JPH098607A - Emergency alert broadcast receiver - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a receiver that automatically maintains a standby state for receiving an emergency alert broadcast even when moving. [Structure] A memory 34 in which NHK frequency data is written, and a decoder 43 for decoding a start signal and an end signal of an emergency alert broadcast are provided. According to the data, the reception frequency of the tuner circuit 12 is changed to select the NHK having a specified reception level or higher. After this channel selection, the output signal of the decoder 43 is monitored and the standby state of the emergency warning broadcast is continued while the reception level of the selected NHK is equal to or higher than the specified level. When the start signal of the emergency alert broadcast is broadcast, the audio signal from the demodulation circuit 14 is supplied to the speaker 23. After the above tuning, when the reception level of the selected NHK is lower than the specified level, the tuning is performed again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency warning broadcast receiver suitable as a car radio.

[0002]

2. Description of the Related Art There is known a system for broadcasting an emergency warning such as a warning about a large-scale earthquake or a warning about a tsunami through a radio or the like. An emergency alert signal having a format as shown in 7 is broadcast.

That is, as shown in FIG. 7C, this signal has a fixed code indicating that it is an emergency alert broadcast signal,
It is composed of an area code indicating the division of the area targeted for emergency alert broadcasting and a time code indicating the time. in this case,
The fixed code has a fixed bit pattern as shown in FIG. 7A, and the area code and the time code have bit patterns corresponding to their contents, and are converted into an FSK signal in the middle range of the audible band as shown in FIG. 7B. To be done.

At the start of the emergency alert broadcast,
As shown in D, the FSK signal is repeatedly broadcast for 15 seconds, and then the content of the emergency alert is broadcast by voice.

Further, when the broadcasting of the emergency alert is finished, the FSK signal is intermittently broadcast as shown in FIG. 7E.

Therefore, in the receiver of the emergency alert broadcast, (1) the broadcast is always received. (2) Turn on the muting of the audio signal system. (3) When continuous FSK signals (Fig. 7D) are received, the muting is turned off. Therefore, the user
You will be able to hear subsequent audio alerts. (4) When receiving the intermittent FSK signal (Fig. 7E), turn on the muting. You can perform the process.

[0007] That is, by doing so, when an emergency alert is broadcast, the alert can be heard.

[0008]

By the way, in order to receive the above-mentioned emergency alert broadcast, in a stationary receiver, the reception frequency should be preset to the local broadcasting station which carries out the emergency alert broadcast. Good.

However, a receiver installed in a car, that is, a car radio may move between service areas of a plurality of broadcasting stations as the car travels. Therefore, even in such a case, when there is an emergency alert broadcast,
To be able to receive this, the reception frequency preset must be changed every time the service area changes.

However, at present, the emergency alert broadcast is N
All stations of HK (Japan Broadcasting Corporation) and some of the stations of private broadcasting are compatible, and not all stations are compatible with emergency alert broadcasting. Therefore, the mere automatic channel selection function cannot preset the broadcasting station that carries out the emergency alert broadcasting.

The present invention is intended to solve such a problem.

[0012]

[Means for Solving the Problems] As described above, the emergency alert broadcasting is carried out only in some stations in private broadcasting, but in NHK, all of the first and second broadcasting of AM broadcasting are carried out. Will be carried out at the station. The NHK first and second broadcast service areas cover almost all of Japan, including low-power relay stations.

Also, with the exception of a few exceptions, the frequency allocation of AM radio broadcasting is limited to NH even in different areas.
K and civilian broadcasts are set not to use the same frequency (commercial broadcasts include FEN (radio broadcast by US Army in Japan). The same applies below).

The present invention pays attention to these points and makes it possible to reliably receive the emergency warning broadcast even in a car radio or the like.

That is, in the present invention, a tuner circuit having a PLL and configured in a synthesizer system,
A demodulation circuit that demodulates the original audio signal from the intermediate frequency signal of the broadcast wave signal selected by the tuner circuit, a speaker, a circuit that outputs a signal indicating the reception level of the broadcast wave signal, and an NHK frequency Having a memory in which data is written and a decoder for decoding the start signal and the end signal of the emergency alert broadcast, according to the data,
By changing the reception frequency of the tuner circuit and selecting an NHK having a specified reception level or higher, after this tuning, the output of the decoder is output during a period in which the reception level of the selected NHK is the specified level or higher. When the signal is monitored and the standby state of the emergency warning broadcast is continued, and when the start signal is broadcast, the audio signal from the demodulation circuit is supplied to the speaker, and after the channel selection, reception of the selected NHK. When the level is lower than the level specified above, the above-mentioned channel selection is performed again as an emergency alert broadcast receiver.

