JPS583621B2 - Transmitter disconnection device for push-button dial telephones - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a handset disconnection device for a push-button dial telephone.

Telephone communication between two terminals using a telephone communication network begins by picking up the transmitter/receiver of the calling party's telephone and sending out a diamond signal.The exchange receives this and calls the called party, and the called party transmits/receives the telephone. By picking up the telephone line, the telephone line between the calling party and the receiving party is connected, and a telephone conversation is possible.

During this process, two telephone lines are connected by the exchange between the two terminals.
The voltage polarity of the line is reversed as shown in FIG.

From the normal state in which the internal circuits of telephones 1 and 2 on the calling and receiving sides are both open (Fig. 1A), the telephone 1 on the calling side
When you pick up the transmitter/receiver, the line goes off-hook (hook switch 7, which will be described later, closes) and the DC circuit is closed, so the exchange 3 starts up and sends a dial tone to the caller (
Figure 1 mouth).

Then, when the telephone 1 sends a dial signal, the exchange 3 starts the outgoing line selection operation (Fig. 1 (c)), and when the called side is acquired, the line voltage on the called side is reversed by the exchange 3, and A ringing signal is sent to the called party and a ringing tone is sent to the calling party from the exchange 3 (FIG. 1-2).

After this, when the called party picks up the transmitter/receiver (off-hook) and answers, the internal DC circuit of telephone 2 is also closed, so both the ringing signal and the ringing tone stop, and the line polarity of the called party remains unchanged. Then, the line voltage on the transmitting side is reversed, and a mutual communication is possible (FIG. 1(e)).

On the other hand, as is well known, the main functions of a telephone as a terminal device are electroacoustic conversion for transmitting voice and transmission and reception of signals for selecting and calling a party.

As a typical example of a push-button dial telephone,
In the figure, a circuit diagram of a 600P type telephone is shown.

In this figure, the telephone has a transmitter 4 and a receiver 5 that perform an electroacoustic conversion function, an oscillation circuit 6 that performs a transmitting and receiving function, a hook switch 7, and a bell 8 as main components, and further includes the above-mentioned components. Four diodes 91, 92, 93, 94 that always supply an operating voltage of constant polarity to the oscillation circuit 6 even if there is a polarity reversal in the telephone line.
A diode bridge full-wave rectifier circuit 9 consisting of a diode bridge full-wave rectifier circuit 9, a side sound prevention circuit consisting of a side sound suppression coil (induction coil) 10 and a balance circuit 11, a click absorption varistor 12, a howling prevention attenuation circuit 13, and a hook switch 7. Spark extinguishing circuit 14 and DC cutoff capacitor 15.16.17
etc.

The oscillation circuit 6 includes a transistor 21 and a low group coil 22L.
and a low group tuning circuit consisting of a capacitor 23L, a high group tuning circuit consisting of a high group coil 22H and a capacitor 23H, and diodes 41 and 4 for opening both ends of these tuning circuits.
2, 43, low and high group positive feedback coils 24L, 25L,
24H, 25H, diode 44 for bias current adjustment
, 45, a resistor 46, a capacitor 28 for preventing abnormal oscillation due to noise, and varistors 27L, 27H for limiting amplitude.

Each tuning circuit is provided with four sets of low group contacts 31, 32, 33, 34 corresponding to the rows of the 12 push buttons, and high group contacts 35, 36, 37 corresponding to the columns. ing.

Additionally, a common contact 30 is provided which operates no matter which of the push buttons is pressed.

To start a call, when the transmitter/receiver is picked up, the hook switch 7 closes and the direct current from the telephone line flows through the diode 94, the break side b of the common contact 30, the diodes 42 and 43, and the transmitter 4. .

Next, push button signal (hereinafter referred to as PB signal)
When one of the pushbuttons on the telephone is pressed in order to send the When the push button is further displaced by about 1.7 (mm), the common contact 300 meter side a closes, and when the push button is displaced by about 1.9 (mm), its break side b opens, and when the push button is displaced by about 2.7 (mm), it closes. The pushbutton hits the board.

Any one of low and high group contacts 31-34, 35-37
When each of them closes, a low and high group tuning circuit is formed, and then when the make side a of the common contact 30 closes, the transistor 21
When the break side b is further opened, the direct current to the coils 22L and 22H of both tuned circuits is cut off, and the Q value becomes dog.
A B signal is sent out.

This PB signal continues until the push button is released and break side b is closed.

The handset 4 is disconnected from the telephone line only while the break side b of the common contact 30 is open.

Table 1 shows the pushbuttons and their corresponding combinations of PB signals consisting of two frequencies.

Note that function pushbuttons (*) and (#) are used for various services; currently, red (*) buttons are used for speed dial services, and blue buttons (#) are used for telephone calculation services. There is.

As indicated above, in current pushbutton dial telephones, the transmitter 4 is connected to the break side b of the common contact 30.
It can only be disconnected from the track when it opens.

Therefore, during the PB signal sending operation, there is a risk that noise due to external noise may be sent to the telephone circuit via the transmitter 4.

