JP2004170563A - Ferrule of slanting pc connector and its polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the ferrule of a PC(physical contact) connector and its manufacturing method with which the tip face of the ferrule can be polished with high accurate at low pressure and also low insertion loss and high return loss can be realized. <P>SOLUTION: In the ferrule 10 of the slanting PC connector, which is to be used in slanting PC connectors which connect slant polished end faces with each other of optical fibers 1 and which consist of a tubular body 20 for ferrule which holds the optical fiber 1 and also whose tip face 23 is formed to be a convex-face shape which is inclined with respect to a plane orthogonal to the axis of the optical fiber 1 and a flange member 30 which is engaged with the rear end part of the tubular body, the tip face 23 of the tubular body 20 is formed to be the convex-face shape in which the radius of curvature near peripheral part of the projected side in the inclination direction is larger and also the radius of curvature to the peripheral part of the other side in the inclination direction is smaller than that of the center area near the optical fiber 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ferrule used for an oblique PC connector for connecting obliquely polished end faces of an optical fiber and a method for manufacturing the ferrule.
[0002]
[Prior art]
In optical connectors used in optical communications, etc., the end face of the optical fiber held by the ferrule is placed on a surface perpendicular to the axis of the optical fiber together with the end face of the ferrule for the purpose of reducing connection loss and reducing reflected return light at the connector connection part. On the other hand, an "oblique PC (Physical Contact) connector" that is polished obliquely to a convex spherical surface is used.
[0003]
Here, a ferrule used for a conventional MU type oblique PC connector will be described.
[0004]
FIG. 12 is a perspective view and a plan view of a ferrule according to the related art.
[0005]
As shown in FIG. 12, the ferrule 310 used for the oblique PC connector includes a ferrule cylindrical body 320 having a cylindrical shape in which a tip surface 323 is provided in a convex spherical shape inclined with respect to a plane orthogonal to the axis. A collar member 330 fitted to the rear end portion of the ferrule tubular body 320; and a collar part protruding in the radial direction on the outer periphery of the ferrule tubular body 310 side in the circumferential direction. 333 are provided. The collar portion 333 has a substantially rectangular cross section in the radial direction, and has a shape similar to the collar portion 333 provided in the plug frame when the ferrule 310 is held by the plug frame of the oblique PC connector. Engaging with the formed engagement hole restricts the movement of the ferrule 310 in the rotation direction around the central axis.
[0006]
Such a ferrule 310 is held in a plug frame, and is connected by an optical connector adapter or the like so that the distal end surfaces 323 of the ferrule tubular body 320 are in contact with each other, thereby achieving low insertion loss and high reflection attenuation. A quantity of optical connections can be made.
[0007]
Such a ferrule 310 for an oblique PC connector can be formed in a convex spherical shape in which the tip end surface 323 is inclined with respect to a plane perpendicular to the optical fiber axis by an end face polishing device.
[0008]
This end face polishing apparatus includes a polishing member on an elastic member mounted on a rotating and oscillating polishing platen, and a rear end side of an oblique PC connector on a jig board in a direction perpendicular to the polishing surface of the polishing member. On the other hand, it can be formed by holding the polishing platen so as to be inclined toward the rotation center of the polishing platen, and pressing the front end surface of the ferrule 310 of the oblique PC connector against the polishing member to polish it. reference.).
[0009]
[Patent Document 1]
JP-A-8-112745 (page 3, FIG. 1)
[0010]
[Problems to be solved by the invention]
However, the ferrule for the oblique PC connector formed in this way is designed to reduce the insertion loss and increase the return loss when they are connected to each other in order to increase the return loss. The apex must be formed in a position within a predetermined range from the center axis of the tip surface of the optical fiber, for example, 50 μm or less, and there is a problem that it is difficult to form it with high precision. Here, the deviation from the center of the ferrule of the tip surface of the ferrule for the oblique PC connector is determined by the end face shape and dimensions of 6.2.4 oblique PC polishing according to JIS C 5963: 2001 General rules for optical connectors with optical fiber cords. It is defined as the amount of spherical eccentricity. The spherical eccentricity is defined by the distance between the center of the ferrule and the vertex of curvature with respect to the angle reference plane.
[0011]
In particular, in the above-mentioned polishing of the ferrule cylindrical body having a small diameter of 1.25 mm used in the conventional MU type or LC type oblique PC connector, the elastic member provided on the polishing surface plate of the conventional end face polishing apparatus. There is a problem that it is difficult to keep the distance between the apex of the tip surface of the ferrule cylindrical body and the center of the tip surface of the optical fiber within a predetermined range due to the influence of the hardness of the polishing member and the warpage of the polishing member.
[0012]
Further, since the hardness of the elastic member used in the conventional end face polishing apparatus is 50 to 60 Hs, the polishing surface formed into a convex spherical shape when the pressure for pressing the front end face of the ferrule cylindrical body against the polishing member is weak. Is not stable.
[0013]
For this reason, it is necessary to press the tip end surface of the ferrule cylindrical body against the polishing member with a high pressure, for example, a pressure of about 1.7 to 2.1 N. When the surfaces are polished at the same time, for example, when 16 ferrule cylinders are simultaneously polished, a jig board holding a plurality of ferrule cylinders is pressed at about 26.7 to 32.9 N. In addition, the end face polishing apparatus is required to have a capability of pressing the jig board at high pressure, and there is a problem that the end face polishing apparatus pressing at low pressure cannot perform polishing.
[0014]
In view of such circumstances, the present invention provides a ferrule of an oblique PC connector and a method of manufacturing the same, which can polish a tip surface with high accuracy at low pressure and can realize low insertion loss and high return loss. The task is to
[0015]
[Means for Solving the Problems]
A first aspect of the present invention that solves the above-mentioned problem is used in an oblique PC connector that connects obliquely polished surfaces of optical fibers to each other. In the ferrule of an oblique PC connector comprising a ferrule tubular body formed in a convex shape inclined with respect to a ferrule and a collar member fitted to a rear end portion of the ferrule tubular body, a tip surface of the ferrule tubular body However, with respect to the radius of curvature of the central region near the optical fiber, the convex shape has a large radius of curvature near the peripheral edge on the inclined direction projecting side and a small radius of curvature near the peripheral edge on the other side in the inclined direction. In the ferrule of the oblique PC connector.
[0016]
According to a second aspect of the present invention, in the first aspect, the distal end face of the ferrule cylindrical body has a change in a radius of curvature per unit distance from a central region of the optical fiber to a peripheral portion on a side protruding in an inclined direction. The ferrule of the oblique PC connector is characterized in that the amount of change per unit distance of the radius of curvature to the peripheral edge on the other side in the tilt direction is smaller than the amount of the amount.
[0017]
A third aspect of the present invention resides in the ferrule of the oblique PC connector according to the first or second aspect, wherein the ferrule cylindrical body has a convex curvature radius of 5.0 mm to 12 mm.
[0018]
According to a fourth aspect of the present invention, in the third aspect, the radius of curvature in the vicinity of the peripheral portion on the side in the inclined direction is larger than the radius of curvature in the vicinity of the peripheral portion on the other side in the inclined direction by 1 mm or more. In the ferrule of the PC connector.
[0019]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a distance between a vertex of a convex end surface of the ferrule cylindrical body and a central axis of the optical fiber end surface is 50 μm or less. The oblique PC connector has a ferrule.
[0020]
A sixth aspect of the present invention is the ferrule of the oblique PC connector according to any one of the first to fifth aspects, wherein the outer diameter of the ferrule cylindrical body is 1.25 mm.
[0021]
A seventh aspect of the present invention is the ferrule of the oblique PC connector according to the sixth aspect, wherein the oblique PC connector is an MU type or an LC type.
