JP2011233953A - Optical communication system, optical communication harness and optical distributor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication system capable of implementing optical communication based on a predetermined protocol, an optical communication harness, and an optical distributor capable of configuring the optical communication system.SOLUTION: Two optical distributors 2a, 2b are connected by an optical communication line, and optical communication apparatuses 10a, ..., 10b, ... are connected to the optical distributors 2a, 2b, respectively, in a star shape. The optical distributors 2a (2b) includes an optical input part 20a (20b) and an optical output part 21a (21b). When the optical communication apparatus 10a including a CAN controller sends a CAN communication signal, that signal is inputted to the input part 20a of the optical distributor 2a, outputted from all the four optical output parts 21a, transmitted to the optical communication apparatuses 10a, ..., while being transmitted to the optical distributor 2b and transmitted from the optical distributor 2b to the optical communication apparatuses 10b, .... At such time, the relevant signal is also transmitted from the optical output part 21b of the optical distributor 2b to the side of the optical distributor 2a, but is attenuated by a filter 40b.

Description

  The present invention relates to a communication system capable of avoiding ringing in a telecommunication line by performing communication using an optical signal and improving communication quality between communication devices, and communication based on an existing protocol performed using an electric signal. The present invention relates to an optical communication system, an optical communication harness, and an optical distribution device capable of realizing the above by optical communication.

  In recent years, systems that connect a plurality of communication devices, assign functions to the communication devices, exchange data with each other, and perform various processes in cooperation have been used in various fields. For example, in the field of an in-vehicle LAN (Local Area Network) arranged in a vehicle, an ECU (Electronic Control Unit) has a communication function, and each ECU performs a process specialized for each other. Various functions are realized as a system by exchanging data.

  While the functions of each ECU are specialized, the number of devices (nodes) provided with communication means is increasing because the functions that should be enabled in the entire communication system tend to increase. However, when many nodes are connected to the communication line, ringing or the like is likely to occur, and there is a problem that the frequency of occurrence of communication failures increases. In communication using the current CAN (Controller Area Network), there is a limit on the number of nodes that can be connected to a communication line.

  As the function of the entire communication system increases and the number of devices increases, the influence of electromagnetic noise on the communication line and other signal lines cannot be ignored. In particular, in the field of vehicles, high voltage cables are arranged in vehicles due to the spread of EV (Electric Vehicle) and HEV (Hybrid EV). In order to eliminate the influence of electromagnetic noise, it is desirable to use a shielded (STP: Shielded Twisted Pair) communication line. However, conventionally used ECUs are configured to transmit and receive signals via UTP, and it is not practical to change all connectors and the like to be compatible with STP.

  In order to prevent ringing, the communication lines are divided into a plurality of parts, ECUs are connected to different communication lines, and the number of nodes connected to one communication line is limited. In these configurations, different communication lines are connected by a gateway (GW) that controls transmission and reception of data. However, in the configuration in which the GW is included in the communication system in order to limit the number of nodes per communication line, the number of parts in the entire communication system increases and the cost of the entire system increases.

  Therefore, it is conceivable to employ optical communication via an optical cable that is not affected by electromagnetic noise. In the field of vehicles, a configuration in which a part is realized by optical communication has been proposed (Patent Document 1).

JP 2008-219353 A

  It is also conceivable to replace all communication between ECUs with optical communication instead of only a part. In this case, it is desirable to be able to construct a system without modifying all conventional ECUs. For this purpose, it is required to implement a system so that the communication function of the conventional communication protocol possessed by each ECU can be used.

  CAN is widely adopted as a protocol for in-vehicle communication. In particular, in the CAN protocol, each node constantly monitors a communication line in order to perform arbitration processing for communication collision. Even when each node transmits itself, the transmission process is continued when the signal transmitted through the communication line matches the signal transmitted by itself, and the transmission process is stopped when they do not match. Even when all are optical communication, it is necessary to configure between optical communication and electrical communication so that each node can detect both signals transmitted by itself and signals from other sources.

