JP3254888B2 - Hollow fiber module inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for a hollow fiber module used in a dialyzer for exchanging a substance between blood passing through a hollow fiber and dialysate passing outside the hollow fiber. More particularly, the present invention relates to an inspection apparatus for a hollow fiber module suitable for detecting a defect such as a bubble mark generated on an end face of an end of a bundle of the hollow fibers solidified with a resin agent.

[0002]

2. Description of the Related Art As is well known, a hemodialyzer comprises blood and a dialysate separated by a semi-permeable membrane. The pressure and the concentration difference between the blood and the dialysate introduced into the dialyzer cause the aforementioned hemodialysis. By exchanging substances between blood and dialysate, impurities in blood are removed and the blood is purified.

As such a hemodialyzer, as shown in FIG. 12, a plurality of hollow fibers made of a semipermeable membrane and open at both ends are placed in a cylindrical dialysis container A having both ends open and symmetrical. There is a type using a hollow fiber module M provided with a substantially cylindrical yarn bundle B constituted by the following. The hollow fiber module M is made of a thermosetting resin material such as urethane resin which is in close contact with the inner peripheral surface of the container A and the outer peripheral surface of the hollow fiber constituting the yarn bundle B at both ends of the container A. It has resin material layers C1 and C2 having a thickness.
C2 separates the blood chamber inside the hollow fiber from the dialysate chamber outside the hollow fiber. That is, in the dialyzer using the hollow fiber module M as shown in FIG. 12, a substance exchange is performed between blood passing through the hollow fiber and dialysate passing outside the hollow fiber in the container A.

A dialyzer (hollow fiber module M) illustrated in FIG. 13 is generally configured as follows.

First, as shown in FIG. 13, a cylindrical yarn bundle B in which a number of hollow fibers are bundled is disposed in the container A so as to pass through the container A.

Next, resin agent layers C 1, C
2 to form a module M shown in FIG. 12, and then end caps D1, D2 on both ends of the container A.
To be configured. These end caps D1, D2
The nozzles d1 and d2 formed in advance in the container A are a blood introduction part and a blood discharge part, respectively.
Reference numeral 4 denotes a dialysate outlet and a dialysate inlet.

Incidentally, in the hollow fiber module constructed as described above, a minute concave portion may be formed on the end faces of the resin agent layers C1 and C2 cut along the end faces of the container A. Such minute concave portions are often traces of air bubbles mixed into the resin material in the step of forming the resin material layers C1 and C2. The reasons for the occurrence of these recesses are not necessarily limited to the above reasons, but hereinafter,
For example, all the small recesses formed on the end faces of the resin agent layers C1 and C2, including the small recesses caused by local cracks and the like, are referred to as "recesses DP".

[0008] The presence of the recess DP does not greatly affect the treatment performance of the dialyzer. However, during the operation of collecting blood into the patient after the treatment is completed, a small amount of blood attached to the recess DP is not recovered. Therefore, there is a possibility that this may cause anxiety to the patient. For this reason, from the treatment site,
There is a strong demand for a dialyzer to use a hollow fiber module without the concave portion DP.

By the way, the above-mentioned concave portion DP can be found with the naked eye when the end faces of the resin material layers C1 and C2 are held over a light source. Therefore, conventionally, the above-described concave portion DP is visually detected by an inspector.

[0010]

However, the detection of the concave portion DP by visual inspection has been required to use a more accurate detection means because of the variation among the inspectors. In addition, the visual inspection as described above has a problem in shortening the operation time when a large number of hollow fiber modules are inspected. In other words, in order to completely automate the manufacturing process and reduce costs,
It is necessary to automatically detect the concave portion DP. As described above, as means for automatically detecting the concave portion DP, means for irradiating the cut surface with illumination light, receiving the reflected light, and performing image processing may be considered.

As a method of automatically detecting the concave portion DP by image processing, for example, as shown by an arrow in FIG. 14A, the entire end surface C11 of the hollow fiber module M is illuminated from an oblique direction, and the concave portion DP is formed on the end surface C11. If there is no DP, a two-dimensional CCD camera 501 is provided at a position where it does not receive specularly reflected light. If there is a concave portion DP such as a bubble mark on the end face C11, the two-dimensional CCD camera 351 moves one end of this concave portion DP. There is a method of receiving strong regular reflection light from the curved surface of the section. In this case, since the luminance of the pixels forming the image of the concave portion DP is higher than the luminance of the other portions, it is possible to detect the presence of the concave portion DP by binarizing the luminance of the pixels of the entire image. It is.
However, in this method, when the two-dimensional CCD camera 351 is fixed, the two-dimensional CCD camera 351 depends on where in the end face C11 the concave portion DP exists.
May or may not be able to receive the specularly reflected light from the concave portion DP. That is, this method is difficult to cope with the difference in the position and the shape of the concave portion DP, and is not practical.

