JP3205195B2 - Output device for automotive equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output device of an in-vehicle device, and more particularly, to an in-vehicle device such as an in-vehicle television and an in-vehicle navigation system, when the traveling speed of the vehicle is reduced to a predetermined speed or less. The present invention also relates to an output device of an in-vehicle device for displaying an electric field intensity of a received television signal on an output unit as electric field intensity image information.

[0002]

2. Description of the Related Art Generally, an in-vehicle television includes a television receiver front end for receiving a signal, a detection circuit for extracting a video signal and an audio signal from a reception signal received by the television receiver front end, A signal selection unit for selectively supplying the video signal and the audio signal obtained by the detection circuit unit to a subsequent output unit, and an output unit (television for reproducing the video signal and the audio signal supplied from the signal selection unit) An image display unit and an audio signal reproduction unit), and a control unit that controls the entire operation. In the vehicle-mounted television having the above configuration, the driver of the car pays attention to the image content displayed on the television image display unit while the vehicle is running, so that the safe driving state is not impaired. Under the control of the control unit, when the vehicle is running, only the audio signal is reproduced by the audio signal reproducing unit (for example, a speaker), and when the vehicle is stopped, the audio signal is reproduced by the audio signal reproducing unit. The display section displays an image of the television video signal.

[0003] When a television signal is received, the in-vehicle navigation system in which the received signal is reproduced by an output unit (image display unit and audio reproduction unit) has a front end for receiving the signal, and a front end for receiving the signal. A detection circuit for extracting a video signal and an audio signal from the received signal;
A navigation operation unit for selectively supplying the video signal and the audio signal obtained by the detection circuit unit to a subsequent output unit; an output unit for reproducing the video signal and the audio signal supplied from the navigation operation unit; And a control unit for controlling the operation of. And in the vehicle-mounted navigation system having the above configuration, under the control of the control unit,
When a television signal is received while the vehicle is running, the map information is displayed on the image display unit, and an audio signal is reproduced on an audio signal reproduction unit (for example, a speaker). When the signal is received, the audio signal reproducing unit reproduces the audio signal, and at the same time, displays the television video signal on the image display unit.

[0004]

In an output device of a known in-vehicle device, in particular, an output device of an in-vehicle television or an in-vehicle navigation system, a display image of a television image signal is viewed while the vehicle is running. It is not possible to know the state of the electric field strength of the television video signal at the place where the car was stopped because the display image of the television video signal can be viewed only by stopping the car. It is. Then, when the state of the electric field strength of the television video signal at the place where the car is stopped is unknown, when the car is stopped at a certain place and the television video signal is displayed there, If the reception state is not good, if the car is moved to another place again and stopped, and the television image signal is displayed at that place, the reception state of the television image signal is again good. If not, the car must be stopped one by one in order to obtain a place with good reception of television video signals, such as moving the car to another place and stopping it, and then stopping at that place It is necessary to repeatedly search for the display of a television image signal, and the output device of a known in-vehicle device, in particular, an in-vehicle television or an in-vehicle navigation system. In the output device down system, there is a problem that can not be stopped with the reception state of the television picture signal to select a good place.

[0005] The present invention is to eliminate the above problems,
It is an object of the present invention to provide an output device of an in-vehicle device capable of knowing a place where a television image signal reception condition is good immediately before a vehicle stops.

[0006]

In order to achieve the above object, the present invention provides a front end for receiving a signal, and a detection circuit for extracting a video signal and an audio signal from a received signal received by the front end. A signal selection unit for selectively supplying a video signal and an audio signal obtained by the detection circuit unit to a subsequent output unit, and an output unit for reproducing a video signal and an audio signal supplied from the signal selection unit And a control unit for controlling the entire operation, and under the control of the control unit, reproduces only the audio signal at the output unit when the vehicle is running, and outputs the video signal and the audio signal at the output unit when the vehicle stops. In the output device of the in-vehicle television for reproducing the, when the control unit detects that the traveling speed of the vehicle has been reduced to a predetermined speed or less, the control unit detects the electric field strength of the received signal received by the front end Via the signal selection unit the detected electric field strength as the electric field strength information supplied to the output section, comprising a first means for displaying in the form of image information in the output section.

