KR101704556B1 - The cutting device and the method of Polarizing plate - Google Patents

Abstract

The present invention relates to a polarizing plate cutting apparatus and a polarizing plate cutting apparatus, the polarizing plate cutting apparatus comprising: a defect detecting unit for detecting a defect in a polarizing plate; A cut portion for cutting the polarizer; And a control unit for controlling the cut unit based on defect position data of the defect detection unit. The method of cutting a polarizer includes: a defect detection step of detecting a defect in the first to nth defect detection units; And the first to the (m-1) -th cut sections are cut to cut the polarizing plate, and when the defects are not detected in the m-th defect detection section, Since a plurality of defect detection sections and a plurality of cut sections are used for cutting by different cutting methods for each defect pattern including the step of cutting, the productivity is improved and the polarizer that is discarded is minimized at the same time.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate cutting apparatus,

The present invention relates to a polarizing plate cutting apparatus and a polarizing plate cutting method.

A polarizing plate is applied to an optical element such as a liquid crystal display device (LCD).

The polarizer is formed by laminating a polarizer protective film typified by triacetyl cellulose (TAC) on one side or both sides of a polarizer (also referred to as a polarizing film) made of a polyvinyl alcohol resin, Layer structure in which a pressure-sensitive adhesive layer, a release film, a surface protective film or a functional coating layer is laminated.

Such a polarizing plate having a multi-layer structure is produced as a sheet-like product wound on a roll, and is cut and used as a sheet of polarizing plate depending on the application.

Defects may be formed on the surface of the sheet-like polarizing plate, and only the portions without defects are used for the polarizing plate to be applied to the final product. A method of cutting such a conventional sheet-like polarizing plate into a single sheet of polarizing plate is largely divided into a post-inspection method and a post-inspection (post) inspection method.

In the post-cutting inspection method, a sheet polarizing plate is cut into a single sheet of polarizing plate, and then a single sheet of polarizing plate is inspected for defects. The defective sheet is treated as a reject sheet, Only a single polarizer is used as a good product. However, this method is disadvantageous in terms of product efficiency, since the rejected product is cut in the same manner as the good quality of the good product, so that even if only a part of the rejected product is defective, the entire sheet is discarded.

On the other hand, the post-inspection (post) inspection is a method of preferentially inspecting the surface of the polarizing plate that is wound in the form of a sheet, and only the defective portion is avoided. However, this method has a problem that the productivity is deteriorated because the position of the polarizing plate corresponding to the cutting standard is inspected by one inspection machine and the cutting position is adjusted every time.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to minimize the portion discarded by defects and achieve high-speed production by enabling high-speed cutting.

According to an aspect of the present invention, there is provided a polarizing plate cutting apparatus comprising: a defect detecting unit for detecting a defect in a polarizing plate; A cut portion for cutting the polarizer; And a control unit for controlling the cutting unit based on defect position data of the defect detecting unit.

The defect detecting unit may include a first through an n-th defect detecting unit, and the cutting unit may include first through n-th cutting units. The control unit may detect the defect location data of the first through n- And determines whether or not the first to n-th cut sections operate.

In addition, the first to n-th cut portions are spaced apart from each other by the cut standard interval of the polarizer in the stretching direction of the polarizer.

The cutting unit may further include: a laser head; And a guide member for guiding movement of the laser head.

The defect detection unit may be a sensor or a camera.

According to an aspect of the present invention, there is provided a method of cutting a polarizer, including: detecting a defect in a first through an n-th defect detectors; And the first to the (m-1) -th cut sections are cut to cut the polarizing plate, and when the defects are not detected in the m-th defect detection section, And cutting.

Further, the method may further include: after the step of operating the first to the n-th cut sections to cut the polarizer, firstly fixing the polarizer plate; And operating the first to n < th > defect detectors to detect defects.

Further, after the step of operating the first to (m-1) -th cut sections to cut the polarizing plate,

Fixing the polarizing plate to a second position; And operating the second to n < th > defect detectors to detect defects.

In the step of detecting a defect by operating the second to the n-th defect detecting units, when the defect is detected in the k-th defect detecting unit, the polarizing plate is cut by operating the first to (k-1) And disconnecting the polarizing plate by operating the first to the n-th cut portions when a defect is not detected in the defect detecting portion.

