WO2017171153A1 - Polarizing plate inspection method and polarizing plate inspection device - Google Patents

Abstract

A method for inspecting a polarizing plate according to the present invention comprises the steps of: (a) preparing a polarizing plate to be inspected having an anisotropic release film on a lower portion of a polarizer to be inspected; (b) positioning a polarizing plate at the side of an inspection device, having a retardation compensation film on an upper portion of the polarizer at the side of the inspection device, below the polarizing plate to be inspected; (c) measuring brightness by a cross-Nicol method when light passes through the polarizing plate to be inspected and the polarizing plate at the side of the inspection device while moving the retardation compensation film on the y-axis, wherein the z-axis is the travel direction of the light, the x-axis is the direction in which the polarizing plate to be inspected moves on a plane perpendicular to the z-axis, and the y-axis is on a plane perpendicular to the z-axis and perpendicular to the x-axis; (d) storing brightness corresponding to a position on the y-axis of the retardation compensation film; (e) moving the retardation compensation film to a y-axis position corresponding to the brightness within 5% from the lowest brightness among the brightness stored in step (d); and (f) inspecting the polarizing plate to be inspected by the cross-Nicol method.

Description

Polarizing plate inspection method and polarizing plate inspection device

The present invention relates to a polarizing plate inspection method and a polarizing plate inspection apparatus which can be inspected even with an anisotropic release film having a high orientation angle.

The polarizing plate is useful as one of the optical components constituting the liquid crystal display device. As the liquid crystal display device is expanded in its use and more precise, defects of the polarizing plate are caused by defects of the liquid crystal display device, and thus it is required to reduce defects of the polarizing plate by inspecting the defects of the polarizing plate.

As an example of a conventional polarizing plate inspection method, an inspection target polarizing plate to be inspected is placed on the inspection polarizing plate in a state of cross nicol, that is, a state in which their polarization axis directions are orthogonal to irradiate light from a light source, and the screen of transmitted light is visually or cameras. It is carried out by the method of observing by.

The release film used in the lower part of the polarizing plate to be inspected mostly uses an anisotropic film. At this time, the phase difference is generated and the optical axis is shifted, which affects the dark state of cross nicol. There is a problem in that it should be limited to an anisotropic release film having an axial angle of 8 ° or less, for example, because it may not be possible to affect the cross inspection.

Looking at the axial angle with respect to the width direction of the release film, the center portion is low anisotropy, the anisotropy increases toward the side. That is, the amount of the anisotropic film that falls within the standard is very limited and therefore inevitably expensive, which is a factor that increases the manufacturing cost of the polarizing plate. Moreover, since the release film is finally peeled off and discarded, it is very wasteful to discuss anisotropic specifications.

Korean Patent Laid-Open Publication No. 2008-0099542 relates to a polarizing plate and a polarizing plate inspection system, and discloses a polarizing plate inspection system including a phase difference correction member positioned between a polarizing plate to be inspected and a polarizing plate for inspection, but applied to an automatic inspection. The following is a somewhat limited situation.

Therefore, there is a demand for development of a system capable of inspecting defects of a polarizing plate irrespective of anisotropy value of a release film and applicable to automatic inspection.

[Preceding technical literature]

[Patent Documents]

(Patent Document 1) Republic of Korea Patent Publication No. 2008-0099542 (2008.11.13.)

An object of the present invention is to provide a polarizing plate inspection method and a polarizing plate inspection apparatus which can be inspected even with a release film having a high orientation angle.

The present invention comprises the steps of: (a) preparing a test polarizing plate having an anisotropic release film provided under the test polarizer; (b) placing an inspector side polarizer having a phase difference compensation film on the inspector side polarizer under the inspected polarizer; (c) measuring brightness when light passes through the inspected polarizing plate and the inspector-side polarizing plate by using the cross nicol method while moving the phase difference compensation film on the y-axis, wherein the z-axis is the progress of the light. Direction, an x axis is a direction in which the inspected polarizer moves on a plane perpendicular to the z axis, and a y axis is on a plane perpendicular to the z axis and perpendicular to the x axis; (d) storing the brightness according to the position on the y-axis of the retardation compensation film; (e) moving the phase difference compensation film to a y-axis position corresponding to brightness within 5% from the smallest brightness among the brightnesses stored in the step (d); And (f) to provide a polarizing plate inspection method comprising the step of inspecting the inspected polarizing plate by a cross nicol method.

In addition, the present invention (a ') receiving the orientation angle information of the anisotropic release film; (b ') preparing an inspected polarizing plate in which the anisotropic release film is positioned below the inspected polarizer; (c ') positioning the inspector side polarizer having the phase difference compensation film positioned on the upper side of the inspector side polarizer; (d ') moving the phase difference compensation film to a y-axis position according to the received alignment angle; And (e ') inspecting the inspected polarizing plate by measuring brightness when light passes through the inspected polarizing plate and the inspector side polarizing plate using a cross nicol method.

In addition, the present invention is an apparatus for inspecting a test polarizing plate provided with an anisotropic release film on one surface of the test polarizer, a light source; An inspector side polarizing plate having a phase difference compensation film positioned on an inspector side polarizer; A light receiving unit for receiving light emitted from the light source through the polarizing plate to be inspected and the inspector-side polarizing plate; Analyze the image obtained from the light receiving unit of the inspector side polarizer and store the brightness and the position on the y axis of the phase difference compensation film corresponding thereto, wherein z axis is the direction of the light travel and x axis is perpendicular to the z axis. An image analyzer in a direction in which the inspected polarizing plate moves in a plane, and a y-axis is on a plane perpendicular to the z-axis and perpendicular to the x-axis; And a control unit configured to move the retardation compensation film in the y-axis direction, and to move the retardation compensation film to a position on the y-axis of the retardation compensation film when the brightness stored in the image analysis unit is smallest. The inspected polarizing plate is positioned to be cross nicol with the inspector side polarizing plate, and the light source and the light receiving unit are respectively located above the inspected polarizing plate and below the inspector side polarizing plate; Or it provides a polarizing plate inspection device located on the lower portion of the inspector side polarizing plate and the upper portion of the inspected polarizing plate.

The present invention also provides a device for inspecting a test polarizing plate provided with a release film, the information of the release film orientation angle is displayed on one surface of the test polarizer, a light source; An inspector side polarizing plate having a phase difference compensation film positioned on an inspector side polarizer; A light receiving unit for receiving light emitted from the light source through the polarizing plate to be inspected and the inspector-side polarizing plate; A recording medium reading unit for reading the information of the orientation angle, or a data storage unit for receiving data including distribution information of the orientation angle of the anisotropic release film on the test polarizing plate; An encoder for measuring the distance from the recording medium reading device to the inspected polarizing plate by transmitting information read from the recording medium reading machine or information from the data storage unit; And move the retardation compensation film to a position of the y-axis of the retardation compensation film according to the distance measured by the encoder, wherein z-axis is the traveling direction of the light and x-axis is the plane to be inspected perpendicular to the z-axis. Direction of movement, and a y-axis is on a plane perpendicular to the z-axis and is perpendicular to the x-axis, wherein the polarizer to be inspected is cross nicolically positioned with the inspector-side polarizer, The light source and the light receiving portion are respectively located above the inspected polarizing plate and below the inspector side polarizing plate; Or it provides a polarizing plate inspection device located on the lower portion of the inspector side polarizing plate and the upper portion of the inspected polarizing plate.

The polarizing plate inspection method according to the present invention has an advantage of inspecting a polarizing plate having a high anisotropic release film having an orientation angle of 8 ° or more.

In addition, the polarizing plate inspection apparatus according to the present invention can easily inspect the polarizing plate having an anisotropic release film having a high orientation angle by automatic inspection.

1 illustrates an example of a polarizing plate inspection apparatus according to some embodiments of the present disclosure.

2 illustrates an example of a polarizing plate inspection apparatus according to some embodiments of the present disclosure.

3 is a diagram illustrating an optical configuration of a polarizing plate inspection apparatus according to some embodiments of the present invention.

It is a figure which shows the change of the orientation angle along the width direction of a film.

5 is a diagram illustrating a change in the orientation angle along the retardation film width direction.

6 is a view showing a change in the orientation angle according to the width direction of the entire anisotropic release film fabric.

Hereinafter, the present invention will be described in more detail.

