JP2008219366A - Optical communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication device enabling each terminal to perform signal processing similarly to a conventional metal LAN even on an optical/metal mixed type passive star type network. <P>SOLUTION: An optical communication device sends out a signal to only an optical fiber 7b when there is an input from only an electric wire 8 and to the electric wire 8 and optical fiber 7b when there is an input from only an optical fiber 7a, and holds both an electric output signal and an optical output signal at H when there are input signals from both the electric wire 8 and optical fiber 7a and one of the electric input signal and optical input signal is at H. Further, when the electric input signal and optical input signal are both at L, the electric input signal and optical input signal are both held at L. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical communication apparatus that can be used in an optical communication system mounted on a vehicle.

  Conventionally, in an in-vehicle communication network (for example, in-vehicle LAN), the number of branches corresponding to an ECU (electronic control unit) corresponding to each node is reduced, and all nodes are connected to a single or a small number of connection points. The mainstream is a passive star network configured by metal wiring.

  In the case of a metal LAN in which a passive star network is configured with metal wiring, reflected waves are generated due to impedance mismatch at each node (ECU) or branch, difference in length of each metal wiring, etc. In some cases, the waveform of the signal is distorted and the electric signal cannot be accurately transmitted.

  In addition, the physical layer of a passive star type metal LAN is often configured in a logical format such as wired OR or wired AND with respect to the electrical signal output from each node, and electrical signals are output simultaneously from two nodes. If so, electrical signals based on these logical forms will be present on the bus. Therefore, each node is provided with a collision detection mechanism for detecting a collision of electrical signals according to these logical forms. For example, when a node does not output “1” (high level H) and “1” is detected on the bus, detection by delaying signal output for a predetermined time at a node with a low priority is detected. It is a function.

  On the other hand, technical development related to a star-type optical communication network using optical communication with little signal waveform deterioration has been performed. For example, in a star-type optical communication network in which a plurality of terminals are connected via an optical fiber and an optical repeater, and the optical repeater is a star branch, an optical signal transmitted from one terminal is received by an optical repeater optical receiver. An optical communication method is proposed in which a received optical signal is temporarily converted into an electrical signal, and the converted electrical signal is further converted into an optical signal and returned to the optical transmitter of each node (see Patent Document 1). ). In this method, an optical signal output from one terminal is transmitted to another terminal by electrically performing star branching.

Further, in a star-type optical communication network in which an optical star coupler is used as a star branch and each node is connected to the optical star coupler, one node is used as an optical repeater, so that an optical LAN and another metal can be connected via the optical repeater. An optical LAN that couples to a LAN has been proposed (see Patent Document 2).
JP 58-106926 A JP-A-63-64437

  However, in the example of Patent Document 1, the star branch is simply configured electrically, and a coupling method to an external metal LAN is not disclosed. On the other hand, in the example of Patent Document 2, a star branch is optically configured, and one of the nodes is connected to a metal LAN with a repeater. When an electrical signal is input from the metal LAN, the repeater converts the electrical signal into an optical signal, and outputs the converted optical signal to the optical LAN. In addition, when an optical signal is input from the optical LAN, the repeater converts the optical signal into an electrical signal, and outputs the converted electrical signal to the metal LAN. Communication can be performed. However, when an electrical signal and an optical signal are input simultaneously to the repeater (ie, when a signal collision occurs), a repeater that simply converts the signal and bypasses it outputs the required electrical or optical signal. I couldn't.

  The problem of signal waveform distortion in a passive star type metal LAN can be solved by using an optical metal hybrid passive star type in which the trunk line of the network is made of metal wiring and the end side from the branch point is made of optical fiber. However, as described above, when signal collision occurs at a branching point between the optical fiber and the metal wiring, there are cases where appropriate signal processing cannot be performed. In particular, a node used on the optical LAN side also becomes a problem when the optical transmission / reception unit and the main body processing unit are configured in the same logical format as the metal LAN.

  In addition, since one of the nodes is connected to the metal LAN as a repeater, for example, an electrical signal input from the metal LAN to the repeater is converted into an optical signal by the repeater, and then passed through a star branch star coupler. Since the signal is transmitted to each node, a signal delay problem may occur due to passing through the repeater.

