JP4832401B2 - Optical connector adapter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical connector adaptor capable of performing the conducting confirmation or contrast inspection of optical fibers nondestructively in a live-line state by connecting the optical connector at the top end of an optical fiber even when an optical fiber with difficulty of confirming leaked light, for example, an optical drop cable is used. <P>SOLUTION: The optical connector adaptor 1 includes an adaptor housing 2 to which optical connectors 21 are connected at both ends, the housing storing a pair of ferrules 9 as parted from each other to which the connectors 21 are to be butted and connected. The ferrules 9 are connected to each other by a relay optical fiber 11 threaded in a fiber storing space 12 in the adaptor housing 2. The ferrule 9 can be moved by pushing the optical connector 21 toward the fiber storing space 12, and by this movement, the relay optical fiber 11 is bent to be able to emit leaked light. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an optical connector adapter, and more particularly to an optical connector adapter that is suitable when continuity confirmation or comparison inspection is required in connector connection work between optical fibers.

As a method of confirming the continuity of each wiring in the optical line and optical fiber contrast inspection, the optical fiber is bent while maintaining the conductive state to generate leaked light, and this leaked light is converted into a cord contrast machine (so-called ID tester). For example, an optical fiber discriminating (controlling) optical fiber using a discrimination function of an optical fiber contrast device is widely used.
In such a method, the optical fiber that generates leakage light is generally an optical fiber core or an optical fiber.
For example, Patent Documents 1 to 4 are known as techniques related to the optical fiber control device.
JP 60-88328 A JP 2005-265524 A JP 2006-119358 A JP 2006-153495 A

Wiring from the aerial optical communication network to the house (subscriber's house) can be installed in a cabinet where the optical drop cable pulled from the aerial closure is connected to the in-home wiring in a cabinet attached to the outer wall of the house. It is normal.
For connector connection between the optical drop cable and the home wiring, an optical connector (optical connector plug) attached to the tip of the optical drop cable is inserted into the optical connector adapter, and the home wiring and connector are connected within the optical connector adapter. Connecting.
In recent years, a so-called outer-grip optical connector that grips and fixes an outer sheath of an optical cable has been widely used.
In the optical connector having this structure, since the optical fiber is not exposed, there is no exposed portion of the optical fiber in the section from the closure to the cabinet. Furthermore, since a general optical drop cable has a structure in which an optical fiber strand is embedded in a jacket, leakage light from the optical fiber strand is difficult to be emitted to the outside.
For this reason, there has been a problem that it is difficult to confirm the continuity of the optical fiber and to perform a comparison test in a state where the connector is connected (live line state).

  The present invention has been made in view of the above problems, and even when an optical fiber, for example, an optical drop cable, in which leakage light is difficult to check, is used by connecting an optical connector at the tip of the optical fiber. The purpose of the present invention is to provide an optical connector adapter that can perform continuity confirmation and control inspection in a non-destructive and live state.

In order to solve the above problems, the present invention provides the following configuration.
In the optical connector adapter according to claim 1 of the present invention, a pair of ferrules to which the optical connector is abutted and connected are accommodated in an adapter housing to which the optical connector is connected from both ends, and the pair of ferrules are separated from each other. The optical fiber is connected to each other by a relay optical fiber drawn through the fiber housing space in the adapter housing, and one or both of the ferrules push the optical connector from the connection position toward the fiber housing space, thereby It is possible to move to the space side, and by this movement, the relay optical fiber can be bent and bent so that leakage light can be emitted.
An optical connector adapter according to a second aspect of the present invention is the optical connector adapter according to the first aspect, wherein the adapter housing is provided with a pair of connector fitting portions to which the optical connector is connected, and the pair of ferrules are respectively connected to the pair of ferrules. Usually, the adapter housing is incorporated in a connector fitting portion, and the distance between the connector fitting portions is variable, and the relay optical fiber does not emit leakage light by changing the distance between the connector fitting portions. It is possible to switch between a state and a light leakage generation state in which leakage light can be emitted by bending.
An optical connector adapter according to a third aspect of the present invention is the optical connector adapter according to the first or second aspect, wherein the adapter housing is urged in a direction in which the ferrules are separated from each other, and the relay optical fiber can be emitted from a leakable state. It is characterized by incorporating a spring that prevents it from being released.
An optical connector adapter according to a fourth aspect of the present invention is the optical connector adapter according to any one of the first to third aspects, wherein leakage light emitted from the relay optical fiber in the fiber housing space is caused to flow into the adapter housing. An opening window is provided as a light emitting portion to be radiated outward.
An optical connector adapter according to a fifth aspect of the present invention is the optical connector adapter according to the fourth aspect, wherein the adapter housing is provided with an opening / closing member that opens and closes the light emitting portion.
An optical connector adapter according to a sixth aspect of the present invention is characterized in that, in the fourth aspect, the light emitting portion is made of a transparent material and is provided with a light transmitting portion through which the leakage light is transmitted.

