JPH0156562B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antenna glass for automobiles that has improved horizontal directivity characteristics when receiving FM broadcasts.

As an antenna for a car radio receiver,
Whip antennas have been widely put into practical use, but recently glass antennas have been used in place of them, in which antenna wires for AM reception and/or FM reception are provided on the surface or inside of the window glass of an automobile. In addition, in order to prevent fogging caused by dew condensation on the rear window of a car, anti-fogging glass has been put into practical use by installing an electrified heater on the glass plate surface or between the glass plates to prevent fogging. A heater with a high-frequency chiyoke coil inserted into each of its lead wires so that it can also be used as an antenna for a radio receiver, or a heater with a separate antenna wire provided in the margin of the anti-fog glass plate, or a heater with a separate antenna wire in the margin of the anti-fog glass plate. Those equipped with a high frequency amplification circuit have been put into practical use or have been proposed.

All of these glass antennas for cars have stronger directional characteristics than whip antennas, especially when receiving FM broadcast waves, depending on the direction of the car.
A shortcoming unique to glass antennas was discovered: FM broadcasts were difficult to receive.

For example, it exhibits an undesirable figure-of-eight directivity characteristic, which generally shows a dip point corresponding to the vehicle's orientation in a direction perpendicular to the direction of the transmitting antenna.
This figure-of-eight characteristic is particularly noticeable when the glass antenna is used in the front or rear window of an automobile. As a result of various studies, the present inventor found that the figure-of-eight characteristics of glass antennas are largely determined by the shape, size, type, etc. of the car body and opening, since FM broadcast waves cause secondary radiation on the car body. I found out that it can be put away.

The present applicant has improved the above point by providing a main antenna wire 2 for power feeding from the side of the glass plate laterally on a glass plate 1 that is fitted into the front window or rear window of an automobile such as a passenger car.
An auxiliary antenna line 3 is provided above or below the main antenna line near the window frame, extending in the lateral direction of the glass plate and at a predetermined distance from the main antenna line, and further connecting the main antenna line and the auxiliary antenna line. The pattern of the antenna glass is provided with a phase adjustment antenna wire 4 that connects the antenna, and when the pattern of the antenna glass is fitted into the front window or rear window of a car, it is asymmetrical with respect to the longitudinal center line of the car. At the same time, the antenna feed point 5 of the antenna glass or its lead-out point is located on the horizontal side of the glass plate, and this antenna feed point or lead-out point is located at the center line of the vehicle body in the longitudinal direction. An application was filed regarding an antenna glass 6 that is positioned on either the left or right side.

A typical example of such an antenna glass with excellent directivity is one having an antenna pattern as shown in FIG. 1, for example.

Although this type of antenna glass significantly improves omnidirectionality during FM reception, it has the disadvantage that gain and omnidirectionality decrease in the high frequency side of the FM broadcast wave band, and the rear window of a car cannot be opened or closed. It has been found that when used in lift-back type vehicles, the gain and omnidirectionality are reduced. For example, antenna glass with a pattern like the one shown in Figure 1 is used in the FM broadcast wave band (76M) in Japan.
Hz to 90MHz), although it is highly omnidirectional.
Broadband FM broadcast wave bands such as the United States.
A drawback was found that the omnidirectionality was poor for the FM broadcast wave band (88MHz to 108MHz).

The present invention was invented as a result of various studies with the aim of improving such drawbacks and providing an antenna glass that has omnidirectionality in a wide band of FM broadcast waves, and which can be attached to the front or rear window of an automobile. a plurality of main antenna wires extending horizontally from the sides of the glass plate toward the center and having an open end on the center side, at least one of which has a different length than the others; It has a center point at a position offset to the left or right with respect to the vertical center line of the glass plate at a predetermined interval above the main antenna line or above the side, and extends in the horizontal direction of the glass plate, and both ends are open. An antenna wire for phase adjustment, in which one end is connected to the power feeding vicinity of the main antenna wire and the other end is connected to the center point of the auxiliary antenna wire or its vicinity. An antenna glass for an automobile, characterized in that a feeding point of the antenna wire or a lead-out point to the feeding point for the antenna is provided on the main antenna wire in a side region of the glass plate. It is related to.

