JP3241687B2 - Facsimile machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a sidetone adjusting function.
Facsimile machine .

[0002]

2. Description of the Related Art Conventionally, sound spoken from a transmitter leaks from a receiver. This leaked sound is called sidetone. The presence of the sidetone allows the words spoken by the user to be heard by the user, giving the user a sense of security.

[0003] However, if this side tone is not reduced, noise from the surroundings wraps around, making it difficult to hear and causing howling. However, if you reduce the sidetone too much,
When the user's ear is blocked by the handset, the user cannot hear his / her own voice which should be heard due to spatial propagation, and feels discomfort.

[0004] Therefore, when a user talks using a telephone receiver, the side volume is appropriately reduced. When a speakerphone or the like that does not use a receiver is used, the side volume is minimized.

In order to determine the loudness of the sidetone, the current flowing through the line is detected, and if the current is small, the sidetone is increased, and if the current is large, the sidetone is decreased. This is based on the premise that the line voltage of the exchange is constant and the current value corresponds to the distance from the exchange. But,
The line voltage of the switch differs depending on the type of switch.

[0006]

As described above, since the line voltage of the exchange is not constant, there are the following problems.

Conventionally, the sidetone is determined based on the value of the line current. Therefore, when the line current is low, a process of increasing the sidetone is performed on the terminal side. However, when the line voltage of the exchange is low, the sidetone becomes too loud, which sometimes hinders the call. This is because the power supply voltage is actually low, and there is no loss in volume.

The present invention has been made in view of the above, and has as its object to control the loudness of the sidetone to an appropriate level regardless of the distance to the exchange and the line voltage of the exchange.

[0009]

A facsimile apparatus according to the present invention.
The device sends a fixed sound to the line and sends the sound from the line.
Sound detecting means for detecting the sound received,
That communicates with other facsimile machines using
X-millimodem and the loudness of the side tone of the sound transmitted to the line
A variable impedance for determining the magnitude,
And a control unit for controlling the value of the impedance.
When the facsimile modem is not communicating
The sound detecting means sends a constant sound to the line,
The sidetone of the sound transmitted to the line is detected, and the sound detection means detects the sidetone.
Based on the loudness of the issued sidetone, the control unit
By controlling the value of the variable impedance,
Determine the size. Thus, usually a call
Using the function of the facsimile modem not used
Making a facsimile modem function as a sidetone detector
With this, even if you do not have a new device,
Regardless of the distance of the
The size can be controlled to an appropriate size. Yo
Thus, cost can be reduced. In addition, the side tone adjusting device of the present invention includes a variable impedance for determining a loudness of a side tone, a side tone detecting unit that sends a constant sound to a line and detects a side tone of the sent sound, A control unit for controlling the value of the variable impedance based on the loudness of the lateral sound detected by the sound detection unit.

As described above, the side tone detecting section of the side tone adjusting device, which is the subscriber terminal side, detects the side tone and controls the loudness of the side tone based on the detected loudness of the side tone. Therefore, the loudness of the sidetone is controlled in the apparatus regardless of the exchange. Therefore, regardless of the distance to the exchange and the line voltage of the exchange, the loudness of the sidetone can be controlled to an appropriate level.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A side tone adjusting device according to a first aspect of the present invention includes a variable impedance for determining a loudness of a side tone, a constant tone transmitted to a line, and a side of the transmitted tone. It has a side tone detection unit for detecting sound, and a control unit for controlling the value of the variable impedance based on the loudness of the side tone detected by the side tone detection unit.

With this configuration, it is possible to detect the sidetone by the sidetone detector, which is the subscriber terminal side, and control the loudness of the sidetone based on the detected loudness of the sidetone. Therefore, the loudness of the sidetone is controlled regardless of the exchange.

According to a second aspect of the present invention, in the side tone adjusting apparatus according to the first aspect, the control section refers to a table storing variable impedance values for determining the magnitude of the side tone. Control.

With this configuration, the control unit controls the value of the variable impedance with reference to the table,
By comparing the loudness of the side tone according to the value of the controlled variable impedance, the optimum loudness of the side tone can be determined. Therefore, the control of the loudness of the sidetone is speeded up.

