PHOTOELECTRIC COMPOSITE CONNECTOR

A photoelectric composite connector mounted on a circuit board is provided, in which assembly of the photoelectric composite connector can be performed easily. A photoelectric composite connector 1 attached to a circuit board, comprising at least one optical ferrule 40, at least one electrical connection terminal 50, a housing 10 to which the optical ferrule 40 and the electrical connection terminal 50 can be attached, and a retainer member 20 that can be fitted in the housing 10, the electrical connection terminal 50 being directly secured to the housing 10, and the optical ferrule 40 being sandwiched between the housing 10 and the retainer member 20 and held in the housing 10.

TECHNICAL FIELD

The present disclosure relates to a photoelectric composite connector.

BACKGROUND

An optical cable using an optical fiber is widely used in information communication for household, industry and the like since high-speed communication of a large amount of information is possible. Further, various electronic devices such as a car navigation system are equipped in an automotive vehicle. Optical communication using an optical cable has begun to be used also for communication in those devices. Particularly, the speed up of communication has accelerated in the field of automotive vehicles in recent years. However, there are many problems in carrying out high-speed communication exceeding several Gbps by an electrical cable. With the speed up of communication, optical cables capable of dealing with high-speed communication are becoming more and more important in in-vehicle communication devices. Particularly, an optical cable provided with an optical fiber made of glass can be suitably used in high-speed communication.

On the other hand, an optical cable is not suitable for supplying an energy necessary to operate a communication device, and a wire provided with a metal wire is also used together with the optical cable. Accordingly, to enable an optical cable and a wire to be easily connected to a printed circuit board of a communication device or the like, connectors capable of collectively connecting an optical cable and a wire to a printed circuit board of a device have been and are being developed. Optical-electrical composite connectors of that type are disclosed in patent literature 1 and the like and some have been put to practical use.

PRIOR ART DOCUMENT

Patent Document

Patent Document 1: International Publication WO 2007/088863

SUMMARY OF THE INVENTION

Problems to be Solved

As described above, photoelectric composite connectors have been and are being developed as a means for collectively connecting an optical cable and a wire to a printed circuit board, but the composite connectors of that type tend to be difficult to manufacture as compared to optical connectors for connecting only an optical cable and electrical connectors for connecting only a wire. Patent literature 1 discloses a photoelectric composite connector to be mounted on a circuit board. A transmission side module including a light emitting element and a reception side module including a light receiving element are incorporated, together with an electrical connector and an optical connector, into this photoelectric composite connector. If the modules for optical communication are incorporated into the connector in this way, the internal structure of a connector housing becomes complicated and high accuracy is required for the alignment of respective members to be accommodated. Then, it is difficult to assemble the composite connector. Further, a manufacturing process and a manufacturing facility are normally totally different for optical connectors and for electrical connectors and it tends to be difficult to assemble a composite connector provided with both an electrical connection part and an optical communication part including modules in the same manufacturing line. Particularly, with the speed up of communication in automotive vehicles, conventionally used plastic optical fibers (POFs) have been replaced by glass optical fibers (AGFs) in recent years. Since AGFs have a smaller diameter than POFs, an optical communication member for AGF is smaller in size than an optical communication member for POF and required to have a high arrangement accuracy. Thus, it is particularly difficult to manufacture a composite connector by precisely arranging the optical communication member for AGF in a connector housing.

Accordingly, it is aimed to provide an easily assemblable photoelectric composite connector to be mounted on a circuit board.

Means to Solve the Problem

The present disclosure is directed to a photoelectric composite connector to be mounted on a circuit board, the photoelectric composite connector being provided with at least one optical ferrule, at least one electrical connection terminal, a housing mountable with the optical ferrule and the electrical connection terminal, and a retainer member fittable to the housing, the electrical connection terminal being directly fixed to the housing, and the optical ferrule being held in the housing by being sandwiched between the housing and the retainer member.

Effect of the Invention

A photoelectric composite connector according to the present disclosure is an easily assemblable photoelectric composite connector to be mounted on a circuit board.

