JPS6288934A - Aligning method for structure measurement of optical fiber - Google Patents

Abstract

PURPOSE:To take a measurement even when the whole of fiber section is not projected on a monitor TV and to attain alignment even when a measurement system has no power meter by moving the TV camera on the basis of the position of the fiber which is obtained by preliminary measuring operation. CONSTITUTION:The TV camera 2, the monitor TV 3, a camera control system 4, a computer 5, and a TV camera position adjusting mechanism 6 are provided to a structure measurement system for the optical fiber; the table on which the TV camera 2 is mounted is controlled and its coordinates are controlled by the adjusting mechanism 6. A preliminary measurement is taken while the fiber to be measured is set in this measurement system to find an approximate circle, and four points A, B, A', and B' inside the outer periphery of a clad in the approximate circle shape are selected by a minimum square-law method. The position of an intersection P of bisectors to segments between the points A and A', and B and B' is found and its coordinates are stored. The distance between this intersection Q and the center point P on the monitor TV 3 is calculated by a computer 5 and a driving instruction is applied from the adjusting mechanism 6 to the TV camera 2, so that a measurement is taken when the whole fiber section is not displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an alignment method for measuring the structure of an optical fiber.

(Prior Art) A system for measuring the structure of an optical fiber is shown in Fig. 4. The cross-sectional image of the optical fiber 1 to be measured, which is displayed on the monitor and TV 3 via the TV camera 2, is transmitted to the camera controller 4. The core diameter, cladding diameter, and non-circularity are determined by image processing using the computer 5.

Find the eccentricity, etc. As for the core, it is a light source.

The cladding is processed by using a light source LJ to project an image by reflected light. Note that the optical fiber 1 to be measured is connected to a dummy fiber 20 by a V-groove connection 21.

However, depending on the set state of the optical fiber, the entire cross section of the fiber may not be visible on the monitor TV, making measurement impossible.

(Problems to be Solved by the Invention) As described above, if the entire fiber 1Flf is not displayed on the monitor TV, measurement is impossible and the fiber must be set again. The problem to be solved by the present invention is to prevent such redoing of the set.

(Means for solving the problem) Perform preliminary measurements with the optical fiber under test still set, obtain an approximate circle, and calculate the cladding of the approximate circle obtained by the least squares method as shown in Figure 2. ≠ Point A, A' on the outer circumference
, B, B', divide them into two sets of two points, draw a perpendicular bisector of the line segment connecting each two points, and make two perpendicular 2
Find the position Q of the intersection of the equal dividing lines and memorize its coordinates. Calculate the distance between this intersection and the center point P of the monitor TV,
By issuing a movement instruction corresponding to this distance from the computer to the newly installed TV camera position adjustment mechanism, the TV left camera position is adjusted so that the center of the fiber is at the center point P in the center of the TV monitor as shown in Figure 3. Adjust.

(Function) The position of the stand on which the TV left camera is fixed is determined by the TV camera position adjustment mechanism, which has a conversion circuit that decodes computer instructions and sends signals to the drive unit, and a drive unit that uses a step motor. control.

(Example) Change the area within the dotted line in Figure 4 as shown in Figure 1 (the light source system is
(exactly the same as the figure). Note that FIG. 1 shows the TV camera 2 and subsequent parts in FIG. 4, including a monitor TV 3, a camera controller 4. A TV camera position adjustment mechanism 6 is added to the computer 5, and its usage is as described in the section on means for solving problems, by making preliminary measurements and bringing the center of the fiber to the center of the monitor TV 3. After that, after alignment, the main measurement is performed.

(Effects of the Invention) By moving the TV left camera based on the fiber position obtained in the preliminary measurement, measurement can be carried out without fail.

This allows alignment even when the measurement system does not include a power meter, such as when measuring structures.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an embodiment of the alignment method for measuring the structure of an optical fiber according to the present invention, Fig. 2 is an explanatory diagram of the optical fiber to be measured as shown on a TV monitor during preliminary measurement, and Fig. The figure is an explanatory diagram in which the image in FIG. 2 is moved to the center of a monitor TV, and FIG. 4 is an explanatory diagram of a conventional optical fiber structure measurement system. 1... Optical fiber to be measured, 2... TV left camera 3.
...Monitor TV, 4...Camera controller, 5...
- Computer, 6... TV camera position adjustment mechanism. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. An optical fiber structure measurement system consisting of a TV camera, a TV monitor, a camera controller, and a computer,
An alignment method for measuring the structure of an optical fiber, characterized in that alignment is performed by adding a TV camera position adjustment mechanism that controls the position of a stand on which a TV camera is mounted and manages its coordinates. 2. The TV camera position adjustment mechanism must have a conversion circuit that decodes the movement instruction issued by the computer and sends a signal to the drive unit, and a drive unit that uses a step motor to ensure position control. An alignment method for measuring the structure of an optical fiber according to claim 1.