  The present invention has been made in view of such circumstances, and by providing generation means for generating a signal to be output based on an optical signal and an electric signal input from an optical fiber and an electric wire, An object of the present invention is to provide an optical communication apparatus that can appropriately perform signal processing similar to that of a conventional metal LAN even in a passive star network.

  An optical communication device according to a first aspect of the present invention is the optical communication device to which the first optical fiber, the second optical fiber, the first electric wire, and the second electric wire are connected. An input receiver that outputs the electrical signal of the first, a generating means that generates the second and fourth electrical signals, and an output driver that outputs the second electrical signal generated by the generating means to the second electric wire An optical receiver that converts the first optical signal received from the first optical fiber into a third electrical signal; and the fourth electrical signal generated by the generating means is converted into a second optical signal. And an optical transmitter for outputting to the second optical fiber, and the generating means is configured to generate the second electric signal based on the third electric signal, and the first electric signal And generating a fourth electrical signal based on the third electrical signal. Characterized in that are configured.

  An optical communication device according to a second invention is the optical communication device according to the first invention, wherein the optical signal detection unit detects the presence or absence of the first optical signal, the electrical signal detection unit detects the presence or absence of the first electrical signal, An arithmetic unit that performs a predetermined logical operation based on the electric signal and the third electric signal, and the generation unit corresponds to the third electric signal when only the first optical signal is detected; The second electric signal and the fourth electric signal are configured to be generated. When only the first electric signal is detected, a fourth electric signal corresponding to the first electric signal is generated. When the first optical signal and the first electric signal are detected, the second electric signal and the fourth electric signal corresponding to the logical operation of the arithmetic unit are generated. It is characterized by being.

  An optical communication apparatus according to a third invention is the optical communication device according to the first invention or the second invention, wherein the first optical fiber is divided into a plurality of optical fibers, and the second optical fiber is divided into a plurality of optical fibers. And an optical demultiplexer, wherein the optical multiplexer and the optical demultiplexer are incorporated.

  According to a fourth aspect of the present invention, in the first or second aspect of the invention, the optical transmitter includes a light emitting element, and the light emitting element is directly optically coupled to the plurality of second optical fibers. The light receiving unit includes a light receiving element, and the light receiving element is configured to be directly optically coupled to the plurality of first optical fibers.

  An optical communication apparatus according to a fifth aspect of the present invention is the optical communication apparatus according to any one of the first to fourth aspects, wherein the first optical fiber and the second optical fiber are shared by the same optical fiber. The second optical signal and the first optical signal are transmitted and received.

  An optical communication device according to a sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the first electric wire and the second electric wire are shared by the same electric wire. .

  According to a seventh aspect of the present invention, there is provided an optical communication apparatus according to the first aspect, wherein the delay circuit outputs a delay signal obtained by delaying the third electric signal based on the third electric signal, the delay signal, and the first signal. An arithmetic unit that performs a predetermined logical operation based on an electric signal, and the generation unit is configured to generate a second electric signal corresponding to the third electric signal, and the arithmetic unit The fourth electrical signal corresponding to the output of is generated.

  In the first invention, the input receiver outputs the first electric signal received from the first electric wire to the generating means. The optical receiver converts the first optical signal received from the first optical fiber into a third electrical signal, and outputs the converted third electrical signal to the generation unit. The generation means generates a second electric signal based on the input third electric signal, and the generated second electric signal is output to the second electric wire by the output driver. The generating unit generates a fourth electric signal based on the input first electric signal and third electric signal, and the generated fourth electric signal is transmitted to the second signal by the optical transmission unit. The optical signal is converted into an optical signal, and the converted second optical signal is output to the second optical fiber. For example, the generation unit can generate an output signal based on a logical form of wired OR or wired AND. Thereby, even when an electric signal and an optical signal are input simultaneously (that is, when a signal collision occurs), the required signal processing can be performed. Further, by outputting an optical signal or an electrical signal based on the input optical signal or electrical signal, it can be used as a star branch of an optical LAN or a metal LAN, and signal delay can be prevented.