  On the other hand, when a communication system is constructed by optical communication, it is preferable to divide into a plurality of networks and connect the optical communication devices in a star shape using a star coupler (passive) in each network in order to suppress a decrease in optical power. . At this time, optical signals can be exchanged between different networks by connecting couplers of different networks with optical communication lines (optical fibers), and GW is not required. A coupler (passive) is an optical device that combines input light. In order to use the CAN protocol, it is necessary to configure such that communication suitable for the communication protocol is performed via each coupler.

  The present invention has been made in view of such circumstances, and an optical communication system, an optical communication harness, and the optical communication system capable of realizing communication based on a predetermined protocol performed by an electric signal also by optical communication. An object of the present invention is to provide an optical distribution device that constitutes the above.

  An optical communication system according to a first aspect of the present invention includes a plurality of light input units and a plurality of light output units, and distributes and outputs light input from one light input unit to a plurality of light output units. A plurality of optical distributors connected by the optical input unit and the optical output unit, and a part of the optical input unit and the optical output unit of each of the plurality of optical distributors via an optical communication line in a star shape And a plurality of optical communication devices that transmit and receive optical signals.

  An optical communication system according to a second aspect of the present invention is connected to an optical output unit connected to another optical distributor among the plurality of optical output units of each of the plurality of optical distributors, and the plurality of optical communication devices are It is characterized by one or more filters that attenuate light having a wavelength different from the wavelength of the optical signal to be transmitted.

  The optical communication system according to the third invention has a plurality of light input sections and a plurality of light output sections, respectively, and distributes and outputs the light input from one light input section to the plurality of light output sections, A first optical distributor and a second optical distributor connected to each other by an optical input unit and an optical output unit, and a part of the optical input unit and the optical output unit of the first and second optical distributors, respectively. A plurality of first and second light sources connected to a star shape via an optical communication line, transmitting an optical signal of the first or second wavelength, and receiving optical signals of a plurality of different wavelengths including the first or second wavelength. A first optical filter that is connected between the two optical communication devices, one optical output unit of the first optical distributor, and one optical input unit of the second optical distributor, and attenuates light of the second wavelength; A first optical output unit of the two optical distributors and a second filter connected between the first optical input unit of the first optical distributor and attenuating the light of the first wavelength; Characterized in that it obtain.

  An optical communication system according to a fourth aspect of the invention is characterized in that the optical communication device includes means for comparing the optical signal being transmitted with the optical signal being received to determine success or failure of transmission.

  An optical communication system according to a fifth aspect is characterized in that the optical communication device transmits and receives an optical signal based on a CAN protocol.

  An optical communication harness according to a sixth aspect of the present invention has a plurality of light input units and a plurality of light output units, and distributes and outputs light input from one light input unit to a plurality of light output units. An optical communication line connected to any one of the plurality of light input units and the light output unit, and a specific light output unit of the plurality of light output units. It is connected to the optical communication line to be connected, and includes one or a plurality of filters that attenuate light of a predetermined wavelength.

  The optical communication harness according to a seventh aspect of the invention is characterized in that the filter is provided inside a connector for connecting an optical communication line to another optical distributor.

  An optical distribution device according to an eighth aspect of the present invention includes a plurality of light input units and a plurality of light output units, and distributes and outputs light input from one light input unit to a plurality of light output units. And one or more filters that are connected to a specific light output unit of the plurality of light output units and attenuate light of a predetermined wavelength.

The present invention includes a plurality of light distributors that have a plurality of light input units and a light output unit, distribute light output from one light input unit to a plurality of light output units, and output each light. An optical communication device that transmits an optical signal to an optical input unit included in the optical distributor and receives an optical signal output from the optical output unit is connected to each of the distributors in a star shape via an optical communication line.
Since the optical distributors are also connected by the optical input unit and the optical output unit, the entire optical communication is realized.

In the present invention, when the optical communication device connected to the optical distributor transmits an optical signal, the transmitted optical signal is input to the optical input unit of one optical distributor. Are output from a plurality of optical output units. One of the plurality of optical output units is connected to the optical communication apparatus that has transmitted the optical signal. Therefore, the optical communication apparatus can monitor the optical signal transmitted by itself. From the optical output unit of the optical distributor, it is also output to other optical communication devices connected in a star shape so that each optical communication device can receive and also input to the optical input unit of the other optical distributor. Similarly, the other optical distributors are also distributed and output from a plurality of optical output units, so that the same optical signal is similarly received by the optical communication devices connected in a star shape.
Thereby, even in optical communication, communication using a protocol such as CAN that requires collision detection, arbitration, and the like is possible.

