JPS641810Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a door-to-door receiver used for municipal disaster prevention administrative radio.

Municipal disaster prevention administrative fixed radio systems are sometimes provided with a rebroadcasting function in which content broadcast during the day is rebroadcast from the master station using a special selective calling system at night. Selective calling signals include a group signal to distinguish from other licensees, a simultaneous signal to call all receivers, and an individual signal with a combination of two waves to call receivers individually. A simultaneous signal is sent out for simultaneous calling, and a group signal and two individual waves are sent out for individual calling. However, conventionally, when rebroadcasting, only a group signal is sent from the master station as a special selective call, and each receiver that wishes to receive it can set the rebroadcast setting switch in advance, even if there is no simultaneous signal or individual signal. The circuit was configured so that it entered the receiving state simply by receiving the group signal. According to this system, all the door-to-door receivers are called from the master station during rebroadcasting, so rebroadcasting cannot be performed to specific door-to-door receivers.

In order to eliminate these drawbacks, the present invention provides a circuit configuration that allows not only simultaneous calling but also individual selective calling even during rebroadcasting.

FIG. 1 shows a selective call signal transmission order according to an embodiment of the present invention. A is the signal sending order for simultaneous paging, B is the signal sending order for individual paging, C is the signal sending order for general paging in rebroadcasting, D is the signal sending order for individual paging in rebroadcasting, and a is the group signal, b is a broadcast signal, c is an individual first signal, d is an individual second signal, and e is a rebroadcast signal. FIG. 2 shows an embodiment of the door-to-door receiver circuit of the present invention. The radio wave received by the antenna 1 is demodulated by the wireless receiver 2 and the audio information signal is sent to the switching circuit 3. The switching circuit 3 transmits the audio information signal to the low frequency amplification circuit 4 only when the receiver is selectively called. to make the speaker 5 sound. In addition, the signal detection circuits 6 to 10 and the gate circuit 11, each of which detects a different signal from the calling signal sent from the radio receiving unit 2, determine whether the door-to-door receiver has been selectively called. Sometimes incoming call memory circuit 1
At the same time, the information is sent to the switching circuit 3 and the switching circuit 3 is brought into the "connected" state. Next, when connected to the calling signal and receiving the rebroadcast signal e shown in FIG. However, if it is a rebroadcast signal, the information is sent to the rebroadcast switch 14. When the rebroadcast setting switch is set here, the switching circuit 3 is left connected without sending reset information to the incoming call storage circuit 12, and when the rebroadcast setting switch is not set, the incoming call is Memory circuit 12
It sends reset information to turn off the switching circuit 3 and operates to prevent the sound from being emitted.
The rebroadcast switch 14 can be composed of only a break switch, or can be a switch circuit as shown in FIG. When the rebroadcast switch 15 is set and in the make state, this switch circuit resets the incoming call storage circuit 12 by the AND circuit 16 even if rebroadcast information is received from the signal length determination circuit 13. Operates so that no signal is sent. Note that in this embodiment, the incoming call storage circuit 12
Although only the output of the rebroadcast switch is connected as a reset input, other reset inputs such as a squelch signal reset, a call end signal reset, etc. may be connected in parallel.

As explained above, according to the present invention, simultaneous calling and individual selective calling can be made possible even during rebroadcasting.

[Brief explanation of drawings]

Fig. 1 is a chart of the order of selective calling signal transmission according to an embodiment of the present invention, Fig. 2 is a system diagram of a door-to-door receiver circuit according to an embodiment of the present invention, and Fig. 3 is a rebroadcast setting switch according to an embodiment of the present invention. It is a circuit diagram. DESCRIPTION OF SYMBOLS 1...Antenna, 2...Radio receiving section, 3...Switching circuit, 4...Low frequency amplification circuit, 5...
Speaker, 6 to 10...Signal detection circuit, 11...
Gate circuit, 12... Incoming call storage circuit, 13... Signal length determination circuit, 14... Rebroadcast setting switch.

Claims (1)

[Scope of utility model claims] It has a radio receiving section that follows the antenna and reproduces the calling signal and the voice information signal, and is composed of a switching circuit that follows the radio receiving section and connects and disconnects the voice information signal, a low frequency amplification circuit, and a speaker. an audio circuit section, a plurality of signal detection circuits following the radio receiving section for detecting a calling signal, a gate circuit following the plurality of signal detection circuits, and a gate circuit following the gate circuit for detecting an incoming call state. In a receiver equipped with a paging signal detecting section configured with a paging signal detecting section configured with a paging signal detecting section that stores a paging signal and an incoming call storage circuit that drives the switching circuit, one of the plurality of signal detecting circuits includes a signal length determining section that follows a frequency detecting circuit for a rebroadcast signal. 1. A door-to-door receiver comprising a rebroadcast setting circuit section comprising a rebroadcast setting switch that follows the signal length determination circuit and is connected to a reset input terminal of the incoming call storage circuit.