JP3733980B2 - Optical fiber connector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber connector.
[0002]
[Prior art]
As an optical fiber connector, Japanese Patent Application Laid-Open No. 5-119225 related to the applicant's application is known.
[0003]
As shown in FIGS. 10 and 11, the optical fiber connector has a sleeve 20 having an insertion hole with an inner diameter slightly larger than the diameter of both optical fibers inserted and abutted, and the sleeve 20 fixed to the upper surface. It consists of a base part 21 and a holding part 22 for fixing the two optical fibers to the base part 21 by being fitted to the base part 21.
[0004]
[Problems to be solved by the invention]
However, this optical fiber connector is composed of two separate parts, a base part and a holding part. The holding part is accurately fitted to the base part, and both optical fibers are sufficiently attached to the base part. In order to hold down with force, a special work tool dedicated to the connection was required, which was problematic in terms of workability and cost. Further, since the base part and the holding part are not connected to each other, there is a problem that one part is lost or one part is soiled and cannot be used during the optical fiber connection work.
[0005]
An object of this invention is to provide the optical fiber connector excellent in workability which solved the problem of the above conventional optical fiber connectors.
[0006]
[Means for Solving the Problems]
An optical fiber connector according to the present invention includes a sleeve having an insertion hole having an inner diameter slightly larger than the diameters of both optical fibers inserted and abutted against each other, and both the light beams on both sides of the insertion hole of the sleeve. A base part having a holding part in which a covering part of the fiber is disposed, and both optical fibers pivotally attached to the upper part of the base part via an elastic body so as to be opened and closed with respect to the holding part. coating portion Ri Do from the first and second pressing piece for pressing the, and, guide groove for guiding an optical fiber into the sleeve of the insertion hole on either side of the anchored sleeve is formed on the base part, the guide The opening direction of the groove is formed in the same direction as the opening direction formed by the base part and the expanded pressing piece .
[0007]
In addition, the optical fiber connector according to the present invention includes a slot that reaches the insertion hole formed in the center of the sleeve, and the pressing piece includes a pressing portion that presses both optical fibers that are abutted at the position of the slot. Features.
[0009]
The optical fiber connector according to the present invention is characterized in that a base part and a holding piece are detachably provided with an opening / closing lever.
[0010]
According to the optical fiber connector of the present invention, first, the pressing piece is separated and released from the base portion against the pressing, and both optical fibers are allowed to pass through the gap and abut in the insertion hole of the sleeve. Both optical fibers can be connected by pressing the covering portions of both optical fibers arranged on the holding part of the base part with a pressing piece by the restoring force of the elastic body. On the other hand, when releasing the connection, the optical fiber can be easily removed simply by separating the holding piece from the covering portions of both optical fibers that have been connected. In this way, alignment work and rematching of both optical fibers can be easily performed, and the optical fiber connector itself can be reused. Moreover, since the guide groove for guiding the optical fiber to the sleeve insertion hole is formed on the base part on both sides of the fixed sleeve, when inserting the ends of both optical fibers into the sleeve insertion hole from both sides, The tip of each optical fiber is moved toward the sleeve insertion hole while pressing the tip of each optical fiber against the groove bottom of the guide groove, so that the tip is guided and regulated by the guide groove and is securely and smoothly inserted into the sleeve insertion hole. it can. In particular, since the opening direction of the guide groove is formed in the same direction as the opening direction formed by the base part and the expanded holding piece, if the opening is slightly opened, it may be opened slightly. The groove bottoms of the guide grooves can be seen in front, the tips of both optical fibers are very easy to see, and the direction of pressing the tips of both optical fibers against the groove bottoms of the guide grooves is from the front of the opening to the back. Therefore, the operation of moving toward the insertion hole of the sleeve while pressing the tips of both optical fibers against the bottom of the groove is easy and easy even with a relatively small opening that is slightly larger than the diameter of both optical fibers. It is very convenient because it can be done smoothly. In addition, since the opening can be set small in this way, the installation position of the pivot can be installed as close as possible to the installation position of the sleeve, and the width of the base part and the holding piece (in the direction perpendicular to the optical fiber axis) It becomes possible to make the size as small as possible.
[0011]
In addition, a slot reaching the insertion hole is formed in the central portion of the sleeve, and the holding piece is provided with a holding portion that holds both optical fibers that are abutted at the position of the slot. As a result, the connection loss can be further reduced, and fluctuations in the connection loss due to changes in ambient temperature can be reduced.