[0022]
An eighth aspect of the present invention is used for an oblique PC connector for connecting obliquely polished surfaces of optical fibers to each other, and has a hole for holding the optical fiber, and has a tip surface perpendicular to an optical fiber axis. In a ferrule cylindrical body of an oblique PC connector formed in an inclined convex shape,
The distal end surface of the ferrule cylindrical body has a larger radius of curvature near the peripheral edge on the inclined direction protruding side than the radius of curvature of the region near the hole on the distal end surface and near the peripheral edge on the other side in the inclined direction. Has a small radius of curvature.
[0023]
According to a ninth aspect of the present invention, in the eighth aspect, the tip end surface of the ferrule cylindrical body has a variation per unit distance of a radius of curvature from a vicinity of the hole to a peripheral edge on a side protruding in an inclined direction. In comparison, the amount of change in the radius of curvature per unit distance to the peripheral edge on the other side in the tilt direction is small.
[0024]
According to a tenth aspect of the present invention, in the eighth or ninth aspect, the convex-shaped radius of curvature of the ferrule cylindrical body is 5.0 mm to 12 mm.
[0025]
An eleventh aspect of the present invention is the oblique aspect according to the tenth aspect, wherein a radius of curvature in the vicinity of a peripheral portion on the inclined direction projecting side is larger by 1 mm or more than a radius of curvature in the vicinity of the peripheral portion on the other side in the inclined direction. It is in the ferrule cylindrical body of the PC connector.
[0026]
According to a twelfth aspect of the present invention, in any one of the eighth to eleventh aspects, the spherical eccentricity of the convex front end surface of the ferrule cylindrical body is 50 μm or less.
[0027]
According to a thirteenth aspect of the present invention, in any one of the eighth to twelfth aspects, the outer diameter of the ferrule cylindrical body is 1.25 mm.
[0028]
A fourteenth aspect of the present invention resides in that the oblique PC connector is of the MU type or the LC type.
[0029]
A fifteenth aspect of the present invention is directed to a diagonal PC for connecting an oblique polishing surface of an optical fiber to a polishing member on an elastic member mounted on a polishing platen that rotates and swings while being supported by an apparatus main body. The ferrule polishing method for an oblique PC connector, in which the tip surface of the ferrule used for the connector is pressed and polished to form the tip surface of the ferrule in a convex shape inclined with respect to a surface orthogonal to the optical fiber axis, Forming a tip surface having an outer diameter smaller than the outer shape of the ferrule tubular body at the tip of the ferrule tubular body, and inclining the ferrule tubular body relative to the polishing surface of the polishing member; Performing rough polishing and medium polishing such that the angle between the axial direction and the polishing surface on the rotation center side of the ferrule cylindrical body is an obtuse angle, and the elastic member The hardness is lower than the step of performing the rough polishing and the medium polishing, and the ferrule cylindrical body is relatively inclined with respect to the polishing surface, and its axial direction is closer to the rotation center side than the ferrule cylindrical body. A step of performing a final polishing so that an angle between the polishing surface and the polishing surface is larger than a step of performing the rough polishing and the medium polishing. .
[0030]
According to a sixteenth aspect of the present invention, in the fifteenth aspect, in the step of forming the distal end surface, the outer diameter of the distal end surface is set to 0.3 mm to 0.9 mm.
[0031]
According to a seventeenth aspect of the present invention, in the fifteenth or sixteenth aspect, when the ferrule cylindrical body is brought into contact with the polishing surface of the polishing member while being inclined relative to the polishing surface, the ferrule cylinder is used. The ferrule polishing of an oblique PC connector, characterized in that the rear end of the body is inclined from the center of rotation of the polishing surface toward the peripheral edge, the polishing surface is inclined, or both. In the way.
[0032]
An eighteenth aspect of the present invention is the method according to the seventeenth aspect, wherein in the step of performing the rough polishing and the medium polishing, the polishing is performed by inclining the polishing surface in a concave shape toward the rotation center, and the step of performing the final polishing. A method for polishing a ferrule of an oblique PC connector, wherein the polishing surface of the polishing member is further inclined than the rough polishing and the medium polishing.
[0033]
According to a nineteenth aspect of the present invention, in any of the fifteenth to eighteenth aspects, in the step of performing the rough polishing, the hardness of the elastic member is selected from a range of 70 Hs to 97 Hs.
[0034]
According to a twentieth aspect of the present invention, in any of the fifteenth to nineteenth aspects, in the step of performing the middle polishing, the hardness of the elastic member is selected from a range of 70 Hs to 97 Hs.
[0035]
According to a twenty-first aspect of the present invention, in any of the fifteenth to twentieth aspects, in the step of performing the finish polishing, the hardness of the elastic member is selected from a range of 60 Hs to 80 Hs.
[0036]
A twenty-second aspect of the present invention is the method according to any one of the fifteenth to twenty-first aspects, wherein in the step of performing the rough polishing, the inclination angle of the polishing surface of the polishing member is 0 ° to 0.3 ° with respect to a horizontal plane. Is to do.
[0037]
According to a twenty-third aspect of the present invention, in the step of performing the medium polishing according to any one of the fifteenth to twenty-second aspects, the inclination angle of the polishing surface of the polishing member is 0 to 0.3 degrees with respect to a horizontal plane. Is to do.
[0038]
In a twenty-fourth aspect of the present invention based on any one of the fifteenth to twenty-third aspects, in the step of performing the final polishing, an inclination angle of a polishing surface of the polishing member is set to 0.4 degrees to 1.3 with respect to a horizontal plane. Degree.
[0039]
According to a twenty-fifth aspect of the present invention, in any one of the fifteenth to twenty-fourth aspects, the size of the abrasive grains of the polishing member is set to 8 μm to 15 μm during the rough polishing.
[0040]
According to a twenty-sixth aspect of the present invention, in any one of the fifteenth to twenty-fifth aspects, the size of the abrasive grains of the polishing member is set to 0.5 μm to 4 μm during the medium polishing.
[0041]
A twenty-seventh aspect of the present invention is the method according to any one of the fifteenth to twenty-sixth aspects, wherein in the step of performing the final polishing, the size of abrasive grains of the abrasive member is set to 0.007 μm to 0.12 μm. is there.
[0042]
According to a twenty-eighth aspect of the present invention, in any one of the fifteenth to twenty-seventh aspects, in the step of forming the distal end face of the ferrule tubular body, an optical fiber is provided at an edge of the distal end face of the ferrule tubular body. It is to form by providing the chamfered part whose inclination angle with respect to the axis is 30 degrees to 45 degrees.
[0043]
According to a twenty-ninth aspect of the present invention, in any one of the fifteenth to twenty-eighth aspects, in the step of forming the distal end surface of the ferrule cylindrical body, the distal end surface having an outer diameter of 0.55 mm to 0.7 mm at the distal end. Is to form
[0044]
According to a thirtieth aspect of the present invention, in any one of the fifteenth to twenty-ninth aspects, in the step of forming the distal end surface of the ferrule cylindrical body, the outer diameter of the distal end surface is provided at the distal end of the ferrule cylindrical body. A ferrule polishing method for an oblique PC connector, comprising forming a cylindrical portion having a small diameter equivalent to that of the ferrule.
[0045]
According to a thirty-first aspect of the present invention, in the thirtieth aspect, in the step of forming the distal end surface of the ferrule cylindrical body, a distal end surface having an outer diameter of 0.3 mm to 0.9 mm is formed at the distal end. is there.
[0046]
According to a thirty-second aspect of the present invention, in any one of the fifteenth to thirty-first aspects, the thickness of the elastic member is 1 mm to 5 mm.
[0047]
In a thirty-third aspect of the present invention, in any one of the fifteenth to thirty-second aspects, in the step of performing the rough polishing and the medium polishing and the step of performing the final polishing, a plurality of the ferrule cylindrical bodies are polished simultaneously. It is in.
