JPS63233627A - Sound multiplexing controller for on-vehicle broadcasting receiver - Google Patents

Abstract

PURPOSE:To remove the mixing of sound due to multiplex broadcast and monaural and to realize broadcasting with resulting high sound definition, by switching a mode at the time of deciding the travel state of a vehicle by a decision means. CONSTITUTION:In a state where the mode is set at a double mode or a stereo mode to receive sound multiplex broadcast by remote control switches 6 and 7, a microcomputer 5 continues the double mode or the stereo mode if the speed of the vehicle is set at less than 1km/h by a signal from a speed sensor 10 when receiving the sound multiplex broadcast, and outputs a main and a sub channel signals of an FM demodulation circuit 3 as they are as voice signals. Also, the microcomputer 5, when judging the speed as the one exceeding 1km/h, that is the vehicle is in travel by the signal from the speed sensor 10, sets the mode at a monaural mode compulsorily by controlling a sound multiplex switching circuit 4, and invalidates the sub channel signal of the FM demodulation circuit 3, and outputs the main channel signal as the voice signal. In such a way, it is possible to set the mode at the monaural mode and to realize the broadcasting with resulting high definition in which no mixing of sound exists.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an audio multiplex control device for a vehicle-mounted broadcast receiver that is mounted on a vehicle and is capable of receiving audio multiplex broadcasts.

(Prior Art) Conventionally, in television audio multiplex broadcasting, it has been possible to listen to stereo or dual audio broadcasting according to control signals included in radio waves output from each broadcasting station. The in-vehicle television receiver installed in the vehicle demodulates the radio waves from the audio multiplex broadcast, making it possible to listen to the audio multiplex broadcast, that is, stereo or dual audio broadcast, inside the car. Ta.

(Problems to be Solved by the Invention) However, in the radio wave carrier space, radio waves interfere with each other due to reflections from buildings, etc., and standing waves are formed. When a vehicle runs through these standing waves, there is a problem in that it is not possible to secure the minimum electric field strength of about 45 dBμ required to discriminate the control signals. In other words, when receiving audio multiplex broadcasts, when the vehicle is in a running state, there will be points at various locations where control signals cannot be received, and it will not be possible to determine whether the audio multiplex broadcasts are monaural or monaural, resulting in confusion between multiplex broadcasts and monaural audio. This resulted in an extreme loss of audio quality.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, to provide an audio multiplexing control device for a car-mounted broadcast receiver, which eliminates the confusion of audio due to multiplex broadcasting and monaural broadcasting, and allows the user to listen to broadcasting with higher audio quality. It is about providing.

(Means for Solving the Problems) The present invention has been made to achieve the above object, and includes a receiver mounted on a vehicle for receiving monaural broadcasts and audio multiplex broadcasts, mode switching means for switching between a multiplex mode for outputting the received signal output from the receiver as a multiplexed audio signal and a monaural mode for outputting the received signal as a monaural audio signal; The gist thereof is a direct audio multiplex control 1A of a vehicle-mounted broadcast receiver, which is equipped with a mode switching control means for switching the mode switching means to the monaural mode when the running state of the vehicle is determined.

(Function) With the above configuration, the determination means determines whether the vehicle is in a stopped state or a running state, and the mode switching control means switches the receiver via the mode switching means when the determination means determines the running state of the vehicle. Even though multiple broadcasting is being received, the received signal output from the same receiver is switched to a monaural mode so as to be output as a monaural audio signal.

(Example) An example embodying the present invention will be described below with reference to the drawings.

FIG. 1 shows the electrical configuration of an audio multiplex control device for a vehicle-mounted television receiver according to the present invention, in which broadcast radio waves transmitted from a broadcasting station are received by an antenna 1 of the receiver. The tuner 2 tunes the frequency of the radio waves of the selected broadcasting station. The output signal from the tuner 2 consists of a video signal to a video system circuit (not shown) and an audio output signal to be output to the FM demodulation circuit 3. This audio output signal includes only the main channel signal in the case of monaural broadcasting, or the main channel signal, sub-channel signal, and control signal for determining whether it is a dual audio signal or a stereo audio signal in the case of audio multiplex broadcasting. include.

The FM demodulation circuit 3 performs audio multiplex demodulation if there is a sub-channel signal and a control signal, and performs monaural demodulation if there is only a main channel signal. Further, the FM demodulation circuit 3 discriminates a control signal from the output signal of the tuner 2, demodulates the main channel signal and the sub-channel signal according to this control signal, and outputs the demodulated main channel signal and the sub-channel signal to the audio multiplexing switching circuit 4. In other words, in the case of dual language broadcasting (double broadcasting), the main channel signal is Japanese and the foreign language is the sub channel signal, and in the case of stereo broadcasting, the main channel signal is the sum of left and right signals as the sub channel signal. Outputs the left and right difference signals.

The audio multiplex switching circuit 4 switches the audio signals to be output based on command signals from a microcomputer 5 serving as determination means, mode switching means, and mode switching control means. The modes of this receiver include a monaural mode in which the audio signal is output as a monaural audio signal, a duplex mode in which the audio signal is output as a dual audio signal, and a stereo mode in which the audio signal is output as a stereo audio signal. and,
In the case of duplex and stereo modes, the input main and sub channel signals are output as they are as audio signals, and in the monaural mode, audio multiplex broadcasting is received and the sub channel signal of the input main channel signal and sub channel signal is output. is disabled and only the main channel signal is output as an audio signal.