In the present invention, among the optical output units included in each optical distributor, the optical communication device transmits to an optical output unit not connected to the optical communication device, that is, an optical output unit connected to another optical distributor. One or more filters that attenuate light having a wavelength different from the wavelength of the optical signal are connected.
As a result, the optical signal transmitted from the optical communication device connected to one optical distributor is input to the one optical distributor and output to another optical communication device connected to the optical distributor. At the same time, it is output to the input section of another optical distributor without being attenuated. In the other optical distributor, the light input from the optical input unit is output from each optical output unit, and thus the light output from one optical distributor and input is output without discrimination. The filter connected to the other distributor attenuates light having a wavelength different from the wavelength of the optical signal transmitted by the optical communication device connected to the other distributor. Therefore, the light output from one optical distributor and input to the other optical distributor is output again from the other optical distributor, but is attenuated by the filter and does not return to the first optical distributor. .

  In the present invention, the optical communication apparatus performs communication based on a predetermined protocol for comparing the optical signal being transmitted and the optical signal being received to determine the success or failure of the transmission. In the present invention, since the transmitted optical signal is input to the optical distributor, the transmitted optical signal is fed back even during transmission, and communication using a predetermined protocol becomes possible. The predetermined protocol is, for example, CAN.

  In the present invention, a plurality of optical distributors, optical communication lines connected to the optical distributors, and optical signals transmitted from the optical communication apparatuses connected to the optical distributors are attenuated. A filter is connected in advance to form a harness. By connecting an optical communication device to the harness, an optical communication system capable of performing predetermined protocol communication can be configured easily.

  In the present invention, a filter may be provided inside the connection connector between the harnesses, whereby an optical communication system capable of performing predetermined protocol communication can be configured easily by connecting the harnesses.

  In the present invention, the filter may constitute an optical distribution device together with the optical distributor. Optical communication that allows easy protocol communication by connecting multiple optical distribution devices with different wavelengths of light to be attenuated by the filter and connecting optical communication devices corresponding to the wavelength of the filter to each optical distribution device The system can be configured.

  According to the present invention, a plurality of optical communication devices are connected to the optical distributor, and the optical distributors are further connected to form a communication system. Thereby, even in the optical communication, each optical communication device can always monitor the signal transmitted to the communication line including the signal transmitted by itself. Even in optical communication, communication using a protocol such as CAN that requires collision detection, arbitration, and the like can be realized.

1 is a block diagram illustrating a configuration of an in-vehicle optical communication system according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of an optical communication device according to Embodiment 1. FIG. FIG. 3 is a schematic diagram schematically showing the configuration of an optical distributor and a connector and transmission / reception of optical signals via the optical distributor and the connector in the first embodiment. 3 is a graph showing the characteristics of the filter in the first embodiment. 6 is a block diagram illustrating a configuration of an in-vehicle optical communication system according to Embodiment 2. FIG. FIG. 6 is a block diagram illustrating a configuration of an optical distribution device in a second embodiment.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
In the following description, an example in which the optical communication system according to the present invention is applied to an in-vehicle communication system in which various control devices arranged in a vehicle are connected and data is transmitted and received based on CAN is given. explain.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the in-vehicle optical communication system according to the first embodiment. The in-vehicle optical communication system is installed in the vehicle 1, and includes a plurality of optical communication devices 10a, 10a, ..., 10b, 10b, ..., optical distributors 2a, 2b, optical communication lines 3, 3, ..., and a connector 4a. , 4b. The optical distributor 2a, the optical communication line 3, and the connector 4a constitute an optical communication harness 5a. Similarly, the optical distributor 2b, the optical communication line 3, and the connector 4b constitute an optical communication harness 5b.

  The plurality of optical communication devices 10a, 10a,... Are connected to the optical distributor 2a in a star shape via the optical communication line 3, respectively. The plurality of optical communication devices 10b, 10b,... Are similarly connected to the optical distributor 2b in a star shape via the optical communication lines 3, respectively.

