JPH033438B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for connecting multiple telephones in parallel to a telephone line (hereinafter referred to as an office line) from a telephone exchange to a terminal telephone of a subscriber's telephone, so that any telephone The present invention relates to a parent-child telephone device that can make calls to a central office line, respond to incoming calls, make calls, make secret calls, and transfer central telephone calls.

(Prior Art) Conventionally, a parent-child telephone device is known in which a plurality of telephones or telephones with additional devices are connected in a multiple manner to a subscriber's premises wiring having a plurality of connection lines including a central office line. In order to provide such a parent-child telephone device with a confidential communication function, a thyristor or the like is used in each telephone. The thyristor in the telephone that captures the office line is made conductive, forming a loop between the office line and the telephone circuit, and the thyristor in the telephone that is not capturing the office line is made non-conductive, and the telephone communication circuit of that telephone and the office line are made non-conductive. and are separated. When transferring, the transferee's telephone is operated to turn on the thyristor of the receiver's telephone to de-privacy the call.

In a method in which an AC signal is generated by operating the forwarding telephone to deconfidence, a dedicated power source such as a commercial power supply or a dry cell battery is installed in the main unit or one of multiple telephones, and each telephone is equipped with a transformer. It was exactly what I needed.

In addition, in conventional parent-child telephone devices, the hold operation and release were performed mechanically or even electronically, as mentioned above, they used the power supply provided in the equipment rather than the central office power supply. .

In the case of a mechanical method, in order to receive a transfer from another transferee's phone, the transferred party must lift the handset and press a button to release the hold, and even in the case of an electronic method, the call is released from hold. Although it was possible to release a call from hold by simply lifting the handset on the telephone itself, it was not possible to release a call from hold by simply lifting the handset on a telephone other than the telephone that was placed on hold.

(Problems to be Solved by the Invention) In such a parent-child telephone device, when only one person operates the telephone, the transfer operation is extremely troublesome.

For example, if a person who has been talking by raising the handset of a telephone installed on the first floor due to an incoming call wants to continue the conversation using a telephone installed on the second floor in order to view materials, etc., the person raising the handset of the telephone installed on the first floor may I had to go to the second floor, pick up the handset of the transferred phone, return to the first floor, lower the handset of the transferred phone, and then go back to the second floor and resume communication with the central office line.
Even if you did not perform this troublesome operation and made a call using the transferred telephone on the second floor while raising the handset of the transmitting telephone on the first floor, you could not make a satisfactory call because the sensitivity would decrease.

Furthermore, although some conventional parent-child telephones have been provided with various functions, it has not been possible to use conventional single telephones for these.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and is to provide a parent-child device that can release the hold by simply lifting up the handset of the transfer or transferee phone, and has additional transfer and confidential conversation functions for a single phone. An object of the present invention is to provide a telephone device.

(Means for solving the problem) A plurality of additional devices each connected to a single telephone set are connected in parallel using two talking lines, one calling line, and one control line, and each additional device is The device is provided with a hold circuit that is activated by a hold operation and released by a voltage drop between the telephone lines, a transfer call signal generation circuit, and a secret call circuit that operates by discriminating the voltage between the telephone lines. A first circuit for operating the confidential communication circuit in series with the telephone communication circuit between the communication lines.
and a second bridge diode for operating the hold circuit and the transfer paging signal generation circuit. A circuit is provided for canceling confidentiality between the DC side of the first bridge diode and the second bridge diode.

A bell signal arriving from the telephone line causes the private call circuit to conduct through the first bridge diode, and operates a bell signal receiving circuit in the telephone call circuit to indicate an incoming call. When a call is put on hold with an additional device of a telephone in use, the holding circuit is activated to put the telephone line on hold, and the transfer ring signal generating circuit of the additional device of another telephone connected in parallel through the calling line is activated. operate to generate a transfer signal. Further, through the control line, an additional device of the other telephone operates a circuit for canceling the confidentiality, thereby canceling the confidentiality. A parent-child telephone device that automatically releases the hold of the hold circuit when the other phone picks up the handset.

(effect) FIG. 1 is a system diagram that is an example of the present invention.

REC ₁ , REC ₂ are rectifiers, TL is a holding circuit, CNT
is a control unit in the holding circuit HL, S is a privacy circuit, SR is a deprivation circuit, and SD is a transfer paging signal generation circuit, that is, a transfer paging signal generator. TEL is a telephone,
ADP is an additional device that is added to the phone.

Control unit provided in the holding circuit HL that performed the transfer
CNT holds the central office line when there is a transfer call operation.
At the same time, the transfer call signal generator SD in all additional devices is activated via the call line _L3 . It also controls the privacy cancellation circuit SR of another additional device via the control line _L4 .

