JPH088529B2 - Optical communication device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optical communication device connected to a single-line / bidirectional optical communication path.

[Conventional technology]

FIG. 17 shows an example of an optical communication device connected to a conventional single-line / bidirectional optical communication path disclosed in, for example, Japanese Patent Laid-Open No. 61-49526.

In the figure, 30 is a switching unit, 31 is a supervisory control unit, 32 is a reproducing unit for amplifying signals, and these are optical communication devices (repeaters).
Make up 34. This device 34 operates the switching unit 30 by a switching control signal from the terminal station, and 35 is a terminal station A.
Side optical fiber, and 36 is an optical fiber on the terminal B side.

The optical communication device 34 configured as described above operates as follows.

Normally, the connection state of the switch of the switching unit 30 takes the state shown by the solid line, the received signal from the terminal station A side is supplied to the input side of the reproducing section 32, amplified by the reproducing section 32, and amplified to the terminal station B side. Send out.
That is, at this time, the device 34 functions as a downlink repeater.

The monitoring control unit 31 constantly monitors the output signal of the reproducing unit 32. When the switching control signal is transmitted from the terminal station A side, the monitoring control unit 31 detects the switching control signal and issues a switching command to the switching unit 30. Emit. By the switching command, the switching state of the switching unit 30 is switched to the state shown by the broken line. The received signal from the terminal station B side is supplied to the input side of the reproducing section 32, amplified by the reproducing section 32 and transmitted to the terminal station A side. At this time, the device 34 functions as an uplink repeater.

In this way, the optical communication device 34 is switched to the uplink or the downlink by the switching control signal from the terminal station and used for the bidirectional communication (bidirectional alternating communication).

[Problems to be Solved by the Invention]

However, in the conventional optical communication device of this type, since the switching control signal of the switching unit must be transmitted from another station, the communication procedure becomes complicated, and the own station monitors and controls the switching control signal. Since parts are required, the circuit becomes complicated, and the device is expensive and large in size.

The present invention has been made in view of the above problems, and an object thereof is to obtain an optical communication device for single-line / two-way optical communication that does not require a switching unit and a switching control signal monitoring control unit. is there.

[Means for solving the problem]

According to the present invention, in order to achieve the above object, the optical communication device is configured as in the following (1) and (2).

(1) Optical-electrical converter, electric-optical converter, single wire
Three or more optical waveguide connection ends to which external optical waveguides for bidirectional communication are connected, an optical waveguide connecting the connection ends to each other, an optical waveguide connecting the connection ends to an input end of the opto-electric converter, An optical branching / coupling unit each having an optical waveguide connecting the output end of the electro-optical converter to the connection end;
Pulse width fixing means for receiving a pulse signal from the output end of the electrical converter, fixing the pulse width from the rising edge to the falling edge of the pulse signal to a predetermined pulse width, and outputting it to the input end of the electro-optical converter. A timing means for detecting the rising edge of the pulse signal and for preventing a re-output of the pulse width fixing means for a predetermined time after the first pulse of the pulse width fixing means is generated.

(2) A pulse which receives the pulse signal from the output end of the optical-electrical converter, adjusts the pulse width of the pulse signal to a prescribed pulse width according to an electrical communication protocol, and supplies the pulse to the output end to the terminal device. Width adjusting means and means for connecting the input end from the terminal device to the input end of the electro-optical converter.

[Operation] According to the configurations (1) and (2), bidirectional communication (however, bidirectional alternating communication) can be performed without passing through the switching unit, and according to the configuration (2), the terminal device is further provided. In addition, it is possible to supply a signal having a specified pulse width by an electric communication protocol.

[Examples] The present invention will be described below with reference to Examples.

FIG. 2 is a configuration diagram of an optical communication device according to a first embodiment of the present invention, and FIG. 3 is an enlarged sectional view of the optical waveguide connection portion A of FIG.

In FIG. 2, reference numeral 1 denotes an optical fiber (external optical waveguide) for transmitting light bidirectionally on a single line, which is connected to an optical communication device on the left side (not shown), and at the station, an optical fiber with three branches. It is connected to a connection portion A which is one of the waveguide connection portions (hereinafter referred to as “connection portion”) A, B, C.