  In the second invention, when only the first optical signal is detected by the optical signal detector, the generating means generates the second electric signal and the fourth electric signal corresponding to the third electric signal. To do. In addition, when only the first electric signal is detected by the electric signal detection unit, the generation unit generates a fourth electric signal corresponding to the first electric signal. Further, when both the first optical signal and the first electric signal are detected, the generation unit corresponds to the logical operation of the arithmetic unit that performs a predetermined logical operation (for example, a logical operation of wired OR or wired AND). The second electric signal and the fourth electric signal are generated. As a result, even in a passive star type network mixed with optical metal, signal processing equivalent to that of the physical layer of the metal LAN can be performed. A metal mixed LAN can be easily constructed. In addition, even when optical LANs are mixed, each node can perform the same processing (for example, collision detection processing) as that of the physical layer of the metal LAN without any change. .

  In the third aspect of the invention, an optical multiplexer that divides the first optical fiber into a plurality of optical fibers (for example, it does not multiplex light having different wavelengths, but simply multiplexes light propagating through the plurality of optical fibers). And an optical demultiplexer that divides the second optical fiber into a plurality of optical fibers (for example, a device that does not divide light into different wavelengths, but simply branches light into a plurality of optical fibers. Built-in). Thereby, optical communication can be performed between a plurality of ECUs (terminal devices) with a simple configuration.

  In the fourth invention, the optical transmission unit includes a light emitting element that directly optically couples with the plurality of second optical fibers, and the optical receiver includes a light receiving element that directly optically couples with the plurality of first optical fibers. Prepare. Thereby, optical communication can be performed between a plurality of ECUs (terminal devices) with a simple configuration.

  In the fifth invention, the first optical signal and the second optical signal are transmitted and received by optical single-core bidirectional communication in which the first optical fiber and the second optical fiber are shared by the same optical fiber. Thereby, the number of optical fibers can be reduced, and the apparatus can be reduced in size and cost.

  In the sixth invention, the first electric wire and the second electric wire are shared by the same electric wire. Thereby, the number of electric wires can be reduced, and the apparatus can be reduced in size and cost.

  In the seventh invention, the delay circuit generates a delay signal obtained by delaying the input third electric signal by a predetermined time, and outputs the delay signal to the generation means. The generation unit generates a second electric signal corresponding to the third electric signal, and generates a fourth electric signal corresponding to the output of the arithmetic unit that performs a predetermined logical operation (for example, OR operation). Thus, a signal to be output is calculated according to the level of the input electric signal and optical signal (high level or low level) (that is, processed in bit units of the signal).

  In the first invention, required signal processing can be performed even when an electric signal and an optical signal are input simultaneously (that is, when a signal collision occurs). Further, by outputting an optical signal or an electrical signal based on the input optical signal or electrical signal, it can be used as a star branch of an optical LAN or a metal LAN, and signal delay can be prevented.

  In the second invention, even in a passive star type network mixed with optical metal, signal processing equivalent to that of the physical layer of the metal LAN can be performed, and the optical LAN is provided at a location where there are many branches of the conventional metal LAN. By connecting these, an optical metal hybrid LAN can be easily constructed. In addition, even when optical LANs are mixed, each node can perform the same processing (for example, collision detection processing) as that of the physical layer of the metal LAN without any change. .

  In the third invention and the fourth invention, optical communication can be performed with a plurality of ECUs (terminal devices) with a simple configuration.

  In the fifth and sixth inventions, the apparatus can be reduced in size and cost.

  In the seventh invention, the signal to be output is calculated according to the level of the input electric signal and optical signal (whether it is high level or low level). it can.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is an explanatory diagram showing an arrangement example of an optical in-vehicle communication network using optical communication devices 10a and 10b according to an embodiment of the present invention. The optical communication devices 10a and 10b according to the present invention are disposed substantially at the front and rear of the automobile 100, and the optical communication devices 10a and 10b are connected by an electric wire (metal cable) 8 as a trunk line of the optical in-vehicle communication network. Yes. ECUs 1, 2, and 3 are connected to the front optical communication device 10a using the optical fiber 7a as a transmission medium. Similarly, ECUs 4, 5, and 6 are connected to the rear optical communication device 10b via optical fibers 7b. As a result, a passive star type optical in-vehicle communication network of an optical metal hybrid is constructed in which the main line of the network is configured by metal wiring and the end side from the branch point is configured by an optical fiber.