According to another aspect of the present invention, there is provided a front end for receiving a signal, a detection circuit for extracting a video signal and an audio signal from a reception signal received by the front end, and the detection circuit. A navigation operation unit that selectively supplies a video signal and an audio signal obtained by the unit to a subsequent output unit; an output unit that reproduces a video signal and an audio signal supplied from the navigation operation unit; And a control unit for controlling the operation. Under the control of the control unit, when the vehicle is running, the output unit reproduces information from the navigation operation unit, and when receiving a television signal, the output unit outputs map information. In the output device of the in-vehicle navigation system, which reproduces the video signal and the audio signal at the output unit when the vehicle stops, The control unit, when detecting that the traveling speed of the vehicle has decreased to a predetermined speed or less, detects the electric field intensity of the reception signal received by the front end, and uses the detected electric field intensity as electric field intensity information as the navigation operation unit. And second means for supplying the image information to the output unit via the display unit and superimposing the map information on the map information in the output unit.

[0008]

In the first means, when the vehicle is traveling at a normal traveling speed, the vehicle approaches a parking (stop) position for stopping the vehicle, and the traveling speed of the vehicle becomes a predetermined speed, for example, 10 km / h.
When the control unit detects that the vehicle has decelerated below, the control unit
The electric field strength of the received signal received by the front end is detected, and the detected electric field strength is supplied to the output unit, that is, the television image display unit via the signal selection unit as the electric field intensity information. The intensity information is displayed in the form of image information, for example, 20 dBμV.

For this reason, according to the first means, when the driver parks (stops) the car, he or she looks at the electric field strength information displayed on the television image display unit, and thereby, the television in advance. It is possible to know a place where the receiving condition of the video signal is good, and to immediately reproduce the image of the television video signal in the good receiving condition when parking (stopping).

In the second means, when the vehicle is traveling at a normal traveling speed, the vehicle stopping the vehicle approaches the parking (stop) position, and the traveling speed of the vehicle is increased to a predetermined speed, for example, 10 km / h. When the control unit detects that the vehicle has decelerated below, the control unit detects the electric field intensity of the received signal received at the front end, and outputs the detected electric field intensity through the navigation operation unit as electric field intensity information, that is, The electric field strength information is supplied to the image display unit, and the electric field intensity information is displayed on the map information in the form of image information, for example, 20 dBμV.

[0011] Therefore, according to the second means, when the driver parks (stops) the car, he / she looks at the electric field strength information displayed on the image display unit, and thereby, the television image is displayed in advance. It is possible to know a place where the signal reception state is good, and to immediately reproduce an image of the television video signal in a good reception state when parking (stopping).

[0012]

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

FIG. 1 is a block diagram showing the configuration of a first embodiment of an output device of a vehicle-mounted device according to the present invention, and shows an example applied to a vehicle-mounted television as the vehicle-mounted device. . FIG. 2 is a display state explanatory diagram showing an example when the electric field intensity display information is displayed on the television image display unit 4V in the first embodiment shown in FIG.

1 and 2, reference numeral 1 denotes a front end of a television receiver, 2 denotes a detection circuit unit, 3 denotes a signal selection unit, 4 denotes an output unit, 4V denotes a television image display unit, and 4S.
Is a speaker (audio signal reproducing unit), 5 is a control unit (control unit), 6 is a vehicle speed detecting unit, 7 is a stop detecting unit, and 8 is a receiving antenna.

