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 a position of a connecting resin.SOLUTION: An inspection method of an optical fiber ribbon in which a plurality of 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 provided with the connecting resin of the optical fiber ribbon, while traveling the optical fiber ribbon in the longitudinal direction, and acquiring an image based on reflection light which is emitted from the light source and reflected from the surface by an imaging device; and detecting the position of the connecting resin on the basis of the 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 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.

[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 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]

[0005] [Patent Document 1] JP 2012-042354 A [Patent Document 2] JP 2017-125780 A [Patent Document 3] JP 2002-304922 A 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 a transparent resin that easily transmits light. Also, when separating the non-connected parts using guide rollers to make it easier to obtain images of the non-connected parts, it is difficult to detect the non-connected parts from the images unless the optical fibers are reliably spaced apart in the non-connected parts. 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 the occurrence of areas where the effect of steps and protrusions is lost.

[0007] The present disclosure provides an optical fiber ribbon inspection method and inspection device capable of detecting the position of connecting resin with high accuracy. [Means for solving the problem]

[0008] The method for inspecting an optical fiber ribbon according to the present disclosure includes: A method for inspecting 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 light from a light source onto the surface of the optical fiber ribbon on which the connecting resin is provided while running the optical fiber ribbon in a longitudinal direction, and acquiring an image based on the light emitted by the light source and reflected from the surface by an imaging device; detecting a position of the connecting resin based on the image; Includes. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide an optical fiber ribbon inspection method and inspection device capable of detecting the position of the connecting resin with high accuracy. [Brief description of the drawings]

[0010] [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 illustrating an image of the optical fiber ribbon in the area of ​​the optical fiber ribbon indicated by the two-dot chain line in FIG. [Figure 9] FIG. 9 shows the luminance distribution along the width direction of the optical fiber ribbon at position P1 of the image shown in FIG. [Figure 10] FIG. 10 shows the luminance distribution along the width direction of the optical fiber ribbon at position P2 in the image of FIG. [Figure 11] FIG. 11 is a diagram illustrating an example of an optical fiber ribbon in which the position of the connecting resin is not within a predetermined range. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0012] (1) The method for producing an optical fiber ribbon according to the present disclosure includes: A method for inspecting an optical fiber ribbon in which a plurality of optical fiber cores are arranged in parallel and the optical fiber cores are intermittently connected in the longitudinal direction by a connecting resin, comprising: While running the optical fiber ribbon in the longitudinal direction, irradiating light from a light source onto the surface of the optical fiber ribbon where the connecting resin is provided, and acquiring, by an imaging device, an image based on the reflected light emitted from the light source and reflected from the surface; Detecting the position of the connecting resin based on the image; and including:

[0013] Between adjacent optical fiber cores, the shape of the surface of the optical fiber ribbon is different between the portion with the connecting resin and the portion without the connecting resin. For example, in the portion with the connecting resin, the reflected light is locally enhanced. According to the above method, since the connecting resin is detected using the image based on the reflected light, even when the connecting resin is transparent, an image with a high contrast of the reflected light can be obtained between the portion with the connecting resin and the portion without the connecting resin. Thereby, the position of the connecting resin can be accurately detected.

[0014] (2) In the above (1), It may include a step of determining whether the detected position of the connecting resin is normal.

[0015] According to such a method, abnormalities such as the arrangement, size, or shape of the connecting resin deviating from a predetermined range can be detected.

[0016] (3) In the above (1) or (2), 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 may be set so that the relational expression T < L / (V / 60) is satisfied.

[0017] 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.

[0018] (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).

[0019] According to such a method, the overlap width of the images acquired before and after the imaging period T is constant, so that even if the traveling speed V of the optical fiber ribbon changes, the position of the connecting resin can be easily detected.

[0020] (5) In any of (1) to (4) above, The imaging device includes: The imaging device may be arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface and the surface is the same as a second angle formed between the reflected light reflected on the surface and incident on the imaging device and the surface.

[0021] According to this method, the specularly reflected light is incident on the imaging device, so that the contrast in the intensity of the reflected light between the connecting resin and the other portions between the adjacent optical fiber cores is large.

