JPS5927626A - Receiver - Google Patents

Abstract

PURPOSE:To attain smooth channel selection for emergency broadcast or the like, by constituting the receiver so that the start of broadcast of other station is detected and informed during the receiving of broadcast. CONSTITUTION:An RF amplifier 1, a mixer 2, an IF amplifier 4, a detector 5 and an AF amplifier 7 constitute an inherent receiving system A and a receiving system B for the detection of an FSK signal is provided in addition. The inherent receiving system and the FSK signal detecting receiving system adopt both the constitution of PLL frequency synthesizers and the receiving frequency of the FSK receiving system is swept by a controller 19 during the reception of the inherent receiving system. When a specific program is broadcast from a prescribed broadcast station, an FSK signal transmitted at the start is detected. This detection signal appears as an output of a comparator 14, the sweep is stopped by the controller 19 and the start of broadcast of the specific program is informed by indicating lamps 21-24.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a receiving device, and more particularly to a receiving device for receiving specific broadcast programs such as emergency broadcasts.

At the start and end of specific programs, including emergency broadcasts that notify of emergencies, traffic information, weather forecasts, etc., for example, one of two low-frequency signals that are identification signals is used as a so-called mark, and the other is used as a space. A method is known in which an FSK signal is also sent as a digital signal.

The first block is the receiver that listens to only such specific programs.
The RF (high frequency) input is RF amplifier 1.
After being amplified in the mixer 2, the signal is mixed with the local oscillator signal from the local oscillator 3 and converted into an IF (intermediate frequency) signal. This IF signal is input to the detector 5 via the IF amplifier 4 and
It is demodulated into an F (71-dio frequency) signal. To this F
The signal is applied to the AF amplifier 7 via the switch 6, amplified, and then drives a speaker (not shown).

B to detect the above FSK signal from the detection output of the detector 5.
Band pass filters (PFs) 8 and 9 are provided, and both BPFs 8 and 9 extract low frequency signals corresponding to marks and spaces, respectively. Output on both sleeves is die A
- The differential amplifier 12 is detected by the wave detector 10.11.
A difference signal between both signal levels is obtained. This difference signal is level-compared with the reference level from the reference signal generator 13 in the comparator 14, and the on/off of the switch 6 is controlled by the comparison output.

In this configuration, the switch 6 is normally open and the speaker is not emitting sound. Here, when the F'SK signal that informs the start of a specific program arrives, BPF8
．． Frequency signals corresponding to marks and spaces are respectively extracted by 9 and detected by detectors 10 and 11. In the differential amplifier 12, the level difference between the two transverse wave outputs (this corresponds to the ratio of marks and spaces) is compared with a predetermined reference level, and the switch 6 is closed.

In this way, it becomes possible to listen to a specific program.

At the end of a specific program, the FSK signal is sent out, and the difference between the outputs of both transverse waves by the detectors 10 and 11 is at a different level than at the start, and this level is detected by the comparator 14 to open the switch 6. In this way, during standby, no sound is output, but the sound is output in response to the start signal of the source you want to listen to, and when that ends, it automatically returns to the standby state again.

In such a conventional configuration, it is possible to detect the presence or absence of a specific program for only one broadcast station and listen to it, but it is necessary to set the receiver to the frequency of the broadcast station and wait. There is a drawback that you cannot listen to specific programs from other stations.

SUMMARY OF THE INVENTION An object of the present invention is to provide a receiving device that can know the start of a specific program of another station even if it is receiving a program of any broadcast station.

In addition to the reception system that receives broadcasts in a predetermined frequency band, the receiving device of the present invention detects a start identification signal sent at the start of a specific program from a predetermined broadcast station to identify the transmission frequency of the predetermined broadcast station. The present invention is characterized in that it includes a signal detection means, and a notification means for announcing the frequency of the predetermined broadcasting station using a detection horn of the detection means.

A preferred embodiment of the detection means is a sweep receiver configuration capable of sweeping frequencies within a predetermined frequency band, and by sweeping the reception frequency, detects the start identification signal of a specific program and identifies the reception frequency at that time. It is characterized by the fact that

An embodiment of the present invention will be described below with reference to FIG. R
"Amplifier 1. Mixer 2. IF amplifier 4° detector 5 and A
The F amplifier 7 constitutes the original receiving system, and in addition, a receiving system for FSK signal detection having substantially the same configuration as that in FIG. 1 is added. That is, R1 - amplifier 1
a, mixer 2a.

IF amplifier 4a, detector 5a, BPF8.9. Diode detector 10, 11. Differential amplifier 12. A receiving system including a reference signal generator 13 and a comparator 14 is provided.

