JPS62106337A - Apparatus for inspecting end surface of fiber of optical connector - Google Patents

Abstract

PURPOSE:To make it possible to measure the eccentricity of a protruded spherical surface by a small and inexpensive apparatus, by impinging the protruded spherical surface provided at the leading end of a ferrule against a transparent flat plate being a member to be inspected and observing the Newton ring generated in the transparent plate by a microscope. CONSTITUTION:The protruded spherical surface 2 provided at the leading end of a ferrule 1 is pushed against to a glass flat plate 7 by upwardly pushing a ferrule presser 6 and placing the ferrule 1 to a V-shaped groove part 5 and held down by the projection 6-1 of the ferrule presser 6. The protruded spherical surface 2 is exposed to light to generate a Newton ring in the glass flat plate 7 and said Newton ring can be observed by a microscope. By this constitution, the radius of the circular locus at the center point of the Newton ring generated when the ferrule was rotated along the V-shaped groove is measured to determine the eccentric quantity of the protruded spherical surface. When the glass plate is vertical to the V-shaped part, the distance AB between the center point of a fiber and that of the Newton ring is measured by rotating the ferrule to determine the eccentricity of the convexed spherical surface.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fiber end face inspection instrument for an optical connector that measures the eccentricity of the convex spherical surface with respect to the optical fiber in an optical connector in which the tip of a ferrule containing an optical fiber is processed to have a convex spherical surface. It is something.

Problems to be solved by conventional techniques and inventions Optical connectors with a convex spherical tip at the tip of the ferrule containing the fiber (
Literature: Suzuki, Ike, 1980 IEICE General Conference, A 26
06) can reduce the reflected return light at the connecting point and reduce the connection loss. However, in order to achieve this, it is important to reduce the eccentricity of the convex spherical surface with respect to the optical fiber axis, and for this purpose, a device that accurately measures the amount of eccentricity is required. In the conventional method, as shown in the above-mentioned document, the convex spherical ferrule 1 shown in FIG.
Briefly, 1 (θ-Nθ laser L is emitted 1!α, the reflected light is drawn on screen S, and the pattern is observed. The pattern becomes a concentric interference pattern and the convex spherical surface is eccentric. By rotating the ferrule 1 at Vt14, etc., the center of the concentric circle is displaced.By measuring the amount of displacement, the amount of eccentricity of the convex spherical surface was measured as an angular deviation.However, in this measurement method, from the above explanation, As described above, the eccentricity between the fiber and the convex spherical surface cannot be directly measured.This method requires a certain distance between the ferrule 1 and the screen S1, which has disadvantages such as an increase in the size of the device.

As a method to compensate for these drawbacks, there is a method using an interference microscope, but this method has the drawback that the device is complicated and expensive.

Means for Solving the Problems The present invention provides an optical connector in which eight fibers are fixed in a ferrule and the tip is processed into a convex spherical surface, and the eccentricity of the optical connector is measured by applying light to the convex spherical surface to generate Newton rings. In the end face inspection apparatus, a ferrule support base provided with a V-groove portion opening upward is provided, and a 7-errule presser is mounted on the upper part of the ferrule support base so as to be able to slide up and down and biased against the lower part, and the ferrule support A glass flat plate is fixed in a V-groove portion on the side surface of the stand with a glass flat temporary holding plate, and a hole is drilled in the glass flat temporary holding plate large enough to allow the groove to be seen when the ferrule is placed in the V-groove portion. A fiber end face inspection member and a microscope are installed, a ferrule is placed on the Va part of the glass flat plate, the convex spherical surface is brought into contact with the flat glass plate, a Newton ring is generated on the glass flat plate, and the Newton ring is detected by the microscope to determine eccentricity. It is configured to measure .

Function The present invention generates Newton rings on a glass flat plate as described above, and directly measures the center of the concentric circles by observing with a microscope, and directly measures the eccentricity based on the amount of displacement of the center.

Since a small fiber end face inspection member that can be seen with a microscope is used, the entire structure can be made compact.

Embodiment FIG. 1 shows a fiber end face inspection device for an optical connector according to the present invention (
This is called an end face inspection device. ) is a perspective view of the fiber end face inspection member (referred to as the inspection member), Figure 2 is a back view seen from the direction of arrow X in Figure 1, and Figure 3 is a side view seen from the direction of arrow Y in Figure 'R1. , is shown.

In the figure, 1 is a ferrule, 2 is a processed convex spherical surface at the tip of the ferrule, 3 is a fiber, 4 is a ferrule support, 5 is a v-groove, 6 is a ferrule holder, 6-1 is a protrusion of the ferrule holder, and 7 is a ferrule holder. 8 is a glass flat plate, 9 is a screw, IO is a screw, l] is a spring, [2 is a microscope, and L is a light source.

The configuration of the inspection member of the present invention will be explained.

For example, a cubic ferrule support 4 made of a metal plate has a V-groove 5 on the top, and a 7-erule presser 6 made of, for example, a prismatic metal plate is arranged on the top, and the center of the lower surface of the ferrule presser 6 is perpendicular to the longitudinal direction. A protrusion 6-1 is formed on the ferrule 6.
In the figure in which the ferrule support 4 is reached from the top surface, two screws 10 are inserted and fixed, a hole is provided in the ferrule holder 6 to protrude from the top of the screw 10, and the screws 10 are inserted and slid. A spring IJ is wound between the head 10-1 of the screw lO and the upper surface of the ferrule holder 6, and the ferrule holder 6 is urged downward by the spring 1].

