JPS5951675A - Sound multiplex receiver - Google Patents

Abstract

PURPOSE:To attain reproduction of reception of stereo and bilingual broadcast even at a small sized receiver, by connecting externally a stereo sound speaker in a television receiver so as to switch an applied sound signal. CONSTITUTION:A pair of output terminals 40, 41 for connecting one system of speaker 37 and a sound reproducer 42 such as stereo headphone are provided. A main sound signal and a sub-sound signal are applied to switching circuits 28, 29 and left and right sound signals at stereo broadcast from a matrix circuit 10 are applied to the switching circuit 29. Each output signal at the switching circuits 28, 29 is switched with switches 30-35. Even if only one speaker 37 is provided, the selection and simultaneous reproduction of the main and sub- sound signals are attained at reproduction of stereo sound and bilingual broadcast by connecting the sound reproducer 42 through the constitution above.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for receiving audio multiplexed signals of television broadcasting.

2. Description of the Related Art Conventional Structures and Problems There is a conventional television receiver capable of receiving audio multiplexed signals as shown in FIG. Here, 1 is an antenna, 2 is a tuner, 3 is a VIP circuit,
4 is a video detection circuit, 6 is a central image processing circuit, and 6 is a cathode ray tube. Reference numeral 7 denotes an SIF/audio detection circuit, which detects an audio multiplex signal consisting of a main channel signal, a sub channel signal, and a subchannel signal during audio multiplex broadcasting.

During monaural broadcasting, only the main channel signal is output. 8 is a main channel filter that takes out only the main channel signal to create a main audio signal; 9 is a sub channel demodulation circuit that takes out only the sub channel signal and performs FM demodulation to create a sub audio signal.

In the case of stereo broadcasting, the main audio signal is a (right + left) audio signal and the sub audio signal is a (right-left) audio signal, which are synthesized in a matrix circuit 10 to create a right audio signal and a left audio signal. do. In the case of double broadcasting, the main audio signal and the sub audio signal are audio signals with independent contents. During monaural broadcasting, only the main audio signal is present. Further, since different pilot signals are sent during stereo broadcasting and dual broadcasting, the pilot detection circuit 11 detects these signals and generates a detection output of the broadcasting system.

The main audio signal and sub audio signal obtained in this way.

The right audio signal and the left audio signal are each added to the switching circuit 12, and switches 13 to 16 select which of these signals to output, and the audio amplification circuits 17 and 18 amplify the signals, and then the signals are sent to the speakers 19 and 20. Add. It is also connected to external stereo headphones 26, 26 via jacks 21, 22 and plugs 23, 24. The mode of switching by the switches 13 to 16 is as shown in the following table. The left column shows the audio signal applied to the speaker 19, and the right column shows the audio signal applied to the speaker 20.

However, in such conventional devices, the speakers 19.
If you do not have a pair of left and right 20s, you will not be able to receive and play back stereo broadcasts, and you will not be able to receive the main audio and sub audio simultaneously during dual broadcasting, which is inconvenient as it can only be used with large television receivers. was there.

In addition, some small television receivers that are equipped with only one speaker system are equipped with a terminal that outputs the audio detection signal externally so that an adapter for audio multiplex reception can be added externally. However, in this case, there was an inconvenience that audio multiplex broadcasting could not be received unless an adder free was added externally.

Purpose of the Invention The present invention solves the conventional inconvenience and enables stereo broadcasting to be received even in a small television receiver equipped with only one speaker system, and also enables simultaneous reception of main audio and sub audio. It is an object of the present invention to provide an audio multiplex reception device that can perform the following functions.

Structure of the Invention In the present invention, a speaker system and a pair of output terminals to which a stereo sound emitter such as stereo headphones can be connected are provided, and a main audio signal or a sub audio signal is added to the speaker. Main audio (i.e. (right + left) audio) during stereo broadcasting from the speakers.

