JPH03204201A - On-vehicle glass antenna - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency and the reception sensitivity by connecting an antenna wire to a conductor film around a slit formed on the conductive film applied to a window glass. CONSTITUTION:A slit 14 is formed on a conductive film 12 at the horizontal middle part of a window glass 2. The slit 14 is formed between the uppermost resistor wire 13c and that just below extended in the direction of the width of the body. Moreover, signal wires 15a and 15b of a coaxial cable 15 are connected to the conductive film 12 with the slit 14 inbetween in the middle of the slit 14 and the coaxial cable 15 is connected to a receiver 16 such as a radio tuner mounted in the vehicle. Thus, the adverse effect from the metal- made car body is avoided and the performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a glass antenna for a vehicle in which the antenna is constructed by effectively utilizing a conductive film coated with a windshield.

(Prior Art) Vehicles are generally equipped with a receiver for AM or FM broadcasts. Recently, in addition to these, various radio devices have been installed, such as television receivers, transmitters/receivers for navigation systems, and transmitters/receivers for citizen bands.

For this reason, vehicles are equipped with wireless antennas,
Since the vehicle body is generally a metal capacitor, a ball antenna is most preferred and is widely used.

On the other hand, since ball antennas are protrusions, antenna wires are printed on the windshield.

Incidentally, recently, from the viewpoint of reducing ultraviolet rays, etc., it has become common to apply a conductive film to almost the entire surface of the window glass. For the window glass coated with this conductive film,
In order to provide an antenna wire without impairing antenna interoperability, it has been proposed to form a conductive film separated from the window frame of the windshield, that is, to insulate the conductive film from the metal car body. There is (Jitko Sho 63-49932
(see publication).

(Problems to be Solved by the Invention) As mentioned above, there is a limit to the ability to improve antenna performance, that is, transmission efficiency and reception sensitivity, by printing antenna wires on the windshield. Measures will be required.

Therefore, an object of the present invention is to provide a glass antenna for a vehicle that has better performance when the antenna is configured on a windshield.

(Structure of the Invention) In order to achieve the above object, the present invention basically has the following structure. That is, in a vehicle in which a conductive film is applied to almost the entire surface of the windshield, a snot is formed in the conductive film applied to the windshield, and an antenna signal line is connected to the conductive film around the slit. The configuration is as follows.

(Operations and Effects of the Invention) As described above, a slot antenna is constructed using a conductive film and a slit formed in the conductive film, and the performance of this slot antenna increases as the conductive film becomes infinitely large. Due to the improved performance, there is no negative influence from the metal car body, and the performance is excellent.In particular, the current sensing type slot antenna can be used as a voltage sensing type by extending the slit horizontally. It is compatible with pole antennas.

Windshields, especially rear windshields, are often coated with anti-fog hot wires. In this case, slits are formed between the hot wires to form a complementary antenna and improve antenna performance. The above is more preferable.

Of course, since the slot antenna is non-directional, it is suitable for use in vehicles that are moved in various directions.

(Embodiment) In FIG. 1, an antenna according to the present invention is constructed on a rear window glass 2 of the windshield provided on a vehicle body 1, and its details are shown in FIG.

The Noah window glass 2 is fixed to the body l via a metal frame 10. As shown in FIG. 3, the window glass 2 has a three-layer sandwich structure in which a conductive film 12 is sandwiched between an outer glass lla and an inner glass llb. This conductive film 12 reflects heat rays such as sunlight and has conductivity. In the embodiment, the conductive film 12 is formed over the entire surface of the window glass 2 except for the slit portion, which will be described later.

The inner surface of the windshield 2, that is, the side surface of the interior glass Ilb, is heated to prevent fogging. ! (Resistance wire) 13 is printed. The hot wire I3 connects a pair of bus berths 13a and 13b that extend vertically at the left and right end positions of the windshield and is connected to a power supply line, and extends in the vehicle width direction by connecting the pair of bus berths 13a and 13b. It has an extending resistance wire 13c.

A slit J4 is formed in the conductive film 12 at a position between the left and right sides of the window glass 2. This slit 14 extends in the vehicle width direction, and the resistance line 13c
It is formed between the uppermost one and the one directly below it. Further, each signal fiber 15a or 15b of the coaxial cable 15 is connected to the conductive film 12 at the left and right intermediate portions of the slit 14, with the slit 14 in between. This coaxial cable 15
is connected to a receiver 16 such as a radio tuner mounted on the vehicle. Of course, a transmitter may be connected instead of this receiver 16. In this way, the slot antenna SA is installed using the conductive film 12 and the slit 14.
is configured.

Here, when the frame 11 is fixed to the body l via a sealing material, the conductive film 12 is attached to the body l through the sealing material.
Although the conductive film 12 may be insulated in any way, the conductive film 12 may be connected (conducted) to a metal member having a large surface area in the body l. Roof panel 2 with a particularly large area
1. Fender 22) The trunk lid 23 and the like are often made of metal, so by making the conductive film 12 conductive to such members, ultimately almost the entire surface of the body l can be covered with the conductive film 12. can be made conductive. By doing so, an effect similar to that of increasing the area of the conductive film 12 is produced, so that the slot antenna SA can be made more ideal.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a vehicle showing an embodiment of the present invention. FIG. 2 is a plan view showing details of the rear window glass portion. FIG. 3 is a sectional view taken along the line X3-X3 in FIG. 2. A 2 3 4 5 6 :Slot antenna :Body :Rear window glass : Conductive film : Anti-fog hot wire :slit twin coaxial cable :Receiver Figure 1 Third figure

Claims (3)

[Claims] (1) In a vehicle in which a conductive film is applied to almost the entire surface of the windshield, a slit is formed in the conductive film applied to the windshield, and an antenna signal line is connected to the conductive film around the slit. A vehicle glass antenna characterized by: (2) According to claim 1, the conductive film is electrically connected to a member that is made of metal and has a large area among the members constituting the body of the vehicle. (3) Either claim 1 or 2
In Item 1, the window glass is provided with anti-fogging hot wires, and the slit is formed between the hot wires.