Manufacturing method and apparatus for colored optical fiber cores

Abstract

A method for manufacturing a colored optical fiber core includes: a step of feeding a colored resin into a mold; a step of passing an optical fiber through the mold and coating the optical fiber with colored resin to form a colored optical fiber core having a colored layer; a step of detecting the color of the colored layer; and a step of determining whether the detected color is good or bad.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for manufacturing colored optical fiber cores.

[0002] This application claims priority based on Japanese Application No. 2020-197905, filed on November 30, 2020, and invokes all the contents set forth in that Japanese application. Background Technology

[0003] Patent document 1 discloses a defect detection device capable of detecting defects in the coloring layer of colored optical fiber strands.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 11-281524 Summary of the Invention

[0007] One aspect of this disclosure relates to a method for manufacturing colored optical fiber cores, which includes:

[0008] The process of feeding the colored resin into the mold;

[0009] The process of passing an optical fiber through the mold and coating the optical fiber with the coloring resin to form a colored optical fiber core with a coloring layer.

[0010] The process of detecting the color of the coloring layer; and

[0011] A process for determining whether the detected color is good or bad.

[0012] Additionally, one aspect of the apparatus disclosed herein relates to the manufacture of colored optical fiber cores, comprising:

[0013] The colored resin is fed into the tank inside the mold.

[0014] A mold through which the optical fiber line passes and around which the coloring resin is applied.

[0015] A sensor that detects the color of the coloring layer formed by the coloring resin around the fiber optic strands, and

[0016] A control unit that determines whether the color detected by the sensor is good or bad. Attached Figure Description

[0017] [ Figure 1 ] Figure 1 This is a schematic configuration diagram showing the manufacturing apparatus for colored optical fiber cores according to embodiments of the present disclosure.

[0018] [ Figure 2 ] Figure 2 This is a diagram showing the color measuring device used in the method for manufacturing a colored optical fiber core according to the first embodiment of this disclosure.

[0019] [ Figure 3 ] Figure 3 It is shown Figure 2 The diagram shows the illumination time of the colored light in the colorimeter and the shooting time of the camera.

[0020] [ Figure 4 ] Figure 4 It is a graph showing the brightness of an image taken with a camera.

[0021] [ Figure 5 ] Figure 5 This is a diagram showing the color measuring device used in the method for manufacturing colored optical fiber cores according to the second embodiment.

[0022] [ Figure 6 ] Figure 6 This is a diagram showing the color measuring device used in the method for manufacturing colored optical fiber cores according to the third embodiment.

[0023] [ Figure 7A ] Figure 7A This is a graph showing the brightness distribution of an image captured by a camera.

[0024] [ Figure 7B ] Figure 7B This is a graph showing the change in brightness distribution when the coloring resin is switched. Detailed Implementation

[0025] (The problem this disclosure aims to solve)

[0026] To facilitate identification of individual optical fibers, a coloring layer is sometimes applied to the surface of the fiber. Previously, the presence and color of the coloring layer were fixed for each fiber manufacturing device. Changing the color of the coloring layer sometimes required replacing or cleaning the mold and piping.

[0027] Therefore, the purpose of this disclosure is to provide a method and apparatus for manufacturing colored optical fiber cores that can flexibly switch the color of the coloring layer.

[0028] (Description of embodiments of this disclosure)

[0029] First, the embodiments of this disclosure are listed and described.

[0030] One aspect of this disclosure relates to a method for manufacturing colored optical fiber cores, which includes:

[0031] (1) The process of feeding the colored resin into the mold;

[0032] The process of passing an optical fiber through the mold and coating the optical fiber with the coloring resin to form a colored optical fiber core with a coloring layer.

[0033] The process of detecting the color of the coloring layer; and

[0034] A process for determining whether the detected color is good or bad.

[0035] According to this method, when changing the color of the coloring resin, it is possible to accurately determine whether the color of the coloring layer is defective (color mixing, etc.). Therefore, when changing the color of the coloring resin, color switching can be performed without replacing or cleaning the equipment used for coloring resin coating. As a result, the color of the coloring layer can be flexibly switched according to inventory and demand.

[0036] (2) In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and a sensor is used to detect a portion of the light irradiated onto the colored optical fiber core to examine the amount of each RGB light component and thus detect the color.

[0037] In the process of determining whether the color is good or bad, the good or bad quality can be determined based on the amount of light.

[0038] This method allows for a simple and convenient determination of the quality of the color in a coloring layer. It should be noted that RGB represents the components of R (red), G (green), and B (blue) light. Light containing RGB refers to light that contains any or all of the red, green, and blue components. The RGB values ​​of light refer to the individual amounts of red, green, and blue light within the light.

[0039] (3) In the process of detecting the color, when the colored optical fiber core is irradiated with RGB light respectively and a portion of each light is detected using the sensor, the irradiation time of each light is synchronized with the detection time of the sensor to check the amount of each RGB light and thus detect the color.

[0040] In the process of determining whether the color is good or bad, the good or bad quality can be determined based on the amount of light.

[0041] According to this method, by using sensors to detect each of the RGB lights illuminating the colored fiber core, the color of the colored layer can be correctly identified.

[0042] (4) In the process of detecting the color, white light is irradiated onto the colored optical fiber core, and a portion of the white light is detected using the sensor to examine the RGB values ​​of the light and thus detect the color.

[0043] In the process of determining whether the color is good or bad, the good or bad quality can be determined based on the amount of light.

[0044] According to this method, it is not necessary to use light sources of different colors, so the color of the coloring layer can be correctly identified with a simple configuration.

[0045] (5) In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and the transmitted light passing through the colored optical fiber core is detected using the sensor to examine the amount of each RGB light component of the light, thereby detecting the color.

