JP2003139994A - Assembling method for optical holder, optical ferrule pressing-in method, and receptacle for optical ferrule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an optical ferrule from being pressed obliquely in an optical holder. SOLUTION: A housing 22 of a receptacle 21 is provided with an optical holder 23 which grips a single-core cylindrical optical ferrule 5 and a sleeve 24 in which a tip of the optical ferrule 5 gripped by the optical holder 23 is fit. The optical holder 23 comprises an optical holder main body 25 and a slit ring 26 which is pressed and held in the optical holder main body 25. The optical ferrule 5 is pressed in the slit ring 26 first. Since the slit ring 26 is easy to increase in diameter, the optical ferrule 5 can be pressed in with a small force straight. Then the slit ring 26 is pressed in the optical holder main body 25 together with the optical ferrule 5 and then the optical holder 23 presses in and grips the optical ferrule 5 straight. The optical holder 23 is loaded in the housing 22 and the optical ferrule 5 is fitted in the sleeve 22. Since the optical ferrule 5 and sleeve 4 are loaded straight, a highly accurate receptacle 21 is realized which is free of difficulty in assembly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receptacle provided with an optical holder for holding a single-core optical ferrule and a sleeve for precisely positioning the optical ferrule. For example, an optical module for coupling an optical fiber and an electronic circuit. The present invention relates to a receptacle for an optical ferrule suitable for being applied to a receptacle built in the optical disk, and also relates to an optical ferrule press-fitting method and an optical holder assembling method.

[0002]

2. Description of the Related 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 hollow cylindrical portion 3a into which a single-core cylindrical optical ferrule 5 is press-fitted and held, and the optical holder 3. This structure is provided with a sleeve 4 made of, for example, stainless steel into which the tip of the optical ferrule 5 is fitted. The housing 2 has a cylindrical hollow sleeve accommodating portion 2a in which the sleeve 4 is accommodated, and 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).
And has a conical guide surface 2c on the outside thereof. 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.

The receptacle 1 is built in an optical module section 11 used as a transmitting section or a receiving section of an optical transceiver 10 of an optical communication system such as a LAN as shown in FIG. 3, which is common to the conventional example and the present invention. Then, an isolator, a polarizing plate or the like is attached to the polishing surface 5b (not shown). In the figure, 12 is a small-sized single-core optical connector plug, and a cylindrical optical ferrule 14 made of zirconia and having an outer diameter of 1.25 mm (half the outer diameter of a so-called SC optical connector optical ferrule) is housed in the housing portion 13. It has a built-in latch 15 for attaching / detaching to / from the optical module unit 11 and the like. Reference numeral 16 is an optical fiber cord. This optical connector plug 12 is an optical transceiver 1
When 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 portion 11, the optical fiber in each optical ferrule is optically connected. Optical module part 11
Includes an optical element 17 such as a laser diode (LD) or a photodiode (PD), and a light emitting portion or a light receiving portion of the optical element 17 has an optical fiber end surface fixedly inserted through the optical ferrule 5 in the receptacle 1. Face. A circuit board 18 is provided in the optical transceiver 10, and lead wires (not shown) drawn from the optical element 17 are provided on the circuit board 18.
Are connected. Reference numeral 19 denotes a lead pin provided on the circuit board 18, which is soldered to a main wiring board (not shown).

As described above, in the conventional receptacle 1, the optical ferrule 5 having the PC polishing surface 5a on the front end side and the slanted polishing surface 5b on the rear end side is press-fitted into the optical holder 3, which is a metal component, to obtain the optical ferrule. The gripping force of 5 is given by the tightening force from the optical holder 3 which is a metal component, and the housing 2 is covered on the optical holder 3.

[0005]

SUMMARY OF THE INVENTION Receptacle 1 described above.
When the optical ferrule 5 is attached to the optical ferrule 5, 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 optical ferrule with the sleeve 4 is covered with the housing 2. As a method of press-fitting the ferrule 5 into the optical holder 3, a method of pressing the oblique polishing surface 5b side of the optical ferrule 5 to press-fit from the rear end side of the optical holder 3 (left side in FIG. 4) and a PC polishing surface 5a of the optical ferrule 5 are used. There are two methods: a method of pushing the side and a press-fitting from the tip side (right side of FIG. 4) of the optical holder 3.

