, In particular, an alternating current in a heating wire of the disc heater passed, with the information modulated on this alternating current or the alternating current is modulated with this information.

there the information can only be sent when the window heating not used for heating.

If the window heating is not used for heating, it is ensured that the alternating current with which the information is sent out can not be disturbed by an electric current, which is used for heating purposes passed through the heating wire of the disc heater.

For example Is it possible, that the information is sent only when an ignition of the Motor vehicle is not activated.

If the ignition of the motor vehicle is not activated, no electric power for heating purposes passed through the heating wire of the window heating as this is usually only the case when the ignition of the Motor vehicle is activated. Therefore, with a disabled ignition the alternating current with which the information is sent can not be disturbed by a heating current of the disc heater.

According to a preferred embodiment of the present invention, the disk heater is a rear window heater, ie a window heater with which a rear window of the motor vehicle is heated. At this Embodiment then an alternating current is passed through the heating wire of the rear window heating, so that by means of the rear window heating a sufficiently strong electromagnetic field is built up in a rear area of the motor vehicle, so that z. For example, an ID transmitter located in the rear area of the keyless entry system of the motor vehicle can receive and process the information via this electromagnetic field.

Thereby is it possible according to the invention that for example, also from the rear of the motor vehicle approaching ID encoders are addressed and recognized by the keyless entry system can, so that z. B. the vehicle unlocked by this ID transmitter can be.

The Electromagnetic field built up by the rear window heater can also cover an area of a rear parcel shelf of the motor vehicle. The parcel shelf is that area in the interior of the motor vehicle, which adjoins the rear window in the interior of the motor vehicle and u. a. for storing hats can be used. Does the vehicle headrests for rear seats, then the area of the parcel shelf inside is limited by these headrests.

By doing the electromagnetic field of the rear window heating also the area the hat rack is covered, receives Also, an ID transmitter, which is placed on the parcel shelf, advantageously this electromagnetic field.

in the The scope of the present invention also provides a device for the Emitting information in the form of an electromagnetic field for a Motor vehicle provided. In this case, the device comprises a Transmitting device and a window heating of the motor vehicle. The Device is designed such that the information by means of the window heating is sent out, with the window heating acts as an antenna and the information in the form of the electromagnetic Field sends out.

The Advantages of this device according to the invention were already in advance in the discussion of the method according to the invention why they are not repeated here.

Furthermore is in the context of the present invention, a keyless entry system for a motor vehicle provided, which an ID transmitter and a device according to the invention to send the information in the form of the electromagnetic field includes.

There the keyless entry system according to the invention the window heating of the motor vehicle used as an antenna is the window heating of the motor vehicle not only to free the corresponding disc of haze and ice, but also to radiate an electromagnetic field used. As the glass heater is then part of the motor vehicle, if the motor vehicle does not include a keyless entry system, keyless entry system according to the invention requires no Space for its LF antenna, whereas a keyless entry system is up to date the technology just for the rear of the motor vehicle built only for use in keyless entry system LF antenna which only for emitting an electromagnetic Field is used in the LF frequency band. Therefore, that requires keyless entry system according to the invention compared to a conventional one Keyless entry system advantageously a smaller space, fewer components and can therefore be more compact and less expensive getting produced.

The The present invention is preferably suitable for use in keyless entry systems to provide a Send information in the LF frequency band to an ID transmitter. Of course it is however, the present invention is not limited to this preferred application limited, but can also be used to provide information in others frequency bands to any receiver to send. In this regard, could For example, the present invention can be used to provide a Traffic information from a motor vehicle to a befindlichem in his vicinity Vehicle to transmit.

The The present invention will be explained in more detail below with reference to FIGS attached Drawing explained with reference to a preferred embodiment.

there the only FIGURE represents a motor vehicle, which comprises a keyless entry system according to the invention.

In the single figure is a motor vehicle 5 illustrated, which has a keyless entry system that a transmitting device 1 and an ID transmitter 3 includes. The ID transmitter 3 is located in the rear of the vehicle 5 , The rear region of a motor vehicle is understood to be a region which covers an area in the direction of travel of the motor vehicle behind the motor vehicle or laterally behind the motor vehicle. The sending device 1 is so with a heated rear window 2 (or better with a heating wire of the rear window heater 2 ) conducts a sinusoidal current at a frequency of, for example, 125 kHz across the heating wire. This stream is from the sending device 1 modulated in such a way that thereby over the disk heating 2 an infor mation, which corresponds to the modulation is sent. This is the rear window heating 2 used by the keyless entry system as LF antenna.

As the rear window heating 2 in the rear window of the motor vehicle 5 is lit, one of the rear window heating 2 generated electromagnetic field, preferably the rear of the motor vehicle 5 out. Therefore, the ID transmitter receives 3 located in the rear area of the motor vehicle 5 located by the rear window heater 2 radiated information. After the ID transmitter 3 Having received and processed this information, he can, for example, in turn, an information to the motor vehicle 5 send out, with which the ID transmitter 3 identified. The keyless entry system of the motor vehicle receives this information and checks the identity sent with this information and, when a legitimate identity has been transmitted, performs a corresponding action, e.g. B. an unlocking of the motor vehicle 5 out.

