KR101082699B1 - Device For Inspecting Defects Of Optical Film - Google Patents

Abstract

The present invention relates to an inspection apparatus for an optical film, the inspection apparatus for an optical film according to the present invention is an inspection apparatus for an optical film for inspecting an optical film having a predetermined polarization direction through a plurality of inspection units including a light source and an image pickup means. The light source is provided to irradiate light to one side of the optical film, and the other side of the optical film is installed to receive the light irradiated from the light source to obtain a captured image of the optical film, the center is the A boundary permeation inspection unit including imaging means spaced apart from and parallel to a point coinciding with the center of the light source; A polarizing film installed on the front portion of the optical film and having a polarization direction orthogonal to the polarization direction of the optical film; And an image processing apparatus for detecting and detecting the foreign matter by displaying and analyzing the captured image of the foreign material picked up by the image pickup means, wherein the image pickup means includes the optical due to the foreign material. By the light leakage phenomenon of the film, the vertical light and the oblique light irradiated from the light source are superimposed together to obtain a captured image of the foreign material, and the captured image is an image of a size corresponding to the foreign material through the vertical light. At the same time, the bend of the adjacent region of the foreign material is imaged through the inclined light to obtain a captured image of the foreign material substantially larger than the size of the foreign material on the optical film. As a result, by acquiring a clear image of the foreign material, it is possible to accurately measure the size of the foreign material to lower the false detection rate, improve the product yield, reduce the manufacturing cost, and detect an undetected very fine foreign film. An inspection device for the device is provided.

Optical film, polarizing film, inspection device, boundary transmission, transmission inspection, reflection inspection, foreign material measurement

Description

Inspection device for optical film {Device For Inspecting Defects Of Optical Film}

The present invention relates to an inspection apparatus for an optical film, and more particularly, to separate the imaging means installed at a position facing the light source for the transmission inspection of the optical film spaced apart at a constant distance in a direction parallel to the optical film. The present invention relates to an optical film inspection apparatus capable of detecting foreign substances by simultaneously receiving inclined light and vertical light emitted from the same.

In general, a polarizing film is used as part of an LCD panel by adhering to one side or both sides of a liquid crystal cell. LCD (Liquid Crystal Display) is a display device developed to replace Cathode Ray Tube (CRT), which is used for monitors such as TVs or computers. It is widely used in industry.

As shown in FIG. 1, the basic structure of the polarizing film 100 as described above is a polarizing element 101 for controlling polarization characteristics by dyeing iodine or dye in PVA (Poly Vinyl Alcohol) and an isotropic film for protecting the same. Tri-Acetyl-Cellulose (TAC) film 102, which is an isotropic film, is positioned on both sides of the polarizer 101, and an adhesive 103 such as a pressure sensitive adhesive (PSA) for attaching to the upper and lower panels of the panel is provided. The polarizing film 100 is formed.

In addition, a release film 104 made of polyethylene terephthalate (PET) material, which protects the adhesive 103, is bonded to the upper portion of the adhesive 103 to protect the polarizing film 100, and to a lower portion of the TAC film. Located on the back of the TAC film 102 located in the form of an optical film (F) attached to the protective film 105 of PET material can be added to the subsequent panel bonding process.

However, as described above, the optical film F is detected when the surface foreign material (b) (c) is detected by inspecting the internal foreign material (a) and the surface foreign material (b) (c) which may be generated during the manufacturing process. The surface foreign material (b) (c) is removed, and when the internal foreign material (a) is detected, the optical film (F) is destroyed. Here, the foreign matter (a) may be a stretching white point such as a sila or wide liquid crystal crack generated through the stretching process, the coating process, the surface foreign matter (b) (c) may be a surface scratch or adhesive contamination.

Through the inspection process for detecting such foreign matters, only the optical film (F) without foreign matters is selected and put into a subsequent panel bonding process. Therefore, in the inspection process, the inspection is performed by using various inspection apparatuses for the determination of the foreign matter (a) or the surface foreign matter (b) of the optical film (F).

2 is a schematic view of a conventional inspection apparatus for an optical film. Referring to FIG. 2, the inspection apparatus includes a transmission inspection unit A, a cross-transmission inspection unit B, and a first reflection inspection unit installed to acquire an image of the optical film F transferred by a predetermined conveying means (not shown). (C) and the second reflection inspection unit (D).

