JPS6231550B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a receiver capable of receiving television audio multiplex broadcasts.

Figure 1 shows a conventional television audio multiplex broadcast receiver, in which 1 is an antenna, 2 is a television front end, 3 is an IF section, and 4 is an FM section.
The detection section inputs the radio waves received by the antenna 1 via the front end 2 and the IF section 3, and outputs a composite signal S obtained by FM modulating the radio waves. 5 is a main audio filter unit which inputs the composite signal S and outputs a sum signal (L+R). Reference numeral 6 denotes a sub-audio detection section which inputs the composite signal S, performs FM modulation on this, and outputs a difference signal (LR). 7 is a control signal detection section;
Inputs composite signal S, detects whether the radio waves received by antenna 1 are stereo broadcast radio waves or dual broadcast radio waves, and if it is stereo broadcast, outputs stereo reception signal B to stereo display 8 to display stereo. If it is a double broadcast, it outputs the double broadcast reception signal C and drives the double broadcast display 9. 10 is a matrix circuit, sum signal (L+R)
and difference signal (L-R), and when receiving a double broadcast and input switching signal A to input terminal D, outputs the main channel signal from output terminals L and R, and outputs switching signal A to input terminal E. When inputting, the sub channel signal is output, and when switching signal A is input to input terminal F, the main/sub channel signal is output, and the receiving mode of the receiver can be set to main channel receiving mode, sub channel receiving mode, and main/sub channel signal. Switch to channel reception mode. Also, when receiving stereo broadcasting, when switching signal A is not input to input terminal G, stereo signals can be output from outputs L and R, and when switching signal A is input, switching signal A can be input to input terminals D, E, and F. It is configured to output a monaural signal regardless of the presence or absence of the signal, and to switch the reception mode between a stereo reception mode and a forced monaural reception mode,
Even when it is difficult to hear in stereo reception mode due to weak received radio waves, it may be possible to hear clearly in monaural reception mode, so stereo broadcasts can be listened to in monaural mode. However, conventionally, switches 11, 12, and 13 for duplex broadcast reception modes and a switch 14 for switching to forced monaural reception mode when receiving double broadcasts are provided separately, and the dual broadcast reception mode setting and forced monaural The reception mode setting was done independently for each. Therefore, if you set the forced monaural reception mode when recording a double broadcast during an answering machine, the mode will remain in monaural reception even if a double broadcast is sent, so for example, Japanese and foreign language In case of double broadcasting, the output would be a composite of Japanese and foreign languages, resulting in recording failures.

In view of the above problems, the present invention is designed so that even if the forced monaural reception mode is set, if a double broadcast is sent, it can be received in the preset double broadcast reception mode. .

Hereinafter, the present invention will be explained according to the illustrated embodiment. In FIG. 2, S1 is a mode changeover switch, which outputs a changeover signal A every time it is turned on. Reference numeral 15 denotes a switching circuit which sends the switching signal A from the switching switch S1 to the flip-flop 16 when the stereo reception signal B is input, and also sends the switching signal A to the shift register 17 when the stereo reception signal B is stopped. The shift register 17 inputs the switching signal A as a clock pulse, and the output terminals H, I, and J of each stage are connected to the input terminals D,
E and F, respectively, and a switching signal A' is sequentially outputted from output terminals H, I, and J every time switching signal A is input. The flip-flop 16 repeats setting and resetting every time the switching signal A is input, and is reset when the dual broadcast reception signal C is input.
In addition to outputting A', a switching signal is generated at reset.
Stop A′.

According to the configuration of the above embodiment, when the antenna 1 receives a stereo broadcast, the stereo reception signal B is input to the switching circuit 15, and the switching circuit 15 transfers the switching signal A from the switching switch S1 to the flip-flop 16.
It becomes possible to send it to the side. In this state, switch S
1, the flip-flop 16 repeats setting and resetting each time it is turned on.
A stereo signal and a forced monaural signal are sequentially output from the output terminals L and R of the matrix circuit 10, and the receiver repeats the stereo reception mode and the monaural reception mode. Further, when the antenna 1 receives a double broadcast, the switching circuit 15 can send the switching signal A to the shift register 17 side, and each time the switching switch S1 is turned on, the shift register 17 inputs the switching signal A and shifts. It operates and outputs the switching signal A' sequentially from the output terminals H, I, and J, so the main channel signal, subchannel signal, and main/subchannel signal are sequentially output from the output terminals L and R of the matrix circuit 10, and the reception The mode is the main channel receiving mode,
Switch sequentially to sub-channel reception mode and main/sub-channel reception mode. Even when the flip-flop 16 is in the set state and the reception mode is monaural reception mode, when a double broadcast is received, the flip-flop 16 is activated to receive the double broadcast reception signal C.
is input and reset, the switching signal A' is stopped and reception can be performed in the preset dual broadcast reception mode.

Note that operations similar to those of the switching circuit 15, flip-flop 16, and shift register 17 may be realized using computer software.

According to the present invention, even when the receiving mode is monaural receiving mode, if a double broadcast signal is input, it can be received in the double broadcast receiving mode, and therefore, for example, when recording a double broadcast while answering, the receiving mode setting can be performed. Recording failures due to mistakes etc. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional example, and FIG. 2 is a block diagram showing an embodiment of the present invention. S1 is a mode changeover switch, and 16 is a flip-flop.

Claims (1)

[Claims] 1. A receiver capable of receiving television audio multiplex broadcasting, which is equipped with a mode changeover switch that outputs a changeover signal when the switch is operated, and a flip-flop that sequentially repeats setting and reset each time the changeover signal is input. It is reset by receiving a double broadcast, and the reception mode is changed to monaural reception mode when the flip-flop is set.
A receiver characterized in that it is set to a dual broadcast reception mode upon reset.