JPH07105846B2 - Intercom system - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an intercom system, and more particularly, to a master unit, slave units provided on each of a plurality of terminals, and between the master unit and each slave unit. An intercom having a speaker line and a microphone line that are interposed as a pair and switching between a call enable state and a call disable state by changing the polarity of a DC power supply applied to the speaker line or the microphone line. Regarding the system.

(Prior art and its problems) As a conventional intercom system of this type, for example,
There is a nurse call system as shown in FIG.

Reference numeral 101 denotes a master unit provided on the nurse station side, and 102 ... each hand slave units provided on the hospital room side. A pair of speaker lines 103 and a microphone line 104 are provided between the parent device 101 and each of the child devices 102, and at least one common line 105 is further provided. Switching between the call-enabled state and the call-disabled state is performed by switching the channel selection switches 106 ... Of the base unit 101, and the speaker lines 103 ... Are connected to the common line 105 ...
... has a diode 108 interposed in series with the microphone 107.
The direct current voltage is applied to the polarity such that the ... Is reverse biased, and the microphones 107 are in a non-functioning state. 109 ...
Is a speaker.

For example, when the nurse call button 110 is pressed on a certain room side, the thyristor 111 is turned on, a current flows through the microphone line 104, and the corresponding called lamp 112 of the base unit 101 is turned on.
Channel selection switch corresponding to the side of the hospital room that was called
When 106 is pressed, the speaker line 103 is connected to the transmitting amplifier 113 and the microphone line 104 is connected to the receiving amplifier 114, and at the same time, the polarity of the DC voltage is inverted. As a result, Mike 10
The diode 108 interposed in series with 7 is biased in the forward direction, and the microphone 107 is brought into a conductive state to enable a call.

Such a nurse call system is spread throughout the hospital, but since it only functions as an intercom, the utilization rate was not so high.

(Object of the Invention) The present invention has been made in view of such circumstances, and makes it possible to use an intercom system currently used as a nurse call system or the like for various data transmissions. The purpose is to

(Structure and effect of the invention) In order to achieve such an object, the present invention is, in the intercom system described at the beginning, a central modem provided on the base unit side and a terminal provided on each of the handset units. A detection means for detecting whether the communication is possible or not by detecting the polarity of the modem and the speaker line or the microphone line; and the speaker line or the microphone line when the detection means detects the communication impossible state. , A switching connection means for switching connection to each of the central modem and the terminal modem.

According to this configuration, when the detecting means detects the call disabled state based on the polarity detection, the switch connecting means connects the speaker line or the microphone line to the central modem and the terminal modem respectively in response thereto, and the line allows the data to be transmitted. Transmission can take place.

Therefore, when the intercom system is in a call-disabled state, taking the case of the nurse call system as an example, it becomes possible to transmit various data such as data such as body temperature and blood pressure. The frequency of use has been increased, and the intercom system can now be used effectively.

(Description of Embodiments) Hereinafter, the present invention will be described in detail based on embodiments illustrated in the drawings. FIG. 1 is a simplified configuration diagram of the present invention, FIG. 2 is a simplified circuit diagram, and FIG. 3 is a detailed circuit diagram.

In these figures, 1 is a bedside unit provided corresponding to each bed on the hospital room side,
Hand cordless handset 2, ..., terminal modem 3, ..., first polarity detecting means 32, ..., first line switching mechanism 4, ..., thermometer 5 for sending digital medical information signals to the terminal modem 3 ..., and blood pressure monitor 6 It consists of ... Each of the hand cordless handsets 2 has a child microphone 7, a child speaker 8, a diode 9 connected in series to the child microphone 7 and a thyristor 10 connected in parallel to the child microphone 7. It consists of a nurse call switch 11 that conducts the thyristor 10.

Reference numeral 12 denotes a master unit provided in the nurse station, which includes a master microphone 13, a corresponding transmitter amplifier 14, a master speaker 15, a corresponding receiver amplifier 16, and a hand slave unit 2.
The number of tuning switches 17 and the called lamps corresponding to the number of ...
18 ..., a broadcast selector switch 19, and a first and second DC power source 20 used to selectively switch the polarity of the voltage applied to the circuit in response to the switching operation of the tuning switch 17 ...
It consists of a and 20b.

