JP2006217581A - Adapter device for car radio - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adaptor device for a car radio capable of improving the receiving state. <P>SOLUTION: The adaptor device 20 for a car radio is connected to a vehicle-mounted antenna connection terminal 12 provided in an FM radio receiver 10 installed within a vehicle room, and includes a signal line inserted between the vehicle-mounted antenna connection terminal 12 and a vehicle-mounted antenna 110; and an in-vehicle antenna 22 branching out from the signal line. A radio wave transmitted from an FM transmitter 40 disposed within the vehicle room via an antenna 42 is received by the radio receiver 10 via the in-vehicle antenna 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adapter device for a car radio that is used by being connected to an on-vehicle car radio.

2. Description of the Related Art Conventionally, an in-vehicle system in which an FM transmitter is connected to an audio playback player and the like and a radio wave transmitted from the FM transmitter is received by a car radio is known (for example, see Patent Document 1). In this in-vehicle system, an in-vehicle antenna is used for receiving radio waves by a car radio.
JP-A-6-309854 (page 3-4, Fig. 1-3)

  By the way, in the vehicle-mounted system disclosed in Patent Document 1 described above, the radio wave transmitted from the FM transmitter installed in the vehicle interior is received using the vehicle-mounted antenna provided outside the vehicle body, so the reception state is poor. There was a problem of becoming. Patent Document 1 describes that the FM transmitter and the vehicle-mounted antenna are extremely close to each other, and therefore can be received without any trouble using the vehicle-mounted antenna. However, most of the vehicle body is metal, and the rear window Is often equipped with a pattern conductor for defrosting, making it difficult for radio waves transmitted from FM transmitters installed in the passenger compartment to reach the vehicle-mounted antennas installed near the trunk, etc. If the transmission level of the radio wave transmitted from the FM transmitter is low, it is difficult to receive the signal through the in-vehicle antenna.

  The present invention has been created in view of such a point, and an object thereof is to provide an adapter device for a car radio that can improve a reception state.

  In order to solve the above-described problem, the adapter device for a car radio according to the present invention is connected to a connection terminal for an in-vehicle antenna provided in an FM radio receiver installed in a vehicle interior. A signal line inserted between the antenna and an in-vehicle antenna branched from the signal line is provided. By mounting the car radio adapter device between the FM radio receiver mounted on the vehicle and the in-vehicle antenna, the in-vehicle antenna is connected to the FM radio receiver, and the transmitted radio wave of the FM transmitter used in the vehicle interior Since it can receive via an in-vehicle antenna, it becomes possible to improve a receiving state compared with the case where it receives by a vehicle-mounted antenna.

  Moreover, it is desirable that the above-described vehicle interior antenna is directly connected to the signal line. As a result, it is possible to receive radio waves transmitted into the vehicle compartment in a relatively good state with a simple configuration.

  Further, it is desirable to further include a balun inserted in the middle of the signal line described above, and to connect the signal line and the vehicle interior antenna via the balun. This makes it easy to achieve impedance matching when connecting both the in-vehicle antenna and the in-vehicle antenna to the FM radio receiver via the car radio adapter device, and supports radio waves received by the in-vehicle antenna and the in-vehicle antenna. Can be efficiently input to the FM radio receiver.

  In addition, the above-described vehicle interior antenna is a conductive wire in which a flexible metal conductor is covered with an insulating member, and is preferably exposed to the outside from a housing in which the signal line is stored. Thereby, the in-vehicle antenna pulled out from the adapter device for car radio can be easily stored in the gap in the dashboard.

  The above-mentioned in-car antenna is a conducting wire in which a non-flexible metal conductor is covered with an insulating member, and is disposed outside the housing in which the signal line is stored and is arranged substantially parallel to the longitudinal direction of the housing. It is desirable that This makes it possible to reduce the amount of protrusion of the in-vehicle antenna to the outside of the car radio adapter device.

  In addition, the above-described vehicle interior antenna is preferably a conductor mounted on the front surface or the back surface of the housing in which the signal line is accommodated. Thereby, it is possible to prevent the in-vehicle antenna from protruding from the car radio adapter device to the outside.

