JP3874405B2 - Assembly method for optical ferrule receptacle - Google Patents

Description

[0001]
[Technical field belonging to the invention]
The present invention relates to an optical ferrule receptacle assembly method for assembling a receptacle having an optical holder for holding a single optical ferrule and a sleeve for precise positioning of the optical ferrule . For example, an optical fiber and an electronic circuit are coupled to each other. The present invention relates to a method for assembling a receptacle for an optical ferrule suitable for being applied to a receptacle built in an optical module .
[0002]
[Prior art]
FIG. 4 shows a conventional receptacle 1. The receptacle 1 is held by a metal or resin housing 2, a metal optical holder 3 having a cylindrical hollow portion 3 a for press-fitting a single-core cylindrical optical ferrule 5, and the optical holder 3. For example, the optical ferrule 5 has a structure including a sleeve 4 made of, for example, stainless steel.
The housing 2 has a distal end side opening 2b having an inner diameter D smaller than the sleeve accommodating portion 2a on the distal end side (right side in FIG. 4) of a cylindrical hollow sleeve accommodating portion 2a in which the sleeve 4 is accommodated, and a conical shape on the outer side thereof. The guide surface 2c is provided.
The optical holder 3 has a cylindrical recess 3b into which the rear end 2d of the housing 2 is press-fitted.
As the sleeve 4, a split sleeve having a slit in the longitudinal direction is usually used so that the optical ferrule 5 can be easily inserted. The optical ferrule 5 has a PC (Physical Contact) polishing surface 5a on the front end side and an oblique polishing surface 5b on the rear end side.
[0003]
The receptacle 1 is incorporated in an optical module unit 11 used as a transmission unit or a reception unit of an optical transceiver 10 of an optical communication system such as a LAN as shown in FIG. An isolator or a polarizing plate is attached to the surface 5b (not shown). In the figure, reference numeral 12 denotes a small single-core optical connector plug. A cylindrical optical ferrule 14 having an outer diameter of 1.25 mm (half the outer diameter of a so-called SC optical connector optical ferrule) made of zirconia is placed in a housing portion 13. It has a built-in latch 15 for attaching to and detaching from the optical module unit 11 and the like. Reference numeral 16 denotes an optical fiber cord.
When this optical connector plug 12 is inserted into the optical module section 11 of the optical transceiver 10, the optical ferrule 14 of the optical connector plug 12 is joined to the optical ferrule 5 in the receptacle 1 of the optical module section 11 and the optical fiber in each optical ferrule. Are optically connected.
The optical module unit 11 incorporates an optical element 17 such as a laser diode (LD) or a photodiode (PD), and is inserted into and fixed to the optical ferrule 5 in the receptacle 1 in the light emitting part or the light receiving part of the optical element 17. The end face of the optical fiber faces. A circuit board 18 is provided in the optical transceiver 10, and lead wires (not shown) drawn from the optical element 17 are connected to the circuit board 18. A lead pin 19 is provided on the circuit board 18 and is soldered to a main wiring board (not shown).
[0004]
As described above, the conventional receptacle 1 presses the optical ferrule 5 having the PC polishing surface 5a on the front end side and the oblique polishing surface 5b on the rear end side into the optical holder 3 which is a metal part, and grips the optical ferrule 5 The structure is such that a force is given by a tightening force from the optical holder 3 which is a metal part, and the optical holder 3 is covered with the housing 2.
[0005]
[Problems to be solved by the invention]
When the optical ferrule 5 is attached to the receptacle 1, after the optical ferrule 5 is press-fitted into the optical holder 3, the optical ferrule 5 is inserted into the positioning sleeve 4, and then the housing 2 is attached to the optical ferrule containing the sleeve 4. However, as a method for press-fitting the optical ferrule 5 into the optical holder 3, (1) a method of pressing the oblique polishing surface 5b side of the optical ferrule 5 and press-fitting from the rear end side (left side in FIG. 4) of the optical ferrule 5; 2) There are two methods: a method in which the PC polishing surface 5a side of the optical ferrule 5 is pushed and press-fitted from the front end side (right side in FIG. 4) of the optical holder 3.