[0022] (6) In (5) above, The second angle may be greater than or equal to 25° and less than or equal to 35°.

[0023] If the second angle is smaller than 25°, the specular reflected light may not enter the imaging device due to slight vibration of the optical fiber ribbon. On the other hand, if the second angle is larger than 35°, scattered light other than the specular reflected light also enters the imaging device, and the contrast in reflected light intensity between the connecting resin and other parts between adjacent optical fiber cores becomes small. According to the above method, since the second angle is 25° or more and 35° or less, it is easy to detect the connecting resin.

[0024] (7) In any of (1) to (6) above, In the process of detecting the position of the connecting resin, a portion where the intensity of reflected light from between adjacent optical fiber cores is higher than the portions before and after it in the longitudinal direction may be determined to be the portion where the connecting resin is formed.

[0025] Since the connecting resin is formed on the depression between adjacent optical fiber cores, the reflected light is locally strong in the portion where the connecting resin is present between adjacent optical fiber cores. According to the above method, the connecting resin is detected based on the contrast of the reflected light intensity between adjacent optical fiber cores, so complicated processing is not required. This allows the optical fiber ribbon to be inspected quickly, and the inspection can be performed even on optical fiber ribbons traveling at high speed.

[0026] (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.

[0027] According to this method, even in the case of a two-core intermittent optical fiber ribbon, the position of the connecting resin can be detected with high accuracy. 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.

[0028] (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 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 and on which the connecting resin is provided; an imaging device for acquiring an image based on light emitted by the light source and reflected from the surface; a control device that detects the position of the connecting resin based on the image; The present invention may also include:

[0029] Between adjacent optical fiber cores, the shape of the surface of the optical fiber ribbon differs between the portion with the linking resin and the portion without the linking resin, and for example, the portion with the linking resin has locally strong reflected light. According to the above configuration, since the linking resin is detected using an image based on the reflected light, even if the linking resin is transparent, for example, an image with high contrast in reflected light can be obtained between the portion with the linking resin and the portion without the linking resin. This allows the position of the linking resin to be detected with high accuracy.

[0030] (10) In (9) above, The control device may determine whether the detected position of the connecting resin is normal.

[0031] With this configuration, it is possible to detect abnormalities such as the arrangement, size, or shape of the connecting resin being outside a predetermined range.

[0032] (11) In either (9) or (10) above, The imaging device includes: a first angle formed between the incident light emitted from the light source and incident on the surface and the surface, and a second angle formed between the reflected light reflected on the surface and incident on the imaging device and the surface, so that It may be arranged.

[0033] According to this configuration, the specularly reflected light is incident on the imaging device, so that the contrast in the intensity of the reflected light between the connecting resin and the other portions between the adjacent optical fiber cores becomes large.

[0034] (12) In (11) above, The second angle may be greater than or equal to 25° and less than or equal to 35°.

[0035] If the second angle is smaller than 25°, the specular reflected light may not enter the imaging device due to slight vibration of the optical fiber ribbon. On the other hand, if the second angle is larger than 35°, scattered light other than the specular reflected light also enters the imaging device, and the contrast in reflected light intensity between the connecting resin and other parts between adjacent optical fiber cores becomes small. According to the above method, since the second angle is 25° or more and 35° or less, it is easy to detect the connecting resin.

[0036] (13) In any of (9) to (12) above, The control device may determine that a portion where the intensity of reflected light from between adjacent optical fibers is higher than portions before and after in the longitudinal direction is a portion where the connecting resin is formed.

[0037] Since the connecting resin is formed on the depression between adjacent optical fiber cores, the reflected light is locally strong in the portion where the connecting resin is present between adjacent optical fiber cores. According to the above method, the connecting resin is detected based on the contrast of the reflected light intensity between adjacent optical fiber cores, so complicated processing is not required. This allows the optical fiber ribbon to be inspected quickly, and the inspection can be performed even on optical fiber ribbons traveling at high speed.

[0038] [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.

[0039] 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.

[0040] (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.

[0041] 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.

