JP2607467Y2 - Multi-station intercom system - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-station intercom system, and more particularly to a multi-station intercom system in which a switch unit for selecting a multi-station interphone can be applied to many models and has few failures.

[0002]

2. Description of the Related Art Conventionally, in hospitals and the like, there has been known a multi-station intercom system in which a call is made between one master unit provided in a nurse station or the like and a plurality of slave units provided in each hospital room. . Figure 2 shows a multi-station intercom system.
As shown in the figure, a plurality of slave units 2 are connected to the master unit 1 via the master unit 1 and the slave unit connection terminal T1, respectively, and a specific slave unit 2 and the master unit 1 are connected in a communicable state. It is provided with a tuning switch 3 corresponding to each slave unit. The tuning switch 3 is connected to a contact 3a connected to the power supply circuit 5, a contact 3b connected to the slave unit connection terminal T1, and a transmission / reception circuit 6 via a display lamp 4 for displaying a call from the slave unit. And a contact 3c. The contact 3a is further connected to a call detection circuit 8 via a diode 7, and the contact 3b
Connected to form a standby state.

In the standby state, power is supplied to the slave unit connection terminal T1 from the power supply circuit 5, and its potential is monitored by the call detection circuit 8. Specific child device 2 to parent device 1
Is called, the potential of the slave unit connection terminal T1 decreases, and the call detection circuit 8 detects the potential of the slave unit connection terminal T1 via the diode 7.
It is detected that the potential of 1 has dropped. At this time, current flows from the power supply circuit 5, the display lamp 4 is turned on, and the potential of the slave unit connection terminal T1 is maintained at the time of calling. When the button 31 of the tuning switch 3 is pressed, the contact 3a is switched, the power supply circuit 5 and the call detection circuit 8 are disconnected from the slave unit connection terminal T1, the display lamp 4 is turned off, and the call state is changed. At the same time, the contact 3c and the contact 3b are connected, and the cordless handset 2 and the transmission / reception circuit 6 are connected, so that a call is possible. Transmission / reception is performed by two wires including a slave unit connection terminal T1 of the slave unit and a common ground 9 of the slave units.

[0004] When a specific slave unit 2 is selected from the master unit 1 and called, the same operation can be performed by pressing the button 31 of the tuning switch 3. When one slave unit and the master unit 1 are in a talkable state, the slave units other than the slave unit in the talk state are in a standby state, and calling of the master unit from another slave unit is also possible.

[0005] Here, a button 31 of the tuning switch 3 is locked when pressed, and a recovery switch 10 is provided which is switched from ON to OFF in conjunction with pressing any of the buttons 31. ing. When the recovery switch 10 is turned on by pressing the recovery switch 10, the channel selection switch 3 is switched in tandem and the contact 3a is restored.
And the contact 3b are connected.

[0006]

In such a multi-station intercom system, a mechanical channel selection switch had to be used, and failures such as poor contact of the contacts were inevitable. In addition, it is necessary to design a switch having the number of switches corresponding to the function of the model for each model, which requires time for the design and deteriorates the manufacturing efficiency.

[0007] Further, if the recovery switch is forgotten to be pressed after the end of the call, it is impossible to respond to a call from the same slave unit again.

Further, the call indicator lamp is turned off during a call, and it is not possible to distinguish between a call and a standby state, so that it is impossible to know which slave unit is talking after pressing the channel selection switch. was there.

The present invention has been made in order to solve the above-mentioned drawbacks, and the same device can be used for any model, thereby improving manufacturing efficiency and reducing failures. In addition, an object of the present invention is to provide a multi-station intercom system that does not forget to press the recovery switch, can always respond to a call after the end of a call, and can appropriately display a display lamp.

[0010]

In order to achieve this object, a multi-station intercom system according to the present invention includes a master unit and a plurality of slave units connected to the master unit via slave unit connection terminals. The master unit includes a tuning switch detection circuit for transmitting a slave unit signal corresponding to the slave unit selected by the tuning switch for selecting each slave unit during standby, and a power switch circuit and a slave unit connection to each slave unit. A power supply circuit that supplies power via the terminal, a call detection circuit that detects a drop in the voltage of the child device connection terminal when a call is made from the child device and outputs a call signal, and a call display unit that displays a call using the call signal. A transmission / reception circuit connected to each of the slave unit connection terminals via a semiconductor switch, and when a call signal and an off-hook signal from the hook switch are input, or an off-hook signal from the hook switch and a channel selection switch. Outputs a drive signal to the semiconductor switch with the slave unit signal transmitted from the detection circuit outputs a power supply stop signal to the power switch circuit when entered,
A call path control circuit for outputting a call state signal to the call detection circuit and displaying a call on the call display section.