[0016]

In any area, the NHK which carries out the emergency alert broadcast is in a standby state for the emergency alert broadcast, and therefore, the emergency alert broadcast can be reliably heard.

[0017]

1 shows an example in which the present invention is applied to a car audio device, which has a receiving circuit 10 for AM radio broadcasting.

Then, in the receiving circuit 10, the AM broadcast wave signal received by the antenna 11 is supplied to the tuner circuit 12 to select the broadcast wave signal having a target frequency and frequency-convert it into an intermediate frequency signal. Then, the intermediate frequency signal is supplied to the demodulation circuit 14 through the intermediate frequency circuit 13 to demodulate the audio signal, and the audio signal is supplied to the function switch circuit 21.

In this case, although not shown, the tuner circuit 12 has a PLL and is constructed in a synthesizer system.
By changing the frequency dividing ratio N of the variable frequency dividing circuit in the PLL, the reception frequency can be arbitrarily changed in the AM broadcast wave band.

Further, in this example, the CD player 5
0 and the audio signal from the mini disc player 60,
It is supplied to the function switch circuit 21.

The function switch circuit 21
At, for example, the audio signal from the demodulation circuit 14 is selected, and the selected audio signal is supplied to the speaker 23 through the amplifier 22.

Further, this car radio has a receiving circuit 1
A microcomputer 30 for controlling 0 and realizing reception of an emergency alert broadcast is provided. That is, the microcomputer 30 includes a CPU 31 and
It has a ROM 32 in which various programs are written, a work area RAM 33, and a memory 34 in which NHK frequency data is written.
Reference numeral 4 is connected to the CPU 31 through the system bus.

In this case, the ROM 32 has a tuning routine 100 shown in FIG. 2, for example, as a part of the program written therein. Further, the memory 34 is a ROM capable of electrically writing data, or, although not shown, a RAM backed up by a battery, that is, the memory 34 is a non-volatile memory and a power source. The written data can be retained even when the switch is turned off.

In the memory 34, for example, FIG.
As shown in, a table FRQT of frequency data of NHK first and second broadcasts throughout Japan, in this example, data N (1) of frequency division ratio N when the tuner circuit 12 selects a channel. A table FRQT of ~ N (MAX) is provided (MAX is the number of frequencies used by NHK). However, in the table FRQT, the right column shows data N (1) to
The frequencies and broadcasting station names corresponding to N (MAX) are shown for reference and are not included in the table FRQT.

Further, the microcomputer 30 has output ports 35 and 36, input ports 37 and 38, and a key interface circuit 39, which are also connected to the CPU 31 through the system bus.

At the time of channel selection, the data of the frequency division ratio N is output from the port 35 as the data for channel selection, and this data is supplied to the PLL variable frequency divider circuit of the tuner circuit 12 to perform channel selection. Be seen. Further, a function switching signal is output from the port 36, and this function switching signal is supplied to the function switch circuit 21 as a control signal for switching.

Further, for example, a part of the intermediate frequency signal is supplied from the intermediate frequency circuit 13 to the detection circuit 41, and a DC voltage whose level changes corresponding to the reception level of the broadcast wave signal currently being received is extracted. A DC voltage is supplied to the A / D converter 42 and a digital signal S42 indicating the reception level is received.
The signal S42 is supplied to the port 37.

When the detection signal from the demodulation circuit 14 is supplied to the decoder circuit 43 and the FSK signal for emergency alert broadcasting is output from the demodulation circuit 14, the data signal S43 decoded from the FSK signal (for example, as shown in FIG. 7A signal) is output from the decoder circuit 43, and this signal S43
Are supplied to the port 38.

Further, the key interface circuit 39 is connected with various operation keys 44 composed of non-lock type push switches, and the key output is supplied to the interface circuit 39.

