JP2001088619A - Antenna device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device for an automobile which has no fear that a hindrance is caused in opening/closing and the visual field is not inhibited as in the case where it is provided on a window glass. SOLUTION: An antenna 5 provided with a transmitting and receiving function of an electric wave is provided on a metal reflection surface 32B of a room mirror 3 disposed at the inside of front shield 2 of automobile 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle antenna device which can be used as an auxiliary antenna for mobile communication equipment.

[0002]

2. Description of the Related Art Recently, communication using mobile communication devices (for example, PHS, portable telephones, personal computers, etc.) has been increasing in automobiles. The characteristics of radio waves used in mobile communications are easily affected by external conditions such as climatic conditions and driving environments (for example, rain, fog, valleys of buildings, etc.), and it is not always possible to communicate in good radio conditions. Not limited,
Communication is often interrupted. In particular, since the body of an automobile is made of metal, the radio wave is weakened.

[0003]

Therefore, it has been proposed to install an auxiliary antenna. However, if the auxiliary antenna is installed on a window glass or the like, the opening and closing of the window glass is hindered and the view is hindered. It is not desirable.

The present invention has been made in consideration of the above circumstances, and has as its object to provide an antenna device for a vehicle which does not have a problem that opening and closing does not hinder or hinders a view as in the case of providing the antenna on a window glass.

[0005]

The invention according to claim 1 is characterized in that an antenna having a function of transmitting and receiving radio waves is installed on a metal reflecting surface of a room mirror disposed inside a front window of an automobile. I do.

According to this antenna apparatus for an automobile, reception of the radio wave from the outside and transmission of the radio wave to the outside are relayed by the antenna provided on the metal reflecting surface of the room mirror. Since the rearview mirror is arranged inside the front window, transmission and reception of radio waves can be performed without being greatly affected by the metal body. Further, since the antenna is provided on the metal reflecting surface, the radio wave is reflected on the metal reflecting surface and concentrated on the antenna, so that the transmission / reception function is enhanced.

[0007] Further, a conventional room mirror is provided with a receiving-only antenna for receiving radio waves of television and radio (for example, Japanese Utility Model Laid-Open No. 63-170349 and Japanese Utility Model Laid-Open No. 3-19).
743, etc., this antenna device has both transmitting and receiving functions, and thus can be used as an auxiliary antenna for mobile communication.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an automobile equipped with the antenna device of the embodiment. In the figure, reference numeral 1 denotes a car body,
Inside the front window 2, a room mirror 3 incorporating an antenna device used as an auxiliary antenna of the mobile communication device 4 is installed.

As shown in FIGS. 2 and 3, the room mirror 3 has a housing 3A as a mirror housing, a metal reflecting surface (eg, aluminum reflecting surface) 3B, a glass 3C, and a metal reflecting surface 3B. And an antenna 5 provided in the antenna.

The antenna 5 is attached to the back side of the metal reflecting surface 3B, and is connected to an auxiliary circuit 6 so as to transmit and receive radio waves S1 and S2 to the outside and to the mobile communication device 4 in the vehicle. ing. In this embodiment, three antennas 5 are provided on the mirror as shown in FIG.

FIG. 4 shows a schematic configuration of the auxiliary circuit 6.

The auxiliary circuit 6 receives a radio wave from the outside, amplifies it, and emits the amplified radio wave to the mobile communication device 4 in the vehicle. A transmission-side circuit system M2 that emits the amplified and amplified radio waves and a duplexer 6A for sharing the antenna 5 for transmission and reception of both systems are provided.

The receiving-side circuit system M1 includes a receiving circuit 6B having an external signal amplification function,
A modulation circuit 6C and a transmission circuit 6D for transmitting to the mobile communication device 4 are provided.
Is provided with a reception circuit 6E for receiving a signal from the mobile communication device 4, a modulation / demodulation circuit 6F, and a transmission circuit 6G for amplifying the signal and transmitting the amplified signal to the outside.

According to the room mirror 3 having such a function, the radio wave from the outside or the radio wave S1 emitted to the outside can be
It is possible to transmit and receive with the built-in antenna 5 inside the front window with relatively good transmission and reception sensitivity,
It is possible to relay between the mobile communication device 4 in the vehicle.

Specifically, when a radio wave S1 from outside the vehicle is received by the antenna 5, the signal is amplified by an auxiliary circuit 6 attached to the antenna 5 and then emitted into the vehicle. Therefore, the mobile communication device 4 can receive the amplified radio wave S2 with high sensitivity. When a radio wave S2 is emitted from the mobile communication device 4, the radio wave S2 is received by the antenna 5, amplified by the auxiliary circuit 6, and then emitted outside the vehicle. Therefore, a strong radio wave can be emitted outside the vehicle through the front window.

As described above, since the antenna 5 serving as a relay for transmitting and receiving radio waves is built in the room mirror 3,
The communication of the mobile communication device 4 can be performed smoothly without interruption. Moreover, since the rearview mirror 3 functions as an auxiliary antenna, there is no need to install an antenna on a window glass or the like, and there is no hindrance to opening / closing or hindrance to the field of view.

By setting the radio band of the built-in antenna 5, the viewing sensitivity of an AM / FM radio or a television can be improved.

[0019]

As described above, according to the present invention,
Since the antenna provided with the transmission / reception function is provided on the metal reflecting surface of the room mirror, when used as an auxiliary antenna for mobile communication devices, the communication state can be smoothly used without interruption. In addition, since the room mirror has an antenna function, unlike the case where the antenna is installed on the window glass, there is no hindrance to opening / closing or hindrance to the field of view.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle equipped with an antenna device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a room mirror incorporating the antenna device according to the embodiment of the present invention.

FIG. 3 is a perspective view of the same room mirror as viewed obliquely from the front.

FIG. 4 is a block diagram showing a schematic configuration of an auxiliary circuit provided in the antenna device of the room mirror.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Car body 2 Front window 3 Rearview mirror 3B Metal reflective surface 4 Mobile communication equipment 5 Antenna

Claims (1)

[Claims] 1. An antenna device for a vehicle, wherein an antenna having a function of transmitting and receiving radio waves is installed on a metal reflecting surface of a room mirror disposed inside a front window of the vehicle.