Optical fiber ribbon inspection method, inspection device, and manufacturing method

Abstract

An optical fiber ribbon inspection method, inspection device, and manufacturing method are provided that can accurately detect the position of connecting resin. [Solution] A method for inspecting an optical fiber ribbon in which multiple optical fiber core wires are arranged in parallel and intermittently connected in the longitudinal direction by connecting resin, the method including the steps of: irradiating the optical fiber ribbon running on a roller with light from a direction parallel to the direction in which the optical fiber ribbon runs and along the tangent to the surface of the roller with which the optical fiber ribbon contacts, and obtaining an image based on the light that has passed around the optical fiber ribbon, in which the optical fiber ribbon forms a shadow and is projected; detecting the spacing between the optical fiber core wires based on the image; and detecting the position of the connecting resin based on the image.

Description

[Technical Field]

[0001] The present disclosure relates to an inspection method, an inspection device, and a manufacturing method for an optical fiber ribbon. [Background technology]

[0002] Patent Documents 1 and 2 disclose an inspection method for an intermittently connected optical fiber ribbon, in which light is irradiated onto one side of the optical fiber ribbon, the illumination light (leakage light) passing through the fiber ribbon is detected by a camera to obtain an image of the optical fiber ribbon, and the connected portions are inspected from the image. In this inspection method, the optical fiber ribbon is supported by a guide roller having a stepped portion, and the non-connected portions are separated.

[0003] Patent Document 3 discloses an inspection method for intermittently connected optical fiber ribbons, in which an image of one surface of the optical fiber ribbon is acquired by a camera and the length of the non-connected portion between connected portions is measured from the image. In this inspection method, the optical fiber ribbon is supported by a guide roller having a stepped portion, and the non-connected portion is separated.

[0004] Patent Document 4 discloses a method for inspecting a flat cable in which light is irradiated onto one surface of the flat cable and a transmitted image of the flat cable obtained by this irradiated light is taken with a CCD camera to inspect the state of the conductor and insulating coating. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-125780 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-181513 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-042354 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-304922 Summary of the Invention [Problem to be solved by the invention]

[0006] When inspecting intermittently connected optical fiber ribbons using transmitted light as described above, it is difficult to obtain a high-contrast image that allows identification of the connected resin because the connected resin is transparent and easily transmits light. Furthermore, when separating non-connected portions using guide rollers to make it easier to obtain images of the non-connected portions, it is difficult to detect the non-connected portions from the image unless the optical fibers are reliably spaced apart in the non-connected portions. In particular, when the traveling speed of the optical fiber ribbon increases, the optical fiber ribbon may vibrate and lift off the guide roller, resulting in areas where the effect of steps or protrusions is lost.

[0007] The present disclosure provides an optical fiber ribbon inspection method, inspection device, and manufacturing method that can accurately detect the position of the connecting resin. [Means for solving the problem]

[0008] The optical fiber ribbon inspection method of the present disclosure includes: An inspection method for an optical fiber ribbon in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, comprising: a step of irradiating the optical fiber ribbon traveling on a roller with light in a direction parallel to the direction of travel of the optical fiber ribbon and along a tangent to the surface of the roller with which the optical fiber ribbon comes into contact, and acquiring an image based on the light that has passed around the optical fiber ribbon and is projected as a shadow of the optical fiber ribbon; detecting the intervals between the optical fiber cores based on the image; detecting the position of the interlocking resin based on the image; Includes. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide an inspection method, an inspection device, and a manufacturing method for an optical fiber ribbon that can accurately detect the position of the connecting resin. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of an optical fiber ribbon inspection device according to this embodiment. [Figure 2] FIG. 2 is a plan view illustrating the configuration of an optical fiber ribbon. [Figure 3] FIG. 3 is a cross-sectional view illustrating a configuration taken along line III-III in FIG. 2, viewed from the direction of the arrows. [Figure 4] FIG. 4 is a cross-sectional view illustrating a configuration taken along line IV-IV in FIG. 2, viewed from the direction of the arrows. [Figure 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 cross-sectional view illustrating a configuration taken along line VI-VI in FIG. 1, viewed from the direction of the arrows. [Figure 7] FIG. 7 is a flowchart illustrating a method for inspecting an optical fiber ribbon. [Figure 8] FIG. 8 is a diagram illustrating an image of an optical fiber ribbon. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0012] (1) The disclosed method for inspecting optical fiber ribbons is a method for inspecting optical fiber ribbons in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in the longitudinal direction by connecting resin, and includes the steps of: irradiating the optical fiber ribbon running on a roller with light in a direction parallel to the direction in which the optical fiber ribbon runs and along the tangent to the surface of the roller with which the optical fiber ribbon contacts; obtaining an image based on the light that has passed around the optical fiber ribbon and in which the optical fiber ribbon casts a shadow; detecting the spacing between the optical fiber core wires based on the image; and detecting the position of the connecting resin based on the image.

