JPS61120554A - Telephone set with loudspeaker function - Google Patents

Abstract

PURPOSE:To prevent a signal tone speed from an exchange from being too excessive into a trouble tone by providing a means detecting talking state depending on a talking enable signal and a cut-off signal and outputting a talking signal and a sound amplification factor change means changing the amplification factor of the sound signal to a speaker in response to the output of the talking signal. CONSTITUTION:A signal is inserted one by one bit to the slot of the signal channel D of a transmission frame, the transmission frame is composed sequentially and transmitted to an exchange on a line T via a pulse transformer 22. When the exchange receives the call signal, a reply signal is given to the signal channel D of the trransmission frame and the data of a dial tone DT in sudible tone is given to a sound channel B and the frame is transmitted to a telephone set. The telephone set receives the transmission frame string on a line R through a pulse transformer 21, converts the reply signal into a parallel digital signal, outputted to a control signal circuit 28, the dial tone data DT is converted into an analog signal and given to a variable gain amplifier 16 and the dial tone DT is generated from a speaker 13. Since the amplifier 16 has a low amplification factor, no trouble is given to the surrounding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telephone with a loudspeaker function equipped with a speaker that is switched and connected to a receiver.

[Prior Art] FIG. 5 is a block diagram showing a telephone with amplification function disclosed in, for example, Japanese Patent Application Laid-Open No. 57-72452. In the figure, (1) is a handset, (2) is a speaker switch, ( 3)
is a lamp, (4) is a relay, (4a) is its make contact, (4b) is its switching contact, (5) is a trigger flip prop, (6) is a telephone circuit, (7) is an audio amplifier, ( 8) is a speaker, (9a) and (9b) are hook switches, and (10) is a telephone line connection terminal.

In the above configuration, to put the speaker in listening mode, press the speaker switch (2), then flip the 10 knobs (5
) output Q goes low, lamp (3) lights up and relay (4) operates. Then, when the relay contact (4a) closes, the telephone circuit (6) is connected to the line via the terminal (10), and the relay switching contact (4b) is also switched to the amplifier (7) side, and the speaker is in listening mode. . Therefore, the exchange detects that the DC loop is on by opening the contact (4a) and sends out a 9 dial tone (dial tone, DT). The operator confirms the dial tone from the speaker (8) and then dials.At the end of six dials, the exchange sends out a ring tone (ringback tone, RBT) indicating that the other party is calling. This ringing tone can also be confirmed through the speaker (8), and when the other party answers, the ringing tone is stopped and the speaker becomes a receiving state.

If the other party is busy, the exchange will emit a busy tone (busy tone).
BT), which is also emitted from the speaker (8).

[Problems to be Solved by the Invention] In the conventional telephone set described above, signal tones such as dial tones and ring tones provided by the exchange are always sent as signals at a constant level. There was a problem in that the noise produced caused a nuisance to people around them.

This problem is solved by the recently developed digital telephone [Research and Practical Application Report published by Dentsu Corporation, Vol. 33, No. 8 (1984).
The same was true for [see pp. 33-45].

- The second invention was made in order to eliminate the above-mentioned problems, and provides a telephone with an amplification function particularly suitable for digital telephones, which prevents the signal tone serviced from the exchange from becoming excessive and becoming a nuisance sound. The purpose is to

[Means for Solving the Problems] The telephone with a public address function according to the present invention is capable of communicating with the other party using a call-ready signal, disconnection signal, etc. in a control signal transmitted and received between the exchange and the exchange on a channel different from the voice signal. means for detecting that a line is connected and a call is in progress and outputting a call-in-progress signal; and audio amplification changing means for changing the amplification of the audio signal to the speaker in accordance with the output of the call-in-progress signal. It is something.

[Function] In this invention, in addition to voice signals, a call is detected from the call enable signal, disconnection signal, etc. in the control signal transmitted and received with the exchange, and a call busy signal is output. The amplification of the audio signal to the speaker is changed depending on the signal, and the amplification of the speaker is kept low until the signal is switched to the speaker, dialed, and the other party is connected and a busy signal is output.
The amplification level of the speaker is increased only while the call signal is being output until the line is disconnected. Therefore, until the line is connected and the speaker is in the receiving state, signal tones such as dial tones and ring tones provided by the exchange are not amplified and do not become excessively loud.

Embodiment] FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to a digital telephone used as a 4-wire private telephone.

