WO2001061397A1 - Optical connector and method of connection - Google Patents

Abstract

There are provided a female connector (2) with one end of a ferrule (3) held within a cylindrical case (4) and a male connector (1) with one end of a ferrule (3') passing through and projecting beyond the opposite end of a cylindrical case (6). The projecting ferrule of the male connector is inserted into the cylindrical case of the female connector to connect them together. For connection using the ferrules (3, 3') kept apart, rather than in contact with each other, an optical fiber is passed through the ferrule (3) of the female connector, while another optical fiber is introduced midway in the ferrule (3') of the male connector, and the optical fiber on the female connector is inserted into the ferrule (3') on the male connector to connect the optical fibers together.

Description

 Optical connector and connection method

 The present invention relates to an optical connector used for connecting an optical fiber and a connecting method thereof. Akita

Background art

 Optical fibers such as silica-based optical fibers are connected by a fusion connection method or an optical connection method. Fusion connection is used for connecting optical fiber cables for long-distance communication, and optical connectors are used for connecting short-distance optical fiber cables and optical fiber cords.

 The optical connector is required to have characteristics such as low connection loss, stable connection loss even after repeated attachment / detachment, and ease of attachment / detachment and light weight. Recently, expectations for permanent connection using optical connectors have been increasing.

 Since the optical fiber is thin and flexible, the optical fiber tends to be misaligned, bent, gapd, and the like at the time of connection, and these cause connection loss. In particular, misalignment is a major factor in connection loss.

Therefore, it is necessary to securely fix the optical fiber in the optical connector so that the axis does not shift. The component for an optical connector for this purpose is ferrule. In other words, the optical connector is fixed by passing an optical fiber with a cross section of a perfect circle and having a thickness of about 0.13 mm through a cylindrical tube so that the position of the cores at the center of the optical fiber is fixed. The connection is intended to be made accurately. The cylindrical tube is a ferrule. The conventional optical connector has, for example, a form as shown in FIG. 13 or FIG. That is, the optical connector shown in FIG. 13 is composed of plugs 41 and 43 containing ferrules 37 and 39 and an adapter 142 containing a sleeve 38. The optical fiber is connected by inserting two plugs into one adapter from the left and right. Also, as shown in Fig. 14, the ferrules of the multi-core ferrule are arranged so as to face each other, and are positioned relative to each other by the guide pin 45 and the guide pin hole 44, and the multi-core ferrule 46 is directly fitted. By doing so, an optical connector for connecting the optical fiber 47 can be obtained.

 However, there is a problem that these optical connectors have a relatively large capacity. Further, in order to reduce the transmission loss, it is necessary to connect the optical fibers so that the cores thereof are aligned with each other, and there is a need for an optical connector that is complicated and easy to connect. An object of the present invention is to provide a low-cost, small-sized optical connector capable of easily connecting optical fibers, which solves these problems. Disclosure of the invention

 A first invention is a female connector in which a ferrule is held by a cylindrical case so that one end of the ferrule stops inside the cylindrical case.

 The second invention is that in the female connector, the length from one end of the ferrule stopped in the cylindrical case to the end of the cylindrical case is 80 to 20% of the entire length of the ferrule. Is a female connector.

 According to a third aspect of the present invention, in a cylindrical case for holding a female connector, a positioning portion of a notch and a fixing portion such as a protrusion or a recess are provided on a side connected to the female connector. It is a female-type connector characterized by the above-mentioned.

In the fourth invention, the ferrule is so formed that one end of the ferrule projects from the cylindrical case. This is an Os-type connector that holds an erule in a cylindrical case.

 The fifth invention is an os-type connector in which the length of the ferrule projecting from the cylindrical case is in the range of 20 to 80% of the entire length of the ferrule.

 According to a sixth aspect of the present invention, in a cylindrical case for holding a female connector, a positioning portion for a notch and a fixing portion such as a protrusion or a recess are provided on the side to be inserted into the female connector. It is an o-type connector characterized by the following.

 A seventh aspect of the invention is a female connector in which the ferrule is tapered from the outside to the inside of the end.

 An eighth aspect of the present invention is an os-type connector, wherein the ferrule is formed into a tapered shape from the outer side to the inner side.

 The ninth invention is characterized in that a positioning portion for a notch portion and a fixing portion such as a projection or a dent portion are provided at a distal end portion of a cylindrical case into which a female type connector or a female type connector is inserted. It is a cylindrical case.