[0013] According to the above method, light is irradiated from a direction parallel to the direction of travel of the optical fiber ribbon and tangent to the surface of the roller with which the optical fiber ribbon comes into contact, so that the light incident on the optical fiber ribbon is reflected by the surfaces of the optical fiber cores and the connecting resin, or refracted within the optical fiber cores and the connecting resin, and as a result, the portions of the image corresponding to the optical fiber cores and the connecting resin are shaded, and the position of the connecting resin can be detected from the image with high accuracy.

[0014] (2) In the above (1), the inspection method for the optical fiber ribbon may include a step of determining whether the spacing between the optical fiber core wires is within a predetermined range, a step of determining whether the position of the connecting resin is at a predetermined position, and a step of outputting the determination results of the spacing between the optical fiber core wires and the position of the connecting resin.

[0015] According to this method, the positions of the optical fiber cores and the connecting resin can be detected with high accuracy, so that it is possible to accurately determine whether the spacing between the optical fiber cores and the position of the connecting resin are within a predetermined range or at a predetermined position.

[0016] (3) In the above (1) or (2), the roller may be shaped like a drum with a bulging center.

[0017] If the spacing between the connecting resins in the longitudinal direction is long, the spacing between the optical fibers running on the drum-shaped roller with a bulge in the center tends to become wider in the arrangement direction. Therefore, it is possible to determine whether the connecting resin has been applied to the predetermined positions from the spacing between the optical fibers in the arrangement direction in the image.

[0018] (4) In any of (1) to (3) above, the optical fiber ribbon may be conveyed so that the connecting resin is applied to one side and the side opposite to the side on which the connecting resin is applied is in contact with the surface of the roller.

[0019] According to this method, the portion of the image where the interlocking resin is projected is farther away than the portion where the roller is projected, making it easy to determine the position of the interlocking resin.

[0020] (5) In any of (1) to (4) above, the step of detecting the spacing between the optical fiber cores may include detecting the vertices of the portions of the image corresponding to each optical fiber core and measuring the spacing between adjacent vertices.

[0021] The cross section of the optical fiber is circular, and the distance between the vertices of adjacent optical fiber can be regarded as the distance between the adjacent optical fiber. Therefore, the distance between the vertices of the optical fiber can be detected by measuring the distance between the vertices of the parts corresponding to the optical fiber in the image.

[0022] (6) The optical fiber ribbon inspection device disclosed herein is an optical fiber ribbon inspection device in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in the longitudinal direction by connecting resin, and includes a light source that irradiates the optical fiber ribbon running on a roller with light parallel to the direction in which the optical fiber ribbon runs and from a direction along the tangent to the surface of the roller with which the optical fiber ribbon contacts, an imaging device that captures an image based on light that has passed around the optical fiber ribbon and in which the optical fiber ribbon casts a shadow, and a control device that detects the spacing of the optical fiber core wires and the position of the connecting resin based on the image.