The present invention will be explained below with reference to the drawings.

In Figures 2 to 9, 11 is a glass plate;
2 is the main antenna line, 13 is the auxiliary antenna line, 14
1 is an antenna wire for phase adjustment, 15 is a feed point for the antenna, 22 is a lead line from the antenna line to the feed point, 1
9 indicates the antenna glass.

In the present invention, the main antenna wire 12 is provided to extend horizontally from the side of the glass plate 11 to the center of the antenna glass when the antenna glass is fitted into the front window or rear window of an automobile. It is. In the present invention, a plurality of two to three or more main antenna wires 12 are provided. Any one of the plurality of main antenna wires 12 is connected to the side end of the glass plate through a lead wire 22 to the antenna feeding point or without a lead wire 22. An antenna feed point 15 is connected. The other end of the main antenna wire 12, that is, the end opposite to the end on the side of the glass plate is preferably an open end. Most commonly, two or three main antenna lines 12 are provided. At least one of the plurality of main antenna lines 12 has a different length from the others.

Further, it is preferable that the main antenna line 12 is asymmetrical with respect to a center line extending vertically at the center of the antenna glass 11 in the horizontal direction. Further, the main antenna line may be branched or folded, or may be curved. In particular, the length of the main antenna line is preferably set to λ/4α±λ/20α of the wavelength λ of a desired intermediate frequency in the FM broadcasting frequency range (α: wavelength shortening rate of the antenna glass). for example,
It is preferably about 20cm to 90cm.

Further, in the present invention, the auxiliary antenna wire 13 extends in the lateral direction of the glass plate, near the window frame above or above the side of the main antenna line 12, or below or above the side of the main antenna line 12, and extends in the lateral direction of the glass plate. It is provided at a predetermined distance from the line 12.

From the viewpoint of receiving sensitivity, it is preferable that this interval be 1 to 5 cm in parallel. In addition, the auxiliary antenna wire 13
When it is provided near the window frame side into which the glass plate 11 is fitted, it is preferably provided at a distance of about 1 to 5 cm from the window frame. Preferably, this auxiliary antenna wire 13 has at least one end, and at least one of the ends is open. In the present invention, the auxiliary antenna wire 13 is provided so that its center point is offset to the left or right with respect to the longitudinal center line of the glass plate.

Further, the length, width, number, etc. of the auxiliary antenna wires 13 are appropriately selected depending on the structure of the vehicle body, the shape of the glass plate, and other various factors. The most preferable pattern of the auxiliary antenna line 13 is that it is arranged above the main antenna line 12 and at a predetermined distance from the window frame, and that the left and right ends are open ends,
Furthermore, there is a phase adjustment antenna wire 14 on the center line or side part.
This is a pattern in which the two are connected.

In addition, the auxiliary antenna line 14 for phase adjustment is composed of the main antenna line 12 and the auxiliary antenna line 13, which have different directivity characteristics.
In order to adjust the phase of the FM broadcast wave at the feed point 15 with the main antenna line 12 and the auxiliary antenna line 13, and to
It is used to operate in a reinforcing manner to increase the sensitivity of broadcast wave reception, and its length is selected so as to adjust the phase of the reception radio wave range. This phase adjustment antenna connects between the feeding point side of the main antenna line 12 and the auxiliary antenna line 13. For example, the length of the antenna wire for phase adjustment should be such that the length including the auxiliary antenna resonates in the FM broadcast wave frequency band (76 to 90MHz).
Wavelength of center frequency of broadcasting frequency band λ/4, 3/
The length may be 4λ, 5/4λ, . . . n/4λ (n: odd number). In fact, λ/4±λ/20, 3/
There is no practical problem if the length is within the range of 4λ±λ/20...n/4λ±λ/20.

In addition, in the case of antenna glass, the wavelength of the received broadcast wave is shortened, so the shortening rate α is added to the length of the above wavelength.
The value multiplied by is selected.

