JPS61281753A - Information transmission system - Google Patents

Abstract

PURPOSE:To simplify a circuit constitution and control operation by inserting a signal conversion means among a data information system, a voice information system and a telephone line so as to select switchingly the transmission/reception of data information and voice information. CONSTITUTION:A 2/4-wire conversion circuit 115 is inserted among the data information system comprised of a MODEM 315 and a CPU 313, the voice information system comprised of an amplifier circuit 121, a speaker 117 and a microphone 119 and a telephone line. Then a 4-signal line circuit of the transmission/reception mode of the data and voice information is converted properly into a 2-signal circuit of a telephone line. Thus, the circuit constitution and control operation are simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical aspects of the invention) The present invention relates to an information transmission system, and particularly to an information transmission system configured to be connected to an IF telephone line and transmit audio and data image information.

(Technical background of the invention and its problems) An example of a conventionally known information transmission system is shown in FIG. 3. In the figure, by the rlf communication line,
Audio information and data information are conveyed. This voice information is exchanged between telephones 311 and other telephones, and calls can be made between the telephones.

Data information, on the other hand, is used by an information processing device forming, for example, a hand belt computer or the like. Here, a central processing unit (CPU) 313 forming the information processing device exchanges data information with other information processing devices, terminals, etc. connected to the telephone line. Such data information is sent and received via modem 315.

In other words, as described above, two information paths for transmitting voice information and data information are subordinate to the telephone line. A network control unit (NCU) 317 is provided in order to accurately organize information paths without causing interference. This N
As the CU 317, for example, there is a known MA type NCU.

However, for example, switching the data information path to the modem 315 and the voice information path to the telephone 311 in the MA type NCU 317 requires a complicated circuit configuration, and the control of its operation is also complicated. Ta.

(Object of the Invention) An object of the present invention is to provide an information transmission system with a simple circuit configuration and control operation.

(Summary of the Invention) The present invention provides a signal conversion means between a data information system, an audio information system, and a telephone line, and uses this signal conversion means to switch and select transmission and reception of data information and audio information. It is characterized by having a structure that allows

(Embodiments of the Invention) Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Note that since the same reference numerals as in FIG. 3 indicate the same parts, detailed explanation thereof will be omitted.

In Figure 1, the NCU connected directly to the telephone line
I11 does not need to be as complex as the MA type NCU explained in FIG. It is only necessary that the impedances of the telephone line and the primary side P of the transformer 113 be matched in phase, and that information false signals can be exchanged.

In the case of this embodiment, if the telephone line side is the primary side, the secondary sides of the voice information path and data information path are separated and insulated by isolating means (air transformer, optical photocoupler, etc.). has been done. In addition, here, we will simply refer to the transformer 1.
The description will be made assuming that it is insulated by 13. Therefore, the primary winding P of the transformer 113 is connected to the NCU III, and the secondary winding S is connected to the two-wire four-wire conversion circuit 115, respectively.

In the data information path, which is one system on the secondary side of this embodiment, the CPU 313 forming the information processing device is connected to the modem 3.
15 to a 2-wire/4-wire conversion circuit 115. In addition, as an audio information path for other systems, speaker 1
17 and a microphone 119 are bidirectional amplifier circuits 12
1 to a 2-wire/4-wire conversion circuit 115.

FIG. 2 shows the two-line and four-line conversion circuit 115 and amplifier circuit 121 shown in FIG. 1 in more detail.

In FIG. 2, one end of the secondary winding S of the transformer 113 is connected to the output terminal of the first operational amplifier 211 through a resistor 214, and to the inverting input terminal of the second operational amplifier 215 through the resistor 213. It is connected. Further, the other end of this winding S is connected to a ground terminal M which is a ground potential on the secondary side, and this ground potential is isolated from the telephone line V on the primary side.

The non-inverting input terminals of both operational amplifiers 211 and 215 are commonly grounded, and a resistor 217 or 21 is connected between the inverting input terminal and the output terminal of each of the operational amplifiers 211 and 215.
9 is connected.

The inverting input terminal of the first operational amplifier 211 is connected to the resistor 221
and another resistor to the microphone 119 via the switch 222? 23 to a modem 315, respectively.

The output terminal of the second operational amplifier 215 is connected to the modem 315 via a resistor 225 and to the audio amplifier 229 via an on/off switch 227.

A DC voltage Vcc is supplied to the operating power supply terminal TmaC of the amplifier 229 via an on/off switch 231. In addition, the amplification output terminal of the amplifier 229 is connected to the speaker 1.
17 are connected.

The opening/closing switches 227, 222 and 2 and 31 are connected so that opening/closing control is performed by a switch control signal Scw output from the CPU 313 (see FIG. 2). Note that these switches 227, 222, and 231 are formed of electromagnetically operated mechanical switches (relays), semiconductor switches, or the like.

Next, the operation of the above-described configuration will be explained.

■ Interchange between the telephone line and the information processing device In this case, there are two modes: the information processing device receives data information carried over the telephone line and performs processing based on it, and There is a mode in which data, etc., is transported and transmitted over a telephone line. Therefore, we will discuss each mode separately.

