JP2013218916A - Photo-electric composite cable and photo-electric composite cable unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photo-electric composite cable which is hardly affected by crosstalk.SOLUTION: In the photo-electric composite cable having an optical fiber and a plurality of electric wires inside a sheath, at least one of the plurality of electric wires is defined as a coaxial electric wire, a high-speed signal is transmitted through the optical fiber, and a low speed control signal is transmitted by using the coaxial electric wire. This can provide a photo-electric composite cable which is hardly affected by crosstalk.

Description

  The present invention relates to a photoelectric composite cable having an electric wire and an optical fiber.

  In electronic devices such as medical devices, portable terminals, small video cameras, personal computers, and PDAs (Personal Digital Assistants), high-speed communication is required as functions become more sophisticated. For this reason, the use of a photoelectric composite cable in which an electric wire and an optical fiber are combined is performed (see Patent Document 1).

JP 2012-43557 A

Such an optical / electrical composite cable includes an optical fiber and a plurality of insulated wires arranged around the optical fiber. In this photoelectric composite cable, there is a possibility that crosstalk may occur due to electromagnetic interference caused by each insulated wire. In particular, when the cable length is long, the influence of this crosstalk becomes significant.
Accordingly, an object of the present invention is to provide a photoelectric composite cable that is less affected by crosstalk.

The photoelectric composite cable of the present invention capable of solving the above problems is
An optical / electrical composite cable having an optical fiber and a plurality of electric wires inside an outer jacket,
Among the plurality of wires, at least one is a coaxial wire,
A high-speed signal is transmitted through the optical fiber, and a low-speed control signal is transmitted through the coaxial cable.

In the photoelectric composite cable according to the present invention,
The optical fiber is accommodated inside the inner tube,
All the electric wires including the coaxial electric wires have the same outer diameter,
All the electric wires including the coaxial electric wire may be wound around the outer side of the inner tube in a state of being arranged at equal intervals in the circumferential direction.

In the photoelectric composite cable according to the present invention,
A plurality of the coaxial wires are provided,
The plurality of coaxial electric wires may be arranged adjacent to each other.

In the photoelectric composite cable according to the present invention,
A plurality of the coaxial wires are provided,
The plurality of coaxial electric wires may be bundled in a tape shape.

In addition, the photoelectric composite cable unit of the present invention that can solve the above problems is
The photoelectric composite cable according to the present invention,
A connector that is attached to both ends of the photoelectric composite cable and includes a control unit that receives and transmits a control signal;
The coaxial cable is connected to the control unit.

  According to the optical / electrical composite cable according to the present invention, a high-speed signal is transmitted through an optical fiber, and a low-speed control signal is transmitted through a coaxial cable. By using the coaxial cable, it is possible to prevent deterioration of signal quality due to crosstalk of the low-speed control signal. Therefore, it is possible to provide an optoelectric composite cable that is less affected by crosstalk.

It is sectional drawing which shows the example of embodiment of the photoelectric composite cable which concerns on this invention. It is sectional drawing which shows a coaxial electric wire. It is a schematic diagram which shows the use condition of the photoelectric composite cable unit which concerns on this invention.

Hereinafter, an example of an embodiment of a photoelectric composite cable according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the photoelectric composite cable 10 includes an optical fiber ribbon 12 and a plurality of electric wires 20 and 30 inside an outer tube 17 that is an outermost layer. An optical fiber ribbon 12 having a plurality of optical fibers 11 is accommodated in an inner tube 13 disposed at the center of the cross section of the photoelectric composite cable 10.

  The optical fiber ribbon 12 is obtained by bundling a plurality of optical fibers 11 in a tape shape and covering the outer periphery of the optical fiber 11 with a resin. The optical fiber core wire 11 is formed by forming a coating layer made of an ultraviolet curable resin around an optical fiber made of a core and a cladding, and has a core diameter of 0.05 to 1.0 mm (for example, 0.08 mm) and a cladding. The outer diameter is 0.125 mm, and the outer diameter of the coating layer is 0.25 mm. Further, a coating layer may be further provided to form an optical fiber core wire 11 having an outer diameter of 0.9 mm, or an optical fiber cord in which the optical fiber core wire 11 is further covered with a tensile fiber and a coating layer.

  As the optical fiber core 11, a hard plastic clad fiber (H-PCF) which is made of glass and a clad is made of high-hardness plastic and is strong against bending (kink) and hardly broken, and the core and clad are made of plastic. It may be a plastic fiber.