Next, when one of the telephones picks up the handset in order to receive the transfer, the deprivation circuit S is activated by control over the deprivation circuit SR from the control line _L4 mentioned above, and the transferred telephone is also connected to the central office line. The transfer phone's hold circuit HL is automatically released from hold. Therefore, the transfer telephone and the transferred telephone can have a transfer meeting call.

In the present invention, a de-pricing circuit is connected to the first bridge diode, a reservation circuit is connected to the second bridge diode, and a de-privacy circuit is connected between the DC sides of the first and second bridge diodes. death,
The incoming bell signal conducts the secret line, activates the bell signal incoming display circuit in the telephone call circuit connected to the additional device, and uses the telephone's switch to separate the additional device from the standalone telephone. It is composed of

Embodiment FIG. 2 is a configuration diagram of a parent-child telephone device which is an embodiment of the present invention.

TEL ₁ , TEL ₂ , TEL ₃ are telephones, ADP ₁ ,
ADP ₂ , ADP ₃ are additional devices added to each of the telephones TEL ₁ , TEL ₂ , TEL ₃ , REC ₁ and REC ₂ are rectifiers, Q ₁ and Q ₂ are transistors forming a confidential communication circuit,
Q ₃ and Q ₄ are transistors that constitute the deprivation circuit,
MOH is a hold music sending circuit, SD is a sounder that generates a transfer call, LED is a transfer indicator that lights up during a transfer call, SCR is a thyristor which is a switching element with a self-holding function and is an example of the control unit CNT, and C ₃ is a capacitor that disables the thyristor by discharging it, and CK ₁ and CK ₂ are the contacts of the call switch that is operated when transferring data.

Note that items having the same function are indicated by the same symbol.

Next, the operation will be explained.

Operation for making a call to a central office line Now, when the handset of telephone TEL ₁ is raised to make a call to a central office line, a switch contact (not shown) operates. As a result, the station line voltage is higher than the operating voltage of the Zener diode ZD ₁ , so the station line current flows from the transistor Q ₁ (E-B) through the Zener diode ZD ₁ , thereby conducting the secret circuit transistors Q ₁ and Q ₂ . Configure the following loop.

Office line connection terminal L ₁ -- Rectifier REC ₁ -- Transistor Q ₁ , Q ₂ -- Call switch contact CK ₁ Diode D ₂ -- Rectifier REC ₁ -- Telephone TEL ₁ -- Office line connection terminal L ₂ .

Through the above-described loop, the confidential communication circuit is made conductive, and the office line communication circuit of telephone TEL ₁ is closed, resulting in the office line capture state.

In this state, another telephone, for example TEL ₃ , attempts to acquire the central office line by raising the handset and activating the switch contact. However, at this time, the line voltage between the office line connection terminals L ₁ and L ₂ has been significantly reduced by the previously acquired telephone TEL ₁ , so the Zener diode ZD ₁ in the additional device ADP ₃
does not conduct and transistor _Q1 does not operate.

Therefore, the secret circuit composed of transistors Q ₁ and Q ₂ does not conduct. Therefore, all telephones other than TEL ₁ are disconnected from the central office line.

Receiving operation When a bell signal arrives from the exchange side when a call is received on the central office line, the bell signal is displayed on the ring tone display of all telephones. Office line connection terminal L ₁ -- Rectifier REC ₁ -- Transistor Q ₁ , Q ₂ -- Contact CK ₁ ---Diode D ₂ ---
Rectifier REC ₁ ---Telephone TEL ₁ --- Office line connection terminal
A bell signal is applied on the _L2 route, and each telephone provides an audible indication of a central office call.

At this time, when the handset of any telephone is raised, the transistors Q ₁ and Q ₂ of the telephone with the handset raised are formed in the same manner as in the case of the above-mentioned call operation to the central office line. The secret line circuit is conductive, but the secret line circuit of a telephone whose handset is not lifted up becomes non-conductive. The central office line is then routed to the telephone with the handset raised, and only this telephone can answer the incoming central telephone call.

Transfer Operation Next, an explanation will be given of an operation when transferring a call from telephone TEL ₁ to telephone TEL ₃ , as an example, during a call on a central office line.

(a) If you operate the call switch installed on the additional device ADP ₁ of telephone TEL ₁ and leave the handset up, the contacts CK ₁ and CK ₂ of the call switch will be in the state shown in Figure 2. Thyristor SCR driven to opposite state by following route
becomes conductive.