[0023] With this configuration, light is irradiated from a direction parallel to the direction in which the optical fiber ribbon travels and along the tangent to the surface of the roller with which the optical fiber ribbon comes into contact, so that the light incident on the optical fiber ribbon is reflected by the surfaces of the optical fiber cores and the connecting resin, or refracted within the optical fiber cores and the connecting resin, and as a result, the portions corresponding to the optical fiber cores and the connecting resin in the image based on the transmitted light are in shadow, and the position of the connecting resin can be detected from the image with high accuracy.

[0024] (7) In the above (6), the control device may determine whether the spacing between the optical fiber cores is within a predetermined range and whether the position of the connecting resin is at a predetermined position, and output the determination results of the spacing between the optical fiber cores and the position of the connecting resin.

[0025] With this configuration, the positions of the optical fiber cores and the connecting resin can be detected with high accuracy, so that it is possible to accurately determine whether the spacing between the optical fiber cores and the position of the connecting resin are within a specified range or at a specified position.

[0026] (8) The method for manufacturing an optical fiber ribbon disclosed herein is a method for manufacturing an optical fiber ribbon in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in the longitudinal direction by a connecting resin, and includes the steps of: irradiating the optical fiber ribbon running on a roller with light in a direction parallel to the direction in which the optical fiber ribbon runs and along a tangent to the surface of the roller with which the optical fiber ribbon contacts, and obtaining an image based on the light that has passed around the optical fiber ribbon, in which the optical fiber ribbon forms a shadow and is projected; detecting the spacing of the optical fiber core wires based on the image; detecting the position of the connecting resin based on the image; determining whether the spacing of the optical fiber core wires is within a predetermined range; determining whether the position of the connecting resin is at a predetermined position; outputting the determination results of the spacing of the optical fiber core wires and the position of the connecting resin; and determining whether the optical fiber ribbon is good or bad using the determination results.

[0027] According to this method, it is possible to accurately determine whether an optical fiber ribbon is good or bad in the manufacturing process of the optical fiber ribbon.

[0028] [Details of the embodiments of the present disclosure] Specific examples of the optical fiber ribbon inspection method, inspection device, and manufacturing method of the present disclosure 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.

[0029] (Optical fiber ribbon inspection device) Fig. 1 is a diagram illustrating the configuration of an inspection device 10 for an optical fiber ribbon 1 according to this embodiment. 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 in the arrangement direction of the optical fiber core wires 21. Figs. 3 and 4 show the cross-sectional shape of the optical fiber ribbon 1 in Fig. 2. In Fig. 1, the arrow indicates the running direction of the optical fiber ribbon 1.

[0030] As illustrated in FIG. 2, the optical fiber ribbon 1 has a plurality of optical fiber cores 21 arranged in parallel and intermittently connected in the longitudinal direction by a connecting resin 3. In this example, the optical fiber ribbon 1 has 12 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 cladding. The coating layer 212 covers the periphery of the glass fiber 211. The coating layer 212 is composed of one or more coating layers. The coating layer 212 may include a colored layer colored in a predetermined color as the outermost layer.

[0031] Two adjacent optical fibers 21 are integrated by a coating resin 22 while continuously contacting each other in the longitudinal direction to form the sub-ribbon 2. The coating resin 22 covers the periphery of the two adjacent optical fibers 21 along the longitudinal direction. The coating resin 22 is formed from a resin material such as an acrylic ultraviolet-curable resin or an epoxy ultraviolet-curable resin. The coating resin 22 is, for example, a transparent resin.

[0032] In this example, as illustrated 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).

[0033] As illustrated in FIG. 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, connected portions 4 where adjacent sub-ribbons 2 are connected by connecting resin 3 and unconnected portions 5 where they are not connected are provided intermittently in the longitudinal direction. Connecting resin 3 is formed from a resin material such as an acrylic ultraviolet-curable resin or an epoxy ultraviolet-curable resin. Connecting resin 3 is, for example, a transparent resin. Connecting resin 3 may be formed from the same resin material as coating resin 22.