[0011]

In this multi-station intercom system, power is supplied from a power supply circuit via a power switch circuit to a slave unit connection terminal to which a plurality of slave units are respectively connected to the master unit, in a standby state. Further, a call detection circuit is connected to the slave unit connection terminal, and when the master unit is called from the slave unit, it monitors that the potential of the called slave unit connection terminal drops. A call display of the slave unit corresponding to the call detected by the call detection circuit is performed by the call display unit, and a call signal is output from the call detection circuit to the communication path control circuit to enter a call state. When the call display of the call display unit is confirmed and the hook switch of the master unit is turned off-hook, the communication path control circuit sends a power supply stop signal to the power switch circuit to release the call state, and drives the semiconductor switch, The transmission / reception circuit is connected to the slave unit connection terminal to form a call state. A call status signal is output to the call detection circuit to cause the call display unit to display a call.

Further, when calling the slave unit from the master unit, the hook switch is off-hook, the channel selection switch is pressed, and the slave unit signal of the slave unit to be called is transmitted from the channel selection switch detection circuit to the communication path control circuit. Similarly, in this case, the communication path control circuit sends a power supply stop signal to the power switch circuit to release the standby state, and at the same time, drives the semiconductor switch to connect the transmission / reception circuit and the slave unit connection terminal to form the communication state. I do. A call status signal is output to the call detection circuit to cause the call display unit to display a call.

For this reason, since switching between the slave unit connection terminal and the transmission / reception circuit is not provided with a mechanical contact, no contact failure occurs, and a semiconductor switch can be used for any model. Manufacturing efficiency can be improved without designing switches according to the number of switches. Also, after the end of the call, there is no need to press the recovery switch, and it is possible to always answer the call again.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a multi-station intercom system according to the present invention;

As shown in FIG. 1, the multi-station intercom system S includes a master unit 11 and a plurality of slave units 12 connected to the master unit 11 via slave unit connection terminals T2.

The base unit 11 has respective child unit connection terminals T
A power supply circuit 16 connected to the power supply circuit 2 for supplying power via a power supply switch circuit 15; and a call detection circuit for detecting a decrease in the potential of the child device connection terminal T2 and outputting a call signal when there is a call from the child device. 13 are connected to the respective slave unit connection terminals T2. A call display unit 14 is connected to the call detection circuit 13, and when a call signal from the call detection circuit 13 is input, a lamp corresponding to the child unit performing the call blinks. Power is supplied to the called sub unit via the sub unit connection terminal T2 whose potential has been lowered by the calling, and the calling state potential is maintained.

Further, the base unit 11 is provided with a communication path control circuit 17 to which a call signal output from the call detection circuit 13 is input.
Are connected by a semiconductor switch 19 provided between the slave unit connection terminal T2 and the transmission / reception circuit 18, so that a communication path is formed. The communication path control circuit 17 includes a transmission / reception circuit 18
An on-hook / off-hook signal from a hook switch 21 of a transmitter / receiver 20 of a base unit connected to the base unit, and a restoration signal from a restoration switch 22 for restoring a standby state after a call is inputted. When a call signal from the detection circuit 13 and an off-hook signal from the hook switch 21 are input, a call state signal is sent to the call detection circuit 13 and the lamp of the call display unit 14 is turned on via the call detection circuit 13. At the same time, a power supply stop signal is output to the power switch circuit 15, and the power supply to the slave unit connection terminal T2 is stopped, so that a call state is established.

Further, the channel control circuit 17 is connected to a tuning switch detecting circuit 24 for transmitting a slave unit signal corresponding to the slave unit selected by the tuning switch 23 for selecting each slave unit during standby. Therefore, when the slave unit signal from the channel selection switch detection circuit 24 and the off-hook signal from the hook switch 21 are input to the communication path control circuit 17, the call detection circuit is activated in the same manner as when there is a call from the slave unit. 13 to turn on the lamp of the call display section 14 via the call detection circuit 13 and to output a power supply stop signal to the power switch circuit 15 so that the slave unit connection terminal T2
Then, the power supply is stopped, the standby state is released, and the slave unit connection terminal T2 and the transmission / reception talk circuit 18 are connected by the semiconductor switch 19, and the communication state is established. A call is made through two wires: a handset connection terminal T2 in which a call path is formed, and a common ground 25 for a plurality of handset units. At this time, the slave units other than the slave unit that is in a talking state with the master unit 11 are in a standby state, and when a master unit is called from another slave unit, a call signal is sent out by the call detection circuit 13, By flashing the lamp of the call display section 14, it is possible to confirm the call on the master unit side.

Further, when the on-hook signal from the hook switch 21 or the recovery signal from the recovery switch 22 is input, the communication path control circuit 17 sends a call termination signal to the call detection circuit 13. The lamp of the call display unit 14 is turned off by the light-off signal of the call detection circuit 13. Then, the communication path control circuit 17 disconnects the slave unit connection terminal T2 and the transmission / reception circuit 18, outputs a power supply signal to the power switch circuit 15, and the power from the power supply circuit 16 is supplied to the slave unit connection terminal T2. , A standby state is formed.

When a state in which no call is made continues and the on-hook signal is not sent from the hook switch 21 and the restoration signal from the restoration switch 22 is not sent,
That is, even if the user forgets to put on the handset 20 or forgets to operate the recovery switch 22, when the timer provided in the communication path control circuit 17 measures for a certain period of time, the communication path control circuit 17 sends the call detection circuit 13 , A power supply signal is output to the power switch circuit 15, a standby state is formed, and it is possible to respond to a call from the child device that made the call again.

