WO2008005515A2

WO2008005515A2 - Optical waveguide connector

Info

Publication number: WO2008005515A2
Application number: PCT/US2007/015548
Authority: WO
Inventors: Tsuneyasu Asada; Akihiro Shimotsu
Original assignee: Molex LLC
Current assignee: Molex LLC
Priority date: 2006-07-06
Filing date: 2007-07-06
Publication date: 2008-01-10
Anticipated expiration: 2009-01-06
Also published as: JP4884110B2; WO2008005515A3; JP2008015243A

Abstract

An optical connector assembly for connecting a first optical waveguide has at least one core part for transmitting light to a second optical component having a second optical waveguide with at least one core part for transmitting light. A housing has a receptacle extending in an optical axis direction for receiving and holding the first optical waveguide therein and a mating face oriented generally perpendicular to the optical axis along a mating axis. The housing is configured to mate with another connector housing by relative movement of the connector housings along the mating axis. The first optical waveguide is positioned within the receptacle and has a tilting surface along the optical axis. The tilting surface engages the at least one core part and is configured to direct light in a direction generally parallel to the mating axis.

Description

OPTICAL WAVEGUIDE CONNECTOR

BACKGROUND OF THE INVENTION

The present invention relates to an optical waveguide connector. Conventionally, in order to connect optical waveguides used in optical communications and the like, an optical connector has been proposed (refer to, for example, Japanese Patent Application Laid-Open (Kokai) No. 2002-107578). In FIG. 14, a plug connector 301 has a connector body 302 made of synthetic resin. Optical waveguide fixing grooves are formed on upper and lower surfaces of the connector body 302, respectively, and two optical waveguides 303 are inserted into the optical waveguide fixing grooves, respectively, to be fixed by a retaining plate 304. Specifically, the optical waveguides 303 are fixed so that tip surfaces thereof are located on the same surface as the fitting end surface of the connector body 302. Furthermore, two guide pins 305 project from the mating or fitting end surface of the connector body 302. A receptacle connector 310 has a connector body 311 also made of synthetic resin.

Optical waveguide fixing grooves are formed on upper and lower surfaces of the connector body 311, respectively, and two optical waveguides 312 are inserted into the optical waveguide fixing grooves, respectively, to be fixed by a retaining plate 313. Specifically, the optical waveguides 312 are fixed so that tip surfaces thereof are located on the same surface as the fitting end surface of the connector body 311. Furthermore, two guide pin receiving holes 314 are formed on the fitting end surface of the connector body 311.

When mating the plug connector 301 and the receptacle connector 310, the guide pins 305 are inserted into the guide pin receiving holes 314 of the connector body 311. This enables positioning of the facing optical waveguides 303 and optical waveguides 312 accurately, and to connect the optical waveguides 303 and the optical waveguides 312.

In the prior art optical connector, the tip surface of the optical waveguide 303 and the tip surface of the optical waveguide 312 are formed so as to confront to each other. Therefore, in order to prevent any space between the tip surface of the optical waveguide 303 and the tip surface of the optical waveguide 312, tip surface polishing is required in order to obtain the equivalent flatness to a high degree of accuracy in the tip surfaces of both optical waveguide 303 and optical waveguide 312. In addition, a high degree of positioning accuracy is required with respect to the optical axis direction and the width direction in order to align the optical axes of the optical waveguides 303 and that of the optical waveguides 312. Such required precision may increase the cost of manufacture.

Biasing members such as springs and the like are also required to biasing plug connector 301 and receptacle connector 310 along the optical axes as well as clamping structures and this further complicates the structure. Further, when mating the plug connector 301 and the receptacle connector 310, it is required to shift or move at least one of the connectors in the direction of the optical axis. If this occurs when the optical waveguides 303 and 312 are mounted along a substrate surface, valuable space is necessary and electronic components and the like may not be mounted on the substrate surface in a relatively large area in order to permit connection of any optical and electrical circuits. In addition, an extra length of waveguide is required to permit shifting in the direction of the optical axis.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical waveguide connector being able to accurately and easily mount optical waveguides and to be manufactured easily and at low costs. Such connector does not require significant amounts of space for the operation of connecting optical waveguides. The connector includes a housing configured so that a tilting surface of the optical waveguide overlaps with that of a mating, identical connector. The waveguides extend in opposite directions and overlap through interengage connector housings. The tilting surfaces of each connector are aligned such that light may be transmitted through reflection on the tilting surfaces.