In such a structure, when the ignition key of the car is turned on, the processing of the CPU 31 starts from step 101 of the routine 100, and then, at step 102, it is checked whether or not it is the radio reception mode. If the switch circuit 21 is connected to the receiving circuit 10 as shown in the figure and is in the radio receiving mode, step 102 is repeated and the receiving mode is continued.

If this radio reception mode is used,
At the time of an emergency alert, there is some broadcast that announces the emergency without taking the format of the emergency alert broadcast, so there is no problem even if the receiving mode of the emergency alert broadcast is not switched.

However, the switch circuit 41 causes the player 50 to
Alternatively, when it is connected to 60, or when the switch circuit 41 is switched from the receiving circuit 10 to the player 50 or 60, or when all the reception and reproduction are stopped, that is, in a mode other than the radio broadcast receiving mode, The process proceeds from step 102 to step 103, in which the receiving circuit 10 is set to the receiving state. Therefore, after that, from the user's point of view, the radio broadcast is not received, but the radio broadcast is received on the back side.

Then, subsequently, in step 111, the variable i is set to the initial value "1", and in step 11
2, the data N (i) of the i-th frequency division ratio N of the frequency table FRQT of the memory 34 is read, and this data N (i) is variable frequency-divided by the PLL of the tuner circuit 12 through the port 35. It is set in the circuit, and from this time point, the reception state of the frequency corresponding to the data N (i) is set.

Then, in step 113, the signal S
By loading 42, the reception level at the reception frequency of the data N (i) selected in step 112 is measured, and the measured value E (i) is stored in the RAM 33.

Then, in step 114, it is checked whether or not the variable i exceeds the maximum value MAX. If not, the process proceeds from step 114 to step 115, and in this step 115, the variable i is exceeded.
Is incremented by "1", then step 1
Return to 12.

Therefore, the loop of steps 112 to 115 is repeated until i = MAX, and the table FRQT
The received levels E (1) to E (MAX) at the frequencies corresponding to all the data N (1) to N (MAX) prepared in the above are measured. That is, the reception levels are measured at all NHK frequencies, and the data E (1) to E (MAX) are obtained in the RAM 33.

When the reception levels of all NHK frequencies are measured in this way, i = MAX
However, this is determined in step 114, and the processing proceeds from step 114 to step 121. In this step 121, the reception levels E (1) to E (MAX) measured in step 113 are checked, and the maximum of them is checked. The frequency (data N (n)) at the reception level E (n) is selected. As a result, NHK with the highest reception level thereafter
The station is selected.

Subsequently, the process proceeds to step 122. In step 122, it is checked whether or not the data signal S43 indicating the start of the emergency alert broadcast is obtained from the decoder circuit 43. If not, that is, the emergency alert is issued. When the broadcast is not started, the process is step 1
From 22 to step 123.

Then, in step 123, the current reception level E (n) of the receiving station is measured, and then in step 124, the reception level E (n) measured in step 123 is higher than the specified value ETH. If it is higher than the specified value ETH, the process returns from step 124 to step 122.

Therefore, even if the vehicle is traveling and the reception environment changes, as long as the current reception level E (n) of the current reception station selected in step 121 remains higher than the specified value ETH, step 122 The loop of ~ 124 is repeated.

When this loop is repeated and an emergency alert broadcast is carried out and a data signal S43 indicating the start of the emergency alert broadcast is obtained, this is step 1
The determination is made in step 22, and the processing proceeds from step 122 to step 131. In step 131, the state of the car audio device at this time, such as the switching position of the function switch circuit 21 at this time, is stored. Further, the amplifier 22 is enabled. That is, when the switch circuit 21 is not connected to the receiving circuit 10, the switch circuit 21 is connected to the receiving circuit 10, and when the amplifier 22 is not supplied with power, power is supplied.

Therefore, from the point in time when this step 131 is executed, if there is an Anus voice signal for issuing an emergency alert following the data signal S43 for starting the emergency alert broadcast,
This is supplied from the demodulation circuit 14 to the speaker 23 through the switch circuit 21 and the amplifier 22, and the emergency warning Anaus is output.

During this time, the processing of the CPU 31 proceeds to step 132, and in this step 132, the detection of the data signal S43 of the end of the emergency alert broadcast is awaited.

