JPS6029269B2 - Extension calling method for button telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device in which a calling telephone calls a called telephone by means of a dial signal and performs mutual extension communication. This invention relates to an extension calling system that includes a reset call function that allows you to call again freely.

Conventionally, in this type of button telephone device, if the called party is busy, the call will be interrupted immediately or after a certain period of time. Even if it ran out, the call could not be started automatically.

In other words, it was not possible to provide an automatic camp-on function that automatically starts calling again when the phone is in a standby state and is no longer busy. Furthermore, if the called party is busy or the called party does not respond easily, and the user wishes to make a new call, the user must hang up the handset and dial again, which is very cumbersome to operate. This point will be explained based on a conventional example of a button telephone device.

FIG. 1 is a circuit configuration diagram showing a conventional example.

For convenience of explanation, an example will be described in which a called telephone is called using a one-digit dial number. The current caller, for example, 2-button phone no. When bL presses the extension button PK and hooks up, the A relay is activated, and the L relay is subsequently activated by closing the al contact.

Shame here. When the terminal EL dials the one-digit number of the called telephone number, the A relay flaps in synchronization, so a dial signal is sent from the a base point to the dial counting circuit CT, and relays lc to nc are sent to the relay group lc to nc according to the number of dial pulses. (omitted) works. In other words, at this time, the C relay operates during the dialing period, and its contact cl causes the above l
Any one of the c to nc relays operates, and even if the dial ends and the C relay attempts to recover, the recovery is slow and slow due to the discharge of the capacitor CW. On the other hand, in this case c is a rhombus point and I
A current is applied to the base of the transistor TRo through any of the contacts C to nc, the eo contact, and the resistor Ro.
The e2 contact closes due to the E relay operation, but when the called party is busy, the hook switch HS is operating, so no current is applied to the base of the transistor TR, so the F relay does not operate. Therefore, the base of the transistor TRo that drives the E relay cannot form a holding loop via the saddle point fo of the F relay, so the operation is restored. When the E relay is restored, the dial counting circuit CT is also restored after the holding loop via the point cl is released. As a result, a new call can be made by making a reset call, that is, by dialing again in a so-called off-hook state in which the handset is not hung up. However, since the holding loop of the dial counting circuit CT is restored every time the called party is busy, the so-called automatic camp-on function automatically switches over and calls even when the called party is no longer busy. cannot have.

That is, this type of conventional key telephone device has a drawback in that even if it has a reset call function, it cannot have an automatic camp-on function at the same time.

The present invention has been made in order to eliminate the above-mentioned drawbacks.The present invention has been made in order to eliminate the above-mentioned drawbacks. The counting circuit is configured to be reset for the first time at the beginning of 2018 and immediately start counting again, so that it is possible to make a reset call while having an automatic camp-on function.

Hereinafter, an example in which the present invention is implemented in a button telephone device will be described in detail with reference to the drawings.

FIG. 2 is a circuit configuration diagram showing an embodiment of the present invention, and is a circuit configuration diagram for a case where an extension call is made using a rotary dial, that is, a direct current pulse.

The current caller, for example, No. When the 2TEL presses the extension button PK and hooks up, a DC loop is formed via the communication network NET, and current is supplied from the communication current supply circuit NT, so the P2 terminal becomes a potential source and is connected to the transistor through the diode Do and resistors R, R2. Current is supplied to the base of TR2, turning it on.

Therefore, this allows the so-called B-B, which is commonly used in crossbar pre-booking machines, to distinguish between the break pulse of the dial pulse and the case where the subscriber hangs up the telephone and disconnects the call. The output of the position circuit BP becomes ``L'' potential.Next, when the calling party No. EL dials the number of the called telephone, for example No. ITEL, the dial pulse passes through the transistor TR2, the inverter, and the AND gate 2. It is sent to a dial counting circuit CT (storage means), where the dial count is stored.

Called telephone number When ITEL is busy, the hook switch HS is operating and no current is supplied to the base of the transistor TR3, so it remains off and the output Q of the flip-flop 3 remains at "H" potential, and the called party Indicates busy. Here, the transistor TR3 and the flip-flop 3 constitute called side busy detection means. At this point, the output of the dial counting circuit CT does not change, and the initially dialed information remains at the output. Therefore, when the called party changes from being busy to ending the call (busy canceled), the called party is immediately called. In other words, automatic camp-on operation becomes possible. In addition, called party No. When ITEL is empty, the output of the dial counting circuit CT is supplied via the hook switch contact HS, so the transistor TR3 is turned on and the output Q of the flip-flop 3 becomes "L" potential.
Therefore, the output of NAND gate 6 is "H", and the output of NAND gate 7 is "H".
Since the output of the NOR gate 8 becomes "L" and the output of the NOR gate 8 becomes "H", the dial counting circuit CT maintains the set state and extension calling continues via the buzzer. Now, called party No. IT
When the EL is busy, the caller's lungs are connected again in a so-called off-hook state without hanging up the handset. EL is the called party, ITE
A case will be described in which a reset call operation is performed by dialing the extension number of L.

When the dialing is completed first, the output Q of the monostable multipipulator 4 changes from "H" potential to "L" potential, so the output Q of the flip-flop 5 (detection means) changes from "L" potential to "L" potential.
The potential is inverted to "H". When the output Q of the monostable multipipulator 4 becomes "L" potential by dialing again, the output Q of the flip-flop 5 is "H" potential, so the output of the NAND gate 6 is also "L" potential.
The output of NOR gate 7 becomes "H" potential.

