Inspection method and inspection device of optical fiber ribbon

Abstract

To provide an inspection method and an inspection device of an optical fiber ribbon which can accurately detect the array of coated optical fibers.SOLUTION: An inspection method of an optical fiber ribbon in which a plurality of colored coated optical fibers are intermittently connected to each other in a longitudinal direction by a connecting resin, in a state where the coated optical fibers are arranged in parallel, includes the steps of: emitting light from a light source to a surface of an optical fiber ribbon while traveling the optical fiber ribbon in the longitudinal direction, and acquiring a two-dimensional color image based on reflection light which is emitted from the light source and reflected from the surface of the optical fiber ribbon by an imaging device; and specifying the color and the position of the coated optical fibers on the basis of the color image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method and apparatus for inspecting optical fiber ribbons. [Background technology]

[0002] Patent Document 1 discloses an inspection method and device for a flat cable composed of dark-colored (e.g., orange, red, blue, green, black, etc.) core wires (signal wires) and light-colored (e.g., white, yellow, etc.) core wires (ground wires). In this inspection device, a line sensor is placed perpendicular to the surface of the flat cable, and a lighting device is positioned so that light is incident obliquely on the surface of the flat cable. The brightness of the image acquired by the line sensor is binarized into light and dark areas, and the number of light or dark areas is calculated to inspect the quality of the arrangement of the core wires.

[0003] Patent Document 2 discloses an inspection method for an intermittently connected optical fiber ribbon, which takes one-dimensional images in the width direction of the optical fiber ribbon with a camera, accumulates them to create a two-dimensional image, and inspects the connected portion from the two-dimensional image. In this inspection method, the optical fiber ribbon is placed between a camera and an illumination device, and illumination light (leakage light) is detected through the optical fiber ribbon to measure the light quantity distribution along the width direction. In addition, the optical fiber ribbon is supported by a guide roller having a stepped portion to separate the non-connected portion.

[0004] Patent Document 3 discloses an inspection method for an intermittently connected optical fiber ribbon, which measures the length of the non-connected portion between connected portions, etc. In this inspection method, the optical fiber ribbon is supported by a guide roller having a stepped portion to separate the non-connected portion, an image of the optical fiber ribbon is obtained by a camera, and the edge interval, the number of edges, etc. are measured from the image.

[0005] Patent Document 4 discloses a method for inspecting a flat cable in which a transmitted image of the flat cable is taken with a CCD camera to inspect the state of the conductor and insulating coating over the length of the flat cable. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-43759 A [Patent Document 2] JP 2017-125780 A [Patent Document 3] JP 2012-042354 A [Patent Document 4] JP 2002-304922 A Summary of the Invention [Problem to be solved by the invention]

[0007] When the above-mentioned inspection method based on the brightness of an image is applied to the inspection of an optical fiber ribbon, for example, when optical fiber core wires colored with colors of similar brightness are arranged adjacent to each other, it is difficult to detect the interchange or reversal of the optical fiber core wires. Also, the inspection method using leakage light can detect the presence or absence of gaps between the optical fiber core wires, but cannot detect the interchange or reversal of the optical fiber core wires.

[0008] The present disclosure provides an optical fiber ribbon inspection method and inspection device that can accurately identify the arrangement of optical fiber cores. [Means for solving the problem]

[0009] The method for inspecting an optical fiber ribbon according to the present disclosure includes: 1. A method for inspecting an optical fiber ribbon in which a plurality of colored optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, comprising: a step of irradiating a surface of the optical fiber ribbon with light from a light source while running the optical fiber ribbon in a longitudinal direction, and acquiring a two-dimensional color image based on the light emitted by the light source and reflected from the surface of the optical fiber ribbon by an imaging device; identifying a color and a position of the optical fiber core based on the color image; Includes. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide an optical fiber ribbon inspection method and inspection device that can accurately identify the arrangement of optical fiber cores. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of an inspection device for optical fiber ribbons according to this embodiment. [Diagram 2] FIG. 2 is a plan view illustrating the configuration of an optical fiber ribbon. [Diagram 3] FIG. 3 is a cross-sectional view illustrating a configuration example taken along line III-III in FIG. 2, as viewed from the direction of the arrows. [Figure 4] FIG. 4 is a cross-sectional view illustrating a configuration example of a cross section taken along line IV-IV in FIG. 2, as viewed from the direction of the arrows. [Diagram 5] FIG. 5 is a schematic diagram illustrating the configuration of an optical fiber ribbon manufacturing apparatus incorporating an inspection device. [Figure 6] FIG. 6 is a diagram illustrating an example of the imaging range (field of view) of the imaging device with respect to the surface of the optical fiber ribbon. [Figure 7] FIG. 7 is a flow chart illustrating a method for inspecting optical fiber ribbons. [Figure 8] FIG. 8 is a diagram for explaining an image of an optical fiber ribbon. [Figure 9] FIG. 9 is a diagram for explaining a reference image of an optical fiber ribbon. [Figure 10] FIG. 10 is a diagram for explaining another example of an image of an optical fiber ribbon. [Figure 11] FIG. 11 is a diagram illustrating an example of an optical fiber ribbon in which an abnormality in the arrangement of optical fiber cores occurs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0013] (1) The inspection method of the optical fiber ribbon of the present disclosure is a method for inspecting an optical fiber ribbon in which a plurality of colored optical fiber cores are arranged in parallel and the optical fiber cores are intermittently connected in the longitudinal direction by a connecting resin, while running the optical fiber ribbon in the longitudinal direction, irradiating light from a light source onto the surface of the optical fiber ribbon, and acquiring, by an imaging device, a two-dimensional color image based on the reflected light emitted by the light source and reflected from the surface of the optical fiber ribbon; a step of specifying the color and position of the optical fiber core based on the color image; and includes.