To this end, an optical waveguide connector is provided for connecting optical waveguides. Each waveguide has at least a core for transmitting light. The connector has a housing with a holding groove extending in the optical axis direction of the optical waveguide. Each connector housing is configured to engage a mating connector housing by relatively moving in a direction perpendicular to the optical axis. The optical waveguide is held and fixed in the holding groove and have a tilting surface tilting relative to the optical axis. The tilting surface of one connector is configured to overlap with that of a mating connector so that the tilting surfaces face in opposite directions when a pair of connectors are mated together, and light to be transmitted in the core parts are reflected on the two tilting surfaces.

A pair of optical connectors may include housings having an identical shape. The tilting surfaces may be formed at a tip of the optical waveguide, and the optical waveguide may have positioning ear parts projecting laterally spaced from the tip. The positioning ear parts being held in ear holding parts included in the holding groove parts. In the alternative, the optical waveguide could have a section removed across the core parts spaced from the tip at which the tilting surface is formed. If desired, the optical waveguide may have a remaining tip part extending from a tip to the removed part, and the remaining tip part of the optical waveguide of a mating connector abuts on the waveguide at a distance spaced from the tilting surface when a pair of connectors are mated. If desired, the remaining tip part maybe adhered to a holding groove. Such adherence could be affected by adhesive and the holding groove may have a recess for receiving adhesive.

An optical connector is provided to facilitate overlapping and engaging a pair of connectors, each of which fixes an optical waveguide having identical shapes and having core parts including tilting surfaces. The tilting surfaces of the optical waveguides overlap with each other in opposing directions so that light may be transmitted by reflecting on the tilting surfaces. This enables mounting and positioning optical waveguides easily and with a high degree of positioning accuracy, and to perform the operation of connecting optical waveguides without requiring any significant amount of space for the connecting operation.

Other aspects, objects and advantages of the present invention will be understood from the following description according to the preferred embodiments of the present invention, specifically including stated and unstated combinations of the various features which are described herein and relevant information which is shown in the accompanying drawings and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a state in which a pair of. optical connectors according to one embodiment are connected to each other;

FIG. 2 is an exploded view showing the structure of the pair of optical connectors of the first embodiment;

FIG. 3 is a perspective view showing the end portion of an optical waveguide of the first embodiment;

FIG. 4 is a cross sectional view showing a pair of optical waveguides of the first embodiment in a connected state; FIG. 5 is an exploded perspective view showing the relationship between the housing of the optical connector and the optical waveguide of the first embodiment;

FIG. 6 is a perspective view showing a state in which the optical waveguide is fixed to the housing of the optical connector of the first embodiment;

FIG. 7A is a cross sectional view showing a state in which the housings of a pair of optical connectors are connected to each other in the first embodiment;

FIG. 7B is an enlarged view of circled area B in FIG. 7A;

FIG. 8 is a perspective view showing the vicinity of the end portion of an optical waveguide according to a second embodiment;

FIG. 9A is a cross sectional view showing a pair of connected optical waveguides of the second embodiment;

FIG. 9B is an enlarged view of circled area C in FIG. 9A;

FIG. 10 is an exploded perspective view showing the structure of the optical connector of the second embodiment;

FIG. 11 is an exploded view showing the relationship between the housing of the optical connector and the optical waveguide of the second embodiment;

FIG. 12 is a perspective view showing a state in which the optical waveguide is fixed to the housing of the optical connector of the second embodiment;

FIG. 13 is a perspective view showing a state in which a pair of optical connectors of the second embodiment are connected to each other; and

FIG. 14 is a perspective view showing a conventional optical connector.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate manner. Referring first to FIGS. 1 and 2, a connector generally designated 20 is disclosed as an optical connector of the first embodiment, which is used to connect optical waveguides 10. As shown in FIG. 3, each of the optical waveguides 10 has core parts 11 serving as optical transmission lines for transmitting light, and a clad part 12 surrounding the core parts 11. In the example as shown in FIG. 3, the number of the core parts 11 is four, however, it is possible to set the number of cores arbitrarily, for example, either one or a plurality of cores.

The optical waveguides 10 may be of single mode type or multimode type. Furthermore, a refractive index of the clad part 12 is, preferably, smaller than that of the core parts 11. For example, when the core parts 11 are formed of material having a refractive index less than 1.55 , it is desirable that the clad part 12 is formed of material having a refractive index being smaller than that of the core part 11 by 0.01 or more. The clad part 12 can be formed of any material, for example, a silicon substrate, a glass substrate, or a flexible resin film, as long as the refractive index is sufficiently less than that of the core. If desired, the clad part 12 located in the vicinity of the core parts 11 may be formed of an air layer (1.000 in a refractive index).

