JP3283397B2 - Optical fiber holding mechanism in optical fiber connector end face inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber holding mechanism for holding an end portion of an optical fiber connector, and more specifically, a simple operation and high accuracy when inspecting the state of the end surface of an optical fiber connector. The present invention relates to an optical fiber holding mechanism that can hold an optical fiber ferrule.

[0002]

2. Description of the Related Art In an optical communication system, it is important to easily and accurately connect optical fibers to each other in order to construct a wide communication network. 2. Description of the Related Art Conventionally, there is an optical fiber connector for connecting an optical fiber end face. In manufacturing this optical fiber connector, the ferrule end face into which the optical fiber is inserted is polished into a spherical shape. The optical fiber is connected by bringing the ferrule end face polished into contact with the spherical shape. However, depending on the state of contact of the ferrule end face, that is, the loss of light at the time of connection depending on the polishing state, there may be a case where the spherical center matches the mechanical center of the ferrule end face. Need to be checked.

[0003]

A number of devices for inspecting the state of the ferrule end face of an optical fiber connector have been proposed to date. In such an inspection apparatus, the applicant of the present invention has proposed a portable inspection apparatus in which the polished end face is not observed directly but projected on a screen and observed (Japanese Patent Application No. 6-315044). This device uses the interference fringes of light to determine the polishing state, and when inspecting whether the center point of the spherical polishing surface is shifted from the mechanical center of the ferrule of the optical fiber connector, The axis of the mechanism holding the optical fiber connector and the optical axis of the objective lens must be exactly aligned.

In the conventional inspection method, even if the mechanical centers of the objective lens and the fiber of the optical fiber connector are adjusted in advance, the individual optical fiber connectors are individually held when setting the optical fiber connectors one by one. Inclination and misalignment between the axis of the mechanism and the optical axis of the objective lens are apt to occur, and must be corrected with screws, knobs, etc., so that the inspection takes a long time and many optical fiber connectors cannot be inspected efficiently. Further, in the method of observing the polished end face of the optical fiber connector with a microscope, an operation for matching the optical axis each time the optical fiber connector is set is required. An object of the present invention is to adjust the relationship between the axis of the holding mechanism and the optical axis of the objective lens in advance so that each time an optical fiber connector is set, the optical axis of the objective lens of the inspection apparatus is adjusted. In contrast, an object of the present invention is to provide an optical fiber holding mechanism in an optical fiber connector end face inspection apparatus which does not need to be corrected with a screw, a knob or the like, and can be set accurately only by inserting a ferrule portion.

[0005]

In order to achieve the above object, an optical fiber holding mechanism in an optical fiber connector end face inspection apparatus according to the present invention has a through hole, and a shaft of the through hole is connected to a ferrule of the optical fiber connector. A fiber holder having an adjusting means for adjusting the optical axis of the objective lens facing the ferrule end face to project the end face, and a slit having an outer diameter smaller than the inner diameter of the through hole and a fixed gap; A sleeve fixed to the fiber holder by being inserted into the through-hole and bonding a part of the outer peripheral surface to the inner peripheral surface of the through-hole, and a through-hole of the fiber holder. It consists of a transparent glass body arranged between one end and the objective lens, and the axis of the through-hole coincides with the optical axis of the objective lens by the adjusting means.
In this manner, the sleeve is inserted from the other end of the sleeve, and the polished end face is pressed into a position where the polished end face comes into contact with the transparent glass body so that the polished end face faces the objective lens and the ferrule of the optical fiber connector is held. ing. Further, the adjusting means holds the fiber holder.
Fix the holder base plate for attachment and the holder base plate
And a holder receiver on which the glass body is mounted,
When attaching the fiber holder to the holder base plate,
The spring was installed through the hole of the holder base plate
Screw it into the holder post and use the flat screw head to
By using a structure to hold down the holder,
Make sure that the ferrule of the Iva connector matches the optical axis of the objective lens.
The fiber holder.
Adjust the set screws to adjust the objective lens
The angle is adjusted so as to be parallel to the optical axis .

[0006]

According to the above construction, the positioning and holding can be performed accurately only by inserting the ferrule of the optical fiber connector, the operation required for mounting and dismounting is facilitated, and the inspection efficiency is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of an optical fiber holding mechanism according to the present invention, and FIG. 2 is a sectional view of the optical fiber holding mechanism. The optical fiber holding mechanism 15 includes a block of a fiber holder 1, a holder base plate 2, and a holder receiver 3. The holder base plate 2 is provided with a screw 21
It is fixed by screwing it into the inspection device die-casting main body 11 through a through 21b. The fiber holder 1 inserts the cylindrical portion 1b into the hole 2a of the holder base plate 2 and the flange portion 1a.
Is held down by the heads of the four flat screws 5 so as not to move with respect to the holder base plate 2. Each of the four flat screws 5 is screwed through the holes 5a to 5d to the screw portion of the holder post 8 on which the spring 7 is mounted, so that the flat screw 5 is applied with a biasing force rightward in FIG.
The flange 1a is pressed down.