  For example, when the photoelectric composite cable 10 is used without being bent to a very small diameter like a medical sensor cord, a glass fiber can be used, such as a USB (Universal Serial Bus) cable or an HDMI (High-Definition). If the cable may be bent to a small diameter such as a multimedia interface cable, it is preferable to use a hard plastic clad fiber.

  Only the optical fiber ribbon 12 may be accommodated inside the inner tube 13, but strength may be increased by accommodating tensile strength wires and intervening together with the optical fiber ribbon 12.

  The inner tube 13 has a function as a cushioning material that absorbs the lateral pressure from the electric wires 20 and 30 and the like while protecting the optical fiber core wire 11 from external force. For this reason, the inner tube 13 is formed of a resin having an elastic modulus of 300 MPa or more and has a thickness of 0.1 mm or more. In this example, the inner tube 13 has an inner diameter of about 0.55 mm, an outer diameter of about 1.05 mm, and a thickness of about 0.25 mm.

  As a material of such an inner tube 13, it is preferable to use a tetrafluoroethylene-ethylene copolymer (ETFE) resin, which is a resin material having excellent mechanical strength, and a polybutylene terephthalate (PBT) resin is used. Also good.

  The inner tube 13 is formed so as to cover the optical fiber core wire 11 by extrusion coating resin around the optical fiber core wires 11 arranged.

  Electric wires 20 and 30 are arranged in the accommodating portion 14 formed outside the inner tube 13. Further, a presser winding 18, a shield layer 19, and an outer tube 17 are sequentially provided on the outer sides of the electric wires 20 and 30.

  As the presser winding 18, a resin tape formed from a polyethylene terephthalate (PET) resin having excellent heat resistance and wear resistance is used. As the presser winding 18, a paper tape or a resin tape made of polytetrafluoroethylene (PTFE) resin may be used.

  The shield layer 19 is formed by braiding a tin-plated copper wire or copper alloy wire having an outer diameter of several tens of μm (for example, an outer diameter of about 0.03 mm or 0.04 mm), and has a thickness of about 0.1 mm. Has been. As the shield layer 19, a copper wire or a copper alloy wire may be wound horizontally, and a metal resin tape in which a copper foil or an aluminum foil is formed on a resin tape formed from a polyethylene terephthalate (PET) resin. It can be rolled up.

  The outer tube 17 is made of polyvinyl chloride (PVC), polyolefin resin, or the like. Non-halogen polyolefin-based resins include mixtures of elastomers such as ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), and styrene ethylene butylene styrene block copolymer (SEBS). Moreover, what added a weathering agent, antioxidant, and anti-aging agent to polyethylene (PE) may be used. In addition, as the outer tube 17 using this polyethylene (PE), the non-flame retardant thing which does not contain a flame retardant may be sufficient. The outer tube 17 has a thickness of 0.1 to 0.5 mm (for example, about 0.25 mm), and an outer diameter of several mm to several tens of mm (for example, 3.0 mm).

  A plurality of electric wires 20 and 30 are arranged in the accommodating portion 14 between the inner tube 13 and the presser winding 18. In the present embodiment, as the electric wires 20 and 30, a plurality (here, two) of insulated wires 20 and a plurality of (here, two) coaxial wires 30 used as signal lines are used.

  The insulated wire 20 is a cable in which a jacket 22 covers a central conductor 21 in which a plurality of strands made of annealed copper wire or copper alloy wire plated with tin are twisted together. For example, a cable of about AWG 20 to 46 according to the AWG (American Wire Gauge) standard can be used.

  As a material of the outer sheath 22 of the insulated wire 20, a fluororesin such as a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin having excellent heat resistance, chemical resistance, non-adhesiveness, and self-lubricating property is used. It is preferable to use it. Further, polyethylene (PE) resin or polyvinyl chloride (PVC) resin may be used.

  FIG. 2 is a cross-sectional view of the coaxial cable 30. As shown in FIG. 2, the coaxial cable 30 includes a central conductor 31, an inner coating 32 disposed on the outer periphery of the central conductor 31, an outer conductor 33 disposed on the outer periphery of the inner coating 32, and the outer conductor 33. It is an electric wire provided with the outer coating | cover 34 which covers.

