JP5274622B2 - Defect inspection apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply determine existence of a false defect of a laminate film. <P>SOLUTION: A polarizing filter 19 is arranged on a laminate film 9 including a polarizing plate 13 and a separator 15. A polarization axis of the polarizing filter 19 is made approximately orthogonal to a polarization axis of the polarizing plate 13. A line light source 17 is arranged just under the laminate film 9 and a line sensor camera 20 is arranged just above the polarizing filter 19. Inspection light 24 is applied from the line light source 17 to the laminate film 9. The inspection light 24 transmitted through the laminate film 9 and the polarizing filter 19 is imaged by the line sensor camera 20. A high luminance area 40 with high luminance is extracted from image data 41 obtained by imaging, as defect image data. When the defect image data is specific defect image data in which two high luminance areas 40 are aligned, a film defect portion corresponding to the defect image data is determined as a false defect. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a defect inspection apparatus and method for inspecting a defect of a laminated film formed by laminating a polarizing plate and a film.

  Various optical functional films are used for liquid crystal displays. A film-like polarizing plate is known as this optical functional film. An adhesive layer for attaching the polarizing plate to a glass substrate of a liquid crystal display is formed on one surface of the polarizing plate. This adhesive layer is covered with a separator until it is attached to a glass substrate or the like. For this reason, the manufacturing process of a liquid crystal display includes the manufacturing process of the laminated film formed by laminating | stacking a polarizing plate and a separator (refer patent document 1).

  Such a laminated film may have various defects such as foreign matters adhering to the film surface or the inside of the film, or contamination or scratches in the production process. For this reason, in the production process of the laminated film, light is emitted from the light source to the laminated film, the transmitted light or reflected light of the laminated film is photographed with a camera, and defect inspection is performed based on the image obtained by this photography. Do.

  Patent Document 2 discloses a defect inspection apparatus that captures the transmitted light of a laminated film with a polarizing filter interposed between the laminated film and a camera. The polarizing filter is arranged so that its polarization axis is a so-called crossed Nicol that is orthogonal to the polarizing axis of the polarizing plate. Thus, if there is no defect in the laminated film, the vibration direction of the transmitted light of the laminated film is orthogonal to the polarization axis of the polarizing filter, so that the transmitted light is blocked by the polarizing filter. For this reason, the transmitted light image is an entire black image. On the other hand, when a defect exists in the laminated film, the polarization state of the transmitted light that has passed through the defective portion is changed, so that the transmitted light of the defective portion is transmitted through the polarizing film. For this reason, the brightness | luminance of the part corresponding to the defective part of a transmitted light image becomes high. Thereby, the presence or absence of the defect of a laminated | multilayer film can be test | inspected.

  Patent Document 3 discloses a flaw inspection method that analyzes an image of a defect portion that is elongated and determines the type of the defect portion. In the scratch inspection method disclosed in Patent Document 3, it is determined whether the defect is a scratch or a stain by obtaining the shape and directionality of the defect from the second moment of the image of the defect.

  Patent Document 4 discloses a defect inspection apparatus that extracts various feature amounts from an image obtained by photographing reflected light of an object to be inspected such as a laminated film, and performs defect inspection based on the feature amounts. . In this defect inspection apparatus, a multiple regression equation is calculated based on each feature amount to obtain a predicted characteristic value, and a discrimination score is calculated from a discriminant function, and the presence or absence of a defect is determined based on these results.

JP 2009-069142 A Japanese Patent Laid-Open No. 2007-213061 JP-A-6-160295 JP-A-7-318508

  The separator of the laminated film is finally peeled off from the polarizing plate in the manufacturing process of the liquid crystal display. For this reason, if the protective function of the adhesive layer is not impaired even if the separator itself has a defect, it is not necessary to treat the defect of the separator as a defect. However, in the inspection methods of Patent Documents 2 and 3, the defect of the polarizing plate and the defect of the separator cannot be distinguished. Therefore, the inspector or the like confirms the occurrence location of the defect, and the actual defect that is the defect of the polarizing plate. It is necessary to determine whether it is a pseudo defect that is a separator defect.

  In the defect inspection apparatus of Patent Document 4, it is not impossible to discriminate a real defect from a pseudo defect by appropriately setting the type of the feature amount extracted from the photographed image. Extraction processing, multiple regression equations and discriminant functions need to be performed. For this reason, there is a problem that the amount of calculation becomes enormous and the processing takes time. As a result, it is extremely difficult to use the defect inspection apparatus disclosed in Patent Document 4 for defect inspection of a laminated film that is traveling on a conveyance line.

  The objective of this invention is providing the defect inspection apparatus and method which can perform the determination of the pseudo defect of a laminated film easily.

  In order to achieve the above object, a defect inspection apparatus according to the present invention is a light source that is arranged on one side of the front and back surfaces of a multilayer laminated film formed by laminating a polarizing plate and a film, and irradiates light on the laminated film And the light that is disposed on the other side of the front and back surfaces, has a second polarization axis that is parallel to the front and back surfaces and substantially perpendicular to the first polarization axis of the polarizing plate, and has passed through a normal portion of the laminated film A polarizing filter for blocking light, a photographing means for photographing light transmitted through the polarizing filter, disposed on a surface opposite to the surface facing the laminated film of the polarizing filter, and the photographing means obtained by the photographing means A defect image extracting means for extracting, as a defect image, a defect portion of the laminated film and a high-luminance region whose luminance is increased by the light transmitted through the polarizing filter from the transmitted light image of the polarizing filter; When the defect image extracted by the fallen image extraction means is a specific defect image in which two high-luminance regions are arranged, the defect portion corresponding to the defect image is a pseudo defect that is not a defect of the polarizing plate. And a pseudo-defect determination unit.

  A plurality of types of feature amounts including at least an average luminance that is an average value of the luminance of the defect image and a central luminance that is a luminance at the center position of the defect image are extracted from the defect image extracted by the defect image extraction unit. A feature amount extracting unit that compares the extraction result of the feature amount extracting unit with a threshold value of each feature amount that is predetermined according to the feature of the specific defect image. Therefore, it is preferable to determine whether or not the defect image is the specific defect image.

  The feature amount preferably includes a difference between the average luminance and the central luminance.

  The specific defect image includes first to N-th specific defect images corresponding to N (N is a natural number of 2 or more) types of first to N-th pseudo defects, respectively, and the threshold value includes the first to N-th specific defect images. N first threshold value to Nth threshold value individually determined according to the features of the N specific defect image, provided in the pseudo defect determining means, and the extraction result of the feature value extracting means is the first First to Nth determination means for individually determining whether or not the defect image is the first to Nth specific defect image by individually comparing with each of the Nth threshold value and the first threshold value. When the determination process by the Nth determination means is executed in a predetermined order, and the defect portion is determined to be the pseudo defect in the Mth [M is a natural number equal to or less than (N−1)] th determination process Includes a determination control unit that stops the (M + 1) th and subsequent determination processes. When, it is preferable to provide.

