JPH0366843B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a glass antenna suitable for various information communication devices such as radio broadcast receivers, television broadcast receivers, car telephones, and personal radios installed in automobiles. .

``Prior art and its problems'' In addition to whip antennas, antennas for automobile radio receivers include glass antennas with printed wires printed and baked with silver paste as antenna elements on the window glass of automobiles, and thin metal wires. Glass antennas are known. However, in such a glass antenna, the printed wire or thin metal wire is opaque, so it obstructs the field of view and is not aesthetically pleasing.
In particular, this tendency becomes stronger as the antenna pattern of the printed wire of the glass antenna or the thin metal wire becomes more complex, or as the number of wires increases. Therefore, there have been cases where such glass antennas have been used in limited areas on the window glass of automobiles, or have had to be used with unsatisfactory performance.

In order to solve this problem, one
A glass antenna using a transparent conductive film as an antenna element has also been proposed. however,
With a planar glass antenna made of a single transparent conductive film, it has been difficult to obtain an antenna with excellent performance in a wide range of receiving frequency bands and to be compatible with various information communication devices.

“Object of the invention” The object of the invention is to
Another object of the present invention is to provide a glass antenna for automobiles that can provide excellent performance in a wide range of reception frequency bands and can also be used with various information communication devices.

"Structure of the Invention" The automotive glass antenna according to the present invention includes a plurality of transparent conductive films each having a different resistance value, film thickness, shape, and area, each of which is independently formed on a window glass of an automobile as an antenna element. It is characterized by the presence of

In this way, by independently forming multiple transparent conductive films that differ in at least one of resistance value, film thickness, shape, and area, antennas with different performances such as gain and directivity can be obtained, and the desired frequency band can be obtained. You can select and use antennas suitable for each, or you can use each antenna separately.
Furthermore, since a transparent conductive film is used, there is almost no obstruction to visibility. Furthermore, by forming a plurality of transparent conductive films on one window glass, the complexity of manufacturing can be reduced.

Embodiments of the Invention As shown in FIG. 5, the automobile 1 is provided with, for example, a front window glass 2a, a rear window glass 2b, a side window glass 2c, and a roof window glass 2d. The glass antenna of the present invention can be applied to any of these window glasses.

FIG. 1 shows an embodiment of a glass antenna according to the invention. This glass antenna is
The present invention is adapted to be applied to the rear window glass 2b of the automobile 1, and also to a diversity reception system. Two transparent conductive films 11a and 11b having different shapes are formed on the left and right sides of the rear window glass 2b. And transparent conductive films 11a, 11
b is provided with current collectors 12a and 12b.
Furthermore, the current collectors 12a and 12b are connected to the feeder wire 13.
a, 13b, and feeder wires 13a, 13
b is connected to a switching circuit 14, and the switching circuit 14 is connected to each communication device (not shown) via or without an amplifier 15. The switching circuit 14 selects the one with higher gain, the one with less noise, or the one with less distortion among the received signals obtained from the transparent conductive films 11a and 11b having different gains and directivity characteristics so as to perform diversity reception. This is an alternative choice.

FIG. 3 shows another embodiment of the glass antenna according to the invention. This glass antenna is applied to a front window glass 2a of an automobile 1. Two transparent conductive films 11a and 11b are formed on the left and right sides of the front window glass 2a. In this case, the transparent conductive films 11a and 11b are
Although the shape and area are said to be almost the same, the thickness and resistance value are different, which causes the antenna performance to be different. The transparent conductive films 11a, 11b are provided with current collectors 12a, 12b, and the current collectors 12a, 12b are connected to the feeder wire 13.
a, 13b. Also in this glass antenna, by selectively using two transparent conductive films 11a and 11b having different antenna performances, it is possible to make it applicable to various communication devices or various frequency ranges. Further, since the transparent conductive films 11a and 11b do not obstruct visibility, no problem occurs even when the front window glass 2a is used.