Therefore, the output of the NOR gate 8 also becomes an "L" potential, and the flip-flop 5 and dial counting circuit CT are reset. Incidentally, the /Agates 7 and 8 constitute a control means. By resetting the flip-flop 5, the output of the NOR gate 8 immediately returns to the "H" potential, and the flip-flop 5 and dial counting circuit CT are set. Since these operate one after another using only the propagation time of each element, the dial pulse ends instantly, passes through inverter 1 and AND gate 2, is counted and stored again in dial counter circuit CT, and is recalled again, that is, a reset call operation is possible. Become. As described above, according to this embodiment, it is possible to realize the automatic camp-on function and the IJ set call function when the called party is busy talking.

Next, an embodiment of the present invention for making a call using a push-button dial system, that is, using a multi-frequency signal, will be described with reference to FIG.

If the caller is, for example, No. When TEL 2 presses the extension button PK and hooks up, a DC loop is formed in the same way as in the embodiment shown in FIG. Since the input of is also at "L" potential, the output is at "H" potential, and flip-flops FF13, FF14 and memory circuit M○ (storage means) are all set.

Caller No. 2TEL is called party number. When the extension number of ITEL is dialed, it is received by the MF receiver MFR, and the MF receiver MFR output is decoded by the decoder DEC to call the called telephone number. The corresponding output terminal of ITEL changes from “L” potential to “H” potential and the memory circuit M
It is stored at O. Caller's lungs. When the power EL finishes dialing, all decoder outputs return to the "L" potential, but the memory circuit MO remains unchanged. Called telephone ship. EL
When transistor TR4 is busy, no current is supplied to the base of transistor TR4, so it remains off and flip-flop 1
The output Q of No. 4 remains at "L" potential, indicating that the called party is busy. Here, the transistor TR4 and the flip-flop 14 constitute called side busy detection means. On the other hand, since one of the decoder outputs becomes an "H" potential, the output of the multi-input OR circuit 15 becomes an "H" potential, and becomes an "L" potential again at the end of dialing. Therefore, the output Q of the flip-flop 13 (sensing means) is inverted and becomes "L" potential, and the inputs of the NOR gate 16 both become "L" potential, so the output becomes "H" potential,
The output of the inverter 17 becomes "L" potential. At this point, if the caller is waiting, the automatic camp-on function described above is valid. Also, when the called party is busy, the calling party No. EL
When dialed again, one of the outputs of the decoder DEC becomes "H" potential, and the output of the multi-input OR circuit 15 becomes "H".
``It becomes electric potential.

Therefore, the output of the inverter 18 becomes "L" potential, and since the output of the inverter 17 is also "L" potential, the output of the NOR gate 19 becomes "H" potential, and the output of the NOR gate 12 also becomes "L" potential, so the flip-flop 13 , 14 and the memory circuit MO are all reset. By resetting the flip-flop 13, its output Q returns to the "H" potential, so the output of the NOR gate 16 is "L" potential, the output of the inverter 7 is "H" potential, and the output of the NOR gate 19 is "L".
” potential, the output of the NOR gate 12 becomes “H” potential again, and the flip-flops 13 and 14 and the memory circuit M
O is set. These NOR gates 12 and 19 constitute a control means. It goes without saying that if the called party is in a vacant state, the extension call will continue via the buzzer BZ as in the embodiment of FIG. The above operation is completed instantaneously, the decoder DEC output is newly input to the memory circuit MO and stored, and an "H" potential is sent to the corresponding extension calling line.

This completes the reset call function. In this way the third
Also in the illustrated embodiment, an automatic camp-on function and a set call function can be realized. As another example of application of the present invention, it is possible to configure the circuit to have a reset call function at any arbitrary digit in the case of a dial call with two or more digits.

For example, there is a circuit that dials two digits and makes a reset call for both digits, or a circuit that dials two digits and makes a reset call for only the last digit. The above does not matter whether the dial is a rotary dial or a push button dial. Furthermore, although all the circuit examples of the present invention have been considered only when the called party is busy, it is easily possible to perform the reset call when the called party is not busy.

That is, even if the other party is not busy and does not answer for a while, the calling party can change the extension call by simply dialing again. As described above, in the present invention, since the dial counting circuit is reset by the first signal of the next dial, automatic camp-on is possible even with the reset call function, and extension calls can be changed without having to use the handset each time. Not only is it easy to operate, but it also has excellent advantages in terms of economy, reliability, and maintainability since it can be constructed entirely from electronic circuits.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a subordinate example, FIG. 2 is a circuit diagram showing an embodiment of the present invention, and FIG. 3 is a circuit diagram showing another embodiment of the invention. Soup - Diagram N Bo Diagram N Bo

Claims (1)

[Claims] 1. In a pushbutton telephone device in which a calling telephone selectively calls a called telephone based on a dialing signal to perform an internal conversation, the dialing signal from the calling telephone is counted and stored, and the corresponding called telephone is called. a storage means for outputting information; a detection means for detecting the end of transmission of a dial signal from the calling side telephone and outputting detection information; a called side busy detecting means for detecting whether the called side telephone is in a busy state and outputting detection information; and a called side busy detecting means detecting whether the called side telephone is in a busy state and outputting detection information, and detecting information from the detecting means and the called side busy detecting means. control means for controlling the storage means based on the detection information of the called side, and when the called side busy detecting means detects that the called side telephone is released from the busy state, the calling information is stored in the called side. When the called side telephone is detected to be busy by the automatic camp-on operation sent to the telephone and the called side busy detection means, the calling side telephone handset is in an off-hook state and the calling side is When a new dial signal is sent from the calling telephone, the new dial signal is newly counted and stored in the storage means, and a reset call operation is performed to make a new call. Features an extension calling system in a button telephone device.