 According to a tenth aspect of the present invention, in connecting the female connector and the female connector, the protruding ferrule portion of the female connector is connected to the cylinder on the side where the female connector of the female connector does not protrude. It is an optical connector inserted into a case.

 The eleventh invention is an optical connector in which two prosthetic connectors are inserted into the cylindrical case from the left and right sides of the protruding fuel rule portion.

 A twelfth invention is an os-type connector characterized in that holes or slits are formed in the fu- sule of the os-type connector.

In the thirteenth invention, the end of the optical fiber passing through the ferrule forming the female connector protrudes from the ferrule, and the end of the optical fiber passing through the ferrule forming the female connector is inserted inside the ferrule. The ferrule stops because there is no space between the files of the female connector and the female connector. When connecting in close contact, the distance between the tip of the optical fiber stopped in the ferrule in the female connector and the tip of the adjacent ferrule and the protrusion in the female connector were determined. In this method, the optical fiber is arranged so that the distance between the tip of the optical fiber and the tip of the adjacent fuel rule matches, and the female connector and the male connector are connected.

 According to a fourteenth aspect, an end of an optical fiber passing through a ferrule forming a female connector protrudes from the ferrule, and an end of an optical fiber passing through a ferrule forming a female connector has an end of the ferrule. When there is a space between the female connector and the ferrule of the male connector, if there is a space between the female connector and the ferrule of the male connector, the tip of the protruding optical fiber in the female connector and the tip of the ferrule close to the female connector Is equal to the distance between the tip of the optical fiber stopped in the ferrule and the tip of the adjacent fuel rule in the oss connection, plus the distance of the space. In this method, a female connector and an os connector are connected to each other by arranging an optical fiber.

 In the fifteenth invention, the length in the longitudinal direction of the ferrule of the space between the ferrule of the female connector and the ferrule of the oss connector is 5% or less of the entire length of the ferrule. This is a method of connecting a female connector and a female connector, which is characterized by being 300%.

 In the sixteenth invention, when connecting the female connector and the female connector, the optical connector is positioned at the terminal end with a notch and fixed with a protrusion or a dent. This is a method for connecting an optical connector.

According to a seventeenth aspect, in connecting the female-type connector and the female-type connector, at least one method of brazing, bonding, press-fitting, clamping, and press-fit crimping utilizing thermal expansion is used. This is a method for connecting an optical connector, which is characterized by being fixed. The optical connector according to the present invention can be reduced in size or capacity to several tenths as compared with the conventional optical connector, and can be miniaturized. By further bundling the optical connectors, a multi-stage multi-core optical connector can be obtained. In addition, by providing a space in the optical connector, it is possible to absorb errors in alignment of the optical fibers. That is, it absorbs the misalignment of the ferrule alone and the error when the ferrule is attached to the optical connector.

 Here, the term “optical connector” is a word that includes both a connector that connects optical fibers or optical fiber cords and a connection terminal that connects optical fibers or optical fiber cords. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is an external view of a ferrule having a tapered end.

 FIG. 2 is a conceptual diagram of the optical connector of the present invention.

 FIG. 3 is a diagram showing an example of a two-core optical connector according to the present invention.

 FIG. 4 is a diagram showing an example of a six-core optical connector linearly arranged according to the present invention.

 FIG. 5 is a diagram showing an example of a seven-core optical connector arranged in a columnar shape according to the present invention.

 FIG. 6 is a diagram showing an example of a 12-core optical connector linearly arranged according to the present invention.

 FIG. 7 is a diagram showing an example of a 144-core multi-core multi-stage optical connector according to the present invention.

 FIG. 8 is a diagram showing the connection of the optical connector according to the present invention.

 FIG. 9 is a diagram showing an example of an optical connector for automatic connection.

FIG. 10 is a diagram showing a cross section in the diameter direction of FIG. FIG. 11 is a diagram showing an optical connector that has been drilled or slit.

 FIG. 12 is a diagram showing a cross section in the longitudinal direction of FIG.

 FIG. 13 is a diagram illustrating an example of a single-core optical connector.

 FIG. 14 is a diagram showing an example of a multi-core optical connector.

 FIG. 15 is a diagram showing connections between two-core Os-type connectors.

