JPH06291529A - Glass antenna for vehicle - Google Patents

Abstract

PURPOSE:To prevent a noise from being mixed, and also, to facilitate fitting of electronic parts by containing circuit board in a metallic case, printing a conductive layer to a windowpane, and electromagnetically shielding almost the whole surface of electronic parts. CONSTITUTION:To the peripheral part of the inside of a car of plate glass 1, a glass antenna 4 of a wire and a feeding point 5, and a conductive layer 6 are printed by conductive paste together with plural cloudproof heating wires 3 in a state that ceramic paste is printed and dried as a black opaque film 2, and calcined and formed. Subsequently, such electronic circuits as an impedance adjustment circuit, an amplifier circuit, a branching filter circuit, a filter circuit, a frequency converting circuit, etc., are mounted, and in a state that a circuit board 7 having an input terminal 71 made of a metal, and a conductive pad 72 is inserted between claws 81, 82, 81' and 82' of a metallic case 8, the input terminal 71, and a projecting part 83 of the metallic case 8 are soldered to the feeding point 5, and a projecting part 61 of the conductive layer, respectively. There-after, an internal conductor of a coaxial cable 9, and an external conductor grounded to a car body in the vicinity of the feeding point are connected to OUT an GND, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna in which an electronic circuit such as an impedance adjusting circuit, an amplifying circuit, a branching circuit, a filter circuit and a frequency converting circuit is mounted on a window glass for a vehicle such as an automobile.

[0002]

2. Description of the Related Art Since the glass antenna itself has a lower receiving gain than the pole antenna, when it is used alone, a reactance element such as a condenser or a coil is provided to adjust the impedance between the antenna and the receiver. It has been attempted to provide an electronic circuit such as an impedance adjusting circuit and an amplifier circuit for amplifying a signal.

In this case, if the reactance element is provided at the end apart from the feeding point, mismatch loss occurs, which is not preferable, and it is preferable to place the reactance element near the feeding point. Japanese Patent Laid-Open No. 2-67804, Japanese Utility Model Laid-Open No. 2-36204, and the like have been proposed to provide such a reactance element near the feeding point.

Also, when an amplifier is provided, noise mixed between the feeding point and the amplifier is amplified, so that it is required to provide it near the feeding point. However, in any case, no appropriate measures have been taken against external noise, so there is no defense against the introduction of noise, and S
There was a risk of lowering the N ratio.

Although there is an example in which the amplifier of the glass antenna for a vehicle is housed in a metal outer box and the outer box is mounted on the vehicle body, even though there is a shielding action, it is between the feeding point and the amplifier. Since it is vulnerable to the noise mixed in, it is unavoidable that the noise is amplified.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a glass antenna in which noise is prevented as much as possible and electronic parts can be easily attached.

[0007]

The present invention relates to a glass antenna for a vehicle in which an antenna and an electronic circuit are provided on a window glass, a circuit board on which the electronic circuit is mounted is housed in a metal case, and the window glass is mounted on the window glass. Is printed with a conductive layer having substantially the same size as the metal case, and the input terminal provided on the circuit board and the feeding point of the antenna, and a part of the metal case and the conductive layer are soldered to each other to make the electronic component Approximately the entire surface is electromagnetically shielded, or the input terminal provided on the circuit board and the feeding terminal soldered to the feeding point of the antenna, the part of the metal case and the grounding terminal soldered to the conductive layer are fitted respectively. It is characterized in that almost all the electronic components are shielded by fitting them together, and the metal case and the circuit board with electronic components are configured to slide. Preferred.

[0008]

When an electronic circuit such as an amplifier circuit for amplifying the output signal of the antenna and an impedance adjusting circuit is provided away from the feeding point of the antenna provided on the window glass, the electronic parts and the feeding point are connected by a single wire. Therefore, the impedance of the antenna seen from the input side of the electronic circuit fluctuates due to the difference in the mounting position of this single wire to the vehicle body, the difference in length, vibration during running, etc., and the transmission becomes unstable. It is better to provide it near the power feeding point. Especially when the electronic component is an amplifier, the noise mixed between the power feeding and the amplifier is amplified by the amplifier, so that the effect is great near the power feeding point.

On the other hand, since the antenna itself is adjusted to have sensitivity to the frequency band to be received, it has almost no sensitivity to noise of frequencies outside the target frequency band. Is difficult to mix.

However, it is difficult to achieve both optimization of circuit performance and reduction of sensitivity of electronic circuit parts to external noise, and it is sensitive to external noise to some extent and noise is mixed. It's getting easier. Therefore, in the present invention, the substrate on which the electronic components are mounted is housed in a metal case, and a conductive layer having substantially the same size as the metal case is printed on the window glass to cover almost the entire surface with a conductive material. Since it is stored, it is electromagnetically shielded and it is possible to prevent noise from entering.

In addition, when simply adhering the metal case to the glass, it is necessary to adhere the metal and the glass to each other for a long time using a special adhesive having an adhesive force. Solder a part of the conductive layer printed with the same conductive paste as the antenna and a part of the metal case, or
The metal case can be easily attached to the glass simply by fitting through the soldered terminals.