DETAILED DESCRIPTION TO EXECUTE THE INVENTION

Description of Embodiments of Present Disclosure

The photoelectric composite connector of the present disclosure is to be mounted on a circuit board and provided with at least one optical ferrule, at least one electrical connection terminal, a housing mountable with the optical ferrule and the electrical connection terminal, and a retainer member fittable to the housing, the electrical connection terminal being directly fixed to the housing, and the optical ferrule being held in the housing by being sandwiched between the housing and the retainer member.

The photoelectric composite connector is provided with the optical ferrule as an optical communication member. An optical fiber can be coupled to this optical ferrule and coupled to an optical communication module including a light emitting element, a light receiving element and the like. Then, even without incorporating an optical communication module into the photoelectric composite connector, an optical signal can be transmitted and received between an optical communication member such as an optical ferrule of a mating connector and the optical communication module. By not incorporating the optical communication module into the photoelectric composite connector, the structure of the photoelectric composite connector is simplified and the photoelectric composite connector is easily assembled. Further, in the above photoelectric composite connector, the optical ferrule is not directly fixed to the housing, but is held in the housing by being sandwiched between the housing and the retainer member fit to the housing. Thus, only by fitting the retainer member to the housing, the optical ferrule can be mounted in the housing and the photoelectric composite connector is more easily assembled. An effect of simplifying an assembly process of the photoelectric composite connector is particularly notable in the case of applying the photoelectric composite connector to optical communication using a thin optical fiber such as an AGF.

Here, the photoelectric composite connector may be further provided with a split sleeve, the optical ferrule being insertable into the split sleeve, and the optical ferrule may be held in the housing by being sandwiched between the housing and the retainer member with a tip portion of the optical ferrule accommodated in the split sleeve. By using the split sleeve, the optical ferrule can be positioned with high accuracy in the photoelectric composite connector. Further, optical communication can be performed with the tip surfaces of the both optical ferrules accurately butted against each other by inserting the optical ferrule of the mating connector into the split sleeve from an opposite side.

The optical ferrule may be coupled to an optical fiber and fixed to the circuit board via the optical fiber or coupled to an optical communication module mounted on the circuit board via the optical fiber. By mounting the photoelectric composite connector on the circuit board in that way, an optical signal can be transmitted and received between an external optical communication member and an optical communication member on the circuit board via the photoelectric composite connector even without providing the optical communication module in the photoelectric composite connector. Further, the same photoelectric composite connector can be used for various applications of optical communication by selecting a fixed position of the optical fiber and the type of the optical communication module coupled to the optical fiber.

The electrical connection terminal may be directly electrically connected to the circuit board at a board connecting portion projecting outwardly of the housing. Then, the configuration of an electrical connection part of the photoelectric composite connector and the configuration of a connected part to the circuit board can be simplified.

In this case, the board connecting portion of the electrical connection terminal may be electrically connected to the circuit board by surface mounting by soldering or being inserted into a through hole. Then, the configuration of the electrical connection part of the photoelectric composite connector can be simplified and electrical connection to the circuit board can be easily established.

Details of Embodiment of Present Disclosure

Hereinafter, a photoelectric composite connector according to an embodiment of the present disclosure is described in detail using the drawings. In this specification, terms indicating the shapes and arrangements of members such as a “hollow cylindrical shape,” a “rectangular tube shape” and “parallel” include not only geometrically strict concepts, but also errors within a generally allowable range as the photoelectric composite connector.

<Summary of Structure of Optical-Electrical Composite Connector>

FIGS.1and2are perspective views respectively showing a photoelectric composite connector (hereinafter, may be merely referred to as a composite connector)1according to one embodiment of the present disclosure when viewed from behind and front.FIG.3shows a state where a retainer member20is removed inFIG.1. The composite connector1according to this embodiment is configured as a board connector to be mounted on a circuit board such as a printed circuit board (PCB), and optical connection for optical communication and electrical connection for conduction are simultaneously performed between the composite connector1and a mating connector.

The composite connector1according to this embodiment is provided with at least one optical ferrule40as an optical communication part and at least one electrical connection terminal50as an electrical connection part. The composite connector1includes a housing10mountable with the optical ferrule40and the electrical connection terminals50, and a retainer member20fittable to the housing10. The electrical connection terminals50are fixed to the housing10, and the optical ferrule40is mounted in the housing10by the retainer member20.