[0015] A side tone adjusting device according to a third aspect of the present invention comprises a variable impedance for determining a loudness of a side tone and a variable for a transmission signal for determining an amplification factor of an amplifier for amplifying the transmission signal. A resistance, a variable resistor for a reception signal that determines an amplification factor of an amplifier for amplifying the reception signal, a side sound detection unit that transmits a constant sound to a line and detects a side sound of the transmitted sound, and a side sound detection unit And a control unit that controls the value of the variable impedance based on the loudness of the side tone detected by the control unit, and controls the resistance value of the variable resistance for the transmission signal and the resistance value of the variable resistance for the reception signal. ing.

[0016] With this configuration, the sidetone detecting unit, which is the subscriber terminal, detects the sidetone and controls the loudness of the sidetone based on the detected loudness of the sidetone. The amplification factor of the transmission signal and the amplification factor of the reception signal can be controlled in accordance with the side tone. Therefore, in the apparatus, the transmission sound volume and the reception sound volume are controlled together with the loudness of the side sounds.

According to a fourth aspect of the present invention, in the side tone adjusting device according to the third aspect, the impedance value for determining the loudness of the side tone, the resistance value of the transmission signal variable resistor corresponding to the impedance, and And a resistance value of the reception signal variable resistor corresponding to the impedance. The control unit includes a table storing the impedance value, the transmission signal variable resistance and the reception signal variable resistance with reference to the table. Controls the resistance value of the variable resistor.

With this configuration, the control unit controls the value of the variable impedance with reference to the table,
The optimum loudness level is determined by comparing the loudness level of the side tone corresponding to the value of the controlled variable impedance, and the resistance value of the transmission signal variable resistor corresponding to the side tone and the receiving signal are determined. The resistance value of the variable resistor can also be controlled with reference to the table. Therefore, the control of the loudness of the side tone, the control of the transmission sound volume and the control of the reception sound volume are speeded up.

A facsimile apparatus according to a fifth aspect of the present invention includes a facsimile modem, and the side tone adjusting device according to any one of the first to fourth aspects, wherein the side tone detecting unit comprises: , A facsimile modem.

As described above, by using the function of a facsimile modem which is not normally used for a telephone call and causing the facsimile modem to function as a side tone detection unit, even if no new device is provided, the exchange The loudness of the sidetone can be controlled to an appropriate level regardless of the distance to the switch and the line voltage of the exchange. Therefore, cost can be reduced.

[0021] A sidetone adjusting method according to a sixth aspect of the present invention comprises the steps of: sending a fixed sound to a line by a modem, detecting the sidetone of the sent sound; Controlling the value of the variable impedance for determining the loudness of the sidetone based on the threshold value.

According to the method including such steps, it is possible to control the loudness of the sidetone to an appropriate level regardless of the distance to the exchange and the line voltage of the exchange. The use of a modem also reduces costs.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing a configuration of a facsimile according to one embodiment of the present invention.

The facsimile apparatus 101 communicates with the local exchange 102 via a transformer 103.

The local exchange 102 is provided with a power supply circuit 104. The power supply circuit 104 supplies a voltage generated from the constant voltage power supply V1 to the line L1 via the resistor R1. R2 is a bias voltage generating resistor, which is connected to the line L2. C1 and C2 are DC cut capacitors that cut off DC components. R3 is a terminating resistor for impedance matching with the subscriber terminal.

The value of the impedance of the subscriber line 105 connecting the subscriber exchange 102 and the facsimile machine 101 as the subscriber terminal depends on the combination of the distance from the subscriber exchange 102 to the subscriber terminal and the diameter of the subscriber line 105. It changes greatly.

On the other hand, the facsimile apparatus 101 is provided with a facsimile modem 106 for performing data communication and facsimile communication. The facsimile modem 106 also digitizes the voice signal.

The facsimile unit 107 is connected to the facsimile modem 106, reads an original, transmits the read information via the facsimile modem 106,
The information received via the facsimile modem 106 is recorded on a recording sheet.

The control unit 108 is, for example, a CPU (Central Processing Unit), and executes a target process according to a program.

The RAM unit 109 is a main memory in which the control unit 108 reads and executes programs and data. The ROM unit 110 is a read-only memory that stores a basic program such as a startup program and various tables.

