JPH07122920A - Grounding structure of film antenna for vehicle - Google Patents

Abstract

PURPOSE:To perform antenna grounding by a simple operation by forming a pattern for grounding at a position capable of obtaining desired performance to the antenna pattern of a film surface or on a glass surface beforehand. CONSTITUTION:A film antenna 1 is constituted of antenna elements 3-5 as radiating patterns horizontally and vertically disposed on a plastic film 2 and a leader line 6 for connecting the antenna elements 3-5 to the core wire of a coaxial power feeder and is stuck to window glass 7 such as side glass and others. A terminal part 8 is provided on the end of the leader wire 6 as a power feeding point, the core wire of the coaxial power feeder is connected on the terminal part 8 and the outer conductor of the coaxial power feeder is connected through a grounding line to the grounding pattern 9. For the grounding pattern 9, for instance, a wire printed type antenna conductor for which conductive silver paste is printed and baked in a prescribed pattern on the window glass 7 is used and it is attached through ceramic paste 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a ground structure of a vehicle film antenna for FM / TV, for example.

[0002]

2. Description of the Related Art In recent years, a film antenna has been attracting attention as a vehicle antenna that can be attached to a window glass of an automobile later.

This film antenna is usually formed by forming an antenna element and a lead wire of the antenna element on a plastic film.

As the signal line of this film antenna,
Generally, a coaxial feed line is used, and an antenna ground is provided by connecting a core wire to a terminal portion at the end of a lead wire and an outer conductor to a vehicle body. A parallel feeder may be used instead of the coaxial feeder line.

[0005]

The grounding of the outer conductor is accomplished by forming a hole in the vehicle body at the other end of a grounding plate, which is a grounding means mounted by pressing one end of the outer conductor into pressure contact with a screw or the like. It is generally performed by mounting or by previously providing a dedicated screw fixing structure for grounding on the vehicle body side.

However, in the case of the above construction, not only the mounting work such as drilling is troublesome, but even when the holes are previously drilled on the vehicle body side, sufficient antenna performance can be exhibited from the viewpoint of vehicle design, that is, the antenna. There is a problem that it is not always possible to provide the ground at the best position where the desired performance can be obtained for the pattern.

The present invention has been made to solve the above problems, and an object thereof is to provide a grounding structure for a vehicle film antenna in which grounding can be set at the best position in terms of antenna performance by a simple mounting operation. is there.

[0008]

By the way, since only the radiation pattern is formed in the vehicle film antenna, if the grounding pattern is formed in advance or when the film antenna is attached, the antenna ground can be easily formed. You can see that you can get it.

The present application has been made in view of the above facts,
In order to solve the above problems, the ground structure for a vehicle film antenna according to claim 1 of the present invention is a vehicle film antenna in which an antenna pattern is arranged on a film and is stuck on a glass surface of the vehicle. The grounding pattern of the vehicle film antenna attached on the surface is previously formed on the glass surface.

According to a second aspect of the present invention, there is provided a ground structure for a film antenna for a vehicle, wherein the antenna pattern is arranged on the film and the film antenna for a vehicle is attached on the glass surface of the vehicle. It is characterized in that a pattern for grounding a film antenna for a vehicle, which is stuck on the film, is formed in advance on the film surface.

[0011]

In the ground structure for a vehicle film antenna according to the present invention, the grounding pattern is formed in advance on the glass surface or at a position where desired performance can be obtained with respect to the antenna pattern on the film surface. Therefore, the antenna ground can be grounded at the best position by a simple operation.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view in which the ground structure of a vehicle film antenna according to the present invention is applied to a vehicle window glass.

The film antenna 1 shown in FIG. 1 has antenna elements 3, 4, and 5 as radiation patterns arranged horizontally and vertically on the plastic film 2 as described above.
The antenna elements 3, 4, and 5 are composed of a lead wire 6 connecting to a core wire of a coaxial power feed line, and attached to a side window or other window glass 7 of a vehicle.

A terminal portion 8 serving as a feeding point is provided at the end of the lead wire 6, the core wire of the coaxial feeding wire is connected to the terminal portion 8, and the outer conductor of the coaxial feeding wire is grounded through a ground wire. It is connected to pattern 9.

The ground pattern 9 is, for example, a linear print type antenna conductor in which a conductive silver paste is printed on a window glass 7 in a predetermined pattern and baked, and a ceramic paste 10 is interposed as shown in FIG. To install.