Then, when the emergency warning broadcast is finished and the data signal S43 of the end is received, this is step 13
2 is detected, the process proceeds from step 132 to step 133, in which the car audio device state stored in step 131 is restored, after which the process proceeds to step 123.

Thus, (A) Steps 112 to 114 detect the NHK having the maximum reception level E (n). (B) NHK detected in (A) is selected in step 121. (C) With respect to the NHK selected in (B), the standby state is set in steps 122 to 124 for the emergency warning broadcast. (D) If there is an emergency alert broadcast, the receiving circuit 10 to the speaker 2
The audio signal line 3 is validated, and the emergency warning broadcast is output from the speaker 23. (E) When the emergency alert broadcast ends, the state returns to the state of (C). If the emergency warning broadcast is performed, the broadcast can be heard regardless of the state of the car audio device at that time.

On the other hand, in the state of the item (C), because the service area changes as the vehicle runs,
When the reception level E (n) of the current reception station selected in step 121 becomes lower than the specified value ETH, this is determined in step 124, and the process returns from step 124 to step 111. Therefore, from here on, (A) to (E)
The terms will be repeated.

When the key 44 is operated while the routine 100 is being executed, the CP is operated by the key operation.
When the process of U31 is interrupted, the process corresponding to the key operation, for example, the switching of the function switch circuit 21 or the change of the reception frequency is executed in the interrupt routine, and when the process is completed, the interrupt routine is terminated. The processing of the routine 100 is continued.

In this way, in this car audio system, even if a car runs and the reception level changes, the receiving station with the highest reception level is always automatically selected and the emergency alert broadcast is made. To wait. Moreover, the receiving station is NHK, and the NHK service area covers almost the whole country. In case of emergency, any NHK station will carry out emergency alert broadcasting in that area, so you can listen to the emergency alert broadcasting reliably. be able to.

Further, although the above is the case of a car audio device, when it is applied to a stationary receiver, after the receiver is purchased, a special operation is performed to receive an emergency alert broadcast. No need. When the power switch is turned off, the muting is applied to the amplifier 22 instead of turning off the power, and the routine 10
If you set it to 0, you can usually listen to any broadcast freely, even if you turn off the power switch,
You can listen to the emergency alert when it is broadcast.

By the way, as described above, with the exception of a few exceptions, the frequency allocation of AM radio broadcasting is such that NHK and private broadcasting do not use the same frequency even in different regions. That is, in other words, some frequencies are assigned to both NHK and commercial broadcasting in different regions.

Therefore, at this frequency step 122
Even if the loop of ~ 124 is executed to wait for reception of the emergency alert broadcast, the emergency alert broadcast may not be received because it is a private broadcast and the emergency alert broadcast may not be received.

Channel selection routine 200 shown in FIGS. 5 and 6.
Shows an example in which such a problem is also solved.

That is, in this case, in the memory 34,
For example, as shown in the upper part of Figure 4, NHK throughout Japan
Of these, a table FRQ1 of data of frequencies used only by NHK first broadcast, in this example, data N1 (1) to N1 of frequency division ratio N when the tuner circuit 12 selects a channel.
A table FRQ1 of (MAX1) is provided (MAX1 is the number of frequencies used only by NHK first broadcast).

Further, in the memory 34, as shown in the lower part of FIG. 4, for example, a table of data of frequencies commonly used by NHK first broadcast and private broadcast among NHK first broadcasts throughout Japan. FRQC, in this example, the data N of the division ratio N when the tuner circuit 12 selects a channel
A table FRQC of C (1) to NC (MAXC) is provided (MAXC
Is the number of frequencies shared by NHK 1st broadcast and commercial broadcasts).

In the tables FRQ1 and FRQC, the right column shows the frequencies and broadcasting station names corresponding to the data N1 (1) to N1 (MAX1) and NC (1) to NC (MAXC) for reference. These are not included in tables FRQ1 and FRQC.

In such a structure, when the ignition key of the car is turned on, the processing of the CPU 31 starts from step 201 of the routine 200, and then, at step 202, it is checked whether or not it is the radio reception mode. If the switch circuit 21 is connected to the receiving circuit 10 and is in the radio receiving mode, step 202 is repeated and the receiving mode is continued.

If this radio reception mode is used,
At the time of an emergency alert, there is some broadcast that announces the emergency without taking the format of the emergency alert broadcast, so there is no problem even if the receiving mode of the emergency alert broadcast is not switched.

