JPS6115643Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an intercom device, and is devised to prevent the contents of the conversation on the base unit from being leaked to the outside through the slave unit, especially when the user forgets to hang up the handset.

As shown in Fig. 1, in the conventional intercom device, when the call key (push button) CK of the slave unit 1A is pressed, power is supplied to the oscillator 2 and amplifier 3 through the switch HS on the base unit 1B side, and the speaker is output.
A predetermined ring tone sounds from SP ₁ .

When you hear this ring tone and remove the handset RT, the power switch HS turns off and the power is cut off, causing the oscillator 2 to become inactive and _the ring tone to stop ringing. When turned on, power is supplied to amplifiers 5 and 6 provided on the handset 1A and base unit 1B sides, respectively. And signal line L connecting slave unit 1A and base unit 1B
Line switches SW _R and SW _T installed at _R and L _T
are turned on in connection with the switch HS, and the signal lines L _R and L _T between the slave unit 1A and the base unit 1B are turned on.
are connected, allowing calls to be made between the inside and the outside.

Note that M is a microphone and SP ₂ is a speaker. Further, 8 is a matching network.

Now, with such conventional intercom devices, if you forget to hang up the handset RT after a call ends, the switch HS will remain in the up position, so switches SW ₁ , SW _R , and SW _T will all remain on and the signal will not be transmitted. The lines L _R and L _T remain connected,
Moreover, since amplifier 6 is powered on, base unit 1
The conversation in the room where B is located is from handset 1A.
leaks to the outside through

In addition, when the handset RT is disconnected, the handset switch HS is turned off, so even if a visitor presses the call key CK in this state, the ring tone does not sound, so the call is not made and the intercom's calling function is lost. Resulting in. In this conventional configuration, there is no way to notify the person inside that the handset RT is disconnected, so the handset RT
There is a risk of leaving the product unattached for a long time.

Therefore, in this invention, when a predetermined period of time has elapsed with the handset RT removed, the signal lines L _R ,
The configuration is such that the L _T is cut off, so that even if the handset RT is forgotten or dropped from the hook, the conversation in the room will not be leaked to the outside through the handset 1A.

An example of this invention will be explained in detail with reference to FIG.

In this invention, a 1-circuit, 2-contact type power switch SW ₁ connected to the power supply path L _O is used, and the amplifiers 5 and 6 are connected to the contact b side as described above, and the oscillator 2 is connected to the contact a side. and amplifier 3 are connected.

Note that a power supply line L _K including a call key CK is further connected to the oscillator 2 and the amplifier 3.

A switch HS is connected in series to the power supply line L _O , but unlike the case described above, the power supply line L _O of the switch HS is closed when the handset RT is disconnected.

The switches SW ₁ , SW _R and SW _T are controlled by a control means, in the example shown, a relay R, and the energization control for this relay R is performed by the output of a timer device 20 driven in conjunction with the switch HS. It can be done. The timer device 20 operates for a certain period of time t after the handset RT is disconnected and the hook switch HS is closed.
(for example, 30 seconds), and only during that time relay R
Power is supplied to energize relay R.

By energizing relay R, switch SW ₁ becomes contact B
switch to the side, and also the other two switches
SW _T and SW _R are each turned on (closed).

In this figure, 30 and 31 indicate backflow preventers.

The operation when configured in this way will be explained.

When the handset RT is placed, the switch HS is off, so when the call key CK is pressed, power is supplied to the oscillator 2 and amplifier 3 via the power supply line L _K , and a ring tone is produced. When the handset RT is picked up, the switch HS is turned on, the relay R is energized, the switch _SW1 is switched to the contact b side, and power is supplied to the amplifiers 5 and 6. Then, the other switches SW _T and S _R are turned on, and the signal lines L _R and L _T are connected, so that a conversation similar to the conventional one can be made.

Now, if the handset RT remains disconnected even after a predetermined time t has elapsed since the handset RT was disconnected due to a call, the timer device 20
As a result, the power supply to relay R is cut off, so that switches SW _R , SW _T and SW ₁ return to the state shown in the figure. For this reason, the signal lines L _T and L _R are cut off, and the amplifiers 5 and 6 become inoperable, so even if the handset RT is disconnected, the state of conversation in the room where the base unit 1B is placed remains unchanged. There will be no leakage to the outside through the handset 1A.

Furthermore, when the handset RT is disconnected, the switch HS is on, and when a certain period of time t has elapsed in this state, the switch SW ₁ is switched to the contact a side, so that the oscillator 2 and the amplifier 3 are A predetermined power is supplied through the power supply path L _O and the alarm begins to sound.

In this case, if a controller 40 for ringing tone formation is connected between the power supply line L _K and the oscillator 2, it can be operated by the power supply line L _K and operated by the power supply line L _O. The ring tone and alarm tone emitted from the speaker SP ₁ can be made different depending on the case, and by doing so, the distinction can be clearly made.

Since the alarm tone continues to sound until the handset RT is placed in a predetermined position (hook), the alarm effect is great in case you forget to turn on the handset RT.

Furthermore, since the hook switch HS is not provided in the power supply path L _K , even if the handset RT is disconnected, pressing the call key CK will produce a ring tone, so the intercom's calling function will not be lost.

As explained above, according to this invention, the signal lines L _R and L _T are automatically disconnected when a predetermined period of time elapses after the handset RT is removed.
Even if you forget to hang up the handset or drop it from the hook, handset 1 will show you the conversation in the room.
There is no leakage to the outside through A.

Note that the control means is not limited to the relay R in the above example. The predetermined time t can be set arbitrarily.

In addition, when this invention is applied to an intercom device with a built-in image pickup tube, in addition to the above-mentioned means, it is necessary to simultaneously cut off the video signal supplied to the monitor television receiver provided on the main unit 1B side. A means may be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional intercom device, and FIG. 2 is a schematic diagram of an example of an intercom device according to this invention. CK is call key, HS is hook switch, 20
is a timer device, RT is a handset, SW ₁ , SW _T ,
SW _R is a switch controlled by relay R, L _R , L
_T is a signal line.

Claims (1)

[Scope of utility model registration request] A line switch provided on the base unit side of the signal line connecting the base unit and the slave unit, a timer device driven in conjunction with the switch, and a control means for controlling the switch operated by the output of the timer device. The timer device operates for a certain period of time after the handset is disconnected and the switch is turned on, and operating power is supplied to the control means, and the line switch is operated only while this operating power is supplied. An intercom device that turns on.