JPH07322160A - Tv reception system on vehicle - Google Patents

Abstract

PURPOSE:To output the audio signal of a broadcast station having a low field intensity in the middle of running by setting the search sensitivity to the field intensity required for satisfactory reception of the audio signal in the running state and setting it to the field intensity required for satisfactory reception of the video signal in the stop state to detect the presence or the absence or receivable broadcast stations. CONSTITUTION:A parking signal and a vehicle velocity signal are inputted to a microcomputer 5, and the microcomputer 5 is connected to not only a detection block 2 through a search line 5a but also a video switch 3 through a control line 5b. In the running state, the search sensitivity is reduced and is set to the field intensity (prescribed value B) for satisfactory reception of the audio signal to automatically search the broadcast stations; and in the stop state, it is raised and is set to the field intensity (prescribed value A) for satisfactory reception of the video signal to automatically search the broadcast stations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted TV receiving system provided with broadcasting station auto search means.

[0002]

2. Description of the Related Art In a vehicle-mounted TV receiving system, when traveling, the TV screen is turned off and only audio is output in order to ensure safety. Further, as is well known, the electric field strength in the video signal of the broadcasting station is stronger than the electric field strength in the audio signal. In the conventional vehicle-mounted TV receiving system, the auto search of the broadcasting station is performed depending on whether the electric field strength of the broadcasting station is a predetermined value or more,
In that case, the search sensitivity is fixed to the electric field strength that enables good reception of the video signal regardless of whether the vehicle is running or stopped.

[0003]

There is no problem even if the search sensitivity is fixed to the electric field strength as long as the search is stopped. However, as described above, in the in-vehicle TV receiving system, when the vehicle is running, the TV screen is turned off and only the sound is output, and the electric field strength of the audio signal is the electric field strength of the video signal. Since it is set lower than that of the broadcasting station, it is possible to use the fixed search sensitivity of the broadcasting station while driving.
If the search is performed, a broadcasting station that does not have a sufficient electric field strength to receive a video signal but has a sufficiently strong electric field strength to receive an audio signal is received. The problem arises that you cannot do it.
Thus, in the conventional vehicle-mounted TV receiving system,
Even if only audio is output while the vehicle is running, the broadcast station's auto search is performed with a search sensitivity that is fixed to an electric field strength that allows good reception of video signals. There is a problem that a broadcasting station that can sufficiently receive (a broadcasting station with a weak electric field strength) cannot be received if an auto search of the broadcasting station is performed with a search sensitivity set to a favorable electric field strength. there were.

The present invention has been made in view of the above problems. By setting the search sensitivity during running to be lower than the search sensitivity during stopping, a broadcasting station with a weak electric field strength, that is, a video signal is improved. A broadcasting station organizer capable of receiving a broadcasting station which does not have a sufficient electric field strength capable of being received by an audio signal, but has a sufficiently strong electric field strength for an audio signal. It is an object of the present invention to provide a vehicle-mounted TV receiving system equipped with a means.

[0005]

In order to achieve the above object, in a vehicle-mounted TV receiving system according to the present invention, a broadcasting station auto-server which automatically searches receivable broadcasting stations.
In an in-vehicle TV system equipped with a check means, the search sensitivity is set to the electric field strength necessary for good reception of an audio signal while running, and the presence or absence of a broadcasting station is detected. The present invention is characterized by including a broadcasting station auto search means for detecting the presence or absence of a broadcasting station by setting the search sensitivity to the electric field strength required for good reception.

[0006]

In the vehicle-mounted TV receiving system having the above structure, the broadcasting station auto-search means sets the search sensitivity to the electric field strength required to properly receive the audio signal while traveling. During the stop, the search sensitivity is set to the electric field strength required to properly receive the video signal, and the presence or absence of a receivable broadcasting station is detected. As a result, it is possible to receive a broadcasting station that does not have enough electric field strength to receive video signals while traveling, but has enough electric field strength to receive audio signals well. Thus, it becomes possible to receive the broadcasting station and output the audio signal of the broadcasting station.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle-mounted TV receiving system according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a vehicle-mounted TV receiving system according to an embodiment.

In the figure, reference numeral 1 denotes an antenna, which is connected to a detection block 2 which extracts a video signal and an audio signal from a broadcasting station which has received the signal. The video signal output terminal 2b of the detection block 2 is connected to the monitor 4 via the video switch 3, and the audio signal output terminal 2c of the detection block 2 is connected.
Is connected to the speaker 7 via the amplifier 6. Further, the detection block 2 is connected to the microcomputer 5 via the electric field strength output line 2a for transmitting the electric field strength of the received broadcasting station. A parking signal and a vehicle speed signal are input to the microcomputer 5 and the microcomputer 5 is connected to the detection block 2 via a search line 5a and a control line 5b. Is connected to the video switch 3 via.

