Connector-equipped optical fiber and method for manufacturing connector-equipped optical fiber

Abstract

The present invention provides a connector-equipped optical fiber that makes it possible to reduce manufacturing costs and securely connect an optical fiber to a connector.　Provided is a connector-equipped optical fiber (1) in which a connector (3) is attached to one end side of an optical fiber (2). The optical fiber (2) and the connector (3) each comprise a thermoplastic resin. A fused and solidified part (4), which is formed by a member constituting the optical fiber (2) and a member constituting the connector (3) being fused by heat and thereafter solidified, is provided between the optical fiber (2) and the connector (3). The optical fiber (2) and the connector (3) are integrally formed with the fused and solidified part (4) interposed therebetween.

Description

Connectorized optical fiber and method of manufacturing connectorized optical fiber

[0001] The present invention relates to a connectorized optical fiber used for connecting an optical fiber to a connection target such as a light source, and a method for manufacturing the connectorized optical fiber.

[0002] A known conventional optical fiber with a connector is one in which a connector is assembled to one end of the optical fiber in order to connect the optical fiber to a connection target such as a light source, and the connector assembled to one end of the optical fiber is engaged with the connection target (see, for example, Patent Document 1).

[0003] Conventional optical fibers with connectors have a core made of acrylic resin and a cladding made of fluororesin, and a ceramic connector such as zirconia or stainless steel connector is connected to one end of the optical fiber using an adhesive.

[0004] Japanese Patent Application Laid-Open No. 2002-214448

[0005] In conventional connectorized optical fibers, the optical fiber and the connector are connected using an adhesive, which requires time for the adhesive to harden and requires a large number of components, making it difficult to reduce manufacturing costs. Furthermore, when an optical fiber having a fluororesin cladding is connected to a ceramic or stainless steel connector using an adhesive, the interface between the connector and the adhesive is bonded by intermolecular forces such as van der Waals forces. Therefore, with conventional connectorized optical fibers, the adhesive strength at the interface between the connector and the adhesive decreases over time, which can cause the connector to fall off the optical fiber.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a connectorized optical fiber and a method for manufacturing a connectorized optical fiber that can reduce manufacturing costs and ensure reliable connection between the optical fiber and the connector.

[0007] The connectorized optical fiber of the present invention is an optical fiber with a connector attached to one end side of the optical fiber, wherein the optical fiber and the connector are each made of a thermoplastic resin, and a molten solidified portion is provided between the optical fiber and the connector, where the components constituting the optical fiber and the components constituting the connector melt when exposed to heat and then solidify, and the optical fiber and the connector are formed integrally via the molten solidified portion.

[0008] Furthermore, it is preferable that the connector-equipped optical fiber of the present invention is such that the connector has a through hole into which one end of the optical fiber can be fitted, the optical fiber is formed integrally with the connector with one end fitted into the through hole, and one end of the optical fiber is positioned flush with the outer surface of the connector or inside the outer surface of the connector.

[0009] In the connectorized optical fiber according to the present invention, the core of the optical fiber and the connector are preferably made of acrylic resin.

[0010] In the connectorized optical fiber according to the present invention, the core of the optical fiber and the connector preferably have refractive indices in the range of 1.48 to 1.50.

[0011] In the connectorized optical fiber according to the present invention, it is preferable that the melting point of the members constituting the connector is higher than the melting point of the members constituting the optical fiber.

[0012] In addition, the method for manufacturing a connector-equipped optical fiber of the present invention is a method for manufacturing a connector-equipped optical fiber in which a connector is attached to one end side of an optical fiber, and includes an optical fiber manufacturing process for manufacturing the optical fiber from a thermoplastic resin, a connector manufacturing process for manufacturing the connector from a thermoplastic resin, an assembly process for assembling the connector manufactured in the connector manufacturing process to one end side of the optical fiber manufactured in the optical fiber manufacturing process, and an integral formation process for forming the optical fiber and the connector integrally by heating and melting the members constituting the optical fiber and the members constituting the connector assembled in the assembly process and then solidifying them.

[0013] Furthermore, in the method for manufacturing a connector-equipped optical fiber according to the present invention, it is preferable that the connector has a through hole into which one end of the optical fiber can be fitted, the assembly process assembles the connector to one end of the optical fiber by fitting one end of the optical fiber into the through hole, and the integral formation process melts the through hole side portion of the connector and the optical fiber in the cross section and then solidifies them, and positions one end of the optical fiber flush with the outer surface of the connector or inside the outer surface of the connector.