Station line connection terminal L ₁ --- Rectifier REC ₁ --- Transistor Q ₁ , Q ₂ --- Contact CK ₁ --- Thyristor
Gate of SCR -- Resistor R ₁₈ -- Rectifier REC ₂ --
- Station line connection terminal L ₂ .

(Although the resistor _R15 is not listed in this route, the description will be omitted if it is considered obvious. The same shall apply hereinafter.) When the thyristor SCR is activated, the central office line is put on hold by the following loop, and the hold sound is The hold tone is sent to the central office line from the sending circuit MOH.

Office line connection terminal L ₁ --- Rectifier REC ₂ --- Hold music sending circuit MOH --- Resistor R ₁₄ --- Thyristor
SCR -- Resistor R ₁₈ -- Rectifier REC ₂ -- Station line connection terminal L ₂ .

The current flowing through resistor R ₁₈ causes transistor Q ₅
conducts and the loop below charges capacitor _C3 .

Station line connection terminal L ₁ --- Rectifier REC ₂ --- Resistor
R ₁₁ - Diode D ₁₃ - Capacitor C ₃ Transistor Q ₅ - Rectifier REC ₂ - Office line connection terminal
_L2 .

Also, due to conduction of transistor Q ₅ , transistors Q ₃ and Q ₄ of the deprivation circuit are connected to capacitor C ₁ ,
Since C ₂ operates after being charged, the following loop is formed and transistor Q ₁ becomes inactive.

Station line connection terminal L ₁ --- Rectifier REC ₁ --- Transistor Q --- Transistor Q ₄ --- Diode
D ₃ --Resistor R ₁ , R ₂ --Diode D ₄ --Transistor Q ₅ --Rectifier REC ₂ --Station line connection terminal
_L2 .

As a result of the above call switch operation, the sounder SD of the transfer side telephone and the sounders of the other telephones ring in the following loop.

Office line connection terminal L ₁ --- (Additional device ADP ₁ ) ---
Rectifier REC ₂ --- Sounder SD --- Resistor R ₉ ---
Contact CK ₂ ---Diode D ₉ ---Transistor
Q ₅ --- Rectifier REC ₂ --- Station line connection terminal L ₂ .

Office line connection terminal L ₁ --- (Additional device ADP ₂ ,
ADP ₃ ) -- Rectifier REC ₂ -- Sounder SD --
Diode D ₁₂ --- Calling line L ₃ --- (Additional equipment
ADP ₁ ) -- Contact CK ₂ -- Diode D ₉ -- Transistor Q ₅ -- Rectifier REC ₂ -- Station line connection terminal L ₂ .

Next, return the call switch. Contact CK ₁ returns as shown in Figure 2, but transistors Q ₃ and Q ₄ continue to operate, so transistor Q ₁ does not operate.
The secret circuit remains inactive (non-conducting).

Also, since contact CK ₂ returns, the additional device on the transfer side
The loops of the sounders SD of ADP ₁ and other additional devices ADP ₂ and ADP ₃ are opened and the sound stops. Please note that the transfer call indicator LED is a contact point.
Lights up if it is on hold regardless of whether CK ₂ is activated or not.

(b) Next, we will explain the case where the handset of telephone TEL ₃ is raised in order to respond to a transfer call. Here, the handset of the transferring telephone TEL ₁ continues to be raised. When the handset of telephone TEL ₃ is raised, the office line current flows as follows.

Office line connection terminal L ₁ --- (Additional device ADP ₃ ) ---
Rectifier REC ₁ -- Transistor Q ₁ -- Diode D ₁ -- Resistor R ₁ , R ₂ -- Diode D ₄ , D ₇ --
Control line L ₄ --- (Additional device ADP ₁ ) -- Contact CK ₂
--Diode _D9 --Transistor _Q5 --Rectifier _REC2 --Station line connection terminal _L2 .

Since the transistor Q ₁ is conductive due to the above loop, the transistor Q ₂ is also conductive and forms the following loop.

Office line connection terminal L ₁ --- (Additional device ADP ₃ ) ---
Rectifier REC ₁ ---Transistors Q ₁ , Q ₂ --- Contacts
CK ₂ ---Diode D ₂ --- Rectifier REC ₁ --- Telephone TEL ₃ --- Office line connection terminal L ₂ .

When the confidential communication circuit composed of the transistors Q ₁ and Q ₂ becomes conductive, the telephone TEL ₃ is connected to the office line, and the voltage between the office lines (between L ₁ and L ₂ ) decreases. The capacitor _C3 in the hold circuit of the transfer side additional device _ADP1 starts discharging due to this voltage drop. This discharge current is capacitor C ₃ (+) -- transistor Q ₆ (E
-B) --Resistors _R12 , _R11 --Zener diode _ZD2 --Resistor _R10 --Capacitor _C3 (-).

flows through the route of and makes transistor _Q6 conductive. Further, due to the conduction of the transistor _Q6 , the discharge current of the capacitor C flows through the following route to activate the transistor _Q7 .