Further, the method may further include: after the step of operating the first to the n-th cut sections to cut the polarizer, firstly fixing the polarizer plate; And operating the first to n < th > defect detectors to detect defects.

Further, after the step of operating the first through the (k-1) -th cut sections to cut the polarizing plate, a second forward fixing of the polarizing plate; And operating the second to n < th > defect detectors to detect defects.

The step of fixing the polarizing plate for the first time is a step of advancing so that the end portion of the longitudinal cutting standard of the polarizing plate is placed on the first cut portion.

In addition, the step of securing the polarizing plate to the second position is a step of advancing so that the longitudinal end portion of the defect is placed on the first cut portion.

The mth defect detection unit may be a top defect detection unit in which defects are detected in the first through nth defect detection units.

The kth defect detecting unit may be a highest-order defect detecting unit in which defects are detected in the first through nth defect detecting units.

According to the present invention, the following effects are achieved.

First, since cutting is performed with a plurality of cutting portions, cutting is performed at a high speed.

Second, since a defect is recognized by a plurality of defect detecting portions and the defect portion is avoided cut, the polarizing plate that is discarded is minimized.

Third, since a plurality of defect detecting portions and a plurality of cut portions are used to cut by different cutting methods for each defect pattern, the productivity is improved and the polarizer that is discarded is minimized at the same time.

1 is a perspective view of a polarizing plate cutting apparatus according to a preferred embodiment of the present invention.
2 is a flowchart of a polarizer cutting method according to a preferred embodiment of the present invention.
3 is a view illustrating a polarizer cutting method according to a preferred embodiment of the present invention.
4 is a view illustrating a method of cutting a polarizer according to a preferred embodiment of the present invention.
5 is a view illustrating a method of cutting a polarizer according to a preferred embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The polarizing plate includes a polarizer, a polarizer protective film for protecting the polarizer, a pressure-sensitive adhesive layer to be in contact with the liquid crystal cell, and a release film are sequentially laminated on one surface of the polarizer, Layer structure.

As the polarizer, a film made of a PVA resin and having a dichromatic dye adsorbed and oriented can be used. As the PVA resin constituting the polarizer, a copolymer of vinyl acetate, which is a homopolymer of vinyl acetate, and vinyl acetate and other monomer copolymerizable therewith, may be used. Examples of other monomers copolymerizable with vinyl acetate at this time include unsaturated carboxylic acids, unsaturated sulfonic acids, olefins, vinyl ethers, and acrylamides having an ammonium group.

The polarizer protective film is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy and the like, and examples thereof include polyester films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate; Cellulose-based films such as diacetylcellulose and triacetylcellulose; Polycarbonate film; Acrylic films such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene-based films such as polystyrene and acrylonitrile-styrene copolymer; Polyolefin-based films such as polyethylene, polypropylene, cyclo-based or norbornene-based polyolefin-based films, and ethylene propylene copolymers; Polyimide-based films; Polyethersulfone-based films; A sulfone-based film or the like can be used.

The pressure-sensitive adhesive layer may be formed of an acrylic copolymer, a natural rubber, a styrene-isoprene-styrene (SIS) block copolymer, a styrene-butadiene-styrene (SBS) block copolymer, a styrene-ethylene butylene- Butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, silicone rubber and the like.

The type of the release film is not particularly limited as long as it is a film ordinarily used in the art, and specific examples thereof include polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, , Ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-vinyl alcohol copolymer; Polyester films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Polyamide-based films such as polyacrylate, polystyrene, nylon 6, and partially aromatic polyamide; Polyvinyl chloride films; Polyvinylidene chloride films; Or a polycarbonate film. These can be appropriately subjected to releasing treatment by a silicone system, a fluorine system, a silica powder or the like.

In addition, the polarizing plate may further include an optical film such as a surface protective film, a reflection plate, a transflective plate, a retardation plate, a viewing angle compensating film, etc. if necessary. Each of the films constituting the polarizing plate may further include a hard coat layer, , An antistatic layer, an antireflection layer, an antiglare layer or a diffusion layer may be further formed.

The polarizing plate having a multilayer structure as described above is wound on a roll in a sheet form and then cut into a single polarizing plate according to the application, and is used in the manufacture of a liquid crystal display panel.