 FIG. 16 is a diagram showing a seven-core optical connector. BEST MODE FOR CARRYING OUT THE INVENTION

 FIG. 2 shows a conceptual diagram of the female connector and the female connector. Both the ferrules 3 and 3 ′ are inserted into the cylindrical cases 4 and 6 for both the female connector 2 and the male connector 1. In the female connector, one end of the ferrule protrudes from the cylindrical case, but the other end of the ferrule stops in the cylindrical case. On the other hand, in the Os-type connection body, a ferrule is inserted in a state where the ferrule projects from both ends of the cylindrical case.

 After inserting the ferrule into the cylindrical case and aligning it, the ferrule can be fixed to the cylindrical case by attaching, bonding, clamping, press-fitting and crimping using thermal expansion, or a combination thereof.

 An optical connector can be obtained by connecting the female connector and the os connector. At this time, it is common to connect the female connector and the female connector in a state where the ferrules of the female connector and the female connector are in close contact with each other. A space may be provided between the ferrules at a distance without adhesion. The space provided between the ferrules has an effect of automatically adjusting the optical fiber misalignment, as described later.

In the female connector, one end of the ferrule projects from the cylindrical case The end stops in the cylindrical case. At this time, the length of the cylindrical case part where the ferrule from the other end of the ferrule to the end of the ferrule is not inserted is set to 80 to 20% of the entire length of the ferrule. Les, which is preferred. This is because if the length is larger than 80%, it becomes difficult to hold the ferrule in the cylindrical case, and if it is smaller than 20%, it becomes difficult to connect with the female connector. .

 In a female connector, both ends of the ferrule protrude from the cylindrical case. At this time, the length of the ferrule part protruding from the cylindrical case on the side connected to the female connector is preferably 20 to 80% of the entire length of the ferrule. . This is for smooth connection with the female connector. Further, in order to improve the connection between the optical connectors, the case may be provided with a fixing portion for preventing the detachment, such as a positioning portion of the cutout 5, a projection 8 or a dent 7 (see FIG. 2 ( b)). The positioning part and the fixing part do not need to be provided, but when they are provided, connection of each connecting body can be performed smoothly.

 As shown in Fig. 1, it is preferable that both ends of the ferrule used for each connecting body be tapered or chamfered at both ends. When an optical fiber is inserted into a ferrule, the optical fiber can easily enter the ferrule. This has the advantage that the optical fiber can be smoothly inserted into the ferrule especially when connecting the female connector and the male connector.

 It is preferable to use the ferrule whose end is tapered by rounding or chamfering as described above for the male-type connector and the female-type connector.

In addition, although two ferrules are shown in the optical connector of FIG. 2, the number of ferrules is not limited to two, but may be one or three or more. FIG. 3 shows an example of a two-core optical connector. Figure 4 is straight Fig. 5 shows an example of a 6-core optical connector arranged in a columnar shape, and Fig. 6 shows an example of a 7-core optical connector arranged in a columnar shape. It shows an optical connector for 12 cores arranged. FIG. 7 shows an example of an optical connector arranged in a 144-core planar shape.

 When connecting the female connector and the female connector, use the cutouts and protrusions in the optical connector, connect by bending or brazing, use adhesive, mold clamping, and thermal expansion. It can be fixed by press-fit crimping, joining with a cover, or a combination thereof. Of course, in order to keep the connection loss of the optical fiber small, it is necessary to connect the ends of the optical fiber in close contact. The optical connector obtained in this way is particularly suitable for permanent connection.

 An optical connector can be obtained by inserting two Os-type connectors into the cylindrical case from the left and right. This state is shown in FIGS. 15 and 16. A cylindrical case 51 into which a ferrule can be inserted is prepared, and from the left and right sides of the cylindrical case 51, the projecting ferrule portions 50, 54 of the os-type connectors 48, 53 are inserted. An optical connector can be obtained. Also in this case, positioning can be performed on the cylindrical case with the cutout portions 58, 59, and 60, and the protrusion can be fixed with the protruding portion 52 or the dent portion 49 to prevent slipping.

FIG. 15 shows the case of a two-core connector, while FIG. 16 shows a seven-core optical connector arranged in a columnar shape. Similarly, an optical fiber can be connected by inserting an Os-type connector into the cylindrical case 55 with right and left forces. At this time, the projection 57 provided on the os-type connection body is combined with the recess 56 provided on the cylindrical case, so that the os-type connection body and the cylindrical case can be fixed. In this case, even when the ferrule and the end face of the optical fiber are connected in a plane, the optical fiber in one of the male-type connectors is protruded and inserted into the ferrule in the other male-type connector. The fibers may be connected to each other. Next, a connection method of the optical connector will be described. FIG. 8 shows a conceptual diagram of a method for connecting an optical connector according to the present invention. The ferrule of each of the female connector 16 and the male connector 15 is inserted into the cylindrical cases 61 and 62. As described above, in the female connector, one end of the ferrule 17 stops in the case, and in the male connector, the ferrule extends beyond one end of the case and is inserted. It is as follows.

