JPS6272264A - Mutual interphone set - Google Patents

Abstract

PURPOSE:To prevent an incoming malfunction caused due to unsharpened pulse wave by bringing a call signal to a signal having a frequency higher than the voice frequency band and sending the call signal to each interphone via a talking line. CONSTITUTION:A channel selection key 11a is operated respectively in the 1st and 2nd interphones A, B to output high frequency signals f1, f2 assigned respectively to the 2nd interphone B and the 1st interphone A from high frequency oscillation circuits 11a, 11b. In sending a proper sound signal from microphones 9a, 9b in response respectively to the 2nd interphone B and the 1st interphone A, the signal is applied respectively to the 1st interphone A and the 2nd interphone B via a talking line T and fed to speakers 7a, 7b via hybrids 5a, 5b and amplifier circuits 6a, 6b. In stopping the oscillation of oscillation circuits 10a, 10b at that point of time, both interphones are brought into the talking stage after that.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a so-called mutual intercom device having mutual calling and communication functions.

2. Description of the Related Art Generally, in a mutual type intercom device, as shown in Fig. 2, a power line V, a calling signal line Y, a communication line T1, and a ground line are connected between each intercom A, B, C, D, and so on. It is configured to be connected by a total of four wires.

Then, as shown in Fig. 3, the call signal line 2 is connected to each intercom A, B, C, D, etc. from an arbitrary intercom.
(assigned to...) a, b, c, d
A call signal whose pulse width is changed by the pulse of the pit assigned to the desired intercom (for example, the pulse of pit C) is transmitted, and thereby the desired intercom (for example, C) is called. It consists of

Problems to be Solved by the Invention However, in this configuration in which pulse trains are sent to each other to call a desired intercom, the distance between each intercom becomes large, so that the desired intercom cannot be accurately called. There was a problem where I could no longer receive calls.

The present invention eliminates the above-mentioned drawbacks of the conventional technology, and has a simple configuration that saves wires.Moreover, it provides an excellent mutual communication system that can accurately call the desired intercom even if the wiring distance is large. The object of the present invention is to provide a type intercom device.

Means for Solving the Problems In order to achieve the above object, the present invention is configured such that the calling signal is a signal of a higher frequency than the voice frequency band, and the calling signal is transmitted to each intercom via the communication line. It is something.

Therefore, according to the present invention, the malfunction of incoming calls caused by the rounding of pulse waveforms, which has been a problem in the past, does not occur at all, and the number of wiring lines can be reduced overall without requiring a special dedicated call line. It has the effect of being able to reduce wiring costs by one, thereby significantly reducing wiring costs.

Embodiment FIG. 1 is a schematic diagram of an embodiment of the mutual intercom device of the present invention. In the figure, A and B are 11th, 2nd and In the intercom 1, a power supply circuit 1 is provided in the first intercom A and supplies power to the second intercom B and the following through a power line V. And 2a,
2b are mutually different frequencies 11 and f assigned to each intercom A1B built in the first and second intercom A1B and transmitted through the communication line T.
Narrow band band pass filters 3a and 3b which pass only the calling signal consisting of the high frequency signal of 2 detect when the output of each band pass filter 2a and 2b appears,
Control circuits 4a, 4 each outputting a predetermined control signal
5a and 5b are oscillator circuits for generating ringing tones operated by the outputs of control circuits 3a and 3b, respectively; 5a and 5b are high-speed circuits that are connected to the communication line T and separate the transmitting signal and the receiving signal; 6a and 6b are Amplification circuits 7a and 7b amplify the respective reception signals, respectively.
b.

A speaker 8a inputs the output of the oscillation circuits 4a and 4b.

8b is an amplifier circuit that amplifies the transmission signal from the microphones 9a and 9b, respectively; IOa and IOb are high frequency oscillation circuits that output a calling signal to the communication line T; and 11a.