  It is preferable that the specific defect image includes an image having the substantially bright cross-shaped high luminance region.

  The film is preferably a separator that is detachably attached to an adhesive layer formed on the surface of the polarizing plate.

  It is preferable to include actual defect determination means that determines the defect portion corresponding to the defect image that has not been determined to be the specific defect image by the pseudo defect determination means as an actual defect that is a defect of the polarizing plate. .

  It is preferable that a marking unit that performs marking indicating the actual damage defect is provided on a portion of the laminated film determined to be the actual damage defect.

  In addition, the defect inspection method of the present invention includes an irradiation step of irradiating light to the laminated film from a light source disposed on one side of the front and back surfaces of a multilayer laminated film obtained by laminating a polarizing plate and a film. The polarizing film that is disposed on the other side of the front and back surfaces, is parallel to the front and back surfaces, and has a second polarization axis that is substantially orthogonal to the first polarization axis of the polarizing plate, and transmits the normal part of the laminated film. A blocking step for blocking light, a shooting step for shooting the light transmitted through the polarizing filter by a shooting means disposed on a surface opposite to the surface facing the laminated film of the polarizing filter, and the shooting step From the transmitted light image of the polarizing filter acquired in Step 1, a defective portion of the laminated film and a high-luminance region where the luminance is increased by the light transmitted through the polarizing filter are defined as a defective image. And when the defect image extracted in the defect image extraction step is a specific defect image in which two high-luminance regions are arranged, the defect portion corresponding to the defect image is And a pseudo defect determination step for determining that the defect is not a defect of the polarizing plate.

  The defect inspection apparatus and method of the present invention extract a high brightness area from a transmitted light image of a polarizing filter as a defect image, and a stack corresponding to a specific defect image in which two high brightness areas are arranged in the defect image. By determining that the defective part of the film is a pseudo defect that is not a defect of the polarizing plate, it is possible to easily execute the determination of the pseudo defect without performing complicated arithmetic processing using multiple regression equations and discriminant functions. Can do. Thereby, since the time required for the inspection process can be shortened, it becomes possible to inspect the laminated film for defects during traveling.

It is the schematic of a defect inspection apparatus. It is a perspective view of a defect inspection apparatus. It is sectional drawing of a laminated film. It is explanatory drawing for demonstrating the pseudo defect of the laminated | multilayer film resulting from the foreign material in a separator. It is explanatory drawing for demonstrating that a pseudo defect does not affect the performance of a polarizing plate. It is the block diagram which showed the electrical structure of the defect inspection apparatus. It is explanatory drawing for demonstrating that disorder arises in the orientation direction of each molecule | numerator in a polarizing plate by the foreign material in a separator. It is explanatory drawing of the image data in which two high-intensity area | regions are located in a line. It is explanatory drawing for demonstrating "two-point arrangement | sequence (1)" which is a pseudo defect. It is explanatory drawing for demonstrating "two-point arrangement | sequence (2)" which is a pseudo defect. It is explanatory drawing for demonstrating the other example of "2 point arrangement | sequence (2)." It is explanatory drawing for demonstrating the extraction process of the defect image data by a 1st extraction pattern. It is explanatory drawing for demonstrating the extraction process of the defect image data by a 2nd extraction pattern. It is explanatory drawing for demonstrating defect image extraction reference | standard data, the feature-value data for pseudo defect classification, and defect position information data. It is a flowchart which shows the flow of the inspection process by a defect inspection apparatus. It is explanatory drawing of the feature-value data for actual damage defect classification for determining the kind of actual damage defect. It is explanatory drawing for demonstrating disorder of the orientation direction of each molecule | numerator in a polarizing plate different from FIG. It is explanatory drawing of the image data containing a cross-shaped high-intensity area | region. It is a block diagram which shows the electric constitution of the defect inspection apparatus of other embodiment which can determine the kind of 2 point | piece arrangement | sequence pseudo defect and a cross pseudo defect. It is explanatory drawing for demonstrating the pseudo defect of the laminated | multilayer film resulting from the foreign material pinched | interposed between a separator and a polarizing plate.

  As shown in FIGS. 1 and 2, a defect inspection apparatus 11 is arranged in a laminated film production line 10 for producing a long laminated film 9. The defect inspection apparatus 11 inspects the defects of the laminated film 9 that runs in the Y direction in the drawing. As shown in FIG. 3, the laminated film 9 to be inspected includes a film-like polarizing plate 13 and a separator (film) 15 laminated on an adhesive layer 14 formed on one surface of the polarizing plate 13. It has a laminated structure.

  The polarizing plate 13 is produced | generated by extending | stretching the film formed by mixing various organic substances in polymers, such as polyvinyl alcohol (PVA), for example in a predetermined direction. Thereby, each molecule | numerator M (refer FIG. 7) in the polarizing plate 13 orientates along an extending | stretching direction. As a result, the polarizing plate 13 transmits polarized light that vibrates in a direction parallel to the alignment direction of each molecule M. Here, it is assumed that the polarization axis D1 (see FIG. 2) of the polarizing plate 13 is parallel to the Y direction in the drawing. The polarizing plate 13 is attached to a glass substrate (not shown) of a liquid crystal display through an adhesive layer 14 formed on one surface thereof.

  The separator 15 is detachably laminated on the adhesive layer 14 and protects the adhesive layer 14 until the polarizing plate 13 is attached to a glass substrate or the like. The separator 15 is finally peeled off from the adhesive layer 14 when the polarizing plate 13 is attached to a glass substrate or the like.

  Returning to FIG. 1 and FIG. 2, the defect inspection apparatus 11 is arranged in the middle of the conveyance line of the laminated film 9. The defect inspection apparatus 11 includes a line light source 17, a polarizing filter 19, a line sensor camera (hereinafter simply referred to as a camera) 20, a marking device 21, and a defect inspection apparatus body (hereinafter simply referred to as an apparatus body). 22.

  Each of the line light source 17 and the polarizing filter 19 has a shape that extends longer than the width of the laminated film 9 in the width direction of the laminated film 9 (hereinafter, simply referred to as the film width direction, X direction in the drawing).

  The line light source 17 is disposed on one surface side (the lower surface side in the drawing) of the front and back surfaces of the laminated film 9. The line light source 17 irradiates the laminated film 9 with linear inspection light 24 parallel to the film width direction. In addition, as the line light source 17, a halogen lamp, LED, etc. can be used.