  A connector 4a is connected to the optical distributor 2a via an optical communication line 3. A connector 4b is connected to the optical distributor 2b via an optical communication line 3. By connecting the connector 4a and the connector 4b, the optical distributor 2a and the optical distributor 2b are connected.

  The optical communication line 3 is an optical fiber. The upstream line from the optical communication device 10a to the optical distributor 2a is distinguished from the downstream line from the optical distributor 2a to the optical communication device 10a. Similarly, an upstream line from the optical communication device 10b to the optical distributor 2b is distinguished from a downstream line from the optical distributor 2b to the optical communication device 10b. Similarly, the optical communication line 3 between the optical distributor 2a and the optical distributor 2b is also distinguished by a line from the optical distributor 2a to the optical distributor 2b and a line from the optical distributor 2b to the optical distributor 2a. Is done.

  FIG. 2 is a block diagram illustrating a configuration of the optical communication device 10a (10b) according to the first embodiment. The optical communication device 10 a includes a microcomputer 11 (described as μC in FIG. 2) and an optical transceiver 12. The optical communication device 10a is an ECU that controls each device mounted on the vehicle. Since the optical communication device 10a and the optical communication device 10b have the same configuration except for the wavelength of the optical signal transmitted from the optical transceiver, a detailed description of the internal configuration of the optical communication device 10b is as follows. Omitted.

  In the microcomputer 11, a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) reads a program stored in a ROM (Read Only Memory) and executes a process of controlling the in-vehicle device (both shown in FIG. Not shown). The microcomputer 11 has the function of the CAN controller 13. Thereby, the microcomputer 11 transmits and receives data based on the CAN protocol, and executes control processing based on the received data.

  The CAN controller 13 outputs to the optical transceiver 12 a transmission signal Tx converted into transmission data in accordance with the data format of the CAN protocol based on an instruction from the processor in the microcomputer 11. The CAN controller 13 receives the reception signal Rx from the optical transceiver 12, interprets the signal based on the CAN protocol, and notifies the processor of the contents. The CAN controller 13 inputs the reception signal Rx while sequentially outputting the transmission signal Tx bit by bit, and compares an arbitration field described later of the reception signal Rx with an arbitration field of the transmission signal Tx of itself. The CAN controller 13 continues the output of the transmission signal Tx when the arbitration field of the transmission signal Tx and the reception signal Rx match, and if not, enters the reception mode and stops the output of the transmission signal Tx. As a result, arbitration processing when signals are simultaneously transmitted from a plurality of optical communication devices 10a (or optical communication devices 10b) is realized.

  A signal transmitted and received by the CAN protocol is a digital signal composed of a plurality of fields such as an arbitration field, a control field, a data field, a CRC (Cyclic Redundancy Check) field, and an ACK (ACKnowledgement) field. Data given from the processor of the microcomputer 11 is stored in the data field. The arbitration field is a field for performing the above-described arbitration processing when a collision occurs in communication, and stores a value corresponding to the priority of the signal. The CAN controller 13 on the transmission side determines whether or not it has been received based on the presence or absence of an ACK bit in the ACK field of the transmitted signal, and determines whether or not retransmission is necessary. In the CAN protocol, “0 (dominant)” of a digital signal is given priority over “1 (recessive)”.

  The optical transceiver 12 converts the transmission signal Tx generated by the CAN controller 13 in accordance with the CAN protocol into an optical signal and sends it to the optical communication line 3. The optical transceiver 12 converts “0 (dominant)” / “1 (recessive)” in the CAN protocol in correspondence with optical “present” / “absent”, respectively. Conversely, the optical transceiver 12 receives a digital signal obtained by converting a signal received via the optical communication line 3, that is, “present” / “absent” of light into “0 (dominant)” / “1 (recessive)”. The signal Rx is output to the CAN controller 13.

