CN111897059B

CN111897059B - Tail line type optical fiber connector

Info

Publication number: CN111897059B
Application number: CN202010816938.6A
Authority: CN
Inventors: 冨永康平; 兼行哲史; 近藤祥; 我妻弘嗣; 箱崎悟史; 佐藤裕希
Original assignee: Namiki Precision Jewel Co Ltd
Current assignee: Obirui Co ltd
Priority date: 2016-05-20
Filing date: 2017-05-19
Publication date: 2022-07-12
Anticipated expiration: 2037-05-19
Also published as: CN111897059A

Abstract

The present invention provides a tail type optical fiber connector, which comprises: a sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a sleeve mounted on a tip side of the sleeve; a holder that holds a rear end side of the ferrule; and an accommodating portion for covering at least a part of the sleeve and the sleeve, wherein the through hole of the sleeve has: a 1 st region corresponding to the width of the optical fiber; and a 2 nd region arranged rearward of the 1 st region, the width of which is enlarged toward the rear end side of the sleeve, and the holder holding a portion of the outer surface of the sleeve rearward of the 1 st region. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability is provided.

Description

Tail line type optical fiber connector

The application is a divisional application of an invention patent application with the application date of 2017, 05 and 19, and the invention name of a tail-line type optical fiber connector, and the national application number of 201780017201.4.

Technical Field

Aspects of the present invention generally relate to pigtail-type optical fiber splices.

Background

An optical fiber connector is used as a component for optically connecting an optical fiber connector (connector) to an optical element such as a light receiving element or a light emitting element in an optical module (module) of a transceiver (transmitter) for optical communication. In addition, a pigtail type optical fiber connector in which an optical fiber is drawn from a ferrule is also known as such an optical fiber connector.

For example, patent document 1 proposes a pigtail type optical fiber connector in which a ferrule holding an optical fiber is held by a holder and the holder is press-fitted into a housing, thereby improving the holding force of each component such as the ferrule and the holder.

In patent document 1, the rear end surface of the ferrule is positioned on the rear end side of the press-fitting region of the housing, thereby reducing the pressure applied from the holder to the rear end portion of the ferrule. This can suppress the inner diameter of the ferrule from shrinking due to press-fitting, and can suppress the external force from locally concentrating on a part of the optical fiber at the rear end portion of the ferrule. Furthermore, a decrease in strength and an increase in loss of the optical fiber caused by concentration of external force can be suppressed, and the reliability of the pigtail optical fiber connector can be improved.

However, in the structure in which the rear end surface of the ferrule is positioned on the rear end side of the press-fitting region of the housing, the ferrule and the holder need to be longer than in the structure in which the rear end of the ferrule is disposed in the press-fitting region. Therefore, in the pigtail type optical fiber connector, it is difficult to miniaturize a connector main body portion (a portion on the tip side of the drawn optical fiber) including a ferrule, a housing, and the like in the longitudinal direction.

In general, the shape of an optical transceiver is standardized, and if the connector body portion becomes long, the space of a circuit including an optical element and the like is reduced. In addition, in the optical transceiver, a high speed is required along with an increase in IP traffic, and a space required for a circuit increases along with an increase in modulation speed of an optical signal emitted from an optical element.

Therefore, in the pigtail type optical fiber splice, it is desired to realize miniaturization without lowering reliability accompanied by local external force concentration to the optical fiber or the like.

Patent document 1: japanese unexamined patent publication No. 2012-230275

Disclosure of Invention

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a pigtail-type optical fiber connector which can be miniaturized without lowering reliability.

The invention of claim 1 is a pigtail type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; and a cylindrical housing portion fitted to an outer surface of the holder and covering at least a part of the sleeve and the sleeve, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region which is disposed rearward of the 1 st region, and in which the width in the orthogonal direction is enlarged toward the rear end side of the sleeve, wherein the through hole of the sleeve in a portion of the outer surface of the sleeve which is rearward of the 1 st region by the holder has a 3 rd region which is disposed rearward of the 2 nd region, and the width change in the orthogonal direction of the through hole in the 3 rd region is linear, and the width change in the orthogonal direction of the through hole in the 2 nd region is convex curved.

According to the pigtail type optical fiber connector, since at least a part of the sleeve and the ferrule are accommodated in the accommodating portion, the lengths of the ferrule and the accommodating portion can be shortened as compared with a structure in which the rear end portion of the ferrule protrudes rearward of the accommodating portion. In addition, the holder holds a portion of the outer side surface of the sleeve that is more rearward than the 1 st region. Thus, for example, even when the ferrule contracts, it is possible to suppress concentration of an external force at a boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability can be provided.

The invention of claim 2 is the pigtail-type optical fiber connector of claim 1, wherein a width variation in the orthogonal direction of the through hole in the 2 nd region is a convex curve.

According to the pigtail type optical fiber splice, it is possible to suppress concentration of an external force on the optical fiber at the boundary portion between the 1 st region and the 2 nd region.

The 3 rd invention is the pigtail type optical fiber connector according to the 2 nd invention, wherein the through hole of the ferrule further includes a 3 rd region disposed further rearward than the 2 nd region, and a width change of the through hole in the 3 rd region in the orthogonal direction is linear.

According to the pigtail type optical fiber connector, it is possible to suppress concentration of external force on the optical fiber in the boundary portion between the 1 st region and the 2 nd region.

The 4 th aspect of the present invention is the pigtail-type optical fiber connector according to any 1 of the 1 st to 3 rd aspects of the present invention, wherein a tip of the protective member is located in the 2 nd region of the through hole.

According to the pigtail-type optical fiber connector, the length of the portion of the optical fiber protruding from the protective member can be shortened as much as possible. This can suppress, for example, the occurrence of bending of the optical fiber, and can facilitate insertion of the optical fiber into the insertion hole of the ferrule. The manufacturability of the pigtail fiber splice can be improved.

The 5 th aspect of the present invention is the pigtail type optical fiber connector according to the 3 rd aspect of the present invention, wherein a tip end of the protective member is located in the 3 rd region of the through hole.

The 6 th aspect of the present invention is the pigtail type optical fiber connector according to any 1 of the 1 st to 5 th aspects of the present invention, wherein the holder holds the rear end side of the ferrule by press-fitting.

According to the pigtail type optical fiber connector, the ferrule can be appropriately held by a simple structure.

The 7 th aspect of the present invention is the pigtail type optical fiber splice according to any 1 of the 1 st to 6 th aspects of the present invention, wherein a rear end of the holder is located rearward of a rear end of the ferrule, the holder surrounds a part of the optical fiber and a part of the protection member, and the optical fiber and the protection member are fixed to the holder by adhesion by an elastic member filled in the through hole and the holder while extending outward of the holder.

According to the pigtail-type optical fiber connector, the portion of the optical fiber protruding from the protective member can be suppressed from being deformed or inclined by an external force. In addition, the protrusion of the optical fiber tip from the ferrule or the retraction of the optical fiber tip due to the application of an external force can be suppressed.

The 8 th aspect of the present invention is the pigtail type optical fiber connector according to the 7 th aspect of the present invention, wherein the inner peripheral surface of the holder includes: a 1 st inner peripheral portion fitted in an outer side surface of the sleeve; and a 2 nd inner circumferential portion located rearward of the 1 st inner circumferential portion, protruding more inward than the 1 st inner circumferential portion, surrounding a part of the optical fiber and a part of the protective member, wherein a gap is provided in the axial direction between a rear end of the ferrule and the 2 nd inner circumferential portion, and the elastic member is also filled in the gap.

According to the pigtail-type optical fiber splice, deformation and displacement of the optical fiber tip portion caused by an external force can be further suppressed.

The 9 th aspect of the present invention is the pigtail type optical fiber connector according to any 1 of the 1 st to 8 th aspects of the present invention, wherein the holder comprises: 1 st rear end face; and a 2 nd rear end surface recessed further toward the tip end side than the 1 st rear end surface at a position further toward the outer peripheral side than the 1 st rear end surface.

According to this pigtail type optical fiber splice, for example, the 1 st rear end face can be used as a receiving face for an adhesive (elastic member) when the optical fiber and the protective member are adhesively fixed, and the 2 nd rear end face can be used as a positioning face for the holder and the housing portion. This can prevent the adhesive from flowing into the positioning surface, and can prevent the holder and the housing portion from being misaligned. Further, by further increasing the length of the 1 st rear end surface portion as compared with the length necessary for holding the holder in the housing portion, the protective member can be adhered and fixed to the housing portion in a longer length. This can further suppress deformation and misalignment of the fiber tip portion.

The 10 th aspect of the present invention is the pigtail type optical fiber connector according to any 1 of the 1 st to 9 th aspects of the present invention, wherein the outer surface of the holder includes: a 1 st outer circumferential portion held by the housing portion; and a 2 nd outer peripheral portion provided at a distal end portion of the holder and recessed inward from the 1 st outer peripheral portion.

According to this pigtail type optical fiber connector, the portion holding the holder in the housing portion can be shifted rearward, and concentration of external force on the optical fiber can be further suppressed in the boundary portion between the 1 st region and the 2 nd region.

The 11 th aspect of the present invention is the pigtail-type optical fiber connector according to any 1 of the 1 st to 10 th aspects of the present invention, wherein the holder has a chamfered portion between the rear end surface and the inner peripheral surface.

According to the pigtail-type optical fiber connector, by providing the chamfered portion, the optical fiber can be easily inserted into the holder, and the manufacturability can be improved. In addition, when the optical fiber and the protective member are adhesively fixed, the chamfered portion can be used as an adhesive reservoir, and the adhesive can be further inhibited from flowing into the positioning surface.

The 12 th aspect of the present invention is the pigtail type optical fiber splice, wherein in the 7 th aspect of the present invention, the elastic member has a protruding portion that protrudes outward of the holder at a rear end side of the holder, and covers an angle portion between the rear end of the holder and an outer side surface of the protective member.

According to the pigtail type optical fiber splice, when a load is applied by an external force, the optical fiber can be suppressed from being partially bent at a corner portion between the rear end of the holder and the outer surface of the protective member.

The 13 th aspect of the present invention is the pigtail type optical fiber connector according to any 1 of 1 st to 12 th aspects of the present invention, wherein the accommodating portion holds the holder by press-fitting.

According to the pigtail-type optical fiber connector, the holder can be appropriately held by a simple structure.