  In this optical in-vehicle communication network, for example, ECUs 1 to 6 for controlling body control, chassis control, temperature control, various sensor controls, dashboard control, navigation, and the like are connected. For example, a signal transmitted from the ECU 1 is transmitted directly to all other ECUs 2, 3, 4, 5, 6 via the optical communication devices 10a, 10b without directly passing through the other ECUs 2, 3,. Can be sent.

  Hereinafter, in the first embodiment, the logic level of the communication physical layer on the metal wiring side includes a high level (hereinafter, H level), a low level (hereinafter, L level), and a no-signal state. It shall be different from the no signal state. Similarly, it is assumed that the logic of the communication physical layer on the optical wiring side also has H level, L level, and no signal state. At the logic level on the optical wiring side, depending on the standard of optical communication, the no-signal state may be an L level, an optical power lower than the L level, or a steady light with a constant optical output. Further, it may be an idling signal composed of a specific signal sequence different from the H level and the L level.

  In general, when a burst signal is transmitted, an optical receiver such as an optical receiver (hereinafter referred to as O / E) often takes time from the start of receiving an optical burst signal until a correct electrical signal can be transmitted. Therefore, in optical communication using an optical burst signal, when an electrical signal is not input to an optical transmitter such as an optical transmitter (hereinafter referred to as E / O), a steady light or an idling optical signal is output to output an optical signal. Some reduce the time from when the receiver starts to receive the optical burst signal until the correct electrical signal can be transmitted. When the idling optical signal is used, the idling optical signal is added by the optical transmitter, and the idling optical signal is removed by the optical receiver. In the following, the state where there is no optical signal includes the case where a standing wave or idling optical signal is used.

  FIG. 2 is a block diagram illustrating a configuration example of the optical communication devices 10a and 10b. The optical communication devices 10a and 10b (hereinafter referred to as 10) include an output driver 11 that outputs an electrical signal, an input receiver 12 that receives the electrical signal, and a switch that has a function of performing a predetermined calculation between the electrical signal and the optical signal. A switch calculation unit 13 that is a circuit, an electric signal detection unit 14 that detects the presence or absence of an input electric signal, a control unit 15 that controls the operation of the optical communication device 10, and an optical signal detection that detects the presence or absence of an input optical signal Unit 16, PD (Photo Diode), O / E 17 that converts an optical signal into an electrical signal, LED or LD (Laser Diode), E / O 18 that converts an electrical signal into an optical signal, and a plurality of optical fibers 7 a And an optical coupler 19 for branching the output optical signal into a plurality of optical fibers 7b, and the like.

  The input receiver 12 outputs an electric signal input through the electric wire 8 to the switch calculation unit 13. The input receiver 12 has an amplification function and the like. The electrical signal detection unit 14 detects the presence or absence of an electrical signal input based on the electrical signal output from the input receiver 12, and outputs the detection result to the control unit 15. Here, the single electric wire 8 is a communication medium that performs two-way communication. However, the electric wire 8 may be a communication medium that includes two communication lines and each transmits a signal in one direction.

  The optical coupler 19 outputs the optical signal transmitted through the optical fiber 7a to the O / E 17. The O / E 17 converts the input optical signal into an electric signal, and outputs the converted electric signal to the switch calculation unit 13. The optical signal detector 16 detects the presence / absence of an optical signal input based on the converted electrical signal output from the O / E 17 and outputs the detection result to the controller 15.

  The switch calculation unit 13 includes switch contacts 13a, 13b, 13c, 13d, 13e, 13f, and the like, and controls opening and closing of the switch contacts 13a,... Based on a control signal input from the control unit 15. When the switches 13c and 13d and the switches 13e and 13f are simultaneously closed (short mode), O / E17 and the wired OR of the output of the input receiver 12 are input to the E / O18. Each of the switch contacts 13a,... Is schematically expressed and can be configured by a semiconductor contact or a logic circuit. In this embodiment, it is unnecessary because it is configured with wired logic. However, in a different embodiment, when logic that cannot be configured with wired OR is required, the switch operation unit 13 uses the logical form of the physical layer of the metal wiring. A logic circuit tailored to is built in.

