JPH07221525A - Glass antenna for automobile - Google Patents

Abstract

PURPOSE:To attain reception of a broadcast wave up to an FM radio broadcast and a TV UHF band broadcast by providing a 2nd antenna in capacitive coupling with at least part of a 1st antenna to an upper layer of a colored opaque band of a circumferential ridge of an automobile. CONSTITUTION:A 1st antenna 3. whose horizontal length is 1100mm and whose vertical length is 110mm and a 1st antenna 3. whose vertical length is 260mm are screen-printed on a rear window glass pane l for an automobile toward a cabin side by using a conductive paste. After the paste is dried, a 2nd antenna 51 and a 2nd antenna 52 horizontal length is 100mm and whose vertical length is 500mm are screen-printed with feeding points 61, 62 and defrosting heater wires 2,...2 by using a conductive paste. Since the glass antenna formed in this way forms an antenna structured to be vertically 2-layers, the space is effectively utilized. The reception gain with respect to an FM radio broadcast and a TV UHF band broadcast is improved without decreasing the reception gain of the 2nd antenna in comparison with the 2nd antenna only of the upper layer by adding the 1st antenna to the lower layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna provided on a rear window glass or a front window glass of an automobile, and more particularly to a glass antenna suitable for receiving FM radio broadcast waves and TV broadcast waves.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a glass antenna for a vehicle for receiving TV broadcast waves other than radio broadcast waves such as AM and FM, and a vertical antenna is provided on the front window glass. What is provided (JP-A-61-2370)
No. 2), etc., but it is not practically used because it may obstruct the driver's field of view. Even if it is provided, the area occupied by the antenna must be small, and it is difficult to obtain sufficient reception gain. Is.

In practice, a glass antenna provided on a rear window glass together with a heating wire for anti-fog occupies the mainstream, and various proposals such as JP-A-61-1121603 and JP-A-2-218202 have been proposed. However, since the plurality of heating filaments occupy most of the area of the rear window glass, the area occupied by the antenna becomes small and it is difficult to obtain a sufficient reception gain.

[0004] Therefore, a device which effectively utilizes the space by providing an antenna on the upper and lower two layers through an insulating layer is disclosed in Japanese Utility Model Publication No. Sho 52-.
No. 147151 and Japanese Patent Laid-Open No. 3-145203 have been proposed, but in both cases, the upper and lower antennas are arranged so as not to be in parallel with each other so that the upper and lower antennas do not interfere with each other. The front surface of the inner glass plate and the back surface of the inner glass plate (the mating surface side)
For example, when it is provided above and below via the insulating glass sheet, it is necessary to cut out the glass sheet to the feeding point on the inside glass sheet surface in order to pull it out from the antenna on the inside glass sheet back surface. In the case where the upper and lower antennas are provided on the surface, it is necessary to newly provide the insulating layers at the intersecting positions, and it is inevitable that the number of processes increases and the cost becomes high.

The present invention has been made in view of the above circumstances, and positively interferes by arranging the two-layer structure antennas so that at least some of them are close to each other and parallel to each other. In addition, it is an object of the present invention to provide a glass antenna in which an insulating layer for insulating the upper and lower antennas also serves as a black colored opaque layer commonly called a black frame.

[0006]

The present invention has at least horizontal stripes, vertical stripes, or horizontal and vertical stripes within the lower layer of the colored opaque band formed on the peripheral portion of the window glass for automobiles. A first antenna is provided, and a second antenna that capacitively couples with at least a part of the first antenna is provided in an upper layer of the colored opaque band. All of the antennas are provided in the lower layer of the colored opaque band, or a part of the antenna is provided so as to protrude from the colored opaque band, and the feeding points of the first antenna and the second antenna are made common or separate. In this case, it is preferable that the feeding points of the first antenna and the second antenna are separated from each other horizontally or vertically.