[0048]
In the present invention, since the angle at the time of final polishing is made larger than the angle at which the ferrule cylindrical body and the polishing surface of the polishing member are brought into contact with each other during the rough polishing and the medium polishing, the polishing is performed. At the beginning of polishing, only the ferrule cylindrical body is polished without polishing the end face of the optical fiber, and the end face of the optical fiber can be gradually polished as the polishing proceeds. Accordingly, it is possible to prevent the optical fiber from being cracked due to the polishing and to perform the polishing with high precision. In addition, by performing polishing using an elastic member having a predetermined hardness, even when the ferrule cylindrical body is pressed at a low pressure, a stable tip surface of the inclined surface can be formed by polishing.
[0049]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments.
[0050]
(Embodiment 1)
FIG. 1 is a perspective view, an axial plan view, and a cross-sectional view of a ferrule according to Embodiment 1 of the present invention.
[0051]
As shown in FIG. 1, a ferrule 10 of the present embodiment includes a ferrule tubular body 20 having an outer diameter of 1.25 mm, and a collar member 30 fitted to one end of the ferrule tubular body 20. And
[0052]
The ferrule cylindrical body 20 has a cylindrical shape, and is provided therein with an optical fiber insertion hole 21 that penetrates in the axial direction to insert and hold the optical fiber 1. At the rear end of the optical fiber insertion hole 21, there is provided a tapered portion 22 whose inner diameter gradually increases toward the opening side. By providing such a tapered portion 22, when the optical fiber 1 is inserted into the optical fiber insertion hole 21, the tip of the optical fiber 1 comes into contact with the end surface of the ferrule cylindrical body 20, and thus the chip is broken or broken. Can be prevented.
[0053]
The ferrule cylindrical body 20 is made of, for example, a ceramic material such as zirconia, a plastic material, a glass material such as crystallized glass, borosilicate glass, quartz, or the like, or a metal material such as stainless steel, nickel, or a nickel alloy. You can give things.
[0054]
Further, the distal end surface 23 of the ferrule cylindrical body 20 is a convex surface inclined with respect to the surface orthogonal to the optical fiber axis together with the distal end surface of the optical fiber 1, and in the present embodiment, is an aspherical surface approximating a convex spherical surface. Is formed.
[0055]
The distal end face 23 has a larger radius of curvature near the peripheral edge on the inclined protruding side and a smaller radius of curvature near the peripheral edge on the other side in the inclined direction with respect to the radius of curvature of the central region near the optical fiber 1. Is formed.
[0056]
Further, such a radius of curvature is formed so as to be within a predetermined range, in this embodiment, 5 to 12 mm.
[0057]
Furthermore, the tip surface 23 formed in a convex shape of the ferrule cylindrical body 20 is compared with the amount of change per unit distance of the radius of curvature from the central region of the optical fiber 1 to the peripheral edge on the side in which the inclination direction protrudes. It is formed so that the amount of change in the radius of curvature per unit distance to the peripheral edge on the other side in the inclination direction is small.
[0058]
The distal end surface 23 of the ferrule cylindrical body 20 formed in such a convex shape has a low insertion loss of, for example, 0.2 dB or less when the convex distal end surfaces 23 are in contact with each other. In order to realize a specification of an ultra-high return loss of 60 dB or more, the apex of the tip surface 23 formed in a convex shape should be 50 μm or less, preferably 30 μm or less from the center of the tip surface of the optical fiber 1. Is formed.
[0059]
In addition, a beveled portion 24 having a predetermined inclination angle with respect to the optical fiber axis in the circumferential direction, in the present embodiment, 30 to 45 degrees is provided at the distal end edge portion of such a ferrule cylindrical body 20. Is provided.
[0060]
Here, FIG. 2 shows the measurement results of the distal end surface 23 of the ferrule cylindrical body 20 of the present embodiment. FIG. 2 is a graph showing the relationship between the distance in the inclined direction and the radius of curvature from the central region near the optical fiber on the distal end surface of the ferrule cylindrical body.
[0061]
As shown in FIG. 2, the distal end surface 23 of the ferrule cylindrical body 20 of the present embodiment has a distance from the center of the distal end surface of the optical fiber 1 to the edge protruding in the inclined direction and the other surface in the inclined direction. Is 0.25 mm.
[0062]
The radius of curvature of the distal end surface 23 is approximately 6.0 mm in the central region near the optical fiber 1, whereas the radius of curvature is approximately 7.0 mm in the region near the peripheral edge on the side in which the tilt direction protrudes. Is larger than the radius of curvature. In the region near the peripheral edge on the other side in the tilt direction, the radius of curvature is about 5.2 mm, which is smaller than the radius of curvature of the central region.
[0063]
In addition, the tip surface 23 has the same distance to the edge in the inclined direction and the edge on the other side, and the amount of change in the radius of curvature to the edge in the inclined direction is 1.0 mm. It can be seen that the amount of change in the radius of curvature up to the edge is as small as 0.8 mm. Such a tip surface 23 can be easily and accurately formed by a ferrule end surface polishing method described later.
[0064]
On the other hand, the collar member 30 is provided with a fitting hole 31 for fitting one end of the ferrule cylindrical body 20 and an optical fiber core insertion for inserting and holding the optical fiber core 2 coated on the outer periphery of the optical fiber 1. A hole 32 and a flange 33 provided on the outer peripheral side of the fitting hole 31 so as to protrude by a predetermined amount in the circumferential direction are provided.
[0065]
The flange 33 is formed so that its cross section in the radial direction is substantially rectangular. The collar 33 allows the center of the ferrule 10 when the ferrule 10 is held by the plug frame of the oblique PC connector to be described in detail later. The movement in the rotation direction about the axis is held in a state where the movement is restricted to a predetermined angle.
[0066]
Such a ferrule 10 can be mounted on, for example, an oblique PC connector such as an MU type and connected to each other with an optical connector adapter or the like.
[0067]
Here, the oblique PC connector will be described. FIG. 3 is an exploded perspective view of the oblique PC connector, and FIG. 4 is an exploded plan view and an assembled cross-sectional view of the oblique PC connector.
[0068]
As shown in the figure, the oblique PC connector 40 of the present embodiment fits into a plug housing 50 that fits into an MU-type optical connector adapter, and the ferrule 10 is inserted into the plug housing 50 from the rear end side. A plug frame 60, a stop ring 70 whose leading end engages with a rear end of the plug frame 60, and is held between the ferrule 10 and the stop ring 70 to urge the ferrule 10 toward the front end in the axial direction. And a biasing spring 80.
[0069]
As shown in FIG. 4, the plug frame 60 has a ferrule insertion hole 61 penetrating in the longitudinal direction, and is formed of, for example, a plastic material having a substantially rectangular cross section. The ferrule insertion hole 61 has a protruding flange portion 63 having an inner diameter slightly larger than the outer diameter of the ferrule cylindrical body 20 and having a protruding hole 62 in which only the ferrule cylindrical body 20 can protrude. Is provided.
[0070]
Further, the ferrule insertion hole 61 has an engagement hole 64 that regulates the movement of the ferrule 10 in the rotation direction around the central axis within a predetermined range by engaging with the flange portion 33 adjacent to the protruding flange portion 63. Is provided. In the present embodiment, since the cross section of the flange 33 is formed in a rectangular shape, the engaging hole 64 is formed in a rectangular shape whose cross section in the radial direction is slightly larger than that of the flange 33.
[0071]
Such an engaging hole 64 is provided with a predetermined vertical and horizontal opening width in the axial direction, thereby forming a predetermined clearance between the collar portion 33 and the engaging hole 64. Thus, the rotation angle of the ferrule 10 around the central axis is set within a predetermined range.
[0072]
Although the apex of the distal end face 23 of the ferrule cylindrical body 20 is set to be 50 μm or less from the center of the distal end face of the optical fiber 1, the ferrule 10 is mounted on the oblique PC connector 40 and the end faces of the ferrule 10 are connected to each other. When the ferrule 10 is rotated by a predetermined angle or more around the central axis with respect to the plug frame 60 when the ferrules are connected to each other, the apex of the distal end surface 23 of the ferrule cylindrical body 20 is at least 50 μm from the center of the distal end surface of the optical fiber 1. As a result, the state becomes the same as the shifted state, and a low insertion loss and a high return loss cannot be realized. For this reason, it is necessary to appropriately set the clearance between the engagement hole 64 of the plug frame 60 and the collar portion 33 so that the rotation angle of the ferrule 10 becomes a desired insertion loss and return loss.
