OPTICAL-PATH CONVERSION RELAY OPTICAL CONNECTOR

BACKGROUND OF THE INVENTION

The present invention relates to an optical-path conversion relay optical connector. Description of the Related Art

Conventionally, an optical connector assembly for use in optical communications or the like has a lens and a prism coupled together and is used to connect optical fibers orthogonally (see, for example, Japanese Patent Application Laid-Open (Kokai) No. S60- 008811). To connect flat-cabled optical fiber tape cores together, an optical connector assembly having lens arrays coupled together is used (see, for example, Japanese Patent Application Laid-Open (Kokai) No. 2005-031556).

FIG. 8 is an exploded view showing the conventional optical connector assembly.

In FIG. 8, an optical element 801, which is formed of a light transmissive material, such as a resin, has a first connecting surface 802 and a second connecting surface 803 substantially orthogonal to each other, and a full reflection surface 804 angled substantially at 45 degrees to the first connecting surface 802 and the second connecting surface 803. A lens array (not shown) including a plurality of collimate lenses is integrally formed at the center portion of each of the first connecting surface 802 and the second connecting surface 803. Light input from the lens array on one connecting surface is reflected at the full reflection surface 804, so that the optical path is changed by 90 degrees and the light leaves from the lens array on the other connecting surface.

Columnar first guide holes 805 perpendicular to the first connecting surface 802 are formed through the first connecting surface 802 in the forward/backward direction on both sides of the lens array thereon. Columnar second guide holes 806 perpendicular to the second connecting surface 803 are formed through the second connecting surface 803 in the up/down direction on both sides of the lens array thereon. The full reflection surface 804 is not provided at positions corresponding to the first guide holes 805 and the second guide holes 806, but provided at a position facing the lens arrays.

A first optical connector 810A and a second optical connector 810B are connected

together via the optical element 801. The first optical connector 810A and the second optical connector 810B are ordinary multi-core optical connectors, and each hold a plurality of optical fibers 811 disposed side by side. A pair of connector-side guide holes 812 are respectively formed on both sides of the optical fibers 811. As guide pins 813 are inserted into the first guide holes 805, the second guide holes 806 and the connector-side guide holes 812, the optical fibers 811 of the first optical connector 810A are orthogonally connected to the optical fibers 811 of the second optical connector 810B while being accurately positioned with respect to the lens arrays of the optical element 801.

Because the individual components of the conventional optical connector assembly are separate from one another, however, the first optical connector 810A and the second optical connector 810B cannot be connected directly to the optical element 801 unless the guide pins 813 are inserted into the first optical connector 810A and the second optical connector 810B, thus lowering the working efficiency. Further, the guide pins 813 of the first optical connector 810A and the second optical connector 810B need to be connected to the first guide holes 805 and the second guide holes 806 of the optical element 801 at a high positioning accuracy while precisely checking the positions of the guide pins 813 with respect to the first guide holes 805 and the second guide holes 806, thus lowering the connecting workability. Because the optical element 801 is not fixed to the first optical connector 810A and the second optical connector 810B, the position of the optical axis of the optical element 801 with respect to the first optical connector 810A and the second optical

, connector 810B may be shifted depending on the use environment, such as vibration, leading to a possible significant reduction in the reliability of optical transmission.

The deviation of the connecting positions of the optical connectors to the optical element can be prevented by fixing the lens as an optical element to the optical connector as proposed in the Japanese Patent Application Laid-Open (Kokai) No. S60-008811. If the optical connectors and the optical element fixed together are mounted on a substrate or in a casing, however, when force originating from some cause, such as pinching force, thermal stress or vibration, is applied thereto, large stress is applied to the optical connectors and the optical element, which may be damaged or deformed as a result. The stress-originated

deformation of the lens may change the refraction index of the lens or the focal distance thereof, increasing the optical loss.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an optical-path conversion relay optical connector which is configured in such a way that two adapter portions in which plugs connected to the axial ends of the optical fiber cores are fitted are orthogonally coupled together, an optical-path conversion optical element having pin guide holes formed in two substantially orthogonal connecting surfaces is provided at a connecting corner portion, guide pins of the plugs are inserted into the pin guide holes to fix the connecting positional relationship between the plugs and the optical-path conversion optical element, the optical-path conversion optical element is rotatably attached to the connecting corner portion, thereby ensuring easier fitting and positioning of the plugs with high accuracy, ensuring easy and low-cost manufacture of the optical-path conversion relay optical connector, and allowing the optical fiber cores to be connected together substantially orthogonally without requiring large space for a work of fitting the plugs, the connecting positions of the optical fiber cores and the optical-path conversion optical element are not shifted, and the plugs and the optical-path conversion optical element are displaceable with respect to the adapter portions, so that the optical-path conversion relay optical connector will not be damaged even if external force is applied thereto.