[0013]
In addition, the present invention includes an opening / closing lever detachably provided on the base part and the pressing piece, so that the operating force can be reduced by mounting the lever during the opening / closing operation. After the connection, the lever can be removed to prevent an unexpected external force from being released, and the width of the base part and the holding piece (the dimension in the direction perpendicular to the optical fiber axis) can be further reduced.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The optical fiber connector of the present invention is pivotally attached to the upper surface of the base part via an elastic body so that the first and second pressing pieces can be opened and closed with respect to the holding part, respectively, and is inserted into the sleeve and protrudes. The cover portions of the two optical fibers positioned together and positioned at the holding portion of the base component are pressed and fixed. When using the optical fiber connector of the present invention, first, prepare both optical fibers whose coating has been removed and whose ends have been precisely cut using a commercially available optical fiber cutter or the like, and the holding piece is resistant to the pressing. Then, a gap is formed between the holding part and the holding piece so as to be separated from the holding part, and both optical fibers prepared therethrough are allowed to pass through the both sides of the sleeve insertion holes fixed to the central part of the base part. Inserted into the sleeve and butted in the sleeve, and then pressed and fixed toward the holding portion by the restoring force of the elastic body with the pressing piece that separated the coated portions of the both optical fibers that were butted from the holding portion. To connect the optical fiber. As the constituent material of this optical fiber connector, both optical fibers that have expanded and abutted due to changes in ambient temperature are pulled apart to worsen the connection loss, or contracted and the tips of both optical fibers become slanted or chipped. It is preferable that the coefficient of expansion is small so that they do not press against each other. Especially, the base part whose length is strict with respect to the butt axis direction of both optical fibers has an expansion coefficient of optical fiber. It is preferable that it is close to. In the case of quartz optical fiber, the expansion coefficient is almost zero. For example, liquid crystal plastic or crystallized glass is suitable as the material for the base part. If the optical fiber is made of resin, it is the same as the optical fiber. Various types of resins and metal materials with similar expansion coefficients are suitable for use. The holding portion provided on the upper surface of the base component that holds the optical fiber covering portion may have a flat surface shape. However, if the shape is a V-shaped groove, a trapezoidal groove, a U-shaped groove or the like, the holding position is more Stable and preferred. In order to increase the tensile strength of the connected optical fiber, the holding part and the holding piece of the base part may be provided with small irregularities or corrugations that increase the friction on the surfaces contacting the covering parts of both optical fibers.
[0015]
As the sleeve, capillaries such as glass, ceramics, metal, and resin can be used. Especially, single-mode optical fibers based on quartz have a high dimensional accuracy and smooth inner surface. A glass-made one is suitable. It is preferable that both openings on both sides of the sleeve insertion hole are provided with tapered portions for facilitating the insertion of the optical fiber, and the air in the insertion hole is exhausted at the central portion of the sleeve where both optical fibers abut. It is preferable to form a slot in which a pressing portion for reducing the insertion resistance of the fiber and aligning the core axes of both optical fibers can be fitted, and the slot has a low connection loss and a high return loss. In order to obtain the above, it is preferable to fill a refractive index matching agent whose refractive index matches that of the core of the optical fiber.
[0016]
As the first and second pressing pieces for pressing the coated portion of the optical fiber, the same material as that of the base part is suitable. Even if the pressing piece itself is formed integrally as an elastic body. Good. As the elastic body, a metal or resin U-shaped spring or coil-shaped spring is suitable. An elastic body such as a spring acts to press the covering portion of the optical fiber disposed in the holding portion of the base component against the first and second pressing pieces pivotally attached to the upper surface of the base component by using the restoring force. In various ways, attachment is performed between the upper surface of the base part and the pressing piece.
[0017]
Further, the pressing portion of the pressing piece presses each optical fiber in preparation for each of the first and second pressing pieces in order to hold both optical fibers abutted at the slot position in the central portion of the sleeve. Alternatively, a pressing portion for pressing both optical fibers may be provided on one pressing piece. An elastic body such as a spring, a polymer material, or rubber may be attached to the holding portion that holds the optical fiber, or a plastic body such as a soft metal such as brass or aluminum may be attached via the elastic body.
[0018]
In addition, the optical fiber connector of the present invention can align not only a pair of optical fibers but also a plurality of pairs of optical fibers and connect them simultaneously.
[0019]
Further, a guide groove for guiding the optical fiber to the sleeve insertion hole is formed on both sides of the sleeve to which the base component is fixed, and the opening direction of the guide groove is defined as the opening direction formed by the base component and the expanded pressing piece. Form in the same direction.