Here, the inspection unit (A) (B) (C) (D) is a light source 111, 121, 131, 141 for irradiating light to the optical film (F) and the light to detect the optical film (F) Photodetectors 112, 122, 132, and 142 for generating an image of an electrical signal.

The transmission inspection unit A is disposed below the optical film F, and transmits light vertically passing through the optical film F from the first light source 111 and the first light source 111. And a first photodetector 112 for generating an electrical signal and outputting the electrical signal to the image processing apparatus 140. Here, the transmission inspection unit A is preferably installed so that the center of the first light source 111 and the center of the lens (not shown) of the first light detector 112 face each other and coincide with each other.

In addition, a known camera such as a CCD camera or a line scan camera may be used as the photodetector 112 (the same reflection inspection unit described below), and a plurality of cameras may be installed in parallel in consideration of the width of the optical film F. have.

The cross-permeation inspection unit A is disposed below the optical film F to vertically pass the optical film F from the second light source 121 and the second light source 121 to irradiate light vertically upward. And a second photodetector 122 for detecting the transmitted light to generate an electrical signal and outputting the electrical signal to the image processing apparatus 140. Here, the light is polarized between the second light source 121 and the optical film F so that the polarization direction is perpendicular to the polarization direction of the optical film F, that is, 90 ° to the polarization direction of the optical film F. The polarizing film 123 formed to be may be disposed.

That is, the light irradiated from the second photodetector 122 is, for example, formed to be polarized in the vertical direction in which the polarizing direction is 90 ° with respect to the polarizing film 123 and the polarizing film formed on the bottom surface in the horizontal direction. While continuously passing through the optical film (F) to detect the light transmitted through the second photodetector 122 to generate an electrical signal. In other words, the image captured by the second photodetector 122 should be expressed in black, but if there is a foreign material, a light leakage phenomenon is generated in the area having the foreign material, and thus, the foreign material is present in the corresponding area.

In addition, the cross-permeation inspection unit (B) is also provided such that the center of the second light source 121 and the center of the lens (not shown) of the second photodetector 112 face each other and coincide with each other like the transmission inspection unit (A). Do.

In addition, a known camera such as a CCD camera or a line scan camera may be used as the photodetector 122 (the same reflection inspection unit described below), and a plurality of cameras may be installed in parallel in consideration of the width of the optical film F. have.

The first reflection inspection unit C installed next to the transmission inspection unit has a third light source 131 for illuminating the lower surface of the optical film F and a third light detector 132 for detecting the reflected light reflected from the third light source 131. ). Here, the third light source 131 is installed so that light is irradiated at an angle with a predetermined incident angle θ ₁ with respect to the vertical axis of the lower surface of the optical film F. The incident angle θ ₁ may reflect a sufficient amount of light, for example, It can be set at 45 degrees.

In addition, the second reflection inspection unit D provided after the first reflection inspection unit C detects the fourth light source 141 illuminating the upper surface of the optical film F and the reflected light reflected from the fourth light source 141. And a fourth photodetector 132. Here, the fourth light source 131 is installed so that light is irradiated obliquely with a predetermined incident angle θ ₂ with respect to the vertical axis of the upper surface of the optical film F. The incident angle θ ₂ is 45 degrees in consideration of the reflection amount, for example. Can be set.

The predetermined electrical signals generated from the third photodetector 122 and the fourth photodetector 132 are input to the image processing apparatus 140 and processed into digital image data represented by a pixel array. In addition, the digital image data detects whether a foreign material exists in the optical film (F).

By the way, as described above, the polarizing film 100 is substantially attached to the liquid crystal panel in the process, but the inspection of the foreign material by being injected into the inspection apparatus is performed by the optical film having the release film 104 and the protective film 105 attached thereto. F) there was a problem that the detection force for detecting the foreign matter by the release film 104 and the protective film 105 is lowered.

Therefore, the inspection of the general optical film is performed in parallel with the transmission inspection through the transmission inspection unit and the reflection inspection through the reflection inspection unit as described above, but there was a problem that the false detection rate was high due to the low accuracy of the imaging of the foreign material.

In addition, as the false detection rate is high, the product yield is low, there is a problem that the manufacturing cost increases.