To achieve the object, an optical-path conversion relay optical connector according to the present invention comprises two adapter portions in each of which a plug connected to an axial end of an optical fiber core is fitted, wherein the adapter portions are coupled together so as to be substantially orthogonal to each other at a connecting corner portion where an optical-path conversion optical element is disposed, the optical-path conversion optical element has two connecting surfaces substantially orthogonal to each other, a full reflection surface angled at approximately 45 degrees to each connecting surface, and lenses respectively formed on the connecting surfaces, and is held by a holder portion rotatably attached to the adapter portions, and the holder portion rotatably holds the optical-path

conversion optical element.

In the optical-path conversion relay optical connector, the plug has a plug front end surface where a front end surface of the optical fiber core is exposed, and plug-side guide pins attached to both sides of the front end surface of the optical fiber core at the plug front end surface and protruding from the plug front end surface, and when the plug is fitted in the adapter portion, the plug front end surface faces one of the connecting surfaces of the optical- path conversion optical element, and the plug-side guide pins enter pin guide holes formed in the connecting surface. hi the optical-path conversion relay optical connector, the holder portion has an urging member, an accommodating portion for accommodating the urging member, and two holding arm portions extending from both ends of the accommodating portion, and the holding arm portions are rotatably engaged near at free ends thereof with side plates of the respective adapter portions.

In this optical-path conversion relay optical connector, the urging member is intervened between the accommodating portion of the holder portion and the optical-path conversion optical element.

In the optical-path conversion relay optical connector, the adapter portion has an accommodating portion which is defined by a top plate, side plates respectively on both sides, and a bottom plate and in which the plug is inserted from a side opposite to the connecting corner portion, and the top plate has a cut-away part formed by removing a portion close to an opposite end to the connecting corner portion. hi the optical-path conversion relay optical connector, the plug fitted into the adapter portion rotates together with the optical-path conversion optical element.

According to the present invention, the optical-path conversion relay optical connector is configured in such a way that two adapter portions in which plugs connected to the axial ends of the optical fiber cores are fitted are orthogonally coupled together, an optical-path conversion optical element having pin guide holes formed in two substantially orthogonal connecting surfaces is provided at a connecting corner portion, guide pins of the plugs are inserted into the pin guide holes to fix the connecting positional relationship

between the plugs and the optical-path conversion optical element, and the optical-path conversion optical element is rotatably attached to the connecting comer portion. This can ensure easier fitting and positioning of the plugs with high accuracy, ensure easy and low- cost manufacture of the optical-path conversion relay optical connector, and allow the optical fiber cores to be connected together substantially orthogonally without requiring large space for a work of fitting the plugs. Further, the connecting positions of the optical fiber cores and the optical-path conversion optical element are not shifted, and the plugs and the optical-path conversion optical element are displaceable with respect to the adapter portions, so that the optical-path conversion relay optical connector will not be damaged even if external force is applied thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a perspective view showing an optical-path conversion relay optical connector according to one embodiment of the present invention; FIG 2 is a cross-sectional view showing the optical-path conversion relay optical connector according to the embodiment of the present invention;

FIG 3 is a perspective view showing an adapter portion in the embodiment of the present invention;

FIG 4 is a perspective view showing a plug in the embodiment of the present invention;

FIG 5 is an exploded perspective view of the optical-path conversion relay optical connector according to the embodiment of the present invention as seen from a connecting corner portion side;

FIGS. 6 A and 6B are cross-sectional views showing around the connecting corner portion of the optical-path conversion relay optical connector according to the embodiment of the present invention;

FIG 7 is a diagram showing the movements of the plug and optical-path conversion optical element in the embodiment of the present invention; and

FIG 8 is an exploded view showing the conventional optical connector assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG 1 is a perspective view showing an optical-path conversion relay optical connector according to one embodiment of the present invention, FIG 2 is a cross-sectional view showing the optical-path conversion relay optical connector according to the embodiment of the present invention, FIG 3 is a perspective view showing an adapter portion in the embodiment of the present invention, and FIG. 4 is a perspective view showing a plug in the embodiment of the present invention. Referring to the diagrams, reference numeral " 1 " denotes a connector as an optical- path conversion relay optical connector according to one embodiment of the present invention. The connector 1 connects a first optical fiber array 191 A and a second optical fiber array 191B, each including a plurality of parallel optical fiber cores, in such a way as to be substantially orthogonal to each other or in such a way that the optical path is bent about 90 degrees. A first plug 101 A is connected to an end of the first optical fiber array 191 A, and a second plug 101B is connected to an end of the second optical fiber array 191B. The connector 1 has a shape bent by nearly 90 degrees. As the first plug 101 A and the second plug 101B are respectively fitted into a first adapter portion 11 A and a second adapter portion 1 IB as adapter portions, which are coupled together in such a way as to be substantially orthogonal to each other, the first optical fiber array 191 A and the second optical fiber array 19 IB are connected in an optically transmittable manner.

