JPH0730685A - Cordless modem - Google Patents

Abstract

PURPOSE:To easily install and move the modem and to unnecessitate wiring. CONSTITUTION:A modem 1 is integrally connected to an RS 232C interface 17 of a personal computer 9. The size of the modem 1 is made smaller than LSIs so as to save space. The I/O data of the personal computer 9 is modulated into a voice signal by a modem circuit 3 of the modem 1 and sent and received by a transmitter/receiver 7 through an antenna 8. A line interface part 2 performs the transmission and reception of radiowave with the modem 1 by a transmitter/receiver 11 and an antenna 10. Thus, the personal computer 9 connecting the modem 1 and a telephone line 13 are connected without cord and the installation and movement of the personal computer 9 is made easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless modem for transmitting data such as characters through a telephone line.

[0002]

2. Description of the Related Art Conventionally, the following is an example of a modem for connecting a personal computer and a telephone line (for example, PCLINK296EX instruction manual, March 10, 1992 (Rev.1.2) P7). ). FIG. 2 is an explanatory diagram of a connection example of a conventional modem. The modem 21 is connected between the personal computer 22 and the telephone line 23. That is, the modem 21 has a terminal connector 24
And a line connector 25. To the terminal connector 24, one connector 27 of the terminal modem connection cable 26 is connected. The other connector 28 of this terminal-modem connection cable 26 is connected to an RS232C connector 29 provided in the personal computer 22. The line connector 25 is connected to one connector 31 of the modem line connection cable 30. The other connector 32 of the modem line connection cable 30 is
It is connected to the modular jack 33 of the telephone line 23.

FIG. 3 shows the internal structure of the modem 21 shown in FIG. As shown in FIG. 3, the modem 21 includes a modulation / demodulation circuit 3
4, a control circuit 35, a terminal interface 36, a line interface 37 and the like. The modulation / demodulation circuit 34 is composed of a circuit including a diode, a transistor, etc.
According to the instruction of 5, modulation and demodulation are performed. That is, in the modulation, a digital signal input from the personal computer 22 shown in FIG. 2 via the terminal / modem connection cable 26 and the terminal interface 36 is placed on a voice signal, and then transmitted via the line interface 37 and the modem line connection cable 30. Output to the telephone line 23 shown in FIG.
In demodulation, the telephone line 23, the modem line connection cable 30 and the line interface 3 shown in FIG.
A digital signal is taken out from the audio signal input via 7 and output to the personal computer 22 shown in FIG. 2 via the terminal interface 36 and the terminal modem connection cable 26.

FIG. 4 shows a physical connection diagram of a conventional modem. FIG. 4 corresponds to FIG. 2, and the same components are designated by the same reference numerals. The description of the connection relation of each unit is omitted because it overlaps with FIG.

[0005]

However, the above-mentioned conventional technique has the following problems. As shown in FIG. 4, it is necessary to secure a space for installing the modem 21. That is, a place for installing the modem 21 is required in addition to a place for installing the personal computer 22, and there is a problem that the modem 21 is an obstacle in a small room or the like. Since the terminal-modem connection cable 26 and the modem-line connection cable 30 are laid, there is a problem that they are an obstacle in an office or the like.

When the installation place of the personal computer 22 and the installation place of the modular jack 33 are distant from each other, the modem line connection cable 30 must be long. Therefore, there is a problem in that this becomes a hindrance in an office or the like. When changing the installation location of the personal computer 22 and the modem 21, there is a problem that the wiring work of the terminal modem connection cable 26 and the modem line connection cable 30 must be redone. The present invention has been made in view of the above points, and an object of the present invention is to provide a cordless modem in which the connection cable does not interfere and the installation location of the device can be easily changed.

[0007]

A cordless modem according to the present invention includes a modem main body section including a modulation / demodulation circuit for converting digital data into a voice signal and a transmission / reception circuit for wirelessly transmitting the voice signal by a wireless transmission medium. A line interface section including a transmission / reception circuit for wirelessly transmitting the voice signal to / from the modem main body by the radio transmission medium and transmitting / receiving the voice signal to / from a telephone line. Is.

[0008]

In the cordless modem of the present invention, the modem body is integrally connected to the RS232C interface of the personal computer. The modem body is an LSI
It is downsized due to factors such as space saving. The input / output data of the personal computer is modulated into a voice signal by the modem circuit of the modem body, and then transmitted / received via the antenna by the transmission / reception circuit. The line interface section transmits and receives radio waves to and from the modem main body section 1 by means of a transmitting / receiving circuit and an antenna. As a result, the connection between the modem and the telephone line becomes cordless, and the installation and movement of the personal computer becomes very easy.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a cordless modem of the present invention. As shown in FIG. 1, the cordless modem of the present invention comprises a modem body 1 and a line interface 2. The modem body 1 includes a modulation / demodulation circuit 3, a control circuit 4, a terminal interface 5, a wireless interface 6, a transmission / reception circuit 7, an antenna 8 and the like. The modem body 1 is connected to the RS232C interface 17 of the personal computer 9 by the connector 16. As a result, the modem body 1 is integrally connected to the personal computer 9 without the connection cable.