[0034] The inspection device 10 is configured to inspect whether the spacing between the optical fiber core wires 21 in the arrangement direction of the optical fiber core wires 21 constituting the optical fiber ribbon 1 and the position of the connecting resin 3 are normal. For example, the inspection of the optical fiber ribbon 1 by the inspection device 10 is carried out during the manufacturing process of the optical fiber ribbon 1, and the optical fiber ribbon 1 is manufactured while determining whether the optical fiber ribbon 1 is good or bad.

[0035] Fig. 5 shows the configuration of a manufacturing apparatus 30 for an optical fiber ribbon 1 incorporating an inspection device 10. The inspection device 10 is configured to inspect the optical fiber ribbon 1 formed by the manufacturing apparatus 30. In Fig. 5, the arrow indicates the running direction of the optical fiber core 21.

[0036] As illustrated in FIG. 5, 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 , and a winder .

[0037] The optical fibers 21A to 21L wound around the supply bobbins 31A to 31L are unwound and transported to a first coating device 32. In the first coating device 32, a coating resin 22 is applied to the periphery of each of two adjacent optical fibers 21 among the plurality of optical fibers 21A to 21L. The coating resin 22 applied to the periphery of the optical fiber 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.

[0038] Next, the multiple sub-ribbons 2 are transported to second coating device 34 while arranged in parallel. In second coating device 34, connecting resin 3 is applied between adjacent sub-ribbons 2. The connecting resin 3 applied between adjacent sub-ribbons 2 is cured in second curing device 35, for example, by ultraviolet radiation. This forms optical fiber ribbon 1 in which the multiple sub-ribbons 2 are intermittently connected in the longitudinal direction by connecting resin 3.

[0039] In this example, the optical fiber core wires 21A to 21L unwound from the supply bobbins 31A to 31L are changed in direction by the upper rollers and then run downward, forming an optical fiber ribbon 1 in which the optical fiber core wires 21A to 21L are arranged side by side in a direction perpendicular to the plane of the paper in Figure 5.

[0040] The optical fiber ribbon 1 is taken up by a take-up machine 36. The operation of each device is controlled by an intermittent coating control device (not shown).

[0041] The inspection device 10 is disposed on the path line of the optical fiber ribbon 1 between the second curing device 35 and the winder 36, and inspects the optical fiber ribbon 1 as it travels.

[0042] 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.

[0043] The light source 11 and the imaging device 12 are arranged to face each other with a roller 37 in between. The roller 37 is arranged on the path line of the optical fiber ribbon 1 to change the running direction of the optical fiber ribbon 1 while guiding the optical fiber ribbon 1. In this example, the running direction of the optical fiber ribbon 1 is changed from obliquely upward to obliquely downward by the roller 37.

[0044] Fig. 6 is a cross-sectional view illustrating the configuration of a cross section taken along line VI-VI in Fig. 1 as viewed from the direction of the arrow. The roller 37 has, for example, a drum-like shape with a bulging central portion. As illustrated in Fig. 6, in a cross section perpendicular to the running direction of the optical fiber ribbon 1, the side surface 37A of the roller 37 is formed in an arc shape. For example, the roller 37 is formed so that the radius of curvature of the side surface 37A in the cross section is 50 mm.

[0045] The optical fiber ribbon 1 runs on the side surface 37A of the rotating roller 37. As illustrated in Fig. 6, the optical fiber ribbon 1 runs on the roller 37 with the multiple optical fibers 21 arranged in an arc along the side surface 37A of the roller 37. For example, the optical fiber ribbon 1 is conveyed such that the connecting resin 3 is applied to only one side of the optical fiber ribbon 1 and the side opposite to the side on which the connecting resin 3 is applied is in contact with the side surface 37A of the roller 37.

[0046] 1, the light source 11 is configured to irradiate light toward the optical fiber ribbon 1 running on the roller 37. The light source 11 emits, for example, white light.

[0047] The light source 11 irradiates the optical fiber ribbon 1 traveling on the roller 37 with light from a direction parallel to the traveling direction of the optical fiber ribbon 1 and along a tangent to the side surface 37A of the roller 37. The side surface 37A corresponds to the surface of the roller with which the optical fiber ribbon 1 of the present disclosure comes into contact.

