KR101898835B1 - A defect inspection method of a laminated optical film, a defect inspection method of an optical film, and a manufacturing method of a laminated optical film - Google Patents

Abstract

The present invention relates to a defect inspection method for a laminated optical film, and a method for inspecting a defect in a laminated optical film according to an embodiment includes a first inspection step for defect inspection of the optical film (11) A step of bonding the protective film 12 and the adhesive material 13 to form the laminated optical films 10A and 10B and the step of forming the laminated optical films 10A and 10B in correspondence with the defects 20 detected in the first inspection step (Mark 30), a second inspection step of performing a defect inspection of the laminated optical film 10B, and a second inspection step of performing lamination optics (not shown) corresponding to the defects 21 detected in the second inspection step And a second marking step of marking the film 10B (of the mark 31). In the second inspection step, the mark 30 is not detected in the first marking step.

Description

A defect inspection method of a laminated optical film, a defect inspection method of an optical film, and a manufacturing method of a laminated optical film

The present invention relates to a defect inspection method for a laminated optical film and a defect inspection method for an optical film, and also relates to a method for producing a laminated optical film.

As an optical film having optical properties, a polarizing plate having polarization characteristics and a retardation plate having birefringence are known. For example, as a polarizing plate, it is known that a TAC (triacetyl cellulose) film is bonded to both sides of a main surface of a polarizing film (polyvinyl alcohol (PVA) as an optical film body. As a phase difference plate, it is known that the phase difference plate is composed of an optical film body alone. In this kind of optical film, a protective film may be bonded, or an adhesive material in a state in which a separate film is attached may be bonded to form a laminated optical film.

In this kind of optical film and laminated optical film, for example, optical defects may occur when foreign matter or bubbles are mixed in the inside or the surface at the time of bonding. Patent Documents 1 and 2 disclose a method for inspecting defects in an optical film and a laminated optical film of this kind.

When a defect is detected by this type of defect inspection method, marking is performed on the surface of the optical film and the laminated optical film so as to surround the defect, for example, in accordance with the defect, and the marked area is excluded from use as a product .

Japanese Patent Application Laid-Open No. 2009-69142 Japanese Patent Laid-Open No. 11-65184

In such a defect inspection method, it is required to accurately count the number of defects. The mark to be marked is required to have a size corresponding to the size of the defect.

Incidentally, in the defect inspection of this type of optical film and the laminated optical film, there are cases where the defect inspection is performed twice or more. For example, there is a case where defect inspection is performed every time the respective layers of the optical film and the laminated optical film are bonded, or different inspection methods are performed in order to detect different defects.

However, in the case where the defect inspection is performed two or more times, in the second and subsequent inspections, marks previously marked before are detected as defects, and corresponding markings (for example, surrounding the defects) are marked, There is a problem that the size is increased.

Therefore, the present invention provides a defect inspection method for a laminated optical film and a defect inspection method for an optical film that can prevent detection of a mark corresponding to a defect detected before the last time when performing defect inspection two or more times The purpose. It is also an object of the present invention to provide a method for producing a laminated optical film.

A defect inspection method for a laminated optical film of the present invention is a method for inspecting defects in a laminated optical film while obtaining a laminated optical film by bonding at least one of a protective film and an adhesive to an optical film, A step of forming a laminated optical film by bonding at least one of a protective film and an adhesive to an optical film, a step of forming a laminated optical film in accordance with defects detected in the first inspection step, And a second marking step of marking the laminated optical film in accordance with the defects detected in the second inspection step, wherein the first marking step, the second marking step, , The mark marked in the first marking step is not detected.

According to the defect inspection method of the laminated optical film, in the second inspection step, the mark marked in the first marking step is not detected. Therefore, when two or more defect inspections are performed, it is possible to prevent the mark corresponding to the defect detected before the last time from being detected.

The defect inspection method in the first inspection step and the defect inspection method in the second inspection step may be the same or different.

A defect inspection method for an optical film according to the present invention is a method for inspecting defects of an optical film, comprising a first inspection step of inspecting defects of an optical film, a marking step of marking the optical film in correspondence with defects detected in the first inspection step A second inspection step of performing a defect inspection different from the defect inspection in the first inspection step as the defect inspection of the optical film, the second inspection step of performing optical inspection of the optical film corresponding to the defects detected in the second inspection step, And a second marking step of marking the film. In the second inspection step, the mark marked in the first marking step is not detected.