According to the optical connector adapter of the present invention, one or both of the pair of ferrules can be moved to the fiber housing space side. Therefore, by changing the distance between the ferrules, bending is applied to the optical fiber for relay, and leakage light By detecting the leakage light, continuity confirmation and control inspection can be performed.
Therefore, even when an optical fiber that is difficult to emit leakage light, such as an optical drop cable, is used, continuity confirmation and control inspection can be realized without destruction.

Hereinafter, an optical connector adapter embodying the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a schematic configuration of an optical connector adapter 1 which is an example of the optical connector adapter of the present invention.
The optical connector adapter 1 includes a pair of connector fitting portions 3 and 3, a spring 4 provided therebetween, and a connection ferrule 9 incorporated in the connector fitting portions 3 and 3 in the adapter housing 2. 9 and a relay optical fiber 11 for connecting the connection ferrules 9 and 9 to each other.
In the following description, the direction in which one connector fitting portion 3 approaches the other connector fitting portion 3 may be referred to as the front, and the opposite direction may be referred to as the rear.

The adapter housing 2 is formed in a sleeve shape, and openings at both ends serve as connector connecting portions 5 to which the optical connector 21 is connected.
The connector fitting portion 3 includes a fitting portion main body 7 and a cylindrical ferrule holding portion 8.
An opening on one end side (connector connection portion 5 side) of the fitting portion main body 7 is a connector insertion portion 10 into which the optical connector 21 is inserted. The fitting portion body 7 is provided so that the direction in which the optical connector 21 is inserted is along the axial direction of the adapter housing 2.

The ferrule holding part 8 is formed in a sleeve shape and is formed along the axial direction of the adapter housing 2.
A stopper protrusion 8a that protrudes inward is formed at the front end of the ferrule holding portion 8, thereby restricting forward movement of the connecting ferrule 9. The ferrule holding part 8 is provided with a split sleeve 8b, and a connecting ferrule 9 is inserted through the split sleeve 8b.

The connection ferrule 9 has an optical fiber introduction hole (not shown) formed along the central axis, and a built-in optical fiber (not shown) made of a bare optical fiber is inserted into the optical fiber introduction hole and fixed. ing. This built-in optical fiber is exposed on the rear end face (connection end face 9 b) of the connection ferrule 9. As the connection ferrule 9, for example, glass or ceramic (zirconia or the like) formed can be used.
At the front end portion of the connection ferrule 9, a flange portion 9a with which the stopper projection 8a abuts is provided.

The relay optical fiber 11 is a fiber that can emit leakage light by applying bending as described later. For example, an optical fiber core or an optical fiber can be used. The relay optical fiber 11 is connected to the front end of the connection ferrule 9 and is optically connected to a built-in optical fiber (not shown) in the connection ferrule 9.
The relay optical fiber 11 is led through the fiber housing space 12 between the connector fitting portions 3 and 3 in the adapter housing 2.

