Optical connector, plug and receptacle

Abstract

To provide the optical connector small in number of components, simple in structure, and allowing reduction in production cost, improvement in productivity and reduction in size.SOLUTION: A first connector 110 includes a first connector housing 120 formed in a cylindrical body having a storage part in the inside; a spacer 400 capable of slidably contacting the inner surface of the storage part in the first connector housing to slidably arrange a first ferrule 130; an energization member 300 for energizing the spacer toward a second connector 210 side; and a stopper 500 fixed to the rear part on the side opposite to the second connector of the first connector housing. A passage passing a first optical cable A is formed in the spacer and the stopper; and the energization member is an optical connector 10 including a pair of coil springs arranged on both sides of the first optical cable A between the spacer and the stopper.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical connector and a plug for optically connecting optical fibers of an optical cable that transmits optical signals. [Background technology]

[0002] Optical fiber cables using optical fibers are capable of transmitting large amounts of information at high speeds, and are therefore widely used for information communication in both domestic and industrial applications. For example, Patent Document 1 (JP Patent Publication No. 10-160969) discloses an optical connector that solves the problem that conventional products such as MPO connectors have a large number of parts, and that tasks such as assembly and removing ferrules from the housing take time.

[0003] The optical connector described in Patent Document 1 comprises a cylindrical holder body that houses one of a pair of ferrules to be butt-connected, a biasing means that biases the one ferrule toward an insertion opening that opens at one end of the holder body in the central axial direction, and an elastic claw that detachably engages with the other ferrule inserted into the holder body from the insertion opening, and by sandwiching the butt-connected ferrules between the elastic claw and the biasing means, the butt-connected ferrules are secured between the joining end faces of the two ferrules.

[0004] Patent Document 2 (JP 2010-54681 A) discloses an optical connector that suppresses increases in connection loss of optical fibers caused by deformation or rattle of the resin, and enables reduced production costs, improved productivity, and miniaturization. The optical connector described in Patent Document 2 is configured such that an elastically deformable locking piece formed on the first connector is locked onto a locking protrusion formed on the second connector, thereby allowing the first and second connectors to fit together and optically connect the optical fibers to each other; a ferrule having a first fiber insertion hole through which an end portion of one optical fiber is inserted is attached to the first connector while being biased toward the second connector by a coil spring; a second fiber insertion hole through which an end portion of the other optical fiber is inserted is formed directly in the second connector; and the second connector is molded from a harder material than the first connector.

[0005] Patent Document 3 (JP 2021-60451 A) discloses an optical connector that can suppress the application of local stress to an optical fiber. The optical connector described in Patent Document 3 includes an optical fiber, a ferrule having an insertion hole through which the optical fiber is inserted, a housing that accommodates the ferrule, two springs that are arranged to sandwich the optical fiber therebetween and urge the ferrule forward, and a support portion that supports the two springs from the rear. The support portion is formed by combining a first divided member and a second divided member, and has at least two latch portions that are respectively engaged with at least two engaging holes formed in the housing. The two latch portions are arranged side by side in the vertical direction.

[0006] Patent Document 4 (JP 2015-184359 A) discloses a versatile and highly reliable optical connector that makes it difficult for an optical fiber cord to come off the optical connector. The optical connector described in Patent Document 4 is equipped with a fixing member consisting of two interlocking halves that press a protective tube covering a stepped portion on the outer surface of a spring-loaded optical fiber mounting portion from the outside toward the optical fiber mounting portion, thereby securely fixing the protective tube to the optical fiber mounting portion.

[0007] Patent Document 5 (JP 2015-22213 A) discloses an optical connector with excellent assembly workability and a method for assembling the optical connector. The optical connector described in Patent Document 5 includes a housing, a ferrule accommodated in the housing, and a biasing member that expands and contracts in one direction within the housing to bias the ferrule. The biasing member has a recess in its widthwise center that extends in the longitudinal direction of the housing and accommodates an optical fiber to be connected to the ferrule. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-160969 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-54681 [Patent Document 3] Patent Publication No. 2021-60451 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-184359 [Patent Document 5] Japanese Patent Application Laid-Open No. 2015-22213 Summary of the Invention [Problem to be solved by the invention]

[0009] In the optical connectors described in Patent Documents 1 and 2, the optical cable is passed through a coil spring that biases the ferrule toward the front of the housing. In this configuration, the optical cable connected to the ferrule and the coil spring cannot be easily separated, which reduces the ease of assembly of the optical connector. Furthermore, when changing the optical cable, the coil spring must also be removed from the housing, which reduces the ease of connection switching.

[0010] Furthermore, the optical connectors described in Patent Documents 3 to 5 use a pair of coil springs for urging the ferrule toward the front of the housing, and these coil springs are arranged on both sides of the optical cable. However, the optical connectors described in Patent Documents 3 to 5 are MPO-type optical connectors that use dedicated adapters, which means they have a large number of parts, a complex configuration, time-consuming assembly, and high costs.In addition, they are larger in size than MT-type optical connectors, making it difficult to mount them densely in devices. Furthermore, in the optical connectors described in Patent Documents 3 to 5, the optical fiber passes through the inside of the optical connector parts (such as a spring bush), so once the ferrule is fixed to the fiber end face, there is a problem in that the optical connector cannot be easily replaced.

[0011] Furthermore, conventional optical fiber wiring was primarily intended for long-distance communications, and because a spring was inserted into the optical fiber and maintenance was not possible, if a malfunction occurred, the entire optical fiber with the optical connector had to be replaced. Therefore, when conventional optical connectors were used in optical wiring mounted on electronic boards inside servers, if a malfunction was discovered in the wiring or connection, it became necessary to cut the optical fiber in order to replace the optical connector (or its components), or to replace the entire board.

[0012] The present invention has been made to overcome the above drawbacks, and its purpose is to provide an optical connector that has a small number of parts, a simple configuration, reduces production costs, improves productivity, and allows for miniaturization. Another object of the present invention is to provide an optical connector that allows the optical connector or connecting parts to be easily replaced without cutting the optical fiber. A further object of the present invention is to provide an optical connector that is small, has low loss, and is capable of high-density wiring. It is still another object of the present invention to provide an optical connector that can easily perform operations such as connecting optical fibers and switching the connection. [Means for solving the problem]

[0013] (1) An optical connector according to one aspect includes a first connector to which a first optical cable A is attached and a second connector to which a second optical cable B is attached, and when the first connector and the second connector are mated, terminals of an optical fiber Af of the optical cable A and an optical fiber Bf of the optical cable B are optically connected to each other. The first connector includes a first connector housing formed of a cylindrical body having an internal receiving portion, a spacer disposed in sliding contact with the inner surface of the receiving portion of the first connector housing so as to allow the first ferrule to slide, a biasing member that biases the spacer toward the second connector side, and a second connector of the first connector housing. The first connector has a stopper fixed to the rear portion opposite the connector, and the second connector has a second connector housing formed of a cylindrical body and an accommodating portion capable of accommodating a second ferrule therein, the first connector housing is provided with a locking piece and a guide piece extending toward the second connector housing, the second connector housing is formed with a locking portion with which the locking piece can be locked and a guide portion for guiding the guide piece, the spacer and the stopper are formed with a passage for passing the first optical cable A, and the biasing member has a pair of coil springs arranged on both sides of the first optical cable A between the spacer and the stopper.

[0014] According to the present invention, the first connector housing is provided with a locking piece and a guide piece extending toward the second connector housing, and the second connector housing is formed with a locking portion into which the locking piece can be locked and a guide portion for guiding the guide piece.Therefore, by moving the first connector housing toward the second connector housing, the locking piece of the first connector housing is locked with the locking portion of the second connector housing and the guide piece of the first connector housing is guided into the guide portion of the second connector housing, the first connector housing and the second connector housing can be fitted together with their positions accurately positioned.

[0015] Furthermore, the biasing member has a pair of coil springs disposed on both sides of the first optical cable A passed through the first connector housing, so that the ends of the optical fiber Af of the optical cable A and the optical fiber Bf of the optical cable B can be butted together while being pressed together by the compressive force of the predetermined coil springs. Furthermore, the spacer is in slidable contact with the inner surface of the accommodating section of the connector housing, enabling accurate parallel movement, so that the pair of optical fibers can be optically connected with little connection loss. In addition, the work of placing the component connecting the first optical cable A and the first ferrule inside the first connector housing and the work of placing the coil spring inside the first connector housing can be performed independently, resulting in excellent workability on site.

[0016] Furthermore, since the spacer and the stopper are formed with grooves through which the first optical cable A passes, by passing the first optical cable A connected to the first ferrule through the grooves formed in the spacer and the stopper, the spacer and the stopper can be housed compactly within the housing and the optical cable can be routed. Also, since the biasing member has a pair of coil springs disposed on both sides of the first optical cable A between the spacer and the stopper, the assembly in which the first ferrule and the first optical cable A are connected and the coil springs can be separately arranged or replaced within the housing, improving the ease of assembly and workability of these components.