The 14 th aspect of the present invention is the pigtail type optical fiber connector according to any 1 of the 1 st to 13 th aspects of the present invention, wherein an outer surface of the ferrule has a 1 st abutting portion abutting against an inner peripheral surface of the holder, an outer surface of the holder has a 2 nd abutting portion abutting against an inner peripheral surface of the accommodating portion, and an intermediate point in the axial direction of the 2 nd abutting portion is located rearward of an intermediate point in the axial direction of the 1 st abutting portion.

According to this pigtail type optical fiber connector, even when the holder is press-fitted into the housing portion, for example, the 2 nd contact portion can disperse the fastening force due to the press-fitting over a wide area, and the concentration of the external force on the optical fiber can be further suppressed in the boundary portion between the 1 st area and the 2 nd area.

The 15 th invention is a pigtail type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; and a cylindrical housing portion fitted to an outer surface of the holder and covering at least a part of the sleeve and the sleeve, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region which is disposed rearward of the 1 st region, in which the width in the orthogonal direction is enlarged toward a rear end side of the sleeve, in which the width in the orthogonal direction of the through hole in the 2 nd region is changed in a curved shape in which a rate of change is increased toward the rear end side, and in which the through hole in the sleeve further includes a 3 rd region which is disposed rearward of the 2 nd region, in which the width change in the orthogonal direction of the through hole in the 3 rd region is linear, and in which the width change in the orthogonal direction of the through hole in the 2 nd region is convex curved.

According to the pigtail type optical fiber connector, since at least a part of the sleeve and the ferrule are accommodated in the accommodating portion, the lengths of the ferrule and the accommodating portion can be shortened as compared with a structure in which the rear end portion of the ferrule protrudes rearward of the accommodating portion. The width of the through hole in the 2 nd region in the orthogonal direction changes in a curved shape in which the rate of change becomes larger toward the rear end side. Thus, for example, even when the ferrule contracts, it is possible to suppress concentration of an external force at a boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability can be provided.

The 16 th invention is a pigtail type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; and a cylindrical housing portion fitted to an outer surface of the holder and covering at least a part of the sleeve and the sleeve, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, wherein the width in the orthogonal direction is enlarged toward the rear end side of the sleeve, and the receiving portion is fitted into the outer surface of the holder at a position rearward of the 1 st region, wherein the through hole of the sleeve further includes a 3 rd region disposed rearward of the 2 nd region, wherein the width variation in the orthogonal direction of the through hole in the 3 rd region is linear, and the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curved.

According to the pigtail type optical fiber connector, since at least a part of the sleeve and the ferrule are accommodated in the accommodating portion, the lengths of the ferrule and the accommodating portion can be shortened as compared with a structure in which the rear end portion of the ferrule protrudes rearward of the accommodating portion. The receiving portion is fitted into the outer surface of the holder at a position rearward of the 1 st region. Thus, for example, in the boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held, the external force caused by fitting the accommodating portion into the outer surface of the holder can be suppressed from concentrating on the optical fiber. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability can be provided.

The 17 th invention is the pigtail type optical fiber connector according to the 16 th invention, wherein the outer side surface of the holder includes: a 1 st outer circumferential portion held by the housing portion; and a 2 nd outer peripheral portion provided at a distal end portion of the holder and recessed inward from the 1 st outer peripheral portion, the 1 st outer peripheral portion being located rearward of the 1 st region.

According to the pigtail type optical fiber connector, in the boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held, the external force caused by fitting the accommodating portion into the outer surface of the holder can be suppressed from concentrating on the optical fiber.

The 18 th invention is the pigtail type optical fiber connector according to the 16 th invention, wherein the inner side surface of the accommodating portion has: a 1 st inner peripheral portion fitted in an outer side surface of the holder; and a 2 nd inner peripheral portion provided on the tip side of the 1 st inner peripheral portion and extending outward of the 1 st inner peripheral portion, the 1 st inner peripheral portion being located rearward of the 1 st region.

The 19 nd invention is the pigtail type optical fiber connector, wherein in the 18 th invention, the 2 nd inner peripheral portion is connected to the 1 st inner peripheral portion via an inclined surface or a curved surface.

According to the pigtail type optical fiber connector, even when the 1 st inner circumferential portion and the 2 nd inner circumferential portion are provided on the inner side surface of the housing portion, the housing portion can be easily formed.

The 20 th invention is a pigtail type optical fiber splice comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; and a cylindrical housing portion attached to the holder and covering at least a part of the sleeve and the sleeve, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, wherein the width in the orthogonal direction is enlarged toward the rear end side of the sleeve, wherein the holder has a flange portion provided at a distal end side of the 2 nd region and projecting outward of the receiving portion, and the receiving portion is attached to the holder at a position on the distal end side of the flange portion, wherein the through hole of the sleeve further has a 3 rd region disposed rearward of the 2 nd region, wherein the width variation in the orthogonal direction of the through hole in the 3 rd region is linear, and the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curved.

According to the pigtail type optical fiber connector, since at least a part of the sleeve and the ferrule are accommodated in the accommodating portion, the lengths of the ferrule and the accommodating portion can be shortened as compared with a structure in which the rear end portion of the ferrule protrudes rearward of the accommodating portion. The holder has a flange portion provided on the tip side of the 2 nd region and protruding outward from the receiving portion, and the receiving portion is attached to the holder at a position on the tip side of the flange portion. Thus, for example, in the boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held, concentration of external force caused by the attachment accommodating portion on the optical fiber can be suppressed. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability can be provided.

The invention of claim 21 is a pigtail type optical fiber connector including: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; a cylindrical housing portion fitted to an outer surface of the holder and covering at least a part of the sleeve and the sleeve; the 1 st elastic component is filled in the through hole and the retainer; and a 2 nd elastic member covering an angle portion between a rear end of the holder and an outer side surface of the protective member, wherein the through hole of the sleeve has: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, the width in the orthogonal direction being enlarged toward the rear end side of the ferrule, the holder holding a portion of the outer surface of the ferrule rearward of the 1 st region, a rear end of the holder being rearward of the rear end of the ferrule, the holder surrounding a portion of the optical fiber and a portion of the protection member, the optical fiber and the protection member extending outward of the holder and being adhesively fixed to the holder by the 1 st elastic member, the 2 nd elastic member having a hardness lower than that of the 1 st elastic member, the through hole of the ferrule further having a 3 rd region disposed rearward of the 2 nd region, the through hole in the 3 rd region having a linearly changing width in the orthogonal direction, the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curve-shaped.

Further, since the optical fiber and the protective member are adhesively fixed to the holder by the 1 st elastic member, the portion of the optical fiber protruding from the protective member can be prevented from being deformed or inclined by an external force. In addition, the protrusion of the fiber tip from the ferrule or the retraction of the fiber tip due to the application of an external force can be suppressed.

Further, by providing the 2 nd elastic member, the bending base point can be separated from the 1 st elastic member when the optical fiber is bent during processing or the like. At this time, by making the hardness of the 2 nd elastic member lower than that of the 1 st elastic member, it is possible to suppress stress applied to the protective member at the boundary with the 2 nd elastic member even when the optical fiber is bent during handling or the like. This can suppress the occurrence of breakage or the like of the protective member in the vicinity of the boundary with the 1 st elastic member and the 2 nd elastic member, and can further reduce the risk of breakage of the optical fiber.

The invention of claim 22 is a pigtail-type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; a cylindrical housing portion that is fitted to an outer surface of the holder and covers at least a part of the sleeve and the sleeve; the 1 st elastic component is filled in the through hole and the holder; and a 2 nd elastic member covering an angle portion between a rear end of the holder and an outer side surface of the protective member, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region which is disposed rearward of the 1 st region, wherein the width in the orthogonal direction is increased toward a rear end side of the ferrule, wherein the width in the orthogonal direction of the through hole in the 2 nd region is changed in a curved shape in which the ratio of change is increased toward the rear end side, wherein a rear end of the holder is located rearward of a rear end of the ferrule, the holder surrounds a part of the optical fiber and a part of the protective member, the optical fiber and the protective member are further extended outward of the holder, and are adhesively fixed to the holder by the 1 st elastic member, wherein the hardness of the 2 nd elastic member is lower than that of the 1 st elastic member, wherein the through hole in the ferrule further includes a 3 rd region which is disposed rearward of the 2 nd region, and wherein the width in the orthogonal direction of the through hole in the 3 rd region is changed linearly, the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curve-shaped.

According to the pigtail type optical fiber connector, since at least a part of the sleeve and the ferrule are accommodated in the accommodating portion, the lengths of the ferrule and the accommodating portion can be shortened as compared with a structure in which the rear end portion of the ferrule protrudes rearward of the accommodating portion. The width of the through hole in the 2 nd region in the orthogonal direction changes in a curved shape with a larger rate of change toward the rear end side. Thus, for example, even when the ferrule contracts, it is possible to suppress concentration of an external force at a boundary portion between the 1 st region where the optical fiber is held and the 2 nd region where the optical fiber is not held. Thus, a pigtail-type optical fiber connector which can be miniaturized without lowering reliability can be provided.

Further, by providing the 2 nd elastic member, the bending base point can be separated from the 1 st elastic member when the optical fiber is bent during processing or the like. At this time, by making the hardness of the 2 nd elastic member lower than that of the 1 st elastic member, even when the optical fiber is bent during processing or the like, stress applied to the protective member at the boundary with the 2 nd elastic member can be suppressed. This can suppress the occurrence of breakage or the like of the protective member in the vicinity of the boundary with the 1 st elastic member and the 2 nd elastic member, and can further reduce the risk of breakage of the optical fiber.

The invention of claim 23 is a pigtail-type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; a cylindrical housing portion that is fitted to an outer surface of the holder and covers at least a part of the sleeve and the sleeve; the 1 st elastic component is filled in the through hole and the retainer; and a 2 nd elastic member covering an angle portion between a rear end of the holder and an outer side surface of the protective member, wherein the through hole of the sleeve includes: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, wherein the width in the orthogonal direction is increased toward the rear end side of the ferrule, wherein the accommodating portion is fitted into an outer surface of the holder at a position rearward of the 1 st region, wherein a rear end of the holder is rearward of a rear end of the ferrule, wherein the holder surrounds a part of the optical fiber and a part of the protective member, wherein the optical fiber and the protective member are further extended outward of the holder, and wherein the optical fiber and the protective member are adhesively fixed to the holder by the 1 st elastic member, wherein the 2 nd elastic member has a hardness lower than that of the 1 st elastic member, wherein the through-hole of the ferrule further includes a 3 rd region disposed rearward of the 2 nd region, and wherein the width in the orthogonal direction of the through-hole in the 3 rd region changes linearly, the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curve-shaped.