The receiver is also provided with a wire remote control switch 6 and a wireless remote control switch 7, both switches 6.7.
The output signal is outputted to the microcomputer 5 via an OR circuit 8 and a decoder 9. Therefore, the microcomputer 5 inputs operation signals for selecting a channel (station), monaural or dual broadcast reception, or stereo broadcast reception using the wire remote control switch 6 or the wireless remote control switch 7. The microcomputer 5 controls the tuner 2 to receive a predetermined station, and sets monaural mode, duplex mode, and stereo mode.

The vehicle speed sensor 10 outputs a signal with a frequency corresponding to the vehicle speed of the vehicle, and the signal is converted into a voltage by the F-V conversion circuit 11. A reference voltage setting circuit 12 consisting of resistors R1 and R2 is a circuit for setting a reference voltage for comparison with the voltage output from the F-V conversion circuit 11, and in this embodiment, the vehicle is traveling at a speed of 1 km/h. The voltage is set to be the same as the voltage output from the F-V conversion circuit 11 via the vehicle speed sensor 10 when the vehicle speed sensor 10 is running.

A comparator 13 compares the voltage value from the F-V conversion circuit 11 and the voltage value from the reference voltage setting circuit 12, and sends a signal indicating whether the vehicle speed is 1 km per hour or more, that is, an H level high level signal to the microcomputer. Output to 5.

In this embodiment, this reference voltage is set so that the vehicle speed is 1 km/h, but it may also be set to zero or to 1 km/h or more.

Based on the signal from the comparator 13, the microcomputer 5 determines whether the vehicle is traveling (at a speed of 1 km per hour or more). When the microcomputer 5 is running, even if the remote control switch 6.7 is set so that the audio multiplex broadcast can be heard, the microcomputer 5 forcibly sets the monaural mode and switches the audio multiplex switching circuit so that it becomes monaural. Control 4.

Next, the operation of the audio multiplexing control device for the vehicle-mounted television receiver configured as described above will be explained based on FIG. 2.

The microcomputer 5 is set to the dual mode or stereo mode to receive the audio multiplex broadcast using the remote control switch 6°7, and when the audio multiplex broadcast is being received, the vehicle speed is determined by the signal from the vehicle speed sensor 10. 1k
If it is less than m, the duplex mode or stereo mode is continued and the main and sub-channel signals of the FM demodulation circuit 3 are output as they are as audio signals. Also, microcomputer 5
When the vehicle determines from the signal from the vehicle speed sensor 10 that the vehicle speed is 1 km per hour or more, that is, the vehicle is running, it controls the audio multiplex switching circuit 4 to forcibly set the monaural mode and disables the sub-channel signal of the FM demodulation circuit 3. to output the main channel signal as an audio signal.

As a result, the minimum electric field strength (45 dBμ
), and there is a problem that the audio multiplex broadcast and monaural are mixed up - However, by forcing the car to go to monaural mode, it is always monaural while driving, and you can listen to high-quality broadcasts without mixing up the sound. .

Note that this invention is not limited to the above embodiments,
For example, in the embodiment described above, monaural sound is forcibly set by detecting the running state by the vehicle speed sensor 10, but it may be implemented by detecting the running state as shown in FIG.

In other words, when the same television receiver is installed in an automatic transmission vehicle, Mission 14
An operation signal from the parking side or neutral side operation is outputted to the OR circuit 15, and an output signal of the OR circuit 15 is outputted to the OR circuit 16. or,
A signal from the operation of the parking brake 17 is output to the OR circuit 16, and a signal from the comparator 13 is output to the OR circuit 16.

Then, if the transmission 14 is operated to a position other than the parking side or neutral side, or the parking brake 17
is released, or the vehicle speed sensor 10 may force the monaural sound when the vehicle is in a running state (1 km/h or more).

Further, an AND circuit is used in place of the OR circuit 16, and when the transmission 14 is operated to the parking side or the neutral side, the parking brake 17 is operated, and the vehicle speed sensor 10 roughly indicates that the vehicle is stopped (1 km/h or less). It is also possible to perform audio multiplexing only when this happens, and force monaural output in all other cases.

Alternatively, the monaural sound may be made forcibly based on any two of the operating position of the transmission 14, the operating position of the parking brake 17, and the vehicle speed.

Effects of the Invention As detailed above, according to the present invention, the system is forcibly set to monaural while driving, and even when passing through a point where control signals cannot be received while driving, the user can listen to high-quality broadcasts without audio disturbances. Demonstrates excellent effects that can be achieved.

[Brief explanation of the drawing]

Figure 1 shows the electrical configuration of the audio multiplexing control device for a vehicle-mounted television receiver that embodies the present invention. It is an electric circuit diagram showing the electrical configuration of the audio multiplexing control device of the vehicle-mounted television receiver as an example. In the figure, 4 is an audio multiplexing switching circuit, and 5 is a determining means. Microcomputer, 10 is a vehicle speed sensor Patent applicant
Nippondenso Toyota Motor Corporation Voluntary procedure amendment 1. Indication of the case 1 Dori meta 0 Patent application filed on March 20, 1986 (1) 2, Name of the invention II Tagawa broadcasting receiver audio multiplex hl'llJ @ Akane 3, Amendment person case and Relationship: Patent applicant 4, agent drawing 6, contents of amendment Figures 1 and 3 of the inner cylinder of the drawing are amended as shown in the attached sheet.

Claims (1)

[Claims] 1. A receiver mounted on a vehicle to receive monaural broadcasts and audio multiplex broadcasts; determining means for determining whether the vehicle is stopped or running; and reception output from the receiver. mode switching means for switching between a multiple mode in which a signal is output as a multiplex audio signal and a monaural mode in which a signal is output as a monaural audio signal; 1. An audio multiplexing control device for a vehicle-mounted broadcast receiver, comprising: mode switching control means for switching to a mode switching control device.