  The polarizing filter 19 is disposed on the other surface side (upper surface side in the figure) of the front and back surfaces of the laminated film 9, more specifically, between the laminated film 9 and the camera 20. The polarizing filter 19 has a polarization axis D2 that is parallel to the front and back surfaces of the laminated film 9 and is substantially orthogonal to the polarization axis D1. Note that “substantially orthogonal” here refers to both the case of being completely orthogonal and the case of being substantially orthogonal (when the angle between the polarization axis D1 and the polarization axis D2 is close to 90 °). Is included. Thereby, the polarizing filter 19 and the polarizing plate 13 have a so-called crossed Nicol relationship.

  The polarizing filter 19 blocks the polarized component light that vibrates in the direction perpendicular to the polarization axis D2 and inspects the incident light 24 that has passed through the laminated film 9 and oscillates in the direction parallel to the polarization axis D2. The light is transmitted as it is. Thereby, the inspection light 24 transmitted through the polarizing filter 19 becomes polarized light that vibrates in a direction parallel to the polarization axis D2.

  The camera 20 is disposed on the surface of the polarizing filter 19 opposite to the surface facing the laminated film 9 and at a position directly above the center of the laminated film 9 in the width direction. The camera 20 has a linear imaging region composed of a plurality of pixels arranged in a line in the film width direction. This imaging region extends longer than the width of the laminated film 9 in the film width direction.

  The camera 20 images the inspection light 24 transmitted through the laminated film 9 and the polarizing filter 19 and outputs an image signal for one line to the apparatus main body 22. The camera 20 continuously performs imaging and image signal output each time the laminated film 9 is conveyed line by line. As a result, an imaging signal of the inspection light 24 transmitted through the entire region of the laminated film 9 is obtained.

  The marking device 21 is disposed on the conveyance path of the laminated film 9 and on the downstream side in the conveyance direction of the laminated film 9 with respect to the line light source 17 and the camera 20. When a specific defect occurs in the laminated film 9 under the control of the apparatus main body 22, the marking device 21 performs a marking indicating the position on the laminated film 9.

  The apparatus body 22 performs a defect inspection based on the image signal input from the camera 20 to determine whether or not a defect has occurred in the laminated film 9. Further, when a defect occurs in the laminated film 9, the apparatus main body 22 determines whether the defect is a pseudo defect generated in the separator 15 or an actual damage defect generated in the polarizing plate 13.

  Here, the pseudo defect is, for example, a defect caused by the foreign matter 26 existing inside the separator 15 as shown in FIG. In this case, although the recess 13a is formed on the surface of the polarizing plate 13 by the foreign matter 26, the foreign matter 26 does not remain on the polarizing plate 13 when the separator 15 is peeled off from the polarizing plate 13 as shown in FIG. . Further, since the recess 13a is also lost due to the restoring force of the polarizing plate 13, the performance of the polarizing plate 13 is not affected. For this reason, if the function of protection of the adhesion layer 14 and the polarizing plate 13 by the separator 15 is not impaired, the pseudo defect originally does not need to be treated as a defect.

  The actual damage defect is, for example, an appearance defect such as a foreign substance adhering to or embedded in the polarizing plate 13, and a defect remaining in the polarizing plate 13 even when the separator 15 is peeled off. Since this actual harm defect affects the performance of the polarizing plate 13, it must be treated as a defect.

  As shown in FIG. 6, the CPU 28 of the apparatus main body 22 comprehensively controls each part of the apparatus main body 22 by sequentially executing various programs and data read from the memory 30 based on the control signal from the operation unit 29. To do. The RAM area of the memory 30 functions as a work memory for the CPU 28 to execute processing and a temporary storage destination for various data. The ROM area of the memory 30 stores various control programs and data.

  The CPU 28 is connected to the operation unit 29, the memory 30, the input I / F 31, the image processing circuit 32, the defect image extraction circuit 33, the feature amount extraction circuit 34, the pseudo defect determination circuit 35, and the actual damage defect determination circuit 36 via the bus Bu. A defect position detection circuit 37, a marking control circuit 38, and the like are connected. The operation unit 29 is used for a defect inspection start / stop operation and the like.

  The input I / F 31 is connected to the camera 20. The input I / F 31 sequentially outputs image signals for one line sequentially input from the camera 20 to the image processing circuit 32.

  The image processing circuit 32 accumulates image signals for one line input from the input I / F 31. For example, every time image signals for a predetermined number of lines are accumulated, two-dimensional image data is obtained based on these image signals. Generate. Thereby, when the laminated film 9 is divided into a plurality of sections in the Y direction, image data obtained by photographing the inspection light 24 transmitted through each section is generated. The image processing circuit 32 sequentially stores image data in the memory 30.

  In the image data, a region corresponding to a normal portion of the laminated film 9 is a black image. This is because the inspection light 24 transmitted through the normal part of the laminated film 9 is orthogonal to the polarization axis D 2, so that the inspection light 24 is blocked by the polarizing filter 19.

  On the other hand, the image data has high brightness in a region corresponding to a defective portion of the laminated film 9 (hereinafter referred to as a film defective portion). This is because when the inspection light 24 passes through the film defect portion, the polarization state changes, so that the linearly polarized light that vibrates in the direction perpendicular to the polarization axis D2 is eliminated and the inspection light 24 passes through the polarizing filter 19. .

  At this time, the amount of inspection light 24 transmitted through the polarizing filter 19 (hereinafter referred to as transmission inspection light amount) varies depending on the polarization state of the inspection light 24 transmitted through the film defect portion. For example, when the inspection light 24 has a large amount of polarized light components that vibrate in the direction parallel to the polarization axis D2, the transmission inspection light amount increases. Note that the polarization state of the inspection light 24 transmitted through the film defect portion varies depending on the orientation direction of the molecules M in the polarizing plate 13.

  For example, when a pseudo defect due to the foreign material 26 shown in FIG. 4 occurs, the orientation of the molecules M (see FIG. 7) in the polarizing plate 13 is disturbed by the pressure from the foreign material 26. Specifically, each molecule M is pulled toward the center of the foreign matter 26 by pressing from the foreign matter 26. As shown in FIG. 7, since the molecule Ma located near the center of the foreign material 26 is only pressed in the thickness direction of the polarizing plate 13 by the foreign material 26, the orientation direction of the molecule Ma is substantially parallel to the polarization axis D1. It remains unchanged.