In the figure, (11) is the receiver, (12) is the transmitter, and (1
3) is the speaker, (14) is the receiver amplifier, (15)
is an amplifier for the transmitter, (16) is a variable amplifier for the speaker,
(17a), (17b), and (17c) are the switch contacts for the public address function that open and close in conjunction with each other, (18) is the dial switch, and (19) is the connection to the reception transmission line (hereinafter referred to as R line) between the switch and the exchange. terminal, (20) is the transmission transmission line (
(hereinafter referred to as the T line), (21) and (22) are pulse transformers, and (23) is a hook switch that connects the R line to the T line.
Opens and closes the DC loop formed by the line and the DC power supply on the exchange side. (24) is a diode that conducts only when receiving a call and closes the DC loop, (25) is a power supply circuit that closes the DC loop to receive power from the exchange and supplies power to the internal circuit, and (26) is a digital In the telephone circuit, there is a line circuit section that receives transmission frames from the R line and transmits them to the T line, a clock generation section that generates a clock from a sequence of received transmission frames, and a section that decomposes the received transmission frames into signal channels and voice channels. , also a signal.

Frame disassembly/assembly unit that assembles transmission frames from audio channels; serial/parallel converter unit that converts serial signal channel data into parallel and parallel data into serial signal channel data; converts analog audio signals into digital and converts digital audio signals into analog It consists of converting copuic etc. (27) is a calling circuit that generates a ringing sound, howling sound, etc. on the telephone side, and (28) is a control signal processing circuit that processes a control signal separated from a voice signal, which is composed of a 1-chip microcomputer. Dial switch (
Signal from 18), switch contact for public address function (17c)
inputs the opening/closing status of the digital telephone circuit (26), sends and receives parallel control signal data to the digital telephone circuit (26), outputs audible sound generation data to the calling circuit (27), and determines whether the call is in progress from the call ready signal or disconnection signal in the control signal. is equipped with a means for detecting a call signal and outputting a busy signal, and transmits the busy signal to a speaker variable amplifier (1).
6).

Furthermore, I1. I2 is an input terminal, 01 and 02 are output terminals, and Ilo is a parallel data input/output terminal.

Figure 2 is a diagram showing the configuration of transmission frames sent and received between the exchange and the R line and T line.
is composed of 1 bit, signal channel D for control signal data is 1 bit, and audio channels BO to B7 for time-division encoded audio data are 8 bits, for a total of 10 bits, and a parity bit is not added to this. transmitted. A digital telephone circuit (26) separates the transmission frame string sequentially transmitted from the exchange into a coded voice data string for the voice channel and serial control signal data for the signal channel, decodes the voice data string, and converts it into an analog signal. The serial control signal data is changed into a parallel signal and outputted to the control signal processing circuit (28). Also, for transmission to the exchange, the transmitter amplifier (15)
The analog signal from the digital telephone circuit (26) is input into the digital telephone circuit (26), where it is time-division encoded and placed on the 8-bit audio channels (BO to B7).
) is converted into serial data, placed on a 1-bit signal channel D, a synchronizing signal F is added to it to form a transmission frame, parity pits are added, and the data is transmitted to the exchange via the T line.

Next, an example of the on-hook dialing operation of the telephone of this embodiment shown in FIG. 1 will be explained with reference to FIGS. 2, 3, and 4. FIG. 3 is a signal sequence diagram with the exchanger, and FIG. 4 is a flowchart showing an example of the operation of the control signal processing circuit (2B).

First, when the loudspeaker function switch is turned on, the contact (17a) is switched to the variable amplifier (16) side, and the contact (17b) is switched to the variable amplifier (16) side.

(17c) is closed. By opening the parallel contact (17b) of the hook switch (23), the R wire, pulse transformer (21), contact (17b), power circuit (25), pulse transformer (22), and T wire are connected from the DC power supply positive terminal of the exchanger. A DC loop is formed to the negative terminal of the DC power supply of the exchange (loop on in Figure 3), the power supply circuit (25) starts operating, and power is supplied to each part of the telephone. Next, the control signal processing circuit (28) starts operating by supplying power, detects the closing of the contact (17c) [Step (29) in Figure 4], and sends a low (L) busy signal to the 02 terminal and terminal. Output C step (30)].

Then, a digital call volume is generated and output in parallel from the I10 terminal to the digital telephone circuit (26) [Step (31)
)]. The digital telephone circuit (26) converts this call signal into a serial signal, inserts one bit at a time into the lock of signal channel D of the transmission frame shown in Fig. 2, and sequentially assembles the transmission frame, and then connects the pulse transformer (22). via the T line and transmitted to the exchange.

Since control signals such as calling signals are usually expressed in 8 bits, transmission of one signal is completed by transmitting the transmission frame eight times. At this time, since the 02 terminal of the processing circuit (28) is L, the amplification degree of the speaker variable amplifier (16) is set low. When the exchange receives this calling signal, it sends a response signal to the signal channel D of the transmission frame and data of an audible dial tone DT to the voice channel B, as shown in FIG. 3, to the telephone. The telephone receives this transmission frame train on Rfi via the pulse transformer (21), converts the response signal into a parallel digital signal in the digital telephone circuit (26), and outputs it to the control signal processing circuit (28). The data of the dial tone DT is converted into analog and outputted to the variable amplifier (16) through the switch contact (17a), and the dial tone DT is generated from the speaker (13).

