JPH02206949A - Switching device for classification of telephone set - Google Patents

Abstract

PURPOSE:To improve convenience by detecting the polarity inversion of a DC voltage of a telephone circuit due to the reply of a called party and switching the generation of signal output by the operation of a dial button from a dial pulse(DP) signal into a pushbutton(PB) signal automatically. CONSTITUTION:A dial signal classification switching equipment of a telephone set 20 is basically made up of a DP signal generating circuit 4, a PB signal generating circuit 6, a signal switching circuit 13 and a reverse detection circuit 14, and the telephone set 20 connects to telephone circuits L1, L2 housed in the exchange system of a central station. The telephone circuits L1, L2 are in this case DP lines. Then the telephone set 20 detects the voltage polarity inversion of the telephone circuits L1, L2 in the connection of a called party and the DP signal and the PB signal are switched automatically in response thereto. Thus, the convenience is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a telephone set, and particularly to a dial signal type switching device thereof.

(Prior Art) In recent years, as seen in telephone subscriber services such as reserved ticket reservation services of railway companies, pushbutton fPBl
Access the center device from the subscriber telephone line of the telephone and press P.
An increasing number of services use B-dial signals as control signals. On the other hand, in a telephone company's telephone contract, the monthly basic charge generally differs depending on the type of selected signal. For example, PB signal subscriptions are more expensive than dial pulse (OP) signal subscriptions. Therefore, in order to receive push-button telephone service on a contract line, telephones that can selectively switch the type of dial signal are generally used.

A telephone that can change the type of dial signal is equipped with a dial button and an operation switch that changes the signal, and when making a call, the user presses the operation switch to D after hooking up.
Set it to the P signal side and input the called party number using the dial button. This causes the telephone to send a DP double signal to the telephone line, identify the dial pulse, and cause the exchange to establish a connection with the called party. If the called party has a general subscription, the calling party's telephone functions as a normal telephone and a call is initiated. However, if the called side is a PB signal telephone service system, when the system is connected to the called side system, there will be a voice guidance response, and the user will then switch the operation switch to the PB signal side.

With this, before making a call, the user operates the dial button and inputs the input data. The telephone converts this manual data into a PB signal and sends it to the telephone line, and the service is started.

(Problems to be Solved by the Invention) Such conventional telephones have a configuration in which the DP double signal and PB double signal are selected by manual switching. Therefore, if this switch is left on the PB signal side before connection, a PB double signal will be sent to the DP line where the telephone is accommodated, and a normal connection will not be established. Also, after connecting to the service center, if switching to the PB side λ is not performed, D
P times signal is transmitted, and of course not only is the service unavailable, but the user also hears this as an unpleasant sound from the receiver.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a telephone dial signal type switching device that eliminates the drawbacks of the prior art, realizes automatic selection of a DP double signal and a PB double signal, and is highly convenient.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a first signal that is connected to a dial pulse subscriber line and sends a dial pulse signal to the subscriber line in response to a dial button. and a second signal generating means connected to the subscriber line and generating a frequency signal within the communication band of the subscriber line in response to a dial button, the first and second signal generating means The telephone dial signal type switching device selectively uses connection detection means for detecting connection with a called party through a subscriber line, and first and second signal generation means in response to the connection detection means. When the connection detection means detects connection with the called party, the selection means is controlled to enable the second signal generation means.

According to the present invention, there is also provided a telephone having such a dial signal type switching device and a dial button.

(Function) According to the present invention, the first signal generating means generates a selection signal, the second signal generating means generates a communication signal, and both are selectively used. .

When a call is made from the telephone, the first signal generating means is activated and a called party selection signal is sent to the subscriber line in dial pulses. Thereafter, when the connection detection means detects connection with the called party through the subscriber line, the selection means enables the second signal generation means, and a frequency signal corresponding to the operation of the dial button is sent to the subscriber line. .

(Example) Next, an example of a dial signal type switching device for a telephone set according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a telephone equipped with a dial signal type switching device according to the present invention.

In conventional telephones having a dial signal type switching function, switching between the Kano signal and the PB double signal was performed manually. The telephone 20 equipped with the dial signal type switching device of this embodiment detects the reversal of voltage polarity on the telephone lines L1 and L2 when a called party is connected, and switches the signal type in response to this.

The dial signal type switching device of the telephone 20 is basically a DP signal generation circuit 4. In this embodiment, a PB signal generation circuit 6, a signal switching circuit 13, and a reverse detection circuit 14 are connected and configured as shown in the figure, and a PB double signal is used for communication with the service system. Ll
Other signals may be used as long as they are frequency signals within the L2 band.

Telephone 20 is connected to telephone lines LL and L2 housed in a central office switching system. Telephone lines 11 and L2 are DP lines in this example.

Through the subscriber lines Ll and L2, the subscriber of the telephone set 20 can be connected to the center equipment of a telephone subscriber service system, such as a designated ticket reservation service of a railway company, through a switching system, and the subscriber can receive a PB dial signal. By accessing the center device as a control signal, it is possible to receive services from the center device.

When the telephone 20 is on-hook, it forms a loop through the telephone lines L1 and L2, the hook switch I, and the tone ringer circuit 11, and this loop is in a no-current state. When the telephone 20 receives a call from the telephone lines L1 and L2, current flows through this loop, and the tone ringer circuit 1
1 detects a discharge signal and causes the sounding body 12 to sound.

