JP2006166010A - Antenna structure for in-car communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna structure for in-car communication which can improve an excellent antenna performance and mounting of an antenna for communication. <P>SOLUTION: The antenna 10 in an antenna structure for in-car communication is provided in a car so as to enable communication between a car-mounted device placed in a car and a device brought by a car's occupant. The antenna 10 is provided on an undersurface of a car-mounted monitor 2 provided in an instrument panel 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle communication antenna structure that is provided in a vehicle so that a portable device and a vehicle-mounted device carried by a vehicle occupant in the vehicle perform processing wirelessly.

2. Description of the Related Art Conventionally, a technique in which a general communication antenna that performs communication processing wirelessly is provided around an in-vehicle monitor of a notebook personal computer (see Patent Documents 1 and 2).
Further, a technique is known in which an in-vehicle communication antenna provided in the vehicle is provided in the periphery of the in-vehicle monitor so that the portable device brought into the vehicle by the occupant and the in-vehicle device perform wireless communication processing (see Patent Document 3). ).
JP 2001-239894 A JP 2003-258520 A JP 2004-129138 A

However, in the inventions described in Patent Documents 1 and 2, there is a problem that an area where radio waves cannot be transmitted / received occurs.
Such a problem can be solved by increasing the number of communication antennas installed on large notebook PCs or installing a patch antenna made of a ceramic substrate on the side of the keyboard. Therefore, it is difficult to actually adopt the antenna due to problems such as antenna size, directivity, and cost, and there is a problem that the installation position of the communication antenna is greatly troublesome and limited in terms of communication characteristics and mounting layout.
On the other hand, in the invention described in Patent Document 3, there is a problem in that the mounting property of the communication antenna is poor and it takes time and effort when mounting.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an in-vehicle communication antenna structure capable of improving the good antenna performance and mountability of the communication antenna.

  According to the first aspect of the present invention, in the in-vehicle communication antenna structure in which an antenna unit is provided in the vehicle so as to enable communication between the in-vehicle device installed in the vehicle and the device brought in by the occupant, the antenna unit Is provided on the back side of the in-vehicle monitor provided on the instrument panel.

  According to the first aspect of the present invention, since the antenna portion is mounted on the side surface or the back surface of the in-vehicle monitor provided on the instrument panel, the good antenna performance and mountability of the communication antenna can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
FIG. 1 is an explanatory diagram of an in-vehicle communication antenna structure according to the first embodiment. FIG. 2 is an explanatory diagram of a vehicle interior using the in-vehicle communication antenna structure of the first embodiment. FIG. 3 is a top sectional view of the card slot portion. 4 is a side cross-sectional view of the card slot portion, FIG. 5 is an exploded view illustrating attachment of the vehicle-mounted monitor and the antenna portion, and FIG. 6 is a diagram illustrating mounting of the antenna portion on the rear surface of the vehicle-mounted monitor.

First, the overall configuration will be described.
As shown in FIGS. 1 and 2, the in-vehicle communication antenna structure according to the first embodiment of the present invention includes an instrument panel 1, an in-vehicle monitor 2, a card slot portion 3, a communication card 4, and a mobile phone 5 in the vehicle interior. ing.

A vehicle-mounted monitor 2 having an 8-inch liquid crystal screen is provided in a central portion between the driver seat and the passenger seat in the instrument panel 1 in the passenger compartment.
A plurality of switches 6 are disposed around the in-vehicle monitor 2, and a card slot portion 3 for inserting the communication card 4 is provided in a part thereof.
As shown in FIGS. 3 and 4, the card slot portion 3 includes an LCD board of an in-vehicle monitor 2, which will be described later, inside the lower surface of a metal U-shaped outer frame portion 7 a provided inside the instrument panel 1. An electrically connected substrate 7b is provided.
Further, an opening 7c for inserting the communication card 4 is formed on the front surface of the outer frame portion 7a, and the communication card 4 is held at a predetermined depth side from the opening 7c, and the communication card A connector portion 7d that is electrically connected to the tip of 4 is provided.
In addition, the opening 7c is provided with a dustproof cover 7e that is pivotable toward the back side with the upper side portion as an axis, and can prevent dust and the like from entering the card slot portion 3. It is like that.

  As shown in FIGS. 5 and 6, an LCD board 9 for controlling the display of liquid crystal is provided on the back side of the in-vehicle monitor 2, and is electrically connected to the LCD board 9 via a connector portion K1, In addition, an antenna unit 10 is provided that is fixed to the three pins P1 so as to be detachable in a stack manner.

The antenna unit 10 is electrically connected to a base substrate 13 on which an RF circuit 11 and a baseband circuit 12 necessary for so-called Bluetooth (registered trademark, hereinafter omitted) communication are mounted, and the base substrate 13 via a connector K2. In addition, it is a module composed of an antenna substrate 14 that is detachably fixed in a stack manner by three pins P2.
Note that the RF circuit 11 and the baseband circuit 12 do not necessarily have to be mounted on the base substrate 13, and when they are provided separately, they are connected by a coaxial cable or the like.

Further, the antenna substrate 14 of the first embodiment is a dielectric antenna and is provided in a state of projecting from the edge of the in-vehicle monitor 2 by an interval of λ / 4 (≈31.5 mm).
Here, the directivity of the antenna unit 10 is determined by the antenna radiating element, the current direction, and its distribution, and in order to realize omnidirectionality, a structure in which current is present in a plurality of directions by the radiating element is desirable.
Therefore, the electromagnetic influence from the in-vehicle monitor 2 is reduced by separating the distance between the antenna substrate 14 and the upper edge of the in-vehicle monitor 2 by λ / 4. A shield conductor may be provided instead of separating by λ / 4.
Moreover, a dielectric antenna is suitable as an antenna having a structure in which currents exist in a plurality of directions, and can perform good impedance matching.