[0048] In this example, the optical fiber ribbon 1 is in contact with an area covering a range of approximately 120 degrees on the side surface 37A of the roller 37 when viewed from the arrangement direction of the optical fiber cores 21 (a direction perpendicular to the paper surface of FIG. 1). The light source 11 irradiates light toward the optical fiber ribbon 1 from a direction along a tangent line (a dashed line in FIG. 1) drawn from the uppermost point in that area.

[0049] In other words, the light source 11 emits light in the direction opposite to the running direction of the optical fiber ribbon 1 to the optical fiber ribbon 1 running on the side surface 37A of the roller 37. In this example, the light source 11 emits light in the direction opposite to the running direction of the optical fiber ribbon 1 (to the left in FIG. 1).

[0050] In this specification, the predetermined direction does not necessarily mean the same direction as the predetermined direction, but some deviation is permitted.

[0051] The imaging device 12 is disposed opposite the light source 11 across the roller 37. The imaging device 12 is configured to capture an image that captures the optical fiber ribbon 1. The image is based on light that has passed around the optical fiber ribbon 1, and the optical fiber ribbon 1 is projected as a shadow. The imaging device 12 is, for example, a CMOS camera.

[0052] Camera control device 13 is, for example, a general-purpose computer having a general-purpose memory and a general-purpose microprocessor that operates in cooperation with the general-purpose memory. Camera control device 13 is configured to control the operation of light source 11 and imaging device 12. Specifically, camera control device 13 outputs control signals to imaging device 12 and light source 11 to control the imaging interval of imaging device 12 and the exposure time of light source 11. For example, camera control device 13 controls the operation of imaging device 12 and light source 11 so that the length of optical fiber ribbon 1 running during exposure (i.e., the amount of measurement deviation) is 3 mm or less. If the length over which connecting resin is applied is 30 mm, the longitudinal measurement error can be kept within 10% if the amount of measurement deviation is 3 mm or less.

[0053] The camera control device 13 acquires image data in which the optical fiber ribbon 1 is captured as a shadow from the imaging device 12, and based on the acquired image, detects the spacing between the optical fiber cores 21 and the position of the connecting resin 3. Then, the camera control device 13 determines whether the detected spacing between the optical fiber cores 21 and the position of the connecting resin 3 are normal.

[0054] The camera control device 13 outputs the determination results of the spacing between the optical fiber cores 21 and the position of the connecting resin 3. The determination results output from the camera control device 13 are output to, for example, a display device and a storage device (not shown), and are displayed on the display device and stored in the storage device.

[0055] (Inspection method for optical fiber ribbons) Next, a method for inspecting the optical fiber ribbon 1 using the inspection device 10 will be described with reference to Figures 7 and 8. Figure 7 is a flowchart showing the method for inspecting the optical fiber ribbon 1.

[0056] First, the light source 11 irradiates the optical fiber ribbon 1 running on the roller 37 with light from a direction parallel to the direction in which the optical fiber ribbon 1 runs and along the tangent to the side surface 37A of the roller 37 with which the optical fiber ribbon 1 comes into contact, and the imaging device 12 captures an image in which the optical fiber ribbon 1 is reflected as a shadow (S1).

[0057] Next, the camera control device 13 detects the intervals between the optical fiber cores 21 based on the image of the optical fiber ribbon 1 acquired from the imaging device 12 (S2).

[0058] Next, the camera control device 13 detects the position of the connecting resin 3 based on the image of the optical fiber ribbon 1 acquired from the imaging device 12 (S3).

[0059] Fig. 8 illustrates an image of the optical fiber ribbon 1 captured by the imaging device 12. Fig. 8 is an image of the optical fiber ribbon 1 in which the connecting resin 3 shown in Fig. 6 is located between the optical fiber core 21D and the optical fiber core 21E and between the optical fiber core 21H and the optical fiber core 21I.

[0060] 8, the white semicircular portion is light emitted from the light source 11 and passed around the optical fiber ribbon 1. The light emitted from the light source 11 and irradiated onto the roller 37 is blocked by the roller 37, and the portion corresponding to the roller 37 is projected as a shadow.