[0046] In the process of determining whether the color is good or bad, the good or bad quality can be determined based on the amount of light.

[0047] According to this method, not only can color be determined based on the ratio of transmitted light, but transparency can also be determined based on the intensity of transmitted light. Therefore, even when switching the color of the colored layer from transparent to opaque, or vice versa, it is possible to detect whether the switch was correct.

[0048] (6) In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and the reflected light of the light reflected by the colored optical fiber core is detected by the sensor to examine the amount of each RGB light component of the light and thus detect the color.

[0049] In the process of determining whether the color is good or bad, the good or bad quality can be determined based on the amount of light.

[0050] According to this method, the quality of the color of the colored layer can be easily determined by using a sensor to detect the light reflected from the colored fiber core.

[0051] (7) In the process of detecting the color, the sensor that detects a portion of the light irradiating the colored fiber core may be a line camera sensor having multiple pixels in the width direction of the colored fiber core.

[0052] A linear scan camera sensor captures an image of one column (multiple pixels) at a time. According to this method, by using a linear scan camera sensor, it is possible to achieve high-speed measurement and to inspect minute color defects along the length of the colored fiber core.

[0053] (8) In the process of detecting the color, the sensor that detects a portion of the light irradiating the colored fiber core may be an area camera sensor having multiple pixels in the width and length directions of the colored fiber core.

[0054] An area-array camera sensor captures the entire field of view in a single shot. According to this method, color deviations within a color layer can be detected using an area-array camera sensor.

[0055] (9) In the process of detecting the color, the sensor can be used to detect a portion of the light irradiated onto the colored fiber core from three directions.

[0056] According to this method, defects with discontinuous color can be detected at any position in the circumferential direction.

[0057] (10) The process prior to the step of feeding the coloring resin into the mold includes:

[0058] The process of heating the optical fiber substrate while simultaneously drawing it into glass fibers; and

[0059] The process of coating the glass fibers with a primary resin to form the optical fiber strand having a primary resin layer.

[0060] The process of feeding the coloring resin into the mold includes:

[0061] The process of feeding the first coloring resin from a tank filled with a first coloring resin used as a secondary resin into the mold, and coating the first coloring resin around the primary resin layer to form a secondary resin layer; and

[0062] The process of feeding the second coloring resin, which is a different color from the first coloring resin, into the mold, and coating the primary resin layer with the second coloring resin to form a secondary resin layer.

[0063] In the process of detecting the color, the color of the secondary resin layer is detected to change from the color of the first coloring resin to the color of the second coloring resin.

[0064] In the process of determining whether the product is good or bad, if it is determined that the color change meets predetermined conditions, the winding of the colored optical fiber core can begin as a good product.

[0065] The above manufacturing method is preferably carried out during the fiber drawing process.

[0066] Additionally, one aspect of the apparatus disclosed herein relates to the manufacture of colored optical fiber cores, comprising:

[0067] (11) The coloring resin is fed into the tank inside the mold.

[0068] A mold through which the optical fiber line passes and around which the coloring resin is applied.

[0069] A sensor that detects the color of the coloring layer formed by the coloring resin around the fiber optic strands, and

[0070] A control unit that determines whether the color detected by the sensor is good or bad.

[0071] Based on this configuration, the quality of the color can be determined when switching the color of the coloring layer. Therefore, even without replacing or cleaning the equipment used for coating the coloring resin, the color of the coloring layer can be flexibly switched according to inventory and demand.

[0072] (Effects of the invention)

[0073] According to this disclosure, a method and apparatus for manufacturing colored optical fiber cores that can flexibly switch the color of the coloring layer can be provided.

[0074] (Detailed description of embodiments of this disclosure)

[0075] Specific examples of the manufacturing method and apparatus for colored optical fiber cores according to embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all variations in the same sense and scope as the claims.

[0076] The optical fiber core used in the coloring method of this embodiment is an optical fiber core with a primary resin layer formed by coating a primary resin onto glass fiber formed during the drawing process using a drawn optical fiber preform. The glass fiber is, for example, composed of a core and cladding of quartz glass. For the optical fiber, in a coating process following the drawing process, a primary resin layer and a secondary resin layer are formed around it as a coating layer. In the coloring method of this embodiment, a secondary resin layer containing coloring pigment (hereinafter referred to as coloring resin) is used. By forming a secondary resin layer around the primary resin layer, a colored optical fiber core is produced. For colored optical fiber cores produced in this way, by changing the color of the coloring resin used for the secondary resin layer, the colored optical fiber cores become easier to identify from each other.

[0077] Figure 1 This is a schematic configuration diagram showing the manufacturing apparatus for the colored optical fiber core according to this embodiment. Figure 1As shown, the manufacturing apparatus 1 for colored optical fiber core wire G2 includes: a resin coating mold 2, a resin tank 3, a coloring measuring device 5, an ultraviolet irradiator 6, an outer diameter measuring device 7, a winding machine 9, and a control unit 10. It should be noted that... Figure 1 G1 in the figure is glass fiber G1 obtained by heating and melting the optical fiber matrix in a drawing device (not shown).

[0078] The resin coating mold 2 is a mold through which glass fiber G1 passes and around which a coating resin is applied. The resin coating mold 2 comprises: a primary mold 21 for applying a primary resin around the glass fiber G1 to form a primary resin layer; and a secondary mold 22 for applying a secondary resin composed of a colored resin around the primary resin layer to form a secondary resin layer. By forming a primary resin layer around the glass fiber G1 through the primary mold 21 and a secondary resin layer around the primary resin layer through the secondary mold 22, a colored optical fiber core wire G2 is obtained.

[0079] It should be noted that in this embodiment, primary resin and secondary resin are coated using a resin coating mold 2, but it is not limited to this and primary resin and secondary resin can also be coated using different molds.