The screw, the long groove, the flat screw, the spring, and the holder post can be adjusted so that the axis of the holding mechanism coincides with the optical axis of the objective lens. The fixing of the fiber holder 1 to the holder base plate 2 is performed by using the screw holes 20a to 20-2 of the holder base plate 2.
0d, four screws are screwed together, and the peripheral portion of the flange portion 1a is
This is done by pressing with the head of a flat screw of the book. Set screws 4 are attached to three places of the fiber holder 1, and by adjusting these set screws 4, the angle of the objective lens with respect to the optical axis can be adjusted to be parallel.

The holder base plate 2 has four countersunk screws 6 passed through countersunk holes 6a to 6d, respectively, and screw holes 3a to 3
It is fixed to the holder receiver 3 by being screwed to d.
The elongated holes 8a to 8d of the holder receiver 3 are relief holes of the holder post 8. A glass container 12 is provided at the rear of the holder receiver 3, and a leaf spring 10 is disposed inside the glass container 12.
By inserting the glass 9 from above the glass housing portion 12, the glass 9 is fixed while being pressed in the direction of the fiber holder 1 by the leaf spring 10. A sleeve 13 into which a ferrule of an optical fiber connector is inserted is fixed in a sleeve holding portion 1a of the fiber holder 1.

FIG. 3 is a view showing details of the vicinity of the sleeve and the sleeve holding portion. The sleeve 13 has a cylindrical shape having a slot 13a as shown in FIG.
The outer diameter of the cylindrical shape is smaller than the inner diameter of the through hole of the sleeve holding portion 1a, and is a dimension that allows a certain gap. FIG. 3 (b)
The sleeve 13 is fixed to the inner peripheral wall of the through hole of the sleeve holding portion 1a with the adhesive 14 as shown in FIG. Adhesive 14
Is bonded between a part of the outer peripheral surface of the sleeve 13 and the inner peripheral wall of the through hole. Therefore, the cylindrical portion of the sleeve that is not bonded with the adhesive can bend outward when the ferrule of the optical fiber connector is inserted. Sleeve 13
Is made of, for example, ceramic.

FIG. 4 is a partial sectional view showing a state in which the ferrule portion of the optical fiber connector is set on the sleeve holding portion. The inner diameter of the sleeve 13 is substantially the same as the outer diameter of the ferrule 23 of the optical fiber connector 24,
When the ferrule 23 is inserted, the sleeve 13 slightly bends outward. The ferrule is inserted until the tip of the ferrule contacts the surface of the glass 9. In this state, the ferrule of the optical fiber connector 24 is held by the holding mechanism. Since the axis of the holding mechanism and the optical axis of the objective lens are adjusted in advance, if the roundness is obtained by polishing, the center of the core portion 22b of the optical fiber 22 inserted into the center of the ferrule Comes into contact with the surface of the glass 9. If the roundness is not achieved, the portion other than the center of the core portion 22b and the clad portion 22a will come into contact with the surface of the glass 9.

FIG. 5 is an assembly view of an optical fiber holding mechanism in the optical fiber connector end face inspection apparatus. As shown in FIG. 5, an optical fiber holding mechanism 15 is provided for the objective lens 16. A half mirror 17 and a CCD 20 are disposed behind the objective lens 16. Half mirror 17
A lens 18 and a light source 19 are arranged on the side surface of. The light emitted from the light source 19 is guided upward by the half mirror 17 via the lens 18 and illuminates the ferrule end face of the optical fiber connector held by the optical fiber holding mechanism through the objective lens 16. The reflected light of the illuminated ferrule end face passes through the objective lens 16 and the half mirror 17
An image is formed on D20. The output of the CCD 20 is connected to a CRT (not shown) via a control circuit, and the image is displayed.

FIG. 6 is a view for explaining an axis deviation inspection by the optical fiber connector end face inspection apparatus. When the optical axis of the objective lens 16 and the axis of the optical fiber holding mechanism 15 are matched in advance, and the contact point is shifted from the center of the ferrule as shown in FIG. ,
A pattern for the Newton ring as shown in FIG. 6b appears. FIG. 7 is a diagram for explaining an undercut inspection by the optical fiber connector end face inspection apparatus. The axis of the optical fiber holding mechanism 15 is shifted from the optical axis of the objective lens 16 by a predetermined amount in advance, and the undercut of the end face of the optical fiber is to be inspected. In the case of undercut, as shown in FIG. 7, interference fringes of the cladding appear on the Newton ring. The undercut means that the end surface of the optical fiber is concave. For example, the undercut occurs when the optical fiber portion is broken due to a break or the like in a ferrule cutting process and cannot be sufficiently removed by polishing.