This causes a malfunction of the PB receiver installed on the exchange 3 side, which receives the PB signal and converts it into a DC code.

However, at present, push-button dial telephones are only used as an alternative to rotary dial telephones, so even if the above-mentioned noise causes the switching equipment 3 to select an incorrect outgoing line, it is not a serious problem. In many cases, this will not be the case.

However, push-button dial telephones have great potential to be applied not only to voice calls, but also to various services in the future, as they are currently being applied to telephone calculation services. Changes are also expected.

For example, in the near future, telephone lines will be used as communication lines to connect computers and terminal equipment installed in data centers, and push-button dial telephones will be used as terminal equipment. Conceivable.

In this case, it will be necessary to use a magnetic card reader to read the ID code written on the magnetic card, convert this ID code into a PB signal, and then send it to a data center for ID verification.

Also, assuming a cashless public phone,
If a magnetic card with an ID code written on it is inserted instead of inserting coins, it may be necessary to send the ID code converted to a PB signal to the station for ID verification.

Furthermore, the telephone number of the called party is encoded and written on a magnetic card, etc., and instead of pressing a push button, the magnetic card is inserted into a card reader, and the read signal is converted into a PB signal and sent to the exchange 3. This method will also be implemented in the near future.

In such a wide range of applications of push-button dial telephones expected in the future, noise is transmitted through the transmitter 4 during the operation of transmitting ID codes etc. converted to PB signals. If an error occurs while demodulating the signal, the purpose is not achieved and a great deal of confusion occurs.

Also, if you want to discover false signals and take countermeasures in advance,
The entire system becomes extremely complex.

In view of the wide range of applications expected in the future for push-button dial telephones, the present invention has been developed by effectively utilizing signals generated by reversing the polarity of the telephone line and off-hook and on-hook of the hook switch. To provide a device which has a simple configuration and can disconnect a transmitter from a line only for a desired period.

Hereinafter, typical embodiments of the present invention, combinations thereof, and procedures for using each push-button/dial type telephone set in the above-mentioned embodiments will be described in detail.

In FIGS. 3 and 7, elements or circuits that are the same as those shown in FIG. 2 are given the same reference numerals, and their explanations are omitted, and the reference numerals of elements, etc. that are not necessary for the explanation of this invention are omitted. is omitted to avoid complication.

In FIG. 3, diodes 9L92 ( (see Fig. 2), the light emitting diode 53 of the photo couplers 51, 52
．． 55 are connected to each other.

Photocouplers 51 and 52 connect these light emitting diodes 53 and 55 and phototransistors 54 and 56, respectively.
It is composed of.

When the transmitter/receiver of the telephone 1 on the calling side is picked up, it goes off-hook, so the DC circuit within the telephone 1 is closed (see Figure 1), and current flows through the light emitting diode 53, causing it to emit light.

When the called party's telephone 2 goes off-hook after calling the called party, the polarity of the calling party's telephone line is reversed (FIG. 1(e)).

Therefore, the current to the diode 53 is stopped, current flows to the light emitting diode 55, and the diode 55 emits light.

After the call ends, hang up the transmitter/receiver of the calling party's telephone 1.
Since the telephone is on-hook and the DC circuit inside the telephone 1 is opened, the power to the light emitting diode 55 is stopped.

Power to the light emitting diode 53 remains stopped.

In this way, by connecting the photocouplers 51 and 52 to the rectifier circuit 9, it is possible to detect that the telephone 1 on the calling side has transitioned to the off-hook and on-hook states, respectively, and that the called side has responded and is ready to talk. It is detected that a condition has occurred, ie, that the polarity of the telephone line has been reversed.

These detection signals are transmitted through phototransistors 54 and 56.
can be taken out from output terminals P2 and P8, respectively, and the above state change is displayed by light emission from each light emitting diode 53,55.

Light emitting diode 53 in photo couplers 51 and 52
, 55 and the phototransistors 54 and 56 are electrically insulated, so that there is no mutual influence between the telephone line and the control circuit, which will be described later, and the effect of preventing malfunction is significant.

Furthermore, in FIG. 3, a DC circuit closing resistor 57 is connected in parallel with the transmitter 4, and a transmitter cutoff contact 50 is used to switch between the transmitter 4 and the resistor 57.
is provided.

Resistor 57 is set to approximately the same value as the internal resistance of transmitter 4.

The contact 50 is normally connected to the a side, and when switched to the b side, the handset 4 is disconnected from the telephone line and the direct current from the telephone line is transferred from the break side b of the common contact 30 to the diode 42. , 43, flows through the b side of the contact 50 and through the resistor 57.

Based on the detection signals from photo couplers 51 and 52,
When sending a PB signal, switch the contact 50 to the b side and transmit the transmitter 4.
A control circuit for disconnecting the telephone line from the telephone line is shown in FIG.

This control circuit includes an off-hook detection circuit 61, a polarity reversal detection circuit 62, a transmitter intermittent control circuit 63, a manual transmission cutoff switch 64, and a relay 65.