[0080] The resin tank 3 is a tank for discharging the coated resin into the resin coating mold 2. The resin tank 3 includes a primary resin tank 31 for discharging primary resin P into the primary mold 21; and secondary resin tanks 32 and 33 for discharging secondary resins S1 and S2 into the secondary mold 22. The secondary resin S1 contained in the secondary resin tank 32 and the secondary resin S2 contained in the secondary resin tank 33 are colored resins of different colors. The primary resin P and the secondary resins S1 and S2 can be, for example, UV-curable resins such as urethane acrylate resins.

[0081] The primary resin tank 31 is connected to the primary mold 21 via a supply pipe 34. Secondary resin tanks 32 and 33 are connected to the secondary mold 22 via a supply pipe 35. For the secondary resin supplied to the secondary mold 22 via the supply pipe 35, either secondary resin S1 or S2 can be selected by controlling the switching valve 36. The primary resin tank 31, secondary resin tanks 32 and 33, and the switching valve 36 are connected to the control unit 10. It should be noted that the number of secondary resin tanks that can be connected to the secondary mold 22 via the supply pipe 35 is not limited to the two secondary resin tanks 32 and 33. For example, three or more secondary resin tanks can be connected; in this case, by controlling the switching valve 36, any one of three or more different colored resins can be selected.

[0082] The colorimetric detector 5 is a device for detecting the color of the coloring resin in the secondary resin layer formed around the primary resin-coated fiber optic strands. As the colorimetric detector 5, a light sensor, image sensor, area scan camera (area scan camera sensor), line scan camera (line scan camera sensor), or similar measuring device can be used. The colorimetric detector 5 is connected to the control unit 10 and sends data related to the detected coloring resin to the control unit 10.

[0083] The ultraviolet irradiator 6 is a device for curing the primary and secondary resins coated on the glass fiber G1 by irradiating them with ultraviolet light. The ultraviolet irradiator 6 is connected to the control unit 10.

[0084] The outer diameter measuring device 7 is a device for measuring the outer diameter of the colored optical fiber core G2, which has a primary resin layer and a secondary resin layer formed thereon. The outer diameter measuring device 7 measures the outer diameter of the colored optical fiber core G2, for example, by irradiating the colored optical fiber core G2 with a laser from the side. The outer diameter measuring device 7 is connected to the control unit 10 and sends the measurement results to the control unit 10.

[0085] The winding machine 9 winds the manufactured colored optical fiber core wire G2 onto the winding spool 91. The colored optical fiber core wire G2 is wound onto the winding machine 9 at a certain tension via the winch 92. The winding machine 9 is connected to the control unit 10.

[0086] The control unit 10 determines the quality of the secondary resin color based on data related to the coloring resin sent from the coloring measuring device 5. Color quality determination refers to determining whether the secondary resin layer is formed with the predetermined color of the coloring resin supplied from the secondary resin tanks 32, 33, etc. Furthermore, the control unit 10 controls the irradiation time or intensity of the ultraviolet irradiator 6 and the winding speed of the winding machine 9 based on data sent from the coloring measuring device 5, the outer diameter measuring device 7, etc.

[0087] Next, the manufacturing method of the colored optical fiber core wire according to this embodiment will be described. The manufacturing method of the colored optical fiber core wire in this embodiment uses... Figure 1 The method for manufacturing colored optical fiber core wire G2 using the manufacturing apparatus 1 shown.

[0088] [First Implementation Method]

[0089] The following is for reference Figures 2 to 4 The manufacturing method of the colored optical fiber core according to the first embodiment will be described. Figure 2 This is a diagram showing the color measuring device 5A used in the method for manufacturing colored optical fiber cores according to the first embodiment. Figure 3 This is a diagram showing the illumination time of the colored light in the colorimeter 5A and the shooting time of the camera. Figure 4 This is a graph showing the brightness of an image captured by a camera. For example... Figure 2As shown, the colorimetric measuring device 5A includes: red illumination 51R, green illumination 51G, blue illumination 51B, a camera 52, and an image display device 53. In the following description, the red illumination 51R, green illumination 51G, and blue illumination 51B are sometimes collectively referred to as RGB illumination. For example, LEDs emitting RGB colors can be used as RGB illuminations 51R, 51G, and 51B. The camera 52 can be, for example, a monochrome area array camera. The camera 52, as an area array camera, has, for example, a two-dimensional imaging element having multiple pixels in the width and length directions of the color fiber core G2. The image display device 53 can be, for example, a personal computer. Each of the RGB illuminations 51R, 51G, and 51B, and the camera 52, is connected to the control unit 10.

[0090] (Wire drawing process)

[0091] First, the optical fiber mother material is heated and drawn into fibers using a drawing device (illustration omitted) to form glass fiber G1.

[0092] (Coating process)

[0093] Next, the control unit 10 controls the primary resin tank 31 and feeds the primary resin P from the primary resin tank 31 to the primary mold 21 via the supply pipe 34. The primary mold 21 coats the primary resin P fed from the primary resin tank 31 around the glass fiber G1 passing through the primary mold 21.

[0094] Next, the control unit 10 selects, for example, the secondary resin S1 in the secondary resin tank 32 by switching the switching valve 36, and feeds the secondary resin S1 from the secondary resin tank 32 to the secondary mold 22 via the supply pipe 35. For example, if the secondary resin tank 32 contains red coloring resin as the secondary resin S1, the red secondary resin S1 is fed from the secondary resin tank 32 to the secondary mold 22. The secondary mold 22 coats the primary resin P of the optical fiber line passing through the secondary mold 22 with the red secondary resin S1 fed from the secondary resin tank 32.