The original receiving system is a so-called PLL (phase-locked loop) frequency synthesizer tuner system, which is a well-known configuration that allows for preset tuning as well as sweeping reception frequency tuning. PLL circuit is VCo (voltage controlled oscillator) 3
, LPF <low-pass filter) 151 phase comparator 16
．． It consists of a programmable frequency divider 17 and a reference oscillator 18, and the output of the VCo3 becomes the local oscillation signal, and the LP
The output of FI5 is used to control the tuning frequency of the tuning circuit of R, F amplifier 1. The frequency division ratio of the programmable frequency divider 17 is controlled by the controller 19, allowing sweep tuning and preset tuning.

Similarly, the reception system for identifying FSK signals is 1] LL synthesizer system, and includes VCO3a, LPF15a,
It consists of a phase comparator 16a, a programmable frequency divider 17a, and a reference oscillator 18a. VC03a output is mixer 2
The output of the LPF 15a becomes a tuning frequency control signal of the RF amplifier 1a, and the controller 19 controls the frequency division ratio of the frequency divider 17a. This frequency division ratio control method is performed in such a way that it is possible to sweep the frequency within the reception frequency band (AM band, FM band, etc.), but it is also possible to sweep the frequency over the entire band. It may also be possible to scan only the frequencies corresponding to stations whose service area is the district.

When the FSK signal is identified by this receiving system, the output from the comparator 14 is sent to the controller 19, and the change in the frequency division ratio of the frequency divider 17a is temporarily stopped.

Further, a display signal is sent from the controller 19 to the display 20, thereby displaying the current receiving frequency of the original receiving system. Furthermore, indicators 21 to 24 are provided, and one of the indicators 21 to 24 corresponding to the reception frequency at the time of detecting the FSK signal is controlled to light up. .

In such a configuration (13), the original receiving system receives one broadcasting station by the preset channel selection operation (X). In this case, the receiving system for FSK signal identification is switched to the receiving frequency sweep state by the controller 19. During this period, the frequency within the receiving band is swept.When a specific program starts to be transmitted from a predetermined broadcasting station during this sweep, F
Since the SK signal is sent out, this receiving system detects it and a detection signal is generated from the comparator 14. Since the frequency division ratio of the programmable frequency divider 17a at this time corresponds to the frequency of the specific broadcast station, one of the display lamps 21 to 24 corresponding to this frequency is controlled to be lit. When this FSK signal identification is performed, the frequency sweep is stopped for a predetermined period of time, the lamp continues to be lit, and a specific program can be announced. If this lamp is associated with a preset button for the original reception system, the user can immediately operate this preset button to listen to a specific program.

When a specific program ends, the indicator lamp will of course turn off in response to the FSK signal at the end.In addition, instead of or together with the notification of the specific station, the controller 19 will set the division ratio corresponding to the frequency of the specific station. It may be set in the branching device 17 to force the original receiving system to receive the specific station.

As a method of announcing a specific program, it goes without saying that not only a visual method but also an audible method may be used, and the original receiving system is not limited to the preset channel selection configuration. Furthermore, not only the FSK signal but also signals of other systems may be used as the identification signal of a specific program, and in this case, a detection configuration corresponding to the signal type may be adopted.

In the above embodiment, the start and end signals of a specific program control the lighting of the display at the position corresponding to the preset button of the preset station, but the specific program is divided into emergency broadcasts and regular programs such as news and traffic information. It is also possible to forcibly switch the station that has been listened to to the emergency broadcasting station during an emergency broadcast by using two detection/judgment circuits, and only display a notification during a normal program.

Although the configuration is shown as a receiver only, it can also be applied to products that are integrated with a tape deck, etc., or to car stereo equipment, where a specific program can be announced even while the tape is being played, and even radio reception. It can be made to switch.

As described above, according to the present invention, even when the original receiving system is receiving normal broadcasting, it is possible to detect a specific program transmitting station by using another receiving system, so the user can detect the station transmitting a specific program as necessary. This has the advantage of making it easier to select a station.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional receiving device, and FIG. 2 is a block diagram of a receiving device of the present invention. , Explanation of symbols of main parts 3...VCO14...Comparator 1
5...LPF 16...Phase comparator 17...Programmable frequency divider 19...
... Controllers 21 to 24 ... Display device applicant Pioneer Co., Ltd. agent Patent attorney Motohiko Fujimura

Claims (3)

[Claims] (1) In addition to a reception system that receives broadcasts in a predetermined frequency band, a detection means detects a start identification signal transmitted at the start of a specific program from a predetermined broadcast station to identify the transmission frequency of the predetermined broadcast station. and notification means for announcing the frequency of the predetermined broadcasting station based on the detection output of the detection means. (2) The receiving device according to claim 1, wherein the detecting means comprises a sweep receiving means capable of sweeping frequencies within the predetermined frequency band. (3) The reception system has a configuration in which the channel can be selected by a preset button, and the notification means indicates the start of broadcasting of the specific program at the preset button corresponding to the transmission frequency identified by the detection means or at the corresponding position of this button. Claim 1 or 2, characterized in that there is an indication indicating that
Receiving device described in section.