Capacitor C ₃ (+) -- Transistor Q ₆ (E
-C) --Resistance R ₁₃ --Transistor Q ₇ (B-
E) -- Capacitor C ₃ (-).

Further, the following loop is formed by the conduction of the transistor _Q7 , which reduces the voltage applied to the anode of the thyristor SCR, and makes the thyristor SCR non-conductive.

Office line connection terminal L ₁ --- (Additional device ADP ₁ ) ---
Rectifier REC ₂ --- Hold music sending circuit MOH --- Resistor R ₁₄ --- Transistor Q ₇ (C-E) --- Transistor Q ₅ --- Rectifier REC ₂ --- Office line connection terminal
_L2 .

Due to the non-conduction of the thyristor SCR, the transistor Q ₅ also becomes non-conductive, and the transistors Q ₃ ,
When Q ₄ becomes non-conductive, the discharge current of capacitor C ₁ in the secret circuit flows through the following route and triggers transistor Q ₁ .

Capacitor C ₁ (+) -- Transistor Q ₁ (E
-B) Diode D ₁ --Resistor R ₁ --Capacitor C ₁ (-).

This causes transistors Q ₁ and Q ₂ to operate, and in the following loop, the transfer side additional device ADP ₁ is desecured and the telephone TEL ₁ is connected to the central office line.

Office line connection terminal L ₁ --- (Additional device ADP ₁ ) ---
Rectifier REC ₁ ---Transistors Q ₁ , Q ₂ --- Contacts
CK ₁ - Diode D ₂ - Rectifier REC ₁ - Telephone TEL ₁ - Office line connection terminal L ₂ .

Therefore, the transfer side telephone TEL ₁ and the transferred side telephone TEL ₃ are both connected to the central office line, and communication to the effect of transfer can be performed using the central office power supply.

When the transfer telephone TEL ₁ lowers the handset, even if it raises the handset again, the office line is pulled into the telephone TEL ₃ and the inter-office line voltage drops significantly.
Zener diode ZD ₁ not working phone
TEL ₃ 's secrets will be kept.

(c) Next, we will explain the case where the person performing the transfer operation and the person receiving the transfer are the same person, and the person continues to talk to the other party using a telephone other than the one on which the handset is raised. Since the operation is the same up to the state (a) mentioned above, we will start from there.

After the transfer operation with the additional device ADP ₁ on the transfer side, when the handset of the telephone TEL ₁ is lowered, transistors Q ₁ and Q ₂ of the privacy circuit and transistor Q ₄ of the de-pricing circuit become non-conductive, and the telephone TEL ₁ is transferred from the central office line loop. is disconnected, and the station line is held only in the following holding loop.

Office line connection terminal L ₁ --- (Additional device ADP ₁ ) ---
Rectifier REC ₂ --- Hold music sending circuit MOH --- Resistor R ₁₄ --- Thyristor SCR --- Resistor R ₁₈ --- Rectifier REC ₂ --- Office line connection terminal L ₂ .

Next, when the person who performed the transfer operation moves and raises the handset of the transferred telephone TEL ₃ , the holding loop of the additional device ADP ₁ is released as described in (b) above, and the office line is placed in the following loop. Connected only to the forwarding phone TEL ₃ .

Office line connection terminal L ₁ --- (Additional device ADP ₃ ) ---
Rectifier REC ₁ ---Transistor Q ₁ , Q ₂ contact CK ₁
--Diode D ₂ --Rectifier REC ₁ --Telephone
TEL ₃ --- Office line connection terminal L ₂ .

Therefore, it is possible for one person to change telephones and continue talking without having to perform any troublesome operations. In addition, even if you put down the handset after performing a transfer operation and forget about it, the voltage on the central office line will drop suddenly due to a momentary interruption when the subscriber is locked out on the exchange side, so please use a capacitor.
_C3 is discharged and the thyristor SCR becomes non-conducting.
Therefore, the hold is automatically released.

In the embodiment, a transistor that operates during suspension
A de-privacy circuit is shown consisting of Q ₃ and transistor Q ₄ which is controlled by whether the handset is up or down. As a result, the de-pricing circuit operates normally regardless of whether L ₁ or L ₂ has a positive voltage.