In this embodiment, representations of directions such as up, down, left, right, front, rear, and the like, used for explaining the structure and movement of the connector 1 and each part of the connector 1, are not absolute, but relative. These representations are appropriate when the connector 1 and each part of the connector 1 are in the position shown in the figures. If the positions of the connector 1 and each part of the connector 1 change, however, it is assumed that these representations are to be changed according to the changes of the positions of the connector 1 and each part of the connector 1.

In the embodiment, a fiber body having a bare (uncoated) fiber as an optical

transmission path coated with a protection coat layer is called "optical fiber core", a fiber body having the protection coat layer removed from the "optical fiber core" or a bare fiber or a fiber equivalent to a bare fiber is called "optical fiber".

In the embodiment, because each part included in the connector 1 which is associated with the first adapter portion 1 IA extending substantially horizontally in FIG 2 and each part included in the connector 1 which is associated with the second adapter portion 1 IB extending substantially vertically in FIG. 2 have similar structures, each part associated with the first adapter portion 1 IA has "first" given to its name and "A" affixed at the end of the reference numeral, and each part associated with the second adapter portion HB has "second" given to its name and "B" affixed at the end of the reference numeral to be distinguishable from each other. In a case where individual parts included in the connector 1 are explained without distinguishing each part associated with the first adapter portion 1 IA from each part associated with the second adapter portion HB, the ordinal numbers "first" and "second" and the letters "A" and "B" are omitted. The first plug 101 A has a first fiber holding portion 118 A as an MT (Mechanically

Transferable) type connector, a first plug housing 11 IA covering around the first fiber holding portion 118A, and a first plug stopper 116A attached to the rear end of the first plug housing 11 IA. A first plug engagement projection 115A is attached to either side of the first plug stopper 116A. Likewise, the first plug 101 A, the second plug 101B has a second fiber holding portion 118B, a second plug housing 11 IB, and a second plug stopper 116B, and a second plug engagement projection 115B is attached to either side of the second plug stopper 116B.

The adapter portion 11 is integrally formed of plastic, such as PBT (PolyButylene Terephthalate), PC (PolyCarbonate), LCP (Liquid Crystal Polymer), PPS (PolyPhyenylene Sulfide), polyamide, or PEEK (PolyEther Ether Ketone), by injection molding or the like. However, the adapter portion 11 may be formed of any material and by any method.

The first adapter portion 1 IA and the second adapter portion 1 IB are connected at a connecting corner portion 19 to each other in such a way as to be substantially orthogonal to

< each other and integrally. The first adapter portion 11 A is a parallelepiped member extending

substantially horizontally, and has a first accommodating portion 13 A as parallelepiped space defined by a first top plate 12 A, first side plates 17A on both sides, and a first bottom plate 16A. The first plug 101 A is accommodated in the first accommodating portion 13 A.

The first top plate 12A has a first cut-away part 14A formed by removing a portion close to the opposite end to the connecting corner portion 19. Accordingly, an operator can see at least a part of the first accommodating portion 13A from above the first adapter portion 1 IA, and can move the first plug 101 A toward the connecting corner portion 19 after moving the front end of the first plug 101 A through the first cut-away part 14A from above and placing the front end into the first accommodating portion 13 A. This can facilitate the work of inserting the first plug 101 A into the first accommodating portion 13A to be fitted into the first adapter portion HA.

A first plug engagement recess portion 15 A is formed in that part of the first side plate 17A which is close to the opposite end thereof to the connecting corner portion 19. When the first plug 101 A is inserted into the first accommodating portion 13A to complete the fitting of the first plug 101 A into the first adapter portion 1 IA, the first plug engagement projection

115A is engaged with the first plug engagement recess portion 15 A, thereby locking the first plug 101 A into the first adapter portion 11 A.

The second adapter portion HB is a parallelepiped member extending substantially vertically, and has a second accommodating portion 13B as parallelepiped space defined by a second top plate 12B, second side plates 17B on both sides, and a second bottom plate 16B. The second plug 101 B is accommodated in the second accommodating portion 13B. Because the structures of the parts of the second adapter portion HB are the same as those of the first adapter portion 1 IA, their descriptions will be omitted.

