JPH02246656A - Telephone system - Google Patents

Abstract

PURPOSE:To obtain a proper sidetone volume independently of the type of an interface circuit by controlling a level variable means of a relevant digital extension telephone set in response to whether the interface circuit connecting to other party is an analog interface or a digital interface in the speech connection of the digital extension telephone set. CONSTITUTION:A central control section 301 calls an opposite party based on a dial signal and detects the reply of an opposite party. The central control section 301 retrieves a storage means 302 based on identification information (port number or the like) of a line circuit LC being a called interface circuit and the identification information of the line circuit being an opposite party interface circuit to detect whether the combination of the connection consists of digital signals or a digital signal and an analog signal, outputs a control signal to turn a switch SW3 to the position of a contact (a) in the case of the combination of digital signals and outputs a control signal to turn the switch SW3 to the position of a contact (b) in the case of the combination of digital signal and analog signal. Then a time division switch TSW is controlled to form a channel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Field of Industrial Application) The present invention relates to a telephone system such as a private branch exchange or a key telephone device.

(Prior Art) In recent years, some private branch exchanges have appeared that can accommodate both digital extension terminals and analog extension terminals, and can be connected to both digital office lines and analog office lines.

By the way, when using a telephone, the speaker's ears are covered by the receiver during a call, so in order to prevent the speaker from hearing his or her own voice, a system is used to obtain sidetone, which is the sound that wraps around from the transmitter to the receiver. I have to. Since this sidetone is the speaker's own voice, it is undesirable to have it too loud or too soft. Conventionally, a fixed level of sidetone was obtained by taking into account the type of line, etc. It was configured so that

The above configuration will be explained with reference to FIG. 300 indicates a digital PBX (private branch exchange) and is connected to a line circuit LC1 which is an interface circuit connected to an extension terminal.
Co and a station line diagram fl COC, -COCIll are provided. 1 - The audio path between these interface circuits is formed via the time division switch 1. Extension terminal and L are digital extension telephones D-meter, D-TEi
, , . . . and to the analog extension telephone - TE1.
．． Digital R telephone D-TI equipped with i+
EI~'? :' is outputted from the transmitter M of the handset ``H3'', and the audio signal is amplified by the amplifier A) 1, and then outputted to the adder ADf) as a predetermined level by the attenuator. Eh, in addition to the received voice signal, it is amplified by amplifier A7 and sent to receiver R.
forming a lateral sound path.

However, in such a telephone system, a digital extension telephone is used. There was a problem in that the side volume differed depending on whether the interface circuit to which the other party was connected was analog or digital, making it difficult to hear. That is,
Digital extension telephone D-TE1. ．． 1 is line circuit L
Talk to digital extension telephone 1-2 via C2.
When transmitting and receiving audio signals, audio signals are transmitted and received through the illustrated paths A1 and A7, and the sidetone path is formed only through the attenuator ATT, but the line circuits LC, which are analog interface circuits, When connected to the analog extension telephone A device via the analog extension telephone A device, voice signals are transmitted and received via paths B1 and B2, and as a sidetone path, in addition to the path via the attenuator ATT, line circuits 1. There is also a path via the Cn hybrid circuit 11YB.

Here, the leakage signal in the hybrid circuit HYB is due to the fact that the impedance of the hybrid circuit IY8 and the impedance of the analog extension telephone HYB do not perfectly match.

(Problems to be Solved by the Invention) As described above, according to the conventional telephone system, when the interface circuit to which the other party of the digital extension telephone is connected is for analog use and when it is for digital use, the digital extension The problem is that the side volumes on the phones are different, making it difficult to hear.

The present invention has been made to completely solve the problems of the conventional telephone system, and its purpose is to provide an appropriate side tone regardless of the type of interface circuit to which the other party of the digital extension telephone is connected. The aim is to provide a telephone system that allows you to obtain

U Structure of the Invention (Means for Solving the Problem) In the present invention, each interface circuit is connected to an extension terminal or a central office line in a telephone system in which analog interface circuits and digital interface circuits coexist. A storage means storing type data indicating whether it is for analog use or digital use.

a digital extension telephone connected to the digital interface circuit and provided in the sidetone path from the transmitter to the receiver, and having a level variable means for changing the level; detects whether the interface circuit to which is connected is analog or digital based on the corresponding type data in the storage means, and controls the level variable means of the digital extension telephone according to this type data. The telephone system is equipped with a control means for giving a control signal to the telephone system.

(Function) According to the above configuration, when a call is connected using a digital extension telephone, the interface circuit connected to the other party is either analog or digital.
'2 Then, the level variable means of the digital extension telephone is controlled so that a voice signal of an appropriate level is provided to the receiver.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows a private branch exchange system according to an embodiment of the present invention. In this figure, the same components as in FIG. 3 are given the same reference numerals, and their explanations will be omitted. The output signal of the transmitter M of the digital extension telephone 100 of this embodiment is transmitted to the amplifier AM.
Two attenuators ATT1 constituting the level variable means are placed on the path (that is, the sidetone path) through which the signal is routed to the receiver R.
゜ATT3 and switch SW3 are arranged so that the switching control of switch SW3 is performed by the output of decoder DCD3. On the other hand, the private branch exchange 300A is provided with a central control section 301, and this central control section 301 is equipped with a storage means 302 and a control means 303. Central control unit 301
is actually a microcomputer configuration, in which a processor functions as a control means 303 using programs and data in the main memory, and a memory table in the main memory functions as a storage means 302. The storage means 302 stores line circuits LC1 to LCo that are each interface circuit.
Type data indicating whether the station line circuits COCl to C0Cm are either analog or digital is stored. When connecting the digital extension telephone 10G for a call, the control means 303 detects, based on the corresponding type data in the storage means 302, that the interface circuit to which the other party is connected is either an analog circuit or a digital circuit. , a control signal for switching and controlling the switch SW3 of the digital extension telephone 100 in accordance with this type data is sent out via the control signal 1cNT. This control signal is applied to the digital extension telephone 100 via the line circuit LC, decoded by the decoder DCD3, and the switch SW3 is switched.