Further, as shown in FIG. 14 (b), when the end face C11 is irradiated from an oblique direction by the diffusive light source 352, the concave portion is formed.
A method is also conceivable in which a shadow is formed on the DP and the specularly reflected light on the end face C11 is grasped by the two-dimensional television camera 353 to detect the shadow of the concave portion DP. However, on the end face C11,
Since there are fine irregularities due to the exposed ends of the thousands of hollow fibers, the illumination method of FIG.
All these irregularities also create fine shadows. The difference between the luminance level of these concave and convex portions and the luminance level of the concave portion DP is small, and the concave portion DP to be detected cannot be separated and detected well. Also, the concave portion DP to be detected is usually
In the end face C11 shown in FIG. 15, there is not much in the central portion (substantially circular to elliptical region) where the yarn bundle B is located, and it often occurs in the annular portion S outside and without hollow fibers. . However, various "strains" are often formed on the annular portion S in the step of forming the end face C11.
Since the reflected light of the distorted portion has a different reflection direction, the intensity of the reflected light grasped by the television camera 353 is lower than that of a normal plane. For this reason, there is a possibility that this distorted portion is erroneously detected as the concave portion DP to be detected, and the annular portion S
Cannot be accurately detected.

In addition to the above, in the method of irradiating the end face 11 with illumination light as shown in FIGS. 14 (a) and 14 (b), since the yarn bundle B becomes a strong diffusion medium, it once enters the resin agent layer. Light is spread from the inside of the resin material layer to the entire end face 11, and the image becomes brighter as a whole, and the difference in brightness between the image of the concave portion DP and the image of the other portion is reduced, so that the concave portion DP and the other portion are distinguished. There was a problem that became difficult.

As another method of automatically detecting the concave portion DP by image processing, as shown in FIG. 14 (c), a narrow slit light having a width substantially equal to or smaller than the concave portion DP to be detected is applied to the end face C11. And the end face C1 by the CCD camera 354.
It is conceivable to adopt a method called a so-called light cutting method, which detects that the slit light image on 1 is partially distorted by the concave portion DP. However, even when this light sectioning method is used, if there is a distortion in the annular portion S, the slit light image is bent, and there is a problem that this distortion is erroneously detected as if it were the concave portion DP. Further, in this light cutting method, when the end face C11 is not formed on a plane perpendicular to the cylindrical central axis of the cylindrical container A in FIG.
The slit light image grasped by the CD element is tilted and is erroneously detected as a certain defect. In addition, a one-dimensional CCD as a detection element
When an element is used, the end face C1 that is non-perpendicular to the axis
In the case of 1, there is also a problem that the slit light image is formed at a position deviated from the CCD element.

An object of the present invention is to provide a hollow fiber module having a resin layer in which the ends of a plurality of hollow fibers are solidified with a resin, for detecting a defect generated on an end face of the resin layer. An object of the present invention is to provide an inspection device for a hollow fiber module, which is capable of easily and accurately detecting a concave portion due to a bubble mark or the like generated on an end surface of a resin layer of the hollow fiber module.

[0016]

According to a first aspect of the present invention, there is provided an inspection apparatus for a hollow fiber module, comprising: a support means for supporting the hollow fiber module; and a slit-shaped irradiation area set on an end surface of the resin material layer. Light irradiating means for irradiating slit light incident on the end face non-orthogonally, moving means for relatively moving the position of the irradiation area with respect to the end face, and the slit light reflected on the end face corresponding to the irradiation area At the position where the reflected light is incident, the light amount for each pixel is measured for the image of the end surface corresponding to the irradiation area, and the light measurement amount for the image in the window set in the image of the irradiation area is output. And a binarization processing unit that binarizes the photometric amount of each pixel output by the photometric unit with a predetermined threshold value and outputs the binarized signal. The width of the region to be illuminated by the slit light is 10 to 150 times the size of the pixel, and the intensity of light at the time when the light intensity of each pixel measured by the photometric means starts to be saturated in at least some of the pixels is 1 to 1 The range is set to four times.

According to a second aspect of the present invention, there is provided the inspection apparatus for a hollow fiber module according to the first aspect, further comprising determining whether the hollow fiber module is defective based on the binarized signal from the binarization processing means. And a classification means for classifying the defective hollow fiber module based on the determination result of the determination means.

According to a third aspect of the present invention, there is provided an inspection apparatus for a hollow fiber module, wherein the light irradiation means in the inspection apparatus of the first aspect is diffusive illumination, and a light shielding plate is provided on an end surface of the resin material layer. The inspection apparatus for a hollow fiber module according to claim 4 is the inspection apparatus according to claim 1 or 3, further comprising a reflecting mirror that changes directions of illumination light and reflected light.

According to a fifth aspect of the present invention, there is provided an inspection apparatus for a hollow fiber module, further comprising the determination means and the separation means of the inspection apparatus according to the second aspect.

[0020]

In the inspection apparatus for a hollow fiber module according to the first aspect,
By irradiating the slit light to the end face of the resin material layer by the light irradiation means, the reflected light of the slit light reflected on the end face of the resin material layer is measured by the photometric means. By setting the light measurement amount of each pixel measured by the light measurement unit to a range of 1 to 4 times the time point at which saturation starts at least in some pixels, when a concave portion due to a bubble mark or the like exists on the end surface of the resin material layer. At least, the measured light amount of the pixel corresponding to the concave portion can be prevented from reaching the saturation value.
By binarizing the measured light amount by the binarization processing means, the pixel can be separated into a pixel corresponding to the concave portion and other pixels. By setting the width of the irradiation area by the slit light to 10 to 150 times the size of the pixel, a detection error due to a finished state of the end surface of the resin material layer and a module mounting position shift does not occur. By means of transportation
By moving the irradiation area of the slit light by the light irradiation unit, the entire end surface of the resin material layer can be separated into a portion corresponding to the concave portion and a portion other than the concave portion.