  The optical transceiver 12 of the optical communication device 10a and the optical transceiver 12 of the optical communication device 10b have different wavelengths of optical signals to be transmitted. The optical transceiver 12 of the optical communication apparatus 10a transmits a signal conforming to the CAN protocol using an optical signal having a wavelength of 650 nm, for example. The optical transceiver 12 of the optical communication device 10a receives both the 550 nm optical signal and the 650 nm optical signal satisfactorily, converts the optical signal into a digital signal, and notifies the CAN controller 13 of the optical signal. However, the optical transceiver 12 of the optical communication device 10a ignores an optical signal weaker than a predetermined power among optical signals of an optical signal of 650 nm.

  The optical transceiver 12 of the optical communication device 10b uses, for example, an optical signal having a wavelength of 550 nm. The wavelengths used by the optical transceiver 12 of the optical communication apparatus 10a and the optical transceiver 12 of the optical communication apparatus 10b are preferably separated from each other by 50 to 100 nm. Other than the wavelength of the optical signal to be transmitted, it is the same as that of the communication device 10a. Both the optical signal of 550 nm and the optical signal of 650 nm are received well, but the optical signal of the optical signal of 550 nm is weaker than a predetermined power. Ignore optical signals.

  FIG. 3 is a schematic diagram schematically illustrating the configuration of the optical distributors 2a and 2b and the connectors 4a and 4b and the transmission and reception of optical signals via the optical distributors 2a and 2b and the connectors 4a and 4b in the first embodiment. . Since the configurations of the optical distributor 2a and the optical distributor 2b are the same, the details of the optical distributor 2a will be described below, and the detailed description of the optical distributor 2b will be omitted.

  In the following description of FIG. 3, in order to simplify the illustration and description, the optical distributor 2a includes four optical input units 20a and four optical output units 21a, to which three optical communication devices 10a are connected. The configuration. Of course, the optical communication device 10a may have five or more optical input units 20a and optical output units 21a, and may be connected to four or more optical communication devices 10a as shown in FIG.

  The optical distributor 2a has four optical input units 20a on one side and four optical output units 21a on the other side. The optical input unit 20a is a guide for introducing an optical signal from the optical communication line 3, and the optical output unit 21a is a guide for introducing the light propagated in the optical distributor 2a to the optical communication line 3 to be connected. is there. The light output unit 21 a may include a light receiving element to receive light again and output it to the optical communication line 3. Thereby, the light input into one light input part 20a is output from all the four light output parts 21a.

  The optical distributor 2a is configured by using four inexpensive optical couplers with two inputs and two outputs. Two optical couplers are provided at the front stage (input side) and the rear stage (output side) two by two, and the two output units of the two optical couplers at the front stage are respectively connected to the two optical couplers at the rear stage. As a result, the light input to one input unit of the two preceding optical couplers is output to each of the two subsequent optical couplers, and is output from all the two output units of each of the two subsequent optical couplers. . The light distributor 2a is formed of a transparent material such as a cylindrical or prismatic transparent resin or glass, and the light input to one light input unit 20a propagates throughout the interior, and all four light output units 21a. May be output.

  When the optical distributor 2a includes eight optical input units 20a and eight optical output units 21a, a configuration in which up to seven optical communication devices 10a are connected to the optical distributor 2a and then connected to one optical distributor 2b. Is possible. When the optical distributor 2a includes the eight optical input units 20a and the optical output unit 21a, 12 inexpensive optical couplers with two inputs and two outputs, that is, four front stages (input side), four middle stages, and rear stages (output) Side) Four 2-input 2-outputs may be branched and connected.

  The connector 4a and the connector 4b guide an optical signal propagating through the connected optical communication line 3, and introduce it to another optical communication line 3a. The connector 4a has a filter 40a inside, and the connector 4b has a filter 40b inside. The filter 40a is an optical filter (HPF: High Path Filter), and the filter 40b is an optical filter (LPF: Low Path Filter). FIG. 4 is a graph showing the characteristics of the filters 40a and 40b in the first embodiment. The filter 40a transmits, for example, a 650 nm optical signal among the optical signals propagating through the optical communication line 3, and attenuates the 550 nm optical signal. The filter 40b transmits, for example, a 550 nm optical signal and attenuates a 650 nm optical signal.

  With such a configuration, even if the in-vehicle optical communication system is all optically communicated as in the first embodiment, the optical communication device 10a and the optical communication device 10b can communicate according to the CAN protocol. Returning to FIG. 3, the details will be described below.