Here, before the structure of the composite connector1according to this embodiment is described in detail, a used state of the composite connector1is described.FIG.5shows an example of the used state of the composite connector1, together with related members. As shown inFIG.5, the housing10of the composite connector1is mounted on a circuit board B. The optical ferrule40and the electrical connection terminals50are mounted in the housing10. Out of these, the electrical connection terminals50are directly electrically connected to the circuit board B at board connecting portions51on rear end sides. The optical ferrule40is used by being coupled to an optical fiber F. The optical fiber F is joined to the optical ferrule40on a tip side, and coupled to an optical communication module M mounted on the circuit board B on a rear end side. Here, the optical communication module M is a module contributing to optical communication by receiving or transmitting an optical signal, and a photodiode (PD) or a laser diode (LD) can be illustrated as such.

The housing10of the composite connector1includes a fitting portion12open forward. A mating connector9can be inserted and fit into this fitting portion12. Here, the mating connector9is, for example, a photoelectric composite cable connector and provided with a mating optical ferrule91and mating electrical connection terminals92. If the mating connector9is connected to the composite connector (board connector)1according to this embodiment fixed to the circuit board B, the tip surfaces of the both optical ferrules40,91are butted against each other to establish optical connection. Further, terminal connecting portions52of the electrical connection terminals50and mating electrical connection terminals92are fit to each other to establish electrical connection. In this way, an optical signal path is formed between an optical cable93and the optical communication module M on the circuit board B and conduction is established between wires94and an electrical circuit on the circuit board B via the composite connector1.

Although the optical fiber F coupled to the optical ferrule40of the composite connector1is directly coupled to the optical communication module M in the shown embodiment, the optical fiber F may be fixed to the circuit board B by bonding or the like. Then, the optical fiber F fixed to the circuit board B may be appropriately used for connection to another member on the circuit board B or by being pulled out to the outside of the circuit board B. For example, an intermediate part of the optical fiber F may be fixed to the circuit board B, one end thereof may be coupled to the optical ferrule40of the composite connector1and the other end thereof may be coupled to the optical communication module M mounted on the circuit board B.

Next, the structure of the photoelectric composite connector according to this embodiment is described in detail.

In this specification, a vertical direction (c direction) is specified such that a connection direction of the composite connector1to the circuit board B is a downward direction. Axial directions of the optical ferrule40and the electrical connection terminals50orthogonal to the vertical direction are specified as a front-rear direction (a direction). Tip sides of the optical ferrule40and the terminal connecting portions52of the electrical connection terminals50are front sides. Further, a direction orthogonal to the vertical direction and front-rear direction is specified as a width direction (b direction). The optical ferrule40and the electrical connection terminals50are arranged in parallel in the width direction.

The optical ferrule40is constituted by a known optical fiber ferrule. The optical ferrule40integrally includes a tip portion41, a flange portion42and a rear end portion43(seeFIG.4B). The tip portion41and the rear end portion43are in the form of bars. The flange portion42has a larger dimension than the tip portion41and the rear end portion43and has a tapered shape widened from the side of the front end portion41toward the side of the rear end portion43. The optical fiber F can be coupled to the optical ferrule40. Here, the details of the types of the optical fiber F and the optical ferrule40are not particularly limited. However, from the perspective of application to high-speed communication, a glass optical fiber (AGF) is preferably used as the optical fiber F. Generally widely used AGFs have a cladding diameter of 125 μm and, even in the case of a multi-mode type, have a small core diameter of 100 μm or less, and the compatible optical ferrule40also has a small tip surface area. The tip of the optical fiber F is coupled and fixed to the optical ferrule40while being held flush with the tip surface of the optical ferrule40.