[0020]
Furthermore, a lever for opening and closing is detachably provided on the base part and the pressing piece.
[0021]
【Example】
FIG. 1 is an explanatory view of a first embodiment of an optical fiber connector according to the present invention, wherein 1 is a base part, 2 is a sleeve, 3a and 3b are first and second pressing pieces, respectively. ing.
[0022]
The sleeve 2 is made of glass, and has an insertion hole 2a having an inner diameter slightly larger than the diameters of both optical fibers 10a and 10b to be inserted and abutted, and tapered openings on both sides of the insertion hole 2a. A slot 2b reaching the insertion hole 2a is formed in the central portion, and the refractive index matching agent 2c is filled from the slot 2b into the butted portion of both optical fibers. The base component 1 is made of a liquid crystal plastic having a small expansion coefficient, a sleeve 2 is fixed to the upper surface thereof, and groove portions in which the covering portions 11 a and 11 b of both optical fibers are disposed on both sides of the insertion hole 2 a of the sleeve 2. Holding portions 1a and 1b. The first pressing piece 3a and the second pressing piece 3b are made of the same resin as that of the base part 1 and are made of spring steel, which is an elastic body, so that the holding parts 1a and 1b can be opened and closed, respectively. The covering portions 11a and 11b of the two optical fibers pivotally attached to the upper surface of the base part 1 via the letter-shaped springs 3e and 3f and arranged on the holding parts 1a and 1b are held by the restoring force of the U-shaped springs 3e and 3f. It presses and fixes toward 1a, 1b.
[0023]
Next, when using the above optical fiber connector to connect a single mode optical fiber having an optical fiber diameter of 125 μm, a diameter of the covering portion of 900 μm, and a zero wavelength dispersion in the 1.31 μm wavelength band of light. Will be described. First, the coatings of both optical fibers are removed, and both optical fibers 10a and 10b whose tips are precisely cut and finished are prepared. Next, the first pressing piece 3a is separated from the holding portion 1a of the base component 1 against the restoring force of the U-shaped spring 3e, and in this state, the optical fiber 10a is tapered to the insertion hole 2a of the sleeve 2. The optical fiber 10a is inserted into the slot 2b where the tip of the optical fiber 10a is located in the center, and then the restoring force of the U-shaped spring 3e is applied at that position to hold the covering portion 11a of the optical fiber 10a with the holding piece 1a. Press toward and fix. Similarly, the second pressing piece 3b is separated from the holding portion 1b against the restoring force of the U-shaped spring 3f, and the optical fiber 10b is inserted into the insertion hole 2a of the sleeve 2 from the other opening and already fixed. The U-shaped spring 3f is abutted against the tip of the optical fiber 10a, and the covering portion 11b of the optical fiber 10b is pressed and fixed to the holding portion 1b by the pressing piece 3b. Thus, in order to evaluate the connection state of the optical fiber connected using the optical fiber connector of the present invention, the connection loss was measured using light sources having wavelengths of 1.31 μm and 1.55 μm. An excellent value of .1 dB or less is obtained. In addition, when a tensile load of 1.5 kgf is applied to the connection portion of the same optical fiber, the fluctuation of the connection loss is 0.01 dB or less, and the detection of the measuring device It was excellent within the error range.
[0024]
FIG. 2 shows a second embodiment according to claim 2 of the present invention, in which the pressing portions 3c and 3d provided on the first pressing piece 3a and the second pressing piece 3b are fitted into the slots 2b. A state in which the optical fibers 10a and 10b are being pressed by the butted portions is shown.
[0025]
FIG. 3 shows a third embodiment of the present invention, in which the pressing pieces 3a and 3b are pivotally attached to the upper surface of the base portion 1 by a pivot 3g so as to be openable and closable with respect to the holding portions 1a and 1b. A state is shown in which the covering portions 11a and 11b of both optical fibers 10a and 10b are pressed by the restoring forces of the coil springs 3h and 3i.
[0026]
FIG. 4 shows a fourth embodiment of the present invention in which the base part 1 and the pressing pieces 3a and 3b are integrally formed of an elastic body made of liquid crystal plastic having a small expansion coefficient.
