JP2011242316A - Bubble detector for linear body and film formation device and method for linear body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bubble detector for a linear body, that can smoothly detect bubbles in a film layer while the film layer is formed at high speed for the linear body, and provide film formation device and method for forming the film layer for the linear body.SOLUTION: The bubble detector and the film formation device for a linear body comprise a coating die 13 for coating an optical fiber 1 with a colored resin; a hardening device 14 for hardening the colored resin applied by the coating die 13; a dark room 22 through which the optical fiber 1 with a film layer formed by hardening a coating liquid is passed through; a stroboscope 23 for irradiating intermittently the optical fiber 1 passing through the dark room 22 with flash light; a photographing device 24 for photographing the optical fiber 1 passing through the dark room 22 in synchronization with the irradiation with flash light of the stroboscope 23; and a control device 61 (image processing unit) for detecting bubbles in the film layer based on an image photographed by the photographing device 24.

Description

  The present invention relates to, for example, a bubble detection device that detects bubbles in a coating layer formed on the surface of a linear body such as an optical fiber, a coating film forming device that forms a coating layer on the surface of a linear body such as an optical fiber, and a coating film It relates to a forming method.

  Conventionally, as a device for detecting abnormalities of the striatum, an image taken by a photographing camera is taken, the image data is subjected to differentiation processing in the traveling direction of the optical cable spacer, and further binarized using a predetermined threshold value. A device that detects an abnormality of a colored tracer according to the binarized data obtained by performing processing is known (see, for example, Patent Document 1).

  In addition, a drawing device is known in which a bubble sensor is provided below the outer diameter measuring device to check whether bubbles are generated in the resin constituting the coating of the optical fiber strand from the scattered light of the irradiated laser. (For example, refer to Patent Document 2).

JP 2009-2790 A JP-A-2005-75664

An optical fiber in which a glass fiber is coated with a resin is further colored by forming a coating layer for identification on the outer periphery thereof. When air bubbles are mixed in the coating layer when forming a coating for identification or the like on the optical fiber in this way, the appearance deteriorates or the loss of the optical fiber increases. Therefore, it is required to detect bubbles at the time of film formation, but the film formation for identification is performed at an extremely fast linear speed (for example, 1000 m / min or more). The photographed image was blurred and it was difficult to perform the bubble detection well. Moreover, since the technique of patent document 2 is a system which detects the scattered light after the irradiated laser permeate | transmits, it cannot apply to the bubble detection at the time of forming the film layer which does not have translucency.
Further, since the identification coating layer to be formed is extremely thin (for example, 10 μm or less), the size of the irregularities formed by the bubbles is extremely small. Therefore, it was difficult to detect air bubbles in the coating layer satisfactorily even using an existing outer diameter measuring device or a bump detector installed in the production line.
For this reason, in order to detect bubbles generated in such a coating layer for identification, the surface layer portion of the optical fiber wound around the bobbin is visually inspected for the presence of bubbles after the formation of the identification coating layer. However, the presence or absence of bubbles in the optical fiber wound on the inner peripheral side of the bobbin could not be inspected.

  An object of the present invention is to provide a bubble detection device for a striatum, which can smoothly detect the presence or absence of bubbles in the coating layer while forming a coating layer on the striatum at high speed, and a coating on the striatum An object of the present invention is to provide a forming apparatus and a film forming method.

The bubble detection device for a striatum according to the present invention capable of solving the above-described problem is a dark room through which a striatum in which a coated coating solution is cured and a coating layer is formed, and
A flash part that intermittently irradiates flash to the striatum passing through the darkroom;
An imaging unit that captures an image of the striatum passing through the darkroom in synchronization with the flash irradiation of the flash unit;
And an image processing unit that detects bubbles in the coating layer based on an image photographed by the photographing unit.