[0017] Therefore, even if an optical cable circuit has been wired once, if a defect is found in the connection portion of the optical cable, the entire connector, including the spacer and stopper (bush), can be easily replaced while leaving the optical cable connected to the ferrule. In particular, when a defect occurs in an optically mounted electronic board and the board needs to be replaced, conventionally it was necessary to replace the entire connector, including the optical connector connected to the optical fiber. On the other hand, with the optical connector of the present invention, when replacing the electronic board, the connector components can be removed and reused to connect to the optical fiber. Furthermore, if there is a defect in the optical connector itself, only the connector components can be replaced without cutting the optical fiber, allowing for maintenance. In this specification, the first connector may be referred to as a plug and the second connector may be referred to as a receptacle plug (or simply as a plug), but it is up to the individual to decide which is the plug and which is the receptacle plug.

[0018] (2) The optical connector of the second invention is an optical connector of one aspect of the invention, wherein the two axis centers of the pair of coil springs are arranged parallel to each other and are arranged on a plane including the central axes of the two guide pin insertion holes of the first ferrule, and the pair of coil springs may be arranged outside the two guide pin insertion holes at a predetermined distance from each other.

[0019] This allows a sufficient, uniform contact force to be applied to all optical fibers.The spacer is slidably in contact with the inner surface of the housing, and the axial centers of the pair of coil springs are on the same plane as the central axis of the guide pin insertion hole, so the two stresses generated by the pair of coil springs can apply accurate and uniform pressure in the connection direction of the ferrule. Furthermore, since the coil spring is positioned at a predetermined equal distance on both the left and right sides of the extension line of the guide pin insertion hole, even with a small ferrule, it is possible to ensure the number of optical fibers placed in the center while also ensuring sufficient spring force from the coil spring. Therefore, even when a small ferrule is used, a reliable connection can be achieved, and even when used for high-density optical connections involving a large number of optical fibers, the optical connector can have low connection loss.

[0020] (3) The optical connector according to the third invention is an optical connector according to one aspect or the second invention, and the groove formed in the spacer and the groove formed in the stopper may open in the same direction and be housed in the first connector housing.

[0021] In this case, the spacer, stopper, and biasing member are arranged in the accommodating portion of the first connector housing so that they open in the same direction. Therefore, an operator can easily assemble the optical connector by attaching the optical fiber with the ferrule to the tip of the spacer and inserting it into the first connector housing together with the stopper. If there is a problem with the electronic board on which the optical fiber is mounted and the board needs to be replaced, the connector parts can be removed by disengaging the stopper, and the board can be used again to connect to the optical fiber. Also, if there is a problem with the optical connector itself, only the connector parts can be replaced without cutting the optical fiber, allowing for maintenance.

[0022] (4) The optical connector according to the fourth invention is an optical connector according to any one of the first to third inventions, wherein the spring constant of one coil spring is 1.0 N / mm or more and 6.0 N / mm or less, and the spacer is arranged to be slidable by 3.0 mm or less.

[0023] This allows the compression distance for one spring to be secured at 1.0 mm or more and 5.0 mm or less relative to the free length, and a contact force of 3.0 N or more and 40 N or less can be applied to the ferrule, ensuring reliable optical connection even when the number of optical fibers connected to the ferrule is N or more. This makes it possible to achieve high-density optical wiring even in a compact size, resulting in an optical connector with high information transmission efficiency. Furthermore, a spring with a spring constant of 1.0 N / mm or more and 6.0 N / mm or less can be used, and the metal thickness of the spring can be set to 0.3 mm or more and 0.6 mm or less, so that a small size and sufficient compression distance can be ensured, and sufficient contact force can be applied to the ferrule. In this case, the sliding distance of the spacer is preferably 0.3 mm to 3.0 mm, more preferably 0.5 mm to 2.5 mm. The deflection amount of each spring is preferably 2.0 mm to 3.0 mm. The spring constant of each coil spring is preferably 1.0 N / mm to 6.0 N / mm, more preferably 2.0 N / mm to 5.0 N / mm.

[0024] (5) The optical connector of the fifth invention is an optical connector of any one of the first to fourth inventions, wherein the first connector housing further has a pin holder, to which a pair of guide pins can be coupled, and the pin holder may be disposed between the first ferrule and the spacer.

[0025] This allows the guide pin for precise positioning of the ferrule to be provided on the first connector side (plug side). Since most of the parts protruding from the optical connector are provided on the first connector side (plug side), the worker only needs to be careful to ensure that the protrusions (especially the guide pieces) of the first connector fit into the second connector, and the guide pins will be attached to the two ferrules, ensuring a reliable optical connection. The pin holder may be stored in the optical connector together with the ferrule when the worker connects the optical cable, or may be stored in the optical connector in advance.

[0026] (6) An optical connector according to a sixth aspect of the present invention is an optical connector according to any one of the first to fourth aspects of the present invention, wherein the second connector housing further has a pin holder, and the pin holder has a pair of guide pins and may be arranged between the second ferrule and the spacer.

[0027] This allows a guide pin for precise positioning of the ferrule to be provided on the second connector side (receptacle plug side). Since the first connector (plug) is provided with a guide portion and the second connector (receptacle plug) is provided with a guide pin, the guide pin is not buried in the guide portion and can be exposed from the second connector. Therefore, the worker can reliably perform optical connection while visually checking both the guide portion and the guide pin.

[0028] (7) The optical connector of the seventh invention is an optical connector of any one of the inventions from one aspect to the sixth, wherein the locking piece has an elastic piece protruding outward from the first connector housing, a claw portion formed at the tip of the elastic piece, and a release portion that can release the locking of the claw portion, and the locking portion has a hole portion in which the claw portion can be locked, and the second connector housing may further have a pin holder.

[0029] In this case, the elastic pieces of the locking pieces are elastically deformed, so that the locking pieces of the first connector housing can be securely locked to the locking portions of the second connector housing. The claw portions formed on the elastic pieces may be provided on opposing sides (inner sides) of the pair of elastic pieces, or on outer sides. Furthermore, the locking piece is provided with a release portion that allows the lock to be released, so the optical connector can be easily disconnected and reconnected. This makes it easy to change the optical wiring circuit or replace parts in the event of a malfunction. Furthermore, when replacing a board on which optical fiber is mounted, the connector parts can be removed and reused to connect to optical fiber. Furthermore, if there is a malfunction in the optical connector itself, only the connector parts can be replaced without cutting the optical fiber, allowing for easy maintenance.

[0030] (8) The optical connector of the eighth invention is an optical connector of any one of the inventions from one aspect to the seventh, wherein the first connector and the second connector can each accommodate a ferrule having a thickness of 1.0 mm or more and 1.5 mm or less, and the outer diameter of the coil spring may be 1.8 mm or more and 2.4 mm or less.

[0031] In this way, it is possible to mount and connect smaller MT ferrules than before, enabling compact, high-density optical connections. Furthermore, because the overall size of the plug is small, it is possible to reliably optically connect optical fibers mounted on a board even in a small space such as inside a computer.

[0032] (9) The optical connector according to the ninth invention is an optical connector according to any one of the first to eighth inventions, and the surfaces of both ends of the coil spring may be processed in a plane perpendicular to the axis.

[0033] The surfaces of both ends (closed ends) of the coil spring are processed or treated in a plane perpendicular to the axis, so that the pressing force of the coil spring acts in the same direction as the axial direction of the optical fiber, allowing a uniform pressing force to be applied to each optical fiber, improving the stability of the spring force. This allows for a highly reliable optical connector with low connection loss.

[0034] (10) The optical connector according to the tenth invention is an optical connector according to any one of the first to ninth inventions, wherein the tip of the first guide piece may extend further toward the second connector than the tip of the locking piece.

[0035] With this configuration, the guide pieces of the first connector housing are guided by the guide portions of the second connector housing, and then the locking pieces of the first connector housing are locked into the locking portions of the second connector housing, so that the first and second connector housings can be accurately positioned and then mated together. Furthermore, even when the connectors are attached or detached, the locking pieces are accurately inserted into the locking portions. Therefore, it is possible to prevent damage to the locking pieces, reduce the amount of misalignment of the optical fibers to be connected, and provide an optical connector with low connection loss.

[0036] (11) The optical connector of the 11th invention is an optical connector according to any one of the first to tenth inventions, wherein the guide pieces are provided on two opposing surfaces different from the surface on which the locking pieces are provided, and the two guide pieces may be formed into rectangular shapes having different shapes.

[0037] As a result, all four surfaces of the first connector (plug) and the second connector (receptacle plug) engage with each other, so that the connectors can be reliably connected and fixed to each other. Furthermore, the two guide pieces have different shapes, which uniquely determines the connection direction of the plug and receptacle plug, ensuring that incorrect connections are prevented. This makes the optical connector easy to connect, even when multiple wires are required, such as inside a server. Furthermore, because the two guide pieces are each formed in a rectangular shape, they are held parallel to each other when connecting the first connector (plug) and the second connector (receptacle plug). This prevents the precisely designed guide pins from colliding with the connecting end faces, ensuring reliable optical connection.