One or both of the connector fitting portions 3 and 3 are movable in the front-rear direction within the adapter housing 2. For this reason, the distance between the ferrules 9 for connection is variable.
As will be described later, the movement width of the connector fitting portion 3 is set so that leakage light can be emitted by curving the relay optical fiber 11.
The connector fitting portion 3 is preferably provided with a locking means (not shown) such as a locking claw that locks the optical connector 21.

A light emitting portion 6 is formed in the middle portion in the length direction of the adapter housing 2. The light emitting portion 6 is an opening window that emits leakage light to the outside of the adapter housing 2.
The light emitting portion 6 is preferably formed on the side where the top of the curved portion of the relay optical fiber 11 is located with respect to the straight line connecting the connecting ferrules 9 (see FIG. 3).
A guide portion (not shown) for guiding the relay optical fiber 11 that moves as the connection ferrule 9 moves may be provided in the adapter housing 2. By forming the guide portion, the curved portion of the relay optical fiber 11 can be surely directed to the light emitting portion 6 to detect leaked light with high accuracy.

The spring 4 is an urging member that is installed so as to urge the connector fitting portions 3 and 3 in a direction away from each other. The spring 4 is preferably a coil spring, but may be any spring that can urge the connector fitting portion 3 and may be an elastic body such as a leaf spring.
The spring 4 is installed so as not to prevent leakage light from the relay optical fiber 11 from being emitted from the light emitting unit 6. The number of springs 4 may be 1 or 2 or more.

Specific examples of the optical connector 21 connected to the adapter housing 2 include, for example, an SC type optical connector (Single fiber Coupling optical fiber connector) defined in JIS C 5973, and an MU type optical connector defined in JIS C 5983. There are various optical connectors such as (Miniature-Unit coupling optical fiber connector).
A built-in optical fiber (not shown) inserted and fixed in a ferrule 23 incorporated in the optical connector 21 constitutes a part of the optical path of the optical fiber 22.
The optical connector 21 is preferably an outer gripping type, for example, a connector body having a ferrule 23 and a gripping mechanism (not shown) for gripping the outer sheath of the optical fiber 22 and fixing it to the connector body. It is. The connector body includes, for example, a ferrule 23, a connection mechanism that connects the built-in optical fiber of the ferrule 23 to the optical fiber drawn from the optical fiber 22, and a housing that accommodates these.

Examples of the optical fiber 22 in which the optical connector 21 is assembled include optical fiber cables such as an optical drop cable and an optical indoor cable. It can also be applied to optical fiber cores, optical fiber cords, and the like.
FIG. 4 is a cross-sectional view showing an example of an optical drop cable. The optical drop cable 51 includes an optical fiber element portion 51d and a support wire portion 51f in which a metal wire 51e attached to a side portion of the optical fiber element portion 51d is covered with a jacket 51c. The optical fiber element portion 51d is obtained by collectively covering an optical fiber 51a and strength members 51b disposed on both sides thereof with an outer sheath 51c.
The optical fiber element portion 51d and the support wire portion 51f are connected via a thin portion 51g of the jacket 51c, and the support wire portion 51f is separated from the optical fiber element portion 51d by cutting the thin portion 51g. it can.
The optical fiber 51a is embedded in the central portion of the cross section of the optical fiber element 51d, and the optical fiber 51a can be exposed by dividing the optical fiber element 51d into two from the notch 51h. The tensile body 51b is a linear body vertically attached along the optical fiber 51a, and the material thereof is, for example, FRP. For example, a steel wire or the like is used as the metal wire 51e of the support wire portion 51f.
The so-called optical indoor cable has the same configuration as the optical fiber element portion 51d, for example.

The wiring of the optical fiber 22 and the installation location of the optical connector adapter 1 can be as follows, for example.
An optical fiber adapter 22 (for example, an optical drop cable) pulled down from an aerial closure (not shown) and an optical fiber 22 (for example, an optical indoor cable), which is a home wiring, are terminated by a connector and connected by an optical connector adapter 1. The optical connector adapter 1 can be installed inside a cabinet (not shown) installed in the user's house.
The optical connector adapter 1 can be installed on the outer wall of the user's house.
In addition, an optical connector adapter 1 is interposed in the optical fiber 22 at an intermediate position between the aerial closure and the user's home cabinet, and the optical connector adapter 1 is installed at an intermediate position of the optical fiber 22 (not shown). It may be housed inside.

