CN111024707B

CN111024707B - Optical film detection device and detection method of optical film

Info

Publication number: CN111024707B
Application number: CN201911167285.7A
Authority: CN
Inventors: 陈奕齐; 洪嘉嬬; 阮祺婷; 黄馨卉
Original assignee: Sumika Technology Co Ltd
Current assignee: Sumika Technology Co Ltd
Priority date: 2019-03-12
Filing date: 2019-11-25
Publication date: 2022-11-18
Anticipated expiration: 2039-11-25
Also published as: TWI676797B; CN111024707A; TW202033952A

Abstract

The present disclosure provides an optical film inspection apparatus and an optical film inspection method. The optical film detection device is used for detecting the defects of the optical film. The device comprises: a conveying system, a first light source assembly and a first shooting assembly. The conveying system is used for carrying and conveying the optical film. The first light source assembly is arranged on one side of the optical film and provides a first light source, and the first light source is provided with a first optical axis. The first shooting component is arranged on one side of the optical film and shoots a first surface of the optical film. In addition, the first optical axis of the first light source is parallel to or offset from the first surface of the optical film. The present disclosure also provides a method for inspecting an optical film.

Description

Optical film detection device and detection method of optical film

Technical Field

The present disclosure relates to an optical film inspection apparatus, and more particularly, to an optical film inspection apparatus for inspecting defects of an optical film and an inspection system including the same.

Background

Optical films are widely used for various articles in daily life, for example, an anti-glare material for lamps, a window heat insulating material, a filter material for digital cameras, a flat panel display, and the like. The flat panel display is one of the most important industries in recent years, and the production value of the liquid crystal display accounts for most of the flat panel display industries.

The optical film applied to the liquid crystal display is in a wide variety of types, and as the liquid crystal display is frequently applied to various precision electronic products, such as mobile phones, wearable devices, computers, and the like, the industrial demand for the quality of the optical film is increasing. The production process of the optical film is the fundamental factor affecting the quality of the optical film, and therefore, it is one of the important subjects to improve the efficiency of the production process of the optical film.

Automatic Optical Inspection (AOI) is widely used in inspection systems for manufacturing optical films, in which optical instruments are used to obtain the surface state of semi-finished products or finished products of optical films, and computer image processing technology is used to inspect defects such as pits, scratches or foreign matters. Generally, after the automatic optical inspection, the manual labor is used to perform classification or screening, so that if the automatic optical inspection cannot perform the desired inspection according to the specific process requirement, the processing time of the following personnel is increased, and the labor cost is increased.

While existing optical film inspection devices generally meet their intended purpose, they have not been completely satisfactory in every aspect.

Disclosure of Invention

According to some embodiments of the present disclosure, an optical film inspection apparatus for inspecting defects of an optical film is provided. The optical film detection device includes: a conveying system, a first light source assembly and a first shooting assembly. The conveying system is used for carrying and conveying the optical film. The first light source assembly is arranged on one side of the optical film and provides a first light source, and the first light source is provided with a first optical axis. The first shooting assembly is arranged on one side of the optical film and shoots the first surface of the optical film. In addition, the first optical axis of the first light source is parallel to or offset from the first surface of the optical film.

According to some embodiments of the present disclosure, a method for inspecting an optical film is provided, which is used for inspecting defects of an optical film to be inspected. The detection method of the optical film comprises the following steps: the optical film to be measured is carried and conveyed by the conveying system, the first light source component provides a first light source, and the first shooting component shoots the first surface of the optical film to be measured. In addition, the first light source assembly is arranged on one side of the optical film to be measured, and the first light source is provided with a first optical axis. The first light source component is arranged by offsetting the optical film to be detected, so that the first optical axis is parallel to or deviates from the first surface of the optical film to be detected.

In order to make the features and advantages of the present disclosure comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1A is a schematic diagram illustrating a side view of an optical film inspection device according to some embodiments of the present disclosure;

FIG. 1B is a schematic top view of an optical film inspection device according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram illustrating a side view of an optical film inspection device according to some embodiments of the present disclosure;

FIG. 3A is a schematic diagram illustrating a side view of an optical film inspection device according to some embodiments of the present disclosure;

FIG. 3B is a schematic top view of an optical film inspection device according to some embodiments of the present disclosure;

FIG. 4 is a flow chart illustrating steps of a method for inspecting an optical film according to some embodiments of the present disclosure;

FIG. 5 is a flow chart illustrating steps in a method for inspecting an optical film according to some embodiments of the present disclosure;

FIG. 6 illustrates a calculation of a size threshold for an image post-processing system according to some embodiments of the present disclosure.

[ description of symbols ]

10. 20, 30 optical film detection device;

10A, 10B optical film detection method;

100 an optical film;

100a first surface;

100b a second surface;

200 a conveying system;

300A first light source component

300B second light source component

302a first light source;

302b a second light source;

304. 304a, 304b light emitting elements;

304p bottom;

304t top;

306 a cover body;

a 400A first camera assembly;

400B a second photographing assembly;

402 a lens unit;

402X, 402X' central axis;

500 image judging system;

a, the size of an unqualified defect;

a1 a first direction;

a2 a second direction;

b, the size of qualified defect;

D ₁ a first distance;

D ₂ a second distance;

D ₃ 、D ₃ ' a third distance;

D ₄ 、D ₄ ' a fourth distance;

D ₅ 、D ₅ ' a fifth distance;

D ₆ a sixth distance;

D ₇ a seventh distance;

LX ₁ a first optical axis;

LX ₁ ' an extension line;

LX ₂ a second optical axis;

s12 to S18, S22 to S28;

an SV threshold;

p projection;

W ₁ a width;

W ₂ breadth;

θ ₁ 、θ ₁ ' a first included angle;

θ ₂ 、θ ₂ ' a second angle;

θ ₃ a third included angle;

θ ₄ a fourth included angle;

θ ₅ a fifth included angle;

θ _d the tolerance angle.

Detailed Description

The following describes the optical film inspection device and the optical film inspection method using the device in detail. It is to be understood that the following description provides many different embodiments, or examples, for implementing different aspects of embodiments of the disclosure. The specific components and arrangements are described below to provide a simple and clear description of certain embodiments of the disclosure. These are, of course, merely examples and are not intended to be limiting. Moreover, similar and/or corresponding reference numerals may be used to identify similar and/or corresponding elements in different embodiments to clearly describe the present disclosure. However, the use of such similar and/or corresponding reference numerals is merely for simplicity and clarity in describing some embodiments of the present disclosure and does not represent any correlation between the various embodiments and/or structures discussed.

It should be understood that the elements of the drawings or devices may take various forms well known to those skilled in the art to which the invention pertains. Relative terms, such as "lower" or "bottom" or "upper" or "top," may be used in addition embodiments to describe a relative relationship of one element to another element of the figures. It will be understood that if the device of the drawings is turned over, with the top and bottom reversed, elements described as being on the "lower" side will be elements on the "upper" side. The embodiments of the disclosure can be understood in conjunction with the accompanying drawings, which are incorporated in and constitute a part of this specification. It should be understood that the drawings of the present disclosure are not drawn to scale and that, in fact, the dimensions of the elements may be arbitrarily increased or reduced to clearly illustrate the features of the present disclosure.