The electrical connection terminal50is configured as an electrical connection terminal for known insulated wire. Although the type and shape of the electrical connection terminal50are not particularly limited, the electrical connection terminal50includes the terminal connecting portion52on a front end side and the board connecting portion51on a rear end side here. The terminal connecting portion52is a connecting portion electrically connectable to the electrical connection terminal92of the mating connector9and, for example, the form of a fitting-type male terminal can be suitably applied. The board connecting portion51is a connecting portion electrically connectable to the circuit board B. In the shown embodiment, the board connecting portion51is configured as a through hole pin to be inserted into a through hole of the circuit board B. Alternatively, the board connecting portion51may be configured as a board connection terminal (SMT terminal) to be surface-mounted by soldering, a press-fit pin to be press-fit into the through hole or the like. In the shown embodiment, the electrical connection terminal50includes a bent portion53in an intermediate part, whereby the terminal connecting portion52extends forward and the board connecting portion51extends downward. Projections54protruding in the width direction in a stepwise manner (seeFIG.4A) are provided on a part between the terminal connecting portion52and the bent portion53.

In the shown embodiment, the composite connector1is provided with one optical ferrule40and a pair of the electrical connection terminals50. However, the numbers of the optical ferrules40and the electrical connection terminals50provided in the composite connector1are not particularly limited as long at least one of each is provided. In the case of providing a plurality of the optical ferrules40, each optical ferrule40is independently coupled to the optical fiber F.

The housing10is a case member made of resin. The housing10is substantially in the form of a rectangular tube including the fitting portion12as a space capable of accommodating the mating connector9on a front side. At positions of a rear wall surface11, the housing10includes a ferrule mounting portion14for mounting the optical ferrule40and a terminal mounting portion15for mounting the electrical connection terminals50, integrally with the rear wall surface11.

The electrical connection terminals50are directly fixed to the housing10in the terminal mounting portion15.FIG.4Aenlargedly shows a transverse cross-section at the position of the terminal mounting portion15, i.e. a cross-section passing through centers of the electrical connection terminals50and perpendicular to the vertical direction. The terminal mounting portion15is provided with terminal insertion holes151as holes penetrating through the rear wall surface11of the housing10. The electrical connection terminals50are inserted through the terminal insertion holes151and held in the terminal mounting portion15at the positions of the projections54. A width d of the terminal insertion hole151of the terminal mounting portion15is smaller than a width of the electrical connection terminal50, and the electrical connection terminal50is fixed to the terminal mounting portion15by being press-fit into the terminal insertion hole151. Further, tops of the projections54bite into the wall surface of the terminal insertion hole151, whereby the electrical connection terminal50is firmly fixed. If the electrical connection terminal50is fixed in the terminal mounting portion15, the terminal connecting portion52projects forward in the fitting portion12of the housing10in a front part of the electrical connection terminal50. On the other hand, a rear part of the electrical connection terminal50projects rearward outside the rear wall surface11of the housing10and the board connecting portion51projects downward across the bent portion53.

The optical ferrule40is held in the housing10in the ferrule mounting portion14, but not directly fixed to the housing10unlike the electrical connection terminals50.FIG.4Bshows a transverse cross-section of the composite connector1at the position of the ferrule mounting portion14, i.e. a cross-section passing through a center of the optical ferrule40and perpendicular to the vertical direction. The ferrule mounting portion14integrally includes a tubular portion145provided in front of the rear wall surface11of the housing10and an open portion140provided behind the housing rear wall surface11. The tubular portion145is a hollow cylindrical part extending forward into the fitting portion12from the rear wall surface11of the housing10and is open on both front and rear ends. An inner diameter of the tubular portion145is set such that a split sleeve60to be described later can be press-fit and the flange portion42of the optical ferrule40cannot be inserted.

The open portion140of the ferrule mounting portion14integrally has a bottom surface141extending rearward from the housing rear wall surface11and side surfaces142rising on both widthwise ends of the bottom surface141. An accommodation space14S surrounded by the bottom surface141and the side surfaces142on both sides is continuous with a hollow part of the tubular portion145. Upper and rear sides of the accommodation space14S are open without being covered by wall surfaces. The accommodation space14S can accommodate the flange portion42and the rear end portion43of the optical ferrule40. Step structures are formed along the front-rear direction inside the side surfaces142such that a front part of the accommodation space14S serves as a flange portion accommodation space S1having a narrow width and a rear part of the accommodation space14S serves as a rear end portion accommodation space S2having a wide width. Engaging projections13are formed outside the side surfaces142on the both sides of the open portion140.