[0042] 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 cladding. The coating layer 212 coats the periphery of the glass fiber 211. The coating layer 212 is composed of a coating layer consisting of one layer or multiple layers. The coating layer 212 may include a colored layer that is colored in a predetermined color as the outermost layer.

[0043] 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.

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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 .

[0049] 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.

[0050] 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).

[0051] In this example, the optical fiber core wires 21A to 21L unwound from the supply bobbins 31A to 31L run downward (in the direction indicated by the arrow A in the figure), and the optical fiber ribbon 1 is formed in a state in which the optical fiber core wires 21A to 21L 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.

[0052] The inspection device 10 is disposed between the second curing device 35 and the winding machine 36, and determines whether the position at which the connecting resin 3 is formed on the optical fiber ribbon 1 running downward from the second curing device 35 is normal or not.

[0053] 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.

[0054] The light source 11 is configured to irradiate light onto the surface 1S of the optical fiber ribbon 1 running in the longitudinal direction, on which the connecting resin 3 is provided. The light source 11 emits, for example, white light. Although the surface 1S has some irregularities, the surface 1S is regarded as a flat surface with the irregularities averaged out.

[0055] The light source 11 is disposed so as to emit light in a direction of a first angle θ1 with respect to the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided, in a cross section perpendicular to the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided and along the longitudinal direction. In other words, the first angle θ1 is an angle formed between the incident light LT1 emitted from the light source 11 and incident on the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided, and the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided. The first angle θ1 is set, for example, to be equal to or greater than 25° and equal to or less than 35°.

[0056] The imaging device 12 is configured to obtain an image based on light emitted from the light source 11 and reflected from the surface 1S on which the connecting resin 3 of the optical fiber ribbon 1 is provided. The imaging device 12 is, for example, a CMOS camera.

[0057] The imaging device 12 is disposed so that, in a cross section perpendicular to the surface on which the connecting resin 3 of the optical fiber ribbon 1 is provided and along the longitudinal direction, light reflected from the surface on which the connecting resin 3 of the optical fiber ribbon 1 is provided is incident in a direction of the second angle θ2 toward the surface 1S on which the connecting resin 3 of the optical fiber ribbon 1 is provided. In other words, the second angle θ2 is the angle between the reflected light LT2 incident on the imaging device 12 and the surface 1S on which the connecting resin 3 of the optical fiber ribbon 1 is provided, which is emitted from the light source 11.

[0058] The second angle θ2 is set to, for example, the same angle as the first angle θ1. Note that "the second angle θ2 is the same angle as the first angle θ1" does not necessarily mean that the second angle θ2 is set to exactly the same angle as the first angle θ1, but also means that the second angle θ2 is set within a range where some error is acceptable. The second angle θ2 is, for example, 25° or more and 35° or less.

[0059] The imaging device 12 periodically captures images of the optical fiber ribbon 1 running in the longitudinal direction. FIG. 6 shows the imaging range (field of view) of the imaging device 12 for the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is formed. In FIG. 6, Ri is the i-th imaging range, R(i+1) is the i+1th imaging range, and R(i+2) is the i+2th imaging range. Note that i is a natural number excluding zero. Each imaging range is defined by the length L [mm] of the optical fiber ribbon 1 in the longitudinal direction and the length W [mm] of the optical fiber ribbon 1 in the width direction.

[0060] The imaging period of the imaging device 12 is set such that, for example, a part of the imaging ranges (e.g., Ri and R(i + 1), or R(i + 1) and R(i + 2)) imaged before and after the imaging period overlaps with 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 running speed of the optical fiber ribbon 1 is V [m / min], the imaging period T is set to satisfy the relational expression of T < L / (V / 60).

[0061] 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 running speed V of the optical fiber ribbon 1 so as to satisfy the relational expression of T = (L - α) / (V / 60) when the overlapping width α is set to a constant. The overlapping width α is set to satisfy the relational expression of, for example, 0.1 < α / L < 0.5.

[0062] Returning to FIG. 1, the camera control device 13 is a general-purpose computer having, for example, a general-purpose memory and a general-purpose microprocessor that operates in cooperation with the general-purpose memory.