[0095] Thus, a red-colored optical fiber core G2 was produced, which was surrounded by a primary resin P and a red secondary resin S1.

[0096] (First inspection procedure)

[0097] Next, in the colorimetric measuring device 5A, the control unit 10 illuminates the fabricated colored fiber core G2 with colored light from red illumination 51R, green illumination 51G, and blue illumination 51B, respectively. The control unit 10 uses a camera 52 to capture the reflected light that is illuminated by red illumination 51R, green illumination 51G, and blue illumination 51B and reflected by the colored fiber core G2.

[0098] like Figure 3 As shown, the control unit 10 sequentially illuminates the red light 51R, green light 51G, and blue light 51B at different times. The control unit 10, in sync with the illumination times of the red light 51R, green light 51G, and blue light 51B, uses the camera 52 to capture the reflected light from the colored optical fiber core G2.

[0099] The control unit 10 processes each image captured by the camera 52 (a monochrome area array camera) under red illumination 51R, green illumination 51G, and blue illumination 51B, and examines the brightness (an example of light intensity) of the reflected light from the colored fiber core G2 in each image. Based on the brightness of each reflected light examined, the control unit 10 determines the color of the secondary resin of the colored fiber core G2. The color determination is based on whether the brightness of each reflected light from the colored fiber core G2 in the red illumination 51R, green illumination 51G, and blue illumination 51B meets preset threshold conditions. In the case where red secondary resin S1 is fed from the secondary resin tank 32 to the secondary mold 22 as in this example, the control unit 10 determines the color of the secondary resin to be red based on the brightness of each reflected light. If the color of the colored resin fed from the secondary resin tank 32 to the secondary mold 22 is the same as the color of the secondary resin determined based on the brightness of the reflected light of the colored fiber core G2, the control unit 10 determines the color of the colored fiber core G2 as "good".

[0100] like Figure 4 As shown, the images captured by camera 52 and the brightness of the reflected light detected in each image can be displayed on image display device 53. The brightness of the reflected light reflected by the red colored fiber core G2 is higher than the brightness of the reflected light when illuminated by red illumination 51R (e.g., brightness 255), but lower than the brightness of the reflected light when illuminated by green illumination 51G and blue illumination 51B (e.g., brightness 10). Control unit 10 determines the color of the secondary resin based on whether these brightness values ​​"255" and "10" meet preset threshold conditions.

[0101] (Curing process)

[0102] Next, the control unit 10 irradiates the colored optical fiber core wire G2 with ultraviolet light by controlling the ultraviolet irradiator 6, thereby curing the primary resin P and the secondary resin S1.

[0103] (Second inspection procedure)

[0104] Next, the outer diameter measuring device 7 measures the outer diameter of the colored optical fiber core G2 after the coating has been cured. The outer diameter measuring device 7 sends the measured outer diameter value to the control unit 10.

[0105] (Winding process)

[0106] Finally, the control unit 10 controls the winding machine 9 based on data sent from the coloring measuring device 5A, the outer diameter measuring device 7, etc., to wind the red colored optical fiber core wire G2 onto the winding spool 91 at a predetermined linear speed while applying a predetermined tension to it.

[0107] Next, the case of manufacturing, for example, a yellow colored optical fiber core G2 after manufacturing a red colored optical fiber core G2 as described above will be explained.

[0108] In the coating process, the control unit 10 changes the delivery of secondary resin to the secondary resin tank of the secondary mold 22 by switching the switching valve 36. The control unit 10 selects, for example, a secondary resin tank 33 containing yellow coloring resin, and delivers yellow coloring resin, i.e., secondary resin S2, from the secondary resin tank 33 to the secondary mold 22 via the supply pipe 35. The secondary mold 22 coats the primary resin P of the optical fiber line passing through the secondary mold 22 with the yellow secondary resin S2 delivered from the secondary resin tank 33.

[0109] However, when the secondary resin tank from secondary resin tank 32 to secondary resin tank 33 is switched via switching valve 36, the yellow secondary resin S2 will not be immediately supplied to the secondary mold 22 because the red secondary resin S1 supplied from secondary resin tank 32 remains in the supply pipe 35 between switching valve 36 and secondary mold 22. Therefore, immediately after switching the secondary resin tank, the red secondary resin S1 or a mixture of red secondary resin S1 and yellow secondary resin S2 is supplied to the secondary mold 22. Then, the secondary mold 22 coats the primary resin P of the optical fiber line passing through it with the red secondary resin S1 or the mixture of red secondary resin S1 and yellow secondary resin S2.

[0110] Therefore, during the color determination by the colorimeter 5A in the first inspection process, when the control unit 10 switches the switching valve 36, although the secondary resin tank 33 containing yellow secondary resin S2 is selected, the color of the secondary resin is not determined to be yellow based on the brightness of the reflected light reflected by the colored fiber core G2. That is, the control unit 10 determines that the brightness of the reflected light does not meet the threshold condition preset for the yellow colored fiber core G2, and determines that the color of the colored resin sent to the secondary mold 22 is different from the color of the secondary resin determined based on the brightness of the reflected light, and determines the color of the colored fiber core G2 as "no (defective)". "The brightness of the reflected light is above the threshold" is an example of "the color change meets the predetermined condition".

[0111] Thus, during the period before the coloring resin (secondary resin) in the supply pipe 35 is replaced when switching valve 36, it is determined that a colored optical fiber core wire G2 with a different color than the set value has been produced. Then, when the coloring resin in the supply pipe 35 is completely replaced, it is determined that the set yellow colored optical fiber core wire G2 has been produced, and the color of the colored optical fiber core wire G2 is determined to be "good".