Furthermore, the elements or devices of the drawings may exist in a variety of forms well known to those of ordinary skill in the art to which the invention pertains. Further, it will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, or parts, these elements, components, or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

As used herein, the term "about", "approximately", "substantially" and "approximately" generally means within 20%, preferably within 10%, more preferably within 5%, or within 3%, or within 2%, or within 1%, or within 0.5% of a given value or range. The amounts given herein are approximate, that is, the meanings of "about", "substantially" and "approximately" may be implied without specifically reciting "about", "approximately", "essentially" and "approximately". Furthermore, the terms "in a range of a first value to a second value" and "in a range of a first value to a second value" mean that the range includes the first value, the second value, and other values therebetween.

In some embodiments of the present disclosure, terms such as "connected," "interconnected," and the like, with respect to bonding, connecting, and the like, may refer to two structures being in direct contact, or may also refer to two structures not being in direct contact, unless otherwise specified, with respect to the structure between which they are disposed. And the terms coupled and connected should also be construed to include both structures being movable or both structures being fixed.

In some embodiments of the present disclosure, the term "optical axis" may be defined as a central axis perpendicular to the light-emitting surface of the light-emitting device, and generally, the optical axis coincides with the mechanical center of the light-emitting device.

Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Embodiments of the present disclosure provide an optical film inspection apparatus, in which a light source assembly can provide a light source with an optical axis parallel to or deviated from a surface of an optical film, that is, the light source assembly irradiates the surface of the optical film through a parallel light source or a side light source to inspect defects on the optical film, such as pits, water marks, scratches, or micro bubbles. By this arrangement, the defect types that cannot be detected by the existing automatic optical inspection apparatus can be more effectively detected. According to some embodiments of the present disclosure, image post-processing can be further performed on the detected defects, so that minor defects can be filtered, the detection efficiency can be improved, and the manual operation time can be reduced.

FIG. 1A is a schematic diagram illustrating a side view of an optical film inspection device 10 according to some embodiments of the present disclosure. It should be understood that additional features may be added to the optical film detection apparatus 10 described below, according to some embodiments. In some embodiments, the optical film inspection device 10 may be used to detect defects on finished or semi-finished products of the optical film 100. The optical film 100 may be a single layer optical film or an optical film laminate. In some embodiments, the optical film 100 processed by the optical film inspection device 10 is in roll form.

In some embodiments, the optical film inspection apparatus 10 may be disposed downstream of a bonding roller (not shown) for bonding a plurality of optical films. In some embodiments, the optical film inspection device 10 may be disposed downstream of a cutting mechanism (not shown). It should be understood that the optical film inspection apparatus 10 can be disposed at any stage of the manufacturing process requiring defect inspection according to actual requirements.

Referring to fig. 1A, the optical film inspection apparatus 10 may include a conveying system 200, a first light source assembly 300A, and a first camera assembly 400A. The transport system 200 may be used to carry and transport the optical film 100. In some embodiments, the transport system 200 may include guide rollers, through which the optical film 100 may be transported in roll form. In some embodiments, conveyor system 200 may comprise a conveyor belt, and optical film 100 may be conveyed in sheet form via the conveyor belt. As shown in fig. 1A, the conveying system 200 may convey the optical film 100 along a first direction A1.

In addition, the optical film 100 may have a first surface 100a and a second surface 100b opposite to the first surface 100a. In some embodiments, the optical film 100 may be a single-layer or multi-layer film, which includes films that are beneficial for optical gain, alignment, compensation, turning, cross-linking, diffusion, protection, anti-sticking, scratch resistance, anti-glare, reflection inhibition, high refractive index, etc., for example, a polarizing film, a release film, a wide-angle cornea, a brightness enhancement film, a reflection film, a protection film, an alignment liquid crystal film with characteristics of controlled viewing angle compensation or birefringence (birefringence), a hard coat film, an anti-reflection film, an anti-sticking film, a diffusion film, an anti-glare film, and various surface-treated films or combinations thereof, but is not limited thereto.

In some embodiments, the optical film 100 may include two protective layers and a polarizing film sandwiched between the protective layers.

In some embodiments, the protective film may have a single-layer or multi-layer structure, and is a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, and the like. The thermoplastic resin may include a cellulose resin (e.g., triacetyl cellulose (TAC) or diacetyl cellulose (DAC)), an acrylic resin (e.g., poly (methyl methacrylate), PMMA), a polyester resin (e.g., polyethylene terephthalate (PET) or polyethylene naphthalate), an olefin resin, a polycarbonate resin, a cyclic olefin resin, an oriented-stretched polypropylene (OPP), a Polyethylene (PE), a polypropylene (PP), a Cyclic Olefin Polymer (COP), a Cyclic Olefin Copolymer (COC), or a combination thereof.

In some embodiments, the polarizing film may be formed of a polyvinyl alcohol (PVA) film adsorbing aligned dichroic pigments or of a liquid crystal material doped with absorbing dye molecules. Polyvinyl alcohol can be formed by saponifying polyvinyl acetate. In some embodiments, the polyvinyl acetate may be a homopolymer of vinyl acetate or a copolymer of vinyl acetate and other monomers, and the like. The other monomer may be an unsaturated carboxylic acid, an olefin, an unsaturated sulfonic acid, a vinyl ether, or the like. In other embodiments, the polyvinyl alcohol may be a modified polyvinyl alcohol, such as aldehyde-modified polyvinyl formaldehyde, polyvinyl acetaldehyde, polyvinyl butyral, or the like.

Referring to fig. 1A, a first light source assembly 300A may be disposed at one side of the optical film 100 and provides a first light source 302a, and the first light source 302a has a first optical axis LX ₁ . According to some embodiments, first optical axis LX of first light source 302a ₁ Parallel to or offset from the first surface 100a of the optical film 100. In some embodiments, the first light source assembly 300A may be disposed in a direction substantially parallel to the first surface 100A of the optical film 100. In some embodiments, the first optical axis LX ₁ Does not intersect optical film 100 or first surface 100a of optical film 100. In other words, the first light source 302a does not directly illuminate the optical film 100, thereby preventing the defect from being difficult to identify due to the film surface being too bright. In some embodiments, the first light source 302a may illuminate the first surface 100a in the form of scattered light.

In light of the foregoing, the optical film 100 is transported along the first direction A1, and in some embodiments, the first direction A1 and the first optical axis LX ₁ Forms a first included angle theta ₁ (not shown). In some embodiments, first included angle θ ₁ Can range from about 0 degrees to about 90 degrees, from about 0 degrees to about 60 degrees, from about 0 degrees to about 45 degrees, or from about 0 degrees to about 35 degrees. In some embodiments, first included angle θ ₁ At 0 degrees as shown in fig. 1A.

