JP3238252B2 - Positioning key for optical connector ferrule - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning key for an optical connector ferrule. More specifically, the present invention relates to a positioning key for fixing the optical connector ferrule at an appropriate position when observing and inspecting the end face state of the optical connector ferrule.

[0002]

2. Description of the Related Art When observing and inspecting the end face state of an optical connector ferrule, the optical connector ferrule is arranged in a measuring optical system and fixed so that the end face is at a predetermined position.

An optical connector ferrule generally has a structure shown in FIG.
(A) and the shape shown in FIG. 1 (B). That is, in FIGS. 1A and 1B,
The optical connector ferrule 1 has a flange 2 on which a keyway 3 is formed.

[0004] Such an optical connector ferrule is held in a measuring optical system by a holder 4 shown in FIG. 2. In FIG. 2, the holder 4 has an optical connector ferrule (not shown). V for holding and holding
The optical connector ferrule which has a V-shaped groove 5 and is housed in the V-shaped groove 5 is pressed by a clamp 6 and is positioned in a key groove of a flange of the optical connector ferrule by a positioning key 7.
Is inserted, and the optical connector ferrule is fixed at a predetermined position and posture.

FIG. 3 shows a conventional positioning key. In FIG. 3, a conventional positioning key 7a is inserted into the key groove 3 of the flange 2 of the optical connector ferrule. The positioning key 7a has a function of preventing rotation of the optical connector ferrule. The positioning key 7a has a spring property so as to be capable of elastic deformation corresponding to the dimensional tolerance of the key groove 3 of the flange 2. Therefore, the key groove 3 and the key 7 are changed due to the dimensional variation of the key groove 3.
It is designed such that the clearance (play) between the fitting and the fitting is always zero.

However, the conventional positioning key 7a as shown in FIG. 3 only has a function of preventing rotation of the optical connector ferrule mounted in the holder (rotation about the longitudinal axis of the ferrule). It does not have a function of fixing the position of the ferrule in the longitudinal axis direction.

When the end face of the optical connector ferrule is observed in the measurement optical guide, the magnification is often adjusted using a lens. At this time, the depth of focus (focus area) is determined by the focal length of the lens used. ,
If the ferrule end face to be observed is not located within the depth of the subject, the end face image becomes unclear and sufficient observation cannot be performed. For this reason, conventionally, a stopper is arranged between the lens and the end face, and the stopper contacts the ferrule end face to control the end face position so that the end face is always within the depth of field.

However, when the stopper comes into contact with the ferrule end face, there are problems such as flaws on the ferrule end face, adhesion of dust, and deformation of the stopper due to wear. Therefore, there has been a strong demand for a solution to the above problems.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a positioning key for an optical connector ferrule which can fix an optical connector ferrule in a predetermined position and therefore does not require the use of a stopper. The positioning key of the present invention fixes the optical connector ferrule held by the holder in the measuring optical system so that the ferrule cannot be rotated around its longitudinal axis and displaced in the longitudinal axis direction.

[0010]

A positioning key for an optical connector ferrule according to the present invention comprises a projection fitted into a key groove of a flange of the optical connector ferrule, and a base supporting the projection. The protruding portion is formed of a triangular prism protruding from the base portion.

[0011]

The positioning key according to the present invention has, for example, the configuration and shape shown in FIG. In FIG. 4, the positioning key 8 of the present invention includes a base 9 and a projection 10.
The protruding portion 10 is formed of a triangular prism protruding from the one side surface 11 of the base portion substantially at right angles thereto.

The protruding portion of the positioning key of the present invention is a triangular prism-shaped body, and one acute angle portion (for example, the acute angle portion 12 in FIG. 4) is fitted into the key groove of the flange of the optical connector ferrule. I do. That is, when the optical connector ferrule is installed in the V-shaped holding groove of the holder, for example, as shown in FIG.
When the ferrule 1 has a rotational displacement as shown in FIG. 5A, the ferrule having such a posture is inserted into the V-shaped groove, and as shown in FIG. An end 14 of one side of the keyway 3 of the ferrule flange 2 contacts one side 13 of the protrusion 10.

