JP2009133718A - Flaw detection method and flaw detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flaw detection method which enables the stable and precise detection of the flaw on a strip of resin film, and a flaw detector. <P>SOLUTION: In the flaw detection method for detecting the flaw on the continuously fed strip of resin film by a detection means, the detection means includes an illumination means, a first imaging means for imaging the surface side of the strip of resin film, a second imaging means for imaging the back of the strip of resin film and a grasping means for grasping both ends of the strip of resin film. The strip of resin film is grasped at least in a flaw detecting inspection region in a state that tension is applied to the strip of resin film in its width direction with respect to the feed direction of the strip of resin film at least by the grasping means. The grasping means is moved at least in the inspection region in connection with the speed in the feed direction of the strip of resin film and the flaw on the strip of resin film is continuously detected by the detection means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a defect detection method for a strip-shaped resin film. More specifically, the present invention relates to a defect detection method and a defect detection apparatus for continuously detecting defects in a continuously running belt-shaped resin film.

  In recent years, foreign matter and scratches on the film surface have been required to have the same quality as glass. Glass is an important material for substrates such as FPDs and LCDs, and minute foreign matter and scratches on the glass surface can cause quality degradation in subsequent processes. Therefore, detection and removal in advance reduces process loss and guarantees quality. .

  As described in Japanese Patent Application Laid-Open No. 2005-274173, the inspection of minute foreign matter on the glass surface has a limited sheet-like laser beam and the field of view of the camera is narrowed in order to improve the detection power. When the area becomes wide, the inspection is performed by moving one camera with a narrow field of view or by arranging a plurality of cameras with a narrow field of view.

  Glasses having excellent transparency and low birefringence have long been used for substrates such as FPDs and LCDs. However, because it is inferior in formability and difficult to reduce in weight, recently, a film that is a polymer material that is excellent in formability, light weight, flexible characteristics, and easy to control properties is increasing as a substitute for glass. It is used for disc substrates, lenses, cables, various display films, etc. according to the characteristics. Since such a film also needs to be inspected and removed in advance for fine foreign matters and scratches on the surface like glass, inspection of these defects has become important. However, since the film has very poor flatness compared to glass, it cannot be inspected in the same way as glass. Therefore, a defect inspection method on the film has been studied.

  For example, a first illumination unit that irradiates a pattern formed on a film-like strip-shaped workpiece from one surface side, a second illumination unit that irradiates from the other surface side, and one or the other surface of the strip-shaped workpiece. There is known a pattern inspection apparatus that is arranged on the side and includes an imaging unit that images a strip-shaped workpiece and a workpiece holding unit that applies tension in the width direction of the strip-shaped workpiece (see, for example, Patent Document 1). However, the inspection method using the pattern inspection apparatus of Patent Document 1 has the following concerns. 1. Since an image is taken for each pattern formed on the film-like strip-shaped workpiece, it is not suitable for inspection of defects occurring at unspecified positions on the film-shaped strip-shaped workpiece. 2. Since inspection is not performed continuously, it takes inspection man-hours. 3. Since the tension applied in the width direction of the belt-like workpiece is only on one side, it may be difficult to maintain flatness, and there is a concern that defects may be inspected. 4). If the meandering is large, there is a risk that the flatness will not be maintained by hitting the guide. 5). Inspection of reflected light or transmitted light is performed separately, and inspection cannot be performed at the same time.

  Foreign matter present on the surface of the sheet-like member is emitted by emitting light having an optical axis parallel to the surface of the sheet-like member along the surface of the sheet-like member, thereby suppressing reflection on the surface of the sheet-like member. There is known a foreign matter inspection method for detecting (see, for example, Patent Document 2).

  However, the foreign matter inspection method of Patent Document 2 has the following concerns. 1. If the member to be inspected has wrinkles, the wrinkles may be detected as foreign matter, so that it takes time to analyze the data after the inspection. 2. The inspection is affected by the flatness of the member to be inspected, and a stable inspection result cannot be obtained. In particular, in the case of a continuous sheet, there is a concern about the reliability of the inspection result. 3. Since a wide visual field is inspected, the inspection resolution is large, and it may be difficult to detect micron-sized defects.

Under these circumstances, it is desired to develop a defect detection method and a defect detection apparatus that can detect defects on the belt-shaped resin film stably and accurately.
JP 2004-28597 A JP 2007-139678 A

  This invention is made | formed in view of the said situation, The objective is to provide the defect detection method and defect detection apparatus which can detect the defect on a strip | belt-shaped resin film stably and accurately. .

  The above object of the present invention has been achieved by the following constitution.

  1. In the defect detection method for detecting defects on the belt-shaped resin film conveyed continuously by the detection means, the detection means illuminates the surface side of the belt-shaped resin film, and the surface side of the belt-shaped resin film. First imaging means for imaging, second imaging means for imaging the back side of the strip-shaped resin film, and gripping means for gripping both ends of the strip-shaped resin film, wherein the strip-shaped resin film has at least the defect In the inspection region to be detected, at least the gripping means is gripped in a state where tension is applied in the width direction with respect to the transport direction of the strip-shaped resin film, and the gripping means is at least in the inspection region and the strip-shaped resin film A defect detection method, wherein the defect is continuously detected by the detection means by moving in conjunction with the speed in the conveyance direction.

  2. 2. The tensile force applied in the width direction with respect to the transport direction of the belt-shaped resin film has a difference of 20% or less between the left end and the right end of the strip-shaped resin film. Defect detection method.

  3. 3. The defect detection method according to 1 or 2 above, wherein the tension is 1% to 100% with respect to the transport tension of the belt-shaped resin film.

  4). 4. The defect detection method according to any one of 1 to 3, wherein the amount of bending of the belt-shaped resin film in the inspection region is 200 μm or less.

  5). 6. The defect detection method according to any one of 1 to 5, wherein a size of the defect is 0.1 μm to 5.0 μm.

  6). A defect detection device for detecting a defect on a belt-shaped resin film that is continuously conveyed, the illumination means for illuminating the surface of the belt-shaped resin film, and a first imaging that images a defect on the surface of the belt-shaped resin film Means, second imaging means for imaging defects on the back surface of the belt-shaped resin film, and gripping means for applying tension in the width direction of the belt-shaped resin film in conjunction with the transport direction speed of the belt-shaped resin film. Feature defect detection device.

  The following configurations are further preferable.

  7. 5. The defect detection method according to any one of 1 to 4, wherein the belt-like resin film has at least one layer having a thickness of 0.05 μm to 2.00 μm.

  It is possible to provide a defect detection method and a defect detection device that can detect defects on the belt-shaped resin film stably and with high accuracy, improve work efficiency of the inspection process, and use a belt-shaped resin film after the inspection. Product quality stability can be improved.

  The embodiment of the present invention will be described with reference to FIGS. 1 to 4, but the present invention is not limited to this.