Further, in some embodiments, the first light source assembly 300A may include at least one set of oppositely disposed light-emitting elements 304, and the light-emitting elements 304 may each provide the first light source 302a. As shown in fig. 1A, light emitting surfaces of the light emitting elements 304 may face each other. In some embodiments, the first optical axis LX is generated by a set of oppositely disposed light-emitting elements 304 ₁ May substantially overlap one another. In some embodiments, the first light source assembly 300A may include 3 to 15 sets of the opposing light-emitting elements 304, preferably 5 to 10 sets of the opposing light-emitting elements 304, but the disclosure is not limited thereto. According to some embodiments, the number of light emitting elements 304 may be adjusted according to the manufacturing process or product requirements (e.g., defects to be detected).

It should be understood that for the sake of clarityFor clarity, only a portion of the first light source 302a and the first optical axis LX are shown in the figure ₁ Actually, the light emitting elements 304 all have the first light source 302a and the first optical axis LX correspondingly ₁ 。

As shown in fig. 1A, according to some embodiments, a plurality of sets of oppositely disposed light emitting elements 304 may be stacked in a tower-type manner, i.e., the spacing between the light emitting elements 304 gradually decreases from a position close to the optical film 100 to a position away from the optical film 100 (e.g., along the Z direction shown in the figure). Specifically, the first light source assembly 300A includes a set of oppositely disposed first light-emitting elements 304 (labeled 304a for convenience of description), and another set of oppositely disposed second light-emitting elements 304 (labeled 304b for convenience of description) disposed on the set of first light-emitting elements 304 a. The first light emitting elements 304a are spaced apart by a first distance D ₁ The second light emitting elements 304b are separated by a second distance D ₂ . In some embodiments, the second distance D between the second light emitting elements 304b ₂ May be smaller than the first distance D between the first light emitting elements 304a ₁ 。

It should be understood that the first light emitting device 304a and the second light emitting device 304b are only illustrated herein, and the other light emitting devices 304 disposed thereon may be correspondingly configured in the same manner.

As mentioned above, the first light source assembly 300A can have a suitable number of sets of oppositely disposed light-emitting elements 304. In some embodiments, the bottom 304P of the light emitting element 304 of the first light source assembly 300A closest to the first camera assembly 400A forms a projection P on the optical film 100. According to some embodiments, the bottom 304p of the light emitting element 304 may be the portion (point or edge) of the light emitting element 304 closest to the optical film 100. In some embodiments, a connection line between the bottom 304P of the light emitting element 304 closest to the first photographing component 400A and the projection P forms an included angle (not shown) with the first surface 100A of the optical film 100, and the included angle may be about 90 degrees. In some embodiments, the connection line between the bottom 304P of the other set of light-emitting elements 304 and the projection P may form an included angle (not shown) with the first surface 100a of the optical film 100, which is substantially in an arithmetic series relationship.

Specifically, as shown in fig. 1A, an included angle formed by a connection line between the bottom 304P and the projection P of each light emitting element 304 and the first surface 100a may have a tolerance angle θ _d . For example, in the embodiment where the first light source assembly 300A has 5 sets of light-emitting elements 304 and the included angle between the connection line between the bottom 304P of the light-emitting element 304 closest to the first camera assembly 400A and the projection P and the first surface 100A is 90 degrees, the tolerance angle θ is _d May be 90/5 degrees, i.e., 18 degrees. In other words, in the foregoing embodiment, the included angles between the connection line between the bottom 304P of the light emitting element 304 and the projection P and the first surface 100a may be 18 degrees, 36 degrees, 54 degrees, 72 degrees, and 90 degrees, respectively.

For example, in other embodiments in which the first light source assembly 300A has n sets of light-emitting elements 304 and the included angle between the connection line between the bottom 304P of the light-emitting element 304 closest to the first camera assembly 400A and the projection P and the first surface 100A is 90 degrees, the tolerance angle θ is _d May be 90/n degrees. As can be understood from the foregoing description that the first light source assembly 300A may include 3 to 15 sets, n =3 to 15, preferably n =5 to 10.

Further, in some embodiments, the bottom 304p of the light emitting element 304 (304 a) closest to the optical film 100 is separated from the first surface 100a of the optical film 100 by a third distance D ₃ . According to some embodiments, the third distance D ₃ May be the distance between the base 304p and the optical film 100 in a direction along the normal to the optical film 100 (e.g., the Z direction as shown in the figure). In some embodiments, the third distance D ₃ Is in the range of about 10mm to about 100mm, or about 10mm to about 40mm.

It should be noted that if the third distance D between the bottom 304p of the light emitting element 304 (304 a) and the optical film 100 is set ₃ Too large (e.g., greater than 100 mm), the first light source 302a provided by the light emitting element 304 may not be able to effectively illuminate the optical film 100; on the contrary, if the third distance D ₃ Too small (e.g., less than 10 mm), the film surface of the optical film 100 may be too bright to make defects easily recognizable.

In some embodiments, the bottom 304p of the light emitting element 304 closest to the first camera assembly 400A and the second camera assembly 100A surface 100a is spaced apart by a fourth distance D ₄ . According to some embodiments, the fourth distance D ₄ May be the distance between the base 304p and the optical film 100 in a direction normal to the optical film 100 (e.g., the Z direction as shown in the figure). In some embodiments, the fourth distance D ₄ May range from about 200mm to about 1000mm, from about 300mm to about 900mm, or from about 400mm to about 800mm, for example, about 500mm.

Similarly, if the fourth distance D between the bottom 304p of the light emitting element 304 closest to the first camera assembly 400A and the optical film 100 is larger than the first distance D ₄ Too large (e.g., greater than 1000 mm), the first light source 302a provided by the light emitting element 304 may not be able to effectively illuminate the optical film 100; otherwise, if the fourth distance D ₄ Too small (e.g., less than 200 mm), the face of optical film 100 may be too bright to allow defects to be easily identified.

In particular, in the first light source assembly 300A of the tower-type stack, the distance and the angle of each group of light-emitting elements 304 with respect to the first surface 100A of the optical film 100 are different, so that light reflection with various angles and intensities can be generated, thereby filtering out the minor deformation defect. In some embodiments, the slight deformation defect may be a defect that can be tolerated by the optical film 100 product, i.e., a defect that meets specifications.

Further, in some embodiments, the light emitting elements 304 may include Light Emitting Diodes (LEDs), micro light emitting diodes (micro LEDs, mini LEDs), organic Light Emitting Diodes (OLEDs), quantum dot organic light emitting diodes (QLEDs), other suitable light emitting elements, or combinations of the foregoing, but are not limited thereto.

In some embodiments, the first light source 302a provided by the light-emitting elements 304 of the first light source assembly 300A may include visible light, for example, having a wavelength ranging from about 390nm to about 780nm. In some embodiments, the color temperature of the first light source 302a provided by the light emitting element 304 may range from about 3000K to about 6500K, from about 4000K to about 6500K, or from about 5000K to about 6000K. In addition, according to some embodiments, the intensity of the first light source 302a may be adjusted according to the process or product requirements (e.g., the type of defect to be detected).

