JPS58107780A - Receiver for sound multiplex broadcast - Google Patents

Abstract

PURPOSE:To obtain two L and R signals without an amplifier, by receiving stereo information of (L+R)/2 and R transmitted on two channels and processing signals through the combination of an adder and a subtractor. CONSTITUTION:In receiving a stereo broadcast, a mode changeover switch 10 is selected as shown in figure, and a signal of (L+R)/2 applied to an input terminal 11 is supplied to a subtractor 8 and an adder 9. An R signal applied to an input terminal 12 is given to the subtractor 8 and a signal of (L-R)/2 is introduced. This signal is summed with the (L+R)/2 at the adder 9 and an L signal is obtained at an output terminal 13. In case of the bilingual broadcast, a signal M1 is applied to the terminal 11, and a signal M2 is to the terminal 12. Since the mode changeover switch 10 is selected to the 10a position, the subtraction by the subtractor 8 is not done, and the signals M1, M2 are outputted as they are at the output terminals 13 and 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an audio multiplex broadcast receiver that receives television audio transmitted over one channel.

In particular, the present invention relates to a receiver suitable for receiving a stereo audio signal consisting of a first channel having information of (L+R)/2 and a second channel having information of R.

Recently, in West Germany, a method was proposed for transmitting stereo information on two channels: (L+R)/2, the first channel of information, and the second channel of information, R. Broadcasting is about to begin. Then, the stereo information transmitted by this method is received, and from now on R,! A receiver equipped with a decoder for separating and deriving two stereo signals of L: is proposed in German Publication No. 2202233 and is well known.

FIG. 1 shows a circuit diagram of this known decoder, and will be described below. Here, / is an amplifier with an amplification factor of 2, C is a subtracter, and 3 is a mode changeover switch that changes the mode between stereo broadcasting and bilingual broadcasting. When receiving stereo broadcasting, the mode changeover switch 3 It is connected to the stereo side terminal 3a.

If a stereo broadcast is received here, one input terminal of this decoder pt is supplied with a signal of (L+R)/2, and the other input terminal jt is supplied with a signal of R. . Supplied to the input terminal (L + R)
The signals of /, 2 are amplified twice by the amplifier /I, and a signal of C (L + R) is thereby derived from the amplifier /I. This signal is supplied to the subtracter's input terminal. On the other hand, the R signal supplied to the input terminal jt is led out as it is to the output terminal 7 of this decoder, and is also supplied to the e input terminal of the subtractor via the mode switching switch 3. As a result, an L signal is derived from the subtracter A to the other output terminal B.

In this way, when receiving a stereo broadcast, L and R stereo signals are separated and derived from the respective output terminals J and 7 of the decoder.

Further, when receiving bilingual broadcasting, the mode switching switch 3 is switched to the bilingual side terminal 3b. At this time, a signal Ml is supplied to one input terminal of the decoder, and this is supplied to the θ input terminal of the subtractor via the mode switching switch 3, and is then supplied to the amplifier. It will be done. In the amplifier /, this signal is amplified into a signal M1 and then supplied to the input terminal of the subtractor. As a result, the original signal Ml is derived from the subtracter at its output/terminal. Note that a signal M2 is supplied to the other input terminal j, and this signal is led out to the output terminal 2 as is.

In this way, when receiving bilingual broadcasting, the original bilingual signals M1 and M2 are respectively derived to the respective output terminals t and 7 of the decoder.

By the way, the decoder configured as above requires an amplifier / having an amplification factor of exactly - times, and a subtracter subtracts the signal passed through this amplifier / and the signal not passed through the amplifier /. Therefore, when the amplification coefficient of the amplifier / is deviated from 2, or when there is a slight phase shift in the signal passed through the amplifier /, there is a drawback that a normal signal cannot be derived as the output of the subtractor.

The present invention has been made in view of these points.
7. The main purpose of this invention is to eliminate the drawbacks of the prior art described above.

In addition, the present invention is particularly capable of transmitting data using one channel (L
+R)/L2 and R stereo information is received, the purpose is to separate and derive the original two stereo signals, bottom and R.