Since the optical fiber and the protective member are adhesively fixed to the holder by the 1 st elastic member, the portion of the optical fiber protruding from the protective member can be prevented from being deformed or inclined by an external force. In addition, the protrusion of the optical fiber tip from the ferrule or the retraction of the optical fiber tip due to the application of an external force can be suppressed.

The 24 th invention is a pigtail type optical fiber connector comprising: a cylindrical sleeve having a through hole extending in an axial direction; an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule; a protective member covering a portion of the optical fiber extending to an outside of the ferrule; a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve; a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve; a cylindrical housing portion attached to the holder and covering at least a part of the sleeve and the sleeve; the 1 st elastic component is filled in the through hole and the retainer; and a 2 nd elastic member covering an angle portion between a rear end of the holder and an outer side surface of the protective member, wherein the through hole of the sleeve has: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, the orthogonal direction width being enlarged toward a rear end side of the ferrule, the holder having a flange portion provided to protrude outward from the accommodating portion on a distal end side of the 2 nd region, the accommodating portion being attached to the holder at a position on the distal end side of the flange portion, a rear end of the holder being rearward of a rear end of the ferrule, the holder surrounding a part of the optical fiber and a part of the protective member, the optical fiber and the protective member extending outward of the holder and being adhesively fixed to the holder by the 1 st elastic member, the 2 nd elastic member having a hardness lower than that of the 1 st elastic member, the through-hole of the ferrule further having a 3 rd region disposed rearward of the 2 nd region, the width change in the orthogonal direction of the through hole in the 3 rd region is linear, and the width change in the orthogonal direction of the through hole in the 2 nd region is convex curved.

The 25 th invention is the pigtail type optical fiber connector according to any 1 of the 21 st to 24 th inventions, wherein a width of the 2 nd elastic member on the rear end surface of the holder is wider than a width of the 1 st elastic member on the rear end surface of the holder.

According to the pigtail type optical fiber splice, the thickness of the 2 nd elastic member can be appropriately secured regardless of the effect of the width of the holder of the 1 st elastic member on the rear end face, and the 2 nd elastic member itself can be suppressed from being damaged or the like even when the optical fiber is bent by external stress or the like.

The 26 th invention is the pigtail type optical fiber connector according to any 1 of the 21 st to 25 th inventions, wherein the holder includes: 1 st rear end surface; and a 2 nd rear end surface recessed further toward a tip end side than the 1 st rear end surface at a position on an outer peripheral side than the 1 st rear end surface, a width of the 2 nd elastic member in a direction orthogonal to the axial direction being narrower than a width of the 1 st rear end surface in the direction orthogonal to the axial direction.

According to this pigtail type optical fiber splice, for example, the 1 st rear end face can be used as a receiving face for an adhesive (elastic member) when the optical fiber and the protective member are adhesively fixed, and the 2 nd rear end face can be used as a positioning face for the holder and the housing portion. This can prevent the adhesive from flowing into the positioning surface, and can prevent the holder and the housing portion from being misaligned. Further, by further increasing the length of the 1 st rear end surface portion as compared with the length necessary for holding the holder in the housing portion, the protective member can be adhesively fixed to the housing portion in a longer length. This can further suppress deformation and misalignment of the fiber tip portion.

Further, the second elastic member is prevented from flowing into the second rear end face 2, and the second elastic member can be appropriately positioned at the time of assembly.

The 27 th aspect of the present invention is the pigtail type optical fiber splice according to any 1 of the 21 st to 26 th aspects of the present invention, wherein the 1 st elastic member has a protruding portion that protrudes outward of the holder at a rear end side of the holder, and covers an angle portion between the rear end of the holder and an outer side surface of the protection member, and the 2 nd elastic member covers the protruding portion.

The 28 th invention is the pigtail type optical fiber connector, wherein in the 27 th invention, the axial length of the 2 nd elastic member is longer than the axial length of the protruding portion.

According to the pigtail type optical fiber splice, the thickness of the 2 nd elastic member can be appropriately secured regardless of the effect of the axial length of the protruding portion, and the 2 nd elastic member itself can be suppressed from being damaged or the like even when the optical fiber is bent by external stress or the like.

The 29 th invention is the pigtail type optical fiber connector according to the 27 th or 28 th invention, wherein an average inclination angle formed by an outer surface of the 2 nd elastic member and a rear end surface of the holder is equal to or larger than an average inclination angle formed by an outer surface of the protruding portion and a rear end surface of the holder.

According to the pigtail type optical fiber splice, the thickness of the 2 nd elastic member can be appropriately secured regardless of the width of the holder of the 1 st elastic member on the rear end face, and the 2 nd elastic member itself can be suppressed from being damaged or the like even when the optical fiber is bent by external stress or the like.

According to the aspect of the present invention, a pigtail-type optical fiber connector which can be miniaturized without reducing reliability is provided.

Drawings

Fig. 1 is a cross-sectional view showing a pigtail-type optical fiber connector according to embodiment 1.

Fig. 2(a) to 2(c) are sectional views showing a specific example of the grommet according to embodiment 1.

Fig. 3 is a cross-sectional view showing a modification of the pigtail type optical fiber connector according to embodiment 1.

Fig. 4 is a cross-sectional view showing a modification of the pigtail type optical fiber splice according to embodiment 1.

Fig. 5 is a cross-sectional view showing the pigtail type optical fiber connector according to embodiment 2.

Fig. 6 is a cross-sectional view showing a modification of the pigtail type optical fiber connector according to embodiment 2.

Fig. 7 is a cross-sectional view showing a modification of the pigtail type optical fiber connector according to embodiment 2.

Fig. 8(a) and 8(b) are cross-sectional views showing modifications of the pigtail type optical fiber connector according to embodiment 2.

Fig. 9 is a cross-sectional view showing a pigtail type optical fiber connector according to embodiment 3.

Fig. 10(a) and 10(b) are cross-sectional views showing modifications of the pigtail optical fiber connector according to embodiment 3.

Fig. 11 is a cross-sectional view showing a pigtail type optical fiber connector according to embodiment 4.

Fig. 12 is a partial cross-sectional view showing an enlarged part of the pigtail type optical fiber connector according to embodiment 4.

Fig. 13(a) to 13(c) are partial cross-sectional views showing modifications of the pigtail type optical fiber connector according to embodiment 4.

Description of the symbols

10. 10a, 10b, 100 a-100 d, 200a, 200b, 300-pigtail type fiber optic connectors; 12-a sleeve; 12 t-through hole; 14-an optical fiber; 16-a protective member; 18-a sleeve; 20. 120, 220-a holder; 20 c-chamfered section; 22. 122, 222-a receiving portion; 24-an elastic member; a 24 p-projection; 302-an elastic member; BS 1-1 st rear face; BS 2-2 nd rear face; CP 1-No. 1 abutment; CP 2-No. 2 abutment; IS 1-1 st inner periphery; IS 2-2 nd inner circumference; OS 1-1 st peripheral portion; OS 2-2 nd peripheral portion; r1-region 1; r2-region 2; SP-gap.

Detailed Description

Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

Embodiment 1

Fig. 1 is a cross-sectional view showing a pigtail type optical fiber connector according to embodiment 1.

As shown in fig. 1, a pigtail-type optical fiber connector (hereinafter, referred to as an optical fiber connector) 10 includes a ferrule 12, an optical fiber 14, a protective member 16, a sleeve 18, a holder 20, and a housing portion 22.

The sleeve 12 has a cylindrical shape with a through hole 12t extending in the axial direction. The through hole 12t is linearly inserted between the front end 12a and the rear end 12b of the sleeve 12. The optical fiber 14 is held by the ferrule 12 while being inserted into the through hole 12t, and extends from the rear end 12b side of the ferrule 12 to the outside of the ferrule 12. In other words, the ferrule 12 holds one end of the optical fiber 14.

The optical fiber 14 is inserted into substantially the entire through hole 12 t. The tip 14a of the optical fiber 14 is located on substantially one face with the tip 12a of the ferrule 12. The distal end 12a of the ferrule 12 and the distal end 14a of the optical fiber 14 form a pc (physical contact) surface with an insertion ferrule (not shown) inserted into the optical fiber connector 10. The optical fiber 14 is optically connected to a plug-in ferrule inserted into the optical fiber connector 10. In this example, the respective

distal ends

12a, 14a are polished in a planar shape. The

respective tips

12a, 14a may be ground into a convex spherical shape, for example.

The end of the optical fiber 14 opposite to the ferrule 12 is optically connected to an optical element such as a semiconductor laser element via an optical connector or the like, for example. Thus, the optical fiber connector 10 optically connects the inserted insertion tube and the optical element via the optical fiber 14.

The sleeve 12 is, for example, cylindrical. The optical fiber 14 is, for example, a thin wire shape having a substantially circular cross section. The through hole 12t is formed corresponding to the cross-sectional shape of the optical fiber 14. That is, the cross-sectional shape of the through hole 12t is substantially circular. More specifically, the "cross section" referred to herein is a cross section orthogonal to the axial direction of the tubular sleeve 12. The outer shape of the sleeve 12 in the cross section orthogonal to the axial direction is not limited to a circle, and may be a polygon or the like.

The sleeve 12 is made of, for example, ceramic or glass. More preferably, zirconia ceramics are used. The optical fiber 14 includes, for example: a core extending in an axial direction; and a cladding surrounding the periphery of the core. The refractive index of the core is higher than that of the cladding. The core and cladding of the optical fiber 14 are made of, for example, quartz glass. Impurities may also be added to the quartz glass. The optical fiber 14 is flexible and can be bent in any direction.

The protective member 16 covers a portion of the optical fiber 14 extending outside the ferrule 12. The protective member 16 is flexible and can be flexed in any direction together with the optical fiber 14. The protective member 16 is made of a resin material such as a polyester elastomer or an acrylate resin. The outer diameter of the protective member 16 is, for example, about 0.2mm to 0.5 mm. The length of the optical fiber 14 and the portion of the protective member 16 extending outward from the ferrule 12 is, for example, about 80 mm. The lengths of the optical fiber 14 and the portion of the protective member 16 extending outward from the ferrule 12 are not limited to this, and may be any length.

The sleeve 18 is fitted into the outer surface 12g of the sleeve 12 and attached to the distal end 12a side of the sleeve 12. The tip end 18a of the sleeve 18 projects more forward than the tip end 12a of the sleeve 12. The sleeve 18 surrounds the tip 12a of the ferrule 12 and the tip 14a of the optical fiber 14 about an axis. The ferrule 18 holds the insertion tube inserted from the distal end side, and can optically connect the optical fiber 14 and the insertion tube.