In the present invention, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

In the present invention, when a part "includes" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

One embodiment of the present invention (a) preparing a test polarizing plate 100 having an anisotropic release film 10 is provided under the test polarizer 30; (b) placing the inspector side polarizer 200 having the phase difference compensation film 20 on the inspector side polarizer 40 below the inspected polarizer 100; (c) measuring brightness when light passes through the inspected polarizing plate 100 and the inspector side polarizing plate 200 by using the cross nicol method while moving the phase difference compensation film 20 on the y-axis. In this case, the z-axis is the direction of the light travel, the x-axis is the direction in which the inspected polarizing plate 100 moves on a plane perpendicular to the z-axis, the y-axis is on a plane perpendicular to the z-axis and the x Perpendicular to the axis; (d) storing the brightness according to the position on the y-axis of the retardation compensation film 20; (e) moving the phase difference compensation film to a y-axis position corresponding to brightness within 5% from the smallest brightness among the brightnesses stored in the step (d); And (f) inspecting the inspected polarizing plate 100 by a cross nicol method.

The step (a) is a step of preparing a test polarizing plate 100 provided with an anisotropic release film 10 in the lower portion of the test polarizer 30.

The inspected polarizer 30 and the inspector side polarizer 40 may be used without limitation as long as they are all known in the art, and may use the same polarizer or may apply the same polarizer. The "same" may be the same thickness, material or size. For example, the polarizer may include a vinyl alcohol resin film such as polyvinyl alcohol, and specifically, a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol resin film, or a polyvinyl chloride (PVC) film. The polyene is formed by the dehydrochlorination reaction of but is not limited thereto.

The anisotropic release film 10 may be an orientation angle of 8 ° or more, specifically 8 ° to 50 °, the material is not limited as long as the release film having an anisotropy commonly used in the art. For example, the anisotropic release film 10 may be a biaxially stretched film, for example, polyolefin-based, polystyrene-based, polyvinylidene chloride-based, ethylene vinyl alcohol, polychlorinated, such as polyester, polyethylene, polypropylene A biaxially oriented film formed of at least one selected from vinyl, polycarbonate, polyamide, polyimide, acrylic, acetate, and polyether sulfone resins may be used. Preferably a biaxially stretched transparent polyester film is used. Moreover, well-known surface treatment, such as corona discharge treatment, can be performed.

The anisotropic release film 10 is generally adhered to the adhesive layer 33 formed on the polarizing plate, and peeled and discarded when applied to an image display device or the like in which the polarizing plate is used.

In general, the release film used in the lower part of the polarizing plate to be inspected mostly uses an anisotropic film. The optical axis of the anisotropic medium with respect to the optical axis of the polarizing plate is twisted by an axial angle, which may cause incomplete cross inspection. In order to generate | occur | produce, the anisotropic release film 10 which has the orientation angle of 8 degrees or less, for example within the orientation angle range which does not affect cross test | inspection is restrict | limited.

However, the polarizing plate inspection method of the present invention is capable of inspecting the polarizing plate applying the anisotropic release film 10 having an orientation angle of 8 ° or more, compared to the polarizing plate applying the anisotropic release film 10 having an existing orientation angle of 8 ° or less. There is an advantage that can reduce the raw material costs.

The test polarizer 30 and the anisotropic release film 10 may be in a bonded state, or the anisotropic release film 10 may be simply positioned below the test polarizer 30. When the anisotropic release film 10 is adhered to the inspected polarizer 30, the adhesive layer may be attached by an adhesive layer, but is not limited thereto. The adhesive layer may be transparent and formed using an isotropic adhesive. If it is not limited to this.

That is, the inspected polarizing plate 100 may refer to a state in which the inspected polarizer 30 and the anisotropic release film 10 are bonded to each other, and the anisotropic release film (below) of the inspected polarizer 30 ( 10) may simply refer to the state where it is located.

When the anisotropic release film 10 is simply positioned at the lower end of the inspected polarizer 30, the inspected polarizer 30 may have a fixed position.

That is, the pre-bonding base material inspection may be performed to advance the anisotropic release film 10 alone through the polarizing plate inspection method of the present invention, and the after-bonding product inspection which is performed after bonding the anisotropic release film 10 to the polarizer. Can be done.

After preparing the inspected polarizing plate 100 in the step (a), the inspector side polarizing plate 200 provided with the phase difference compensation film 20 on the inspector side polarizer 40 of the inspected polarizing plate 100 (B) positioning it downward.

The retardation compensation film 20 is an anisotropic material having the same x-axis refractive index and y-axis refractive index as the anisotropic release film 10, and is rotated 180 ° about the y-axis from the arrangement of the anisotropic release film 10. It may be arranged.

The retardation compensation film 20 is located between the inspected polarizing plate 100 and the inspector side polarizer 40, and may perform a role of canceling and correcting a phase difference that is distorted due to the anisotropy of the anisotropic release film 10. have.

As long as the retardation compensation film 20 has the same x-axis refractive index and y-axis refractive index as the anisotropic release film 10, the type is not limited, but the same film as the anisotropic release film 10 is used. desirable.

In the polarizing plate inspection method, the inspected polarizing plate 100 is prepared, the inspector side polarizing plate 200 is positioned below the inspected polarizing plate 100, and the phase difference compensation film 20 is disposed on the y-axis. (C) measuring the brightness of the light passing through the polarizing plate 100 and the inspector-side polarizing plate 200 using the cross nicol method while moving. At this time, z-axis is the direction of the light travel, x-axis is one axis that exists on a plane perpendicular to the z-axis, y-axis is on a plane perpendicular to the z-axis and is perpendicular to the x-axis.

The retardation compensation film 20 is located on the inspector side polarizer 40, and the lower end of the retardation compensation film 20 may not be in contact with the upper end of the inspector side polarizer 40. Specifically, the lower end of the phase difference compensation film 20 may be a distance of the upper end of the inspector side polarizer 40 may be 1mm to 50mm.

The " distance " is from one point of the lower end of the phase difference compensation film 20, between the surface containing the point and the surface including one point of the upper end of the inspector side polarizer 40 while being parallel to the surface. The shortest length of the straight line can be called.

Since the phase difference compensation film 20 is not in contact with the inspector side polarizer 40, only the phase difference compensation film 20 can be moved without moving the inspector side polarizer 40.

That is, while the phase difference compensation film 20 is moved on the y-axis between the inspected polarizing plate 100 and the inspector side polarizer 40, light is transmitted using the cross nicol method to the inspected polarizing plate 100 and the inspector. The brightness when passing through the inspector side polarizing plate 200 can be measured.

In the present specification, the x and y axes mean the x and y axes existing on the xy plane perpendicular to the z axis, and the z axis means the direction in which light travels.

Alternatively, in the present specification, the "x-axis direction" may mean the longitudinal direction of the anisotropic release film 10 or the longitudinal direction of the retardation compensation film 20, and the "y-axis direction" refers to the anisotropic release film 10. The width direction or the width direction of the retardation compensation film 20 may mean.

In other words, "length direction" may mean the x-axis direction, "width direction" may mean the y-axis direction.

The step (d) may be a step of storing the brightness according to the position on the y-axis of the retardation compensation film 20. That is, in the polarizing plate inspection method, when the light passes through the inspected polarizing plate 100 and the inspector-side polarizing plate 200 by using the cross nicol method while moving the retardation compensation film 20 to the y-axis, the brightness is measured. After measuring and storing the position on the y-axis of the phase difference compensation film 20, the phase difference compensation film 20 is moved to the stored y-axis position in the step (d) through the step (e), After the cross nicol method includes the step (f) of inspecting the inspected polarizing plate 100.

In one embodiment of the present invention, step (d) may be a step of storing the brightness according to the position on the y-axis of the phase difference compensation film 20.

The stored position in step (e) may be a position corresponding to a brightness within 5% of the smallest brightness among the brightnesses according to the stored position in step (d).

In another embodiment of the present invention, step (e) may be a step of moving to a point at the y-axis position corresponding to the smallest brightness among the brightnesses stored in step (d). Specifically, in the polarizing plate inspection method, after storing the position where the brightness is the smallest among the stored positions, the cross nicol method after moving the phase difference compensation film 20 to the position where the brightness is the lowest, that is, the darkest position. It may be to test using.

In the present invention, the expression "small brightness" or "dark" means that the amount of phase difference change by the anisotropic release film 10 and the phase difference compensation film 20 is canceled from each other and the brightness of the transmitted light measured is less than 50 gray, preferably May be an expression referring to the case of less than 30 gray. That is, in the present invention, the "lowest brightness" or "darkest location" is typically the brightness of the transmitted light measured by offsetting the amount of phase difference change by the anisotropic release film 10 and the retardation compensation film 20. The position where the gray value is measured the smallest among the positions when less than 50 gray, preferably less than 30 gray can be referred to.