According to the hollow fiber module inspection apparatus of the second aspect, the determination means determines whether or not the inspected hollow fiber module is a defective hollow fiber module. Separated from other hollow fiber modules by the separation means.

According to the hollow fiber module inspection apparatus of the third aspect, the end surface of the resin material layer is illuminated from multiple directions.
Even if the end surface of the resin material layer is inclined and distorted, the reflected light surely enters the photometric device and does not erroneously detect them.
Further, since the yarn bundle B has a strong light diffusing property, the illumination light incident on the end surface of the resin agent layer is diffused by the yarn bundle to increase the brightness of the entire end surface and to reduce the contrast of light reflected by the concave portion DP. In addition, since the light shielding plate blocks unnecessary illumination light, the contrast does not decrease.

According to the hollow fiber module inspection apparatus of the present invention, since the directions of the illumination and the reflected light are bent by the reflecting mirror, the light irradiating means and the photometer in the direction perpendicular to the axis C0 of the hollow fiber module M are provided. The width of the means can be reduced.

According to the hollow fiber module inspection apparatus of the fifth aspect, in addition to the operation of the apparatus of the fourth aspect, the determination means determines whether or not the inspected hollow fiber module is a defective hollow fiber module. A hollow fiber module determined as a defective hollow fiber module is separated from other hollow fiber modules by a separating means.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An end face C of a hollow fiber module M according to the present invention.
An inspection device (hereinafter, referred to as an inspection device) for detecting the presence or absence of the concave portion DP of No. 11
It is simply called an inspection device. 1) is shown in FIG. 1 includes a support device 1, a light irradiation device 2, a photometric device 3, a detection signal forming device 4, a discriminating device 5, a display device 6, and an operation command unit 7 for the hollow fiber module M.

As shown in FIG. 2, the support device 1 includes a support table 101, a drive motor 102, a drive roller 103, module support rollers 104 and 105, a driven roller 106, and a belt 107. The drive motor 102
The rollers 103 to 106 are attached to the support 101. The drive roller 103 includes a drive motor 102
Is driven to rotate.

The supporting device 1 mounts the hollow fiber module M with its axis C0 kept horizontal, and the hollow fiber module M mounted on the supporting device 1 It rotates around the axis C0. The setting, starting, and stopping of the rotation amount of the drive motor 102 are controlled by a drive control unit 108.
The drive control unit 108 receives a command signal given by an operation command unit 7 described later, and drives the drive motor 102. The rotation angle of the drive roller 103, which is rotationally driven by the drive motor 102, is detected by a rotation angle detector 109 such as a known optical encoder, and is provided to an operation command unit 7 described later.

Further, the supporting device 1 uses a vertical movement mechanism (not shown) to move the mounted hollow fiber module M to the shaft center C0.
Can be moved up and down while maintaining horizontal. Thus, the axis C0 of the hollow fiber module M can be set at a predetermined position regardless of the diameter of the hollow fiber module M.

The attachment / detachment of the hollow fiber module M to / from the support device 1 can be automatically performed by, for example, a hollow fiber module transfer mechanism 8 as schematically shown in FIG. The hollow fiber module transfer mechanism 8 attaches the hollow fiber module M taken out of the supply unit 81 to the support device 1 by the automatic hand 80, and attaches the hollow fiber module M removed from the support device 1 to a non-defective product. The next process transfer section 82 and the defective hollow fiber module collection section 86 for defective products are sorted. Attachment / detachment / sorting to these units by the automatic hand 80 is automatically performed by a command from the operation command unit 7. Therefore, the auto hand 80 can move along the guide 83 as shown by the two-dot chain line.

The light irradiation device 2 includes a light source 201 and a slit light irradiation unit 202.

The light source 201 is formed of a halogen lamp or the like, and controls on / off of light emission and adjustment of light intensity based on a command given from an operation command unit 7 described later. The light source 201 adjusts the light intensity so that the luminance measured by the photometric device 3 described later becomes a light intensity that is saturated in any of the pixels. The adjustment of the light intensity will be described later.

The slit light irradiating section 202 is connected to the light source 201 by, for example, a plurality of optical fibers 203. After arranging these optical fibers 203 in a horizontal line, the slit irradiating section 202 irradiates light emitted from the terminals of these optical fibers 203. The light is condensed in a slit shape by a cylindrical lens (not shown), and this slit light is emitted. As shown in FIG. 3, the slit-shaped light is generated when the end face C11 of the resin material layer C1 of the hollow fiber module M is an ideally formed face that is perpendicular to the axis C0 over the entire end face. Is incident on the diameter of the end face C11 at an incident angle α, and irradiates a slit-shaped irradiation area H having a width h including the diameter of the end face C11. In the following, the irradiation region H of the slit light applied to the end surface C11 when the end surface is the ideal forming surface will be described as the irradiation region H for an arbitrary end surface C11.

When the end face C11 is the ideal end face, the slit light L emitted from the slit light emitting portion 202
As shown by the solid line in FIG. 4, the light is reflected at the reflection angle β1 at the slit-shaped irradiated area H and becomes regular reflection light R1.

