WO2009014277A1

WO2009014277A1 - Field assembly type optical connector

Info

Publication number: WO2009014277A1
Application number: PCT/KR2007/004563
Authority: WO
Inventors: Hyung Cheol Kim; Sun Ae Shin; Chan Su Kim
Original assignee: Korea Optron Corp.
Priority date: 2007-07-20
Filing date: 2007-09-19
Publication date: 2009-01-29

Abstract

Provided is a field assembly optical connector comprising: a first unit which includes a housing, a frame provided within the housing, and a fixing member installed in the frame; a ferrule unit which has a portion inserted into the fixing member and into which a core of an optical fiber is inserted; an optical fiber fastening means which is installed in an end of the ferrule unit and pressurizes an outer face of the optical fiber having the core inserted into the ferrule unit to fasten the optical fiber; and a second unit which is coupled to the fixing member and fixes positions of the ferrule unit and the optical fiber fastening means. According to the field assembly optical connector, since an outer face of an optical fiber led in an optical connector is directly fixed by a collet unit including a plurality of groups, splicing of the optical fiber can be strengthened, and the optical fiber can be prevented from being affected by the horizontal external force. Furthermore, since an optical connector assembling work is simplified and accurate core alignment is accomplished, loss of light occurring during core splicing can be prevented.

Description

Description FIELD ASSEMBLY TYPE OPTICAL CONNECTOR

Technical Field

[1] The present invention relates to an optical connector, and more particularly, to a field assembly optical connector enabling optical fiber splicing without loss of light during spiking in a work field, such as a construction field. Background Art

[2] Generally, an optical connector is attached to opposite ends of an optical fiber that has been cut according to a predetermined parameter. In an optical connector, loss of light can be minimized during optical fiber splicing such that a worker aligns a core- inserted ferrule of the optical fiber in a factory, fixes an optical central axis, and then performs epoxy bonding and cross-sectional polishing. A patchcord in the form of a finished product, in which an optical connector is attached to opposite ends of an optical fiber, has generally been used for installing optical cables in a work field.

[3] A patchcord is factory-manufactured in the form of a finished product in which the length of an optical fiber is fixed according to given parameters. As a result, at the time of splicing optical cables, splicing a fiber distribution panel and an optical transmission system, or splicing optical transmission systems in the fiber distribution panel and an optical termination box provided for connection and disconnection between the optical transmission systems and the optical fiber cables, the patchcord manufactured with a specific length encounters a limitation in its length.

[4] Thus, an optical connector provided at opposite sides of the patchcord is modified in an assembly type so that optical fibers having various lengths can be conveniently assembled in a field.

[5] One of conventional optical connectors modified in an assembly type is disclosed in

Korea Patent Registration No. 10-0507543.

[6] The disclosed conventional optical connector includes a housing, a frame inserted into the housing, a ferrule which elastically slides within the frame, a core alignment unit which aligns a core of an optical fiber inserted into the ferrules, a fixing member which surrounds a portion of the ferrule and is fitted into the frame, an optical fiber connection member engaged with and coupled to the fixing member in a longitudinal direction, and a fastening member which fastens an outer face of the optical fiber connection member in the form of a clip to fix the optical fiber inserted through into the optical fiber connection member. [7] In the case of the conventional optical connector, the optical fiber is inserted into the optical fiber connection member in a pre-assembled state of the frame, the ferrule, the fixing member, the optical fiber connection member, and the fastening member. The core of the inserted optical fiber is inserted into the ferrule to splice to a previously inserted core of the ferrule. The outer face of the optical fiber connection member is pressurized by means of the fastening member to fix the inserted optical fiber. Thereafter, a protective boot is assembled such that the fastening member and the optical fiber connection member are embedded in the frame-embedded housing.

[8] However, in the conventional optical connector, the fastening member for pressurizing the outer face of the optical fiber connection member in the form of a clip is provided as a means for fixing the optical fiber led in the optical fiber connection member. For this reason, the optical fiber connection member has to be made of a flexible material in order to deliver the pressure of the fastening member to the optical fiber through the optical fiber connection member.