In addition, the "brightness" in the present invention may refer to the brightness of the transmitted light measured by the amount of phase difference change by the anisotropic release film 10 and the phase difference compensation film 20 cancel each other out.

In another embodiment of the present invention, the retardation compensation film 20 includes a first compensation film 21 and a second compensation film 22, the first compensation film 21 and the second compensation film ( 22) is present on the same xy plane, the first compensation film 21 increases or decreases the alignment angle on the y axis, and the second compensation film 22 increases or decreases the alignment angle on the y axis. May be decreasing.

The first compensation film 21 and the second compensation film 22 may use the same thing symmetrically with respect to the x-axis, or may use a film that is not the same, but the x-axis of the anisotropic release film 10 The retardation value between the direction and the + y-axis direction should be distributed to have the retardation value between the x-axis direction and the -y-axis direction of the first compensation film 21 or the second compensation film 22.

That is, a film having the same distribution as that of the phase difference distribution of the anisotropic release film 10 is disposed on the first compensation film 21 in a state of being symmetrically inverted on the y axis, and the anisotropic release film 10 is based on the x axis. In order to reverse the rotation by 180 degrees, the second compensation film 22 should have a distribution in which the first compensation film 21 is symmetrically reversed with respect to the first compensation film 21.

Specifically, the first compensation film 21 and the second compensation film 22 are located on the same plane on the xy plane, for example, the first compensation film 21 may have an orientation value of + value. The second compensation film 22 may have an orientation value of -value. Alternatively, when the first compensation film 21 has an orientation value of −, the second compensation film 22 may have an orientation angle of +.

Referring to FIG. 4, the orientation angle may increase (−) or decrease (+) according to the length of the film. That is, the retardation compensation film 20 of the present invention includes a first compensation film 21 having an increased or decreased orientation angle on the y axis and a second compensation film 22 having an increased or decreased orientation angle on the y axis. Since it includes all, there is an advantage of easy inspection of the polarizing plate through an automated process.

In addition, although the distribution of the orientation angles is constantly increased or decreased in the width direction of the film in FIG. 4, in some sections, the opposite trend is partially shown.

The first compensation film 21 and the second compensation film 22 has a distribution inverted symmetrically with respect to the y-axis and the anisotropic release film 10, this position-specific characteristics and the anisotropic release film 10 and This means that the distribution characteristic of the alignment angle of the first compensation film 21 or the second compensation film 22 is canceled. However, this means that the characteristics of the first compensation film 21 and the second compensation film 22 are symmetric with each other.

In another embodiment of the present invention, the first compensation film 21 and the second compensation film 22 while moving in the x-axis direction before the step (c) and the first compensation film 21 and The method may further include selecting any one of the second compensation films 22 to enable cross nicolization, and wherein selecting one to enable cross nicolization may include the anisotropic release film 10 and the phase difference compensation film. The amount of phase difference change by (20) cancels each other so that the brightness of the transmitted light measured may be selected to be less than 50 gray, preferably less than 30 gray.

The retardation compensation film 20 includes the first compensation film 21 and the second compensation film 22, and the first compensation film 21 and the second compensation film 22 are on the same xy plane. The first compensation film 21 is an anisotropic release film when the orientation angle is increased or decreased on the y axis, and the second compensation film 22 is increased or decreased on the y axis. The polarizing plate is easily inspected by selecting one of the first compensation film 21 and the second compensation film 22 according to the orientation angle distribution profile of (10). .

That is, the retardation compensation film 20 includes a first compensation film 21 and a second compensation film 22, and the first compensation film 21 and the second compensation film before step (c). While selecting the compensation film that can be inspected using the anisotropic release film 10 and the cross nicol method while moving 22 in the x-axis direction, the position of the y-axis is stored while the selected retardation compensation film 20 is moved to the y-axis. Can be.

In some embodiments of the present invention, the retardation compensation film 20 may have a profile in which the orientation angle distribution profile along the width direction is symmetric with the orientation angle distribution profile along the width direction of the anisotropic release film 10. have.

In another embodiment of the present invention, the retardation compensation film 20 has a profile in which the retardation value distribution profile along the width direction is symmetric with the retardation value distribution profile along the width direction of the anisotropic release film 10. Can be.

Referring to c) of FIG. 3, when the orientation angle of the anisotropic release film 10 has a profile that increases from + 8 ° to + 10 °, the orientation angle of the phase difference compensation film 20 is -8 °. It can have a profile to decrease to -10 °.

In another embodiment of the present invention, the first compensation film 21 has the same orientation angle distribution profile along the width direction as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the 2 the orientation angle distribution profile along the width direction of the compensation film 22 is symmetrically distributed with the orientation angle distribution profile along the width direction of the first compensation film 21; Alternatively, the second compensation film 22 may have an orientation angle distribution profile along the width direction of the second compensation film 22 which is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the width direction of the first compensation film 21 may be different. The orientation angle distribution profile according to the present invention may be symmetrically distributed with the orientation angle distribution profile along the width direction of the second compensation film 22.

Referring to FIG. 5, as shown in a) of FIG. 5, the orientation angle of the first compensation film 21 is 0 mm, that is, about −9 ° and about −8 ° at 2000 mm from the starting position of the first compensation film. When the orientation angle of the film is increased along the width direction of the film, the orientation angle of the second compensation film 22 is 0 mm as shown in b) of FIG. 5, that is, at a position where the second compensation film starts. It is about -9 degrees at -8 degrees, 2000 mm, and it can have a profile which reduces an orientation angle along the width direction of a film.

In the polarizing plate inspection apparatus according to the present invention, one of the first compensation film 21 and the second compensation film 22 is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the other one. Since there is an symmetric distribution with the orientation angle distribution profile along the width direction of the anisotropic release film 10 has an advantage that can be automated inspection.

In another embodiment of the present invention, the method may further include initializing a position of the inspector side polarizer 200. Initializing the position of the inspector-side polarizer 200 may be performed after the step (a) or (b), but is not limited thereto. However, it is preferable to perform after the step (b) in terms of measurement time. For example, if the position of the inspector-side polarizing plate 200 is a center point, unnecessary movement may occur because it has to pass through the already measured position once again in order to move to the unmeasured portion after measuring in one direction. have.

One embodiment of the present invention (a ') receiving the orientation angle information of the anisotropic release film 10; (b ') preparing an inspected polarizing plate 100 in which the anisotropic release film 10 is positioned below the inspected polarizer 30; (c ') positioning the inspector side polarizer 200 having the phase difference compensation film 20 positioned on the upper side of the inspector side polarizer 40; (d ') moving the retardation compensation film 20 to a y-axis position according to the received alignment angle; And (e ') inspecting the inspected polarizing plate 100 by measuring brightness when light passes through the inspected polarizing plate 100 and the inspector side polarizing plate 200 using the cross nicol method. In this case, z-axis is the direction of the light travel, x-axis is the direction in which the inspected polarizing plate 100 is moved on a plane perpendicular to the z-axis, y-axis is on a plane perpendicular to the z-axis and the x A method for inspecting a polarizing plate perpendicular to an axis.

The contents related to the anisotropic release film 10, for example, the orientation angle, the material, and the use of the anisotropic release film 10 are as described above.

Since the polarizing plate inspection method of the present invention can inspect the polarizing plate to which the anisotropic release film 10 having an orientation angle of 8 ° or more can be inspected, the raw material cost is reduced compared to the polarizing plate to which the anisotropic release film 10 having an existing alignment angle of 8 ° or less is applied. This has the advantage of being effective.

Receiving the orientation angle information of the anisotropic release film 10 in the step (a ') may be a step of receiving the information by measuring the orientation angle information of the anisotropic release film 10 in real time, before the process In the step may be a step of receiving the orientation angle information displayed on the anisotropic release film 10.

In one embodiment of the present invention, the orientation angle of step (a ') may be measured at one end and the other end of the anisotropic release film 10 in the x-axis direction.

For the contents related to the x, y and z axes, the above description may be applied.

The "one end" and "other end" are the two-dimensional areas in the direction parallel to the side from the side having the shortest length among the sides forming the two-dimensional plane of the same film as the anisotropic release film 10, respectively. An area of 5% or less with respect to the total length of may be referred to.

Alternatively, the "other end" may refer to a portion facing the "one end".

The orientation angle may be an angle measured at any point of the region corresponding to the “one end” and the “other end”.

The measurement of the orientation angle can be measured through a method generally known in the art, and the method is not limited. For example, the birefringence can be calculated by measuring the retardation and diameter of the film stretched with a white light source using a polarizing microscope, and can also be measured using the KOBRA equipment of Princesa Instruments.