[0014] According to such a method, since the color and position of each optical fiber core constituting the optical fiber ribbon can be specified from the two-dimensional color image based on the reflected light, the arrangement of the optical fiber cores can be accurately specified.

[0015] (2) In the above (1), it may include a step of determining whether the arrangement of the optical fiber cores is normal based on the specified color and position of the optical fiber cores.

[0016] According to such a method, it is possible to detect abnormalities in the arrangement such as replacement or inversion of the optical fiber cores in one or more units.

[0017] (3) In the above (1) or (2), the imaging period T [ms] of the imaging device, the length L [mm] in the longitudinal direction of the imaging range of the imaging device, and the running speed V [m / min] of the optical fiber ribbon may be set so that the relational expression T < L / (V / 60) is satisfied.

[0018] According to this method, the i-th (i is a natural number except zero) image acquired in the longitudinal direction of the optical fiber ribbon and the i+1-th image acquired partially overlap each other, thereby enabling inspection without gaps over the entire length of the optical fiber ribbon.

[0019] (4) In (3) above, When the overlap width α [mm] in the longitudinal direction of the imaging range imaged before and after the imaging period T is a constant, the imaging period T may be changed in accordance with the running speed V of the optical fiber ribbon so as to satisfy the relational equation T = (L - α) / (V / 60).

[0020] According to this method, the overlap width of the images acquired before and after the imaging period T is constant, so that it is easy to identify the color and position of the optical fiber core even if the running speed V of the optical fiber ribbon changes.

[0021] (5) In any of (1) to (4) above, The imaging device includes: The optical fiber ribbons may be arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface of the optical fiber ribbon and the surface of the optical fiber ribbon is different from a second angle formed between the reflected light reflected from the surface of the optical fiber ribbon and incident on the imaging device and the surface of the optical fiber ribbon.

[0022] According to this method, the incidence of specularly reflected light on the imaging device can be suppressed, so that the occurrence of whiteout on the surface of the optical fiber ribbon in the image can be prevented.

[0023] (6) In (5) above, The first angle is equal to or greater than 25° and equal to or less than 35°; The second angle may be greater than or equal to 85° and less than or equal to 95°.

[0024] If the first angle is smaller than 25°, the intensity of the scattered light from the optical fiber ribbon is weak, making it difficult to identify the color and position of the optical fiber core. On the other hand, if the first angle is larger than 35°, depending on the subtle shape of the surface of the optical fiber ribbon, the regular reflected light may enter the imaging device, causing part of the image to be blown out. According to the above method, since the first angle is 25° or more and 35° or less, it is easy to identify the color and position of the optical fiber core. Also, since the second angle is 85° or more and 95° or less, and is approximately 90°, the reflected light from a direction approximately perpendicular to the surface of the optical fiber ribbon enters the imaging device, and the scattered light can be received most efficiently.

[0025] (7) In any of (1) to (6) above, The step of identifying the color and the position of the optical fiber core based on the color image includes: identifying an area in the color image in which each optical fiber core is captured; identifying a color for each identified region; may include:

[0026] According to this method, since the area corresponding to each optical fiber core and the color of the area are specified, noise removal processing such as removing whiteout is not required. This makes it possible to quickly inspect the optical fiber ribbon, and the inspection can be performed even on optical fiber ribbons traveling at high speed.

[0027] (8) In any of (1) to (7) above, The optical fiber ribbon may have a plurality of sub-ribbons, each sub-ribbon having two optical fiber cores and a coating resin that continuously covers the two optical fiber cores in the longitudinal direction, and the sub-ribbons may be arranged in parallel and adjacent sub-ribbons may be intermittently connected in the longitudinal direction by the connecting resin.

[0028] According to this method, even in the case of a two-core intermittent optical fiber ribbon, the arrangement of the optical fiber core wires can be accurately specified. In addition, since a two-core intermittent optical fiber ribbon has multiple sub-ribbons intermittently connected, the flexibility of the optical fiber ribbon is improved and it can be stored in an optical cable at a high density. In addition, since the optical fiber core wires are integrated into each sub-ribbon, it is easy to handle when fusion splicing multiple optical fiber core wires that make up the optical fiber ribbon all at once.

[0029] (9) The optical fiber ribbon manufacturing apparatus according to the present disclosure comprises: An inspection device for an optical fiber ribbon in which a plurality of colored optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, a light source that irradiates light onto a surface of the optical fiber ribbon that runs in a longitudinal direction; an imaging device for acquiring a two-dimensional color image based on light emitted by the light source and reflected from a surface of the optical fiber ribbon; a control device for identifying a color and a position of the optical fiber core based on the color image; has.

[0030] According to this configuration, the color and position of each optical fiber that constitutes the optical fiber ribbon can be identified from a two-dimensional color image based on reflected light, so that the arrangement of the optical fiber can be grasped with high accuracy.