Next, a method of connecting the optical fibers 22 and 22 to the optical connector adapter 1 and confirming the conduction will be described.
As shown in FIG. 2, optical connectors 21 and 21 are respectively connected to the connector insertion portions 10 and 10 of the connector fitting portions 3 and 3 from both ends of the adapter housing 2.
The ferrule 23 of the optical connector 21 is inserted into the ferrule holding part 8, and is abutted with the rear end face (connection end face 9 b) of the connecting ferrule 9 in the ferrule holding part 8. Thereby, the optical fiber 22 and the connection ferrule 9 are optically connected.

Since the pair of connection ferrules 9 and 9 in the adapter housing 2 are optically connected via the relay optical fiber 11, the optical fibers 22 and 22 at both ends of the optical connector adapter 1 are optically connected to each other.
The position of the connector fitting portion 3 shown in FIG. 2 is called a connection position. At this connection position, the relay optical fiber 11 is in a straight state. The relay optical fiber 11 may be bent with a curvature that does not cause bending loss when the connector fitting portion 3 is in the connection position.
As described above, a state in which the relay optical fiber 11 is bent straight or with a curvature that does not cause bending loss is referred to as a normal state.

As shown in FIG. 3, in a state where light is incident on the optical fiber 22, one or both of the optical connectors 21 are pushed toward the fiber housing space 12, so that the connector fits against the urging force of the spring 4. The joint part 3 is moved forward.
As the distance between the two connector fitting portions 3 and 3 decreases, the connecting ferrules 9 and 9 approach each other, the relay optical fiber 11 is bent, and is bent with a curvature that causes bending loss. This curved portion is denoted by reference numeral 11a. In the illustrated example, the curved portion 11 a is a substantially central portion of the relay optical fiber 11.
Due to this bending, leakage light is emitted from the relay optical fiber 11. In this way, a state where the relay optical fiber 11 is bent so as to be able to emit leakage light is referred to as a leakage generation state.

The leaked light generated from the relay optical fiber 11 is emitted to the outside of the adapter housing 2 through the light emitting portion 6. The leak light can be detected by a general-purpose photodetector (not shown). Based on the presence or absence of the leakage light emission, the continuity of the optical fibers 22 and 22 can be confirmed.
Further, it is determined whether or not the optical fiber 22 is the target optical fiber by injecting the test light into the optical fiber 22 and examining the characteristics (for example, wavelength characteristics) of the leaked light detected by the optical connector adapter 1. A control test can be performed.

  It is preferable that the bending state of the relay optical fiber 11 maintains a transmission loss that does not affect the working line. As a result, even in a situation where the optical fiber 22 is used as a working line, it is possible to perform continuity confirmation and comparison inspection without affecting the communication of the working line.

  When the pressing of the optical connector 21 in the pushing direction is stopped, the connector fitting portion 3 is retracted by the urging force of the spring 4, the distance between the two connector fitting portions 3 and 3 is increased, and the relay optical fiber 11 is normally used. Return to state.

In the optical connector adapter 1, the connection ferrule 9 is movable. Therefore, by changing the distance between the connection ferrules 9, the relay optical fiber 11 is bent to emit leakage light. By detecting light, continuity confirmation and control inspection can be performed.
Therefore, even when an optical fiber 22 that is difficult to emit leakage light, such as an optical drop cable, is used, continuity confirmation and control inspection can be realized without destruction.

FIG. 5 is a cross-sectional view showing a specific configuration example of the optical connector adapter of the present invention. In the following description, common points with the optical connector adapter 1 shown in FIG.
The optical connector adapter 31 shown here is incorporated in a sleeve-shaped adapter housing 2 into a pair of connector fitting portions 33, 33, a spring 4 provided therebetween, and the connector fitting portions 33, 33. Connecting ferrules 9 and 9 and a relay optical fiber 11 are provided.