In addition, by inserting a contact point of a calling switch for forwarding calls and a diode _D2 for blocking reverse current in series with the privacy circuit composed of transistor Q ₁ and transistor Q ₂ , the telephone that is talking to the central office line can be connected to the calling switch. The hold circuit can only be activated when the

In the embodiment, if only the telephone TEL ₁ is provided with the function of transferring, the hold circuit only needs to be provided in the additional device ADP ₁ .

In the embodiment, the telephone set and the additional device are described separately, but there is no particular need to separate them, and the additional device may be incorporated into the telephone set.

Although a circuit diagram of a parent-child telephone device is shown in the embodiment, the present invention is not limited to this circuit diagram.

In this embodiment, when the transfer is on hold, the transfer side communication circuit is separated from the office line, so that it is easier to release the hold by lifting the handset of any telephone.

Next, if you connect only one telephone with the additional device of the present invention to the central office line, it will be equipped with a hold function, so if you operate the hold switch mid-way through the conversation, even if you have a meeting with someone nearby, you will not be able to communicate via the central office line. This eliminates the need for the other party to hear the hold music, and if a hold music sending circuit is also provided, the hold music can be sent out.

Furthermore, a parent-child telephone device can be constructed simply by connecting the required number of telephones of the present invention in parallel to a pair of office lines.

Furthermore, in this embodiment, since the CPU and the like are not used to suppress hold, no current from the exchange is required when the central office line is released.

(Effects) As explained above, in the parent-child telephone device of the present invention, in order to release the call from hold, it is sufficient to simply lift the handset of one of the telephones. Further, by connecting an additional device to an existing standalone telephone, it is possible to easily configure a parent-child telephone device having hold, transfer, and private conversation functions. Furthermore, when receiving a call, the bell signal incoming call display circuit of the above-mentioned individual telephone can be used.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of the present invention, and FIG. 2 is a parent-child telephone device that is an example of the present invention. TEL, TEL ₁ , TEL ₂ , TEL ₃ ...Telephone, ADP,
ADP ₁ , ADP ₂ , ADP ₃ ...Additional equipment, REC ₁ , SEC ₂
... Rectifier forming the diode bridge, S... Encryption circuit, Q ₁ , Q ₂ ... Transistor forming the encryption circuit, SR... Disciplining circuit, Q ₃ , Q ₄ ... Transistor forming the communication cancellation circuit, ZD ₁ ... Zener diode, CK ₁ , CK ₂ ...Call switch contact, C ₁ , C ₂
…Capacitor, HL…Holding circuit, CNT…Holding circuit
HL internal control unit, SD...sounder, MOH...held music sending circuit, SCR...thyristor, _C3 ...capacitor,
Q ₅ , Q ₆ , Q ₇ ...Transistor, LED...Transfer indicator.

Claims (1)

[Scope of Claims] 1 A plurality of additional devices each connected to a single telephone set are connected in parallel with two call lines, one calling line, and one control line, and each of the additional devices is , a hold circuit that is activated by a hold operation and released by a voltage drop between the telephone lines, a transfer call signal generation circuit, and a confidential communication circuit that operates by discriminating the voltage between the telephone lines; A first bridge diode for operating the confidential communication circuit and a second bridge diode for operating the holding circuit and transfer call signal generation circuit are provided in series with the telephone conversation circuit between the two, A circuit is provided between the direct current side of the bridge diode and the second bridge diode, and the privacy circuit is made conductive via the first bridge diode in response to a bell signal coming from the telephone line. A bell signal incoming circuit in the telephone call circuit is operated to display an incoming call, and when the telephone in use performs a hold operation, the holding circuit is operated to put the telephone line on hold, and the call is connected in parallel through the calling line. operating a transfer call signal generating circuit of an additional device of the other connected telephone to generate a transfer signal, and operating a circuit for canceling the decryption of the additional device of the other telephone through the control line to decrypt the decryption; . A parent-child telephone device, characterized in that the parent-child telephone device is configured to automatically release the hold of the holding circuit when the other telephone picks up the handset. 2. The confidential circuit constitutes a circuit having a self-holding function using first and second transistors of PNP type and NPN type, and a third transistor that operates when suspended is connected between the base and emitter of the first or second transistor. Consists of a fourth transistor that operates when the direct current loop of the telephone communication circuit is formed.
2. The parent-child telephone device according to claim 1, further comprising a deprivation circuit constituted by an AND circuit. 3 Construct a circuit having a self-holding function using a PNP type as a secret line circuit and a first transistor and a second transistor of the NPN type, and connect a contact point of a call switch for transfer calling and a backflow prevention circuit in series with the secret line circuit. 2. The parent-child telephone device according to claim 1, wherein a diode is inserted so that the hold circuit is operated only when a telephone call switch is operated during a call to a telephone line.