Moreover, the film forming apparatus for a striatum according to the present invention includes an application unit that applies a coating liquid to the striatum, and a curing unit that cures the coating liquid applied by the application unit,
A dark room through which the striatum in which the coating solution is cured to form a coating layer;
A flash part that intermittently irradiates flash to the striatum passing through the darkroom;
An imaging unit that captures an image of the striatum passing through the darkroom in synchronization with the flash irradiation of the flash unit;
And an image processing unit that detects bubbles in the coating layer based on an image photographed by the photographing unit.

In addition, the method for forming a film of a striatum according to the present invention forms a film layer by applying a coating liquid to the striatum and curing it.
Pass the striatum formed with the coating layer into a dark room,
Irradiating flash light intermittently to the striatum passing through the dark room, photographing the striatum in synchronization with the flash irradiation,
The photographed image is subjected to image processing to detect bubbles in the coating layer, and a portion where bubbles are present is removed.

According to the present invention, when the coating layer is formed on the striatum at a high speed, the surface of the optical fiber is continuously observed based on images taken intermittently and instantaneously. It can be detected smoothly and with high accuracy. In addition, the presence or absence of bubbles can be reliably detected regardless of the presence or absence of translucency of the coating layer formed on the striatum, compared to the case where bubbles are detected by a transmission type detector.
That is, while forming a coating layer on the striatum at a high speed, the presence or absence of bubbles in the coating layer can be detected smoothly and with high accuracy, and the outflow of abnormal portions having bubbles can be minimized. .

It is a schematic block diagram of the film formation apparatus containing the bubble detection apparatus of a linear body which concerns on this embodiment. It is a schematic block diagram which shows the internal structure of the bubble detection apparatus provided in the film formation apparatus. It is a top view of the optical fiber which shows an example of the bubble formed in the coating layer of an optical fiber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of embodiments of the bubble detecting device for a striatum, the film forming apparatus for a striatum, and the film forming method according to the present invention will be described below with reference to the drawings.
In the present embodiment, an optical fiber is exemplified as the linear body, and a case where a coating layer made of a colored resin is formed on the optical fiber is described as an example.

  As shown in FIG. 1, the film forming apparatus 11 includes a supply bobbin 12 around which an optical fiber (wire body) 1 is wound. The optical fiber 1 is pulled out from the supply bobbin 12 at a high speed (1000 m / min). The optical fiber 1 drawn out from the supply bobbin 12 is a glass fiber having a core and a clad with an outer periphery coated with a resin.

  On the downstream side of the supply bobbin 12, a coating die (coating portion) 13, a curing device (curing portion) 14, and an outer diameter measuring device 15 are provided in this order, and the optical fiber 1 is coated by guide rollers 16 and 17. Guided to dice 13.

The coating die 13 applies a colored resin as a coating solution to the optical fiber 1, and the colored resin is thinly applied to the outer periphery of the optical fiber 1 by passing through the coating die 13. This colored resin is an ultraviolet curable resin and is coated to a thickness of about 5 μm.
The curing device 14 cures the colored resin applied to the outer periphery of the optical fiber 1 by the application die 13 by irradiating with ultraviolet rays. When the optical fiber 1 coated with the colored resin passes through the curing device 14, the colored resin is cured, and a coating layer made of the colored resin is fixedly formed on the surface of the optical fiber 1.

  The outer diameter measuring device 15 provided on the downstream side of the curing device 14 is a measuring device that measures the outer diameter of the optical fiber 1 having a colored resin coating layer formed on the outer periphery thereof by a laser.

  A bubble detecting device 21 is provided on the downstream side of the outer diameter measuring device 15. As shown in FIG. 2, the bubble detection device 21 has a dark room 22, and the optical fiber 1 on which a coating layer is formed passes through the dark room 22. A strobe (flash unit) 23 is provided in the dark room 22. This strobe 23 irradiates flash light intermittently toward the optical fiber 1 passing through the dark room 22. The flash irradiation interval of the strobe 23 is, for example, 0.2 seconds.

