JPH09197187A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized and inexpensive optical connector by reducing the number of constitutional parts without deteriorating its characteristics. SOLUTION: A ferrule 2 is constituted of an outer diameter part 2a, a flange part 2b and an engaging part 2c, where the optical fiber 1 is fixed, and a screw part 3 having a diameter larger than that of the flange part 2b is engaged with the engaging part 2c so as to be freely rotatable. The outer diameter parts 2a of a pair of ferrules 2 are inserted into a divided sleeve 4 and butted into each other and a tension coil spring 5 is spanned between both screw parts 3. When the pitch of the spring 5 is set up smaller than the pitch of the screw parts 3, a ferrule depressing function and a clamping function to be attained by the spring 5 are suitable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector for connecting optical fibers transmitting optical signals.

[0002]

2. Description of the Related Art In Japanese Utility Model Laid-Open No. 3-117211, two ferrules each holding an optical fiber are inserted in the central portion, and the end faces of both ferrules are butted against each other to align the optical fibers. A sleeve for an optical fiber connector in which a ceramic thin film is formed on the inner surface of a metal split sleeve is described.

This optical fiber connector sleeve constitutes a split sleeve having elasticity equal to that of a metal sleeve and wear resistance equal to that of a ceramic sleeve.

[0004]

The conventional optical connector comprises a plug to be attached to an optical fiber and an adapter for connecting the plugs. The plug has an exterior portion that encloses the ferrule and the coil spring, and a fastening portion (female screw) that is connected to the adapter on the inner peripheral surface of the exterior portion. The adapter has an exterior part that encloses the split sleeve and a fastening part (male thread) that connects to the plug. Further, the adapter may have a flange portion having a screw hole for fixing to a panel or the like.

As described above, the conventional optical connector is composed of many parts and has a large outer diameter. Therefore, there are drawbacks that the cost is high and it cannot be used in a narrow space.

Therefore, the present invention provides a compact and inexpensive optical connector by improving the drawbacks of the conventional optical connector, reducing the number of components without deteriorating the characteristics of the optical connector.

[0007]

The present invention employs the following means to solve the above-mentioned problems.

(1) A ferrule is composed of an outer diameter portion to which an optical fiber is fixed, a flange portion and a mating portion, and a screw portion having a diameter larger than that of the flange portion is mated to the mating portion to form a pair of ferrules. An optical connector that inserts both outer diameter parts into a sleeve, butts them together, and stretches a tension coil spring between both screw parts.

(2) The optical connector according to (1), wherein the screw portion is rotatably engaged with the engaging portion.

(3) The ferrule is composed of an outer diameter portion to which an optical fiber is fixed and a threaded portion having a diameter larger than this outer diameter portion, and both outer diameter portions of a pair of ferrules are inserted into a sleeve and abutted to each other. An optical connector that spans tension coil springs between threads.

(4) The optical connector according to (1), (2) or (3), wherein the pitch of the tension coil spring is smaller than the pitch of the threaded portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS.
This will be described with reference to FIG.

The optical fiber 1 has an outer diameter portion 2 of a ferrule 2.
It is adhesively fixed on the central axis of a. The end surface of the ferrule 2 is formed in a required shape so that the optical fiber 1 is a mirror surface. For example, it is polished into a convex spherical shape with the optical fiber 1 at the apex and a spherical radius of 20 mm. At the center of the ferrule 2, a cylindrical flange portion 2b having an outer diameter larger than that of the outer diameter portion 2a is provided. The screw portion 3 is arranged behind the flange portion 2b. The manufacture of the optical connector is completed by passing the threaded portion 3 through the optical fiber 1, bonding the ferrule 2 to the optical fiber 1, and polishing the ferrule 2. The threaded portion 3 can freely rotate on the mating portion 2c of the ferrule 2, and is formed in a male screw shape having a surface that comes into contact with the end surface of the flange portion 2b. The tension coil spring (hereinafter also referred to as “coil spring”) 5 is set to have a linear shape and a center diameter that can be screwed into the thread of the screw portion 3. The winding pitch of the coil spring 5 is smaller than the screw pitch of the screw portion 3, and the inner diameter of the coil spring 5 is set larger than the outer diameter of the flange portion 2b. The free length of the coil spring 5 is set shorter than the distance between the flange portions 2b when the ferrules 2 are butted against each other and the screw portions 3 are brought into close contact with the flange portions 2b.