  FIG. 1 is a schematic diagram showing a method for detecting defects on a belt-shaped resin film. Fig.1 (a) is a schematic diagram which shows the detection method of the defect on the strip | belt-shaped resin film using a defect detection apparatus. FIG. 1B is an enlarged schematic view of a portion indicated by P in FIG. FIG.1 (c) is a schematic diagram which shows the detection method of the foreign material adhering to the surface and back surface of a transparent strip | belt-shaped resin film with the detection means shown in FIG.1 (b).

  In the figure, reference numeral 1 denotes a defect detection apparatus. The defect detection apparatus 1 includes a supply unit 2, a detection unit 3, and a winding unit 4. In the supply unit 2, a roll-shaped strip-shaped resin film wound around the winding core is fed out by a feeding device (not shown), and the strip-shaped resin film 5 is supplied to the inspection unit in which the detection means 3 is disposed. Yes. The belt-shaped resin film 502 may be transparent or opaque, and can be selected as necessary. The feeding device (not shown) has a brake function for controlling the feeding amount in order to apply tension to the fed belt-shaped resin film 5.

  The detection unit 3 includes an illumination unit 301 that irradiates the surface 501a of the strip-shaped resin film 5, a first imaging unit 302 that images the surface, a second imaging unit 303 that captures the back surface 501b of the strip-shaped resin film 5, and a strip-shaped resin. First gripping means 304a that grips the film 5 and grips both ends of the strip-shaped resin film 5 in order to apply tension in a direction perpendicular to the transport direction of the strip-shaped resin film 5 (arrow direction in the figure) (see FIG. 3). ) And second gripping means 304b (see FIG. 3). The portion where the inspection detecting means 3 is disposed serves as an inspection portion that can continuously detect the presence or absence of defects in the belt-shaped resin film 5 conveyed from the supply portion 2.

  When the strip-shaped resin film 5 uses a transparent resin film, the first imaging unit 302 images the surface 501a of the strip-shaped resin film 5, and the second imaging unit 303 captures the surface of the strip-shaped resin film 5 on the back surface 501b side. It is possible to detect defects on the front surface 501a and the back surface 501b of the belt-shaped resin film 5 at the same time. In addition, when the strip-shaped resin film 5 uses an opaque resin film, it is possible to detect defects by imaging only the surface 501a of the strip-shaped resin film 5 with the first imaging means 302.

  In the winding unit 4, the strip-shaped resin film 5 that has been inspected is wound around the winding core and collected as a roll. The tension in the transport direction can be controlled by the winding speed of the strip-shaped resin film 5 at the winding section 4 and the amount of feeding of the strip-shaped resin film 5 at the supply section 2.

  θ1 represents the illumination angle of illumination from the illumination means 301 to the surface 501a of the belt-shaped resin film 5. The irradiation angle θ1 is preferably 5 ° to 60 ° in consideration of the surface reflection amount of the inspection, contact with the inspection object, and the like.

  θ2 is the regular reflection of the first imaging means 302 and shows the same angle as θ1. The angle θ2 is preferably 5 ° to 60 ° in consideration of the surface reflection amount of the inspection, contact with the inspection object, and the like.

  θ3 represents the light receiving angle of the transmission optical system of the second imaging means 303. The angle [theta] 3 is preferably 5 [deg.] To 135 [deg.] In consideration of the amount of light scattered by a minute foreign substance in the transmission optical system, contact with the inspection object, and the like.

  E shows the distance from the light source of the illumination means 301 to the surface 501a of the strip-shaped resin film 5. The distance E is preferably 30 mm to 150 mm in consideration of contact with the object to be inspected, uniform illumination to the inspection area, illumination intensity of the inspection area illumination, and the like.

  F indicates the distance from the condensing optical system of the first imaging means 302 to the surface 501a of the belt-shaped resin film 5. The distance F is preferably 30 mm to 200 mm in consideration of the inspection area, inspection resolution, and the like.

  G shows the distance from the condensing optical system of the 2nd imaging means 303 to the back surface 501b of the functional film 5. FIG. The distance G is preferably 30 mm to 200 mm in consideration of the inspection area, inspection resolution, and the like. The thickness of the belt-shaped resin film 5 is preferably 90 μm to 200 μm in consideration of tensile strength, transparency, and the like. In the present invention, the defect means adhesion of foreign matter, scratches, dents, and the like, and the size is 0.1 μm to 5.0 μm.

  There is no limitation in particular as the strip | belt-shaped resin film 5, For example, the multilayer resin film which laminated | stacked the single layer transparent and opaque resin film and at least 1 layer is mentioned. The thickness of at least one layer to be laminated is preferably 0.05 μm to 2 μm.

  In the case of a multilayer resin film, it is possible to inspect the defect by incorporating the detection means 3 on-line in the process of laminating the layer on the belt-shaped resin film 502.

  FIG. 2 is a schematic diagram showing a method for detecting foreign matter adhering to the front and back surfaces of a transparent belt-shaped resin film by the detecting means shown in FIG. FIG. 2A is a schematic diagram showing a foreign matter detection method of a transparent belt-shaped resin film in which large and small foreign matters are attached only to the surface by the detection means shown in FIG. FIG. 2B is a schematic diagram showing a method for detecting foreign matter on a transparent belt-shaped resin film in which a large foreign matter is attached to the front surface and a small foreign matter is attached to the back surface by the detection means shown in FIG. FIG. 2C is a schematic diagram showing a foreign matter detection method for a transparent belt-shaped resin film in which large foreign matter adheres to the front and back surfaces by the detection means shown in FIG. For the sake of explanation in this drawing, it is assumed that the size of a large foreign object is 10 μm and the size of a small foreign object is 1 μm.

  The detection method of the foreign material adhering to the surface of a transparent strip | belt-shaped resin film with the detection means shown in FIG.1 (b) with the schematic diagram of Fig.2 (a) is demonstrated. In the figure, J indicates a foreign matter having a size of 10 μm attached to the surface of the transparent belt-shaped resin film 5. K represents a foreign matter having a size of 1 μm attached to the surface of the transparent belt-shaped resin film 5.

  On the surface, the light S emitted from the illumination unit 301 strikes the foreign matter K attached to the surface. The light S impinging on the foreign matter K is reflected and becomes scattered light, which is picked up and detected by the first image pickup means 302. Further, the light S emitted from the illumination unit 301 strikes the foreign matter J adhering to the surface. The light S that hits the foreign object J is reflected and becomes scattered light, which is picked up and detected by the first image pickup means 302.

  Since the foreign matter J appears to be a shadow on the back surface, the second imaging means 303 captures and detects the foreign matter attached (defect). Since the foreign matter K is small, the second image pickup unit 303 cannot detect it because the light is diffracted and does not become a shadow on the back surface.

  In the analysis after the inspection is completed, the position information of the foreign matter (defect) of the imaging result of the first imaging unit 302, the size information of the foreign matter (defect), and the foreign matter (defect) of the imaging result of the second imaging unit 303 are used. Foreign matter attached to the surface of the belt-like resin film 5 with high accuracy by comparing the position information with the information on the size of the foreign matter (defect) and separating the foreign matter (defect) from the foreign matter (defect) on the back surface. (Defects) can be detected.