The television receiver front end 1 includes a high-frequency signal amplifier for amplifying a received high-frequency (RF) signal, and a frequency converter for converting the high-frequency signal into an intermediate frequency signal using a local oscillation frequency. And an intermediate frequency circuit for amplifying and limiting the amplitude of the intermediate frequency signal. The input of the high frequency signal amplifier is connected to the receiving antenna 8, and the output of the intermediate frequency signal of the intermediate frequency circuit is connected to the next detection circuit 2
Supplied to The detection circuit unit 2 detects the input intermediate frequency signal to generate a television video signal and an audio signal, and the obtained television video signal and audio signal are supplied to a subsequent signal selection unit 3. You. Signal selector 3
Under the control of the control unit 5, selectively supplies the input television video signal to the television image display unit 4V, and similarly selectively supplies the input audio signal to the speaker 4S. The output unit 4 includes a television image display unit 4V and a speaker 4S. The television image display unit 4V displays the supplied television video signal as an image, and the speaker 4S outputs the supplied audio signal. The control unit 5 controls the operation of each unit according to a predetermined built-in program, and includes a television receiver front end 1, a signal selection unit 3, a vehicle speed detection unit 6,
It is connected to the stop detection unit 7 and the like. The vehicle speed detector 6 detects that the traveling speed of the vehicle has decreased to a predetermined speed or less, for example, 10 km / h or less, and generates, for example, a vehicle speed pulse and the like, and the vehicle speed pulse is supplied to the control unit 5. You. When the control unit 5 detects that the vehicle has decelerated to a predetermined speed or less, for example, 10 km / h or less, based on the vehicle speed pulse supplied from the vehicle speed detection unit 6, it determines that a deceleration signal has been supplied. The stop detection unit 7 detects a stop state of the vehicle, and generates, for example, a parking signal indicating that the vehicle is in a parking brake setting state, and the parking signal is supplied to the control unit 5.

The on-vehicle television output device having the above configuration operates as follows.

If the vehicle is parked or stopped with the parking brake set, the stop detecting unit 7 generates a parking signal and supplies it to the control unit 5. The control unit 5 supplies a first switching signal to the signal selection unit 3 in response to the supply of the parking signal, and switches the signal selection unit 3 to the first switching state, that is, displays the television image signal on a television image. It is set to a state of supplying the audio signal to the speaker 4S and supplying the audio signal to the speaker 4S. In the first switching state, when a television signal is received by the television receiver front end 1, the television signal is
The signal is converted into an intermediate frequency signal by a television receiver front end 1 and then detected by a detection circuit section 2 to output a television video signal and an audio signal. Detection circuit 2
The television video signal and the audio signal obtained in the step (a) are supplied to the subsequent signal selection unit 3. However, since the signal selection unit 3 is in the first switching state as described above, the television video signal is The audio signal is supplied to the loudspeaker 4S and supplied to the speaker image display unit 4V. For this reason, the image display of the television video signal is performed on the television image display unit 4V, and at the same time, the audio signal is output from the speaker 4S.
In a vehicle-mounted television, images and sounds are reproduced and output at the same time.

Next, assuming that the vehicle starts traveling and the average traveling speed is a normal traveling speed, for example, about 40 km / h, no parking signal is generated from the stop detecting unit 7 and the vehicle speed detecting unit 6 does not generate a deceleration signal. In this case, the control unit 5 enters a state in which the parking signal and the deceleration signal are not supplied, supplies a second switching signal to the signal selection unit 3, and sets the signal selection unit 3 to the second switching state, that is, the television. The video signal is not supplied to the television image display unit 4V, and the audio signal is supplied to the speaker 4S. In the second switching state,
When the television signal is received as in the previous case, when the television video signal and the audio signal extracted and output by the detection circuit unit 2 are supplied to the signal selection unit 3, the signal selection unit 3 , The television video signal is not supplied to the television image display unit 4V, and the audio signal is supplied to the speaker 4S. For this reason, while no image is displayed on the television image display unit 4V, an audio signal is emitted from the speaker 4S, and only the audio is reproduced and output alone on the vehicle-mounted television.

Subsequently, when the driver of the running car tries to put the car in a parking (parking) place such as a parking lot in order to view the image of the television image signal being received, the car is targeted. Assuming that the speed of the vehicle decreases when approaching a parking lot or the like, and decreases to, for example, 10 km / h or less, a speed reduction signal is generated from the vehicle speed detection unit 6 and supplied to the control unit 5. In this case, since the parking signal is not supplied from the stop detecting unit 7, the control unit 5 continues to supply the second switching signal to the signal selecting unit 3, and sets the signal selecting unit 3 to the second switching state, that is, the second switching state. In this state, the television video signal is not supplied to the television image display unit 4V, and the audio signal is supplied to the speaker 4S. On the other hand, the control unit 5 detects the electric field strength of the television signal received by the television receiver front end 1 in response to the supplied deceleration signal, and uses the detected electric field strength as electric field strength information, that is, The signal is converted into the form of a display image indicating the electric field strength and supplied to the signal selection unit 3. Here, when the television signal is received as in the previous case, when the television video signal and the audio signal extracted and output by the detection circuit unit 2 are supplied to the signal selection unit 3, the signal selection unit 3 Is in the second switching state, the television video signal is not supplied to the television image display unit 4V, and the audio signal is
S, but the signal selection unit 3 supplies the electric field intensity information supplied from the control unit 5 to the television image display unit 4V. As shown in FIG. 5, the electric field strength information, that is, the display image indicating the electric field strength is, for example, 20d
It is displayed as BμV.