Further, the other optical fiber 3 is, for example, similarly to the right adjacent optical communication device, and the further optical fiber 2 is similarly branched to the left and right adjacent optical communication devices (hereinafter also referred to as “station”). There is) and is connected to another station. The optical fibers 2 and 3 are connected to the connection parts B and C in the station.

Next, in the station, the optical branching coupling by the optical waveguide is configured as follows. A thin optical fiber is used as an optical waveguide. First, an optical-electrical converter for reception (hereinafter referred to as "O / E converter") 4 and an electric-optical converter for transmission (hereinafter referred to as "E / O converter") in the optical communication device 11a of the station. 5)
To provide. 1/4 each from the three branch connections A, B, C
The spectrally separated optical fibers of A _r , B _r , and C _r are connected to the O / E converter 4. The connecting portions A, B, C is A _t, B _t, is connected to the transmitting E / O converter 5 with wire optical fiber C _t.

Furthermore, since the light directly passes between the connection parts A, B, and C (hereinafter referred to as "pass-through"), ab, B, and C are created between the connection parts A and B.
A thin-line optical fiber with bc in the space and ac in the space between A and C is connected (see FIG. 3). The above connecting portion and the thin optical fiber form an optical branching / coupling portion.

In addition, when the optical signal is further amplified and relayed to another station, the optical pulse signal sent from the own station is re-amplified by the amplification relay of the other station, and the repeat reception / transmission due to the response delay causes a continuous optical state. , Monostable multivibrator 6c, resistor 6b, capacitor to prevent communication loss
A pulse width fixing circuit 6 including 6a and the like is provided. The input side of the circuit 6 is connected to the output side of the O / E converter 4, and the output side thereof is connected to the input side of the E / O converter 5.

Reference numeral 7 is a pulse width adjustment circuit (received signal waveform adjustment circuit), which is a monostable multivibrator 7c, a resistor 7b, and a capacitor 7a.
Etc., with the received signal from the O / E converter 4 as input,
The output is supplied to the input terminal RD of the communication terminal device 8.

FIG. 4 is an external perspective view of the optical communication device 11a of the first embodiment. In the figure, 9 is optical pass-through, reception, relay,
FIG. 10 is a graphic diagram drawn on the optical communication device 11a to display each function of transmission, and 10 is O / E in the optical communication device,
It is the graphic figure which drew E / O conversion. These graphic diagrams show that the device uses the optical fibers 1, 2 and 3 from adjacent stations in three directions by inserting them into the respective connection parts A, B and C, respectively.

Next, the operation of the optical communication device 11a of the first embodiment configured as described above will be described.

In FIG. 2, first, the optical signals coming from the adjacent stations in the three directions through the optical fibers 1, 2, and 3 are respectively transmitted to the optical communication device 1
The light is dispersed within 1a, passes through each of the thin optical fibers ab, bc, and ac, and is directly transmitted to the opposing next station. Further, the optical signals from each of the three directions are respectively transmitted to each of the thin wire optical fibers.
It is received by the O / E converter 4 through A _r , B _r , and C _r, and is converted from an optical signal to an electric signal.

Further, oscillation signal from the station, E / O converter 5 from each wire optical fiber A _t, B _t, via the C _t, the respective optical fibers 1, 2 and 3 for between optical transmission respectively stations It is incident.

Here, the relay amplification operation of the optical signal, which is an important point of this embodiment, will be described. For example, a digital optical signal coming from the adjacent station on the left passes through the optical fiber 1, part of which is pass-through to each of the optical fibers 2 and 3 of the next station, and part of which is received by the O / E converter 4. and is amplified by an electric circuit to be described below, including the E / O converter 5 from each wire optical fiber a _t, B _t, an optical fiber 1 that the optical signal has come by C _t, the optical fiber
Inject light into two or three. For example, as shown in FIG. 5 as an example of the system configuration, even if many such stations are branched and connected in a bus shape, digital optical signals are sequentially amplified and relayed at each station, and the optical signals of each station are transmitted to the next station. It is possible to overcome the optical loss due to the fiber connection and transmit.

The pass-through is performed in the optical branching / coupling unit in such a bus type communication, for example, in the case of a network communication system in which 100 stations are connected, even if there is a failure for one station, the pass-through is performed. This is so that it can be received by the next station. The operation of the entire network communication can be ensured as long as two stations do not continuously fail. Even when one station alone fails in a distributed manner, the other stations continue to operate as normal stations. The failure of two stations in succession is extremely small in probability, and the reliability of the entire system can be improved.