However, the switch circuit 41 causes the player 50 to
Alternatively, when it is connected to 60, or when the switch circuit 41 is switched from the receiving circuit 10 to the player 50 or 60, or when all the reception and reproduction are stopped, that is, in a mode other than the radio broadcast receiving mode, The process proceeds from step 202 to step 203, where the receiving circuit 10 is set to the receiving state. Therefore, after that, from the user's point of view, the radio broadcast is not received, but the radio broadcast is received on the back side.

Then, subsequently, in step 211, the variable i is set to the initial value "1", and in step 21
2, the data N1 (i) of the i-th frequency division ratio N in the frequency table FRQ1 of the memory 34 is read out, and this data N1 (i) is variable frequency division of the PLL of the tuner circuit 12 through the port 35. It is set in the circuit, and from this time point, the reception state of the frequency corresponding to the data N1 (i) is set.

Then, in step 213, the signal S
By receiving 42, the reception level at the reception frequency of the data N1 (i) selected in step 212 is measured, and the measured value E1 (i) is stored in the RAM 33.

Then, in step 214, it is checked whether or not the variable i exceeds the maximum value MAX1. If not, the process proceeds from step 214 to step 215, in which the variable i is changed.
Is incremented by "1" and then step 2
Return to 12.

Therefore, the loop of steps 212 to 215 is repeated until i = MAX1, and the table FRQ1
The reception levels E1 (1) to E1 (MAX1) at the frequencies corresponding to all the data N1 (1) to N1 (MAX1) prepared in the above are measured. That is, the reception level is measured at all frequencies used only by NHK first broadcasting, and the data E1 (1) to E1 (MA
X1) will be obtained in the RAM 33.

Then, when the reception levels of all the frequencies used only by the NHK first broadcast are measured in this way, i = MAX1, which is the step 2
14, the process proceeds from step 214 to step 221. In step 221, the reception levels E1 (1) to E1 (MAX1) measured in step 213 are checked, and the maximum reception level E1 (n) among them is checked. The selected frequency (the frequency of the data N1 (n)) is selected. As a result, thereafter, in the frequency used only by the NHK first broadcast, the NHK first broadcast having the maximum reception level is selected.

Subsequently, the process proceeds to step 222, and in step 222, it is checked whether the current reception level E1 (n) of the receiving station is higher than the specified value ETH1, and when it is higher than the specified value ETH1. The process proceeds from step 222 to step 223.

Then, in this step 223, it is checked whether or not the data signal S43 indicating the start of the emergency alert broadcast is obtained from the decoder circuit 43, and when it is not obtained, that is, when the emergency alert broadcast is not started, the processing is performed. The process proceeds from step 223 to step 224.

Then, in this step 224, the reception level E1 (n) of the current receiving station is measured, and then in step 225, the reception level E1 (n) measured in step 224 is higher than the specified value ETH. If it is higher than the specified value ETH, the process returns from step 225 to step 223.

Therefore, even if the vehicle is driven and the reception environment changes, as long as the current reception level E1 (n) of the current reception station selected in step 221 remains higher than the specified value ETH, step 223 The loop of ~ 225 is repeated.

Then, while this loop is repeated, the emergency alert broadcast is carried out, and when the data signal S43 indicating the start thereof is obtained by the decoder circuit 43, this is step 2
The determination is made in step 23, and the process proceeds from step 223 to step 231. In step 231, the state of the car audio device at this time, such as the switching position of the function switch circuit 21 at this time, is stored. Further, the amplifier 22 is enabled. That is, when the switch circuit 21 is not connected to the receiving circuit 10, the switch circuit 21 is connected to the receiving circuit 10, and when the amplifier 22 is not supplied with power, power is supplied.

Therefore, from the point in time when this step 231 is executed, if there is an Anus voice signal for issuing an emergency alert, following the data signal S43 for starting the emergency alert broadcast,
This is supplied from the demodulation circuit 14 to the speaker 23 through the switch circuit 21 and the amplifier 22, and the emergency warning Anaus is output.

Further, during this time, the processing of the CPU 31 proceeds to step 232, and in this step 232, the detection of the data signal S43 indicating the end of the emergency alert broadcast is awaited.