[0061] Light emitted from the light source 11 and incident on the optical fiber ribbon 1 is reflected on the surfaces of the optical fiber core 21 and the connecting resin 3, or refracted within the optical fiber core 21 and the connecting resin 3. As a result, in the image shown in Figure 8, the portion corresponding to the optical fiber ribbon 1 is projected as a shadow.

[0062] The camera control device 13 detects the intervals between the optical fiber cores 21 and the positions of the connecting resin 3 from the shadows corresponding to the optical fiber ribbon 1 based on the image shown in FIG.

[0063] 3, the optical fiber 21 has a circular cross section, and the distance between the vertices of adjacent optical fiber 21 can be considered to be the distance between adjacent optical fiber 21. The vertex of the optical fiber 21 is the point where the thickness of the optical fiber 21 is greatest in the thickness direction of the optical fiber ribbon 1 (the direction perpendicular to the longitudinal direction and the arrangement direction), and is the point where an imaginary line extending from the center of the optical fiber 21 in the thickness direction intersects with the outer periphery of the optical fiber 21.

[0064] The camera control device 13 measures the distance D between the vertices of adjacent shadows in the shadows 61A to 61L of the optical fiber cores 21A to 21L in the image shown in Fig. 8. The vertex of the shadow corresponding to the optical fiber core 21 is the highest point among the shadows corresponding to the optical fiber core 21. For example, in Fig. 8, the vertices of the shadows 61D and 61E corresponding to the optical fiber cores 21D and 21E are indicated by plus (+) marks.

[0065] The camera control device 13 detects the distance D between the vertices of the shadows corresponding to the measured coated optical fibers 21 as the distance between the corresponding coated optical fibers 21 .

[0066] 3, the connecting resin 3 is provided in the recessed portions between the optical fiber core wires 21 of adjacent sub-ribbons 2. That is, the recessed portions between the optical fiber core wires 21 of adjacent sub-ribbons 2 where the connecting resin 3 is provided are higher than the recessed portions between the adjacent optical fiber core wires where the connecting resin 3 is not provided.

[0067] 8, the camera control device 13 determines that the shadow 63, in which the recessed portion between adjacent shadows in the shadows 61A to 61L of the optical fiber cores 21A to 21L is higher than the recessed portion between other adjacent shadows, is the portion where the connecting resin 3 is provided. In this example, the recessed portions between adjacent shadows 61D and 61E and between adjacent shadows 61H and 61I are higher than the recessed portions between other adjacent shadows. The camera control device 13 determines that the connecting resin 3 is provided between the optical fiber cores 21D and 21E corresponding to the shadows 61D and 61E, and between the optical fiber cores 21H and 21I corresponding to the shadows 61H and 61I.

[0068] 7, when the intervals between the optical fiber cores 21 and the positions of the connecting resin 3 are detected, the camera control device 13 determines whether the detected intervals between the optical fiber cores 21 and the positions of the connecting resin 3 are normal or not. Then, the determination results of the intervals between the optical fiber cores 21 and the positions of the connecting resin 3 are output to a display device or a storage device (S4).

[0069] Specifically, it is determined whether the spacing between the optical fiber cores 21 is within a predetermined range. It is also determined whether the position of the connecting resin 3 is located at a predetermined position, for example, between specific optical fiber cores 21 among the multiple optical fiber cores 21 that make up the optical fiber ribbon 1. The predetermined range and predetermined position are set appropriately, for example, within a range that allows for tolerances for the size of the optical fiber cores 21, the arrangement of the set connecting resin 3, and errors in size and shape.

[0070] The judgment result includes, for example, an image of the optical fiber ribbon 1 including the optical fiber core wire 21 or connecting resin 3 that has been judged to be abnormal, and positional information of the optical fiber core wire 21 or connecting resin 3 that has been judged to be abnormal in the longitudinal direction of the optical fiber ribbon 1.