A holder portion 31 for holding an optical -path conversion optical element 91 in a rotatable manner is disposed at the connecting corner portion 19. As shown in FIG 2, the holder portion 31 holds the optical-path conversion optical element 91 by urging the optical- path conversion optical element 91 in such a way as to press the optical-path conversion optical element 91 against the first fiber holding portion 118 A of the first plug 101 A and the second fiber holding portion 118B of the second plug 101 B by using an urging member 41.

Although a first spacer 43 A and a second spacer 43B are intervened between the optical-path conversion optical element 91 and the first fiber holding portion 118A and the second fiber holding portion 118B in the embodiment, the first spacer 43 A and the second spacer 43B can be omitted whenever needed. The holder portion 31 has holding arm portions 33 on both sides, and circular engagement holes 34 formed in the vicinity of the free ends of the holding arm portions 33 are rotatably engaged with a rotation shaft 37 having a circular or semicircular cross section and protruding from the connecting portion of the first side plate 17A and the second side plate 17B. Accordingly, the holder portion 31 is attached to the connecting corner portion 19 rotatably. A fixing member 81 is attached to the first adapter portion 1 IA to fix the connector 1 to a surface of a circuit board, a casing or the like. The fixing member 81 is a plate-like member having an approximately gate-like shape, and has a flat-shaped center portion 81a so disposed as to lie above the first top plate 12 A, and fixing leg portions 82 extending downward from both ends of the center portion 81a. An uneven portions is formed at the tip portion of each fixing leg portion 82, so that the fixing leg portions 82 are inserted into and engaged with fixing through holes or the like formed in the surface of the circuit board, a casing or the like. The fixing member 81 has engagement openings 81b. As the engagement openings 81b are engaged with fixing leg engagement projections 38 formed on the first side plates 17 A, the fixing member 81 is fixed to the first adapter portion HA. Although the fixing member 81 is attached only to first adapter portion 11 A in the illustrated embodiment, the fixing member 81 may be attached to the second adapter portion HB as needed.

The structures of the first plug 101 A and the second plug 101 B will be explained in detail below. Because the structures of the first plug 101 A and the second plug 101B are substantially identical to each other, the ordinal numbers "first" and "second" and the letters "A" and "B" are omitted in FIG 4.

The fiber holding portion 118 is integrally formed of plastic, such as PBT, PC, LCP, PPS, polyamide, or PEEK, by injection molding or the like, and has parallel-arrayed optical fiber cores of the optical fiber array 191 fixed therein by an adhesive or the like. The fiber holding portion 118 may be formed by a combination of a plurality of parts. A front end

surface 192 of the optical fiber core is exposed at a plug front end surface 195 as the front end surface of the fiber holding portion 118.

A pair of plug-side guide holes 193 or through holes having a circular cross section extending in the fitting direction of the fiber holding portion 118, i.e., in the optical axial direction of the optical fiber core. Plug-side guide pins 194 which are columnar rod members are mounted into the plug-side guide holes 193. In this case, each plug-side guide pin 194 is mounted in such a way that a portion extending from the tip by a predetermined length protrudes from the plug front end surface 195 and is immovable at least in the axial direction.

The fiber holding portion 118 is inserted into the parallelepiped box-like plug housing 111 and mounted thereto in such a way that a portion of the fiber holding portion 118 extending from the tip by a predetermined length protrudes from the front end surface of the plug housing 111. Further, the plug stopper 116 is mounted to the rear end of the plug housing 111. In this case, the plug stopper 116 is engaged with the plug housing 111 as the front end portion of the plug stopper 116 is fitted into the rear end portion of the plug housing 111, and the engagement projections 119 formed on both side surfaces of the front end portion of the plug stopper 116 are engaged with engagement openings 117 formed in both side surfaces of the rear end portion of the plug housing 111. The fiber holding portion 118 is fixed with the position of the rear end restricted by the plug stopper 116.

The structure of fixing the optical-path conversion optical element 91 to the connecting corner portion 19 will be explained in detail below.

FIG 5 is an exploded perspective view of the optical-path conversion relay optical connector according to the embodiment of the present invention as seen from the connecting corner portion side.