[0073]
The plug frame 60 is formed with two locking holes 65 communicating with the ferrule insertion hole 61 and opening to the outer periphery. The locking holes 65 are provided at the distal end of the stop ring 70. The locking portion 75 is locked.
[0074]
The stop ring 70 is formed of, for example, a metal such as stainless steel or a plastic material having a cylindrical shape having an axially penetrating through hole 71 into which the rear end of the collar 33 can be inserted.
[0075]
The through-hole 71 is constituted by a large-diameter portion 72 into which a biasing spring 80 can be inserted at the front end portion, and a small-diameter portion 73 into which the rear end portion of the collar member 30 can be inserted at the rear end portion. One end of the biasing spring 80 comes into contact with a stepped portion 74 due to an inner diameter difference between the large diameter portion 72 and the small diameter portion 73.
[0076]
The other end of the biasing spring 80 abuts on the rear end side end face of the collar portion 33 so that the collar member 30 is biased axially forward with respect to the stop ring 70.
[0077]
Further, a locking portion 75 that protrudes into the locking hole 65 when the stop ring 70 is inserted into the ferrule insertion hole 61 of the plug frame 60 is provided on the outer circumference of the distal end side of the stop ring 70. The locking portion 75 is formed in a tapered shape in which the amount of protrusion gradually decreases toward the front end. The locking portion 75 enters the ferrule insertion hole 61 while pushing and expanding the rear end portion of the plug frame 60. And is locked in the locking hole 65.
[0078]
In order to hold the ferrule 10 in the plug frame 60 configured as described above, the ferrule 10 holding the optical fiber 1 is inserted into the ferrule insertion hole 61 of the plug frame 60, and the biasing force previously inserted into the optical fiber 2 is inserted. The locking portion 75 of the stop ring 70 is locked in the locking hole 65 of the plug frame 60 by sequentially inserting the spring 80 and the stop ring 70. As a result, the stop ring 70 is fixed to the plug frame 60. At this time, since the distal end surface of the collar portion 33 of the ferrule 10 abuts against the projecting flange portion 63 of the plug frame 60, the ferrule 10 is moved from the projecting hole 62 in a state where movement toward the distal end side is restricted. The fixed amount is protruded and biased and held to the front side in the axial direction.
[0079]
The outer periphery of the plug frame 60 thus assembled is provided with two engaging projections 66 that engage with the plug housing 50. The oblique PC connector 40 is formed by engaging the plug frame 51 with the plug frame 50 so as to be movable within a predetermined range in the axial direction.
[0080]
Further, in such a ferrule 10, for example, the distal end surface of the ferrule cylindrical body 20 is formed in a plane perpendicular to the axis of the optical fiber 1, and is mounted on the oblique PC connector 40. The inclined convex front end surface 23 can be formed by polishing. Of course, the ferrule 10 can be polished alone.
[0081]
Here, an example of the end face polishing apparatus of the present embodiment will be described. FIG. 5 is a schematic sectional view of the end face polishing apparatus.
[0082]
As shown in FIG. 5, the center of a first rotation transmission board 92 is fixed to the rotation shaft of the rotation motor 91, and a plurality of concentric circles having the rotation center as a fulcrum are fixed to the first rotation transmission board 92. The first connecting pin 93 is fixed. Each of the first connection pins 93 is rotatably connected to an eccentric portion of each of the rotation transmission boards 94, and a second connection pin 95 is fixed to each of the rotation transmission boards 94 at the eccentric section. Each second connection pin 95 is rotatably connected to a second rotation transmission board 96.
[0083]
On the other hand, a central portion of a drive gear 98 is fixed to the rotation shaft of the revolving motor 97, and a driven gear 99 meshes with the drive gear 98. The driven gear 99 is fixedly connected to a lower outer periphery of the revolution transmission shaft 100, and a bearing cylinder portion 102 of the apparatus main body 101 is fitted to an upper outer periphery of the revolution transmission shaft 100. A rotation shaft 103 for rotation is rotatably fitted to the revolving transmission shaft 100 at a position eccentric from the center of rotation by a predetermined amount. The lower end of the rotation shaft 103 for rotation is located at the center of the second rotation transmission plate 96. Has been consolidated.
[0084]
A polishing platen 105 is removably connected to the upper end of the rotation shaft 103 via a connecting member 104. A polishing member 106 is provided on an upper surface of the polishing platen 105 via an elastic member 107.
[0085]
Such a polishing platen 105 has a disk shape made of metal or the like, and the surface on which the elastic member 107 is provided is such that the polishing surface of the polishing member 106 provided on the elastic member 107 faces the center of rotation. It is provided so as to be concavely inclined toward the center of rotation so as to be concavely inclined.
[0086]
In such a polishing platen 105, a plurality of polishing platens 105 having different inclination angles of a surface on which the elastic member 107 is provided are prepared by respective polishing processes such as rough polishing, medium polishing, and finish polishing described later in detail. .
[0087]
The elastic member 107 provided on the polishing platen 105 is made of, for example, rubber, an elastomer, a resin, or the like. Multiple are prepared.
[0088]
Further, as the polishing member 106 provided on the elastic member 107, for example, a polishing sheet having polishing abrasive grains made of diamond, silicon oxide, cerium oxide, silicon carbide, or the like can be used.
[0089]
The polishing member 106 made of the polishing sheet is also prepared with a plurality of members having different abrasive grain diameters in respective polishing steps such as rough polishing, medium polishing and finish polishing.
[0090]
On the other hand, the apparatus main body 101 supports a jig board 120 to which a plurality of ferrules 10 or an oblique PC connector 40 holding the ferrules 10 is fixed by a support mechanism 110.
[0091]
Here, the support mechanism 110 and the jig board 120 will be described in detail.
[0092]
6 is a perspective view and a side view of the jig board, FIG. 7 is a top view of the jig board, FIG. 8A is a sectional view taken along the line AA ′ of FIG. 7, and FIG. FIG. 8 is a sectional view of a main part of the support mechanism 110 and a plane BB ′ of FIG.
[0093]
As shown in the drawing, the jig board 120 holds the oblique PC connector 40 holding the ferrule 10 in the present embodiment, and has a plurality of recesses 131 provided in a circumferential direction in a peripheral portion thereof. It includes a base body 130 and a plurality of holding members 140 provided corresponding to the respective recesses 131.
[0094]
The jig board main body 130 has a disk shape, and has a plurality of concave portions 131 provided in the vicinity of the peripheral portion in the circumferential direction. The concave portion 131 holds the oblique PC connector 40 between the concave portion 131 and the holding member 140 by fitting the distal end of the oblique PC connector 40 holding the ferrule tubular body 20. In the present embodiment, 16 sets of the concave portion 131 and the holding member 140 are provided so that the jig board 120 can hold 16 oblique PC connectors 40 at the same time. The number is not limited to this, and a larger number may be set.
[0095]
On the bottom surface of the concave portion 131, a cylindrical body 132 having a cylindrical shape to be fitted to the distal end of the ferrule cylindrical body 20 is provided. The cylindrical body 132 penetrates in the thickness direction of the jig board main body 130 and cures only the distal end of the ferrule cylindrical body 20 of the oblique PC connector 40 held between the concave portion 131 and the holding member 140. It is designed to protrude from the bottom surface of the component body 130.
[0096]
As will be described in detail later, when the diagonal PC connector 40 is held on the jig board 120, the rear end side of the diagonal PC connector 40 has the jig board body 130. Is provided at an angle of inclination such that it is inclined and held from the center toward the peripheral edge with respect to the thickness direction of the sheet.