In the multi-station intercom system configured as described above, the power supply circuit 16 of the master unit 11 applies a voltage to the slave unit connection terminal T2 to which the slave unit 12 is connected via the power switch circuit 15. When one of the plurality of slave units 12 calls the master unit 11, the potential of the slave unit connection terminal T2 to which the called slave unit is connected decreases.
When the call detection circuit 13 detects this decrease in potential, it outputs a call signal to the call display unit 14 and blinks a lamp corresponding to the child device that is calling. At this time, the power supply switch circuit 15 and the child device connection terminal T
Power is supplied from the power supply circuit 16 via 2 and the state at the time of calling is maintained.

Further, a call signal is output from the call detection circuit 13 to the communication path control circuit 17. The call path control circuit 17 to which the call signal has been input further receives an off-hook signal from the hook switch 21 of the handset 20 of the master unit.
A power supply stop signal is transmitted to the power switch circuit 15 to stop supplying power to the slave unit connection terminal T2 of the called slave unit. Therefore, the calling state of this slave unit is released. At the same time, a semiconductor switch 19 provided between the handset connection terminal T2 called from the communication path control circuit 17 and the transmission / reception circuit 18 is connected to form a communication path, and the handset connection terminal T2 is connected to the common ground. A call is made by 25 lines. A call state signal is output from the call path control circuit 17 to the call detection circuit 13, and the lamp of the call display unit 14 is turned on.

In the meantime, if a call is received from another handset, the call detection circuit 13 similarly detects the call, causes the lamp of the call display section 14 to blink, and calls the child called by the power supply from the power supply circuit 16. Power is supplied to the machine and the calling state is maintained. The caller of base unit 11 can confirm the call.

When the call ends, the hook switch 21
The communication path control circuit 17 which has received the on-hook signal of the above or the recovery signal from the recovery switch 22 sends a power supply signal to the power switch circuit 15 and a call end signal to the call detection circuit 13, respectively. Is turned off, power is supplied to the slave unit connection terminal T2, and a standby state is set.

When calling the slave unit 12 from the master unit 11, the off-hook signal from the hook switch 21 is input to the communication path control circuit 17, and the channel selection switch 23 of the slave unit to be called is further operated to select the slave unit. When a handset signal corresponding to the handset is input from the channel selection switch detection circuit 24 to the communication path control circuit 17, the communication path control circuit 17 A call state signal is sent to the power switch circuit 13 and the lamp of the call display section 14 is turned on via the call detection circuit 13.
5, a power supply stop signal is output, the power supply to the slave unit connection terminal T2 is stopped, the standby state is released, and the communication state is established. At the end of the call, it is the same as calling from the child device.

The above description relates to an embodiment of the present invention, and the present invention is not limited to this, and may not include a recovery switch.

[0027]

As is clear from the above description, according to the multi-station intercom system of the present invention, the switching between the call detection circuit and the transmission / reception circuit is not performed by a mechanical switch, but a semiconductor switch is used. Is not caused, the connection is securely made electrically, the invention can be applied to any model, and the production efficiency can be improved. In addition, the size of the device can be reduced, and by changing the display on the display unit,
Standby, calling, and talking can be distinguished.
It is possible to answer a call again without mistaken judgment.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment according to the present invention.

FIG. 2 is a circuit diagram showing a conventional multi-station intercom system.

[Explanation of symbols]

 11: Master unit 12: Child unit 13: Call detection circuit 14: Call display unit 15: Power switch circuit 16: ..... power supply circuit 17 ...... speech path control circuit 18 ...... handset circuit 19 ...... semiconductor switch 21 ...... hook switch 23 ... … Tuning switch 24… Tuning switch detection circuit T2

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-107965 (JP, A) JP-A-55-166368 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04M 9/00-9/10

Claims (1)

(57) [Scope of request for utility model registration] (1) Master device(11)And the slave unit connection terminal
(T2)Slave units connected via the(12)And
Uh, the parent machineSelect a slave unit to select each slave unit during standby.
Selected by switch (23)Slave unit signal corresponding to slave unit
Channel selection switch detection circuit(24)And the slave unit
Each ofPower switch circuit(15)And the slave unit
Power supply circuit for supplying power through connection terminals(16)And before
When calling from the handset, reduce the voltage of the handset connection terminal.
A call detection circuit that detects and outputs a call signal(13)And before
By calling signalCallCall display section for display(14)
And the slave unit connection terminalEach ofSemiconductor switch(1
9)Transmission / reception circuit connected via(18)And the call
Outgoing signal and hook switch(21)Off-hook message from
issueIs entered orOff from the hook switch
Hook signal and transmitted from the channel selection switch detection circuit
Slave unit signalIs enteredApply power to the power switch circuit.
A power supply stop signal is output to the semiconductor switch.
Output drive signalAnd a call status signal is sent to the call detection circuit.
Output and call display on the call display sectionCall control
Your circuit(17)AndEstablishmentMulti-station interface
-Phone system.