[0071] The processes from S1 to S4 are repeated until the entire length of the optical fiber ribbon 1 has been imaged (NO in S5). On the other hand, if the entire length of the optical fiber ribbon 1 has been imaged (YES in S5), this process ends.

[0072] However, for example, when light is irradiated onto one surface of the optical fiber ribbon 1 (the surface along the arrangement direction and longitudinal direction of the optical fiber core wires) and an image is obtained based on the light that passes through the optical fiber ribbon, since transparent connecting resins allow light to easily pass through, the connecting resins are not easily projected in the image, making it difficult to identify the connecting resins from the image.

[0073] However, according to the inspection device 10, inspection method, and manufacturing method for the optical fiber ribbon 1 of this embodiment, light is irradiated from a direction along the tangent to the side surface 37A of the roller 37, so that the light incident on the optical fiber ribbon 1 is reflected by the surfaces of the optical fiber cores 21 and the connecting resin 3, or refracted within the optical fiber cores 21 and the connecting resin 3. As a result, the portions of the image acquired by the imaging device 12 that correspond to the optical fiber cores 21 and the connecting resin 3 are in shadow, and the position of the connecting resin 3 can be accurately detected from the image.

[0074] 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.

[0075] In the above embodiment, the camera control device 13 may determine whether the connecting resin 3 is applied at a predetermined position based on the spacing between adjacent optical fiber cores 21. For example, as shown in Fig. 6, when the optical fiber ribbon 1 runs on a drum-shaped roller 37 with a bulging center, if the spacing between the connecting resins 3 in the longitudinal direction is long, the spacing between the optical fiber cores 21 in the arrangement direction running side by side on the roller 37 in an arc tends to increase. Therefore, it is possible to determine whether the connecting resin 3 is applied at a predetermined position in the longitudinal direction based on the spacing between the optical fiber cores 21 in the arrangement direction in the image.

[0076] In the above embodiment, the light source 11 and the imaging device 12 are arranged to face each other with the roller 37 in between. However, the light source 11 and the imaging device 12 may be arranged to face each other with a roller other than the roller 37 in between, as long as the roller changes the running direction of the optical fiber ribbon 1. For example, as shown in FIG. 1 , the light source 11 and the imaging device 12 may be arranged to face each other with the roller 38 in between.

[0077] In the above embodiment, the light source 11 irradiates the optical fiber ribbon 1 with light from a direction along a tangent drawn from the uppermost point of the region where the optical fiber ribbon 1 contacts the side surface 37A of the roller 37. However, the light source 11 may be configured to irradiate the optical fiber ribbon 1 with light from a direction along a tangent drawn from a point other than the uppermost point of the region where the optical fiber ribbon 1 contacts the side surface 37A of the roller 37.

[0078] In the above embodiment, the sub-ribbon 2 is formed by integrating two coated optical fibers 21. However, the sub-ribbon 2 may be formed by integrating three or more coated optical fibers 21.

[0079] 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.

[0080] In the above embodiment, the inspection device 10 is configured to inspect the optical fiber ribbon 1 that runs in the vertical direction. However, the inspection device 10 may be configured to inspect the optical fiber ribbon 1 that runs in the horizontal direction.

[0081] In the above embodiment, the camera control device 13 may be configured integrally with a display device and a storage device.

[0082] 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 .

[0083] In the above embodiment, the number of coated optical fibers 21 constituting the optical fiber ribbon 1 is 12, but the number of coated optical fibers 21 is not limited.