  In addition, the above-described vehicle interior antenna is desirably formed in a spiral shape along the front surface or the back surface of the housing. Thereby, while ensuring the length of a vehicle interior antenna, it can suppress that a vehicle interior antenna protrudes outside a housing | casing.

  Further, the above-described vehicle interior antenna is a bar antenna in which a coil is wound around a magnetic core, and is preferably disposed in a housing in which a signal line is accommodated. Thereby, a vehicle interior antenna can be reduced in size and it can accommodate reliably in a housing | casing.

  In addition, the above-described vehicle interior antenna is preferably connected to the signal line via a loading coil. Since the effective length of the entire antenna including the loading coil and the in-vehicle antenna can be increased, a short in-vehicle antenna can be used, and the in-vehicle antenna can be easily built in the adapter device for the car radio. It is possible to reduce the size of the adapter device.

  Moreover, it is desirable that the housing described above is formed using a flexible member. Thereby, it becomes possible to install the adapter device for car radios using the narrow space in a dashboard.

  Hereinafter, a car radio adapter device according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of an in-vehicle system including a car radio adapter device according to an embodiment. The in-vehicle system shown in FIG. 1 includes a radio receiver 10, an adapter device 20, a portable device 30, and an FM transmitter 40 mounted on the vehicle 100. The radio receiver 10 is mounted on the dashboard of the vehicle 100, receives FM radio broadcasts and AM radio broadcasts, and outputs audio signals corresponding to the contents of each broadcast. This audio signal is output from a speaker (not shown) mounted on the vehicle 100 toward the vehicle interior. The radio receiver 10 has a connection terminal 12 for an in-vehicle antenna, and an in-vehicle antenna 110 exposed to the outside of the vehicle 100 is connected to the connection terminal 12 via an adapter device 20.

  The adapter device 20 is for branching the in-vehicle antenna 22 between the radio receiver 10 and the in-vehicle antenna 110. FIG. 2 is a diagram illustrating the configuration of the adapter device 20. As shown in FIG. 2, the adapter device 20 includes a signal line 21 inserted between the connection terminal 12 provided in the radio receiver 10 and the in-vehicle antenna 110, and an in-vehicle antenna 22 branched from the signal line 21. It has. In this example, a branch to the vehicle interior antenna 22 is provided at an intermediate position of the signal line 21 constituted by a coaxial cable or the like. The adapter device 20 includes a connection terminal 24 to which one end of the signal line 21 is connected in order to connect the vehicle-mounted antenna 110. The connection terminal 24 has the same shape as the connection terminal 12 provided in the radio receiver 10. Thereby, in the conventional case (when the adapter device 20 is not used), the connection destination in which the end of the connection line on the vehicle-mounted antenna 110 side is connected to the connection terminal 12 of the radio receiver 10 is changed to the adapter device 20. It is only necessary to change to the connection terminal 24, and it is not necessary to change the wiring form on the vehicle-mounted antenna 110 side at all.

  A portable device 30 shown in FIG. 1 is an audio device or a mobile phone that is carried by a passenger such as a driver, and an output audio signal is input to the FM transmitter 40. The FM transmitter 40 FM-modulates the audio signal input from the portable device 30 and transmits it from the antenna 42.

  Thus, by mounting the adapter device 20 between the radio receiver 10 mounted on the vehicle 100 and the in-vehicle antenna 110, the in-vehicle antenna 22 is connected to the radio receiver 10, and the FM transmitter used in the vehicle interior. Since 40 radio waves can be received by the radio receiver 10 via the in-vehicle antenna 22, the reception state can be improved as compared with the case of receiving by the in-vehicle antenna 110. In particular, by directly connecting the vehicle interior antenna 22 to the signal line 21 in the adapter device 20, it is possible to receive radio waves transmitted to the vehicle interior in a relatively good state with a simple configuration.

