KR20170046182A - Method for manufacturing polarizing plate and method for manufacturing liquid crystal panel - Google Patents

Abstract

A method capable of producing a polarizing plate in which the direction of an absorption axis is accurately directed in a predetermined direction and a manufacturing method of a liquid crystal panel are disclosed. _A method of manufacturing a polarizing plate according to an embodiment is a method of manufacturing a polarizing plate 10 in which the direction of an absorption axis S _A is directed in a predetermined direction, And a processing step S16 of obtaining the polarizing plate 10 by processing the polarizing plate in the processing step S16. The absorption axis detecting step S14 detects the absorption axis of the polarizing plate 10 S _A is oriented in a predetermined direction in the polarizing plate 10 to be obtained.

Description

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

The present invention relates to a method of manufacturing a polarizing plate, and also relates to a method of manufacturing a liquid crystal panel.

A linearly polarizing plate is known as a polarizing plate. The linearly polarizing plate has an absorption axis and a transmission axis orthogonal to the absorption axis, absorbs light oscillating in the absorption axis direction, and transmits light oscillating in the transmission axis direction. Such a polarizing plate is manufactured, for example, by cutting a band-shaped polarizing plate to a predetermined size (see Patent Documents 1 and 2). Here, the strip-shaped polarizing plate is manufactured by laminating a protective film on both sides or one side of a strip-shaped polarizer film, for example. The strip-shaped polarizer film is usually produced by uniaxially stretching the strip-shaped raw film in the longitudinal direction. In this manufacturing method, the direction of the absorption axis of the band-shaped polarizing plate is parallel to the direction in which the raw film is stretched in uniaxial stretching. Since the uniaxial stretching of the raw film is performed in the longitudinal direction, it is assumed that the longitudinal direction of the band-shaped polarizing plate coincides with the absorption axis direction. Therefore, the polarizing plate is produced from the band-shaped polarizing plate such that the absorption axis in the polarizing plate is oriented in a predetermined direction in the polarizing plate with respect to the longitudinal direction of the band-shaped polarizing plate. Conventionally, the polarizing plate produced in this way can withstand practical use even if it is applied to, for example, a liquid crystal display device.

Patent Document 1: JP-A-11-231129 Patent Document 2: JP-A-11-2724

When a polarizing plate is manufactured by assuming that the longitudinal direction of the band-shaped polarizing plate is the direction of the absorption axis, a slight deviation (for example, 0.2 deg.) Between the predetermined direction of the absorption axis required for the product polarizing plate and the actual absorption axis of the polarizing plate ~ 0.3 deg.) May occur. Such a shift is caused by a shift occurring between the stretching direction when the raw film is uniaxially stretched in the production of the strip-shaped polarizing plate to be a polarizing plate and the longitudinal direction of the strip-shaped polarizing plate, and the error in cutting the polarizing plate from the strip- And the like. On the other hand, in recent years, for example, in displays for small and medium-sized portable apparatuses, higher contrast is required. When contrast is increased in a display or the like, when a slight deviation occurs in a predetermined direction of an absorption axis required for a polarizing plate as a product and in a direction of an absorption axis of an actual polarizing plate, there is a possibility that a deterioration in image quality due to the deviation occurs.

Accordingly, it is an object of the present invention to provide a method capable of producing a polarizing plate in which the direction of an absorption axis is accurately directed in a predetermined direction, and further, to provide a method of manufacturing a liquid crystal panel.

A method of manufacturing a polarizing plate according to one aspect of the present invention is a method of manufacturing a polarizing plate in which a direction of an absorption axis is directed in a predetermined direction, comprising a plate absorption axis detecting step of detecting a direction of an absorption axis in a polarizing plate plate, In the processing step, the polarizing plate original plate is processed so that the direction of the absorption axis of the polarizing plate original plate detected in the original plate absorption axis detecting step is directed in a predetermined direction in the polarizing plate to be obtained.

In this method, the absorption axis of the polarizer plate is detected. Then, a polarizing plate is manufactured based on the detection result of the absorption axis. Since the detection result of the absorption axis is used in this manner, a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction can be produced.

In one embodiment, in the processing step, the end face of the polarizing plate may be cut so that the direction of the absorption axis of the polarizing plate original plate detected in the plate absorption axis detecting step is directed in a predetermined direction in the polarizing plate to be obtained.

In a mode of cutting the end face of the polarizer plate, a method of manufacturing a polarizer includes a sheet cutoff process for cutting a sheet-like polarizer from a strip-shaped polarizer, an intermediate step for cutting a polarizer plate intermediate from the sheet polarizer, A cutting process may be further provided.

In this case, the polarizer intermediate, which is a polarizer plate, is cut from the sheet polarizer cut from the strip-shaped polarizer. The direction of the absorption axis of the polarizing plate intermediate plate which is the polarizing plate original plate may deviate from the absorption axis direction assumed in advance in the band-shaped polarizing plate due to the influence of the cutting error or the like in each cutting process. Even in this case, in the above production method, the direction of the absorption axis of the polarizing plate intermediate which is the polarizing plate original plate was detected, and a polarizing plate was obtained based on the detection result. Therefore, it is possible to more reliably obtain a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction.

In one embodiment, in the processing step, the polarizing plate original plate may be cut so that the direction of the absorption axis of the polarizing plate original plate detected in the original plate absorption axis detecting step is directed in a predetermined direction in the polarizing plate to be obtained.

In one embodiment, the processing step includes an intermediate cutting step of cutting the polarizing plate intermediate from the polarizing plate disk, an intermediate absorption axis detecting step of detecting the direction of the absorption axis of the polarizing plate intermediate body, and a step of cutting the end face of the polarizing plate intermediate body In the step of cutting off the polarizer plate so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is equal to that of the polarizer plate intermediate to be obtained and the end face of the polarizer plate intermediate is cut , The end face of the polarizing plate original plate may be cut so that the direction of the absorption axis of the polarizing plate intermediate detected in the intermediate absorption axis detecting step is directed to a predetermined direction in the polarizing plate to be obtained.