  A method for detecting a foreign substance having a size of 10 μm attached to the surface of a transparent belt-like resin film by the detection means shown in FIG. 1B will be described with reference to the schematic diagram of FIG. In the figure, J indicates foreign matter adhering to the surface of the transparent belt-shaped resin film 5. L indicates a foreign matter having a size of 1 μm attached to the back surface of the transparent belt-shaped resin film 5.

  On the surface, the light S emitted from the illuminating means 301 strikes the foreign matter J adhering to the surface. The light S that hits the foreign object J is reflected and becomes scattered light, which is picked up and detected by the first image pickup means 302. The light S emitted from the illumination means 301 passes through the transparent belt-shaped resin film 5 and hits the foreign matter L having a size of 1 μm attached to the back surface. The light S that hits the foreign matter L becomes scattered light and again passes through the belt-shaped resin film 5 but is not detected by the first imaging means 302 because it is not a light amount that can be detected as the light S ′.

  On the back side, the light S that has passed through the transparent belt-shaped resin film 5 and impinged on the foreign matter L becomes the diffracted light S ′ ″, so that it is not picked up by the second image pickup means 303. The image is detected and detected as a foreign object by the means 303.

  In the analysis after the inspection is completed, the position information of the foreign matter (defect) of the imaging result of the first imaging unit 302, the size information of the foreign matter (defect), and the foreign matter (defect) of the imaging result of the second imaging unit 303 are used. Foreign matter attached to the surface of the belt-like resin film 5 with high accuracy by comparing the position information with the information on the size of the foreign matter (defect) and separating the foreign matter (defect) from the foreign matter (defect) on the back surface. (Defects) can be detected.

  The detection method of the foreign material adhering to the surface of a transparent strip | belt-shaped resin film with the detection means shown in FIG.1 (b) with the schematic diagram of FIG.2 (c) is demonstrated. In the figure, J indicates a foreign matter having a size of 10 μm attached to the surface of the belt-shaped resin film 5. M represents a foreign matter having a size of 10 μm attached to the back surface of the belt-shaped resin film 5.

  On the front surface, the light S emitted from the illuminating means 301 passes through the transparent belt-shaped resin film 5 and hits the foreign matter M adhering to the back surface. The light S that hits the foreign matter M becomes scattered light, and part of the light S again passes through the belt-shaped resin film 5 and emerges on the surface as light S ′, and is imaged by the first imaging means 302. However, since the light S ′ is a part of the scattered light, the amount of light is less than that of the light S. For this reason, both the position information and the size information are imaged as the foreign matter M ′ by the first imaging means 302 smaller than the actual size of the foreign matter M. Further, the light S that has hit the foreign matter J adhering to the surface is reflected and picked up as light S ″ by the first image pickup means 302. At this time, the light S ″ does not pass through the transparent belt-shaped resin film 5, and thus the amount of light. Since there is no loss, the first imaging unit 302 accurately captures the size of the foreign matter J together with the position information. In other words, the first imaging unit 302 captures an image in a state where there are two foreign matters, a foreign matter J and a foreign matter M ′ (not shown).

  On the back side, the second imaging means 303 images the foreign matter M and the shadow of the foreign matter J adhering to the front surface together with position information and size information.

  In the analysis after the inspection is completed, the position information of the foreign matter (defect) of the imaging result of the first imaging unit 302, the size information of the foreign matter (defect), and the foreign matter (defect) of the imaging result of the second imaging unit 303 are used. Foreign matter attached to the surface of the belt-like resin film 5 with high accuracy by comparing the position information with the information on the size of the foreign matter (defect) and separating the foreign matter (defect) from the foreign matter (defect) on the back surface. (Defects) can be detected.

  As shown in FIGS. 2 (a) to 2 (b), in the detection method of the present invention, even if foreign matter (defect) exists on the front and back of the transparent belt-shaped resin film, the front and back are separated with high accuracy. ) Can be detected.

  FIG. 3 is an enlarged schematic plan view of a portion indicated by P in FIG. FIG. 3A is an enlarged schematic plan view of the portion indicated by P in FIG. 1 on the first imaging means side. FIG. 3B is an enlarged schematic plan view of the portion indicated by P in FIG. 1 on the second imaging means side.

  In the figure, reference numeral 501a denotes the surface of the belt-shaped resin film 5. Reference numeral 502a denotes an end portion on the left side with respect to the conveyance direction of the belt-shaped resin film 5 (the arrow direction in the figure). 502b shows the edge part of the right side with respect to the conveyance direction (arrow direction in a figure) of the strip | belt-shaped resin film 5. FIG.

  Reference numeral 304a denotes a first gripping means for gripping the left end portion 502a with respect to the transport direction of the belt-shaped resin film 5 (the arrow direction in the figure). The first gripping means 304a has a plurality of gripping devices 304a1, each connected by a flexible belt 304a2, and rotated in the horizontal direction (in the direction of the arrow in the figure) in conjunction with the transport speed of the belt-shaped resin film 5. The operation of holding the end 502a of the belt-shaped resin film 5 in the foreign substance inspection area and releasing the holding outside the foreign substance inspection area is continuously repeated. The gripping member 304a1 grips the end portion 502a of the strip-shaped resin film 5, and then interlocks with the transport of the strip-shaped resin film 5, and in the width direction with respect to the transport direction of the strip-shaped resin film 5 in the foreign matter inspection area of the strip-shaped resin film 5. The tension is applied to.

  The second gripping means 304b also has a plurality of gripping members 304b1, and has the same mechanism as the first gripping means 304a. That is, the gripping member 304b1 grips the end portion 502b of the strip-shaped resin film 5, and then interlocks with the transport of the strip-shaped resin film 5, and has a width with respect to the transport direction of the strip-shaped resin film 5 in the foreign matter inspection region of the strip-shaped resin film 5. It is designed to apply tension in the direction.

  The end portion 502a is gripped by the first gripping means 304a, the end portion 502b is gripped by the second gripping means 304b, and the gripping means 304 is operated in conjunction with the conveyance speed of the strip-shaped resin film 5, thereby causing the strip-shaped resin film 5 in the foreign matter inspection region. A tension is applied in the width direction with respect to the conveying direction of the sheet, and a certain amount of bending can be maintained.

  In this figure, the upstream side from the first imaging means 302 (second imaging means 303 (see FIG. 1)) is the standby / preparation area, and the first imaging means 302 (second imaging means) with respect to the conveying direction of the belt-shaped resin film 5. 303 (see FIG. 1)) and the illumination means 301 are referred to as an inspection area, and the downstream side from the illumination means 301 is referred to as an inspection end area.

  In the present invention, interlocking means that when the transport speed of the belt-shaped resin film 5 is V1 m / min, the moving speed of the first gripping means 304a is V2 m / min, and the moving speed of the second gripping means 304b is V3 m / min, V1 = Indicates that V2 = V3.