Whether the antenna of the present invention is used for diversity reception, or the plurality of antennas of the present invention are provided for diversity reception, respectively.
It is more preferable to provide a plurality of antennas of the present invention and add another antenna for diversity reception.

[0008]

In the conventional two-layer structure antenna, it is considered that it is better not to interfere with each other because the reception gain is lowered when capacitively coupled. This is for capacitively coupling to improve the reception gain. Further, if it is close to the glass edge, the reception gain is lowered due to the influence of the body (metal) of the automobile. Therefore, generally, it is separated from the glass edge by, for example, about 50 mm. In the present invention, the electrostatic capacitance formed by the upper and lower antennas is formed between the filament of the antenna and the metal body even if the colored opaque layers are provided in the upper and lower layers of the glass peripheral portion in the present invention. Since it is much larger than the electrostatic capacitance, it can be ignored, and the reception gain is hardly reduced. Compared with the case of only the upper layer antenna, the FM radio broadcasting wave to the TV broadcasting wave are wider. It can be received with high gain over a frequency range.

In this case, the distance between the upper and lower antennas forming the electrostatic capacitance is determined by the thickness of the colored opaque layer (generally 10 μm).
.About.20 .mu.m) or more and 10 mm or less, preferably 5 mm or less, and when the length of the filaments in which the antennas of the upper and lower two layers are close and parallel to each other, the reception gain is improved for radio waves of low frequency Since the frequency of the radio wave to be improved becomes higher as it becomes shorter, when improving the reception gain for FM radio broadcast waves, improve the reception gain for radio waves in the TV broadcast wave UHF band with a frequency of 500 mm or more and higher. In case of making it 50m or more, 300m
It is better to set it in the range of m.

When the first antenna and the second antenna are separately provided at the feeding point, if they are provided in the vicinity, not only the reception gain but also the directional characteristics become similar. Therefore, it is better to make the directional characteristics different.

Since the colored opaque layer also serves as the insulating layer, it is possible to effectively use the blank portion without newly providing an insulating layer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 1 to 5 are all front views in which the glass antenna of the present invention is provided on a rear window glass for an automobile.
Shows Example 1 and Example 2, FIG. 2 shows Example 3, FIG. 3 shows Example 4, FIG. 4 shows Example 5 and Example 6, and FIG. 5 shows Example 7.

First Embodiment, Second Embodiment As shown in FIG. 1, a case where two antennas of the first embodiment and the second embodiment having a common feeding point are provided will be illustrated.

First of all, the first antenna 3 ₁ in the first embodiment having a horizontal length of 1100 mm and a vertical length of 110 mm is provided inside the plate glass 1 constituting the rear window glass for an automobile.
(Indicated by a dotted line) and the first antenna 3 ₂ (indicated by a dotted line) in Example 2 having a vertical length of 260 mm are screen-printed with a conductive paste and dried, and thereafter, the outline thereof is indicated by a dotted line in the peripheral portion of the window glass. The wide black colored opaque layer 4 shown is screen-printed with a ceramic paste except for the power feeding portion and dried, and then the anti-fogging heating wire 2,
2, ..., 2 is a well-known antenna as the second antenna 5 ₁ in the first embodiment, and an antenna having a vertical length of 500 mm and a horizontal length of 100 mm is the second antenna in the second embodiment. 5 ₂ is screen printed with a conductive paste together with the feeding points 6 ₁ and 6 ₂ .