In this case, the polarizer intermediate plate is cut from the polarizer plate by cutting the polarizer plate so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is the same in the polarizer plate intermediate. Therefore, it is possible to obtain a polarizing plate intermediate in which the absorption axis directions coincide with each other. Then, the absorption axis of the polarizing plate intermediate was detected again, and a polarizing plate was obtained based on the detection result. Since the polarizing plate is obtained based on the detection result of the polarizing plate intermediate in the absorption axis direction, it is easy to produce a polarizing plate in which the absorption axis direction is directed in a predetermined direction. Further, since the polarizing plate is obtained from the polarizing plate intermediate body based on the detection result of the direction of the absorption axis of the polarizing plate intermediate, the influence of the error in cutting the polarizing plate intermediate from the polarizing plate original plate can be reduced. As a result, it is easy to manufacture a polarizing plate in which the absorption axis direction is directed in a predetermined direction.

In a mode of obtaining a polarizer intermediate plate or polarizer plate from a polarizer plate, the sheet polarizer may further include a sheet cutoff process for cutting the sheet polarizer, which is a polarizer plate, from the band-shaped polarizer.

The sheet polarizer, which is a polarizer plate, is cut from a strip-shaped polarizer. In this case, there may be a case where the direction of the absorption axis of the single-sided polarizing plate, which is the original plate of the polarizing plate, deviates from the absorption axis assumed beforehand with respect to the band-shaped polarizing plate, due to the influence of cutting errors or the like. The absorption axis directions assumed in the band-shaped polarizing plate may not coincide with each other. Even in such a case, in the above production method, the direction of the absorption axis of the sheet-like polarizing plate as a polarizing plate is detected, and a polarizing plate is obtained based on the detection result. Therefore, it is possible to more reliably obtain a polarizing plate in which the direction of the absorption axis is directed in a predetermined direction.

In one embodiment, the polarizer plate is a strip-shaped polarizer. In the processing step, the polarizer plate may be cut so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is oriented in a predetermined direction.

The absorption axis directions assumed in the band-shaped polarizing plate may not coincide with each other. Even in such a case, in the above-mentioned manufacturing method, the direction of the absorption axis of the band-shaped polarizing plate as the polarizing plate was detected, and a polarizing plate was obtained based on the detection result. Therefore, it is possible to more reliably obtain a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction.

The processing step in the method for producing a polarizing plate in the form that the polarizing plate is a strip-shaped polarizing plate is characterized in that the processing step in the polarizing plate manufacturing method includes an intermediate cutting step of cutting the polarizing plate intermediate from the polarizing plate disc, an intermediate absorption axis detecting step of detecting the direction of the absorption axis of the polarizing plate intermediate, And a step of cutting the end face of the polarizing plate intermediate. In the intermediate cutting process, the polarizing plate original plate is cut so that the direction of the absorption axis of the polarizing plate original detected in the original plate absorption axis detecting step is the same in the polarizing plate intermediate to be obtained In the step of cutting the end face of the polarizing plate intermediate, the end face of the polarizing plate original plate is cut so that the direction of the absorption axis of the polarizing plate intermediate detected in the intermediate absorption axis detecting step is directed in a predetermined direction in the polarizing plate to be obtained Maybe.

The absorption axis of the band-shaped polarizing plate is detected, and the polarizing plate intermediate is cut off from the band-shaped polarizing plate on the basis of the detection result. Therefore, even if the directions of the absorption axes assumed in the band-like polarizing plate are not coincident with each other, a polarizing plate intermediate in which the direction of the absorption axis is directed in the same direction in the polarizing plate intermediate body can be obtained. Further, since the absorption axis of the polarizing plate intermediate is detected and the polarizing plate is obtained based on the detection result, the influence of the error when the polarizing plate intermediate is cut off can also be reduced. As a result, it is easy to manufacture a polarizing plate in which the direction of the absorption axis is accurately oriented in a predetermined direction.

The band-shaped polarizing plate may include a uniaxially stretched polarizing layer.

When the polarizing layer is uniaxially stretched, the direction of the absorption axis can be assumed as the stretching direction. However, due to the effect of bowing during uniaxial stretching, the direction of the absorption axis of the band-shaped polarizing plate tends to be inconsistent. Therefore, in the case where the strip-shaped polarizing plate includes the uniaxially stretched polarizing layer, the above manufacturing method having the step of detecting the direction of the absorption axis can more reliably obtain the polarizing plate in which the direction of the absorption axis is accurately directed in the predetermined direction It is possible.

The width of the band-shaped polarizer may be 1000 mm or more. In this case, the effect of the above-described bowing tends to occur. Therefore, the manufacturing method having the step of detecting the direction of the absorption axis is effective for obtaining a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction.

In one embodiment, the shape of the polarizing plate as viewed in a plane is rectangular or square, and the diagonal length of the polarizing plate may be 350 mm or less, usually 12.5 mm or more, and preferably 50 mm or more.

Such a polarizing plate tends to be used in a small / medium-sized display requiring a high contrast. Therefore, the above-described manufacturing method is effective in which a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction is effective.

The polarizing plate may be a polarizing plate for a liquid crystal panel of VA (Vertical Alignment) type or IPS (In-Place-Switching) type.

In a liquid crystal display device of the VA or IPS type, image display with high contrast can be performed, and therefore image display with higher contrast tends to be required. Therefore, the above-described manufacturing method is effective in which a polarizing plate in which the direction of the absorption axis is accurately directed in a predetermined direction is effective.

A manufacturing method of a liquid crystal panel according to another aspect of the present invention is to manufacture a liquid crystal panel by manufacturing a polarizing plate by a manufacturing method of a polarizing plate according to one aspect of the present invention and joining the obtained polarizing plate to the liquid crystal cell.