As the center conductor 31, a conductor in which a plurality of strands made of annealed copper wire or copper alloy wire plated with tin is twisted can be used. For the center conductor 31, a cable of about AWG 20 to 46 according to the AWG standard can be used. These two coaxial electric wires 30 are arranged so as to be adjacent to each other, and are further bundled in a tape shape and integrated with a tape resin 35 in this state.
The outer conductor 33 is a net of a plurality of tin-plated copper alloy strands, and is wound around the outer peripheral surface of the inner coating 32.
For the inner coating 32 and the outer coating 34, a fluororesin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin excellent in heat resistance, chemical resistance, non-adhesiveness, self-lubricating property, etc., or polyethylene (PE) resin and polyvinyl chloride (PVC) resin can be used.

  Further, as shown in FIG. 1, when a gap is generated in the accommodating portion 14 in which the insulated wire 20 and the coaxial cable 30 are arranged, the interposition 16 may be arranged in the accommodating portion 14 so as to fill the gap. As the interposition 16, for example, a string of fibers such as rayon or nylon can be used.

  In such an optical / electrical composite cable 10, the outer diameters of all the electric wires 20, 30 including the coaxial electric wire 30 are set to be equal to each other. Further, the electric wires 20 and 30 are spirally wound around the outer periphery of the inner tube 13 in a state of being arranged at equal intervals in the circumferential direction. For this reason, it is hard to produce an unevenness | corrugation in the outer peripheral surface of the photoelectric composite cable 10. In addition, although the two coaxial electric wires 30 are covered with the tape resin 35, since the thickness of the tape resin 35 is small, the unevenness | corrugation which arises on the outer peripheral surface of the photoelectric composite cable 10 is small.

FIG. 3 is a schematic diagram showing an example of a usage state of an optical / electrical composite cable unit using the optical / electrical composite cable 10 according to the present invention.
As shown in FIG. 3, the photoelectric composite cable unit 60 is used to transmit signals between a personal computer 51 and a monitor 52. The photoelectric composite cable unit 60 is configured by attaching connectors 40 to both ends of the photoelectric composite cable 10. By attaching this connector 40 to the personal computer 51 and the monitor 52, the photoelectric composite cable unit 60 connects the personal computer 51 and the monitor 52.

The connector 40 includes a photoelectric conversion circuit 41 including a light emitting / receiving element and a control circuit 42 (control unit) that receives and transmits a control signal.
The control circuit 42 reads information such as the type and resolution of the monitor 52 and transmits this information as an electrical signal to the personal computer 51 via the coaxial cable 30.
The personal computer 51 receives information about the monitor 52 and outputs an image signal corresponding to the monitor 52 toward the monitor 52. The photoelectric conversion circuit 41 converts an electrical signal as an image signal output from the personal computer 51 into an optical signal, and transmits the optical signal to the monitor 52 through the optical fiber core wire 11 at high speed.

  Further, the insulated wire 20 can be configured to transmit a connection signal that notifies the personal computer 51 that the monitor 52 is connected while the monitor 52 is connected. For example, when the connection signal of the monitor 52 is turned off using this connection signal, the personal computer 51 can determine that the connection of the monitor 52 has been released and stop outputting the image signal. Moreover, the insulated wire 20 can also be used as a feeder line.

  As described above, according to the photoelectric composite cable 10 according to the present embodiment, an image signal that needs to transmit a large amount of information at a high speed is transmitted through the optical fiber core wire 11, and a relatively low speed control from the control circuit 42 is performed. The signal is transmitted through the coaxial cable 30. Therefore, even if the length of the optical / electrical composite cable 10 exceeds 5 m, for example, the control signal is transmitted through the coaxial cable 30, so that signal deterioration is suppressed. For this reason, even if it is the long photoelectric composite cable 10, high quality transmission quality can be maintained.

  In particular, when different signals are transmitted by the plurality of electric wires 20, 30, there is a possibility that crosstalk occurs between the electric wires 20, 30. However, according to the optical / electrical composite cable 10 according to the present embodiment, the outer conductor 33 is arranged outside the center conductor 31 in the coaxial cable 30 through which the control signal is transmitted. For this reason, even if the cable length of the photoelectric composite cable 10 is increased, the control signal can be transmitted without deterioration of the signal quality.

  More specifically, when the length of the photoelectric composite cable was 30 m, a control signal having a voltage of 3.3 V was transmitted through the insulated wire 20, and a crosstalk of about 1.5 V was observed. However, when the photoelectric composite cable 10 according to the present embodiment is used, even when the cable length is 30 m, the control signal having a voltage of 3.3 V is transmitted through the coaxial cable 30, and the influence of crosstalk is not observed. It was confirmed that the communication quality was high.