(i) Mode for sending from the information processing device In this mode, data information consisting of digital signals is supplied from the CPU 313 forming the information processing device to the modem 315, where it is digital-to-analog (D/A) converted. The analog signal 5Asp after the D/A conversion is supplied to the inverting input terminal of the first operational amplifier 211 via the resistor 223.

Now, the switch 222 is controlled to open, and the microphone 11
If the audio signal SSS from the first operational amplifier 211 is not supplied, the amplified signal is converted from the output side of the first operational amplifier 211 according to the amplification degree determined by the ratio of the resistance values of the resistor 223 and the resistor 217. It is supplied to both ends of the secondary winding S of the device 113. A signal corresponding to the winding ratio of the primary winding P of the transformer 113 is induced and supplied to the NCU III, and data information is output to the telephone line.

In this way, the data information sent from the CPU 313 is carried on the telephone line and conveyed to other information processing devices.

(ii) Mode for receiving data from a telephone line In this mode, data information transmitted via a telephone line is taken in to the CPU 313 forming the information processing device, that is, the NC
Data information consisting of an analog signal output from UIII is first guided to the secondary side of transformer 113. The signal generated at both ends of the secondary winding S is amplified according to the amplification degree determined by the ratio of the resistance values of both resistors 213 and 219. The amplified signal e generated at the output terminal of the second operational amplifier 215
ozlK is provided through resistor 225 to modem 315 as signal SARD.

Since the signal SAND received in this manner is an analog signal, it is analog-to-digital (A/D) converted by the modem 315. The digital signal after A/D conversion is supplied to the CPU 313.

In this way, the data information on the telephone line is
Given to CPO213.

By the way, since the CPU 313 was in a mode in which data information was taken in, the CPU 313 generated the switch control signal Scw to maintain both the opening/closing switches 227 and 231 in the open state. Therefore, the second
The output signal eol/J of the operational amplifier 215 is sent to the amplifier 229.
At the same time, since the operating DC voltage Vcc is not supplied to this amplifier 289, it is not energized, and the speaker 117 does not even produce noise.

(2) Transmission and reception of voice information In this case, there is a reception mode in which voice (call) information carried by a telephone line is produced by a speaker, and a transmission mode in which voice is transmitted from a macrophone.

Therefore, each mode will be described below.

(i) Speech mode In this mode, the switch 222 is closed by the switch control signal Scw, and the microphone 119 generates the speaker's speech signal Sss, which is transmitted to the first operational amplifier 211.
supplied to The subsequent operation is the same as described in (j) transmission mode of "I. Mutual communication between telephone line and information processing device".

As a result, the voice information uttered by the caller is placed on the telephone line and transmitted to another telephone device (telephone).

(ii) Receiving mode In this mode, first, the switch control signal Scw output from the CPU 313 controls the opening/closing switch 2.
Both 27 and 231 are closed. Thereby,
While energizing the amplifier 229, the second operational amplifier 215
The output signal of is introduced.

The voice information carried on the telephone line is output to the transformer 113 via the NCU 111, and then to the second operational amplifier 215.
is amplified by The audio output signal eOzt5s of the second operational amplifier 215 is expressed as eozt5s = −-e
is expressed as Furthermore, R21? , Is R213 a resistor?
The resistance value is 19.213, and eRS is the signal voltage of audio information (analog signal) induced to the secondary side of the transformer 113.

The audio signal e 0z15 S expressed by the above equation is amplified by the audio amplifier 229, and the amplified signal SnuR is produced by the speaker 17 as a received audio signal.

As a result, the speaker 17 provides voice information from another transmitting device (telephone) carried by the telephone line to the receiver.

i; 2-wire 4-wire conversion circuit 115 and amplifier circuit 121 described above
With the configuration and operation of , the four-signal line circuit for the data information transmission and reception mode and the audio information transmission and reception mode is appropriately converted into a two-signal circuit for the telephone line.

(Effects of the Invention) According to the present invention, the circuit configuration and control operation are simple;
It is possible to realize an information transmission system in which data information and voice information can be easily sent and received between telephone lines.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an information transmission system according to an embodiment of the present invention, FIG. 2 is a detailed program diagram showing the main parts of FIG. FIG. 2 is a block diagram showing the configuration of a transmission method. 111------m-Network control unit (NCU), 113-----One transformer. 115------ 2-wire 4-wire conversion circuit, 121---
---1 audio amplification circuit, 211.2 L 5--1 operational amplifier, 311--
1--Telephone, 313--1----Central processing unit (CPU), 315
--1--Modem, 3 L 7--MA network control unit. Figure 2 cw Figure 3

Claims (1)

[Scope of Claims] 1. An information transmission system that controls the transmission of voice information and processed data information of a telephone and an information processing device via a network unit connected to a telephone line, which includes the information processing device and its necessary information. A signal converting means is interposed between the data information system of the signal format converting device, the audio information system of the transmitting/receiving means, and the network section, and the signal converting means converts the telephone line and the data information system. 1. An information transmission system characterized in that the transmission and reception of data information between each other and the transmission and reception of voice information between the telephone line and the voice information system are switched and selected. 2. The information transmission system according to claim 1, wherein the signal format conversion device is configured to convert data information signals in both directions: digital-to-analog and analog-to-digital. . 3. The information transmission system according to claim 1, wherein the transmitting/receiving means includes at least one speaker and a microphone.