To prevent the actual function of the rear window heating 2 namely, a heating of the rear window 7 of the motor vehicle 5 , with the function of rear window heating 2 interfering with the antenna is the transmitting device 1 over a line 6 with an ignition 4 of the motor vehicle 5 connected. About this line 6 becomes the transmitting device 1 communicated whether the ignition 4 active or not active. The transmitting device is now designed such that it the rear window heating 2 only then via a relay (not shown) controls when the ignition 4 is not active. This ensures that the electromagnetic LF field from the rear window heater 2 only when the ignition is switched off 4 is built so that there is no collision between the two functions of the rear window heating, ie the heating of the rear window 7 and radiating the electromagnetic LF field.

Since it is the main task of the keyless entry system, the motor vehicle 5 to unlock if the keyless entry system has a legitimate ID provider 3 recorded, and the motor vehicle 5 to lock if no authorized ID transmitter 3 is detected more, both when unlocking and when locking the ignition 4 is disabled, the limitation that poses the electromagnetic field from the rear window heater 2 is constructed only with deactivated ignition, according to the invention is not a practically relevant limitation.

A particular advantage of the illustrated embodiment over the prior art is that for the keyless entry system no additional LF antenna for the rear of the motor vehicle 5 is required, whereby no space for this additional LF antenna is needed. This advantageously reduces the piece and production costs for a keyless entry system.

1

transmitting device

2

rear window defroster

3

ID transmitter

4

ignition

5

motor vehicle

6

management

7

rear window

Claims (17)

Method for emitting information in the form of an electromagnetic field for a motor vehicle ( 5 ), characterized in that the information by means of a window heating ( 2 ) of the motor vehicle ( 5 ) is transmitted as an antenna. Method according to claim 1, characterized in that that the electromagnetic field has a frequency of 18 kHz to 300 kHz. A method according to claim 1 or 2, characterized in that the information from an ID transmitter ( 3 ) for a keyless entry system ( 1 - 3 ) of the motor vehicle ( 5 ) is received and processed by means of the electromagnetic field. Method according to one of the preceding claims, characterized in that in a heating wire of the window heating ( 2 ) an alternating current is passed, whereby the information is sent by a corresponding modulation of this current. Method according to one of the preceding claims, characterized in that the information is sent only when the window heating ( 2 ) is not used for heating. Method according to one of the preceding claims, characterized in that the information is sent only when an ignition ( 4 ) of the motor vehicle ( 5 ) is not activated. Method according to one of the preceding claims, characterized in that the window heating a rear window heating ( 2 ), and that the electromagnetic field in a rear portion of the motor vehicle ( 5 ), so that an ID transmitter located in the rear area ( 3 ) for a keyless entry system ( 1 - 3 ) of the motor vehicle ( 5 ) can receive and process the information by means of the electromagnetic field. A method according to claim 7, characterized in that the electromagnetic field is also radiated into an interior of the motor vehicle, so that the ID transmitter ( 3 ), which is located in an area of a parcel shelf, which is fitted to a rear window ( 7 ) of the motor vehicle is located, can receive and process the information by means of the electromagnetic field. Device for emitting information in the form of an electromagnetic field for a motor vehicle ( 5 ), characterized in that the device comprises a transmitting device ( 1 ) and a window heating ( 2 ) of the motor vehicle ( 5 ) and that the device ( 1 . 2 ) is configured such that the information about the window heating ( 2 ) is emitted as an antenna in the form of the electromagnetic field. Apparatus according to claim 9, characterized in that the transmitting device ( 1 ) is configured such that the electromagnetic field has a frequency of 18 kHz to 300 kHz. Apparatus according to claim 9 or 10, characterized in that the transmitting device ( 2 ) is configured such that the transmitting device ( 1 ) in a heating wire of the window heating ( 2 ) conducts an alternating current, and that the transmitting device ( 1 ) modulates the current so that thereby the information is sent. Device according to one of claims 9-11, characterized in that the window heating a rear window heating ( 2 ) of the motor vehicle ( 5 ). Device according to one of claims 9-12, characterized in that the transmitting device ( 1 ) is configured such that the transmitting device ( 1 ) a signal ( 6 ) can be supplied that the transmitting device ( 1 ) by this signal ( 6 ) detects whether an ignition ( 4 ) of the motor vehicle ( 5 ), and that the transmitting device ( 1 ) only sends the information when the ignition ( 4 ) is not activated. Keyless entry system for a motor vehicle ( 5 ), characterized in that the keyless entry system is an ID transmitter ( 3 ) and a device ( 1 . 2 ) according to any one of claims 9-13. Keyless entry system according to claim 14, characterized in that the ID transmitter ( 3 ) is configured such that the information from the ID transmitter ( 3 ) is received and processed by means of the electromagnetic field. Keyless entry system according to claim 14 or 15, characterized in that the window heating a rear window heating ( 2 ) is that the keyless entry system ( 1 - 3 ) is configured such that the transmitting device ( 1 ) the electromagnetic field in a rear area of the motor vehicle ( 5 ), so that the ID transmitter located in the rear area ( 3 ) can receive and process the information by means of the electromagnetic field. Keyless entry system according to claim 16, characterized in that the transmitting device ( 1 ) emits the electromagnetic field in an interior of the motor vehicle, so that the ID transmitter ( 3 ), which is located in an area of a parcel shelf, which is fitted to a rear window ( 7 ) of the motor vehicle is located, can receive and process the information by means of the electromagnetic field.