The sleeve 18 is, for example, cylindrical. The inner diameter of the sleeve 18 is substantially the same as the outer diameter of the casing 12. Thereby, the sleeve 18 is fitted into the outer surface 12g of the sleeve 12. The cross-sectional shape of the sleeve 18 corresponds to the cross-sectional shape of the sleeve 12. For example, when the outer shape of the sleeve 12 is a quadrangle, the sleeve 18 is formed in a quadrangular tube shape.

In addition, the sleeve 18 has a slit extending in the axial direction. More specifically, the sleeve 18 has a substantially C-shaped cross section. The sleeve 18 is a so-called split sleeve. The slit is provided as necessary and may be omitted. The sleeve 18 may also be cylindrical in shape that is annularly continuous around the shaft.

The sleeve 18 is made of, for example, a resin material, a metal material, or a ceramic material. More preferably, zirconia ceramics are used.

The holder 20 is fitted into the outer surface 12g of the sleeve 12 and holds the rear end 12b side of the sleeve 12. The holder 20 is, for example, cylindrical. Like the sleeve 18, the cross-sectional shape of the retainer 20 corresponds to the cross-sectional shape of the sleeve 12. The holder 20 may be a cylinder corresponding to any cross-sectional shape of the sleeve 12. The holder 20 is made of a metal material such as stainless steel. The material of the holder 20 may also be a resin material, ceramic, or the like.

The housing portion 22 is fitted into the outer surface 20g of the holder 20, and covers the sleeve 12 and the sleeve 18. The housing portion 22 covers the sleeve 12 and the sleeve 18 around the shaft, and protects the sleeve 12 and the sleeve 18 from external force and the like. Thus, the holder 20 holds the sleeve 12 and the sleeve 18 in the accommodating portion 22. The housing portion 22 is, for example, cylindrical. The outer diameter of the retainer 20 is larger than the outer diameter of the sleeve 18. The inner diameter of the receiving portion 22 is substantially the same as the outer diameter of the holder 20. The housing portion 22 is fitted only to the outer surface 20g of the holder 20 without being fitted to the outer surface of the sleeve 18.

The housing portion 22 may be a tube having an arbitrary cross-sectional shape corresponding to the holder 20. In this example, the housing portion 22 covers substantially the entire outer surface of the sleeve 18. In other words, the entire sleeve 18 is housed in the housing portion 22. The sleeve 18 may be partially projected forward of the receiving portion 22. The housing portion 22 may cover at least a part of the sleeve 18. The housing portion 22 is made of a metal material such as stainless steel. The material of the housing portion 22 may be a resin material, ceramic, or the like.

The through hole 12t of the sleeve 12 has a 1 st region R1 and a 2 nd region R2. The 1 st region R1 is a region whose width in the orthogonal direction orthogonal to the axial direction corresponds to the width in the orthogonal direction of the optical fiber 14. That is, the 1 st region R1 is a portion having substantially the same diameter as the outer diameter of the optical fiber 14 in the through hole 12 t. The 1 st region R1 has a substantially constant diameter along the axial direction. In addition, the 1 st region R1 is continuous with the tip 12a of the cannula 12. The ferrule 12 retains the optical fiber 14 in region 1R 1.

The 2 nd region R2 is disposed rearward of the 1 st region R1. The 2 nd region R2 is continuous with the 1 st region R1. In addition, in this example, the 2 nd region R2 is continuous with the rear end 12b of the sleeve 12. The 2 nd region R2 is a region in which the width in the orthogonal direction becomes larger toward the rear end 12b side of the sleeve 12. That is, the 2 nd region R2 is a portion of the through hole 12t that increases in diameter toward the rear end 12b side.

In the 2 nd region R2, for example, the diameter continuously increases toward the rear end 12b side. The diameter in the 2 nd region R2 may be gradually increased toward the rear end 12b side, for example. However, since the diameter of the 2 nd region R2 is continuously increased, for example, when the optical fiber 14 is inserted into the through hole 12t, the tip 14a of the optical fiber 14 can be easily inserted into the through hole 12t along the inclination of the 2 nd region R2. For example, the manufacturability of the optical fiber connector 10 can be improved.

The holder 20 holds only a portion of the outer side surface 12g of the sleeve 12 that is rearward of the 1 st region R1. In this example, the holder 20 holds only a portion of the outer side surface 12g of the sleeve 12 that is opposite to the 2 nd region R2.

The tip 16a of the sheathing member 16 is located in the 2 nd region R2 of the through-hole 12 t. The protective member 16 covers the portion of the optical fiber 14 not retained by the ferrule 12.

The holder 20 holds the rear end 12b side of the sleeve 12 by, for example, press fitting. The sleeve 12 is press-fitted and fixed to the holder 20. The receiving portion 22 holds the holder 20 by, for example, press-fitting. The holder 20 is press-fitted and fixed to the housing portion 22. The holding of the holder 20 to the sleeve 12 and the holding of the holder 20 by the housing portion 22 are not limited to press fitting, and may be bonding or the like. However, by press-fixing the members as described above, the holding force can be improved as compared with the case of adhesion fixation or the like. Each member can be appropriately held by a simple structure. The minimum axial length of the retainer 20 for press-fitting the fixing sleeve 12 is, for example, about 0.3mm to 0.5 mm. However, the outer diameter of the sleeve 12 and the inner diameter of the holder 20 may be adjusted to increase the fastening force, thereby further shortening the length.

The rear end 20b of the retainer 20 is located more rearward than the rear end 12b of the sleeve 12. The holder 20 surrounds a portion of the optical fiber 14 and a portion of the protective member 16 around the shaft. The optical fiber 14 and the protective member 16 further extend to the outside of the holder 20. That is, the optical fiber 14 and the protective member 16 are drawn out rearward from the rear end 20b of the holder 20 in a state inserted through the cylindrical ferrule 12 and the holder 20.

The optical fiber connector 10 also has an elastic member 24 (1 st elastic member). The elastic member 24 is filled in the through hole 12t of the sleeve 12 and in the holder 20. The elastic member 24 adhesively fixes the optical fiber 14 and the protective member 16 to the ferrule 12 and the holder 20. The elastic member 24 is made of a resin material such as epoxy resin. The elastic member 24 is, for example, a cured adhesive.

The elastic member 24 may be inserted into at least a part of the through hole 12t and at least a part of the holder 20. The through hole 12t and the inside of the holder 20 may not necessarily be entirely filled with the elastic member 24. "filling" also includes, for example, a case where a part has a void or the like.

The inner peripheral surface 20n of the holder 20 has a 1 st inner peripheral portion IS1 and a 2 nd inner peripheral portion IS 2. The 1 st inner peripheral portion IS1 IS fitted in the outer side surface 12g of the sleeve 12. The 2 nd inner peripheral portion IS2 IS located rearward of the 1 st inner peripheral portion IS1, protrudes inward from the 1 st inner peripheral portion IS1, and surrounds a portion of the optical fiber 14 and a portion of the protective member 16 around the shaft.

The inner diameter of the 1 st inner peripheral portion IS1 portion of the holder 20 IS substantially the same as the outer diameter of the sleeve 12. On the other hand, the inner diameter of the 2 nd inner peripheral portion IS2 portion of the holder 20 IS smaller than the outer diameter of the sleeve 12. Thus, the 2 nd inner peripheral portion IS2 IS located more rearward than the rear end 12b of the grommet 12.

The inner diameter of the 2 nd inner peripheral portion IS2 IS set to a value larger than the outer diameter of the protective member 16 and smaller than the outer diameter of the sleeve 12, for example. The inner diameter of the 2 nd inner peripheral portion IS2 portion IS smaller than, for example, the opening diameter on the rear end 12b side of the through hole 12t enlarged in the 2 nd region R2.

A gap SP IS provided in the axial direction between the rear end 12b of the sleeve 12 and the 2 nd inner peripheral portion IS 2. The elastic member 24 is also filled in the gap SP. The axial distance of the gap SP is, for example, larger than the outer diameter of the optical fiber 14. The axial distance of the gap SP is, for example, about 0.125mm to 0.2 mm. In other words, the axial distance of the gap SP IS the axial distance between the rear end 12b of the sleeve 12 and the 2 nd inner peripheral portion IS 2. In other words, the outer diameter of the optical fiber 14 is the length of the optical fiber 14 in the direction perpendicular to the axial direction.

The holder 20 has a 1 st rear end surface BS1 and a 2 nd rear end surface BS 2. The 2 nd rear end surface BS2 is recessed further toward the tip end side than the 1 st rear end surface BS1, at a position on the outer peripheral side than the 1 st rear end surface BS 1. In this example, the rear end 20b of the holder 20 is the 1 st rear end face BS 1. The 1 st rear end surface BS1 is, for example, in a ring shape surrounding the rear end 20b side opening end of the cylindrical holder 20. The 2 nd rear end surface BS2 is, for example, in a ring shape surrounding the 1 st rear end surface BS1 when the holder 20 is viewed in the axial direction. The 1 st rear end surface BS1 and the 2 nd rear end surface BS2 are, for example, planes orthogonal to the axial direction. As described above, the holder 20 protrudes inward in the vicinity of the rear end of the inner circumferential surface 20 n. This makes it possible to make the areas of the 1 st rear end face BS1 and the 2 nd rear end face BS2 relatively large.

The holder 20 has a chamfered portion 20c between the 1 st rear end surface BS1 (rear end surface) and the 2 nd inner circumferential portion IS2 (inner circumferential surface 20 n). In other words, the opening of the holder 20 on the rear end 20b side has a larger diameter toward the rear end 20b side. The chamfered portion 20C may be a so-called C-shaped surface obtained by linearly grinding a corner portion between the 1 st rear end surface BS1 and the 2 nd inner peripheral portion IS2, or may be a so-called R-shaped surface obtained by chamfering a corner portion between the 1 st rear end surface BS1 and the 2 nd inner peripheral portion IS 2.

The elastic member 24 has a protruding portion 24p that protrudes to the outside of the holder 20 in the rear end 20b side of the holder 20, covering an angular portion between the rear end 20b of the holder 20 and the outside surface of the protective member 16. The outer surface of the projection 24p is, for example, concave toward the corner portion side, and has a concave curved surface shape that smoothly connects the rear end 20b of the holder 20 and the outer surface of the protective member 16.

