JPH11139213A - Communication device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve performing of communication by electromagnetic coupling. SOLUTION: An antenna coil 4a of a communication device for a vehicle is resin molded (its mold unit is shown by a code 18) in rectangular annular shape, and this antenna coil 4a is mounted in a side surface (surface in door window side of a driver's seat) of a head rest 17. This antenna coil 4a is formed so as to be connected to a main unit part of the vehicle communication device 1 through a connecting connector 4b. The head rest 17 is coated with a cover 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle communication device having an antenna coil for receiving a signal transmitted from outside or inside a vehicle by a portable transmitter.

[0002]

A vehicle communication device of this type has the following structure. That is, the main part of the vehicle communication device that communicates with the portable transmitter is provided behind the instrument panel of the vehicle,
The antenna coil is provided in a key cylinder or a door portion. On the other hand, a portable transmitter includes a transponder, and for example, there is a portable transmitter which is built in a key grip.

[0003] A vehicle communication device transmits a power signal (magnetic field signal) from an antenna coil, and a portable transmitter of a key receives a transmission signal from the vehicle communication device through its transponder by electromagnetic coupling. Operating power is generated in response to the reception, and an ID code signal is transmitted to the vehicle communication device. In the vehicle communication device, the ID code is compared with an ID code set in advance on the vehicle side, and if they match, door lock or door unlock, or engine start control is performed.

When a communication device for a vehicle and a portable transmitter such as a key perform communication by electromagnetic coupling, the presence of a metal object on the antenna coil side of the communication device for a vehicle adversely affects the electromagnetic coupling. I will come out. However, in the related art, as described above, since the antenna coil of the vehicle communication device is provided in the key cylinder or the door portion, the above-described influence may be concerned.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle communication device in which communication by electromagnetic coupling is favorably performed.

[0006]

According to a first aspect of the present invention, there is provided an antenna coil for receiving a signal transmitted from outside or inside a vehicle by a portable transmitter. It is characterized in that it is provided in a headrest of a driver seat provided in a vehicle.

In a vehicle, the headrest of the seat is
There are few metal parts and most are made of resin. In the above configuration, since the headrest is provided with the antenna coil of the vehicle communication device, it is less affected by communication by electromagnetic coupling, and good communication can be expected.

[0008] The invention of claim 2 is characterized in that the antenna coil is provided from the side surface to the front surface of the headrest. In this configuration, since the antenna coil is disposed from the side surface to the front surface of the headrest, the signal transmitted from the antenna coil propagates from the side surface of the headrest to the outside of the vehicle, and also from the front surface of the headrest toward the instrument panel. Also propagates to Therefore, for example, when the occupant carrying the portable transmitter is outside the vehicle, the portable transmitter can satisfactorily receive the signal transmitted from the antenna coil. Even if you are in the office, you can communicate well.

The invention according to claim 3 is characterized in that the antenna coil is disposed from the side surface of the headrest to the front surface and further to the lower surface. In this configuration,
Since the antenna coil is provided from the side surface to the front surface of the headrest and also provided from the lower surface, the communication performance when the occupant carrying the portable transmitter is in the vehicle is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, the vehicle communication device 1 will be described with reference to FIG. The vehicle communication device 1 includes a control circuit 2 mainly composed of a microcomputer, a power amplifier 3, a resonance circuit unit 4, a detection circuit 5, and an amplifier 6, and the resonance circuit unit 4 includes an antenna coil 4a and a resonance capacitor 4b. Consisting of A control program is stored in the control circuit 2, and the control circuit 2 turns on and off the power amplifier 3 based on the control program, thereby transmitting a power signal (magnetic field signal) having a frequency of, for example, about 125 kHz from the antenna coil 4a. Send. Further, a door lock mechanism 7 is connected to the control circuit 2.