  The end portion 502a is gripped by the first gripping means 304a, the end portion 502b is gripped by the second gripping means 304b, and the gripping means 304 is operated in conjunction with the transport speed of the strip-shaped resin film 5, whereby the strip-shaped resin film 5 is Tension is applied in the width direction with respect to the transport direction, and a certain amount of bending can be maintained. In the present invention, the width direction means that tension is applied in the range of an angle of 84 ° to 96 ° in the width direction with respect to the central axis in the conveying direction of the belt-shaped resin film 5.

  The amount of bending refers to the distance that deviates to the maximum with respect to the line connecting the grip points at both ends of the belt-shaped resin film 5, and the shorter the distance, the better the flatness. The distance deviating from the line connecting the grip points at both ends of the belt-shaped resin film 5 is preferably 200 μm or less in consideration of the uniformity of illumination, the amount of illumination light, the focal length of the imaging unit, and the lower limit of 200 μm or less is 0 μm. It is preferable that The amount of deflection indicates a value measured using a digital theodolite manufactured by Topcon Corporation.

  The conveyance speed of the belt-shaped resin film 5 is preferably 1 m / min to 10 m / min in consideration of defect detection accuracy, inspection efficiency, and the like.

  The tension applied in the direction perpendicular to the transport direction of the belt-shaped resin film 5 is preferably 1% to 100% with respect to the transport tension of the belt-shaped resin film 5 in consideration of the slippage and meandering of the belt-shaped resin film.

  The difference between the tension applied in the direction perpendicular to the transport direction of the belt-shaped resin film 5 by the first gripping means 304a and the tension applied in the direction perpendicular to the transport direction of the belt-shaped resin film 5 by the second gripping means 304b is In consideration of slippage and meandering of the belt-shaped resin film, it is preferably 0% to 20%.

  Reference numerals 302 a to 302 e denote a plurality of first imaging means constituting the first imaging means 302. The number of the plurality of first imaging means can be appropriately changed according to the width of the belt-shaped resin film 5 and the photographing area range of the first imaging means.

  Reference numerals 303 a to 303 e denote a plurality of second imaging means constituting the second imaging means 303. The number of the plurality of second image pickup means can be appropriately changed according to the width of the belt-shaped resin film 5 and the photographing region range of the individual second image pickup means.

  The imaging region ranges of the first imaging unit 302 and the second imaging unit 303 preferably have a relationship of 90% to 100% with respect to the moving amount (conveying speed) of the belt-shaped resin film 5.

  In this figure, with respect to the conveying direction of the belt-shaped resin film 5, the upstream side from the first image pickup means 302 (second image pickup means 303) is a standby / preparation area, the first image pickup means 302 (second image pickup means 303) and the illumination means. An area between the area 301 and the area downstream of the illumination means 301 is referred to as an inspection end area.

  FIG. 4 is an enlarged schematic view of the gripping device shown in FIG. FIG. 4A is an enlarged schematic perspective view of the gripping device of the first gripping means shown in FIG. FIG. 4B is a schematic enlarged cross-sectional view along AA ′ of FIG.

  In the figure, 304a1 indicates a gripping device. The gripping device 304a1 includes a base 304a12, an L-shaped angle 304a13, a gripping plate 304a14, a ball screw 304a15, a motor 304a16, a spring member 304a17, a tension meter 304a18, and a guide rail 304a19.

  The L-shaped angle 304a13 can move (in the direction of arrow A in the drawing) along the guide rail 304a19 disposed on the pedestal 304a12. 6a indicates a gripping member disposed on the L-shaped angle 304a13, and 6b indicates a gripping member disposed on the gripping plate 304a14 at a position facing the gripping member 6a. It is possible to grip the end of the belt-shaped resin film 5 (see FIG. 3) between the gripping member 6a and the gripping member 6b.

  7a indicates an electromagnet disposed on the L-shaped angle 304a13, and 7b indicates an electromagnet disposed on the holding plate 304a14 at a position facing the electromagnet 7a. The electromagnet 7a and the electromagnet 7b have independent circuits (not shown) so that a repulsive or attractive current flows. When the sensor 9 attached to the grip plate 304a14 detects that the end of the belt-shaped resin film 5 (see FIG. 3) enters between the grip member 6a and the grip member 6b, the electromagnet 7a and the electromagnet 7b are attracted to each other. The electric current which works flows, the space | interval of the holding member 6a and the holding member 6b is closed, and the edge part of the strip | belt-shaped resin film 5 (refer FIG. 3) is hold | gripped. The sensor 9 is not particularly limited, and examples thereof include a small CCD camera or a photoelectric sensor. By applying a current that causes repulsive force to the electromagnet 7a and the electromagnet 7b, the gap between the gripping member 6a and the gripping member 6b is increased and the gripping of the end of the belt-shaped resin film 5 (see FIG. 3) is released. Yes.

  The gripping plate 304a14 can move (in the direction of arrow B in the figure) along the guide member 8 disposed on the L-shaped angle 304a13 by the action of the electromagnets 7a and 7b.

  One side of the ball screw 304a15 is fixed to the L-shaped angle 304a13, and the other side is arranged to move in the direction of arrow C in the drawing as the motor 304a16 rotates. The amount of movement can be determined by the amount of rotation of the motor 304a16. The motor 304a16 is not particularly limited, and examples thereof include a stepping motor.

  One side of the spring 304a17 is fixed to the L-shaped angle 304a13, and the other side is fixed to the tension meter 304a18. The amount of rotation of the motor 304a16 is determined by information from the tension meter 304a18, and tension is applied in a direction perpendicular to the conveying direction of the belt-shaped resin film 5 (see FIG. 3).

  FIG. 5 is a schematic flow diagram showing from the start of gripping of the end portion of the belt-shaped resin film to the release of grip using the gripping device shown in FIG.

  The process from the start of gripping of the end portion 502a of the belt-shaped resin film 5 by the gripping device 304a1 from the standby / preparation area to the inspection end area will be described with reference to the flowchart.

  Step 1 shows a state in which the gripping device 304a1 is in the standby / preparation area upstream from the first imaging unit 302 (second imaging unit 303) (see FIG. 3). At this stage, the amount of electricity that causes a repulsive force flows between the electromagnet 7a and the electromagnet 7b, and the gripping plate 304a14 is placed upward along the guide member 8 (the interval between the gripping member 6a and the gripping member 6b is It ’s open.)

  In Step 2, as the belt to which the gripping device 304a1 is attached rotates and the gripping device 304a1 approaches the end of the strip-shaped resin film, the motor 304a16 is driven to reach a position where the end of the strip-shaped resin film can be gripped. A state where the first imaging unit 302 (second imaging unit 303) (see FIG. 3) that has moved the L-shaped angle 304a13 is in the standby / preparation area on the upstream side is shown. At this stage, the gap between the gripping member 6a and the gripping member 6b is open.

  Step 3 indicates the initial state of the inspection area. As the belt to which the gripping device 304a1 is attached rotates, it is confirmed by the sensor 9 that the end of the belt-shaped resin film has entered between the gripping member 6a and the gripping member 6b of the gripping device 304a1. In accordance with the information, an electric current is applied to the electromagnet 7a and the electromagnet 7b, and the gap between the gripping member 6a and the gripping member 6b is closed and the end of the belt-shaped resin film 5 is gripped. The gripping device 304a1 moves in conjunction with the transport speed of the belt-shaped resin film 5.