[9] Thus, the optical fiber connection member is easily bent by a horizontal external force due to its flexibility. As a result, the optical fiber inserted into the optical fiber connection member is also bent, causing loss of light after splicing and thus a splicing failure of the optical fiber.

[10] Moreover, since the fixation of the optical fiber inserted into the optical fiber connection member depends on only the elastic force of the pressurizing member in a clip form, there is a limitation in firmly fixing the optical fiber.

[11] Meanwhile, in the conventional optical connector which is of a type where the core of the optical fiber is inserted into the ferrule for splicing, the optical fiber is led in the optical fiber connection member without a separate guide means. As a result, in case of any shake occurring during a lead-in operation of the optical fiber, the core of the optical fiber cannot be accurately inserted into the ferrule through a core insertion hole of the core alignment unit. In particular, it is very difficult to accurately insert the core into the core insertion hole having a diameter corresponding to a diameter of about 125 μm of the core.

Disclosure of Invention Technical Problem

[12] To solve the above problems, it is an object of the present invention to provide a field assembly optical connector capable of firmly fixing an optical fiber led in the optical connector and preventing the optical fiber from being bent due to a horizontal external force.

[13] It is another object of the present invention to provide a field assembly optical connector capable of reducing the connection loss of an optical fiber by means of easy and accurate core splicing during the assembly of the optical connector. Technical Solution

[14] According to an aspect of the present invention, there is provided a field assembly optical connector comprising a first unit which includes a housing, a frame provided within the housing, and a fixing member installed in the frame; a ferrule unit which has a portion inserted into the fixing member and into which a core of an optical fiber is inserted; an optical fiber fastening means which is installed in an end of the ferrule unit and pressurizes an outer face of the optical fiber having the core inserted into the ferrule unit to fasten the optical fiber; and a second unit which is coupled to the fixing member and fixes positions of the ferrule unit and the optical fiber fastening means.

[15] According to another aspect of the present invention, there is provided a field assembly optical connector comprising: a first unit which includes a housing, a frame provided within the housing, a fixing member which is installed in the frame, and a first ferrule which is installed to elastically slide within the fixing member and having a first core inserted thereinto; a second unit which is coupled to the fixing member and includes a second ferrule having a second core, which is to be spliced with the first core, inserted thereinto to come into contact with the first ferrule; and a sleeve which is perforated at its center so that the first ferrule and the second ferrule are inserted into the center and come into contact with the sleeve for splicing the first core and the second core to then guide the first ferrule and the second ferrule.

[16] According to the present invention, an outer face of an optical fiber led in an optical connector is directly fixed by a collet unit including a plurality of jaws, thereby strengthening splicing of the optical fiber.

[17] Moreover, since the outer face of the optical fiber is pressurized by the plurality of jaws included in the collet unit to fix the optical fiber, a main body of the collet unit can be made of a metal material that is strong to a horizontal external force, thereby preventing the optical fiber from being affected by the horizontal external force.

[18] Furthermore, since core splicing is made between ferules having cores inserted thereinto, an optical connector assembling work can be simplified and accurate core alignment can be accomplished, thereby preventing loss of light occurring during core splicing. Brief Description of the Drawings

[19] FIG. 1 is an exploded view illustrating various parts of a field assembly optical connector according to an embodiment of the present invention;

[20] FIG. 2 is a cross-sectional view illustrating an assembled state of the field assembly optical connector shown in FIG. 1;

[21] FIG. 3 is a cross-sectional view illustrating an exploded state of the field assembly optical connector shown in FIG. 1 ;

[22] FIG. 4 illustrates an operation example of a collet unit that is an optical fiber fastening means of the field assembly optical connector shown in FIG. 1; and

[23] FIG. 5 is a partial cross-sectional view of another example of the optical fiber fastening means of the field assembly optical connector shown in FIG. 1. Best Mode for Carrying Out the Invention

[24] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. A structure of a field assembly optical connector according to an embodiment of the present invention is illustrated in FIGS. 1 through 3.