[0027]
FIG. 5 is an exploded perspective view showing a fifth embodiment of the present invention, FIG. 6 is a front view of the fifth embodiment, FIG. 7 is a plan view showing a state in which the pressing piece of the fifth embodiment is mounted, and FIG. ) (B) (C) is a vertical side view of the fifth embodiment when viewed from the positions AA, BB, and CC in FIG. 6, and FIG. 9 is the center of the fifth embodiment. FIG. 10 is a longitudinal front view of a state in which an optical fiber is pressed by a pressing piece. In the fifth embodiment, the pressing pieces 4a, 4b, and 4c that are divided into three parts can be opened and closed with respect to the base part 1 around the pivot axis 4d. The structure which pivotally attached and provided the closing force by the coil springs 4e, 4f, and 4g is shown, respectively. Then, V-shaped guide grooves 1c and 1d for guiding the optical fibers 10a and 10b to the insertion holes 2a of the sleeve 2 are formed on both sides of the sleeve of the base component 1, and the opening direction of the V-shaped guide grooves 1c and 1d is defined in the base direction. It is formed in the same direction as the opening direction formed by the component 1 and the expanded pressing pieces 4a, 4b, and 4c.
[0028]
With the above configuration, when the tips of both optical fibers 10a and 10b are inserted into the insertion hole 2a of the sleeve 2 from both sides, the optical fibers 10a and 10b are formed at the bottoms of the V-shaped guide grooves 1c and 1d. By moving the distal end toward the insertion hole 2a of the sleeve 2 while pressing the distal end, the distal end is guided and regulated by the V-shaped guide grooves 1c and 1d, and is reliably and smoothly aligned in the insertion hole 2a of the sleeve 2. Can be inserted. In particular, since the opening direction of the V-shaped guide grooves 1c and 1d is formed in the same direction as the opening direction formed by the base part 1 and the expanded pressing pieces 4a, 4b and 4c, the opening is made larger. Even if it is not opened, if it is opened slightly, the groove bottoms of the V-shaped guide grooves 1c and 1d can be seen in front, making it very easy to see the tips of both optical fibers 10a and 10b, and the V-shaped guide. Since the direction of pressing the groove bottoms of the grooves 1c and 1d is the direction from the front of the opening toward the back, the ends of the optical fibers 10a and 10b are pressed against the groove bottoms toward the insertion hole 2a of the sleeve 2. The moving operation is very convenient because it can be performed easily and smoothly even if the opening is small. Further, since the opening can be made small in this way, the installation position of the pivot 4d can be installed as close as possible to the installation position of the sleeve 2, and the width dimension of the base part 1 and the pressing pieces 4a, 4b, 4c ( The dimension in the direction perpendicular to the optical fiber axis can be made as small as possible.
[0029]
In addition, a lever mounting hole (not shown) is provided in the base component 1 and the pressing pieces 4a and 4b on both sides so that the levers 1e, 1f, 4h and 4i for opening and closing are detachable. By mounting the opening / closing levers 1e, 1f, 4h, and 4i, the operating force for opening the pressing pieces 4a, 4b, and 4c with respect to the base part 1 around the pivot 4d is reduced. In addition, with the above configuration, after the optical fibers 10a and 10b are connected, the levers 1e, 1f, 4h, and 4i can be removed to prevent an unexpected external force from being released, and the base component 1 and the pressing pieces 4a and 4b can be prevented. The width of 4c (the dimension in the direction orthogonal to the optical fiber axis) can be made more compact.
[0030]
An interlocking pin 4j is inserted into the pressing pieces 4a and 4b on the both sides and the central pressing piece 4c so that when the pressing pieces 4a and 4b on both sides are opened and closed, the central pressing piece 4c is simultaneously opened and closed. Yes. The center pressing piece 4c is provided with a gap in, for example, the engagement holes 4p and 4q of the interlocking pin 4j so as to be interlocked and opened with some play with respect to the pressing pieces 4a and 4b on both sides. When the pressing piece 4c is closed, the optical fibers 10a and 10b thinner than the covering portions 11a and 11b can be surely pressed by moving closer to the base part 1 than the closing positions of the pressing pieces 4a and 4b on both sides.
[0031]
Furthermore, both optical fibers 10a and 10b are provided on both sides of the refractive index matching agent 2c supplied and filled in the butted portion of both optical fibers 10a and 10b butted in the insertion hole 2a of the sleeve 2 in the center pressing piece 4c. Pressing parts 4c ′ and 4c ′ to be pressed are formed.
[0032]
Further, meshing portions 1g, 4k, 4m, and 4n are formed on the front surface in the opening direction of the base part 1 and the pressing pieces 4a, 4b, and 4c to maintain the closed airtightness after the connection.