In the present invention, a polarizing plate having a usual structure is described as a sheet-like product, but a polarizing plate having a functional coating layer such as an anti-glare layer, an antireflection layer and a diffusion layer, or a polarizing plate having a reflective plate, It is obvious that the present invention can be applied to a sheet-like product other than a polarizing plate.

In the present invention, 'defects' in the polarizing plate means a minute deformation such as fine scratches, warps or twists, generation of bubbles and cracks, incorporation of foreign substances on the surface or inside, scratches or contamination, and the like, but the present invention is not limited thereto .

In the present invention, the 'stretching direction' means the direction in which the polarizing plate is moved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

A preferred embodiment of the present invention will be described with reference to Fig.

The roll-shaped polarizing plate 10 wound on the feeding roll 20 after being slit by the stretching echo of the polarizing plate 10 is set on the unwinding portion. The feeding roll 20 is rotatably mounted on a bracket (not shown) to pull out the polarizing plate 10.

The polarizing plate 10 drawn out from the feeding roll 20 is carried into the accumulator 30 at a predetermined position by a plurality of rollers.

When cutting the polarizing plate 10, the cutting device is accelerated and decelerated. At this time, the polarity of the polarizing plate 10 is prevented from being distorted, and the polarizing plate 10 is hunted by the sudden acceleration / . The accumulator 30 ascends and descends in the vertical direction in the stretching direction so as to easily shorten acceleration and deceleration of the cutting apparatus.

When the polarizing plate 10 is accelerated in the cutting apparatus, the accumulator 30 reduces displacement in the upward or downward direction to prevent hunting of the polarizing plate 10. When the polarizing plate 10 is decelerated in the cutting apparatus The accumulator 30 increases the displacement in the upward direction or the downward direction to prevent hunting of the polarizing plate 10. [

The center position and the side deformation of the flat plate 10 passing through the accumulator 30 are corrected by the correcting means 40. [

The polarizing plate 10 performs inkjet marking on the polarizing plate 10 in the marking portion for defect detection. The inkjet marking can be performed before winding the polarizing plate 10 on the feeding roll 20, and can be performed even after the polarizing plate 10 is unwound from the feeding roll 20.

The marked polarizing plate 10 is moved to a cutting position and fixed using a clamp.

The defect detecting unit detects a defect in the polarizing plate 10 that has been marked. The defect detector detects the size and position of the defect using a sensor or a camera.

The cut portion 50 may be a laser cutter or a blade cutter. The cut portion 50 avoids defects detected by the defect detection portion and cuts the polarizer 10 with a laser cutter or a blade cutter.

The laser cutter includes a laser head provided at least one in the stretching direction of the polarizing plate 10 and a guide member provided in a direction perpendicular to the stretching direction of the polarizing plate 10 and guiding the movement of the laser head.

The cut polarizing plate 10 with respect to the defective portion of the polarizing plate 10 is loaded on the defective loading box 80 separately installed.

The defect-free polarizing plate 10 is cleaned by the cleaner 70, and then loaded on the good article loading tray 90. The cleaner 70 is installed in a direction perpendicular to the stretching direction of the polarizing plate 10.

A polarizing plate cutting apparatus according to a preferred embodiment of the present invention includes a defect detecting unit for detecting a defect in a polarizing plate, a cutting unit for cutting the polarizing plate, and a control unit for controlling the cutting unit based on defect position data of the defect detecting unit.

In particular, the defect detection unit includes first through n-th defect detection units, the cut-off unit includes first through n-th cut units, and the control unit controls the first through n-th defect detection units based on the defect position data of the first through n- It is determined whether or not the n-th cutting section is operated. Where n is a natural number.

The defect detecting unit detects the presence or absence of defects by the cutting standard (width and width) of the sheet-like polarizing plate. When the defect detecting unit is constituted by the first to nth defect detecting units, do.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG.

First, the first to nth defect detection sections are operated (S10).

Next, it is determined whether a defect is detected in the first to nth defect detection units (S20).

If a defect is detected in the m-th defect detecting section in step (S20), the polarizing plate is cut by operating the first to (m-1) -th cut sections and if no defect is detected in the m-th defect detecting section The n-cut section is operated to cut the polarizing plate (S40). Here, m and n are natural numbers, and m satisfies a relation of 1 < m? N.