Further, the facsimile apparatus 101 includes operational amplifiers 111 and 112 and a feedback resistor R having a variable resistance value.
4, R5, a variable impedance 113 for attenuation, and resistors R6, R7, R8.

The line L3 is a line for transmitting a voice signal output from the facsimile modem 106 to the operational amplifier 111. The line L4 is a line for transmitting the signal output from the operational amplifier 112 to the facsimile modem 106.

The line L5 is a line for transmitting a transmission signal input from a transmission means of a handset (not shown) of the facsimile apparatus 101 to the operational amplifier 111. The line L6 is a line for outputting a signal output from the operational amplifier 112 as a reception signal via a reception unit of a handset (not shown) of the facsimile apparatus 101. As described above, the facsimile apparatus 101 can talk using the handset.

By the way, the facsimile modem 106
It is also used as a side tone detection unit that sends out a fixed sound to the line and detects a side tone of the sent out sound. The feature of the present embodiment is that the facsimile modem 106 functions as the side tone detection unit when the facsimile modem 106 does not perform its original function.

The operation when the facsimile modem 106 also uses the operation of the side tone detection unit, which is a feature of the above embodiment, will be described in detail with reference to a flowchart.

FIG. 2 is a flowchart for explaining the operation of the side tone adjusting device of the above embodiment.

For example, when the facsimile apparatus 101 is connected to a line and a start-up operation is performed, the facsimile modem 106 transmits an audio signal having a constant volume from the facsimile modem 106 to the line L3 (ST).
1).

This audio signal is input to the non-inverting terminal of the operational amplifier 111. This audio signal is supplied to the operational amplifier 111
Amplified by The voltage amplification factor of the operational amplifier 111 is
It can be set by changing the resistance value of the feedback resistor R4.

The audio signal amplified and output by the operational amplifier 111 is split into two parts, one is input to the inverting terminal of the operational amplifier 112 via the resistor R6, and the other is
The signal is attenuated via the resistor R7 according to the impedance value of the variable impedance 113, and
Is input to the non-inverting terminal.

The operational amplifier 112 amplifies a potential difference between the potential applied to the non-inverting terminal and the potential applied to the inverting terminal. The voltage amplification factor of the operational amplifier 111 can be set by changing the resistance value of the feedback resistor R5.

The signal output from the operational amplifier 112 is input to the facsimile modem 106 via the line L4. Then, the facsimile modem 106 detects the input signal as a side tone of the sound transmitted by itself (S
T2).

The control unit 108 controls the facsimile modem 10
6 determines the loudness of the detected side tone, and if the loudness is not appropriate, controls to change the impedance value of the variable impedance 113 (ST4), and sends the same to the facsimile modem 106 again to the line L3. Control to transmit a sound of a fixed volume (ST1).

The control unit 108 controls the facsimile modem 10
This control is repeated until the loudness of the sidetone detected in 6 becomes appropriate.

Here, based on the characteristic of the curve indicating the relationship between the side tone level and the impedance value as shown in FIG. 3, the control unit 108 changes the side tone as the impedance value of the variable impedance 113 is gradually changed. From the state where the level has been changed to decrease, the sidetone level at which the sidetone level has started to change to increase is determined to be minimal,
This impedance value may be adopted as an appropriate impedance value.

Alternatively, a table storing impedance values as shown in FIG. 4 is provided in the ROM section 110, and the control means 108 changes the impedance value of the variable impedance 113 with reference to this table. The side tone based on the changed impedance value is detected by the facsimile modem 106. Then, the control unit 106 may determine the optimal impedance value by comparing the detected loudness of the sidetone.

When the control unit 108 determines in ST3 that the loudness of the sidetone is appropriate, the control unit 108 responds to the impedance value of the variable impedance 113 by
The resistance of the feedback resistor R4 for determining the amplification factor of the operational amplifier 111 for amplifying the transmission signal and the feedback resistor R5 for determining the amplification factor of the operational amplifier 112 for amplifying the reception signal are determined (ST6).

Further, these resistance values are stored in a table as shown in FIG. 4, and the control unit 108 reads out the resistance values corresponding to the impedance values of the variable impedance 113 from this table, and Set the resistance value of each.