  When the electrical signal detection unit 14 detects the input of the electrical signal, the control unit 15 outputs the control signal to the switch computation unit 13 and inputs it by closing the switch contacts 13c and 13d of the switch computation unit 13. An electric signal is output to E / O18. The E / O 18 converts the input electrical signal into an optical signal, and outputs the converted optical signal to the optical branching device 20. The optical branching device 20 performs optical branching using an optical fiber, and transmits an optical signal input through the optical fiber 7b to each ECU.

  Further, in this embodiment, the optical fiber 7a that transmits a signal in a direction (hereinafter referred to as uploading direction) from each optical terminal (ECU) toward the optical communication device 10, and from the optical communication device 10 to each terminal (ECU). The optical fiber 7b for transmitting a signal in the direction of travel (hereinafter referred to as the download direction) is separate. However, each terminal (ECU) has one fiber, that is, bidirectional communication can be performed with one fiber. It may be summarized as follows. In this case, it is desirable that the optical coupler 19 and the optical branching device 20 are combined into one.

  Here, the optical coupler 19 and the optical branching device 20 may be branched by an optical component such as a substrate-type optical waveguide branch or a prism or a half mirror in addition to the branching of the optical signal by the optical fiber. In FIG. 2, the optical coupler 19 and the optical branching device 20 are built in the optical communication device 10. However, in general, optical components such as the optical coupler and the optical branching device are difficult to reduce in size. You may install outside the housing | casing of the optical communication apparatus 10. FIG. Further, the E / O side may be configured to output the same optical signal to a plurality of optical fibers using a laser array instead of the optical branching unit 20, or a plurality of light emitting elements (LED, LD, etc.) may be used. In this case, a plastic optical fiber (POF) having a cladding thickness smaller than the core diameter can reduce the amount of light that is not incident on the core. It is. Similarly, the O / E side may have a configuration in which optical signals are input from a plurality of optical fibers using a PD array, or a configuration in which optical signals are input from a plurality of optical fibers to one PD.

  When the optical signal detection unit 16 detects the input of the optical signal, the control unit 15 outputs a control signal to the switch calculation unit 13 and closes the switch contacts 13 a and 13 b of the switch calculation unit 13, thereby causing the O / E 17. The electrical signal output from is output to the output driver 11. The output driver 11 outputs an electric signal input through the electric wire 8. The output driver 11 has an amplification function and the like. Further, by closing both the switch contacts 13e and 13f of the switch calculation unit 13, the electrical signal output from the O / E 17 is output to the E / O 18. The E / O 18 outputs an optical signal through the optical splitter 20 and the optical fiber 7b.

  The control unit 15 detects the input of the electrical signal by the electrical signal detection unit 14 and detects the input of the optical signal by the optical signal detection unit 16, that is, when the electrical signal and the optical signal are input simultaneously, The control signal is output to the switch calculation unit 13, the switch contacts 13a and 13b, the switch contacts 13c and 13d, and the switch contacts 13e and 13f of the switch calculation unit 13 are closed, and the O / E 17 and the input receiver 12 output An electric signal is output to the output driver 11 and the E / O 18. Thereby, while outputting an electrical signal through the electric wire 8, an optical signal is output through the optical fiber 7b. Note that the logic of the outputs of the O / E 17 and the input receiver 12 in this case will be described later.

  FIG. 3 is an explanatory diagram illustrating a calculation example of the switch calculation unit 13 and a logical calculation example of the switch calculation unit when an electric signal and an optical signal are simultaneously input. As shown in Table A of FIG. 3, the state 1 is a state in which there is no input signal (electrical signal, optical signal) from either the electric wire 8 or the optical fiber 7a, and the optical communication device 10 includes the electric wire 8 and the optical fiber. No signal (electric signal, optical signal) is output to any of 7b. Depending on the optical communication standard, an L level, steady light, or idling optical signal may be output to the optical fiber 7b.

  In Table A, state 2 is a state in which there is an input signal (optical signal) only from the optical fiber 7a, and the optical communication device 10 transmits a signal (for example, the same electrical signal and optical signal) corresponding to the input signal to the electric wire. 8 and the optical fiber 7b.

  In Table A, state 3 is a state in which an input signal (electrical signal) is present only from the electric wire 8, and the optical communication device 10 outputs the same signal (optical signal) as the input signal to the optical fiber 7b.