If there is a concave portion DP due to a bubble mark or the like on the end face C11, the regular reflection light R2 of the slit light L is generated as shown in FIG.
As shown by an imaginary line, the light is reflected at the concave portion DP at a reflection angle β2 different from the reflection angle β1. It is preferable that the reflected light does not receive irregularly reflected light but receives specularly reflected light.

Further, even when the end face C11 is cut obliquely with respect to the ideal end face or has a distorted end face, the regular reflection light R1 'of the slit light L is different from the reflection angle β1. The light is reflected at the reflection angle β1 ′. But,
In this case, the inclination of the end face C11 in the irradiation area H is
The reflection angle β1 ′ of the regular reflection light R1 ′ is closer to the reflection angle β1 at the ideal end face than the reflection angle β2 of the regular reflection light R2 as compared with the case of the concave portion DP.

The width h of the slit-shaped irradiated area H
The setting method of will be described later.

The photometric device 3 is mainly composed of a known two-dimensional television camera. The photometric device 3 is provided with the end face C
11 images are captured two-dimensionally. In addition, this photometric device 3
Outputs an analog image signal representing the luminance of light of each pixel of the image in the window W corresponding to the diameter of the end face C11 as indicated by a virtual line in FIG.

The width w of the window W is set to, for example, at least five times the pixel width σ. The pixel is the 2
If the three-dimensional television camera is a model that uses a CCD element, the dimensional resolution is determined by conditions such as the CCD element of the camera, the focal length of the lens, and the distance between the television camera and the end face C11. This is the minimum constituent unit of the end face C11. That is, when the photometric device 3 is a two-dimensional CCD camera, an end face image is formed on a large number of two-dimensionally arrayed CCD elements and an image is formed from the output of each CCD element. The pixel and the minimum unit of the CCD element have a one-to-one correspondence. The width σ of the pixel is preferably １ ／ or less, more preferably 以下 or less, of the width d of the smallest recess DP among the recesses DP to be detected. If the pixel width σ is increased so that no pixel is completely included in the image of the concave portion DP, the detection accuracy decreases. FIG.
Then, the width d of the smallest concave portion DP for detecting the width σ of the pixel
1/4. In FIG. 6, the pixels are square, but may be rectangular.

The width w of the window W has a great influence on the processing speed of the inspection apparatus. In order to improve the processing speed, it is preferable to increase the width w of the window W. However, as will be described later, if the width w of the window W is too large, there is a problem that a part of the window W may not be uniformly irradiated when the inclination or distortion of the end face C11 is large. For this reason,
It is preferable that the width w of the window W be equal to or less than の of the width h of the irradiation area H to be described later.

The width of the window W may be changed according to the type of the hollow fiber module M.

The width h of the slit-shaped irradiated area H is determined by the window W when the reflected light received by the photometric device 3 is the regular reflected light R1 or R1 'shown in FIG.
Is set to a width which can be positioned in the light receiving range of the regular reflection light R1 or R1 '. In this embodiment, as shown in FIG. 6, a width (2d + 2σ) in which the width σ of each pixel is added to both sides of a width (2d) that is twice the width d of the minimum recess DP.
Is the width h of the irradiation area H. As described above, since the width d of the minimum concave portion DP is four times the pixel width σ, the width h of the irradiated region H is 10σ, that is, 1 of the pixel width σ.
This means that the width is set to 0 times.

The width h of the irradiated area H is preferably
It is preferable that the width is set to be 10 times the pixel width σ (in the case of FIG. 6) or more. According to the experiment, when the width h of the irradiation area H is smaller than 10 times the width σ of the pixel, when the end face C11 is obliquely cut or the end face C11 is distorted, such distortion or the like is within an allowable range. However, the regular reflection light R1 or R
1 'may shift. In such a case, although there is no concave portion DP to be detected, the luminance of the pixel in a portion where the regular reflection light R1 or R1 'is not irradiated due to a shift is approximately the same as that of the portion corresponding to the concave portion DP. A down problem occurs.

As described above, it is preferable that the width h of the irradiation area H be at least twice the width w of the window W. Thereby, the end face C1 of the hollow fiber module M
It is possible to prevent the window W from having a pixel portion which is not irradiated with the regular reflection light R1 or R1 'due to the inclination of the hollow fiber module 1 or the mounting error of the hollow fiber module M with respect to the support device 1.

When the slit-shaped irradiation area H is set as described above, if the end face C11 is an ideal end face, the window W is, as shown in FIG. It is set at the center of the light receiving area H1 of the regular reflection light R1 reflected by H. That is, Windu W
Is entirely illuminated by specularly reflected light R1.

When the end face C11 is cut at an angle, if the inclination is within an allowable range, the window W is reflected by the slit-shaped irradiated area H as shown in FIG. 5 (b). The position is set at a position H1 'deviated in the width direction of the light receiving area H1 of the regular reflection light R1', or set at a position inclined as shown in FIG. 5 (c). However, also in this case, since the inclination is within the allowable range, the entire area of the window W is illuminated by the regular reflection light R1 '.