In some embodiments of the present disclosure, the method may further include displaying the orientation angle information on the anisotropic release film 10 before the step (a '), but is not limited thereto.

In some embodiments of the present invention, the displaying of the orientation angle information on the anisotropic release film 10 may include recording the orientation angle information on a recording medium 50 and then recording the recording medium 50 to the anisotropy. Attaching to the release film 10 may be a step of printing or printing. The recording medium 50 is not limited as long as it can record the information of the orientation angle, but may be, for example, in the form of a barcode in convenience, but is not limited thereto.

In another embodiment of the present invention, the step of receiving the orientation angle information of the anisotropic release film 10 of the step (a ') is anisotropic release film 10 attached or printed on the anisotropic release film 10 It may be to read the orientation angle information of.

The step (b ') is a step of preparing the inspected polarizing plate 100 in which the anisotropic release film 10 is positioned below the inspected polarizer 30.

Details of the inspected polarizer 30 and the inspector-side polarizer 40, specifically, materials, relative positions with other components, and adhesive states may be applied to the above-described contents.

Step (c ') is a step of positioning the inspector side polarizer 200 provided with the phase difference compensation film 20 positioned on the upper side of the inspector side polarizer 40.

The content related to the retardation compensation film 20 may be described above.

In another embodiment of the present invention, the retardation compensation film 20 includes a first compensation film 21 and a second compensation film 22, the first compensation film 21 and the second compensation film ( 22) is present on the same xy plane, the first compensation film 21 increases or decreases the alignment angle on the y axis, and the second compensation film 22 increases or decreases the alignment angle on the y axis. It may be reduced, and the above-described details may be applied.

In some embodiments of the present invention, the retardation compensation film 20 may have a profile in which the orientation angle distribution profile along the width direction is symmetric with the orientation angle distribution profile along the width direction of the anisotropic release film 10. have.

In another embodiment of the present invention, the retardation compensation film 20 has a profile in which the retardation value distribution profile along the width direction is symmetric with the retardation value distribution profile along the width direction of the anisotropic release film 10. Can be.

Referring to c) of FIG. 3, when the orientation angle of the anisotropic release film 10 has a profile that increases from + 8 ° to + 10 °, the orientation angle of the phase difference compensation film 20 is -8 °. It can have a profile to decrease to -10 °.

In another embodiment of the present invention, the first compensation film 21 has the same orientation angle distribution profile along the width direction as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the 2 the orientation angle distribution profile along the width direction of the compensation film 22 is symmetrically distributed with the orientation angle distribution profile along the width direction of the first compensation film 21; Alternatively, the second compensation film 22 may have an orientation angle distribution profile along the width direction of the second compensation film 22 which is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the width direction of the first compensation film 21 may be different. The orientation angle distribution profile according to the present invention may be symmetrically distributed with the orientation angle distribution profile along the width direction of the second compensation film 22.

Referring to FIG. 5, as shown in a) of FIG. 5, the orientation angle of the first compensation film 21 is 0 mm, that is, about −9 ° and about −8 ° at 2000 mm from the starting position of the first compensation film. When the orientation angle of the film is increased along the width direction of the film, the orientation angle of the second compensation film 22 is 0 mm as shown in b) of FIG. 5, that is, at a position where the second compensation film starts. It is about -9 degrees at -8 degrees, 2000 mm, and it can have a profile which reduces an orientation angle along the width direction of a film.

In the polarizing plate inspection apparatus according to the present invention, one of the first compensation film 21 and the second compensation film 22 is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the other one. Since there is an symmetric distribution with the orientation angle distribution profile along the width direction of the anisotropic release film 10 has an advantage that can be automated inspection.

In some embodiments of the present invention, one of the first compensation film 21 and the second compensation film 22 is selected to enable cross nicol according to the alignment angle received before the step (d '). The method may further include moving the phase difference compensation film 20 on the x-axis.

Specifically, the first compensation film 21 or the second compensation film 22 is selected according to the inclination direction of the inputted alignment angle. The "tilt direction" may be a relative concept. For example, when the orientation angle of the anisotropic release film 10 is based on one axis of the width direction of the anisotropic release film 10, the orientation angle exists on the right side. The case is referred to as a + direction, and the reverse case may be referred to as a-direction, but is not limited thereto, and may have the same meaning as commonly understood in the art.

When the inclination direction of the inputted alignment angle is +, a compensation film having a negative value of an orientation angle of the first compensation film 21 or the second compensation film 22 may be selected to enable cross nicolization. When the inclination direction of the received alignment angle is −, a compensation film having an alignment angle of + value may be selected among the first compensation film 21 or the second compensation film 22. Thereafter, the selected compensation film is adjusted to the position of the x-axis so that cross nicol is possible.

Orientation angle information for each position of the retardation compensation film 20, that is, the first compensation film 21 or the second compensation film 22 may be measured in advance, and the roll shape corresponding to the orientation angle The positional information of the motor 5 may also be stored in advance in a storage device such as a PC.

The step (d ') is a step of moving the retardation compensation film 20 to the y-axis position according to the received orientation angle, and after moving the retardation compensation film 20 to the y-axis position, the cross nicol method. Inspection of the polarizing plate is possible by performing the step (e ') of inspecting the inspected polarizing plate 100.

Specifically, the step (e ') is to measure the brightness when the light passes through the test polarizing plate 100 and the inspector side polarizing plate 200 by using the cross nicol method to measure the test polarizing plate 100 It is a step of checking.

At this time, the z-axis is the direction of the light travel, the x-axis is the direction in which the inspected polarizing plate 100 is moved on a plane perpendicular to the z-axis, the y-axis is on a plane perpendicular to the z-axis and on the x-axis Vertical.

In some embodiments of the present invention, the y-axis position according to the alignment angle in the step (d ') is measured by offsetting the amount of retardation by the anisotropic release film 10 and the retardation compensation film 20 to each other. The brightness of the transmitted light may be less than 50 gray, preferably less than 30 gray.

Orientation angle information for each position of the retardation compensation film 20, that is, the first compensation film 21 or the second compensation film 22 may be measured in advance, and the roll shape corresponding to the orientation angle The positional information of the motor 5 may also be stored in advance in a storage device such as a PC. That is, in the polarizing plate inspection method according to the present invention, the orientation angle information for each position of the first compensation film 21 or the second compensation film 22 is measured in advance, and the anisotropic release film 10 is supplied. When the orientation angle information of the anisotropic release film 10 is received when the input can be inspected by moving to a previously stored position, wherein the position by the anisotropic release film 10 and the phase difference compensation film 20 It is a position where the brightness of the transmitted light measured by canceling the phase difference change amount becomes less than 50 gray, preferably less than 30 gray.

Another aspect of the present invention is an apparatus for inspecting a test polarizing plate 100 provided with an anisotropic release film 10 on one surface of a test polarizer, the light source (1); An inspector side polarizer 200 having a phase difference compensation film 20 positioned on the inspector side polarizer 40; A light receiving unit 2 for receiving the light irradiated from the light source 1 through the test polarizer 100 and the inspector side polarizer 200; Analyze the image obtained from the light receiving unit 2 of the inspector side polarizer 200 and store the brightness and the position on the y-axis of the phase difference compensation film 20 corresponding thereto, wherein the z-axis is the direction of travel of the light. The x-axis is a direction in which the inspected polarizing plate 100 moves in a plane perpendicular to the z-axis, and the y-axis is on a plane perpendicular to the z-axis and is perpendicular to the x-axis (3 ); And shifting the phase difference compensation film 20 in the y-axis direction, and moving the phase difference compensation film 20 to the position on the y axis of the phase difference compensation film 20 when the brightness stored in the image analysis unit is the smallest. And a control unit 4 configured to move, wherein the inspected polarizing plate 100 is cross-callable with the inspector side polarizing plate 200, and the light source 1 and the light receiving unit 2 are each inspected. Located at an upper portion of the polarizing plate 100 and a lower portion of the inspector side polarizing plate 200; Or it relates to a polarizing plate inspection device located on the lower side of the inspector-side polarizing plate 200 and the upper portion of the inspected polarizing plate 100.