  In Table A, state 4 is a state in which there are input signals (electrical signals, optical signals) from both the electric wires 8 and the optical fiber 7a, and the optical communication device 10 will be described later based on the input electrical signals and optical signals. A predetermined calculation is performed, and a signal (electric signal, optical signal) corresponding to the calculation result is output to the electric wire 8 and the optical fiber 7b. As described above, the state where there is no electrical output signal is, for example, that the output impedance is set to a high impedance state, and not a low level (L).

  Table B in FIG. 3 shows the contents of the logical operation of the switch operation unit 13 in the case of state 4 in Table A. A case where the electrical signal and the optical signal are at a high level is indicated by H, and a case where the electrical signal and the optical signal are at a low level is indicated by L. In the logical operation shown in Table B, when each node (ECU) is connected to the metal wiring LAN, the interface of each node is constituted by, for example, an open collector inverter of a PNP transistor and has a wired OR logic form. . In the optical communication apparatus 10, it is assumed that the O / E 17 and the input receiver 12 have the same interface configuration. Therefore, in this embodiment, there is no logic gate, but if the output interface when the output interface of the O / E 17 and the input receiver 12 and each node (ECU) are connected by the metal wiring LAN is different, A logic gate is required.

  When both the electrical input signal and the optical input signal are H, both the electrical output signal and the optical output signal are set to H. When the electrical input signal is H and the optical input signal is L, both the electrical output signal and the optical output signal are set to H. When the electrical input signal is L and the optical input signal is H, both the electrical output signal and the optical output signal are set to H. When both the electrical input signal and the optical input signal are L, both the electrical output signal and the optical output signal are set to L.

  Thereby, even if an electrical signal and an optical signal are simultaneously input from the electric wire 8 and the optical fiber 7a, a signal can be output to all the ECUs connected to the optical communication device 10. In addition, the signal acquired by each ECU is the same as the signal (logical form) received in the case of a network configured only by a metal LAN without an optical LAN, and a new collision detection mechanism needs to be configured on the network. In each ECU, the conventional collision detection mechanism can be used as it is without any change. Further, the optical communication device 10 can directly connect the electric wire 8 and the optical fibers 7a and 7b in a star shape. For example, two optical LANs can be connected via the electric wire 8 without intermediating each node of the two optical LANs as a repeater. Since the optical LAN can be directly connected by the optical communication device 10, it is possible to prevent signal delay due to passing through the repeater.

  Note that even if the optical transmission / reception unit in the terminal (ECU) used on the optical LAN side and the main body processing unit are configured in the same logical format as that of the metal LAN, the optical transmission / reception unit of the terminal performs this implementation. In the configuration of the optical communication apparatus 10 of the example, it is possible to use a configuration that does not include the optical splitter 20 and the optical coupler 19, but in this case, since it is not a star type, it can also be applied to a normal repeater. .

  FIG. 4 is a block diagram showing a configuration example of a terminal (ECU) 50 connected to the optical LAN when a repeater is used. The terminal 50 includes an E / O 51, an O / E 52, a transmission interface unit 53, a reception interface unit 54, a main body processing unit 55, and the like. The O / E 52 receives the optical signal from the optical fiber 7 b and outputs it to the reception interface unit 54 of the main body processing unit 55. On the other hand, the E / O 51 receives an optical signal from the transmission interface unit 53 of the main body processing unit 55 and outputs it to the optical fiber 7a. As the repeater, it is possible to use a configuration in which the optical branching device 20 and the optical coupler 19 are omitted from the configuration of the optical communication apparatus 10 of the present embodiment. Even when the configuration of the optical communication apparatus 10 of this embodiment is used or when a repeater is used, in order to avoid the logic level being locked to H, the metal wiring between the optical transmission / reception unit and the main body processing unit is shown in FIG. As shown in FIG. 4, the upload direction and the download direction need to be separately wired, but there is no problem even if separate wiring is provided in the terminal because the distance between the optical transmission / reception unit and the main body processing unit is short. .

  Next, a second embodiment will be described. In the case of a metal LAN, there is a standard in which it cannot be determined whether there is no output signal from each node in a short period of time or whether a high level or low level signal is present. Even in such a case, in the present invention, signal calculation can be performed as follows.