[0038] (12) A plug according to a twelfth aspect of the present invention is a plug connectable to the first connector or the second connector of the optical connector according to any one of the first to eleventh aspects of the present invention.

[0039] Connection is possible even if one of the optical connectors is mounted on a circuit board. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is a schematic perspective view of an optical connector according to a first embodiment. [Figure 2] 1 is a reference top view of the optical connector of the first embodiment when the divided body is opened. FIG. [Figure 3] FIG. 2 is a left side view of the optical connector of the first embodiment. [Figure 4] 4 is a cross-sectional view of the optical connector of the first embodiment taken along line AA' in FIG. 3. FIG. [Figure 5] 4 is a cross-sectional view of the optical connector of the first embodiment taken along line BB' in FIG. 3. FIG. [Figure 6] 6 is a cross-sectional view showing the first connector and the second connector of FIG. 5 when connected together. [Figure 7] FIG. 2 is a schematic perspective view for explaining a pin holder of the optical connector of the first embodiment. [Figure 8] FIG. 2 is a schematic perspective view for explaining a ferrule of the optical connector of the first embodiment. [Figure 9] FIG. 10 is a reference top view of the optical connector of the second embodiment when the divided body is opened. [Figure 10] FIG. 4 is a schematic perspective view illustrating an end portion of a coil spring. [Figure 11] FIG. 10 is a schematic perspective view of an optical connector according to a third embodiment. [Figure 12] FIG. 11 is a reference top view of the optical connector of the third embodiment when the divided body is opened. [Figure 13] FIG. 13 is a partially enlarged view of FIG. [Figure 14] FIG. 10 is a schematic explanatory view showing the connection end face of the optical connector of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Although multiple embodiments of the present invention will be described, each embodiment may be implemented alone or in combination with one or more of the multiple embodiments. In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same, so detailed description thereof will not be repeated.

[0042] <Embodiment 1> (Optical Connector 10) Fig. 1 is a schematic perspective view showing an optical connector 10 according to the first embodiment. Fig. 2 is a reference top view when the split bodies of the optical connector 10 are opened, with a portion of the first connector housing 120 and the second connector housing 220 removed. Fig. 3 is a left side view of the optical connector 10, with a portion of the first ferrule 130 that is hidden by a stopper 500 and is shown by a dotted line. Fig. 4 is a cross-sectional view of the optical connector 10 taken along line A-A' in Fig. 3, and Fig. 5 is a cross-sectional view of the optical connector 10 taken along line B-B' in Fig. 3.

[0043] As shown in Figures 1 to 5, the optical connector 10 is an optical connector that can optically connect optical cables A and B by mating a first connector 110 to which optical cable A is attached with a second connector 210 to which optical cable B is attached. Optical cable A has a plurality of optical fibers Af (not shown) bundled in a tape-like shape, and a first ferrule 130 fixed to the end portion of optical cable A. Similarly, optical cable B has a plurality of optical fibers Bf (not shown) bundled in a tape-like shape, and a second ferrule 230 fixed to the end portion of optical cable B. The connecting end face of the first ferrule 130 and the connecting end face of the second ferrule 230 are brought into contact with each other with a predetermined pressing force due to the biasing force of coil spring 300, so that the ends of optical fiber Af and optical fiber Bf are optically connected to each other. In each drawing, for the sake of simplicity, the first optical cable A and the first ferrule 130, and the optical cable B and the second ferrule 230 may be indicated by dotted lines.

[0044] (First connector 110) In this embodiment, the first connector 110 is an optical connector for connecting the end of the optical cable A, and has a first connector housing 120 that can store a first ferrule 130 of the optical cable A. The first connector housing 120 is an integral resin molded product, and has an accommodating section inside. The housing portion of the first connector 110 houses the first ferrule 130, the spacer 400, the stopper 500, and the coil spring 300, and the connecting end face of the first ferrule 130 protrudes from the housing portion. In the first connector 110, the first ferrule 130 and the spacer 400 are slidable in a direction parallel to the connection direction, and are biased in the connection direction by the coil spring 300. As a result, when the first connector 110 and the second connector 210 are mated and connected, the first ferrule 130 and the second ferrule 230 come into contact with each other, and the first ferrule 130 and the spacer 400 slide toward the rear end of the first connector 110 (in the direction opposite to the connection direction). As a result, the coil spring 300 is compressed, generating a biasing force, which applies a contact force to the first ferrule 130 and the second ferrule 230 .

[0045] The first connector housing 120 of this embodiment is made up of a first connector housing main body in the shape of a rectangular parallelepiped, with two locking pieces 122 and two guide pieces 124, 124' each extending in the connection direction (towards the second connector). The first connector housing body preferably has a width of 10 mm to 15 mm, more preferably 12 mm to 14 mm. Its height is preferably 3 mm to 10 mm, more preferably 4 mm to 6 mm. Its depth is preferably 20 mm to 60 mm, more preferably 30 mm to 50 mm. This allows for easy connection of optical wiring even in small environments such as servers.

[0046] (Divided body of first connector housing 120) As shown in Fig. 5, first connector housing 120 can be separated into divided bodies 120A and 120B in a direction perpendicular to the connection direction (vertical direction). Fig. 2 shows a reference top view of first connector housing 120 with divided body 120A removed. When the split body 120A is removed from the first connector housing 120, the first ferrule 130 and the optical cable A can be attached to the split body 120B of the first connector housing 120 without separating them, and the first ferrule 130 and the optical cable A can be removed from the first connector 110 without separating or cutting them.

[0047] In this embodiment, an example has been shown in which the first connector housing 120 is made up of the divided bodies 120A and 120B, but the first connector housing 120 may also be a cylindrical, one-piece molded product. Even when first connector housing 120 is cylindrical, spacer 400, stopper 500, and biasing member 300 are arranged to open in the same direction, so by inserting these components from the rear of first connector housing 120, first ferrule 130 and optical cable A can be attached and detached without separating them. Therefore, each component can be replaced or added later, and first connector 110 can be assembled by combining these components.

[0048] (Spacer 400) The spacer 400 of this embodiment is disposed between the coil spring 300 and the first ferrule 130, and is a member that applies the biasing force of the coil spring 300 to the first ferrule 130. The spacer 400 is paired with a stopper 500 to hold the two coil springs 300 in parallel, and allows the two coil springs 300 to be compressed simultaneously.

[0049] The spacer 400 has a shape configured to be slidable in the front-to-rear direction within the accommodation portion of the first connector housing 120. The spacer 400 is disposed in sliding contact with the inner surface of the accommodation portion of the first connector housing 120 and slides parallel to the connection direction, thereby accurately applying a biasing force in a direction parallel to the axis of the guide pin 40 that penetrates the ferrule. This allows a uniform contact force to be applied in a direction perpendicular to the connection end face of the ferrule, thereby reducing connection loss. The connection end face of the ferrule is sometimes polished at an 8° angle to reduce reflection. In this case, applying a contact force acts to displace the first ferrule 130 and the second ferrule 230 from each other, but the spacer 400 can continue to apply a contact force in the connection direction parallel to the axis of the guide pin 40. In this case, the overall length of the spacer 400 in the connection direction is preferably at least one-fourth, and more preferably at least one-third, of the maximum length of the coil spring 300 stored in the accommodating portion. The overall length of the spacer 400 in the connection direction is also preferably at least one-half, and more preferably at least two-thirds, of the length of the long side of the connecting end face of the ferrule. This ensures a sufficient distance for the spacer 400 to slide against the inner surface of the accommodating portion of the first connector housing 120, and allows the biasing force to be applied in the correct direction.

[0050] Spacer 400 has a cylindrical cavity 420 formed therein so that the front ends of coil springs 300 can be recessed, and holds two coil springs 300 in parallel. This ensures the distance at which spacer 400 slides against the inner surface of the accommodating portion of first connector housing 120, while also ensuring the length of coil springs 300, and further enables the overall size of first connector 110 (particularly the length in the connection direction) to be reduced. In this case, the length of the cylindrical cavity 420 provided in the spacer 400 is preferably at least one-fourth, and more preferably at least one-third, of the maximum length of the coil spring 300 stored in the storage portion.

[0051] (Stopper 500) The stopper 500 of this embodiment is disposed on the rear end side of the coil spring 300, i.e., on the side opposite to the connection direction, and is engaged with and fixed to the first connector housing 120. The stopper 500 is a member that pairs with the spacer 400 and holds the two coil springs 300 in parallel. 2 and 4, the stopper 500 is fitted into and fixed to the rear end portion of the first connector housing 120. That is, a protruding engagement portion 550 is provided on the outer surface of the stopper 500, and the stopper 500 is fixed to the first connector housing 120 by fitting the engagement portion 550 of the stopper 500 into a recess 125 formed on the inner surface of the rear portion of the first connector housing 120.