The polarizing plate bonded to the liquid crystal cell by the manufacturing method of the liquid crystal panel is manufactured by the manufacturing method of the polarizing plate according to one aspect of the present invention. Therefore, in the produced polarizing plate, the absorption axis is accurately directed in a predetermined direction. Therefore, it is possible to improve the image quality when an image is displayed on the liquid crystal panel.

According to the present invention, it is possible to provide a method capable of producing a polarizing plate in which the direction of the absorption axis is exactly the predetermined direction.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a plan view of a polarizing plate produced by a polarizing plate manufacturing method according to one embodiment. FIG.
Fig. 2 is a schematic view of a band-shaped polarizer for producing the polarizer shown in Fig.
3 is a cross-sectional view taken along the line III-III in Fig.
4 is a flowchart of a method of manufacturing a polarizing plate according to one embodiment.
Fig. 5 (a) is a schematic view for explaining the step of cutting the sheet-like polarizer plate from the band-shaped polarizer plate. Fig. 5 (b) is a plan view of a band-shaped polarizer for schematically showing a cut position of the band-shaped polarizer.
6 (a) is a schematic view for explaining a step of cutting the polarizer intermediate from the sheet polarizer. Fig. 6 (b) is a plan view schematically showing the cutting position of the polarizer intermediate in the sheet polarizer. Fig.
7 is a diagram schematically showing a process of detecting an absorption axis.
Fig. 8 is a view showing a region in which a polarizer is scraped off from a polarizer intermediate body, based on the detection result of the absorption axis. Fig.
9 is a schematic diagram showing a step of machining an end face.
10 is a flowchart showing a method of manufacturing a polarizing plate according to another embodiment.
Fig. 11 is a view for explaining the cutting process of the single sheet polarizer.
12 is a flowchart showing a method of manufacturing a polarizing plate according to still another embodiment.
Fig. 13 is a view for explaining a case where the sheet-like polarizer is cut from the strip-shaped polarizer, based on the detection result of the absorption axis.
Fig. 14 is a diagram schematically showing a configuration of a liquid crystal panel manufactured by a manufacturing method of a liquid crystal panel according to an embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same elements are denoted by the same reference numerals. Duplicate description will be omitted. The dimensional ratios in the drawings do not necessarily coincide with those in the description. In the description, the words indicating the directions of " phase ", " lower ", and the like are convenience terms based on the states shown in the drawings.

(First Embodiment)

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a plan view of a polarizing plate produced by a polarizing plate manufacturing method according to one embodiment. FIG. The polarizing plate 10 has an absorption axis S _A and a transmission axis S _T orthogonal to the absorption axis (polarization axis) S _A. The polarizing plate 10 is an optical element that absorbs light that oscillates in the direction of the absorption axis S _A and has polarization characteristics that selectively pass light that oscillates in the direction of the transmission axis S _T.

The polarizing plate 10 is applied to a liquid crystal display device. For example, the polarizing plate 10 may be bonded to both surfaces of the liquid crystal cell to form a part of the liquid crystal panel. An example of the shape of the polarizing plate 10 viewed from the plane (the shape seen from the thickness direction) is a rectangle such as a rectangle or a square as shown in Fig. The direction of the absorption axis S _A of the polarizing plate 10 is directed to a predetermined direction in the polarizing plate 10.

The predetermined direction is a predetermined angle? Direction from the reference side with reference to one side of the polarizing plate 10. For example, when the shape of the polarizing plate 10 viewed from the plane is a rectangle, the predetermined direction may be a direction in which a predetermined angle? = 0 (i.e., a direction parallel to a long side) the direction of [theta] = 45 [deg.], and the like can be exemplified. For the sake of simplicity, unless otherwise stated, the shape of the polarizing plate 10 in a plan view is rectangular and the predetermined direction is a long side direction.

The size of the polarizing plate 10 may be set according to the device in which the polarizing plate 10 is used. An example of the size of the polarizing plate 10 is a polarizing plate having a diagonal length of 50 mm to 350 mm, that is, a length corresponding to so-called 2-inch to 12-inch. When the polarizing plate 10 is applied to a liquid crystal display device, the liquid crystal panel to which the polarizing plate 10 is bonded is not particularly limited. For example, VA (Vertical Alignment) type and IPS (In-Place-Switching) ) Liquid crystal panel is exemplified.

The polarizing plate 10 is made of the band-shaped polarizing plate 12 shown in Fig. Fig. 2 is a schematic view of a band-shaped polarizer for producing the polarizer shown in Fig.

An example of the length in the longitudinal direction of the strip-shaped polarizing plate 12 is 1000 m to 2000 m. The band-shaped polarizing plate 12 is wound in a roll shape. The roll formed by winding the strip-shaped polarizing plate 12 is referred to as a disc roll 14. An example of the width of the band-shaped polarizing plate 12 is 1000 mm or more.

3 is a cross-sectional view taken along the line III-III in Fig. The band-shaped polarizing plate 12 is a laminate having a polarizing film 12a as a polarizing layer for selectively passing light that vibrates in one direction. An example of the polarizer film 12a is a film in which a dichroic dye is adsorbed and oriented on a PVA film uniaxially stretched in the longitudinal direction of the band-shaped polarizer 12. The dichroic dye is oriented in the stretching direction of the PVA film and adsorbed on the PVA film. Thus, the polarizer film 12a absorbs light in the alignment direction of the dichroic dye (that is, in the direction of the major axis of the molecule) and has dichroism, that is, polarization characteristic, to transmit light in a direction orthogonal to the alignment direction. Examples of dichroic dyes are iodine and dichroic organic dyes. An example of the thickness of the polarizer film 12a is 1 mu m to 30 mu m.