The optical-path conversion optical element 91 according to the embodiment has a structure and functions similar to those of the optical-path conversion optical element disclosed in Japanese Patent Application Laid-Open (Kokai) No. 2005-031556, and can be used bidirectionally to couple optical fiber arrays 191 together in the fields of optical communications or the like. The optical-path conversion optical element 91 is a transparent member integrally formed of a light transmissive material, such as a resin or glass. The

optical-path conversion optical element 91 has a first connecting surface 92 A and a second connecting surface 92B substantially orthogonal to each other, and a full reflection surface 96 angled substantially at 45 degrees to the first connecting surface 92A and the second connecting surface 92B. A first lens array and a second lens array (both not shown) each including an array of collimate lenses are integrally formed at the center portions of the first connecting surface 92A and the second connecting surface 92B, respectively. Light input from one lens array is reflected at the full reflection surface 96, so that the optical path is changed by 90 degrees and the light leaves from the lens array on the other lens array. With the optical-path conversion optical element 91 fixed to the connecting corner portion 19, the first connecting surface 92 A and the second connecting surface 92B abut on the end portions of the first adapter portion 11 A and the second adapter portion 11 B located on the connecting corner portion (19) side and the front end surfaces of the first fiber holding portion 118Aof the first plug 101 A and the second fiber holding portion 118B of the second plug 101 B, which are respectively _. fitted into the first adapter portion 1 IA and the second adapter portion 1 IB, via the first spacer 43 A and the second spacer 43B.

Projections which surround the first connecting surface 92 A and the second connecting surface 92B may be formed integrally on the optical-path conversion optical element 91. In this case, the front surfaces of the projections abut on the end portion of the adapter portion 11 located on the connecting corner portion (19) side and the front end surface of the fiber holding portion 118, so that the spacer 43 can be omitted.

First pin guide holes 95 A (to be described later) with a circular cross section perpendicular to the first connecting surface 92A are formed in the first connecting surface 92 A on both sides of the first lens array in such a way as to penetrate through the optical-path conversion optical element 91 in the forward/backward direction (left/right direction in FIGS. 6A and 6B). Second pin guide holes 95B (to be described later) with a circular cross section perpendicular to the second connecting surface 92B are formed in the second connecting surface 92B on both sides of the second lens array in such a way as to penetrate through the optical-path conversion optical element 91 in the up/down direction (up/down direction in

FIGS. 6A and 6B). The full reflection surface 96 is provided at a position facing the lens arrays, not at positions corresponding to the pin guide holes 95.

The holder portion 31 has an accommodating portion 32 having a recess portion to accommodate the urging member 41, and the holding arm portions 33 extending from both ends of the accommodating portion 32. The holding arm portions 33 is an approximately square-shaped plate member having a circular engagement hole 34 formed in the vicinity of the free end thereof. The accommodating portion 32 is a recessed member having a bottom plate inclined so as to be substantially in parallel to the full reflection surface 96 of the optical-path conversion optical element 91, and supports the urging member 41 on the bottom plate.

In the embodiment, the urging member 41 is a thick plate-like member of an elastic material, such as silicone rubber, and is intervened between the bottom plate of the accommodating portion 32 and the optical-path conversion optical element 91 to urge the optical-path conversion optical element 91 in such a way as to press the optical-path conversion optical element 91 against the first fiber holding portion 118 A of the first plug 101 A and the second fiber holding portion 118B of the second plug 101 B . The urging member 41 should not necessarily be a thick plate- like member of silicone rubber or the like, and may be a spring member, such as a coil spring or a leaf spring, or any other type of member as long as it can urge the optical-path conversion optical element 91. If the accommodating portion 32 of the holder portion 31 and the optical-path conversion optical element 91 have such sizes as to be accommodated with less rattling, the optical-path conversion optical element 91 may be placed directly in the accommodating portion 32 without accommodating the urging member 41 therein.

With the urging member 41 accommodated in the accommodating portion 32, the holder portion 31 is attached to the adapter portion 11 by pressing the optical-path conversion optical element 91 against the connecting corner portion 19. In this case, the optical-path conversion optical element 91 is attached in such a way that the first connecting surface 92 A and the second connecting surface 92B abut on the end portions of the first adapter portion HA and the second adapter portion HB on the connecting corner portion (19) side, and the

first fiber holding portion 118 A of the first plug 101 A and the second fiber holding portion 118B of the second plug 101B, which are respectively fitted into the first adapter portion HA and the second adapter portion 1 IB, via the first spacer 43 A and the second spacer 43B. As the circular engagement hole 34 formed in the holding arm portions 33 is engaged with the rotation shaft 37, the holder portion 31 is engaged with the adapter portion 11.

Accordingly, the optical-path conversion optical element 91 is fixed to the connecting corner portion 19 while being held between the connecting corner portion 19 and the holder portion 31. hi this case, the optical-path conversion optical element 91 is pressed by the urging member 41. That is, the first connecting surface 92 A and the second connecting surface 92B are pressed against the end portions of the first adapter portion 1 IA and the second adapter portion 1 IB on the connecting corner portion (19) side and the front end surfaces of the first fiber holding portion 118A of the first plug 101 A and the second fiber holding portion 118B of the second plug 101B, which are respectively fitted into the first adapter portion 1 IA and the second adapter portion 1 IB, via the first spacer 43 A and the second spacer 43B.