[0052] The cross-sectional shape of the stopper 500 is formed to be substantially the same as the cross-sectional shape of the spacer 400 . Stopper 500 has a cylindrical cavity 520 inside so that the rear ends of coil springs 300 can be recessed, and holds two coil springs 300 in parallel. This ensures the length of coil springs 300 and also makes it possible to reduce the overall size of first connector 110. In this case, the length of the cylindrical cavity 520 provided in the stopper 500 is preferably at least one-fourth, and more preferably at least one-third, of the maximum length of the coil spring 300 stored in the storage portion. A recessed groove 501 for passing the optical cable A is formed on the upper surface of the stopper 500. The recessed groove 501 communicates with the outside of the first connector housing 120, and the recessed groove 501 opens to the outside of the first connector housing 120.

[0053] In this embodiment, the first connector housing 120 and the stopper 500 are separate members, but the first connector housing 120 and the stopper 500 may be integrally molded. In addition, in this embodiment, the stopper 500 has a cavity 520 formed therein so that the rear end of the coil spring 300 can be recessed, but the coil spring 300 may also be held in place by forming a convex protrusion on the stopper 500 that is inserted into the center of the coil spring 300.

[0054] As described above, a pair of coil springs 300 serving as biasing members are provided between the spacer 400 and the stopper 500. The spacer 400 and the stopper 500 are provided with recessed grooves 401, 501, respectively, through which the optical cable A is passed. Each of the recessed grooves 401, 501 is formed to a size that allows the optical cable A to pass therethrough, and opens in the direction in which the divided bodies 120A, 120B of the first connector housing 120 are separated. This means that if there is a problem with the optical wiring connection or if the optical fiber connection circuit needs to be changed, the ferrule and optical fiber can be easily removed and replaced by simply separating the divided bodies 120A and 120B from the first connector housing 120.

[0055] (biasing member) Two biasing members of this embodiment are disposed between the spacer 400 and the stopper 500, and apply a biasing force to the first ferrule 130, thereby applying a contact force between the end faces of the first ferrule 130 and the second ferrule 230. Although a coil spring 300 is used as the biasing member of this embodiment, an elastic member such as rubber, a leaf spring, a sponge, or the like may also be used. The biasing member of this embodiment is shown in FIG. The coil spring 300 of this embodiment is disposed so as to bridge between first support portions 430 formed on both sides of the spacer 400 and second support portions 530 formed on both sides of the stopper 500. The space between the two coil springs 300 functions as a passage for the optical cable A. Therefore, the optical cable A connected to the first ferrule 130 passes through the recessed groove 401 of the spacer 400, the space, and the recessed groove 501 of the stopper 500 and extends to the outside of the first connector housing 120.

[0056] Although stainless steel wire or piano wire can be used for the coil spring 300, it is preferable to use high-strength stainless steel wire. The spring constant of one coil spring 300 is preferably 1.0 N / mm or more and 6.0 N / mm or less, and more preferably 2.0 N / mm or more and 5.0 N / mm or less. The outer diameter of the coil spring 300 is preferably 1.8 mm to 2.4 mm, and more preferably 2.1 mm to 2.3 mm. In this case, the thickness of the first ferrule 130 and the second ferrule 230 is preferably 1.0 mm to 1.5 mm, and more preferably 1.2 mm to 1.3 mm. This allows the size of first connector 110 to be reduced while still providing a sufficient contact force to the connection end faces of the optical fibers.

[0057] The specifications of the coil spring 300 are selected appropriately depending on the type of optical fiber Af to be connected, but when a 16-core MT ferrule is used, the spring constant of one coil spring 300 is preferably 1.0 N / mm or more and 6.0 N / mm or less, and more preferably 3.8 N / mm or more and 4.5 N / mm or less. Furthermore, as described above, the closed ends (both ends) of the coil spring 300 are machined or processed so that the surfaces of each end are perpendicular to the axis, and the bottoms of the cavities 420, 520 formed in the spacer 400 and the stopper 500, respectively, are formed into flat surfaces. As a result, the pressing force of coil spring 300 acts in the same direction as the axial direction of the optical fibers, so that a uniform pressing force can be applied to each optical fiber, improving the stability of the spring force. Also, the size of first connector 110 can be made small while still applying sufficient contact force to the connection end face of each optical fiber.

[0058] Moreover, it is preferable that the surfaces of both end portions 301 (closed ends) of the coil spring 300 are machined or processed to be perpendicular to the axis. Generally, a coil spring is formed by winding a metal wire in a spiral shape, and therefore the end of the coil spring (for example, a circular arc wound one full turn) is also spirally wound. However, in this embodiment, the full or half-circle arc of the end is not machined or processed to form a spiral shape, but rather a circle or arc coaxial with the axis of the coil spring, so that the surface of the circular arc of end 301 is positioned in a plane perpendicular to the axis. 10, end 301 of coil spring 300 is the portion that abuts against the bottom surface of cylindrical cavity 420 (or cavity 520), and by processing or treating the surface of end 301 in a plane perpendicular to the axis, the pressing force of the coil spring acts in the same direction as the axial direction of the optical fibers, so that a uniform pressing force can be applied to each optical fiber, improving the stability of the spring force. Note that this end may be polished to obtain an accurate perpendicular surface.

[0059] 3 is a left side view of the optical connector 10 (a view showing the rear end face of the first connector 110), and shows the cavities of the first ferrule 130 and the spacer 400, which are hidden by the shadow of the stopper 500, by dotted lines (see FIG. 2). The two axis centers P of the pair of coil springs 300 are provided on the same plane as the central axes of the two guide pin insertion holes 116 of the first ferrule 130. The extensions of the guide pin insertion holes 116 are arranged inside the pair of coil springs 300 at the same predetermined distance, and the optical cable A is arranged inside the two guide pin insertion holes 116. This configuration allows for reliable connections even when using small ferrules, and the optical connector 10 has low connection loss even when used for high-density optical connections involving a large number of optical fibers.

[0060] The predetermined distance in the present invention is selected appropriately depending on the size of the ferrule, etc., and may be selected, for example, from the range of 1.0 mm to 10.0 mm, and specifically may be 2.0 mm, 4.0 mm, or 8.0 mm. Furthermore, "on the same plane" in the present invention means that the distance from the plane containing the central axes of the two guide pin insertion holes 116 is within 10% of the distance between the two guide pin insertion holes 116, or within ±3 mm.

[0061] (Second connector 210) The second connector 210 has a second connector housing 220 formed of a cylindrical body having an approximately rectangular cross section, a second ferrule 230 arranged in a storage section formed within the second connector housing 220, a pin holder 600 for holding the guide pin 40, and a fixing member 510 for fixing the pin holder 600. Since the stopper 500 of the first connector 110 and the fixing member 510 of the second connector 210 have similar external shapes, it is possible to use common parts, thereby reducing manufacturing costs.

[0062] The second connector housing 220 is integrally formed in a generally cylindrical shape from, for example, a synthetic resin material, similar to the first connector housing 120. Similarly to the first ferrule 130, the second ferrule 230 is also integrally molded in a thin plate shape from a synthetic resin material.

[0063] (Second connector housing 220) A locking portion 222 capable of locking the locking piece 122 is formed on the opposing first and second side surfaces of the second connector housing 220, and guide portions 224, 224' for guiding the guide pieces 124, 124' are formed on the opposing third and fourth side surfaces of the second connector housing 220. The second connector housing 220 has a rectangular parallelepiped shape, and its width is preferably 10 mm to 15 mm, more preferably 12 mm to 14 mm. Its height is preferably 3 mm to 10 mm, more preferably 4 mm to 6 mm. Its depth is preferably 10 mm to 30 mm, more preferably 10 mm to 20 mm. This allows for easy connection of optical wiring even in small environments such as servers.

[0064] (Divided body of second connector housing 220) As shown in Fig. 5, second connector housing 220 can also be separated into divided bodies 220A and 220B, and is separated in a direction perpendicular to the connection direction (up and down direction). Fig. 2 shows a reference top view of second connector housing 220 with divided body 220A removed. When the split body 220A is removed from the second connector housing 220, the second ferrule 230 and the optical cable B can be attached to the split body 220B of the second connector housing 220 without separating them, and the second ferrule 230 and the optical cable B can be removed from the split body 220B without separating and cutting them.

[0065] In this embodiment, the second connector housing 220 is made up of the divided bodies 220A and 220B, but the second connector housing 220 may be a cylindrical, integrally molded product. Even when second connector housing 120 is cylindrical, fixing member 510 and pin holder 600 are arranged to open in the same direction, so by inserting these parts from the rear of second connector housing 220, second ferrule 230 and optical cable B can be attached and detached without separating them. Therefore, each part can be replaced or added later, and second connector 210 can be assembled by combining these parts.