After the defects are not detected in the mth defect detection unit, the polarizing plate is fixed in the first forward (S50) and the first to nth defect detection units are operated (S10 ).

Here, fixing the polarizing plate in the first forward direction is to fix the sheet-like polarizing plate by a predetermined cutting position by electrostatically fixing it. More specifically, the polarizing plate is moved forward so that the end portion on the opposite side to the stretching direction of the polarizing plate is placed on the first cutting portion .

On the other hand, after the defects are not detected in the mth defect detection section, the polarizing plate is fixed by the second forward operation after operating the first through m-1 cut sections to cut the polarizing plate (S60), and the second through nth defect detection sections (S70).

Here, fixing the polarizing plate to the second forward is to fix the sheet-like polarizing plate by a predetermined cutting position, and more specifically, advance and fix so that the opposite end portion of the defect in the stretching direction lies on the first cutting portion.

When a defect is detected in the kth defect detecting section in operation S80 of detecting the defects by operating the second through nth defect detecting sections, the first through k-1 cut sections are operated to cut the polarizing plate (S90) If no defect is detected in the k defect detection section, the first to n &lt; th &gt; cut sections are operated to cut the polarizing plate (S100).

Here, k and n are natural numbers, and k satisfies a relation of 1 < k? N.

After the step (S100) of cutting the polarizing plate by operating the first to nth cut portions, the polarizing plate is fixed for the first time (S50), and the first to nth defect detecting portions are operated (S10). On the other hand, after the step (S90) of operating the first to (k-1) -th cut sections to cut the polarizing plate, the polarizing plate is fixed for the second time (S60), and the second to the n-th defect detecting sections are operated.

Here, the m &lt; th &gt; defect detection section and the k &lt; th &gt; defect detection section are topmost defect detection sections among the defect detection sections in which defects are detected in the second to n & For example, when the defects are detected in the second and third defect detection sections in the second to fourth defect detection sections, the topmost defect detection section becomes the second defect detection section.

A preferred embodiment of the present invention will be described in detail with reference to Figs. 3 to 5. Fig. FIGS. 3 to 5 show an example of the operation of the defect detecting portion and the cut portion for each defect pattern of the polarizing plate, and the first to fourth defect detecting portions and the first to fourth cut portions will be described as an example. Here, numerals (1) to (4) denote first to fourth defect detection units, numerals 1 to 4 denote first to fourth cuts, and a star denotes defect.

As shown in Fig. 3 (a), if no defects are detected in the first through fourth defect detection units, the first through fourth cutouts are operated to cut the polarizer, as shown in Fig. 3 (b). Then, as shown in Fig. 3 (c), the polarizing plate is clamped by the clamp to fix the polarizing plate first. The first advancing fixation means that the end portion opposite to the stretching direction with respect to the cutting standard of the polarizing plate is advanced to be placed on the first cut portion.

On the other hand, as shown in Fig. 4 (a), when a defect is detected in the fourth defect detecting section, the polarizing plate is cut by operating the first to third cut portions as shown in Fig. 4 (b). Then, as shown in Fig. 4 (c), the polarizing plate is clamped by the clamp to fix the polarizing plate in the second forward position. The second forward fixation means that the opposite end of the defect in the elongation direction is advanced to rest on the first cut. Then, as shown in Fig. 4 (d), the second to fourth defect detecting portions are operated to detect defects. If no defects are detected in the second to fourth defect detecting portions, the first to fourth cut portions are operated to cut the polarizing plate as shown in Fig. 4 (e). On the other hand, as shown in Fig. 4 (f), when a defect is detected in the third defect detecting section, the polarizing plate is cut by operating the first to second cut portions as shown in Fig. 4 (g).

On the other hand, as shown in Fig. 5 (a), when a defect is detected in the second defect detecting section and the fourth defect detecting section, the polarizing plate is cut by operating the first cut section as shown in Fig. 5 (b). Then, as shown in Fig. 5 (c), the polarizing plate is clamped by the clamp to fix the polarizing plate in the second forward position. The second forward fixation means that the opposite end of the defect in the elongation direction is advanced to rest on the first cut. 5 (d), it is determined whether or not a defect is detected by operating the second to fourth defect detecting portions. When the defect is detected by the third defect detecting portion, as shown in FIG. 5 (e) To cut the polarizing plate.