The outer surface 12g of the sleeve 12 has a 1 st contact portion CP1 that contacts the inner peripheral surface 20n of the holder 20. The outer surface 20g of the holder 20 has a 2 nd contact portion CP2 that contacts the inner peripheral surface of the housing portion 22. The axial intermediate point m2 of the 2 nd contact portion CP2 is located rearward of the axial intermediate point m1 of the 1 st contact portion CP 1.

As described above, in the optical fiber connector 10 according to the present embodiment, since at least a part of the ferrule 18 and the ferrule 12 are housed in the housing portion 22, the lengths of the ferrule 12 and the housing portion 22 can be shortened as compared with a structure in which the rear end 12b of the ferrule 12 protrudes rearward of the housing portion 22. The holder 20 holds a portion of the outer surface 12g of the sleeve 12 rearward of the 1 st region R1. Thus, for example, even when the diameter of the ferrule 12 shrinks as the holder 20 is pushed into the housing 22 and the ferrule 12 is pushed into the holder 20, the concentration of external force at the boundary between the 1 st region R1 where the optical fiber 14 is held and the 2 nd region R2 where the optical fiber 14 is not held can be suppressed. Thus, the optical fiber connector 10 can be miniaturized without lowering the reliability.

In the optical fiber connector 10, the distal end 16a of the protective member 16 is located in the 2 nd region R2 of the through hole 12 t. This can shorten the length of the portion of the optical fiber 14 protruding from the protective member 16 as much as possible. For example, the optical fiber 14 can be easily inserted into the insertion hole 12t of the ferrule 12 while suppressing the occurrence of bending of the optical fiber 14. For example, the manufacturability of the optical fiber connector 10 can be improved.

In the optical fiber connector 10, the holder 20 is press-fitted to hold the rear end 12b side of the ferrule 12. This improves the holding force, and the sleeve 12 can be appropriately held by a simple structure.

In the optical fiber connector 10, the optical fiber 14 and the protective member 16 further extend outward of the holder 20, and are adhesively fixed to the holder 20 by the elastic member 24. This can prevent the portion of the optical fiber 14 protruding from the protective member 16 from being deformed or inclined by an external force. Further, the protrusion of the distal end 14a of the optical fiber 14 from the distal end 12a of the ferrule 12 or the retraction of the distal end can be suppressed from occurring with the application of an external force.

In the optical fiber connector 10, the elastic member 24 IS also filled in the gap SP between the rear end 12b of the ferrule 12 and the 2 nd inner peripheral portion IS 2. This can further suppress deformation and displacement of the tip portion of the optical fiber 14 due to external force.

In the optical fiber connector 10, the holder 20 has a 1 st rear end face BS1 and a 2 nd rear end face BS 2. Thus, for example, by using the 1 st rear end surface BS1 as a receiving surface for the adhesive of the elastic member 24, the adhesive can be prevented from flowing into the 2 nd rear end surface BS 2. When the holder 20 is press-fitted into the housing portion 22, the 2 nd rear end face BS2 is used as a positioning surface, and the 2 nd rear end face BS2 is pressed and press-fitted into the housing portion 22, whereby the holder 20 and the housing portion 22 can be prevented from being misaligned.

For example, when the adhesive is applied to one plane and the holder 20 is positioned, the adhesive may flow into the positioning surface, and only the holder 20 corresponding to the cured adhesive may be deeply pressed into the receiving portion 22. By providing the 1 st rear end face BS1 and the 2 nd rear end face BS2, such misalignment can be suppressed, and the positional accuracy of the holder 20 and the accommodating portion 22 can be improved.

Further, by providing the gap SP, the distance between the 2 nd rear end surface BS2, which is the positioning surface, and the distal end 12a of the ferrule 12, which is the PC surface, can be determined more accurately. For example, when the rear end 12b of the sleeve 12 IS in contact with the 2 nd inner circumferential portion IS2 without the gap SP, the length from the 2 nd rear end face BS2 to the tip end 12a of the sleeve 12 changes due to the effects (errors, unevenness, etc.) of the overall length of the sleeve 12 and the thickness of the holder 20. On the other hand, by providing the gap SP as in the optical fiber connector 10, the length from the 2 nd rear end face BS2 to the distal end 12a of the ferrule 12 can be determined more accurately without depending on the effects of the components. In addition, reliability and productivity of the optical fiber connector 10 can be improved.

If the gap SP IS not provided, the rear end 12b of the sleeve 12 and the 2 nd inner circumferential portion IS2 may have a right angle effect, whereby the sleeve 12 may be fixed obliquely, the sleeve 12 may be missing, and the holder 20 may be deformed. In the optical fiber connector 10, by providing the gap SP, the sleeve 12 can be prevented from being pressed obliquely, and the component can be prevented from being damaged or deformed, regardless of the effect of the component.

The error in the overall length dimension of the sleeve 12 is, for example, about ± 0.05mm (amplitude 0.1 mm). The error in the thickness dimension of the holder 20 is, for example, about ± 0.05mm (width 0.1 mm). In this case, the axial distance of the gap SP is preferably about 0.2 mm. Thus, the axial distance of the gap SP is greater than the outer diameter of the optical fiber 14. The axial distance of the gap SP is set to be about 0.125mm to 0.2 mm. This can further improve the reliability and productivity of the optical fiber connector 10.

Further, by further increasing the length of the 1 st rear end surface BS1 portion as compared with the length (length necessary for press-fitting) necessary for holding the holder 20 in the receiving portion 22, the protective member 16 can be adhesively fixed to a longer length. This can further suppress deformation and displacement of the tip portion of the optical fiber 14.

In the optical fiber connector 10, the chamfered portion 20c is provided between the rear end surface and the inner peripheral surface of the holder 20, so that the optical fiber 14 can be easily inserted into the holder 20, and the manufacturability can be improved. When the adhesive is applied to the 1 st rear end face BS1, the chamfered portion 20c can be used as an adhesive reservoir, and the adhesive can be further prevented from flowing into the 2 nd rear end face BS2 (positioning surface).

In addition, in the optical fiber connector 10, the elastic member 24 has a protruding portion 24 p. Thus, when a load is applied by an external force, the optical fiber 14 can be suppressed from being partially bent at the corner portion between the rear end 20b of the holder 20 and the outer surface of the protective member 16. For example, the bending base point of the optical fiber 14 can be located away from the boundary between the 1 st region R1 and the 2 nd region R2.

In the optical fiber connector 10, the housing portion 22 holds the holder 20 by press-fitting. This improves the holding force, and the holder 20 can be appropriately held by a simple structure.

In the optical fiber connector 10, the intermediate point m2 of the 2 nd contact portion CP2 of the holder 20 is located rearward of the intermediate point m1 of the 1 st contact portion CP1 of the ferrule 12. Accordingly, even when the holder 20 is press-fitted into the housing portion 22, for example, the 2 nd contact portion CP2 can disperse the tightening force due to the press-fitting over a wide area, and the concentration of the external force on the optical fiber 14 can be further suppressed at the boundary portion between the 1 st region R1 and the 2 nd region R2.

As shown in fig. 2a, in this example, the change in the diameter (the width in the orthogonal direction) of the through hole 12t in the 2 nd region R2 is linear. In a cross section parallel to the central axis of the through hole 12t (cross section shown in fig. 2), the inner peripheral surface of the 2 nd region R2 of the through hole 12t is linear. Thus, the change in diameter in the 2 nd region R2 is, for example, linear. The spread angle θ of the diameter of the through hole 12t in the 2 nd region R2 is, for example, 60 ° or more and 90 ° or less. For example, when the divergent angle θ is 60 ° and the diameter of the through hole 12t in the 1 st region R1 is 0.8mm, the axial length of the 2 nd region R2 is about 0.6 mm.

At this time, when the inner diameter of the ferrule 12 shrinks due to press-fitting or the like, although stress is applied to the portion of the 1 st region R1 in the optical fiber 14 inserted into the through hole 12t, stress due to shrinkage is not substantially applied to the portion of the 2 nd region R2. Therefore, in the boundary portion between the 1 st region R1 and the 2 nd region R2, the stress difference applied to the optical fiber 14 becomes large.

Accordingly, when the sleeve 12 shown in fig. 2(a) is used, the holder 20 holds the portion of the outer side surface 12g of the sleeve 12 that is rearward of the 1 st region R1, as described above. This suppresses the diameter shrinkage in the 1 st region R1, and can reduce the stress difference generated at the boundary between the 1 st region R1 and the 2 nd region R2. In the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be suppressed.

As shown in fig. 2(b), in this example, the diameter of the through hole 12t in the 2 nd region R2 changes in a convex curve shape that is convex toward the central axis side of the through hole 12 t. In a cross section parallel to the central axis of the through hole 12t, the inner peripheral surface of the 2 nd region R2 of the through hole 12t is convex curved. The inner peripheral surface of the 2 nd region R2 of the through hole 12t smoothly connects the inner peripheral surface of the 1 st region R1 of the through hole 12t and the rear end surface of the sleeve 12, for example. Thus, the change in diameter in the 2 nd region R2 is, for example, convex curved.

At this time, the stress applied to the optical fiber 14 accompanying the contraction of the inner diameter of the ferrule 12 gently changes in accordance with the curved surface of the inner peripheral surface of the 2 nd region R2. That is, the stress applied to the optical fiber 14 is suppressed from changing abruptly at the boundary portion between the 1 st region R1 and the 2 nd region R2, and the stress difference at the boundary portion between the 1 st region R1 and the 2 nd region R2 can be alleviated. Accordingly, in the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be further suppressed.

As shown in fig. 2(c), in this example, the through hole 12t of the sleeve 12 further includes a 3 rd region R3 disposed rearward of the 2 nd region R2. The 3 rd region R3 is continuous with the 2 nd region R2. In addition, in this example, the 3 rd region R3 is continuous with the rear end 12b of the sleeve 12.

Similarly to the example of fig. 2(b), the diameter change of the through hole 12t in the 2 nd region R2 is a convex curve shape protruding toward the central axis side of the through hole 12 t. On the other hand, the diameter of the through hole 12t in the 3 rd region R3 changes linearly. In the 3 rd region R3, the diameter of the through hole 12t continuously increases linearly toward the rear end 12b side. In other words, in this example, the shape of the 2 nd region R2 is a shape in which the intersection portion of the straight 1 st region R1 and the 3 rd region R3 is chamfered.