[0066] (Pin holder 600) As shown in Figures 2 and 4, the pin holder 600 of this embodiment is disposed between the second ferrule 230 and the fixing member 510, and holds the guide pin 40 for precisely aligning the connection end faces of the first ferrule 130 and the second ferrule 230. 7, the pin holder 600 (with pin) has a pin holder main body 610 (without pin) having an outer shape substantially equal to the cross-sectional shape of the second ferrule 230, and a guide pin 40 protrudes from the pin holder main body 610 toward the first connector 110. The guide pin 40 is inserted into a guide hole formed in the second ferrule 230, and the tip of the guide pin 40 protrudes from the joining end surface of the second ferrule 230.

[0067] Furthermore, a fixing member (stopper) 510 is disposed on the rear end side of the pin holder 600 (the side opposite to the connecting end face of the second ferrule 230) to fix the pin holder 600 to the second connector housing 220. The pin holder 600 and the fixing member 510 are provided with recessed grooves 601 and 511, respectively, so that the optical cable B connected to the second ferrule 230 can pass through and be removed. As shown in Fig. 7(a), the pin holder 600 of this embodiment can be made by bending a single metal plate. The pin holder 600 shown in Fig. 7(a) has a bottom plate (pin holder main body) 610, wall pieces 620 bent from both ends of the bottom plate 610, and pin guide pieces 630, and the pin guide pieces 630 are provided with support holes 635 through which the guide pins 40 pass. A guide pin groove (not shown) is formed on the circumference of the guide pin 40, and by passing the guide pin 40 through the support hole 635, the guide pin groove engages with the support hole 635, and the guide pin 40 is stably held in the pin holder 600.

[0068] The pin holder 600 is not limited to the one shown in FIG. 7(a), but may be, for example, a resin molded body made by a mold as shown in FIG. 7(b), in which the guide pin 40 is fixed inside. 7(c) may also be used as the pin holder 600. That is, a flange 42 may be provided on the rear end side (opposite the connecting end face) of the guide pin 40', and the pin holder 600 may be provided with a counterbore portion 602 deep enough to fit the flange 42. In this case, the flange 42 of the guide pin 40' and the counterbore portion 602 of the pin holder 600 engage with each other to hold the guide pin 40'. For example, if the diameter of the guide pin 40' is 0.7 mm, the diameter of the flange may be 2.0 mm, and the depth of the counterbore portion may be 0.2 mm, with the diameter being 2.0 mm. The pin holder 600 may be made of metal or resin. Furthermore, in the pin holder 600 shown in FIGS. 7(a) to (c), a recess for passing an optical fiber is formed.

[0069] (Latching piece 122, locking portion 222) As shown in Figures 1, 2 and 4, the first connector housing 120 of this embodiment is a rectangular tube-shaped first connector housing 120 with a cross section that is long in the horizontal direction, and has locking pieces 122 (clutch mechanism) that extend toward the second connector housing 220 on opposing first and second side surfaces of the first connector housing 120.

[0070] A pair of locking pieces 122, 122 are provided to protrude outward from the opposing left and right side surfaces of the first connector housing 120. The shape of the locking pieces 122 can be modified in various ways. In this embodiment, the locking piece 122 has an elastic piece 122c that protrudes outward from the first connector housing 120 and a claw portion 122a formed at the tip of the elastic piece 122c. The locking portion 222 formed in the second connector housing 220 has a hole portion in which the claw portion 122a can be locked. The locking pieces 122, 122 are provided with a convex release portion 122b, which can be pinched between fingers to release the lock.

[0071] (Guide piece 124, guide part 224) In this embodiment, the first connector housing 120 is a rectangular tube with a cross section that is long in the horizontal direction, and has guide pieces 124, 124' that extend toward the second connector housing 220 on opposing third and fourth side surfaces of the first connector housing 120. The first connector housing 120 has a pair of locking pieces 122, 122 protruding outward from the opposing left and right side surfaces, and a pair of guide pieces 124, 124' protruding outward from the opposing upper and lower side surfaces of the first connector housing 120. The second connector housing 220 is provided with guide portions 224, 224' that correspond to the shapes of the guide pieces 124, 124' of the first connector housing 120.

[0072] In this embodiment, the guide piece 124 is rectangular, and the guide piece 124' is tongue-shaped, thereby preventing the optical cables A and B from being connected in the wrong way. In addition, in this embodiment, the tips of the guide pieces 124, 124' extend further toward the second connector than the tips of the locking pieces 122, 122. This allows the first connector housing 120 and the second connector housing 220 to be fitted together after being positioned with high precision. Furthermore, the extension length of the tongue-shaped guide piece 124' may be longer than that of the rectangular guide piece 124. This allows the two to be fitted together smoothly.

[0073] (First ferrule 130, second ferrule 230) Details of the first ferrule 130 and the second ferrule 230 are as follows. The first and second ferrules 130 and 230 each have a substantially rectangular parallelepiped or thin plate-like appearance, and are molded from, for example, resin. The first and second ferrules 130, 230 may be made of a moldable resin such as polyphenylene sulfide or liquid crystal polymer (LCP), and may contain additives such as silica (SiO2) to enhance the strength and stability of the resin, or may be made of an inorganic material such as ceramics.

[0074] As shown in Fig. 8, the first and second ferrules 130, 230 have flat first and second end faces 112, 112' provided at one end in the connection direction, and rear end faces 113, 113' provided at the other end. The first and second ferrules 130, 230 also have a pair of side faces extending along the connection direction, a bottom face, and a top face. In Fig. 8(b), the optical fiber insertion hole 114 into which the optical fiber is inserted is indicated by a dotted line. A pair of guide pin insertion holes (guide holes) 116 are formed in the first end face 112 and the second end face 112' and aligned in a direction intersecting a cross section along the optical axis of the optical fiber. A pair of guide pins 40, 40 are inserted into the pair of guide pin insertion holes 116. That is, the pair of guide pins 40, 40 determine the relative positions of the first ferrule 130 and the second ferrule 230.

[0075] A plurality of optical fiber insertion holes 114 into which optical fibers are inserted are formed in the first end face 112. An introduction hole 117 for receiving a ribbon fiber (optical cable) consisting of a plurality of optical fibers is formed in the rear end faces 113 of the first and second ferrules 130, 230 (FIG. 8(c)). The width of the introduction hole can be 1.5 mm or more and 5 mm or less, and particularly preferably 2 mm or more and 4 mm or less. When the width of the introduction hole is 2 mm, it can accommodate 8-core fibers, when the width of the introduction hole is 3 mm, it can accommodate 12-core fibers, and when the width of the introduction hole is 4 mm, it can accommodate 16-core fibers. The width of the introduction hole can be changed as appropriate depending on the thickness of the secondary coating of the ribbon fiber. Although the present embodiment shows an example in which a ribbon fiber is used, an assembly of a plurality of single-core fibers may be used, and each fiber may be inserted into each introduction hole 117 .

[0076] The plurality of optical fiber insertion holes 114 are formed so as to penetrate from the first end face 112 to the introduction hole 117 side. Optical fibers are inserted into and held in the optical fiber insertion holes 114, respectively. The optical fibers each extend along the connection direction and are arranged in a row in the horizontal direction intersecting the connection direction. The number of optical fiber insertion holes 114 can be determined depending on the purpose. There may be one (in which case it becomes a single-core ferrule) or multiple (in which case it becomes a multi-core ferrule). In this embodiment, an example of a multi-core MT ferrule with 12 cores, 16 cores, etc., in which the optical fibers are arranged in a row is shown.

[0077] The first ferrule 130 and the second ferrule 230 used in this embodiment are shown in FIG. The first ferrule 130 and the second ferrule 230 used in this embodiment are smaller than the ferrules defined by normal standards (MT connector of JIS C5981, MT ferrule of JIS C5964-5). That is, the length of the ferrule (width in FIG. 8(b)) is 4 mm, the length of the connection end face (longer side in FIG. 8(a)) is 6.4 mm, and the thickness of the ferrule (short side in FIG. 8(a)) is 1.25 mm. The first ferrule 130 and the second ferrule 230 used in this embodiment are 12-fiber ferrules with a hole diameter of Φ125 μm. When the load generated by one coil spring 300 is approximately 5 N, a sufficient contact force of approximately 10 N can be applied to the connection end faces of the first ferrule 130 and the second ferrule 230. For example, when PC connecting 12 fibers, a contact force of 10 N is preferable, and when PC connecting 16 fibers, a contact force of 20 N is preferable. Therefore, the load generated by the coil spring 300 can be designed appropriately depending on the number of fibers to be connected or the connection method.

[0078] Here, FIG. 6 is a cross-sectional view showing a mated state of the first connector 110 (a male plug in this embodiment) and the second connector 210 (a female receptacle plug in this embodiment) in this embodiment. As the pair of coil springs 300 are compressed, the first ferrule 130 slides toward the rear end of the housing body (opposite the connection direction). In this embodiment, the connection end faces of the first ferrule 130 and the second ferrule 230 move toward the rear end of the first connector housing body. Therefore, the connection end faces that are visible before connection move inside the first connector housing body after connection, protecting the connection end faces from contamination and the like.