[0084] In the above embodiment, inspection by the inspection device 10 is incorporated into the manufacturing process of the optical fiber ribbon 1. However, inspection by the inspection device 10 may be performed independently. Alternatively, 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 process of applying marking to the optical fiber ribbon 1. [Explanation of symbols]

[0085] 1: Optical fiber ribbon 2, 2A, 2B, 2C, 2D, 2E, 2F: Sub-ribbon 3, 3A, 3B, 3C: Connection resin 4:Connection part 5: Unconnected part 10: Inspection equipment 11:Light source 12: Imaging device 13: Camera control device 21: Optical fiber core 21A, 21A, 21B, 21C, 21D, 21E, 21F, 21G, 21H, 21I, 21J, 21K, 21L: Optical fiber core 22: Coating resin 30: Manufacturing equipment 31, 31A, 31B, 31C, 31D, 31E, 31F, 31G, 31H, 31I, 31J, 31K, 31L: Supply bobbin 32: First coating device 33:First curing device 34: Second coating device 35:Second curing device 36: Winding machine 37: Laura 37A: Side 38: Laura 61A, 61B, 61C, 61D, 61E, 61F, 61G, 61H, 61I, 61J, 61K, 61L: Shadows corresponding to optical fiber cores 63: Shadow corresponding to the connected resin 211: Glass fiber 212: Covering layer D: Spacing

Claims

1. An inspection method for an optical fiber ribbon in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, comprising: a step of irradiating the optical fiber ribbon traveling on a roller with light in a direction parallel to the direction of travel of the optical fiber ribbon and along a tangent to the surface of the roller with which the optical fiber ribbon comes into contact, and acquiring an image based on the light that has passed around the optical fiber ribbon and is projected as a shadow of the optical fiber ribbon; detecting the intervals between the optical fiber cores based on the image; detecting the position of the interlocking resin based on the image; 10. A method for inspecting an optical fiber ribbon, comprising:

2. determining whether the intervals between the optical fibers are within a predetermined range; determining whether the connecting resin is at a predetermined position; a step of outputting the determination results of the intervals between the optical fiber cores and the position of the connecting resin; 2. The method for inspecting an optical fiber ribbon according to claim 1, comprising:

3. 3. The optical fiber ribbon inspection method according to claim 1, wherein the roller has a drum-like shape with a bulging central portion.

4. 3. An optical fiber ribbon inspection method as described in claim 1 or claim 2, wherein the optical fiber ribbon has the connecting resin applied to one side and is transported so that the side opposite to the side on which the connecting resin is applied comes into contact with the surface of the roller.

5. 3. An optical fiber ribbon inspection method as described in claim 1 or claim 2, wherein the step of detecting the spacing between the optical fiber cores detects the vertices of the portions corresponding to each optical fiber core in the image and measures the spacing between adjacent vertices.

6. An inspection device for an optical fiber ribbon in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in the longitudinal direction by a connecting resin, a light source that irradiates the optical fiber ribbon traveling on the roller with light in a direction parallel to the traveling direction of the optical fiber ribbon and along a tangent to the surface of the roller with which the optical fiber ribbon comes into contact; an imaging device that captures an image based on light that has passed around the optical fiber ribbon, the image being a shadow projected by the optical fiber ribbon; a control device that detects the intervals between the optical fiber cores and the position of the connecting resin based on the image; An optical fiber ribbon inspection device comprising:

7. The optical fiber ribbon inspection device described in claim 6, wherein the control device determines whether the spacing between the optical fiber core wires is within a predetermined range and whether the position of the connecting resin is at a predetermined position, and outputs the determination results of the spacing between the optical fiber core wires and the position of the connecting resin.

8. A method for manufacturing an optical fiber ribbon, in which a plurality of optical fiber core wires are arranged in parallel and intermittently connected in a longitudinal direction by a connecting resin, a step of irradiating the optical fiber ribbon traveling on a roller with light in a direction parallel to the direction of travel of the optical fiber ribbon and along a tangent to the surface of the roller with which the optical fiber ribbon comes into contact, and acquiring an image based on the light that has passed around the optical fiber ribbon and is projected as a shadow of the optical fiber ribbon; detecting the intervals between the optical fiber cores based on the image; detecting the position of the interlocking resin based on the image; determining whether the intervals between the optical fibers are within a predetermined range; determining whether the connecting resin is at a predetermined position; a step of outputting the determination results of the intervals between the optical fiber cores and the position of the connecting resin; a step of determining whether the optical fiber ribbon is good or bad using the determination result; A method for manufacturing an optical fiber ribbon, comprising:

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