As the engagement hole 34 is engaged with the rotation shaft 37, the holder portion 31 is rotatably attached to the connecting corner portion 19. This can allow the optical-path conversion optical element 91 to rotate within a predetermined angular range with respect to the connecting corner portion 19. The operation of fitting the plug 101 into the connector 1 will be explained in detail below.

FIGS. 6 A and 6B are cross-sectional views showing around the connecting corner portion of the optical-path conversion relay optical connector according to the embodiment of the present invention, and FIG 7 is a diagram showing the movements of the plug and optical-path conversion optical element in the embodiment of the present invention. FIG 6B is an enlarged view of a part A in FIG. 6A.

First, the operation of fitting the first plug 101 A into the first adapter portion 11 A of the connector 1 will be explained in detail. It is assumed that the first adapter portion 1 IA of the connector 1 is fixed to the surface of a circuit board, a casing or the like (not shown) in

parallel by the fixing member 81.

In this case, the operator holding the first plug 101 A with fingers or so makes the front end surface of the first fiber holding portion 118 A or a first plug front end surface 195 A face the opposite end surface of the first plug 101 A to the connecting corner portion 19. Next, the operator moves the first plug 101 A toward the connecting corner portion 19 in the fitting direction or in the axial direction of the first plug 101 A to insert the first plug 101 A into the first accommodating portion 13A from the front end of the first fiber holding portion 118A. Then, the operator further moves the first plug 101 A, so that as shown in FIGS. 6A and 6B, the first plug front end surface 195 A abuts on the first spacer 43 A fixed to the connecting corner portion 19, thereby stopping the first plug 101 A. As the first plug engagement projection 115Ais engaged with the first plug engagement recess portion 15 A, the first plug 101 A is locked into the first adapter portion HA. This accomplishes positioning of the first plug 101 A to the first adapter portion 1 IA in the fitting direction, thereby completing the fitting of the first plug 101 A into the first adapter portion 1 IA. The up/down-directional size of the first accommodating portion 13A in FIGS. 6 A and 6B is larger than the up/down-directional size of the first adapter portion 11 A to allow for the up/down-directional displacement of the inserted first plug 101 A. Likewise, the up/down-directional size of the first plug engagement recess portions 15 A is larger than the up/down-directional size of the first plug engagement projection 115A to allow for the up/down-directional displacement of the engaged first plug 101 A. Even when the first plug 101 A is locked into the first adapter portion 1 IA and positioning of the first plug 101 A to the first adapter portion 1 IA in the fitting direction is carried out, therefore, the first plug 101 A can be slightly displaced in the up/down direction in FIGS. 6A and 6B with respect to the first adapter portion HA. When the first plug front end surface 195 A comes close to the first spacer 43 A, the front end portions of the pair of plug-side guide holes 193 A mounted into the first plug-side guide holes 193 A of the first fiber holding portion 118A enter the pair of first pin guide holes 95 A of the optical-path conversion optical element 91. This accomplishes positioning of the first plug 101 Ato the optical-path conversion optical element 91 in a direction orthogonal to

the fitting direction.

Because the first top plate 12 A of the first adapter portion HA has the first cut-away part 14A formed by removing a portion close to the opposite end to the connecting corner portion 19, the operator can move the front end of the first plug 101 A from above and place the front end thereof into the first accommodating portion 13A through the first cut-away part 14 A, for example, in a case where the operator is difficult to see the first accommodating portion 13 A from the opposite side of the first plug 101 A to the connecting corner portion 19 or in a case where the space secured around the opposite end portion of the first plug 101 A to the connecting corner portion 19 is not large enough for the operator to move the first plug 101 A in the fitting direction. Thereafter, the operator can move the first plug 101 A toward the connecting corner portion 19, and insert the first plug 101 A into the first accommodating portion 13 A to be fitted into the first adapter portion 1 IA as described above. Accordingly, the operator can easily perform a work of fitting the first plug 101 A into the first adapter portion HA. As the holder portion 31 is rotatably attached to the connecting corner portion 19 and the optical-path conversion optical element 91 can be rotated to a certain degree with respect to the connecting corner portion 19, the front end portions of the first plug-side guide pins 194A can be placed into the first pin guide holes 95 A even if the axes of the first plug-side guide pins 194 A are precisely aligned with the axes of the first pin guide holes 95 A. The operation of fitting the second plug 10 IB into the second adapter portion HB is the same as the fitting operation for the first plug 101 A. That is, the operator holding the second plug 10 IB with fingers or so makes the front end surface of the second fiber holding portion 118B or a second plug front end surface 195B face the opposite end surface of the second plug 101B to the connecting corner portion 19. Next, the operator moves the-second plug 101 B toward the connecting corner portion 19 in the fitting direction or in the axial direction of the second plug 101B to insert the second plug 101 B into the second accommodating portion 13B from the front end of the second fiber holding portion 118B. Then, the operator further moves the second plug 101B, so that as shown in FIGS. 6A and 6B, the second plug front end surface 195B abuts on the second spacer 43B fixed to the