FIG. 4 shows yet another embodiment of the glass antenna according to the invention. This glass antenna is applied to a side window glass 2c of an automobile 1. The side window glass 2c has three transparent conductive films 11a, 11 having different shapes and areas.
b, 11c are formed. Each transparent conductive film 11
a, 11b, 11c have current collecting parts 12a, 12b,
12c is provided, and the current collecting parts 12a, 12b, 12
c is connected to feeder lines 13a, 13b, and 13c. In this glass antenna, three transparent conductive films 11a and 11 having different antenna performances are used.
By selecting and using b and 11c, it becomes possible to cover a wider frequency band or apply to more communication devices.

In addition, Figures 1 and 3 show two transparent conductive films with different antenna performance formed on the window glass of a car, and
Figure 4 shows an example in which three transparent conductive films with different antenna performances were similarly created, but it is also possible to form four or more independent transparent conductive films with different antenna performances on a single glass plate. .

In the glass antenna of the present invention, two transparent conductive films 1 having different shapes, resistance values, film thicknesses, areas, etc.
1a and 11b may be used as selective antennas of a diversity receiving antenna system, or the two transparent conductive films 11a,
For example, one of the transparent conductive films 11a and 11b can be used as an antenna for TV broadcasting, the other as an antenna for radio broadcasting, or one can be used as an antenna for AM radio broadcasting. and the other as FM
Use it as a radio broadcasting antenna or as one side.
Use the antenna for VHF TV broadcasting, and use the other side as a UHF antenna.
You can use them as antennas for TV broadcasts, or use one antenna as a TV broadcast antenna and the other as a car phone antenna, or use each as an antenna for other different frequencies.
It becomes possible to apply it to various communication devices or broadcasting in various frequency bands. Furthermore, since the transparent conductive films 11a and 11b do not obstruct visibility,
The shape and area can be freely set to obtain desired antenna performance.

In addition, in the above embodiment, the transparent conductive film 11
Examples of a and 11b include In ₂ O ₃ (containing Sn),
SnO ₂ (containing Sb or F), TiO ₂ /Ag/TiO ₂ ,
SnO ₂ /Ag/SnO ₂ , SnO ₂ /Au/SnO ₂ , SnO ₂ /
Various transparent conductive films made of Al/SnO ₂ , ZnS/Ag/ZnS, etc. can be used. These transparent conductive films may be formed in one layer or may be laminated in two or more layers. Further, in order to improve durability or improve optical characteristics, it may be laminated with a transparent dielectric film made of various materials. The transparent conductive film can be produced by vacuum evaporation method, sputtering method, CVD method, spray method,
It may be formed directly on the glass surface by an appropriate film forming method such as CLC method or printing method, or a transparent conductive film may be formed on the surface of a transparent plastic film by the same method as above, and this plastic film is then placed on the glass surface. It may be formed by laminating. This transparent conductive film can obtain a desired resistance value by adjusting the material and thickness. In addition, the front window glass 2a and the rear window glass 2 of the automobile 1
In b, there is a rule that the visible light transmittance is 70% or more, so the visible light transmittance of the transparent conductive film is preferably 70% or more.

In addition, in the above embodiment, the current collectors 12a, 1
2b is made of a material with higher conductivity than the transparent conductive films 11a and 11b, and is used to attach the feeder wires 13a and 13b via a solder layer, a conductive adhesive layer, or the like. The current collectors 12a and 12b are made of a conductive material such as conductive paste, conductive adhesive, copper foil, aluminum foil, or copper mesh wire.

"Effects of the Invention" As explained above, according to the present invention, a plurality of transparent conductive films having different at least one of resistance value, film thickness, shape, and area are independently formed on the window glass of an automobile. Therefore, by selecting each transparent conductive film and using it as an antenna, it becomes possible to cover a wide frequency band and apply it to various communication devices. Further, since the transparent conductive film does not obstruct visibility, it can be formed in any shape and area on any part of the window glass, thereby achieving desired performance. Furthermore, since a plurality of transparent conductive films are formed on a single window glass, the complexity of manufacturing is also reduced.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of a glass antenna for an automobile according to the present invention, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. FIG. 4 is a front view showing yet another embodiment of the glass antenna for an automobile according to the present invention, and FIG. 5 is a plan view showing an example of an automobile to which the present invention is applied.

Claims (1)

[Claims] 1. A glass antenna for an automobile, characterized in that a plurality of transparent conductive films each having a different resistance value, film thickness, shape, and area are independently formed as antenna elements on a window glass of an automobile.