JPS60185433A - Radio receiver - Google Patents

Abstract

PURPOSE:To detect surely traffic information even in an amplitude modulation broadcast by detecting an identification signal comprising plural simple tones modulated by one modulation system to switch the broadcast into the traffic information. CONSTITUTION:An output in an audible frequency from a tuner 25 is fed to an amplifier circuit 29 via a relay switch 28 and outputted from a speaker 71. When the traffic information is received by a tuner 26 during the reception of a radio broadcast, the relay switch 28 of a relay 27 is switched and the traffic information is outputted from the speaker 71. An output from the tuner 26 is fed to filters 30, 31, the identification signal is extracted by a detection circuit 32, a comparator circuit 34 and a time discrimination circuit 37 or the like, monostable multivibrator circuits 44, 47 detect that the identification continues for a prescribed time to excite a relay coil 50 of the relay 27.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radio receiving device that receives so-called traffic information such as the status of traffic congestion on a road using radio broadcasting.

The times at which traffic information is broadcast in radio broadcasts vary, and are not broadcast at regularly set times. Therefore, there is a risk that traffic information may be missed.

Typical prior art is, for example, Japanese Patent Application Laid-Open No. 49-12860.
As described in 1, the general broadcast content of frequency modulation broadcasting is frequency-multiplexed with traffic information that is sent irregularly and a warning signal that indicates when the traffic information will start broadcasting or is being broadcast. However, the system is configured so that the arrival of traffic information can be confirmed based on this warning signal, and the traffic information can be automatically switched and listened to even while listening to general broadcasting. Such prior art is based on frequency modulation multiplex broadcasting, and the notice signal has a single frequency, so when such a system is applied to amplitude modulation broadcasting and normal frequency modulation broadcasting, In normal radio broadcasting, there is a very high possibility that a signal having the same frequency as the preview signal will be received, and false detection is likely to occur.

Therefore, such prior art can only be used in frequency modulation multiplex broadcasting.

An object of the present invention is to provide a radio receiving device that can reliably detect traffic information without error even in amplitude modulation broadcasting and normal frequency broadcasting.

The present invention provides that, during transmission of a radio broadcast, a series of identification signals of an audible frequency consisting of a plurality of mutually different single tones modulated by the same modulation method as that of the radio broadcast is fJl.
traffic information is then transmitted, 1 and then a series of identification signals are transmitted in a second order different from the first order, 1 selectively audifying said traffic information. A radio receiving device for use in the radio system, comprising: a tuner that receives radio waves and derives an audible frequency signal; a filter that selects and derives the identification signal from among the outputs from the tuner; identification signal detection means for detecting each identification signal by comparing each level with the output; and in response to the output from the identification signal detection means, when the identification signal continues for a predetermined time or more, a time determination signal is derived. means for outputting a switching control signal when the time determining means outputs another time determining signal within a predetermined time after outputting the first time determining signal; This radio receiving device is characterized by having a switching means for switching between broadcasting and broadcasting.

FIG. 1 is a block diagram of a radio broadcast transmitting station according to an embodiment of the present invention. This radio broadcast is generally a widely used medium wave amplitude modulation broadcast. Traffic information and other sounds are converted into electrical signals by the microphone 1 and sent to the transmitting device 6 from one individual contact 3 of the changeover switch circuit 2 through the common contact 4. Transmitting device 6
performs medium wave amplitude modulation on the signal from the microphone 1 and other audible frequency signals, and transmits the modulated signal from the antenna 7. The monostable circuit 9 is activated by the output from the start switch 8 which is suppressed when transmitting traffic information. A further monostable circuit 10.11 is connected in cascade to the monostable circuit 9. Signals from the monostable circuits 9, 10.11 are applied to an OR gate 12. The monostable circuit 13 is activated by a signal from the end switch 72 which is suppressed when the transmission of traffic information is finished. monostable circuit 1
Furthermore, monostable circuits 14 and 15 are connected in cascade to 3.