Further, by adopting a structure in which the metal case and the substrate with electronic parts slide, the stress due to the difference in expansion coefficient between the metal and the glass can be released.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. 1 to 3 are a front view of a main part, an exploded perspective view of the main part, and a perspective view of the main part showing a relationship between a circuit board and a claw of a metal case, respectively. FIG. 4 is a main part of the second embodiment. It is an exploded perspective view.

Example 1 As shown in FIGS. 1 to 3, a ceramic opaque film 2 is first printed and dried as a black opaque film 2 on the periphery of the inside of a plate glass 1 mounted as a vehicle window. With a plurality of anti-fogging heating wires 3, 3, ...
The linear glass antenna 4, the feeding point 5, and the conductive layer 6 are formed by printing with a conductive paste and firing together with an opaque film.

Next, an impedance adjusting circuit and an amplifier
Circuits, demultiplexing circuits, filter circuits, frequency conversion circuits, etc.
An electronic circuit (not shown) is mounted and a metal input end
Child 7 ₁, Conductive pad 7₂The circuit board 7 having
Claw 8₁, 8₂, 8₁', 8₂’(An anti-illustration
(Also on the other side), input terminal 7₁To
At the feeding point 5, the protruding portion 8 of the metal case 8₃The protruding of the conductive layer
Part 6₁Solder to and attach to the window glass.

After that, the inner conductor of the coaxial cable 9 connected to a radio receiver, a TV receiver, a transceiver such as a car phone, etc. is connected to OUT, and an outer conductor grounded to the vehicle body near the feeding point is connected to GND. If a power supply is required in the case of an amplifier circuit or the like, connect it to the + B terminal with another lead wire.

The glass antenna thus obtained has almost no noise and can be transmitted and received satisfactorily. Even if the temperature rises and the difference in expansion coefficient between metal and glass increases, the circuit board 7 claw 8 ₁ and 8 ₂ of Matsume 8 ₁ '
And 8 ₂ ′ and the like slide while contacting the conductive pad 7 ₂ and the claw 8 ₁ , so that the stress caused by the difference in expansion coefficient is absorbed.

Example 2 As shown in FIG. 4, the conductive layer 6, the feeding point 5 and the like were directly printed on the plate glass, and the metal case and the input terminals provided on the circuit board were respectively fitted to the metal terminals. This is an example, the input terminal mounted on the circuit board 7 is bent at a right angle, the protruding portion of the metal case 8 is eliminated, and the power feeding terminal 10 is connected to the power feeding point 5.
The same configuration as in Example 1 was adopted except that the ground terminal 11 was soldered to the conductive layer 6, the input terminal 7 ₁ was fitted to the power supply terminal 10, and a part of the metal case was fitted to the ground terminal 11. is there.

The glass antenna thus obtained can be transmitted / received satisfactorily with almost no noise, and can absorb the stress caused by the difference in expansion coefficient.

Although the preferred embodiments have been described above, the present invention is not limited to these, and various applications are possible. Various electronic circuits such as an impedance adjusting circuit, an amplifier circuit, a demultiplexing circuit, a filter circuit, and a frequency conversion circuit can be mounted on the electronic circuit.

The metal case for accommodating the circuit board has a small opening area, and it is preferable that the number is small in terms of electromagnetic shielding. However, if the opening area is small, it may be formed of mesh metal.

[0022]

The glass antenna of the present invention can prevent noise from being mixed in, and can be mounted with an electronic circuit very easily.

[Brief description of drawings]

FIG. 1 is a front view of a main part according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of essential parts in the first embodiment.

FIG. 3 is a perspective view of essential parts showing the relationship between the circuit board and the claws of the metal case according to the first embodiment.

FIG. 4 is an exploded perspective view of a main part of the second embodiment.

[Explanation of symbols]

1 Plate Glass 3 Heating Wire 4 Glass Antenna 5 Feed Point 6 Conductive Layer 7 Circuit Board 7 ₁ Input Terminal 7 ₂ Conductive Pad 8 Metal Case 8 ₃ Projection 9 Coaxial Cable

Claims (3)

[Claims] 1. A glass antenna for a vehicle having an antenna and an electronic circuit provided on a window glass, wherein the circuit board on which the electronic circuit is mounted is housed in a metal case, and the window glass has substantially the same size as the metal case. The conductive layer is printed, and the input terminal provided on the circuit board and the feeding point of the antenna, a part of the metal case and the conductive layer are respectively soldered to electromagnetically shield almost the entire electronic component. A glass antenna for a vehicle characterized by the above. 2. A glass antenna for a vehicle having an antenna and an electronic circuit provided on a window glass, wherein the circuit board on which the electronic circuit is mounted is housed in a metal case, and the window glass has substantially the same size as the metal case. The conductive layer is printed, and the input terminal provided on the circuit board and the feeding terminal soldered to the feeding point of the antenna, the part of the metal case and the grounding terminal soldered to the conductive layer are fitted together. A glass antenna for a vehicle, characterized in that almost all the electronic components are shielded by doing so. 3. The vehicle glass antenna according to claim 1, wherein the metal case and the circuit board on which the electronic circuit is mounted have a structure of sliding.