FIG. 5 shows a procedure in the case of a method of pressing the obliquely polished surface 5b side of the optical ferrule 5 and press-fitting it into the optical holder 3. As shown in the figure, a guide member 7 having a guide hole 7a is provided, and the guide hole 7a is provided in the cylindrical hollow portion 3a of the optical holder 3.
The optical ferrule 5 and the press-fitting pin 8 are inserted into the guide hole 7a of the guide member 7, and the press-fitting pin 8 is pushed to press-fit the optical ferrule 5 into the hollow cylindrical portion 3a 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-fitting pin 8, as shown in FIG. A directional force (indicated by a dashed arrow) is generated, and the optical ferrule 5 causes the optical holder 3 to
There is a problem that it is inclined and pressed into. In addition,
When the vertical surface portion 5c which is not the slanted 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 largely deviated from the center, and thus the optical ferrule 5 is inclined to the optical holder 3 as well. Is pressed in.

Further, in the case of a system in which the PC polishing surface 5a side of the optical ferrule 5 is pushed and press-fitted from the tip side of the optical holder 3, the same guide member (not shown) arranged at the tip side of the optical holder 3 is used. The optical ferrule 5 is press-fitted into the hollow cylindrical portion 3a of the optical holder 3, but the inner surface of the hollow cylindrical portion 3a of the optical holder 3 is scratched by the edge of the rear end surface (obliquely polished surface 5b) of the optical ferrule 5. However, there is a problem in that the hole diameter of the cylindrical hollow portion 3a becomes large, a prescribed gripping force cannot be obtained, and the optical ferrule 5 is prone to tilt because a tight grip is not possible. As described above, it can be said that the receptacle 1 having the conventional structure has a structure in which the optical ferrule 5 easily tilts, regardless of the method described above or any one of the methods. When the optical ferrule 5 is press-fitted to the optical holder 3 in a tilted state, the positioning sleeve 4 attached to the optical ferrule 5 is also tilted to the optical holder 3. The tilted state means that the center line of the optical holder 3 in the left-right direction in the drawing is tilted with respect to the center line of the optical ferrule in the longitudinal direction. 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 aligned when assembled, the sleeve 4 and the optical ferrule 5 are inclined with respect to the housing 2. It will be.

Further, as shown in FIG. 6, the receptacle 1
Since the optical ferrule 14 of the optical connector plug 12 inserted in the sleeve 4 is not completely pressed into the sleeve 4, there is a risk that the optical ferrule 14 slightly tilts until it hits the inner surface of the front end side opening 2b of the housing 2 (circle A portion, And 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 faces of the two optical ferrules 5 and 14 are There is a problem that the junction is easily separated and the optical loss fluctuates. In order to reduce this phenomenon, it is necessary to prevent the optical ferrule 14 from floating by making the inner diameter dimension D of the front end side opening 2b of the housing 2 as small as possible. However, in order to prevent the insertion of the optical ferrule 14 of the optical connector plug 12 from becoming impossible with the highly accurate front end side opening 2b in which the inner diameter dimension D is made small and the dimensional tolerance is tight, the axial centers of the optical ferrule 5 and the sleeve 4 are set. It must be aligned with the axis of the receptacle. That is, the center line of the optical ferrule sleeve 4 integrated with the optical holder 3 and the center line of the housing 2 coincide with each other, and the housing 2 is viewed from the outside in the right side of the drawing.
The inner circumference of the sleeve 4 should be positioned concentrically with the inside of the insertion opening of the above and visible. However, in the structure of the conventional receptacle 1, as described above, the optical ferrule 5 is used.
Is easily tilted, it is difficult to realize a highly accurate receptacle in which the inner diameter D of the front end side opening 2b is made small. 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 on the connector plug side are the same. Axes match. On the other hand, the optical axis of the ferrule on the holder side is inclined from the above-mentioned axial direction, and this inclination affects the connection state of the ends of both optical ferrules and deteriorates or makes the optical characteristics unstable.