  Step 4 indicates a state in which inspection is performed in the inspection region. The state where the motor 304a16 is driven in the state of Step 3 and the L-shaped angle 304a13 is moved is shown. By moving, a tension of 1% to 100% is applied in a direction perpendicular to the tension in the transport direction of the belt-shaped resin film 5. As for the tension to be applied, the drive of the motor 304a16 is controlled according to the information from the tension meter, and the movement amount of the L-shaped angle 304a13 is controlled.

  Step 5 shows an initial state of the inspection end region on the downstream side from the illumination unit 301 (see FIG. 3). When the belt to which the gripping device 304a1 is attached rotates and the gripping device 304a1 enters the downstream inspection end region from the illumination means 301 (see FIG. 2), a current that causes an attractive force flows in the electromagnet 7a and the electromagnet 7b. Then, the gap between the gripping member 6a and the gripping member 6b is opened, and the gripping of the end portion of the belt-shaped resin film 5 is solved. In addition, the timing at which the current that causes the attractive force flows in the electromagnet 7a and the electromagnet 7b is calculated in advance from the conveyance speed of the belt-shaped resin film 5 and the distance of the inspection area, and is incorporated in the circuit of the electromagnet 7a and the electromagnet 7b, so Switching between current and attractive current is controlled.

  Step 6 shows the state of the inspection end region on the downstream side from the illumination unit 301 (see FIG. 3). When the gripping device 304a1 enters the downstream inspection end region from the illumination means 301 (see FIG. 3) by the rotation of the belt to which the gripping device 304a1 is attached, the motor 304a16 is driven in the state of Step5, and Step1 and It becomes the same state. Thereafter, by repeating Step 1 to Step 6 continuously, the gripping device is operated in conjunction with the transport speed of the speed belt-shaped resin film 5 in a state where tension is applied in a direction perpendicular to the transport direction of the belt-shaped resin film 5 by the gripping device. By moving it, it is possible to continuously inspect minute foreign matters.

  The following effect was acquired by detecting the defect of a strip | belt-shaped resin film with the defect detection method shown in FIGS.

  1. Since measurement can be continuously performed in a state where tension is applied in a direction perpendicular to the conveyance direction in conjunction with the conveyance direction of the belt-shaped resin film, it is possible to detect defects with high stability and accuracy.

  2. When the belt-shaped resin film is transparent, defects existing on the front surface and the back surface can be detected separately, so that it is possible to detect defects with high stability and accuracy.

  3. With continuous measurement, production efficiency can be improved.

  4). The quality stability of products using the strip-shaped resin film after inspection can be improved.

  5). Inspection of only the surface can be performed continuously and with high resolution, and production efficiency can be improved.

  6). Since both the front and back surfaces can be inspected at the same time, only defects can be inspected with high accuracy, thereby improving production efficiency.

As a strip-shaped resin film according to the present invention, a TiO ₂ film having an optical function or an antiglare film is often used on PET. These optically utilized photocatalysts or antireflections are desired to be free from minute omissions. Next, an example of a strip-shaped resin film targeted by the defect detection method of the present invention will be described.

(Resin film)
The resin film constituting the fine ITO film or the antiglare film is not particularly limited. For example, ethylene tetrafluoroethyl copolymer (ETFE), high density polyethylene (HDPE), expanded polypropylene (OPP), polystyrene (PS) ), Polymethyl methacrylate (PMMA), stretched nylon (ONy), polyethylene terephthalate (PET), polycarbonate (PC), polyimide, polyether styrene (PES), polyethylene naphthalate film (PEN), etc. The thermoplastic resin film material currently used can be used. As these thermoplastic resin films, a multilayer film produced by coextrusion with a different film, a multilayer film produced by bonding with different stretching angles, etc. can be used as required. Further, it is naturally possible to combine the density and molecular weight distribution of the film used to obtain the required physical properties.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
(Preparation of transparent belt-shaped resin film)
Using a transparent PET-based Teijin Tetron film (Teijin-DuPont film) with a thickness of 100 μm, length of 200 m, and width of 1100 mm, the foreign material whose size is changed as shown in Table 1 is used as a pseudo defect in the transport direction. 100 pieces are adhered per 1 m length of the belt-shaped resin film No. 1-1 to 1-4. As the foreign material, standard particles of Moritex Corporation were used.

(Defect detection test)
The prepared belt-shaped resin film No. When the inspection is performed by using the first gripping means and the second gripping means shown in FIG. 2 in the defect detection method shown in FIG. On the other hand, by changing the moving speed of the gripping means as shown in Table 2, the detection test No. The results obtained as 101 to 123 are shown in Table 2. The detection test No. Reference numeral 123 denotes a comparative detection test performed without using the gripping means. Conditions for detecting defects are shown below. Prior to detection, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The moving speeds of the first holding means and the second holding means of the holding means are the same. The conveyance speed of the belt-shaped resin film was 2 m / min. The belt-shaped resin film had a conveyance tension of 200 N (the conveyance tension is a value measured using an imada tensiometer (digital force gauge)). The angle for applying tension in the width direction with respect to the transport direction of the belt-shaped resin film by the first gripping means and the second gripping means was 90 °. A linear light source (fluorescent lamp) that illuminates the width direction of the belt-shaped resin film was used as the illumination means, and irradiation was performed under the conditions of a distance from the surface of the belt-shaped resin film of 50 mm, an illuminance of 800 lx, and an irradiation angle of 10 °.

  As the first imaging means, a 7450-bit CCD digital line sensor was used, and eight pieces were arranged at intervals of 60 mm in the width direction of the belt-shaped resin film. The angle was 10 °. The distance from the surface of the belt-shaped resin film was 200 mm, and the photographing region range was 95% with respect to the movement amount (conveying speed) of the belt-shaped resin film. The angle indicates a value measured using an angle meter (protractor) of Niigata Seiki. As the second imaging means, a 7450-bit CCD digital line sensor was used, and eight pieces were arranged at intervals of 60 mm in the width direction of the belt-shaped resin film. The angle was 90 °. The distance from the surface of the belt-shaped resin film was 50 mm, and the photographing region range was 95% with respect to the movement amount (conveying speed) of the belt-shaped resin film. The angle indicates a value measured using an angle meter (protractor) of Niigata Seiki. The tension applied in the width direction by the first gripping means and the second gripping means was 10% of the transport tension of the belt-shaped resin film. The amount of bending of the belt-shaped resin film in the imaging region range was 80 μm. The amount of deflection indicates a value measured using a digital theodolite manufactured by Topcon Corporation.

  The total number of defects detected is 200 m, and the average value of the cumulative number of detected defects per 1 m is shown.