Accordingly, an object of the present invention is to solve such a conventional problem, and by moving the transmission inspection camera from a point coinciding with the center of the corresponding light source to a point in the area where the camera is not defocused, a clear foreign material It is to provide an inspection apparatus for an optical film that can accurately measure the size of the foreign material by obtaining an image to lower the false detection rate.

In addition, as the false detection rate is lowered to improve the product yield provides an inspection apparatus for an optical film that can reduce the manufacturing cost.

In addition, an object of the present invention is to provide an inspection apparatus for an optical film that can detect very fine foreign matter that has not been detected.

The above object is, according to the present invention, in the inspection device of an optical film for inspecting an optical film having a predetermined polarization direction through a plurality of inspection unit including a light source and an image pickup means, the light irradiation on one side of the optical film The light source is installed to receive the light emitted from the light source on the other side of the optical film to obtain a captured image of the optical film, the center is spaced apart in parallel from the point coinciding with the center of the light source A boundary permeation inspection unit comprising an imaging means; A polarizing film installed on the front portion of the optical film and having a polarization direction orthogonal to the polarization direction of the optical film; And an image processing apparatus for displaying and analyzing a captured image captured by the image pickup means, wherein the image pickup means includes, when foreign matter is present on the optical film, the light source due to light leakage of the optical film due to the foreign material. The vertical light and the inclined light irradiated from the light are superimposed together to obtain a captured image of the foreign material. The captured image is an image of a size corresponding to the foreign material through the vertical light and the foreign material through the inclined light. The curvature of the adjacent region of can be achieved by the optical film inspection apparatus, characterized in that to obtain a captured image of the foreign material substantially larger than the size of the foreign material on the optical film.

Here, the captured image of the foreign material obtained by the imaging means is a substantially three-dimensional captured image, the three-dimensional captured image can be analyzed by the image processing apparatus the surface curvature of the optical film or the height of the foreign material. have.

On the other hand, a light source for irradiating light to be inclined at a predetermined angle with the optical film on one side of the optical film, the light irradiated from the light source is reflected on the optical film, the image of the optical film through the reflected light The apparatus may further include a reflection inspection unit installed to capture an image.

According to the present invention, the transparent inspection camera is moved from a point coinciding with the center of the light source to a point in an area where the camera is not defocused, thereby obtaining a clear image of a foreign object, thereby accurately measuring the size of the foreign object and thus detecting a false detection rate. There is provided an inspection device for an optical film that can lower the.

In addition, as the false detection rate is lowered, the product yield is improved to provide an inspection apparatus for an optical film that can reduce the manufacturing cost.

In addition, there is provided an inspection apparatus for an optical film that can detect very fine foreign matter that has not been detected.

Prior to the description, in the various embodiments, components having the same configuration will be representatively described in the first embodiment using the same reference numerals, and in other embodiments, different configurations from the first embodiment will be described. do.

Hereinafter, an inspection apparatus of an optical film according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is an inspection apparatus of an optical film according to a first embodiment of the present invention. Referring to FIG. 3, an apparatus for inspecting an optical film according to a first exemplary embodiment of the present invention may include a housing 2, an optical film feeder 10 installed outside the housing 2, and an inside of the housing 2. The line marker 20, the first reflection inspection unit 30, the second reflection inspection unit 40, the cross-permeation inspection unit 50, the boundary penetration inspection unit 60, and the image processing apparatus 70 installed in the predetermined portion. It may be configured to include).

Here, the optical film 1 provided may have the same configuration as the optical film described in the background art and may be provided in the form of a sheet. The first embodiment of the present invention shows that the supply in a continuous form, that is, an in-line form.

The optical film feeder 10 may be configured to release the optical film 1 wound in the form of a roll and provide it in an inline form. Although the illustrated form is installed outside the housing 2, In order to maintain the clean state of the optical film 1, it may be installed on the inner side of the housing (2).

The line marker 20 may be configured to display the optical film 1 provided in the inline form from the optical film feeder 10 for each small length. The line marker 10 is a means for marking the optical film 1 to be cut in the form of each sheet after the inspection is completed. In addition, the length of each sheet may be configured to be changed depending on the size of the panel to be attached.

The first reflection inspection unit 30 installed after the line marker 20 may include a first light source 31 and a first imaging unit 32. In this case, the first light source 31 is installed to irradiate the lower side surface of the optical film 1 at a predetermined angle, and the first imaging unit 32 receives light reflected from the first light source 31 to capture the light. The image may be converted into predetermined image data and transmitted to the image processing apparatus 70 to be described later. That is, it is provided so that the foreign material by the light reflection in the lower part can be detected by irradiating light to the lower side of the optical film 1, and imaging an image.