[0097]
Further, the holding member 140 includes a support 141 fixed to each of the recesses 131 of the jig board main body 130, a support 142 provided movably in the axial direction on the outer periphery of the support 141, An urging spring 143 held between the support 141 and the holding part 142 is provided on the outer peripheral surface of the part 141.
[0098]
The support part 141 is fixed to the jig board main body in the same inclination direction and angle as the corresponding concave part 131 and the cylindrical body 132. That is, in the present embodiment, the end of the support portion opposite to the fixed end is fixed so as to be inclined toward the peripheral edge with respect to the thickness direction of the jig board main body.
[0099]
Further, the holding portion 142 is fitted to the outer periphery of the support portion 141 and is provided so as to be movable in the axial direction of the support portion 141, and the holding portion 142 extends from one end of the slide portion 144 and is located on the upper side of the recess 131. And an arm part 145 protruding therefrom.
[0100]
The arm portion 145 is provided with a rectangular fitting portion 146 that penetrates the tip portion in the thickness direction and has one side penetrated. The fitting portion 146 is fitted to the rear end portion of the oblique PC connector 40. It has become.
[0101]
Further, an urging spring 143 is provided on the outer peripheral surface on the end side opposite to the fixed end of the column section 141.
[0102]
The biasing spring 143 has one end in contact with the end of the slide portion 144 and the other end in contact with a stopper 147 provided on the end opposite to the fixed end of the column 141. , The holding portion 142 is urged toward the recess 131 in the axial direction of the support portion 141. In other words, the holding portion 142 urged toward the concave portion 131 is inclined with the distal end portion of the ferrule tubular body 20 protruding a predetermined amount from the bottom surface of the jig board main body 130 between the concave portion 131 and the holding portion 142. Can be held.
[0103]
As described above, the jig board 120 causes the oblique PC connector 40 to be inclined by a predetermined amount from the center of the jig board body 130 toward the peripheral edge side by the jig board body 130 and the holding portion 140 so that the rear end side is inclined. Can be held.
[0104]
A boss 133 is provided at the center of the jig board main body 130. The boss 133 urges the jig board 120 toward the polishing member 106 by the support mechanism 110 and engages with the support mechanism 110 to rotate the jig board 110 in the rotation direction of the polishing member 106. Has been prevented.
[0105]
Here, a support mechanism 110 that supports such a jig board 120 is provided with a support arm 111 movably provided on the apparatus main body 101 toward the polishing platen 105 side, and a jig provided on the tip side of the support arm 111. A pressing portion 112 fixed to the boss portion of the fixture board 120, and a regulating pin 113 provided on the support arm 111 for regulating the movement of the jig board 120 in the rotation direction are provided. Are pressed in the direction of the polishing platen 105 by pressing means (not shown) provided in the table.
[0106]
That is, the support arm 111 pressed by the pressing means polishes the jig board 120 by the tapered portion 112 a provided at the tip of the pressing portion 112 abutting against the tapered recess 134 of the boss 133 of the jig board 120. It is pressed in the direction of the platen 105.
[0107]
On the other hand, when the regulating pin 113 is engaged with the regulating hole 135 of the boss 133 of the jig board 120, the movement of the jig board 120 in the rotation direction accompanying the rotation of the polishing member 106 is regulated.
[0108]
That is, the jig board 120 is urged toward the polishing platen 105 by the pressing portion 112 in a state where the movement in the rotation direction is regulated by the regulating pin 113 of the support mechanism 110, and the obliquely held by the jig board 120. The ferrule tubular body 20 of the PC connector 40 is supported on the polishing member 106 via the distal end surface 23. Then, by rotating and swinging the polishing member 106, a convex distal end surface 23 inclined with respect to a plane perpendicular to the optical fiber axis can be formed at the distal end of the ferrule cylindrical body 20.
[0109]
The pressing unit that presses the support arm 111 is not particularly limited, and examples thereof include a unit that can be manually pressed by a lever or the like and a unit that can be automatically pressed by a drive motor or the like. Further, it is preferable that the pressing means can grasp the pressure at which the distal end surface 23 of the ferrule cylindrical body 20 comes into contact with the polishing member 106. For example, it is preferable to provide a pressure detecting means such as a load cell.
[0110]
Here, a method for polishing the end face of the ferrule 10 of the oblique PC connector 40 using such an end face polishing apparatus will be described in detail. 9 is a plan view of a main part of a ferrule cylindrical body showing a method of polishing an end face of a ferrule, and FIG. 10 is a cross-sectional view of a main part of a ferrule and an end face polishing apparatus showing a method of polishing an end face of a ferrule.
[0111]
First, from the state of the ferrule tubular body 20 shown in FIG. 9A, as shown in FIG. 9B, the tip of the ferrule tubular body 20 holding the optical fiber 1 is perpendicular to the optical fiber axis. A tip surface 223 having an outer diameter of 0.3 to 0.9 mm is formed.
[0112]
In the present embodiment, a predetermined outer diameter is obtained by forming a chamfered portion 24 in which the edge of the distal end surface 223 of the ferrule cylindrical body 20 is inclined by 30 to 45 degrees with respect to the optical fiber axis in the circumferential direction. Was formed.
[0113]
In the formation of the distal end surface 223, the distance between the apex of the convex distal end surface 23 formed by polishing the distal end surface 223 of the ferrule cylindrical body 20 in a later step and the center of the end surface of the optical fiber 1 is 50 μm or less. Can be realized by setting the outer diameter of the front end face 223 before polishing to 0.3 to 0.9 mm. However, the chamfered portion 24 is inclined at an inclination angle of 32.5 to 40 degrees and the front end face before polishing is formed. By forming the outer diameter of 223 to be 0.55 to 0.7 mm, it can be reduced to 30 μm or less.
[0114]
Next, the tip end surface 223 of the ferrule tubular body 20 is polished to form a convex tip end surface 23 inclined with respect to a plane orthogonal to the optical fiber axis on the ferrule tubular body 20.
[0115]
More specifically, first, as shown in FIG. 10A, the distal end surface 223 of the ferrule cylindrical body 20 is roughly polished to form the distal end surface 23a.
[0116]
In this rough polishing, the ferrule cylindrical body 20 is brought into contact with the polishing surface of the polishing member 106a while being inclined relative to the polishing surface, and the axial direction of the ferrule cylindrical body 20 is rotated more than the ferrule cylindrical body 20. Rough polishing is performed so that the angle α formed between the central polishing member 106a and the polishing surface is an obtuse angle.
[0117]
In the present embodiment, the jig board 120 of the above-described end face polishing apparatus is configured such that the rear end side of the ferrule cylindrical body 20 is moved outward from the rotation center of the polishing member 106 a with respect to the moving direction of the jig board 120. Since the polishing member 106a is inclined and held so that the polishing surface of the polishing member 106a becomes concave toward the rotation center, the axial direction of the ferrule cylindrical body 20 and the rotation center side with respect to the ferrule cylindrical body 20 The angle α between the polishing member 106a and the polishing surface can be an obtuse angle.
[0118]
By moving the jig board 120 in the direction of the polishing platen 105a in such a state, the distal end surface 223 of the ferrule tubular body 20 is caused to abut against the polishing surface of the polishing member 106a while being inclined relative to the polishing surface. By rotating and oscillating the polishing platen 105a, it is possible to form a convex front end surface 23a inclined with respect to the axis at the front end of the ferrule cylindrical body 20.
The jig board 120 holds the ferrule cylindrical body 20 at an angle of 8 degrees with respect to the vertical direction, and the inclination angle of the surface on which the elastic member 107a of the polishing platen 105a is provided, that is, the polishing surface of the polishing member 106a. Is preferably 0 to 0.3 degrees with respect to the horizontal plane. In this embodiment, the jig board 120 holds the ferrule cylindrical body 20 at an angle of 8 degrees with respect to the vertical direction, and the surface of the polishing platen 105a on which the elastic member 107a is provided, that is, the surface of the polishing member 106a. The polished surface was inclined 0.125 degrees from the horizontal direction.