This article has been made in order to solve the above-mentioned conventional drawbacks, and solves the problem of tilting when the optical ferrule is press-fitted into the optical holder, and is a high-accuracy receptacle without difficulty in assembly. It is an object of the present invention to provide a method of press-fitting an optical ferrule that facilitates attachment of the optical ferrule to this highly accurate receptacle.

[0010]

SUMMARY OF THE INVENTION The present invention, which solves the above problems, provides a housing for a receptacle, an optical holder for holding a single-core cylindrical optical ferrule, and a tip portion of the optical ferrule held by the optical holder. In a receptacle for an optical ferrule having a sleeve for inserting the optical holder, the optical holder includes an optical holder main body having a large-diameter cylindrical hollow portion having an inner diameter larger than an outer diameter of the optical ferrule, and the large-diameter cylinder of the optical holder main body. It is characterized in that it is constituted by a slit ring that is press-fitted and held in the hollow portion and press-fits and holds the optical ferrule therein.

A second aspect of the present invention is an optical ferrule press-fitting method of press-fitting the optical ferrule into the optical ferrule receptacle of claim 1, wherein the optical ferrule is press-fitted into the slit ring, and then the rear end surface of the slit ring is It is characterized in that the slit ring is pressed into the large-diameter cylindrical hollow portion of the optical holder body together with the optical ferrule.

A third aspect of the present invention is the optical ferrule press-fitting method according to the second aspect, wherein the optical ferrule has a PC polishing surface on the front end side and an oblique polishing surface on the rear end side.

According to a fourth aspect of the present invention, there is provided an optical holder assembling method,
When assembling the cylindrical optical ferrule to the optical holder,
The optical ferrule is inserted into a slit ring of an article different from the sleeve in advance, and then the rear end surface of the slit ring is pressed against the optical holder to press the slit ring together with the optical ferrule into the housing portion of the optical holder. It is characterized by doing.

[0014]

1 (A) is a sectional view of a receptacle 21 according to an embodiment of the present invention, and FIG. 1 (B) is FIG. 1 (A).
FIG. The receptacle 21 includes a metal or resin housing 22 and a metal or resin optical holder 2 which holds a single-core cylindrical optical ferrule 25 made of metal or resin and which is cylindrical or rectangular in a left side view.
3 and a sleeve 24 made of, for example, stainless or ceramic into which the tip of the optical ferrule 5 held by the optical holder 23 is fitted. The housing 22 has a tip side opening 22b having an inner diameter d smaller than that of the sleeve accommodating portion 22a on the tip side (right side in FIG. 1) of the cylindrical hollow sleeve accommodating portion 22a in which the sleeve 24 is accommodated, and a conical outside thereof. It has a guide surface 22c.
The sleeve 24 has an outer diameter of 1.25 mm, as shown in FIG.
This is the size into which the small-diameter optical ferrule 14 is inserted. Since the optical ferrule 5 can be press-fitted straight into the optical holder 23 as will be described later, the sleeve 24 of the embodiment uses a simple cylindrical sleeve without a slit in the longitudinal direction. May be used. Further, the size of the gap 29 between the housing 22 and the sleeve 24 is designed as needed. 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.

The light holder 23 is composed of a light holder body 25 and a slit ring 26, both of which are made of metal, for example. The optical holder body 25 has a large-diameter cylindrical hollow portion 25a having an inner diameter larger than the outer diameter of the optical ferrule 5 at the center thereof, and a cylindrical recess 25b into which the rear end portion 22d of the housing 22 is fitted. . The slit ring 26 has a slit 26a in the longitudinal direction and has an inner diameter capable of elastically gripping the optical ferrule 5. The material may be, for example, phosphor bronze, ceramic, stainless steel, or the like. The spacing between the slits 26a is, for example, about 0.4 to 0.5 mm.

The receptacle 21 is, as described above,
For example, as shown in FIG. 3, it is built in the optical module unit 11 used as a transmitting unit or a receiving unit of the optical transceiver 10 of an optical communication system such as a LAN, but the re-explanation of FIG. 3 is omitted.