  Further, among the molecules Mb located around the molecule Ma, those pulled in the direction parallel to the polarization axis D1 toward the center of the foreign material 26 are merely translated as they are and the orientation direction does not change. On the other hand, among the molecules Mb, those that are pulled in the oblique direction toward the center of the foreign material 26 are inclined in the orientation direction toward the center of the foreign material 26.

  The inspection light 24 transmitted through such a place where the alignment direction of the molecule M is disturbed is not linearly polarized light that vibrates in a direction perpendicular to the polarization axis D2, and thus passes through the polarization filter 19. As a result, when this inspection light 24 is imaged, as shown in FIG. 8, two high-intensity areas 40 (indicated by white portions in the figure) having high luminance in the black image (indicated by dots in the figure). The image data (transmitted light image) 41 in which are arranged is acquired. Hereinafter, a pseudo defect in which two high-luminance regions 40 are observed side by side is referred to as a “two-point aligned pseudo defect”.

  There are N types (N is a natural number greater than or equal to 2) of the two-point aligned pseudo-defects in which the brightness, the number of pixels, the interval, etc. of both high-luminance regions 40 are different. 1) "," Two point arrangement (2) "..." Two point arrangement (N) ". For example, as shown in FIG. 9, in the “two-point arrangement (1)”, both high-intensity regions 40 are completely separated.

  As shown in FIG. 10, the “two-point arrangement (2)” is actually connected even though the two high-luminance regions 40 appear to be separated by visual observation. In addition, in the two-point arrangement (2), as shown in FIG. 11, the areas and luminances of both high luminance regions 40 are large, and it is possible to visually confirm that the two high luminance regions 40 are connected. included.

  On the other hand, the actual defect includes “foreign matter” in which spherical or polygonal foreign matter adheres to the polarizing plate 13, “elongated foreign matter” in which a foreign matter that is narrower than “foreign matter” adheres to the polarizing plate 13, and the polarizing plate 13. There are at least three types of “Keba” in which fibrous foreign matter is embedded. Note that “foreign matter (small)” in which the size of the foreign matter is lower than the predetermined lower limit standard value does not affect the performance of the polarizing plate 13, and thus is not determined as an actual harm defect.

  Returning to FIG. 6, the defect image extraction circuit 33 extracts from the image data 41 stored in the memory 30 the high-intensity region 40 resulting from the film defect portion as defect image data in accordance with a predetermined condition. This condition is, for example, the lower limit value of the luminance value of each pixel constituting the high luminance region 40 or the lower limit value of the number of pixels. As a result, a high luminance region 40 in which a predetermined number of pixels having luminance values equal to or higher than a predetermined value are connected is extracted as defect image data. Further, the defect image extraction circuit 33 extracts defect image data using two types of extraction patterns, ie, a first extraction pattern and a second extraction pattern.

  As shown in FIG. 12, in the first extraction pattern, a circumscribed rectangle 43a is set along the outer periphery of the high luminance region 40, and the inside of the circumscribed rectangle 43a is extracted as defect image data 42a. For example, when a plurality of high brightness areas 40 are gathered like a two-point aligned pseudo defect, a circumscribed rectangle 43a including an aggregate of the high brightness areas 40 is set, and the inside of the circumscribed square 43a is defined as a defect image. Extracted as data 42a. In addition, even when three or more high-luminance areas 40 are aggregated, an aggregate of all the high-luminance areas 40 is extracted as defect image data 42a.

  On the other hand, when the high-intensity region 40 exists alone, the circumscribed rectangle 43a including the high-luminance region 40 is set, and the defect image data 42a is extracted. An upper limit is set for the size of the circumscribed rectangle 43a. Therefore, the high luminance region 40 that does not enter the circumscribed rectangle 43a is regarded as being caused by another film defect portion and is separately extracted.

  As shown in FIG. 13, in the second extraction pattern, when a plurality of high-luminance regions 40 are gathered, a circumscribed rectangle 43b including the high-luminance region 40 with a large number of pixels is set, and the inside of the circumscribed rectangle 43b is set. Are extracted as defect image data 42b. When the high brightness area 40 exists alone, the circumscribed square 43b including the high brightness area 40 is set, and the defect image data 42b is extracted. In this case, the defect image data 42a and the defect image data 42b are the same. The defect image extraction circuit 33 stores the defect image data 42 a and 42 b extracted from the image data 41 in the memory 30 in association with each other.

  Returning to FIG. 6, the feature quantity extraction circuit 34 extracts feature quantities from the defect image data 42 a and 42 b stored in the memory 30. The feature amount includes, for example, “average brightness”, “center brightness”, “average brightness−center brightness”, “maximum brightness”, “number of pixels”, “area ratio 1”, “area ratio 2”, “width”. , “Length”, “aspect ratio”, “average width”, “average width aspect ratio”, and the like.

  “Average luminance” is an average value of the luminance of each pixel constituting the defect image data 42a. “Center luminance” is the luminance of the pixel at the center position of the defect image data 42a. “Average brightness−center brightness” is “average brightness” − “center brightness”.

  The “number of pixels” is the number of pixels constituting the high luminance area 40 in the defect image data 42a and 42b. “Area ratio 1” is “the number of pixels” in the defect image data 42 a ÷ “the number of pixels outside the high brightness region 40”, and “area ratio 2” is “the number of pixels” in the defect image data 42 b ÷ “ The number of pixels outside the high luminance area 40 ”.

  “Width” is the width of the defect image data 42a (the width of the circumscribed rectangle 43a). The “length” is the length of the defect image data 42a (the length of the circumscribed rectangle 43a). “Aspect ratio” is “length” ÷ “width”. The “average width” is an average value of the width of the high brightness area 40 in the defect image data 42a. “Average width aspect ratio” is “length” ÷ “average width”. The feature amount extraction circuit 34 stores the feature amounts extracted from the defect image data 42a and 42b in the memory 30 in association with the defect image data 42a and 42b of the extraction source.

  The pseudo defect determination circuit 35 determines whether or not two film defect portions corresponding to the defect image data 42 a and 42 b in the memory 30 are arranged in a pseudo defect. In this case, there are N types of two-point arrangement pseudo defects, “two-point arrangement (1)” to “two-point arrangement (N)”. Therefore, the pseudo defect determination circuit 35 individually determines whether the film defect portion is “two-point alignment (1)”... “Two-point alignment (N)”. ) To N-th determination circuit 46 (N).

  The first determination circuit 46 (1) is configured to display the first specific defect image data (where the defect image data 42 a and 42 b indicate “two-point alignment (1)”) based on the feature amounts of the defect image data 42 a and 42 b in the memory 30. 14), it is determined whether or not the film defect portion is “two-point alignment (1)”. The first determination process includes a first threshold value 54 (1) of each feature amount predetermined according to each feature amount of the defect image data 42a and 42b and the feature of the first specific defect image data (FIG. 14). And the reference).