Further, when the end face C11 is distorted, the light receiving area H1 'of the regular reflection light R1' reflected by the slit-shaped irradiated area H depends on the distortion manner, for example, as shown in FIG.
It has a curved shape as shown in (d). However, if the distortion is within an allowable range, the window W is set within the light receiving area H1 ', and the window W is
1 'illuminates the entire area.

If there is a concave portion DP due to a bubble mark or the like on the end face C11, the reflected light R reflected at the concave portion DP
2 is received at a position outside the window W.
Therefore, the concave portion DP is provided at a position corresponding to the window W.
Is present, the luminance at that position decreases.

The photometric device 3 measures the luminance levels of all the pixels in the window W, and gives the luminance levels to the detection signal forming device 4.

The detection signal forming device 4 includes an A / D converter 40
1, an image storage unit 402, a binarization processing unit 403, and a binarized image display unit 404.

The A / D converter 401 converts the analog image signal into a digital image signal and supplies the digital image signal to the image storage unit 402.

The image storage unit 402 includes an A / D conversion unit 401
Temporarily stores the digital image signal given by

The binarization processing section 403 reads out the digital image signal, that is, the digital image signal in the window W area shown in FIG. The digital image signal is binarized at a predetermined threshold value Sp. That is, the binarization processing unit 403 replaces an image signal whose level is higher than the threshold Sp with a white level, and replaces an image signal whose level is lower than the threshold Sp with a black level.

By the way, in the conventional method of detecting a concave portion using light, the intensity of the light irradiated by the light irradiating device is determined by measuring the light intensity of the reflected light by the light measuring luminance by the light measuring device 3. The level is set so as not to be partially saturated. As described above, when the slit light having the light intensity is irradiated by the conventional method, the brightness level in the window W is increased or decreased due to the unevenness due to the end portions of the large number of hollow fibers exposed on the end face C11 in FIG. As shown in FIG. Further, every time the hollow fiber module M to be inspected is replaced, the minute uneven shape of the end face C11 changes, and accordingly, the luminance level also moves up and down. For this reason, the luminance level difference between the concave portion DP and the normal portion is small, and when the image signal is binarized by the binarization processing section 403, a portion other than the concave portion DP to be detected is replaced with a black level. An error is likely to occur.

In order to prevent the above detection error,
In the present invention, the light intensity of the slit light irradiated by the light irradiation device 2 is set to be higher than the light intensity at the time when the luminance of each pixel starts to be saturated in some pixels. FIG. 7 (c) shows that the intensity of the slit light is first changed to the end face C1.
FIG. 7 (a) shows a luminance level at a position corresponding to FIG. 7 (a) when it is set to about twice the time when a part of 1 begins to saturate. As can be seen from FIG. 7 (c), the end face C11
Since the light diffusing property of the end of the yarn bundle B exposed to the light is strong, as the light intensity of the slit light is increased, the brightness of the end face C11 first starts to saturate from the central portion where the yarn bundle B is located. FIG. 7 (d) shows the light intensity distribution of FIG. 7 when the light intensity of the slit light is set to four times that at the time when a part of the end face C11 first starts to be saturated.
(a) shows the luminance level at the position corresponding to (a). In FIG. 7D, all the luminance levels other than the position corresponding to the concave portion DP have reached the saturation value. The number of times that the light intensity of the slit light is increased from the time when a part of the end face C11 first starts to be saturated depends on the molding accuracy of the end face C11 and the positional relationship between the end face C11 and the photometric device 3. If set to a value that exceeds
The luminance level of the portion corresponding to the concave portion DP to be detected approaches or reaches the saturation value.
When a CD camera is used, an abnormal phenomenon peculiar to the CCD camera, such as a smear phenomenon or a blooming phenomenon, may occur strongly. Therefore, in the present invention, the light intensity of the slit light is first partially saturated at the end face C11. 4 when I started
It is specified within double.

On the other hand, it is effective to increase the light intensity as much as possible for the following reason described with reference to FIG.

FIG. 8 shows a lamp voltage and a threshold value for a hollow fiber module M having a concave portion DP having a diameter of 0.8 mm in an almost ideal end face C11 and a hollow fiber module M having no defective concave portion DP but having large surface distortion. This is for explaining the change of the binarized image due to Sp. The characteristic curve K1 shown in FIG.
Indicates a change with respect to the lamp voltage of the limit threshold value Sp for detecting only the concave portion DP having a diameter of 0.8 mm alone in the binarization processing section 403. That is, the end face C1
If 1 is an ideal surface, an arbitrary threshold value Sp above the characteristic curve K1 can be adopted. On the other hand, the characteristic curve K
If a threshold value lower than 1 is adopted, a low-luminance portion other than the concave portion DP is erroneously detected. However, if the end face C11 is an end face with strong distortion, as the threshold value Sp is increased, a distortion portion other than the concave portion DP to be detected is detected, and a detection error starts to occur. A characteristic curve K2 in FIG. 8 shows a change in the threshold value Sp at which a detection error starts to occur with respect to the lamp voltage, particularly for a hollow fiber module having a strong distortion.
It can be seen that the detection error can be avoided by using the threshold Sp below the characteristic curve K2. That is, in order to detect the above-mentioned diameter 0.8 mm and the corresponding concave portion DP without error, it is preferable to use the region E (hatched portion in FIG. 8) sandwiched between the characteristic curves K1 and K2. As can be seen from FIG. 8, as the light intensity increases in the region E, the range of the usable threshold value Sp increases. Therefore, in order to widen the selection range of the threshold value Sp, the light intensity of the slit light described above is first set to the end face C11.
It can be said that it is preferable to set the light intensity within four times that at the time when a part of the saturation starts to be saturated and high light intensity. As the light intensity increases, the image diameter of the binarized concave portion DP decreases, so it is not preferable to set the highest light intensity,
Increasing the light intensity makes it easier to detect the concave portion DP as described above, and improves the detection accuracy.