On both sides of the polarizer film 12a, protective films 12b and 12c as protective layers for protecting the polarizer film 12a are bonded. An example of the protective films 12b and 12c is a cellulose-based film, and an example of a cellulose-based film is a TAC (triacetylcellulose) film. An example of the thickness of the protective films 12b and 12c is 10 mu m to 200 mu m.

In the above description, the band-shaped polarizer 12 having a structure in which the polarizer film 12a is sandwiched between the protective films 12b and 12c has been described. However, the band- A protective film may not be laminated on the other side.

A surface protective film (or protective film) 12d for protecting the protective film 12b may be bonded to the protective film 12b. An example of the thickness of the surface protective film 12d is 30 mu m to 100 mu m. Examples of the material of the surface protective film 12d are polyethylene, polypropylene and polyester.

The protective film 12c may be provided with a pressure-sensitive adhesive layer 12e for bonding the polarizing plate 10 as a product to another member such as a liquid crystal cell. An example of the thickness of the pressure-sensitive adhesive layer 12e is 5 占 퐉 to 30 占 퐉. Examples of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 12e include an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive. In the form in which the pressure-sensitive adhesive layer 12e is formed, the separate film 12f may be peelably bonded on the pressure-sensitive adhesive layer 12e. The separate film 12f is a film for preventing other regions of the strip-shaped polarizing plate 12 and dust or the like from adhering to the pressure-sensitive adhesive layer 12e until the polarizing plate 10 as a product is used. An example of the thickness of the separate film 12f is 30 mu m to 100 mu m.

The strip-shaped polarizing plate 12 is manufactured, for example, as follows. That is, the strip-shaped raw film is uniaxially stretched in its longitudinal direction. An example of the raw film is a PVA film which is not drawn, that is, has no orientation. An example of a draw ratio is 4 to 5 times. The uniaxial stretching method may be either the dry uniaxial stretching method or the wet uniaxial stretching method. The uniaxial stretching can be realized, for example, by stretching the raw film with tension applied in the longitudinal direction while bringing the raw film into contact with a heat roll. After uniaxially stretching the raw film, the dichroic dye is adsorbed and oriented on the PVA film by immersing the PVA film as the raw film after uniaxially stretching in an aqueous solution containing the dichroic dye to obtain the polarizer film 12a. Then, the protective film 12b and 12c are bonded to both surfaces of the polarizer film 12a, respectively, to obtain the above basic structure. Thereafter, the surface protective film 12d, the pressure-sensitive adhesive layer 12e, and the separate film 12f are appropriately formed to obtain the band-shaped polarizing plate 12.

In the example of the method for producing the band-shaped polarizing plate 12, the dichroic dye is adsorbed and oriented on the PVA film obtained by uniaxially stretching the raw film. However, the raw film may be uniaxially stretched during the adsorption orientation of the dichroic dye or after the adsorption orientation.

The polarizer film 12a (more specifically, the PVA film) included in the band-shaped polarizing plate 12 is uniaxially stretched in the longitudinal direction of the band-shaped polarizing plate 12. Therefore, in the band-shaped polarizing plate 12, the absorption axis S _A direction substantially coincides with the longitudinal direction of the band-shaped polarizing plate 12. However, when uniaxially stretched, bowing may occur in which the edge slightly curves inward in the width direction. Therefore, there may be a case where the absorption axis S _A is deviated from the longitudinal direction depending on the position of the band-shaped polarizer 12, as shown in Fig. The shift angle from the longitudinal direction in the absorption axis S _A direction is, for example, about 0.2 to 0.3 degrees. In Fig. 2, this deviation angle is exaggerated.

Next, a method of producing the polarizing plate 10 shown in Fig. 1 from the band-shaped polarizing plate 12 shown in Fig. 2 will be described in detail.

4 is a flowchart of a method of manufacturing a polarizing plate according to one embodiment. When the polarizing plate 10 is manufactured, first, the sheet polarizer (first polarizer plate intermediate) 16 is cut from the strip-shaped polarizer 12 (sheet cutting process S10). Next, the polarizing plate intermediate (second polarizing plate intermediate) 22 is cut off from the sheet polarizer 16 (intermediate cutting step S12). Subsequently, the absorption axis S _A of the cut polarizing plate intermediate body 22 is detected (absorption axis detecting step S14). Thereafter, the end face of the polarizing plate intermediate body 22 is cut (end face machining) to obtain the polarizing plate 10 (end face machining step S16). Hereinafter, each process will be described.

(1) Sheet cutting process S10

The sheet cutting process S10 will be described with reference to Figs. 5A and 5B. Fig. 5 (a) is a schematic view for explaining the step of cutting the sheet-like polarizer plate from the band-shaped polarizer plate. Fig. 5 (b) is a plan view of a band-shaped polarizer for schematically showing a cut position of the band-shaped polarizer.

In the sheet cutting process S10, the strip-shaped polarizer 12 is unwound from the original roll 14. Then, the unzipped strip-shaped polarizing plate 12 is carried into the cutting device 18 disposed in the unwinding direction (or the transporting direction) of the strip-shaped polarizing plate 12. The cutting device 18 cuts the band-shaped polarizing plate 12 to a predetermined length by the cutting edge 18a and cuts the sheet-like polarizing plate 16 from the band-shaped polarizing plate 12. The cutting position of the band-shaped polarizing plate 12 may be set at a constant interval in the longitudinal direction, for example, as shown in a hypothetical cutting line indicated by a chain double-dashed line in Fig. 5 (b). The position of the virtual cut line may be input to the cutting device 18 in advance. In the cutting device 18, the strip-shaped polarizing plate 12 may be cut by a laser beam instead of the cutting edge 18a.

(2) Intermediate cutting process S12

The intermediate cutting process S12 will be described with reference to Figs. 6 (a) and 6 (b). 6 (a) is a schematic view for explaining a step of cutting the polarizer intermediate from the sheet polarizer. Fig. 6 (b) is a plan view schematically showing the cutting position of the polarizer intermediate in the sheet polarizer. Fig.

