JPH0349445Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field] The present invention relates to a glass antenna for automobiles, and particularly to a glass antenna for automobiles that exhibits good gain for radio waves belonging to the television radio wave frequency band.

[Prior art] Glass antennas for automobiles include those made by disposing a transparent conductive film on the bonded surface of laminated glass;
A linear antenna conductor made of thin metal wire is enclosed in an appropriate pattern on the bonding surface of laminated glass, or a conductive paste such as silver paste is printed in an appropriate pattern on the bonding surface of laminated glass or the surface of a single glass plate. It is also well known to have a linear antenna conductor made by baking.

Among these, automotive glass antennas that use linear antenna conductors are mainly applied to rear window glass from the perspective of securing forward visibility.
Furthermore, in this case, efforts have been made to develop antenna patterns for the purpose of receiving AM broadcast waves and FM broadcast waves having relatively long wavelengths.

[Problems to be solved by the invention] For this reason, at present, glass antennas for automobiles that have a linear antenna conductor are not suitable for radio waves that belong to the higher frequency bands of the VHF wave band among TV radio waves. The situation was such that sufficient consideration and ingenuity had not yet been attempted regarding the development of an antenna pattern that indicates sensitivity.

On the other hand, according to industry regulations (Automobile Manufacturers Association regulations), when attempting to provide the windshield with the function of an automobile glass antenna by arranging a linear antenna conductor, as shown in Figure 3, In order not to obstruct the driver's forward vision, the area 21 within 100 mm from the outermost edge 20 of the opening surface of the front window glass as the glass plate 1 attached to the window frame (within the range of a = 100mm), and width 65mm symmetrically to the vertical center line of the front window glass (b = 65mm in the figure)
A linear antenna conductor (the line width of the elements constituting the linear antenna conductor is 0.25 mm or less, and the number of such elements is 2 or less) is provided in the band-shaped portion 22 provided with is considered preferable. Furthermore, regarding the installation position of the feeding point with respect to the linear antenna conductor, it has been considered desirable to adopt a bottom feeding system from the viewpoint of securing the field of view. However, when trying to use the above-mentioned bottom feeding method while keeping the antenna pattern as before, it is not possible to secure good gain for radio waves above the higher frequency band in the VHF band, so it is necessary to improve it. In order to achieve this, it was necessary to use a top-feeding method in which the feeding point was placed on the upper side of the antenna conductor, which left a problem when trying to secure a favorable field of view.

[Purpose of the invention] The purpose of the invention is to provide a function as a glass antenna for an automobile by arranging a linear antenna conductor on one or both of the left and right side edges of the windshield. In this case, the above industry regulations must be met, and the product must have good sensitivity to radio waves in the VHF band, especially to radio waves in the higher frequency bands of the VHF band or higher (specifically, the frequency band of 170 MHz or higher). An object of the present invention is to provide a glass antenna for an automobile having the following features.

[Means for Solving the Problems] In order to achieve the above object, the present invention was constructed as follows.

That is, in the present invention, the left and/or right side edges of the glass plate surface have vertically straight parts, and the intermediate part has a bent part that protrudes toward the outer edge of the glass plate. The structure is characterized by the arrangement of a linear antenna conductor.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a typical pattern example of the automotive glass antenna according to the present invention. Peripheral 20 to 100
A linear antenna conductor 2 is disposed on the side edge portion located in the area portion 21 within mm. In addition to the illustrated example, this linear antenna conductor 2 is arranged on the right side edge (area portion 21) of the glass plate 1, or on the left and right side edges (each area portion 21). It may be something that has been set up.

When disposing the linear antenna conductor 2 on the glass plate 1, the front window glass is covered with a laminated interlayer film 14 made of polyvinyl butyral or the like as shown in FIG.
In the case of a laminated glass type in which the outer glass 12 and the inner glass 13 are joined via a
It is desirable to locate the bonding surface on either side of the outer glass plate 12 and the laminated interlayer film 14 or between the inner glass plate 13 and the laminated interlayer film 14, preferably on the bonding surface on the inner glass plate 13 side as in the illustrated example. When the front window glass is a safety glass type (not shown) made by bonding a single glass and a plastic film, a linear antenna conductor 2 is attached to the bonding surface of the single glass and the plastic film.
In addition, when the antenna is made of only reinforced single glass, it is preferable to arrange a fired printed wire type linear antenna conductor 2, which will be described later, on the inside surface of the vehicle.