The optical film of the present invention is not limited to a single-layer optical film composed of the optical film main body but also an optical film including the optical film main body and a laminated optical film obtained by bonding at least one of a protective film and an adhesive material to the optical film It is a concept to include.

In the defect inspection method of this optical film, since the marks marked in the first marking step are not detected in the second inspection step, when two or more defects are inspected, a mark corresponding to the defect detected before the last time Detection can be prevented.

The method for producing a laminated optical film of the present invention is a method for producing a laminated optical film by bonding at least one of a protective film and an adhesive to an optical film, and includes a defect inspection method for the above laminated optical film. According to this method for producing a laminated optical film, the same advantages as the defect inspection method for the above-mentioned laminated optical film can be obtained.

According to the present invention, it is possible to prevent the detection of a mark corresponding to a defect detected before the last time when the defect inspection of the optical film and the laminated optical film is performed two or more times. As a result, the final mark size becomes large, It is possible to prevent the yield of the optical film from deteriorating.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a defect inspection method and a manufacturing method of a laminated optical film according to a first embodiment of the present invention. FIG.
2 is a diagram showing a defect inspection method and a manufacturing method of a laminated optical film according to the first embodiment of the present invention.
Fig. 3 is a view for explaining the first marking step in the defect inspection method of the laminated optical film according to the first embodiment of the present invention, and shows one main surface of the laminated optical film.
4 is a cross-sectional view of the laminated optical film along the line IV-IV in Fig.
Fig. 5 is a view for explaining the second marking step in the defect inspection method of the laminated optical film according to the first embodiment of the present invention, showing one main surface of the laminated optical film. Fig.
6 is a cross-sectional view of the laminated optical film along the line VI-VI in Fig.
Fig. 7 is a view for explaining the first marking step in the conventional defect inspection method, showing one main surface of the laminated optical film in the conventional defect inspection method. Fig.
8 is a cross-sectional view of the laminated optical film taken along the line VIII-VIII in Fig.
9 is a view for explaining a marking step after the marking step shown in Fig. 7 in the conventional defect inspection method, and showing one main surface of the laminated optical film in the conventional defect inspection method.
10 is a sectional view of the laminated optical film along the line XX in Fig.
11 is a view showing a defect inspection method and a manufacturing method of a laminated optical film according to a second embodiment of the present invention.
12 is a view showing a defect inspection method and a manufacturing method of a laminated optical film according to a second embodiment of the present invention.
Fig. 13 is a view for explaining the first marking step in the defect inspection method of the laminated optical film according to the second embodiment of the present invention, and shows one main surface of the laminated optical film.
14 is a cross-sectional view of the laminated optical film along the line XIV-XIV in Fig.
15 is a view for explaining the second marking step in the defect inspection method of the laminated optical film according to the second embodiment of the present invention, showing one main surface of the laminated optical film.
16 is a cross-sectional view of the laminated optical film along the line XVI-XVI in Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals.

[First Embodiment]

1 and 2 are views showing a defect inspection method and a manufacturing method of a laminated optical film according to the first embodiment of the present invention. 3 and 5 are views showing one main surface of the laminated optical film in the different processes of the defect inspection method shown in Fig. 1, and Figs. 4 and 6 are views showing the laminated optical films shown in Figs. 3 and 5 Sectional view. Figs. 1 to 6 show XY plane coordinates. The X direction indicates the width direction of the laminated optical film, and the Y direction indicates the length direction of the laminated optical film.

First, as shown in Fig. 1, the optical film 11 is unwound from the original roll 101. Then, as shown in Fig. The optical film (11) includes an optical film main body having optical characteristics. Examples of the optical film 11 include a polarizing plate having polarization characteristics and a retardation plate having birefringence. For example, when the optical film 11 is a polarizing plate, a polyvinyl alcohol (PVA) is included as an optical film body, and TAC (triacetyl cellulose) films are bonded to both sides of the polarizer. On the other hand, when the optical film 11 is a phase difference plate, the phase difference plate corresponds to the optical film main body.

Subsequently, light is irradiated onto the optical film 11 by a light source (not shown) disposed on the other main surface 11b side of the optical film 11, and light is irradiated onto one main surface 11a of the optical film 11, And the defect inspection of the optical film 11 is performed based on the received transmitted light (the first inspection step, the second inspection step, and the second inspection step) Permeability test).