[0079] In this embodiment, a ferrule and an optical connector for optically coupling multimode optical fibers together have been described, but the present invention can also be applied to a ferrule and an optical connector for optically coupling single-mode optical fibers together.

[0080] <Second embodiment> An optical connector 10 according to a second embodiment is shown in Fig. 9. In the second embodiment, a pin holder 600 is provided on the first connector 110 side. Therefore, compared to the first embodiment, the length of the spacer 400 is shorter by the length of the pin holder 600 . In this case, all protruding members including the guide pins 40 are provided on the first connector 110 side, so the second connector 210 side (receptacle plug side) can be made flat. For example, when mounting optical wiring on a substrate, the second connector 210 (receptacle plug) can be arranged on the substrate side, and the first connector 110 (plug) can be provided on the connection cable side. In this case, the pin holder 600 used in the first embodiment and the pin holder 600 used in the second embodiment may be pin holders 600 of the same shape. On the other hand, in the third embodiment described below, the first connector housing 120 and the second connector housing 220 have different internal shapes, so when the pin holder 600 is provided in the first connector housing 120, it is preferable that the shape of the pin holder 600 be different from that of the pin holder 600 provided in the second connector housing 220.

[0081] <Third embodiment> Regarding the third embodiment, differences from the first embodiment will be described.

[0082] (First connector 110) 11, the first connector housing 120 has three guide pieces 124, 124'a, and 124'b that extend in the connection direction (toward the second connector). The guide piece 124 is disposed on the bottom surface side of the first connector housing 120, and the guide pieces 124'a and 124'b are disposed on the top surface side (the surface opposite to the guide piece 124).

[0083] Fig. 12 is a reference top view of the optical connector 10 of embodiment 3 when the split body is opened. Optical cables A and B, a first ferrule 130, a second ferrule 230, etc. are indicated by dashed lines. Fig. 14(a) is a schematic explanatory diagram showing the connection end face of the first connector 110 of embodiment 3, and Fig. 14(b) is a schematic explanatory diagram showing the connection end face of the second connector 210 of embodiment 3. In Fig. 14, the ferrules are indicated by dotted lines. The first connector housing 120 is provided with a receiving portion 126 for receiving the first ferrule 130, and an opening 126a is provided so that the connecting surface of the first ferrule 130 can protrude. As shown in FIG. 14(a), the opening 126a is preferably set to the same size (opening area) as the connecting surface of the first ferrule 130. The size of the opening 126a may be, for example, a width dimension (opening length in the direction in which the optical fibers are arranged) of 4 mm to 8 mm, preferably 6 mm to 7 mm. The height dimension may be 0.5 mm to 3 mm, preferably 1 mm to 2 mm. The size of the opening 126a is set to be the same as the size of the connection surface of the first ferrule 130, and furthermore, it is preferable that a tolerance of 0 to +0.2 mm is provided in the width direction, and a tolerance of 0 to +0.2 mm is provided in the height direction. The first ferrule 130 moves horizontally in the connection direction within the first connector housing 120 each time it is connected or disconnected. By designing the opening 126a as described above, the first ferrule 130 can be securely fixed without swinging diagonally within the accommodating portion 126. Therefore, even if the first ferrule 130 is smaller than a normal MT ferrule, connection loss can be minimized, and variation in connection loss due to connection and disconnection can also be minimized.

[0084] (Stopper 500) 12, engagement portions 550 for engaging with recesses 125 are formed symmetrically on both sides of the rear end portion of stopper 500 of this embodiment, and engagement portions 550 include extension portions 552 that extend in the opposite direction to the connector connecting direction, and protrusions 551 formed at the tips of extension portions 552. Protrusions 551 are fitted into recesses 125 formed in the rear portion of first connector housing 120, whereby stopper 500 is fixed to first connector housing 120. To remove stopper 500 once it has been fitted, protrusion 551 engaged with recess 125 can be pushed inward from the outside with tweezers or the like. In this case, the length of extension 552 is preferably 3 mm or more and 7 mm or less, and more preferably 4 mm or more and 6 mm or less. This allows extension 552 to elastically deform, making it possible to easily remove stopper 500 from the rear of first connector 110.

[0085] Boot holding portions 540 are formed to protrude in the direction opposite to the connecting direction from both ends on the rear side of the stopper 500. The boot holding portions 540 are capable of holding a boot (not shown). It is preferable that a part of the boot holding portion 540 is designed to extend outward from the rear end portion of the first connector housing 120. This allows the boot holding portion 540 to be held and pushed in when fitting the stopper 500 from behind, making it easy to fit the stopper 500. In this case, the boot may be a component that is opened in one direction, similar to components such as the spacer 400 and the stopper 500, and can be attached later during the assembly of the first connector 110. Note that the boot may be cylindrical and pre-assembled by inserting it into the optical fiber, as is used in existing MPOs and the like.

[0086] (Second connector 210) 11, in the second connector 210, guide portions 224, 224'a, and 224'b are formed on opposing third and fourth side surfaces of the second connector housing 220. The guide portions 224, 224'a, and 224'b serve to guide the guide pieces 124, 124'a, and 124'b of the first connector housing 120, respectively.

[0087] As shown in Fig. 12, the second connector housing 220 is provided with an accommodating portion 226 that accommodates the second ferrule 230, the guide pin 40, and the pin holder 600, and has an opening 226a that allows the connecting surface of the second ferrule 230 to protrude. As shown in Fig. 14(b), the opening 226a is preferably set to the same size (opening area) as the connecting surface of the second ferrule 230. The size of the opening 226a can be, for example, a width of 4 mm to 8 mm, preferably 6 mm to 7 mm. The height can be 0.5 mm to 3 mm, preferably 1 mm to 2 mm. The size of the opening 226a is set to be the same as the size of the connection surface of the second ferrule 230, and furthermore, it is preferable that a tolerance of 0 to +0.2 mm is provided in the width direction, and a tolerance of 0 to +0.2 mm is provided in the height direction.

[0088] As shown in FIG. 12, the receiving portion 226 of the second connector 210 receives the second ferrule 230, the guide pin 40, and the pin holder 600. It is preferable to employ a floating structure in which the size of accommodation section 226 is processed to be slightly larger than the combined size of second ferrule 230 and pin holder 600. Specifically, it is preferable to design the length of accommodation section 226 in the connection direction to be the same as the combined length of second ferrule 230 and pin holder 600 in the connection direction, while setting a processing tolerance of 0 mm in the negative direction and 0.1 mm or more in the positive direction. As a result, the ferrules are processed so that there is a slight gap before mating, and after mating, the connection end faces of the first ferrule 130 and the second ferrule 230 can be aligned perpendicular to the stress direction (connection direction) of the coil spring 300. In other words, by providing a fine adjustment mechanism with a float structure, connection loss can be minimized, and variations in connection loss due to connection and disconnection can also be minimized.

[0089] (Latching piece 122, locking portion 222) As shown in Fig. 11, locking pieces 122, 122 extend from opposing first and second side surfaces of first connector housing 120. As shown in Figs. 12 and 13, height M of locking pieces 122 is preferably the same as height N of locking portions 222, which will be described later, and can be, for example, 2 mm to 4 mm, and preferably 2.8 mm to 3.2 mm. In this case, the tolerance of height M of locking pieces 122 is preferably 0 to -0.05 mm. Furthermore, the width P of the locking piece 122 is preferably the same as the width O of the locking portion 222 described below, and can be, for example, 1 mm or more and 2 mm or less, and preferably 1.4 mm or more and 1.7 mm or less.

[0090] In this embodiment, the locking piece 122 includes a claw portion 122a that locks with the locking portion 222, a release portion 122b and an elastic piece 122c for releasing the lock, and a guide portion 122d that makes it easier to insert into the locking portion 222. As shown in FIG. 12, if necessary, a processed portion 122e may be provided at the corner of the locking portion 222. This allows for clearance during cutting, thereby improving processing accuracy. Furthermore, taking into consideration the fit with the claw portion 122a, a processed portion 122e with a C-face or a radius r may be provided at the corner where the locking portion 222 and the claw portion 122a fit together. In this case, the processed portion 122e may be a circle with a radius r of 0.2 mm or more and 0.4 mm or less. This allows the locked state of the claw portion 122a to be firmly maintained for a long period of time. Furthermore, the claw portion 122a has a guide portion 122d formed by chamfering the inner corner of the end of the claw portion 122a. The angle θ1 of the guide portion 122d is preferably 5 degrees or more and 15 degrees or less, and more preferably 8 degrees or more and 12 degrees or less. This makes it easier for the claw portion 122a to be inserted into the locking portion 222. Furthermore, the angle θ2 (the angle added to 270° of the radius r) provided in the processed portion 122e is preferably 1 degree or more and 15 degrees or less, and more preferably 5 degrees or more and 12 degrees or less, which allows the locking piece 122 to be engaged securely and for a long period of time.