The linear antenna conductor 2 of the present invention is made by applying a conductive paste made by mixing and suspending a conductive metal powder (for example, silver), a low-melting glass frit, a vehicle, and other desired components onto a glass plate in a predetermined pattern. In addition to the printed lines that are printed and fired, and further plated as necessary,
A wire formed using an appropriate conductive thin metal wire such as a Holman copper wire can be used. Regarding the wire diameter (line width) of the linear antenna conductor 2 in this case,
As mentioned above, so as not to obstruct the forward view.
It is preferable to set it to 0.25 mm or less, and when it is a conductive metal thin wire made of formal copper wire, etc.
It is preferable to use a wire with a diameter of 0.12 mm, and when it is a printed wire, a wire with a width of 0.2 mm.

Linear antenna conductor 2 formed in this way
has straight portions 3 and 4 on the upper and lower sides, and has a bent portion 5 in the middle thereof that is bent in a substantially U-shape toward the side edge of the glass plate 1 (towards the window frame when installed). It is formed by It is preferable that the substantially U-shaped bending direction of the bent portion 5 is in the direction of the side edge of the glass plate 1, that is, toward the vehicle body side of the automobile. Also, a of the bent portion 5
The optimal length is 70 to 250 mm, and the length of b is 40 to 100 mm. According to the illustrated example, the linear antenna conductor 2 is shown as having two wires of the same length arranged at equal intervals, but it may be composed of one wire, or three or more wires if necessary. You may also configure
Furthermore, their overall lengths may be different, and the intervals may also be gradually increased or decreased. Regarding the arrangement of the linear antenna conductors 2 in this case, it is desirable to arrange at least two wire antenna conductors, since there is a tendency that as the number of wire antenna conductors increases, the frequency band in which high gain can be obtained becomes wider. , when considering the relationship between the distance between the linear antenna conductors 2 and the gain,
It is desirable to set it appropriately within the range of 100 mm to 300 mm, preferably 150 mm to 250 mm. Furthermore, the linear antenna conductor 2 is composed of two long and short wires, both of which are
As a VHF antenna, or for the long one as a VHF antenna, for the short one
It may also be used as a UHF antenna. Further, the tip of the linear antenna conductor 2 may be bent laterally at the upper side of the glass plate 1, if necessary. The overall length of the linear antenna conductor 2 varies depending on the required specifications of the antenna, the shape of the windshield, the shape of the vehicle body to which it is mounted, and other various conditions. However, in general, VHF
Radio waves that belong to a higher frequency band than waves,
(λ/4) α of the wavelength of the intermediate frequency of the desired band
It is preferable to set it to ±(λ/20) α (α: wavelength shortening rate of the front window glass), for example, VHF/UHF
270~360mm for dual use, 400~500mm for VHF reception, 190~ for UHF reception
It can be said that 250 mm is a practical length.

On the other hand, the bent portion 5 forming the linear antenna conductor 2
In this case, the linear portion 6 formed substantially parallel to the linear portions 3 and 4 is located at the outermost edge 20 ( It is preferable to provide it in a region 21 within 30 mm from (see FIG. 3). The protruding position of the bent portion 5 in the linear antenna conductor 2 varies depending on the shape of the vehicle body, the mounting angle of the glass plate 1 that is the front window glass, and the overall length of the linear antenna conductor 2 itself. Although it cannot be determined unconditionally, in general, the straight portion 4 located on the lower side
It is desirable to form it between 350mm and 450mm from the bottom edge of Note that the bent portion 5 of the linear antenna conductor 2 should always be bent toward the outer edge even when the linear antenna conductor 2 is disposed on either the left or right edge of the glass plate 1. It is formed by