[0014] According to the present invention, it is possible to integrate a connector on the tip side of an optical fiber without using adhesive, thereby reducing the time required for manufacturing and the number of materials used, thereby reducing manufacturing costs. Furthermore, since the connector is integrated on the tip side of the optical fiber by melt-mixing the components constituting the optical fiber and the components constituting the connector, it is possible to suppress a decrease in adhesive strength between the optical fiber and the connector over time, and it is possible to reliably connect the optical fiber and the connector.

[0015] Fig. 1 is a side cross-sectional view of a connectorized optical fiber and a light source according to a first embodiment of the present invention. Fig. 2 is a side cross-sectional view of the connectorized optical fiber according to the first embodiment of the present invention. Fig. 3 is a diagram illustrating a method for manufacturing a connectorized optical fiber according to the first embodiment of the present invention. Fig. 4 is a diagram illustrating a method for manufacturing a connectorized optical fiber according to a second embodiment of the present invention. Fig. 5 is a diagram illustrating a method for manufacturing a connectorized optical fiber according to a third embodiment of the present invention.

[0016] 1 to 3 show a first embodiment of the present invention, in which Fig. 1 is a side cross-sectional view of a connectorized optical fiber and a light source, Fig. 2 is a side cross-sectional view of the connectorized optical fiber, and Fig. 3 is a diagram illustrating a method for manufacturing the connectorized optical fiber.

[0017] The connector-equipped optical fiber 1 of this embodiment is, for example, a component constituting a medical device for irradiating an affected area of ​​the human body with laser light, and as shown in Figure 1, is detachably connected to a light source device 10 as a connection target having an illuminant such as an LED.

[0018] As shown in Figures 1 and 2, this connector-equipped optical fiber 1 has an optical fiber 2 that transmits light emitted from a light source device 10, and a connector 3 that connects one end of the optical fiber 2 to the light source device 10.

[0019] The optical fiber 2 has a core 2a located at the center and a cladding 2b surrounding the outer periphery of the core 2a. The core 2a is made of an acrylic resin such as a methacrylic resin. The cladding 2b is made of a fluororesin. The cladding 2b has a thickness of 10 μm or less.

[0020] The connector 3 is a cylindrical member made of acrylic resin such as methacrylic resin. The outer periphery of one axial end of the connector 3 is formed into a shape that allows it to fit into the light source device 10. The connector 3 also has a through-hole 3a formed on the inner periphery that passes through in the axial direction and into which the optical fiber 2 can fit.

[0021] Here, it is preferable that the compositions of the optical fiber 2 and the connector 3 are adjusted so that the melting point of the material constituting the connector 3 is slightly higher than the melting point of the material constituting the optical fiber 2.

[0022] In addition, between the optical fiber 2 and the connector 3, a molten solidified portion 4 is provided, in which the components constituting the optical fiber 2 and the components constituting the connector 3 are melted by heat and then solidified.

[0023] The molten solidified portion 4 is a portion in which at least a portion of the components constituting the optical fiber 2 and at least a portion of the components constituting the connector 3 are melted and mixed together by heat, and then cooled and solidified. The optical fiber 2 and the connector 3 are integrally formed via the molten solidified portion 4. Here, the fluororesin constituting the cladding 2b of the optical fiber 2 melts and expands when heated, so that the gap between the outer peripheral surface of the optical fiber 2 and the inner peripheral surface of the through hole 3a of the connector 3 is filled by the molten solidified portion 4. Furthermore, one end of the optical fiber 2 formed integrally with the connector 3 is flush with one axial end face of the connector 3 or is positioned closer to the center in the axial direction than one axial end face of the connector 3. In other words, one end of the optical fiber 2 does not protrude from one axial end face of the connector 3.

[0024] A method for manufacturing the connectorized optical fiber 1 configured as above will be described with reference to FIG.

[0025] In manufacturing the connectorized optical fiber 1, a heating device 20 for heating the optical fiber 2 and the connector 3 and a holding member 30 for holding the connector 3 on the heat dissipation surface of the heating device 20, which will be described later, are used.

[0026] The heating device 20 extends horizontally and has a heat dissipation surface 21 facing upward, and heat from a heat source (not shown), such as a sheathed heater, is dissipated from the heat dissipation surface 21. The output of the heat source of the heating device 20 is adjusted so that the temperature of the heat dissipation surface 21 becomes, for example, 180 degrees.