[0091] 13, the locking portion 222 formed on the second connector housing 220 has a rectangular opening on the connecting surface side for inserting the claw portion 122a. The width O of the locking portion 222 is preferably the same as the width P of the locking piece 122, and can be, for example, 1 mm or more and 2 mm or less, and preferably 1.4 mm or more and 1.7 mm or less. In this case, the processing tolerance of the width O is preferably 0 to +0.1 mm. Furthermore, the height N of the locking portion 222 is preferably the same as the height M of the locking piece 122, and can be, for example, 2 mm to 4 mm, and preferably 2.8 mm to 3.2 mm. In this case, the processing tolerance of the height N is preferably 0 to +0.05 mm. As a result, when locking piece 122 is locked with locking portion 222, first connector 110 and second connector 210 are fixed more stably. In particular, even if an external force in the torsional direction is applied due to connection / disconnection, the external force is less likely to be transmitted to the connection end face. Therefore, first ferrule 130 and second ferrule 230 can be more reliably brought into contact with each other, minimizing connection loss and variations in connection loss due to connection / disconnection.

[0092] (Guide piece 124, guide part 224) In the first connector housing 120 of this embodiment, rectangular guide pieces 124'a, 124'b and 124 are provided to protrude in the connection direction from a third side surface (upper surface) and a fourth side surface (lower surface). The second connector housing 220 is provided with guide portions 224 ′ a , 224 ′ b and 224 that correspond to the shapes of the guide pieces 124 ′ a , 124 ′ b and 124 of the first connector housing 120 .

[0093] In this embodiment, the two guide pieces 124'a and 124'b protruding from the third side surface are spaced apart. The width of the guide pieces 124'a and 124'b is preferably between ¼ and ½ of the width of one guide piece 124 protruding from the fourth side surface. The distance (pitch) between the guide pieces 124'a and 124'b is preferably between ¼ and ⅓ of the width of the first connector housing 120. The protruding length of each guide piece 124 (the length in the connection direction of the portion overlapping with each guide portion 224) is preferably between ⅙ and ½ of the width of the first connector housing 120 (the length in the optical fiber alignment direction). In this embodiment, the number of guide pieces protruding from the third side surface is different from the number of guide pieces protruding from the fourth side surface, so there is no risk of mistaking the connection direction (vertical direction) of the first connector 110 and the second connector 210. Furthermore, because the two guide pieces 124'a and 124'b are each formed in a rectangular shape on the third side surface, they guide the first connector 110 and the second connector 210 so that they are reliably connected in parallel. Therefore, when connecting the first connector housing 120 and the second connector housing 220, the guide pin 40 is reliably guided into the guide pin insertion hole 116 of the first ferrule 130, preventing the guide pin 40 from colliding with the connecting end surface of the first ferrule 130. The number of protruding guide pieces 124'a and 124'b is not limited to two, and may be three. Furthermore, the guide pieces 124, 124'a, 124'b of this embodiment are provided with chamfered portions at the tips of their rectangular shapes, which makes it easier to connect the first connector 110 and the second connector 210.

[0094] Examples of the present invention will be described below, but the configuration of the present invention is not limited to the following examples. Example 1 A first connector 110 (connector) and a second connector 210 (receptacle) according to the first embodiment were fabricated as follows, and designated as Example 1. The first connector housing 120 and the second connector housing 220 of this example were manufactured by cutting polyacetal resin (POM resin). The widths of the first connector housing 120 and the second connector 210 were 13.5 mm. Furthermore, the openings 126a, 226a from which the first ferrule 130 and the second ferrule 230 protrude had a width Q of 6.60 mm and a height R of 1.55 mm. The height M of the locking piece 122 of the first connector housing 120 was set to 2.5 mm and the width P was set to 1.3 mm. The width O of the locking portion 222 of the second connector housing 220 was set to 1.5 mm and the height N was set to 3.5 mm. The first connector housing 120 and the second connector housing 220 of the embodiment are each a cylindrical, integrally molded product.

[0095] The guide piece 124 on the lower surface side of the first connector housing 120 is rectangular with a width of 6.5 mm and a protruding length of 5.4 mm, and the guide piece 124' on the upper surface side is tongue-shaped with a width of 5.5 mm, a protruding length of 5.4 mm and a curvature radius of 2.75 mm. The stopper 500 of the first connector housing 120 was obtained by cutting PPS resin. A recessed groove 501 was formed in the center of the stopper 500 and the spacer 400. The length of the stopper 500 (length in the connection direction) was 5.9 mm, and the width (length in the optical fiber alignment direction) was 12.1 mm.

[0096] In Example 1, a repeated mating / disconnection test was conducted to confirm the performance and mating / disconnection reproducibility of the optical connector 10. In the repeated mating / disconnection test, a 12-core small MT ferrule to which 12 single-mode optical fibers (φ125 μm) were fixed was mounted on the first connector 110 and the second connector 210. A coil spring 300 with a spring constant of 2.1 N / mm was used to apply a force of 10 N to the mating end face, and connection loss measurements (IEC61300-3-45, JIS C61300-3-45) were conducted using an optical signal with a wavelength of 1.31 μm. The first connector 110 and the second connector 210 were then attached and detached, the connection end faces were cleaned after each attachment and detachment, and the connection loss was measured after each connection. Using the same optical connector, the attachment and detachment, cleaning, and measurement were repeated three times, resulting in an average connection loss of 0.44 dB and a standard deviation σ of 0.28.

[0097] <Example 2> A first connector 110 (connector) and a second connector 210 (receptacle) according to the third embodiment were fabricated as follows, and designated as Example 2. Similar to Example 1, the first connector housing 120 and the second connector housing 220 of this example were manufactured by cutting polyacetal resin (POM resin). The widths of the first connector housing 120 and the second connector 210 were 13.5 mm. The openings 126a and 226a for the first ferrule 130 and the second ferrule 230 to protrude had widths Q of 6.5 mm and heights R of 1.3 mm. The height M of the locking piece 122 of the first connector housing 120 was 3.0 mm and the width P was 1.55 mm. The radius r of the processed portion 122e was 0.3 mm and the angle θ of the guide portion 122d was 10 degrees. The width O of the locking portion 222 of the second connector housing 220 was 1.6 mm and the height N was 3.0 mm. Rectangular guide pieces 124'a, 124'b, and 124 are formed to protrude from the first connector housing 120. Guide pieces 124'a and 124'b have a width of 2.2 mm, a protruding length of 5.2 mm, and are formed at an interval (pitch) of 2.2 mm. Guide piece 124 has a width of 6.6 mm and a protruding length of 5.2 mm.

[0098] The stopper 500 of the first connector housing 120 was manufactured using PPS resin in the same manner as in Example 1. The length dimension (length in the connection direction) of the stopper 500 was 13.9 mm, and the width dimension (length perpendicular to the connection direction) was 12.0 mm. The length of the extension portion 552 of the stopper 500 was 5.4 mm, and the length of the boot holding portion 540 of the stopper 500 was 8.4 mm.

[0099] In Example 2, a repeated connection / disconnection test was also carried out in the same manner as in Example 1. Using the same optical connector, connection / disconnection, cleaning, and measurement were repeated five times, and the average connection loss was 0.18 dB, with a standard deviation σ of 0.19. Therefore, Example 2 had lower connection loss and less variation than Example 1. Therefore, by configuring and setting the dimensions as in Example 2, and further providing a fine adjustment mechanism with a float structure, it is possible to optically connect optical fibers with even less connection loss. The connection performance of Example 2 was comparable to that of existing MPO connectors, etc.

[0100] In the present invention, the optical connector 10 corresponds to the "optical connector", the first connector 110 corresponds to the "first connector", the second connector 210 corresponds to the "second connector", the optical cable A corresponds to the "first optical cable A", the optical cable B corresponds to the "second optical cable B", the first ferrule 130 corresponds to the "first ferrule", the second ferrule 230 corresponds to the "second ferrule", the coil spring 300 corresponds to the "urging member", and the spacer 400 corresponds to the "biasing member". corresponds to a "spacer", stopper 500 corresponds to a "stopper", pin holder 600 corresponds to a "pin holder", guide pin 40 corresponds to a "guide pin", locking piece 122 corresponds to a "locking piece", guide portions 224, 224' correspond to "guide portions", grooves 501, 401, 511, 601 correspond to "grooves", fixing member 510 corresponds to a "fixing member", claw portion 122a corresponds to a "claw portion", release portion 122b corresponds to a "release portion", and elastic piece 122c corresponds to an "elastic piece".