The method for determining these resistance values is as follows.
A method other than the method of referring to the table, for example, a method of linearly increasing and decreasing the resistance value may be used.

Hereinafter, how the transmission signal and the reception signal are communicated will be described.

The transmission signal input from the line L5 is input to the non-inverting terminal of the operational amplifier 111 and amplified. The voltage amplification factor of the operational amplifier 111 can be freely set by changing the resistance value of the feedback resistor R4. The amplified transmission signal is sent to the local exchange 102 via the transformer 103.

A reception signal transmitted from the subscriber exchange 102 is input to the facsimile apparatus 101 via the transformer 103. The input signal is input to the inverting terminal of the operational amplifier 112 and amplified. The voltage amplification factor of the operational amplifier 112 is freely set by the resistance value of the feedback resistor R5. This amplified signal is output via the line L6.

As described above, according to the above-described embodiment, the facsimile modem 10 provided in the apparatus on the subscriber terminal side
6, the facsimile modem 106 detects the sound emitted to the line again, and detects the side tone itself. Therefore, the distance from the subscriber exchange 102, the line voltage or the diameter of the subscriber line 105, etc. Irrespective of the size of the sidetone can be determined.

In the above embodiment, the facsimile modem 106, which is normally unrelated to a call, sends out a fixed volume to the line, and is also used as a side tone detection unit for detecting a side tone for the sent out sound. ing. Therefore, cost and space can be reduced.

Further, in the above embodiment, the volume of the transmission signal and the volume of the reception signal can be set to an appropriate volume corresponding to the side tone. Therefore, the transmission volume and the reception volume do not become too large or too small. Therefore, the user can make a comfortable call.

In the above embodiment, a facsimile apparatus provided with a facsimile modem has been described as an example.
The communication device may include a modem. Further, any device other than the modem may be used as long as it transmits a fixed volume to the line and detects the return sound.

[0057]

As described above, according to the present invention,
Since the sidetone is detected in the equipment at the subscriber terminal and the sidetone that was appropriate for the line can be determined based on the detection result, the loudness of the sidetone is appropriate regardless of the distance to the exchange and the line voltage of the exchange. The size can be controlled.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a facsimile according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the side tone adjusting device of the embodiment.

FIG. 3 is a diagram showing a characteristic curve showing a relationship between a sidetone level and an impedance value.

FIG. 4 is a table storing impedance values for determining the loudness of side sounds and resistance values for determining the amplification factors of amplifiers for amplifying a transmission signal and a reception signal;

[Explanation of symbols]

 Reference Signs List 101 facsimile apparatus 102 subscriber exchange 104 power supply circuit 105 subscriber line 106 facsimile modem (sidetone detection section) 107 facsimile section 108 control section 109 RAM section 110 ROM section 111, 112 operational amplifier 113 variable impedance R4, R5 feedback resistance

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04M 1/00 H04M 1/24 H04M 1/58-1/62 H04M 1/66-1/78 H04M 11 / 00-11/10 H04N 1/00

Claims (3)

(57) [Claims] 1. A method for transmitting a fixed sound to a line,
Sound detection means for detecting sound transmitted from the line,
Communication with other facsimile machines using the sound detection means
Facsimile modem to perform and the sound sent to the line
A variable impedance for determining the loudness of the sidetone,
A control unit for controlling a value of the variable impedance.
The facsimile model when the communication is not performed.
The sound detection means of the system sends a constant sound to the line,
Detecting a side tone of the sound transmitted to the recording line, and
Based on the detected loudness of the sidetone, the control unit
By controlling the value of the variable impedance,
A facsimile machine characterized by determining the size. 2. A method for adjusting sidetone when a line is connected.
The facsimile apparatus according to claim 1, wherein 3. An amplification factor of an amplifier for amplifying a transmission signal.
A variable resistor for the transmission signal to be set, and an amplifier for amplifying the reception signal.
A receiving signal variable resistor for determining the amplification factor of the
Value of the impedance,
Resistance value of a variable resistor for a transmission signal,
The resistance value of the variable resistor for the reception signal corresponding to the
And a table for storing the impedance value.
Controlling the resistance value of each resistor corresponding to
3. The facsimile apparatus according to claim 1, wherein