JPH0746019A - Automotive glass antenna - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce the noise mixed in the glass antenna. [Structure] A conductive film 5 is provided on an entire interior surface of a rear glass 1 provided with an antenna pattern 2 and a defocator heat ray pattern 3 by pattern printing with an insulating film 4 interposed therebetween. Thereby, the noise from the air can be absorbed by the conductive film 5, and the mixing of noise can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle glass antenna, and more particularly to a technique for reducing noise mixed in the antenna.

[0002]

2. Description of the Related Art In recent years, a glass antenna in which an antenna pattern 2 is pattern-printed on a vehicle glass, for example, a rear glass 1, is adopted as shown in FIG. It's starting. In the figure, 3 is a defogger heat ray pattern, which is also pattern printed.

[0003]

By the way, in a rear glass antenna, for example, in order to increase the antenna sensitivity,
The area of the antenna is increased by capacitively coupling a part of the heat wire pattern of the defogger to the antenna and using a part of the heat wire as an antenna. However, when the area of the antenna is increased, there arises a problem that noise generated during the operation of the on-vehicle electrical equipment, particularly noise generated from the engine ignition system using a high voltage, is easily mixed from the air.

In view of the above conventional problems, it is an object of the present invention to provide a glass antenna capable of reducing noise mixed in from the air.

[0005]

Therefore, in the glass antenna of the present invention, the conductive film electrically insulated from the antenna pattern is provided on the entire surface of the glass inside the passenger compartment.

[0006]

According to this structure, since a part of the noise mixed in the antenna from the air is absorbed by the conductive film provided on the entire surface of the glass inside the vehicle interior, the noise mixed in the antenna can be reduced. It will be possible to increase the practical sensitivity of the radio.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first glass antenna according to the present invention.
1 is a cross-sectional view of a portion A of FIG. 3, FIG. 2 is a view seen from the vehicle rear side, and FIG. 3 is a view seen from the side of the vehicle. Incidentally, the same elements as those of the related art shown in FIG.

In the figure, an insulating film 4 of, for example, zinc oxide is provided on the interior side of the rear glass 1 on which the antenna pattern 2 and the heat ray pattern 3 are printed.
A conductive film 5 of, for example, titanium nitride is provided on the above. According to this configuration, the noise that enters from the air is
Since it is absorbed by the conductive film 5, noise mixed in the antenna pattern 2 can be reduced as compared with the conventional case.
The practical sensitivity of the radio can be improved.

4 and 5 show the measurement results of the S / N sensitivity with and without the conductive film 5. As shown in FIG. 6, the configuration of the measurement system includes a radio 6 and an antenna pattern 2
Is connected with a cable 7, and a noise meter 11 is connected to a speaker cable 9 that connects a radio 6 and a speaker 8 with a circuit box 10 that prevents noise from entering, while a signal generator 12 is connected outside the vehicle. A transmission antenna 14 that is connected via a cable 13 and radiates a radio wave is provided.

Carrier frequency 603 Hz Modulation frequency 1 KHz Modulation rate 30% No stereo modulation Load resistance 4 Ω Output standard 0 dB = 1.4 V Filter used Din Peak Note that the surface resistance of the glass of the glass antenna is 40 ~
A conductive film of 50Ω / □ was provided.

Comparing FIG. 4 showing the measurement result when the conductive film is not provided and FIG. 5 showing the measurement result when the conductive film is provided, it can be seen that the noise level during engine run is reduced by about 5 dB. . Further, when zinc oxide or the like is used for the insulating film 4 as in the present embodiment, there is an advantage that it is possible to prevent the generation of sunburn, spots, freckles, etc. on the human body due to ultraviolet rays due to the ultraviolet ray cutting effect. The use of titanium nitride or the like has an advantage of being able to prevent the discomfort caused by the temperature rise in the vehicle interior due to infrared rays and the reduction of the cooling capacity of the air conditioner due to the infrared ray cutting effect.

FIG. 7 shows a second embodiment. The second embodiment is an example in which a laminated glass is used as the glass 1 of the glass antenna. In this case, the outer glass 21 of the laminated glass is used.
The antenna pattern 2 and the heat ray pattern 3 are printed and provided between the inside glass 22 and the inside glass 22,
The insulating film 4 and the conductive film 5 are provided.

In the second embodiment, as in the first embodiment,
Has a noise reduction effect. In the case of laminated glass, the conductive film 5 and the antenna pattern 2 can be insulated from each other by the inner glass 22, so that the insulating film 4 is not necessarily provided. By the way, as described above, in the rear glass antenna, a part of the defogger heat ray pattern 3 is used as an antenna in order to increase the area of the antenna. In this case, there is noise mixed through the power supply harness connected to the heating wire pattern 3.