Here, the pulse width fixing circuit 6 for preventing the signal of the optical fiber between the stations from becoming a continuous optical signal and being unable to transmit the signal, and the conventional electric communication protocol are used as they are in the communication terminal device 8. The operation of the pulse width adjusting circuit 7 that enables optical communication between stations will be described.

The optical signal transmitted from another station is converted into an electrical signal by the O / E converter 4 in the optical communication device 11a. The received signal converted into an electric signal has a fluctuation in signal pulse width due to the influence of the propagation delay time of the optical signal and the like. This received signal is fixed to a constant pulse width by the pulse width fixing circuit 6 regardless of the pulse width of the received signal, is amplified, and is E / O.
It is transmitted in three directions as an optical signal via the converter 5. Further, the received signal is output to the terminal device 8 by the pulse width adjusting circuit 7 with the pulse width of the signal being the same pulse width (regulated by the communication protocol) as in the conventional electric type using an electric wire as a communication medium. .

Further, the electric signal generated in the own station is output from the signal transmission terminal TD of the terminal device 8 and transmitted in three directions as an optical signal via the E / O converter 5.

Next, the operation of the pulse width fixing circuit 6 and the pulse width adjusting circuit 7 will be described in detail with reference to FIGS. 5, 6 (a) and 6 (b). FIG. 5 shows the optical communication device of the first embodiment.
It is a figure which shows an example of the system using 11a. Now, consider a case in which a circuit for simply performing relay amplification is provided between the O / E converter 4 and the E / O converter 5. FIG. 6 (a) shows each timing chart of the X station transmission signal, the Y station reception signal, and the Z station reception signal at this time.

If the transmission signal terminal TD of the terminal device 8 of the X station outputs a pulse signal having a pulse width t ₁ hour, this signal is converted into an optical signal by the E / O converter 5 of the X station and transmitted in three directions. To be done. The optical signals transmitted in the three directions are converted into electrical signals with a propagation delay time t ₂ delayed by the O / E converter 4 of the adjacent Y station, for example. The signal converted into an electric signal is amplified by the pulse width fixing circuit 6, converted into an optical signal by the E / O converter 5 of the Y station and transmitted to the Z station and also to the X station. That is, the operation of the Y station causes the X station to receive the reflected light of the transmission signal of the own station. Furthermore, from station Y 3
The optical signal transmitted in the direction arrives from the Y station to the X station with a delay of time t _{2 and} from the Y station to the Z station with a delay of t ₃ hours from the start of the transmission signal of the Y station. It is converted into an electric signal by the converter 4 and received. Here, attention is paid particularly to signal transmission between the X station and the Y station.
Signals are transmitted and received by the above process, but at the X station,
Even when the time corresponding to the transmission pulse width t ₁ has passed and the output pulse changes from the “H” level to the “L” level, the reflected light of the propagation delay from the X station to the Y station and from the Y station to the X station Reception of station X by signal continues. This received signal is amplified and E / O
Once converted, station X will continue to transmit light. Therefore, the Y station always receives the continuous optical signal, so that the received signal is always in the "H" level state. Therefore, the Y station cannot receive the transmission signal of the X station, and similarly, the Z station cannot receive the signal.

Next, signal transmission will be considered with reference to the timing chart of FIG. 6B when the pulse width fixing circuit 6 is provided between the O / E converter 4 and the E / O converter 5. Fig. 6 (b)
Is the X station transmission signal, Y station transmission signal, Y station reception signal, Z
4 is a timing chart of station transmission signals and Z station reception signals.