[0031] (10) In (9) above, The control device may determine whether an arrangement of the optical fiber cores is normal based on the identified colors and positions of the optical fiber cores.

[0032] According to such a configuration, it is possible to detect anomalies in the arrangement, such as the replacement or reversal of optical fiber core wires, in units of one or more.

[0033] (11) In (9) or (10) above, The imaging device includes: The optical fiber ribbons may be arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface of the optical fiber ribbon and the surface of the optical fiber ribbon is different from a second angle formed between the reflected light reflected from the surface of the optical fiber ribbon and incident on the imaging device and the surface of the optical fiber ribbon.

[0034] According to this configuration, incidence of specularly reflected light into the imaging device can be suppressed, so that the occurrence of whiteout on the surface of the optical fiber ribbon in the image can be prevented.

[0035] (12) In (11) above, The first angle is equal to or greater than 25° and equal to or less than 35°, The second angle may be greater than or equal to 85° and less than or equal to 95°.

[0036] If the first angle is smaller than 25°, the intensity of the scattered light from the optical fiber ribbon is weak, making it difficult to identify the color and position of the optical fiber core. On the other hand, if the first angle is larger than 35°, depending on the subtle shape of the surface of the optical fiber ribbon, the regular reflected light may enter the imaging device, causing part of the image to be blown out. According to the above configuration, since the first angle is 25° or more and 35° or less, it is easy to identify the color and position of the optical fiber core. Also, since the second angle is 85° or more and 95° or less, and is approximately 90°, the reflected light from a direction approximately perpendicular to the surface of the optical fiber ribbon enters the imaging device, and the scattered light can be received most efficiently.

[0037] (13) In any of (9) to (12) above, The control device includes: Identifying an area in which each optical fiber core is captured in the color image; A color may be specified for each identified region.

[0038] According to this configuration, since the area corresponding to each optical fiber core and the color of the area are specified, noise removal processing such as removing whiteout is not required. This makes it possible to quickly inspect the optical fiber ribbon, and the inspection can be performed even on optical fiber ribbons traveling at high speed.

[0039] [Details of the embodiment of the present disclosure] Specific examples of the inspection method and the inspection device for optical fiber ribbons disclosed herein will be described with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0040] In the drawings, arrow U indicates the upward direction of the illustrated structure. Arrow D indicates the downward direction of the illustrated structure. Arrow F indicates the forward direction of the illustrated structure. Arrow B indicates the rearward direction of the illustrated structure. Arrow R indicates the rightward direction of the illustrated structure. Arrow L indicates the leftward direction of the illustrated structure. These directions are relative directions set for the optical fiber ribbon inspection apparatus 10 shown in FIG. 1.

[0041] (Optical fiber ribbon inspection device) 1 is a diagram illustrating the configuration of an inspection device 10 for an optical fiber ribbon 1 according to the present embodiment. The inspection device 10 is a device used for inspecting an optical fiber ribbon 1 in which a plurality of optical fiber cores are arranged in parallel and intermittently connected in the longitudinal direction by a connecting resin.

[0042] Fig. 2 shows an example of the optical fiber ribbon 1. Fig. 2 shows the optical fiber ribbon 1 in a state in which the non-connected portions 5 are spread out in the arrangement direction of the optical fiber cores 21. Figs. 3 and 4 show the cross-sectional shape of the optical fiber ribbon 1 in Fig. 2.

[0043] As illustrated in Fig. 2, the optical fiber ribbon 1 has a plurality of optical fiber cores 21. As illustrated in Fig. 3, each optical fiber core 21 has a glass fiber 211 and a coating layer 212. The glass fiber 211 is composed of, for example, a core and a clad. The coating layer 212 coats the periphery of the glass fiber 211. The coating layer 212 is composed of a plurality of coating layers including a colored layer colored in a predetermined color as the outermost layer. For example, the colored layers of each optical fiber core 21 are colored in a different color.

[0044] Two adjacent optical fibers 21 are integrated with the coating resin 22 while being in continuous contact in the longitudinal direction to form the sub-ribbon 2. The coating resin 22 covers the periphery of the two adjacent optical fibers 21 in the longitudinal direction. The coating resin 22 is formed of a resin material such as an acrylic ultraviolet-curing resin or an epoxy ultraviolet-curing resin. The coating resin 22 is, for example, a transparent resin.

[0045] 2, multiple sub-ribbons 2 are arranged in parallel and intermittently connected in the longitudinal direction by connecting resin 3. As a result, in optical fiber ribbon 1, connecting portions 4 where adjacent sub-ribbons 2 are connected by connecting resin 3 and non-connecting portions 5 where they are not connected are provided intermittently in the longitudinal direction. Connecting resin 3 is formed of a resin material such as, for example, an acrylic ultraviolet-curing resin or an epoxy ultraviolet-curing resin. Connecting resin 3 is, for example, a transparent resin. Connecting resin 3 may be formed of the same resin material as coating resin 22.

[0046] In this example, as shown in Figures 3 and 4, the optical fiber ribbon 1 has 12 optical fiber cores 21A to 21L, and two adjacent optical fiber cores 21 (21A and 21B, 21C and 21D, 21E and 21F, 21G and 21H, 21I and 21J, 21K and 21L) form sub-ribbons 2 (2A, 2B, 2C, 2D, 2E, 2F).