[0027] The holding member 30 is made of a material with low thermal conductivity, such as ceramic, and is formed in a ring shape so that the connector 3 can be fitted to its inner periphery. With the connector 3 fitted to its inner periphery, the holding member 30 is placed on the heat dissipation surface 21 of the heating device 20 so that the tip of the connector 3 faces the heat dissipation surface 21. The connector 3 held by the holding member 30 has its tip abutting against the heat dissipation surface 21.

[0028] When manufacturing the connectorized optical fiber 1 using the heating device 20 and the holding member 30, the optical fiber 2 is first manufactured from a thermoplastic resin (optical fiber manufacturing process). At this time, the manufactured optical fiber 2 has a core 2a formed from an acrylic resin and a cladding 2b formed from a fluororesin.

[0029] Furthermore, the connector 3 is manufactured from acrylic resin (connector manufacturing process).

[0030] Next, the connector 3 held by the holding member 30 is placed on the heat dissipation surface 21 of the heating device 20, the tip of the connector 3 is abutted against the heat dissipation surface 21, and the connector 3 is heated by the heat emitted from the heat dissipation surface 21.

[0031] Then, the optical fiber 2 is inserted into the through hole 3a of the connector 3 placed on the heat dissipation surface 21 of the heating device 20, the connector 3 is assembled to one end side of the optical fiber 2 (assembly process), and one end of the optical fiber 2 is abutted against the heat dissipation surface 21 of the heating device 20.

[0032] Finally, the components constituting the optical fiber 2 and the components constituting the connector 3 are melted by heating, and then the heating by the heating device 20 is stopped, and the melted portions of the optical fiber 2 and the connector 3 are solidified to form a molten solidified portion 4, thereby integrating the optical fiber 2 and the connector 3 (integral formation process).

[0033] Thus, according to the connectorized optical fiber of this embodiment, the connectorized optical fiber 1 has a connector 3 attached to one end side of the optical fiber 2, and the optical fiber 2 and the connector 3 are each made of a thermoplastic resin, and a molten solidified portion 4 is provided between the optical fiber 2 and the connector 3, where the components constituting the optical fiber 2 and the components constituting the connector 3 melt when exposed to heat and then solidify, and the optical fiber 2 and the connector 3 are formed integrally via the molten solidified portion 4.

[0034] Furthermore, according to the manufacturing method of the connectorized optical fiber of this embodiment, a manufacturing method of a connectorized optical fiber 1 in which a connector 3 is attached to one end side of an optical fiber 2 includes an optical fiber manufacturing process in which the optical fiber 2 is manufactured from a thermoplastic resin, a connector manufacturing process in which the connector 3 is manufactured from a thermoplastic resin, an assembly process in which the connector 3 manufactured in the connector manufacturing process is assembled to one end side of the optical fiber 2 manufactured in the optical fiber manufacturing process, and an integral forming process in which the components constituting the optical fiber 2 and the components constituting the connector 3 assembled in the assembly process are melted by heating and then solidified to form the optical fiber 2 and the connector 3 into an integral body.

[0035] This makes it possible to integrate the connector 3 on the tip side of the optical fiber 2 without using adhesive, thereby reducing the time required for manufacturing and the number of materials used, thereby enabling a reduction in manufacturing costs. Furthermore, since the connector 3 is integrated on the tip side of the optical fiber 2 by melt-mixing the members constituting the optical fiber 2 and the members constituting the connector 3, it is possible to suppress a decrease in adhesive strength between the optical fiber 2 and the connector 3 over time, and it is possible to reliably connect the optical fiber 2 and the connector 3.

[0036] Furthermore, it is preferable that the connector 3 has a through hole 3a into which one end of the optical fiber 2 can be fitted, the optical fiber 2 is formed integrally with the connector 3 with one end fitted into the through hole 3a, and one end of the optical fiber 2 is positioned flush with the outer surface of the connector 3 or inside the outer surface of the connector 3.

[0037] As a result, one end of the optical fiber 2 is fitted into the through hole 3a, making it possible to standardize the attachment state of the optical fiber 2 relative to the connector 3, and when connectorized optical fibers 1 are mass-produced, there will be no variation in the position of the optical fiber 2 relative to the connector 3 for each individual optical fiber 2.

[0038] Furthermore, the core 2a of the optical fiber 2 and the connector 3 are preferably made of acrylic resin.