Phase adjustment antenna wire 1 including one side of the auxiliary antenna wire 13 of the antenna glass 11 shown in FIG.
4 is the length equivalent to 3/4λ x α (λ is approximately 83MHz in the center of the FM broadcast wave frequency band. α is the wavelength shortening rate of the antenna glass and is approximately 0.7), that is, approximately
This example shows a length of 1900mm. For the antenna glass of the front window or rear window of a typical automobile, the above-mentioned length of 3/4λ is practical due to the size of the antenna glass, restrictions on the area where the antenna wire can be formed, etc. In addition, within the range of ±1/20λ before and after 3/4λ (for example, 1900mm±100mm)
It can be used practically without any problems.

The phase adjustment antenna wire described above also has an asymmetrical pattern with respect to the vertical center line of the antenna glass, and the horizontal portion of the phase adjustment antenna wire is connected to the main antenna wire 12 and the auxiliary antenna wire 13.
It is preferable that the line be placed on a different level at a predetermined distance from the lateral portion of the line, or be substantially parallel to these lines.

Further, the pattern of the phase adjustment antenna wire may further include a folded portion 16 in a part thereof.

In particular, in the present invention, one or more wires are provided in a predetermined portion of the phase adjustment antenna wire 14 in order to further increase reception sensitivity to AM broadcast waves, or to further increase reception sensitivity and omnidirectionality to FM broadcast waves. Preferably, an additional antenna line 18 is provided. This additional antenna line 18 may be provided so as to intersect with the phase adjustment antenna line 14, may be provided so as to branch, or may be provided so that a part of the phase adjustment antenna line 14 is extended. good.
Further, an additional antenna line 18 may be provided via a coupling line. Further, additional antenna wires 18 may be provided in double, triple, or even overlapping manner.

Phase adjustment antenna wire 14 and main antenna wire 12
The connection with the main antenna line 12 reception sensitivity and FM
It is preferable to prevent the directional characteristics of broadcast waves from being impaired. For example, the part of the main antenna line 12 that is not the main operating part, that is, the feeding point 1 of the main antenna line 12
It is optimal to connect the phase adjustment antenna wire 14 near 5. It is also preferable that the phase adjustment antenna line 14 and the auxiliary antenna line 13 are connected so that the receiving sensitivity of the auxiliary antenna line 13 and the directivity of the FM broadcast waves are not impaired. For example, it is preferable to connect the antenna wire 14 near the center or end portion of the auxiliary antenna wire 13.

Also, feeding point 15 or antenna wire feeding point 1
The lead-out point to 5 is preferably provided in the side region of the glass plate 11, connected to the main antenna line 12. It should be noted that the side areas of the glass plate 11 may be either left or right, upper or lower, or in the middle, and the positions are selected as appropriate depending on the design. By providing the power feeding point on the side in this way,
It is possible to deflect the vertical center line in front of the car and the operational center line of the antenna glass, and it is possible to reduce the influence of secondary radiation caused by FM broadcast waves on the car body, resulting in figure-eight characteristics. can be improved.

In the antenna glass of the present invention, in order to improve the reception sensitivity of AM and/or FM broadcast waves, an antenna for AM or FM is placed near the feeding point of the antenna glass.
Alternatively, a dual-use high frequency amplification circuit can be provided.

Further, the antenna glass of the present invention can be provided with an energized heater in the blank area where the antenna wire is not provided in order to prevent fogging due to dew condensation on the glass plate surface. 2 to 7 show examples in which this energizing heater 20 is provided. This energized heating heater is connected to the antenna wire 1 as shown in Figures 2, 3, 5, and 6.
2, 13, and 14 may be provided separately, or alternatively, as shown in Fig. 8, the energizing heating heater 20 and the antenna wire may be connected, and the conductive wire of the energizing heating heater may also be used as the antenna wire. You can also. In the former case, it is preferable to separate the antenna wire and the energizing heater wire by at least 2 to 3 cm to avoid electrical connection, and in the latter case, it is preferable to separate the antenna wire and the energizing heating heater wire by 2 to 3 cm or more, and in the latter case, high frequency It is preferable to insert a chiyoke coil so that the radio is suspended in high frequency when receiving radio broadcasts. In addition, as shown in Fig. 4, the heater 20 is placed close to the antenna wire with a spacing of about 0.5 cm to 1.5 cm so that high frequency current is transmitted and received between the two, so that the heater 20 also serves as an antenna. You can also do this.