Referring to FIG. 4, in the first embodiment, the tip surface of the optical waveguide 10 is formed so as to have a tilting or inclined surface 13. The angle of tilt or incline of the tilting surface 13 should be suitably changed in design according to the refractive index of the core parts 11 and the clad part 12 so that optical loss may be optimized. The tilting surface 13 can be formed by a dicing process or by machining with a laser. In the first embodiment, the angle of tilt of the tilting surface 13 is 43 degrees, and the optical waveguide 10 is formed of a material having the core parts 11 with refractive indexes of 1.550 and the clad part 12 with a refractive index of 1.518. The optical waveguide may, however, be formed of any material having any refractive index, and the angle of tilt of the tilting surface 13 would then likely be changed.

Still referring to FIG. 4, by overlapping the tips of a pair of optical waveguides 10 with each other in a thickness direction (i.e., perpendicular to the plane of waveguide 10), light can be transmitted from the core parts 11 of one optical waveguide 10 to the core parts 11 of the other optical waveguide 10. In this case, the tips of the optical waveguides 10 are overlapped with each other so that the optical axes of the optical waveguides 10, though being dislocated in the thickness direction, may become parallel with each other and the tilting surfaces 13 may face in the opposite directions. As such, the tilting or angled surfaces are parallel to each other so that the tilting surfaces 13 face in opposite directions. The optical waveguides 10 are overlapped with each other in such a direction that the optical waveguides 10 are arranged so that the corners being formed obtusely between the surface of the optical waveguides 10 abutting on holding groove parts 22 to be described later, and the tilting surfaces 13 may be positioned on the side of the holding groove parts 22. In other words, the corners being formed obtusely as stated above may not abut with each other. Thus, the light to be transmitted through the core parts 11 is reflected on the two tilting surfaces 13, and turns twice at approximately 90 degrees each, as indicated by the line A to which the arrow is added in FIG.4, thereby being transmitted. In the example illustrated, the angle of tilt of the tilting surfaces 13 is at an angle of 43 degrees relative to the optical axis of the optical waveguides 10. As shown in FIG. 2, each connector 20 is made up of identical connectors. Each connector has a housing 21 in the form of nearly a rectangular parallelepiped, and formed of resin, such as PBT (polybutylene terephthalate), PC (polycarbonate), LCP (liquid crystal polymer), PPS (polyphenyl sulfide), polyamide, PEEK (polyether ether ketone), or epoxy. Housing 21 is formed integrally by a method of molding, such as injection molding, casting molding, or the like.

Each housing 21 has a holding groove 22 formed on an engaging or mating side at which the connector engages the other connector 20and extending in the direction of the optical axis of the optical waveguide 10. The groove 22 receives and holds therein the tip of the optical waveguide 10. Guide pins 25 are formed on both sides of the holding groove part 22, and project toward the mating connector 20. Guide holes 26 are positioned and dimensioned to receive the guide pins 25 of the other connector 20 upon mating of two connectors 20 together. In other words, the guide pins 25 are on a portion of housing 21 that extends past the end of waveguide 10. The housing 21 also has waveguide retention recesses or slots 31 for holding a fixing member 34 that fixes the tip of the optical waveguide 10 and the vicinity thereof, and a second locking recess or slot 33 for receiving a locking member 35 configured to engage another mating connector. Housing 21 also has first recesses or slots 32 positioned and dimensioned to receive the arms of locking member 35 of a mating connector. This structure results in preventing relative movement between the pair of housings 21 in both the direction of the optical axis of the optical waveguides 10 and in a vertical direction.

As shown in FIG. 3, positioning concave or cutout portions 15 are formed on both sides in the vicinity of the tip of each of the optical waveguides 10, and positioning or cutout notch portions 16 are formed on both sides of the tip of the optical waveguide 10. The remaining parts between the positioning concave portions 15 and the positioning notch portions 16 form positioning ear portions 17 projecting laterally. The positioning concave portions 15 and the positioning notch portions 16 can be formed by a dicing process or laser beam machining or other cutting processes. It is desirable that front edges 17a of the positioning ear parts 17 are processed with a high degree of accuracy, as they function to accurately position the tilting surfaces 13 along the optical axis.