  Further, when a differential signal is transmitted as a control signal by a pair of coaxial cables 30, since two coaxial cables 30 are bundled in a tape shape, a loop between signals is small, and differential mode noise (normal) Mode noise) can be prevented.

  Further, since the plurality of coaxial electric wires 30 are arranged adjacent to each other and are bundled in a tape shape in this state, the plurality of coaxial electric wires 30 are collectively arranged in a part in the circumferential direction of the photoelectric composite cable 10. ing. Therefore, when connecting the coaxial cable 30 to the connector 40, a plurality of coaxial cables 30 can be intensively connected to the control circuit 42, and the connection work is easy.

  Further, the end of the coaxial cable 30 needs to be exposed to a laser beam to peel off the outer coating 34, the outer conductor 33, and the inner coating 32 to expose the center conductor 31 of a predetermined length. Even in this case, since the plurality of coaxial electric wires 30 are collected in a part in the circumferential direction, it is easy to irradiate the plurality of coaxial electric wires 30 with a laser beam, and the extraction process can be efficiently performed.

  In particular, a pair of terminals for inputting / outputting differential signals are arranged in one place on the board of the connector 40, such as being provided adjacent to each other. In the optical / electrical composite cable 10 according to the present embodiment, since a pair of coaxial electric wires 30 that transmit differential signals are bundled in a tape shape, connection work with a pair of terminals that input and output the differential signals is easy. It is.

In the above-described embodiment, an example in which the photoelectric composite cable 10 connects the personal computer 51 and the monitor 52 has been described. However, this example is merely an example, and the present invention is not limited to this example.
Further, although an example in which the control circuit 42 and the photoelectric conversion circuit 41 are provided inside the connector 40 has been described, the present invention is not limited to this example. For example, the connector 40 may not be equipped with the control circuit 42 or the photoelectric conversion circuit 41, and an external device such as the personal computer 51 may output an optical signal or a low-speed control signal.

  Moreover, the number of the optical fiber core wire 11, the insulated wire 20, the coaxial wire 30, and the interposition 16 is not restricted to the example of the said embodiment. Moreover, these thickness and kind are not limited to the example of the said embodiment. In addition, the insulated wires 20, the coaxial wires 30, and the interpositions 16 may not have the same thickness but may have different thicknesses.

  Furthermore, in the above-described embodiment, an example in which a pair of coaxial electric wires 30 are bundled in a tape shape has been described, but each may be disposed inside the outer tube 17 alone. When the differential signal is not transmitted through the coaxial cable 30, the pair of coaxial cables 30 may not be arranged adjacent to each other but may be arranged at positions separated from each other.

10: photoelectric composite cable, 11: optical fiber core wire (optical fiber), 12: optical fiber tape core wire, 13: inner tube, 14: housing portion, 16: interposition, 17: outer tube (outer jacket), 20 : Insulated wire (electric wire), 21: center conductor, 22: insulation coating, 30: coaxial cable (wire), 31: center conductor, 32: inner coating, 33: outer conductor, 34: outer coating, 35: tape resin, 40: connector, 41: photoelectric conversion circuit, 42: control circuit, 51: personal computer, 52: monitor

Claims (5)

An optical / electrical composite cable having an optical fiber and a plurality of electric wires inside an outer jacket,
Among the plurality of wires, at least one is a coaxial wire,
A photoelectric composite cable, wherein a high-speed signal is transmitted through the optical fiber, and a low-speed control signal is transmitted through the coaxial cable. The optical fiber is accommodated inside the inner tube,
All the electric wires including the coaxial electric wires have the same outer diameter,
2. The photoelectric composite cable according to claim 1, wherein all the electric wires including the coaxial electric wires are wound around the outer side of the inner tube in a state of being arranged at equal intervals in the circumferential direction. A plurality of the coaxial wires are provided,
The optoelectric composite cable according to claim 1, wherein the plurality of coaxial electric wires are arranged adjacent to each other. A plurality of the coaxial wires are provided,
The photoelectric composite cable according to claim 1, wherein the plurality of coaxial electric wires are bundled in a tape shape. The photoelectric composite cable according to any one of claims 1 to 4,
A connector that is attached to both ends of the photoelectric composite cable and includes a control unit that receives and transmits a control signal;
The coaxial electric cable is connected to the control unit, and is a photoelectric composite cable unit.

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