[25] Referring to FIGS. 1 through 3, the field assembly optical connector according to an embodiment of the present invention includes a housing 110, a frame 120 provided in the housing 110, a ferrule unit 400 installed to elastically slide within the frame 120 and to protrude outward at one end, and an optical fiber fastening means 210 coupled to the ferrule unit 400 and fastening or disengaging a second optical fiber having a second core to be spliced to a first core inserted into the ferrule unit 400 by pressurizing an outer face of the second optical fiber.

[26] The ferrule unit 400 includes a first ferrule 410 having the first core inserted thereinto to be factory-cut and polished, a second ferrule 420 having the seoond core inserted thereinto to be cut in a field, the second core to be spliced to the first core, and a sleeve 430 perforated at its center to guide the first ferrule 410 and the second ferrule 420 to come into accurately contact with each other.

[27] In other words, the first ferrule 410 and the second ferrule 420 are connected with each other within the sleeve 430.

[28] In an alternative embodiment of the present invention, the field assembly optical connector may not include the optical fiber fastening means 210. In other words, as mentioned above, the ferrule unit 400 may be divided into the first ferrule 410 and the second ferrule 420, which are then mounted on the first unit 100 and the second unit 200, respectively. Further, the first ferrule 410 and the seoond ferrule 420 may be connected with each other within the sleeve 430 when the first unit 100 and the seoond unit 200 are connected to each other.

[29] In the current embodiment of the present invention, it has illustrated by way of example that the ferrule unit 400 is divided into the first ferrule 410 and the seoond ferrule 420 into which the first core and the seoond oore to be spliced with each other are inserted, respectively, and the divided first and seoond ferrules 410 and 420 are accurately guided by the sleeve 430. Ebwever, the invention is not limited to the illustrated example, and according to the present invention, the ferrule unit 400 may also be a single ferrule and the first oore and the second oore may be spliced with each other in the single ferrule.

[30] According to the current embodiment of the present invention, the field assembly optical connector a ferrule unit divided into a first ferrule and a seoond ferrule may comprise the first unit 100 and the second unit 200. The first unit 100 includes may include the housing 110, the frame 120 provided in the housing 110, the first ferrule 410 installed to elastically slide in the frame 120 by means of elastic support means 300 and to protrude outward at one end, and the sleeve 430 perforated at its center to allow a protrusion of the first ferrule 410 to be inserted thereinto. The seoond unit 200 includes the seoond ferrule 420 fitted into the sleeve 430 to come into contact with the first ferrule 410 so that the seoond core spliced with the first core of the first ferrule 410 is inserted thereinto, the optical fiber fastening means 210 connected with the second ferrule 420 to fasten or disengage the second optical fiber by pressurizing an outer face of the second optical fiber, and a protective boot 220 provided in the second optical fiber to be led in and coupled to the housing 110 while surrounding the optical fiber fastening means 210.

[31] The housing 110 has an elongated hollow at its center so that the frame 120 is inserted into the hollow, and has first fixing holes 111 perforated in opposite sides on its outer face for splicing to the frame 120.

[32] The frame 120 has an elongated hollow at its center so that the first ferrule 410 is inserted into the hollow, and has first protrusion members 121 protruding outwardly on its opposite side faces for coupling to the first fixing holes 111 of the housing 110.

[33] The elastic support means 300 includes a rib unit 310, a flange member 320, a fixing member 330, and an elastic member 340. The rib unit 310 annularly protrudes from an inner circumference of the perforated frame 120. The flange member 320 is provided on an outer face of the first ferrule 410 to be suspended on the rib unit 310 when the first ferrule 410 is inserted into the frame 120. The fixing member 330 is inserted into the first ferrule 410 in the same direction as the first ferrule 410 is fitted into the frame 120 to be spaced a predetermined space apart from the rib unit 310 of the frame 120 in such a way to allow the first ferrule 410 to slide a predetermined distance within the frame 120. The elastic member 340 is provided between the flange member 320 and the fixing member 330 to apply an elastic force in the sliding direction of the first ferrule 410.

[34] The fixation of the frame 120 and the fixing member 330 is achieved by means of coupling between a seoond fixing hole 122 perforating an outer side face of the frame 120 and a second protrusion member 331 protruding from an outer face of the fixing member 330.

