JPS6130124A - Program discriminating receiver - Google Patents

Abstract

PURPOSE:To prevent failure in hearing of information by hearing information program in remote places, which a user does not desire to hear, and relatively important information in the region in distinction between them and reproducing surely signals in the region when they come. CONSTITUTION:The high frequency input from an antenna 1 is attanuated by an attenuating circuit 2 and passes a high frequency amplifier 3 and an intermediate frequency amplifier 4 and is detected and demodulated by a detecting and demodulating circuit 5. The demodulated output is not only outputted to an output terminal Out but also applied to a program discriminating signal detecting circuit 6 and a sound recorder 14. A program discriminating code superposed to a part of a carrier wave or an audio band is discriminated by the detecting circuit 6 and is applied to a coincidence detecting circuit 7. Outputs from a program start code pattern setting circuit 8 connected to a program selecting switch 10 and a program end code pattern setting circuit 9 are applied to this circuit 7, and relatively important information programs in the region are distringuished from other programs by the circuit 7. The output of the circuit 7 is applied to a DR circuit 13, to which a changeover switch 15 is connected, and the sound recorder 14 through an FF11, and only important program in the region are reproduced and recorded surely.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention receives broadcast radio waves on which a program identification signal is superimposed when broadcasting specific information such as traffic information, weather forecasts, or news. It relates to radio receivers.

[Conventional technology]

The traffic information broadcasting system (commonly known as ARI) currently in use in West Germany uses AM to superimpose a low-frequency signal for identification on 57 KHz, and this signal is constantly sent out while traffic information is being broadcast.

Therefore, the receiver side is equipped with means for detecting a low frequency signal for identification, and traffic information can be heard using the output from this means as a key.

However, in such a system, although it can be effectively used to transmit one specific piece of information, such as traffic information, it can also be used to transmit different types of programs, such as weather forecasts and news, depending on the type. There is a limit to how many types of discrimination can be made so that only the necessary things can be heard.

[Purpose of the invention]

Therefore, this invention transmits a different program identification code for each type of program, and the receiver side sets the necessary listening programs in advance, so that only one type of necessary information or multiple types of information can be transmitted. It is an object of the present invention to provide a program identification receiver that can receive such broadcasting systems.

Another object of the present invention is to provide a program identification receiver that prevents reception and demodulation of information programs broadcast from remote locations and can reliably receive only information programs closely related to the region.

[Embodiments of the invention]

As mentioned above, this invention is capable of identifying and receiving the information content sent by broadcasting, but before explaining the configuration of the receiver, we will explain the broadcasting method used in this invention. There will be a need.

Figure 2 shows the outline of the format of the programs to be sent out.Traffic information and other information programs have different starting code patterns as shown by X in Figure 2.
2 bits x 4 words are sent for 3 seconds. After that, traffic information etc. are sent, and when this ends, a termination code pattern of 12 bits x 4 words is sent for 3 seconds as shown by Y, and the program moves on to the next program B.

These start and end code patterns take, for example, 24Hz and 32Hz in the audio signal, and are converted into FSK (Frequency Code).
y 5hift Keying) modulation to 0,
The pattern is sent out as 1 data. Therefore, on the receiver side, a 12-bit pattern output can be obtained by an FSK demodulator that discriminates between 24 Hz and 32 Hz.

The start code pattern at this time can be set in various combinations within the range of several bits out of the 12 bits, and the combination of 1.0 makes it possible to identify many types of broadcast content. can. Note that there is no problem in operation if only one type of termination code pattern is set.

The broadcasting system explained above is an example in which an identification signal is superimposed on the low frequency part of an audio signal, but for example, in the case of medium wave radio broadcasting, it is also possible to frequency modulate the carrier wave and send out an FSK signal. In this case, the receiver side receives F from the intermediate frequency signal.
It is possible to extract the SK signal.

FIG. 1 is a block diagram showing an embodiment of the present invention.
is an antenna, and 2 is an attenuation circuit that attenuates the high frequency input from the antenna 1. 3 is a high frequency amplification circuit, 4 is an intermediate frequency amplification circuit, and 5 is a detection demodulation circuit, the demodulation output of which is connected to the output terminal Out, where the demodulation output of the receiver is obtained.

Reference numeral 6 denotes a program identification signal detection circuit connected to the output end of the detection demodulation circuit 5, and the output end thereof is connected to the coincidence detection circuit 7. Outputs from a program start code pattern setting circuit 8 and a program end code pattern setting circuit 9 are applied to the coincidence detection circuit 7, and the program start code pattern setting circuit 8 is further provided with a program selection switch 10. It is connected.

The first coincidence detection output from the coincidence detection circuit 7 is the first R
The second coincidence detection output from the coincidence detection circuit 7 is connected to the cent input terminal S of the -S flip-flop circuit 11 and the cent input terminal R of the second R-S flip-flop circuit 12. Cent input terminal S of the S flip-flop circuit 12 and the first R-S flip-flop circuit 1
'1 are respectively connected to the reset input terminal R. The Q output terminal of this first flip-flop circuit 11 is connected to one input terminal of the OR circuit 13, and the recorder 14
The Q output terminal of the flip-flop circuit 12 of phrase 2 is connected to the recording command input terminal REC of the recorder 14.
is connected to the rewind command input terminal REW.

Note that a DX changeover switch 15 is connected to the other input terminal of the OR circuit 13, and this DX changeover switch 15
By providing a higher H output, the attenuation effect in the attenuation circuit 2 is stopped, and the high frequency input signal from the antenna 1 is applied to the high frequency amplification circuit 3 as it is.