In addition, the second reflection inspection unit 40 installed after the first reflection inspection unit 30 may include a second light source 41 and a second imaging means 42.
That is, it may be configured in the same manner as the first reflection inspection unit 30 described above, and the difference from the first reflection inspection unit 30 is provided on the upper portion of the optical film 1, the upper portion of the optical film 1 It may be configured to capture an image of the optical film 1 by light reflection, convert the captured image into predetermined image data, and transmit the image to the image processing apparatus 70 to be described later.

On the other hand, the cross-permeable inspection unit 50 installed after the second reflection inspection unit 40 may include a third light source 51 and the third imaging means 52. The third light source 51 may be installed under the optical film 1, and may be installed to irradiate the optical film 1 with light vertically upward. In this case, as described in the prior art, the front portion to which the light of the third light source 51 is irradiated is installed so as to transmit through the first polarizing film 51a having a 90 ° difference from the optical film 1 provided. Can be.

In addition, the third imaging means 52 is installed on the upper portion of the optical film 1, and the center of the third light source 51 and the center of the lens (not shown) of the third imaging means 52 are installed to match. It can be installed so that only the vertical light irradiated perpendicularly to the optical film 1 from the third light source 51 can be reached, and the captured image is converted into predetermined image data and transmitted to the image processing apparatus 70 to be described later. It can be configured to be. In this case, the image of the optical film 51a may be captured by the light reaching the third imaging unit 52.

Here, the photographed image should be photographed in black since the polarization directions of the first polarizing film 51a and the optical film 1, which are two films that are transmitted, are 90 ° apart from each other. However, when the light leakage phenomenon occurs in a certain region in black through the image processing apparatus 70 to be described later, it may be determined that there is a foreign material in the light leakage region through the light transmitted through the corresponding light leakage region.

Next, the boundary permeation inspection unit will be described. 4 is a schematic diagram of the boundary permeation inspection unit according to the first embodiment of the present invention, and FIG. 5 is a light transmission state diagram of the boundary permeation inspection unit. 3 and 4, the boundary permeation inspection unit 60 may be installed after the cross-permeation inspection unit 50 described above, and may include a fourth light source 61 and a fourth image pickup means 62. Can be.
The fourth light source 61 may be installed to irradiate light vertically downward from the upper portion of the optical film 1 transferred from the optical film feeder 10.
The polarizing film 61a is positioned between the fourth light source 61 and the optical film 1. In this case, the polarizing film 61a may be provided to have a polarization direction orthogonal to the polarization direction of the optical film 1 (a polarization direction that is 90 ° different from the polarization direction of the optical film).
That is, the light irradiated from the fourth light source 61 may pass through the polarizing film 61a and be irradiated to the optical film 1.

On the other hand, the fourth imaging means 62 is installed under the optical film 1, and coincides with the center of the fourth light source 61 and the center of the lens (not shown) provided in the fourth imaging means 62. It is installed so as to be spaced apart by a predetermined distance (l) in a direction parallel to the optical film 1 from the center to be able to capture the image of the optical film (1). In this case, the captured image may be converted into predetermined image data and transmitted to the image processing apparatus 70 to be described later.

Here, the spaced distance is out of focusing that is out of focus of the image captured by the fourth imaging means 62 from the center of the lens of the fourth imaging means 62, which is a point coinciding with the center of the fourth light source 61. It may be any one of the distance within the boundary distance to the boundary.

That is, when the transmission test is performed by configuring two centers of the conventional light source and the image pickup means, the image is captured by the vertical light emitted from the light source.

On the contrary, as shown in FIG. 5, in the present invention, the distance is spaced apart by a certain distance (l) according to the lens within the out-focusing area, but does not deviate from the boundary distance, which is a distance at which the focal point of the fourth imaging means 62 does not deviate. By spaced apart in parallel with the optical film 1 within, the area where the vertical light n reaches reaches partially, and the light reaching from the fourth light source 61 is inclined, i.e., the inclined light s arrives. This area is partially generated.