When making/receiving calls, if you go off-hook, telephone lines L1 and L
2, a direct current loop is formed that passes through the hook switch 1, the input terminals a and 2 of the diode bridge 2, and the reverse detection circuit 14. Diode bridge 3 is
The current flowing between the input terminal a and the same is full-wave rectified and output from the output terminals C and d, thereby forming a DC loop 16 in the telephone 20 passing through the terminals CJB and d, the contact 5, and the communication circuit 8. be done.

The telephone set 20 has a dial button 3, which in this embodiment is mainly used for inputting a called party number and for inputting communication data or control signals to a service center.

The output 18 is selectively connected to the DP signal generation circuit 4 or the PB signal generation circuit 6 by the signal switching circuit 13.

The signal switching circuit 13 is composed of a semiconductor switch, and its control push force 22 is connected to the output of the reverse detection circuit 14. The signal switching circuit 13 is normally set to connect the output 18 of the dial button 3 to the OP signal generating circuit 4. The reverse detection circuit 14 detects the reversal of the voltage polarity of the telephone lines L1 and L2 at the time of the old call connection,
When this is detected, the output 22 is energized. In response to this, the signal switching circuit 13 changes the output 18 of the dial button 3 to D.
The P signal generation circuit 4 is switched to the PB signal generation circuit 6.

The Kano-i No. 4 generation circuit 4 is a circuit whose control output 24 is connected to the drive circuit of the contact 5, and creates a DP double signal by opening and closing the contact 5 according to the signal input from the dial button 3. . The PB signal generating circuit 6 is a circuit whose output 26 is connected to the DC loop 16 through the capacitor 7, and generates a PB multiplied signal in response to a signal manually input from the dial button 3.

This PB signal or PB double signal and the voice signal received at the handset IO are generated in the DC loop 16, which are applied from the diode bridge 2 to the exchange through the telephone lines L1 and L2.

Next, the operation of accessing the push button service system in this embodiment will be explained according to the operation flow shown in FIG. When the handset is hooked up in step 100, hook switch l is closed and current flows from the switching office into the loop of telephone lines Ll and L2. The caller listens to the dial tone from the exchange through the receiver 9, and in step 110 operates the dial button 3 to enter the selected digits manually. Signal switching circuit 13
In the initial state, the output 18 of the dial button 3 is connected to the leaf signal generation circuit 4. Therefore, the DP signal generating circuit 4 opens and closes the contact 5 according to the selected number 1, thereby transmitting the dial pulse to the communication circuit 8 and the diode bridge 2.
to telephone lines Ll and L2.

When the required number of digit dial pulses are sent out, the exchange calls the called party terminal corresponding to the selected digits. When the called party hooks up and answers, the called party terminal is connected to the switch. In step 120, the exchange reverses the polarity of the DC voltage applied to the calling party's telephone lines Ll and L2. The reverse detection circuit 14 detects this polarity reversal and energizes its output 22, whereby the signal switching circuit 13
The output 18 of the dial button 3 is connected to the PB signal generation circuit 6.
Switch to the side.

If the called party is a general subscriber, the call continues as normal. If the called party is a telephone subscriber service center device, the calling party listens to the voice service guidance from the center device in step 130, and then presses the dial button 3.
Input more necessary communication data, ie, control signals. In response to this, the PB signal generation circuit 6 generates a PB double signal,
This signal is sent through the capacitor 7 to the telephone lines L1 and L2, thereby allowing communication between the calling party and the center device.

At step 140, the line connection is released upon hook-down of the caller and subsequent recovery of the called device.

On telephone 2a, hook switch 1 is restored and telephone line L
The voltage polarities of 1 and L2 are reversed. The reverse detection circuit 14 then de-energizes its output 22, thereby placing the signal switching circuit 13 in a dormant state in which it is restored to the connection position shown.

(Effects of the Invention) As explained above, according to the present invention, the polarity reversal of the DC voltage of the telephone line due to the response of the called party is detected, and the generation of the signal output due to the dial button operation is changed from the DP signal to the PB multiplied signal. Switch automatically. Therefore, after connection, it is possible to reliably send the PB double signal to the pushbutton telephone service system, eliminating the possibility of sending erroneous dial signals6.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing an embodiment of a dial signal type switching device for a telephone according to the present invention, and FIG. 2 is a flow diagram showing an example of the operation flow of the embodiment shown in FIG. Explanation of the main part 181. Hook switch 230. Diode Bridge Dial Button DP Signal Generation Circuit PB Signal Generation Circuit Talking Circuit Handset Transmitter Tone Ringer Circuit Signal Switching Circuit Reverse Detection Circuit Telephone Patent Applicant Oki Electric Industry Co., Ltd. Agent Writer Takao Takao Kazan

Claims (1)

[Scope of Claims] 1. A first signal generating means connected to a dial pulse subscriber line and transmitting a dial pulse signal to the subscriber line in response to a dial button; a second signal generating means for generating a frequency signal within the communication band of the subscriber line in response to the dialing button, and selectively using the first and second signal generating means. The signal type switching device includes: connection detection means for detecting connection with a called party through the subscriber line; and selectively switching the first and second signal generation means in response to the connection detection means. and selection means for enabling the second signal generation means, and the connection detection means controls the selection means to enable the second signal generation means when detecting connection with the called party. Telephone dial signal type switching device. 2. A telephone comprising the dial signal type switching device according to claim 1 and the dial button.