Subsequently, the protective film 12 is unwound from the disk roll 102, and the protective film 12 is laminated on the side of the main surface 11a of the optical film 11. As the protective film 12, a PET (polyethylene terephthalate) film or the like is used. Subsequently, the optical film 11 and the protective film 12 are bonded to each other by the bonding roll 103 to produce a laminated optical film 10A.

Subsequently, in accordance with defects detected in the first inspection step (by a droplet method) using the inkjet printer 113 disposed on the protective film 12 side of the laminated optical film 10A, the laminated optical film 10A on the protective film 12 side (first marking step).

For example, as shown in FIGS. 3 and 4, in the case where three defects 20 generated by the incorporation of foreign matter into the laminated optical film 10A are detected, The mark 30 in the linear direction is marked on the surface of the protective film 12 of the laminated optical film 10A so as to surround the defect 20 so that the defect 20 is sandwiched by marking the linear mark 30 in the Y direction Marking is performed.

Fig. 4 schematically shows only one defect 20 in Fig. 3 and schematically shows two linear marks 30 corresponding to the defects 20. Fig. 1 schematically shows only one defect 20 in FIG. 3 and two linear marks 30 corresponding to this defect 20. In FIG.

Subsequently, the laminated optical film 10A is wound around the disk roll 104. Then,

Subsequently, the laminated optical film 10A is unwound from the disk roll 104 and a separate film (release film) 14 is removed from the disk roll 105, as shown in Fig. 2 The adhesive material 13 with the separate film bonded to the adhesive material 15 is released and the adhesive material 13 with the separate film attached to the optical film 11 side of the laminated optical film 10A is laminated. As the material of the separate film, PET (polyethylene terephthalate) or the like is used. Subsequently, the laminated optical film 10A and the adhesive material 13 having the separate film attached thereto are bonded together by the bonding roll 106 to produce a laminated optical film 10B.

Subsequently, light (not shown) disposed on the other main surface 10b side (the side of the adhesive material 13 to which the separate film is attached) of the laminated optical film 10B is irradiated with light And the light transmitted through the laminated optical film 10B is received by the inspection device 115 disposed on the side of the main surface 10a (on the side of the protective film 12) of the laminated optical film 10B, The defect inspection of the laminated optical film 10B is performed based on one transmitted light (second inspection step, transmission inspection). In the first embodiment, the tester 115 is a transmission tester.

In the second inspection step, the marked mark 30 is not detected in the first marking step. For example, a mark 30 formed by a droplet method using an inkjet printer is usually large in relation to defects to be detected by inspection using a transmission tester. From this, the tester 115 can identify the mark 30, for example, based on the size. Alternatively, the tester 115 may recognize the mark 30 based on the shape of the marked mark 30 in the first marking step. The tester 115 may include a filter unit for removing information on the mark 30 from the information of the transmitted light received by the tester 115.

Subsequently, in accordance with defects detected in the second inspection step (by a droplet method) using an inkjet printer 119 disposed on the side of one main surface 10a of the laminated optical film 10B, a laminated optical film 10B on the side of the main surface 10a side (second marking step).

For example, as shown in FIGS. 5 and 6, in the case where two defects 21 generated by the incorporation of foreign matter into the laminated optical film 10B are detected, Of the laminated optical film 10B on the side of the main surface 10a side so as to surround the defect 21 so that the defect 21 is sandwiched by marking the linear mark 31 in the Y direction Marking is performed.

Fig. 6 schematically shows only one defect 20 in Fig. 3 and schematically shows two linear marks 30 corresponding to the defects 20, as in Fig. Fig. 6 schematically shows only one defect 21 in Fig. 5, and schematically shows two linear marks 31 corresponding to this defect 21. Fig. In Fig. 2, similarly to Fig. 1, only one defect 20 or 21 in Fig. 5 and two linear marks 30 or 31 corresponding to this defect 20 or 21 are schematically shown do.

Subsequently, the laminated optical film 10B is wound around the disk roll 107. Then,

Figs. 7 and 9 are views showing one main surface of the laminated optical film in the different processes of the conventional defect inspection method, and Figs. 8 and 10 are sectional views of the laminated optical film shown in Figs. 7 and 9. Fig.

The conventional defect inspection method differs from the defect inspection method of the present embodiment in that the second inspection step is not provided with a function of not detecting the marked mark in the first marking step.