The modulation / demodulation circuit 3 is composed of a circuit including a diode, a transistor, etc., and performs modulation and demodulation according to an instruction from the control circuit 4. That is, in the modulation, the digital signal input from the personal computer 9 through the terminal interface 5 is placed on the audio signal and output to the transmission / reception circuit 7 through the wireless interface 6. The transmission / reception circuit 7 has a well-known configuration, and includes a modulation / demodulation circuit, an amplifier, and the like. That is, the transmission / reception circuit 7 puts an audio signal input from the modulation / demodulation circuit 3 via the wireless interface 6 on a radio wave that is a carrier wave, amplifies it, and transmits it from the antenna 8. This radio wave is received by the antenna 10 of the line interface unit 2. The line interface unit 2 includes a transmission / reception circuit 11 and a wireless line interface 1.
Composed of 2 etc. The transmission / reception circuit 11 has the same function as the transmission / reception circuit 7. In addition, the wireless line interface 12
Has the same function as the wireless interface 6.

On the other hand, in demodulation, the telephone line 13 to the modular jack 14 and the modem line connection cable 1
5 and the voice signal input via the wireless line interface 12 are placed on the radio wave by the transmission / reception circuit 11 and the antenna 10
Send from This radio wave is received by the antenna 8 of the modem body 1 and input to the modulation / demodulation circuit 3 via the transmission / reception circuit 7 and the wireless interface 6. A digital signal is extracted from the input voice signal by the modulation / demodulation circuit 3,
Output to the personal computer 9 via the terminal interface 5 and the connector 16.

FIG. 5 shows an example of the actual connection of the cordless modem of the present invention. FIG. 5 corresponds to FIG. 1, and the same components are designated by the same reference numerals. The modem body 1 is downsized by using an LSI or the like, and is integrally connected to the RS232C interface 17 of the personal computer without a connection cable. On the other hand, the line interface unit 2 is connected to the modular jack 14 of the telephone line 13 via a connection cable 15.

FIG. 6 shows another example of the actual connection of the cordless modem of the present invention. FIG. 6 shows a modified example in which the connection cable 15 is omitted in the embodiment of FIG. 1, and the same components as those in FIGS. 1 and 5 are designated by the same reference numerals. In the example of FIG. 6, the line interface unit 2 is integrally connected to the modular jack 14 of the telephone line 13 without a connection cable. In addition, FIG.
An example in which a modem body 1 ', which is similar to the modem body 1 of FIG. 1, is connected to a laptop personal computer 9'is shown. FIG. 8 shows an enlarged view of the modem body 1'shown in FIG. On the other hand, FIG. 9 shows an enlarged view of the line interface unit 2 of FIG. The line interface unit 2 includes a plug-type connector 40, which is connected to the modular jack 14.

FIG. 10 shows a modification of the line interface section 2 of FIG. The line interface unit 2'shown in FIG. 10 includes two jack-type connectors 41,
42 are provided. One connector 41 is for connecting the connection cable 15 connected to a telephone line, and is connected to a plug-type connector 43 provided at one end of the connection cable 15. The other connector 42 is for connecting a connection cable to be connected to a telephone, and is connected to a plug-type connector 44 provided at one end of the connection cable.

The following methods (1) to (2) are available as methods for supplying power to the modem body 1. A power supply circuit (not shown) is provided inside the modem body 1 in response to the supply of AC power. An AC / DC conversion adapter is installed externally, and DC
Receive power supply. DC power is supplied from the personal computer 9 side through an empty pin of the RS232C interface 17. Power is obtained from the signal output itself of the personal computer 9. A battery is built in the modem body 1.

The following methods (1) to (2) are available as methods for supplying power to the line interface section. A power supply circuit (not shown) is provided inside the line interface unit 2 in response to the supply of AC power. An AC / DC conversion adapter is installed externally, and DC
Receive power supply. Get power from the central office. That is, by saving the power of the transmission / reception circuit 11 by using an LSI or the like, it is possible to operate the transmission / reception circuit 11 and the wireless line interface 12 only with the power used for the telephone. A battery is built in the line interface unit 2. Although the antennas 8 and 10 are provided outside the modem body 1 and the line interface unit 2 in the above-described embodiment, each housing is made of a radio wave transmitting material such as plastic, and each antenna 8 and It is also possible to house 10 inside the housing.