When the pulse with the pulse width t ₁ hour is output from the X station, it is received by the Y station with a delay of the propagation delay time t ₂ . At this time, the pulse width fixing circuit 6 of the Y station is triggered by the rising edge of the received signal to generate a fixed signal having a fixed pulse width t ₅ hours irrelevant to the received signal width, and the E / O converter Supply to 5. This fixed pulse width signal is converted into an optical signal by the E / O optical converter 5, and each optical fiber 3, 21, 2 shown in FIG.
It is transmitted in 3 directions of 2, and passes through the optical fiber 3 to the X station,
The signals are received by the Z stations through the optical fiber 22 with respective propagation delay times. The optical fiber 21 is sequentially communicated with another unillustrated next station. Then, in the X station, when the transmission pulse has passed from t ₁ hour to the time when it goes from the “H” level to the “L” level, the width of the transmission pulse of the Y station is fixed at t ₅ , The X station is not affected by the reflected light from the Y station, and the reception signal of the X station becomes "L" level. That is, the Y station receives the optical signal from the X station with a slight delay, and the Y station transmits the optical signal whose pulse width is limited to t5 by the pulse width fixing circuit 6, and this optical signal is slightly delayed. Input to X station. However, since these delays are small, the pulse width fixing circuit 6 of the X station is still in the pulse generating operation at this time, and even if the pulse width fixing circuit 6 of the X station is triggered by the optical signal from the Y station, the above-mentioned pulse is not generated. The generation operation does not change, and the pulse width of the optical signal transmitted from the X station does not change. Same thing for Y station, Z
The same applies to stations. Although the optical signal from a farther station has a large delay, the attenuation at the optical branching / coupling section and the optical fiber is large and becomes less than the reception threshold value of the X station. 6 is unaffected.

Therefore, the continuous light state does not occur. Therefore, the X station does not transmit a continuous optical signal, and the Y and Z stations can receive accurate signals. That is, the pulse width fixing circuit 6 allows the transmission prohibition time t ₄ to be provided, and an accurate optical pulse signal can be transmitted to the entire system. Further, by adjusting the received signal to have the same signal width as that of the conventional electric type by the pulse width adjusting circuit 7, the optical communication device 11a without modifying the communication device (terminal device) by the electric type communication protocol.
Just by adding, it becomes possible to communicate by an electric communication protocol.

In the above-described first embodiment, the optical branching / coupling unit has three branches / couplings, but as shown in FIG.

Subsequently, a second example in which the reset operation of the pulse width fixing circuit can be controlled to more reliably prevent the generation of continuous optical signals
This will be described as an example.

FIG. 1 is a block diagram of the optical communication apparatus of the second embodiment. In the figure, reference numeral 12 is a mask time limit circuit, which has the same configuration as in FIGS. 2, 3, and 4 except for this circuit portion.

 Therefore, the explanation will focus on the mask time limit circuit 12.

As shown, the mask time limit circuit 12 is configured to control the reset of the pulse width fixing circuit 6.

The optical communication device 11b receives the optical signal coming from the left station by the O / E converter 4, shapes the waveform by the pulse width fixing circuit 6, and amplifies it.
With the E / O converter 5, the right station (direction of the optical fiber 3)
Transmit to another station (direction of optical fiber 2), but at the same time,
The optical signal will be returned to the left station (direction of the optical fiber 3). At this time, if there is the same device as the optical communication device 11b of the station on the left side, the mask time limit circuit of the left station.
Reference numeral 12 manages resetting of the pulse width fixing circuit 6 so that the circuit 6 does not amplify and transmit until the reflected light signal disappears for a certain period. As a result, optical signals can be transmitted one after another into the network without being affected by the reflected optical signal in the station.

The mask time limit circuit 12 keeps the output Q constant so as not to release the reset R for a certain time at the same time as the pulse width fixing circuit 6 receives the rising trigger in order to prevent (mask) the reception of the amplified reflected light of the next station. Hold on time “H” side. As a result, the pulse width fixing circuit 6 operates so as not to output the pulse signal again until the reset R is released. The mask time limit circuit 12 sets a time limit so as to prevent the influence of the amplified reflected light of the next station and the next station due to pass-through.

In the above operation, no matter which direction of the three stations the optical pulse signal comes from, the relevant station relays and amplifies the signal and transmits the light in the three directions, and the multi-bus type and the multi-tree type. It is of great significance to realize the optical communication network.

Next, the operations of the pulse width fixing circuit 6, the pulse width adjusting circuit 7, and the mask time limit circuit 12 will be described in detail with reference to FIGS. 8 and 9. FIG. 8 is an optical communication device of this embodiment.
It is a figure which shows an example of the system configuration using 11b.

In the figure, the optical communication device 11b and the terminal device 8 of this embodiment are sequentially connected to the optical fiber 1 or 2 in a multi-bus form, 201 stations, 202
Stations, 203 stations and 204 stations are connected. Further next 205
The stations are divided into 206 and 207 stations in a multi-tree form. In this way, the network is gradually branched to form a network. Here, as an example, the above-mentioned operation from the 201st station to the 204th station will be described with reference to FIG.

