JPH01107218A - Tape-type multi-core optical fiber connection observation device - Google Patents

Abstract

PURPOSE:To measure the misalignment between the respective fibers of tape type multicored optical fiber tapes with good accuracy by projecting the juncture of the above-mentioned optical fibers from two directions diagonally with the tape faces and magnifying and measuring the misalignments of the respective fibers by each piece with the transmission images in the respective directions. CONSTITUTION:An operator drives a driving mechanism 7 by a motor 6 and moves a supporting member 5 toward the left or right while emitting light rays from light sources 1, 2 and observing the images from TV cameras 3, 4. All the optical fibers are then positioned successively by each piece on the visual axes of the TV cameras 3, 4. The images of the juncture in the upper right-lower right directions of the optical fibers can be observed with the TV camera 3 and the images of the juncture in the lower left-upper right directions can be observed with the TV camera 4 at this time. The measurement error of the misalignment is thereby decreased.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention illuminates the spliced portion of a tape-type multi-core optical fiber from behind before or after fusion splicing, and identifies the spliced portion from the transmitted image. The present invention relates to a tape-type multi-core optical fiber connection observation device for observing the axis misalignment of each fiber.

[Prior Art] FIG. 6 is a schematic explanatory diagram of a conventional example of a tape-type multi-core optical fiber connection observation device disclosed in Japanese Patent Application Laid-Open No. 62-103608, and FIG. 7(a) is a diagram of this conventional example. FIG. 7(6) is an enlarged explanatory view of the connection portion 14 in FIG. 7(a), and FIG. 8 is a vertical transmission image of the tape surface of the tape-type multicore optical fiber 10 obtained by Bright line width W of the transparent image of the core wire
It is a graph showing the relationship between y and the axis deviation y of the core wire from the tape surface at the connection portion.

Now, let the direction of the connection part on the tape surface (reference plane including the axis of each fiber) of the tape-type multi-core optical fiber IO be the X axis, and the direction perpendicular to the tape surface on the connection part be the y axis. Then, the light emitted from the light source 12 in the y-axis direction and transmitted through the tape-type multi-core optical fiber IO is observed by the TV left camera 3, and the optical fiber 10 shown in FIGS. 7(a) and 7(b) is observed. A transmitted image of the image is obtained, and it is possible to measure the axis deviation dX in the X-axis direction from this image. Furthermore, a bright portion 15 is observed at the center of the image of each optical fiber. The width W of this bright portion 15 has the relationship shown in FIG. (See FIG. 5 in "Optical Fiber Positional Displacement Measuring Method Using Directional Observation Images", IEICE technical report, 0QE87-9. April 20, 1987). In FIG. 8, the O mark indicates the experimental value, the solid line indicates the theoretical value when the incident light to the optical fiber 10 is a parallel ray, and the broken line indicates the theoretical value when the angular component is taken into consideration in the incident light.
The dashed dotted line is the theoretical value when the angular component and depth of field are considered. Therefore, for the left and right optical fibers,
By measuring the widths wl and w2 of these bright areas, the axis deviation y1+3'2 from the reference position can be determined for each, and the difference between these '/I+'/2 is the y-axis direction of the optical fiber. The axis deviation becomes d.

[Problems to be Solved by the Invention] The above-described conventional tape-type multi-core optical fiber joint observation device images a large number of optical fibers within the screen.

Normally, one screen is sampled into about 500 pixels both vertically and horizontally, so taking into consideration the space between the fibers, the number of pixels allocated to each optical fiber is the same as that of a 5-fiber tape. In this case, there are only 500 pixels. In this case, the positioning accuracy △ corresponding to one pixel of sampling error is equal to the optical fiber outer diameter 1
25. , for a commonly used tape-type multi-core optical fiber with a fiber spacing of 125-, △・(optical fiber outer diameter)/(number of pixels allocated per fiber)-
125750 = 2.5 scales. In particular, when the optical fiber is a single mode type, the outer diameter of the core wire is only 5u+, and the above-mentioned accuracy △ is 2
．． It is easy to see that 5- is insufficient. Furthermore, if the number of core wires is greater than five, it becomes impossible to measure axis misalignment.

On the other hand, in the y-axis direction, the measurement error of the bright line width W is 2.5 scales on one side, so the total error on both sides is 5 p (
-2.5ga x 2). In Fig. 8, even if the most sensitive solid line relationship is used, an error of 5 scales will result in an error of approximately 1 rho axis deviation Y + + '/2, and the value of ':Jr-y2 is This results in an even larger error.

As described above, the conventional apparatus that images a large number of optical fibers on one screen and measures the bright line width W and the axis deviation dX has the disadvantage that the error in measuring the axis deviation is extremely large.