Next, when this plate glass is bent in a heating furnace, it is fired at the same time. When the glass antenna for a vehicle thus obtained is mounted as a rear window glass for an automobile, the size of each part is A ₁ = 1200 mm, A
_{2 = 1370mm, B = 850mm,} a 1 = a 2 = 50
0 mm, b = 800 mm, c = 480 mm, d = 110
mm, e = 20 mm, f = 30 mm, and the distance between the first antenna and the second antenna forming the capacitive coupling is substantially planarly overlapped. The length of Example 1 is 1000 mm,
According to the second embodiment having 260 mm, 76 MHz
FM radio broadcast wave of up to 90 MHz, TV broadcast wave of 1 to 3 channels VHF band low channel (hereinafter referred to as TV
Broadcast wave VHF-L band, TV broadcast wave VHF band high channel (hereinafter, T) in channels 4 to 12
V broadcast wave VHF-H band) 470 MHz to 7
The reception gain in the UHF band of the 70 MHz TV broadcast wave is measured independently, and the gain difference (hereinafter referred to as the dipole ratio) when the reception gain of the standard dipole antenna is 0 dB is shown in FIG. The antennas have average values of -17.8 dB, -17.1 dB, and -23.3d, respectively.
B, -19.1 dB, and the respective reception gains in the case where there is no first antenna indicated by the dotted line are -19.9 d in average value.
B, -17.5 dB, -23.5 dB, -18.9 dB
Therefore, TV broadcast wave VHF-H band, TV broadcast wave UH
Equal in the F band and higher in other bands, especially FM
It can be seen that the reception gain for radio broadcast waves has improved.

The antenna of the _second embodiment, in which the first antenna is 3 ₂ , the second antenna is 5 ₂ and the feeding point is 6 ₂ , the FM radio broadcast wave, TV broadcast wave VHF-L band, T
When the reception gains of the V broadcast wave VHF-H band and the TV broadcast wave UHF band are individually measured and shown by the dipole ratio, the average values are -222.4 dB, -19.2 dB, and -1 respectively.
It becomes 8.8 dB and -18.2 dB, and the respective reception gains in the case where there is no first antenna indicated by the dotted line are -2 on average.
7.2 dB, -19.9 dB, -18.4 dB, -1
Since it is 9.2 dB, it is equivalent in the TV broadcast wave VHF-H band, and is higher in other bands, and it can be seen that the reception gain for FM radio broadcast waves is improved.

Further, the reception gain of a good glass antenna for a vehicle, which has been put to practical use in the past, has an FM radio broadcast wave, T
V broadcast wave VHF-L band, TV broadcast wave VHF-H band, TV
Approximately -20d on average for each broadcast wave UHF band
B, about -20 dB, about -20 dB, and about -18 dB, the antennas of Example 1 and Example 2 are almost the same as or above, and it can be seen that they are good antennas.

The glass antenna having the structure shown in FIG. 1 has a whip antenna (not shown) to receive AM radio broadcast waves by the whip antenna.
For the M radio broadcast wave to TV broadcast wave UHF band, diversity reception is performed by the whip antenna, the antenna of the first embodiment of the present invention, and the antenna of the second embodiment.
Of course, diversity reception may be performed in combination with an antenna (not shown).

Embodiment 3 As shown in FIG. 2, this is an example in which the feeding points are separate, and the first side of the flat glass 1 having the same dimensions as in Embodiment 1 is composed of horizontal and vertical filaments inside the vehicle. antenna 3 ₃ the screen printing by the feeding point 6 ₃₁ a conductive paste and dried, after which the colored opaque layer 4 of black peripheral portion of the glass sheet, screen printing a ceramic paste except feeding point 6 ₃₁ parts Te, dried, defogging heater strips 2, 2, ..., substantially antennas having the same structure as that of example 1 with 2 as the second antenna 5 _3, the feeding point 6 ₃₂
At the same time, screen printing and firing are performed using a conductive paste.

When the glass antenna for a vehicle thus obtained is mounted as a rear window glass for an automobile,
The dimensions of each part are g = 1100 mm, h = 400 mm, i =
Depending on the size of 220 mm, FM radio broadcast wave, T
V broadcast wave VHF-L band, TV broadcast wave VHF-H band, TV
The reception gain of the broadcast wave UHF band is measured individually,
In terms of dipole ratio, the first antennas have average values of -19.3 dB, -20.1 dB, and -18.5 d, respectively.
B, -19.5 dB, and the second antenna has an average value of -18.7 dB, -17.5 dB, -21.3 dB, respectively.
It becomes -19.1 dB, and the reception gain of the second antenna when there is no first antenna indicated by the dotted line is -1 in average value.
9.9 dB, -17.5 dB, -23.5 dB, -1
Since it is 8.9 dB, it can be seen that the second antenna has an improved reception gain particularly in the TV broadcast wave VHF-H band.