[0033]
Further, the refractive index matching agent 2c injected into the abutting portions of the optical fibers 10a and 10b may be injected into the covering portions 11a and 11b of the optical fibers 10a and 10b to maintain the airtightness.
[0034]
The fifth embodiment of the present invention has the above configuration, but the number of divisions of the pressing piece may be two. In addition, when the pressing piece is divided into three, an opening / closing lever may be detachably provided.
[0035]
【The invention's effect】
According to the optical fiber connector of the present invention, after both optical fibers are butted in the insertion hole of the sleeve, the optical fiber can be easily attached by simply pressing the coating portion of the optical fiber with the first and second pressing pieces. Because it can be connected, it does not require a special work tool dedicated to connection, reducing the work man-hours and cutting tool costs, and it is no longer possible to lose or contaminate one of the parts. This provides an excellent practical effect that improves work efficiency. In addition, the guide grooves formed on both sides of the fixed sleeve allow the tip of the optical fiber to be reliably and easily inserted into the insertion hole of the sleeve. Therefore, the opening between the base part and the pressing piece can be made small, and the base part and the pressing piece can be downsized.
[0036]
Further, the optical fiber butt is brought into contact with the optical fiber butt by inserting the butt portion of the optical fiber into the sleeve slot and pressing it with a part of the first and second pressing pieces or the third pressing piece (center portion). It is possible to reduce the connection loss by preventing the optical part from being lifted from the slot and suppressing the deviation of the optical axis.
[0038]
Furthermore, since the lever for opening and closing is detachably provided on the base part and the holding piece, the operating force can be reduced by attaching the lever at the time of opening and closing operation. By removing the lever, it is possible to prevent opening due to unexpected external force, and it is possible to further reduce the width dimension (dimension in the direction perpendicular to the optical fiber axis) of the base part and the pressing piece.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a first embodiment of an optical fiber connector of the present invention. FIG. 2 is an explanatory diagram of a second embodiment of the present invention. FIG. 3 is an explanatory diagram of a third embodiment of the present invention. FIG. 4 is an explanatory view showing a fourth embodiment of the present invention. FIG. 5 is an exploded perspective view showing the fifth embodiment of the present invention. FIG. 6 is a front view of the fifth embodiment of the present invention. The top view of the state which mounted | wore the press piece of 5th Example of this FIG. 8 (A) (B) (C) was seen from the AA line, BB line, and CC line position in FIG. FIG. 9 is a longitudinal front view of a state in which an optical fiber is pressed by a central pressing piece according to a fifth embodiment of the present invention. FIG. 10 is an explanatory diagram of a conventional optical fiber connector. 11 is a cross-sectional view of the optical fiber connector shown in FIG.
1 Base parts 1a, 1b Holding portion 1c, 1d V-shaped guide groove 1e, 1f Lever 1g Engaging portion 2 Sleeve 2a Insertion hole 2b Slot 2c Refractive index matching agent 3a, 3b Holding piece 3c, 3d Holding portion 3e, 3f U-shaped Spring 3g Pivot 3h, 3i Coil springs 4a, 4b, 4c Pressing piece 4d Pivot 4e, 4f, 4g Coil spring 4h, 4i Lever 4j Interlocking pins 4k, 4m, 4n Engaging portions 10a, 10b Optical fibers 11a, 11b Covering part

Claims (3)

A sleeve having an insertion hole having an inner diameter slightly larger than the diameter of both optical fibers inserted and abutted against each other, and a holding portion in which the sleeve is fixed to the upper surface and the covering portions of both optical fibers are disposed on both sides of the insertion hole of the sleeve A first base member and a first base member that presses the covering portions of both optical fibers that are pivotally attached to the upper surface of the base component through elastic bodies so as to be openable and closable with respect to the holding portion. Ri Do and a second pressing piece, and a guide groove for guiding the both sides in the optical fiber into the sleeve of the insertion hole of the anchored sleeve is formed on the base part, the opening direction of the guide groove, the base part and the expansion An optical fiber connector characterized by being formed in the same direction as the opening direction formed by the opened pressing piece .   2. An optical fiber connector according to claim 1, wherein a slot reaching the insertion hole is formed at a central portion of the sleeve, and a pressing portion is provided with a pressing portion for pressing both optical fibers abutted at the position of the slot. . The optical fiber connector according to claim 1 or 2 , wherein an opening / closing lever is detachably provided on the base part and the pressing piece.

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