JPS62295521A - Cordless interphone set - Google Patents

Abstract

PURPOSE:To select other handset optionally by setting call signals of different frequencies to each handset. CONSTITUTION:Call signals of different frequencies are set to each handset 1 and a selection switch 43 selecting a handset 1 desired to be called is provided on the front face of the handset 1 and the selection switch 43 is made of a slide switch. Further, a call signal generator 23 consists of oscillator circuits 23a-23c generating, e.g., signals of 1kHz, 3kHz and 5kHz, any of the oscillation circuits 23a-23c is connected to a transmission circuit 14 by the switching of switches SW1-SW3 of the selector switch 43 to generate a call signal corresponding to each handset 1. A call signal detection circuit 24 detects all the call signals coresponding to each handset 1 and the call tone generating circuit 24 discriminates whether or not the output of the call signal detection circuit 24 is coincident with the frequency of the call signal set to itself.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Technical Field 1 The present invention relates to a cordless intercom equipped with a plurality of transceivers that simultaneously perform wireless transmission and reception using different transmission and reception frequencies.

[Background Art 1] Conventionally, in a cordless intercom equipped with a plurality of transmitters and receivers that simultaneously perform wireless transmission and reception using different transmission and reception frequencies, in a call standby state, the transmission frequency is set to the first frequency, and the reception frequency is set to the above-mentioned first frequency. For example, when the call button of a certain transceiver is operated, the transmitting frequency of this transceiver is switched to the second frequency, and the receiving frequency of this transceiver is switched to the first frequency. , it was possible to make simultaneous calls with both transmitters and receivers. However, with this transceiver, it was possible to talk to all transceivers when the call button was operated, but it was not possible to select and call a specific party.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and its object is to provide a cordless intercom that allows the user to select the person to call.

[Disclosure of the Invention 1 (Example 1) Figures 1 to 4 are diagrams showing an example of the present invention,
This embodiment is a cordless intercom equipped with a plurality of transceivers 1 that simultaneously perform wireless transmission and reception using different transmission and reception frequencies, and as shown in FIG. 3, a calling signal of a different frequency is set in each transceiver 1. By doing so, it is possible to arbitrarily select another transceiver 1.

For this purpose, there is a selection switch 43 for selecting the transceiver 1 to be called, and a calling signal generation circuit 23 for generating a calling signal corresponding to each transceiver 1 at the output of this selection switch 43.
, a ring signal detection circuit 24 that detects a ring signal transmitted from another transceiver 1, and a ringer that generates a ring tone when the output of this ring signal detection circuit 24 matches the frequency of the ring signal set for itself. The sound generating circuit 25 is also provided.

Hereinafter, the entire circuit breakdown of the transceiver 1 of this embodiment will be described in detail with reference to FIG. 4. The transceiver 1 of this embodiment shares a transmitting antenna and a receiving antenna, and is therefore provided with a duplexer 12. Receiving circuit 13 and transmitting circuit 14
has the same configuration as a normal transmitting/receiving circuit, the receiving circuit 13 is composed of a high frequency amplifying circuit 15, a mixer 16, a demodulating circuit 17, and an oscillating circuit 18 as a local oscillating circuit, and the transmitting circuit 14 is composed of a modulating circuit 20, Oscillation circuit 1 shared with the high frequency amplifier circuit 19 and the local oscillation circuit of the receiving circuit 13
It consists of 8 parts. The demodulated output of the receiving circuit 13 includes:
The audio amplifier 21 that amplifies this demodulated output, the speaker 4 that outputs audio from the output of the audio amplifier 21, and the transmitter/receiver 1 that makes the call when the call button 11 is operated also ring a ring tone. An operation sound generation circuit 27 is connected to generate an operation sound to confirm the operation. Further, the transmitting circuit 14 is connected to a microphone 5 into which audio is input, and an audio amplifier 22 which amplifies the output of the microphone 5 and inputs the amplified signal to the transmitting circuit 14. Furthermore, an intermittent reception pulse circuit 28 that generates an intermittent reception pulse that intermittently supplies power to the reception circuit 13 so that the transmission signal from the transceiver 1 can be received in a standby state is omitted in the drawing. However, it is provided with a power supply circuit that actually controls the supply of power to the reception circuit 13 using the output of the pulse generation circuit 28 for intermittent reception.