[0014]

As described above, according to the present invention, there is provided a fiber holder having an adjusting means for adjusting the axis of a through hole with respect to the optical axis of an objective lens. A cylindrical shape having a possible outer diameter, a sleeve fixed to the fiber holder by bonding a part of the outer peripheral surface to the inner peripheral surface of the through hole, and a transparent glass body provided at one end of the through hole of the fiber holder. By adjusting the relationship between the axis of the through hole and the optical axis of the objective lens by the adjusting means in a predetermined relationship, the sleeve is inserted through the other end of the sleeve and the polished end face is pushed into contact with the transparent glass body to thereby set the polished end face to the objective. It is configured to hold the ferrule of the optical fiber connector facing the lens.

Therefore, the optical fiber connector can be held in an accurately positioned state only by inserting the ferrule of the optical fiber connector to be inspected without screwing or fine adjustment. Therefore, the operation required for attachment / detachment becomes easier as compared with the conventional inspection apparatus, and there is an effect that the inspection efficiency is improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an optical fiber holding mechanism according to the present invention.

FIG. 2 is a sectional view of the optical fiber holding mechanism assembled from the exploded view of FIG. 1;

FIG. 3 is a diagram showing details of the vicinity of a sleeve and a sleeve holding portion.

FIG. 4 is a partial cross-sectional view showing a state where a ferrule portion of an optical fiber connector is mounted on a sleeve holding portion.

FIG. 5 is an assembly view of an optical fiber holding mechanism in the optical fiber connector end face inspection apparatus.

FIG. 6 is a view for explaining an axis deviation inspection by an optical fiber connector end face inspection apparatus.

FIG. 7 is a diagram for explaining an undercut inspection by the optical fiber connector end face inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fiber holder 2 ... Holder base plate 3 ... Holder receiver 4 ... Set screw 5 ... Flat screw 6 ... Countersunk screw 7 ... Spring 8 ... Holder post 9 ... Transparent glass 10 ... Leaf spring 11 ... Die cast main body 12 ... Glass accommodating part 13 ... Sleeve 14 ... Adhesive 15 ... Fiber holding mechanism 16 ... Objective lens 17 ... Half mirror 18 ... Lens 19 ... Light source 20 ... CCD 22 ... Optical fiber 23 ... Ferrule 24 ... Optical fiber connector

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Ishii 2800 Nagachi, Okaya-shi, Nagano Kyocera Corporation Nagano Okaya Plant (72) Inventor Yujiro Hirata 2800 Nagachi, Okaya-shi Nagano Prefecture Nagano Okaya Plant ( 72) Inventor Noriaki Ito 2800 Nagachi, Okaya-shi, Nagano Kyocera Corporation Nagano Okaya Plant (56) References JP-A-62-106337 (JP, A) JP-A-6-208044 (JP, A) 5-113520 (JP, A) Fully open 1986-152947 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 102 G01M 11/00-11 / 08 G02B 6/38-6/40

Claims (2)

(57) [Claims] 1. A fiber having a through-hole and adjusting means for adjusting an axis of the through-hole with respect to an optical axis of an objective lens facing the ferrule end face so as to project a ferrule end face of the optical fiber connector. A cylindrical shape having an outer diameter smaller than an inner diameter of the through hole and having a constant gap, and a part of an outer peripheral surface being inserted into the through hole and forming a part of an inner peripheral surface of the through hole; A sleeve fixed to the fiber holder by bonding to a surface; and a transparent glass body disposed between one end of the through-hole of the fiber holder and the objective lens. and the optical axis of the objective lens is one
The sleeve is inserted from the other end of the sleeve, and the polished end face is pushed into a position where the polished end face comes into contact with the transparent glass body so that the polished end face faces the objective lens to hold the ferrule of the optical fiber connector. An optical fiber holding mechanism in an optical fiber connector end face inspection apparatus. 2. The adjusting means holds the fiber holder.
Fix the holder base plate for attachment and the holder base plate
And, comprising a holder receiver for mounting the glass body, when attaching the fiber holder to the holder base plate,
Insert a flat screw through the hole in the holder base plate and attach a spring
Screwed into the holder post that was
By using a structure that holds down the fiber holder,
Align the ferrule of the fiber connector with the optical axis of the objective lens.
Adjust so that the two setscrews provided on the fiber holder
Is adjusted so that it is parallel to the optical axis of the objective lens.
2. The optical fiber holding mechanism according to claim 1 , wherein the angle is adjusted so as to adjust the angle .