The auto search method of the broadcasting station in the vehicle-mounted TV receiving system configured as described above will be described with reference to FIG. FIG. 2 is a flow chart showing the operation of the microcomputer 5. First, in step 1, it is determined whether the vehicle is stopped or running. In the case of the vehicle-mounted TV receiving system according to the embodiment,
Based on the parking signal indicating ON / OFF of the parking brake and the vehicle speed signal indicating the vehicle speed, it is determined whether the vehicle is stopped or traveling. That is, if the parking signal is turned on (= parking brake is applied) and the vehicle speed is zero, it is determined that the vehicle is stopped. In other cases, it is determined that the vehicle is running. When it is determined that the vehicle is running, the process proceeds to step 2, and when it is determined that the vehicle is stopped, the process proceeds to step 4.

In step 2, the video switch 3 is turned off, and the video signal output from the video output terminal 2b of the detection block 2 is not transmitted to the monitor 4. Next, in step 3, is the electric field strength of the broadcasting station transmitted from the detection block 2 via the electric field strength output line 2a equal to or greater than a predetermined value B (electric field strength necessary for good reception of audio signals)? It will be judged. If it is determined that the electric field strength of the broadcasting station is equal to or higher than the predetermined value B, the process proceeds to step 6 and the server
Hatch operation is stopped, and the audio signal of the received broadcasting station is sped up.
It is output from mosquito 7. On the other hand, if it is determined that the electric field strength of the broadcasting station has not reached the predetermined value B, the process moves to step 7, the next broadcasting station is searched, and the process from step 1 is performed again.

In step 4, the video switch 3 is turned on, and the video signal output from the video signal output terminal 2b of the detection block 2 is transmitted to the monitor 4. Next step 5
At the detection block 2 via the electric field strength output line 2a.
It is determined whether or not the electric field strength of the broadcasting station transmitted from is equal to or higher than a predetermined value A (the electric field strength required to satisfactorily receive the video signal). Here, the predetermined value A and the predetermined value B
Is in a relation of A = B + α, and α represents a difference between the electric field intensity B required to properly receive the audio signal and the electric field intensity A required to properly receive the video signal. Also α>
It is 0.

When it is determined that the electric field strength of the broadcasting station is equal to or higher than the predetermined value A, the process proceeds to step 6, the search operation is stopped, and the video signal of the received broadcasting station is output to the monitor 4 and the audio signal is output. The signal is output to the speaker 7. On the other hand, when it is determined that the electric field strength of the broadcasting station has not reached the predetermined value A, the process moves to step 7, the next broadcasting station is searched, and the process from step 1 is performed again.

As described above, the vehicle-mounted T according to the embodiment
In the V reception system, the search sensitivity is set low to the electric field strength (predetermined value B) at which the audio signal can be satisfactorily received while the vehicle is running, and the broadcasting station auto-search is performed. During the stop, the search sensitivity is set high to the electric field strength (predetermined value A) that allows good reception of the video signal, and the auto search of the broadcasting station is performed. That is, while the vehicle is stopped, the auto search of the broadcasting station is performed by a method similar to that of the conventional vehicle-mounted TV receiving system, but when the vehicle is running, the search sensitivity is set to a predetermined value B lower than when the vehicle is stopped. Therefore, in the vehicle-mounted TV receiving system according to the embodiment, the broadcasting station with a weak electric field strength (= the video signal can be received satisfactorily during traveling). A broadcasting station that does not have the electric field strength of, but has an electric field strength that can receive audio signals sufficiently well) can output the audio of the received broadcasting station. it can.

[0014]

As described in detail above, in the vehicle-mounted TV receiving system according to the present invention, the conventional vehicle-mounted T
The broadcasting station can be received in the same manner as in the V reception system. On the other hand, since the search sensitivity is set to the electric field strength capable of receiving the audio signal satisfactorily during traveling, it does not have the electric field strength capable of receiving the video signal satisfactorily. -A broadcasting station with an electric field strength higher than the sensitivity (a conventional vehicle-mounted T
It becomes possible to receive a broadcasting station which could not be received by the V system), and it is possible to output the received audio signal of the broadcasting station having a weak electric field strength.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a vehicle-mounted TV receiving system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the microcomputer.

[Explanation of symbols]

 2 Detection block 2a Electric field strength output line 2b Video signal output terminal 2c Audio signal output terminal 3 Video switch 5 Microcomputer (broadcasting station search means) 5a Search line

Claims (1)

[Claims] 1. An in-vehicle TV receiving system equipped with a broadcasting station auto search means for automatically searching a receivable broadcasting station, which is required for good reception of an audio signal while traveling. The presence or absence of a broadcasting station is detected by setting the search sensitivity to the electric field strength, and the presence or absence of the broadcasting station is detected by setting the search sensitivity to the electric field strength necessary to receive a good video signal while stopped. An in-vehicle TV receiving system comprising a broadcasting station auto search means.