[Means for Solving the Problem] The tape-type multi-core optical fiber joint observation device of the present invention includes: a support member; and a support member that is parallel to the tape surface of the tape-type multi-core optical fiber and perpendicular to the longitudinal direction of the optical fiber and a drive mechanism that moves the support member in a direction perpendicular to the longitudinal direction of the optical fiber. Obtain a transparent image of the direction,
It has observation means installed on the support member.

[Function] The present invention irradiates a tape-type multi-core optical fiber from two diagonal directions on one side of the tape surface, and measures the axis deviation of the core fibers for each transmitted image, and calculates the above-mentioned X from those measured values. This allows calculation of axis deviations in the axial and y-axis directions, and by moving the observation means along the connection, it is possible to enlarge and sequentially observe all optical fiber lines one by one. , it is possible to significantly reduce the measurement error of axis misalignment.

Next, the principle of the present invention will be explained with reference to the drawings.

Fig. 3 is a schematic diagram showing the arrangement relationship between the tape-type multi-core optical fiber and the TV left camera observation means), Fig. 4 is an enlarged transmission image of the fiber connection section on the TV left camera image plane, and Fig. 5 is a FIG. 4 is an explanatory diagram for calculating the axis deviation dimension of a line.

The irradiation light beam is irradiated obliquely to the tape surface from one side of the tape surface, and is installed on the support member with the viewing axis of the TV left camera aligned with the optical axis P of the light beam. Each core wire 31. The light beam that has passed through 315 passes through the TV left camera lens 32 and forms a transmitted image on the TV left camera image plane 33. The incident angle θ of the optical axis P with respect to the tape surface (X-axis direction) can be appropriately selected so that adjacent core lines do not overlap in the obtained transmitted image.

In addition, since all the core wires are sequentially conveyed and observed one by one by the drive mechanism of the support member, it is possible to observe each core wire under magnification. is easily determined. In this way, the axis deviation dimensions dX, d in the X-axis and y-axis directions of the core wire can be determined from the axis deviation dimensions d1 and d2 obtained in the two directions, respectively. Next, the calculation method will be explained with reference to FIG.

Now, the axis of one core wire is vector AB at the connection part.
Assuming that there is an axis misalignment, the X axis (tape surface)
The axis deviation dl obtained from a transmitted image by a light ray incident from the direction of angle θ1 with respect to the The axis deviation d2 corresponds to 80 in the figure. From this, B = d+ ・jan ((θ1+02)
) Therefore, the X-axis direction component dX and the y-axis direction component d of vector 80 can be obtained from d, l= d, -cos(-10,), respectively.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic front view of an embodiment of the tape-type multi-core optical fiber connection observation device of the present invention.

The tape-type multi-core optical fiber 10 is placed on its support frame 11 with its longitudinal direction perpendicular to the plane of the paper. The drive mechanism 7 is driven by the motor 6 and can move the support member 5 in a direction parallel to the tape surface of the optical fiber 1O and perpendicular to the longitudinal direction of the optical fiber 1O (in the direction of the plane of the paper). The light sources 1 and 2 have their optical axes tilted at 45° with respect to the tape surface of the optical fiber 1o within a plane perpendicular to the longitudinal direction of the optical fiber 10,
Therefore, the angle between both optical axes is 90°, and it is installed on the support member 5 on one side of the tape surface. The TV left cameras and 4 are installed on the support member 5 on the opposite side of the light sources 1 and 2, with their viewing axes aligned with the optical axes of the corresponding light sources 1 and 2.

Therefore, light is emitted from the light sources 1 and 2, and while images from the TV left camera and 4 are observed, the drive mechanism 7 is driven by the motor 6 to move the support member 5 leftward or rightward. In this way, all the optical fibers are located one by one on the viewing axis of the TV left camera and 4, and at this time, the TV left camera images the connection part of the optical fibers in the upper left-lower right direction. can be observed, and the TV left camera can capture an image of the connecting portion in the lower left-upper right direction, making it possible to easily measure the axis deviations dl and d2.

Next, from equations (1) and (2), the following is obtained as θ-θ2-45°.

FIG. 2(a) is a schematic front view of another embodiment of the tape-type multi-core optical fiber connection observation device of the present invention, and FIG. 2(b) shows that the mirror 8 of this embodiment FIG. 4 is a diagram showing the arrangement when moved inside.

This embodiment differs from the above embodiment except for the TV left camera.
Instead, the light rays emitted from light source 2 are
It has a mirror 8 that reflects the light at the intersection of both optical axes of the TV and directs it toward the viewing axis of the TV left camera.
It is fixed to a mirror moving drive mechanism 9 installed above, and when passing the irradiated light from the light source 1, it is moved from the intersection of both optical axes to a position where it does not interfere (FIG. 2(a)).