Therefore, the driver of the car decelerates appropriately in the parking lot or the like while watching the display image indicating the electric field strength displayed on the television image display section 4V, and the reception state of the television image signal is compared. If the vehicle is parked (stopped) in a place with a good target, it is possible to view the image display of the television image signal in a relatively good reception state in the parked (stopped) vehicle.

As described above, in the present embodiment, when parking (stopping) the car, the driver of the car looks at the electric field intensity information displayed on the television image display section, and thereby, the television driver previously performs the operation. It is possible to know a place where the reception condition of the video signal is good, and when parking (stopping), without searching for a place where the reception condition of the television video signal is good, the television picture is immediately received in a good reception condition. The signal can be reproduced as an image.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the output device of the vehicle-mounted device according to the present invention, showing an example in which the output device is applied to a vehicle-mounted navigator system as the vehicle-mounted device. It is. FIG. 4 is a display state explanatory diagram showing an example of a case where electric field strength display information is displayed on the image display section 11V in the second embodiment shown in FIG.

3 and 4, 1 'is a front end, a diversity receiving unit, 10 is a navigator operating unit, 11 is an output unit, 11V is an image display unit, 11S is a speaker (audio signal reproducing unit), and 12 (1 ) To 12 (4)
Is a diversity antenna, and the same components as those shown in FIG. 1 are denoted by the same reference numerals.

The front end 1 'is substantially the same as the front end 1 of the television receiver shown in FIG. 1, and includes a high frequency signal amplifying section for amplifying a received high frequency (RF) signal, And a frequency converter for converting the intermediate frequency signal into an intermediate frequency signal using the local oscillation frequency, and an intermediate frequency circuit for amplifying and limiting the amplitude of the intermediate frequency signal.
And the intermediate frequency signal output of the intermediate frequency circuit is supplied to the succeeding detection circuit 2. The diversity receiving unit 9 selects the radio wave in the best reception state among the radio waves received by the plurality, in this example, four, of the diversity antennas 12 (1) to 12 (4), and successively selects the radio wave as a received signal. To the front end 1 ′. The navigator operation unit 10 achieves the functions of a normal navigator system and controls the detection circuit unit 2 under the control of the control unit 5.
Is selectively supplied to the image display unit 11V, and the audio signal is selectively supplied to the speaker 11S.
To supply. The output unit 11 includes an image display unit 11V and a speaker 11S. The image display unit 11V displays the supplied various image signals as images, and the speaker 11S outputs the supplied audio signal. Also, the detection circuit unit 2,
The configurations and functions of the control unit 5, the vehicle speed detection unit 6, and the stop detection unit 7 are the same as those of the detection circuit unit 2, the control unit 5, the vehicle speed detection unit 6, and the stop detection unit 7 illustrated in FIG. Therefore, description of these configurations and functions will be omitted.

The output device of the on-vehicle navigator system according to the above configuration operates as follows.

First, when the vehicle is parked or stopped with the parking brake set, a parking signal from the stop detecting unit 7 is supplied to the control unit 5. The control unit 5 supplies the first switching signal to the navigator operation unit 10 in response to the supply of the parking signal, and switches the navigator operation unit 10 to the first switching state, that is, displays the image signal on the image display unit 1.
It is set to a state where it is supplied to 1 V and an audio signal is supplied to the speaker 11S. When the television signal is received by the diversity receiving unit 9 in the first switching state, the television signal is converted into an intermediate frequency signal by the front end 1, then detected by the detection circuit unit 2, and The video signal and the audio signal are output. The television video signal and audio signal obtained by the detection circuit unit 2 are supplied to the subsequent navigator operation unit 10, but since the navigator operation unit 10 is in the first switching state as described above,
A television image signal is supplied to the image display unit 11V,
The audio signal is supplied to the speaker 11S. For this reason, an image display of the television video signal is performed on the image display unit 11V, and at the same time, an audio signal is output from the speaker 11S. In the in-vehicle navigator system, the image and the audio of the received television signal are reproduced simultaneously. Is output.