Next, the operation of the above-mentioned device will be described. In FIG. 1, personal computer 9 to telephone line 1
When transmitting data to the modem 3, digital data output from the RS232C interface 17 of the personal computer 9 is transmitted via the connector 16 to the modem body 1
Entered in. In the modem body 1, the modulation / demodulation circuit 3 modulates a signal input via the terminal interface 5 according to an instruction from the control circuit 4, and outputs the modulated signal to the transmission / reception circuit 7 via the wireless interface 6. The transmission / reception circuit 7 transmits the signal modulated by the modulation / demodulation circuit 3 from the antenna 8 to the antenna 10 of the line interface unit 2 by radio waves. In the line interface unit 2, the antenna 10
The radio wave received by is returned to the voice signal by the transmission / reception circuit 11, and the wireless line interface 12 and the connection cable 15
And to the telephone line 13 via the modular jack 14.

When receiving data from the telephone line 13 to the personal computer 9, the line interface unit 2 receives an audio signal from the telephone line 13 via the modular jack 14 and the connection cable 15. In the line interface unit 2, the wireless line interface 1
A voice signal is transmitted from the antenna 10 to the antenna 8 of the modem body 1 via the radio wave in the transmission / reception circuit 11 via the radio wave.
In the modem body 1, the electric wave received by the antenna 8 is returned to the voice signal by the transmitting / receiving circuit 7. Then, the modulation / demodulation circuit 3 demodulates this audio signal into digital data according to the instruction of the control circuit 4, and inputs it to the personal computer 9 via the RS232C interface 17. The modulation / demodulation circuit 3 and the transmission / reception circuits 7 and 11 described above are independently provided with a modulation circuit, a demodulation circuit, a transmission circuit, and a reception circuit.
The data is transmitted and received at the same time.

In the above-described embodiments, an example in which radio waves are used as the wireless transmission medium has been described, but the present invention is not limited to this, and electromagnetic waves such as infrared rays or light or ultrasonic waves may be used. You can also In the case of infrared rays or light, the portions of the antennas 8 and 10 in FIG. 1 are changed to a light emitting element and a light receiving element. In the case of ultrasonic waves, those parts are changed into ultrasonic wave transmitting elements and ultrasonic wave receiving elements. In these modifications, the cordless modem described above can be installed even in a place where there is a radio interference. Also, the modem body 1
Is RS232C by the connector 16 fixed to this.
Although the interface 17 is directly and integrally connected, the present invention is not limited to this, and the modem body 1 is fixed to a predetermined position of the personal computer 9, and the connector 16 and RS2 are connected.
The 32C interface 17 may be connected with a short cable. Further, the same effect can be obtained by moving the wireless transmission means between the personal computer and the terminal interface (terminal interface section) as shown in FIG. 11 instead of the line interface section.

[0020]

As described above, according to the cordless modem of the present invention, the modem main body portion including the transmission / reception circuit is downsized and integrally connected to the terminal device such as a personal computer, and the connection cable between them is eliminated. Along with
Since the area between the modem body and the telephone line is wireless, the following effects are obtained. It is not necessary to secure a space for installing the modem, and it is possible to effectively use the indoor space. Since it is not necessary to lay the connection cable between the terminal modem and the connection cable between the modem lines, these do not interfere in the office and the like, and the installation work and the transfer work of the terminal device and the like become very simple. In particular, when the installation place of the terminal device and the installation place of the modular jack of the telephone line are distant from each other, the above-mentioned effect becomes remarkable.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a cordless modem of the present invention.

FIG. 2 is a block diagram of a connection example of a conventional modem.

FIG. 3 is a block diagram of an internal configuration of a conventional modem.

FIG. 4 is a diagram showing a physical connection example of a conventional modem.

FIG. 5 is a diagram showing an example of a physical connection of the cordless modem of the present invention.

FIG. 6 is a diagram showing another example of the physical connection of the cordless modem of the present invention.

FIG. 7 is a diagram showing an example of application of the cordless modem of the present invention to a laptop personal computer.

FIG. 8 is an enlarged view of the modem body of FIG.

9 is an enlarged view of the line interface unit in FIG. 7.

FIG. 10 is a diagram showing a modified example of the line interface unit in FIG.

FIG. 11 is a diagram showing an example in which the position of the wireless transmission means is moved.

[Explanation of symbols]

 1 modem body 2 line interface 3 modulation / demodulation circuit 4 control circuit 7, 11 transmission / reception circuit 8, 10 antenna 15 connection code

Claims (1)

[Claims] 1. A modem transmission unit for converting digital data into an audio signal and a transmission / reception circuit for wirelessly transmitting the audio signal by a wireless transmission medium, and the wireless transmission between the modem main unit. A cordless modem comprising: a line interface unit including a transmission / reception circuit for wirelessly transmitting the voice signal through a medium and transmitting / receiving the voice signal to / from a telephone line.