  Detection test No. 1 in which the first gripping means and the second moving speed are moved in conjunction with the transport speed of the belt-shaped resin film. 102, 105, 108, 111, 114, and 116 to 122 all showed detection results with high accuracy for defects. 116 and 121, as a result of setting the angle for applying the tension in the width direction to the transport direction of the belt-shaped resin film outside the preferred range, both wrinkles occur slightly in the belt-shaped resin film, flatness is not maintained by this wrinkle, Since the newly detected scattered light of minute unevenness was detected, the number of detections was higher than the theoretical number, and the detection result was low. Detection test No. 1 in which the first gripping means and the second moving speed were made slower than the conveying speed of the belt-shaped resin film. 101, 104, 107, 110, 113, 115, 116, 121 and accelerated detection test Nos. 103, 106, 109, 112, and 115 are wrinkles generated in the belt-like resin film, and the flatness is not maintained by this wrinkle, and the newly formed scattered light of minute unevenness is detected, so the number is larger than the theoretical number. The detection result with low accuracy was detected. Detection test No. conducted without applying tension in the width direction. No. 123 detects a number larger than the theoretical number, and the detection test No. Detection results inferior to those of 102, 105, 108, 111, 114, and 116 to 121 were shown. The effectiveness of the present invention was confirmed.

Example 2
(Preparation of opaque strip-shaped resin film)
Using transparent polyvinyl carbonate (PVC) -based vinyl foil (film manufactured by Mitsubishi Plastics Co., Ltd.) with a thickness of 100 μm, length of 200 m, and width of 600 mm, foreign materials with different sizes as shown in Table 3 are conveyed as pseudo defects. 100 pieces are attached per 1 m length in the direction, and the belt-like resin film no. 2-1 to 2-3. As the foreign material, standard particles of Moritex Corporation were used.

(Defect detection test)
The prepared belt-shaped resin film No. When performing inspection using the first gripping means and the second gripping means shown in FIG. 2 in the defect detection method shown in FIG. 1 using 200 m of 2-1 to 2-3, in the transport direction of the belt-shaped resin film On the other hand, by changing the moving speed of the gripping means as shown in Table 1, the detection test No. The results obtained as 201 to 222 are shown in Table 4. The detection test No. Reference numeral 223 denotes a comparative detection test performed without using the gripping means. Conditions for detecting defects are shown below. Since the object to be inspected is an opaque belt-like resin film, the second imaging means was not used. The moving speeds of the first gripping means and the second gripping means of the gripping means are the same. The conveyance speed of the belt-shaped resin film was 2 m / min. The belt-shaped resin film had a conveyance tension of 200 N (the conveyance tension is a value measured using an imada tensiometer (digital force gauge)).

  A linear light source (fluorescent lamp) that illuminates the width direction of the belt-shaped resin film was used as the illumination means, and irradiation was performed under the conditions of a distance from the surface of the belt-shaped resin film of 50 mm, an illuminance of 800 lx, and an irradiation angle of 10 °. As the first imaging means, a 7450-bit CCD line sensor was used, and eight pieces were arranged at intervals of 60 mm in the width direction of the belt-shaped resin film. The angle was 10 °. The distance from the surface of the belt-shaped resin film was 200 mm, and the photographing region range was 95% with respect to the movement amount (conveying speed) of the belt-shaped resin film. The angle indicates a value measured using an angle meter (protractor) of Niigata Seiki. The tension in the width direction by the first gripping means and the second gripping means was 10% of the transport tension of the belt-shaped resin film. The amount of bending of the belt-shaped resin film in the imaging region range was 80 μm. The amount of deflection indicates a value measured using a digital theodolite manufactured by Topcon Corporation.

  The total number of defects detected is 200 m, and the average value of the cumulative number of detected defects per 1 m is shown.

  Detection test No. 1 in which the first gripping means and the second moving speed are moved in conjunction with the transport speed of the belt-shaped resin film. 202, 205, 208, 211, 214, and 216 to 222 all showed detection results with high accuracy for defects. 216 and 221 are the result of making the angle to apply the tension in the width direction with respect to the transport direction of the belt-like resin film out of the preferred range, both wrinkles occur slightly in the belt-like resin film, flatness is not maintained by this wrinkle, Since the newly detected scattered light of minute unevenness was detected, the number of detections was higher than the theoretical number, and the detection result was low. Detection test No. 1 in which the first gripping means and the second moving speed were made slower than the conveying speed of the belt-shaped resin film. 201, 204, 207, 210, 213, 215, 216, 221 and accelerated detection test Nos. 203, 206, 209, 212, and 215 all show wrinkles in the belt-shaped resin film, the flatness is not maintained by the wrinkles, and the newly formed scattered light with unevenness is detected, so the number is larger than the theoretical number. The detection result with low accuracy was detected. Detection test No. conducted without applying tension in the width direction. No. 223 detects a number larger than the theoretical number. The detection results inferior to those of 202, 205, 208, 211, 214, and 216 to 221 were shown. The effectiveness of the present invention was confirmed.

Example 3
(Preparation of strip-shaped resin film)
(Preparation of transparent belt-shaped resin film)
Using a transparent PET-based Teijin Tetron film (Teijin-DuPont film) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, as shown in Table 5, foreign materials with different sizes are used as pseudo defects and the length in the transport direction 100 pieces per 1 meter are attached, and a belt-shaped resin film No. 3-1 to 3-3. As the foreign material, standard particles of Moritex Corporation were used.

(Defect detection test)
The prepared belt-shaped resin film No. Using 200 m of 3-1 to 3-3, the detection test No. of Example 1 When the defect is detected by the same detection method as in 1-4, the tension of the first gripping means and the first gripping means and the second gripping means are applied at 90 ° in the width direction with respect to the transport direction of the belt-shaped resin film, respectively. 2 The detection test No. 1 of Example 1 except that the percentage% of the difference with the tension of the gripping means is shown in Table 6. Detection test No. 1 under the same conditions as in 1-4. The results are shown in Table 6. Before conducting the detection test, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The total number of defects detected is 200 m, and the average value of the cumulative number of detected defects per 1 m is shown.

  Detection test No. 1 in which the tension difference between the first gripping means and the second gripping means was 20% or less. Nos. 302 to 306 all showed detection results with high accuracy with respect to the theoretical number, but the detection test Nos. With a tension difference between the first gripping means and the second gripping means exceeding 20%. 301 is a detection test No. 301. The detection result slightly inferior to 305-309 was shown. The effectiveness of the present invention was confirmed.

Example 4
(Preparation of strip-shaped resin film)
Using a transparent PET-based Teijin Tetron film (Teijin-DuPont film) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, as shown in Table 7, foreign materials with different sizes were used as pseudo defects in the length in the transport direction. 100 pieces per 1 meter are attached, and a belt-shaped resin film No. 4-1 to 4-3. As the foreign material, standard particles of Moritex Corporation were used.