The off-hook detection circuit 61 includes photocouplers 51 and 52.
Detects the state in which the transmitter/receiver of the telephone is picked up and the hook switch 7 is closed,
Outputs off-hook detection signal F.

This circuit 61 is constituted by an AND circuit in this embodiment.

Referring to FIG. 5, in a normal state where the transmitter/receiver of the telephone is placed, the hook switch 7 is open, no current flows through either of the light emitting diodes 53, 55, and the photo coupler 51, Since the output terminals P2 and P8 of 52 are at the "H" level, the off-hook detection signal F is also "H".
level.

When the transmitter/receiver is picked up (off-hook), the hook switch 7 is closed, current flows through the light emitting diode 53, and the level of the terminal P2 of the photocoupler 51 is reversed to "L", so the detection signal F is also It is also inverted to "L".

When the called side responds (called side goes off-hook) and the telephone line of the calling side is reversed, the output of the photo coupler 51 becomes "H" and the output of the photo coupler 52 becomes "L".
Detection signal F is still at "L" level.

After using the telephone, when you hang up the transmitter and receiver (on-hook), the outputs of both photocouplers 51 and 52 become “
Since it becomes "H", the off-hook detection signal F also becomes "H".
become.

When in the off-hook state, the telephone is in some use state, and at this time the off-hook detection signal F is "L".

The polarity reversal detection circuit 62 detects, based on the signals from the photocouplers 51 and 52 and the off-hook detection signal F, that the telephone line is off-hook and the polarity of the telephone line on the calling side has been reversed. At times, a polarity inversion detection signal S of "L" level is output.

Since the polarity of the telephone line is not reversed even if the telephone line goes off-hook from a normal state, the reversal detection signal S is still at the "H" level.

When the called party answers and the polarity of the telephone line is reversed, the signal S
is also inverted to "L".

When you finish using your phone and it goes on hook, it goes off
Since the hook detection signal F is inverted to "H", the inversion detection signal S also becomes "H".

When the polarity reversal detection signal S is at the "L" level, a telephone call or data conversation is possible.

The manual transmitter cutoff switch 64 is used to generate a trigger for disconnecting the transmitter 4 .

The transmitter intermittent control circuit 63 outputs an off-hook detection signal F,
Based on the polarity reversal detection signal S and the transmitter cutoff trigger signal TS from the switch 64, it determines the period during which the transmitter 4 should be disconnected from the telephone line, and outputs the relay drive signal TR. , can be constructed using a simple logic circuit.

Based on the drive signal TR, the relay 65 switches the contact 50 to the b side only for a predetermined period.

After the telephone is taken off-hook, the switch 64 is turned on before pressing the push button to send a PB signal to the exchange in order to call the called party.

Then, the trigger signal TS instantaneously inverts to "L", and at the time of the rise of this signal TS, the drive signal T of the control circuit 63
R is inverted to "L".

As a result, the relay 65 is driven, the contact 50 is switched to the b side, and the transmitter 4 is disconnected from the telephone line.

After sending the PB signal, if the receiving side (data center) is captured, the polarity reversal detection signal S changes from “H” to “L”.
At this point, the relay drive signal TR is “H”.
”, the contact 50 returns to side a, and the transmitter 4 is connected to the telephone line again.

Since the transmitter 4 is connected to the line, it becomes possible to talk to the called party.

When sending a predetermined command or data to the data center using a PB signal after a call (data conversation)
, when the switch 64 is turned on again, the trigger signal TS is instantaneously inverted, and at the rising edge of this signal, the drive signal T
R flips back to “L” level again.

Then, by this “L” level signal TR, the relay 6
5 is activated and the contact 50 is switched to the b side, so that the transmitter 4 is again disconnected from the telephone line.

After the data conversation ends, when the on-hook state is established, the polarity reversal detection signal S is inverted from the "L" level to the "H" level.
As a result, the contact point 50 returns to the a side and becomes the same state as the initial normal state.

In this manner, the transmitter intermittent control circuit 63 switches the switch 64 when the off-hook detection signal F is at the "L" level.
When the trigger signal TS is sent from , the relay drive signal TR is inverted to "L" level, and after the signal TR is inverted to "L" level, if the polarity reversal detection signal S is inverted, the drive signal T is
It operates to return R to the "H" level.

When the transmitter cutoff trigger signal TS is obtained from the manual switch 64 as in this embodiment, a contact 70 (FIG. 7), which will be described later, may be used in place of the contact 50.

As described above, when transmitting a PB signal for calling the called party or during a data conversation, the transmitter 4 is disconnected from the telephone line, so there is a situation where noise is transmitted along with the PB signal via the transmitter 4. is prevented.

Further, when a call is required, the transmitter 4 is connected to the telephone line, so that normal calls can be made without any problem.

Furthermore, when the phone goes on-hook, the contact 50 returns to the a side and the transmitter 4 is returned to the state connected to the telephone line, so the control circuit may become inoperable due to a power outage in the commercial AC power supply. Even in such cases, there is no problem with conventional telephone functions.