Next, when the vehicle starts running and the average running speed is a normal running speed, for example, about 40 km / h, the parking signal generated by the stop detecting unit 7 and the vehicle speed detecting unit 6 generate the signal. Is not supplied to the control unit 5. In this case, the control unit 5 supplies the second switching signal to the navigator operation unit 10 by not supplying the parking signal and the deceleration signal, and switches the navigator operation unit 10 to the second switching state, that is, only the predetermined image signal. Is supplied to the image display unit 4V, and the audio signal is supplied to the speaker 4S. In the second switching state, when the television signal is received by the diversity receiving unit 9 as in the previous case, the television video signal and the audio signal extracted and output by the detection circuit unit 2 are transmitted to the navigator operating unit. When 10 is supplied, the navigator operation unit 10 is in the second switching state, so that only the map information is supplied to the image display unit 11V without the television image signal being supplied to the image display unit 11V. The audio signal is supplied to the speaker 4S. For this reason, a map screen is displayed on the image display unit 11V, and at the same time, an audio signal is emitted from the speaker 11S. In the in-vehicle navigator system, only the audio of the received television signal is reproduced and output alone. .

Subsequently, when the driver of the running car tries to put the car in a parking (parking) place such as a parking lot in order to see the image of the television image signal being received, the car is the target. Assuming that the speed of the vehicle decreases when approaching a parking lot or the like and, for example, decreases to 10 km / h or less, a deceleration signal generated from the vehicle speed detection unit 6 is supplied to the control unit 5. Also in this case, since the parking signal is not supplied from the stop detection unit 7, the control unit 5 still supplies the second switching signal to the navigator operation unit 10 and sets the navigator operation unit 10 to the second switching state, that is, In this state, the television image signal is not supplied to the image display unit 11V, and the audio signal is supplied to the speaker 11S. Further, the control unit 5 responds to the supplied deceleration signal,
The electric field intensity of the received television signal obtained by the television receiver front end 1 is detected, and the detected electric field intensity is converted into electric field intensity information, that is, converted into a display image indicating the electric field intensity. Supply. Here, when the television signal is received, the television video signal and the audio signal extracted and output by the detection circuit section 2 are supplied to the navigator operation section 10 when the navigator operation section 10 is supplied.
According to the second switching state, only the map information is supplied to the image display unit 11V without supplying the television image signal to the image display unit 11V, and only the audio signal is supplied to the speaker 11S. The unit 10 displays the electric field strength information supplied from the control unit 5 on the image display unit 11.
4, the electric field intensity information, that is, a display image indicating the electric field intensity is displayed on the image display unit 11V so as to be superimposed on the map information, for example, 20 dBμV, as shown in FIG. Become so.

Also in this case, the driver of the car
While watching the display image indicating the electric field strength displayed on the image display unit 11V, the vehicle is appropriately decelerated in a parking lot or the like, and parked (stopped) in a place where the reception state of the television image signal is relatively good. Then, it is possible to view the image display of the television image signal in a relatively good reception state in the parked (stopped) vehicle.

As described above, also in the present embodiment, when parking (stopping) the car, the driver of the car looks at the electric field strength information displayed on the image display section 11V, and thus the television picture is displayed in advance. It is possible to know a place where the signal reception condition is good, and when parking (stopping), the television picture signal is immediately received in a good reception state without searching for a place where the television picture signal reception condition is good. Can be reproduced as an image.

[0031]

As described in detail above, claim 1 is as follows.
In the invention described in the above, when the vehicle is traveling at a normal traveling speed, the vehicle approaches a parking (stop) position for stopping the vehicle, and controls that the traveling speed of the vehicle is reduced to a predetermined speed, for example, 10 km / h or less. When the unit 5 detects, the control unit 5 detects the electric field strength of the received signal received by the front end 1,
The detected electric field intensity is supplied as electric field intensity information to the output unit 4 via the signal selecting unit 3, that is, the television image display unit 4V, and the television image display unit 4V converts the electric field intensity information into a form of image information, for example, It is displayed as 20 dBμV.