[0063] The camera control device 13 is configured to control the operation of the imaging device 12. For example, the camera control device 13 determines the imaging period T of the imaging device 12 based on the overlapping width α of the imaging range, the length L of the imaging range, and the running speed V of the optical fiber ribbon 1. Then, the camera control device 13 outputs a control signal CS for causing imaging at the determined imaging period T to the imaging device 12. The imaging device 12 sets or changes the imaging period T based on the control signal CS. The camera control device 13 is connected to, for example, the winder 36, and acquires information VI on the winding speed of the optical fiber ribbon 1 as information on the running speed V of the optical fiber ribbon 1 from the winder 36.

[0064] Furthermore, the camera control device 13 acquires from the imaging device 12 the data ID of the image in which the optical fiber ribbon 1 is captured. The camera control device 13 detects the position of the connecting resin 3 based on the acquired image. The camera control device 13 then judges whether the detected position of the connecting resin 3 is normal. For example, if the arrangement, size and shape of the connecting resin 3 are within a predetermined range, the camera control device 13 judges that the position of the connecting resin 3 is normal. On the other hand, if at least one of the arrangement, size and shape of the connecting resin 3 is not within the predetermined range, the camera control device 13 judges that the position of the connecting resin 3 is not normal. The predetermined range is set as appropriate, for example, within a range in which the errors in the set arrangement, size and shape of the connecting resin 3 are acceptable.

[0065] The camera control device 13 outputs the determination result of the position of the connected resin 3. 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 position of the connected resin 3 to the display device 14, and causes the display device 14 to display the determination result of the position of the connected resin 3. In addition, the camera control device 13 outputs the determination result JI of the determination result of the position of the connected resin 3 to the storage device 15, and causes the storage device 15 to store the determination result of the position of the connected resin 3.

[0066] (Inspection method for optical fiber ribbon) Next, a method for inspecting the optical fiber ribbon 1 using the inspection device 10 will be described with reference to Figures 7 to 11. Figure 7 is a flow chart showing the method for inspecting the optical fiber ribbon 1.

[0067] 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 on which the connecting resin 3 is provided, and an image based on the light emitted by the light source 11 and reflected from the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided is obtained by the imaging device 12 (STEP 1).

[0068] 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 (STEP 2).

[0069] For example, Fig. 8 illustrates an image of the optical fiber ribbon 1 acquired by imaging an area X of the optical fiber ribbon 1 indicated by a two-dot chain line in Fig. 2. Fig. 9 illustrates a luminance distribution (reflected light intensity distribution) along the width direction of the optical fiber ribbon 1 at position P1 in the image shown in Fig. 8. Fig. 10 illustrates a luminance distribution (reflected light intensity distribution) along the width direction of the optical fiber ribbon 1 at position P2 in the image shown in Fig. 8.

[0070] Between adjacent optical fiber cores 21, the shape of the surface of the optical fiber ribbon 1 differs between the portion with the connecting resin 3 and the portion without the connecting resin 3, and the reflected light is locally stronger in the portion with the connecting resin 3. Specifically, on the surface 1S of the optical fiber ribbon 1 on which the connecting resin 3 is provided, the connecting resin 3 is formed in the depression between adjacent optical fiber cores 21, so that the intensity of the light reflected from the depression is weaker and the intensity of the light reflected from the connecting resin 3 formed in the depression is stronger.

[0071] For example, as shown in Figure 9, in the brightness distribution in the width direction of the optical fiber ribbon 1 at position P1 of the optical fiber ribbon 1 where the connecting resin 3 is not formed, the brightness values ​​are high at the locations corresponding to the first to twelfth optical fiber cores 21, and the brightness values ​​are low between adjacent optical fiber cores 21.

[0072] 10, in the luminance distribution in the width direction of the optical fiber ribbon 1 at position P2 of the optical fiber ribbon 1 where the connecting resin is formed, the luminance value is high at the location corresponding to the optical fiber core wires 21, and the luminance value is low between adjacent optical fiber core wires 21 where the connecting resin 3 is not formed. Furthermore, the luminance value is high between adjacent optical fiber core wires 21 where the connecting resin 3 is formed (the fourth and fifth optical fiber core wires 21, and the eighth and ninth optical fiber core wires 21).