(Defect detection test)
The prepared belt-shaped resin film No. 4-1 to 4-3 were used in 200 m, and the detection test No. 1 of Example 1 was performed. As shown in Table 7, when the defect is detected by the same detection method as 1-4, the first gripping means and the second gripping means respectively apply tensions at 90 ° in the width direction with respect to the transport direction of the belt-shaped resin film. Otherwise, the detection test No. 1 of Example 1 was performed. Detection test No. 1 under the same conditions as in 1-4. The results are shown in Table 8. Before conducting the detection test, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The tension indicates the ratio (%) to the transport tension of the belt-shaped resin film, and the tensions of the first gripping means and the second gripping means are the same. The total number of detected defects is 200 m, and indicates the average value of the accumulated number of detected defects per 1 m.

  Detection test No. 1 was conducted under the condition that the tension applied in the width direction was 1% to 100% with respect to the transport tension of the belt-shaped resin film. Nos. 402 to 413 all showed detection results with high accuracy with respect to the theoretical number, but the detection test No. conducted under the condition that the tension applied in the width direction was 0.8% with respect to the transport tension of the belt-shaped resin film. 401 and the detection test No. conducted under the condition that the tension applied in the width direction is 110.0% with respect to the transport tension of the belt-shaped resin film. 414 is a detection test No. 414. Results slightly inferior to 402-413 were obtained. The effectiveness of the present invention was confirmed.

Example 5
(Preparation of strip-shaped resin film)
Using a transparent PET-based Teijin Tetron film (film made by Teijin DuPont) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, as shown in Table 9, minute foreign materials with different sizes are used as pseudo defects in the transport direction. 100 pieces are adhered per 1 m length, and the belt-shaped resin film No. 5-1 to 5-6. Standard particles from Moritex Co., Ltd. were used as the minute foreign matter.

(Defect detection test)
The prepared belt-shaped resin film No. 5-1 to 5-6 were used for 200 m, and the detection test No. of Example 1 When a defect is detected by applying the tension in the 90 ° direction in the transport direction of the strip-shaped resin film by the first gripping means and the second gripping means using the same detection method as in 1-3, the amount of flexure of the strip-shaped resin film is displayed. 9 except for the detection test No. 1 in Example 1. The detection test was conducted under the same conditions as in 1-3. The results are shown in Table 10 as 501 to 507. Before conducting the detection test, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The amount of deflection indicates a value measured using a digital theodolite manufactured by Topcon Corporation. The amount of deflection was changed by changing the ratio (%) of the tension of the first gripping means and the second gripping means to the transport tension of the belt-shaped resin film. The tension of the 1st holding means and the 2nd holding means was made the same. The total number of defects detected is 200 m, and the average value of the accumulated number of defects detected every 1 m is shown.

  Detection test No. 1 was conducted under the condition that the amount of bending of the belt-shaped resin film in the inspection region was 200 μm or less. Nos. 502 to 507 all showed detection results with high accuracy with respect to the theoretical number. 501 is a detection test No. 501. Results slightly inferior to 502-507 were obtained. The effectiveness of the present invention was confirmed.

Example 6
(Preparation of strip-shaped resin film)
Uses a transparent PET-based Teijin Tetron film (Teijin DuPont film) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, in which 100 standard particles of 0.5 μm and 5 μm are dispersed in advance per 1 m in the conveying direction. As shown in Table 11, a strip-shaped resin film having a different thickness of the TiO ₂ film was prepared by the CVD method. 6-1 to 6-18.

(Defect detection test)
The prepared belt-shaped resin film No. 6-1 to 6-18 were used in 200 m, and the detection test No. 1 of Example 1 was performed. The belt-shaped resin film No. 1 in which defects were prepared by the first gripping means and the second gripping means by the same detection method as in 1-3. The detection test No. 1 of Example 1 except that a tension of 20 N / m was applied to the direction of 90 ° in the width direction with respect to the conveyance direction of 6-1 to 6-9. Detection test No. 1 under the same conditions as in 1-3. The results are shown in Table 12. Before conducting the detection test, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The tension of the 1st holding means and the 2nd holding means was made the same. The total number of defects detected is 200 m, and the average value of the accumulated number of defects detected every 1 m is shown.

  Detection test No. using a belt-shaped resin film having a layer thickness of 0.05 μm to 2.00 μm. Nos. 602 to 607 and 611 to 617 showed highly accurate detection results with respect to the theoretical number, but no detection test No. using a belt-shaped resin film having a layer thickness of 0.04 μm. 601 and 610, and a detection test No. using a belt-shaped resin film having a layer thickness of 2.2 μm. 609 and 618 are detection test Nos. A slightly inferior result was obtained with respect to 602 to 607 and 611 to 617. The effectiveness of the present invention was confirmed.

Example 7
(Preparation of strip-shaped resin film)
Using a transparent PET-based Teijin Tetron film (film made by Teijin DuPont) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, a strip-shaped resin film with a TiO ₂ film thickness of 0.5 μm is prepared by CVD. At the time, as shown in Table 13, 100 pieces of foreign matter having a size changed as a pseudo defect per 1 m in the conveyance direction were adhered to the belt-like resin film no. It was set to 7-1 to 7-6. As the foreign material, standard particles of Moritex Corporation were used.

(Defect detection test)
The prepared belt-shaped resin film No. 7-1 to 7-6 were used for 200 m, and the detection test No. 1 of Example 1 was performed. The belt-shaped resin film No. 1 in which defects were prepared by the first gripping means and the second gripping means by the same detection method as in 1-4. The detection test No. 1 of Example 1 except that a tension of 20 N / m was applied to the direction of 90 ° in the width direction with respect to the conveying direction of 7-1 to 7-6. Detection test No. 1 under the same conditions as in 1-4. The results are shown in Table 14. Before conducting the detection test, the back surface was cleaned with an adhesive roll XCHPlatform-3 manufactured by Techneck Corporation. The tension of the 1st holding means and the 2nd holding means was made the same. The total number of defects detected is 200 m, and the average value of the accumulated number of defects detected every 1 m is shown.

  Detection test No. using a strip-shaped resin film having a foreign matter (defect) size of 0.1 μm to 5.0 μm. 702 to 705 showed detection results with high accuracy with respect to the theoretical number. Detection test No. using a strip-shaped resin film having a foreign matter (defect) size of 0.08 μm. 701 is a detection test No. 701. The result was slightly inferior to 702-705. Detection test No. using a strip-shaped resin film having a foreign matter (defect) size of 6.0 μm. 706 is a detection test No. 706. Similar to 702 to 705, the detection result was high in accuracy with respect to the theoretical number, but when the size of the foreign matter (defect) is 6.0 μm, the amount of scattered light is large, so that the plane of the belt-shaped resin film is as in the present invention. There is no need to maintain sex. The effectiveness of the present invention was confirmed.

Example 8
(Preparation of strip-shaped resin film)
Using a transparent PET-based Teijin Tetron film (film made by Teijin DuPont) with a thickness of 100 μm, a length of 200 m, and a width of 1100 mm, the foreign matter whose size was changed as shown in Table 15 on the front and back For each 1 m length in the transport direction, 100 pieces were adhered to each other, and the belt-shaped resin film No. 8-1 to 8-4. Standard particles from Moritex Co., Ltd. were used as the minute foreign matter. Here, the front side indicates the side where the illumination unit and the first imaging unit shown in FIG. 1 are present, and the back side indicates the side where the second imaging unit is present.