■Place the glass flat plate 7 in close contact with one side of the ferrule support plate 4 provided with the groove 5, and attach the glass flat plate 7 to the ferrule support plate 4 with screws 9 using the glass temporary holding plate 8 with holes 8-1 drilled from above.
I'm going to fix it with . As shown in FIGS. 2 and 3, the size of the inspection member is L-about 3 cm %W=about 2Crn1T=about 1c
It is rank rn.

The glass flat plate 7 and the V-groove portion 5 are arranged substantially perpendicularly.

The operation of the end face inspection apparatus of the present invention will be explained.

The convex spherical surface 2 at the tip of the ferrule is pushed upward by the ferrule holder 6, the ferrule 1 is atffied into the groove 5, and is pressed against the glass flat plate 7 and pressed by the protrusion 6-1 of the ferrule holder 6. Light is applied to the convex spherical surface 2 to produce Newton rings on the glass flat plate 7, which can be observed with a microscope 12.

FIG. 4 shows an enlarged view of the ferrule tip in contact with the glass flat plate. If the glass flat plate 7 and the V-groove 5 are perpendicular in the longitudinal direction, a Newton ring will occur at the center of the convex spherical surface 2 + line B point, and the distance AB from the fiber center point A will be the eccentricity 1 of the convex spherical surface 2. . Further, when the ferrule 1 is rotated along the V'ruj portion 5, the center point of the Newton ring 13, that is, the convex spherical center point B, draws a circular locus with the fiber center point A as the center, as shown in FIG. 5G. Next, FIG. 6 shows a case where the glass flat plate 7 is tilted at an angle θ with respect to the plane 15 perpendicular to the v1 portion. The position where Newton's ring is generated is 0 point at a distance R cos θ from point B in the direction of the inclination.

Therefore, as shown in FIG. 7, when the Newton ring is rotated along the groove of the ferrule, the locus of the center point C of the Newton ring becomes a circle displaced by R cos θ from the locus of the B point. The amount of eccentricity of the convex spherical surface at this time is the radius of the circular locus 16 at the 0 point.

Since the present invention has the above structure, the amount of eccentricity of the convex spherical surface is determined by measuring the radius of the circular locus 160 of the center point C of the Newton ring when it is rotated along the V groove of the ferrule. .

If the glass plate and the groove are perpendicular, the eccentricity of the convex spherical surface can also be determined by directly measuring the distance between the fiber center point and the Newton ring center point without rotating the ferrule. The symmetry of Newton's rings also reveals the symmetry of convex spherical surfaces.

Effects of the Invention: The present invention makes it possible to measure the eccentricity of the convex spherical surface by abutting the convex spherical surface of the tip of the ferrule against a transparent flat plate of an inspection member of approximately the above-mentioned size and observing the Newton rings generated on the transparent flat plate using a microscopic wave. The device can be made smaller and the cost of the end face inspection device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the fiber of the optical connector of the present invention and a fiber G-plane inspection member of the front surface inspection device, FIG. 2 is a rear view seen from the direction of arrow X in FIG. Viewed from the arrow Y direction in the figure (lI! 1 side view, Figure 4 is an enlarged view of the ferrule tip in contact with the glass flat plate, Figure 5 is the locus of the center of the convex spherical surface, Figure 6 is the vertical plane of the V groove part) An enlarged view of the tip of the ferrule in contact with the glass plate when the glass plate is tilted at an angle θ, Fig. 7 is the locus of the Newton ring center point in Fig. 6, and Fig. 8 is an explanation of a conventional end face inspection device. figure,
shows. 1: Ferrule 2: Convex spherical surface at the tip of the 7-ferrule 3: Fiber 4: Ferrule support 5: V-groove 6: Ferrule holder 6-1 = Projection 7: Glass flat plate
8 Glass flat plate holding plate 9: Screw 10: Screw
l] Nispring 12: Microscope 13: Newton ring 14: Locus of center point of convex spherical surface 15: Surface perpendicular to v-groove 16: Locus of center point of Newton ring Patent applicant: Patent attorney representing Nippon Kameshin Telephone Co., Ltd.
Isao Abe 21st 3rd
Figure 8

Claims (1)

[Claims] In an optical connector fiber end face inspection device that measures eccentricity by applying light to the convex spherical surface of an optical connector in which an optical fiber is fixed in a ferrule and the tip is processed to have a convex spherical surface, a V-groove that opens upward is used. A ferrule support is provided, a ferrule presser is attached to the top of the ferrule support so that it can slide up and down and is biased downward, and a glass flat plate is attached to the glass flat plate presser in a V groove on the side of the ferrule support. A hole large enough to allow the V-groove to be seen in the state in which the ferrule is placed in the V-groove is bored in the glass flat plate holding plate, and a fiber end face inspection member and a microscope configured therein are provided. A ferrule is placed in the V-groove, the convex spherical surfaces are brought into contact with each other, light is applied to generate Newton rings on the glass flat plate, and eccentricity is measured by detecting the Newton rings with a microscope. Edge inspection equipment.