  The second determination circuit 46 (2) performs a second determination process for determining whether or not the defect image data 42a and 42b is second specific defect image data (see FIG. 14) indicating “two-point alignment (2)”. By performing, it is determined whether the film defect portion is “two-point alignment (2)”. Similarly, the Nth determination circuit 46 (N) performs an Nth determination process for determining whether or not the defect image data 42 a and 42 b is the Nth specific defect image data indicating “two-point alignment (N)”. Thus, it is determined whether or not the film defect portion is “two-point alignment (N)”.

  In the second to Nth determination processes, the feature amounts of the defect image data 42a and 42b are converted into the second to Nth feature amounts individually determined in advance according to the features of the second to Nth specific defect image data. It is executed by comparing with each of the threshold values 54 (2) to 54 (N) (see FIG. 14).

  The actual defect determination circuit 36 determines whether or not the film defect portion corresponding to the defect image data 42a and 42b stored in the memory 30 is an actual defect. The actual defect determination circuit 36 determines that the film defect portions corresponding to the defect image data 42a and 42b that are not determined to be the first to Nth specific defect image data by the pseudo defect determination circuit 35 are actual damage defects. .

  The defect position detection circuit 37 detects the position coordinates in the laminated film 9 of the film defect portion determined to be a pseudo defect and an actual defect by arranging two points by the pseudo defect determination circuit 35 and the actual damage defect determination circuit 36, respectively. The position coordinates include, for example, detection information from a front end detection sensor (not shown) that detects passage of the front end of the laminated film 9, known conveyance speed of the laminated film 9, and defect image data 42 a in the image data 41. It is calculated | required from the positional information on 42b. In addition to this method, the position coordinates of the film defect portion may be detected using various known detection methods. The defect position detection circuit 37 stores the position coordinate data of the two-point aligned pseudo defect and the actual harm defect in the memory 30.

  The marking control circuit 38 controls the marking device 21 based on the position coordinate data (hereinafter referred to as actual damage defect position coordinate data) of the actual damage defect in the memory 30 to indicate the position of the actual damage defect on the laminated film 9 on the conveyance path. Mark. The marking control circuit 38 moves the position corresponding to the actual harm defect position coordinate data of the laminated film 9 (hereinafter referred to as position coordinate corresponding position) based on the detection information from the tip detection sensor, the known conveyance speed of the laminated film 9, and the like. Monitor. Thereby, the marking to the position corresponding to the position coordinate of the laminated film 9 becomes possible.

  The CPU 28 functions as the pseudo defect determination control unit 28 a by sequentially executing various programs read from the ROM area of the memory 30. The pseudo defect determination control unit 28a performs determination processing by the first to Nth determination circuits 46 (1) to 46 (N) in a predetermined order (for example, the first determination circuit 46 (1) and the second determination circuit 46 (2). ,... Are executed by the Nth determination circuit 46 (N)).

  Further, the pseudo defect determination control unit 28a stops the second to Nth determination processes when it is determined in the first determination process that the film defect portions are arranged in two points (1), and the second determination process When it is determined that the film defect portion is the two-point alignment (2), the third to Nth determination processing is stopped. For this reason, when it is determined in the M-th [M is a natural number equal to or less than (N−1)] determination that two film defect portions are arranged and are pseudo defects, the subsequent determination processing is not performed.

  As shown in FIG. 14, the ROM area of the memory 30 stores defect image extraction reference data 60, pseudo defect classification reference data 61, and defect position information data 62 in addition to various programs.

  The defect image extraction reference data 60 is used as reference data for the defect image extraction circuit 33 to extract the defect image data 42 a and 42 b from the image data 41. The defect image extraction reference data 60 stores the lower limit value of the luminance value and the lower limit value of the number of pixels that constitute the high luminance region 40. Thereby, the defect image extraction circuit 33 extracts the defect image data 42 a and 42 b from the image data 41 with reference to the defect image extraction reference data 60.

  The pseudo defect classification reference data 61 is data used for the first to Nth determination processing by the first to Nth determination circuits 46 (1) to 46 (N). The pseudo defect classification reference data 61 includes first to Nth threshold values 54 (1) to 54 (N) of respective feature amounts respectively predetermined according to the features of the first to Nth specific defect image data. Stored.

  For example, the first threshold value 54 (1) is determined according to the appearance characteristics of the first specific defect image data. Specifically, (a1) the high-intensity region 40 having a larger area is substantially circular, (b1) the two high-intensity regions 40 are separated on visual observation, and (c1) both high-intensities. For example, the regions 40 are arranged close to each other. In the first threshold value 54 (1), “area ratio 2” is set to be equal to or greater than a predetermined value β corresponding to (a1). Corresponding to (b1), “average luminance−center luminance” is set to 0.0 or more (positive value). Corresponding to (c1), the “aspect ratio” is set to a predetermined value of 1.0 or less and the “area ratio 1” is set to a predetermined value α or more.

  Further, the second threshold value 54 (2) is arranged such that the appearance characteristics of the second specific defect image data, specifically, (a2) two substantially circular high-intensity regions 40 partially overlap. , Etc. are determined according to the characteristics. The second threshold value 54 (2) corresponds to (a2), in which “aspect ratio” is 1.0 or less, “average luminance-center luminance” is a predetermined value γ or more, and “area ratio 1” is a predetermined value. More than δ and the “average width aspect ratio” is set to a predetermined value ε or less.

  The first to Nth determination circuits 46 (1) to 46 (N) refer to the first to Nth threshold values 54 (1) to 54 (N), respectively, so that the defect image data 42a and 42b are the first. It is individually determined whether or not it is 1st to Nth specific defect image data.

  The defect position information data 62 stores the position coordinate data of the two-point aligned pseudo defect and the actual harm defect extracted by the defect position detection circuit 37. Thereby, the marking control circuit 38 can acquire the actual defect position coordinate data by referring to the defect position information data 62.

  Next, the operation of the defect inspection apparatus 11 having the above configuration will be described with reference to FIG. When an inspection start operation is performed at the operation unit 29, an inspection process by the defect inspection apparatus 11 is started simultaneously with the start of transport of the laminated film 9. First, the inspection light 24 is irradiated from the line light source 17 toward the laminated film 9.

  The inspection light 24 incident on the normal part of the laminated film 9 is converted into linearly polarized light that vibrates in a direction parallel to the polarization axis D <b> 1 and passes through the laminated film 9. On the other hand, the inspection light 24 incident on the film defect portion does not become linearly polarized light that vibrates in a direction parallel to the polarization axis D <b> 1 due to a change in the polarization state when passing through the film defect portion. The inspection light 24 transmitted through these normal portions or film defect portions enters the polarizing filter 19.