[0112] In the winding process, the control unit 10, for example, winds the colored fiber core wire G2, which is determined to be "no (defective)" in color, onto the winding spool 91 for defective products, and winds the yellow colored fiber core wire G2, which is determined to be "good" in color, onto the winding spool 91 for good products. In this way, the colored fiber core wire G2 (defective) determined to be "no (defective)" in color and the yellow colored fiber core wire G2 (good) determined to be "good" in color can be wound onto different winding spools 91, or the colored fiber core wire G2 of the defective product and the colored fiber core wire G2 of the good product can be wound continuously onto the same winding spool 91. When the defective and good products are wound continuously onto the same winding spool 91, it is preferable to be able to identify the starting position of the winding of the yellow colored fiber core wire G2 determined to be good.

[0113] It should be noted that the manufacturing methods after color switching in other processes are the same as those described above, so the descriptions are omitted.

[0114] As described above, the method for manufacturing colored optical fiber cores according to the first embodiment includes: a step of feeding colored resin (secondary resins S1, S2) into a secondary mold 22; a step of passing an optical fiber through the secondary mold 22 and coating the optical fiber with colored resin to form a colored optical fiber core G2 having a colored layer; a step of detecting the color of the colored layer of the colored optical fiber core G2; and a step of determining whether the detected color of the colored layer is good or bad. According to this method, the color of the colored resin supplied to the secondary mold 22 can be switched by switching the switching valve 36. Furthermore, the color measuring instrument 5A can determine whether the colored optical fiber core G2 is correctly colored with the color of the switched resin (the colored layer changes from a bad color state to a good state). Therefore, when changing the color of the colored resin coated on the glass fiber G1, it is not necessary to replace / clean the equipment (mold, piping, etc.) used for coating the colored resin. Thus, the color of the colored layer of the colored optical fiber core G2 can be flexibly switched according to the inventory and demand of the colored resin.

[0115] Furthermore, in the method for manufacturing colored optical fiber cores, during the color detection step, the colored optical fiber core G2 is illuminated with RGB light, and the reflected RGB light is captured by a camera 52 to inspect the brightness (light intensity) of the reflected light. Then, in the step of determining the quality of the color, the quality of the color of the coloring layer is determined based on the brightness of the reflected light. According to this method, by using RGB illumination 51R, 51G, 51B and a camera 52, the quality of the color after changing the color of the coloring resin can be easily determined.

[0116] Furthermore, in the method for manufacturing colored fiber cores, during the color detection process, light from RGB illuminations 51R, 51G, and 51B is sequentially irradiated, and the irradiation times of each RGB light are synchronized with the shooting time using camera 52. According to this method, since camera 52 captures the reflected light of the colored fiber core G2 for each RGB light, the brightness of each reflected light can be accurately measured, thereby enabling accurate determination of the quality of the colored layer's color.

[0117] In addition, the method for manufacturing colored optical fiber cores includes, before the step of feeding the colored resin into the secondary mold 22, a step of drawing the optical fiber mother material while heating it to form glass fiber G1; and a step of coating the glass fiber G1 with primary resin P to form an optical fiber core having a primary resin layer. Then, the process of feeding the coloring resin into the secondary mold 22 includes: feeding the first coloring resin from a secondary resin tank 32 filled with a first coloring resin used as secondary resin S1 into the secondary mold 22, and coating the primary resin layer with the first coloring resin to form a secondary resin layer; and feeding the second coloring resin from a secondary resin tank 33 filled with a second coloring resin of a different color than the first coloring resin into the secondary mold 22, and coating the primary resin layer with the second coloring resin to form a secondary resin layer. In the color detection process, the color of the secondary resin layer is detected to change from the color of the first coloring resin to the color of the second coloring resin. In the process of determining the quality of the color, if the color change is determined to meet a predetermined condition, winding as a good product of the colored optical fiber core G2 begins. According to this method, the color of the coloring layer can be determined based on a predetermined threshold, and good products of the colored optical fiber core G2 that meet the threshold condition can be wound. Therefore, the color of the coloring resin can be changed without increasing the waste portion that cannot be a good product.

[0118] Furthermore, the fiber optic core manufacturing apparatus 1 includes: secondary resin tanks 32 and 33 that supply coloring resin to the secondary mold 22; the secondary mold 22 that allows the fiber optic core to pass through and coats the fiber optic core with coloring resin; a coloring measuring device 5 (sensor) that detects the color of the coloring layer formed by the coloring resin around the fiber optic core; and a control unit 10 that determines the quality of the color of the coloring layer detected by the coloring measuring device 5. With this configuration, when changing the color of the coloring resin supplied to the secondary mold 22, the coloring measuring device 5A can determine whether the colored fiber optic core G2 is colored with the changed resin color (changing from a poor coloring state to a good state). Therefore, when changing the color of the coloring resin coated on the glass fiber G1, it is not necessary to replace or clean the equipment (mold, piping, etc.) used for coating the coloring resin. Thus, the color of the coloring layer of the colored fiber optic core G2 can be flexibly changed according to the availability and demand of the coloring resin.

[0119] It should be noted that in the above embodiment, the colorimetric detector 5 is positioned between the resin coating mold 2 and the ultraviolet irradiator 6, but it is not limited to this. The colorimetric detector 5 can be positioned between the resin coating mold 2 and the winding machine 9, or it can be positioned in other locations. However, since the color of the resin changes before and after curing, it is necessary to set threshold values ​​according to each state to detect the color.

[0120] Furthermore, in the above embodiments, the secondary resin coated around the primary resin-coated optical fiber strand is used as the coloring resin, but this is not a limitation. For example, primary and secondary resins may be coated around the glass fiber and used as the optical fiber strand, and a coloring layer composed of coloring ink may be formed around the secondary resin of the optical fiber strand through a coloring process.