  FIG. 3 is a diagram illustrating a modification of the adapter device. The adapter device 20 </ b> A illustrated in FIG. 3 includes a balun 26. The balun 26 is an impedance conversion transformer, and the in-vehicle antenna 110 is connected to the primary side winding via the connection terminal 24, the radio receiver 10 is connected to one side winding of the secondary side, and the inside of the vehicle is connected to the other side winding. An antenna 22 is connected.

  FIG. 4 is a diagram illustrating another modification of the adapter device. 4 includes a balun 28. The adapter device 20B illustrated in FIG. The balun 28 has a configuration different from that of the balun 26 shown in FIG. 3. A tap provided on the primary winding is grounded, and the vehicle-mounted antenna 110 is connected to one end of the winding, and the other end is connected. The in-vehicle antenna 22 is connected to. The radio receiver 10 is connected to the secondary winding.

  As described above, when the balun 26 shown in FIG. 3 and the balun 28 shown in FIG. 4 are used, when both the in-vehicle antenna 110 and the in-vehicle antenna 22 are connected to the radio receiver 10 through the adapter devices 20A and 20B. Therefore, it is possible to reduce the loss of a signal corresponding to the radio wave received by each of the in-vehicle antenna 110 and the in-vehicle antenna 22 and efficiently input the radio receiver 10.

  FIG. 5 is a diagram illustrating a specific example of an in-vehicle antenna connected to the adapter device 20. An in-vehicle antenna 22 </ b> A shown in FIG. 5 is a conducting wire in which a flexible metal conductor is covered with an insulating member, and is exposed to the outside from the housing of the adapter device 20. Thereby, the vehicle interior antenna 22A pulled out from the adapter device 20 can be easily stored in the gap in the dashboard.

  FIG. 6 is a diagram illustrating another specific example of the vehicle interior antenna connected to the adapter device 20. The in-vehicle antenna 22B shown in FIG. 6 is a conducting wire in which an inflexible metal conductor is covered with an insulating member, and is arranged outside the housing of the adapter device 20 and substantially parallel to the longitudinal direction of the housing. Yes. Thereby, it becomes possible to reduce the protrusion amount of the in-vehicle antenna 22B to the outside of the adapter device 20.

  FIG. 7 is a diagram illustrating another specific example of the vehicle interior antenna connected to the adapter device 20. The in-vehicle antenna 22 </ b> C illustrated in FIG. 7 is attached to the surface of the housing of the adapter device 20. Thereby, the in-vehicle antenna 22C from the adapter device 20 to the outside can be prevented from protruding. The in-vehicle antenna 22C may be mounted on the back surface (inner surface) of the housing.

  FIG. 8 is a diagram illustrating another specific example of the vehicle interior antenna connected to the adapter device 20. 8 is formed in a spiral shape along the surface of the housing of the adapter device 20. Thereby, while ensuring the length of in-vehicle antenna 22D, it can suppress that in-vehicle antenna 22D protrudes outside a housing | casing. The vehicle interior antenna 22D may be mounted on the back surface (inner surface) of the housing.

  FIG. 9 is a diagram illustrating another specific example of the vehicle interior antenna connected to the adapter device 20. An in-vehicle antenna 22E shown in FIG. 9 is a bar antenna in which a coil is wound around a magnetic core such as a ferrite core, and is provided in a housing of the adapter device 20. Thereby, the in-vehicle antenna 22E can be reduced in size and securely stored in the housing.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, the casing of the adapter device 20 may be formed using a flexible member. Thereby, it is possible to change the shape of the housing according to the shape of the space on the back side of the radio receiver 10 using the narrow space in the dashboard, and the adapter device 20 can be easily installed. It becomes.

  In the embodiment described above, in the example shown in FIGS. 5 to 8, the antennas 22 </ b> A to 22 </ b> D are formed outside the casing of the adapter device 20 or on the surface of the casing. Good. Further, it is desirable that the various in-vehicle antennas 22A and the like illustrated in FIGS. 5 to 9 are installed in a direction in which the reception state is favorable with respect to the antenna 42 provided in the FM transmitter 40. For example, the in-vehicle antenna 22B shown in FIG. 6, the in-vehicle antenna 22C shown in FIG. 7, and the in-vehicle antenna 22E shown in FIG. 9 are desirably arranged so that the longitudinal direction is substantially perpendicular to the direction in which the antenna 42 exists. . Further, it is desirable that the antenna 22D shown in FIG. 8 is arranged such that the spiral center line is substantially parallel to the direction in which the antenna 42 exists.