The outputs from monostable circuits 13-15 are also connected to OR gate 1
given to 2. The output from the OR gate 12 is given to the changeover switch circuit 2. Changeover switch circuit 2
makes the common contact 4 conductive to the other individual contact 5 when the signal from the OR gate 12 is at a high level. OR
When the signal from gate 12 is at a low level, common contact 4 is electrically connected to individual contact 3. monostable circuit 9,
The output from 15 is given to switch circuit 17 via OR gate 16. Further, the outputs from the monostable circuits 11 and 13 are provided to a switch circuit 19 via an OR gate 18. Switch circuit 17.19 is OR game 1-16
, 18 is conductive only when the signal applied from the terminals 18 to 18 is at the no-no level.

The identification signal of audio frequency 71, /2 from the oscillator circuit 20.21 is sent to the individual contact 5 via the switch circuit 17.19.
Commonly given to

Figure 2 (1) shows the common contact 4 of the changeover switch circuit 2.
This is an audio frequency signal waveform given to the transmitting device 6 from the transmitter 6. When transmitting traffic information during radio broadcast transmission, the start switch 8 is first suppressed. The output from the start switch 8 is shown in FIG. 2(2). The monostable circuit 9 responds to the signal from the start switch 8 in FIG.
3) A signal having a pulse width W1 is derived as shown in FIG. A signal from the monostable circuit 9 is applied to the changeover switch circuit 2 via an OR gate 12. Therefore, the common contact 4 is electrically connected to the individual contact 5. The output from the monostable circuit 9 causes the switch circuit 17 to conduct, so that a signal having an audio frequency 11 from the oscillation circuit 20 is applied from the changeover switch circuit 2 to the transmitting device 6 . In this way, an identification signal having an audio frequency of 11 is transmitted during the transmission of a radio broadcast for a period of pulse width W1 of the output from the monostable circuit 9. The monostable circuit 10 derives a signal having a pulse width W2 from the falling edge of the signal from the monostable circuit 9, as shown in FIG. 2(4). Thereafter, the monostable circuit 11 responds to the fall of the signal from the monostable circuit 10 and derives a signal V having a pulse width W3 as shown in FIG. 2 (5). A signal from the monostable circuit 11 causes the switch circuit 19 to conduct. As a result, an identification signal having an audible frequency of 12 from the oscillation circuit 21 is provided to the transmitter 6 via the changeover switch circuit 2. In this way, prior to transmitting traffic information, the audio frequency f1. Identification signals having f2 are sent out sequentially in this order.

After the output from the monostable circuit 11 falls, the output from the OR gate 12 becomes low level. Therefore, the common contact 4 of the changeover switch circuit 2 is electrically connected to the individual contacts 3. In this way, traffic information inputted from the microphone 1 is given to the transmitter 6 and broadcast on the radio.

When the broadcast of traffic information ends, the end switch 72 is suppressed. The output from the termination switch 72 is shown in FIG.
6). The output having a pulse width W4 from the monostable circuit 13 is shown in FIG. This causes the common contact 4 to become electrically connected to the individual contact 5 again.

The output from monostable circuit 13 also causes switch circuit 19 to conduct. As a result, an identification signal having an audible frequency f2 from the oscillation circuit 21 is provided to the transmitting device 6.

Thereafter, the output shown in FIG. 2(8) having a pulse width W5 from the monostable circuit 14 is derived.

Next, an output having a pulse width W6 from the monostable circuit 15 is derived as shown in FIG. 2 (9). An identification signal having an audible frequency 11 from an oscillation circuit 20 is provided to the transmitter 6 by the output from the monostable circuit 15 . In this way, after the traffic information ends, the audible frequency f2. f
The identification signals with L are sent out in this order, ie in a different order than before the sending of the traffic information.

FIG. 3 is a block diagram of the receiving device. Radio waves from the antenna 7 at the transmitting station shown in the first diagram are received by the antenna 22, passed through the branching circuit 24, and sent to the two tuners 25.
．． 26. The tuners 25,26 differ in their tuned frequencies and therefore in the radio broadcasts they are receiving.

The audio frequency output from the tuner 25 is sent to the relay 2.
Amplification circuit 29 via switching relay switch 28 of 7
and output from the speaker 71. During reception of a radio broadcast tuned by the tuner 25, when traffic information is received in the radio broadcast being received by the tuner 26, the relay switch 28 of the relay 27 is switched as described below. Traffic information is output from the speaker 71.