[0006]
FIG. 5 shows the point in the case of the method {circle around (1)} in which the obliquely polished surface 5b side of the optical ferrule 5 is pushed into the optical holder 3. As shown in the figure, a guide member 7 having a guide hole 7a is arranged with the guide hole 7a facing the cylindrical hollow portion 3a of the optical holder 3, and the optical ferrule 5 and press-fitting into the guide hole 7a of the guide member 7 are arranged. The pin 8 is inserted and the press-fit pin 8 is pressed to press-fit the optical ferrule 5 into the cylindrical hollow portion 3 a of the optical holder 3.
In this case, since the rear end surface (obliquely polished surface 5b) of the optical ferrule 5 is inclined, when the optical ferrule 5 is pushed by the press-fit pin 8, as shown in FIG. There is a problem that a directional force (indicated by a broken line arrow) is generated and the optical ferrule 5 is tilted and press-fitted into the optical holder 3 as indicated by a two-dot chain line. When the vertical surface portion 5c that is not the oblique polishing surface 5b on the rear end side of the optical ferrule 5 is pushed horizontally, the position of the vertical surface portion 5c is greatly deviated from the center. It is press-fitted with a tilt.
[0007]
Further, in the case of the method (2) in which the PC polishing surface 5a side of the optical ferrule 5 is pushed and press-fitted from the distal end side of the optical holder 3, a guide member (not shown) similar to the above is disposed on the distal end side of the optical holder 3. The optical ferrule 5 is press-fitted into the cylindrical hollow portion 3a of the optical holder 3, but the inner surface of the cylindrical hollow portion 3a of the optical holder 3 is damaged at the edge of the rear end surface (obliquely polished surface 5b) of the optical ferrule 5. Further, there is a problem that the hole diameter of the hollow cylindrical portion 3a is increased so that a prescribed gripping force cannot be obtained, and the optical ferrule 5 is easily tilted because the gripping cannot be performed tightly.
As described above, the receptacle 1 having the conventional structure can be said to have a structure in which the optical ferrule 5 is easily tilted regardless of which of the methods (1) and (2) described above.
When the optical ferrule 5 is press-fitted in a state inclined with respect to the optical holder 3, the positioning sleeve 4 attached to the optical ferrule 5 is also inclined with respect to the optical holder 3.
Here, the tilted state means that the center line in the left-right direction in the drawing of the light holder 3 is tilted with respect to the center line in the longitudinal direction of the optical ferrule.
Therefore, since the optical holder 3 and the housing 2 are manufactured so that the center lines in the left-right direction are aligned and match when assembled, the sleeve 4 and the optical ferrule 5 are inclined with respect to the housing 2. It will be.
[0008]
Further, as shown in FIG. 6, the optical ferrule 14 of the optical connector plug 12 inserted into the sleeve 4 of the receptacle 1 is not completely compressed into the sleeve 4 and therefore hits the inner surface of the distal end side opening 2b of the housing 2. (See the portion of the circle A and the angle θ).
On the other hand, since the optical ferrule 5 and the sleeve 4 in the receptacle 1 are fixed to the optical holder 3 side, when a lateral external force acts on the optical connector plug 12, the end surfaces of the two optical ferrules 5 and 14 are in contact with each other. There is a problem that the joining is easily detached and the optical loss varies. In order to reduce this phenomenon, it is necessary to prevent the floating of the optical ferrule 14 by making the inner diameter dimension D of the front end side opening 2b of the housing 2 as small as possible. However, in the highly accurate front end side opening 2b in which the inner diameter dimension D is reduced and the dimensional tolerance is tightened, the optical ferrule 5 and the sleeve 4 are axially arranged so that the optical ferrule 14 of the optical connector plug 12 cannot be inserted. Must match the axis of the receptacle. That is, the center line of the sleeve 4 with the optical ferrule integrated with the optical holder 3 and the center line of the housing 2 coincide with each other, and the inside of the insertion opening of the housing 2 is viewed from the right side in the figure. The inner circumference of the sleeve 4 should be concentrically visible and visible.
However, in the structure of the conventional receptacle 1, as described above, the optical ferrule 5 is easily inclined, so that it is difficult to realize a highly accurate receptacle in which the inner diameter D of the distal end side opening 2b is reduced.
