JPH04180500A - Sound signal processor - Google Patents

Abstract

PURPOSE:To reduce noise from a center speaker by detecting broadcasting except a 3-1 system and cutting off output from a signal-processing means to the center speaker by a discriminating control signal with a muting means. CONSTITUTION:When a sound source is broadcasting except a 3-1 system, the output of channels 1 to 4 from an MUSE decoder 1 is switched by a sound switching circuit 15, a left signal is added to a left signal processing circuit 16, a right signal is added to a right signal processing circuit 17, a non-signal is added to a center signal processing circuit 18 and the left and right signals are added to a rear signal processing circuit 19 when the left and right signals of a sound signal exist but a center signal and a rear signal does not exist, for instance. Then, the processing circuit pseudo-generates a signal S' from input. The output of the center signal processing circuit 18 can be made muted by a control signal discriminated with the broadcasting except the 3-1 system by the MUSE decoder 13 and the noise portion of the output from a center speaker can be removed irrespective of sound volume and can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a television receiver having four channels of sound, in which three front speakers, left, center, and right, are arranged in the front and a rear speaker is arranged in the rear. The invention relates to audio signal processing devices such as machines.

Conventional technologyIn the early days of television broadcasting, the audio was on one channel, but in 1969, experimental broadcasting of audio multiplexing began, and soon two channels of audio were being sent, leading to dual-language broadcasting and stereo audio broadcasting. It has started to be done.

Furthermore, in recent years, there have been significant improvements in digital audio and sound quality in satellite broadcasting. In addition to these developments, the sense of realism in images has increased due to the higher image quality and wider angle of view associated with the development of high-definition, and the audio has also changed from the conventional stereo system to high-quality, realistic sound that matches the image. One method is to use three front speakers (upper left speaker, one center speaker C, one right speaker R), and two rear speakers S, as shown in Figure 2.
(hereinafter referred to as the 3-1 method) is adopted.

In this way, the television receiver 1, which has four channels of sound in the 3-1 system, is equipped with three types of functional speakers, L, C, and R, and when broadcasting in the 3-1 system, these three types are used. Speakers L, C, and R and the rear rear speaker S operate.

Problems to be Solved by the Invention However, in the conventional configuration described above, when broadcasting other than 3-1 stereo broadcasting, for example, 2-channel stereo broadcasting, the center speaker C is in a state where there is no audio source. If you raise the volume of the television receiver in this silent state, you will either get a normal level of audio output from the speakers and R, or you will get a lot of noise from speaker C because there is no audio source. This has caused a problem in that the quality of the audio is significantly impaired.

The present invention solves the above conventional problems, and aims to provide an audio signal processing device that can reduce noise from speakers without an audio source during broadcasting other than 3-1 stereo broadcasting. It is something.

Means for Solving the Problems In order to solve the above problems, the audio signal processing device of the present invention employs a 3-1 system in which a front speaker, which is a left speaker, a center speaker, and a right speaker, and a rear speaker are arranged. a signal processing means for processing signals as audio signals to the speaker, center speaker, right speaker, and rear speaker, respectively; a detection means for detecting whether the broadcast is based on the 3-1 system; 1
and muting means for cutting off the output from the signal processing means to the central speaker in response to a discrimination control signal when it is detected that the broadcast is of a different format.

Effect With the above configuration, the muting means cuts off the output from the signal processing means to the central speaker in response to the discrimination control signal from the detection means which detects that the broadcast is of a method other than 3-1. When broadcasting, the output from the signal processing means to the center speaker is no signal, and even if it is output due to noise, it is not output from the center speaker, and the noise from the center speaker without an audio source is reduced. become.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an audio signal processing device showing one embodiment of the present invention. In FIG. 1, a BS antenna 11 is connected to a BS tuner 12, and the BS tuner 12 converts a signal received by the BS antenna 11 into a video signal. B
The S tuner 12 is connected to the MUSE decoder 13,
The USE decoder 13 has a detection function of decoding into video and audio signals, detecting whether or not it is a 3-1 broadcast, and applying a discrimination control signal. MUS
The E decoder 13 is connected to the CRT via the video signal processing section 14.
(not shown), the video signal is processed by the video signal processing circuit 14, and the video is displayed on the CRT.