In the intermediate trimming step S12, the sheet-like polarizing plate 16 is carried into the cutting apparatus 20 arranged on the conveying direction. The cutting apparatus 20 cuts a plurality of polarizer intermediate members 22 from the sheet polarizer 16 by a cutting edge 20a. The polarizing plate intermediate 22 is a polarizing plate intermediate having a size in which a cutting margin (for example, 0.5 mm width) is set for the shape of the polarizing plate 10 to be produced. In the present embodiment, the polarizer plate intermediate body 22 corresponds to the polarizer plate. The cut position of the sheet polarizing plate 16 may be set as a virtual cut line for the polarizing plate intermediate body 22 indicated by a chain double-dashed line in Fig. 6 (b). The cutting line for the polarizing plate intermediate body 22 can be set on the assumption that the absorption axis S _A is along the conveying direction of the sheet polarizing plate 16 (that is, the longitudinal direction of the strip-shaped polarizing plate 12). The cutting line (cut position) for the polarizing plate intermediate body 22 may be input to the cutting apparatus 20 in advance. The cutting edge 20a of the cutting device 20 may be mounted on the cutting device 20 so as to change the direction of the cutting edge 20a in order to cut along the cutting line. In the cutting apparatus 20, the sheet-like polarizing plate 16 may be cut by a laser beam instead of the cutting blade 20a.

(3) Absorption axis detecting step S14

The absorption axis detecting step S14 will be described with reference to Fig. 7 is a diagram schematically showing a process of detecting the absorption axis direction. The absorption axis S _A can be detected by a rotation analyzer method.

Specifically, the light from the light source 24 disposed on one side (the lower side of the polarizing plate intermediate body 22 in Fig. 7) with respect to the polarizing plate intermediate body 22 in the thickness direction of the polarizing plate intermediate body 22 is passed through the polarizing plate intermediate body 22 ). The light to be irradiated is usually unpolarized. For example, light emitted from an ordinary light source such as an incandescent lamp, a fluorescent lamp, and an LED is usually unpolarized light. The light having passed through the polarizing plate intermediate body 22 is irradiated to the photodetector (not shown) disposed on the other side (the upper side of the polarizing plate intermediate body 22 in Fig. 7) with respect to the polarizing plate intermediate body 22 in the thickness direction of the polarizing plate intermediate body 22 26). A linearly polarizing plate 28 is disposed between the polarizer plate intermediate member 22 and the photodetector 26 so that the direction of the absorption axis S _A and the direction of the transmission axis S _T are known, And the linearly polarizing plate 28 as rotation centers. The amount of rotation of the linearly polarizing plate 28 may be controlled by a control device such as a computer. The signal from the photodetector 26 is also processed by the control device.

When detecting the absorption axis S _A of the polarizing plate intermediate 22, light is output from the light source 24. When the light output from the light source 24 is incident on the polarizer plate intermediate body 22, light that vibrates in the direction of the transmission axis S _T of the polarizer plate intermediate body 22 selectively passes through the polarizer plate intermediate body 22. Therefore, when the linearly polarizing plate 28 is rotated about the optical axis of the light output from the light source 24 as the central axis, the absorption axis S _A of the linearly polarizing plate 28 and the absorption axis S _A ) are orthogonal to each other, that is, when the cross-Nicol state is attained, the amount of light incident on the photodetector 26 is minimized. Therefore, the absorption axis _(A S), the direction at which the quantity of light incident on the photodetector 26 is minimized, linear polarization plate 28, the absorption axis _(A S), the Intermediate polarizer 22 direction.

The detection of the absorption axis S _A direction may be performed at a plurality of positions in the polarizing plate intermediate body 22. The detection point in the absorption axis S _A direction can be set, for example, with respect to the width direction of the polarizing plate intermediate body 22.

The absorption axis direction detecting device including the light source 24, the linearly polarizing plate 28 and the photodetector 26 is disposed on the return line of the polarizing plate intermediate member 22 cut from the sheet polarizing plate 16 Or may be provided separately from the conveying line.

The light source 24, the linearly polarizing plate 28 and the photodetector 26 are not particularly limited as long as they are used for detecting the absorption axis S _A. The arrangement relationship of the light source 24, the linearly polarizing plate 28 and the photo detector 26 is not particularly limited as long as it is an arrangement in which the polarizing plate intermediate body 22 and the linearly polarizing plate 28 can realize the Cross Nicol state. For example, the linearly polarizing plate 28 may be disposed between the light source 24 and the polarizing plate intermediate 22. Further, linearly polarizing plates 28 may be arranged above and below the polarizing plate intermediate body 22, respectively. In this case, the two linearly polarizing plates 28 may be arranged in a parallel Nicol state and rotated synchronously.

Examples of devices capable of realizing the detection method of the absorption axis S _A direction shown in Fig. 7 include KOBRA manufactured by Oji Measurement Instruments Co., Ltd., RETS-100 and RE-100P manufactured by Otsuka Electronics Co.,

The detected absorption axis S _A direction may be recorded. This recording may be performed by, for example, marking the direction of the absorption axis S _A on the area to be cut off when the polarizing plate 10 is cut from the polarizing plate intermediate body 22.

(4) End face machining step S16

In the end face machining step S16, the end faces 22a, 22b, 22c, and 22d of the polarizing plate intermediate body 22 are cut based on the detection result of the absorption axis S _A direction. Thus, the polarizing plate 10 can be obtained. The cutting process also includes polishing of the end faces 22a, 22b, 22c, and 22d. The end face machining step S16 will be described with reference to Figs. 8 and 9. Fig.