[0101] Although a preferred embodiment of the present invention has been described above, the present invention is not limited thereto. It will be understood that various other embodiments can be made without departing from the spirit and scope of the present invention. Furthermore, although the actions and effects of the configuration of the present invention are described in this embodiment, these actions and effects are merely examples and do not limit the present invention. [Explanation of symbols]

[0102] 10 Optical Connector 40 guide pin 110 First Connector 120 first connector housing 122 Locking piece 122a Claw part 122b Release part 122c Elastic piece 122d Guidance part 122e Processing section 124 Guide piece 224 Guide section 130 First ferrule 210 Second Connector 220 Second connector housing 230 Second Ferrule 300 coil spring 400 spacer 500 stopper 600 Pin Holder 501,401,511,601 groove 510 Fixing member

Claims

1. A plug having a first connector to which an optical cable A is attached, the connector includes a first connector housing formed of a cylindrical body having an accommodating portion therein, a spacer disposed in sliding contact with the inner surface of the accommodating portion of the first connector housing so as to allow a first ferrule to slide thereon, a biasing member biasing the spacer toward the receptacle, and a stopper fixed to a rear portion of the first connector housing on the opposite side from the receptacle, the biasing member has a pair of coil springs disposed on both sides of the optical cable A between the spacer and the stopper, the stopper has a pair of engaging portions on both sides in a width direction and is engageable with the first connector housing; the first connector housing is a cylindrical one-piece body with an open rear portion, and the first optical cable A, the first ferrule, the spacer, the biasing member, and the stopper are detachable from the rear end side of the first connector housing, The spacer and the stopper have grooves formed therein that are perpendicular to the connection direction and open in the same direction, and the optical cable A is replaceable.

2. 2. The plug according to claim 1, wherein the first connector housing further has a locking piece and a guide piece extending toward a receptacle to be connected to the plug, the locking piece being capable of engaging with a locking portion formed on the receptacle, and the guide piece being guided by a guide portion formed on the receptacle.

3. A plug having a first connector to which an optical cable A is attached, the connector includes a first connector housing formed of a cylindrical body having an accommodating portion therein, a spacer disposed in sliding contact with the inner surface of the accommodating portion of the first connector housing so as to allow a first ferrule to slide thereon, a biasing member biasing the spacer toward the receptacle, and a stopper fixed to a rear portion of the first connector housing on the opposite side from the receptacle, the biasing member has a pair of coil springs disposed on both sides of the optical cable A between the spacer and the stopper, the stopper has a pair of engaging portions on both sides in a width direction and is engageable with the first connector housing; the first connector housing is a cylindrical one-piece body having an open rear portion, The spacer and the stopper each have a pair of cylindrical cavities that house the pair of coil springs.

4. 4. The plug according to claim 3, wherein both end portions of the coil spring are machined or processed so that the end surfaces are perpendicular to the axis of the coil spring.

5. 4. The plug according to claim 3, wherein the length of the cylindrical cavity of the spacer is equal to or greater than one-fourth of the maximum length of the coil spring.

6. two axial centers of the pair of coil springs are arranged in parallel and on a plane including central axes of the two guide pin insertion holes of the first ferrule; 4. The plug according to claim 3, wherein the pair of coil springs are disposed outside the two guide pin insertion holes at a predetermined distance from each other.

7. The spring constant of one of the coil springs is 1.0 N / mm or more and 6.0 N / mm or less, 4. The plug according to claim 3, wherein the spacer has an overall length in the connection direction that is at least half the length of the long side of the connection end face of the first ferrule, and is arranged to be slidable by 3.0 mm or less.

8. A plug having a first connector to which an optical cable A is attached, the connector includes a first connector housing formed of a cylindrical body having an accommodating portion therein, a spacer disposed in sliding contact with the inner surface of the accommodating portion of the first connector housing so as to allow a first ferrule to slide thereon, a biasing member biasing the spacer toward the receptacle, and a stopper fixed to a rear portion of the first connector housing on the opposite side from the receptacle, the biasing member has a pair of coil springs disposed on both sides of the optical cable A between the spacer and the stopper, the first connector housing is a cylindrical one-piece body having an open rear portion, A plug in which the stopper has a pair of engaging portions formed symmetrically on both widthwise sides for engaging with the first connector housing, the engaging portions having an extending portion extending in a direction opposite to the connection direction of the first connector and a protrusion formed at the tip of the extending portion, the stopper being fixed to the first connector housing by fitting the protrusion into a recess formed in the rear of the first connector housing.

9. boot holding portions for holding a boot are formed on both sides of a rear end portion of the stopper, protruding in a direction opposite to a connecting direction of the first connector; The plug according to claim 8 , wherein a portion of the boot retaining portion extends outward from the rear end of the first connector housing.

10. An optical connector comprising a first connector to which a first optical cable A is attached and a second connector to which a second optical cable B is attached, wherein, by fitting the first connector and the second connector together, terminals of an optical fiber Af of the optical cable A and an optical fiber Bf of the optical cable B are optically connected to each other, The first connector includes a first connector housing formed of a cylindrical body having an accommodating portion therein, a spacer disposed in sliding contact with the inner surface of the accommodating portion of the first connector housing so as to allow a first ferrule to slide thereon, a biasing member biasing the spacer toward the second connector, and a stopper fixed to a rear portion of the first connector housing on the opposite side from the second connector, the second connector has a second connector housing formed of a cylindrical body and an accommodating portion capable of accommodating a second ferrule therein; the first connector housing is a cylindrical one-piece body having an open rear portion, and is provided with a locking piece and a guide piece extending toward the second connector housing, The second connector housing is formed with a locking portion to which the locking piece can be locked, and a guide portion to guide the guide piece, the biasing member has a pair of coil springs disposed on both sides of the first optical cable A between the spacer and the stopper, The stopper has a pair of engaging portions on both sides in the width direction, the locking piece has an elastic piece protruding outward from the first connector housing, a claw portion formed at a tip end of the elastic piece, and a release portion capable of releasing the locking of the claw portion, and the locking portion has a hole portion capable of locking the claw portion, An optical connector, wherein the inner tip of the claw portion is chamfered at an angle of 5 degrees or more and 15 degrees or less, the locking surface that engages with the hole portion of the claw portion is formed at an acute angle of 75 degrees or more and 89 degrees or less with respect to the connection direction, and the corner portion of the locking surface has a C-surface or an R-surface formed.

11. 11. The optical connector according to claim 10, wherein a tip of at least one of the guide pieces extends further toward the second connector than a tip of the locking piece.

12. The optical connector according to claim 10, wherein the guide pieces are provided in pairs on two opposing surfaces different from the surface on which the locking pieces are provided, and the pair of guide pieces are each formed into a rectangular shape having a different shape.

13. An optical connector comprising a first connector to which a first optical cable A is attached and a second connector to which a second optical cable B is attached, wherein, by fitting the first connector and the second connector together, terminals of an optical fiber Af of the optical cable A and an optical fiber Bf of the optical cable B are optically connected to each other, The first connector includes a first connector housing formed of a cylindrical body having an accommodating portion therein, a spacer disposed in sliding contact with the inner surface of the accommodating portion of the first connector housing so as to allow a first ferrule to slide thereon, a biasing member biasing the spacer toward the second connector, and a stopper fixed to a rear portion of the first connector housing on the opposite side from the second connector, the second connector has a second connector housing formed of a cylindrical body and an accommodating portion capable of accommodating a second ferrule therein; the first connector housing is a cylindrical one-piece body having an open rear portion, and is provided with a locking piece and a guide piece extending toward the second connector housing, The second connector housing is formed with a locking portion to which the locking piece can be locked, and a guide portion to guide the guide piece, the biasing member has a pair of coil springs disposed on both sides of the first optical cable A between the spacer and the stopper, The stopper has a pair of engaging portions on both sides in the width direction, an optical connector, wherein the accommodating portion has an opening to allow the connection surface of the second ferrule to protrude, the second ferrule, a guide pin, and a pin holder to be accommodated, the opening has a width tolerance of 0 to +0.2 mm and a height tolerance of 0 to +0.2 mm, and the length of the accommodating portion in the connection direction has a tolerance of 0 to +0.1 mm relative to the sum of the lengths of the second ferrule and the pin holder in the connection direction.

14. The spacer has a pair of shoulders on both sides in the width direction, The receiving portion of the first connector housing has a pair of narrowed portions on both sides thereof, 14. The optical connector according to claim 13, wherein the sliding distance of the spacer in the connecting direction is restricted by the pair of narrowed portions.

15. A receptacle to which an optical cable B is attached and which has a second connector, a second connector housing formed of a cylindrical body having an internal accommodating portion, the accommodating portion capable of accommodating a second ferrule therein, and a fixing member supporting the second ferrule or the pin holder from a rear end side; the fixing member has a pair of engaging portions on both sides in a width direction, and is engageable with the second connector housing; the second connector housing is a cylindrical one-piece body having an open rear end, and the optical cable B, the second ferrule, and the fixing member are detachable from the rear end side of the second connector housing; The fixing member has a groove formed therein that opens in a direction perpendicular to the connection direction, and the optical cable B is replaceable.

16. 16. The receptacle according to claim 15, wherein the second connector housing further has a locking portion that can lock a locking piece of a plug to be connected to the receptacle, and a guide portion that can guide the guide piece of the plug.

Images