[0047] The inspection of the optical fiber ribbon 1 by the inspection device 10 is carried out, for example, during the manufacturing process of the optical fiber ribbon 1.

[0048] 5 shows the configuration of a manufacturing apparatus 30 for the optical fiber ribbon 1 in which the inspection apparatus 10 is incorporated. The inspection apparatus 10 is configured to inspect the optical fiber ribbon 1 formed by the manufacturing apparatus 30.

[0049] Specifically, the manufacturing apparatus 30 includes a supply bobbin 31, a first coating device 32, a first curing device 33, a second coating device , a second curing device 35, and a winder .

[0050] The optical fibers 21A to 21L wound around the supply bobbins 31A to 31L are unwound and transported to a first coater 32. Then, in the first coater 32, a coating resin 22 is applied around each of two adjacent optical fibers 21 in the plurality of optical fibers 21A to 21L. Next, the coating resin 22 applied around the optical fibers 21 is cured in a first curing device 33 by, for example, ultraviolet light irradiation. As a result, a plurality of sub-ribbons 2 are formed in which the two optical fibers 21 are integrated with the coating resin 22.

[0051] Next, the multiple sub-ribbons 2 are transported to second coating device 34 while being arranged in parallel. Then, in second coating device 34, connecting resin 3 is applied between adjacent sub-ribbons 2. Next, the connecting resin 3 applied between adjacent sub-ribbons 2 is cured in second curing device 35, for example, by irradiation with ultraviolet light. In this way, an optical fiber ribbon 1 is formed in which the multiple sub-ribbons 2 are intermittently connected in the longitudinal direction by the connecting resin 3. Then, optical fiber ribbon 1 is taken up by winder 36. The operation of each device is controlled by an intermittent coating control device (not shown).

[0052] In this example, the optical fiber core wires 21A to 21L fed from the supply bobbins 31A to 31L run downward (in the direction indicated by the arrow A in the figure), forming the optical fiber ribbon 1 in a state in which the optical fiber core wires are arranged side by side in a direction perpendicular to the paper surface of Fig. 5 (the left-right direction in the figure). In this example, the optical fiber ribbon 1 runs with its longitudinal direction aligned along the up-down direction.

[0053] The inspection device 10 is disposed between the second curing device 35 and the winding machine 36, and inspects whether the arrangement of the multiple optical fiber cores 21 constituting the optical fiber ribbon 1 running downward from the second curing device 35 is normal.

[0054] Specifically, as illustrated in FIG. 1, the inspection device 10 includes a light source 11, an imaging device 12, and a camera control device 13. The camera control device 13 corresponds to the control device in the present disclosure. The light source 11 is configured to irradiate light onto a surface 1S of the optical fiber ribbon 1 running in the longitudinal direction. The surface 1S of the optical fiber ribbon 1 onto which the light is irradiated from the light source 11 is a surface along the arrangement direction of the multiple optical fiber cores 21, and is a surface of the optical fiber ribbon 1 on which the connecting resin 3 is provided or a surface opposite to the surface on which the connecting resin 3 is provided. The light source 11 emits, for example, white light. Although the surface 1S has some unevenness, the surface 1S is regarded as a flat surface obtained by averaging out the unevenness.

[0055] The light source 11 is disposed so as to emit light in a direction at a first angle θ1 with respect to the surface 1S of the optical fiber ribbon 1 in a cross section perpendicular to the surface 1S of the optical fiber ribbon 1 and along the longitudinal direction. In other words, the first angle θ1 is the angle between the incident light LT1 emitted from the light source 11 and incident on the surface 1S of the optical fiber ribbon 1 and the surface 1S of the optical fiber ribbon 1. The first angle θ1 is set to, for example, 25° or more and 35° or less.

[0056] The imaging device 12 is configured to obtain a two-dimensional color image based on the light emitted from the light source 11 and reflected from the surface 1S of the optical fiber ribbon 1. The imaging device 12 is, for example, a CMOS camera.

[0057] The imaging device 12 is arranged such that, in a cross-section perpendicular to the surface 1S of the optical fiber ribbon 1 and along the longitudinal direction, light reflected from the surface 1S of the optical fiber ribbon 1 in a direction of a second angle θ2 with respect to the surface 1S of the optical fiber ribbon 1 is incident thereon. In other words, the second angle θ2 is an angle formed by the reflected light LT2 incident on the imaging device 12 and the surface 1S of the optical fiber ribbon 1. The second angle θ2 is set to an angle different from the first angle θ1. The second angle θ2 is set to, for example, 90°.

[0058] The imaging device 12 periodically acquires images with respect to the optical fiber ribbon 1 traveling in the longitudinal direction. FIG. 6 shows the imaging range (field of view) of the imaging device 12 with respect to the surface 1S of the optical fiber ribbon 1. In FIG. 6, Ri is the imaging range imaged at the i-th time, R(i + 1) is the imaging range imaged at the (i + 1)-th time, and R(i + 2) is the (i + 2)-th imaging range. Note that i is a natural number excluding zero. Each imaging range is defined by the longitudinal length L [mm] of the optical fiber ribbon 1 and the lateral length W [mm] of the optical fiber ribbon 1.