As shown in FIG. 5, holding groove 22 of the housing 21 is defined on both sides of sidewalls 23. Guide pins 25 are formed so as to project from the upper surfaces of the sidewalls 23, respectively. The sidewalls 23 are provided with first convex or extension portions 23a and second convex or extension portions 23b, respectively, projecting toward the central axis of the holding groove part 22. The first convex portions 23 a have a shape corresponding to the positioning concave portions 15 of the optical waveguide 10, so as to engage the positioning concave portions 15. The second convex portions 23b are located adjacent at the tip of the holding groove 22, and have a shape corresponding to the positioning notch portions 16 of the optical waveguide 10, so as to engage the positioning notch portions 16. Ear holding portions 22a of the holding groove 22 are defined between the first convex portions 23 a and the second convex portions 23b, and the ear holding portions 22a engage the positioning ear parts 17 of the optical waveguide 10. An abutting surface 24 extends from housing 21 in the longitudinal direction and at a lower position relative to a bottom surface 22b of the holding groove 22. Upon mating a pair of connectors 20 together, the upper surface of the sidewall parts 23 of each connector will abut the abutting surface 24 of the opposite connector, hi addition, the guide holes 26 for receiving the guide pins 25 of the other connector 20 are formed in the abutting surface 24.

Waveguide retention recesses 31 are formed at positions corresponding to the ear holding portions 22a in the sidewalls on the both sides of the housing 21. The waveguide retention recesses 31 have a groove-like shape extending vertically so as to receive the leg portions on the fixing member 34, and fixing projections 31a extending from housing 21 engage fixing openings 34a in fixing member 34 to retain fixing member 34 within waveguide retention recess 31.

The fixing member 34 is formed of a resilient plate material with a pressing portion 34b projecting downward at a central part thereof, and having a generally M- shaped contour. The fixing member 34 may be made of resilient metal or resin, but most any kind of material may be used as long as the material has sufficient resiliency to exert a sufficient urging force so that pressing portion 34b engages and fixes the optical waveguide 10 to the bottom surface 22b of the holding groove 22.

First recesses 32 are formed at positions corresponding to the first convex portions 23 a on the sidewalls on both sides of the housing 21. The first locking recess 32 have a groove-like shape extending vertically so as to receive the leg portions on both sides of the locking member 35. Tapered or concave portions 32a are formed at lower (as viewed in FIG. 5) or the non-mating face of housing 21 for receiving the locking convex portions 35b of the locking member 35. A second locking recess 33 is formed at a position corresponding to the abutting surface 24 on the sidewalls on both sides of the housing 21. The second locking concave recess 33 has a groove-like shape extending continuously as if surrounding three wall surfaces except for the abutting surface 24, in order to hold not only the leg portions on both sides of the locking member 35 but also a central part 35c thereof. Projections 33a are formed within the second locking concave portion 33 and are configured to lock locking member 35 within recess 33 to engage with the locking openings 35a of the locking member 35.

The locking member 35 is formed of a resilient plate material and has a generally U-shaped contour. The locking member 35 may be made of resilient metal or resin, but most any kind of material may be used as long as the member has sufficient resiliency to exert a sufficient urging force so that connectors 20 remain engaged with each other once locked.

During assembly, an operator grasps the optical waveguide 10 and in an attitude as shown in FIG. 5, moves the optical waveguide 10 into the holding groove 22. The optical waveguide 10 is oriented such that the tilting surface 13 faces downward (as shown in FIG. 4). In this case, the positioning ear parts 17 of the optical waveguide 10 are held into the ear holding portions 22a, and the first convex portions 23 a and the second convex portions 23b fit within the positioning concave portions 15 and the positioning notch portions 16 in the optical waveguide 10, and thereby the optical waveguide 10 and the housing 21 are engaged so that the optical waveguide 10 is accurately positioned relative to the housing 21.

Preferably, the side surfaces of the sidewall parts 23 that define the three surfaces of the ear holding parts 22a (except for the side surfaces nearer the tip of the holding groove part 22), form tapered surfaces spreading upwardly tilted at about 1 to 10 degrees to a direction perpendicular to the bottom surface 22b of the holding groove part 22. This renders the positioning ear parts 17 to move along the tapered surfaces when they are held into the ear holding portions 22a, and thereby the optical waveguide 10 is automatically positioned in a direction of the tip of the holding groove part 22 and in a direction of the center thereof. Through such structure the edge portions 17a (FIG. 3) of the positioning ear parts 17 abut the side surfaces nearer the tips of the ear holding portions 22a, and thereby accurately position the tilting surfaces 13 along the optical axis

Once the waveguide 10 is inserted into holding groove 22, the fixing member 34 is slid onto housing 21 such that the leg portions on both sides fit into the waveguide retention recesses 31 until the fixing openings 34a engage the fixing projections 31a.