In addition, referring to fig. 1A, the first photographing element 400A may be disposed at one side of the optical film 100 and photograph the first surface 100A of the optical film 100. In detail, the first photographing assembly 400A may photograph a reflected light image generated from the first surface 100A. As shown in fig. 1A, in some embodiments, the first light source assembly 300A and the first camera assembly 400A may be disposed on the same side of the optical film 100, and the first light source assembly 300A may be disposed between the first camera assembly 400A and the optical film 100.

In some embodiments, the first camera assembly 400A may include a Charge Coupled Device (CCD) camera or video camera that converts images into electrical signals, i.e., digitizes the images. In some embodiments, the first capture assembly 400A may include a lens unit 402, and the lens unit 402 may have a central axis 402X. According to some embodiments, the central axis 402X is a central axis of the lens unit 402 in a normal direction (e.g., a Z direction) of the first surface 100a of the optical film 100. In some embodiments, first optical axis LX of first light source 302a ₁ Has a second included angle theta with the central axis 402X of the lens unit 402 ₂ . In some embodiments, second included angle θ ₂ Is in a range of about 30 degrees to about 90 degrees, about 45 degrees to about 90 degrees, or about 60 degrees to about 90 degrees. In some embodiments, second included angle θ ₂ Is about 90 degrees.

Furthermore, in some embodiments, the lens unit 402 and the light emitting device 304 closest to the first camera assembly 400A are separated by a fifth distance D ₅ . According to some embodiments, the fifth distance D ₅ May be a distance between the lens unit 402 and the light emitting element 304 in a normal direction (e.g., Z direction shown in the figure) of the optical film 100. In some embodiments, the fifth distance D ₅ Is in the range of about 50mm to about 400mm, or about 100mm to about 300mm, for example, about 200mm.

It should be noted that if the fifth distance D between the lens unit 402 and the light emitting element 304 closest to the first camera assembly 400A is reached ₅ Too large (e.g., greater than 400 mm) or too small (e.g., less than 50 mm), the first capture assembly 400A may not be able to effectively takeLike this.

In addition, according to some embodiments, the optical film inspection apparatus 10 further includes an image determination system 500, and the image determination system 500 may be coupled to the first camera assembly 400A. The image determination system 500 may further process the electronic signals generated from the images captured by the first capturing component 400A. In some embodiments, the image determination system 500 can determine whether a defect exists on the first surface 100a of the optical film 100 according to the brightness difference of the light reflected from the first surface 100a of the optical film 100. Specifically, the defect may generate reflection in a different direction from the normal area, so that a portion of the pixels of the first camera assembly 400A receive different brightness, and thus the defect may be significantly different from other areas in the formed image. For example, the brightness at the defect may be low, and the brightness of a flat portion without defects may be high.

In some embodiments, the image determination system 500 may include software and hardware (central processing unit, CPU, memory, etc.), application-specific integrated circuit (ASIC), application specific circuit, firmware, etc. The image processing of the image determination system 500 can be realized by the cooperation of the aforementioned components.

Next, referring to fig. 1B, fig. 1B is a schematic top view illustrating an optical film inspection apparatus 10 according to some embodiments of the present disclosure. As shown in fig. 1B, the first camera assembly 400A may be disposed between the first light source assemblies 300A. In some embodiments, the first camera assembly 400A is disposed substantially in the middle of the first light source assembly 300A, in other words, the distance between the first camera assembly 400A and the first light source assemblies 300A on both sides is substantially the same.

Furthermore, the light emitting elements 304 of the first light source assembly 300A have a width W ₁ The optical film 100 has a width W ₂ . According to some embodiments, the width W ₁ Is the width of the light emitting elements 304 in a direction substantially perpendicular to the first direction A1 of the optical film 100 transport (e.g., the Y direction shown in the figure). In some embodiments, the width W of the light emitting element 304 ₁ Greater than the width W of the optical film 100 ₂ . The first light source 302a provided by the first light source assembly 300A may completely illuminate the first surface 100A of the optical film 100.

In addition, as shown in fig. 1B, in some embodiments, the optical film inspection device 10 may have a plurality of first photographing components 400A. In some embodiments, the suitable number of the first photographing assembly 400A may be determined according to the maximum width of the optical film 100, and in detail, the full-view width of the first photographing assembly 400A is greater than the maximum width of the optical film 100.

Generally, a light source module with a single angle illumination is difficult to directly identify the defect shape, and the defects with different degrees cannot be effectively filtered because light sources at other angles cannot be used for light supplement. Compared with the optical film detection device using a light source assembly with single-angle illumination, the optical film detection device 10 can use light sources with different angles and distances to illuminate the optical film 100, so that the defects can be supplemented at multiple angles to further identify the defects with different degrees, and slight defects which are not required to be detected can be filtered. In some embodiments, the minimum defect size detectable by the optical film inspection device 10 can be about 1 pixel (e.g., about 30 μm or 33 μm). Furthermore, in some embodiments, the optical film inspection device 10 may primarily detect a dent defect on the optical film 100.

Referring to fig. 2, fig. 2 is a schematic side view of an optical film inspection device 20 according to other embodiments of the present disclosure. It should be understood that the same or similar components or elements are denoted by the same or similar reference numerals, and the same or similar materials and functions are the same or similar to those described above, so that the detailed description thereof will be omitted.

The optical film inspection device 20 shown in fig. 2 is substantially similar to the optical film inspection device 10 shown in fig. 1A, except that in this embodiment, the optical film inspection device 20 further includes a second light source assembly 300B and a second camera assembly 400B. In this embodiment, the optical film inspection apparatus 20 can simultaneously inspect the first surface 100a and the second surface 100b of the optical film 100.

In detail, the second light source assembly 300B and the first light source assembly 300B may be respectively disposed on two opposite sides of the optical film 100, and the second camera 400B and the first camera 400A are also disposed on two opposite sides of the optical film 100. In some embodiments, the second light source assembly 300B and the second camera assembly 400B may be disposed on the same side of the optical film 100, and the second light source assembly 300B may be disposed between the second camera assembly 400B and the optical film 100.

Moreover, the second camera module 400B can be used for taking an image of the second surface 100B of the optical film 100, the second light source module 300B can provide the second light source 302B, and the second light source 302B has a second optical axis LX ₂ . According to some embodiments, the second optical axis LX ₂ Parallel to or offset from the second surface 100b of the optical film 100. In some embodiments, the second light source assembly 300B may be disposed in a direction substantially parallel to the second surface 100B of the optical film 100. In some embodiments, the second optical axis LX ₂ Does not intersect the optical film 100 or the second surface 100b of the optical film 100. In addition, in some embodiments, the second light source assembly 300B and the first light source assembly 300A are substantially symmetrically disposed with respect to the optical film 100. The second light source assembly 300B is configured in substantially the same manner as the first light source assembly 300A.