Further, since the connector plug 12 is inserted in parallel with the housing 2 and the pressing force by the optical ferrule pressing mechanism on the connector plug side is mainly directed in the above parallel direction, the pressing force direction and the optical fiber are on the connector plug side. Axial direction matches. On the other hand, the optical ferrule axis on the holder side is inclined from the axial direction, and this inclination affects the connection state of the ends of both optical ferrules, thereby degrading or making the optical characteristics unstable.
[0009]
This article was made to eliminate the above-mentioned conventional drawbacks, and solves the problem of tilting when the optical ferrule is press-fitted into the optical holder, thereby realizing a high-accuracy receptacle without any difficulty in assembly. It is another object of the present invention to provide an optical ferrule receptacle assembly method that facilitates mounting of the optical ferrule on the highly accurate receptacle.
[0010]
[Means for Solving the Problems]
The present invention that solves the above-described problems includes a light holder that holds a single-core cylindrical optical ferrule having an obliquely polished surface on the rear end side in a receptacle housing, and a tip portion of the optical ferrule that is held by the optical holder An optical ferrule receptacle assembly method for assembling an optical ferrule receptacle provided with a sleeve for inserting
The optical holder is press-fitted and held in a large-diameter cylindrical hollow portion having an inner diameter larger than the outer diameter of the optical ferrule, and the large-diameter cylindrical hollow portion of the optical holder main body. together they comprise a slit ring for press-fit grasping,
Press the optical ferrule into the slit ring,
Next, the rear end surface of the slit ring is pushed by the flat surface of the pushing member, and the optical ferrule is assembled to the optical holder by press-fitting the slit ring together with the optical ferrule into the large-diameter cylindrical hollow portion.
Simultaneously with or after the assembly, the optical ferrule tip is inserted or inserted into the sleeve,
Next, the rear end portion of the housing is fitted and fixed to a cylindrical recess formed on the front surface side of the optical holder body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 (a) is a cross-sectional view of a receptacle 21 of one embodiment assembled by applying the optical ferrule receptacle assembly method of the present invention, and FIG. 1 (b) is a left side view of FIG. 1 (a). The receptacle 21 includes a metal or resin housing 22 and a metal or resin optical holder 23 that holds a single core cylindrical zirconia optical ferrule 25 in a left side view made of metal or resin. The structure includes a sleeve 24 made of, for example, stainless steel or ceramic, into which the tip of the optical ferrule 5 held by the light holder 23 is fitted.
The housing 22 has a distal end side opening 22b having an inner diameter d smaller than the sleeve accommodating portion 22a on the distal end side (right side in FIG. 1) of a cylindrical hollow sleeve accommodating portion 22a in which the sleeve 24 is accommodated, and a conical shape on the outer side thereof. A guide surface 22c is provided.
The sleeve 24 has a size into which the above-described thin optical ferrule 14 of FIG. 3 having an outer diameter of 1.25 mm is inserted. As will be described later, since the optical ferrule 5 can be press-fitted straight into the optical holder 23, the sleeve 24 of the embodiment uses a simple cylindrical sleeve without a slit in the longitudinal direction, but a split sleeve with a slit as necessary. May be used.
The size of the gap 29 between the housing 22 and the sleeve 24 is designed as necessary.
The optical ferrule 5 has a PC (Physical Contact) polishing surface 5a on the front end side and an oblique polishing surface 5b on the rear end side.
[0015]
The optical holder 23 includes an optical holder main body 25 and a slit ring 26, both of which are made of metal, for example. The optical holder main body 25 has a large-diameter cylindrical hollow portion 25a having an inner diameter larger than the outer diameter of the optical ferrule 5, and a cylindrical recess 25b into which the rear end portion 22d of the housing 22 is fitted. . The slit ring 26 includes a slit 26 a in the longitudinal direction, and has an inner diameter that can elastically hold the optical ferrule 5. For example, phosphor bronze, ceramic, stainless steel or the like may be used. The interval between the slits 26a is, for example, about 0.4 to 0.5 mm.
[0016]
As described above, the receptacle 21 is built in the optical module unit 11 used as the transmission unit or the reception unit of the optical transceiver 10 of the optical communication system such as a LAN as shown in FIG. Description of is omitted.