This causes the pressing portion 34b of the fixing member 34 to press and fix the optical waveguide 10 to the bottom surface 22b of the holding groove 22. Consequently, in this embodiment, it is possible to fix the optical waveguide 10 to the housing 21 without using any adhesive. Locking member 35 is then slid onto housing 21 from the direction opposite that in which fixing member 34 was slid. The central part 35c of locking member 35 and the leg portions on both sides fit into the second locking recess 33 to engage the locking openings 35a and the locking projections 33a. The leg portions of the locking member 35 mounted on the housing 21 project in the same direction as guide pins 25 and are located adjacent guide holes 26.

Since the connectors 20 are identical or hermaphroditic, the mating operating is relatively simple. A pair of connectors 20 are positioned such that the sidewall parts 23 and the abutting surface 24 of one housing 21 face the sidewall parts 23 and the abutting surface 24 of the other housing 21, respectively, as shown in FIG. 2. In addition, locking legs 35b are positioned to align with first recess 32. The connectors 20 are then moved towards each other so that the sidewall parts 23 and the abutting surface 24 of the one housing 21, and the sidewall parts 23 and the abutting surface 24 of the other housing 21 eventually abut each other. During this mating operation, the guide pins 25 of one connector 20 are inserted into the guide holes 26 formed on the other connector 21, and thereby accurate positioning between the connectors 21 is achieved. Further, the leg portions of the locking member 35 mounted on one connector 20 are inserted into the first recesses formed on the other connector 20, and thereby the locking legs 35b of locking member 35 engage the locking tapered portions 32a of the first locking recess 32.

In the state in which the housings 21 are engaged with each other, the tips of the optical waveguides 10 overlap in a thickness direction, and abut each other, as shown in FIG. 7. This renders the light being transmitted through the core parts 11 to be reflected on the two tilting surfaces 13 and to turn twice at approximately 90 degrees each, and thereby to be transmitted from one optical waveguide 10 to the other optical waveguide 10.

As described above, since each connector is identical, it is possible to manufacture the same easily and at low costs. In addition, no discrimination of male and female in the housings 21 simplifies the handling and manufacture thereof. When the optical waveguides 10 are fixed to the housings 21, the optical waveguides 10 and the housings 21 may be just moved up and down without any need for movement of the same in the direction of the optical axis. Similarly, when the connectors 20 are mated together, the connectors may be just moved up and down without any need for movement of the same in the direction of the optical axis. Therefore, for example, even if the connectors 20 and the optical waveguides 10 are mounted along the surface of the substrate, less space is required in the operations of fixing the optical waveguides 10 to the housings 21 and connecting the housings 21 each other.

Since the tips of the optical waveguides 10 overlap with each other rather than butting up against each other, no urging members such as springs are required to urge the tip faces of the optical waveguides 10 in the direction of the optical axis. This enables a reduction in the number of the components of the connector 20 and to simplify the structure thereof. Additionally, as can be seen from FIG. 4, even if the positions of the tilting surfaces of the optical waveguides 10 are dislocated slightly in the optical axis direction, light will still be transmitted.

FIGS. 8-13 depict a second preferred embodiment. Components having the same structures as those of the first preferred embodiment utilize the same reference numerals and the description thereof is omitted. The description of the same movement and effect as those of the first preferred embodiment is also omitted. Referring first to FIG. 8, the second preferred embodiment, an optical waveguide

10 has a slit-like removed part 14 formed in the vicinity of the tip thereof, and a tilting surface 13 formed adjacent in the removed part 14. The removed part 14 is an elongated through-hole extending in the width direction of the optical waveguide 10 (transverse to the optical axis) so as to cross throughout a plurality of core parts 11, and extends through the optical waveguide 10 in the thickness direction thereof, as shown in FIG. 9.