Referring to FIG. 3, the transponder 8 will be described. The transponder 8 includes a transponder resonance circuit unit 9 having an electromagnetic coupling coil 9a and a resonance capacitor 9b, a power supply circuit 10, and a detection circuit 1.
1. a control circuit 12 mainly composed of a microcomputer;
For example, a nonvolatile memory 13 composed of an EEPROM, a CR
The oscillator circuit 14 and the modulation circuit 15 are provided.

When a power signal is applied to the transponder 8 from the antenna coil 4a of the vehicular communication device 1, the power signal is received by the transponder resonance circuit unit 9. This power signal is rectified and sufficiently smoothed by the power supply circuit 10 and is made constant voltage, and the constant voltage power supply is supplied to each circuit. When the constant voltage power supply is supplied, the ID code is read from the nonvolatile memory 13 and transmitted to the vehicle communication device 1. Vehicle communication device 1
When the ID code is transmitted from the transponder 8,
It is determined whether or not the ID code matches a preset ID code in the vehicle communication device 1. If the ID code matches, a door lock command or a door unlock command is output to the door lock mechanism 7. I have.

Now, in the vehicle communication device 1, at least the main part 1a except for the antenna coil 4a is removed.
The antenna coil 4a is provided on a headrest 17 of a driver's seat (not shown) of the vehicle 16 as shown in FIG. Is provided. The headrest 17 is made of a relatively flexible synthetic resin material. The antenna coil 4a is resin-molded in a rectangular ring shape (the molded body is indicated by reference numeral 18), and the side surface of the headrest 17 (the surface of the driver's seat on the door window side) is provided in advance with the antenna coil 4a. A groove 17a having a shape corresponding to the rectangular shape is formed.

The molded body 18 of the antenna coil 4a
Are fitted into and bonded to the groove 17a. In addition,
The antenna coil 4a is provided with a connector 4b, and is connected to the main body 1a of the vehicle communication device 1 via the connector 4b. A cover 19 is attached to the headrest 17. On the other hand, the transponder 8 is built in the key grip 20a of the key 20, as shown in FIG. 2, and therefore, the key 20 also serves as a portable transmitter. The key cylinder (not shown) of the vehicle 16 includes:
A key remind switch (not shown) is provided, and is turned on when the key 20 is inserted.

In the above configuration, when the key 20 is not inserted into the key cylinder (this is detected by the key remind switch), the vehicle communication device 1 outputs a transmission signal. The transmission signal is output from the antenna coil 4 a on the side surface of the headrest 17 to the outside of the vehicle 16. For example, when the occupant carrying the key 20 gets off the vehicle 16 and the key 20 enters the transmission range from the antenna coil 4a of the headrest 17, the transponder 8 of the key 20 outside the vehicle 16 receives this transmission signal. Then, the ID code is returned as described above. In this case, the antenna coil 4 of the vehicle communication device 1
a, there is no metal member near the antenna coil 4.
The communication performance between a and the transponder 8 is improved. Further, since the transmission signal is directed to the outside of the vehicle from the side of the headrest 17, the communication performance is also improved.
Then, the control circuit 2 of the vehicle communication device 1 checks the ID codes, and when they match, when the occupant carrying the key 20 moves away (detected by a change in communication strength), the control circuit 2 issues a door lock command to the door lock mechanism 7. And the door is locked, and when the occupant carrying the key 20 is approaching, the door is unlocked.

In this embodiment, since the headrest 17 is provided with the antenna coil 4a of the vehicle transmitter 1, the influence of metallic objects on communication by electromagnetic coupling is reduced, and good communication is achieved. Can be expected. In particular, since the antenna coil 4a is provided on the side surface of the headrest 17, the transmission signal from the vehicle communication device 1 is directed to the outside of the vehicle from the side surface of the headrest 17, and the portable transmitter (key 20) from outside the vehicle Good communication with the