In this way, the through hole 12t may be provided with a 3 rd region R3 having a diameter linearly changing behind the 2 nd region R2 having a diameter changing in a convex curve. Even at this time, similarly to the example of fig. 2(b), the stress applied to the optical fiber 14 is suppressed from changing abruptly at the boundary portion between the 1 st region R1 and the 2 nd region R2, and the stress difference at the boundary portion between the 1 st region R1 and the 2 nd region R2 can be alleviated. In the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be further suppressed. The region in which the diameter changes in a convex curve shape may be provided at least directly behind the 1 st region R1.

In addition, when the 3 rd region R3 is provided, the tip 16a of the protective member 16 may also be located within the 3 rd region R3 of the through hole 12 t. Even at this time, as in the case where the distal end 16a is located in the 2 nd region R2, the length of the portion protruding from the protective member 16 of the optical fiber 14 can be shortened as much as possible. The optical fiber 14 can be easily inserted into the through hole 12t of the ferrule 12 while suppressing the occurrence of bending of the optical fiber 14. The manufacturability of the optical fiber splice 10 can be improved.

When the sleeve 12 is made of ceramic, the shape of the through hole 12t in each of the examples shown in fig. 2(a) to 2(c) can be formed by inserting a pin-like mold corresponding to the shape of the through hole 12t into the bulk ceramic before firing.

As shown in fig. 3, in the optical fiber connector 10a, the holder 20 holds a portion of the outer surface 12g of the ferrule 12 located rearward of the 1 st region R1, and also holds a portion facing the 1 st region R1. Parts having substantially the same functions and configurations as those of the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

For example, as shown in fig. 2(b) and 2(c), when the diameter change of the through hole 12t in the 2 nd region R2 is a convex curve, the stress difference in the boundary portion between the 1 st region R1 and the 2 nd region R2 can be appropriately alleviated by only the shape of the through hole 12 t. Thus, at this time, the holder 20 can also hold the portion opposite to the 1 st region R1. Even in the optical fiber connector 10a, miniaturization can be achieved without lowering reliability.

However, the sleeve 12 in which the diameter of the through hole 12t changes in a convex curve shape is used, and only a portion rearward of the 1 st region R1 of the sleeve 12 is held by the holder 20. This can more appropriately reduce the stress difference at the boundary between the 1 st region R1 and the 2 nd region R2. In the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be further suppressed.

As shown in fig. 4, in the optical fiber connector 10b, the rear end 22b of the accommodating portion 22 is located more rearward than the rear end 20b of the holder 20 and the protruding portion 24p of the elastic member 24. That is, in the optical fiber connector 10b, the receiving portion 22 further covers the holder 20 around the shaft, and further covers the protruding portion 24p of the elastic member 24 around the shaft.

In the optical fiber connector 10b, for example, the projecting portion 24p of the elastic member 24 can be protected by the receiving portion 22. It is possible to suppress application of an external force to the protruding portion 24 p. Concentration of external force at the boundary portion between the 1 st region R1 and the 2 nd region R2 of the optical fiber 14 can be further suppressed. The optical fiber 14 can be protected more appropriately from external force or the like.

Embodiment 2

As shown in fig. 5, in the optical fiber splice 100, the outer surface 120g of the holder 120 includes the 1 st outer peripheral portion OS1 and the 2 nd outer peripheral portion OS 2.

The 1 st outer peripheral portion OS1 is held in the storage portion 22. The outer diameter of the 1 st outer peripheral portion OS1 of the holder 120 is substantially the same as the inner diameter of the receiving portion 22. For example, the holder 120 is held in the housing 22 by pressing the 1 st outer peripheral portion OS1 into the housing 22.

The 2 nd outer peripheral portion OS2 is provided at the tip end portion of the holder 120. The 2 nd outer peripheral portion OS2 is provided in front of the 1 st outer peripheral portion OS1, for example, and is continuous with the 1 st outer peripheral portion OS1 and also continuous with the tip 120a of the holder 120. The 2 nd outer peripheral portion OS2 is recessed inward from the 1 st outer peripheral portion OS 1. The outer diameter of the 2 nd outer peripheral portion OS2 of the holder 120 is smaller than the outer diameter of the 1 st outer peripheral portion OS 1. The 1 st outer peripheral portion OS1 is located further rearward than the 1 st region R1. The receiving portion 22 is fitted into the outer surface 120g of the holder 120 at a position rearward of the 1 st region R1.

In this way, in the optical fiber connector 100, the portion holding the holder 120 in the housing portion 22 can be shifted rearward by reducing the outer diameter of the distal end portion of the holder 120. This can further suppress concentration of external force on the optical fiber 14 at the boundary between the 1 st region R1 and the 2 nd region R2.

In the optical fiber connector 100, the holder 120 holds only a portion behind the 1 st region R1 of the ferrule 12. This can further suppress concentration of external force on the optical fiber 14 at the boundary between the 1 st region R1 and the 2 nd region R2.

In the optical fiber connector 100, the holder 120 holds the ferrule 12 only by the 2 nd outer peripheral portion OS 2. That is, the periphery of the sleeve 12 is not pressed into the housing portion 22. This can suppress, for example, the transmission of the tightening force accompanying the pressing of the holder 120 into the housing 22 to the boundary portion between the 1 st region R1 and the 2 nd region R2 of the optical fiber 14 via the holder 120. Accordingly, in the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be further suppressed.

As shown in fig. 6, in the optical fiber connector 100a, the holder 120 holds a portion of the outer surface 12g of the ferrule 12 located rearward of the 1 st region R1 and also holds a portion facing the 1 st region R1. In the optical fiber splice 100a, the 1 st outer peripheral portion OS1 of the holder 120 is located further rearward than the 1 st region R1.

In this way, when the 1 st outer peripheral portion OS1 and the 2 nd outer peripheral portion OS2 are provided in the holder 120, at least the 1 st outer peripheral portion OS1 may be located more rearward than the 1 st region R1, and the holder 120 may hold a portion facing the 1 st region R1 of the sleeve 12.

That is, at least the periphery of the boundary between the 1 st region R1 and the 2 nd region R2 need not be pressed into the housing portion 22. Even at this time, the fastening force accompanying the pressing of the holder 120 into the housing portion 22 can be suppressed from being transmitted to the boundary portion between the 1 st region R1 and the 2 nd region R2 of the optical fiber 14 via the holder 120.

However, as shown in fig. 5, the holder 120 is provided with the 1 st outer peripheral portion OS1 and the 2 nd outer peripheral portion OS2, and only a portion behind the 1 st region R1 of the sleeve 12 is held by the holder 120. This can further suppress the transmission of the tightening force associated with the press-fitting to the optical fiber 14. In the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be more appropriately suppressed.

As shown in fig. 7, in the optical fiber connector 100b, the inner surface 122n of the housing portion 122 includes a 1 st inner circumferential portion 122a and a 2 nd inner circumferential portion 122 b. The 1 st inner circumferential portion 122a is fitted into the outer circumferential surface 20g of the holder 20. The inner diameter of 1 st inner circumferential portion 122a is substantially the same as the outer diameter of holder 20. The receiving portion 122 is attached to the holder 20 by, for example, pressing the 1 st inner circumferential portion 122a into the holder 20. The 1 st inner circumferential portion 122a is formed in an annular shape over the entire circumference of the inner surface 122n of the housing portion 122, for example. For example, the 1 st inner circumferential portions 122a may be arranged in a dispersed manner along the inner circumference of the housing portion 122.

The 2 nd inner peripheral portion 122b is provided further toward the tip end side than the 1 st inner peripheral portion 122 a. Second inner circumferential portion 122b is expanded outward beyond first inner circumferential portion 122 a. Inner diameter of 2 nd inner circumferential portion 122b is larger than that of 1 st inner circumferential portion 122 a.

The 1 st inner peripheral portion 122a is located more rearward than the 1 st region R1. Accordingly, the receiving portion 122 is fitted into the outer surface 20g of the holder 20 at a position rearward of the 1 st region R1.

In this way, in the optical fiber connector 100b, the inner diameter of the 2 nd inner circumferential portion 122b of the accommodating portion 122 is increased, so that the 1 st inner circumferential portion 122a of the accommodating portion 122 can hold the holder 20 in a rearward offset manner. Accordingly, similarly to the optical fiber splice 100 and the like described with reference to fig. 5, in the boundary portion between the 1 st region R1 and the 2 nd region R2, concentration of external force on the optical fiber 14 can be suppressed.

In fig. 7, the holder 20 holds the 1 st region R1 and the 2 nd region R2. Even when the receiving portion 122 is used, the holder 20 may hold only a portion rearward of the 1 st region R1 of the sleeve 12. This can further suppress the transmission of the tightening force associated with the press-fitting to the optical fiber 14.

As shown in fig. 8(a), in the housing portion 122 of the optical fiber connector 100c, the 2 nd inner circumferential portion 122b is connected to the 1 st inner circumferential portion 122a via an inclined surface 122 c. As shown in fig. 8(b), in the housing portion 122 of the optical fiber connector 100d, the 2 nd inner circumferential portion 122b is connected to the 1 st inner circumferential portion 122a via a curved surface 122 d. The curved surface 122d is, for example, a concave curved surface smoothly continuing to the 2 nd inner peripheral portion 122 b.

In this way, the 1 st inner circumferential portion 122a and the 2 nd inner circumferential portion 122b are preferably smoothly connected by the inclined surface 122c or the curved surface 122 d. Thus, even when the 1 st inner circumferential portion 122a and the 2 nd inner circumferential portion 122b are provided on the inner surface 122n of the accommodating portion 122, the accommodating portion 122 can be easily formed. For example, the manufacturability of the housing portion 122 is improved, and the manufacturing cost of the optical fiber splices 100c, 100d can be suppressed.

Embodiment 3

Fig. 9 is a cross-sectional view showing the pigtail-type optical fiber connector according to embodiment 3.

As shown in fig. 9, in the optical fiber connector 200, the receiving portion 222 is attached to the tip side of the holder 220.

The holder 220 has a mounting portion 220a for mounting the receiving portion 222. The mounting portion 220a is provided at the tip end portion of the holder 220. The receiving portion 222 has a mounted portion 222a mounted to the mounting portion 220a of the receiving portion 222. The attached portion 222a is provided at the rear end of the receiving portion 222. The mounting portion 220a and the mounted portion 222a are cylindrical. The attached portion 222a is fitted to the outside of the attaching portion 220 a. Thus, the receiving portion 222 is attached to the tip side of the holder 220.

The holder 220 has a flange portion 220 f. The flange portion 220f is provided further toward the tip side than the 2 nd region R2. The tip of the flange portion 220f is positioned further forward than the tip of the 2 nd region R2. The flange portion 220f projects outward from the receiving portion 222 attached to the attachment portion 220 a. The flange portion 220f is used for positioning the optical fiber connector 200, for example.