[0017]
When the optical ferrule 5 is attached to the receptacle 21, first, the optical ferrule 5 is press-fitted into the optical holder 23. The procedure for press-fitting the optical ferrule 5 into the optical holder 23 will be described. First, the optical ferrule 5 is press-fitted into the slit ring 26 as shown in FIG. The inner diameter of the slit ring is initially slightly narrower than that of the optical ferrule 5, but since the diameter is easily increased by the slit 26a, the optical ferrule 5 can be press-fitted with a small force. Will not tilt. That is, the center lines in the left and right direction on both papers are easily parallel and coincide. If the rear end surface of the slit ring 26 is pushed in until it coincides with the rear end of the optical ferrule, then the rear end surface of the slit ring 26 holding the optical ferrule 5 is pushed in as shown in FIG. The slit ring 26 is press-fitted into the large-diameter cylindrical hollow portion 25 a of the optical holder body 25 together with the optical ferrule 5. The inner diameter of the hollow portion 25a can be press-fitted with an optical ferrule with a slit ring (slit ring 26 fitted with the optical ferrule 5), but is small enough that it cannot be easily removed once press-fitted.
In this case, in spite of pushing the rear end face side (obliquely polished surface 5b side) of the optical ferrule 5, the slightly inclined vertical surface portion 5c of the optical ferrule 5 is pushed instead of directly pushing the obliquely polished surface 5b. Become.
Alternatively, the edge of the optical ferrule 5 can be pushed while leaving the edge.
However, the pressing force from the rear end surface of the slit ring 26 mainly acts as a force for moving the optical ferrule 5 forward by the inner surface of the slit ring tightening the optical ferrule 5.
Accordingly, press-fitting can be performed with a uniform pressure, and the slit ring 26 does not tilt, so that the optical ferrule 5 held horizontally by the slit ring 26 does not tilt.
As described above, there is no difficulty in press-fitting the optical ferrule 5 into the optical holder 23, and the optical ferrule 5 can be easily press-fitted straight into the optical holder 23 with high accuracy without tilting.
Here, straight means that the axes of the optical holder and the optical ferrule are parallel as already described.
[0018]
Next, when the front end portion of the optical ferrule 5 is inserted or inserted into the sleeve 24, the rear end portion 22 d of the housing 22 is press-fitted inside the cylindrical recess 25 b of the optical holder body 25.
The inner diameter of the cylindrical recess 25b is, for example, a size that is somewhat narrower than the outer shape of the housing.
In the case of a size that cannot be press-fit, an adhesive may be used, or a press-fit and an adhesive may be used in combination.
Since a slight gap is required between the sleeve and the housing, the slit ring is thicker than the sleeve in this embodiment. However, it is easy to create a gap by adjusting the thickness of other portions.
[0019]
In the receptacle 21 described above, since the optical ferrule 5 and the sleeve 24 are mounted straight on the housing 22 with high accuracy even if the inner diameter dimension d of the front end opening 22b of the housing 22 is smaller than the conventional inner diameter dimension D, the sleeve Thus, there is no problem that the optical ferrule 14 on the side of the optical connector plug 12 cannot be inserted because the front end opening 24 faces the opening 22a of the housing 22 without being displaced.
[0020]
Note that the material of the slit ring 26 is not limited to slender, and other metals can be used. Further, the slit formed in the slit ring 26 is not limited to a simple straight line when viewed from above, but may be a wave shape or a saw blade shape.
Since the optical ferrule 5 can be press-fitted straight into the optical holder 23 with high accuracy, a simple cylindrical sleeve 24 having no slit is used in the embodiment, but a split sleeve may be used.
The material of the sleeve 24 may be phosphor bronze, ceramic, or other metal instead of stainless steel .
Also further, in each of the foregoing embodiments, after assembling the optical ferrule to the optical holder has a step of inserting a ferrule into the sleeve, to make the insertion of the pressing and the sleeve into the light holder at the same step It is not excluded.
[0021]
Although the said embodiment demonstrated as the receptacle 21 incorporated in the optical module part 11 of the optical transceiver 10, this invention is not restricted to this, The optical holder for holding a single-core optical ferrule, and the precision positioning of an optical ferrule The present invention can be applied to receptacles for various applications including a sleeve, and can correspond to optical ferrule receptors having various shapes regardless of the shape of the optical receptacle.