Fig. 8 is a view showing a region in which a polarizer is scraped off from a polarizer intermediate body, based on the detection result of the absorption axis. Fig. 8, the broken line indicates the absorption axis S _A0 direction in the case where the longitudinal direction of the band-shaped polarizing plate 12 is assumed to be the absorption axis direction, and the chain double-dashed line indicates the absorption axis S _{A of the} detected absorption axis S _A Polarizing plate region A based on the orientation of the polarizing plate. The polarizing plate region A is a portion of the polarizing plate 10 to be cut by cutting the end faces 22a to 22d in the polarizing plate intermediate body 22. [ The polarizing plate area A is set so that the absorption axis S _A is directed in a predetermined direction (longitudinal direction in this embodiment) in the polarizing plate 10.

9 is a schematic diagram showing a step of machining an end face. 9, processing of the end faces of a plurality of polarizer intermediate bodies 22 is carried out by using the laminate 30 in which a plurality of polarizer plate intermediate bodies 22 in which the direction of the absorption axis S _A is detected is laminated .

The end face machining step S16 is performed by using the end face machining device 32 shown in Fig. The end face machining device 32 has a pair of holding members 34A and 34B holding the stacked body 30 sandwiched between the stacking direction. One of the holding members 34B of the pair of holding members 34A and 34B is disposed on the rotating table 36. [ The other holding member 34A is provided with a pressing member 38 for pressing the holding member 34A toward the holding member 34B. The rotary table 36 and the pressing member 38 are attached to a support (not shown) so as to be movable in one direction. The pressing member 38 is attached to the support table so as to rotate in the same direction as the rotation table 36 in synchronization with the rotation of the rotation table 36. [

The end face machining device 32 has a pair of cutting members 40A and 40B on the moving direction of the rotary table 36. [ The pair of cutting members 40A and 40B are disposed so as to oppose to the stacking direction of the polarizing plate intermediate body 22 in the laminated body 30 and the direction orthogonal to the moving direction of the rotary table 36. [ The pair of cutting members 40A and 40B have rotary members 42A and 42B that are rotatable about the direction in which the cutting members 40A and 40B are arranged as rotary shafts and are disposed on the inner side surfaces of the rotary members 42A and 42B And a cutting edge 44 is attached to the surface facing the layered body 30).

An example of the step S16 of processing the end face of the polarizing plate intermediate body 22 performed using the end face machining device 32 having the above-described structure will be described.

_A plurality of polarizing plate intermediate bodies 22 on which the absorption axis S _A is detected are laminated to constitute a laminated body 30. The direction of the absorption axis S _A of the polarizing plate intermediate body 22 constituting the laminate 30 is the same. In the laminate 30, the plurality of polarizer plates 22 are laminated such that the polarizer regions 40 shown in Fig. 8 overlap in the lamination direction. The prepared stacked body 30 is sandwiched between a pair of holding members 34A and 34B and pressed in the stacking direction by the pressing member 38 to hold the stacked body 30 with the holding members 34A and 34B. Thereafter, the rotary table 36 is moved in the moving direction, and the stacked body 30 is sent between the pair of cutting members 40A and 40B. At this time, the rotary members 42A and 42B of the cutting members 40A and 40B are rotated. 9) of the four end faces 22a to 22d of each polarizer plate intermediate body 22 constituting the laminate 30 and the cutting members 40A and 40B, (I.e., the cut surfaces 22c and 22d) are cut (or polished) with the cutting members 40A and 40B. The cutting edge 44 and the end faces of the end faces 22a to 22d facing the cutting members 40A and 40B are cut by the rotary table 36 so as to cut the polarizing plate area 40 indicated by the chain double- The distance between the cutting members 40A and 40B and the end face may be appropriately controlled. When cutting of the pair of end faces on the opposite sides of the polarizing plate intermediate body 22 is completed, the rotating table 36 is rotated to process the other pair of end faces.

As described above, the end faces 22a to 22d of the polarizer intermediate body 22 are cut by the end face machining device 32 to cut out the polarizer 10 from the polarizer intermediate body 22, (10) can be obtained.

Since the polarizing plate 10 is made of the band-shaped polarizing plate 12 as described above, the sectional configuration (or layer configuration) of the polarizing plate 10 is the same as the sectional configuration of the band-shaped polarizing plate 12 shown in Fig. 3 Do.

In the above manufacturing method, the direction of the absorption axis S _A is detected in the polarizing plate intermediate body 22, which is the polarizing plate original plate before the end face machining. Subsequently, based on the detection result, the end faces 22a to 22d of the polarizing plate intermediate body 22 are cut so that the absorption axis S _A is directed in a predetermined direction in the polarizing plate 10, The polarizer 10 is cut out from the liquid crystal layer 22. Therefore, the direction of the absorption axis S _{A in the} polarizing plate 10 is directed to a predetermined direction required in a member (for example, a liquid crystal panel) to which the polarizing plate 10 is applied. In the polarizing plate 10, the absorption axis S _A direction coincides with a predetermined direction with higher accuracy.

The absorption axis S _{A of the} band-shaped polarizing plate 12 is parallel to the stretching direction of the polarizing film 12a and substantially follows the longitudinal direction of the band-shaped polarizing plate 12. Therefore, it is also considered to manufacture a polarizing plate by assuming the longitudinal direction of the band-shaped polarizing plate 12 to be the direction of the absorption axis S _A. However, due to the effect of the bowing in the uniaxial stretching when the band-shaped polarizing plate 12 is produced, the direction of the absorption axis S _A from the longitudinal direction of the band-shaped polarizing plate 12 There may be a case where a shifted region is generated. A cutting error may occur during cutting processing in the sheet cutting process S10 and the intermediate cutting process S12. As a result, as shown in Fig. 8, in the polarizing plate intermediate body 22, the imaginary absorption axis S _A0 direction in the case where the longitudinal direction of the band-shaped polarizing plate 12 is assumed as the absorption axis, In the direction of the absorption axis (S _A ).