In addition, in normal calls that do not involve data conversation,
As soon as the call ends, the handset is hung up and turned on.
It becomes a hook, but when the call is in progress, the signal TR is “H”.
" level, so even if it becomes on-hook and the reversal detection signal S is reversed, the contact 50 remains connected to side A, and the transmitter 4 remains connected to the line. It will be done.

In addition, if it is necessary to return to a state in which communication is possible after the data conversation ends, a trigger generation switch or the like is provided to return to the communication state, or the drive signal TR is activated by the trigger signal TS from the switch 64. It is also possible to easily configure the control circuit 63 to invert the signal to "H" level.

If the above operations are viewed as a series of flows, it will be clear that they are represented by the flow chart shown in FIG.

In other words, if you pick up the transmitter/receiver from the "normal state", you will be "off hook", and after "checking the dial tone" from the exchange, if you turn "switch 64 on", the transmitter 4 will turn off. The device is disconnected from the telephone line, and in this state, by pressing a push button, it ``sends a PB signal'' and calls the called party (data center).

If the called party responds to this and goes off-hook, the calling party's telephone line polarity is reversed, and the handset is connected to the line in response to this reversed signal. , it becomes possible to make a call.

When the "call" ends and you want to start a data conversation, turn on the switch 64 again to disconnect the handset 4 from the telephone line, start the "data conversation", and after the data conversation ends,
By hanging up the transmitter/receiver, you will be “on hook”.
Return to "normal state".

In FIG. 7, a contact 70 for transmitter cutoff and automatic dialing is shown.
are connected in parallel to the common contact 30 within the oscillation circuit 6.

In this circuit, when the contact 70 is switched to the b side, a DC voltage is applied to the oscillation circuit 6 regardless of whether the common contact 30 is opened or closed, and the transmitter 4 is disconnected from the telephone line.

In addition, the low and high group tuning circuits of the oscillation circuit 6 include automatic dialing low and high group contacts 71 to 74, in parallel with the low and high group contacts 31 to 34 and 35 to 37 corresponding to the push buttons, respectively.
75 to 77 are connected.

The telephone shown in Figure 7 uses a magnetic card to automatically
This is useful when transmitting a B signal, or when converting an ID code into a PB signal and transmitting it at a cashless public telephone or during a data conversation.

In FIG. 8, the code written on the magnetic card 80 is read, the contact 70 is switched to the b side, and the low and high group contacts 7
A device is shown that automatically sends out a PB signal by closing any one of terminals 1 to 74 and 75 to 77.

This device includes a magnetic card reader 81, a decoder 82,
Data processing circuit 83, high group contact interface 84
, an oscillation control circuit 85, and an oscillation control interface 86.

The ID number or telephone number (dial number) of the called party is coded and written in the center of the magnetic card 80, and before and after that are STX (start of text) and ETX (end of text). text), LRC
Control codes such as (horizontal redundancy check) are written.

The card reader 81 has a magnetic head 87 that reads data on the card 80, and a photo sensor 88 that detects that the card 80 has been sent along the feeding path.

The signal read by the magnetic head 87 is amplified and then sent to the decoder 82.

The photo sensor 8B outputs a scanning signal CS while the card 80 is being fed.

The decoder 82 decodes the signal sent from the magnetic head 87 while the scanning signal CS is being input into a switching signal, and converts this into a card data signal CD.
It is sent to the data processing circuit 83 as a.

The processing circuit 83 performs serial/parallel conversion on the signal CD and decodes it in decimal evolution, and the interface 84 for low and high group contacts decodes the low and high group contacts 71 based on the signal corresponding to the numerical value of each pushbutton. One contact is selected from each of ~74, 75~77, and the relay of the contact is driven after a certain period of time has elapsed.

The oscillation control circuit 85 and the oscillation control interface 86 have the same functions as the transmitter intermittent control circuit 63 and the relay 65, respectively.

In FIG. 4, the switch 64 is used as a trigger generation source, but here the scanning signal CS is used as a trigger signal for transmitter cutoff and automatic dialing.

Referring to FIG. 9, after going off-hook, when a magnetic card 80 on which the telephone number of the called party is coded and written is inserted into a card reader 81, an "L" level scanning signal CS is output. At the same time, the card 80 is read.

After reading the data, the scanning signal CS becomes “H”
When it returns to the level, this rise causes the oscillation control circuit 85 to
The "L" level oscillation control signal TX is output from the oscillation control signal TX, the relay is driven, and the contact 70 is switched to the b side, so that the transmitter 4 is disconnected from the telephone line and an operating voltage is applied to the oscillation circuit 6. .

During this time, the data read by the magnetic head 87 is decoded by the decoder 82 as a code/data signal CD, and then sent to the processing circuit 83, where it is sent to the processing circuit 83.
The telephone number is converted into a decimal number and input into the interface 84.