Then, when the emergency warning broadcast is finished and the data signal S42 for the end is received, this is step 23.
2 is detected in step 2, the process proceeds from step 232 to step 233, in which the state of the car audio device stored in step 231 is restored, and then the process proceeds to step 224.

On the other hand, in step 222, the reception level E1 at the frequency selected in step 221
When (i) is lower than the specified value ETH1, the process proceeds from step 222 to step 241.

Then, in step 241, the variable i is set to the initial value "1", and in step 242, the data NC (i) of the i-th frequency division ratio N in the frequency table FRQC of the memory 34 is stored. This data NC (i) is read out and the PLL of the tuner circuit 12 is read through the port 35.
Is set in the variable frequency divider circuit of
The reception state of the frequency corresponding to (i) is set.

Then, in step 243, the signal S
By loading 42, the reception level at the reception frequency of the data NC (i) selected in step 242 is measured, and the measured value EC (i) is stored in the RAM 33.

Then, at step 244, it is checked whether or not the variable i exceeds the maximum value MAXC. If not, the process proceeds from step 244 to step 245, where the variable i is changed.
Is incremented by "1" and then step 2
Return to 42.

Therefore, the loop of steps 242-245 is repeated until i = MAXC and the table FRQC is reached.
The reception levels EC (1) to EC (MAXC) at frequencies corresponding to all the data NC (1) to NC (MAXC) prepared in the above are measured. That is, the reception level will be measured at all frequencies commonly used by NHK first broadcast and commercial broadcast, and the data EC (1) to EC (MAXC) will be obtained in the RAM 33. Become.

Then, when the reception level is measured for all the frequencies of the data NC (1) to NC (MAXC) prepared in the table FRQC in this way, i = MAXC, which is step 244. In step 251, the reception levels EC (1) to EC (MAXC) measured in step 243 are checked and the maximum reception level EC (n) among them is determined. The selected frequency (frequency of data NC (n)) is selected. As a result, after that, among the stations of data NC (1) to NC (MAXC) prepared in the table FRQC,
The broadcasting station with the highest reception level is selected.

In this case, the data NC (1) to NC (MAXC) prepared in the table FRQC include the frequency data of the private broadcast which does not carry out the emergency alert broadcast, but in the area where the private broadcast can be received. The table FRQ1 contains frequency data of NHK first broadcast in the area. Therefore, according to the frequency data of the table FRQ1, N
The HK No. 1 broadcast will be selected, and the private broadcasts of Table FRQC will not be selected.

Subsequently, the processing proceeds to step 222, and thereafter, as described above, the loop of steps 223 to 225 causes a standby state for the emergency alert broadcast, and when the emergency alert broadcast is carried out, this is received by step 231. To be done.

When the loop of steps 223 to 225 is repeated and the system is in a standby state for the emergency alert broadcast, the service area changes as the vehicle runs, and the current channel selected in step 221 or 251 is selected. When the reception level E (n) of the receiving station becomes lower than the specified value ETH, this is determined in step 224, and the process returns from step 224 to step 211.
Therefore, the above process is repeated thereafter.

When the key 44 is operated while the routine 200 is being executed, the CP is operated by the key operation.
When the process of U31 is interrupted, the process corresponding to the key operation, for example, the switching of the function switch circuit 21 or the change of the reception frequency is executed in the interrupt routine, and when the process is completed, the interrupt routine is terminated. The processing of the routine 200 is continued.

In this way, in this car audio system, even if a car runs and the reception level changes, the receiving station with the highest reception level is always automatically selected to perform the emergency warning broadcast. To wait. Moreover, the receiving station is NHK, and the NHK service area covers almost the whole country. In case of emergency, any NHK station will carry out emergency alert broadcasting in that area, so you can listen to the emergency alert broadcasting reliably. be able to.

Furthermore, even if NHK is using the frequency used by commercial broadcasting in other areas, the NH
K can be tuned in and can therefore respond to emergency alert broadcasts.

In the above description, the NHK with the highest reception level is selected, but steps 112 to 1
While repeating the loop of 15, the reception level is checked for each frequency, and when the reception level NHK higher than the prescribed reception level ETH is received, step 12
You may make it advance to 2.