Furthermore, in some embodiments, the optical film 100 transmits the first direction A1 and the second optical axis LX ₂ Forms a first included angle theta ₁ ' (not shown), the first angle theta ₁ ' may range from about 0 degrees to about 45 degrees, from about 0 degrees to about 40 degrees, or from about 0 degrees to about 35 degrees. In some embodiments, first included angle θ ₁ ' is 0 degrees, as shown in FIG. 2.

Similarly, in some embodiments, the second light source assembly 300B may include at least one set of oppositely disposed light-emitting elements 304, and the light-emitting elements 304 may each provide the second light source 302B. As shown in fig. 2, light emitting surfaces of the light emitting elements 304 may face each other. In some embodiments, the second optical axis LX is generated by a set of oppositely disposed light-emitting elements 304 ₂ May substantially overlap one another. In some embodiments, the second light source assembly 300B can include 3 to 15 sets of oppositely disposed light-emitting elements 304, preferably 5 to 10 sets of oppositely disposed light-emitting elements 304, but the disclosure is not limited thereto. According to some embodiments, the number of light emitting devices 304 may be adjusted according to the manufacturing process or product requirements (e.g., defects to be detected).

As shown in fig. 2, according to some embodiments, the plurality of sets of oppositely disposed light-emitting elements 304 of the second light source assembly 300B can be stacked in a tower-type manner, i.e., the spacing between the light-emitting elements 304 gradually decreases from a position close to the optical film 100 to a position away from the optical film 100 (e.g., along the-Z direction shown in the figure).

In addition, in some embodiments, in the second light emitting assembly 300B, the top 304t of the light emitting device 304 closest to the optical film 100 is separated from the second surface 100B of the optical film 100 by a third distance D ₃ '. According to some embodiments, the top 304t of the light emitting element 304 may be the portion (point or edge) of the light emitting element 304 closest to the optical film 100. According to some embodiments, the third distance D ₃ ' may be a distance between the top 304t and the optical film 100 along a normal direction of the optical film 100 (e.g., the Z direction shown in the figure). In some embodiments, the third distance D ₃ ' ranges from about 10mm to about 100mm, or from about 10mm to about 40mm.

In some embodiments, in the second light emitting device 300B, the top 304t of the light emitting element 304 closest to the second photographing device 400B is separated from the second surface 100B of the optical film 100 by a fourth distance D ₄ '. According to some embodiments, the fourth distance D ₄ ' may be a distance between the top 304t and the optical film 100 along a normal direction of the optical film 100 (e.g., the Z direction shown in the figure). In some embodiments, the fourth distance D ₄ ' may range from about 200mm to about 1000mm, from about 300mm to about 900mm, or from about 400mm to about 800mm, for example, about 500mm.

In some embodiments, the second light source 302B provided by the light emitting element 304 of the second camera assembly 400B may include visible light, for example, having a wavelength ranging from about 390nm to about 780nm. In some embodiments, the color temperature of the second light source 302b provided by the light emitting element 304 may range from about 3000K to about 6500K, from about 4000K to about 6500K, or from about 5000K to about 6000K. In addition, according to some embodiments, the intensity of the second light source 302b may be adjusted according to the process or product requirements (e.g., the type of defect to be detected). In some embodiments, the wavelength and/or color temperature of first light source 302a and second light source 302b may be the same or different.

In addition, the second camera assembly 400B may include a CCD (charge coupled device) camera or a video camera, which converts an image into an electrical signal, i.e., digitizes the image. In some embodiments, the second capture assembly 400B may include a lens unit 402, and the lens unit 402 may have a central axis 402X'. According to some embodiments, the central axis 402X' is a central axis of the lens unit 402 in a normal direction (e.g., the Z direction shown in the figure) of the second surface 100a of the optical film 100. In some embodiments, second optical axis LX of second light source 302b ₂ Has a second included angle theta with the central axis 402X' of the lens unit 402 ₂ '. In some embodiments, second included angle θ ₂ Ranges of' are from about 30 degrees to about 90 degrees, from about 45 degrees to about 90 degrees, or from about 60 degrees to about 90 degrees. In some embodiments, second included angle θ ₂ ' is about 90 degrees.

Furthermore, in some embodiments, the lens unit 402 and the light emitting device 304 closest to the second camera assembly 400B are separated by a fifth distance D ₅ '. According to some embodiments, the fifth distance D ₅ ' may be a distance between the lens unit 402 and the light emitting element 304 in a normal direction (e.g., a Z direction shown in the drawing) of the optical film 100. In some embodiments, the fifth distance D ₅ ' ranges from about 50mm to about 400mm, or from about 100mm to about 300mm, for example, about 200mm.

In some embodiments, the second capturing component 400B may also be further coupled to the image determination system 500. In some embodiments, the first camera assembly 400A and the second camera assembly 400B may be coupled to the same image determination system 500, i.e., the image determination system 500 may process the electronic signals generated by the images captured by the first camera assembly 400A and the second camera assembly 400B simultaneously. In some embodiments, the first camera assembly 400A and the second camera assembly 400B may be separately coupled to different image determination systems 500.

In the optical film inspection apparatus 20, the first light source assembly 300A and the second light source assembly 300B stacked in the tower shape can irradiate the first surface 100A and the second surface 100B of the optical film 100 with light rays of various angles and intensities, so as to filter out slight deformation defects and reduce the time required for subsequent screening.

Referring to fig. 3A, fig. 3A is a schematic side view of an optical film inspection apparatus 30 according to other embodiments of the present disclosure. As shown in FIG. 3A, the optical film inspection device 30 can include a conveying system 200, a first light source assembly 300A, and a first camera assembly 400A. In this embodiment, the transport system 200 may include guide rollers, through which the optical film 100 may be transported in a roll form. In this embodiment, the first light source assembly 300A and the first camera assembly 400A may be disposed at a production stage having an upper and lower difference.

Further, the conveying system 200 can convey the optical film 100 along the second direction A2. In some embodiments, the section of the optical film 100 to be inspected can be disposed in a direction substantially perpendicular to the ground (i.e., with the second direction A2 substantially perpendicular to the ground), reducing the impact of an ambient light source (e.g., a light source disposed in a ceiling) on the accuracy of the inspection. In some embodiments, the section of the optical film 100 to be inspected may be disposed at an angle within about 0 degrees to about 60 degrees from the normal direction of the ground, i.e., the second direction A2 is at an angle of about 0 degrees to about 60 degrees, about 0 degrees to about 45 degrees, or about 0 degrees to about 30 degrees from the normal direction of the ground.

As shown in FIG. 3A, a first light source assembly 300A can be disposed on one side of the optical film 100, and a first light source 302a is provided, wherein the first light source 302a has a first optical axis LX ₁ . In some embodiments, the first light source assembly 300A may be disposed below the optical film 100 or on the side opposite to the ambient light source. According to some embodiments, the first optical axis LX of the first light source 302a ₁ Parallel to or offset from the second surface 100b of the optical film 100. In some embodiments, the first light source assembly 300A may be arranged substantially parallel toThe direction of the second surface 100b of the optical film 100 is set. In some embodiments, the first optical axis LX ₁ Does not intersect the optical film 100 or the second surface 100b of the optical film 100. In other words, the first light source 302a does not directly illuminate the optical film 100, thereby preventing the defect from being difficult to identify due to the film surface being too bright.