Now, suppose that “1101” is transmitted as digital bit information from the signal transmission terminal TD of the terminal device of the 201 station, and the optical signal indicated by 201a is transmitted from the connection parts A and B of the 201 station in both left and right directions. In the right adjacent station 202, the pulse width fixing circuit 6 receives the signal through the O / E converter 4, fixes the pulse width to T ₁ time, relays and amplifies and transmits. The optical signal 202 is still 202
Transmitted to both left and right sides of the station. Similarly, at the next 203 stations, 2
03b becomes a light emission signal and is transmitted in both directions. 201 a, 20
From the rises of the optical signals 2a and 203a, it can be seen that the phases are successively delayed by the propagation time of the light and the amplification delay time. 202B is the waveform of the output Q of the mask time limit circuit 12 in the 202 station. This output controls the reset of the circuit 6 so as to inhibit the re-reception relay amplification of the pulse width fixing circuit 6 of the 202 station for the time t set shorter than the transmission communication bit rate period T ₂ .

Thereby, for example, at the 202 station, the reflected light signal 202 from the 203 station can be ignored. Also, the reflected optical signal 202 d coming from the 204 station to the 202 station through the pass-through part ab of the 203 station,
At station 202, it can be ignored because it is within the mask time period (see waveform 202b). In this way, the optical signal in the transmission direction is 202, 203, while the reflected optical signal in the direction opposite to the transmission direction is ignored.
204 stations ... Repeatedly amplified and transmitted to the stations.

[Application example]

Hereinafter, application examples of the present invention using the optical communication devices of the first and second embodiments described above will be described.

(A) FIG. 10 shows an application example in which the optical communication device of the present invention is used for controlling an air conditioner. Optical communication device in the outdoor unit 51
11a and the communication terminal device 8, there are an inverter variable speed motor control unit 52, a compressor 53, and a fan 54 connected to the device 8. Each of the indoor units 55, 56, 57 and the remote control device 58 is a case in which a small-sized optical communication device 11a is built in and branch bus type communication is performed by an optical fiber OF. With this configuration,
A conventional telecommunication protocol can be used to make a communication network without any modification.

(B) FIG. 11 shows an application example in which the optical communication device of the present invention is used to control a large aircraft for transportation.

As shown in the figure, the optical communication device 11a is arranged in the main control target equipment of the aircraft, and each optical fiber OF is arranged in a branched manner (the terminal device 8 is not shown). With this configuration, the stewardess service display unit 75, the left,
Control information can be communicated to the control units 72 and 73 and the tail control unit 74 of the right engine E. In particular, an aircraft having a high-power engine has a large number of electromagnetic noise sources, and when performing multi-bus type communication with an electric coaxial cable or the like, adding a circuit or the like for noise guard causes a great cost. It was hanging. However, according to this application example, there is no fear of electromagnetic noise, and the communication protocol of the conventional electric multi-bus type serial communication can be used. Further, if the optical communication device 11a
Even if one station fails electrically, the entire network communication is alive unless two stations fail continuously.

(C) FIG. 12 shows an application example in which the optical communication device of the present invention is used for controlling an automobile. This example is an application similar to the example of the aircraft described above. In the figure, 81 is an engine tachometer, 82 is a distributor, 83 is an engine speed detector, 84 and 85 are left and right headlight controllers, and 86 and 87 are left and right rear winker lighting controllers. (The terminal device 8 is not shown). According to this configuration, a large amount of wiring in the conventional electric type used for communication is unnecessary, and control that does not need to worry about malfunction due to electromagnetic noise around the engine can be easily realized at low cost and in a small size. .

(D) FIG. 13 shows an application example in which the optical communication device 11b of the present invention is used in a ring-shaped single-line optical fiber, a bidirectional communication network. In the figure, 201 to 207 and 202 'to 206' are optical communication devices provided with a mask time limit circuit 12 as shown in FIG.
The optical communication station is composed of a plurality of rings and is connected by a single optical fiber 1 to form a single-line optical fiber / two-way communication network.