It is possible to select and play either the main audio or sub audio during dual broadcasting, or the audio during monaural broadcasting, and furthermore, it is possible to select whether to add the main audio signal or the sub audio signal to the pair of output terminals. By switching between adding both the main and sub audio signals or adding both the left and right audio signals,
The stereo sound emitter allows you to select and play stereo audio, main audio, sub audio, and monaural audio.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 2, the same parts as those in the prior art are designated by the same reference numerals as in FIG. 1, and their explanation will be omitted. In the device shown in Figure 2,
The switching circuit 2 switches between the main audio signal from the main channel filter 8 and the auxiliary audio signal from the auxiliary channel demodulation circuit 9.
In addition to 8.29, the switching circuit 29 also includes a right audio signal and a left audio signal from the matrix circuit 10 during stereo broadcasting. Each output signal from the switching circuits 28 and 29 is switched by switches 30 to 36. The output signal of the switching circuit 28 is amplified by an audio amplification circuit 36 and then applied to one system of speakers 37. A pair of output signals for two systems are taken out from the switching circuit 29, amplified by audio amplification circuits 38 and 39, respectively, and then output to a pair of output terminals 40 and 41. These output terminals can be connected to a pair of sound emitters 43 and 44 of the stereo sound emitter 42, such as stereo headphones.

Here, the switching circuits 28 and 29 are set to select and supply audio signals to the system bee force 37 and the sound emitters 43 and 44 respectively in the following switching manner by operating the switches 3 to 35. ing. In the table, the left column is the audio signal supplied to the speaker 37, the middle column is the sound signal supplied to the sound emitter 43, and the right column is the audio signal supplied to the sound emitter 44.

That is, the switch 3o is forcibly switched to reproduce only the main audio in monaural mode regardless of the broadcast mode. The switch 31 is switched so that stereo sound/voice can be reproduced using the external stereo sound emitter 42 during stereo broadcasting. The switch 32 switches the speaker 37 to reproduce the main audio while the stereo sound emitter 42 reproduces the sub audio during double broadcasting, and the switch 33 to the opposite state. The switch 34 is switched to reproduce only the sub-audio during double broadcasting. Then, the switch 36 is switched so that the stereo sound emitter 42 can reproduce both the main audio and the sub audio during double broadcasting.

Such switching can be easily achieved by providing analog gate circuits in the switching circuits 28 and 29 and controlling them by switching the switches 3o to 36.

With this configuration, even if the television receiver is equipped with only one system of speakers 37, the stereo sound emitter 42 can be connected externally, and the stereo sound emitter 42 can be connected to the outside. By also switching the audio signal added to 42, the stereo sound emitter 4 can be used during stereo broadcasting.
2 allows you to play stereo audio. It is still very convenient to be able to selectively or simultaneously play back the main audio and sub audio during double broadcasting.

Note that the stereo sound emitter 42 can be used for stereo headphones, stereo earphones, or other stereo sound emitters 42.
A system speaker may also be used.

Effects of the Invention As described above, according to the present invention, even a small television receiver equipped with only one speaker system can receive and reproduce stereo broadcasts and double broadcasts, which is very convenient. you can get something.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional audio multiplex receiver, and FIG. 2 is a block diagram of an audio multiplex receiver according to an embodiment of the present invention. 7...SIF/audio detection circuit, 8...
Main channel filter, 9... Sub channel filter, 10... Matrix circuit, 11...
...Pilot detection circuit, 2B, 29.・・・・・・
Switching circuit, 30.31.32゜33.34.35...
...Switch, 36, 38. 39...Audio amplification circuit, 37...Speaker, 4o. 41...Output terminal, 42...Stereo sound emitter, 43.44...Sound emitter.

Claims (1)

[Claims] a detection circuit that creates a main audio signal from the main channel signal of the audio multiplex signal; a demodulation circuit that creates a sub audio signal from the sub channel signal of the audio multiplex signal; A matrix circuit that creates a signal and a left audio signal, one system of speakers,
A pair of output terminals to which a stereo sound emitter such as stereo headphones can be connected; An audio multiplex receiver comprising a switching circuit for switching between adding an audio signal, adding the sub audio signal, or adding the right audio signal and the left audio signal.