The output from tuner 26 is given to filters 30 and 31 and level setting circuit 53. Filter 30.31
is the frequency f1. Each identification signal having f2 is selected and derived. The output from filter 30.31 is given to detection circuit 32.33. Detection circuit 32 includes a coupling capacitor 51, a detection diode 52, and an integrating capacitor 36. The detection circuit 33 is the detection circuit 3
It has the same structure as 2. The output from the detection circuit 32.33 is given to one input of the comparison circuit 34.35.

A signal from the level setting circuit 53 via the detection circuit 54 is applied to the other input of the comparison circuits 34 and 35. The detection circuit 54 has the same structure as the detection circuits 32 and 33.

The outputs from the comparison circuits 34 and 35 are sent to the time judgment circuit 37.
38 respectively.

The time judgment N path 37 includes a resistor 39 and an integrating capacitor 40.
, a comparator circuit 41 , and a diode 42 connected in parallel to a resistor 39 . One input of the comparator circuit 41 is given an output from an integrating capacitor 40 . Comparison circuit 4
A signal at a predetermined level is applied from the terminal 43 to the other input of the terminal 1. Another time determination circuit 38 has the same structure as the time determination circuit 37.

The output from the time determination circuit 37 is applied to one input of an AND gate 45 via an optical stability circuit 44 and directly to one input of an A N I) gate 46 . The output from the time determination circuit 38 is the monostable circuit 47
and is applied directly to the other input of AND gate 45. A N I) The output of gate 45 sets flip-flop 48 and the output from AND gate 46 resets flip-flop 48. transistor 49
is made conductive by the set output from flip-flop 48, and relay coil 50 of relay 27 is energized. By energizing the relay coil 50, the relay switch 28 guides the signal from the tuner 26 to the amplifier circuit 29.

Referring to FIG. 4, a case will be established in which a signal shown in FIG. 4(1) is derived from the tuner 26 in a radio broadcast being received by the tuner 26.

The filter 30 selects only the identification signal having the audio frequency f1 and supplies it to the detection circuit 32. As a result, the output of the integrating capacitor 36, ie, the output of the detection circuit 32, becomes as shown in FIG. 4(2). The identification signal having the audible frequency f1 is sent from the level setting path 53 to the detection circuit 54.
is applied to determine the discrimination level of the comparison circuit 34. When only the identification signal having the audible frequency 11 is being received, the output from the detection circuit 54 and therefore the comparison circuit 34
The discrimination level of is low. Therefore, when an identification signal having an audible frequency f1 exceeding this discrimination level is input from the detection circuit 32, the comparison circuit 34 derives the waveform shown in FIG. 4(3). The output from this comparison circuit 34 is integrated by an integrating capacitor 40 via a resistor 39. The output waveform of the integrating capacitor 40 is shown in FIG. 4 (4). When the output of the integrating capacitor 40 exceeds the discrimination level given to the terminal 43 after a predetermined time T1 has elapsed, the comparator circuit 4
1 derives the time determination signal of the NO level shown in FIG. 4(5). In this way, the comparator circuit 41 derives an output only when the identification signal of the audio frequency 11 is continuously received for a time T1 or more. The monostable circuit 44 is shown in FIG.
), a pulse having a predetermined pulse width W7 is derived. During the period of this pulse width W7, an identification signal having an audible frequency of 12 is received and detected as described below.

When an identification signal having an audible frequency of 12 is output from the tuner 26, the identification signal is selected by the filter 31 and detected by the detection circuit 33. Detection circuit 33
The output from is shown in FIG. 4(6). Comparison circuit 35
The output from the time determination circuit 38 is shown in FIG. 4 (7), and the output from the time determination circuit 38 is shown in FIG. 4 (8). The output from the time determination circuit 38 is derived when the identification signal having an audible frequency of 12 is greater than or equal to time T2. In this way, the AND gate 45 obtains the waveform shown in FIG. Output.