However, since the degree of amplification of the variable amplifier (16) is low, it will not cause trouble to the surroundings. When the processing circuit (28) inputs the response signal [step (32)], it takes in the dial signal from the dial switch (18), creates a coded dial character, and outputs it to the digital telephone circuit (26). [Step (33)]. The digital telephone circuit (26) carries this dial character on signal channel D of the transmission frame and sends it to the exchange. When the exchange receives the first dial character, it stops transmitting data for one dial tone DT. When the transmission of the dial character is completed, the exchange selects the other party's telephone and sends a ringing signal to the other party, and also sends a ring tone R to the calling party's telephone.
The BT data is transmitted on audio channel B of the transmission frame. This ringing tone RBT is received by the digital telephone circuit (26) and a ringing tone is generated by the speaker (13), but since the degree of amplification of the speaker variable amplifier (16) is low, the ringing tone is suppressed to a low sound.

When the other party's phone answers and an incoming call signal is sent.

The exchange transmits a call-ready signal to the calling telephone on the signal channel of the transmission frame, and stops transmitting the ringing tone data. Telephone control signal processing circuit (28)
detects the call enable signal of this signal channel data [step (34)] and sets the output terminal 02 to high (H) [step (22)]. This high level of the 02 terminal increases the amplification degree of the variable amplifier (16), and sets the amplification level of the speaker to an appropriate volume for voice reception. Also, when one call ends and the other party hangs up, a disconnection signal is sent from the exchange on the signal channel, and the control signal processing circuit (
28) detects this disconnection signal [step (22)]
Then, the terminal -02 is set to low level [step (37)], and the amplification degree of the speaker variable amplifier is lowered again.At the end of one call, the loudspeaker function switch is turned off, and the contact (17a) (
17b) Set (17c) to the state shown [Step (38
)], it enters a standby state.

When there is a call from the outside, the exchange applies a DC voltage of opposite polarity between the R and T wires, completing a DC loop through the diode (24) and activating the power supply circuit (25), which connects the telephone. Power is supplied to each part, and at the same time, a calling signal is sent from the exchange as a control signal, which is sent to the processing circuit (28
) and outputs audible sound generation data from the 01 terminal to the calling circuit (27), and the ringer sound generated by the calling circuit (27) is sounded by the speaker (13). Then, the operator completes the line by raising the handset consisting of the transmitter (11) and receiver (12) and closing the hook switch (23) or turning on the loudspeaker function switch (17). The signal is exited and the call-ready signal is received, and the processing circuit (28) detects the call-ready signal and sends 02
A high call signal is output to the terminal to increase the amplification degree of the variable amplifier (16), and a call state is established.

In the above embodiment, the amplification degree of the speaker variable amplifier (16) is always kept low, and the amplification degree is increased from the input of the 1-call-ready signal to the input of the disconnection signal to output a busy signal. , the amplification degree of the variable amplifier (16) may be raised at all times, and a signal may be output that reduces the amplification degree from generation of the call signal to input of the call ready signal.

Furthermore, although the above embodiments show examples in which the present invention is applied to digital telephones, the present invention can also be applied to other types of private telephones in which control signals and voice signals are transmitted and received through separate channels. It is.

[Effects of the Invention] As described above, the present invention changes the degree of amplification of the audio signal to the speaker according to the output of the busy signal.
It is possible to lower the amplification level of the signal tone serviced from the exchange other than during a call to the minimum necessary audible sound level, which has the effect of reducing the nuisance to those around you6.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure shows a configuration diagram of a transmission frame transmitted and received with the exchange in this embodiment, Figure 3 shows a signal sequence diagram between the exchange and Figure 4 shows an example of the operation of the control signal processing circuit in this embodiment. The flowchart and FIG. 5 are block diagrams showing a conventional telephone with amplification function. In the figure, (11) is the receiver, (12) is the transmitter, (
13) is a speaker, (14) is a variable amplifier which is an audio amplification degree changing means, (17a) (17b) (17c)
is a switch contact for the public address function, (26) is a digital telephone circuit, (28) is a control signal processing circuit, and o2 is this circuit (2).
This is the busy signal output terminal of the busy signal output means in 8). The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Sending and receiving audio signals such as call sounds, dial tone, ring tone, busy tone, etc., and control signals such as calling signal, incoming call signal, call clear signal, disconnection signal, etc. to and from the exchange. In a telephone with a loudspeaker function that is switchable and connected to a receiver, means for detecting a call in progress based on the call enable signal, disconnection signal, etc. and outputting a call in progress signal; 1. A telephone with a loudspeaker function, characterized in that it is provided with an audio amplification degree changing means for changing the amplification degree of an audio signal. (2) The telephone set has a control signal processing circuit that transmits and receives transmission frames having voice channel data and signal channel data obtained by digitizing the voice signal and control signal, respectively, to and from the exchange, and processes the control signal. 2. A telephone with amplification function according to claim 1, which is a digital telephone provided with said busy signal output means.