  In the inspection light 24 incident on the polarization filter 19, linearly polarized light that vibrates in a direction parallel to the polarization axis D 1 (direction perpendicular to the polarization axis D 2) is blocked by the polarization filter 19. On the other hand, the inspection light 24 that has not become linearly polarized light that oscillates in a direction parallel to the polarization axis D <b> 1 by passing through the film defect portion passes through the polarization filter 19 and enters the camera 20.

  The camera 20 images the inspection light 24 that has passed through the polarization filter 19 and outputs an image signal for one line to the apparatus main body 22. Hereinafter, the camera 20 continuously performs imaging and image signal output each time the laminated film 9 is conveyed line by line.

  The image signal for one line output from the camera 20 is sequentially input to the image processing circuit 32 via the input I / F 31. The image processing circuit 32 accumulates one line of image signals input from the input I / F 31 and each time image signals for a predetermined number of lines are accumulated, two-dimensional image data 41 is obtained based on these image signals. Generated and stored in the memory 30.

  The CPU 28 issues a defect image extraction command to the defect image extraction circuit 33 when new image data 41 is stored in the memory 30. In response to this instruction, the defect image extraction circuit 33 reads the image data 41 in the memory 30. Then, the defect image extraction circuit 33 starts extracting the high brightness area 40 resulting from the film defect portion from the image data 41 in accordance with the standard defined by the defect image extraction standard data 60 in the memory 30.

  First, the defect image extraction circuit 33 extracts the high luminance region 40 using the first extraction pattern as shown in FIG. As a result, when a plurality of high brightness areas 40 are gathered like a two-point aligned pseudo defect, an aggregate of these high brightness areas 40 is extracted as defect image data 42a. If the high brightness area 40 exists alone, the high brightness area 40 is extracted as the defect image data 42a.

  Next, the defect image extraction circuit 33 extracts the high luminance region 40 with the second extraction pattern as shown in FIG. As a result, when a plurality of high brightness areas 40 are gathered like a two-point aligned pseudo defect, the high brightness area 40 having the maximum number of pixels is extracted as the defect image data 42b. If the high-intensity region 40 exists alone, the high-intensity region 40 is extracted as the defect image data 42b, so that the defect image data 42b is the same as the defect image data 42a. The defect image extraction circuit 33 stores the defect image data 42 a and 42 b in the memory 30.

  The CPU 28 issues a feature amount extraction command to the feature amount extraction circuit 34 when new defect image data 42 a and 42 b are stored in the memory 30. In response to this command, the feature amount extraction circuit 34 extracts various feature amounts from the defect image data 42 a and 42 b in the memory 30. The feature amount extraction circuit 34 stores each feature amount in the memory 30 in association with the defect image data 42a and 42b of the extraction source.

  Next, the CPU 28 issues a determination command to the pseudo defect determination circuit 35 and the actual harm defect determination circuit 36. First, under the control of the pseudo defect determination control unit 28 a, the first determination circuit 46 (1) performs the first processing on each feature amount of the defect image data 42 a and 42 b in the memory 30 and the pseudo defect classification reference data 61. The threshold value 54 (1) is compared. Based on the comparison result, the first determination circuit 46 (1) performs a first determination process for determining whether or not the defect image data 42a and 42b are the first specific defect image data. Thereby, it is determined whether or not the film defect portion is “two-point alignment (1)”.

  The pseudo defect determination control unit 28a activates the second determination circuit 46 (2) when it is determined that the film defect portion is not “two-point alignment (1)”. The second determination circuit 46 (2) compares the feature amounts of the defect image data 42a and 42b with the second threshold value 54 (2), and the defect image data 42a and 42b are the second specific defect image data. A second determination process is performed to determine whether or not there is. Thereby, it is determined whether or not the film defect portion is “two-point alignment (2)”.

  Similarly, until the film defect portion is determined to be a two-point aligned pseudo defect, the pseudo defect determination control unit 28a performs the third determination by the third determination circuit 46 (3) to the Nth determination circuit 46 (N). The Nth determination process is sequentially executed to determine the presence or absence of two-point aligned pseudo defects.

  Most of the pseudo defects of the laminated film 9 are caused by the foreign matter 26 inside the separator 15. In the pseudo defect caused by the foreign matter 26, two high-luminance regions 40 are arranged as shown in FIGS. 7 to 8. Observed at. For this reason, in the defect image data 42a and 42b extracted from the image data 41, the film defect portion corresponding to the defect image data 42a in which the two high-intensity regions 40 are arranged can be determined as a pseudo defect. As a result, the presence / absence of a pseudo defect can be determined without performing feature amount extraction processing or complex calculation using multiple regression equations and discriminant functions for all of the image data 41 as in the past. As a result, the time required for the inspection process can be shortened, so that it is possible to inspect the laminated film 9 during traveling.

  The pseudo-defect determination control unit 28a stops the subsequent determination process when it is determined in any one of the first to (N (1)) determination processes that two film defect portions are pseudo-defects. Thereby, since useless determination processing is not performed, the inspection can be performed more quickly.

  The actual damage defect determination circuit 36 monitors the first to Nth determination processes by the first determination circuit 46 (1) to the Nth determination circuit 46 (N). The actual defect determination circuit 36 determines that the film defect portion is an actual defect when it is not determined as a pseudo defect by arranging two points in any of the determination processes.

  The CPU 28 issues a position detection command to the defect position detection circuit 37 when it is determined that the film defect portion is a two-point arrangement and is a pseudo defect or an actual defect. Upon receiving this command, the defect position detection circuit 37 detects the position coordinates in the laminated film 9 of the film defect portion determined to be a two-point arrangement pseudo defect or an actual defect. Next, the defect position detection circuit 37 stores the position coordinate data of the two-point aligned pseudo defect or the actual harm defect in the defect position information data 62 in the memory 30.

  The CPU 28 issues a marking command to the marking control circuit 38 when the actual harm defect position coordinate data is stored in the defect position information data 62. In response to this command, the marking control circuit 38 reads the actual defect position coordinate data from the defect position information data 62.

  Next, the marking control circuit 38 monitors the movement of the position corresponding to the position coordinate in the laminated film 9 based on the detection information from the leading end detection sensor, the conveyance speed of the laminated film 9, and the like. Then, when the position coordinate corresponding position moves directly below the marking device 21, the marking control circuit 38 operates the marking device 21 to perform marking at the position coordinate corresponding position. Thereby, the position of the actual harm defect in the laminated film 9 can be easily determined.