[0039] This allows for high light transmittance and makes it possible to prevent a decrease in the light transmission properties of the optical fiber 2.

[0040] Furthermore, it is preferable that the melting point of the material that constitutes the connector 3 is higher than the melting point of the material that constitutes the optical fiber 2 .

[0041] This allows the optical fiber 2 to melt from the center, making it possible to suppress deformation of the connector 3 and improve the dimensional accuracy of the connector 3.

[0042] 4 shows a second embodiment of the present invention, and is a diagram illustrating a method for manufacturing a connectorized optical fiber. Note that the same components as those in the previous embodiment are designated by the same reference numerals.

[0043] In the manufacturing method of the connectorized optical fiber 1 of this embodiment, a heating device 20, a holding member 30, and a heat transfer regulating plate 40 provided between the heat dissipation surface 21 of the heating device 20 and the holding member 30 are used.

[0044] The heat transfer limiting plate 40 has a heat transfer portion 41 that transfers heat radiated from the heat dissipation surface 21 of the heating device 20 to the portion of the connector 3 on the side of the through hole 3a in its cross section and to the optical fiber 2, and a heat transfer blocking portion 42 that blocks the conduction of heat radiated from the heat dissipation surface 21. The heat transfer portion 41 is made of a metal with high thermal conductivity, such as copper or aluminum. The heat transfer blocking portion 42 is made of a material with low thermal conductivity, such as ceramic. The heat transfer limiting plate 40 has the heat transfer portion 41 arranged near the center and the heat transfer limiting portion 42 arranged on the outer periphery of the heat transfer portion 41.

[0045] In the manufacturing method of the connectorized optical fiber 1 of this embodiment, a heat transfer regulating plate 40 is disposed between the heat dissipation surface 21 of the heating device 20 and the holding member 30, and a heat transfer portion 41 of the heat transfer regulating plate 40 abuts against the inner periphery, which is the portion of the connector 3 on the through hole 3a side in the cross section, and the optical fiber 2, and a heat transfer blocking portion 42 abuts against the outer periphery of the connector 3 and the holding member 30. As a result, the heat released from the heat dissipation surface 21 of the heating device 20 is mainly conducted through the heat transfer portion 41, so that the portion of the connector 3 on the through hole 3a side in the cross section and the optical fiber 2 mainly melt and then solidify, forming a molten solidification portion 4.

[0046] As described above, according to the method for manufacturing a connectorized optical fiber of this embodiment, as in the first embodiment, it is possible to integrate the connector 3 on the tip side of the optical fiber 2 without using adhesive, thereby reducing the time required for manufacturing and the number of materials used, thereby enabling a reduction in manufacturing costs. Furthermore, since the connector 3 is integrated on the tip side of the optical fiber 2 by melt-mixing the members constituting the optical fiber 2 and the members constituting the connector 3, it is possible to suppress a decrease in the adhesive strength between the optical fiber 2 and the connector 3 over time, and it is possible to reliably connect the optical fiber 2 and the connector 3.

[0047] Furthermore, it is preferable that the connector 3 has a through hole 3a into which one end of the optical fiber 2 can be fitted, and that the assembly process assembles the connector 3 to one end of the optical fiber 2 by fitting one end of the optical fiber 2 into the through hole 3a, and that the integral formation process melts the portion of the connector 3 on the through hole 3a side in the cross section and the optical fiber and then solidifies them, and positions one end of the optical fiber 2 flush with the outer surface of the connector 3 or inside the outer surface of the connector 3.

[0048] This makes it possible to suppress deformation of the connector 3 by maintaining the shape of the parts of the connector 3 other than the through hole 3a side in the cross section, thereby making it possible to reliably connect the optical fiber 2 to the connection target part.

[0049] 5 shows a third embodiment of the present invention, and is a diagram illustrating a method for manufacturing a connectorized optical fiber. Note that the same components as those in the previous embodiment are designated by the same reference numerals.

[0050] In the manufacturing method of the connectorized optical fiber 1 of this embodiment, a holding member 30 and a carbon dioxide laser device 50 are used for forming a molten solidified portion 4 by laser welding between the optical fiber 2 and the connector 3.

[0051] The carbon dioxide laser device 50 has an oscillation tube that uses gaseous carbon dioxide as a medium for amplifying light, and oscillates laser light L.