Furthermore, in this embodiment, a carrier detection circuit 29 detects that the transmission sound signal from the transceiver 1 is received by the reception circuit 13 by the presence or absence of a carrier, and a carrier detection circuit 29 that detects the presence or absence of a carrier, and A timer 31 that generates a time output, and the output of the timer 31 and the output of the call button 11 are logically summed to supply power to all circuits from the time the call button 11 is operated until the time limit of the timer 31 ends. OR circuit 38
, 39, and an inverter 33 for inverting the output of the carrier detection circuit 29 in order to prevent a calling signal or operation sound from being emitted during a call, and this inverter 33.
It is provided with AND circuits 34 and 35 for performing logical product of the output and the output of the OR circuit 39 or the output of the call button 11. In addition, in this embodiment, the oscillation circuit 18 described in "1" is connected to the oscillation circuits 18a,
One oscillation circuit 118a has a transmission frequency fls and a reception frequency f2, and the other oscillation circuit 18b has a transmission frequency 12 and a reception frequency fl. A contact rltr2 is connected between both oscillation circuits 18g and 18b and the transmitting/receiving circuits 13 and 14,
Which oscillation circuit 18a, 18b is connected to the transmitter/receiver circuit 13゜1
4. The relay 40 is provided with a relay 40 that makes it possible to select whether to connect to the relay 40 or not. The operation of this relay 40 is operated by the call button 11.

The above is a description of the basic configuration of this embodiment, and the features of this embodiment will be explained below.

In this embodiment, since calling signals of different frequencies are set for each transmitting/receiving device 1, a selection switch for selecting the transmitting/receiving device 1 to be called is provided on the front of the transmitting/receiving device 1, as shown in FIG. 43 is provided, and this selection switch 43 is constituted by a slide switch.Furthermore, as shown in FIG.
It is composed of oscillation circuits 23a to 23e that generate signals of various frequencies of KHz, 3KHz, and 5KHz, and one of the oscillation circuits 23a to 23c is connected to the transmission circuit 14 by opening and closing switches SW and SW3 of the selection switch 43. and generate a corresponding paging signal for each transceiver 1.

The ringing signal detection circuit 24 can detect all the ringing signals corresponding to each transceiver 1, and the ringing tone generation circuit 24 checks whether the output of the ringing signal detection circuit 24 matches the frequency of the ringing signal set for itself. It has a function to judge.

The operation of this embodiment having the above-described configuration will be described below.

When calling another transceiver 1, the number corresponding to the transceiver 1 to be called is selected using the selection switch 43. By switching this selection switch 43, the oscillation circuits 23a to 23c each generate a frequency corresponding to the calling signal of the called party among the oscillation circuits 23a to 23c that oscillate different frequencies.
23e is selected. When the call button 11 is pressed in this state, a call signal is transmitted to the other transceiver 1 via the call signal generation circuit 23 and the transmission circuit 14. Here, in this embodiment, how to enter the transmitting/receiving state will be explained. When the call button 11 is operated, the relay 40 switches the receiving frequency of the transceiver 1 to f2 and the transmitting frequency to f. At this time, the reception frequency of the other transceiver 1 is f1, and the transmission frequency is f2, so that transmission and reception with any other transceiver 1 is possible. When this call button 11 is operated, an operation sound is emitted on the side of the transmitter/receiver 1 that made the call. Incidentally, when the call button 11 is operated, the timer 31 detects the falling edge of the call button 11, and thereafter the timer 31 outputs for 20 seconds, for example. Therefore, once the call button 11 is operated, power is continuously supplied to all circuits for a predetermined period of time even if the press state of the call button 11 is released.
The device is ready for calls.

The transmission signal transmitted from this transceiver 1 is received by another transceiver 1 performing intermittent reception, and the paging signal detection circuit 24 of each transceiver 1 detects the paging signal. Then, the ringing tone generating circuit 25 determines whether the ringing signal detected by the ringing signal detection circuit 24 matches the frequency of the ringing signal set for itself, and if it matches, the ringing signal is activated. Sound is emitted from the speaker 4 via the audio amplifier 21. Then, when a call switch (not shown) of another transceiver 1 is operated, power is supplied to all circuits and a call is started. And transmitter/receiver 1
When the call ends, the transmitter/receiver 1 cancels the call state by releasing the suppressed state of the call switch.

(Embodiment 2) Figs. 5 and 6 are diagrams showing other embodiments of the present invention. In the above-mentioned Embodiment 1, you can have one call with any desired party, but you can If the user presses the call button 11 without knowing that the transmitter/receiver is in a call state, there is a risk of interrupting the call of another transmitter/receiver 1. Therefore,
In this embodiment, when a ringing signal is detected by the ringing signal detection circuit 24, and the frequency of the ringing signal at this time does not match the ringing signal set for itself, the ringing sound generation circuit 24 detects the ringing signal.
In addition to the indicator light 44 shown in FIG. 2, which is turned on at the rising edge of the calling signal and turned off at the falling edge of the carrier detection circuit 29 output that detects the presence or absence of a carrier in the transmitted signal. , and a transmission control circuit (not shown) that stops the power supply operation of the power supply circuit that supplies power to the mote transmission circuit 14 while the indicator light 44 is on. Note that the function of the transmission control circuit is provided by the power supply circuit described in 1 above, which supplies power to the transmission circuit 14 side.