In the present invention, the defogging heaters 20 provided on the glass plate 11 are formed in parallel with each other at intervals of 2 cm to 4 cm in the lateral direction of the glass plate, and have a line width of 0.5 mm to 4 cm, as shown in each figure. The most common type is one having a large number of heater wires 23 of about 2 mm and a bus bar 24 connected to the heater wires for supplying current to the heater wires 23, but of course it is not limited to these. It's not a thing.

In addition, in the above-mentioned type of energizing heating heater 20 for defogging, the pattern of the power supply circuit of the energizing heating heater 20 for defogging is copied, for example, as shown in Figures 2 to 5, so that the omnidirectionality of the antenna is improved. One of the opposing busbars 24 is divided into two vertically, and lead wires 25 and 25' are connected to the busbars 24a and 24b, respectively, so that the supplied current flows from the busbar 24a or 24b through the busbar 24. It is also possible to make the liquid flow in a U-shape along the bus bar 24b or 24a.

Of course, as shown in FIGS. 6 and 7, the bus bars 24 of the energizing heater 20 may be provided one by one to face each other, thereby providing a facing power supply system.

The antenna wire in the present invention includes Ag,
An electrokinetic paste made by mixing conductive metal powder such as Al or Pd or other conductive material powder with glass frit, binder, and other desired additives is applied to the glass plate surface with thin lines in a predetermined pattern. Conductive wires formed by printing and baking strips using a screen printing method, conductive thin metal wires, or various other conductive materials can be used. The various antenna wires described above may be formed on the surface of the glass plate, or may be sealed inside the laminated glass.

Next, examples of the present invention will be described.

Example 1 As shown in FIG. 9, a silver paste containing silver powder and glass frit is applied to the surface of a glass plate for a rear window of an automobile.
The antenna wires including the antenna wire 14 for phase adjustment, the additional antenna wire 18, and the pattern of the energizing heater 20 are printed using a silk screen printing method, dried, and then placed in a heating furnace for 650 minutes. The antenna glass was manufactured by heating and baking at ℃. In this antenna glass,
The dimensions of each part were as follows.

A=470mm B=380mm C=200mm D=545mm E=100mm F=150mm G=100mm H=295mm I=45mm J=30mm K=50mm L=40mm Regarding this antenna glass, from 88MHz to 1M
Measure the average gain, minimum value of gain in each direction, and directivity (average gain value - minimum gain value) for radio waves with a horizontal polarization plane at each frequency up to 108MHz every Hz, and calculate the relationship with these frequencies. They are shown in FIGS. 12 to 14 as an average gain-frequency characteristic diagram, a directivity-frequency characteristic diagram, and a minimum gain value-frequency characteristic diagram, respectively. Note that the product of the present invention is shown as line A.

In addition, the results of measuring the directional characteristics of this antenna glass at each FM broadcast frequency are shown in the 18th to
It is shown in each a of Figure 38.

Each measurement was performed in a 60 dB uniform electric field.

Example 2 As shown in FIG. 10, a silver paste containing silver powder and glass frit is applied to the surface of a glass plate for a rear window of an automobile.
The pattern of the antenna wire including the antenna wire 14 for phase adjustment and the additional antenna wire 18 as well as the energizing heater 20 is printed using a silk screen printing method, dried, and then placed in a heating furnace for 650 minutes. The antenna glass was manufactured by heating and baking at ℃. In this antenna glass,
The dimensions of each part were as follows.

A=490mm B=480mm C=350mm D=490mm E=100mm F=240mm G=110mm H=250mm I=45mm J=30mm K=100mm L=150mm Regarding this antenna glass, from 76MHz to 1M
Measure the average gain, minimum value of gain in each direction, and directivity (average gain value - minimum gain value) for radio waves with a horizontal polarization plane at each frequency up to 90MHz every Hz, and calculate the relationship with these frequencies. They are shown in FIGS. 15 to 17 as an average gain-frequency characteristic diagram, a directivity-frequency characteristic diagram, and a minimum gain value-frequency characteristic diagram, respectively. Note that the product of the present invention is shown as line A.