1 shows an example of a polarizing plate inspection apparatus according to some embodiments of the present invention. Referring to FIG. 1, the inspected polarizer 100 is a state in which a release film 10 is provided under the inspected polarizer 30 and the inspected polarizer 30, and the inspected polarizer 30 and the anisotropic release property. The base film 32 is provided between the films 10, and the base film 32 and the protective film 31 are provided on the inspected polarizer 30, but are not limited thereto. The inspector-side polarizing plate 200 is positioned at the lower end of the crossover side so that cross nicol is possible. At this time, the inspector side polarizer 200 is made to include a phase difference compensation film 20 and the inspector side polarizer 40 located at the bottom of the phase difference compensation film 20, the phase difference compensation film 20 Although not limited thereto, the first compensation film 21 and the second compensation film 22 are provided side by side on the xy plane. The anisotropic release film 10 is movable according to the moving direction 8 of the anisotropic release film, and the roller-shaped motor 5 at both ends of the first compensation film 21 and the second compensation film 22. ) Is provided so that the phase difference compensation film 20 can be moved on the y axis by the controller 4, and the phase difference compensation film 20 can be moved on the x axis. The light source 1 and the light receiving part 2 may be located above and below the inspected polarizing plate 100 and above and below the inspector side polarizing plate 200, respectively, and the light source 1 and the light receiving part 2 may inspect the polarizing plate. Those skilled in the art may move the position as appropriate for ease of operation. This is illustrated in FIG. 3. The light irradiated from the light source 1 arrives at the light receiving unit 2, and the image obtained from the light receiving unit 2 is interpreted by the image analyzing unit 3, and according to this information, the control unit 4 generates the light. The position of the retardation compensation film 20 is moved.

The above-described information may be applied to the inspected polarizer 30, the inspector side polarizer 40, the anisotropic release film 10, the inspected polarizer 100, and the inspector side polarizer 200.

The light source 1 is for irradiating light to identify a defect of the polarizing plate 100 to be inspected, and the type of light source 1 is not limited as long as it is generally used in the art, for example, light having a wavelength of 400 nm to 650 nm. It may be to emit. The light source 1 may be the same or similar to the light source 1 of the liquid crystal display device in which the polarizing plate is to be used. White light may be used, but it is more preferable to use green light of 510 nm to 550 nm.

The light emitted from the light source 1 passes through the polarizing plate 100 and the inspector side polarizing plate 200 and is received by the light receiving unit 2.

The light receiving unit 2 may be a light receiving device such as a CCD camera, but is not limited thereto and may be an image receiving device generally used in the cross nicol method in the art.

The image obtained from the light receiving unit 2 of the inspector side polarizer 200 is interpreted by the image analyzer 3 to store the brightness and the position on the y axis of the phase difference compensation film 20 corresponding thereto.

Thereafter, the phase difference compensation film 20 is moved in the y-axis direction through the controller 4. Specifically, the controller 4 moves the phase difference compensation film 20 to a position on the y axis of the phase difference compensation film 20 when the brightness stored in the image analysis unit is the smallest.

In this case, the inspected polarizing plate 100 is positioned to be cross nicol with the inspector side polarizing plate 200, and the light source 1 and the light receiving unit 2 are the inspected polarizing plate 100 and the inspector side polarizing plate, respectively. It may be located above and below the 200. For example, when the light source 1 is positioned above the inspected polarizing plate 100, the light receiving unit 2 is positioned below the inspector side polarizing plate 200, and the light source 1 is located on the inspector side polarizing plate. When the light emitting unit 2 is positioned below the light receiving unit 2, the light receiving unit 2 may be positioned above the inspected polarizing plate 100.

In another embodiment of the present invention, the retardation compensation film 20 includes a first compensation film 21 and a second compensation film 22, the first compensation film 21 and the second compensation film 22 is on the same xy plane, the first compensation film 21 increases or decreases the alignment angle on the y axis, and the second compensation film 22 increases the alignment angle on the y axis. Or decrease.

The first compensation film 21 and the second compensation film 22 may use the same thing symmetrically with respect to the x-axis, or may use a film that is not the same, but the x-axis of the anisotropic release film 10 The retardation value between the direction and the + y-axis direction should be distributed to have the retardation value between the x-axis direction and the -y-axis direction of the first compensation film 21 or the second compensation film 22.

In other words, the retardation compensation film 20 is disposed on the first compensation film 21 in a state in which the film having the same distribution as the phase difference distribution of the anisotropic release film 10 is symmetrically inverted on the y-axis, the anisotropic release In order for the film 10 to be rotated by 180 degrees with respect to the x-axis, the second compensation film 22 should have a distribution in which the first compensation film 21 is symmetrically reversed in the x-axis direction. .

The first compensation film 21 and the second compensation film 22 has a distribution inverted symmetrically with respect to the y-axis and the anisotropic release film 10, this position-specific characteristics and the anisotropic release film 10 and This means that the distribution characteristic of the alignment angle of the first compensation film 21 or the second compensation film 22 is canceled. However, this means that the characteristics of the first compensation film 21 and the second compensation film 22 are symmetric with each other.

When the retardation compensation film 20 includes the first compensation film 21 and the second compensation film 22, the anisotropic release film 10 of the orientation angle distribution profile of the retardation compensation film 20 may be used. Inverted according to the orientation angle distribution profile of, in other words, a compensation film suitable for the anisotropic release film 10 is selected from the first compensation film 21 and the second compensation film 22 without the need for a symmetrical setting process. There is an advantage to the automation process as it only needs to be done.

In another embodiment of the present invention, the retardation compensation film 20 has a profile in which the orientation angle distribution profile along the width direction is symmetric with the orientation angle distribution profile along the width direction of the anisotropic release film 10. The first compensation film 21 may have an orientation angle distribution profile along a width direction of the first compensation film 21 which is the same as an orientation angle distribution profile along the width direction of the anisotropic release film 10. The orientation angle distribution profile along the width direction is symmetrically distributed with the orientation angle distribution profile along the width direction of the first compensation film 21; Alternatively, the second compensation film 22 may have an orientation angle distribution profile along the width direction of the second compensation film 22 which is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the width direction of the first compensation film 21 may be different. Orientation angle distribution profile according to may be a symmetric distribution with the orientation angle distribution profile of the second compensation film (22).

In the polarizing plate inspection apparatus according to the present invention, one of the first compensation film 21 and the second compensation film 22 is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the other one. Since there is an symmetric distribution with the orientation angle distribution profile along the width direction of the anisotropic release film 10 has an advantage that can be automated inspection.

In another embodiment of the present invention, the image analysis unit 3 analyzes the image obtained from the light receiving unit 2 of the inspector side polarizing plate 200, its brightness and corresponding phase difference compensation film 20 It is possible to store the position on the x-axis, the control unit 4 is capable of moving the retardation compensation film 20 in the x-axis direction.

The retardation compensation film 20 may be moved on the x-axis through the controller 4, and the image analyzer 3 may store a position on the x-axis of the retardation compensation film 20. As the retardation compensation film 20 can be moved and stored in the position of the x-axis, the polarizer may be easily inspected regardless of the shape of the anisotropic release film 10.

In another embodiment of the present invention, a conveyor belt for moving the retardation compensation film 20 in the y-axis direction may be further provided. In detail, the retardation compensation film 20 drops two roll-shaped motors 5 connected to the controller 4 in the y-axis direction by a suitable distance and then connects the motors 5 with each other. It may be provided in the form of. The length of the conveyor belt may be adjusted according to the length of the phase difference compensation film 20.

The inspected polarizing plate 100 may further include a protective film 31, a base film 32, an adhesive layer 33, and the like on at least one surface thereof, and the protective film 31 and the base film 32 are sugars. The adhesive layer 33 may be formed by a method commonly used in the art, but is not limited thereto. However, it is preferable that the anisotropic release film 10 and the phase difference compensation film 20 face each other. The base film 32 may serve as a protective film.

3 illustrates an optical configuration of a polarizing plate inspection apparatus according to some embodiments of the present invention. For example, as illustrated in FIG. 3A, an inspector side polarizing plate 200 in which the phase difference compensation film 20 is positioned below the inspector side polarizer 40 is prepared, and an anisotropic release film (below) of the inspector side polarizer 200 is prepared. 10), the adhesive layer 33, the base film 32, the test polarizer 30, the base film 32, the protective film 31 is provided with a test polarizing plate 100 in order, and the light source ( 1) and the light receiving unit 2 may be provided on the outer side of the inspected polarizing plate 100 and the inspector side polarizing plate 200, respectively. In this case, the anisotropic release film 10 and the compensation film 20 are provided to face each other.

In case of a) of FIG. 3, primary polarization occurs by the inspected polarizer 30 and secondary polarization occurs by the inspector side polarizer 40.

3B illustrates an example in which the light source 1 and the light receiving unit 2 are provided on the outer side of the inspector side polarizing plate 200 and the inspected polarizing plate 100, respectively. In this case, primary polarization occurs at the inspector side polarizer 40 and secondary polarization occurs at the inspected polarizer 30.