21 ... is a speaker line, 22 ... is a microphone line, and 23 is a common line.
... Each is installed as a pair between the bedside unit 1 ... and the base unit 12.

Reference numeral 24 is a second line switching device including a number of second line switching mechanisms 56 ... Corresponding to the number of hand slaves 2, ... Reference numeral 25 is a communication control device used by being connected to the second line switching device 24. Communication control device
25 comprises a central modem 26 and a communication control unit 27.

The first line switching mechanism 4 ... Each is a speaker line.
21 is composed of relay contacts 28 and 29 for selectively switching connection between the terminal modem 3 side and the handset unit 2 side, and the second line switching mechanism 56 ... Each is a bedside unit 1
Central modem 26 side of the speaker line 21 located on the side and the base unit
It is composed of relay contacts 31 and 30 for selectively switching the connection to 12, and the first line switching mechanism 4 ... And the second line switching mechanism 56 ..

Further, each of the first polarity detecting means 32 ... is provided in a short circuit of the microphone line 22 and the common line 23, and a phototransistor 34 which is conducted when the DC power source 20a is used by switching the tuning switch 17. , And a relay coil 35 that is excited when it is conductive and operates the relay contacts 28 and 29. On the other hand, the second polarity detecting means 33 is also provided in the short circuit of the microphone line 22 and the common line 23, and is a phototransistor which is conducted when the DC power supply 20a is used by switching the tuning switch 17. 36 and the relay contact 3
It is composed of a relay coil 37 for operating 0 and 31.
By the above-mentioned first and second polarity detection means 32 ..., 33 ...
The detection means of the microphone line 22 ... Is configured.

Next, the operation of this embodiment will be described.

In FIG. 3, the bedside unit 1 located above is in a call-enabled state and the bedside unit 1 located below is in a call-disabled state (data transmission possible).

Call disabled state In this state, by switching the tuning switch 17, the DC power source 20a is used as the power source of the microphone line 22,
The diode 9 is set as a reverse bias and the microphone line 22 is not conducted in the child microphone 7. On the other hand, the phototransistor 34 is driven by a forward bias to be conductive, and the relay coil
35 is excited, the relay contact 28 is connected, and the speaker line 21 is connected to the terminal modem 3. Furthermore, the phototransistor 36 is driven by a forward bias to conduct, and the relay coil
37 is excited, the relay contact 31 is connected, and the speaker line 21 is connected to the central modem 26 side. In this way
The speaker line 21 switched between the terminal modem 3 and the central modem 26 is used for data transmission.

That is, the digital signals from the thermometer 5 and the blood pressure monitor 6 are converted into analog signals by the terminal modem 3, transmitted through the speaker line 21 and the common line 23, converted into digital signals by the central modem 26 and sent to the communication control unit 27. .

Callable state In the call disabled state, when the nurse call switch 11 is pressed on the bedside unit 1 side, the thyristor 10 becomes conductive and the called lamp 18 lights up. After confirming that the called lamp 18 is lit, by switching the tuning switch 17 corresponding to the bedside unit 1 on which the nurse call switch 11 is pressed, the DC power source 20b is used and the microphone line 2 is used.
Change the polarity of the applied voltage of 2. Due to this change in polarity, the diode 9 is brought into conduction, the microphone line 22 is brought into conduction in the child microphone 7, and a call is possible. On the other hand, since the phototransistors 34 and 36 do not conduct, the relay coil 35 and
37 is not excited, the relay contacts 29 and 30 are closed, and the speaker line 21 is connected between the hand slave unit 2 and the master unit 12, respectively.
On the base unit 12 side, the speaker line 21 is connected to the transmission amplifier 14
Connected to.

The characteristic operation of the above embodiment will be described below.

Terminal modem power-off state (Fig. 4) When the terminal modem 3 located in the upper part of the figure is in a power-off state and the terminal modem 3 is cut off, the relay coils 35 and 38 are restored and the second line switching device 24 The following line is formed between the speaker and the terminal modem 3 via the speaker line 21 and the common line 23.