The method of connecting the optical connector will be described below. As shown in FIG. 1, the split sleeve 4 is inserted into the outer diameter portion 2a of the right optical connector. The coil spring 5 is screwed into the screw portion 3 of the optical connector on the left side of FIG. Outer diameter part 2a on the left side of FIG.
Is inserted into the split sleeve 4. The split sleeve 4 holds the opposing outer diameter portions 2a coaxially with each other by an appropriate tightening force. Thereby, the optical fibers 1 can be aligned on the same axis. The coil spring 5 is pulled, applied to the cut end of the screw of the screw part 3 on the right side of FIG. 1, and the screw part 3 is rotated to screw the coil spring 5 into the screw part 3. Coil spring 5
Screw to the end of the screw portion 3. In this state, the ferrule 2 is butted with a required force by the coil spring 5. By the coil spring 5 exerting a straight and stable force in the axial direction of the ferrule 2, stable characteristics can be obtained. Coil spring 5 and thread 3
Since the winding pitches are different, the coil spring 5 tightens the thread of the screw portion 3, and the coil spring 5 does not come off from the screw portion 3 even if an external force such as vibration or shock acts.

In the above description, the split sleeve 4 is mounted on the right side of FIG. 1 and the coil spring 5 is mounted on the left side. However, the split spring 4 may be mounted in the opposite direction, or the coil spring 5 and the split sleeve 4 may be mounted on either one of them for connection. it can. Further, although the split sleeve 4 and the coil spring 5 are attached at the time of making the connection, they may be attached in advance at the time of manufacturing the optical connector as shown in FIG. In this case, the end surface of the ferrule 2 is split sleeve 4 and coil spring 5 respectively.
Has an advantage that it is protected from scratches and is less likely to be scratched.

When it is desired to particularly reduce the connection loss in the connection of this optical connector, when the ferrules 2 are connected to each other through the split sleeve 4, the ferrule 2 is rotated and adjusted so that the connection loss becomes the minimum value. It can be realized by doing.

By attaching a cap 6 screwed to the screw portion 3 as shown in FIG. 3A or a cap 6'which is elastically deformed and inserted into the screw portion 3 as shown in FIG. 3B. , While preventing dust from attaching to the optical connector,
It is possible to prevent the screw portion 3 from moving behind the ferrule 2 and being lost before the optical connector is connected.
This cap can be mass-produced inexpensively by manufacturing it with a synthetic resin.

Further, as shown in FIG. 4 (a), the screw portion 3 has a two-sided cut 7, or as shown in FIG. 4 (b), a slit 8 is provided.
Etc., and by using a jig that fits this,
The coil spring 5 can be smoothly screwed into the screw portion 3. Therefore, the operability of handling is not impaired even if it is small.

Since this optical connector can be made small (lightweight), it can be handled like a part of an optical fiber and can be used without fixing it to a panel or the like as in the conventional case.

Further, in the above embodiment, the screw portion 3 is engaged with the engaging portion 2c so as to be freely rotatable, but a design change may be made so that the screw portion 3 is incapable of rotating. it can.

Further, in the above-mentioned one embodiment, the ferrule 2 has an outer diameter portion 2a, a flange portion 2b and a mating portion 2c.
It is composed of and, but this can be redesigned as follows. That is, the flange portion 2b and the mating portion 2c are omitted, and the ferrule 2 is composed of the outer diameter portion and the screw portion. However, in this case, the diameter of the threaded portion is made larger than the diameter of the outer diameter portion.

[0022]

As is apparent from the above description, according to the present invention, the tension coil spring has the ferrule pressing function and the fastening function, so that the number of parts is small, the size is small, and the cost is low. The connector can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state before connection of an optical connector according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state after connection of the optical connector according to the embodiment of the present invention.

3A and 3B are cross-sectional views showing a state in which a cap is attached to the optical connector according to the embodiment of the present invention, FIG. 3A shows a cap having a threaded portion, and FIG. 3B shows a cap having no threaded portion. , Respectively.

FIG. 4 is a front view of a screw portion of an optical connector according to an embodiment of the present invention, in which (a) is provided with a double-sided cut, and (b) is shown.
Indicates those provided with a slot.

[Explanation of symbols]

 1 Optical fiber 2 Ferrule 2a Outer diameter part 2b Flange part 2c Mating part 3 Screw part 4 Split sleeve 5 Coil spring 6, 6'Cap 7 Two-sided cut 8 Slot split

Claims (4)

[Claims] 1. A ferrule comprising an outer diameter portion to which an optical fiber is fixed, a flange portion, and a mating portion, and a threaded portion having a diameter larger than that of the flange portion is mated to the mating portion to form a ferrule. An optical connector characterized in that an outer diameter portion is inserted into a sleeve and abutted against each other, and a tension coil spring is spanned between both screw portions. 2. The optical connector according to claim 1, wherein the screw portion is rotatably engaged with the engaging portion. 3. A ferrule comprising an outer diameter portion to which an optical fiber is fixed and a threaded portion having a diameter larger than that of the outer diameter portion, and both outer diameter portions of a pair of ferrules are inserted into a sleeve and abutted to each other. An optical connector characterized in that a tension coil spring is bridged between the parts. 4. The pitch of the tension coil springs is made smaller than the pitch of the threaded portions.
Optical connector as described.