The optical ferrule40is accommodated into the tubular portion145of the ferrule mounting portion14with the tip portion41accommodated in the split sleeve60. The split sleeve60is a tubular member made of metal and formed with a slit along an axial direction, and squeezes and holds the optical ferrule40inserted thereinto inwardly with a resilient force. The split sleeve60functions to make the positioning of the optical ferrule40easier and more accurate and further enhance the accuracy of connection to the optical ferrule91of the mating connector90.

In the ferrule mounting portion14, the split sleeve60having the tip portion41of the optical ferrule40inserted therein is inserted into the tubular portion145from behind. In a state after insertion, the split sleeve60is press-fit in the tubular portion145and the tip portion41of the optical ferrule40is press-fit in a rear part of the split sleeve60. The flange portion42and the rear end portion43of the optical ferrule40are accommodated into the accommodation space14S of the open portion140and project rearwardly of the housing rear wall surface11. The flange portion42of the optical ferrule40is accommodated into the flange portion accommodation space S1, and the rear end portion43is accommodated into the rear end portion accommodation space S2. Note that a space, into which the optical ferrule91of the mating connector9can enter, is left in front of the split sleeve60.

The retainer member20can be fit to the ferrule mounting portion14of the housing10having the optical ferrule40mounted in this way. The retainer member20includes a ceiling portion21and a pair of engaging portions22and a pair of inserting portions23as plate-like members respectively hanging down from the ceiling portion21. The engaging portions22are provided on both widthwise ends of the retainer member20, and the inserting portions23are provided inwardly of the engaging portions22in the width direction.

If the retainer member20is arranged above the ferrule mounting portion14of the housing10and mounted from above to cover the open portion140of the ferrule mounting portion14from above by the ceiling portion21of the retainer member20(arrow A ofFIG.3), the engaging portions22of the retainer member20are arranged outside the side surfaces142of the ferrule mounting portion14while being resiliently deformed to be pushed and expanded outward in the width direction. The engaging portions22of the retainer member20are provided with holes penetrating in a plate thickness direction, and the engaging projections13provided on the side surfaces142of the ferrule mounting portion14are fit into and engaged with these holes, whereby the retainer member20is fixed to the ferrule mounting portion14.

With the retainer member20mounted on the ferrule mounting portion14in this way, the inserting portions23of the retainer member20are inserted in the accommodation space14S of the open portion140of the ferrule mounting portion140. More particularly, the inserting portions23of the retainer member20are inserted in the rear end portion accommodation space S2on the rear side, out of the accommodation space14S. The rear end portion43of the optical ferrule40is already accommodated in the rear end portion accommodation space S2, and the inserting portions23of the retainer member20are press-fit into gaps formed between the rear end portion43of the optical ferrule40and the side surfaces142of the ferrule mounting portion14. Pressing portions231serving as parts projecting inward in the width direction are integrally provided on tip sides of the inserting portions23of the retainer member20, and these pressing portions231contact the rear end portion43of the optical ferrule40. By press-fitting the inserting portions23into the narrow gaps, the inserting portions23are resiliently deformed and inward forces in the width direction act between the pressing portions231of the pair of inserting portions23. By these forces, the optical ferrule40is held at the rear end portion43. Further, the optical ferrule40is prevented from coming out rearward by the contact of front end parts of the inserting portions23of the retainer member20with the rear end surface of the flange portion42of the optical ferrule40.

In this way, the optical ferrule40is accommodated into the ferrule mounting portion14of the housing10and the retainer member20is fit to the ferrule mounting portion14, whereby the optical ferrule40is sandwiched between the housing10and the retainer member20. By this sandwiching, the optical ferrule40is held at a predetermined position of the housing10. By using the retainer member20in this way, the optical ferrule40can be mounted and held in the housing10even without being directly fixed to the housing10.

Further, the housing10is provided with a plurality of pins16for physically fixing the composite connector1to the circuit board B. The pins16are respectively insertable into through holes of the circuit board B. By inserting the pins16into the through holes of the circuit board B and appropriately fixing the pins16by soldering or the like, the composite connector1can be fixed to the circuit board B.