  The optical communication device 10a transmits a data signal so that the data obtained by its own processing can be used by another optical communication device 10a or the optical communication device 10b. The data signal is transmitted as an optical signal having a wavelength of 650 nm. This optical signal is input to one optical input unit 20 a of the optical distributor 2 a connected via the optical communication line 3.

  The optical distributor 2a outputs an optical signal input to one optical input unit 20a from all four optical output units 21a. Since three of the four optical output units 21a are connected to the three optical communication devices 10a including the optical communication device 10a that is the transmission source, the data signals from the transmission sources in all the three optical communication devices 10a. Can be received. As a result, in the optical communication apparatus 10a that is the transmission source, the CAN controller 13 can compare the arbitration field of the data signal being output from itself with the arbitration field of the received signal that is input, and conforms to the CAN protocol. Communication can be realized.

  The remaining one of the four light output portions 21a of the light distributor 2a is connected to the other light distributor 2b via a connector 4a that incorporates a filter 40a. Since the filter 40a transmits 100% of light of the wavelength (650 nm) of the optical signal transmitted by the optical communication device 10a connected to the optical distributor 2a, the optical signal transmitted from one optical communication device 10a is It also reaches the distributor 2b.

  Similarly, an optical signal input to one optical input unit 20b of the optical distributor 2b is output from all four optical output units 21b of the optical distributor 2b. Three of the four optical output units 21b are connected to the three optical communication devices 10b via the optical communication lines 3, respectively. Since the optical communication device 10b receives the optical signals output from these three optical output units 21b regardless of the wavelength, the optical communication device 10b can receive the optical signals transmitted from the optical communication device 10a. Thereby, the light transmitted from the optical communication device 10a can also be received by the optical communication device 10b.

  The remaining one of the four light output portions 21b of the light distributor 2b is connected to the light distributor 2a via a connector 4b having a built-in filter 40b. Therefore, the optical signal transmitted from the optical communication device 10a and output from the optical distributor 2a is input to the optical distributor 2b, and then output from the output unit 21b of the optical distributor 2b without being distinguished from other optical signals. Then, it tries to return to the light distributor 2a again. However, the filter 40b of the connector 4b transmits 100% of the light of the wavelength (550 nm) of the optical signal transmitted by the optical communication device 10b connected to the optical distributor 2b, but attenuates light of a different wavelength (650 nm). Let Therefore, the optical signal transmitted from the optical communication device 10a and output from the optical distributor 2a is weak in power even after returning to the optical distributor 2a after being input to the optical distributor 2b. It is not received by the transceiver 12.

  The same applies to the case where the optical communication device 10b transmits a data signal so that the data obtained by its own processing can be used by another optical communication device 10b or the optical communication device 10a. The optical signal having a wavelength of 550 nm transmitted from the optical communication device 10b is input to one optical input unit 20b of the optical distributor 2b and output from the four optical output units 21b. Thereby, the optical signal from the optical communication device 10b can be received by the four optical communication devices 10b including the transmission source. The optical signal is output from one optical output unit 21b of the four optical output units 21b to the optical distributor 2a side via the connector 4b incorporating the filter 40b. Since the filter 40b transmits an optical signal having a wavelength of 550 nm and attenuates an optical signal having a wavelength of 650 nm, the optical signal from the optical communication device 10b is transmitted. Therefore, the optical signal from the optical communication device 10b reaches the optical distributor 2a. The optical signal is input to the optical input unit 20a of the optical distributor 2a and output from the optical output unit 21a connected to the optical distributor 2b, but is attenuated by the filter 40a and returns to the optical distributor 2b. Even so, the power is weak and is not received by the transceiver 12 of the optical communication device 10b.

  In this way, by connecting the optical distributor 2a and the optical distributor 2b, the optical communication device 10a and the optical communication device 10b can transmit and receive optical signals based on CAN, and the optical distribution is achieved by including the filter 40a and the filter 40b. The loop phenomenon of the optical signal between the optical device 2a and the optical distributor 2b can be avoided.