[35] The first ferrule 410 and the seoond ferrule 420 have core insertion holes perforating lengthwise at their centers to allow a core of an optical fiber to be fittingly inserted. Here, the perforating of the core insertion holes of the first ferrule 410 and the seoond ferrule 420 is performed sich that the centers of the first ferrule 410 and the second ferrule 420 are aligned in a line when the first ferrule 410 and the seoond ferrule 420 slide by means of the sleeve 430 to then oome into contact with each other.

[36] When a first core Cl is fitted into the first ferrule 410, a second core C2 is led in the second ferrule 420, and the first ferrule 410 and the second ferrule 420 come into contact with each other within the sleeve 430, the first oore Cl and the second core C2 are spliced with each other.

[37] When the flange member 320 is fitted into the first ferrule 410, and the first ferrule

410 is fitted into the frame 120, the flange member 320 has a diameter greater than that of the first ferrule 410 so that it is suspended on the rib unit 310 of the frame 120.

[38] As the elastic member 340, a spring inserted into the first ferrule 410 may be used, and the elastic member 340 is installed svch that the flange member 320 and the fixing member 330 may be supported to opposite sides of the spring, respectively.

[39] Although the spring inserted into the first ferrule 410 is taken as an example of the elastic member 340 in the current embodiment of the present invention, any other member can be used as the elastic member 340 as long as it can elastically support the flange member 320 and the fixing member 330 by applying an elastic force in an axial direction of the first ferrule 410.

[40] The optical fiber fastening means 210 is oonnected to the second ferrule 420 and includes a collet unit 211 and a fastening member 212. The oollet unit 211 includes the optical fiber lead-in hole 211a perforated at its center into which the second optical fiber having the seoond core C2 embedded therein is inserted, and a plurality of jaws 211" divided along the circumference at the leading edge of the collet unit 211. The fastening member 212 is threaded with the plurality of jaws 211" divided along the circumference of the collet unit 211 to be fastened with the plurality of jaws 211", thereby reducing the cross-sectional area of the optical fiber lead-in hole 211a.

[41] Connection means includes a connection member 230 perforated at its center to allow the second ferrule 420 and the collet unit 211 to be inserted into opposite ends of the connection member 230.

[42] The center of the connection member 230 is perforated, in which the diameters of opposite ends of the connection member 230 are different from each other according to the diameters of the second ferrule 420 and the collet unit 211 inserted into the opposite ends of the connection member 230.

[43] The collet unit 211 includes a main body 211' perforated at its center with the optical fiber lead-in hole 21 Ia to allow the second optical fiber to be led in, and the plurality of jaws 211" divided along the circumference by a plurality of slits formed lengthwise at a side of the main body 211'.

[44] The plurality of jaws 211" are provided to elastically gather towards the center of the optical fiber lead-in hole 211a, and have a larger thickness than the main body 211' such that the cross-sectional area of the optical fiber lead-in hole 21 Ia is reduced during rotating of the plurality of jaws 211" towards the center of the optical fiber lead- in hole 211a. Screw threads are formed on an outer face of the plurality of jaws 211".

[45] The fastening member 212 is perforated to allow the second optical fiber to be inserted into the center of the fastening member 212, and includes a fastening unit 212a at its one side and a fixing unit 212b at its other side. Screw threads are formed in the inner circumferential face of the fastening unit 212a to be threaded with the plurality of jaws 211". The fixing unit 212b comes into contact with and fixed to an outer face of the second optical fiber by being pressurized by a first compression ring 240 inserted into the outer circumferential face for fixing with the second optical fiber.

[46] The screw threads formed in the inner circumferential face of the fastening unit 212a are inclined such that the inner diameter of the fastening unit 212a gradually decreases in a direction ranging from an inlet unit through which the plurality of jaws 211" are induced. Thus, when the plurality of jaws 211" are threaded with the fastening unit 212a, the plurality of jaws 211" gradually rotate towards the center of the optical fiber lead-in hole 211a due to the gradually reduced inner diameter of the fastening unit 212a, thereby reducing the cross-sectional area of the optical fiber lead-in hole 211a. In this way, the rotating plurality of jaws 211" pressurize the outer face of the seoond optical fiber inserted into the optical fiber lead-in hole 211a, thereby firmly fixing the second optical fiber.