FIG. 3 c is a side view of FIG. 1, which schematically illustrates b) of FIG. 3, wherein the inspector side polarizer includes a light source 1, an inspector side polarizer 40, and a phase difference compensation film 20. 200 and the anisotropic release film 10, other film layer (eg, protective film 31, base film 32, adhesive layer 33, etc.) on the inspector side polarizer 200 and The inspected polarizing plate 100 and the light receiving unit 2 including the inspected polarizer 30 are provided, and as shown in b) of FIG. 3, primary polarization occurs in the inspector side polarizer 40 and the inspected polarizer ( Secondary polarization may occur in 30). As shown in c) of FIG. 3, the retardation compensation film 20 may be selected such that the direction of the anisotropic release film 10 and the orientation angle are opposite to each other.

Referring to FIG. 6, when the film used in the anisotropic release film 10 is stretched in the width direction, an orientation angle may gradually increase from the center of the anisotropic release film 10 to both ends. Conventionally, only the film part showing an orientation angle of 8 ° or less is cut out from the entire fabric film, but the polarizing plate inspection method according to the present invention uses an anisotropic release film 10 including a portion having an orientation angle of 8 ° or more, for example, FIG. Since the use of the anisotropic release film 10 corresponding to the 0-1300mm section, 2700-4000mm section of 6 can be used to reduce the raw material cost. However, in this case, the orientation angle may vary depending on the amount of stretching, and the phase difference compensation film 20 uses the same stretched product as the anisotropic release film 10 or uses the film used for the anisotropic release film 10. It is preferable to use the entire stretched anisotropic release film 10 fabric.

Another embodiment of the present invention is an apparatus for inspecting the test polarizing plate 100 provided with an anisotropic release film 10, the information of the anisotropic release film 10 orientation angle is displayed on one surface of the test polarizer 30, Light source 1; An inspector side polarizer 200 having a phase difference compensation film 20 positioned on the inspector side polarizer 40; A light receiving unit 2 for receiving the light irradiated from the light source 1 through the test polarizer 100 and the inspector side polarizer 200; A recording medium reading machine (6) for reading information of the orientation angle; An encoder (7) for transmitting the information read by the recording medium reading machine (6) to measure the distance from the recording medium reading machine (6) to the polarizing plate under test (100); And move the retardation compensation film 20 to a position of the y-axis of the retardation compensation film 20 according to the distance measured by the encoder, wherein z-axis is the traveling direction of the light and x-axis is the z-axis. And a control unit 4 which is a direction in which the inspected polarizing plate 100 moves on a plane perpendicular to the axis, and a y-axis exists on a plane perpendicular to the z-axis and is perpendicular to the x-axis. The polarizing plate 100 is positioned to be cross nicol with the inspector side polarizing plate 200, and the light source 1 and the light receiving unit 2 are respectively formed on the upper part of the inspected polarizing plate 100 and the inspector side polarizing plate 200. Located at the bottom; Or it relates to a polarizing plate inspection device located on the lower side of the inspector-side polarizing plate 200 and the upper portion of the inspected polarizing plate 100.

In still another aspect of the present invention, the present invention provides a device for inspecting a test polarizing plate provided with an anisotropic release film on one surface of the test polarizer, the light source (1); An inspector side polarizer 200 having a phase difference compensation film 20 positioned on the inspector side polarizer 40; A light receiving unit 2 for receiving the light irradiated from the light source 1 through the test polarizer 100 and the inspector side polarizer 200; A data storage unit for receiving data including distribution information of an orientation angle of the anisotropic release film 10 on the inspected polarizing plate 100; An encoder (7) receiving information from the data storage unit and calculating an inspection position of the inspected polarizing plate 100; And move the retardation compensation film 20 to the position of the y-axis of the retardation compensation film 20 according to the distance calculated by the encoder, wherein z-axis is the traveling direction of the light and x-axis is the z-axis. And a control unit 4 which is a direction in which the inspected polarizing plate 100 moves on a plane perpendicular to the axis, and a y-axis exists on a plane perpendicular to the z-axis and is perpendicular to the x-axis. The polarizing plate 100 is positioned to be cross nicol with the inspector side polarizing plate 200, and the light source 1 and the light receiving unit 2 are respectively formed on the upper part of the inspected polarizing plate 100 and the inspector side polarizing plate 200. Located at the bottom; Or it relates to a polarizing plate inspection device located on the lower side of the inspector-side polarizing plate 200 and the upper portion of the inspected polarizing plate 100.

Specifically, the encoder 7 may be used to measure the distance to confirm the point of time when the products having different orientation angles reach the inspection point, that is, the bottom of the inspected polarizing plate 100. The position of the encoder 7 is not particularly limited, but may be positioned in contact with a driving roll for moving the anisotropic release film 10 or a guide roll for changing a film traveling path.

For example, when the anisotropic release film 10 having an orientation angle of 10 degrees is supplied while the anisotropic release film 10 having an orientation angle of 20 degrees is being inspected, the recording medium reading machine 6 reads the information of the recording medium 50. In addition, the encoder 7 measures the moving distance of the film to determine the point of time when the anisotropic release film 10 having an orientation angle of 10 degrees reaches the lower portion of the polarizing plate 100 to be inspected, and thus the position of the phase difference compensation film 20. The polarizing plate inspection can be performed by automatically adjusting.

Alternatively, although not shown, the data storage unit receives data including distribution information of the orientation angles of the anisotropic release film 10 on the polarizing plate 100 to be inspected, and the encoder 7 receives information from the data storage unit. The polarizing plate inspection may be performed by calculating the inspection position of the inspected polarizing plate 100 and automatically adjusting the position of the retardation compensation film 20 by receiving the signal.

2 shows an example of a polarizing plate inspection apparatus according to some embodiments of the present invention. Referring to FIG. 2, a bar code on which the orientation angle information is recorded is printed on the lower portion of the anisotropic release film 10, and the polarizing plate under test 100 is disposed under the polarizer 30 under test and the polarizer 30 under test. The anisotropic release film 10 is provided, and a base film 32 is provided between the inspected polarizer 30 and the anisotropic release film 10, and the substrate is disposed above the inspected polarizer 30. The film 32 and the protective film 31 are provided, but are not limited thereto.

The barcode according to FIG. 2 is printed on the lower portion of the anisotropic release film 10, but is not limited thereto and may be attached or printed on the upper portion. In this case, the lower portion of the anisotropic release film 10 may refer to a surface where the anisotropic release film 10 does not contact the base film 32. The inspector side polarizing plate 200 is located at the lower end of the inspected polarizing plate 100 so as to be cross nicol. At this time, the inspector side polarizer 200 is made to include a phase difference compensation film 20 and the inspector side polarizer 40 located at the bottom of the phase difference compensation film 20, the phase difference compensation film 20 Although not limited thereto, the first compensation film 21 and the second compensation film 22 are provided side by side on the xy plane. The anisotropic release film 10 is movable according to the moving direction 8 of the anisotropic release film, and the roller-shaped motor 5 at both ends of the first compensation film 21 and the second compensation film 22. ), The retardation compensation film 20 may be moved on the y-axis by the controller 4, and the retardation compensation film 20 may be movable on the x-axis. The light source 1 and the light receiving unit 2 may be positioned above and below the inspected polarizing plate 100 and above and below the inspector side polarizing plate 200. The light source 1 and the light receiving unit 2 may be inspected by the polarizing plate. Those skilled in the art may move the position as appropriate for ease. This is illustrated in FIGS. 3A and 3B, but is not limited thereto. The recording medium reading machine 6 reads the information of the barcode and transmits the information of the orientation angle of the anisotropic release film 10 to the encoder 7, and after the encoder 7 transmits the information, The distance to the polarizing plate under test 100 is measured, and the retardation compensation film 20 is moved to an appropriate position in the controller 4. Thereafter, the light emitted from the light source 1 passes through the polarizing plate 100 and the inspector side polarizing plate 200 to be received by the light receiving unit 2 to complete the inspection.

In the polarizing plate inspection apparatus according to the present invention, the brightness of the transmitted light measured by offsetting the amount of phase difference change by the anisotropic release film 10 and the retardation compensation film 20 so as to read the information of the orientation angle and thus cross nicol inspection is possible. Automatic inspection is possible by automatically adjusting the position of the retardation compensation film 20 so that is less than 30 gray.