connecting comer portion 19, thereby stopping the second plug 101 B. As the second plug engagement projection 115B is engaged with the second plug engagement recess portion 15B, the second plug 101B is locked into the second adapter portion HB. This accomplishes positioning of the second plug 101B to the second adapter portion HB in the fitting direction, thereby completing the fitting of the second plug 101B into the second adapter portion 1 IB.

The left/right-directional size of the second accommodating portion 13B in FIGS. 6 A and 6B is larger than the left/right-directional size of the second adapter portion 1 IB to allow for the left/right-directional displacement of the inserted second plug 101 B. Likewise, the left/right-directional size of the second plug engagement recess portions 15B is larger than the left/right-directional size of the second plug engagement projection 115B to allow for the left/right-directional displacement of the engaged second plug 101B. Even when the second plug 101B is locked into the second adapter portion HB and positioning of the second plug 101B to the second adapter portion HB in the fitting direction is carried out, therefore, the second plug 10 IB can be slightly displaced in the left/right direction in FIGS. 6 A and 6B with respect to the second adapter portion 1 IB.

When the second plug front end surface 195B comes close to the second spacer 43B, the front end portions of the pair of plug-side guide holes 193B mounted into the second plug-side guide holes 193B of the second fiber holding portion 118B enter the pair of second pin guide holes 95B of the optical-path conversion optical element 91. This accomplishes positioning of the second plug 10 IB to the optical-path conversion optical element 91 in a direction orthogonal to the fitting direction.

Because the second top plate 12B of the second adapter portion HB has the second cut-away part 14B formed by removing a portion close to the opposite end to the connecting corner portion 19, the operator can move the front end of the second plug 10 IB from the side and place the front end thereof into the second accommodating portion 13B through the second cut-away part 14B, for example, in a case where the operator is difficult to see the second accommodating portion 13B from the opposite side of the second plug 101B to the connecting corner portion 19 or in a case where the space secured around the opposite end portion of the second plug 101 B to the connecting corner portion 19 is not large enough for

the operator to move the second plug 101B in the fitting direction. Thereafter, the operator can move the second plug 101 B toward the connecting corner portion 19, and insert the second plug 101B into the second accommodating portion 13B to be fitted into the second adapter portion 1 IB as described above. Accordingly, the operator can easily perform a work of fitting the second plug 101B into the second adapter portion HB.

As the holder portion 31 is rotatably attached to the connecting corner portion 19 and the optical-path conversion optical element 91 can be rotated to a certain degree with respect to the connecting corner portion 19, the front end portions of the second plug-side guide pins 194B can be placed into the second pin guide holes 95B even if the axes of the second plug- side guide pins 194B are precisely aligned with the axes of the second pin guide holes 95B. As the first plug 101 A and the second plug 101B are respectively fitted into the first adapter portion HA and the second adapter portion 11B of the connector 1 through the operations, the first optical fiber array 191 A and the second optical fiber array 191B are orthogonally connected to each other via the optical-path conversion optical element 91. There may be a case where the operator erroneously applies pinching force to the first optical fiber array 191 A or the second optical fiber array 191B, or the circuit board, the casing or the like to which the connector 1 is fixed is thermally expanded due to the heat generated, or a shock or vibration is applied to the circuit board, the casing or the like during the use of the connector 1, so that stress is applied to the connector 1 or the first plug 101 A or the second plug 101B thermal stress or vibration. According to the embodiment, even in such a case, because the holder portion 31 can be attached to the connecting corner portion 19 in a ratable manner to permit the optical-path conversion optical element 91 to be rotated to some degree, and the first plug 101 A and the second plug 101 B can be displaced with respect to the first adapter portion 1 IA and the second adapter portion 1 IB, the optical-path conversion optical element 91, the first plug 101 A and the second plug 101B can rotate together with respect to the connector 1, thereby letting the stress escape.