Therefore, according to the first aspect of the present invention, when the driver parks (stops) the vehicle, he or she looks at the electric field intensity information displayed on the television image display unit 4V, and thereby, Thus, it is possible to know a place where the television video signal is received in a good state, and to immediately reproduce an image of the television video signal in a good reception state when parking (stopping).

Further, in the invention according to claim 2,
When the vehicle is traveling at a normal traveling speed, when the control unit detects that the vehicle stopping the vehicle approaches the parking (stop) position and the traveling speed of the vehicle has been reduced to a predetermined speed, for example, 10 km / h or less, The control unit 5 detects the electric field intensity of the received signal received by the front end 1 ′, and supplies the detected electric field intensity to the output unit 11, that is, the image display unit 11V via the navigation operation unit 10 as electric field intensity information. In the image display section 11V, the electric field intensity information is displayed in the form of the image information, for example, 20 dBμV so as to be superimposed on the map information.

Therefore, according to the second aspect of the present invention, when the driver parks (stops) the car, he or she looks at the electric field strength information displayed on the image display section 11V, and thus, the driver can use the electric field strength information in advance. It is possible to know a good place for receiving the television image signal, and when parking (stopping)
There is an effect that the television video signal can be immediately reproduced in a good reception state.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of an output device of a vehicle-mounted device according to the present invention.

FIG. 2 is a display state explanatory diagram showing an example of a case where electric field intensity display information is displayed on a television image display unit in the first embodiment shown in FIG.

FIG. 3 is a block diagram showing a configuration of a second embodiment of the output device of the vehicle-mounted device according to the present invention.

FIG. 4 is a display state explanatory diagram showing an example of a case where electric field strength display information is displayed on an image display unit in the second embodiment shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Television receiver front end 1 'Front end 2 Detection circuit part 3 Signal selection part 4, 11 Output part 4V Television image display part 4S, 11S Speaker (audio signal reproduction part) 5 Control unit (control part) 6 Vehicle speed detection Unit 7 Stop detection unit 8 Receiving antenna 9 Diversity receiving unit 10 Navigator operating unit 11V Image display unit 12 (1) to 12 (4) Diversity antenna

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-168477 (JP, A) JP-A-5-22171 (JP, A) JP-A-6-99778 (JP, A) JP-A-6-99778 276452 (JP, A) JP-A-1-189289 (JP, A) JP-A-5-224597 (JP, A) JP-A-57-166465 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60R 16/02 640 H04B 1/16 H04N 5/445 H04N 5/64 521

Claims (2)

(57) [Claims] 1. A front end for receiving a signal, a detection circuit for extracting a video signal and an audio signal from a reception signal received by the front end, and a video signal and an audio signal obtained by the detection circuit. A signal selector for selectively supplying the next output unit, an output unit for reproducing a video signal and an audio signal supplied from the signal selector, and a control unit for controlling the overall operation; By the control of the unit, in the output device of the in-vehicle television that reproduces only the audio signal at the output unit when the vehicle is running, and reproduces the video signal and the audio signal at the output unit when the vehicle stops. Detecting that the traveling speed of the vehicle has decreased to a predetermined speed or less, detecting the electric field intensity of the received signal received by the front end, and using the detected electric field intensity as electric field intensity information, An output device for an in-vehicle television, wherein the output device supplies the image data to the output unit via an external device, and displays the image information in the output unit in the form of image information. 2. A front end for receiving a signal, a detection circuit for extracting a video signal and an audio signal from a reception signal received by the front end, and a video signal and an audio signal obtained by the detection circuit. A navigation operation unit for selectively supplying a next output unit, an output unit for reproducing a video signal and an audio signal supplied from the navigation operation unit, and a control unit for controlling overall operation; By the control of the unit, when the car is running, the output unit reproduces information from the navigation operation unit,
In the output device of the in-vehicle navigation system, which reproduces map information and an audio signal at the output unit when receiving a television signal, and reproduces a video signal and an audio signal at the output unit when the vehicle stops. When detecting that the traveling speed of the vehicle has been reduced to a predetermined speed or less, the electric field intensity of the received signal received by the front end is detected, and the detected electric field intensity is used as electric field intensity information via the navigation operation unit. Output to the output unit, and the output unit superimposes and displays the map information in the form of image information.