Further, it can be seen that both the first antenna and the second antenna are equal to or more than the good glass antennas for vehicles which have been put to practical use in the past, and are good antennas.

The glass antenna having the structure shown in FIG. 2 has a whip antenna (not shown) to receive AM radio broadcast waves by the whip antenna,
For the M radio broadcast wave to TV broadcast wave UHF band, diversity reception is performed by the whip antenna and the antenna of the present embodiment, but diversity reception may be performed in combination with other antennas not shown.

Embodiment 4 As shown in FIG. 3, this is an example in which a feeding point is provided separately, and the horizontal length of the first antenna 3 ₄ (feeding point 6 ₄₁ ) is 300 m.
It has the same structure and dimensions as those of the third embodiment shown in FIG. However, the second antenna was 5 ₄ and the feeding point was 6 ₄₂ .

With the glass antenna for a vehicle thus obtained, FM radio broadcast waves and TV broadcast waves VHF-
When the reception gains of the L band, the TV broadcast wave VHF-H band, and the TV broadcast wave UHF band are individually measured and shown by the dipole ratio, the first antennas each have an average value of -24.5d.
B, -24.2 dB, -18.2 dB, -16.9d
B and the second antenna each have an average value of -18.8d
B, -18.9 dB, -17.4 dB, -19.9 dB
And the respective reception gains in the case where there is no first antenna indicated by the dotted line are −19.9 dB and −17.5 dB on average.
Since it is -23.5 dB and -18.9 dB, it can be seen that the second antenna has a particularly improved reception gain for the TV broadcast wave VHF band and the UHF band.

Further, it can be seen that both the first antenna and the second antenna are equal to or more than the glass antennas for vehicles used in the prior art and are good antennas.

The glass antenna having the configuration shown in FIG. 3 is for performing diversity reception by adding the whip antenna (not shown) by the method shown in the second embodiment, but for diversity reception in combination with other antennas (not shown). Of course it is also good.

Fifth Embodiment, Sixth Embodiment As shown in FIG. 4, a first antenna 3 ₅ and a second antenna 5 _{5 according} to a fifth embodiment, a first antenna 3 ₆ , and a second antenna 5 ₆ .
The feeding point is also common to the sixth embodiment shown by the antenna 5 ₆ of the above (the feeding point of the _fifth embodiment is 6 ₅ and the feeding point of the sixth embodiment is 6 ₆
Example 5 is an example provided in the upper margin of the heating wire, and Example 6 is an example provided in the lower margin of the heating wire. The antenna of Example 5 is FM radio broadcast wave to TV broadcast wave. UHF
Up to the band, it is better than the conventional good antenna, and the reception gain for the FM radio broadcast wave is particularly improved as compared with the case where the dotted first antenna is not provided, and the antenna of the sixth embodiment is also a wideband antenna, especially the TV broadcast wave UHF. It is intended to improve the reception gain of the band.

In the antenna having such a structure, it is more preferable to add a whip antenna or the like to the antennas of the fifth embodiment and the antenna of the sixth embodiment for diversity reception. Example 7 As shown in FIG. 5, this is an example in which a part of the first antenna 3 ₇ protrudes from the colored opaque layer 4, and the second antenna 5 ₇ and the feeding point 6 ₇ are commonly used. This is an example in which another antenna 7 is provided in the space below the filament, and the antenna of this embodiment is also FM radio broadcast wave to TV broadcast wave UH.
The reception gain is high over a wide band up to the F band, and the reception gain for the FM radio broadcast wave is improved more than in the case where the first antenna shown by the dotted line is not provided.