Common line 23 → Second line switching device power supply 39 → Resistor 40 → Phototransistor 41 → Zener diode 42 → Zener diode 43 → Relay contact 31 → Speaker line 21 → Relay contact
29 → relay contact 44 → resistor 45 → common line 23 This excites the relay coil 46, and the relay contact 47
Disconnects the terminal modem 3 from the central modem 26 and polls the other terminal modems 3 ...
26 is prevented from being affected by the low impedance of the speaker line 21.

When the nurse call switch 11 is pressed in this state, the relay coil 37 is restored and the relay contact 30 connects the hand slave unit 2 and the master unit 12 to enable a call. At this time, the relay contact 31 disconnects the central modem 26 and the speaker line 21. As a resistor, a child speaker 8 of the hand-held handset 2 ...
It is necessary to use one that is sufficiently larger than the impedance of.

Broadcasting state (Fig. 5) The broadcast selector switch 19 is switched to the broadcasting side, and the audio signal at the time of broadcasting broadcasts the monomulti 48 ..., Conducting the transistors 49 ..., and energizing the relay coils 50. As a result, the relay contacts 51 ... Disconnect the microphone line 21 ...
The bedside unit 1 ... and the relay coils 35, 37 of the second line switching device 24 are restored, and the speaker line 21 ... is positioned between the hand slave unit 2 ... and the master unit 12 ... to enable simultaneous broadcasting. .

When the audio signal at the time of broadcasting is stopped for a certain period of time, for example, 5 to 6 seconds, the output (Q) of the monomulti 48 ... Is restored to the low level, so the relay coils 35, 37 ... 21 ... is connected between the terminal modem 3 ... and the central modem 26 ... Speaker line 21 ...
Since it is used as a switching signal of the above, the voice signal at the beginning of the talk is not placed on the speaker line 21 ... However, if the switching time is 0.1 seconds or less, there is no problem in the announcement.

In addition, in order to prevent the reset of the monomulti 48 ... by the disconnection of the microphone line 21 ... by the relay contact 51 ... and the restoration of the relay coil 37 ..., the clear terminal 52 is used as a reference via the relay contact 53. It is fixed to the power supply 54.

When the terminal modem is not used (Fig. 6) When the terminal modem 3 is not connected, the second line switching device 24
The speaker switch 21 not used for data transmission is disconnected by the disconnection switch 55 provided in the above, and thereby the other data transmission lines used are prevented from having a low impedance.

The intercom system of the present invention can be used in schools, factories, etc. in addition to the nurse call system described above.

[Brief description of drawings]

FIG. 1 is a simplified configuration diagram of an embodiment of the present invention, FIG. 2 is a simplified circuit diagram of the same, FIG. 3 is a detailed circuit diagram of the same, and FIGS. 4 to 6 show different usage states. FIG. 3 equivalent diagram and FIG. 7 are circuit diagrams showing a conventional example. 2 ... is a hand slave unit (slave unit), 3 ... is a terminal modem, 4
...... is the first line switching mechanism (switch connection means), 12 is the base unit,
21 ... is a speaker line, 22 ... is a microphone line, 26 is a central modem, 32 ... is a first polarity detecting means (detecting means),
33 is the second polarity detection means (detection means), 56 ... is the second line switching mechanism (switch connection means).

Claims (1)

[Claims] 1. A master unit, a slave unit provided on each of a plurality of terminals, and a speaker line and a microphone line interposed between the master unit and each slave unit in pairs, In an intercom system configured to switch between a call-enabled state and a call-disabled state by changing the polarity of a DC power source applied to a speaker line or a microphone line, a central modem provided on the base unit side and a slave unit side respectively A terminal modem provided in the speaker line, a detection unit that detects whether the call is possible or not possible by detecting the polarity of the speaker line or the microphone line, and the speaker line when the detection unit detects the call disabled state. Alternatively, an intercom system including switching connection means for switching and connecting a microphone line to each of the central modem and the terminal modem Tem.