The method of determining the binarization threshold Sp is not only a method of inputting and reading out a predetermined value (which can be changed depending on the type and lamp voltage) based on the data of FIG. Each of the generally known methods may be applied, such as calculating from the standard deviation or range of the luminance distribution in the window imaged in the above.

The binarized image display unit 404 is an image obtained from the image signal replaced with the white level and the black level by the binarization processing unit 403, that is, the window W in which only the concave portion DP is shown in black. Display an image.

The determination device 5 includes a storage unit 501 and an operation determination unit 502.

The operation judging section 502 includes the binarizing section 4
03, the pixel replaced with the black level is detected, and based on the number of pixels constituting the concave portion DP here, the positional relationship, and the like,
The feature amounts such as the size and area of the concave portion DP formed by these pixels are calculated.

The storage unit 501 receives a command from the operation determination unit 502 and selects a reference value relating to the feature value for each product number of the hollow fiber module M from a reference value relating to the feature value by a data input device such as a keyboard, which is not described. The reference value of the input product number is read and provided to the operation determination unit 502.
The reference value can be determined empirically.

The operation judging section 502 also compares the characteristic quantities such as the size and area of the concave portion DP with reference values output from the storage section 501 to judge the quality of the hollow fiber module M, and based on the judgment result. And a separating function for separating the hollow fiber module M removed from the support device 1 from the defective product. That is, when the comparison result satisfies the reference value> calculated feature value, it is determined to be non-defective, and when the reference value ≦ calculated feature value, the product is determined to be defective. Give 7

The display unit 6 includes a CRT display and a printer. The comparison and determination result output by the calculation determination unit 502 for each hollow fiber module, that is, the characteristic value such as the size and area of the concave portion DP is smaller than the reference value. The result of the comparison determination as to whether is larger or smaller is displayed.

The operation command section 7 receives a timing command from the operation determination section 502 and gives a command signal to the drive control section 108. As described above, upon receiving this command signal, the drive control unit 108 controls the drive motor 102 to drive the shaft center C0.
Is driven so as to rotate at a constant speed for a predetermined time or a predetermined angle around the center, and is stopped.

The operation command section 7 is provided with the detector 1
09 every time the rotation angle of the hollow fiber module M detected by the rotation of the hollow fiber module M reaches 180 degrees or more.
Is operated, the hollow fiber module M mounted on the support device 1 is removed, and a new hollow fiber module M is mounted on the support device 1.

The operation command section 7 is provided in the storage section 5.
In accordance with the information on the part number of the hollow fiber module M given in No. 01, the shaft center C0 of the hollow fiber module M of the part number coincides with the position corresponding to the window W (not shown) for the support device 1. Control the vertical movement mechanism.

The operation instructing unit 7 further performs the following based on the comparison and judgment result given by the operation and judgment unit 502.
If the result of the determination is that the hollow fiber module M mounted on the support device 1 is a non-defective product, the hollow fiber module transfer device 8 shown in FIG. A command to move M to the next process transfer unit 82 is issued. If the result of the determination is that the hollow fiber module M is defective, the hollow fiber module transfer device 8 is removed from the support device 1. A command is issued to move the hollow fiber module M to the defective hollow fiber module collection unit 86.

With the inspection apparatus configured as described above, a concave portion DP due to a trace of bubbles generated on the end surface of the resin agent layer C1 or C2 of the hollow fiber module M is detected, and the hollow fiber module having the concave portion DP is detected. It can be eliminated as defective.

With the above apparatus, the conditions A to C shown in Table 1 were used.
Inspection was performed to detect the concave portion DP in the above, and the following detection results were obtained.

[0070]

[Table 1] Condition A sets the width h of the irradiated region H / the width σ of the pixel to “7”. Under the condition A, the hollow fiber module M having a relatively good finish of the end face C11 has a diameter of 1 m.
m or less can be detected, but the end face C11
Is cut or the end face C11 is distorted, a detection error has occurred since the degree of the degree is large because part of the window W is not irradiated with the specularly reflected light. However, this detection error is due to a problem in setting the width h of the irradiation area H and the width w of the window W.

In order to suppress such a detection error, the width h of the irradiation area H and the width w of the window W are set as follows.
It is conceivable to spread while maintaining the relationship. However, in increasing the width h of the irradiation region H, it is necessary to note that the contrast of the image of the concave portion DP which is a defect image is likely to be deteriorated due to the strong light diffusion effect of the end face C11. On the other hand, the width w of the window W is, as described above,
In order to suppress the occurrence of inspection errors, the width h
Is set to be as large as possible in consideration of the processing speed for inspecting the entire end face C11.