In operation, as shown in FIG. 5, when the calling signal matches the frequency set for the self, the indicator light 44
does not light up, and the power supply circuit supplies power to all circuits, making it possible to talk. When the calling signal does not match the frequency set for itself, the indicator light 44 lights up at the rising edge of the falling edge when the calling signal is detected, as shown in the tIS6 diagram, and the carrier detection circuit 29 turns on. The indicator light 44 remains lit until the signal falls, that is, until the transmission from the other transceiver 1 is completed. When the indicator light 44 is on, the power supply circuit does not supply power to the transmitting circuit 14, so that there is no interruption in the communication of other transceivers 1.

(Embodiment 3) FIGS. 7 and 8 are diagrams showing still another embodiment of the present invention, and in the above-mentioned second embodiment, it is not possible to interrupt a call of another transmitter/receiver 1. However, if the caller 1111 is operated at this time, power is supplied to the receiving circuit 13, and there is a risk that the contents of the call between the other transmitters/receivers may be eavesdropped. Therefore, in this embodiment, if the frequency of the calling signal detected by the calling signal detection circuit 24 does not match the calling signal set for itself, the audio amplifier 2
A relay 45 is provided as a cut-off means having a contact r3 for cutting off the audio line between the output 1 and the speaker 4. Note that the relay 45 of this embodiment stops the audio line cutoff operation 1 when the call of another transmitter/receiver 1 ends, and normally switches the audio amplifier 21 on.
and speaker 4. As a result, the audio line is cut off while other transceivers 1 are talking, making it impossible to eavesdrop.

[Effect of the invention 1] As described above, the present invention sets a calling signal of a different frequency to each transceiver, and uses a selection switch to select the transceiver to be called, and the output of this selection switch to correspond to each transceiver. a ringing signal generation circuit that generates a ringing signal to be transmitted; a ringing signal detection circuit that detects a ringing signal transmitted from another transceiver; Since it is equipped with a ring tone generation circuit that generates a ring tone and a ring tone, you can switch the selection switch to correspond to the party you want to call, and depending on the output of this selection switch, the ring signal generation circuit will generate a ring signal for the other party. A ringing signal with the matching frequency is transmitted, and the other transmitter/receiver that receives this transmission signal detects this ringing signal with a ringing signal detection circuit, and further detects the ringing signal detected by this ringing signal detection circuit with itself. When the ring tone generation circuit determines that the ring signal matches the set ring signal, the ring tone is emitted, so that only the transmitter/receiver of the party you wish to call will emit the ring tone, allowing you to select the party you wish to call. It produces the effect that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of an embodiment of the present invention, FIG. 2 is an external perspective view of the same, FIG. 3 is an explanatory diagram of the operation of the same, and FIG. 5 and 6 are operation explanatory diagrams of other embodiments of the present invention, FIG. 7 is a main circuit configuration diagram of still another embodiment of the present invention, and FIG. 8 is an operation explanatory diagram of the same. . 1 is a transceiver, 13 is a receiving circuit, 14 is a transmitting circuit, 23
24 is a ringing signal generation circuit, 24 is a ringing signal detection circuit, 25 is a ringing tone generation circuit, 29 is a carrier detection circuit, 43 is a selection switch, 44 is an indicator light, 45 is a relay, and r3 is a contact point. Agent Patent Attorney Shi [l 艮 7 Figure 1 L, -J Figure 2 Figure 3 Subaru 1 S No. 138996 No. 2, Name of the invention Cordless intercom 3, Relationship to the case of the person making the amendment Patent applicant address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative Fujii 1 Husband 4 Agent postal code 530 5. Date of amendment order 6. Number of inventions to be increased by amendment None 7. Subject of amendment 111 Page 7 of the specification of the present application [Ring tone generation circuit 24] on the 20th line is corrected to "ring tone generation circuit 25." [21 Same as above, page 11, line 17, 1 indicates] is corrected to 1 indicating 1.

Claims (3)

[Claims] (1) In a cordless intercom equipped with multiple transceivers that simultaneously perform wireless transmission and reception using different transmitting and receiving frequencies, a selection switch sets a calling signal of a different frequency to each transceiver and selects the transceiver to be called. , a ringing signal generation circuit that generates a ringing signal corresponding to each transceiver at the output of this selection switch, a ringing signal detection circuit that detects a ringing signal transmitted from another transceiver, and an output of this ringing signal detection circuit. a ringing tone generation circuit that generates a ringing tone when the frequency of the cordless intercom matches the frequency of a ringing signal set in the cordless intercom. (2) A carrier detection circuit that detects the presence or absence of a transmission signal by detecting a carrier, and a ringing signal when the frequency of the ringing signal detected by the ringing signal detection circuit does not match the ringing signal set for itself. A display means that lights up when the detection circuit rises and turns off when the carrier detection circuit/output falls, and a transmission control circuit that stops power supply to the transmission circuit when the display means is lit. A cordless intercom according to claim 1, characterized in that the cordless intercom comprises: (3) The invention further comprises a cutoff means for cutting off the audio line when the frequency of the ringing signal detected by the ringing signal detection circuit does not match the ringing signal set for itself. The cordless intercom described in item 1.