[0121] Furthermore, in the above embodiment, in order to shorten the color switching time of the coloring resin when switching the switching valve 36, the position of the switching valve 36 may be set further closer to the secondary mold 22. In such a case, for example, by switching the switching valve 36 correspondingly when changing the winding spool 91, the color of the coloring resin during drawing can be changed while suppressing the amount of color-determined "no (defective)" colored optical fiber core G2.

[0122] Furthermore, in the above embodiment, the switching valve 36 can be switched accordingly when the front end of the optical fiber mother material is led out. In this case, colored optical fiber cores G2 that are determined to be "no (defective)" can be used as the line speed increases, thereby enabling the early acquisition of good products by winding colored optical fiber cores G2 that are determined to be "good" onto the winding spool 91. Thus, the color of the coloring resin can be changed while suppressing the amount of colored optical fiber cores G2 that are determined to be "no (defective)".

[0123] [Second Implementation]

[0124] The following is for reference Figure 5 The manufacturing method of the colored optical fiber core wire according to the second embodiment will be described. Figure 5 This is a diagram showing the color measuring device 5B used in the method for manufacturing colored optical fiber cores according to the second embodiment. Figure 5 As shown, the colorimetric measuring device 5B includes: a red laser source 151R, a green laser source 151G, a blue laser source 151B, a red camera 152R, a green camera 152G, and a blue camera 152B. A red filter 153R that transmits red laser light is mounted on the red camera 152R. A green filter 153G that transmits green laser light is mounted on the green camera 152G. A blue filter 153B that transmits blue laser light is mounted on the blue camera 152B. The red laser source 151R and red camera 152R, the green laser source 151G and green camera 152G, and the blue laser source 151B and blue camera 152B are respectively positioned opposite each other with a colorimetric fiber core wire G2 between them. Each laser source 151R, 151G, 151B and each camera 152R, 152G, 152B is connected to the control unit 10.

[0125] In the colorimetric measurement of the colorimetric measuring device 5B in the first inspection process, the control unit 10 irradiates colored light onto the colored fiber core G2 from the red laser light source 151R, the green laser light source 151G, and the blue laser light source 151B, respectively. The control unit 10 uses the red camera 152R, the green camera 152G, and the blue camera 152B to inspect the amount of light transmitted through the colored fiber core G2 irradiated by the red laser light source 151R, the green laser light source 151G, and the blue laser light source 151B, respectively.

[0126] The control unit 10 determines the color of the secondary resin of the colored fiber core wire G2 based on the amount of light detected by each transmitted light source. The color determination is based on whether the amount of light from each transmitted light source of the colored fiber core wire G2 in the red laser source 151R, green laser source 151G, and blue laser source 151B meets preset threshold conditions. If the amount of light from each transmitted light source meets the preset threshold conditions, the control unit 10 determines that the color of the colored resin sent to the secondary mold 22 is the same as the color of the secondary resin determined based on the amount of light from each transmitted light source, and thus determines the color of the colored fiber core wire G2 as "good". Conversely, if the amount of light from each transmitted light source does not meet the preset threshold conditions, the control unit 10 determines that the color of the colored resin sent to the secondary mold 22 is different from the color of the secondary resin determined based on the amount of light from each transmitted light source, and thus determines the color of the colored fiber core wire G2 as "no (bad)".

[0127] As described above, in the method for manufacturing colored optical fiber core wire according to the second embodiment, in the color detection step, the colored optical fiber core wire G2 is irradiated with each color of RGB light, and the amount of transmitted light of each color of RGB light passing through the colored optical fiber core wire G2 is inspected using cameras 152R, 152G, and 152B corresponding to each color of light. In the step of determining the quality of the color, the quality of the color of the colored layer is determined based on the amount of each transmitted light. According to this method, the quality of the color of the colored layer after changing the color of the colored resin can be easily determined based on the ratio of the transmitted light amounts of RGB light. In addition, in the method of the second embodiment, the transparency of the colored layer can be measured based on the intensity of the transmitted light. Therefore, even when the color of the colored layer is switched from transparent to opaque or from opaque to transparent, it is possible to detect whether the switch is correct. Furthermore, by using a single sensor instead of cameras 152R, 152G, and 152B (e.g., area scan camera, line scan camera, etc.), camera image processing is not required, thus enabling a high-speed and low-cost color measuring device 5B.

[0128] It should be noted that in the above embodiments, cameras 152R, 152G, and 152B were used to check the amount of transmitted light from each laser source 151R, 151G, and 151B, but this is not the only method used. For example, a laser inspection sensor can also be used to check the amount of light.

[0129] [Third Implementation Method]

[0130] The following is for reference Figure 6 , Figure 7A as well as Figure 7B The manufacturing method of the colored optical fiber core wire according to the third embodiment will be described. Figure 6This is a diagram showing the color measuring device 5C used in the method for manufacturing colored optical fiber cores according to the third embodiment. Figure 7A This is a graph showing the brightness distribution of an image captured by a camera using a colorimeter 5C. Figure 7B This is a graph showing the change in brightness distribution when the coloring resin coated on the fiber optic cable is switched. (See figure.) Figure 6 As shown, the colorimeter 5C includes three white illumination units 251 and three color cameras 252 arranged in three rotationally symmetrical directions to surround the colored fiber core G2. In this configuration, one white illumination unit 251 and one color camera 252 are integrated into one unit. The white illumination unit 251 may be a white LED, for example. The color camera 252 may be a line scan camera, for example. The color camera 252, as a line scan camera, may have a one-dimensional imaging element having multiple pixels in the width direction of the colored fiber core G2. The shooting interval of the color camera 252 is preferably 1 kHz or more (1 msec or less). Each white illumination unit 251 and each color camera 252 is connected to the control unit 10.

