JPS6343405A - On-vehicle antenna system - Google Patents

Abstract

PURPOSE:To attain excellent radio communication even if vibration arises without marring the external appearence of a car body by using a conductor imbedded in a plate glass used as a cabin window of the car body as an antenna. CONSTITUTION:Two glass plates 11a, 11b are bonded by a glass bond part 12. A copper thin wire conductor 13 is imbedded in the glass bond part 12 as a loop. Both tips of the loop conductor 13 are connected electrically to electrodes 14a, 14b provided at lower end position of the bonded glass plates 11a, 11b via welded parts 15a,15b respectively. The welded parts 15a, 15b between the conductor 13 and the electrodes 14a, 14b are reinforced and protected by epoxy resins 16a, 16b and external leads 17 are led out of the electrodes 14a, 14b.

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to AVI (Aut) of toll roads, for example.

matic Vehicle Identific
The present invention relates to a vehicle antenna device that is used to exchange data with a roadside communication device when using a roadside communication device.

[Prior art] For example, when adopting the AVI method as a toll collection system for a reference road, a communication device is installed in the vehicle using the toll road, and wireless communication is performed with the on-road communication device installed at the toll gate etc. It is necessary to carry out the transaction and exchange the data necessary for toll collection. In this case, it is necessary to install an antenna for the in-vehicle device somewhere on the vehicle body, but generally, the antenna for the vehicle is installed as a bar-shaped conductor protruding from the roof or near the trunk of the vehicle body. Here, when an inductive radio method is used as a wireless communication method between the road device and the vehicle-mounted device, a loop antenna is used.

[Problems to be Solved by the Invention] However, the loop antenna described above is susceptible to electromagnetic effects on the steel plate of the vehicle body, and the antenna body must be mounted away from the vehicle body. For this reason, the protrusion of the antenna from the car body becomes large, which not only spoils the aesthetic appearance of the car body, but also makes it susceptible to vibration depending on the installation location.
There are drawbacks that prevent good wireless communication.

On the other hand, if a portable communication device is used as an in-vehicle device, there is no need to install a separate antenna, but the window must be opened and closed at the communication location with the on-road device, which detracts from the advantages of the AVI system.

The present invention has been made in view of the above-mentioned problems, and provides an antenna device for a vehicle that is capable of performing good wireless communication even when subjected to vibrations without impairing the aesthetic appearance of the vehicle body. The H objective is to provide the following.

[Means and effects for solving the problems] That is, the antenna device for a vehicle according to the present invention includes a plate glass used as a window for a passenger compartment of a vehicle, and a conductor embedded in the plate glass, and a conductor embedded in the plate glass. It is constructed so that its body can be used as an antenna.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

Figures 1 (A) and (B) respectively show the external configuration and cross-sectional configuration when the present invention is implemented as a loop antenna. These two glass plates 11a and 11b are bonded together by a glass joint 12. This glass joint 12
A conductor 13 made of a thin copper wire is buried in a loop shape, and the tip of the loop-shaped conductor 13 is as follows.
Bonded glass 11. It is electrically connected to electrodes 14a and 14b provided at the lower end positions of electrodes a and llb via welded portions 15a and 15b, respectively. This conductor 13 and electrode 14a,
The welded parts 15a and 15b with 14b are made of epoxy resin 16.
The electrode 14a is reinforced and protected by the electrodes a and 16b.

14b is led out by an external lead 17 and connected to an antenna terminal of an on-vehicle device (not shown).

In other words, the transmission signal from the on-vehicle device is received by the on-road device via the on-road device antenna due to the generation of magnetic force in the conductor 13, and the transmission signal from the on-road device is received by the above-mentioned conductor 13 due to the magnetic force generated in the on-road device antenna. is received by the on-vehicle device. In this case, in FIG. 1, the conductor 13 having a one-turn loop is used, but in reality, the number of turns is increased appropriately to adjust the output of the transmitted and received signals.

Figure 2 shows this antenna device installed on the rear glass of a vehicle.
This shows the case where it is shared with 21 anti-fog heaters.
The conductor 13 shown in FIG. 1 is embedded in the rear glass 21 as a three-turn loop heater antenna 22. In the figure, 23 is a canopy of a tollgate, and, for example, a roadside device antenna 24 is attached to this canopy 23. FIG. 3 shows an equivalent electric circuit of the heater/antenna 22. The on-vehicle unit 31 and the heater/antenna 22 are connected via a filter circuit 32, and only the transmitted and received signals can pass through by cutting the DC component. shall be. In addition, heater antenna 2
The heater power in 2 is supplied from the battery 33.

Therefore, by using a thin wire-shaped conductor buried in the vehicle interior glass as an on-vehicle antenna, there is no need to install a nantenna that protrudes outside the vehicle body, which not only does not spoil the aesthetic appearance but also reduces vibration etc. Good transmission and reception is possible with the on-road device without any adverse effects.

Further, since the conductor in this embodiment is completely buried in the glass plate joint, it is not affected by weather changes, moisture due to glass cleaning, friction, etc., and deterioration and damage of the conductor itself can be prevented.

In the above embodiment, the case where a conductor is buried as a loop antenna between a pair of glass plates has been described.
As shown in FIGS. (A) and (B), the conductor may be configured as a dipole antenna with a negative side of λ/4.

Here, the conductor in the above example was replaced with tin oxide (Sn
If the transparent conductor 43 is made of O2), the appearance 1- can be further improved.

[Effects of the Invention] As described above, according to the present invention, there is provided a glass plate used as a window for a passenger compartment of a vehicle, and a conductor embedded in the glass plate, and the conductor is configured to be used as an antenna. Therefore, it is possible to provide a vehicle antenna device that is capable of performing good wireless communication even when subjected to vibrations without impairing the aesthetic appearance of the vehicle body.

[Brief explanation of drawings]

FIGS. 1(A) and (B) are an external configuration diagram and a cross-sectional configuration diagram respectively showing a vehicle antenna device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the vehicle antenna device in FIG. Fig. 3 is a diagram showing an equivalent electrical circuit of the heater antenna in Fig. 2, Fig. 4 (A) and (B) are They are an external configuration diagram and a cross-sectional view t13 thereof, respectively, showing other embodiments of the present invention. 11a, llb...Glass plate, 12...Glass joint,
13-...Conductor, 14a, 14b=-Electrode, 15a. 15 b--Welded part, 16.16a, 16b--Epoxy resin, 17... External lead, 21... Rear glass, 22... Heater antenna, 31... Vehicle-mounted unit, 3
2... Filter circuit, 33... Battery, 43...
・Transparent conductor. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 2

Claims (1)

[Claims] 1. An antenna device for a vehicle, comprising a glass plate used as a window for a passenger compartment of a vehicle, and a conductor embedded in the glass plate, the conductor being used as an antenna.