FIG. 4 shows a second embodiment of the present invention. In this embodiment, the mounting configuration of the antenna coil 4a is different from that of the first embodiment. That is, the antenna coil 4a is mounted on a bracket 21 made of synthetic resin,
This bracket 21 is attached to the headrest 17. The upper surface of the bracket 21 is substantially U-shaped, and a bobbin 21b is formed at an intermediate plate portion 21a.
a is wound and mounted. Locking projections 21e are formed at the inner ends of the plate portions 21c and 21d on both sides of the bracket 21, respectively. The plate portions 21c and 21d on both sides of the bracket 21 are elastically deformed so as to be expanded, and are fitted to the headrest 17 from the lateral direction in this state, whereby the locking projection 21e is engaged with the headrest 17 by an elastic restoring force. Then, the antenna coil 4a is attached to the headrest 17. After that, the cover 19 is attached to the headrest 17. In this embodiment, the headrest 17 of the antenna coil 4a is
The antenna coil 4a can be easily attached to the existing headrest 17 while being easily attached to the headrest 17.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, the mounting configuration of the antenna coil 4a is different from that of the first embodiment. A plurality of pins 18a are formed integrally with the molded body 18 of the antenna coil 4a, and a hole (not shown) for fitting the pins 18a is formed in the headrest 17, and the pins 18a are formed in the holes.
a is inserted and fitted. Also in this embodiment, the mounting of the antenna coil 4a to the headrest 17 is simplified, and the antenna coil 4a is connected to the existing headrest 17.
Can be easily retrofitted to

FIGS. 6 and 7 show a fourth embodiment of the present invention. This embodiment differs from the first embodiment in the following points. The antenna coil 4a is molded in a flat plate shape using a flexible synthetic resin (the molded body is indicated by reference numeral 31).
The antenna coil 4a is disposed from the side surface to the front surface of the headrest 17 from the side surface to the front surface of the headrest 17, for example. Further, in addition to the door lock mechanism 7, an engine start ECU 32 is connected to the control circuit 2 on the vehicle side.

In this embodiment, in addition to performing door lock and door unlock control, engine start control is performed. That is, the vehicle communication device 1 always transmits a transmission signal. In this case, the transmission signal is
In particular, it has directivity from the side of the antenna 4a to the outside of the vehicle, and has directivity from the front of the antenna 4a to the instrument panel.

For example, when the occupant carrying the key 20 is outside the vehicle, when the transponder 8 of the key 20 receives the transmission signal, the transponder 8 returns an ID code and returns the ID code to the vehicle communication device 1.
Then, the ID codes are collated, and if they match, the door lock mechanism 7 is subjected to door lock control or door unlock control. When the occupant carrying the key 20 gets into the driver's seat, the transponder 8 of the key 20 receives this transmission signal. In this case, the antenna coil 4a is
7, the transmission signal has directivity and the communication performance is good as described above.

When the transponder 8 receives the transmission signal, it returns an ID code as described above. The vehicle communication device 1 determines whether or not this ID code matches the set ID code.
Is established under the condition that the key is inserted into the key cylinder (this insertion is detected by the key remind switch), and when the key 20 is turned, the engine is started.

In this embodiment, since the antenna coil 4a is provided from the side to the front of the headrest 17, the transmission signal from the vehicle communication device 1 is directed from the side of the headrest 17 to the outside of the vehicle, and A situation in which the vehicle is directed from the front to the instrument panel, and the key 20 is outside the vehicle (a situation in which an occupant carrying the key 20 is outside the vehicle).
Communication with the driver and the key 20
Good communication is performed in a certain situation (a situation where the occupant carrying the key 20 is in the driver's seat in the vehicle or a situation where the occupant is inserted into the key cylinder).

FIG. 8 shows a fifth embodiment of the present invention. This embodiment is different from the fourth embodiment in the following points. That is, the mold body 31 is
The antenna coil 4a is disposed from the side surface of the headrest 17 to the front surface or the lower surface, for example, by bonding from the side surface to the front surface or the lower surface of the headrest 7.