[47] Another exemplary optical fiber fastening means for the field assembly optical connector according to the present invention are illustrated in FIGS. 4 and 5.

[48] Referring to FIGS. 4 and 5, the optical fiber fastening means 210 according to another embodiment of the present invention may include a collet unit 211-1 as the collet unit 211, an auxiliary fastening member 213, and a fastening member 212-1. In the collet unit 211-1, any screw thread is not formed on the outer face of the plurality of jaws 211". The auxiliary fastening member 213 is slidably provided in the collet unit 211-1 to rotate the plurality of jaws 211" towards the center of the optical fiber lead-in hole 211a. The fastening member 212-1 is threaded with the auxiliary fastening member 213.

[49] The collet unit 211-1 is formed as described above for the oollet unit 211, but no screw thread is formed on the outer face of the plurality of jaws 211".

[50] The auxiliary fastening member 213 is perforated at its center in order to slide while being inserted into the main body 211' of the collet unit 211-1, in which an inner face at one side of the auxiliary fastening member 213 is inclined such that an inner diameter of the auxiliary fastening member 213 is gradually reduced. In other words, when the plurality of jaws 211" are led in the inclined inner face at one side of the auxiliary fastening member 213, they rotate towards the center of the optical fiber lead-in hole 211a due to the gradually reduced inner diameter of the auxiliary fastening member 213, thereby reducing the cross-sectional area of the optical fiber lead-in hole 211a.

[51] Screw threads are formed on the outer circumferential face of the auxiliary fastening member 213 in order to be threaded with the fastening member 212-1.

[52] The fastening member 212-1 includes the fastening unit 212a and the fixing unit

212b like the fastening member 212. Fbwever, screw threads formed on the inner circumferential face of the fastening unit 212a in order to be threaded with the auxiliary fastening member 213 are not inclined and form an inner circumferential face having a shape corresponding to the shape of the outer face of the auxiliary fastening member 213, in which screw threads are formed on the inner circumferential face. A pressurizing protrusion 212C is formed protruding annularly on the inner circumferential face spaced apart by a predetermined distance from an entry to the fastening unit 212a. [53] The protective boot 220 is perforated at its center to allow insertion of the second optical fiber and includes a receiving space 221 for receiving the optical fiber fastening means 210 in its center. The protective boot 220 receives the optical fiber fastening means 210 and is coupled to the fixing member 330.

[54] The protective boot 220 and the fixing member 330 are fixed by coupling between a suspension member 222 protruding on the inner circumferential face of a leading edge of the receiving space 221 towards the center of the protective boot 220 and an insertion groove 332 formed to a predetermined depth on the outer face of the fixing member 330.

[55] A second compression ring 250 is provided to cause the protective boot 220 to come into contact with the second optical fiber by pressurizing the outer face of the protective boot 220 when the protective boot 220 is fixed to the fixing member 330 by being led in the housing 110 of the first unit 100 while surrounding the optical fiber fastening means 210.

[56] Hereinafter, an operation of the field assembly optical connector according to the current embodiment of the present invention will be described.

[57] The field assembly optical connector according to the current embodiment of the present invention is directed to facilitation of a field assembling work while minimizing loss of light during splicing in svch a manner that the ferrule is by finely factory-cut and polished to then be manufactured in units, instead of cutting and polishing a ferrule into which a core of an optical fiber is inserted in a field.

[58] To this end, the first ferrule 410 is provided by being finely cut and polished while having the first core Cl inserted into its core insertion hole. The first ferrule 410, the flange member 320, the elastic member 340, and the fixing member 330 are coupled such that the first ferrule 410 can elastically slide within the frame 120 while exposing its one portion. The frame 120, in which the first ferrule 410, the flange member 320, the elastic member 340, and the fixing member 330 are coupled and mounted, is fittingly inserted into the housing 110, thereby providing the first unit 100 in sush a way to be detachably installed in an optical adaptor.