  In the dark room 22, for example, an imaging device (imaging unit) 24 such as a CCD camera is provided. The photographing device 24 photographs a predetermined range including the optical fiber 1 passing through the dark room 22, and photographs the optical fiber 1 in synchronization with the flash light irradiation of the strobe 23. That is, the photographing device 24 photographs a predetermined range including the optical fiber 1 at intervals of 0.2 seconds, for example, in accordance with the timing of flash light irradiation of the strobe 23. Note that the shutter speed of the photographing device 24 is set to about 1/120 seconds.

On the downstream side of the bubble detection device 21, an unevenness detection device 31 for detecting unevenness on the surface of the optical fiber 1 is provided, and the optical fiber 1 that has passed through the bubble detection device 21 is detected by the guide roller 32. Guided to 31.
A capstan 35 is provided on the downstream side of the unevenness detecting device 31, and the optical fiber 1 that has passed through the unevenness detecting device 31 is guided to the capstan 35 by guide rollers 36 and 37. The capstan 35 pulls the optical fiber 1 downstream while applying a predetermined tension.

  A screening device 41 is provided on the downstream side of the capstan 35, and the optical fiber 1 is fed into the screening device 41 from the capstan 35. The screening device 41 includes a screening roller 42, a guide roller 43, and a tension detector 45.

  The optical fiber 1 fed from the capstan 35 is wound around the guide roller 43 and then wound around the screening roller 42. The screening roller 42 pulls the optical fiber 1 with the frictional force of the surface, and generates a predetermined screening tension with the capstan 35. The tension detector 45 is provided between the guide roller 43 and the screening roller 42 and detects the tension of the optical fiber 1.

  A winding bobbin 51 is provided on the downstream side of the screening device 41, and the optical fiber 1 sent out from the screening device 41 is guided by the guide rollers 52, 53, 54 and guided to the winding bobbin 51. Then, the optical fiber 1 is wound around the winding bobbin 51.

  The film forming apparatus 11 includes a control device 61, to which the outer diameter measuring device 15, the bubble detecting device 21, and the unevenness detecting device 31 are connected. Based on detection signals from the outer diameter measuring device 15, the bubble detection device 21, and the unevenness detection device 31, the control device 61 detects an abnormal outer diameter of the optical fiber 1, bubbles in the coating layer of the optical fiber 1, and unevenness of the optical fiber 1. Determine the presence or absence.

Next, the case where a coating layer is formed on the optical fiber 1 by the coating film forming apparatus 11 will be described.
The optical fiber 1 drawn from the supply bobbin 12 at a linear speed of 1000 m / min is passed through the coating die 13 to apply an identification coloring resin, and further to the curing device 14, the optical fiber 1. The applied colored resin is cured by passing through.

  Thereafter, the outer diameter measuring device 15, the bubble detecting device 21, and the unevenness detecting device 31 respectively detect an abnormality in the outer diameter of the optical fiber 1, detect bubbles in the coating layer made of a colored resin formed on the optical fiber 1, and the optical fiber. 1 is detected and wound around a winding bobbin 51 via a capstan 35 and a screening device 41.

  In the bubble detection device 21, the optical fiber 1 passing through the dark chamber 22 of the bubble detection device 21 is irradiated with flash light intermittently, for example, at intervals of 0.2 seconds by the strobe 23. The inside of the dark room 22 including the optical fiber 1 is photographed by the photographing device 24 at a shutter speed of about 1/120 seconds in synchronization with the irradiation. The imaging data of the imaging device 24 of the bubble detection device 21 is transmitted to the control device 61, and the presence or absence of bubbles in the coating layer of the optical fiber 1 is determined by the image processing unit constituting the control device 61.