According to the above structure, the present invention is cut at a high speed because it is cut into a plurality of cut portions. Further, since the defects are recognized by the plurality of defect detecting portions and the defective portions are avoided cut, the polarizing plate that is discarded is minimized. In addition, since a plurality of defect detecting portions and a plurality of cut portions are used to cut by different cutting methods for each defect pattern, productivity improvement and minimization of a discarded polarizing plate are simultaneously achieved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be apparent to those skilled in the art.

The present invention can be applied to an apparatus for cutting a polarizing plate.

10: Polarizing plate 20: Feeding roll
30: Accumulator 40: Position correction means
50: Cutting section 70: Cleaner
80: Defective goods box 90: Good article box

Claims (15)

First to n &lt; th &gt; defect detectors for detecting the presence or absence of defects for each of the cutoff standards of the polarizer;
First to n-th cut portions disposed between the first to n-th defect detecting portions, the first to n-th defect detecting portions being spaced apart from each other by a cut standard interval of the polarizing plate in the stretching direction of the polarizing plate;
And a controller for determining whether to operate the first to the n-th cutting units based on the defect position data of the first to n &lt; th &gt;
Wherein the polarizing plate is a polarizing plate.
Here, n is a natural number. delete delete The method according to claim 1,
The cut-
A laser head;
And a guide member for guiding movement of the laser head. The method according to claim 1,
Wherein the defect detecting unit comprises a sensor or a camera. A first to an n-th defect detecting unit for detecting the presence or absence of defects in accordance with a cutting standard of the polarizing plate; and a second to n-th defect detecting unit for cutting the polarizing plate, And the first to the n-th cut portions disposed between the first to n-th cut portions, the method comprising the steps of:
A defect detecting step of detecting a defect in the first to n < th &gt;
And detecting a defect in the mth defect detecting unit of the defect detecting unit, operating the first through m-1 cut units to cut the polarizing plate,
If no defects are detected in the mth defect detection section, the step of operating the first through the n-th cut sections to cut the polarizing plate
Wherein the polarizing plate is a polarizing plate.
Here, m and n are natural numbers, and m satisfies the relation of 1 &lt; m? N. The method according to claim 6,
A step of operating the first to n-th cuts to cut the polarizing plate, and then fixing the polarizing plate for the first time;
And detecting defects by operating the first to n &lt; th &gt; defect detectors. The method according to claim 6,
After the step of operating the first to (m-1) -th cut sections to cut the polarizing plate,
Fixing the polarizing plate to a second position;
And detecting defects by operating the second to the n-th defect detecting sections. 9. The method of claim 8,
When a defect is detected in the kth defect detecting section of the defect detecting section by operating the second through the nth defect detecting sections, the first through the (k-1) th cut sections are operated to cut the polarizing plate,
And if the defect is not detected in the kth defect detecting section, operating the first to nth cut sections to cut the polarizing plate
Wherein the polarizing plate is a polarizing plate.
Here, k and n are natural numbers, and k satisfies a relation of 1 < k? N.
10. The method of claim 9,
After the step of operating the first through the n-th cut sections to cut the polarizing plate,
Fixing the polarizing plate in a first forward position;
And detecting defects by operating the first to n &lt; th &gt; defect detectors. 10. The method of claim 9,
The step of operating the first to (k-1) -th cut sections to cut the polarizing plate, secondly fixing the polarizing plate;
And detecting defects by operating the second to the n-th defect detecting sections. 8. The method of claim 7,
Wherein the step of fixing the polarizing plate for the first time is a step for advancing the polarizing plate such that the end portion on the opposite side to the stretching direction of the polarizing plate is placed on the first cut portion. 9. The method of claim 8,
Wherein the step of securing the polarizing plate for the second time is a step of advancing so that the opposite end portion of the defect in the stretching direction is placed on the first cut portion. 9. The method of claim 8,
Wherein the mth defect detection unit is the highest order defect detection among the defect detection units in which defects are detected in the second through nth defect detection units. 10. The method of claim 9,
Wherein the kth defect detection unit is the highest order defect detection among the defect detection units in which defects are detected in the second through nth defect detection units.

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