FIG. 3 shows the program identification signal detection circuit 6 in FIG.
match detection circuit 7, program start code pattern setting circuit 8, program end code pattern setting circuit 9, and program selection switch 1
This shows a specific example of 0. That is, in FIG. 3, the program identification signal detection circuit 6 includes a low-pass filter 61, a frequency discrimination circuit 62, and a comparator 63, and only the low-frequency components of the demodulated output from the mi-detection demodulation circuit 5 are selected by the filter 61. FSX signal is extracted. As mentioned above, this FSK signal has, for example, 24Hz and 32H.
This signal is obtained by shift keying the z signal, which is discriminated by a frequency discrimination circuit 62, and the shift information is extracted by a comparator 63 as a 12-bit digital signal.

This 12-bit digital signal is applied as a serial signal to a shift register 71, which converts this serial signal into a parallel signal and provides it to terminal Do=Du.

Each output terminal Do"Du of this shift register 71
are connected to one input terminal of an exclusive OR circuit (hereinafter referred to as EX-OR) 72. (3rd
In the figure, EX-OR is shown as a representative one, and the others are omitted) In addition, each other input terminal of this EX-OR 72 is connected to the output terminal of 12 columns in the program start code pattern setting circuit 8, and each EX-OR - Each bit of the shift register 71 and the program start code pattern setting circuit 8 are compared by OR43. Each comparison output of this EX-OR72 is NO.
It is input to the R circuit 73, and therefore the shift register 7
1 and each bit in the program start code pattern setting circuit 8 match, the NOR circuit 73 is activated.
It acts to provide a higher output.

Similarly to the above, each output terminal Do=Du of the shift register 71
is connected to each input terminal of the EX-OR 74, and each output terminal of the program end code pattern setting circuit 9 is connected to the other input terminal, and the output of each EX-OR 74 is connected to the NOR circuit 7.
5 is entered.

Therefore, only when each bit of the shift register 71 and the program end code pattern setting circuit 9 match, the NOR circuit 75
More H output will be provided.

The program selection switch 10 is composed of, for example, a button switch that can be turned on or off independently, and by turning it on, a predetermined 12-bit pattern corresponding to a specific program is set in the program start code pattern setting circuit. 8 is output as parallel data.

In the above configuration, while the first and second flip-flop circuits 11 and 12 are waiting to receive an information program,
The first flip-flop circuit 11 is in the reset state and the second flip-flop circuit 11 is in the reset state.
The flip-flop circuit 12 is set to be in a set state.

Therefore, the Q output of the first flip-flop circuit 11 is L, the output of the OR circuit 13 is L if the DX changeover switch 15 is output, and the attenuation circuit 2 is in a state where the high frequency input signal is attenuated by a predetermined amount. It becomes. At this point, the information program for that area starts, and this is selected by the program selection switch 1.
If the information program is selected by 0, the program start code superimposed on the broadcast program by the match detection circuit 7 and the output from the program start code pattern setting circuit 8 match,
An H output is provided from the NOR circuit 73 of the coincidence detection circuit 7, and as a result, the first flip-flop circuit 11 is switched to the set state and the second flip-flop circuit 12 is switched to the reset state.

Therefore, the Q output from the first flip-flop circuit 11 becomes H, and an H output is provided to the attenuation circuit 2 via the OR circuit 13, and this attenuation circuit 2 stops its attenuation effect, and the high frequency input from the antenna 1 is applied to the high frequency amplifier circuit 3 as is. Therefore, the information program at this time is reproduced as is, and the recording v&14 also starts recording the information program by the H output from the first flip-flop circuit 11.

When the broadcast of the information program ends, the program end code superimposed on the broadcast program in the match detection circuit 7 matches the output from the program end code butterfly setting circuit 9, and the first flip-flop circuit 11 It is reset and the second flip-flop circuit 12 is set. Therefore, recorder 1
At No. 4, the recording is stopped and the tape is rewinded to the starting point of the tape or to the initial setting value of the tape counter (not shown).

Here, if the information program is broadcast from a remote location, there is little need to listen to (or record) the information, and if the output from the changeover switch 15 is set to L as described above, the attenuation circuit 2 operates to block its reception. In other words, listen to (or record) only information from that area.
It will be possible.

The above-mentioned changeover switch 15 is switched to provide an H output to the OR circuit 13, thereby stopping the function of the attenuation circuit 2 and setting the mode for listening to other programs other than the specific information program. be able to.

〔Effect of the invention〕

As is clear from the above explanation, the present invention allows for listening to information programs in a remote area that one does not wish to listen to while distinguishing them from relatively important information programs in that area. In this case, the reproducing action can be performed reliably and information can be prevented from being missed.

In the above embodiments, an attenuation circuit is inserted into the input stage of the high frequency amplifier circuit, but other circuit means that achieve a certain attenuation effect in the high frequency amplifier circuit, intermediate frequency amplifier circuit, detection demodulation circuit, etc. are shown. Similar effects can be obtained by using

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a formant diagram of a program in the broadcasting system used in this invention, and Fig. 3 is a specific example of a program identification signal detection circuit and a coincidence detection circuit. FIG. DESCRIPTION OF SYMBOLS 1... Antenna, 2... Attenuation circuit, 3... High frequency amplification circuit, 4... Intermediate frequency amplification circuit, 5... Detection demodulation circuit, 6... Program identification signal detection circuit, 7. ... Coincidence detection circuit, 11.12 ... Flip-flop circuit, 1
3...OR circuit, 14...recorder, 15...changeover switch.

Claims (1)

[Claims] In a receiver that receives broadcast waves with a program identification code superimposed on a carrier wave or a part of the audio band, means for reducing the reception gain of the receiver, and a means for reducing the reception gain from the carrier wave or reception demodulation output in a state where the reception gain is reduced. a coincidence detection means for detecting a coincidence between the obtained program start code and a program start identification code preset on the receiver side; and means for increasing the gain.