[0119]
The elastic member 107a used for the rough polishing was selected from the range of hardness of 70 to 97 Hs, and the polishing member 106a was a polishing sheet having abrasive grains having a particle size of 8 to 15 μm.
[0120]
In such rough polishing, since the elastic member 107a has a relatively high hardness, even if the jig board 120 holding the ferrule tubular body 20 is pressed with a relatively small pressure, the ferrule tubular body 20 can be pressed. A tip surface 23a having a stable inclination angle can be formed at the tip of.
[0121]
In the present embodiment, it is possible to press the ferrule tubular body 20 at a pressure of 0.74 to 1.47 N / piece, and in the above-described jig board 120 holding 16 ferrule tubular bodies 20. The pressing means may press the jig board 120 at a pressure of 11.8 to 23.5 N, and the pressing at such a relatively low pressure can be easily performed.
[0122]
Next, as shown in FIG. 10B, the tip surface 23a of the ferrule cylindrical body 20 is polished to form a tip surface 23b.
[0123]
In the middle polishing, the ferrule cylindrical body 20 is brought into contact with the ferrule cylindrical body 20 at the same angle as that in the rough polishing using a polishing member 106b made of a polishing sheet having a smaller abrasive grain diameter than the polishing member 106a in the rough polishing. By performing the polishing in this manner, a distal end surface 23b is formed at the distal end of the ferrule cylindrical body 20.
[0124]
In addition, as the polishing member 106b, it is preferable that the particle diameter of the polishing abrasive grains is between 0.5 μm and 4 μm. Here, a 1 μm polishing sheet is used, and the elastic member 107a at the time of rough polishing is used.
[0125]
In such a middle polishing step, since the elastic member 107a has a relatively high hardness equivalent to that of the rough polishing, even if the jig board 120 holding the ferrule cylindrical body 20 is pressed with a relatively small pressure, the elastic member 107a can be used for the ferrule. A tip surface 23b with a stable inclination angle can be formed at the tip of the tubular body 20.
[0126]
In this embodiment, the ferrule cylindrical body 20 can be pressed at a pressure of 0.74 to 2.06 N / piece, and the jig board 120 for holding 16 ferrule cylindrical bodies 20 has the above-described configuration. The jig board 120 may be pressed at a pressure of 11.8 to 32.9 N, and the pressing at such a relatively low pressure can be easily performed.
[0127]
Next, as shown in FIG. 10C, the distal end surface 23b of the ferrule cylindrical body 20 is finish-polished to form the distal end surface 23.
[0128]
In this finish polishing, a ferrule cylinder is used by using an elastic member 107b having a lower hardness than the elastic member 107a during the middle polishing and using a polishing member 106c having a smaller abrasive particle diameter than the polishing member 106b during the middle polishing. The body 20 is made to abut against the polishing surface of the polishing member 106c while being inclined relative to the polishing surface, so that the axial direction of the ferrule cylindrical body 20 and the polishing surface closer to the center of rotation than the ferrule cylindrical body 20 are formed. Finish polishing is performed so that the angle is larger than in the step of performing rough polishing and medium polishing.
[0129]
Actually, in the jig board 120 of the above-described end face polishing apparatus, the inclination angle of the ferrule cylindrical body 20 held by the jig board 120 cannot be changed, so that the inclination angle of the polishing surface of the polishing member 106c is increased. ing. In the step of performing the final polishing, the inclination angle of the polishing surface of the polishing member 106c is from 0.4 to 1.3 degrees, preferably from 0.8 to 1.0 degrees, more preferably 0.9 degrees with respect to the horizontal plane. It is better to do.
[0130]
As described above, in order to increase the inclination angle of the polishing member 106c, by using the polishing platen 105b in which the surface to which the elastic member 107b is fixed is inclined at a larger angle than the polishing platen 105a, the polishing surface of the polishing member 106c is reduced. The ferrule tubular body 20 can be made to contact the polished surface of the polishing member 106c at a larger angle than in the step of performing the rough polishing and the medium polishing by tilting the ferrule cylindrical body 20 more.
[0131]
In the present embodiment, the elastic member 107b at the time of finish polishing is selected from a range of hardness of 60 to 80 Hs so that the hardness is lower than the hardness selected when performing rough polishing and medium polishing. Just fine.
[0132]
In addition, as the polishing member 106c at the time of the final polishing, a polishing sheet having a polishing abrasive particle diameter of 0.02 μm was used.
[0133]
As described above, the angle at which the ferrule cylindrical body 20 is brought into contact with the polishing surface of the polishing member 106c is set to be larger than that at the time of rough polishing and medium polishing. Without contact, only the ferrule cylindrical body 20 is polished. Then, as the polishing proceeds, the tip end surface of the optical fiber 1 can be gradually brought into contact with the polishing member 106c for polishing. Thereby, cracking of the optical fiber 1 during polishing can be prevented, and polishing with a high yield can be performed with high accuracy.
[0134]
In such finish polishing, since the hardness of the polishing member 106c is relatively high, even if the jig board 120 holding the ferrule cylindrical body 20 is pressed with a relatively small pressure, the ferrule cylindrical shape can be obtained. A tip surface 23 having a stable inclination angle can be formed at the tip of the body 20.
[0135]
Specifically, in the present embodiment, the ferrule cylinder 20 can be pressed against the ferrule cylinder 20 at a pressure of 0.74 to 1.23 N / piece, and the above-described 16 ferrule cylinders 20 are held. In the jig board 120, the jig board 120 may be pressed with a pressure of 11.8 to 19.6N, and the pressing with such a relatively low pressure can be easily performed.
[0136]
In this manner, the tip surface of the ferrule tubular body 20 before polishing is formed so as to have a predetermined outer diameter, and a series of rough polishing, medium polishing, and finish polishing are performed. At the tip, a convex tip end surface 23 having a vertex of 50 μm or less from the center of the tip surface of the optical fiber 1 can be formed with high precision. That is, the amount of spherical eccentricity can be set to 50 μm or less.
[0137]
The method of polishing the ferrule 10 of the oblique PC connector 40 is not limited to the ferrule 10 described above. For example, the method of polishing the ferrule 10 for the oblique PC connector having a conventional shape may be applied with high precision. it can.
[0138]
Although the ferrule has been described above, the above-described polishing method can be applied to a ferrule in which the ferrule and the brim member are integrated. Furthermore, after the ferrule cylindrical body is polished to form a pre-dome ferrule, the optical fiber may be fixed in the ferrule and polished.
[0139]
(Embodiment 2)
FIG. 11 is a perspective view, an axial plan view, and a cross-sectional view of a ferrule according to Embodiment 2 of the present invention. Note that the same reference numerals are given to the same members described in the first embodiment, and the overlapping description will be omitted.
[0140]
As shown in FIG. 11, the ferrule 10A of the second embodiment includes a ferrule cylindrical body 20A having an outer diameter of 1.25 mm, and a flange member 30 fitted to one end of the ferrule cylindrical body 20A. And
[0141]
The distal end surface 23A of the ferrule cylindrical body 20A has a convex surface inclined with respect to a surface orthogonal to the optical fiber axis together with the distal end surface of the optical fiber 1 in the same manner as in the above-described first embodiment. Is formed with an aspherical surface similar to
[0142]
That is, the distal end surface 23A has a convex shape in which the radius of curvature near the peripheral edge on the side protruding in the inclined direction is larger and the radius of curvature near the peripheral edge on the other side in the inclined direction is smaller than the radius of curvature in the central region near the optical fiber 1. The radius of curvature of the central region near the optical fiber 1 and the radius of curvature near the peripheral edge on both sides in the inclined direction are formed in a predetermined range, in this embodiment, 5 mm to 12 mm.
[0143]
Furthermore, the tip surface 23A formed in a convex shape of the ferrule cylindrical body 20A is compared with the amount of change per unit distance of the radius of curvature from the central region of the optical fiber 1 to the peripheral portion on the inclined direction protruding side, It is formed so that the amount of change in the radius of curvature per unit distance to the peripheral edge on the other side in the inclination direction is small.