Then, after a certain period of time has passed after the scanning signal CS is inverted to the "H" level, the automatic dialing contacts corresponding to the telephone numbers are closed in a certain order, and a PB signal consisting of two frequencies, low and high, is sent to the exchange. Send towards.

In the figure, the low group PB signal sending signal DL and the high group PB signal sending signal DH represent that low and high group signals are being sent, respectively, and the PB signal sending signal DS is a P signal consisting of two frequencies.
This indicates that the B signal is being sent.

After sending the pB signal, when the receiving side (data center) goes off-hook, the polarity reversal detection signal S is inverted to "L" level, so the contact 70 returns to the a side and the transmitter 4 connects to the telephone line. The device is connected and ready to talk.

If you want to have a data conversation after a call, and it is necessary to send the ID code to the data center in advance, insert the magnetic card 80 on which the ID code is written, and the scanning signal CS will similarly go to "L" level. During this time, the data on the card 80 is read out.

Then, when the scanning signal CS is inverted to the "H" level, the contact 70 is switched to the b side again, so that the transmitter 4 is disconnected from the telephone line and the oscillation circuit 6 becomes ready for oscillation.

After a certain period of time has elapsed, the ID code is converted into a PB signal and sent to the data center.

Then, as will be described later, once the ID code has been verified, it becomes possible to send data such as commands using the push button.

After the data conversation is completed, when the transmitter/receiver is hung up, the telephone becomes on-hook and the contact 70 is connected to the a side, returning to the normal state.

After the call ends, immediately hang up the handset and turn it on.
Even when hooked up, the transmitter 4 remains connected to the line.

The above-mentioned operations or operations in the case of a normal telephone call can be summarized as a series of flowcharts shown in FIG.

If you pick up the transmitter/receiver from the "normal state", you will be "off hook", and after "checking the dial tone" from the exchange, you can check whether the magnetic card 80 is dialing automatically or not.
In the case of automatic dialing, the magnetic card 80 is inserted into the card reader 81.

If it is not automatic dialing, a ``PB signal by push button'' is sent to the exchange.

When the magnetic card 80 is inserted into the card reader 81,
Scanning signal CS by “card scanning”
Immediately, the contact 70 is switched to the b side, and the handset is "disconnected from the telephone line."

After this, the data processing circuit 83 checks whether there is any error in the format of the card data.
If there is no error, any one of the low and high group contacts 71 to 74 and 75 to 76 is sequentially closed via the interface 84 to "send the PB signal."

If there is any of the above errors, an "error display" is displayed and the card 80 is inserted into the card reader 81 again.

After sending the PB signal, if the called party is captured and the called party goes off-hook, the polarity of the telephone line is reversed, and the reversal detection signal S causes the gap contact 70 to return to the a side, causing the "transmission" to occur. The handset is connected to the line and ready to make a call.

After the call ends, if you hang up the transmitter/receiver, it becomes "on hook" and the transmitter 4 remains connected to the line.
Return to "normal state".

The flow of operations or operations when a telephone line is connected to a data center and a data conversation is performed is shown in FIG.

In this figure, the "called party off-hook" in Figure 10 is
becomes "off-hook on the data center side", and the flow before that is the same as that shown in FIG.

If the data center side goes off-hook, the polarity of the telephone line is reversed, so the contact 70 is returned to side A based on the reversal detection signal S, and the transmitter 4 is connected to the telephone line. It will be connected and you can make a call.

After the call, when the magnetic card 80 on which the ID code is written is inserted into the card reader 81, a scanning signal CS is output by "card scanning", and the contact 70 is immediately switched to the b side again. If "the transmitter is disconnected" and there is no "error in the format of the card data", "the ID code is converted to a PB signal and sent to the data center side".

After this, when you use the push button to "send a 4-digit code number," the data center performs "■D verification."
If the ID code and PIN number match, there is a response from the data center saying it is OK to start a data conversation, and if they do not match, the data center is on-hook.
and ends.

After the data conversation start response is received, the data conversation begins.

For example, when a push button is used to ``convert a command signal into a PB signal and send it out,'' the data center sends ``guidance and other responses.''

Various responses from the data center are sent by PB signals, and as described later, are sent to the recording device 133 shown in FIG.
and/or displayed on the display device 134.

Data transfer with the data center is repeated several times as necessary, and when the data conversation ends and you hang up the transmitter/receiver, it becomes "on hook", so contact 70 is on side A. The process returns to the "normal state" in which the transmitter 4 is connected to the telephone line.

The telephone shown in FIG. 7 and the device shown in FIG. 8 can also be applied to the case where the card 80 is inserted into the card reader 81 instead of inserting coins at a cashless public telephone.

At this time, an ID code has been written on the magnetic card 80.

The operation or operating procedure in this case is represented by the flow chart shown in FIG.

If you pick up the transmitter/receiver from the "normal state" and go "off-hook" and immediately insert the card 80 into the card reader 81, "the transmitter is disconnected" in the same manner as above, and the "card data" is If there is no error in the format, the D code is converted to a PB signal and sent to the station.