It is possible to detect the direction of the absorption axis S _A of the polarizing plate intermediate body 22 and detect the direction of the absorption axis S _A in the predetermined direction in the polarizing plate 10 The polarizer plate 10 is cut out from the polarizer plate intermediate body 22 so as to face the polarizer plate. Therefore, the polarizing plate 10 in which the absorption axis S _A is in the desired direction can be more reliably obtained.

In the polarizing plate applied to liquid crystal panels of VA type and IPS type capable of image display with a high contrast, in order to display an image of high contrast, the absorption axis S _A is oriented in a predetermined direction required in a polarizing plate as a product It is required that they coincide with each other. Therefore, the above-described manufacturing method capable of manufacturing the polarizing plate 10 in which the direction of the absorption axis S _A coincides with the predetermined direction with higher accuracy is effective for producing polarizing plates for VA and IPS liquid crystal panels . When the liquid crystal panel is a VA type, it may be an ASV (Advanced Super View) type.

Unlike a large-sized TV having a large screen size, a display for a small-sized portable device such as a 12-inch (diagonal length 350 mm) or less tends to require a high contrast because the user tends to view the screen at a close distance. Therefore, the above-described manufacturing method capable of manufacturing the polarizing plate 10 in which the absorption axis S _A direction coincides with a predetermined direction with higher accuracy is effective for manufacturing a polarizing plate used in displays for small and medium-sized portable apparatuses.

A size of about 0.5 to 12 in the shape of a rectangle or a square when viewed from the plane of the polarizing plate 10 and a diagonal length of 12.5 mm to 350 mm and a length corresponding to 2 types (diagonal length 50 mm) or more The polarizing plate 10 is easy to be used for displays for small and medium-sized portable apparatuses and the like. Therefore, the above-described manufacturing method capable of manufacturing the polarizing plate 10 in which the absorption axis S _A direction coincides with the predetermined direction with higher precision is characterized in that the shape when seen in a plane is a rectangle or a square and the diagonal length is 12.5 mm To 350 mm.

In the case where the width of the band-shaped polarizing plate 12 is 1000 mm or more, the influence of the above-described bowing tends to increase. Therefore, the absorption axis (S _A), the above-described method comprising a detection step in the direction of the, width of more than 1000 mm, typically the absorption axis (S _A), the direction is a predetermined direction from the strip-shaped polarizer (12) of less than 3000 mm Which is more effective in terms of obtaining the polarizing plate 10 of the present invention.

(Second Embodiment)

10 is a flowchart showing a method of manufacturing a polarizing plate according to another embodiment. In the manufacturing method shown in Fig. 10, first, the sheet-like polarizing plate 16 is cut from the strip-shaped polarizing plate 12 (sheet cutting step S20). Next, the direction of the absorption axis S _A in the sheet polarizer 16 is detected (absorption axis detecting step S22). Subsequently, the polarizing plate intermediate body 22 is cut off from the sheet polarizer 16 (intermediate cutting step S24). Thereafter, the absorption axis direction of the polarizer intermediate body 22 is detected (absorption axis detection step S26). Then, the end face of the polarizing plate intermediate body 22 is cut (end face machining) to obtain the polarizing plate 10 (end face machining step S28). The intermediate cut step S24, the intermediate cut step S24, the absorption axis detecting step S26 and the end face machining step S28 correspond to the step of obtaining the polarizing plate 10 based on the detection result of the absorption axis S _A direction do. Hereinafter, each process will be described.

The sheet cutting step S20 is the same as the cutting step S10 of the sheet-like polarizing plate 16 shown in Fig. 4, and therefore the description thereof will be omitted.

In the absorption axis detecting step S22, the direction of the absorption axis S _A of the single sheet polarizer 16 is detected. The detection method is the same as the detection method of the direction of the absorption axis S _A of the polarizing plate intermediate body 22 described with reference to Fig. That is, in FIG. 7, instead of the polarizer plate intermediate body 22, the sheet polarizer plate 16 may be disposed and detected. The absorption axis direction detecting device including the light source 24, the linearly polarizing plate 28 and the photodetector 26 may be disposed on the conveying line of the sheet-fed polarizing plate 16 or may be disposed separately from the conveying line Or the like. The detection of the direction of the absorption axis S _A of the sheet polarizing plate 16 may be performed at a plurality of positions in the polarizing plate intermediate body 22. The detection point in the absorption axis S _A direction can be set, for example, with respect to the width direction of the polarizing plate intermediate body 22.

In the intermediate trimming step S24, the sheet polarizer 16 is conveyed to the cutting apparatus 20 while conveying the sheet polarizer 16 in the same manner as in FIG. 6A, and a plurality of polarizer plates 22 are cut from the sheet polarizer 16. At this time, based on the detected direction of the absorption axis S _A , the polarizing plate intermediate body 22 is moved from the sheet polarizing plate 16 to the polarizing plate intermediate body 22 so that the absorption axis S _A is directed in the same direction in the polarizing plate intermediate body 22 And cut with a cutting blade 20a. Will be described in detail with reference to FIG.

Fig. 11 is a view for explaining the cutting process of the single sheet polarizer. Fig. 11 shows a plan view of the single-sheet polarizer 16. As shown in Fig. 11 shows an example of a plurality of detected absorption axis S _A directions. 11, at the central portion in the width direction of the sheet polarizing plate 16, the absorption axis S _A is parallel to the longitudinal direction, whereas in the vicinity of the edge in the width direction of the sheet polarizing plate 16, The absorption axis S _A is inclined with respect to the longitudinal direction. In such a case, as shown by the chain double-dashed line in FIG. 11, a virtual cutting line is set as a cutout area of the polarizer intermediate body 22 in the region where the absorption axis S _A direction coincides. In one embodiment, as shown in Fig. 11, a virtual cut line is set so that the absorption axis S _A is directed in the longitudinal direction of the polarizing plate intermediate body 22. In Fig. 11, virtual cutting lines are set in the vicinity of the central portion and in the vicinity of the edges on both sides in the width direction. Then, the sheet edge polarizer 16 is cut with a cutting device along the cut line set by the cutting edge 20a, and the polarizer intermediate body 22 is cut from the sheet polarizer 16. In the respective regions set by the imaginary cutting lines, the directions of the absorption axes S _A do not have to be strictly the same, and the directions of the absorption axes S _A , .