As a result, when the overlapped light arrives, a diffraction phenomenon of light, etc., which may occur in a conventional reflection test, is generated, and thus, the foreign material can be captured by including the adjacent area of the foreign material.

In addition, the illustrated form shows only the distance (l) just before the lens (not shown) provided in the fourth imaging means 62 to be out of focus, but may include all cases shorter than the distance (l). .

In addition, the separation direction of the fourth imaging means 62 is spaced in parallel with respect to the optical film (1), the conveying direction of the optical film (1) to be transferred, the reverse direction of the conveyance and the left and right width direction of the optical film (1) 360 ° included in any direction. That is, it can be spaced apart so as to be parallel to the optical film 1 in any direction within the focusing distance.

The image captured by the boundary permeation inspection unit 60 installed as described above is irradiated from the fourth light source 61 as well as the vertical light n irradiated from the fourth light source 61 and transmitted to the optical film 1. Since the oblique light s transmitted through (1) is superimposed and received together, the image of the foreign matter present in the optical film 1 can be captured very clearly.

In addition, by receiving not only the vertical light n but also the inclined light s, the image can be captured as the size of the foreign material up to the curvature of the periphery of the foreign material present on the captured image. As a result, the curvature of the adjacent region of the foreign material present on the captured image can be captured together, so that the size of the foreign material can be captured substantially larger.

Therefore, although the foreign material having a very fine size is not detected through the conventional permeation inspection unit, the boundary permeation inspection unit according to the present invention can be detected as the foreign matter by imaging the curvature of the adjacent region of the foreign matter.

In addition, the conventional permeation inspection unit was unable to image the surface bending, etc., but the boundary permeation inspection unit according to the present invention images the surface bending and the like to determine the surface curvature degree of the optical film known through the conventional reflection inspection. It can also be measured by the program.

In addition, the conventional transmission inspection was able to obtain only a two-dimensional planar image by receiving only the vertical light, but through the boundary transmission inspection unit according to the present invention by receiving not only vertical light but also oblique light present in the optical film The shape of the foreign material can be captured close to the three-dimensional image, it is possible to measure the height of the foreign material through a predetermined program.

Next, the image processing apparatus 70 may be configured to display and analyze image data received from the first, second, third, and fourth imaging means 32, 42, 52, and 62 described above. Can be. If it is determined that the foreign material through each image data transmitted to the image processing apparatus 70 is discarded in the process after the optical film (1).

Next, application examples of the boundary permeation inspection unit of the inspection apparatus for optical films according to the first embodiment of the present invention will be described.

6 is an application example of an inspection apparatus for an optical film according to a first embodiment of the present invention. 6, as the configuration used in the present application, the light source 81 is a metal halide 80,000 Lux, the camera 82 is ATMEL 4K SCAN, the lens of the camera 82 is a 90mm lens for TAMRON Corporation Applied.

A light source 81 is installed at the lower portion of the optical film 1 that is continuously provided so as to irradiate light perpendicularly to the optical film 1, and is spaced 14.5 cm apart from the optical film 1.

At this time, the camera 82 as an image pickup means is installed so that the lens of the camera 82 and the optical film 1 is parallel to the upper portion of the optical film 1 to receive the light irradiated from the light source 81, the optical film It can be installed 43.5cm apart to focus to acquire the image of (1).

In addition, the center of the lens of the camera 82 is installed spaced apart from the center of the light source 81, it can be installed to move in parallel to the optical film (1) in the region does not go out of focus (focus). In this application example, imaging was spaced apart by 1.4 cm, which is a range in which focus does not deviate.

7 to 10 (a) is an image picked up through the conventional transmission inspection, Figure 7 to 10 (b) is a picked up image taken through the boundary permeation inspection according to the present invention.

Referring to FIGS. 7 to 10, it can be seen that the surface image of the image captured by the conventional transmission inspection unit is not imaged, and the surface image of the image captured by the boundary permeation inspection unit according to the present invention is imaged.

In addition, the image photographed by the conventional transmission inspection unit receives only the normal light transmitted through the image to be picked up, so that the pit (pit) of the pit shape as shown in Figure 7 a, Figure 8 c, Figure 9 e Figure 10 g A foreign object such as a sila is not only an image of a planar form is photographed, but also the image of the image is not clear.