A colored ceramic paste is used as the ceramic paste 10. The ceramic paste 10 is provided with a width of about 40 mm in the portion where the ground pattern 9 is provided. I am trying.

In this embodiment, the ground pattern 9 is formed in a reverse L shape in a front view having a pattern extending in the horizontal direction and the vertical direction, but it may be formed in an annular shape over the entire circumference of the window glass, for example.

The ground pattern 9 is formed on the vehicle body (not shown).
Is formed in parallel with a predetermined distance (about 10 mm) between the grounding pattern 9 and the vehicle body, and electrostatic capacitance is generated between the grounding pattern 9 and the vehicle body. I can do things.

The ground pattern 9 has a width of 10 to 30 mm in order to obtain a sufficient ground function. This also serves to increase the mechanical strength of the ground pattern 9 at the same time.

The length of the ground pattern 9 is 200 to 600 m
The installation space is set to about m so that the installation space is not used so much. However, as described above, it is possible to obtain a more sufficient grounding function by extending in the length direction and forming an annular shape over the entire circumference of the window glass.

The ground pattern 9 may be formed of a transparent conductive film in a predetermined pattern on the glass plate surface.

The connection of the outer conductor to the ground pattern 9 is carried out in advance, for example, as shown in FIG.
The terminal 11 is attached by soldering or the like at a desired position above, and when the film antenna 1 is attached, the terminal 11 is used as a ground point by soldering or the like, and as shown in FIG. 4 and FIG. Alternatively, the tape 12 may be directly attached to the ground pattern 9.

In FIGS. 4 and 5, reference numeral 13 denotes a core wire of the coaxial feeder 14, and 15 denotes an outer conductor of the coaxial feeder 14.

Further, the ground pattern 9 is made of a conductive ink in which carbon, silver, copper or the like is kneaded with an acrylic, epoxy or vinyl resin together with the antenna elements 3, 4, 5 when the film antenna 1 is formed. It is also possible to print on a predetermined shape and position by screen printing, dry it, and form it. Then, as shown in FIG. 6, the film antenna 1 may be attached at the same time as the ceramic paste 10 is attached. .

In actual mounting, in order to prevent rust and the like due to moisture or the like, for example, a window portion (not shown) in which a connector corresponding to the ground point or the terminal portion 8 is previously formed on the plastic film 2 is formed, This is done by connecting the terminal provided on the back surface of the connector to the terminal portion 8 exposed at the window and the grounding point with a conductive pressure-sensitive adhesive and pulling out the coaxial power supply line from this connector.

In FIGS. 2 and 6, the arrows a and b indicate the attaching directions of the film antenna, respectively.

Since the person skilled in the art can easily make various changes to the present invention without departing from the concept of the invention, the present invention is not limited by the scope of the claims.

[0028]

As described above, the ground structure for a vehicle film antenna according to the present invention has the following effects.

Since the antenna ground can be taken on the glass surface when mounting the film antenna, it is not necessary to make a hole in the vehicle body and fasten with a screw, and the antenna ground can be mounted even when the film antenna is mounted later. It can be taken easily.

Since the ground can be provided at the best position from the viewpoint of antenna performance such that it is difficult to pick up interference waves, it is possible to easily provide an antenna having excellent performance such as an improved SN ratio.

[Brief description of drawings]

FIG. 1 is a front view in which a ground structure for a vehicle film antenna according to the present invention is applied to a vehicle window glass.

FIG. 2 is a cross-sectional view of a ground printed on glass.

FIG. 3 is a cross-sectional view of a ground wire connecting portion when soldering is used.

FIG. 4 is a cross-sectional view of a ground wire connecting portion when a conductive adhesive tape is used.

FIG. 5 is a perspective view of a ground wire connecting portion when a conductive tape is used.

FIG. 6 is a sectional view when a ground is formed on the film.

[Explanation of symbols]

 1 film antenna 2 plastic film 3, 4, 5 antenna element 6 lead wire core wire 7 window glass 8 terminal portion 9 ground pattern 10 ceramic paste 11 terminal 12 conductive adhesive tape 13 core wire 14 coaxial power supply wire 15 outer conductor

Claims (2)

[Claims] 1. An antenna pattern is provided on a film,
A vehicle film antenna attached on a glass surface of a vehicle, wherein a grounding pattern is formed in advance on the glass surface. 2. A vehicle film antenna, wherein an antenna pattern is provided on a film and is attached to a glass surface of a vehicle, wherein a grounding pattern is previously formed on the film surface on which the film antenna is formed. The grounding structure of the film antenna for vehicles.