Each measurement was performed in a 60 dB uniform electric field.

Comparative Example As shown in Figure 11, a silver paste containing silver powder and glass frit was printed on the surface of a glass plate for a rear window of an automobile using a silk screen printing method to form an antenna pattern as shown in the figure, dried, and then The antenna glass was manufactured by putting it into a heating furnace and heating it to 650℃ and baking it. In this antenna glass, the dimensions of each part were as follows.

A′=200mm B′=400mm C′=480mm D′= 10mm E′= 30mm F′= 50mm G′=45 Regarding this antenna glass (comparative example product),
Measure the average gain, minimum value of gain in each direction, and directivity characteristics (average gain value - minimum gain value) for radio waves with a horizontal polarization plane at each frequency from 76MHz to 108MHz every 1MHz,
The relationship with these frequencies is shown as an average gain-frequency characteristic diagram, a directivity-frequency characteristic diagram, and a minimum gain-frequency characteristic diagram, respectively, from 76MHz to 90MHz.
For the range up to, line B in Figures 12 to 14
15th for frequencies 88MHz to 108MHz.
It is shown in line B in Figure 17. In addition, the results of measuring the directivity characteristics of this antenna glass at each frequency from 88MHz to 108MHz every 1MHz are shown in Sections 18 to 3.
It is shown in each b of Figure 8. Each measurement was performed in a 60 dB uniform electric field.

FIG. 12 shows the characteristics of the antenna glass according to the example of the present invention and the antenna glass according to the comparative example.
As can be seen from Fig. 38, the antenna glass of the present invention can be used in a wide FM broadcast wave band, such as the FM broadcast wave band in the United States (88MHz to 108MHz) and the FM broadcast band in Japan (76MHz to 90MHz). Higher omnidirectionality than glass can be obtained.

Of course, the antenna glass of the present invention has a high gain even for AM broadcast waves.

The antenna glass of the present invention is most suitable as a glass plate for the rear window of an automobile equipped with an electric heating heater for defogging as shown in Figs. 2 to 7. It is also ideal as a glass plate for automobile rear windows or automobile front windows that are not equipped with electrical heating heaters.

Furthermore, according to the present invention, the phase adjustment of the basic antenna pattern of the present invention can also be used for the rear window of a liftback type automobile whose rear window opens and closes, where it has been difficult to obtain excellent omnidirectionality. A superior antenna glass can be provided by adding an additional antenna wire to the antenna wire.

[Brief explanation of drawings]

1 and 11 are front views showing an example of a conventional antenna glass for a rear window of an automobile, and FIGS. 2 to 10 are front views showing specific examples of the antenna glass according to the present invention. Figures 12 and 15 show the average gain-frequency characteristics diagrams of the inventive product and the comparative example.
Figures 3 and 16 are directivity-frequency characteristic diagrams, and 14,
FIG. 17 is a drawing showing a minimum gain value-frequency characteristic diagram, and FIGS. 18 to 38 are drawings showing the results of measuring the directivity characteristics of the product of the present invention and a comparative example. 11: antenna glass, 12: main antenna wire,
13: Auxiliary antenna line, 14: Phase adjustment antenna line, 15: Feeding point, 16: Folding part, 17:
Branch part, 18: Additional antenna wire, 19: Antenna glass, 20: Current heating heater, 22: Extraction point.

Claims (1)

[Claims] 1 A glass plate attached to a front window or rear window of an automobile has a glass plate that extends horizontally from the side of the glass plate toward the center, and has an open end on the center side, and at least one of the glass plates is longer than the other. A glass plate having a plurality of main antenna lines of different heights, and having a central point at a position offset to the left or right with respect to the vertical center line of the glass plate at a predetermined interval above or above the main antenna lines, and An auxiliary antenna wire extending in the horizontal direction of the plate and having both ends open is provided, and one end of the wire is connected to the feeding point of the main antenna wire, and the other end is connected to the feed point of the auxiliary antenna wire. A phase adjustment antenna wire connected to or near the center point is provided, and a feed point of the antenna wire or a lead-out point to the antenna feed point is provided on the main antenna wire in a side region of the glass plate. Characteristic automotive antenna glass.