In the antenna having such a structure, it is more preferable to add a whip antenna or the like to the antenna of the seventh embodiment and another antenna 7 for diversity reception. Other Embodiments The preferred embodiments have been described above, but the present invention is not limited to these, and various applications are possible.

Regarding the antenna pattern, various antennas capable of receiving FM radio broadcast waves and TV broadcast waves can be adopted as the second antenna, and the first antenna is designed to be capacitively coupled with the filament closest to the glass edge. It is possible to adopt a wire having a different line.

Although the power feeding is not described in the embodiment, the power is fed by the coaxial cable through the usual method of connecting the inner conductor of the coaxial cable to the feeding point or through an impedance matching circuit, an amplifier or the like provided near the feeding point. But of course In this case, the outer conductor of the coaxial cable is grounded to the metal body of the automobile near the feeding point.

Although the antenna of the present invention can be used alone, the antenna of the present invention can be used for diversity reception, or the antenna of the present invention can be provided for diversity reception. It is more preferable to provide a plurality of antennas and add another antenna for diversity reception.

In this case, of course, diversity reception may be performed by adding another glass antenna provided on the front or side window glass or a pole antenna such as a whip antenna.

Further, the antenna of the present invention may be provided not only on the rear window glass but also above and below the colored opaque band of the front window glass, and further above and below the colored opaque band of the side rear quarter. .

[0035]

Since the glass antenna of the present invention forms an antenna having an upper and lower two-layer structure, it is possible to effectively use the space. By adding the first antenna to the lower layer, the glass antenna of the upper layer can be used. Compared to the case of using only the antenna, the reception gain of the FM radio broadcast wave or TV broadcast wave can be improved without lowering the reception gain of the second antenna, and it is colored and opaque as an insulating layer. It also has the advantage of also serving as a layer.

[Brief description of drawings]

FIG. 1 is a front view showing Example 1 and Example 2 in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

FIG. 2 is a front view showing a third embodiment in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

FIG. 3 is a front view showing a fourth embodiment in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

FIG. 4 is a front view showing Example 5 and Example 6 in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

FIG. 5 is a front view showing a seventh embodiment in which the glass antenna of the present invention is provided on a rear window glass for an automobile.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Plate glass 2 Anti-fogging heating wire 3 _{1 to} 3 ₇ 1st antenna 4 Colored opaque layer 5 _{1 to} 5 ₇ 2nd antenna 6 _{1 to} 6 ₇ Feeding point 7 Another antenna

Claims (8)

[Claims] 1. A first antenna having at least a horizontal filament, a vertical filament or a horizontal filament and a vertical filament is provided within the lower layer of a colored opaque band formed on the peripheral portion of a window glass for an automobile, and the coloring is performed. A glass antenna for an automobile, wherein a second antenna capacitively coupled to at least a part of the first antenna is provided on an upper layer of the opaque band. 2. The glass antenna for an automobile according to claim 1, wherein all of the first antennas are provided under the colored opaque band. 3. The glass antenna for an automobile according to claim 1, wherein a part of the first antenna is provided so as to protrude from the colored opaque band. 4. The glass antenna for an automobile according to claim 1, wherein the feeding points of the first antenna and the second antenna are common. 5. A feed point for the first antenna and a feed point for the second antenna are separately provided.
The glass antenna for an automobile according to claim 3. 6. The glass antenna for an automobile according to claim 5, wherein the feeding points of the first antenna and the second antenna are arranged so as to be separated from each other in the left-right direction or in the vertical direction. 7. A glass antenna for an automobile, wherein at least one antenna different from the antennas according to any one of claims 1 to 6 is adapted to receive diversity. 8. A plurality of antennas according to any one of claims 1 to 5 are provided, and diversity reception is performed by the plurality of antennas or by adding another antenna to the plurality of antennas. Glass antenna for automobiles.