  As shown in FIG. 1 of the first embodiment, the optical communication harnesses 5a and 5b are configured, and the optical communication devices 10a, 10a,..., 10b, 10b,. Thus, an optical communication system that realizes optical communication based on CAN without a GW can be easily constructed. Thereby, it is possible to realize an optical communication system based on the conventional CAN protocol while suppressing the influence of electromagnetic noise and ringing.

(Embodiment 2)
In the first embodiment, the filter 40a is included in the connector 4a connected to the optical output unit 21a to which the optical communication device 10a in the optical output unit 21a of the optical distributor 2a is not connected. On the other hand, in the second embodiment, the filter corresponding to the filter 40a is integrated with the optical distributor 2a.

  The configuration of the in-vehicle optical communication system in the second embodiment is the same as the configuration in the first embodiment. However, it replaces with the optical distributor 2a and the connector 4a, and is set as the structure containing the connector which is not provided with the optical distribution apparatus 6 and the filter 40a.

  FIG. 5 is a block diagram showing a configuration of the in-vehicle optical communication system according to the second embodiment. The in-vehicle optical communication system according to the second embodiment is installed in the vehicle 1, and includes a plurality of optical communication devices 10a, 10a, ..., 10b, 10b, ..., optical distribution devices 6a and 6b, and optical communication lines 3, 3, and so on. … And. The optical distributor 6a and the optical communication line 3 constitute an optical communication harness 7a. Similarly, the optical distributor 6b and the optical communication line 3 constitute an optical communication harness 7b.

  The plurality of optical communication devices 10a, 10a,... Are connected to the optical distribution device 6a in a star shape via the optical communication line 3, respectively. The plurality of optical communication devices 10b, 10b,... Are also connected to the optical distribution device 6b in a star shape via the optical communication line 3 in the same manner. The light distribution device 6a and the light distribution device 6b are distinguished from each other by a line from the light distribution device 6a to the light distribution device 6b and a line from the light distribution device 6b to the light distribution device 6a via the optical communication line 3. Connected.

  FIG. 6 is a block diagram showing a configuration of the light distribution device 6a according to the second embodiment. Since the configurations of the light distribution device 6a and the light distribution device 6b are the same, the details of the light distribution device 6a will be described below, and the detailed description of the light distribution device 6b will be omitted.

  The light distribution device 6a includes a light distributor 60a and a filter 64a.

  Similar to the optical distributor 2a in the first embodiment, the optical distributor 60a is configured by using four inexpensive optical couplers with two inputs and two outputs, and has four optical input portions 61a on one side and the other side. Have four light output portions 62a. The light distributor 60a may be formed of a transparent material such as a cylindrical or prismatic transparent resin or glass. Three of the four optical input units 61a of the optical distributor 60a are connected to the connection terminal and the optical communication line so as to be connected to the optical communication device 10a, and the remaining one is the other It is connected to the terminal 63a via an optical communication line so as to be connected to the optical distribution device 6b. One of the four optical output units 62a is connected to the filter 64a, and the other three optical output units 62a are connected via the connection terminal and the optical communication line so as to be connected to the optical communication device 10a. It is connected.

  The filter 64a is an optical filter, and is connected to the terminal 65a via an optical communication line so as to be connected to the optical distribution device 6b. The filter 64a is the same as the filter 40a in the first embodiment, transmits 100% of the light of the wavelength (650 nm) of the optical signal transmitted by the optical communication device 10a connected to the optical distribution device 6a, and transmits the light to the optical distribution device 6b. The HPF attenuates light having a wavelength (550 nm) of an optical signal transmitted by the connected optical communication device 10b.

  Although not shown, the filter 64b built in the optical distribution device 6b to which the optical communication device 10b is connected is the same as the filter 40b in the first embodiment, and the optical communication device 10b connected to the optical distribution device 6b transmits. It is an LPF that transmits 100% of the light (550 nm) of the optical signal to be transmitted and attenuates the light of the wavelength (650 nm) of the optical signal transmitted by the optical communication device 10a connected to the optical distribution device 6a.