In this embodiment, the vehicle communication device 1
From the side of the headrest 17 to the outside of the vehicle, and from the front of the headrest 17 to the direction of the instrument panel, and further to the direction slightly below the instrument panel. Further, the communication performance in a situation where the key 20 is present on the driver's seat side (a situation where the occupant carrying the key 20 is in the driver's seat in the vehicle or a situation where the key 20 is inserted into the key cylinder) is further improved. Become. That is, even when the occupant is in the breast pocket or the pants pocket, the key 20 can be satisfactorily communicated.

In each of the above embodiments, the door lock is automatically set,
Although the smart entry for unlocking the door has been described, it may be used for keyless entry for unlocking the door and unlocking the door by operating a button after collating the ID code.

Also, a so-called ID tag is used as a portable transmitter, and ID code collation is performed by communication between the ID tag and the vehicle communication device. If the ID codes match, an operation member on the vehicle side is operated to start the engine. (Immobilizer function)
May be performed. Further, the present invention can be applied to an electronic steering lock function in which a lock operation and a release operation of the steering lock are controlled by a key built in the transponder or an ID tag.

In particular, as for the immobilizer function and the electronic steering lock function, for example, a switch for detecting an occupant may be provided in the seat, and the ID code may be collated when the switch is turned on. In addition, the control target includes a smart entry function, a keyless entry function, an immobilizer function, an electronic steering lock function, and the like as described above, and these may be controlled in an appropriate combination (for example, a smart entry function, It may be a combination of the immobilizer function and the electronic steering lock function).

[0029]

As apparent from the above description, the present invention has the following effects. According to the first aspect of the present invention, since the headrest is provided with the antenna coil, it is less affected by communication by electromagnetic coupling, and good communication can be expected.

According to the second aspect of the present invention, since the antenna coil is disposed from the side surface to the front surface of the headrest, a signal transmitted from the antenna coil propagates well from the side surface of the headrest to the outside of the vehicle. Therefore, the vehicle propagates well from the front of the headrest toward the instrument panel, so that when the occupant carrying the portable transmitter is outside the vehicle, or when the occupant carrying the portable transmitter is inside the vehicle, Even if there is, it can communicate well. According to the third aspect of the present invention, since the antenna coil is disposed from the side surface to the front surface or the lower surface of the headrest, the communication performance when the occupant carrying the portable transmitter is in the vehicle is further improved. I do.

[Brief description of the drawings]

FIG. 1 is a perspective view of a headrest portion showing a first embodiment of the present invention.

FIG. 2 is a schematic plan view of a vehicle and a key.

FIG. 3 is a diagram showing an electrical configuration.

FIG. 4 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 5 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;

FIG. 6 is a view corresponding to FIG. 1, showing a fourth embodiment of the present invention;

FIG. 7 is a diagram corresponding to FIG. 1;

FIG. 8 is a view corresponding to FIG. 1, showing a fifth embodiment of the present invention.

[Explanation of symbols]

1 is a vehicle communication device, 4a is an antenna coil, 2 is a control circuit, 7 is a door lock mechanism, 8 is a transponder, 12
Is a control circuit, 16 is a vehicle, 17 is a headrest, 18 is a molded body, 18a pin portion, 19 is a cover, 20 is a key (portable transmitter), 21 is a bracket, 21e is a locking projection, 31 is a molded body, Reference numeral 32 denotes an engine start ECU.

Claims (3)

[Claims] An antenna coil for receiving a signal transmitted from outside or inside a vehicle by a portable transmitter, the antenna coil being provided in a headrest of a driver seat provided in the vehicle. A communication device for a vehicle. 2. The vehicle communication device according to claim 1, wherein the antenna coil is disposed from a side surface to a front surface of the headrest. 3. The communication device for a vehicle according to claim 1, wherein the antenna coil is disposed from a side surface of the headrest to a front surface and further to a lower surface.