[0059] The imaging period of the imaging device 12 is set such that, for example, a part of the imaging ranges imaged before and after the imaging period (for example, Ri and R(i + 1), or R(i + 1) and R(i + 2)) overlap each other. Specifically, for example, when the imaging period is T [ms], the longitudinal length of the optical fiber ribbon 1 in the imaging range is L [mm], and the traveling speed of the optical fiber ribbon 1 is V [m / min], the imaging period T is set to satisfy the relational expression T < L / (V / 60).

[0060] Alternatively, when the overlapping width in the longitudinal direction of the imaging ranges imaged before and after the imaging period T is α [mm], the imaging period T may be set to change in accordance with the traveling speed V of the optical fiber ribbon 1 so as to satisfy the relational expression T = (L - α) / (V / 60) when the overlapping width α is set to a constant. The overlapping width α is set to satisfy, for example, the relational expression 0.1 < α / L < 0.5.

[0061] Returning to FIG. 1, the camera control device 13 is, for example, a general-purpose computer having a general-purpose memory and a general-purpose microprocessor operating in cooperation with the general-purpose memory.

[0062] The camera control device 13 is configured to control the operation of the imaging device 12. For example, the camera control device 13 determines an imaging cycle T of the imaging device 12 based on the overlap width α of the imaging ranges, the length L of the imaging ranges, and the running speed V of the optical fiber ribbon 1. Then, the camera control device 13 outputs a control signal CS to the imaging device 12 for imaging at the determined imaging cycle T. The imaging device 12 sets or changes the imaging cycle T based on the control signal CS. The camera control device 13 is connected to, for example, a winding machine 36, and obtains information VI of the winding speed of the optical fiber ribbon 1 from the winding machine 36 as information on the running speed V of the optical fiber ribbon 1.

[0063] The camera control device 13 also acquires from the imaging device 12 the data ID of the color image in which the optical fiber ribbon 1 is captured. The camera control device 13 identifies the color and position of each optical fiber 21 in the optical fiber ribbon 1 based on the acquired color image. The camera control device 13 then determines whether the arrangement of the multiple optical fiber cores 21 constituting the optical fiber ribbon 1 is normal based on the identified color and position of each optical fiber core 21. For example, when the multiple optical fiber cores 21 are arranged in a predetermined order, the camera control device 13 determines that the arrangement of the optical fiber cores 21 is normal. On the other hand, when the multiple optical fiber cores 21 are not arranged in the predetermined order, the camera control device 13 determines that the arrangement of the optical fiber cores 21 is abnormal.

[0064] The camera control device 13 outputs the determination result of the arrangement of the optical fiber cores 21. For example, the inspection device 10 is equipped with a display device 14 and a storage device 15. The camera control device 13 outputs the determination result JI of the arrangement of the optical fiber cores 21 to the display device 14, and causes the display device 14 to display the determination result of the arrangement of the optical fiber cores 21. The camera control device 13 also outputs the determination result JI of the arrangement of the optical fiber cores 21 to the storage device 15, and causes the storage device 15 to store the determination result of the arrangement of the optical fiber cores 21.

[0065] (Inspection method for optical fiber ribbon 1) An inspection method for the optical fiber ribbon 1 using the inspection device 10 will be described below with reference to Figures 7 to 11. Figure 7 is a flow chart showing the inspection method for the optical fiber ribbon 1.

[0066] First, while running the optical fiber ribbon 1 in the longitudinal direction, light is irradiated from the light source 11 onto the surface 1S of the optical fiber ribbon 1, and a two-dimensional color image based on the light emitted by the light source 11 and reflected from the surface 1S of the optical fiber ribbon 1 is acquired by the imaging device 12 (STEP 1).

[0067] Next, the camera control device 13 identifies the color and position of the optical fiber cores 21 that make up the optical fiber ribbon 1 based on the color image of the surface 1S of the optical fiber ribbon 1 acquired from the imaging device 12 (STEP 2).

[0068] Specifically, the camera control device 13 identifies an area in the color image in which each optical fiber 21 appears, and identifies the color of each identified area.

[0069] Fig. 8 shows a color image P1 of the optical fiber ribbon 1 captured by the imaging device 12. In Fig. 8, differences in color in the image P1 are represented by different hatching patterns. The camera control device 13 identifies the area in which each optical fiber 21 is captured based on the color of each pixel constituting the image P1.

[0070] The color image acquired by the imaging device 12 is, for example, a color image expressed in the HSV hue space in which colors are expressed by hue, saturation, and value. The camera control device 13 specifies, for example, an area surrounded by a group of pixels having the same hue, saturation, and value as an area in which one optical fiber core is captured, based on the values ​​in the HSV hue space indicated by each pixel constituting the image.

[0071] In image P1 shown in Figure 8, area A1, area B1, area C1, area D1, area E1, area F1, area G1, area H1, area I1, area J1, area K1 and area L1 are identified as areas in which the optical fiber core 21 is captured.

[0072] Next, the camera control device 13 digitizes the colors contained in each identified area, and compares the digitized color value of each area with the color value of the optical fiber core in the reference image to identify the color of each area.