In the image processing unit of the control device 61, for example, in an image block obtained by photographing the optical fiber 1 in a range of 1 mm in width and 3 mm in length, the number of bright spots generated by irregular reflection at the bubble portion is counted, and the counted value is If it is more than a threshold value, it will determine with the bubble B shown in FIG.
When the control device 61 determines that bubbles are present in the optical fiber 1, the control device 61 stops the film forming line of the optical fiber 1, and notifies the operator, for example, by an alarm. Alternatively, the range of the length in which bubbles are present in the entire length of the optical fiber 1 is stored in the control device 61, and after being wound on the winding bobbin 51, the optical fiber 1 in that range can be removed as appropriate. Like that.
In a subsequent process, when the winding bobbin 51 is rewinded to another bobbin, the optical fiber 1 in a range where bubbles are present is removed.

  As described above, according to the embodiment, when the coating layer is formed on the optical fiber 1 at high speed, the surface of the optical fiber 1 is continuously observed based on the images photographed intermittently and instantaneously. Air bubbles in the layer can be detected smoothly and with high accuracy. Compared with the method of detecting bubbles with a transmission type detector, the bubbles can be reliably detected regardless of whether or not the coating layer formed on the optical fiber 1 has translucency.

  That is, while forming a coating film on the optical fiber 1 at a high speed, bubbles in the coating film can be detected smoothly and quickly, and the outflow of abnormal portions having bubbles can be minimized.

  A plurality of imaging devices 24 of the bubble detection device 21 may be provided. By providing a plurality of photographing devices 24 and photographing the inside of the dark room 22 including the optical fiber 1 from a plurality of directions (for example, three orthogonal directions), bubbles in the coating layer of the optical fiber 1 can be detected with higher accuracy.

  Moreover, although the said embodiment demonstrated taking the case where the film liquid which applied the coating liquid which consists of colored resin to the linear body which consists of the optical fiber 1 was formed as an example, as a linear body, it is limited to an optical fiber. Alternatively, an electric wire or the like may be used. The coating liquid applied to the striatum may be any substance that has fluidity and can be solidified.

  In the above embodiment, in the coloring step of forming a colored resin film on the optical fiber 1 drawn from the supply bobbin 12, the bubble detection device 21 detects bubbles in the film. In the drawing process of the optical fiber in which the glass fiber is drawn from the material and then the resin is coated on the glass fiber, the coating die 13 and the curing are continuously performed until the glass fiber is coated with the resin and then wound on the bobbin. A film may be formed by the device 14, and bubbles in the film may be detected by the bubble detection device 21. Moreover, it is good also as detecting the bubble which arose on the surface of the coating layer coat | covered by the drawing process.

DESCRIPTION OF SYMBOLS 1: Optical fiber (striate body), 11: Film formation apparatus, 13: Application | coating die (application | coating part), 14: Curing apparatus (hardening part), 21: Bubble detection apparatus, 22: Dark room, 23: Strobe (flash part) ), 24: imaging device (imaging unit), 61: control device (image processing unit)

Claims (3)

A dark room through which the striate body in which the applied coating solution is cured and a coating layer is formed;
A flash part that intermittently irradiates flash to the striatum passing through the darkroom;
An imaging unit that captures an image of the striatum passing through the darkroom in synchronization with the flash irradiation of the flash unit;
An image processing unit that detects bubbles in the coating layer based on an image photographed by the photographing unit. An application part that applies a coating liquid to the striatum, and a curing part that cures the coating liquid applied by the application part,
A dark room through which the striatum in which the coating solution is cured to form a coating layer;
A flash part that intermittently irradiates flash to the striatum passing through the darkroom;
An imaging unit that captures an image of the striatum passing through the darkroom in synchronization with the flash irradiation of the flash unit;
An image processing unit that detects air bubbles in the coating layer based on an image photographed by the photographing unit. A coating solution is applied to the striatum and cured to form a coating layer,
Pass the striatum formed with the coating layer into a dark room,
Irradiating flash light intermittently to the striatum passing through the dark room, photographing the striatum in synchronization with the flash irradiation,
A method for forming a film of a striatum, wherein a bubble in the coating layer is detected by performing image processing on a photographed image, and a portion where the bubble is present is removed.

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