After this, if you use the push button to "send the recitation number",
On the station side, "■D verification" is performed, and if the ID number and PIN number match, the bureau will ``send a dial tone'', and if they do not match, ``no dial tone will be sent'' and the PIN number will be sent again, etc. This operation will need to be repeated.

When a dial tone is sent out from the station side, the station ``confirms the dial tone'' and then ``sends a PB signal using a push button.''

The subsequent flow is the same as that shown in FIG.

Note that instead of sending the PB signal using a push button,
It is also possible to insert a magnetic card 80 with the called party's telephone number written into the card reader 81 and perform the procedure shown in FIG.

In the telephone shown in FIG. 7, the oscillator circuit 6 includes a transmitter cutoff and automatic dialing contact 70 for selecting either the oscillating circuit 6 or the transmitter 4, and a contact 70 for both low and high group tuning circuits. Low and high group contacts 31 to 3 corresponding to the provided pushbuttons
4. Low and high group contacts 71 to 74 and 75 to 77 for automatic dialing are connected in parallel with 35 to 37, respectively, so the PB is automatically used as a card data reading signal. It is possible to send signals.

In addition, in the device shown in FIG. 8, the scanning signal CS of the card 80 is used as a trigger signal for transmitter cutoff and automatic dialing, so the telephone user can switch the transmitter 4 without any manual operation. can be disconnected from the telephone line, and at the same time, the oscillation circuit 6 can be brought into an operable state.

Moreover, from the time of scanning the card 80, the transmitter 4
Therefore, when the automatic PB signal transmission operation is performed after card scanning, the handset 4 is already disconnected from the telephone line, and malfunctions due to noise can be reliably prevented.

This is particularly important in data conversations, allowing error-free data transmission.

Note that the contact 50 shown in FIG. 3, the contact 70 shown in FIG.
71 to 77 can be replaced with non-contact switching means such as semiconductor switching elements.

In addition, in the device shown in FIG. 8, a scanning signal CS is used as a trigger signal for transmitter cutoff and automatic dialing, but a fourth signal CS is used instead of this scanning signal CS.
It will be readily understood that the signal TS from the manual switch 64 shown in the figure can also be used.

In the telephones of FIGS. 3 and 7, a response sound search coil 100 is coupled to the sidetone suppression coil 10. In the telephone of FIGS.

The signals induced in the coil 100 include a PB signal, a tone (400 Hz) from the exchange, and an intermittent response tone from the data center that is different in frequency from the tone and is assumed to be intermittent. After these signals are amplified, they are extracted by a band pass filter 101.

The dial tone from the exchange and the intermittent response tone from the data center are further sent to a timer 102, and when both of the tones continue for a predetermined period of time (for example, 3 seconds), a response tone confirmation signal DT is output.

This response tone confirmation signal DT includes a dial tone confirmation signal DT1 from the exchange, which will be described later, and an intermittent response tone confirmation signal DT2 from the data center.

The specific configuration of the bandpass filter 101 and the circuits and devices added thereto are shown in FIG.

In this figure, a filter 101 has a voltage controlled oscillation circuit that has the same center oscillation frequency as the frequencies of the tone from the exchange and the intermittent response tone from the data center, as well as the low and high frequencies that make up the PB signal. PLL (phase locked loop) provided respectively, 111, 112, 121
~127.

The tone from the exchange passes through PLL111 and is sent to timer 1.
02 and continues for a predetermined period of time, a beep confirmation signal DT will be emitted.
1 is output.

PLL1 that allows intermittent response tones to pass from the data center
A regular period intermittent detection circuit 103 is provided on the output side of 12 to determine whether or not this intermittent response sound is intermittent at a predetermined period, and to confirm that it is an intermittent response sound from the data center. It is preferable.

If it is confirmed that the response tone from the data center is intermittent at a predetermined period and continues for a predetermined period of time, an intermittent response tone confirmation signal DT2 is output.

The outputs of PLLs 121 to 127 are sent to the hexadecimal decoding circuit 13.
1, where the PB signal consisting of two frequencies, low and high, is decoded into signals representing numeric buttons and function buttons based on the combinations shown in Table 1.

This decimal encoded signal is stored in a memory 132, and is recorded on a magnetic card or the like by a recording device 133, or displayed on a multi-digit display device 134, if necessary.

These outfits! 133 and 134 use push buttons to send the called party's telephone number to the exchange, or to confirm by displaying the sent PB signal when sending data to the data center, It is suitably used to display or record the content of data conversations including guidance and responses sent from a data center.

The above-mentioned response tone confirmation signal DT is generated by a manual switch 64 in the control circuit shown in FIG.
It can be used in place of S, or in place of the scanning signal CS from the photo sensor 88 of the card reader 81 in the device shown in FIG.

A time chart for disconnecting the telephone line from the telephone line using the answer tone confirmation signal DT is shown in FIG.