[0052] In the manufacturing method of the connectorized optical fiber 1 of this embodiment, one end of the connector 3 held by the holding member 30 and one end of the optical fiber 2 are irradiated with laser light L oscillated from the carbon dioxide laser device 50. As a result, the irradiated laser light L melts only the portion of the connector 3 on the through hole 3a side in the cross section and the optical fiber 2, and then solidifies to form a molten solidified portion 4.

[0053] As described above, according to the method for manufacturing a connectorized optical fiber of this embodiment, as in the first embodiment, it is possible to integrate the connector 3 on the tip side of the optical fiber 2 without using adhesive, thereby reducing the time required for manufacturing and the number of materials used, thereby enabling a reduction in manufacturing costs. Furthermore, since the connector 3 is integrated on the tip side of the optical fiber 2 by melt-mixing the members constituting the optical fiber 2 and the members constituting the connector 3, it is possible to suppress a decrease in the adhesive strength between the optical fiber 2 and the connector 3 over time, and it is possible to reliably connect the optical fiber 2 and the connector 3.

[0054] Furthermore, as in the second embodiment, by maintaining the shape of the parts of the connector 3 other than the through hole 3a side in the cross section, it is possible to suppress deformation of the connector 3, thereby making it possible to reliably connect the optical fiber 2 to the connection target portion.

[0055] In the above embodiment, the connectorized optical fiber 1 is used to connect the optical fiber 2 to the light source device 10 as the connection target, but the present invention is not limited to this. For example, the connectorized optical fiber of the present invention may be used as the connection target to connect one optical fiber to another optical fiber.

[0056] In addition, although the above embodiment shows the connectorized optical fiber 1 as a component constituting a medical device, the present invention is not limited to this. The connectorized optical fiber of the present invention may be a component constituting equipment other than medical equipment, such as communication equipment or measuring equipment.

[0057] In the above embodiment, the core 2 a of the optical fiber 2 and the connector 3 are each formed from an acrylic resin, but this is not a limitation. The core of the optical fiber and the connector may be made of any thermoplastic resin, and are not limited to acrylic resin. In this case, the refractive index of the core of the optical fiber and the connector is preferably within the range of 1.48 to 1.50. The cladding 2 b of the optical fiber 2 may also be made of a resin other than fluororesin, as long as the refractive index of the material is smaller than that of the core.

[0058] REFERENCE SIGNS LIST 1 Optical fiber with connector 2 Optical fiber 2a Core 3 Connector 3a Through hole 4 Melted and solidified portion

Claims

1. A connectorized optical fiber having a connector attached to one end of an optical fiber, wherein the optical fiber and the connector are each made of a thermoplastic resin, and a molten solidified portion is provided between the optical fiber and the connector where components of the optical fiber and the connector melt and then solidify due to heat, and the optical fiber and the connector are integrally formed via the molten solidified portion.

2. The connector-attached optical fiber according to claim 1, wherein the connector has a through-hole into which one end of the optical fiber can be fitted, the optical fiber is formed integrally with the connector with one end fitted into the through-hole, and one end of the optical fiber is positioned flush with the outer surface of the connector or inside the outer surface of the connector.

3. The connectorized optical fiber according to claim 1, wherein the core of the optical fiber and the connector are each made of acrylic resin.

4. The connectorized optical fiber according to claim 1, wherein the refractive index of the core of the optical fiber and the connector is within the range of 1.48 to 1.

50.

5. The connectorized optical fiber according to claim 1, wherein the melting point of the material constituting the connector is higher than the melting point of the material constituting the optical fiber.

6. A method for manufacturing a connectorized optical fiber in which a connector is attached to one end of an optical fiber, comprising: an optical fiber manufacturing process for manufacturing the optical fiber from a thermoplastic resin; a connector manufacturing process for manufacturing the connector from a thermoplastic resin; an assembly process for assembling the connector manufactured in the connector manufacturing process to one end of the optical fiber manufactured in the optical fiber manufacturing process; and an integral forming process for integrally forming the optical fiber and the connector by heating and melting the members constituting the optical fiber and the members constituting the connector assembled in the assembly process and then solidifying them.

7. A method for manufacturing a connectorized optical fiber as described in claim 6, wherein the connector has a through hole into which one end of the optical fiber can be fitted, the assembling step assembles the connector to one end of the optical fiber by fitting the one end of the optical fiber into the through hole, and the integral forming step melts and then solidifies the through hole side portion of the connector in cross section and the optical fiber, and positions one end of the optical fiber flush with the outer surface of the connector or more inward than the outer surface of the connector.

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