The condition B is set in the irradiation area H in consideration of the above.
Width h / pixel width σ is set to 50. In the experimental apparatus, under this condition B, the concave portion DP having a diameter of 1 mm or less should be detected without any problem with respect to the inclined cut of the end face C11 or the displacement of the mounting position of the hollow fiber module M with respect to the support device 1.
Was detected, but a detection error occurred in some workpieces with strong surface distortion.

In condition C, the width h of the irradiation area H is increased and the width w of the window W is reduced as compared with the condition B. As a result, even in the hollow fiber module M having a strong surface distortion in which a detection error has occurred under the condition B, the concave portion can be surely formed.
DP could be detected. There are several types of hollow fiber modules M. Among them, in the case of the hollow fiber tube having a large wall thickness, each hollow fiber opening end protrudes clearly on the end face C11 to form a surface having irregularities, and the surface distortion of the end face C11 is generated. Tend to be even stronger. In such a hollow fiber module M, a detection error easily occurs at the protruding portion of the hollow fiber opening end or at a surface distortion portion around the protruding portion. Further, depending on the manufacturing conditions of the manufacturing line, the end face C11 may be extremely transparent (the surface is very smooth), and a detection error is likely to occur in the above-mentioned surface distortion portion.

FIG. 10 shows an embodiment applied to these samples of the end face C11.

FIG. 10 shows that light from a light source (not shown) is guided to a slit light irradiating section 202 by an optical fiber 203.
An inspection apparatus is shown in which the emitted light is changed to diffusive illumination by a light diffusion sheet or a light diffusion plate 205 to illuminate the end face C11, and light reflected from the end face is detected by the photometric device 3. In this case, between the end face C11 and the light diffusion plate 205,
Preferably, a light shielding plate or a mask 206 is provided as close as possible to the end face C11 to regulate the illumination range of the end face C11.

In the light diffusion sheet 205, the light irradiation section 202
Although the directivity of the slit light emitted from the light source is weakened, the light does not become completely diffused light with no directivity, so that the decrease in light intensity is relatively small. In addition, as another method of obtaining diffuse illumination, it is possible to use a light source with less directivity, such as using a fluorescent lamp having a large diameter, but it is possible to obtain a stronger light intensity and to adjust the light intensity. From the viewpoint, the method of FIG. 10 is preferable. End face C
Lighting plate 20 depending on the lighting method and lighting attachment position for 11
In some cases, it is not necessary to provide the light shielding plate 6, but it is preferable to provide a light shielding plate because the detection accuracy of the concave portion Dp is high.

In the embodiment shown in FIGS. 1 and 10, the incident angle α and the reflection angle β of the illumination light are 45 degrees, and the end face C11 is used.
The space occupied by the illumination systems 202 and 205 and the photometric device 3 in front of the device is relatively large, and it is necessary to reduce the size when the inspection device shown in the embodiment is installed in a limited space of the production line.

The inspection apparatus shown in FIG. 11 has been improved for this purpose.

That is, the light irradiation device 2 and the photometric device 3
Are provided with reflecting mirrors 207 and 208, respectively, to change the directions of the illumination light and the reflected light, thereby shortening the width L of the illumination / reflection system. The light irradiating unit 202 guides the halogen lamp light with an optical fiber light guide, arranges the light emitting ends linearly to form slit light, and converts the slit light into diffusive illumination light with the light diffusion sheet 205. In addition, a light shielding plate 206 is provided to restrict the end face C11 from being widely illuminated. The light shielding plate is not limited to the light shielding plate 206 as shown in FIG.
06 may be combined, or a mask (not shown) that covers the entire end face C11 with a cutout hole only in the illumination range may be used. In addition, the diffusion sheet 205 may not be provided, and the reflection reflector 207 may be replaced with a diffusion reflection plate that also functions as the diffusion sheet and the reflection mirror 207.

In the above embodiment, the photometric device 3 measures the luminance level of the entire end face C11 by driving the drive motor 102 to rotate the hollow fiber module M by a predetermined amount. The brightness level of the end face C11 may be measured by moving the hollow fiber module M upward or downward by the width h of the window W by a vertical movement mechanism that is not used.

Further, in the above-described embodiment, as a means for improving detection accuracy, for example, by increasing the amount of light measured for each pixel of the photometric device 3,
Although a method of increasing the intensity of the slit light is illustrated, the aperture of the camera lens attached to the photometric device 3 may be opened or replaced with a bright lens.
Further, a method using amplification and a saturation characteristic function by a signal amplifier included in the photometric device 3 may be used. However, a method of increasing the intensity of the slit light is more preferable because it is easy to use.

Further, in the above embodiment, a two-dimensional television camera capable of obtaining information on the luminance level of the pixels in the window W at one time is used as the photometric device 3, but in another inspection device according to the present invention, As the photometric device 3, a line sensor such as a one-dimensional CCD camera in which CCD elements are arranged one-dimensionally can be used.

In the inspection device shown in FIG. 1, only one end of the hollow fiber module M is inspected. However, the inspection apparatus for the hollow fiber module according to the invention is:
Needless to say, a device capable of inspecting both ends simultaneously is included.

Further, as the light irradiation device 2, a light irradiation device in which laser light is converted into slit light by an optical element may be used. However, even if the light intensity decreases, the light intensity can be periodically managed and adjusted by the lamp voltage.
It is more preferable to use a light irradiation device of the type used in the embodiment.