When you pick up the transmitter/receiver and go off-hook, a dial tone is sent from the exchange, so a dial tone confirmation signal DT1 is output after a predetermined time (3 seconds) has elapsed since the off-hook, and the falling edge of this signal DT1 , the contact 50 or 70 is switched to the b side and the transmitter 4 is disconnected from the telephone line.

When transmitting the PB signal manually, the push button is pressed after the transmitter 4 is disconnected.

In the case of automatic dialing using the magnetic card 80, if the card 80 is inserted into the card reader 81 after off-hook, the contact 70 is switched to the b side, the oscillation circuit 6 becomes ready for oscillation, and the transmission starts. After the handset 4 is disconnected from the telephone line, any one of the low and high group contacts 71-74 and 75-77 is sequentially closed by the interface 84, and a PB signal is sent out.

When the called side (data center) goes off-hook, the polarity of the calling side telephone line is reversed, so the polarity reversal detection signal S is reversed to "L", and the contact 50 or 70 returns to the a side and sends the signal. The handset 4 is connected to the telephone line and becomes ready for conversation.

When conducting a data conversation, an intermittent response tone is sent from the data center, so if the response tone continues for a predetermined period of time, an intermittent response tone confirmation signal DT2 is output, and the transmitter 4 is disconnected from the telephone line again. be separated.

Then, with the transmitter 4 disconnected from the telephone line, transmission of the ID code and other necessary data and responses are performed using push buttons or automatic dialing.

When the data conversation is completed and the transmitter/receiver is hung up, the handset becomes on-hook, the contacts 50 and 70 return to side a, and the transmitter 4 is connected to the telephone circuit again, returning to the normal state.

FIG. 15 shows a series of the above operations or operations.

After going ``off-hook'' from the ``normal state'', if the continuation of the tone from the exchange is confirmed, a ``tone confirmation signal is output'' and the ``talker is disconnected'' automatically.

Then, when a ``PB signal is sent'' by a pushbutton or automatic dialing and the called party goes off-hook, ``the polarity of the telephone line is reversed,'' and this reversed signal is used to is connected to the line and ready to make calls.

During a data conversation, an intermittent response tone is sent from the data center, and if this continues for a predetermined period of time, a ``data center response tone confirmation signal'' is output, and the ``telephone is disconnected'' automatically again. .

After the "data conversation" ends, you can hang up the transmitter/receiver and
"on hook" and returns to "normal state".

In this embodiment, a sidetone suppression coil 10 in the telephone
Of the signals extracted by the response sound search coil 100 coupled to the telephone, only the response sound from the exchange or data center is detected by the band pass filter 101, and this detection signal is used as a trigger signal to transmit the response sound to the transmitter 4. Since the disconnection is performed, manual operation is not required, which is very convenient, and the configuration is simple, so that it can be easily implemented in a telephone that is not equipped with peripheral equipment such as the card reader 81.

Furthermore, since the search coil 100 is insulated from the telephone line in direct current, it will not cause any trouble to the telephone line, and even if the commercial AC power supply fails, the telephone function will not be disturbed.

Since the continuation of the response sound is confirmed by the timer 102, the operation is extremely reliable.

Furthermore, it is applicable even when a magnetic card reader 81 is installed, and it becomes possible to automatically disconnect the transmitter 4 by a response sound before the scanning signal CS is output.

As described above in detail, the transmitter disconnection device for the push-button dial telephone according to the present invention includes a switching means for disconnecting the transmitter provided in the transmitter circuit;
Means for detecting the off-hook state of the telephone set and the polarity reversal state of the telephone line and outputting a state detection signal, and determining the timing at which the handset should be disconnected from the telephone line and outputting a handset disconnection trigger signal. and means for controlling the switching means on and off so as to disconnect the handset from the telephone line only for a required period based on the state detection signal and the handset disconnection trigger signal. from,
During the PB signal sending operation, it becomes possible to disconnect the handset from the telephone line by manual operation or automatically, thereby preventing noise caused by external noise from being transmitted to the telephone line through the handset. All kinds of malfunctions can be prevented.

This invention is applicable not only to normal telephone usage in which a push button is used to send a PB signal to an exchange in order to call the called party, but also to use a magnetic card or the like on which the telephone number of the called party is written.・When automatically sending a PB signal for calling the called party by inserting it into the reader,
At cashless public telephones, instead of inserting coins, insert a magnetic card with an ID code written on it and use the I.D.
Push-button/dial telephones that will be realized in the future will be used when converting the D code into a PB signal and sending it to the central office, or when using the PB signal to conduct data conversations with a data center. Its power is fully demonstrated in various usage forms, and highly reliable data transmission can be achieved.

Particularly in data conversations, when a telephone is equipped with a device that decodes, records, and displays data from PB signals sent from a data center, it is absolutely necessary to eliminate false signals caused by noise. According to the present invention, the object can be achieved very easily without complicating the entire system.