The MUSE decoder 13 also includes an audio switching circuit 15,
Subsequent left, right, center and rear signal processing circuits 1
The audio switching circuit 15 switches the audio signals from the MUSE decoder 13, and the audio signals are processed by the signal processing circuits 16-19, respectively. Further, the left signal processing circuit 16 is connected to the left audio output circuit 20 of the speaker L, the right signal processing circuit B17 is connected to the right audio output circuit 21 of the speaker R, and the central signal processing circuit I8 is connected to the center of the speaker C via the mute circuit 24. Audio output circuit 22
And, the rear signal processing circuit 19 is connected to the rear audio output circuit 23 of the speaker S, respectively. Furthermore, M.U.
The SE decoder 13 is connected to the mute circuit 24, and the discrimination control signal is sent from the MUSE decoder 13 to the mute circuit H12.
4, and the mute circuit 24 is operated to mute the output from the central signal processing circuit 18 when broadcasting in systems other than the 3-1 system.

The operation of the above configuration will be explained below. First, when the audio source is 3-1 broadcasting, the satellite broadcast signal is taken in by the BS antenna 11, and the BS tuner 12
and convert it into a video signal. For the sake of complete explanation, if this video signal is a high-definition MUSE signal, BS tuner 1
The video signal from 2 is input to the MUSE decoder 13, where the MUSE signal is decoded into a high-definition video signal and an audio signal, and the video signal is sent to a CRT (not shown) via a video signal processing circuit 14. Display the image. Also, the audio signal is from CH (channel) 1 to
4 signals are output from the MUSE decoder 13 to the audio switching circuit 15, and from the audio switching circuit 15 to the respective speakers L and R of each channel.

The C and S signals are applied in through form to the left, right, center, and rear signal processing circuits 16 to 19, respectively. Each of these signal processing circuits 16 to 19 corresponds to, for example, a sound quality circuit, a surround circuit, and other audio feature circuits. Furthermore, each signal that has passed through each signal processing circuit 16 to 19 is sent to speakers L and R.

The C and S audio output circuits 20 to 23 amplify the audio signals, and the speakers L, R, C, and S reproduce the audio signals.

Here, the audio signal from the central signal processing circuit 18 passes through the mute circuit 24, or is processed by the discrimination control signal determined by the MUSE decoder 13 as 3-1 broadcasting.
The mute circuit 24 does not operate and passes the audio signal.

Next, when the audio source is broadcasting in a format other than 3-1,
Is it the output of CHI~4 from the USE decoder 13?For example, are there L (left) and R (right) signals of the audio signal?If there are no C (center) signal and S (rear) signal of the audio signal? , the audio switching circuit 15 is switched and the input of the left signal processing circuit 16 is either the L signal or the right signal processing circuit 1.
7 has an R signal, or is there no signal in the central signal processing circuit 18?
Then, the L and R signals are applied to the post-signal processing circuit 19.

At this time, the post-signal processing circuit 19 generates a pseudo signal S' from the input L and R signals.

Here, regarding the output from the central signal processing circuit 18, the output from the MUSE decoder 13 is either no signal, that is, is output in a muted state, or the no signal output from the MUSE decoder 13 is output by audio switching. In the process of passing through the circuit 15 and the central signal processing circuit 18, the signal is subjected to various noises within the television receiver. The output from the central signal processing circuit 18 is muted by operating the mute circuit 24 in response to a discrimination control signal detected by the MUSE decoder 13 as broadcasting other than the 3-1 system, and is output from the central speaker C. It is possible to remove noise regardless of the volume. Incidentally, the volume circuit is built in each of the signal processing circuits 16 to 9.

Effects of the Invention As described above, according to the present invention, it is possible to reduce noise from a central speaker without an audio source during broadcasting other than 3-1 broadcasting, regardless of the volume.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an audio signal processing apparatus according to an embodiment of the present invention, and FIG. 2 is a layout diagram showing the state of use of a television receiver having four channels of 3-1 audio. 13...MUSE decoder, 16...Left signal processing circuit, 17...Right signal processing circuit, 18...Central signal processing circuit, 19...Rear signal processing circuit, 24...Mute circuit.

Claims (1)

[Claims] 1. Signal processing in which signals are processed as audio signals to the left speaker, center speaker, right speaker, and rear speaker, respectively, in a 3-1 method in which a front speaker and a rear speaker, which are a left speaker, a center speaker, and a right speaker, are arranged. means, a detecting means for detecting whether or not the broadcast is based on the 3-1 system, and the detecting means detects whether the broadcast is based on the 3-1 system.
an audio signal processing device comprising: muting means for cutting off output from the signal processing means to the central speaker according to a discrimination control signal when it is detected that broadcasting is in a format other than the first one;