That is, as shown in Figs. 9 and 10, in the conventional defect inspection method, the mark 30 formed in the first marking step is detected as a defect in the second inspection step. As a result, in the second marking step, corresponding to the defects 20 detected in the first inspection step and the marks 30 formed in the first marking step, the defects 20 and the marks 30 are sandwiched in correspondence with the marks 30 formed in the first marking step. In other words, the mark 31 is formed so as to surround the defect 20 and the mark 30.

As described above, in the conventional defect inspection method, when two or more defects are inspected, the marks marked before the last inspection are detected as defects in the second inspection and the subsequent inspection, and marking is also performed in the vicinity of the defects correspondingly, As a result, there is a problem that the final mark size is increased, and the yield of the optical film is lowered.

However, according to the defect inspection method and the manufacturing method of the laminated optical film of the first embodiment, in the second inspection step, since the mark 30 marked in the first marking step is not detected, It is possible to prevent the mark 30 corresponding to the previously detected defect from being detected. As a result, the defect rate can be obtained with high accuracy, and the final mark size is increased, and the yield of the optical film is prevented from being lowered.

[Modifications of First Embodiment]

In the first embodiment, the same kind of defect inspection (penetration inspection) is performed plural times before and after the step of bonding the protective film 12 and the adhesive material 13 with the separate film to the optical film 11 However, the idea of the present invention is that a different type of defect inspection is combined as described below in detail, for example, in the first embodiment, the penetration inspection is performed as the first inspection step, The present invention is also applicable to a form in which reflection inspection is performed as an inspection process.

[Second Embodiment]

In the first embodiment, a method of performing a plurality of defect inspections before and after the step of bonding the protective film 12 and the adhesive material 13 with the separate film to the optical film 11 is exemplified. However, The mapping can also be applied to a method in which a plurality of defects are inspected for the same laminated optical film.

For example, different inspection (for example, transmission inspection and reflection inspection) may be performed in combination for the same laminated optical film. For example, the penetration test is suitable for the detection of foreign matter of the black color mixed in the inside of the optical film, but it is difficult to detect small bubbles incorporated into the surface of the optical film. On the other hand, the reflection inspection is suitable for the detection of small bubbles incorporated into the surface of the optical film, but it is difficult to detect the foreign matter of black color mixed into the optical film.

Hereinafter, a defect inspection method which is performed by combining different tests for the same laminated optical film will be exemplified. In this second embodiment, a defect inspection method of a laminated optical film is exemplified. However, the idea of the present invention is also applicable to a defect inspection method which is performed by combining different inspection for a single-layer optical film.

11 and 12 are diagrams showing a defect inspection method and a manufacturing method of a laminated optical film according to a second embodiment of the present invention. 13 and 15 are views showing one main surface of the laminated optical film in the different processes of the defect inspection method shown in Figs. 11 and 12, and Fig. 14 and Fig. Sectional view of the optical film.

First, as shown in Fig. 11, the laminated optical film 10B is unwound from the disk roll 101. Then, as shown in Fig. The laminated optical film 10B is irradiated with light by a light source (not shown) disposed on the other main surface 10b side of the laminated optical film 10B, The transmission inspection tester 111 disposed on the side of the laminated optical film 10a receives the light transmitted through the laminated optical film 10B and performs defect inspection of the laminated optical film 10B based on the received transmitted light , Transmission test).

Subsequently, in accordance with defects detected in the first inspection step (by a droplet method) using the inkjet printer 113 disposed on the side of the main surface 10a of the laminated optical film 10B, the laminated optical film 10A on the side of one main surface 10a (first marking step).

For example, as shown in FIGS. 13 and 14, in the case where three defects 20 produced by the incorporation of foreign matter into the laminated optical film 10B are detected, The mark 30 in the linear direction is marked in the Y direction so as to surround the defect 20 so that the defect 20 is sandwiched between the defect 20 and the surface of the laminated optical film 10B on the main surface 10a side Marking is performed.

Fig. 14 schematically shows only one defect 20 in Fig. 13, and schematically shows two linear marks 30 corresponding to the defects 20. Fig. 11 schematically shows only one defect 20 in Fig. 13 and two linear marks 30 corresponding to this defect 20. In Fig.

Subsequently, the laminated optical film 10B is wound on the master roll 104. Then,

Subsequently, as shown in Fig. 12, the laminated optical film 10B is unwound from the disk roll 104. Then, as shown in Fig. Subsequently, the laminated optical film 10B is irradiated with light by a light source (not shown) disposed on the side of the main surface 10a of the laminated optical film 10B, The tester 115 disposed on the side of the stacked optical film 10a receives the light reflected by one main surface 10a of the laminated optical film 10B and performs defect inspection of the laminated optical film 10B based on the received reflected light (Second inspection step, reflection inspection). In the second embodiment, the tester 115 is a reflection tester.