  The optical distribution device 6a and the optical distribution device 6b configured as described above are connected by the optical communication line 3 between the terminal 63a and the terminal 65b, the terminal 65a and the terminal 63b, and the optical communication device 10a is connected to the connection terminal of the optical distribution device 6a. , 10a,... Are connected to the connection terminals of the optical distribution device 6b. As a result, the configuration shown in FIG. 3 in the first embodiment is the same as that shown in FIG. 3, and the optical communication device 10a and the optical communication device 10b can transmit and receive optical signals based on CAN, and include the filter 64a and the filter 64b. The optical signal loop phenomenon between the optical distributor 6a and the optical distributor 6b can be avoided.

  As shown in FIG. 5 of the second embodiment, the optical communication harnesses 7a and 7b are configured, and the optical communication devices 10a, 10a,..., 10b, 10b,. Thus, an optical communication system that realizes optical communication based on CAN without a GW can be easily constructed. Thereby, it is possible to realize an optical communication system based on the conventional CAN protocol while suppressing the influence of electromagnetic noise and ringing.

  In the first and second embodiments, the system capable of optical communication based on CAN has been described. However, the present invention is not limited to CAN, and communication based on a protocol that constantly monitors and detects a collision including a signal transmitted to a communication line, particularly a signal transmitted by itself, is realized by an optical signal. Applicable to all systems.

  In the first and second embodiments, the example applied to the in-vehicle network has been described. However, the present invention is not limited to in-vehicle use, and can be applied to CAN communication such as FA (Factory Automation).

  The disclosed embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

10a Optical communication device (first optical communication device)
10b Optical communication device (second optical communication device)
2a Optical distributor (first optical distributor)
2b Optical distributor (second optical distributor)
3 Optical communication line 4a, 4b Connector 40a Filter (first filter)
40b filter (second filter)
5a, 5b Optical communication harness 6a, 6b Optical distribution device 60a Optical distributor 64a Filter (first filter)

Claims (8)

Has multiple light input units and multiple light output units, distributes and outputs light input from one light input unit to multiple light output units, and connects them with the light input unit and the light output unit A plurality of optical distributors,
A plurality of optical communication devices connected in a star shape via an optical communication line and transmitting / receiving optical signals to a part of the optical input unit and the optical output unit of each of the plurality of optical distributors. An optical communication system. Of the plurality of optical output units of the plurality of optical distributors, connected to an optical output unit connected to another optical distributor, and having a wavelength different from the wavelength of the optical signal transmitted by the plurality of optical communication devices. The optical communication system according to claim 1, further comprising one or more filters for attenuating light. Each has a plurality of light input units and a plurality of light output units, and distributes and outputs the light input from one light input unit to the plurality of light output units. A connected first optical distributor and a second optical distributor;
Each of the optical input unit and the optical output unit of the first and second optical distributors is connected in a star shape via an optical communication line, and transmits an optical signal of the first or second wavelength, A plurality of first and second optical communication devices that receive optical signals of a plurality of different wavelengths including the first or second wavelength;
A first filter connected between one light output of the first light distributor and one light input of the second light distributor and attenuating light of the second wavelength;
A light comprising: one optical output unit of the second optical distributor; and a second filter connected between one optical input unit of the first optical distributor and attenuating light of the first wavelength. Communications system. The optical communication device is:
The optical communication system according to any one of claims 1 to 3, further comprising means for comparing the optical signal being transmitted with the optical signal being received to determine success or failure of transmission. The optical communication system according to any one of claims 1 to 4, wherein the optical communication apparatus is configured to transmit and receive optical signals based on a CAN protocol. A light distributor having a plurality of light input units and a plurality of light output units, and distributing and outputting the light input from one light input unit to the plurality of light output units;
An optical communication line connected to each of the optical input unit and the optical output unit among the plurality of optical input units and the optical output unit;
An optical communication harness comprising: one or a plurality of filters which are connected to an optical communication line connected to a specific light output unit among the plurality of light output units and attenuate light of a predetermined wavelength. The optical communication harness according to claim 6, wherein the filter is provided inside a connector for connecting an optical communication line to another optical distributor. A light distributor having a plurality of light input units and a plurality of light output units, and distributing and outputting the light input from one light input unit to the plurality of light output units;
One or a plurality of filters connected to a specific light output unit among the plurality of light output units and attenuating light of a predetermined wavelength.

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