FIG. 7 shows an example where the optical-path conversion optical element 91, the first plug 101 A and the second plug 101B rotate together counterclockwise with respect to the connector 1. It is apparent that in this case, the rotation produces a gap α between the first

plug stopper 116A of the first plug 101 A and the first bottom plate 16A of the first adapter portion 1 IA and a gap β between the second plug housing 11 IB of the second plug 101 B and the second top plate 12b of the second adapter portion HB.

As the first plug-side guide pins 194 A enter the first pin guide holes 95 A, the first plug 101 A is positioned to the optical-path conversion optical element 91, and as the second plug-side guide pins 194B enter the second pin guide holes 95B, the second plug 10 IB is positioned to the optical-path conversion optical element 91, so that the aforementioned rotation does not change the positional relationship between the optical-path conversion optical element 91 and the first plug 101 A and the second plug 101B. Even if the optical- path conversion optical element 91, the first plug 101 A and the second plug 101B rotate with respect to the connector 1 , therefore, it is possible to surely keep the optical transmittable state via the optical-path conversion optical element 91 between the first optical fiber array 191 A and the second optical fiber array 191B whose optical paths are substantially orthogonal to each other. According to the embodiment, as apparent from the above, the adapter portions 11 are coupled together at the connecting corner portion 19 where the optical-path conversion optical element 91 is disposed in such a way as to be substantially orthogonal to each other. The optical-path conversion optical element 91 has the two connecting surfaces 92 substantially orthogonal to each other, the full reflection surface 96 angled substantially at 45 degrees to the connecting surfaces 92, the lens arrays formed on the connecting surfaces 92, and pin guide holes 95 formed on both sides of each lens array and extending in a direction orthogonal to each first connecting surface 92 to penetrate through the optical-path conversion optical element 91, and is rotatably attached to the adapter portions 11 by the holder portion 31. Each plug 101 has the plug-side guide pins 194 to be inserted into the pin guide holes 95 formed in the associated connecting surface 92 of the optical-path conversion optical element 91, and is positioned to the optical-path conversion optical element 91.

This can allow the positioning of the optical-path conversion optical element 91 to be carried out easily with high accuracy. It is therefore possible to realize optical transmission between the first optical fiber array 191 A and the second optical fiber array 19 IB via the

optical-path conversion optical element 91 with a high efficiency.

The plug 101 has the plug front end surface 195 where the front end surface 192 of the optical fiber core is exposed, and the plug-side guide pins 194 attached to both sides of the front end surface 192 of the optical fiber core at the plug front end surface 195 and protruding from the plug front end surface 195, so that when the plug 101 is fitted into the adapter portion 11, the plug front end surface 195 faces the connecting surface 92 of the optical-path conversion optical element 91 and the plug-side guide pins 194 enter the pin guide holes 95 formed in the connecting surface 92.

This can ensure easier positioning of each plug 101 and the optical-path conversion optical element 91 with high accuracy, and can ensure highly-efficient optical transmission via the optical-path conversion optical element 91.

Further, the holder portion 31 has the accommodating portion 32 to accommodate the urging member 41 and the two holding arm portions 33 extending from both sides of the accommodating portion 32, and the holding arm portions 33 are rotatably engaged in the vicinity of the free ends with the side plates 17 of the adapter portion 11.

This makes it possible to attach the holder portion 31 easily and fix the optical-path conversion optical element 91 easily and surely. Because only the single and small holder portion 31 is needed, the structure of the connector 1 can be simplified and the size of the connector 1 can be made smaller to reduce the rear size thereof. This leads to cost reduction of the connector 1 and reduction of the space on the circuit board, the casing or the like needed to mount the connector 1.

Further, the adapter portion 11 has the accommodating portion 13 which is defined by the first top plate 12, both side plates 17 and the bottom plate 16 and in which the plug 101 is inserted from the opposite side to the connecting corner portion 19, and the top plate 12 has the cut-away part 14 formed by removing a portion close to the opposite end to the connecting corner portion 19.

Accordingly, the operator can see at least a part of the accommodating portion 13 through the cut-away part 14, and can move the plug 101 toward the connecting corner portion 19 after moving the front end of the plug 101 through the cut-away part 14 and

placing the front end into the accommodating portion 13. This can facilitate the work of inserting the plug 101 into the accommodating portion 13 to be fitted into the adapter portion 11.

Further, the plug 101 fitted into the adapter portion 11 rotates together with the optical-path conversion optical element 91, thus letting stress escape to prevent the plug 101, the optical-path conversion optical element 91, etc. from being damaged by the stress. It is also possible to surely keep the optical transmission between the optical fiber cores via the optical-path conversion optical element 91.

The present invention is not limited to the above-described embodiment, and may be changed in various ways based on the gist of the present invention, and these changes are not eliminated from the scope of the present invention.