11b is a channel selection button for arbitrarily switching the oscillation frequency of the oscillation circuits 10a and 10b to the oscillation frequencies fx, f2, etc. assigned to the intercom of the desired party, respectively, and selecting the intercom of the party to call. be.

In the above embodiment, from the first intercom A to the second intercom
The case where the first intercom A is called from the second intercom B1 and the second intercom B will be described.

In this case, operate the channel selection buttons 11a on the 11th and 2nd intercoms A and B, and select the high frequency oscillation circuit +1a.
, Ilb respectively assigned to the second intercom B1 and the first intercom A. A high frequency signal of fl is output. In this way, each of them is transmitted to the second intercom B1, the first intercom A through the communication line T, and the band pass filter 2b,
The oscillation circuit 4b is detected through the control device 2a and the oscillation circuits 4b and 4a for generating a ringing tone are driven.
, 4a and 4a, a calling signal is output from each speaker 7b,
7a Yoshi ringtone will be emitted. Therefore, when the second intercom B1 and the first intercom A respectively transmit appropriate audio signals from the microphones 9a and 9b in response, the signals are transmitted to the first intercom A1 and the second intercom B via the communication line T. It is inputted and applied to the speakers 7a, 7b via the hybrid 5a, 5b amplifier circuits 6a, 6b, and it becomes clear that the second intercom B1 has responded to the first intercom A. When the oscillation of the oscillation circuit 10a and Job is stopped, the two parties can communicate from then on.

In this way, according to the above embodiment, each intercom A, B
By outputting a calling signal of a frequency assigned to each intercom to be called, the intercom to be called can be easily called, and the calling signal is transmitted to each intercom via a communication line. Therefore, it has the advantage that no special call signal line is required. Furthermore, according to the above embodiment, high frequency signals with mutually different frequencies assigned to each ink-phone are used as a calling signal, so even if the distance between each intercom becomes large and the line resistance becomes large, there is little difference in the line resistance. This is extremely advantageous in practice because it allows you to accurately call the desired intercom without being affected.

In the above embodiment, the frequency of the calling signal is desirably set to a frequency higher than the highest frequency of the audio frequency band, for example, 20 KHz or more, in order to clearly distinguish it from the call signal.

Effects of the Invention As is clear from the above embodiments, the present invention uses different high frequency signals assigned to each intercom as a calling signal, transmits this signal to each intercom via a communication line, and , each is configured to emit a ringing tone when the above-mentioned high-frequency signal assigned to its own intercom arrives, and different high-frequency signals assigned to each intercom are used as the calling signal. It has the advantage that malfunctions due to waveform rounding as in the prior art can be almost completely prevented and more accurate calling is possible. Further, according to the present invention, the configuration is such that the calling signal is transmitted to each intercom via the communication line, so there is no need for a separate dedicated calling signal line, and the overall wiring can be reduced by one, thereby reducing the wiring cost. It has the advantage of being able to significantly reduce

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the mutual intercom device of the present invention, FIG. 2 is a schematic configuration diagram of a conventional mutual intercom device, and FIG. 3 is a waveform diagram of a calling signal used in the device. It is. A, B...intercom, l...power supply circuit, 2a,
2b...Narrow band pass filter, 3a, 3b...
・II Control circuit, 4a, 4b...Oscillation circuit, 5a
, 5b... hybrid circuit, 6a, 6b, 8a, 8
b-Amplification circuit, 7a, 7b... Speaker, 9a, 9b
...Microphone, 10a, IOb...Oscillation circuit for generating a ringing signal, Ila, llb...Selection button Name of agent Patent attorney Masao Nakao and one other person 2Ffl

Claims (1)

[Claims] A high-frequency signal with a different frequency assigned to each intercom is used as a calling signal, and when this signal is transmitted to each intercom via a communication line, each intercom selects the above-mentioned calling signal assigned to its own intercom. A mutual intercom device configured to receive a signal from the user and output a ring tone based on the reception.