Therefore, FIGS. 8 and 9 show a third embodiment in which, in addition to the noise from the air, the noise mixed from the harness is also reduced. In the figure, the antenna pattern 2 of the rear glass 1 and a part of the heat ray pattern 3 are arranged close to each other and capacitively coupled, and a part of the heat ray pattern 3 can be used as an antenna.
Further, a conductive film (not shown) for reducing noise from the air is provided on the passenger compartment side of the rear glass 1.

A choke coil 32 is provided on the power supply line 31 for connecting the heating wire pattern 3 to the battery so as to make the heating wire pattern 3 high impedance at high frequencies.
Between the terminal B1 of the choke coil 32 and the power supply terminal A1 of the heating wire pattern 3 and between the terminal B2 of the choke coil 32 and the ground terminal A2 of the heating wire pattern 3, a normally open type relay 33 that operates in conjunction with each other is used. Each contact point D
1, E1 and D2, E2 are provided. The terminals C1 and C2 of the choke coil 32 are connected to the battery and the ground, respectively.

The coil of the relay 33 is connected to the ground via the power switch 34 of the defogger. The mounting position of the relay 33 is at each terminal A of the heating wire pattern 3.
Wiring 3 of each contact D1, D2 of 1, A2 and relay 33
As shown in FIG. 9, the corner pillars 37 are attached near the center of the corner pillars 37 so that the lengths of 5, 36 are as short as possible and have the same length.

Therefore, the defogger power switch 34 O
With N-OFF, both contacts of relay 33 are interlocked and turned ON.
-OFF, power supply to the heat ray pattern 3 is controlled. Next, the operation will be described. When a part of the heat wire pattern 3 is used as an antenna, in the conventional power supply circuit of the defocker, a choke coil is directly connected to the power supply terminal A1 and the ground terminal A2 of the heat wire pattern 3, and a relay is provided between the choke coil and the battery. Since the configuration is provided, the harness connected to the power supply terminal A1 and the ground terminal A2 when the defocker is not used is long, and the ratio of noise mixed therein is large.

Therefore, in this embodiment, a relay 33 for connecting and disconnecting the heating wire pattern 3 and the battery by turning on and off the power switch 34 is provided between the power supply terminal A1 and the ground terminal A2 and the choke coil 32, and a defoker is provided. When not in use, the power supply harness can be disconnected as close as possible to the heating wire pattern 3. Therefore, the power supply terminal A1 of the heating wire pattern 3 when the defocker is not used
Also, the length of the harness connected to the ground terminal A2 is shorter than that of the conventional circuit, and noise mixed therein can be reduced, which is 4 to 5 dB lower than that of the conventional circuit. Therefore, the noise from the harness can be reduced in addition to the effect of reducing the noise from the air by the conductive film 5, and the practical sensitivity of the radio can be further improved.

When the defocker is used, noise does not propagate to the defocker because the battery constitutes the power supply line 31, the heating wire pattern 3, and the circuit of relatively low ground. 10 and 11 show a fourth embodiment. In this embodiment, a separate relay 33 is provided so as to directly connect relay contacts to the power supply terminal A1 and the ground terminal A2 of the heating wire pattern 3.
A and 33B are provided.

In the case of this embodiment, the harness connecting to the power supply terminal A1 and the ground terminal A2 of the heating wire pattern 3 does not exist, so that the effect of reducing the noise from the harness is greater than that of the third embodiment. Therefore, the noise mixed in from the hearth neck is reduced by 7 to 8 dB as compared with the conventional circuit.

[0021]

As described above, according to the present invention, since the antenna pattern is insulated and the conductive film is provided on the entire surface of the glass on the inside of the vehicle interior of the vehicle-mounted glass antenna, it is generated from the vehicle-mounted electric components and the like. Therefore, the noise mixed in the antenna pattern can be reduced, and the practical sensitivity of the in-vehicle radio can be increased.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of part A in FIG.

FIG. 2 is a view of the glass antenna according to the first embodiment of the present invention as seen from the vehicle rear side.

FIG. 3 is a view of the first embodiment as seen from the side of the vehicle.

FIG. 4 is a diagram showing the S / N sensitivity measurement results of a glass antenna without a conductive film.

FIG. 5 is a diagram showing S / N sensitivity measurement results of a glass antenna provided with a conductive film.

FIG. 6 is a diagram showing the configuration of the S / N sensitivity measurement system of FIGS. 4 and 5;

FIG. 7 is a cross-sectional view of essential parts showing a second embodiment of the glass antenna of the present invention.

FIG. 8 is a configuration diagram showing a third embodiment of the present invention.

FIG. 9 is a diagram showing a relay mounting position of the third embodiment.

FIG. 10 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a relay mounting position of the fourth embodiment.

FIG. 12 is a diagram showing a conventional glass antenna.

[Explanation of symbols]

 1 Rear glass 2 Antenna pattern 3 Heat ray pattern 4 Insulating film 5 Conductive film

Claims (1)

[Claims] 1. An on-vehicle glass antenna having an antenna pattern formed on glass, wherein a conductive film electrically insulated from the antenna pattern is provided on the entire inner surface of the glass inside the vehicle compartment. antenna.