The connector fitting portion 33 includes a fitting portion main body 37 and a ferrule holding portion 38 extending rearward from the fitting portion main body 37.
The fitting portion main body 37 includes a block-shaped main portion 35 having an outer surface shape that conforms to the inner surface shape of the adapter housing 2 and a cylindrical extending portion 36 that extends rearward from the peripheral edge portion of the rear end surface of the main portion 35. Have. The inner side of the cylindrical extension part 36 is a connector insertion recess 36a into which the optical connector 21 is inserted.
The main portion 35 is formed with an insertion hole 35a through which the connection ferrule 9 is inserted along the front-rear direction. A stopper protrusion 35b that protrudes inward from the inner surface of the insertion hole 35a is formed at the front end of the main portion 35.

The ferrule holding part 38 is formed in a cylindrical shape extending rearward from the center of the rear end surface of the main part 35, and a split sleeve 32 into which the connecting ferrule 9 is inserted is provided therein.
The front portion of the split sleeve 32 is inserted into the insertion hole 35 a of the main portion 35.
A flange portion 9 a having an outer diameter larger than the inner diameter of the split sleeve 32 is formed on the outer periphery of the connection ferrule 9, and the flange portion 9 a abuts the front end portion of the split sleeve 32 so that the rear side of the connection ferrule 9 Movement is restricted.

A spring 34 through which the connecting ferrule 9 is inserted is provided in the insertion hole 35a. The spring 34 has a rear end in contact with the flange portion 9a and a front end in contact with the stopper projection 35b. The spring 34 urges the connecting ferrule 9 rearward so as to apply a butting force to the ferrule 23 of the optical connector 21.
The relay optical fiber 11 connected to the front end of the connection ferrule 9 is led through the fiber housing space 12 between the connector fitting portions 33 and 33.
One or both of the connector fitting portions 33 and 33 are movable in the front-rear direction within the adapter housing 2.

In order to confirm the continuity of the optical fiber 22 connected to the optical connector adapter 31, the optical connector 21 is inserted into the connector insertion recess 36a by being connected to the connector fitting portion 33, and then the connector fitting portion 33, At least one of 33 is moved forward to bend the relay optical fiber 11 to generate leaked light, and this leaked light is detected.
Reference numeral 11a in FIG. 5 is a curved portion of the relay optical fiber 11, and reference numeral 11b is a top portion of the curved portion 11a.

6 to 8 show modifications of the optical connector adapter of the present invention.
In the example shown in FIG. 6, an opening / closing member 41 that opens and closes the light emitting portion 6 is provided on the outer surface of the adapter housing 2.
The opening / closing member 41 is slidable along the outer surface of the adapter housing 2, and is a closed position that covers the light emitting portion 6 as indicated by a solid line and an open position that opens the light emitting portion 6 as indicated by a two-dot chain line. Can move between.
In the example shown in FIG. 7, the opening / closing member 41 is connected to the adapter housing 2 by a hinge portion 41 a provided at an end portion. The opening / closing member 41 opens and closes the light emitting portion 6 by rotating around the hinge portion 41a between a closed position indicated by a solid line and an open position indicated by a two-dot chain line.

According to this configuration, the light emitting unit 6 can be closed during normal operation, and the light emitting unit 6 can be opened only when conducting continuity check or control test.
Since the light emitting portion 6 can be closed, dust or the like can be prevented from entering the adapter housing 2 at normal times, the inside of the optical connector adapter 1 can be kept clean, and highly accurate leakage light detection can be performed.

In the example shown in FIG. 8, the light emitting portion 6 is closed by the light transmitting portion 42. The translucent part 42 is made of a transparent material (for example, glass or synthetic resin), and can transmit leakage light.
According to this configuration, dust and the like are prevented from entering the adapter housing 2, the inside of the optical connector adapter 1 is kept clean, and leak light detection with high accuracy is possible.
Alternatively, a fluorescent material that emits fluorescence by leakage light may be applied to the surface of the light transmitting portion 42, and the fluorescent portion may be formed on this surface. This facilitates detection of leakage light.