The polarizing plate inspection apparatus according to the present invention is a phase difference compensation amount by the anisotropic release film 10 and the retardation compensation film 20 is canceled by measuring the position of the retardation compensation film 20 when the brightness of the transmitted light is 50 gray or more The polarizing plate inspection can be performed again by making fine adjustments and moving in the y-axis direction.

The above-described information may be applied to the inspected polarizer 30, the inspector side polarizer 40, the anisotropic release film 10, the inspected polarizer 100, and the inspector side polarizer 200.

In another embodiment of the present invention, the retardation compensation film 20 includes a first compensation film 21 and a second compensation film 22, the first compensation film 21 and the second compensation film 22 is on the same xy plane, the first compensation film 21 increases or decreases the alignment angle on the y axis, and the second compensation film 22 increases the alignment angle on the y axis. Or decrease.

For the first compensation film 21 and the second compensation film 22, the above-described information may be applied.

In another embodiment of the present invention, the retardation compensation film 20 has a profile in which the orientation angle distribution profile along the width direction is symmetric with the orientation angle distribution profile along the width direction of the anisotropic release film 10. Can be.

In some embodiments of the present disclosure, the retardation compensation film 20 may have a profile in which the retardation distribution profile along the width direction is symmetric with the retardation distribution profile along the width direction of the anisotropic release film 10. In this case, the above description may be applied.

In the polarizing plate inspection apparatus according to the present invention, one of the first compensation film 21 and the second compensation film 22 is the same as the orientation angle distribution profile along the width direction of the anisotropic release film 10, and the other one. Since there is an symmetric distribution with the orientation angle distribution profile along the width direction of the anisotropic release film 10 has an advantage that can be automated inspection.

For the light source 1 and the light receiving unit 2, the above-described information may be applied.

Positions of the inspected polarizing plate 100, the inspector side polarizing plate 200, the light source 1, and the light receiving unit 2 may apply the above-described contents.

In another embodiment of the present invention, a conveyor belt for moving the retardation compensation film 20 in the y-axis direction may be further provided, and the above description may be applied.

The inspected polarizing plate 100 may further include a protective film 31, a base film 32, an adhesive layer 33, and the like on at least one surface thereof.

3 illustrates an optical configuration of a polarizing plate inspection apparatus according to some embodiments of the present invention. For example, as illustrated in FIG. 3A, an inspector side polarizing plate 200 in which the phase difference compensation film 20 is positioned below the inspector side polarizer 40 is prepared, and an anisotropic release film (below) of the inspector side polarizer 200 is prepared. 10), the adhesive layer 33, the base film 32, the test polarizer 30, the base film 32, the protective film 31 is provided with a test polarizing plate 100 in order, and the light source ( 1) and the light receiving unit 2 may be provided on the outer side of the inspected polarizing plate 100 and the inspector side polarizing plate 200, respectively. In this case, the anisotropic release film 10 and the retardation compensation film 20 are provided to face each other.

In case of a) of FIG. 3, primary polarization occurs by the inspected polarizer 30 and secondary polarization occurs by the inspector side polarizer 40.

3B illustrates an example in which the light source 1 and the light receiving unit 2 are provided on the outer side of the inspector side polarizing plate 200 and the inspected polarizing plate 100, respectively. In this case, primary polarization occurs at the inspector side polarizer 40 and secondary polarization occurs at the inspected polarizer 30.

FIG. 3 c is a side view of FIG. 2, which schematically illustrates b) of FIG. 3, wherein the inspector side polarizing plate including the light source 1, the inspector side polarizer 40, and the phase difference compensation film 20 is provided. 200 and the anisotropic release film 10, other film layer (eg, protective film 31, base film 32, adhesive layer 33, etc.) on the inspector side polarizer 200 and The inspected polarizing plate 100 and the light receiving unit 2 including the inspected polarizer 30 are provided, and as shown in b) of FIG. 3, primary polarization occurs in the inspector side polarizer 40 and the inspected polarizer ( Secondary polarization may occur in 30). As shown in c) of FIG. 3, the retardation compensation film 20 may be selected such that the direction of the anisotropic release film 10 and the orientation angle are opposite to each other.

Referring to FIG. 6, when the film used for the anisotropic release film 10 is stretched in the width direction, an orientation angle may gradually increase from the center of the anisotropic release film 10 to both ends thereof. The above description can be applied.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the embodiments according to the present disclosure may be modified in various other forms, and the scope of the present specification is not to be interpreted as being limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

[Examples 1 to 4]

An anisotropic release film of Mitsubishi Chemical Holdings, whose angle of orientation is + 11 °, is shown in Table 1 below by using the cross nicol method for inspecting the anisotropic release film using the polarizing plate inspection apparatus according to the present invention. At this time, when referring to Figure 6, the anisotropic release film was used by cutting about 1300mm (0 ~ 1300mm section, 2700 ~ 4000mm section) from both ends in a film of 4000mm in total width, the angle of the orientation angle KOBRA equipment (prince measuring equipment Co., Ltd.). At this time, the phase difference compensation film of the polarizing plate inspection apparatus was cut out and used the same product (Mitsubishi Chemical Holdings) as an anisotropic release film.

[Examples 5 to 8]

The angles of the orientation angles of one end and the other end of the anisotropic release film of Mitsubishi Chemical Holdings were measured using KOBRA equipment (Principal Instrument, Inc.), and then recorded on a barcode and attached to the anisotropic release film. At this time, when referring to Figure 6 the anisotropic release film was used to cut about 1300mm (0 ~ 1300mm section, 2700 ~ 4000mm section) from both ends in the film of the full width 4000mm.

Then, the image and the brightness (gray) of the anisotropic release film inspected by the cross nicol method using the polarizing plate inspection apparatus according to the present invention are shown in Table 2 below. At this time, the phase difference compensation film of the polarizing plate inspection apparatus was cut out and used the same product (Mitsubishi Chemical Holdings) as an anisotropic release film.

Comparative Example 1

An anisotropic release film having an angle of an orientation angle of + 11 ° was inspected by a cross nicol method using the polarizing plate inspection apparatus according to the present invention, and the image and brightness (gray) inspected without including a phase difference compensation film in the polarizing plate inspection apparatus. ) Is shown in Table 1 below.

Comparative Example 2

After measuring the angles of the orientation angles of one end and the other end of the anisotropic release film, it was recorded on the barcode and attached to the anisotropic release film. Thereafter, the anisotropic release film is inspected by the cross nicol method using the polarizing plate inspection apparatus according to the present invention, but the image and the brightness (gray) inspected in the state of not including the phase difference compensation film in the polarizing plate inspection apparatus are shown in Table 2 below. Indicated.

Looking at the Table 1, even when using an anisotropic release film having a high orientation angle in the case of using the polarizing plate inspection apparatus according to the present invention, the brightness is 30 gray level, it was possible to implement cross nicol stable, polarizing plate inspection apparatus according to the present invention If not used, the average brightness is 230 gray or more, it can be seen that the polarizing plate inspection is not possible through the cross nicol method.

In addition, referring to Table 2, even when using an anisotropic release film having a high orientation angle when using the polarizing plate inspection apparatus according to the present invention, the brightness is 30 gray level, stable cross nicol implementation was possible, but the polarizing plate inspection according to the present invention If the device is not used, the average brightness is 230 gray or more, it can be seen that the polarizing plate inspection is not possible through the cross nicol method.