[0131] In the colorimetric measurement of the colorimetric measuring device 5C in the first inspection process, the control unit 10 issues an instruction to illuminate the colored fiber core G2 with white light from each white illumination 251. Additionally, the control unit 10 issues an instruction to capture the reflected light from the white illumination 251 and reflected by the colored fiber core G2 using each color camera 252. Furthermore, the control unit 10 processes the images captured by each color camera 252 (line scan camera) and examines the RGB brightness (an example of light intensity) of the reflected light from the colored fiber core G2 in each image.

[0132] The control unit 10 determines the color of the secondary resin of the colored fiber core wire G2 based on the RGB brightness of each reflected light detected. The color determination is based on whether the RGB brightness of each reflected light from the colored fiber core wire G2 in the white illumination 251 meets preset threshold conditions. If the RGB brightness of the reflected light is determined to meet the preset threshold conditions, the control unit 10 determines that the color of the colored resin sent to the secondary mold 22 is the same as the color of the secondary resin determined based on the RGB brightness of the reflected light, and thus determines the color of the colored fiber core wire G2 as "good". Conversely, if the RGB brightness of the reflected light is determined not to meet the preset threshold conditions, the control unit 10 determines that the color of the colored resin sent to the secondary mold 22 is different from the color of the secondary resin determined based on the RGB brightness of the reflected light, and thus determines the color of the colored fiber core wire G2 as "no (bad)".

[0133] For example, if the secondary resin of the colored fiber core G2 is yellow, such as Figure 7A As shown, the RGB brightness of the reflected light from the colored fiber core G2 is tested, and the brightness of R (red) and G (green) is high, while the brightness of B (blue) is low. When these tested RGB brightness values ​​meet the preset yellow threshold condition, the control unit 10 determines the color of the secondary resin to be yellow.

[0134] Next, for example, the color measurement of the color measuring device 5C when switching from the state of producing blue colored fiber core G2 to the state of producing yellow colored fiber core G2 will be described.

[0135] As described in the first embodiment above, when the coloring resin (secondary resin) supplied from the secondary resin tank is switched by the switching valve 36, there is a period during which the coloring resin before and after the switch are mixed and supplied to the secondary mold 22.

[0136] Therefore, in the case of switching from the fabrication of blue-colored fiber core G2 to the fabrication of yellow-colored fiber core G2, as in this example, Figure 7B As shown, during the predetermined period T1 of the switching, the RGB brightness of the reflected light reflected by the colored fiber core G2 becomes unstable.

[0137] In this case, during the predetermined period T1, the control unit 10 determines that the RGB brightness of the detected reflected light does not meet the threshold condition set in advance for the yellow colored fiber core G2, and determines that the color of the colored resin sent to the secondary mold 22 is different from the color of the secondary resin determined based on the RGB brightness, thereby determining the color of the colored fiber core G2 as "no (defective)".

[0138] Then, after a predetermined period T1, the RGB brightness of the reflected light becomes stable. When it is determined that the threshold condition set in advance for the yellow colored fiber core G2 is met (during T2), the control unit 10 determines that the color of the colored resin sent to the secondary mold 22 is the same as the color of the secondary resin determined based on the RGB brightness of the reflected light, and thus determines the color of the colored fiber core G2 as "good".

[0139] It should be noted that in the above embodiment, three white lights 251 and three color cameras 252 are used to measure RGB brightness, but it is not limited to this. For example, one white light 251 and one color camera 252 can also be used for measurement.

[0140] As described above, in the method for manufacturing colored optical fiber cores according to the third embodiment, in the color detection step, white light is irradiated onto the colored optical fiber core G2 from white illumination 251, and the reflected light of the white light reflected by the colored optical fiber core G2 is captured by a color camera 252 to examine the RGB brightness of the reflected light. In the step of determining the quality of the color, the quality of the color of the colored layer is determined based on the RGB brightness of the reflected light. According to this method, since it is not necessary to use light sources of different colors, the RGB brightness of each reflected light can be accurately measured with a simple configuration, thereby enabling accurate determination of the quality of the color of the colored layer.

[0141] Furthermore, in the manufacturing method of the colored fiber core, during the color inspection process, a color camera 252 is used to photograph the colored fiber core G2 from three directions. According to this method, by configuring the color cameras 252 in three directions, the color of the entire circumference of the colored fiber core G2 can be inspected without omission, thus enabling accurate determination of the quality of the color of the color layer. Additionally, since the images are taken from three directions, defects such as color discontinuities can be detected at any position in the circumferential direction. Furthermore, by using a line-scan camera, i.e., the color camera 252, capable of high-resolution imaging, small color defects in the length direction can be inspected. Therefore, for example, discontinuous coloring omissions such as ring marks coated on the colored fiber core G2 can also be detected.

[0142] The present disclosure has been described in detail above with reference to specific embodiments. However, 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 disclosure. Furthermore, the number, position, shape, etc., of the constituent components described above are not limited to the above embodiments and can be changed to the preferred number, position, shape, etc., for implementing the present disclosure.