Regarding power feeding to the linear antenna conductor 2 arranged on the surface of the glass plate 1 in this way, when the glass plate 1 is laminated glass as shown in FIG. 1 or 2, the lower side of the glass plate 1 It is preferable to use a bottom feeding system in which the feeding point 7 is arranged on an exposed surface 9 exposed through a cutout edge 8 provided in the section, but if necessary, a side feeding system or a top feeding system may be used. A power feeding method can also be used. Regarding the connection relationship between the linear antenna conductor 2 and the feeding point 7 in this case, each end of the linear antenna conductor 2 is concentrated and connected to one feeding point 7 as shown in the illustrated example, and this feeding point In addition to connecting the lead wire 10 having the power feeding connector 11 through the point 7, the lead wires are individually taken out from each linear antenna conductor 2 and these lead wires are connected to the lead wire all at once. It may be something like this.

In the automobile glass antenna of the present invention, a 1
One or two antenna wires may also be provided. The feeding point of the antenna wire in the center may be located at a separate location from the feeding point of the linear antenna conductor 2 provided on the left and/or right side edges of the glass plate, but it is better to provide it nearby because the structure is better. It is preferable.

[Function] Since the automobile glass antenna according to the present invention is constructed in this way, the linear antenna conductor 2 arranged on one surface of the glass plate serving as the front window glass
In this case, the bent part 5 interposed between the upper straight part 3 and the lower straight part 4 has a phase adjustment function,
In the lower frequency band of the VHF band (for example, 170MHz or less), the upper and lower straight parts 3 and 4 are bent parts 5.
The entire antenna functions as an antenna without being separated into upper and lower parts, and good reception can be obtained in this frequency band.However, in higher frequency bands of the VHF band (for example, 170MHz or higher), the upper straight part 3 and the lower part The upper straight part 4 is separated, and the upper straight part 3 is separated.
It is thought that it mainly functions as an antenna in the higher frequency band of the VHF band, and that the voltage obtained on the upper side and some voltage obtained on the lower side are superimposed to obtain good gain. In this way, it is possible to exhibit good antenna performance for both lower and higher frequency bands of the VHF band, as well as for UHF.

The position adjustment function by the above-mentioned bending part 5, that is,
The short-circuiting function of the stub is such that the protruding direction of the approximately U-shaped portion of the bent portion 5 is directed toward the side edge of the glass plate 1;
That is, by placing the glass plate 1 on the side of the window frame (vehicle body) of the automobile into which it is fitted, it is strongly exerted. Furthermore, the linear antenna conductor 2 is arranged within the region 21 shown in FIG. The glass can function as a glass antenna for automobiles without obstructing the forward field of view.

[Effects of the invention] As described above, according to the invention, the glass plate surface constituting the front window glass has a bent portion approximately in the middle of the side edges that do not obstruct visibility. Since the linear antenna conductor is installed, it is able to meet various industry regulations based on the perspective of securing the field of view, while also protecting against TV radio waves, especially radio waves that belong to the higher frequency bands of the VHF band or higher in TV radio waves. A glass antenna for automobiles having good antenna gain can be provided.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a pattern of a linear antenna conductor in a glass antenna for an automobile according to the present invention, FIG. 2 is an enlarged vertical cross-sectional view of the main part of FIG. 1,
FIG. 3 is an explanatory diagram showing a preferred arrangement position of the linear antenna conductor on the windshield. 1... Glass plate, 2... Linear antenna conductor,
3, 4... Straight part, 5... Bent part, 6... Linear part, 7... Power feeding point, 8... Notch edge, 9... Exposed surface, 10... Lead wire, 11... For power feeding Connector, 12...Outer glass, 13...Inner glass,
14... Laminated interlayer film, 20... Outermost edge, 21...
...area part, 22...band-shaped part.

Claims (1)

[Scope of utility model registration request] A linear antenna conductor having vertically straight parts on the left and/or right side edges of the glass plate surface, and a bent part protruding toward the outer edge of the glass plate in the middle part. An automotive glass antenna characterized by being provided with.