  In the above-described embodiment, the in-vehicle antenna 22 or the like is connected to the signal line 21 in the adapter device directly or through the baluns 26 and 28. However, the in-vehicle antenna 22 or the like is connected through the loading coil. Also good.

  FIG. 10 is a diagram showing a specific example of an adapter device in which a loading coil is built. The adapter device 20C shown in FIG. 10 is inserted between the signal line 21, the balun 26 (or balun 28), the built-in U-shaped (or linear) in-vehicle antenna 22F, and the balun 26 and the in-vehicle antenna 22F. Loading coil 23 is provided. By providing the loading coil 23, the effective length of the entire antenna including the loading coil 23 and the in-vehicle antenna 22F can be increased, so that the short in-vehicle antenna 22F can be used. For this reason, it becomes easy to incorporate the vehicle interior antenna 22F in the adapter device 20C, and the adapter device 20C can be miniaturized. In addition, you may make it add the loading coil 23 in the various adapter apparatuses shown in FIGS.

1 is a diagram illustrating an overall configuration of an in-vehicle system including a car radio adapter device according to an embodiment. It is a figure which shows the structure of an adapter apparatus. It is a figure which shows the modification of an adapter apparatus. It is a figure which shows the other modification of an adapter apparatus. It is a figure which shows the specific example of the vehicle interior antenna connected to an adapter apparatus. It is a figure which shows the other specific example of the vehicle interior antenna connected to an adapter apparatus. It is a figure which shows the other specific example of the vehicle interior antenna connected to an adapter apparatus. It is a figure which shows the other specific example of the vehicle interior antenna connected to an adapter apparatus. It is a figure which shows the other specific example of the vehicle interior antenna connected to an adapter apparatus. It is a figure which shows the specific example of the adapter apparatus with which the loading coil was incorporated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Radio receiver 12, 24 Connection terminal 20 Adapter apparatus 21 Signal line 22 Car interior antenna 26, 28 Balun 30 Portable apparatus 40 FM transmitter 42 Antenna 100 Vehicle 110 Car-mounted antenna

Claims (10)

A car radio adapter device connected to an in-vehicle antenna connection terminal of an FM radio receiver installed in a vehicle interior,
A car radio adapter device comprising: a signal line inserted between the in-vehicle antenna connection terminal and the in-vehicle antenna; and an in-vehicle antenna branched from the signal line. In claim 1,
The car radio adapter device, wherein the vehicle interior antenna is directly connected to the signal line. In claim 1,
Further comprising a balun inserted in the middle of the signal line,
A car radio adapter device, wherein the signal line and the in-vehicle antenna are connected via the balun. In any one of Claims 1-3,
The car radio adapter device, wherein the vehicle interior antenna is a conducting wire in which a flexible metal conductor is covered with an insulating member, and is exposed to the outside from a housing in which the signal line is stored. In any one of Claims 1-3,
The in-vehicle antenna is a conductive wire in which a non-flexible metal conductor is covered with an insulating member, and is disposed outside the casing in which the signal line is accommodated and substantially parallel to the longitudinal direction of the casing. A car radio adapter device. In any one of Claims 1-3,
The car radio adapter device, wherein the vehicle interior antenna is a conductor mounted on a front surface or a back surface of a housing in which the signal line is stored. In claim 6,
The car radio adapter device, wherein the vehicle interior antenna is formed in a spiral shape along a front surface or a back surface of the housing. In any one of Claims 1-3,
The car radio adapter device, wherein the vehicle interior antenna is a bar antenna in which a coil is wound around a magnetic core, and the vehicle interior antenna is disposed in a housing in which the signal line is accommodated. In claim 1,
The car radio adapter device, wherein the in-vehicle antenna is connected to the signal line via a loading coil. In any one of Claims 4-9,
The car radio adapter device, wherein the casing is formed using a flexible member.

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