The opposite side of the tip in the removed part 14, namely, the sidewall in the backside (the upper right side as viewed in FIG. 8) forms the tilting or angled surface 13. As is the case with the first preferred embodiment, it is desirable that the angle of tilt of the tilting surface 13 is approximately 45 degrees to the optical axis direction of the optical waveguide 10. However, as previously described, it may be desirable to change the angle. In addition, the removed part 14 and the tilting surface 13 can be formed by laser beam machining. In the example shown in FIGS. 9 A and 9B, the sidewall on the tip side in the removed part 14, namely the sidewall on the side opposite to the tilting surface

13 is nearly perpendicular to the direction of the optical axis of the optical waveguide 10, however, the angle of the sidewall can be set arbitrarily, for example, the angle may be equivalent to that of the tilting surface 13. That is to say, it is merely necessary that any open space exists on the tip side of the tilting surface. 13.

As shown in FIGS. 9A and 9B, by overlapping portions around the removed parts

14 of a pair of optical waveguides 10 in a thickness direction, the light can be transmitted from the core parts 11 of one optical waveguide 10 to the core parts 11 of the other optical waveguide 10. In this case, though the optical axes of the optical waveguides 10 are dislocated in a thickness direction, the optical waveguides 10 are overlapped with each other so that the waveguides may become parallel to each other and the tilting surfaces 13 may face in opposite directions. Thus, the light to be transmitted through the core parts 11 is reflected on the two tilting surfaces 13, and turns twice at approximately 90 degrees each, thereby being transmitted. Here, the core parts 11 within tip remaining part 18 ( or the portion extending from the removed part 14 to the tip surface in each of the optical waveguides 10) does not contribute to the transmission of the light. In this second embodiment, both side edges of waveguide 10 in the vicinity of the tip are linear compared to the various recesses or concave portions (positioning concave portions 15, positioning notch portions 16 , and positioning ear parts 17) in the first preferred embodiment. Hence, it is not required to perform any dicing process or laser beam machining in forming the vicinity of the tip of the optical waveguide 10, particularly in forming the contour thereof.

As shown in FIG. 10, each connector 20 has a housing 21 generally in the form of a thick plate. Each housing 21 has a holding groove 22 formed on an engaging side that faces a mating connector and extends in the direction of the axes of the optical waveguide 10. The holding groove secures the waveguide 10 having the portion around the removed part 14 and tilting surface 13. A front wall 27 defines the tip of the holding groove 22 and guide holes 26 receive guide pins 25 from a mating connector. The guide pins 25 and guide holes 26 are arranged on a diagonal line on both sides of the holding groove 22 and the front wall 27. Preferably, the depth of the holding groove 22 is less than the thickness of the optical waveguide 10. This enables the optical waveguides 10 to abut each other when a pair of connectors 10 are engaged with each other. Each of the housings 21 also has a waveguide retention recess or slot 31 for receiving a fixing member 34 to secure the optical waveguide 10 within holding groove 22. First locking recesses 32 and second locking recesses 33 are provided for holding a locking member 35 and for locking the engaged housings 21 together. Thus, the pair of housings 21 can be engaged with each other by aligning the connectors along the optical axis and relatively moving the connectors along a direction perpendicular to the optical axes.

As shown in FIG. 11, the holding groove 22 of the housing 21 is defined by the front wall 27 and the sidewall parts 23 being formed on both sides of the groove. The guide pins 25 are positioned on a diagonal line and one extends from the upper surface of the front wall 27 and one extends from the sidewall part 23. Similarly, the guide holes 26 are positioned on a diagonal line and one is formed on the upper surface of the front wall 27 on the opposite edge relative to guide post 25 mounted on front wall 27 a second guide hole 26 is formed in the other sidewall relative to the sidewall having post 25. The sidewall parts 23 in the second preferred embodiment are linear, without having any first convex portions 23a and the second convex portions 23b (refer to FIG. 5) as described in the first preferred embodiment. The rear side of the front wall 27 abut the tip surface of the optical waveguide 10 to position the optical waveguide 10 in the direction of optical axis, and the opposite side surfaces of the sidewall parts 23 on both sides of the groove part abut on both sides of the optical waveguide 10 to position the optical waveguide 10 transverse to the optical axes.. The side surfaces of a portion corresponding to remaining tip part 18 of the optical waveguide 10 in the sidewall parts 23 are formed with a higher degree of accuracy than other portions, in order to accurately position the optical waveguide 10 in the width or transverse direction thereof. A shoulder hole 36 is formed adjacent in the bottom surface 22b of the holding groove 22 adjacent the location in which the remaining tip portion 18 of waveguide 10 will be positioned. The shoulder hole 36 extends through the housing 21 in the thickness direction thereof and has a stepped cross-section that is larger in areas adjacent the bottom surface 22b of the holding groove 22 and is smaller as it extends through outer surface 33a (FIG. 10) of second locking recess 33. If desired, shoulder hole 36 may include undulations or bumps 36a. The shoulder hole 36 is filled with adhesive, preferably ultraviolet cure adhesive, for adhering the optical waveguide 10 to the bottom surface 22b of the holding groove part 22.