When the traffic information radio broadcast ends, the audible frequency f2. Identification signals having f1 are derived from tuner 26 in this order. When an identification signal having an audible frequency of 12 is detected, a signal having a predetermined pulse width W8 is derived from the monostable circuit 47. Pulse l1g'
W8 may be equal to the pulse width W7. During the period when the output is being derived from the monostable circuit 47, when an identification signal having an audible frequency f1 is detected, A N'
The output from D-gate 46 causes flip-flop 48 to be reset. Therefore, the relay switch 28 guides the signal from the tuner 25 to the amplifier circuit 29, and the radio broadcast being received by the tuner 25 can be heard again from the stereo 71.

In the embodiment described above, the audible frequency f1. When a signal having a frequency spectrum over a wide frequency band including f2 is derived from the tuner 26, the level setting circuit 53
The level t of the signal passing through the detection circuit 54, that is, the discrimination level of the comparison circuits 34 and 35 is high. Therefore, comparison circuit 3
The outputs of 4 and 35 remain at low level. In this way, the i listening frequency/1. , /2 is received by the tuner 26, a high level output is obtained from the comparator circuit 34.35 as described above. This prevents erroneous detection of traffic information. Also, the time determination circuit 37.
38, the audible frequencies fL and f2 change over time T1 (Fig.
5)) and the time T2 (see FIG. 4(8)), the time determination circuit 37.
Output is obtained from 38. Therefore, it is possible to more reliably prevent erroneous detection of traffic information. Furthermore, due to the action of the monostable circuits 44 and 47, the audible frequency 71. , f
2 for a predetermined time W7. Noritsubu flop 48 operates only when the signal is generated continuously in W8. This also further reliably prevents erroneous detection of traffic information.

The diode 42 included in the time determination circuit 37 immediately connects the capacitor 4 when the output of the comparison circuit 34 becomes low level.
It functions to discharge zero charge. Therefore, the output of the comparator circuit 34 which is inputted next is connected to the capacitor 4 via the resistor 39.
can be reliably integrated by 0 and the exact time TI
can be obtained.

Audible frequency f1 of the identification signal. f2 may be selected to have a chord relationship that satisfies the first equation to obtain good hearing.

/ 2 = 1.5·fl (1) fl is, for example, 900 Hz, and f2 is 1,350 H2.

FIG. 5 is a block diagram of a portion of the receiving side of another embodiment of the present invention. In this embodiment, as shown in FIG. 6(1), three different audible frequencies/1. ,/2.

Identification signals □ having f3 are sent out in sequence, and then traffic information is broadcast. After the traffic information broadcast ends, the audible frequency f3. f2. The identification signals with f1 are sent out in this order, ie in a different order than before the sending of the traffic information. In order to detect the order of such identification signals, a filter 56, a detection circuit 57, a comparison circuit 58, a time determination circuit 59, and a monostable circuit 60 are additionally provided. The remaining parts corresponding to the previous embodiments are given the same reference numerals. When the identification signal of the audible frequency 11 is derived from the tuner 26, the comparator circuit 34 derives the signal shown in FIG.
) is derived. Next, when the identification signal of the audible frequency 12 is derived from the tuner 26, the comparator circuit 35 derives the signal shown in FIG. AN signal of W8
D game 1-45, 46 will be given. Monostable circuit 44.4
The pulse width of the output from W7.7. During the W8 period,
An identification signal at audio frequency f3 is received. 1=iJ When an identification signal having an audio frequency of 13 is derived from the tuner 26, the identification signal is selected by the filter 56,
The signal is applied to a comparison circuit 58 via a detection circuit 57. The comparison circuit 58 derives the signal shown in FIG. 6(6). The time determination circuit 59 derives the output shown in FIG. 6(7) after the elapse of time T3. The monostable circuit 60 derives an output having a pulse width W9 as shown in FIG. 6(8). The output of the AND gate 45 has the waveform shown in FIG. 6(9) and sets the flip-flop 48.

Therefore, as described above, the transistor 49 becomes conductive, and the relay switch 28 of the relay 27 is switched to switch the tuner 2.
The traffic information received by the speaker 6 is output from the speaker 71. A similar operation is achieved when the broadcast of traffic information ends, and the output of FIG. 6(10) from the AND gate 46 resets the flip-flop 48 to return to its original state.

In the embodiment shown in FIGS. 5 and 6, the audio frequencies fl, f2 . If the durations of the f3 identification signals and the pause periods between them are chosen to be equal, the pulse widths W7', W8°W9 may be determined so as to satisfy the second equation.