 In the female connector, the ends of the optical fibers 18 to be connected are arranged so as to pass through the ferrule. In a fossil connector, the optical fiber is placed in the ferrule without the end to be connected protruding from the end of the ferrule. It is necessary to adjust the dimensions of the optical fiber such that the ends of the optical fibers are connected to each other when the female connector and the female connector are connected.

 In general, the female connector and the female connector are connected by bringing the ferrule of the female connector into close contact with the ferrule of the female connector. At this time, it is necessary to arrange the optical fiber so that the optical fiber attached to the female connector is closely connected to the optical fiber attached to the female connector.

 In this case, the end of the optical fiber passing through the ferrule forming the female connector protrudes from the ferrule, and the end of the optical fiber passing through the ferrule forming the female connector stops inside the ferrule. Therefore, the distance between the tip of the optical fiber stopped in the ferrule in the female connector and the tip of the adjacent ferrule, and the ferrule close to the tip of the protruding optical fiber in the female connector By arranging the optical fibers so that the distance to the tip of the optical fibers is close to each other, the optical fibers can be connected to each other in close contact.

Next, FIG. 9 shows the state of the optical connector when the optical fiber is attached and the female connector and the male connector are connected in the optical connector having a space. I have. Characteristically, a space is formed in the optical connection body, that is, a space is formed between the ferrules, and they are arranged apart from each other without being in close contact with each other. In this space, the optical fiber is deformed within its elastic limit in this space, and has the effect of correcting the misalignment of the core between the optical fibers. When connecting the female connector and the male connector, it is inevitable that a slight error will occur. The resulting slight error is absorbed by the space due to slight deformation of the optical fiber in the space. FIG. 10 shows that the optical fibers 19 and 22 are slightly eccentric. It automatically adjusts for errors that occur due to the eccentricity of the optical fiber. That is, by providing a space in the optical connector 20, an optical connector for automatic connection adjustment can be obtained.

 At this time, the length of the space between the ferrule of the female connector and the ferrule of the female connector in the longitudinal direction of the ferrule should be 5% to 300% of the entire length of the ferrule. Is preferred. If the length of the space is short, the effect of the automatic adjustment is small, and if it is too long, the holding of the optical fiber becomes unstable. Even when a space is provided, the optical fibers need to be closely connected. The distance between the tip of the protruding optical fiber in the female connector and the tip of the adjacent ferrule is close to the tip of the optical fiber stopped in the ferrule in the female connector. By arranging the optical fibers so as to match the distance between the tip of the ferrule and the distance of the space, the optical fibers can be connected in close contact.

 The ferrule used in the present invention may be any of ceramics, plastics, stainless steel and electroformed. Among them, those obtained by tube processing and electrode processing can be suitably used.

The case for inserting ferrules is made of noble metals, stainless steel, aluminum, copper, iron, nickel, titanium, magnesium, zinc, tin, tungsten, and metal. It can be made from butene, zirconium, dumet, their alloys or plastics. This case may be flat, variously shaped, or perforated.

 The optical connector is made of a material that is corrosion-resistant, such as stainless steel and nickel, and is suitable for molding. An optical connector with a ferrule made of stainless steel, nickel, zirconium, etc. is generally preferred. .

 At the time of connecting the optical connector, an adhesive or the like can be used when joining the optical fibers within the ferrule of the os-type connector or the os-type terminal. At this time, it is necessary to eliminate the generation of air bubbles and the excess amount of adhesive in the fuiruru, but these can be discharged by forming a small-diameter hole in the ferrule at the connection point of the optical fiber. .

 Figures 11 and 12 show the situation. The ferrule 26 of the female connector 23 is inserted into and connected to the female connector 27. A hole or slit 24 is provided in the ferrule 26 of the female connector 23. When connecting the female-type connector and the female-type connector, an adhesive is applied to the vicinity of the connection end of the optical fiber 30. At this time, the excess adhesive is eliminated from the slit 24 force. In the female connector, the ferrule 26 through the optical fiber 30 is held by the case 25, and in the female connector, the ferrule 28 through the optical fiber 36 is held by the case 29. I have.