In this embodiment, an example in which a hollow fiber module is used for a dialyzer is shown. However, this is merely an example, and the inspection apparatus of the present invention also includes a water treatment module using a hollow fiber module, The present invention can be suitably applied to a foaming test of a water purifier module or the like.

[0086]

According to the inspection apparatus for a hollow fiber module of the present invention, a concave portion due to a bubble mark or the like generated on an end face of a resin material layer to be inspected is reliably detected even if the end face is inclined or distorted. can do.

The concave portion can be detected without performing complicated pre-processing such as signal filtering / differential processing by appropriately adjusting the intensity of photometric light. It can be obtained at low cost.

According to the inspection apparatus of the hollow fiber module of the second aspect, by separating the defective hollow fiber module having the concave portion, it is possible to eliminate the absurdity of processing such a defective hollow fiber module in a later process. be able to.

According to the inspection apparatus of the hollow fiber module of the third aspect, various surfaces such as a large unevenness due to the surface protrusion of the open end of the hollow fiber on the end face (C11) of the hollow fiber module and an extremely smooth end face are provided. In the hollow fiber module having the shape, the concave portion (Dp) is surely formed.
Inspection accuracy is high because

According to the inspection apparatus for the hollow fiber module of the fourth aspect, the light irradiation means and the photometry means can be miniaturized.
Installation and adjustment are easy at production sites where installation space is limited. According to the hollow fiber module inspection device of claim 5,
Since the determination device and the classification device are provided, the labor of the inspection operation can be further reduced in addition to the effect of the inspection device of the fourth aspect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an inspection apparatus for a hollow fiber module according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a support device.

FIG. 3 is a diagram showing an irradiation state of slit light on an end face.

FIG. 4 is a diagram illustrating a reflection state at an end face.

FIG. 5 is a diagram showing a relationship between a light receiving area of end face reflected light and a window.

FIG. 6 is a diagram showing a relationship between a concave portion and a pixel.

FIG. 7 is a diagram showing a measured luminance level corresponding to light intensity.

FIG. 8 is a graph showing a relationship between light intensity and a threshold value for binarization.

FIG. 9 is a schematic plan view showing a transfer mechanism of the hollow fiber module.

FIG. 10 is a view showing a light irradiation device and a photometric device of the inspection device according to the embodiment of the present invention.

FIG. 11 is a diagram showing a light irradiation device and a photometric device of the inspection device according to the embodiment of the present invention.

FIG. 12 is a sectional view of a hollow fiber module.

FIG. 13 is a diagram illustrating a process of manufacturing a hollow fiber module.

FIG. 14 is a diagram illustrating an example of an inspection method according to a known method.

FIG. 15 is a diagram showing a binarized image of an end face.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support device 2 ... Light irradiation device 3 ... Photometric device 4 ... Detection signal forming device 5 ... Discrimination device 6 ... Display part 7 ... Operation command part 102 ... Drive motor 103 ... Drive rollers 104 and 105 ... Module support roller 106 ... Follower Rollers 107: Belts 207, 208 ... Reflector mirrors 206, 209: Light shielding plate A: Dialysis container B: Thread bundle C11: End face M: Hollow fiber module

Continuation of front page (56) References JP-A-6-2811591 (JP, A) JP-A-6-273126 (JP, A) JP-A-7-5112 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) G01N 21/84-21/958 B01D 61/00-71/82 G01B 11/00-11/30

Claims (5)

(57) [Claims] An inspection apparatus for a hollow fiber module for detecting a defect generated on an end face of a resin material layer in a hollow fiber module having a resin material layer in which ends of a plurality of hollow fibers are solidified with a resin material. A supporting means for supporting the hollow fiber module; a light irradiating means for irradiating a slit-shaped irradiation area set on an end face of the resin material layer with slit light incident non-orthogonally on the end face; Moving means for relatively moving the position of the irradiation area with respect to the end face; and an image of the end face corresponding to the irradiation area at a position where the reflected light of the slit light reflected on the end face corresponding to the irradiation area is incident. For each pixel, and
A photometric unit that outputs the light intensity of the image in the window set in the image of the irradiated area; and a binarization unit that binarizes the light intensity of each pixel output by the photometric unit with a predetermined threshold. And a width of a region to be illuminated by the slit light irradiated by the light irradiating unit is 10 to 150 times the size of a pixel, and is measured by the photometric unit. An inspection apparatus for a hollow fiber module, wherein an intensity of light measured for each pixel is set in a range of 1 to 4 times the intensity at the time when saturation starts in at least some of the pixels. A determining means for determining whether or not the hollow fiber module is defective based on a binarized signal from the binarizing processing means; and a defective hollow fiber module based on a result of the determination by the determining means. And a separation means for separating the hollow fiber module. 3. The inspection apparatus for a hollow fiber module according to claim 1, wherein said light irradiation means is diffusive illumination, and a light shielding plate is provided on an end face of said resin agent layer. 4. The inspection apparatus for a hollow fiber module according to claim 1, further comprising a reflector for changing directions of illumination light and reflected light. 5. The inspection apparatus for a hollow fiber module according to claim 4, comprising the determination means and the classification means according to claim 2.