[59] In a state in which the second core C2 is led in the second ferrule 420 by the optical fiber fastening means 210, the second optical fiber is firmly supported and the second ferrule 420 having the second oore C2 led in is finely cut, thereby providing the second unit 200.

[60] The thus provided first and second units 100 and 200 are coupled to each other. At this time, since the second ferrule 420 is securely guided by means of the sleeve 430 inserted into the first ferrule 410 for insertion, the first and seoond cores Cl and C2 of the first and second ferrules 410 and 420 are accurately aligned and connected, respectively. The protective boot 220 of the second unit 200 is allowed to slide to cause the optical fiber fastening means 210 to be led in the housing 110 while surrounding the optical fiber fastening means 210 and then cause the optical fiber fastening means 210 to be fixed to the fixing member 330. The protective boot 220 fixed to the fixing member 330 is fixed to the second optical fiber by the second compression ring 250, thereby completing optical connector splicing. An index matching gel, which is typically used as a connection loss reducing material, is injected into a space between the first ferrule 410 and the second ferrule 420 connected within the sleeve 430.

[61] The second optical fiber having the second core C2 to be led in the core insertion hole of the second ferrule 420 is firmly supported such that the second core C2 can maintain a state of being securely led in the core insertion hole of the second ferrule 420 by means of the optical fiber fastening means 210 connected to the second ferrule 420. In other words, the second optical fiber is led in the optical fiber lead-in hole 211a of the collet unit 211. The second core C2 of the led- in second optical fiber is inserted into the core insertion hole of the second ferrule 420 connected to the collet unit 211 by means of the connection member 230.

[62] While the second core C2 being inserted into the core insertion hole of the second ferrule 420, the plurality of jaws 211" of the collet unit 211 are threaded with the fastening unit 212a of the fastening member 211. Here, the plurality of jaws 211" rotate towards the center of the optical fiber lead-in hole 211a and the outer face of the second optical fiber is pressurized by the rotating plurality of jaws 211", so that the second optical fiber is fixed within the optical fiber lead-in hole 211a, rather than sliding.

[63] Referring to FIG. 4, the auxiliary fastening member 213 is slid on the collet unit

211-1 in order to cause the plurality of j aws 211 " of the collet unit 211-1 to be inserted into the auxiliary fastening member 213. At this time, the plurality of jaws 211" rotate towards the center of the optical fiber lead-in hole 21 Ia to pressurize the outer face of the second optical fiber led in the optical fiber lead-in hole 211a. While the outer face of the second optical fiber being pressurized, the auxiliary fastening member 213 and the fastening member 212-1 are threaded with each other.

[64] Upon screw-engagement between the auxiliary fastening member 213 and the fastening member 212-1, the top face of the plurality of jaws 211" are pressurized by the pressurizing protrusion 212c of the fastening member 212-1, whereby the plurality of jaws 211" are forcibly fitted into the auxiliary fastening member 213. Thus, the plurality of jaws 211" are fixed while pressurizing the outer face of the second optical fiber led in the optical fiber lead-in hole 211a.

[65] In this way, a state where the rotating plurality of jaws 211" pressurize the outer face of the second optical fiber is maintained by screw-engagement between the plurality of jaws 211" and the fastening member 212 and screw-engagement between the auxiliary fastening member 213 and the fastening member 212-1, thereby firmly fixing the second optical fiber.

[66] The fastening member 212 or 212- 1 is fixed to the second optical fiber by means of the first compression ring 240 which simultaneously compresses a portion of the fastening member 212 or 212-1 and a portion of the second optical fiber.

[67] As such, since the optical fiber is fixed by being pressurized on its outer face by means of the rotating plurality of jaws 211", the collet unit 211 or 211- 1 can be manufactured by using a solid metal material. Therefore, the optical fiber can be protected from a horizontal external force by means of the collet unit 211 or 211-1 made of a solid metal material Industrial Applicability

[68] According to the present invention, an outer face of an optical fiber led in an optical connector is directly fixed by a collet unit including a plurality of groups, thereby strengthening splicing of the optical fiber.