In light of the foregoing, the optical film 100 is transported along the second direction A2, and in some embodiments, the second direction A2 is parallel to the first optical axis LX ₁ Is extended line LX ₁ ' form a third angle theta ₃ Third angle θ ₃ Can range from about 0 degrees to about 90 degrees, from about 0 degrees to about 60 degrees, from about 0 degrees to about 45 degrees, or from about 0 degrees to about 35 degrees.

In this embodiment, the first light source assembly 300A may include at least one light emitting element 304 and a cover 306 surrounding the light emitting element 304. The cover 306 may prevent the first light source 302a provided by the light emitting element 304 from directly illuminating the second surface 100b of the optical film 100. In some embodiments, the enclosure 306 may be formed of a material having light blocking properties. For example, in some embodiments, the material of the cover 306 may comprise a polymer material, a metal material, other suitable materials, or a combination of the foregoing. The polymer material may include Polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polypropylene (PP), or acrylonitrile-butadiene-styrene copolymer (ABS resin), polyester fiber, but is not limited thereto. In some embodiments, an epoxy material or a polyester material may also be used as a coating for the cover 306. In some embodiments, the cover 306 may also include additives, such as, but not limited to, frosting powder or light diffuser.

As mentioned above, the light emitting elements 304 of the first light source assembly 300A may include Light Emitting Diodes (LEDs), micro light emitting diodes (micro LEDs, mini LEDs), organic Light Emitting Diodes (OLEDs), quantum dot organic light emitting diodes (QLEDs), other suitable light emitting elements, or combinations thereof, but are not limited thereto.

In some embodiments, the first light source 302a provided by the light-emitting elements 304 of the first light source assembly 300A may comprise visible light, for example, having a wavelength ranging from about 390nm to about 780nm, or from about 520nm to about 640nm. In some embodiments, the first light source 302a may be yellow light. In some embodiments, the color temperature of the first light source 302a provided by the light emitting element 304 may range from about 3000K to about 6500K, from about 4000K to about 6500K, or from about 5000K to about 6000K. In addition, according to some embodiments, the intensity of the first light source 302a may be adjusted according to the process or product requirements (e.g., the type of defect to be detected). For example, in some embodiments, the intensity of the first light source 302a may be about 1000Lux or more.

In addition, in this embodiment, the first light source assembly 300A and the first camera assembly 400A may be disposed on two opposite sides of the optical film 100, and the first camera assembly 400A may capture a refracted light image generated by the optical film 100. In detail, in this embodiment, the cover 306 can reflect the first light source 302a, and when the reflected light irradiates the defect on the optical film 100, the unevenness of the defect can refract the light to the first camera element 400A, so that the defect can be easily identified. In contrast, in a conventional optical film inspection apparatus installed with a backlight light source, light directly irradiates the film surface and transmits through the film surface to the camera module, and the light is difficult to be refracted due to the unevenness of the defect itself, and the difference of the amount of light refracted to the lens is difficult to be recognized when the amount of light of the light is too sufficient.

As described above, the first photographing element 400A may include a photo-coupled device (CCD) camera or video camera that converts an image into an electrical signal, i.e., digitizes the image. In some embodiments, the first capture assembly 400A may include a lens unit 402, and the lens unit 402 may have a central axis 402X. According to some embodiments, the central axis 402X is a central axis of the lens unit 402 in a normal direction of the first surface 100a of the optical film 100. In some embodiments, the first optical axis LX1 of the first light source 302a and the central axis 402X of the lens unit 402 form a fourth angle θ ₄ . In some embodiments, fourth included angle θ ₄ Ranges from about 0 degrees to about 90 degrees, from about 30 degrees to about 80 degrees, or from about 45 degrees to about 70 degrees.

Furthermore, in some embodiments, the central axis 402 of the lens unit 402A fifth included angle theta is formed between X and the first surface 100a or the second surface 100b of the optical film 100 ₅ . In some embodiments, fifth included angle θ ₅ Ranges from about 0 degrees to about 90 degrees, from about 30 degrees to about 90 degrees, or from about 45 degrees to about 90 degrees. It should be noted that if the fifth included angle θ ₅ Is too large (e.g., greater than 90 degrees), the first camera assembly 400A may not be able to effectively identify the defect.

Furthermore, the first light axis LX of the first light source 302a provided by the first light source assembly 300A ₁ A first minimum distance D from the optical film 100 ₆ . In some embodiments, the first minimum distance D ₆ Is in the range of about 5cm to about 60cm, about 10cm to about 50cm, or about 20cm to about 40cm, e.g., about 30cm. Note that the first optical axis LX ₁ The distance from the optical film 100 should not be too large, otherwise the first light source 302a may not be reflected to the optical film 100, which may cause insufficient light source.

In addition, the lens unit 402 of the first photographing assembly 400A has a second minimum distance D from the optical film 100 ₇ . In some embodiments, the second minimum distance D ₇ Is in the range of about 5cm to about 100cm, about 20cm to about 80cm, or about 40cm to about 70cm, e.g., about 50cm. It should be noted that the distance between the lens unit 402 and the optical film 100 should not be too large or too small, otherwise the lens unit 402 may not be able to effectively capture images.

As mentioned above, according to some embodiments, the optical film inspection apparatus 30 further includes an image determination system 500, and the image determination system 500 may be coupled to the first camera assembly 400A. The image determination system 500 may further process the electronic signals generated from the images captured by the first camera assembly 400A.

In some embodiments, the image determination system 500 can determine whether a defect exists on the first surface 100a of the optical film 100 according to the brightness difference of the light refracted from the optical film 100. Specifically, when the optical film 100 has defects such as foreign substances or bubbles, the light emitted from the first light source assembly 300A is scattered by the foreign substances or the bubbles, and a part of the scattered light enters the first camera assembly 400A. On the other hand, in the case where there is no defect such as a foreign substance or a bubble, since no scattered light is generated, the image captured by the first camera module 400A becomes dark. Therefore, the defect is clearly different from other areas in the formed image. For example, the brightness at the defect may be high, and the brightness of a flat portion without defects may be low.

In some embodiments, the image determination system 500 may comprise software and hardware (central processing unit (CPU), memory, etc.), and may also comprise Application Specific Integrated Circuit (ASIC), application specific circuitry, firmware, etc. The image processing of the image determination system 500 can be realized by the cooperation of the aforementioned components.

Next, referring to fig. 3B, fig. 3B shows a schematic top view of an optical film inspection device 30 according to some embodiments of the present disclosure. As shown in fig. 3B, in some embodiments, the first camera assembly 400A may be disposed downstream compared to the first light source assembly 300A. However, in other embodiments, the first light source assembly 300A and the first camera assembly 400A may partially overlap in a normal direction of the optical film 100.