  Hereinafter, the case where the electrical signal and the optical signal are at the high level is indicated by H, and the case where the electrical signal and the optical signal are at the low level is indicated by L. When each node (ECU) is connected to the metal wiring LAN, the logical form on the interface of each node is, for example, a wired OR formed by an open collector inverter of a PNP transistor. Further, it is assumed that a level that cannot be distinguished from a state where there is no electrical signal is a low level (L), and the optical fiber and the metal wiring have only a state of H and L.

  FIG. 5 is a block diagram illustrating a configuration example of the optical communication device 60. In the drawing, the optical coupler and the optical branching device are omitted. A signal input from the optical fiber 65 a is converted into an electrical signal by the O / E 67, and the converted electrical signal is output to the output driver 61 and the delay circuit 64. The output driver 61 outputs the input electrical signal to the electric wire 8. It is assumed that the output impedance of the output driver 61 is high (high impedance state) when the electrical signal to be output is L. On the other hand, the input receiver 62 outputs an electric signal input through the electric wire 8 to the OR circuit 63. The OR circuit 63 ORs both the output of the delay circuit 64 and the output of the input receiver 62 and outputs the result to the E / O 68. The E / O 68 outputs an optical signal to the optical fiber 65b. The delay time of the delay circuit 64 is that the output signal of the O / E 67 is transmitted to the OR circuit 63 via the output driver 61, the electric wire 8, and the input receiver 62, and the output signal of the O / E 67 is passed through the delay circuit 64. The delay time transmitted to the OR circuit 63 is set to be equal.

  FIG. 6 is an explanatory diagram showing the calculation of the optical communication device 60. State 1 is a state in which both the electrical input signal and the optical input signal are L. The output driver 61 sets the electrical output signal to “no” (a state in which the output impedance is high), and sets the optical output signal to L. . State 2 is a state in which the electrical input signal is L and the optical input signal is H, and both the electrical output signal and the optical output signal are H. This state 2 transitions to state 4 described later. State 3 is a state in which the electrical input signal is H and the optical input signal is L. The electrical output signal is “None” and the optical output signal is H. State 4 is a state in which both the electrical input signal and the optical input signal are H, and both the electrical output signal and the optical output signal are H.

  In this embodiment, there is no input signal in a no-signal state, and the signal is only a binary value of H or L. Therefore, the input signal operates in conjunction with the signal detection circuit as in the first embodiment or the signal detection circuit. There is no need for a switch circuit. A signal to be output is calculated according to the level of the input electric signal and optical signal (high level or low level) (that is, processed in bit units of the signal).

  The reason for including the delay circuit 64 is that the delay time to the optical fiber 65b when the input from the optical fiber 65a transits from H to L is the same as the delay time at the transition from L to H. This is to avoid the occurrence of pulse width distortion.

  In an optical in-vehicle communication network, depending on the location of an ECU corresponding to a node, in an optical metal hybrid passive star type network, there is a case where an optical LAN is desired to be branched into a star type in the middle of a trunk line composed of metal wiring. . In this case, the output terminals of the output drivers 11 and 61 and the input terminals of the input receivers 12 and 62 may be connected in the middle of the main line.

  As described above, in the present invention, required signal processing can be performed even when an electric signal and an optical signal are input simultaneously (that is, when a signal collision occurs). . Further, it can be used as a star branch of an optical LAN and a metal LAN, and signal delay can be prevented. In addition, even in a configuration in which a plurality of optical fibers and a plurality of metal wirings are branched, the required signal processing can be performed, and the degree of freedom in the configuration of a passive star network in which optical metals are mixed is improved. be able to. In addition, even a passive star type network mixed with optical metal can perform signal processing equivalent to that of the physical layer of the metal LAN, and an optical metal is connected to a location where there are many branches of the conventional metal LAN. A hybrid LAN can be easily constructed. Each node can perform the same processing as that of the physical layer of the metal LAN without any change even if the optical LAN is mixed.

  In the above-described embodiment, the number of ECUs to be used, arrangement examples, and the like are examples, and the present invention is not limited to these. The present invention is not limited to the examples.