The tip of remaining tip part 18 of the optical waveguide 10 has a tip face 19 for abutting the front wall 27 of the housing 21 to position the waveguide relative to housing 21 along the optical axis..

Waveguide retention recesses 31 are formed at positions in the vicinity of the rear end in the sidewalls on both sides of the housing 21, and fixing projections 31a extend from the housing to engage fixing openings 34a of the fixing member 34. Housing 21 also includes a recess 28 spaced from holding groove 22 for receiving therein the central part 34c of the fixing member 34 of a mating connector. The upper surface of the front wall part 27 extends between and separates holding groove 22 and recess 28. The fixing member 34 in the second preferred embodiment is different from the fixing member of the first preferred embodiment in that central part 34c is not provided with the pressing portion 34b (refer to FIG. 5) as described in the first preferred embodiment but both have a generally U-shaped contour.

First locking recess 32 and second locking portions 33 are formed at positions in the vicinity of the center in sidewalls on both sides of the housing 21. Locking concave portions 32a in the form of a tilting surface, which are engaged with the locking convex portions 35b of the locking member 35, are formed at the ends of the first locking recess 32, and locking projections 33a engage with the locking openings 35a of the locking member 35.

During manufacturing, an operator injects a given amount of ultraviolet cure adhesive into shoulder hole 36. Subsequently, the optical waveguide 10 is inserted into the holding groove 22 with the tilting surface 13 of the optical waveguide 10 facing downward (FIG. 11). In this case, the optical waveguide 10 is positioned in the direction of the optical axis with the tip face 19 abutting on the side surfaces on the rear side of the front wall part 27, and is positioned in the width or transverse direction with both sides thereof abutting on the opposed side surfaces of the sidewall parts 23. Alternatively, it is possible to inject the adhesive into shoulder hole 36 after the optical waveguide 10 is positioned within holding groove 22 through outer surface 33a of second locking recess 33.

Ultraviolet ray is provided to the surface of the holding groove 22 from above to cure the adhesive within the shoulder hole 36 and thereby adhere the optical waveguide 10 to the holding groove 22. Alternatively, it is also possible to irradiate ultraviolet ray through the shoulder hole 36 from the opposite side of the bottom surface 22b of the holding groove part 22. Since the shoulder hole 36 is formed in the position corresponding to the remaining tip part 18, only the tip remaining part 18 is adhered to the holding groove 22. Since the adhesive does not fill the removed part 14, adhesive does not adhere to the tilting surface 13, and the reflectance ratio of the tilting surface 13 remains unchanged.

The leg portions of fixing member 34 are then slid onto housing 21 and fixing openings 34a and the fixing projections 31a engage each other. Thus, the fixing member 34 presses and fixes the optical waveguide 10 to the bottom surface 22b in the vicinity of the rear end of the holding groove 22.

Locking member 35 is then slid onto housing 21 in a direction opposite that in which fixing member 34 was slid. Central part 35c and the leg portions on both sides slide into the first locking recess 33, and causes the locking openings 35a and the locking projections 33a to engage with each other. In this case, the leg portions of the locking member 35 mounted on the housing 21 project from both sides of the abutting surface 24 in the same direction as the guide pins 25.

To mate a pair of connectors 20, both connectors are positioned such that the sidewall parts 23 of one housing 21 face the sidewall parts 23 of the other housing 21, respectively. The guide pins 25 are inserted into the guide holes 26 formed in the other housing 21, to thereby position the connectors relative to each other. The central part 34c of the fixing member 34 mounted on one connector 20 is held in recess 28 of the other connector 20. Further, the leg portions of the locking member 35 mounted on each connector 20 are inserted into the first locking recess 32 formed in the other connector 20. This results in a pair of connectors being secured together, as shown in FIG. 13.