Furthermore, the light emitting element 304 may have a width W ₁ The optical film 100 has a width W ₂ . According to some embodiments, the width W ₁ Is the width of the light emitting element 304 in a direction substantially perpendicular to the second direction A2 in which the optical film 100 is transported (e.g., the Y direction shown in the figure). In some embodiments, the width W of the light emitting elements 304 ₁ Greater than the width W of the optical film 100 ₂ . The first light source 302a provided by the first light source assembly 300A may completely illuminate the first surface 100A of the optical film 100.

In addition, it should be understood that although only one first camera assembly 400A is shown in the embodiment shown in fig. 3B, in other embodiments, the optical film detection apparatus 30 may have a plurality of first camera assemblies 400A. In some embodiments, the suitable number of the first photographing assembly 400A may be determined according to the maximum width of the optical film 100, and in detail, the full-view width of the first photographing assembly 400A is greater than the maximum width of the optical film 100.

As described above, the optical film inspection apparatus 30 can inspect defects such as stains or water marks, as well as air bubbles, particularly fine air bubbles and scratches on the optical film 100, mainly by the first light source unit 300A and the first imaging unit 400A disposed at specific relative positions to the optical film 100. The light source may illuminate the surface of the optical film 100 in the form of scattered light, increasing the detection efficiency of the aforementioned defects and reducing the miss rate.

Next, referring to fig. 4, fig. 4 is a flowchart illustrating steps of a method 10A for inspecting an optical film according to some embodiments of the present disclosure. The optical film inspection method 10A can be implemented by the optical film inspection apparatus of the foregoing embodiment, and can be used to inspect the defect of the optical film 100 to be inspected. Here, the following description will be given taking as an example the optical film detection method 10A performed by using the optical film detection apparatus 10.

It is understood that additional processing steps may be provided before, during, and/or after the optical film inspection method 10A is performed, according to some embodiments. According to other embodiments, some of the stages (or steps) described may be deleted or replaced, as appropriate, or the order of the steps interchanged, as appropriate.

As shown in fig. 4, the method 10A for inspecting an optical film may include the steps of: carrying and conveying the optical film 100 to be tested by the conveying system 200 (step S12); providing a first light source 302a with a first light source assembly 300A (step S14); and the first surface 100A of the optical film 100 to be measured is photographed by the first photographing assembly 400A (step S16).

In detail, in step S12, the conveying system 200 can convey the optical film 100 to be tested along the first direction A1. In view of the foregoing, in some embodiments, the first direction A1 transmitted by the optical film 100 and the first optical axis LX of the first light source 302a ₁ Forms a first included angle theta ₁ (not shown). In some embodiments, first included angle θ ₁ Is about 0 degrees.

In step S14, the first light source assembly 300A is disposed by shifting the optical film 100 to be measured such that the first optical axis LX of the first light source 302a ₁ May be parallel to or offset from the first surface 100a of the optical film 100 to be measured. According to some embodiments, the first light source 302a irradiates the optical film to be measured in the form of scattered light100, 100a.

In addition, in step S16, the first photographing component 400A may be disposed such that the central axis 402X of the lens unit 402 and the first optical axis LX ₁ Has a second included angle theta ₂ . In some embodiments, second included angle θ ₂ Is in a range of about 30 degrees to about 90 degrees, about 45 degrees to about 90 degrees, or about 60 degrees to about 90 degrees. In some embodiments, second included angle θ ₂ Is about 90 degrees.

In addition, as shown in fig. 4, according to some embodiments, the method 10A further includes determining whether the optical film 100 to be tested has a defect by the image determination system 500 (step S18). The image determination system 500 can perform the determination according to the brightness difference of the light reflected from the first surface 100a of the optical film 100 to be measured.

Next, referring to fig. 5, fig. 5 is a flowchart illustrating steps of a method 10B for inspecting an optical film according to some embodiments of the present disclosure. As shown in fig. 5, compared to the optical film inspection method 10A, the optical film inspection method 10B may further include the following steps before the step S12 of carrying and conveying the optical film 100 to be inspected by the conveying system 200: detecting the standard optical film sample with qualified defects, and recording image parameters of the qualified defects through an image judgment system 500 (step 22); detecting the optical film standard sample with unqualified defects, and recording the image parameters of the unqualified defects through the image judgment system 500 (step 24); and adjusting a brightness threshold for detecting the defect of the optical film 100 to be tested according to the image parameters of the qualified defect and the image parameters of the unqualified defect (step 26).

The image determination system 500 can further adjust the parameters of the image captured by the first capture assembly 400A through the aforementioned steps 22 to 26. Specifically, the defects can be divided into qualified defects and unqualified defects, wherein qualified defects can be defined as slight defects allowable in the process or product, and unqualified defects can be defined as defects not allowable in the process or product, such as more serious pits, etc. It is understood that the criteria for determining pass defects and fail defects may vary according to different embodiments depending on the actual requirements of the optical film product.

In steps 22 and 24, the optical film standard sample with acceptable defect and the optical film standard sample with unacceptable defect can be prepared appropriately according to the actual requirement of the optical film product. In some embodiments, the image parameters of the pass and fail defects, such as the brightness parameter (gray level), may be recorded by a memory in the image determination system 500.

In step 26, the brightness threshold for detecting defects of the optical film 100 to be tested can be adjusted according to the image parameters obtained in steps 22 and 24. Specifically, in some embodiments, the threshold of each pixel of the rejected defect to be filtered out may be adjusted to the maximum gray scale number. For example, in some embodiments, the pixel threshold for a non-defective defect may be adjusted to 255 bits (bit).

In addition, according to some embodiments, the method 10B for inspecting an optical film may further include screening the detected defects with an image post-processing system (not shown) (step 28) after the step S18 of determining whether the optical film 100 to be inspected has the defects with the image determination system 500.

In some embodiments, the image post-processing system adjusts the size threshold for screening the defects detected by the above steps according to the image parameters of the qualified defects and the image parameters of the unqualified defects. Specifically, due to different defect types, the edges of some qualified defects after being supplemented with light may generate noise that cannot be filtered out, and further be classified as unqualified defects, so the detected defects can be further screened by the image post-processing system, for example, the size threshold of the defects can be further set, and such noise can be filtered out.

In detail, referring to fig. 6, fig. 6 shows a calculation method of a size threshold of an image post-processing system according to some embodiments of the present disclosure. According to some embodiments, a defect size threshold SV (denoted by X in the figures) for an image post-processing system may be calculated by the following formula (I):

(A-B)/2 + B is shown as formula (I).

In formula (I), a is the size (threshold) of the defective defect, and B is the size (threshold) of the acceptable defect. Through the setting of the defect size threshold SV of the image post-processing system, qualified defects which are mistakenly classified as unqualified defects after light supplement can be further filtered.