[0144]
A small-diameter cylindrical portion 25 having an outer diameter equal to that of the distal end surface 23A is provided at the distal end of the ferrule cylindrical body 20A.
[0145]
The outer diameter of the small-diameter cylindrical portion 25 is provided to form the distal end surface 23A having a predetermined outer diameter before the convex distal end surface 23A is formed by polishing. The outer diameter of the small-diameter cylindrical portion is also 0.3 to 0.9 mm so that the outer diameter of the vertical tip surface of the cylindrical body for use 20A before polishing is 0.3 to 0.9 mm.
[0146]
Further, a chamfered portion 24A is formed at an edge of the ferrule cylindrical body 20A where a step due to a difference in outer diameter from the small-diameter cylindrical portion 25 is formed.
[0147]
Such a ferrule tubular body 20A can be easily and accurately formed by forming the small-diameter tubular portion 25 in advance and polishing the same as in the first embodiment.
[0148]
In order to keep the distance between the apex of the convex distal end surface 23A of the ferrule cylindrical body 20A and the center of the distal end surface of the optical fiber 1 at 50 μm or less, the distal end surface before polishing and the small-diameter cylindrical portion are required. 25 can be realized by setting the outer diameter of 0.3 to 0.9 mm, but by setting the outer diameter of the small-diameter cylindrical portion 25 and the tip end surface 23A to 0.55 to 0.7 mm, 30 μm or less. Can be. The small-diameter cylindrical portion 25 can be formed by, for example, grinding.
[0149]
(Other embodiments)
Although the first and second embodiments of the present invention have been described above, the ferrule of the oblique PC connector and the method of polishing the same according to the present invention are not limited to those described above.
[0150]
For example, in Embodiment 1 described above, the polishing platens 105, 105a, and 105b are inclined concavely toward the center of rotation, and the rear end side of the oblique PC connector 40 is attached to the jig board 120 by the thickness of the jig board body 130. By inclining from the center toward the peripheral portion with respect to the direction, that is, by providing an inclination angle that holds the shape of the inverted ferrule, the distal end surface of the ferrule cylindrical body has a radius of curvature of a central region near the optical fiber. On the other hand, the radius of curvature in the vicinity of the peripheral edge on the inclined direction protruding side is large, and the radius of curvature in the vicinity of the peripheral edge on the other side in the inclined direction is small, but the polishing platen is inclined convexly toward the rotation center. Also, the jig board may be provided at an inclined angle such that the rear end side of the oblique PC connector is inclined toward the center with respect to the thickness direction of the jig board body, that is, is held in a C-shape. Can be polished
[0151]
Further, for example, in Embodiment 1 described above, the jig board 120 of the end face polishing apparatus holds the oblique PC connector 40 at an angle, and the polishing surfaces of the polishing members 106a to 106c are subjected to rough polishing, medium polishing, and finish polishing. By changing the inclination angle, the angle at each polishing step was adjusted, but is not limited to this.For example, the polishing surface of the polishing member was not changed at each polishing step, and the ferrule cylindrical shape was not changed. The jig board holding the body may be structured so that the inclination angle of the ferrule cylindrical body can be changed in each polishing step.
[0152]
As described above, if the angle between the axial direction of the ferrule cylindrical body and the polishing surface of the polishing member can be adjusted in each polishing step, the end face polishing apparatus is not limited to the above-described one.
[0153]
In the above-described first and second embodiments, the ferrule for the MU-type oblique PC connector is illustrated. However, the ferrule for the LC-type oblique PC connector may be used.
[0154]
Furthermore, in Embodiments 1 and 2 described above, the outer diameter of the ferrule cylindrical body is 1.25 mm, but the present invention is not limited to this. It may be a ferrule for an oblique PC connector such as a mold.
[0155]
Even with such a ferrule, the outer diameter of the front end surface before polishing, the adjustment of the inclination angle in each polishing step, the hardness of the elastic member, and the like, as in the first and second embodiments described above, make it easy and highly accurate. A convex tip end surface can be formed.
[0156]
【The invention's effect】
As described above, in the present invention, polishing is performed by increasing the angle at the time of finish polishing as compared with the angle at which the ferrule cylindrical body and the polishing surface of the polishing member are brought into contact with each other during rough polishing and medium polishing. Therefore, it is possible to prevent the optical fiber from cracking and to perform highly accurate polishing. In addition, by performing polishing using an elastic member having a predetermined hardness, stable polishing can be performed even when the ferrule cylindrical body is pressed at a low pressure. Thereby, a ferrule of an oblique PC connector having a low insertion loss and a high return loss can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view, an axial plan view, and a sectional view of a ferrule according to a first embodiment of the present invention.
FIG. 2 is a graph showing a relationship between a distance in a tilt direction and a radius of curvature from a central region near an optical fiber on a distal end surface of a ferrule cylindrical body according to the first embodiment of the present invention.
FIG. 3 is an exploded perspective view of the oblique PC connector according to Embodiment 1 of the present invention.
FIG. 4 is an exploded plan view and an assembled cross-sectional view of the oblique PC connector according to the first embodiment of the present invention.
FIG. 5 is a schematic sectional view of the end face polishing apparatus according to the first embodiment of the present invention.
FIG. 6 is a perspective view and a side view of the jig board according to the first embodiment of the present invention.
FIG. 7 is a top view of the jig board according to Embodiment 1 of the present invention.
8A and 8B are cross-sectional views of the jig board according to the first embodiment of the present invention, wherein FIG. 8A is a cross-sectional view of the supporting mechanism and AA ′ of FIG. 7, and FIG. 8B is a cross-sectional view of BB ′ of FIG. FIG.
FIG. 9 is a plan view of a main part of the ferrule cylindrical body showing the ferrule end face polishing method according to the first embodiment of the present invention.
FIG. 10 is a sectional view of a main part of a ferrule and an end surface polishing apparatus showing a ferrule end surface polishing method according to the first embodiment of the present invention.
FIG. 11 is a perspective view, an axial plan view, and a sectional view of a ferrule according to a second embodiment of the present invention.
FIG. 12 is a perspective view, a plan view in an axial direction, and a plan view in an end face direction of a ferrule according to a conventional technique.