  In the above-described embodiment, an example in which the optical communication device is used in an in-vehicle optical communication network has been described. However, the present invention is not limited to in-vehicle use. In addition, the optical fiber as an example of the optical transmission line is not limited to POF, and may be glass fiber, plastic clad silica fiber, etc., depending on the place and environment in which it is used. A configuration like an optical waveguide may be used.

  When an electric wire and an optical fiber are connected to the optical communication device of the present invention, the optical communication device can be appropriately mounted and miniaturized according to the arrangement location of the optical communication device and the arrangement location of the electric wire and the optical fiber.

It is explanatory drawing which shows the example of arrangement | positioning of the optical vehicle-mounted communication network using the optical communication apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structural example of an optical communication apparatus. It is explanatory drawing which shows the example of a logic operation of the switch calculating part when the example of a calculation of a switch calculating part and an electric signal and an optical signal are input simultaneously. It is a block diagram which shows the structural example of the terminal (ECU) 50 connected to optical LAN in the case of using a repeater. It is a block diagram which shows the structural example of an optical communication apparatus. It is explanatory drawing which shows the calculation of an optical communication apparatus.

Explanation of symbols

1, 2, 3, 4, 5, 6 ECU
7a, 7b, 65a, 65b Optical fiber 8 Electric wire 10, 10a, 10b, 60 Optical communication device 11, 61 Output driver 12, 62 Input receiver 13 Switch operation unit 14 Electric signal detection unit 15 Control unit 16 Optical signal detection unit 17, 52, 67 O / E
18, 51, 68 E / O
DESCRIPTION OF SYMBOLS 19 Optical coupler 20 Optical splitter 53 Transmission interface part 54 Reception interface part 55 Main body process part 63 OR circuit 64 Delay circuit

Claims (7)

In the optical communication device to which the first optical fiber and the second optical fiber, and the first electric wire and the second electric wire are connected,
An input receiver for outputting a first electrical signal received from the first electric wire;
Generating means for generating a second electrical signal and a fourth electrical signal;
An output driver for outputting the second electric signal generated by the generating means to the second electric wire;
An optical receiver for converting the first optical signal received from the first optical fiber into a third electrical signal;
An optical transmitter that converts the fourth electrical signal generated by the generating means into a second optical signal and outputs the second optical signal to the second optical fiber;
The generating means includes
Configured to generate a second electrical signal based on the third electrical signal;
An optical communication device configured to generate a fourth electrical signal based on the first electrical signal and the third electrical signal. An optical signal detector for detecting the presence or absence of the first optical signal;
An electrical signal detector for detecting the presence or absence of the first electrical signal;
An arithmetic unit that performs a predetermined logical operation based on the first electric signal and the third electric signal;
The generating means includes
When only the first optical signal is detected, the second electric signal and the fourth electric signal corresponding to the third electric signal are generated.
When only the first electrical signal is detected, a fourth electrical signal corresponding to the first electrical signal is generated, and
When the first optical signal and the first electric signal are detected, the second electric signal and the fourth electric signal corresponding to the logical operation of the arithmetic unit are generated. The optical communication device according to claim 1. An optical multiplexer for dividing the first optical fiber into a plurality of optical fibers;
An optical demultiplexer that divides the second optical fiber into a plurality of optical fibers,
The optical communication apparatus according to claim 1, wherein the optical multiplexer and the optical demultiplexer are built in. The optical transmitter includes a light emitting element,
The light emitting element is configured to be optically coupled directly to the plurality of second optical fibers,
The light receiving unit includes a light receiving element,
The optical communication apparatus according to claim 1, wherein the light receiving element is configured to be directly optically coupled to the plurality of first optical fibers.   The second optical signal and the first optical signal are transmitted and received by optical single-core bidirectional communication in which the first optical fiber and the second optical fiber are shared by the same optical fiber. The optical communication device according to claim 1.   The optical communication device according to claim 1, wherein the first electric wire and the second electric wire are configured to be shared by the same electric wire. A delay circuit that outputs a delayed signal obtained by delaying the third electrical signal based on the third electrical signal;
An arithmetic unit that performs a predetermined logical operation based on the delay signal and the first electric signal;
The generating means includes
A second electrical signal is generated in response to the third electrical signal;
The optical communication device according to claim 1, wherein the optical communication device is configured to generate a fourth electrical signal corresponding to the output of the arithmetic unit.

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