On the other hand, looking at the image picked up through the boundary transmission unit according to the present invention, in Fig. 7b, the vertical light as well as the inclined light is transmitted to the adjacent region of the pit (pit) is imaged by the image pickup means conventionally pit (pit) In addition to being sharper than the shape of the), the surface curvature of the adjacent region of the pit can be imaged so that the shape of the pit can be made larger.

In addition, in FIG. 8D, FIG. 9F, and FIG. 10H, the foreign material in the silo form is not only clearly captured, but also the surface curvature of the adjacent area is included, so that the size of the foreign material may be further increased.

That is, the conventional transmission inspection unit can not capture by simply photographing a two-dimensional planar image by imaging using only vertical light, but could not detect foreign matter that may exist, the boundary permeation inspection unit according to the present invention By imaging using not only vertical light but also inclined light, foreign matter that cannot be conventionally imaged can be imaged by a changed size of surface curvature.

In addition, in the prior art, it may be determined that the object is not a foreign material according to the captured image, but the boundary permeation inspection unit according to the present invention has a clear image of the foreign material and is imaged up to the surface curvature so that the image is larger than the conventional foreign object captured image, so The detection rate can be reduced.

In addition, conventionally, by using only the vertical light to capture the image of the planar image surface curvature was not known, but through the boundary permeability inspection unit according to the present invention by imaging not only the vertical light but also the inclined light of the optical film Surface curvature may be imaged, and thus surface curvature may be measured and analyzed using a predetermined analysis program.

The scope of the present invention is not limited to the above-described embodiment, but may be embodied in various forms of embodiments within the scope of the appended claims. Without departing from the gist of the invention claimed in the claims, it is intended that any person skilled in the art to which the present invention pertains falls within the scope of the claims described in the present invention to various extents which can be modified.

1 is a block diagram of an optical film,

2 is a schematic view of a conventional inspection device for optical films,

3 is a schematic view of an inspection apparatus for an optical film according to a first embodiment of the present invention;

4 is an enlarged view of the boundary permeation inspection unit according to the first embodiment of the present invention;

5 is a light transmission state diagram of the boundary permeation inspection unit according to the first embodiment of the present invention;

6 is an application example of the boundary permeability inspection unit of the inspection device for an optical film according to the first embodiment of the present invention,

7 to 10 (a) is an image captured by a conventional transmission inspection unit,

7-10 (b) is an image picked-up image taken through the boundary permeation | inspection inspection part which concerns on this invention.

<Explanation of symbols for the main parts of the drawings>

DESCRIPTION OF SYMBOLS 1 Optical film 2 Housing 10 Optical film feeder

20: line marker 30: first reflection inspection unit 40: second reflection inspection unit

50: cross-permeation inspection unit 60: boundary permeation inspection unit 70: image processing apparatus

Claims (3)

An optical film inspection apparatus for inspecting an optical film having a predetermined polarization direction through a plurality of inspection units including a light source and an imaging means, A light source installed to irradiate light on one side of the optical film, and a light source irradiated from the light source on another side of the optical film to obtain a captured image of the optical film, the center of which is the center of the light source A boundary permeation inspection unit including an imaging unit spaced apart from and parallel to the point corresponding to the boundary; A polarizing film positioned between the light source and the optical film of the boundary permeation inspection unit and having a polarization direction orthogonal to the polarization direction of the optical film; And an image processing apparatus for displaying and analyzing the captured image captured by the imaging means. When the image pickup means has a foreign material on the optical film, the vertical light and the oblique light irradiated from the light source are superimposed together by the light leakage phenomenon of the optical film due to the foreign material to obtain a captured image of the foreign material, The captured image is an image of a size corresponding to the foreign material through the vertical light and the bend of the adjacent region of the foreign material is captured by the inclined light, the foreign material substantially larger than the size of the foreign material on the optical film Inspection device for an optical film, characterized in that to obtain a captured image. The method of claim 1, The captured image of the foreign material obtained by the imaging means is substantially a three-dimensional captured image, wherein the three-dimensional captured image is characterized in that the surface curvature of the optical film or the height of the foreign material is analyzed by the image processing apparatus. Inspection device for optical film. The method according to claim 1 or 2, A light source for irradiating light to one side of the optical film to be inclined at a predetermined angle with the optical film, and the light irradiated from the light source is reflected on the optical film, and to capture an image of the optical film through the reflected light Inspection device for an optical film, characterized in that it further comprises a reflection inspection unit installed.

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