Now, from station 201, digital optical signal '1 as shown in Fig. 9
If 101 'is sent, both directions 202, 203 ...
..., 202 ', 203' ... are relay-amplified and transmitted as described above. Now, suppose that 207 stations receive the information signal. To 207 stations, due to variations in the length of the optical fiber in the middle and variations in the relay amplification delay time, 206 stations, 20
Either of the 6'stations will transmit the optical signal for an instant, and at that time, at 207 stations, the masking time circuit 12 will cause the optical signal from the next station that came later as described above. It will be ignored. Also, at 207 stations, the pulse width fixing circuit 6
Therefore, the optical signals reversely transmitted to the 206 station and 206 'station are ignored by the mask time limit circuit 12 of each station, and no extra optical signal is generated. Therefore, the optical signal transmitted from station 201 can be normally received at station 207. This also applies to the case where 207 stations are transmitting and 201 stations are receiving. Further, it is obvious that any station on the way can normally send and receive.

Here, even if the optical fiber 1 between the 204th station and the 205th station is broken as shown by 401, communication can be normally performed by the counterclockwise route.

(E) FIG. 14 shows an application example in which the optical communication device 11b of the present invention is used in a mesh-shaped single-line optical fiber / two-way communication network system. Now, assume that the 20K station receives and uses the digital optical signal '1101' as shown in FIG. 9 transmitted from the 201 station. From station 201, as described above, through station 202, through the connection part c of the third branch to the connection part C of station 207, 206 stations, 2
0B station …… 20H station …… Transmitted to 20K station. This is the root of α. By the way, because it is a mesh network,
As another route, from 201 station to 202 station ... 205 station to 20A
Β routes from stations, 209 stations, 20E stations, 20F stations to 20K stations are also conceivable.

The α and β routes operate on the same principle as described in FIG. That is, even if the light is transmitted from both the left and right sides and the light collides with each other on the way, the excess optical signal reflected and amplified by the pulse width fixing circuit 6 and the mask time limit circuit 12 is ignored between the adjacent stations, and the normal 20K An optical signal is transmitted to the station. However, if the length between each station is very large, the reflected amplified optical signal, such as 202d in FIG.
When the period of "L" of the waveform of 02B is entered, the pulse width fixing circuit 6 emits a pulse there and relays and amplifies the abnormal pulse having a shifted period, resulting in communication abnormality.

Therefore, in this network system, the following network construction conditions are set by the transmission baud rate, inter-station distance, etc.

Example of network construction conditions B: Transmission rate (baud rate) X: Maximum inter-station distance in network configuration S: Optical propagation speed in optical fiber τ: Optical relay amplification delay time t: Mask time limit k ₁ : Constant (pass-through capability for one station Hours 4, 2 hours 6) The baud rate and maximum distance between stations are restricted by the above formula.

(F) FIG. 15 shows an application example in which the optical communication device of the present invention is used to control building air conditioning. In the figure, 502 is a man-machine system for centrally managing the air conditioners 501 on each floor. Control information of the individual air conditioner 501 from 502 is supplied from the optical communication device 11b to the respective floors from 1F to 4F through the terminal device 8 through the single-line optical fiber 1 and is relayed and amplified by each optical communication device 11b. Each air conditioner 501 has a built-in optical communication device 11b, and a multi-tree type network is constructed.

(G) FIG. 16 shows an application example of bus type optical communication in which the optical communication device of the present invention is used for communication between a personal computer (personal computer) and communication between a personal computer and an FA controller.

An example in which an optical communication device 11b connected to adjacent stations in three directions is built in each personal computer 61, 62, 64 or the like is shown. In the figure, optical communication device
Only 11b is shown, and the communication terminal device 8 is not shown.

Here, an optical signal is sent from the personal computer 61 to the personal computer 64, for example.
When the optical communication device 11b in the personal computer 62 is electrically broken, the optical signal passed through is transmitted from the personal computer 61 to the AF controller 63 and the personal computer 64.
Transmission is performed through OF corresponding to the thin optical fibers ab and ac in the figure. Therefore, a highly reliable optical communication network can be constructed, and even if there is a strong electromagnetic noise source on the way, the optical communication system enables communication without malfunction.

Although the embodiments and application examples of the present invention have been described above, the pulse width fixing circuit 6, the mask time limit circuit 12, and the pulse width adjusting circuit 7, which are the element parts of each embodiment, are processed by program software by a microcomputer or the like. You can change it.