The photoelectric composite connector1according to this embodiment is easily assembled by having the configuration described above. As described with reference toFIG.5, the optical ferrule40is provided as an optical communication member in the composite connector1and the optical ferrule40can be fixed to the circuit board B and coupled to the optical communication module M mounted on the circuit board B via the optical fiber F by coupling the optical fiber F to the optical ferrule40. Thus, even without incorporating an optical communication module into the composite connector1, optical communication between the mating connector9and the optical communication module M fixed to the circuit board B can be performed via the composite connector1. Since it is not necessary to incorporate the optical communication module into the composite connector1, the structure of the composite connector1is simplified and the optical communication module needs not be precisely arranged inside the connector. Thus, an assembling operation of the composite connector1is easily performed. Particularly, if the optical communication module is incorporated into the connector used to relay communication using an AGF, small-size optical communication members need to be incorporated into the connector and those optical communication members are required to be arranged with high accuracy since the AGF is thin in diameter. However, by applying the configuration of the composite connector1according to this embodiment, a high effect is obtained in improving assemblability. Note that it is not prevented to incorporate the optical communication module inside the composite connector1according to this embodiment, but it is preferable not to incorporate the optical communication module in terms of simplifying the structure and assembly process of the composite connector1.

Further, in the composite connector1according to this embodiment, the optical ferrule40is held in the housing by being sandwiched between the housing10and the separate retainer member20without being fixed to the housing10. Since the optical ferrule40can be mounted only by fitting the retainer member20to the ferrule mounting portion14having the ferrule40at the predetermined position in the housing10, the convenience of an operation of incorporating the optical ferrule40into the composite connector1is enhanced. Also in the case of mounting the small-size optical ferrule40such as an optical ferrule for AGF, the convenience of the mounting operation remains substantially unchanged.

In this composite connector1, the optical ferrule40is held in the housing10using the retainer member20and fixed to the circuit board B or coupled to the optical communication module M via the optical fiber F, but the electrical connection terminals50are directly fixed to the housing10and also directly electrically connected to the circuit board B. The configuration of the entire composite connector1can be simplified by simplifying a mounting mechanism into the housing10and a connecting mechanism to the circuit board B for the electrical connection terminals50.

OTHER EMBODIMENTS

As described above, the type and number of the electrical connection terminals50are not particularly limited. For example, either ordinary terminals not supposed to comply with specific standards or terminals satisfying predetermined standards such as Ethernet (registered trademark) standards may be used as the electrical connection terminals50. The use of ordinary terminals is better due to low cost and the use of terminals satisfying predetermined standards is better in being able to ensure performances of electrical connecting portions such as communication performance.

In the case of providing a plurality of the electrical connection terminals50, an arrangement direction of those electrical connection terminals50is also not particularly limited. In the above embodiment, the pair of electrical connection terminals50are arranged in the width direction (b direction) together with the optical ferrule40(hereinafter, referred to as “series arrangement”) as shown. However, for example, the pair of electrical connection terminals50arranged in the vertical direction (c direction) and the optical ferrule40may be arranged in the width direction (b direction) (hereinafter, referred to as “parallel arrangement”). Which of the series arrangement and the parallel arrangement should be adopted may be selected according to the use application of the composite connector1, the type of the electrical connection terminals50and the like. The parallel arrangement is excellent in space saving since the entire composite connector1is easily set to have a small size. On the other hand, the series arrangement is preferable in terms of ensuring communication performance. This is because, if the series arrangement as shown is adopted, the pair of electrical connection terminals50are laterally arranged along the surface of the circuit board B and electrical connection paths from the electrical connection terminals92of the mating connector9to the circuit board B, i.e. distances from the tips of the terminal connecting portions52of the electrical connection terminals50to the tips of the board connecting portions51, are easily made equal between the pair of electrical connection terminals50. In the case of the parallel arrangement, the pair of electrical connection terminals50are vertically arranged with respect to the circuit board B and lengths of a pair of electrical connection paths tend to be different. Particularly, in the case of using terminals satisfying communication standards such as Ethernet standards as the electrical connection terminals50, the series arrangement may be adopted in terms of ensuring communication performance.

The present invention is not limited at all by the above embodiment and various modifications can be made without departing from the gist of the present invention.

LIST OF REFERENCE NUMERALS