Further, in the present invention, the means for outputting the state detection signal includes a light emitting diode, and the light emitting diode is connected to a diode bridge rectifier circuit for always supplying an operating voltage of a constant polarity even when the polarity of the telephone line is reversed. photocouplers connected to two adjacent sides of the telephone, and an off-hook detection circuit for detecting that the telephone is in an off-hook state based on the output signals from these photocouplers; It also includes a polarity reversal detection circuit that detects that the polarity of the telephone line has been reversed based on the output signals from the photocoupler and the off-hook detection circuit.

Since the light emitting diode for receiving the state detection signal is also used as the diode of the diode bridge rectifier circuit, the configuration is extremely simple.

Furthermore, since the light emitting diode and light receiving element (phototransistor) in the above photocoupler are electrically insulated, the telephone line and each control circuit of the transmitter disconnection device do not affect each other. Malfunction of the handset disconnection device is prevented, and highly reliable signal transmission is achieved without any disturbance from the handset disconnection device being mixed into the PB signal transmitted to the telephone line.

[Brief explanation of the drawing]

FIG. 1 is an operational diagram showing polarity reversal of a telephone line, FIG. 2 is a circuit diagram showing the internal circuit of a conventional push-button dial telephone, and FIGS. 3 to 15 show embodiments of the present invention.
Figure 3 is a circuit diagram showing the internal circuit of the telephone, Figure 4 is a block diagram showing the handset disconnection device, Figure 5 is a time chart showing the operation of the device in Figure 4, and Figure 6 is a manual switch. 7 is a circuit diagram showing the internal circuit of the telephone used for automatic dialing. FIG. 8 is a block diagram showing the automatic dialing device. FIG. 9 is a time chart showing the operation of the device shown in Figure 8, Figure 10 is an operation flow chart for automatic dialing, Figure 11 is an operation flow chart for data conversation, and Figure 12 is a cashless public service. Operation flow chart in telephone, 1st
Fig. 3 is a block diagram showing a bandpass filter and a device added thereto, Fig. 14 is a time chart when the transmitter disconnection operation is performed by a response tone confirmation signal, and Fig. 15
The figure is an operational flow chart for the same operation. 1, 2...Push button/dial telephone, 4.
...Telephone, 7...Hook switch,
9...Diode bridge rectifier circuit, 50...
...Telephone cutoff contact, 51, 52...Photo coupler, 53, 55...Light emitting diode, 61...Off hook detection circuit, 62 ...
...Polarity reversal detection circuit, 63...Telephone intermittent control circuit, 64...Manual switch, 65...
...Relay, 70...Contact for transmitter cutoff and automatic dialing, 81...Card reader, 88.
... Photo sensor, 85 ... Oscillation control circuit, 86 ... Oscillation control interface,
100...Response sound search coil, 101...
...bandpass filter.

Claims (1)

[Scope of Claims] 1. Switching means for cutting off the transmitter provided in the transmitter circuit, means for detecting the off-hook state of the telephone set and the polarity reversal state of the telephone line and outputting a state detection signal, and the transmitter. means for determining the timing at which the telephone line should be disconnected from the telephone line and outputting the transmitter cutoff trigger signal; The means for outputting the state detection signal includes a light emitting diode, and the light emitting diode always maintains a constant polarity in response to reversal of polarity of the telephone line. The phone goes off-hook based on the photocouplers connected to two adjacent sides of the diode bridge rectifier circuit to supply the operating voltage and the output signals from these photocouplers. and a polarity reversal detection circuit that detects that the polarity of the telephone line has been reversed based on the output signals from the photocoupler and the off-hook detection circuit. A transmitter disconnection device for push-button dial telephones. 2 The switching means switches the direct current from the telephone line to
A transmitter in a push-button dial telephone according to claim 1, which is a contact for switching to either a transmitter or a DC circuit closing resistor connected in parallel to the transmitter. Detachment device. 3. Transmission in a push-button dial telephone set forth in claim 1, wherein the switching means is a contact point that switches the direct current from the telephone line to either a transmitter or an oscillation circuit within the telephone set. Talk disconnect device. 4. Transmitter disconnection in a push-button dial telephone according to any one of claims 1 to 3, wherein the means for outputting the transmitter disconnection trigger signal is a manually operated switch. Device. 5. The push button according to any one of claims 1 to 3, wherein the means for outputting the transmitter cutoff trigger signal is a card scanning detection means provided in a card reader. A transmitter disconnection device for a button-dial telephone. 6 The means for outputting the transmitter cutoff trigger signal includes a response sound search coil coupled to a sidetone suppression coil in the telephone set, and a desired response sound among the signals extracted by the response sound search coil. A transmitter disconnection device in a push-button dial telephone according to any one of claims 1 to 3, comprising a band-pass filter that allows only signals to pass. 7. The means for outputting the transmitter cutoff trigger signal includes a response tone search coil coupled to a sidetone suppression coil in the telephone set, and a desired response tone among the signals extracted by the response tone search coil. Any one of claims 1 to 3, comprising a band-pass filter that allows only a signal to pass through, and a timer that confirms that the output of the band-pass filter continues for the required time. A transmitter disconnection device in a push-button/dial type telephone set forth in .