When the ferrule 1 is further inserted in the direction indicated by the arrow in FIG. 5B, the vertical and horizontal displacement of the ferrule causes the V-shaped groove of the retainer to move.
Since it is constrained by the ferrule clamp 2, the end of one side of the flange key groove and one of the triangular prism-shaped protrusions 10
While maintaining the contact with the side surface 13, it starts to rotate in the direction indicated by the arrow in FIG.

As shown in FIG. 6B, when the end 15 on the opposite side of the flange groove 3 comes into contact with the other side 16 of the triangular prism-shaped projection 10, the rotation of the ferrule is stopped. finish. At this time, the flange 1 can take a normal posture as shown in FIG.

As shown in FIG. 6B, when the triangular prism-shaped protrusion 10 and the key groove 3 of the ferrule flange 2 are fitted, the ferrule 1 is displaced in the vertical and horizontal directions and the longitudinal axis thereof is shifted. The rotation around it becomes impossible and it is accurately positioned.

FIG. 7 shows a main part of the state where the ferrule is positioned on the holder 4 by the positioning key of the present invention as described above and is arranged in the measuring optical system. That is, since the measured end surface of the ferrule positioned is fixed within the width A of the focus area of the lens 17, there is no possibility that the end surface is damaged or stained by a stopper or the like.

The taper angle θ of the fitting acute angle portion 12 of the triangular prism-shaped protrusion 10 can be determined by the following equation. θ = tan ⁻¹ (dimension of key groove width / width of focus area) When the taper angle θ is determined in this way, even if the key groove width varies within the dimensional tolerance, the ferrule end face is always within the focus area. The ferrule can be fixedly held.

[0018]

By using the positioning key of the present invention, the optical connector ferrule can be connected in the optical measurement system.
The ferrule can be prevented from being damaged or soiled by the use of a stopper or the like, which is accurately fixed to the retainer so that it cannot rotate and cannot be displaced vertically and horizontally.

[Brief description of the drawings]

FIG. 1A is an explanatory front view of an example of an optical connector ferrule. FIG. 1B is an explanatory side view of the optical connector ferrule of FIG. 1A.

FIG. 2 is an explanatory front view of an example of an optical connector ferrule holder.

FIG. 3 is an explanatory side view showing a conventional positioning key fitted into a key groove of an optical connector ferrule.

FIG. 4 is an explanatory perspective view of an example of an optical connector ferrule positioning key according to the present invention;

FIG. 5A is an explanatory view showing a ferrule flange in an inclined posture. FIG. 5B is an explanatory diagram showing a contact start state between the key groove of the flange and the triangular prism-shaped protrusion of the positioning key of the present invention.

FIG. 6A is an explanatory view showing a ferrule flange in a normal posture. FIG. 6B is an explanatory view showing a state in which the key groove of the ferrule flange and the triangular prism-shaped protrusion of the positioning key of the present invention have been fitted.

FIG. 7 is an explanatory view showing a state where the optical connector ferrule fixed to the holder by the positioning key of the present invention is arranged in the measuring optical system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical connector ferrule 2 ... Flange 3 ... Key groove 4 ... Optical connector ferrule holder 5 ... V-shaped groove 6 ... Clamp 7 ... Positioning key 7a ... Conventional positioning key 8 ... Positioning key of the present invention 9 ... Base Part 10: Triangular prism-shaped protrusion 11: Side surface 12: A sharp angle portion to be fitted in the key groove 13: One side of the triangular prism-shaped protrusion 14: One side end of the key groove of the ferrule flange 15: Opposite to the key groove of the ferrule flange Side surface end 16: Other side surface of triangular prismatic projection 17: Lens θ: Taper angle of fitting acute angle portion of triangular prismatic projection A: Width of focus area

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 1-2232308 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/36 G01M 11/00

Claims (1)

(57) [Claims] 1. An optical connector ferrule comprising: a protruding portion fitted into a key groove of a flange of an optical connector ferrule; and a base portion supporting the protruding portion. A positioning key for an optical connector ferrule.