  Hereinafter, the above-described processing is repeatedly executed until the inspection of the entire region of the laminated film 9 is completed.

  In the above embodiment, the actual defect determination circuit 36 only determines whether or not the film defect portion is an actual defect, but when the film defect portion is an actual defect, the type (“foreign matter”, “elongated” Determination of “foreign matter”, “bare”, etc.) may be performed. In this case, as shown in FIG. 16, actual defect classification criteria data 64 is stored in the ROM area of the memory 30.

  In the actual damage defect classification reference data 64, threshold values of respective feature amounts respectively determined in advance according to the types of actual damage defects such as “foreign matter”, “elongated foreign matter”, and “bare” are stored. Thereby, the actual damage defect determination circuit 36 can determine the type of the actual damage defect by referring to the actual damage defect classification reference data 64 based on the extraction result of the feature amount extraction circuit 34.

  In the above embodiment, the case where the “two-point aligned pseudo defect” shown in FIGS. 7 to 11 occurs as a pseudo defect due to the foreign substance 26 in the separator 15 has been described as an example. There is a case where a pseudo defect having a shape (hereinafter referred to as a cross pseudo defect) occurs. In addition, “X” is included in “cross” here.

  When the foreign substance 26 exists in the separator 15, a depression 13 a is formed on the surface of the polarizing plate 13 in response to the pressure from the foreign substance 26 as shown in FIG. 4. At this time, if the dent 13a is formed in a shape close to an ideal circle, as shown in FIG. 17, the molecule Mc located on or near the straight line L1 passing through the center of the foreign material 26 and parallel to the polarization axis D1 is The alignment direction is not changed by merely translating in the direction parallel to the polarization axis D1. In addition, the molecular Md positioned on or near the straight line L2 passing through the center of the foreign substance 26 and perpendicular to the polarization axis D1 is merely translated in the direction perpendicular to the polarization axis D1, and the alignment direction does not change. On the other hand, the orientation direction of the molecules Me positioned obliquely with respect to the center of the foreign material 26 is inclined obliquely toward the center of the foreign material 26.

  Since the inspection light 24 transmitted through the molecules Mc and Md is linearly polarized light oscillating in a direction parallel to the polarization axis D1 (direction perpendicular to the polarization axis D2), the inspection light 24 is blocked by the polarization filter 19. The On the other hand, the vibration direction of the inspection light 24 that has passed through the molecule Me is not linearly polarized light that vibrates in a direction perpendicular to the polarization axis D2, and thus passes through the polarization filter 19. As a result, when the inspection light 24 is imaged, as shown in FIG. 18, a black image (displayed with dots in the drawing) includes a cross-shaped high-intensity region 66 (displayed with a white portion in the drawing). Image data 41 is acquired.

  As described above, when the pseudo defect caused by the foreign material 26 in the separator 15 includes both the “two-point aligned pseudo defect” and the “cross pseudo defect”, the pseudo defect determination circuit 35 includes the Xth determination circuit 46 ( X) is provided, and the Xth threshold value 54 (X) is registered in the pseudo defect classification reference data 61.

  The X-th determination circuit 46 (X) performs the X-th determination process for determining whether or not the defect image data 42a and 42b is the X-th specific defect image data indicating the “cross-fault defect”, so that the film defect portion Is a “cross pseudo defect”.

  The Xth threshold value 54 (X) is data used for the Xth determination process, and is determined according to the appearance characteristics of the Xth specific defect image data. Specifically, (aX) the high luminance region 40 has a substantially cross shape, and (bX) the luminance of the central portion of the cross is equal to or darker than the luminance of other portions. Further, in (aX), when the high-luminance area 40 has a substantially cross shape, (aX-1) the circumscribed square 43a has a substantially square shape, and (aX-2) the high-luminance area within the circumscribed square 43a For example, the ratio of the area of 40 becomes a predetermined value or less.

  The first threshold value 54 (1) is set in a predetermined range (ζ or more and η or less) in which the “aspect ratio” includes 1.0, corresponding to (aX−1). Corresponding to (aX-2), “area ratio 1” is determined within a predetermined range of 0.5 or less, and “average width aspect ratio” is determined within a predetermined range of 3.0 or less. Corresponding to (bX), “average luminance−center luminance” is set to a value close to 0 of −5.0 or more.

  The X-th determination circuit 46 (X) can perform the X-th determination process by comparing the extraction result of the feature amount extraction circuit 34 with the X-th threshold value 54 (X). In addition, you may change suitably the order which performs a Xth determination process in each determination process, for example to the 1st. In this case, when it is determined that the film defect portion is the “cross pseudo defect”, the pseudo defect determination control unit 28 a stops the subsequent determination processing.

  Further, the present invention can be applied to a case where there are not only one type of “cross pseudo defect” but also a plurality of types. In this case, similarly to the “two-point aligned pseudo defect”, the threshold value of each feature amount predetermined for each type of “cross pseudo defect” is stored in the pseudo defect classification reference data 61. Thereby, the pseudo defect determination circuit 35 can determine the type of “cross pseudo defect” by referring to the pseudo defect classification reference data 61.

  In the above-described embodiment, the pseudo defect caused by the foreign material 26 included in the separator 15 is described as an example of the pseudo defect of the laminated film 9. For example, as illustrated in FIG. The present invention can also be applied to inspection of a pseudo defect caused by the foreign matter 68 existing between the plate 13 and the plate 13. When the separator 15 is peeled off from the polarizing plate 13, the foreign matter 68 may remain in the adhesive layer 14, but the foreign matter 68 is removed by a cleaning process performed before the polarizing plate 13 is attached to a glass substrate of a liquid crystal display. The For this reason, even if the foreign material 68 is generated, the performance of the polarizing plate 13 is not affected. The inspection of the pseudo defect caused by the foreign substance 68 can be performed by the same method as the inspection of the two-point aligned pseudo defect or the cross pseudo defect caused by the foreign substance 26 described above.

  In the above embodiment, the inspection light 24 transmitted through the polarizing filter 19 is imaged by the camera 20, but the inspection light is used by using various cameras (imaging means) such as an area camera movable in the width direction of the laminated film 9. 24 may be imaged.

  In the above embodiment, “average luminance”, “center luminance”, and the like have been described as examples of feature amounts extracted by the feature amount extraction circuit 34 from the defect image data 42a and 42b. You may extract the feature-value other than the above useful for determination of a pseudo defect.

  In the above-described embodiment, the two-point aligned pseudo defect or the cross pseudo defect is determined as the pseudo defect of the laminated film 9. It may be determined as 9 pseudo defects.