[0073] Therefore, the camera control device 13 detects the position of each optical fiber core 21 based on the reflected light intensity in the image of the optical fiber ribbon 1, and determines that the area where the intensity of the reflected light from between adjacent optical fiber cores 21 is higher than the areas before and after it is the area where the connecting resin 3 is formed.

[0074] Next, the camera control device 13 judges whether the position of the detected connecting resin 3 is normal (STEP 3). Specifically, the camera control device 13 judges whether the arrangement, size and shape of the connecting resin 3 are within a predetermined range based on the position of the portion judged to be the connecting resin 3. In this way, for example, the camera control device 13 can detect connecting resin 3A having a short length along the longitudinal direction of the optical fiber ribbon 1, connecting resin 3B having a misaligned position in the longitudinal direction, or connecting resin 3C having a long length in the width direction of the optical fiber ribbon 1, as exemplified in FIG. 11.

[0075] Next, camera control device 13 outputs the determination result of the position of connected resin 3 to display device 14 and storage device 15 (STEP 4 in FIG. 7). The determination result of the position of connected resin 3 is displayed on display device 14 and recorded in storage device 15. The determination result of the position of connected resin 3 includes, for example, an image of optical fiber ribbon 1, position information of connected resin 3 that is outside a predetermined range, etc.

[0076] 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.

[0077] According to the inspection device 10 and manufacturing method for the optical fiber ribbon 1 of the present embodiment, the connecting resin 3 is detected using an image based on reflected light, so even if the connecting resin 3 is transparent, for example, it is possible to obtain an image with high contrast in reflected light between a portion with the connecting resin 3 and a portion without the connecting resin 3. This allows the position of the connecting resin 3 to be detected with high accuracy.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] In the above embodiment, the display device 14 and the storage device 15 may be configured integrally with the camera control device 13 .

[0086] 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 .

[0087] 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.

[0088] 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]

[0089] 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 3A: Connecting resin 3B: Connecting resin 3C: Connecting 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 X:Area CS: Control signal P1:Position P2:Position 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. A method for inspecting 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 light from a light source onto the surface of the optical fiber ribbon on which the connecting resin is provided while running the optical fiber ribbon in a longitudinal direction, and acquiring an image based on the light emitted by the light source and reflected from the surface by an imaging device; detecting a position of the connecting resin based on the 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 the step of determining whether the detected position of the connecting resin is normal.

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 ribbon is arranged so that a first angle formed between the incident light emitted from the light source and incident on the surface and the surface is the same as a second angle formed between the reflected light reflected on the surface and incident on the imaging device and the surface.

6. The optical fiber ribbon inspection method according to claim 5 , wherein the second angle is greater than or equal to 25° and less than or equal to 35°.

7. An optical fiber ribbon inspection method as described in claim 1 or claim 2, wherein, in the process of detecting the position of the connecting resin, a portion where the intensity of reflected light from between adjacent optical fiber cores is higher than the portions before and after it in the longitudinal direction is determined to be the portion where the connecting resin is formed.

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 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 and on which the connecting resin is provided; an imaging device for acquiring an image based on light emitted by the light source and reflected from the surface; a control device that detects the position of the connecting resin based on the image; An optical fiber ribbon inspection device comprising:

10. 10. The optical fiber ribbon inspection device according to claim 9, wherein the control device determines whether the detected position of the connecting resin is normal.

11. The imaging device includes: a first angle formed between the incident light emitted from the light source and incident on the surface and the surface, and a second angle formed between the reflected light reflected on the surface and incident on the imaging device and the surface, so that 11. The optical fiber ribbon inspection device according to claim 9 or 10,

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

13. The optical fiber ribbon inspection device described in claim 9 or claim 10, wherein the control device determines that a portion where the intensity of reflected light from between adjacent optical fiber cores is higher than the portions before and after in the longitudinal direction is a portion where the connecting resin is formed.

Images