In the second inspection step, the marked mark 30 is not detected in the first marking step. That is, in the second inspection step, the defect 25 which is not detected in the first inspection step and is detected for the first time in the second inspection step is detected (see Figs. 15 and 16). The method for not detecting the mark 30 in the tester 115 can be the same as that in the first embodiment. That is, the tester 115 may recognize the mark 30 by its size, shape, or the like. The tester 115 may include a filter unit for removing information on the mark 30 from the information contained in the reflected light received.

Subsequently, in accordance with defects detected in the second inspection step (by a droplet method) using an inkjet printer 119 disposed on the side of one main surface 10a of the laminated optical film 10B, a laminated optical film 10B on the side of the main surface 10a side (second marking step).

For example, as shown in Figs. 15 and 16, in the case where two defects 25 produced by the incorporation of bubbles into the surface of the laminated optical film 10B are detected, Of the laminated optical film 10B on the side of the main surface 10a side so as to surround the defect 25 so that the defect 25 is sandwiched by marking the linear mark 31 in the Y direction Marking is performed.

Fig. 16 schematically shows only one defect 20 in Fig. 13 and schematically shows two linear marks 30 corresponding to the defects 20, as in Fig. Fig. 16 schematically shows only one defect 25 in Fig. 15, and schematically shows two linear marks 31 corresponding to this defect 25. Fig. 12 schematically shows only one defect 20 or 25 in FIG. 15 and two linear marks 30 or 31 corresponding to the defect 20 or 25, as in FIG.

Subsequently, the laminated optical film 10B is wound by a disk roll 107. Then,

The same advantages as those of the defect inspection method and the manufacturing method of the laminated optical film of the first embodiment can be obtained in the defect inspection method and manufacturing method of the laminated optical film of the second embodiment.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the present embodiment, the defect inspection is performed twice, but the idea of the present invention is also applicable to the defect inspection performed three times or more.

In the present embodiment, penetration inspection and reflection inspection are exemplified as types of defect inspection, but the kind of defect inspection is not limited to this. The idea of the present invention is also applicable to a defect inspection method including Cross-Nicol inspection and the like.

10A, 10B: laminated optical film 11: optical film
12: protective film 13: adhesive material with separate film
14: Separate film 15: Adhesive material
20, 21, 25: defect 30, 31: mark
101, 102, 104, 105, 107: a disk roll 103, 106:
111: Transmission tester 113, 119: Ink-jet printer
115: Inspector (Transmission Inspector or Reflector Inspector)

Claims (5)

A method for inspecting defects in the laminated optical film by two or more defects while obtaining a laminated optical film by bonding at least one of a protective film, a protective film, and an adhesive material with a separate film to an optical film,
A first inspection step of performing defect inspection of the optical film;
A step of bonding at least one of the protective film and the adhesive material having the separator film to the optical film to produce the laminated optical film,
A first marking step of marking the laminated optical film in accordance with defects detected in the first inspection step,
A second inspection step of performing defect inspection of the laminated optical film,
A second marking step of marking the laminated optical film in accordance with defects detected in the second inspection step
/ RTI >
In the second inspection step, in the first marking step,
(Method for Inspection of Defects in Laminated Optical Film). The defect inspection method for a laminated optical film according to claim 1, wherein the defect inspection method in the first inspection step and the defect inspection method in the second inspection step are the same. The defect inspection method for a laminated optical film according to claim 1, wherein the defect inspection method in the first inspection step and the defect inspection method in the second inspection step are different. As a method for inspecting defects of an optical film by two or more defect inspections,
A first inspection step of performing defect inspection of the optical film;
A first marking step of marking the optical film in accordance with defects detected in the first inspection step,
A second inspection step of performing a defect inspection different from the defect inspection in the first inspection step as the defect inspection of the optical film,
A second marking step of marking the optical film in accordance with defects detected in the second inspection step
/ RTI >
In the second inspection step, in the first marking step,
A defect inspection method for an optical film. A protective film, and a pressure-sensitive adhesive material with a separate film attached to an optical film,
A method for inspecting defects of a laminated optical film according to any one of claims 1 to 3,
A method for producing a laminated optical film.

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