Further, in the pulse width fixing circuit 6 and the mask time limit circuit 12 in FIG. 1, the output Q of the circuit 6 is input to the fall detection input of the circuit 12, and the output of the circuit 12 is output for a certain period of time after the output Q falls. There is also a method in which Q is supplied to the reset terminal of the circuit 6 and held at the reset "H" and masked.

Further, although the optical fiber is used for the optical waveguide in each of the embodiments, the present invention is not limited to this, and an optical waveguide or the like three-dimensionally formed on the semiconductor substrate may be used.

Furthermore, although the respective embodiments have positive logic, it goes without saying that negative logic can be applied without being limited to this.

From the network construction condition I, it can be said that if the transmission rate (baud rate) is increased, the maximum inter-station distance must be shortened, because the optical transmission signal is transmitted in the base band. For example, if the optical modulation signal different from the optical modulation signal received by each station is relayed and amplified and the received modulation signal is automatically phased loop-locked, the transmission speed is set to the inter-station distance. It can speed up regardless.

For example, in the baseband system, the maximum distance between stations is 10
When it is 0m, the transmission speed is about 200Kbps (as pass-through capability for one station), but there is no restriction on the distance between stations in the optical modulation signal processing method, and a single line by optical transmission of several Mbps is used.
A multi-tree type optical network as shown in FIG. 4 can be realized by bidirectional communication.

〔The invention's effect〕

As described above, according to claim 1 of the present invention,
An optical communication device for single-line / two-way optical communication can be constructed in a simple, inexpensive, and compact form without the need for a switching unit and a monitoring control unit for switching control signals. Furthermore, an optical signal can be transmitted to an adjacent station by pass-through. Since it can be bypassed, the communication of the entire system can be normally performed even if some stations have troubles such as a failure of an electric part and a power supply stop.

Further, according to claim 2, since the optical communication device enables a communication network to be set up without changing the conventional electrical communication protocol, conventional communication software assets can be used as they are.

[Brief description of drawings]

1 is a block diagram of an optical communication device according to a second embodiment of the present invention, FIG. 2 is a block diagram of an optical communication device according to the first embodiment of the present invention, and FIG. 3 is an optical waveguide of FIG. FIG. 4 is an enlarged cross-sectional view of the connection portion A, FIG. 4 is an external perspective view of the first embodiment, FIG. 5 is a diagram showing an example of a system configuration using the device of the same embodiment, and FIG. 6 is a device of the same embodiment. 7 is a timing chart for explaining the operation of FIG. 7, FIG. 7 is a diagram showing a modification of the same embodiment, FIG. 8 is a diagram showing a part of a system configuration using the device of the second embodiment, and FIG.
The figure is a timing chart showing the operation of the apparatus of the embodiment,
10 to 16 are views showing an application example of the present invention, and FIG. 17 is a view showing a conventional example. In the figure, A, B and C are optical waveguide connection portions, 4 is an optical-electrical converter,
Reference numeral 5 is an electro-optical converter, 6 is a pulse width fixing circuit, 7 is a pulse width adjusting circuit, and 12 is a mask time limit circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. An optical-electrical converter, an electric-optical converter, and three or more optical waveguide connecting ends to which an external optical waveguide for single-wire / two-way communication is connected, and an optical waveguide connecting the connecting ends to each other. ,
An optical waveguide connecting the connection end to an input end of the opto-electric converter, an optical branching coupling part having an optical waveguide connecting the output end of the electro-optic converter to the connection end, and the opto-electrical A pulse width fixing means for receiving a pulse signal from the output end of the converter, fixing the pulse width from the rising edge to the falling edge of the pulse signal to a predetermined pulse width, and outputting the pulse width to the input end of the electro-optical converter; Detecting the rising edge of the pulse signal,
An optical communication device, comprising: a time limit means for preventing re-output of the pulse width fixing means for a predetermined time period after the first pulse is generated by the pulse width fixing means. 2. The pulse signal is received from an output end of the optical-electrical converter, the pulse width of the pulse signal is adjusted to a prescribed pulse width according to an electric communication protocol, and the pulse width is supplied to an output end to a terminal device. 2. The optical communication device according to claim 1, further comprising: a pulse width adjusting means for connecting the input terminal of the terminal device to an input terminal of the electro-optical converter.