When the connectors 20 are engaged with each other, the portions around the removed parts 14 of the optical waveguides 10 overlap with each other in a thickness direction, and abut with each other, as shown in FIG. 8. Thus, the light to be transmitted through the core parts 11 is reflected on the two tilting surfaces 13, and turns twice at approximately 90 degrees each, thereby transmitting light from one optical waveguide 10 to the other optical waveguide 10. In this case, since the remaining tip part 18 located nearer the tip side than the removed part 14 abuts a portion nearer the rear than the removed part 14 of the other optical waveguide 10, the pair of optical waveguides 10 presses to each other throughout the entire surface in a wide range around the removed parts 14. This structure stabilizes the attitudes of the optical waveguides 10 around the removed parts 14, preventing the optical waveguides from bending or becoming otherwise deformed. A stable positioning relationship is also created between the two tilting surfaces 13 and improves the connecting property of the optical waveguides 10.

As described above, in the second preferred embodiment, each of the optical waveguides 10 has the removed part 14 formed so as to cross through the core parts 11 at a distance spaced the tip, and the tilting surface 13 is formed on the opposite side of the tip of the optical waveguide 10 in the removed part 14. This simplifies and increases the accuracy of mounting and positioning the optical waveguides 10. Since the tilting surfaces 13 are located in the removed part 14, instead of being located at the tip, the tilting surfaces 13 is afforded some degree of protection from damage such from bumping against machine tools or various items during manufacturing.

Each of the optical waveguides 10 is secured at both remaining tip part 18 and fixing member 34 and when the pair of housings 21 is engaged with each other, the remaining tip part 18 of the other optical waveguide 10 abuts a portion of the waveguide rearward from the removed part 14. Therefore, since a pair of optical waveguides 10 presses each other along a substantial length of the waveguide on all sides of removed part 14, a very stable base for the optical waveguides 10 around the removed parts 14 is formed. This prevents the optical waveguides from bending or becoming otherwise deformed. This structure also enables a stable positioning relationship between the two tilting surfaces 13, and improves the connecting property of the optical waveguides 10.

The present invention should not be limited to the above-described embodiments; it is possible to transform the embodiments in various ways based on the gist of the present invention, and these transformations are not eliminated from the scope of the present invention.

Claims

WHAT IS CLAIMED IS:

1. An optical connector assembly for connecting a first optical waveguide having at least one core part for transmitting light to a second optical component having a second optical waveguide with at least one core part for transmitting light, the connector comprising: a housing having a receptacle extending in an optical axis direction for receiving and holding the first optical waveguide therein and a mating face oriented generally perpendicular to the optical axis along a mating axis, the housing being configured to mate with another connector housing by relative movement of said connector housings along said mating axis; the first optical waveguide being positioned within said receptacle and having a tilting surface along the optical axis, the tilting surface engaging the at least one core part and being configured to direct light in a direction generally parallel to said mating axis.

2. The optical connector assembly according to claim 1 wherein the tilting surface is formed at a tip of the first optical waveguide.

3. The optical connector assembly according to claim 2 wherein the first optical waveguide has positioning projections extending laterally relative to the optical axis, and engage the housing with the projections extending into recesses in sidewalls of the housing.

4. The optical connector assembly according to claim 1 wherein the first optical waveguide has a tip and a slot therein extending across the at least one core part and spaced from the tip and the tilting surface is formed adjacent said slot along said core part.

5. The optical connector assembly according to claim 4 wherein said slot has two edges across the optical axis and the tilting surface is along said edge spaced furthest from said tip of the optical waveguide.

6. The optical connector assembly according to claim 5 wherein a portion of the optical waveguide between the slot and the tip is adhered to the receptacle.

7. The optical connector assembly according to claim 6 wherein the portion of the optical waveguide between the slot and the tip is adhered to the receptacle through the use of an adhesive.

8. The optical connector assembly according to claim 7 wherein the receptacle includes a recess for holding the adhesive.

9. The optical connector assembly according to claim 1 wherein the housing is configured to mate with a connector assembly having an identical housing.

10. The optical connector assembly according to claim 1 wherein the tilting surface is positioned and configured relative to the mating face such that upon mating first and second optical connector assemblies, the tilting surface of each assembly faces in opposite directions and light to be transmitted through the at least one core part is reflected from the tilting surface of the first optical connector assembly to the tilting surface of the second optical connector assembly.

11. The optical connector assembly according to claim 10 wherein the optical waveguide has a remaining tip portion extending between a tip of the waveguide and the tilting surface and the remaining tip portion engages and supports a surface of a mating waveguide of a mating connector.