Furthermore, it is an object of the present invention to derive one stereo signal of L and R by combining an adder and a subtracter without using a special amplifier with an amplification factor of 2.

Another object of the present invention is to make it possible to easily receive Japanese language broadcasts by changing a switch.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the embodiments of the present invention will be explained according to the embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of a decoder used in the present invention, where ♂ is a subtracter, 2 is an adder, and 10 is a mode changeover switch.
- When a stereo broadcast is received here and now, the mode selector switch 10 is in the position shown in the figure, and at this time, a signal of (L + R) / is supplied to one input terminal of the decoder. and R is connected to the other input terminal/co.
This signal can be supplied completely. (L) supplied to input terminal //
The +R)/- signals are supplied to the input terminal ♂ of subtracter ♂ and also to adder 2. On the other hand, the signal R supplied to the input terminals f/2 is supplied to the e input terminal of the subtracter ♂ via the mode changeover switch /θ. As a result, the subtracter ♂ subtracts the signal (L+R)/co and the signal R, and the subtracter ♂! A signal (R-L)/2 is derived from this and is supplied to the other input terminal of the adder. At this time, the subtracter 2 adds the signal (L-R)/2 to the signal (L+R)/2, and the adder 2 outputs a signal L to the output terminal /3 of the decoder. At this time, the signal R supplied to the input terminal /co is directly derived from the output terminal /41 of the other decoder.

In this way, when receiving stereo broadcasting, each output terminal i3 of the decoder. L and R stereo signals are separately derived from iy.

On the other hand, when receiving bilingual broadcasting, the mode selector switch 10
The switch is switched to the bilingual terminal lOa side. In this case, one input terminal // of the decoder is supplied with a signal M1, and the other input terminal /- is supplied with a signal M2. Here, the signal Ml supplied to the input terminal // is supplied to both the input terminals ♂ and θ of the subtracter ♂, and is also supplied to the adder 2. At this time, the subtractor ♂
The signals Ml supplied to the subtracter ♂ cancel each other out, and no output appears from the subtracter ♂. Therefore, in this case, the signal supplied directly from the input terminal // to the adder is sent directly to the output terminal /3 of the decoder. is derived. On the other hand, the signal M2 supplied to the input terminal /A is directly derived from the other output terminal /DA of the decoder.

In this way, when receiving bilingual broadcasting, each output terminal of the decoder /3. The original Ml and M2 bilingual signals are respectively derived.

In addition, in the above embodiment, if the on/off control is performed to determine whether multiplex broadcasting, stereo broadcasting or bilingual broadcasting, is being received, it is possible to automatically switch the receiving mode of the decoder in the receiver. becomes.

As described above, according to the audio multiplex broadcasting receiver of the present invention, a stereo audio signal consisting of a /th channel having information of (L+R)/2 and a second channel having information of R can be obtained. It is possible to receive and derive R and L stereo signals, but in this case, it can be easily configured using a subtracter and an adder without using a special amplifier as in the conventional case.

Furthermore, according to the audio multiplex broadcasting receiver of the present invention, L and R stereo signals are obtained by simply adding or subtracting the signals of two channels, which causes a phase shift, etc. that would occur when using a conventional amplifier. Regular L and R stereo signals can be derived without any fear.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a decoder used in a conventional audio multiplex broadcast receiver, and FIG. 2 is a block diagram of a decoder used in the receiver of the present invention. ! ...subtractor, ta...adder, /θ...mode changeover switch, //, /J...input terminal, /
3. /G...Output terminal. Agent Patent Attorney Aihiko Fukushi

Claims (1)

[Claims] 1. An audio multiplex broadcasting receiver that receives stereo information transmitted by a first channel and a first channel,
A mode changeover switch that switches between the first channel information and the first channel information, and a seventh channel information and the first or second channel information obtained through the mode changeover switch are subtracted. with a subtractor. An audio multiplex broadcast receiver comprising a decoder comprising an adder that adds the output of the subtracter and the information of the first channel.