W7-2·W8=W9 (2) As another embodiment of the present invention, identification signals having a larger number of mutually different audible frequencies may be used in order to prevent false detection of traffic information.

As another embodiment of the present invention, a tape player may use, for example, a cassette pack instead of the tuner 25. When traffic information is broadcast on the radio while a tape is being played by such a tape player, the signal from the tape player may be switched to a signal from the tuner 26 so that the traffic information can be heard.

As described above, according to the present invention, the following effects are achieved.

In the present invention, when receiving so-called traffic information such as traffic jam conditions using radio broadcasting such as amplitude modulation and normal frequency modulation, (1) the frequency component of the identification signal from the tuner is filtered. (11) detecting the identification signal by selectively deriving the identification signal through the tuner and comparing the level of the identification signal with the level of the output from the tuner; judge,
(IV) detecting that a series of identification signals prior to or after the traffic information are received within a predetermined time; Detect each of these conditions (1)
Since the traffic information is audible only when ~(1v) holds, false detections can be extremely reduced. Therefore, it is possible to almost completely prevent erroneous detection of identification signals due to frequency components in radio broadcast information or the influence of external noise, and it can be used as a transmission/reception method between broadcasting stations and in-vehicle receivers that are susceptible to external noise. Particularly effective.

According to the invention, the identification signal is an audio frequency signal. Therefore, this identification signal can also serve as an alarm sound. Therefore, even if the receiving side is a conventional radio receiving device (that is, a radio receiving device consisting only of an antenna, a tuner, an amplifier, and a speaker), during the broadcast of traffic information by an identification signal while listening to the radio broadcast,
It becomes possible to listen to traffic information with concentrated attention,
It is possible to attract the listener's attention. thus,
Listening to traffic information becomes extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a transmitting station according to an embodiment of the present invention, and FIG.
The figure is a waveform diagram for explaining the operation of the transmitting station shown in the first figure.
FIG. 3 is a block diagram of a radio receiving device according to an embodiment of the present invention, FIG. 4 is a waveform diagram for explaining the operation of the block diagram shown in FIG. 3, and FIG. 5 is a still another embodiment of the present invention. FIG. 6 is a waveform diagram for explaining the operation of the block diagram of FIG. 5. DESCRIPTION OF SYMBOLS 1... Microphone, 2... Changeover switch circuit, 6... Transmitter, 8... Start switch, 9-11
．． 13~15,44,47.60...monostable circuit, 2
0゜21...Oscillation circuit, 25.26...Tuner,
27... Relay, 30, 31.56... Filter,
32, 33.54.57...detection circuit, 34.35.
58... Comparison circuit, 37, 38. 59... Time judgment circuit, 48... Flip-flop agent Patent attorney Kei Nishi Partial procedural amendment (method) March 29, 1985 Patent application 1982 -227066 2. Name of the invention Radio receiving device 3. Relationship with the amended case Applicant address Name: Fujitsu Ten Ltd. Representative 4, Agent address: Shinkosan Building, 1-13-38 Nishihonmachi, Nishi-ku, Osaka Country equipment EX 0525-5985 INTAPT
J International FAX GITI&Gl (06)538-02
476, drawings subject to amendment 7, engraving of drawings with content of amendment (no change in content). -Hi 2-

Claims (1)

[Claims] During the transmission of a radio broadcast, a series of identification signals of audible frequencies consisting of a plurality of mutually different tones modulated by the same modulation method as the radio broadcast are sequentially transmitted in a first order. Next, traffic information is transmitted, and then a series of plural identification signals are transmitted in a second order different from the first order, and the radio receiving device is configured to selectively make the traffic information audible. a tuner that receives radio waves and derives an audio frequency signal; a filter that selects and derives the identification signal from the output from the tuner; and each level of the output from the tuner and the output from the filter. identification signal detection means for detecting each identification signal by comparing the identification signals; means for deriving a time determination signal when the identification signal lasts for a predetermined time or more in response to the output from the identification signal detection means; means for outputting a switching control signal when the time determining means outputs another time determining signal within a certain period of time after outputting the first time determining signal; 1. A radio receiving device comprising: switching means for switching.