Further, the shape of the optical holder is not limited to the above embodiment, and is a general term for members that hold and fix the optical ferrule, and the present invention is widely applicable when assembling the optical ferrule straight to such a member. It is.
Furthermore, the type of optical fiber built in the optical ferrule is not limited, and optical fibers with various diameters and transmission forms can be employed.
[0022]
【The invention's effect】
According to the method for assembling the optical ferrule receptacle of the present invention , the optical holder in the optical holder holding the single optical ferrule and the receptacle provided with the sleeve for performing precision of the optical ferrule, the optical holder main body and the optical holder main body A slit ring that is press-fitted into the slit ring, and after the optical ferrule is press-fitted into the slit ring, the rear end surface of the slit ring is pushed by the flat surface of the pushing member, and the slit ring is joined together with the optical ferrule to the large diameter of the optical holder body. Since the optical ferrule is assembled into the optical holder by press-fitting into the hollow cylindrical portion, it is possible to press-fit into the optical holder without tilting the optical ferrule, and the optical ferrule and the sleeve are mounted straight in the receptacle with high accuracy. It became possible.
Thereby, even if the inner diameter d of the opening on the front end side of the housing is reduced, there is no problem that the optical ferrule on the optical connector plug side to be inserted into the receptacle cannot be inserted, and therefore there is no difficulty in assembly. A highly accurate receptacle could be realized, and a highly accurate receptacle structure could be manufactured efficiently and at low cost.
And the insertion property of an optical ferrule improved and it became possible to obtain the outstanding optical characteristic by the connection state between optical ferrules being stabilized.
[0023]
Moreover, it is easy to press-fit and hold the optical ferrule without tilting the optical ferrule, and the optical ferrule can be easily mounted straight in the receptacle .
[0024]
In the present invention, the ferrule is press-fitted to the light holder, since the rear end side and has a diagonal polishing surface, the above effects can be obtained effectively.
[Brief description of the drawings]
1A is a cross-sectional view of a receptacle of an embodiment assembled by applying the method for assembling an optical ferrule receptacle of the present invention, and FIG. 1B is a left side view of FIG.
2A and 2B are diagrams for explaining a procedure for press-fitting an optical ferrule into the optical holder of FIG. 1, wherein FIG. 2A is a step of press-fitting the optical ferrule into the slit ring, and FIG. 2B is a press-fit of the slit ring into the optical holder body. Each process is shown.
FIG. 3 is a side view of an optical transceiver incorporating a receptacle and an optical connector plug connected to the receptacle, showing an example of use of the receptacle.
FIG. 4 is a cross-sectional view of a conventional receptacle.
5 is a diagram for explaining a procedure for press-fitting an optical ferrule into an optical holder in the receptacle of FIG. 4 and a problem at that time. FIG.
6 is a diagram for explaining a problem in performance of the receptacle of FIG. 4; FIG.
[Explanation of symbols]
5 Optical ferrule 21 Receptacle 22 Housing 22a Sleeve accommodating portion 22b Front end opening 22c Guide surface 22d Recess 23 Optical holder 24 Sleeve 25 Optical holder body 25a Large diameter cylindrical hollow portion 25b Cylindrical recess 26 Slit ring 26a Slit 27 Pushing member

Claims (1)

A light provided with a light holder for holding a single-core cylindrical optical ferrule having an obliquely polished surface on the rear end side in a receptacle housing, and a sleeve for fitting a front end portion of the optical ferrule held by the optical holder An assembly method of an optical ferrule receptacle for assembling a ferrule receptacle,
The optical holder is press-fitted and held in a large-diameter cylindrical hollow portion having an inner diameter larger than the outer diameter of the optical ferrule, and the large-diameter cylindrical hollow portion of the optical holder main body. together they comprise a slit ring for press-fit grasping,
Press the optical ferrule into the slit ring,
Next, the rear end surface of the slit ring is pushed by the flat surface of the pushing member, and the optical ferrule is assembled to the optical holder by press-fitting the slit ring together with the optical ferrule into the large-diameter cylindrical hollow portion.
Simultaneously with or after the assembly, the optical ferrule tip is inserted or inserted into the sleeve,
Next, the optical ferrule receptacle assembly method is characterized in that the rear end portion of the housing is fitted and fixed in a cylindrical recess formed on the front surface side of the optical holder body.

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