A/D in FIG. 1 is an analog-to-digital converter, D
/A is a digital-to-analog converter, TX is a digital signal sending circuit, RV is a digital signal receiving circuit, DPS is a display device consisting of an LED, etc., XI is a button switch including a hook switch and numeric keypad, etc., RVD is a control signal receiving circuit, TXD is a control signal output path, D-CO is a digital office line, A-CO is a digital office line, [00P is a loop power supply control circuit, and RNG is a bell signal detection circuit. The attenuator A1-1 guarantees the sidetone level when the interface circuit is for digital use, and the attenuator ATT3 has an attenuation amount that guarantees the sidetone level when the interface circuit is for analog use.

The central control unit 301 of the private branch exchange system configured as described above controls calls of the digital extension telephone 100 according to a program shown in a flowchart as shown in FIG. That is, calls from the digital extension telephone 100 are transmitted to the digital signal sending circuit TX and the control signal receiving circuit RV.
When the central control unit 301 receives the message via o (201),
A dial signal is sent by operating the button switch SW, and the central control unit 301 receives this dial signal through the same route (202).

The central control unit 301 calls the other party based on this dial signal (203), and detects a response from the other party (203).
04). Here, the central control unit 301 stores information from the identification information (boat number, etc.) of the line circuit LC, which is the interface circuit that made the call, and the identification information of the line circuit, which is the interface circuit of the other party that made the call. Search means 302 to detect whether the combination of connections is digital and digital or digital and analog 20
5) If it is a combination of digital and digital, switch SW3! in step 206! ! : Outputs a control signal to turn the contact a side, and if it is a combination of analog and digital, outputs a control signal to turn the switch SW3 to the contact side in step 207. Thereafter, the time division switch TSW is controlled to form a communication path (208).

With this operation, the digital extension telephone 1001
When making a call with the digital extension telephone 1002, voice signals are sent and received through the paths At and A2 in the figure, and the switch SW3 is turned to the contact a side and the attenuator ATT is turned on.
1 is selected and becomes the sidetone level due to digital attenuation. On the other hand, when the digital extension telephone 1001 makes a call with the analog extension telephone A device, audio signals are sent and received through the route 81 and B2 in the figure, and the switch SW
3 is placed on the contact side and has one attenuator. is selected to provide the attenuated sidetone level for analog. In other words, when combining digital and analog, the hybrid circuit H
Even if the side volume is obtained by adding the leakage signal due to YB to the signal via the attenuator ATT3, there is no attenuation so as not to make the sound difficult to hear. The above description has been made regarding the connection between extension lines (7), but it also applies to calls made from the digital telephone 100 via the office line circuits COCl to C0CIn. That is, when the station line circuit COC is digital, one attenuator 1 is selected, and the station line circuit COC
When it is analog like l1i, attenuator ATT3 is selected. Note that switching of the attenuator ATT is also performed on the called side if the digital extension telephone 100 is used.3 In addition, in this embodiment, there are two types of attenuators ATT, and the switching is performed depending on whether the interface circuit is an extension line or a central office line. Therefore, there may be four types of combinations of digital and analog in the above embodiment. In this way, you can control the side volume more precisely. Furthermore, the attenuator ATT may be one that continuously changes the amount of attenuation.

[Effects of the Invention] As explained above, according to the present invention, when a call is connected using a digital extension telephone, the interface circuit to which the other party is connected is either an analog circuit or a digital circuit. Then, the level variable means of the digital extension telephone is controlled so that an appropriate level of audio signal is given to the handset, and an appropriate side volume can be obtained regardless of the type of interface circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the operation of an embodiment of the present invention.
FIG. 3 is a block diagram of a conventional telephone system. 1001, 1002...Digital extension telephone 30
0^...Private branch exchange i 301...Central control unit 302...Storage means 303...To control means -H...Analog extension telephones LC1-l, C,...Line circuits COCl-C0C1m ...Station line circuit TSW...Time division switch ^TTt, ATT
a...Attenuator SW...Switch DCD・
...Decoder agent Patent attorney Book 1) Takashi

Claims (1)

[Claims] In a telephone system in which analog interface circuits and digital interface circuits connected to extension terminals or office lines coexist, each interface circuit is either analog or digital. a storage means storing type data indicating the type of phone; and a digital extension telephone having a level variable means connected to the digital interface circuit and provided in a sidetone path from the sending path to the receiver to change the level. , When making a call connection using this digital extension telephone, it is detected whether the interface circuit to which the other party is connected is analog or digital, based on the corresponding type data in the storage means, and according to the type data. A telephone system comprising: control means for providing a control signal for controlling the level variable means of the digital extension telephone.