Therefore, when the drive mechanism 7 is driven by the motor 6 in this state, cross-sectional images of each optical fiber in the upper left-lower right direction are sequentially obtained. Next, as shown in FIG. 2(b), the mirror moving drive mechanism 9 is driven to move the mirror 8 to the intersection of both optical axes. Here, the light emitted from the light source 2 travels toward the lower right, is reflected by the mirror 8, and then is imaged on the TV left camera, so when the drive mechanism 7 is driven, each optical fiber is sequentially moved from the lower left to the upper right. A cross-sectional image of the direction is obtained. Thereafter, the axis misalignment dX, d is determined in the same manner.

In any of the above-mentioned embodiments, each fiber of the tape-type multi-core optical fiber IO is observed one by one.
Since a book can be enlarged to almost occupy one screen (500×500 pixels), it is easy to allocate around 200 pixels per optical fiber. Therefore, for an optical fiber core wire with an outer diameter of 125μ, the positioning error Δ for one sampling error pixel is Δ=125/200 = 0.6 scales, which is sufficient accuracy even if the optical fiber 10 is a single mode type. It is.

[Effects of the Invention] As explained above, the present invention illuminates the connection portion of a tape-type multi-core optical fiber diagonally from two directions with respect to the tape surface, and determines the axis of each fiber for transmitted images in each direction. By enlarging and measuring the misalignment one by one, it is possible to measure the misalignment with extremely high accuracy, making it possible to readjust the position of the optical fiber before fusion splicing, and also to adjust the position of the optical fiber before fusion splicing. The effect is that the loss after fusion splicing can be accurately measured from the relationship between axis misalignment and splicing loss.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of an embodiment of a tape-type multi-core optical fiber connection observation device of the present invention, and FIG. 2(a) is a schematic front view of another embodiment of the present invention. (b) is a layout diagram when the mirror 8 of this embodiment is moved into the optical path from the light source 1, FIG. 3 is a schematic diagram showing the arrangement relationship between the tape-type multicore optical fiber and the TV left camera, and FIG. The figure shows an enlarged transmission image of the fiber connection part on the left camera image plane of the TV, Figure 5 is an explanatory diagram for calculating the axis deviation dimension of the fiber, and Figure 6 shows the conventional tape-type multi-core optical fiber connection part observation device. 7(a) is a vertical transmission image of the tape surface obtained by this conventional example, and FIG. 7(b) is an enlarged view of the portion 14 in FIG. 7(a). FIG. 8 is a graph showing the relationship between the bright line width W of the transmitted image of the optical fiber core and the axis deviation y of the core wire from the tape surface at the connection portion. 1.2...Light source, 3.4-TV camera, 5...
- Supporting member, 6... Motor, 7... Drive mechanism, 8... Mirror, 9... Drive mechanism for mirror movement, 10... Tape type multi-core optical fiber, 11-... Support frame , 31, ~315--Optical fiber core wire, 32--Lens, 33--TV left camera image plane, P... Optical axis, d, d,, d2. dX, d, ---axis misalignment,
θ, θ1. θ2...angle, A, B, C, D...point, x, y...coordinate axis.

Claims (1)

[Claims] 1. Illuminating the spliced portion of a tape-type multi-core optical fiber from behind before or after fusion splicing, and observing the axis misalignment of each fiber at the spliced portion from the transmitted image. A tape-type multi-core optical fiber connection observation device comprising a support member and a drive for moving the support member in a direction parallel to the tape surface of the tape-type multi-core optical fiber and perpendicular to the longitudinal direction of the optical fiber. a mechanism, and a support member that illuminates the connection part from two directions on one side of the tape surface, each having a predetermined angle with respect to the tape surface on a plane perpendicular to the longitudinal direction of the optical fiber, to obtain transmitted images in each direction. A tape-type multi-core optical fiber connection observation device with an observation means installed in the 2. The two directions having the predetermined angles are directions in which the transmitted image of the optical fiber core irradiated from each direction is observed without being superimposed on the transmitted image of the other core wire, and the observation means is , a tape type according to claim 1, comprising light sources in two directions, and two TV cameras installed on the opposite side of the tape surface from the light sources with their viewing axes aligned in the two directions. Multi-core optical fiber connection observation device. 3. The two directions having the predetermined angle are directions in which the transmitted image of the optical fiber core irradiated from each direction is observed without being superimposed on the transmitted image of the other core wire, and the observation means is , a light source in each of the two directions, a TV camera installed on the opposite side of the tape surface from the light source with the viewing axis aligned in one of the two directions, and a TV camera on the viewing axis of the TV camera. The transmitted ray from one of the two directions at the position is T
The tape-type multi-core optical fiber connection unit according to claim 1, comprising an optical path changing means that reflects or refracts in the direction of the visual axis of the V camera and is movable to or from the position. Observation device.