The optical ferrule 5 is attached to the receptacle 21.
When attaching the optical ferrule 5 to the optical holder 23,
Press fit. To explain how to press fit the optical ferrule 5 into the optical holder 23, as shown in FIG. 2A, first, the optical ferrule 5 is press fitted into the slit ring 26. The inner diameter of the slit ring is slightly narrower than that of the optical ferrule 5 at first, but it can be easily expanded by the slit 26a, so that the optical ferrule 5 can be press-fitted with a small force. Does not tilt. That is, the center lines of the two papers in the left-right direction on the paper easily become parallel and coincide with each other. If the rear end face of the slit ring 26 is pushed to a position where it coincides with the rear end of the optical ferrule, then, as shown in FIG. 2B, the rear end face of the slit ring 26 holding the optical ferrule 5 is pushed into the pushing member 27. Then, the slit ring 26 is pressed together with the optical ferrule 5 into the large-diameter cylindrical hollow portion 25a of the optical holder main body 25 by pushing horizontally on the plane. The inner diameter of the hollow portion 25a is such that an optical ferrule with a slit ring (slit ring 26 into which the optical ferrule 5 is fitted) can be press-fitted, but cannot be easily pulled out once press-fitted. In this case, even though the rear end face side (oblique polishing surface 5b side) of the optical ferrule 5 is pressed, the vertical polishing surface 5c of the slightly remaining optical ferrule 5 is pressed instead of directly pressing the oblique polishing surface 5b. Become. Or leave an edge,
It is also possible to push the edge of the optical ferrule 5. However,
The pressing force from the rear end surface of the slit ring 26 mainly acts as a force for advancing the optical ferrule 5 due to the inner surface of the slit ring tightening the optical ferrule 5. Therefore, it is possible to press-fit 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, the optical ferrule 5 is attached to the optical holder 2
There is no difficulty in the operation of press-fitting into the optical ferrule 3, and the optical ferrule 5 can be easily press-fitted straight into the optical holder 23 with high precision without tilting. Here, "straight" means that the axes of the optical holder and the optical ferrule are parallel to each other, as described above.

Next, when the tip portion of the optical ferrule 5 is fitted into or inserted into the sleeve 24, the housing 22
The rear end portion 22d is connected to the cylindrical recess 25b of the optical holder body 25.
It is press-fitted inside. The inner diameter of the cylindrical recess 25b is, for example, slightly smaller than the outer shape of the housing. If the size cannot be press-fitted, an adhesive may be used, or the press-fitting and the adhesive may be used together. In addition,
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.

In the receptacle 21 described above, even if the inner diameter dimension d of the front end side opening 22b of the housing 22 is made smaller than the conventional inner diameter dimension D, the optical ferrule 5 and the sleeve 24 are mounted on the housing 22 in a straight line with high precision. Therefore, there is no problem that the front end opening of the sleeve 24 accurately faces the front end side opening 22a of the housing 22 without being displaced, and the optical ferrule 14 on the optical connector plug 12 side cannot be inserted.

The material of the slit ring 26 is not limited to the stainless steel, but other metal can be used. Further, the slits formed in the slit ring 26 are not limited to those having a simple linear shape when viewed from the top surface, and may have a corrugated shape or a sawtooth shape. Since the optical ferrule 5 can be directly and press-fitted into the optical holder 23 with high precision, a simple 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. Further, the optical ferrule 5 of the embodiment has a structure having an obliquely polished surface 5b on the rear end surface, and is particularly effective when pressing an optical ferrule having an obliquely inclined surface, but it is not necessarily limited to this, and only a vertical surface may be used. It can be structured. Furthermore, in each of the above-described embodiments, the step of inserting the optical ferrule into the sleeve after the optical ferrule has been assembled to the optical holder has been described. However, it is possible to eliminate pressing the optical holder and inserting the sleeve in the same step. Not something to do.

Although the above embodiment has been described as the receptacle 21 built in the optical module section 11 of the optical transceiver 10, the present invention is not limited to this, and an optical holder for holding a single-core optical ferrule and a precision optical ferrule. The present invention can be applied to receptacles for various purposes provided with a positioning sleeve, and can be applied to optical ferrule receptors of various shapes regardless of the shape of the optical receptacle.
Further, the shape of the optical holder is not limited to the above embodiment,
This is a general term for members that hold and fix the optical ferrule, and the present invention is widely applicable to the case where the optical ferrule is assembled straight to such a member. Furthermore,
The type of optical fiber incorporated in the optical ferrule is not limited, and optical fibers having various diameters and transmission forms can be adopted.