  In the illustrated example, the leakage light is emitted directly through the light radiating portion 6. However, the present invention is not limited to this, and a reflection portion that reflects the leakage light and guides it to the light radiating portion 6 may be provided in the adapter housing 2. Good. A general-purpose mirror can be used as the reflecting portion.

Example 1
After connecting the optical connector 21 to the connector fitting portion 33 using the optical connector adapter 31 shown in FIG. 5, test light (wavelength: 1.55 μm, intensity: −20 dBm) is incident on the optical fiber 22, and the connector is fitted. The joint portions 33 and 33 were pushed in a direction approaching each other to bend the relay optical fiber 11. The pushing amount of the connector fitting part 33 (approach distance of the connector fitting parts 33 and 33) was 1.6 mm. The relay optical fiber 11 is an optical fiber.
Light leaked from the relay optical fiber 11 was measured by a photodetector. As the photodetector, a light receiving unit of an optical fiber core wire contrast machine (Fujikura, FID12R) was used. The measurement limit (lower limit) of this photodetector is −60 dBm.

  As shown in Table 1, if the length of the relay optical fiber 11 is appropriately set (for example, 22 to 28 mm), it is possible to detect leaked light while keeping the increase in connection loss low.

It is sectional drawing which shows schematic structure of the optical connector adapter 1 which is an example of the optical connector adapter of this invention. It is sectional drawing which shows the state which connected the optical connector to the optical connector adapter shown in FIG. In the optical connector adapter shown in FIG. 1, it is sectional drawing which shows the state which provided the bending to the optical fiber for relay. It is sectional drawing which shows an example of the optical fiber cable which can apply this invention. It is sectional drawing which shows the specific structural example of the optical connector adapter of this invention. It is sectional drawing which shows the modification of the optical connector adapter of this invention. It is sectional drawing which shows the modification of the optical connector adapter of this invention. It is sectional drawing which shows the modification of the optical connector adapter of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical connector adapter, 2 ... Adapter housing, 3, 33 ... Connector fitting part, 4 ... Spring, 6 ... Light emission part, 9 ... Connection ferrule, 11 ..Relay optical fiber, 12... Fiber housing space, 41 .. opening / closing member, 42.

Claims (6)

In the adapter housing (2) to which the optical connector (21) is connected from both ends, a pair of ferrules (9) to which the optical connector is butted and connected are stored separately from each other,
The pair of ferrules are connected to each other by a relay optical fiber (11) drawn through a fiber storage space (12) in the adapter housing,
One or both of the ferrules can be moved to the fiber storage space side by pushing the optical connector from the connection position to the fiber storage space side, and this movement causes the relay optical fiber to bend and bend. An optical connector adapter (1) characterized in that leakage light can be emitted. The adapter housing is provided with a pair of connector fitting portions (3, 33) to which the optical connector is connected,
The pair of ferrules are respectively incorporated in the pair of connector fitting portions,
In the adapter housing, the distance between the connector fitting portions is variable. By changing the distance between the connector fitting portions, the relay optical fiber does not emit leakage light, and the leakage light is caused by bending. The optical connector adapter according to claim 1, wherein the optical connector adapter can be switched to a light leakage generation state that can be emitted.   The adapter housing incorporates a spring (4) for urging the ferrules in a direction away from each other and making the relay optical fiber in a state in which leakage light can not be emitted. Item 3. The optical connector adapter according to Item 1 or 2.   The said adapter housing is provided with the opening window as a light emission part (6) which radiates | emits the leak light emitted from the relay optical fiber in the said fiber accommodation space to the outer side of the said adapter housing. Item 5. The optical connector adapter according to any one of Items 1 to 3.   The optical connector adapter according to claim 4, wherein the adapter housing is provided with an opening / closing member (41) for opening and closing the light emitting portion.   The optical connector adapter according to claim 4, wherein the light emitting portion is provided with a light transmitting portion (42) made of a transparent material and through which the leakage light is transmitted.

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