(Defect detection test)
The prepared belt-shaped resin film No. 8-1 to 8-4 are used in 200 m, and the defect detection test No. 1 is performed under the following conditions using the first gripping means and the second gripping means shown in FIG. The results of 801 to 804 are shown in Table 16. The moving speed of the first gripping means and the second gripping means was the same as the transport speed of the belt-shaped resin film. The conveyance speed of the belt-shaped resin film was 2 m / min. The belt-shaped resin film had a conveyance tension of 200 N (the conveyance tension is a value measured using an imada tensiometer (digital force gauge)). The angle for applying tension in the width direction with respect to the transport direction of the belt-shaped resin film by the first gripping means and the second gripping means was 90 °. A linear light source (fluorescent lamp) that illuminates the width direction of the belt-shaped resin film was used as the illumination means, and irradiation was performed under the conditions of a distance from the surface of the belt-shaped resin film of 50 mm, an illuminance of 800 lx, and an irradiation angle of 10 °.

  As the first imaging means, a 7450-bit CCD digital line sensor was used, and eight pieces were arranged at intervals of 60 mm in the width direction of the belt-shaped resin film. The angle was 10 °. The distance from the surface of the belt-shaped resin film was 200 mm, and the photographing region range was 95% with respect to the movement amount (conveying speed) of the belt-shaped resin film. The angle indicates a value measured using an angle meter (protractor) of Niigata Seiki. As the second imaging means, a 7450-bit CCD digital line sensor was used, and eight pieces were arranged at intervals of 60 mm in the width direction of the belt-shaped resin film. The angle was 90 °. The distance from the surface of the belt-shaped resin film was 50 mm, and the photographing region range was 95% with respect to the movement amount (conveying speed) of the belt-shaped resin film. The angle indicates a value measured using an angle meter (protractor) of Niigata Seiki. The tension applied in the width direction by the first gripping means and the second gripping means was 10% of the transport tension of the belt-shaped resin film. The amount of bending of the belt-shaped resin film in the imaging region range was 80 μm. The amount of deflection indicates a value measured using a digital theodolite manufactured by Topcon Corporation. The total number of detected defects is 200 m, and the average value of the cumulative number of detected defects per 1 m is shown.

  Detection test No. In 801, since the foreign matter adhering to the back surface is small, the amount of scattered light generated by the irradiation light passing through the back surface is small, so that it does not reach the surface and is not detected on the surface. As a result, the detection result was highly accurate with respect to the theoretical number. The front surface is not affected by foreign matter on the back surface. Further, the transmitted light on the back surface cannot be detected because the foreign matter is small and the diffracted light cannot be shaded by the foreign matter. Therefore, it is possible to accurately detect only small foreign matters on the surface.

  Detection test No. In 802, since the foreign matter adhering to the back surface is large, the amount of scattered light generated by the irradiation light passing through the back surface is increased and reaches the surface and is detected on the surface. The result includes the number of foreign matter on the back side. For this reason, the position information of the detection result on the front surface and the detection result on the back surface is collated, and the number of matches between the detection result on the front surface and the detection result on the back surface is deleted, so that the number of foreign objects on the front surface is obtained. Even if the foreign matter is large, the foreign matter attached to the surface can be detected with high accuracy.

  Detection test No. In 803, since the foreign matter adhering to the back surface is small, the irradiating light that has passed through is irradiated onto the foreign matter on the back surface and becomes scattered light. For this reason, only the surface can be detected. On the back side, small foreign matter on the back side cannot be detected because the irradiated light becomes diffracted light, but large foreign matter on the front side becomes a shadow and is detected. By comparing the size information and position information of the front and back surface defects in the analysis after the inspection is completed, it is possible to accurately detect that there is a defect only on the front surface.

  Detection test No. In 804, since the foreign matter adhering to the back surface is large, the amount of scattered light generated by the irradiation light passing through the back surface is increased and reaches the surface and is detected on the surface. The result includes the number of foreign matter on the back side. The back surface is a combined detection of the foreign material on the front surface and the back surface. For this reason, in the analysis after the inspection is completed, the position information of the detection result on the front surface and the detection result on the back surface and the size information are collated, and the number of matches between the detection result on the front surface and the detection result on the back surface is deleted. Thus, the number of foreign matters on the front surface and the back surface can be obtained, and the foreign matters on the front surface and the back surface can be detected simultaneously with high accuracy. The effectiveness of the present invention was confirmed.

It is a schematic diagram which shows the detection method of the defect of a strip | belt-shaped resin film. It is a schematic diagram which shows the detection method of the foreign material adhering to the surface and the back surface of a transparent strip | belt-shaped resin film with the detection means shown in FIG.1 (b). It is an expansion schematic plan view of the part shown by P of FIG. FIG. 3 is an enlarged schematic view of the gripping device shown in FIG. 2. It is a schematic flowchart which shows from the grip start of the edge part of a strip | belt-shaped resin film to grip cancellation | release using the holding | grip apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Defect detection apparatus 2 Supply part 3 Detection means 301 Illumination means 302 1st imaging means 303 2nd imaging means 304 Gripping means 304a 1st holding means 304a1, 304b1 Gripping device 304b 2nd holding means 4 Winding part 5 Band-shaped resin film 502a 502b end

Claims (6)

In the defect detection method for detecting defects on the belt-shaped resin film continuously conveyed by the detection means,
The detection means is an illumination means for irradiating the surface side of the belt-shaped resin film, a first imaging means for imaging the surface side of the belt-shaped resin film, a second imaging means for imaging the back surface side of the belt-shaped resin film, Holding means for holding both ends of the belt-shaped resin film,
The belt-shaped resin film is gripped in a state in which tension is applied in the width direction with respect to the transport direction of the belt-shaped resin film, at least by the gripping means, at least in the inspection region for detecting the defect,
The gripping means moves at least in the inspection region in conjunction with the conveyance direction speed of the belt-shaped resin film,
A defect detection method characterized in that the detection means continuously detects the defect. The tension applied in the width direction with respect to the conveying direction of the belt-shaped resin film has a difference of 20% or less between the left end and the right end of the strip-shaped resin film. Defect detection method. The defect detection method according to claim 1, wherein the tension is 1% to 100% with respect to the transport tension of the belt-shaped resin film. The defect detection method according to any one of claims 1 to 3, wherein an amount of bending of the belt-shaped resin film in the inspection region is 200 µm or less. The defect detection method according to claim 1, wherein the size of the defect is 0.1 μm to 5.0 μm. A defect detection device for detecting a defect on a belt-shaped resin film that is continuously conveyed, the illumination means for illuminating the surface of the belt-shaped resin film, and a first imaging that images a defect on the surface of the belt-shaped resin film Means, second imaging means for imaging defects on the back surface of the belt-shaped resin film, and gripping means for applying tension in the width direction of the belt-shaped resin film in conjunction with the transport direction speed of the belt-shaped resin film. Feature defect detection device.

Images