 As described above, the optical connector and the optical terminal according to the present invention can be manufactured at relatively low cost and have high dimensional accuracy. Further, the size and capacity of the optical connector of the present invention can be significantly reduced as compared with the conventional optical connector. By providing a space inside the optical connector, an error in alignment of the optical fiber can be absorbed, and an optical connector that can be automatically aligned at the time of connection can be obtained.

Claims

The scope of the claims 1. A female connector with a ferrule held in a cylindrical case so that one end of the ferrule stops inside the cylindrical case. 2. In the female connector, the length from one end of the ferrule stopped in the cylindrical case to the end of the cylindrical case is 80 to 20% of the entire length of the ferrule. 2. The female connector according to claim 1, wherein: 3. In the cylindrical case that holds the female connector, the positioning part of the notch and the fixing part such as a protrusion or a dent are provided on the side connected to the female connector. The female connector according to claim 1 or claim 2. 4. An Os-type connector in which the ferrule is held in a cylindrical case so that one end of the ferrule projects from the cylindrical case. 5. The female-type connection according to claim 4, wherein the length of the ferrule protruding from the cylindrical case is within a range of 20 to 80% of the entire length of the ferrule. body. 6. In the cylindrical case that holds the female connector, the positioning of the notch and the fixing portion such as the protrusion or the dent are provided on the side to be inserted into the female connector. 6. The male connector according to claim 4 or claim 5, characterized in that: 7. The female connector according to any one of claims 1 to 3, wherein the ferrule is machined in a tapered shape from the outside to the inside of the end. 8. The oss type connection body according to any one of claims 4 to 6, wherein the ferrule is formed in a tapered shape from the outside to the inside of the end. 9. Cylindrical case characterized by providing a notch positioning part and a fixing part such as a protrusion or a dent part at the tip of a cylindrical case into which a female or female connector is inserted. . 10. When connecting the female connector according to any one of claims 1 to 3 and the male connector according to any one of claims 4 to 6, An optical connector in which the protruding ferrule of the mold connector is inserted into the cylindrical case of the female connector on the side where the ferrule does not project. 11. An optical connector in which two protruding ferrules are inserted into a cylindrical case from the left and right, each of the two female connectors according to any one of claims 4 to 6. 1 2. Os-type connector according to any one of claims 4 to 6, or claim 8, characterized in that holes or slits are formed in the ferrule of the os-type connector. Connected body. 13. The end of the optical fiber that passes through the ferrule that constitutes the female connector according to any one of claims 1 to 3 protrudes from the ferrule, and any one of claims 4 to 6 The end of the optical fiber that passes through the ferrule that constitutes the female connector described in the above-mentioned item is stopped inside the ferrule, and there is no space between the ferrules of the female connector and the female connector, and there is no ferrule. When the optical fiber is connected in close contact, the distance between the tip of the optical fiber stopped in the ferrule in the female connector and the tip of the adjacent ferrule and the protruding light in the female connector are determined. A method of connecting the female connector and the female connector by arranging the optical fiber so that the distance between the tip of the fiber and the tip of the adjacent ferrule matches. 14. The end of the optical fiber that passes through the ferrule that constitutes the female connector according to any one of claims 1 to 3 protrudes from the ferrule and is any one of claims 4 to 6. The end of the optical fiber passing through the ferrule constituting the os-type connector described in (1) stops inside the ferrule, and a space is provided between the female-type connector and the ferrule of the os-type connector. In some cases, the distance between the tip of the protruding optical fiber in the female connector and the tip of the adjacent ferrule is close to the tip of the optical fiber that has stopped in the ferrule in the male connector. A method of connecting the female connector and the female connector by arranging optical fibers so as to match the distance between the tip of the ferrule and the distance of the space. 1 5. The longitudinal length of the ferrule in the space between the ferrule of the female connector and the ferrule of the oss connector is 5% to 300% of the entire length of the ferrule. The female connector according to claim 14, wherein How to connect to a wireless connection. 16. A claim 13 or claim characterized in that, when connecting the female connector and the female connector, the connector is positioned at the notch at the end of the connector and fixed with a protrusion or a recess. 15. The method for connecting an optical connector according to claim 14. 17. When connecting the female connector and the female connector, the connector is fixed by at least one of brazing, bonding, press-fitting, mold-clamping, and press-fit crimping utilizing thermal expansion. 17. The method for connecting an optical connector according to any one of claims 13 to 16.