The mounting portion 220a is provided further toward the tip end side than the flange portion 220 f. Thus, the housing portion 222 is attached to the holder 220 at a position closer to the tip end side than the flange portion 220 f.

The optical fiber connector 200 has a flange portion 220f protruding outward from the housing portion 222, and the housing portion 222 is attached to the holder 220 at a position closer to the distal end side than the flange portion 220 f. This can reduce the lengths of the ferrule 12, the holder 220, and the accommodating portion 222, compared with a case where the accommodating portion 222 is attached to the holder 220 at a position closer to the rear end side than the flange portion 220f, while suppressing concentration of external force due to the attachment of the accommodating portion 222 to the optical fiber 14 in a boundary portion between the 1 st region R1 where the optical fiber 14 is held and the 2 nd region R2 where the optical fiber 14 is not held, for example. Thus, the pigtail type optical fiber connector 200 can be miniaturized without lowering the reliability.

In fig. 9, the holder 220 holds the 1 st region R1 and the 2 nd region R2. Even in the structure of the mounting receiver 222, the holder 220 may hold only a portion more rearward than the 1 st region R1 of the sleeve 12. This can further suppress the transmission of the tightening force associated with the press-fitting to the optical fiber 14.

Fig. 10(a) and 10(b) are cross-sectional views showing modifications of the pigtail type optical fiber connector according to embodiment 3.

As shown in fig. 10(a), in the optical fiber connector 200a, the receiving portion 222 is attached to the distal end side of the holder 220 by fitting the attached portion 222a into the attaching portion 220 a. Thus, the attached portion 222a may be fitted to the outside or the inside of the attaching portion 220 a. The structures of the attaching portion 220a and the attached portion 222a are not limited to the above, and any structure capable of attaching the receiving portion 222 to the tip end side of the holder 220 may be used.

As shown in fig. 10(b), in the optical fiber connector 200b, the mounting portion 220a extends further toward the distal end side than the mounting portion 220a of the optical fiber connector 200 shown in fig. 9. Thus, the position of the mounting portion 220a (mounting position of the receiving portion 222) may be any position on the tip side of the flange portion 220 f.

Embodiment 4

As shown in fig. 11, the optical fiber connector 300 includes an elastic member 302 (No. 2 elastic member).

In the optical fiber connector 300, the configuration other than the elastic member 302 is the same as that of the optical fiber connector 10 according to embodiment 1, and therefore, detailed description thereof is omitted. The configuration of the optical fiber connector 300 other than the elastic member 302 may be the same as that of any of the

optical fiber connectors

10a, 10b, 100a to 100d, 200a, and 200b described in the above embodiments, and is not limited to the configuration of the optical fiber connector 10.

Fig. 12 is a partial cross-sectional view showing an enlarged portion of the pigtail optical fiber connector according to embodiment 4.

As shown in fig. 11 and 12, the elastic member 302 covers a corner portion between the rear end 20b of the holder 20 and the outer side surface of the protective member 16. When the elastic member 24 has the protruding portion 24p, the elastic member 302 covers the protruding portion 24 p. The elastic member 302 covers, for example, the entire outer surface of the projection 24 p. In other words, the elastic member 302 covers the boundary portion of the elastic member 24 and the protective member 16.

The elastic member 302 has a lower hardness than the elastic member 24. In other words, the elastic member 302 has a smaller elastic modulus than the elastic member 24. The elastic member 24 has a higher hardness than the protection member 16. The hardness of the elastic member 302 is, for example, the same level as the hardness of the protective member 16. The hardness of the elastic member 302 is, for example, 0.8 to 1.2 times the hardness of the protective member 16. The hardness of the protective member 16 is, for example, approximately shore D20 to 30. At this time, the hardness of the elastic member 302 is similarly about shore D20 to 30.

As described above, the protective member 16 is made of a resin material such as a polyester elastomer or an acrylate resin. As described above, the elastic member 24 is made of a resin material such as epoxy resin. As the elastic member 302, a resin material such as polyester resin, acryl resin, or silicone resin is used. The elastic member 24 and the elastic member 302 are made of, for example, a resin adhesive. At this time, the hardness of the elastic member 24 and the hardness of the elastic member 302 are the hardness after the adhesive is cured (after the adhesive is completely cured).

The width W2 of the elastic member 302 on the 1 st rear end face BS1 (rear end face) of the holder 20 is wider than the width W1 of the elastic member 24 on the 1 st rear end face BS1 of the holder 20. More specifically, the widths W1 and W2 are widths (lengths) in a direction perpendicular to the axial direction. The width W2 of the elastic member 302 in the direction orthogonal to the axial direction is narrower than the width Wbs of the 1 st rear end face BS1 in the direction orthogonal to the axial direction. The width W1 of the elastic member 24 is equal to or less than the width (outer diameter) of the chamfered portion 20c of the holder 20 in the direction perpendicular to the axial direction. That is, the elastic member 24 does not spread outward beyond the chamfered portion 20 c.

The axial length L2 of the elastic member 302 is larger than the axial length L1 of the protrusion 24p of the elastic member 24. The axial length L2 of the elastic member 302 is, for example, 2 to 4 times the axial length L1 of the protruding portion 24p of the elastic member 24.

The average inclination angle θ 2 formed by the outer surface of the elastic member 302 and the 1 st rear end face BS1 of the holder 20 is equal to or greater than the average inclination angle θ 1 formed by the outer surface of the protrusion 24p and the 1 st rear end face BS1 of the holder 20.

Here, more specifically, the average inclination angle θ 1 of the outer surface of the protruding portion 24p is a minor angle of angles formed by the imaginary line VL1 and the direction orthogonal to the axial direction. The imaginary line VL1 is, for example, an imaginary line connecting the front end portion 24a of the outer surface of the projection 24p in a cross section parallel to the axial direction and the rear end portion 24b of the outer surface of the projection 24p in the cross section. Also, the average inclination angle θ 2 of the outer surface of the elastic member 302 is, for example, a minor angle among angles formed by the imaginary line VL2 and the direction orthogonal to the axial direction. The imaginary line VL2 is, for example, an imaginary line connecting the front end portion 302a of the outer surface of the elastic member 302 in a cross section parallel to the axial direction and the rear end portion 302b of the outer surface of the elastic member 302 in the cross section.

In fig. 12, for convenience, the outer surface of the elastic member 302 and the outer surface of the protruding portion 24p are illustrated as linear inclined surfaces. The outer surface of the elastic member 302 and the outer surface of the protruding portion 24p are not limited to this, and may be, for example, convex curved surface, concave curved surface, or the like. The shape of the outer surface of the elastic member 302 and the shape of the outer surface of the protruding portion 24p may be any shape.

At the root end portion of the optical fiber 14 protruding from the holder 20 (the rear end portion of the holder 20), stress is likely to be applied to the optical fiber 14 during bending of the optical fiber 14 during handling, and the optical fiber 14 is likely to be broken. Then, in order to relieve stress on the optical fiber 14, the optical fiber 14 is covered with the protective member 16. Furthermore, a protector such as a hose (see, for example, japanese patent application laid-open No. 2013-200352) or a sheath (see, for example, japanese patent application laid-open No. 2016-224346) is attached to the root end portion.

However, when a protector such as a hose or a sheath is attached, the holder 20 and the like have to be lengthened according to a portion covering the protector, and the axial length of the optical fiber connector is lengthened, which leads to an increase in size of the product. Therefore, when miniaturization is required, the optical fiber 14 is protected by being mounted inside a product with only the protective member 16.

The protection member 16 is adhesively fixed to the holder 20 by the elastic member 24. Generally, the protective member 16 has a lower hardness than the elastic member 24. Therefore, when the optical fiber 14 is bent during handling, a high stress is generated at the boundary between the protective member 16 and the elastic member 24, and in the worst case, the protective member 16 may be damaged, and the protective function for the optical fiber 14 may be degraded.

In contrast, in the optical fiber connector 300 according to the present embodiment, the elastic member 302 is provided, so that the bending base point can be separated from the elastic member 24 when the optical fiber 14 is bent during processing or the like. At this time, by making the hardness of the elastic member 302 lower than that of the elastic member 24, stress applied to the protective member 16 at the boundary with the elastic member 302 can be suppressed even when the optical fiber 14 is bent during handling or the like. This can suppress the occurrence of breakage or the like of the protective member 16 in the vicinity of the boundary with the elastic member 24 or the elastic member 302, and can further reduce the risk of breakage of the optical fiber 14. In addition, the size of the product can be further reduced as compared with the case where a protector such as a hose or a sheath is provided.

In the optical fiber connector 300, the width W2 of the elastic member 302 at the 1 st rear end face BS1 of the holder 20 is larger than the width W1 of the elastic member 24 at the 1 st rear end face BS1 of the holder 20. Accordingly, regardless of the width W1 of the holder 20 of the elastic member 24 on the rear end face, the thickness of the elastic member 302 can be appropriately ensured, and even when the optical fiber 14 is bent by external stress or the like, the elastic member 302 itself can be prevented from being damaged or the like.

In the optical fiber connector 300, the width W2 of the elastic member 302 in the direction orthogonal to the axial direction is narrower than the width Wbs of the 1 st rear end face BS1 in the direction orthogonal to the axial direction. This suppresses the flow of the elastic member 302 into the 2 nd rear end face BS2, and enables appropriate positioning during assembly.

In addition, in the optical fiber connector 300, the axial length L2 of the elastic member 302 is longer than the axial length L1 of the protrusion 24 p. Accordingly, the thickness of the elastic member 302 can be appropriately ensured regardless of the axial length of the protruding portion 24p, and the elastic member 302 itself can be prevented from being damaged even when the optical fiber 14 is bent by external stress or the like.

The length L2 of the elastic member 302 is, for example, 2 times or more the length L1 of the protrusion 24 p. This can more appropriately suppress the elastic member 302 from being damaged by itself. The length L2 of the elastic member 302 is, for example, 4 times or less the length L1 of the protrusion 24 p. This can appropriately suppress an increase in size of the product.

In the optical fiber connector 300, the average inclination angle θ 2 formed by the outer surface of the elastic member 302 and the 1 st rear end face BS1 of the holder 20 is equal to or greater than the average inclination angle θ 1 formed by the outer surface of the protrusion 24p and the 1 st rear end face BS1 of the holder 20. Accordingly, regardless of the width of the elastic member 24 on the 1 st rear end face BS1 of the holder 20, the thickness of the elastic member 302 can be appropriately ensured, and even when the optical fiber 14 is bent by external stress or the like, the elastic member 302 itself can be prevented from being damaged or the like.