[0143] Explanation of symbols

[0144] 1: Manufacturing equipment

[0145] 2: Resin coating mold

[0146] 3: Resin tank

[0147] 5 (5A, 5B, 5C): Colorimeter

[0148] 6: Ultraviolet irradiator

[0149] 7: Outer diameter measuring instrument

[0150] 9: Winding machine

[0151] 10: Control Department

[0152] 21: Primary mold

[0153] 22: Secondary mold

[0154] 31: Primary Resin Tank

[0155] 32, 33: Secondary resin tank

[0156] 34, 35: Supply Management

[0157] 36: Switching valve

[0158] 51R: Red lighting

[0159] 51G: Green Lighting

[0160] 51B: Blue Lighting

[0161] 52: Camera

[0162] 53: Image display device

[0163] 91: Winding spool

[0164] 92: Winch

[0165] 151R: Red laser source

[0166] 151G: Green Laser Source

[0167] 151B: Blue laser source

[0168] 152R: Red camera

[0169] 152G: Green camera

[0170] 152B: Blue camera

[0171] 153R: Red filter

[0172] 153G: Green Filter

[0173] 153B: Blue filter

[0174] 251: White Lighting

[0175] 252: Color Camera

[0176] G1: Glass fiber

[0177] G2: Colored fiber optic core

[0178] P: Primary resin

[0179] S1, S2: Secondary resins

Claims

1. A method for manufacturing a colored optical fiber core, comprising: The process of heating the optical fiber substrate while drawing it into glass fiber; The process of coating a primary resin around the glass fiber to form an optical fiber with a primary resin layer. The process of feeding the colored resin into the mold; The process of passing the optical fiber core through the mold and coating the optical fiber core with the coloring resin to form a colored optical fiber core with a coloring layer. The process of detecting the color of the coloring layer; as well as The process of determining whether the detected color is good or bad. The process of feeding the colored resin into the mold includes: The process of feeding the first coloring resin from a first tank filled with a first coloring resin used as a secondary resin into the mold, and coating the first coloring resin around the primary resin layer to form the first primary resin layer. and The process involves switching from the first tank to a second tank filled with a second coloring resin of a different color than the first coloring resin, which serves as a secondary resin, and then feeding the second coloring resin into the mold. The second coloring resin is then applied around the primary resin layer to form the secondary resin layer. In the process of detecting the color, the color change from the first coloring resin in the first primary resin layer to the second coloring resin in the second primary resin layer is detected. In the process of determining whether the product is good or bad, if it is determined that the color change is above a predetermined threshold, the winding of the colored optical fiber core wire is started as a good product.

2. The method for manufacturing colored optical fiber cores according to claim 1, wherein, In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and a sensor is used to detect a portion of the light irradiated onto the colored optical fiber core to examine the amount of each RGB element of the light, thereby detecting the color. In the process of determining whether the color is good or bad, the good or bad color is determined based on the amount of light.

3. The method for manufacturing colored optical fiber cores according to claim 2, wherein, In the process of detecting the color, when the colored optical fiber core is irradiated with RGB light and a portion of each light is detected using the sensor, the irradiation time of each light is synchronized with the detection time of the sensor to verify the RGB light intensity of each light and thus detect the color. In the process of determining whether the color is good or bad, the good or bad color is determined based on the amount of light.

4. The method for manufacturing colored optical fiber cores according to claim 2, wherein, In the process of detecting the color, white light is irradiated onto the colored optical fiber core, and a portion of the white light is detected using the sensor to examine the RGB values ​​of the light, thereby detecting the color. In the process of determining whether the color is good or bad, the good or bad color is determined based on the amount of light.

5. The method for manufacturing colored optical fiber cores according to any one of claims 2 to 4, wherein, In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and the transmitted light passing through the colored optical fiber core is detected using the sensor to examine the amount of each RGB element of the light, thereby detecting the color. In the process of determining whether the color is good or bad, the good or bad color is determined based on the amount of light.

6. The method for manufacturing colored optical fiber cores according to any one of claims 2 to 4, wherein, In the process of detecting the color, the colored optical fiber core is irradiated with light containing RGB, and the reflected light from the colored optical fiber core is detected using the sensor to examine the amount of each RGB element of the light, thereby detecting the color. In the process of determining whether the color is good or bad, the good or bad color is determined based on the amount of light.

7. The method for manufacturing colored optical fiber cores according to any one of claims 2 to 4, wherein, In the process of detecting the color, the sensor that detects a portion of the light illuminating the colored fiber core is a line-scan camera sensor having multiple pixels in the width direction of the colored fiber core.

8. The method for manufacturing colored optical fiber cores according to any one of claims 2 to 4, wherein, In the process of detecting the color, the sensor that detects a portion of the light illuminating the colored fiber core is an area array camera sensor having multiple pixels in the width and length directions of the colored fiber core.

9. The method for manufacturing colored optical fiber cores according to any one of claims 2 to 4, wherein, In the process of detecting the color, the sensor is used to detect a portion of the light illuminating the colored fiber core from three directions.

10. A manufacturing apparatus for colored optical fiber cores, comprising: A fiber drawing device that heats the optical fiber substrate while drawing it to form glass fibers; and a primary resin tank that delivers primary resin into a primary mold. A primary mold is formed by passing the glass fiber through and coating the glass fiber with the primary resin to form an optical fiber wire having a primary resin layer. The coloring resin is fed into the secondary resin tank inside the secondary mold. A secondary mold through which the optical fiber conductor passes and around which the coloring resin is applied, A sensor that detects the color of the coloring layer formed by the coloring resin around the fiber optic strands, and The control unit determines whether the color detected by the sensor is good or bad. The secondary resin tank delivers the first coloring resin from the first tank, which is filled with the first coloring resin used as the secondary resin, into the secondary mold. The secondary mold coats the first coloring resin around the primary resin layer to form the first primary resin layer. The secondary resin tank is switched from the first tank to a second tank filled with a second coloring resin of a different color than the first coloring resin, which is used as the secondary resin, and the second coloring resin is then fed into the secondary mold. The secondary mold applies the second coloring resin around the primary resin layer to form a second secondary resin layer. The sensor detects the color change from the first coloring resin in the first primary resin layer to the second coloring resin in the second secondary resin layer. When the control unit determines that the color change is above a predetermined threshold, it begins winding the colored optical fiber core as a good product.

Images