[69] Moreover, since the outer face of the optical fiber is pressurized by the plurality of groups included in the collet unit to fix the optical fiber, a main body of the collet unit can be made of a metal material that is strong to a horizontal external force, thereby preventing the optical fiber from being affected by the horizontal external force.

[70] Furthermore, splicing of cores is made between a core-inserted ferrule to a ferrule, thereby easily and aαxirately aligning the cores and thus preventing loss of light during splicing of the cores.

[71] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. It is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than the foregoing description to indicate the scope of the invention.

Claims

[1] A field assembly optical connector comprising: a first unit which includes a housing, a frame provided within the housing, and a fixing member installed in the frame; a ferrule unit which has a portion inserted into the fixing member and into which a core of an optical fiber is inserted; an optical fiber fastening means which is installed in an end of the ferrule unit and pressurizes an outer face of the optical fiber having the core inserted into the ferrule unit to fasten the optical fiber; and a second unit which is coupled to the fixing member and fixes positions of the ferrule unit and the optical fiber fastening means.

[2] The field assembly optical connector of claim 1, wherein the ferrule unit comprises: a first ferrule which is installed to elastically slide within the fixing member and into which a first core inserted; a second ferrule which includes the optical fiber fastening means installed in its end and into which a second core spliced to the first core is inserted; and a sleeve which is perforated at its center to allow the first and second ferrules to be inserted thereinto and come into contact with each other and which guides the first ferrule and the second ferrule for splicing the first and second cores.

[3] The field assembly optical connector of claim 2, wherein the optical fiber fastening means comprises: a collet unit which is connected to the second ferrule by connection means and which has an optical fiber lead-in hole perforated at its center into which a second optical fiber having the second core is inserted and perforates, the collet unit including a plurality of jaws divided along the circumference at a leading edge of the collet unit to then rotate; and a fastening member which is fixed to the second optical fiber and threaded with the plurality of jaws divided along the circumference and which is rotated in a radial direction to reduce a cross-sectional area of the optical fiber lead-in hole.

[4] The field assembly optical connector of claim 2, wherein the optical fiber fastening means comprises: a collet unit which is connected to the second ferrule by connection means and has an optical fiber lead-in hole perforated at its center into which a second optical fiber having the seoond core is inserted and perforates, the collet unit including a plurality of jaws divided along the circumference at a leading edge of the collet unit to then rotate; an auxiliary fastening member which is inserted into the plurality of jaws and slides by rotating the plurality of jaws in a radial direction to reduce a cross- sectional area of the optical fiber lead-in hole; and a fastening member which is threaded with the auxiliary fastening member and is fixed to the second optical fiber in a state where the auxiliary fastening member rotates the plurality of jaws in a radial direction to reduce a cross-sectional area of the optical fiber lead-in hole

[5] The field assembly optical connector of claim 3 or 4, wherein the first unit comprises: a frame which is fitted into the housing and perforates inside the frame so that the first unit is inserted into the frame; a flange member which is fitted into the first ferrule and is suspended within the frame; a fixing member which has a portion of the first ferrule fittingly embedded therein and which is fixed to the frame; and an elastic member which is provided between the fixing member and the flange member to allow the first ferrule to elastically move within the frame, and wherein the connection means comprises a connection member which has an internal hollow so that the first ferrule and the collet unit are inserted into opposite ends of the connection member to connect the first ferrule with the collet unit.

[6] A field assembly optical connector comprising: a first unit which includes a housing, a frame provided within the housing, a fixing member which is installed in the frame, and a first ferrule which is installed to elastically slide within the fixing member and having a first core inserted thereinto; a second unit which is coupled to the fixing member and includes a second ferrule having a second core, which is to be spliced with the first core, inserted thereinto to come into contact with the first ferrule; and a sleeve which is perforated at its center so that the first ferrule and the second ferrule are inserted into the center and come into contact with the sleeve for splicing the first core and the second core to then guide the first ferrule and the second ferrule.