[0073] FIG. 9 is a diagram for explaining the reference image P10. The reference image P10 is a two-dimensional color image obtained by capturing an image of the optical fiber ribbon 1 in which the optical fiber cores 21 are normally arranged in advance. In this example, the reference image P10 captures the optical fiber ribbon 1 in which 12 optical fiber cores 21 are arranged side by side in the following colors from top to bottom: blue, orange, green, brown, gray, white, red, black, yellow, purple, pink, and light blue. The colors of the regions A10 to L10 in which the optical fiber cores 21 are captured in the reference image P10 are digitized in advance. The reference image P10 and the colors, numerical values, and position information of the regions A10 to L10 in which the optical fiber cores 21 are captured are stored in the memory of the camera control device 13 or the storage device 15.

[0074] The camera control device 13 quantifies the color of the area A in the image P1 shown in Fig. 8 based on, for example, the values ​​of hue, saturation, and brightness in the HSV hue space. Then, the camera control device 13 compares the color numerical value of the area A with the color numerical values ​​of the areas A10 to L10 in the reference image P10 in Fig. 9, and classifies the color of the area A into the color of the area among the areas A10 to L10 in the reference image P10 that shows the closest numerical value to the color of the area A in the image P1. For example, if the color numerical value of the area A1 in the image P1 shown in Fig. 8 is the same as the color numerical value of the area A10 in the reference image P10 shown in Fig. 9, the color of the area A1 in the image P1 shown in Fig. 8 is classified into "blue," which is the color of the area A10 in the reference image P10.

[0075] Similarly, the colors of the areas B1 to L1 in the image P1 shown in FIG. 8 are classified based on the reference image P10. As a result, the color of region B1 in image P1 is classified as "orange," which is the color of region B10 in the reference image P10; the color of region C1 is "green," which is the color of region C10 in the reference image P10; the color of region D1 is "brown," which is the color of region D10 in the reference image P10; the color of region E1 is "gray," which is the color of region E10 in the reference image P10; the color of region F1 is "white," which is the color of region F10 in the reference image P10; the color of region G1 is "red," which is the color of region G10 in the reference image P10; the color of region H1 is "black," which is the color of region H10 in the reference image P10; the color of region I1 is "yellow," which is the color of region I10 in the reference image P10; the color of region J1 is "purple," which is the color of region J10 in the reference image P10; the color of region K1 is "pink," which is the color of region K10 in the reference image P10; and the color of region L1 is "light blue," which is the color of region L10 in the reference image P10.

[0076] Next, the camera control device 13 judges whether the arrangement of the multiple optical fiber cores 21 constituting the optical fiber ribbon 1 is normal based on the color and position of each identified optical fiber core 21 (STEP 3 in Fig. 7). Specifically, the camera control device 13 determines the arrangement of the optical fiber cores 21 based on the color of each classified area in the image P1 shown in Fig. 8, and judges whether the determined arrangement of the optical fiber cores 21 is the same as the arrangement of the optical fiber cores 21 in the reference image P10.

[0077] For example, the camera control device 13 determines that the optical fiber ribbon 1 reflected in the image P1 has 12 optical fiber cores 21 arranged side by side from top to bottom in the colors blue, orange, green, brown, gray, white, red, black, yellow, purple, pink, and light blue, based on the colors and positions of the areas A1 to L1 in the image P1 shown in Fig. 8. Then, the camera control device 13 determines that the arrangement of the optical fiber cores 21 in the image P1 shown in Fig. 8 is the same as the arrangement of the optical fiber cores 21 in the reference image P10 shown in Fig. 9.

[0078] On the other hand, Fig. 10 shows an image P2 of an optical fiber ribbon 1 composed of optical fiber core wires 21 arranged differently from Fig. 8. In the image P2 shown in Fig. 10, an optical fiber ribbon 1 in which optical fiber core wires 21 of green, brown, blue, orange, gray, white, red, black, yellow, purple, light blue, and pink are arranged side by side in correspondence with the area A2, the area B2, the area C2, the area D2, the area E2, the area F2, the area G2, the area H2, the area I2, the area J2, the area K2, and the area L2 is captured. Therefore, the camera control device 13 determines that the arrangement of the optical fiber core wires 21 constituting the optical fiber ribbon 1 captured in the image P2 shown in Fig. 10 is not the same as the arrangement of the optical fiber core wires 21 in the reference image P10 shown in Fig. 9.

[0079] The camera control device 13 may be configured to identify the cause of the abnormality in the arrangement of the optical fiber cores 21. For example, the color of the area A2 in the image P2 shown in Fig. 10 is the same as the color of the area C10 in the reference image P10 shown in Fig. 9, and the color of the area B2 in the image P2 shown in Fig. 10 is the same as the color of the area D10 in the reference image P10 shown in Fig. 9. Also, the color of the area C2 in the image P2 shown in Fig. 10 is the same as the color of the area A10 in the reference image P10 shown in Fig. 9, and the color of the area D2 in the image P2 shown in Fig. 10 is the same as the color of the area B10 in the reference image P10 shown in Fig. 9. As a result, the camera control device 13 may determine that a replacement X1 of the sub-ribbons 2 has occurred between the adjacent sub-ribbons 2A and 2B as illustrated in Fig. 11.