[Description of the code]

1: light source 2: light receiving unit

3: image analysis unit 4: control unit

5: motor 6: recording medium reading machine

7: Encoder 8: Movement direction of anisotropic release film

10: anisotropic release film 20: retardation compensation film

21: first compensation film 22: second compensation film

30: test polarizer 31: protective film

32: base film 33: adhesive layer

40: inspector side polarizer

50: recording medium

100: test polarizing plate

200: inspection side polarizer

Claims (19)

(a) preparing an inspected polarizing plate having an anisotropic release film under the inspected polarizer; (b) placing an inspector side polarizer having a phase difference compensation film on the inspector side polarizer under the inspected polarizer; (c) measuring brightness when light passes through the inspected polarizing plate and the inspector-side polarizing plate by using the cross nicol method while moving the phase difference compensation film on the y-axis, wherein the z-axis is the progress of the light. Direction, an x axis is a direction in which the inspected polarizer moves on a plane perpendicular to the z axis, and a y axis is on a plane perpendicular to the z axis and perpendicular to the x axis; (d) storing the brightness according to the position on the y-axis of the retardation compensation film; (e) moving the phase difference compensation film to a y-axis position corresponding to brightness within 5% from the smallest brightness among the brightnesses stored in the step (d); And (f) inspecting the polarizing plate to be inspected by the cross nicol method. The method of claim 1, Wherein (e) is a step of moving to the point of the y-axis position corresponding to the smallest brightness among the brightness stored in the step (d). (a ') receiving orientation angle information of the anisotropic release film; (b ') preparing an inspected polarizing plate in which the anisotropic release film is positioned below the inspected polarizer; (c ') positioning the inspector side polarizer having the phase difference compensation film positioned on the upper side of the inspector side polarizer; (d ') moving the phase difference compensation film to a y-axis position according to the received alignment angle; And (e ') inspecting the inspected polarizing plate by measuring brightness when light passes through the inspected polarizing plate and the inspector side polarizing plate using a cross nicol method; At this time, the z axis is the direction of the light travel, the x axis is the direction in which the inspected polarizing plate is moved on a plane perpendicular to the z axis, the y axis is on a plane perpendicular to the z axis and perpendicular to the x axis method of inspection. The method of claim 3, wherein And displaying the orientation angle information on the anisotropic release film before the step (a '),  The orientation angle of the step (a ') is the polarizing plate inspection method that is measured at one end and the other end of the x-axis direction of the anisotropic release film. The method according to claim 1 or 3, The retardation compensation film includes a first compensation film and a second compensation film, and the first compensation film and the second compensation film exist on the same xy plane, The first compensation film has an increasing or decreasing orientation angle on the y axis, The second compensation film is a polarizing plate inspection method of increasing or decreasing the orientation angle on the y-axis. The method according to claim 1 or 3, The retardation compensation film has a profile in which the orientation angle distribution profile along the width direction is symmetrical with the orientation angle distribution profile along the width direction of the anisotropic release film, or  And the retardation compensation film has a profile in which the retardation value distribution profile along the width direction is symmetrical with the retardation value distribution profile along the width direction of the anisotropic release film. The method of claim 5, The first compensation film has an orientation angle distribution profile in the width direction is the same as the orientation angle distribution profile in the width direction of the anisotropic release film, The orientation angle distribution profile in the width direction of the second compensation film is symmetrically distributed with the orientation angle distribution profile in the width direction of the first compensation film; or The second compensation film has the same orientation angle distribution profile along the width direction as the orientation angle distribution profile along the width direction of the anisotropic release film, Orientation angle distribution profile in the width direction of the first compensation film is a polarizing plate inspection method that is symmetrically distributed with the orientation angle distribution profile in the width direction of the second compensation film. The method of claim 5, Before the step (c) further comprising the step of moving the first compensation film and the second compensation film in the x-axis direction and selecting any one of the first compensation film and the second compensation film to enable cross-calling The polarizing plate inspection method. The method of claim 4, wherein Displaying the orientation angle information on the anisotropic release film is a step of attaching or printing the recording medium to the anisotropic release film after recording the orientation angle information on a recording medium, Wherein (a ') receiving the orientation angle information of the anisotropic release film is a polarizing plate inspection method for reading the orientation angle information of the anisotropic release film attached or printed on the anisotropic release film. The method of claim 5, Moving the retardation compensation film to an x-axis by selecting any one of the first compensation film and the second compensation film to enable cross nicol according to the alignment angle received before the step (d '); The polarizing plate inspection method. The method of claim 3, In the step (d '), the y-axis position according to the alignment angle is a position where the amount of phase difference change caused by the anisotropic release film and the phase difference compensation film cancels each other so that the brightness of the transmitted light measured is less than 50 gray. method of inspection. An apparatus for inspecting a test polarizing plate provided with an anisotropic release film on one surface of the test polarizer, Light source; An inspector side polarizing plate having a phase difference compensation film positioned on an inspector side polarizer; A light receiving unit for receiving light emitted from the light source through the polarizing plate to be inspected and the inspector-side polarizing plate; Analyze the image obtained from the light receiving unit of the inspector side polarizer and store the brightness and the position on the y axis of the phase difference compensation film corresponding thereto, wherein z axis is the direction of the light travel and x axis is perpendicular to the z axis. An image analyzer in a direction in which the inspected polarizing plate moves in a plane, and a y-axis is on a plane perpendicular to the z-axis and perpendicular to the x-axis; And A control unit configured to move the retardation compensation film in the y-axis direction, and to move the retardation compensation film to a position on the y-axis of the retardation compensation film when the brightness stored in the image analysis unit is smallest; The inspected polarizing plate is positioned to be cross nicol with the inspector side polarizing plate, The light source and the light receiving unit are respectively located above the inspected polarizing plate and below the inspector side polarizing plate; Or a polarizing plate inspection device positioned below the inspection-side polarizing plate and above the inspected polarizing plate. An apparatus for inspecting a test polarizing plate provided with a release film, the information of the release film orientation angle is displayed on one surface of the test polarizer, Light source; An inspector side polarizing plate having a phase difference compensation film positioned on an inspector side polarizer; A light receiving unit for receiving light emitted from the light source through the polarizing plate to be inspected and the inspector-side polarizing plate; A recording medium reading machine for reading information of an orientation angle of the release film on the inspected polarizing plate; An encoder for transmitting the information read by the recording medium reading machine to measure a distance from the recording medium reading machine to the inspected polarizing plate; And The retardation compensation film is moved to a position of the y-axis of the retardation compensation film according to the distance measured by the encoder, wherein the z-axis is the traveling direction of the light, and the x-axis is a plane perpendicular to the z-axis. A direction of movement, the y axis being on a plane perpendicular to the z axis and perpendicular to the x axis, The inspected polarizing plate is positioned to be cross nicol with the inspector side polarizing plate, The light source and the light receiving unit are respectively located above the inspected polarizing plate and below the inspector side polarizing plate; Or a polarizing plate inspection device positioned below the inspection-side polarizing plate and above the inspected polarizing plate. An apparatus for inspecting a test polarizing plate provided with an anisotropic release film on one surface of the test polarizer, Light source; An inspector side polarizing plate having a phase difference compensation film positioned on an inspector side polarizer; A light receiving unit for receiving light emitted from the light source through the polarizing plate to be inspected and the inspector-side polarizing plate; A data storage unit for receiving data including distribution information of an orientation angle of the anisotropic release film on the test polarizing plate; An encoder which receives information from the data storage unit and calculates an inspection position of the inspected polarizing plate; And The retardation compensation film is moved to the position of the y-axis of the retardation compensation film according to the distance calculated by the encoder, wherein the z-axis is the traveling direction of the light, and the x-axis is a plane perpendicular to the z-axis. A direction of movement, the y axis being on a plane perpendicular to the z axis and perpendicular to the x axis, The inspected polarizing plate is positioned to be cross nicol with the inspector side polarizing plate, The light source and the light receiving unit are respectively located above the inspected polarizing plate and below the inspector side polarizing plate; Or a polarizing plate inspection device positioned below the inspection-side polarizing plate and above the inspected polarizing plate. The method according to any one of claims 12 to 14, The retardation compensation film includes a first compensation film and a second compensation film, and the first compensation film and the second compensation film exist on the same xy plane, The first compensation film has an increasing or decreasing orientation angle on the y axis, The second compensation film is a polarizing plate inspection apparatus that the orientation angle is increased or decreased on the y-axis. The method according to any one of claims 12 to 14, The retardation compensation film has a profile in which the orientation angle distribution profile along the width direction is symmetrical with the orientation angle distribution profile along the width direction of the anisotropic release film, or And the retardation compensation film has a profile in which an orientation angle distribution profile along a width direction is symmetric with an orientation angle distribution profile along the width direction of the anisotropic release film. The method of claim 15, The first compensation film has an orientation angle distribution profile in the width direction is the same as the orientation angle distribution profile in the width direction of the anisotropic release film, The orientation angle distribution profile in the width direction of the second compensation film is symmetrically distributed with the orientation angle distribution profile in the width direction of the first compensation film; or The second compensation film has the same orientation angle distribution profile along the width direction as the orientation angle distribution profile along the width direction of the anisotropic release film, An orientation angle distribution profile in the width direction of the first compensation film is a polarizing plate inspection device that is symmetrically distributed with the orientation angle distribution profile in the width direction of the second compensation film. The method of claim 12, The image analyzer may analyze an image obtained from the light receiver of the inspector-side polarizing plate and store the brightness and the position on the x-axis of the phase difference compensation film corresponding thereto. The control unit is a polarizing plate inspection device that is capable of moving the phase difference compensation film in the x-axis direction. The method according to any one of claims 12 to 14, Polarizing plate inspection apparatus further comprising a conveyor belt for moving the phase difference compensation film in the y-axis direction.

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