[Explanation of symbols]
10, 10A ferrule
20, 20A Cylindrical body for ferrule
23, 23a, 23b, 23A Tip surface
24, 24A chamfer
25 Small diameter cylindrical part
30 brim members
33 brim
40 Oblique PC connector
50 plug housing
60 plug frame
70 Stop Ring
80 biasing spring
105, 105a, 105b Polishing surface plate
106, 106a, 106b, 106c Polishing member
107, 107a, 107b elastic member
110 Support mechanism
120 jig board

Claims (33)

A ferrule cylindrical shape used for an oblique PC connector for connecting obliquely polished surfaces of optical fibers to each other, holding the optical fiber and forming a convex surface having a tip end surface inclined with respect to a surface orthogonal to the optical fiber axis. A ferrule of an oblique PC connector comprising a body and a collar member fitted to a rear end of the ferrule tubular body;
The distal end surface of the ferrule cylindrical body has a large radius of curvature near the peripheral edge on the inclined direction projecting side and a large radius of curvature near the peripheral edge on the other side in the inclined direction with respect to the radius of curvature of the central region near the optical fiber. The ferrule of an oblique PC connector characterized by having a small convex shape. 2. The ferrule of an oblique PC connector according to claim 1, wherein a tip end surface of the ferrule cylindrical body is compared with a change amount per unit distance of a radius of curvature from a central region of the optical fiber to a peripheral portion on a side protruding in an inclined direction. A ferrule of an oblique PC connector, wherein a change amount of a radius of curvature per unit distance to a peripheral portion on the other side in the inclination direction is small. 3. The ferrule of an oblique PC connector according to claim 1, wherein the ferrule cylindrical body has a convex curvature radius of 5.0 mm to 12 mm. 4. The ferrule of an oblique PC connector according to claim 3, wherein a radius of curvature near a peripheral edge on the side in the inclined direction is larger than a radius of curvature near a peripheral edge on the other side in the inclined direction by 1 mm or more. Ferrule. The ferrule of the oblique PC connector according to any one of claims 1 to 4, wherein a spherical eccentricity of a convex end surface of the ferrule cylindrical body is 50 µm or less. Ferrule. The ferrule of an oblique PC connector according to any one of claims 1 to 5, wherein an outer diameter of the ferrule cylindrical body is 1.25 mm. 7. The ferrule of an oblique PC connector according to claim 6, wherein the oblique PC connector is an MU type or an LC type. It is used for an oblique PC connector for connecting obliquely polished surfaces of optical fibers to each other. The oblique PC connector has a hole for holding the optical fiber, and a tip surface is formed in a convex shape inclined with respect to a surface orthogonal to the optical fiber axis. In the ferrule cylindrical body of the PC connector,
The distal end surface of the ferrule cylindrical body has a larger radius of curvature near the peripheral edge on the inclined direction protruding side than the radius of curvature of the region near the hole on the distal end surface and near the peripheral edge on the other side in the inclined direction. A ferrule cylindrical body for an oblique PC connector, characterized by having a convex shape having a small radius of curvature. 9. The ferrule of an oblique PC connector according to claim 8, wherein a tip end surface of the ferrule cylindrical body is compared with a variation per unit distance of a radius of curvature from a vicinity of the hole to a peripheral portion on a side protruding in an inclined direction. A ferrule cylindrical body for an oblique PC connector, wherein the amount of change in the radius of curvature per unit distance to the peripheral edge on the other side in the tilt direction is small. 10. The ferrule tube for an oblique PC connector according to claim 8, wherein the ferrule tube has a convex curvature radius of 5.0 mm to 12 mm. Shape. 11. The ferrule cylindrical body for an oblique PC connector according to claim 10, wherein a radius of curvature near a peripheral edge on the inclined direction projecting side is larger than a radius of curvature near a peripheral edge on the other side in the inclined direction by 1 mm or more. Ferrule cylindrical body for oblique PC connector. The ferrule cylindrical body for an oblique PC connector according to any one of claims 8 to 11, wherein a spherical eccentricity of a convex end surface of the ferrule cylindrical body is 50 µm or less. Ferrule cylindrical body for oblique PC connector. The ferrule cylindrical body for an oblique PC connector according to any one of claims 8 to 12, wherein an outer diameter of the ferrule cylindrical body is 1.25 mm. The ferrule for an oblique PC connector according to claim 8, wherein the oblique PC connector is an MU type or an LC type. The tip surface of a ferrule used in a diagonal PC connector for connecting diagonally polished surfaces of optical fibers to a polishing member on an elastic member mounted on a polishing platen that rotates and swings while being supported by the apparatus body. By pressing and polishing, in a ferrule polishing method for an oblique PC connector in which the tip end surface of the ferrule is formed in a convex shape inclined with respect to a surface orthogonal to the optical fiber axis,
Forming a tip surface having an outer diameter smaller than the outer diameter of the ferrule tubular body at the tip of the ferrule tubular body, and positioning the ferrule tubular body relative to a polishing surface of the polishing member; Performing rough polishing and medium polishing such that the angle between the axial direction and the polishing surface on the rotation center side of the ferrule cylindrical body is an obtuse angle; and The member has a hardness lower than that of the step of performing the rough polishing and the medium polishing, and the ferrule cylindrical body is inclined relative to the polishing surface, and its axial direction is rotated more than the ferrule cylindrical body. A step of performing a final polishing so that an angle between the central surface and the polishing surface is larger than a step of performing the rough polishing and the medium polishing. . The ferrule polishing method for an oblique PC connector according to claim 15, wherein in the step of forming the tip end surface, an outer diameter of the tip end surface is 0.3 mm to 0.9 mm. 17. The ferrule cylindrical body according to claim 15 or 16, wherein the ferrule cylindrical body is inclined relative to a polishing surface of the polishing member to contact the ferrule cylindrical body. A rear end portion of the ferrule is inclined from the center of rotation of the polishing surface toward the peripheral portion, or the polishing surface is inclined, or both are brought into contact with each other. The ferrule polishing method for an oblique PC connector according to claim 17, wherein the step of performing the rough polishing and the intermediate polishing includes polishing the polishing surface by inclining the polishing surface in a concave shape toward the center of rotation, and performing the finish polishing. A method of polishing a ferrule of an oblique PC connector, wherein a polishing surface of the polishing member is polished while being further inclined than the rough polishing and the medium polishing. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 18, wherein in the step of performing the rough polishing, the hardness of the elastic member is selected from a range of 70Hs to 97Hs. A ferrule polishing method for PC connectors. 20. The oblique PC connector ferrule polishing method according to any one of claims 15 to 19, wherein in the step of performing the middle polishing, the hardness of the elastic member is selected from a range of 70Hs to 97Hs. A ferrule polishing method for PC connectors. 21. The ferrule polishing method for an oblique PC connector according to claim 15, wherein in the step of performing the finish polishing, the hardness of the elastic member is selected from a range of 60 Hs to 80 Hs. A ferrule polishing method for PC connectors. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 21, wherein, in the step of performing the rough polishing, an inclination angle of a polishing surface of the polishing member is 0 degree to 0.3 with respect to a horizontal plane. A method for polishing a ferrule of an oblique PC connector, the method comprising: 23. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 22, wherein, in the step of performing the intermediate polishing, an inclination angle of a polishing surface of the polishing member is 0 degree to 0.3 with respect to a horizontal plane. A method for polishing a ferrule of an oblique PC connector, the method comprising: 24. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 23, wherein, in the step of performing the final polishing, an inclination angle of a polishing surface of the polishing member is set to 0.4 degrees to 1 with respect to a horizontal plane. 3. A ferrule polishing method for an oblique PC connector, wherein the ferrule is set to 3 degrees. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 24, wherein the size of the abrasive grains of the polishing member is 8 µm to 15 µm during the rough polishing. Connector ferrule polishing method. 26. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 25, wherein the size of polishing abrasive grains of the polishing member is 0.5 μm to 4 μm during medium polishing. A ferrule polishing method for PC connectors. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 26, wherein in the step of performing the final polishing, the size of the polishing abrasive grains of the polishing member is set to 0.007 µm to 0.12 µm. A method for polishing a ferrule of an oblique PC connector. 28. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 27, wherein, in the step of forming a distal end surface of the ferrule tubular body, an edge of the distal end surface of the ferrule tubular body is provided. A ferrule polishing method for an oblique PC connector, wherein the ferrule is formed by providing a chamfer having an inclination angle of 30 to 45 degrees with respect to an optical fiber axis. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 28, wherein, in the step of forming a distal end surface of the ferrule tubular body, the distal end has an outer diameter of 0.55 mm to 0.7 mm. A ferrule polishing method for an oblique PC connector, wherein a tip surface is formed. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 29, wherein, in the step of forming a distal end surface of the ferrule tubular body, a tip end surface of the ferrule tubular body is provided. A ferrule polishing method for an oblique PC connector, wherein a cylindrical portion having a small diameter equivalent to an outer diameter is formed. 31. The ferrule polishing method for an oblique PC connector according to claim 30, wherein, in the step of forming the distal end surface of the ferrule cylindrical body, a distal end surface having an outer diameter of 0.3 mm to 0.9 mm is formed at the distal end. Ferrule polishing method for oblique PC connectors. The method for polishing a ferrule of an oblique PC connector according to any one of claims 15 to 31, wherein the elastic member has a thickness of 1mm to 5mm. The ferrule polishing method for an oblique PC connector according to any one of claims 15 to 32, wherein, in the step of performing the rough polishing and the medium polishing and the step of performing the final polishing, a plurality of the ferrule cylindrical bodies are simultaneously formed. A method for polishing a ferrule of an oblique PC connector, characterized by polishing.

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