  In the said embodiment, although the laminated | multilayer film 9 is a 3 layer structure, this invention is applicable also when performing the test | inspection of the laminated film of 2 layers or 4 layers or more including the polarizing plate 13 at least. Further, the separator 15 may be attached to both surfaces of the polarizing plate 13 via the adhesive layer 14.

  Although the defect inspection apparatus 11 arrange | positioned in the lamination film manufacturing line 10 which manufactures the lamination | stacking film 9 used for a liquid crystal display was mentioned as an example, it demonstrated, and the defect inspection apparatus of the lamination | stacking film used other than a station layer display The present invention can be applied.

  Hereinafter, examples for demonstrating the effects of the present invention will be shown to specifically describe the present invention. However, the present invention is not limited to these examples.

  As shown in Table 1 below, in the embodiment, the defect inspection apparatus 11 acquires 1139 sheets of image data 41 (data of about 7500 m of the laminated film 9), and defect image data for each individual image data 41. Acquisition of 42a, 42b, acquisition of each feature amount from the defect image data 42a, 42b, and determination of the presence / absence of a two-point aligned pseudo defect and an actual defect were performed.

  A film defect portion determined to be a pseudo defect and an actual defect by the defect inspection apparatus 11 was visually confirmed by an inspector. As a result, there were 10 cases in which the two-point aligned pseudo defect was determined to be a chipping, and one one in which a double-point aligned pseudo defect was determined to be a pseudo defect was generated. Among the actual 606 (= 597 + 10−1) two-point aligned pseudo defects, 11 misjudgments were made, and the misjudgment rate was about 1.81%. As a result, it was confirmed that the defect inspection apparatus 11 can execute the determination of the presence or absence of two-point aligned pseudo defects with high accuracy.

DESCRIPTION OF SYMBOLS 9 Laminated film 11 Defect inspection apparatus 13 Polarizing plate 15 Separator 17 Line light source 19 Polarization filter 20 Line sensor camera 21 Marking apparatus 22 Apparatus main body 24 Inspection light 28 CPU
33 Defect Image Extraction Circuit 34 Feature Amount Extraction Circuit 35 Pseudo Defect Determination Circuit 36 Actual Defect Defect Determination Circuit 40, 66 High Brightness Area 42a, 42b Defect Image Data 46 (1) to 46 (N) First Determination Circuit to Nth Determination Circuit 54 (1) to 54 (N) First threshold value to Nth threshold value 61 Pseudo defect classification reference data

Claims (9)

A light source that is disposed on one side of the front and back surfaces of a multilayer laminated film formed by laminating a polarizing plate and a film, and irradiates light to the laminated film;
Arranged on the other side of the front and back surfaces, having a second polarization axis parallel to the front and back surfaces and substantially perpendicular to the first polarization axis of the polarizing plate, and blocking the light transmitted through the normal portion of the laminated film A polarizing filter,
An imaging unit that is disposed on the side opposite to the side of the polarizing filter that faces the laminated film, and that captures the light that has passed through the polarizing filter;
A defect image extracting means for extracting, from the transmitted light image of the polarizing filter acquired by the photographing means, a defective portion of the laminated film and a high brightness region whose brightness is increased by the light transmitted through the polarizing filter as a defect image; ,
When the defect image extracted by the defect image extraction means is a specific defect image in which two high-luminance regions are arranged, the defect portion corresponding to the defect image is a pseudo defect that is not a defect of the polarizing plate. Pseudo-fault determination means for determining that there is,
A defect inspection apparatus comprising: A plurality of types of feature amounts including at least an average luminance that is an average value of the luminance of the defect image and a central luminance that is a luminance at the center position of the defect image are extracted from the defect image extracted by the defect image extraction unit. Feature amount extraction means
The pseudo defect determination unit compares the extraction result of the feature amount extraction unit with a threshold value of each feature amount that is predetermined according to the feature of the specific defect image, so that the defect image is identified. The defect inspection apparatus according to claim 1, wherein it is determined whether or not the image is a defect image.   The defect inspection apparatus according to claim 2, wherein the feature amount includes a difference between the average luminance and the central luminance. The specific defect image includes first to N-th specific defect images corresponding to N (N is a natural number of 2 or more) types of first to N-th pseudo defects, respectively, and the threshold value includes the first to N-th specific defect images. It consists of first to Nth threshold values individually determined according to the characteristics of the N specific defect image,
The defect image is provided in the pseudo defect determination unit, and the defect image is the first to Nth specific defect image by individually comparing the extraction result of the feature amount extraction unit with the first to Nth threshold values. First to Nth determination means for individually determining whether or not there are;
The determination processes by the first to Nth determination means are executed in a predetermined order, and the defect portion is determined to be the pseudo defect in the Mth [M is a natural number equal to or less than (N−1)] th determination process. 4. The defect inspection apparatus according to claim 2, further comprising: a determination control unit that cancels the (M + 1) th and subsequent determination processes when the determination is made.   The defect inspection apparatus according to any one of claims 1 to 4, wherein the specific defect image includes an image having the high-intensity region having a substantially cross shape.   The defect inspection apparatus according to claim 1, wherein the film is a separator that is detachably attached to an adhesive layer formed on a surface of the polarizing plate.   It comprises actual defect determination means for determining that the defect portion corresponding to the defect image that has not been determined to be the specific defect image by the pseudo defect determination means is an actual defect that is a defect of the polarizing plate. The defect inspection apparatus according to any one of claims 1 to 6.   The defect inspection apparatus according to claim 7, further comprising a marking unit that performs marking indicating the actual harmful defect in a portion of the laminated film that is determined to be the actual harmful defect. An irradiation step of irradiating light to the laminated film from a light source disposed on one side of the front and back surfaces of a multilayer laminated film formed by laminating a polarizing plate and a film,
The light that has been transmitted through the normal portion of the laminated film by a polarizing filter that is disposed on the other side of the front and back surfaces and has a second polarization axis that is parallel to the front and back surfaces and substantially perpendicular to the first polarization axis of the polarizing plate. A blocking step for blocking
A photographing step of photographing the light transmitted through the polarizing filter by photographing means disposed on the surface opposite to the surface facing the laminated film of the polarizing filter;
A defect image extraction step for extracting, as a defect image, a defect portion of the laminated film and a high-luminance region whose luminance is increased by the light transmitted through the polarization filter from the transmitted light image of the polarization filter acquired in the photographing step;
When the defect image extracted in the defect image extraction step is a specific defect image in which two high-luminance regions are arranged, the defect portion corresponding to the defect image is a pseudo defect that is not a defect of the polarizing plate. A pseudo-defect determination step for determining that there is,
A defect inspection method characterized by comprising:

Images