[0080] Moreover, the color of the area K2 in the image P2 shown in Fig. 10 is the same as the color of the area L10 in the reference image P10 shown in Fig. 9, and the color of the area L2 in the image P2 shown in Fig. 10 is the same as the color of the area K10 in the reference image P10 shown in Fig. 9. This allows the camera control device 13 to determine that an inversion X2 of the optical fiber 21 has occurred between adjacent optical fiber 21K, 21L as illustrated in Fig. 11.

[0081] Next, the camera control device 13 outputs the determination result of the arrangement of the optical fiber cores 21 to the display device 14 and the storage device 15 (STEP 4 in FIG. 7). The determination result of the arrangement of the optical fiber cores 21 is displayed on the display device 14 and recorded in the storage device 15. The determination result of the arrangement of the optical fiber cores 21 includes, for example, an image of the optical fiber ribbon 1 as well as information such as the position where an abnormality in the arrangement of the optical fiber cores 21 has occurred and the cause thereof.

[0082] Then, the camera control device 13 repeats the processes in STEP 1 to STEP 4 until the entire length of the optical fiber ribbon 1 is imaged (NO in STEP 5). On the other hand, when the entire length of the optical fiber ribbon 1 is imaged (YES in STEP 5), the camera control device 13 ends the process.

[0083] According to the inspection device 10 and manufacturing method for the optical fiber ribbon 1 of this embodiment, the color and position of the optical fiber core wires 21 are identified based on the color images P1, P2 formed by reflected light, so that the arrangement of the optical fiber core wires 21 can be identified with high accuracy.

[0084] Furthermore, in this embodiment, when the overlap width α of the imaging range imaged before and after the imaging cycle T is a constant, the imaging cycle T changes in accordance with the running speed V of the optical fiber ribbon 1 so as to satisfy the relational expression T=(L-α) / (V / 60). As a result, the overlap width of the images acquired before and after the imaging cycle T becomes constant, so that it is easy to identify the color and position of the optical fiber core even if the running speed V of the optical fiber ribbon changes.

[0085] The overlap width α is set so as to satisfy, for example, the relational expression 0.1<α / L<0.5. If α / L is 0.1 or less, when a deviation occurs between the running speed of the optical fiber ribbon 1 used in determining the imaging period T while the running speed of the optical fiber ribbon 1 is increasing and decreasing and the actual running speed of the optical fiber ribbon 1, there may be sections that are not photographed. On the other hand, if α / L is 0.5 or more, the i-th imaging range Ri and the i+2-th imaging range R(i+2) will overlap, which will unnecessarily limit the increase in the running speed of the optical fiber ribbon 1.

[0086] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present invention.

[0087] In the above embodiment, the camera control device 13 determines the imaging period T of the imaging device 12. However, the imaging device 12 may be configured to determine the imaging period T. In this case, the imaging device 12 may be configured to obtain information on the running speed of the optical fiber ribbon 1 from the camera control device 13 or the winding machine 36.

[0088] In the above embodiment, the colored layers of the 12 optical fibers 21 constituting the optical fiber ribbon 1 are colored in different colors. However, the inspection method of the present disclosure can also be applied to an optical fiber ribbon 1 in which the colored layers of the optical fibers 21 located at a distance where there is a low possibility of swapping or reversing in the arrangement direction of the optical fibers 21 are colored in the same color.

[0089] In the above embodiment, the sub-ribbon 2 is formed by integrating two optical fiber cores 21. However, the sub-ribbon 2 may be formed by integrating three or more optical fiber cores 21.

[0090] In the above embodiment, adjacent sub-ribbons 2 are intermittently connected in the longitudinal direction by the connecting resin 3. However, adjacent single-core optical fibers 21 may be intermittently connected in the longitudinal direction by the connecting resin 3 without forming the sub-ribbons 2.

[0091] In the above embodiment, the inspection device 10 is configured to inspect the optical fiber ribbon 1 that runs along the vertical direction. However, the inspection device 10 may be configured to inspect the optical fiber ribbon 1 that runs along the horizontal direction.

[0092] In the above embodiment, the display device 14 and the storage device 15 may be configured integrally with the camera control device 13 .

[0093] In the above embodiment, the camera control device 13 may be integrated with an intermittent coating control device that controls the operation of the manufacturing device 30 for the optical fiber ribbon 1 .

[0094] In the above embodiment, the number of the optical fiber cores 21 constituting the optical fiber ribbon 1 is 12, but the number of the optical fiber cores 21 is not limited.

[0095] In the above embodiment, the inspection by the inspection device 10 is incorporated into the manufacturing process of the optical fiber ribbon 1. However, the inspection by the inspection device 10 may be performed separately. Alternatively, the inspection by the inspection device 10 may be incorporated into a process of performing some kind of processing on the optical fiber ribbon 1, such as a marking processing process of applying marking to the optical fiber ribbon 1. [Explanation of symbols]