  Further, the base substrate 13 is configured such that the radiating element is not exposed from the back surface of the ground, and when the volume of the radiating element and the grant side is compared, since the ground side is larger, the gain to the front of the radio wave radiation is increased. Can be improved.

Next, the operation will be described.
The Bluetooth communication is a communication method in a short range with a communication range of several tens of meters. In the first embodiment, the mobile phone 5 has a circuit and an antenna for performing Bluetooth communication built therein, and the in-vehicle device. And short-range wireless communication at a frequency of 2.4 GHz.
As a basic usage of the card slot portion 3 of the first embodiment, by inserting a card-type memory, for example, data sharing between a home or company and an in-vehicle device of a vehicle is enabled. . Data can also be exchanged by the user.
One way to use this card slot is to insert a card-type portable terminal as in the first embodiment and perform communication in the communication method with a portable device carried by an occupant.
As an advantage of using a card-type portable terminal, if the in-vehicle device has a function as a platform, various communication methods can be used by replacing the communication card 7 in the vehicle.
This is a technology corresponding to various types and functions, and is important for improving the usability of the in-vehicle device of the vehicle.

In the first embodiment, the communication between the occupant's portable device and the in-vehicle device is performed by Bluetooth communication. Since the occupant is present on the driver side and the passenger seat side, the occupant has a built-in Bluetooth function. In order to ensure stable communication between the mobile phone 5 and the vehicle-mounted device side, it must be positioned between the driver seat side and the passenger seat side of the instrument panel 12 located in front of the passenger in the vehicle, that is, in the center. Don't be.
However, for the same reason, the in-vehicle monitor 2 and the switch 6 are also concentrated on this part.

On the other hand, in Example 1, since it was provided on the back side of the in-vehicle monitor 2, specifically, the LCD substrate 9 of the in-vehicle monitor 2, the antenna unit 10 does not affect the layout of the instrument panel 1, and good communication is achieved. An antenna can be placed at a position.
Therefore, the design freedom of the instrument panel 1 is sufficiently secured.
Further, compared to the conventional invention, the antenna unit 10 can be easily mounted in a space-saving manner and can be easily attached and detached, so that it is possible to easily cope with variations in the substrate size and the monitor size.

Next, the effect will be described.
As described above, in the in-vehicle communication antenna structure of the first embodiment, the vehicle is provided with the antenna unit 10 to enable communication between the in-vehicle device installed in the vehicle and the device brought in by the passenger. In the in-vehicle communication antenna structure, since the antenna unit 10 is provided on the back side of the in-vehicle monitor 2 provided on the instrument panel 1, it is possible to improve the good antenna performance and mountability of the communication antenna.

  In addition, since the antenna unit 10 includes a module in which an RF circuit or a baseband circuit is integrally formed, space can be saved and extra costs such as a coaxial cable can be reduced.

  Further, since the antenna unit 10 is configured to be detachable from the in-vehicle monitor 2 with the pins P1 and P2, it is possible to easily cope with variations in the substrate size and the monitor size.

  In addition, since the antenna unit 10 uses a dielectric antenna, it has a structure in which currents exist in a plurality of directions, and can perform good impedance matching.

  Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.

For example, as another example of the dielectric antenna, a so-called meander line antenna 20 in which the antenna is configured in a meander shape (zigzag shape) on the back and front of the substrate as shown in FIGS. You may do it.
In this case, the matching of 50Ω required for Bluetooth communication is facilitated, so there is no need to provide a matching element around it, and a decrease in forward and upward gain due to secondary radiation of the substrate can be suppressed. The effect can be obtained.
Further, the antenna unit 10 may be provided on the side as long as it is the back surface of the in-vehicle monitor 2.

It is explanatory drawing of the antenna structure for in-vehicle communication of Example 1. FIG. It is explanatory drawing of the vehicle interior using the antenna structure for in-vehicle communication of Example 1. FIG. It is a top sectional view of a card slot part. It is side surface sectional drawing of a card slot part. It is an exploded view explaining attachment with a vehicle-mounted monitor and an antenna part. It is a back view of the vehicle-mounted monitor explaining mounting of an antenna part. It is a top view of the vehicle-mounted monitor explaining mounting of the antenna part of the other Example. It is a front view of the vehicle-mounted monitor explaining mounting of the antenna part of another Example.

Explanation of symbols

K1, K2 Connector part P1, P2 Pin 1 Instrument panel 2 In-vehicle monitor 3 Card slot part 4 Communication card 5 Mobile phone 6 Switch 7a Outer frame part 7b Substrate 7c Opening part 7d Connector part 7e Dustproof cover 9 LCD board 10 Antenna part 11 RF circuit 12 Baseband circuit 13 Base substrate 14 Antenna substrate 20 Meander line antenna

Claims (4)

In-vehicle communication antenna structure in which an antenna unit is provided in the vehicle so as to enable communication between the in-vehicle device installed in the vehicle and the device brought in by the occupant,
An antenna structure for in-vehicle communication, wherein the antenna portion is provided on the back side of an in-vehicle monitor provided on an instrument panel. In the vehicle communication antenna structure according to claim 1,
An antenna structure for in-vehicle communication, wherein the antenna unit includes a module integrally configured with an RF circuit or a baseband circuit. The antenna structure for in-vehicle communication according to claim 1 or 2,
An antenna structure for in-vehicle communication, wherein the antenna unit is configured to be detachable from an in-vehicle monitor. In the vehicle communication antenna structure according to any one of claims 1 to 3,
The antenna unit uses a dielectric antenna, and has an in-vehicle communication antenna structure.

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