As shown in fig. 13(a), the average inclination angle θ 2 formed by the outer surface of the elastic member 302 and the 1 st rear end face BS1 may be smaller than the average inclination angle θ 1 formed by the outer surface of the protrusion 24p and the 1 st rear end face BS 1.

However, at this time, the thickness of the elastic member 302 is locally thinned. For example, the thickness of the elastic member 302 is reduced at a rear end side portion covering a boundary portion between the elastic member 24 and the protective member 16. Therefore, when the optical fiber 14 is bent by external stress, for example, the elastic member 302 itself is likely to be damaged. Therefore, the inclination angle θ 2 is preferably equal to or larger than the inclination angle θ 1. As a result, as described above, the thickness of the elastic member 302 can be appropriately ensured, and the elastic member 302 itself can be prevented from being damaged or the like.

As shown in fig. 13(b), the width W1 of the elastic member 24 may also be larger than the width of the chamfered portion 20c of the holder 20 in the direction orthogonal to the axial direction. The elastic member 24 may also be expanded further outward than the chamfered portion 20 c.

However, in this case, for example, the difference between the width W1 of the elastic member 24 and the width W2 of the elastic member 302 is small, and it is difficult to form the elastic member 302. In addition, the thickness of the elastic member 302 in the vicinity of the 1 st rear end face BS1 becomes thin, and the risk of breakage of the elastic member 302 itself increases. Accordingly, the width W1 of the elastic member 24 is preferably equal to or less than the width of the chamfered portion 20c of the holder 20 in the direction orthogonal to the axial direction. This can facilitate formation of the elastic member 302, for example. The thickness of the elastic member 302 can be appropriately secured, and occurrence of breakage or the like of the elastic member 302 itself can be suppressed.

As shown in fig. 13(c), the elastic member 24 may not have the projection 24 p. Even in this case, by providing the elastic member 302, it is possible to further reduce the risk of breaking the optical fiber 14 by suppressing the breakage or the like of the protective member 16 in the vicinity of the boundary with the elastic member 24 or the elastic member 302 while suppressing the increase in size of the product.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above description. The present invention is not limited to the above-described embodiments, and those skilled in the art can appropriately design and modify the present invention. For example, the shapes, dimensions, materials, arrangements, and the like of the elements included in the optical fiber splices 10, 10a, 10b, 100a, 200a, 200b, 300, and the like are not limited to those illustrated, and may be appropriately modified.

Further, the elements included in the above-described embodiments may be combined as long as they are technically feasible, and the invention combining these elements is also included in the scope of the invention as long as the invention includes the features of the invention.

Claims

1. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

an optical fiber which is held by the ferrule in a state of being inserted into the through hole and which extends from a rear end side of the ferrule to an outer side of the ferrule;

a protective member covering a portion of the optical fiber extending to an outside of the ferrule;

a cylindrical sleeve fitted to an outer surface of the sleeve and attached to a tip end side of the sleeve;

a cylindrical holder fitted to an outer surface of the sleeve and holding a rear end side of the sleeve;

and a cylindrical housing part fitted to an outer surface of the holder and covering at least a part of the sleeve and the sleeve,

the through hole of the bushing has: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, the width in the orthogonal direction being enlarged toward a rear end side of the grommet,

the holder holds a portion of the outer side surface of the sleeve more rearward than the 1 st region,

the through-hole of the sleeve further has a 3 rd region disposed further rearward than the 2 nd region,

the width variation in the orthogonal direction of the through hole in the 3 rd region is linear,

the width variation in the orthogonal direction of the through hole in the 2 nd region is convex curve-shaped.

2. The pigtail-type fiber optic connector of claim 1, wherein a tip of the protective member is located in the 2 nd region of the through-hole.

3. The pigtail-type fiber optic connector of claim 1, wherein a top end of the protective member is located in the 3 rd region of the through-hole.

4. The pigtail-type optical fiber connector according to claim 1 or 2, wherein the holding member holds the rear end side of the ferrule by press-fitting.

5. The pigtail-type optical fiber connector according to claim 1 or 2,

the rear end of the holder is located more rearward than the rear end of the sleeve,

the holder encloses a portion of the optical fiber and a portion of the protective member,

the optical fiber and the protective member are further extended to the outside of the holder, and are adhesively fixed to the holder by an elastic member filled in the through hole and the holder.

6. The pigtail-type fiber optic splice of claim 5,

the inner peripheral surface of the holder has: a 1 st inner peripheral portion fitted in an outer side surface of the sleeve;

and a 2 nd inner peripheral portion located rearward of the 1 st inner peripheral portion and projecting more inward than the 1 st inner peripheral portion so as to surround a part of the optical fiber and a part of the protective member,

a gap is provided in the axial direction between the rear end of the sleeve and the 2 nd inner peripheral portion,

the elastic member is also filled in the gap.

7. The pigtail-type optical fiber connector according to claim 1 or 2, wherein the holding member has: 1 st rear end face; and a 2 nd rear end surface recessed further toward the tip end side than the 1 st rear end surface at a position further toward the outer peripheral side than the 1 st rear end surface.

8. The pigtail-type optical fiber connector according to claim 1 or 3,

the outer side surface of the holder has: a 1 st outer circumferential portion held by the housing portion;

and a 2 nd outer peripheral portion provided at a distal end portion of the holder and recessed inward from the 1 st outer peripheral portion.

9. The pigtail-type optical fiber connector according to claim 1 or 2, wherein the holder has a chamfered portion between the rear end face and the inner peripheral face.

10. The pigtail-type optical fiber connector according to claim 5, wherein the elastic member has a protruding portion that protrudes outward of the holder at a rear end side of the holder, covering an angle portion between the rear end of the holder and an outer side surface of the protection member.

11. The pigtail-type optical fiber connector according to claim 1 or 2, wherein the receiving portion holds the holder by press-fitting.

12. The pigtail-type optical fiber connector according to claim 1 or 2,

the outer side surface of the sleeve is provided with a 1 st abutting part abutting against the inner peripheral surface of the retainer,

the outer side surface of the holder has a 2 nd abutting part abutting against the inner peripheral surface of the receiving part,

an intermediate point in the axial direction of the 2 nd abutting portion is located more rearward than an intermediate point in the axial direction of the 1 st abutting portion.

13. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

the through-hole of the bushing has: a 1 st region having a width in an orthogonal direction orthogonal to the axial direction corresponding to a width in the orthogonal direction of the optical fiber; and a 2 nd region disposed rearward of the 1 st region, the width in the orthogonal direction being enlarged toward a rear end side of the grommet,

the width of the through hole in the 2 nd region in the orthogonal direction changes in a curved shape in which the rate of change increases toward the rear end side,

14. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

a cylindrical sleeve which is fitted into an outer surface of the sleeve and is attached to a tip side of the sleeve;

the receiving portion is fitted into an outer surface of the holder at a position rearward of the 1 st region,

15. The pigtail-type fiber optic splice of claim 14,

and a 2 nd outer peripheral portion provided at a distal end portion of the holder and recessed inward from the 1 st outer peripheral portion,

the 1 st outer peripheral portion is located further rearward than the 1 st region.

16. The pigtail-type fiber optic splice of claim 14,

the inner side surface of the accommodating part is provided with: a 1 st inner peripheral portion fitted in an outer side surface of the holder;

and a 2 nd inner peripheral portion provided on the tip side of the 1 st inner peripheral portion and extending outward of the 1 st inner peripheral portion,

the 1 st inner peripheral portion is located more rearward than the 1 st area.

17. The pigtail-type optical fiber connector according to claim 16, wherein the 2 nd inner circumferential portion is connected to the 1 st inner circumferential portion via an inclined surface or a curved surface.

18. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

and a cylindrical housing portion attached to the holder and covering at least a part of the sleeve and the sleeve,

the holder has a flange portion provided on the tip side of the 2 nd region and projecting outward of the housing portion,

the receiving portion is attached to the holder at a position closer to the distal end side than the flange portion,

19. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

a cylindrical housing portion that is fitted to an outer surface of the holder and covers at least a part of the sleeve and the sleeve;

the 1 st elastic component is filled in the through hole and the retainer;

and a 2 nd elastic member covering an angle portion between a rear end of the holding member and an outer side surface of the protective member,

the optical fiber and the protective member are further extended to the outside of the holder and are adhesively fixed to the holder by the 1 st elastic member,

the hardness of the 2 nd elastic member is lower than that of the 1 st elastic member,

20. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

the 1 st elastic component is filled in the through hole and the retainer;

21. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

the 1 st elastic component is filled in the through hole and the retainer;

22. A pigtail-type fiber optic splice having:

a cylindrical sleeve having a through hole extending in an axial direction;

a cylindrical housing portion attached to the holder and covering at least a part of the sleeve and the sleeve;

the 1 st elastic component is filled in the through hole and the retainer;

the holder has a flange portion provided on the tip side of the 2 nd region and protruding outward of the housing portion,

the rear end of the retainer is located more rearward than the rear end of the sleeve,

23. The pigtail-type optical fiber connector of any 1 of claims 19-22, wherein a width of the 2 nd elastic member on a rear end surface of the holder is wider than a width of the 1 st elastic member on the rear end surface of the holder.

24. The pigtail-type optical fiber connector according to any 1 of claims 19-22,

the holder has: 1 st rear end face; and a 2 nd rear end surface recessed further toward the tip end side than the 1 st rear end surface at a position closer to the outer peripheral side than the 1 st rear end surface,

a width of the 2 nd elastic member in a direction orthogonal to the axial direction is narrower than a width of the 1 st rear end surface in the direction orthogonal to the axial direction.

25. The pigtail-type optical fiber connector according to any 1 of claims 19-22,

the 1 st elastic member has a protruding portion that protrudes outward of the holder at a rear end side of the holder, covering an angle portion between the rear end of the holder and an outer side surface of the protective member,

the 2 nd elastic member covers the protruding portion.

26. The pigtail-type fiber optic connector of claim 25, wherein the axial length of the 2 nd resilient member is longer than the axial length of the protrusion.

27. The pigtail-type optical fiber connector of claim 25, wherein an average inclination angle formed by the outer surface of the 2 nd elastic member and the rear end surface of the holder is equal to or greater than an average inclination angle formed by the outer surface of the protrusion and the rear end surface of the holder.