Alternatively, step 121 is omitted, and the reception level E (i) is compared with the reception level stored in the RAM 33 while repeating the loop of steps 112 to 115,
The data of the higher reception level and the frequency division ratio N can be stored in the RAM 33 again.

At any processing position of the routine 100, when an emergency alert broadcast is received, the amplifier 22
It is also possible to enable the speaker 23 and output the sound of the emergency alert broadcast. Furthermore, when the electric field strength of the receiving station suddenly weakens in a tunnel or the like, the station that has been stably received immediately before that may be continuously received.

Further, instead of providing the detection circuit 41, A
It is also possible to supply the GC voltage to the A / D converter 42 to obtain the signal S42 indicating the reception level. Furthermore, when the switch circuit 21 is not provided and only the radio function is provided,
Depending on the power switch on / off, the amplifier 22 power on / off or muting control (off / off)
(ON), and the power supply for other circuits may be left ON.

[0088]

According to the present invention, even if a vehicle runs and the reception level changes, a receiving station having an appropriate reception level is automatically selected and an emergency alert broadcast is made. stand by. Moreover, the receiving station is NHK, and the NHK service area covers almost the whole country,
In the event of an emergency, any NHK station will carry out an emergency alert broadcast of the area, so that the emergency alert broadcast can be heard without fail.

Furthermore, in the case of a stationary receiver,
After purchasing the receiver, no special operation is required to receive the emergency alert broadcast.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of the present invention.

FIG. 2 is a flowchart showing an example of the present invention.

FIG. 3 is a diagram for explaining the present invention.

FIG. 4 is a diagram for explaining the present invention.

FIG. 5 is a flowchart showing a part of an example of the present invention.

FIG. 6 is a flowchart showing an example of a continuation of FIG.

FIG. 7 is a diagram for explaining the present invention.

[Explanation of symbols]

 10 reception circuit 12 tuner circuit 14 demodulation circuit 23 speaker 30 microcomputer 31 CPU 32 ROM 34 memory 41 detection circuit 42 A / D converter 43 decoder circuit 100 channel selection routine 200 channel selection routine

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Morita 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (2)

[Claims] 1. A tuner circuit having a PLL and configured in a synthesizer system, a demodulation circuit for demodulating an original audio signal from an intermediate frequency signal of a broadcast wave signal selected by the tuner circuit, and a speaker. A circuit for outputting a signal indicating the reception level of the broadcast wave signal, a memory in which data of the NHK frequency is written, and a decoder for decoding the start signal and the end signal of the emergency alert broadcast are provided. Therefore, the reception frequency of the tuner circuit is changed to select an NHK having a specified reception level or higher, and after this selection, the decoder is operated while the reception level of the selected NHK is the specified level or higher. The output signal of the above is monitored and the standby state of the emergency alert broadcast is continued, and when the start signal is broadcast, the audio signal from the demodulation circuit is switched to the speed Supplying, after the channel selection, when the received level of NHK that station the election is lower than the level defined above, the receiver of the emergency alert broadcast so as to perform the channel selection again. 2. The receiver of the emergency alert broadcast according to claim 1, wherein the data of the frequency of the NHK written in the memory is the first data of the frequency used only by the NHK, and It is divided into the second data of the frequency commonly used by NHK and commercial broadcasting, and the reception frequency of the tuner circuit is changed according to the first data to select the NHK of the specified reception level or higher. After this tuning, during the period when the reception level of the selected NHK is equal to or higher than the specified level, the output signal of the decoder is monitored and the standby state of the emergency alert broadcast is continued, and the start signal is When broadcast, the audio signal from the demodulation circuit is supplied to the speaker. After the tuning, when the reception level of the selected NHK is lower than the specified level, the Station again running, the following first data, when changing the receiving frequency of the tuner circuit, the above reception level specified N
When HK cannot be tuned in, the reception frequency of the tuner circuit is changed according to the second data to tune to a NHK above the specified reception level, and after this tune, the selected NHK During the period when the reception level is higher than the specified level, the output signal of the decoder is monitored and the standby state of the emergency alert broadcast is continued, and when the start signal is broadcast, the audio signal from the demodulation circuit is output. A receiver of an emergency alert broadcast, which is supplied to the speaker and after the channel selection, when the received level of the selected NHK is lower than the specified level, the channel selection is performed again.