In summary, according to some embodiments of the present disclosure, the light source assembly of the optical film inspection apparatus can provide a light source with an optical axis parallel to or away from the surface of the optical film, that is, illuminate the surface of the optical film through a parallel light source or a side light source, so as to inspect defects such as pits, scratches, water marks, or micro-bubbles on the optical film. With this arrangement, the types of defects that cannot be detected by the existing automatic optical inspection apparatus can be detected more efficiently. According to some embodiments of the present disclosure, light supplement can be further performed or the detected defects can be screened for the defects with a slight degree, so as to filter the slight defects to be eliminated, thereby improving the detection efficiency and reducing the manual operation time.

Although the embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but on the contrary, the intention is to cover all embodiments of the subject matter, means, methods and steps, which are presently known or later developed, such that the appended claims are capable of performing substantially the same function or achieving substantially the same result as the presently claimed subject matter. Accordingly, the scope of the present disclosure includes the processes, machines, manufacture, compositions of matter, means, methods, and steps described above. In addition, each claim constitutes a separate embodiment, and the scope of the present disclosure also includes combinations of the respective claims and embodiments. The scope of the present disclosure is to be determined by the claims appended hereto.

Claims

1. An optical film inspection apparatus for inspecting a defect of an optical film, the optical film inspection apparatus comprising:

a conveying system for carrying and conveying the optical film;

the first light source component is arranged on one side of the optical film and provides a first light source, wherein the first light source is provided with a first optical axis; and

a first photographing assembly disposed at one side of the optical film and photographing a first surface of the optical film, wherein the first optical axis of the first light source is parallel to or deviated from the first surface of the optical film,

the first light source assembly comprises a plurality of groups of oppositely arranged light-emitting elements which are stacked in a tower-shaped manner, wherein the plurality of groups of light-emitting elements comprise a group of oppositely arranged first light-emitting elements and a group of oppositely arranged second light-emitting elements arranged on the group of first light-emitting elements, a first distance is formed between the group of first light-emitting elements, a second distance is formed between the group of second light-emitting elements, and the second distance is smaller than the first distance;

wherein the bottom of the group of light-emitting elements closest to the first shooting assembly forms a projection on the optical film, and the connection lines between the bottoms of the other plural groups of light-emitting elements and the projection have an arithmetic progression relationship with a tolerance angle formed by the first surface of the optical film.

2. The apparatus of claim 1, wherein the optical film is transported along a first direction, the first direction forms a first angle with an extension line of the first optical axis, and the first angle is in a range of 0 degrees to 90 degrees.

3. The apparatus of claim 1, wherein the first optical axis does not intersect the first surface of the optical film.

4. The device of claim 1, wherein the first camera element has a lens unit, and a second angle is formed between the first optical axis and a central axis of the lens unit, the second angle being in a range of 30 degrees to 90 degrees.

5. The apparatus of claim 1, wherein the first light source module and the first camera module are disposed on the same side of the optical film, and the first light source module is disposed between the first camera module and the optical film.

6. The apparatus of claim 1, wherein the first light source assembly comprises 3 to 15 sets of oppositely disposed light-emitting elements.

7. The apparatus of claim 1, wherein the plurality of sets of oppositely disposed light emitting elements have a width that is greater than a width of the optical film.

8. The device of claim 1, wherein the bottom of the group of light-emitting elements closest to the optical film has a third distance from the first surface of the optical film, wherein the third distance is a distance between the bottom and the optical film along a normal direction of the optical film; or the third distance ranges from 10mm to 100mm.

9. The device of claim 1, wherein a bottom of the group of light emitting elements closest to the first camera module is separated from the first surface of the optical film by a fourth distance, wherein the fourth distance is a distance between the bottom and the optical film along a normal direction of the optical film; or the fourth distance ranges from 200mm to 1000mm.

10. The apparatus of claim 1, further comprising an image determination system coupled to the first camera, wherein the image determination system determines whether a defect exists according to a brightness difference of the light reflected from the first surface of the optical film.

11. The apparatus as claimed in claim 1, further comprising a second light source module and a second camera module, wherein the second light source module and the first light source module are disposed on opposite sides of the optical film, and the second camera module and the first camera module are disposed on opposite sides of the optical film.

12. The apparatus as claimed in claim 11, wherein the second light source module provides a second light source having a wavelength ranging from 390nm to 780nm; or the color temperature range of the second light source is 3000K to 6500K.

13. The apparatus of claim 11, wherein the second camera assembly captures an image of a second surface of the optical film, the second light source assembly provides a second light source having a second optical axis, and the second optical axis is parallel to or offset from the second surface of the optical film.

14. The apparatus as claimed in claim 11, wherein the second light source assembly comprises a plurality of sets of light-emitting elements disposed opposite to each other, the plurality of sets of light-emitting elements are stacked in a tower-shaped manner, and the distance between the plurality of sets of light-emitting elements is gradually reduced from a position close to the optical film to a position away from the optical film.

15. The apparatus of claim 1, wherein the tolerance angle is 90/n degrees, and n is the number of the plurality of light emitting devices.

16. A method for detecting an optical film is used for detecting defects of an optical film to be detected, and comprises the following steps:

carrying and conveying the optical film to be detected by a conveying system;

providing a first light source by a first light source component, wherein the first light source component is arranged on one side of the optical film to be detected and is provided with a first optical axis; and

a first shooting component shoots a first surface of the optical film to be detected, wherein the first light source component is arranged by deviating the optical film to be detected so that the first optical axis is parallel to or deviates from the first surface of the optical film to be detected,

17. The method as claimed in claim 16, wherein the first light source irradiates the first surface of the optical film to be tested in a form of scattered light.

18. The method as claimed in claim 16, wherein the optical film under test is transported along a first direction, the first direction and the extension line of the first optical axis form a first included angle, and the first included angle ranges from 0 degree to 90 degrees.

19. The method of claim 16, wherein the first camera module has a lens unit, and a second angle is formed between the first optical axis and a central axis of the lens unit, and the second angle ranges from 30 degrees to 90 degrees.

20. The method as claimed in claim 16, wherein the first light source module and the first camera module are disposed on a same side of the optical film, and the first light source module is disposed between the first camera module and the optical film.

21. The method as claimed in claim 16, further comprising determining whether the optical film has defects by an image determination system, wherein the image determination system determines the defects according to a brightness difference of the light reflected from the first surface of the optical film.

22. The method as claimed in claim 16, further comprising, before the step of carrying and transporting the optical film to be tested by the transporting system:

detecting an optical film standard sample with qualified defects, and recording image parameters of the qualified defects through the image judgment system;

detecting an optical film standard sample with unqualified defects, and recording image parameters of the unqualified defects through the image judgment system; and

and adjusting the brightness threshold value for detecting the defects of the optical film to be detected according to the image parameters of the qualified defects and the image parameters of the unqualified defects.

23. The method of claim 22, further comprising screening an image post-processing system for a detected defect.

24. The method of claim 23, wherein the image post-processing system adjusts a size threshold for screening the inspected defect based on the image parameters of the acceptable defect and the image parameters of the unacceptable defect.

25. The method for inspecting optical film according to claim 24, wherein the size threshold is set according to the following formula (I):

(A-B)/2B formula (I), wherein A is the size of the failed defect and B is the size of the qualified defect.