[0022]

According to the present invention, the optical holder in the receptacle provided with the optical holder for holding the single-core optical ferrule and the sleeve for performing precision of the optical ferrule,
Since it consists of the optical holder body and the slit ring that is press-fitted and held in the optical holder body, it is possible to press-fit and hold the optical ferrule without tilting the optical ferrule, and the optical ferrule and the sleeve can be accurately straightened in the receptacle. It has become possible to attach it to. As a result, even if the inner diameter d of the front end side opening of the housing is reduced, the problem that the optical ferrule on the optical connector plug side to be inserted into this receptacle cannot be inserted does not occur, and therefore, there is no difficulty in assembly. A high-accuracy receptacle can be realized, and a high-accuracy receptacle structure can be efficiently manufactured at low cost. Then, the insertability of the optical ferrule is improved and the connection state between the optical ferrules is stabilized, so that it becomes possible to obtain excellent optical characteristics.

According to the optical ferrule press-fitting method of the second aspect, the optical ferrule can be easily press-fitted and held in the optical holder without being tilted, and the optical ferrule can be mounted straight in the receptacle.

According to a third aspect of the present invention, the optical ferrule press-fitted into the optical holder has a PC polishing surface on the tip side,
It is particularly effective when it has an inclined polishing surface on the rear end side.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of a receptacle according to an embodiment of the present invention, and FIG. 1B is a left side view of FIG.

2A and 2B are views for explaining the procedure for press-fitting the optical ferrule into the optical holder shown in FIG. 1, wherein (A) is a step of press-fitting the optical ferrule into the slit ring, and (B) is a press-fitting process of the slit ring into the main body of the optical holder. Each step is shown.

FIG. 3 is a side view of an optical transceiver incorporating the receptacle and an optical connector plug connected to the optical transceiver, showing an example of use of the receptacle.

FIG. 4 is a sectional view of a conventional receptacle.

5A and 5B are diagrams illustrating 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 illustrating a performance problem of the receptacle of FIG.

[Explanation of symbols]

5 optical ferrule 21 Receptacle 22 housing 22a Sleeve accommodation section 22b Tip side opening 22c guide surface 22d recess 23 Optical holder 24 sleeves 25 Optical holder body 25a Large diameter hollow cylinder 25b cylindrical recess 26 slit ring 26a slit 27 Push-in member

Continued front page    (72) Inventor Yoshikazu Nomura             1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Sa Co., Ltd.             Inside the warehouse F term (reference) 2H036 QA19 QA20 QA32 QA44 QA57

Claims (4)

[Claims] 1. A receptacle for an optical ferrule comprising an optical holder for holding a cylindrical optical ferrule having a single core, and a sleeve into which a tip end of the optical ferrule held by the optical holder is fitted, in a housing of the receptacle. , The optical holder main body having a large-diameter cylindrical hollow portion having an inner diameter larger than the outer diameter of the optical ferrule, and the optical holder main body is press-fitted and held in the large-diameter cylindrical hollow portion, and the optical holder A receptacle for an optical ferrule, comprising a slit ring for press-fitting and gripping a ferrule. 2. An optical ferrule press-fitting method in which the optical ferrule is press-fitted into the optical ferrule receptacle according to claim 1, wherein the optical ferrule is press-fitted into the slit ring, and then,
An optical ferrule press-fitting method, characterized in that the slit ring is pressed into the large-diameter cylindrical hollow portion of the optical holder body by pressing the rear end surface of the slit ring together with the optical ferrule. 3. The optical ferrule press-fitting method according to claim 2, wherein the optical ferrule has a PC polishing surface on the front end side and an oblique polishing surface on the rear end side. 4. When assembling a cylindrical optical ferrule into an optical holder, the optical ferrule is previously inserted into a slit ring of an article different from the sleeve, and then the rear end face of the slit ring is pressed against the optical holder. Thus, the method of assembling the optical holder, characterized in that the slit ring is press-fitted into the housing portion of the optical holder together with the optical ferrule.