[0096] 1: Optical fiber ribbon 1S:Surface 2: Sub-ribbon 2A: Sub-ribbon 2B: Sub-ribbon 2C: Sub-ribbon 2D: Sub-ribbon 2E: Sub-ribbon 2F: Sub-ribbon 3: Interlocking resin 4:Connection part 5: Unconnected part 10: Inspection equipment 11:Light source 12: Imaging device 13: Camera control device 14:Display device 15:Storage device 21: Optical fiber core 21A: Optical fiber core 21B: Optical fiber core 21C: Optical fiber core 21D: Optical fiber core 21E: Optical fiber core 21F: Optical fiber core 21G: Optical fiber core 21H: Optical fiber core 21I: Optical fiber core 21J: Optical fiber core 21K: Optical fiber core 21L: Optical fiber core 22: Coating resin 30: Manufacturing equipment 31: Supply bobbin 31A: Supply bobbin 31B: Supply bobbin 31C: Supply bobbin 31D: Supply bobbin 31E: Supply bobbin 31F: Supply bobbin 31G: Supply bobbin 31H: ​​Supply bobbin 31I: Supply bobbin 31J: Supply bobbin 31K: Supply bobbin 31L: Supply bobbin 32: First coating device 33:First curing device 34: Second coating device 35:Second curing device 36: Winding machine 211: Glass fiber 212: Covering layer A1,A2,A10:Area B1,B2,B10: Area C1,C2,C10: area D1,D2,D10: Area E1,E2,E10: Area F1,F2,F10: Area G1,G2,G10:Area H1,H2,H10:Area I1,I2,I10: area J1,J2,J10: Area K1,K2,K10: Area L1,L2,L10: area CS: Control signal P1: Image P2:Image P10: Reference image ID: Image data JI: Judgment result L: Length of the optical fiber ribbon in the longitudinal direction LT1: Incident light LT2: Reflected light Ri: Imaging range R(i+1): Imaging range R(i+2): Imaging range VI: Winding speed information W: Width of the optical fiber ribbon α: overlap width θ1: first angle θ2: second angle

Claims

1. 1. A method for inspecting an optical fiber ribbon in which a plurality of colored optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, comprising: a step of irradiating a surface of the optical fiber ribbon with light from a light source while running the optical fiber ribbon in a longitudinal direction, and acquiring a two-dimensional color image based on the light emitted by the light source and reflected from the surface of the optical fiber ribbon by an imaging device; identifying a color and a position of the optical fiber core based on the color image; 13. A method for inspecting an optical fiber ribbon, comprising:

2. 2. The method for inspecting an optical fiber ribbon according to claim 1, further comprising a step of determining whether an arrangement of the optical fiber cores is normal based on the identified color and position of the optical fiber cores.

3. 3. An optical fiber ribbon inspection method as described in claim 1 or claim 2, wherein the imaging period T [ms] of the imaging device, the longitudinal length L [mm] of the imaging range of the imaging device, and the running speed V [m / min] of the optical fiber ribbon are set so as to satisfy the relationship T < L / (V / 60).

4. The optical fiber ribbon inspection method of claim 3, wherein the imaging period T is changed in accordance with the running speed V of the optical fiber ribbon so as to satisfy the relationship T = (L - α) / (V / 60) when the overlap width α [mm] in the longitudinal direction of the imaging range imaged before and after the imaging period T is a constant.

5. The imaging device includes: A method for inspecting an optical fiber ribbon as described in claim 1 or claim 2, wherein the optical fiber ribbons are arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface of the optical fiber ribbon and the surface of the optical fiber ribbon is different from a second angle formed between the reflected light reflected from the surface of the optical fiber ribbon and incident on the imaging device and the surface of the optical fiber ribbon.

6. The first angle is equal to or greater than 25° and equal to or less than 35°, The method for inspecting an optical fiber ribbon according to claim 5 , wherein the second angle is greater than or equal to 85° and less than or equal to 95°.

7. The step of identifying the color and the position of the optical fiber core based on the image includes: Identifying an area in the image in which each optical fiber core is captured; identifying a color for each identified region; Including, 3. The method for inspecting an optical fiber ribbon according to claim 1 or 2.

8. 3. The optical fiber ribbon inspection method as described in claim 1 or claim 2, wherein the optical fiber ribbon has a plurality of sub-ribbons each having two optical fiber cores and a coating resin that continuously covers the two optical fiber cores in the longitudinal direction, and the sub-ribbons are arranged in parallel and adjacent sub-ribbons are intermittently connected to each other in the longitudinal direction by the connecting resin.

9. An inspection device for an optical fiber ribbon in which a plurality of colored optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, a light source that irradiates light onto a surface of the optical fiber ribbon that runs in a longitudinal direction; an imaging device for acquiring a two-dimensional color image based on light emitted by the light source and reflected from a surface of the optical fiber ribbon; a control device for identifying a color and a position of the optical fiber core based on the color image; An optical fiber ribbon inspection device having the following features.

10. 10. The optical fiber ribbon inspection device according to claim 9, wherein the control device determines whether an arrangement of the optical fiber cores is normal based on the identified color and position of the optical fiber cores.

11. The imaging device includes: An optical fiber ribbon inspection device as described in claim 9 or claim 10, wherein the optical fiber ribbon inspection device is arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface of the optical fiber ribbon and the surface of the optical fiber ribbon and a second angle formed between the reflected light reflected from the surface of the optical fiber ribbon and incident on the imaging device and the surface of the optical fiber ribbon are different.

12. The first angle is equal to or greater than 25° and equal to or less than 35°, The optical fiber ribbon inspection device according to claim 11 , wherein the second angle is greater than or equal to 85° and less than or equal to 95°.

13. The control device includes: Identifying an area in which each optical fiber core is captured in the color image; 11. The optical fiber ribbon inspection device according to claim 9, further comprising: identifying a color of each identified region.

Images