Since the absorption axis detecting step S26 and the end face machining step S28 are the same as the absorption axis detecting step S14 and the end face machining step S16 shown in Fig. 4, the description thereof will be omitted.

In this manufacturing method, the direction of the absorption axis S _A of the sheet-like polarizing plate 16 corresponding to the original plate of the polarizing plate is detected in the present embodiment. Then, based on the detection result, the sheet-like polarizing plate 16 was processed to obtain the polarizing plate 10. Therefore, the deviation between the absorption axis S _A0 assumed as the longitudinal direction of the band-shaped polarizing plate 12, which is generated for the same reason as in the first embodiment, and the detected actual absorption axis S _A direction is corrected, (10). As a result, the polarizing plate 10 having the absorption axis S _A direction in a predetermined direction can be obtained.

Since the polarizer plate intermediate body 22 is cut from the sheet polarizer plate 16 so that the absorption axis S _A direction coincides with the polarizer plate intermediate body 22, the influence of, for example, the bowing is reduced in the polarizer plate intermediate body 22 . Since the polarizing plate 10 is obtained from the polarizing plate intermediate 22 in which the absorption axis S _A coincides with the direction of the absorption axis S _A , it is easy to produce the polarizing plate 10 in which the absorption axis S _A is directed in a predetermined direction.

The direction of the absorption axis S _A of the polarizing plate intermediate body 22 was detected again, and the polarizing plate 10 was obtained based on the detection result. Therefore, the influence of the error when the polarizing plate intermediate body 22 is cut off can also be reduced. As a result, it is possible to more reliably obtain the polarizing plate 10 having the absorption axis S _A in the predetermined direction.

10, the polarizing plate 10 having the absorption axis S _A in a predetermined direction can be obtained as described above. Therefore, the above manufacturing method is effective for the liquid crystal panel of the VA type and the IPS type or the polarizing plate applied to the small / medium type display is the same as that of the first embodiment. It is preferable that the width of the band-shaped polarizing plate 12 is 1000 mm or more, the shape of the polarizing plate 10 when viewed from the plane is rectangular or square and the length of the diagonal line is 350 mm or less, preferably 12.5 mm or more, It is also the same as in the case of the first embodiment that the above-described manufacturing method is effective for a shape of 50 mm or more.

Here, the intermediate step S24 is provided, but the polarizing plate 10 may be cut directly from the sheet-like polarizing plate 16. In this case, the polarizing plate 10 may be cut from the sheet polarizing plate 16 so that the direction of the absorption axis S _A detected by the sheet polarizing plate 16 faces the predetermined direction in the polarizing plate 10. As described above, in the mode in which the polarizing plate 10 is directly obtained from the sheet-like polarizing plate 16, the polarizing plate 10 can be manufactured more easily.

In the flowchart shown in Fig. 10, an absorption axis detecting step S26 for detecting the absorption axis S _A direction of the polarizing plate intermediate body 22 is provided. However, the absorption axis detecting step S26 may not be provided. The detection of the absorption axis (S _A) of the polarizing plate Intermediate 22 absorption axis (S _A) direction is the direction of the match, and the absorption axis (S _A) in each of the polarizer Intermediate 22, the single wafer polarizing plate 16 of the It is a base by. 8, the polarizing plate area A is set based on the direction of the absorption axis S _{A in the} polarizing plate intermediate body 22, and in the same manner as in the case of the end face machining step S16, The polarizing plate 10 may be cut away from the polarizing plate intermediate body 22 by the end face machining apparatus 32.

In the case where the absorption axis detecting step S26 is not provided, for example, when the polarizing plate intermediate body 22 is regarded as the polarizing plate 10, the sheet polarizing plate 16 is moved so that the detected absorption axis S _A is directed in a predetermined direction. The polarizing plate intermediate 2 may be cut off. In this case, the direction of the absorption axis S _A in the polarizing plate intermediate body 22 is directed in a predetermined direction of the polarizing plate 10. Therefore, the end faces 22a to 22d of the polarizing plate intermediate body 22 can be cut to have a constant width, so that the processing of the end faces is easy.

(Third Embodiment)

12 is a flowchart showing a method of manufacturing a polarizing plate according to still another embodiment. In the manufacturing method shown in Fig. 12, first, the absorption axis direction of the band-shaped polarizing plate 12 is detected (absorption axis detecting step S30). Next, the polarizing plate intermediate body 22 is cut off from the strip-shaped polarizing plate 12 (intermediate cutting step S32). The absorption axis direction of the polarizing plate intermediate body 22 is detected (absorption axis detecting step S34). Thereafter, the end face of the polarizing plate intermediate body 22 is cut (end face machining) to obtain the polarizing plate 10 (end face machining step S36). The intermediate cutting process S32, the intermediate cutting process S32, the absorption axis detecting process S34, and the end face machining process S36 are performed in the process of obtaining the polarizing plate 10 on the basis of the detection result of the absorption axis S _A direction Respectively. Hereinafter, each process will be described.

In the absorption axis detecting step S30, after the strip-shaped polarizing plate 12 is unwound from the disc roll 14, the direction of the absorption axis S _A of the strip-shaped polarizing plate 12 in the unrolled region is detected. The detection method is the same as the detection method of the polarizing plate intermediate body 22 described with reference to Fig. 7 in the absorption axis S _A direction. That is, in FIG. 7, a band-shaped polarizing plate 12 may be disposed in place of the polarizing plate intermediate body 22 to detect it. The absorption axis direction detecting device including the light source 24, the linearly polarizing plate 28 and the photodetector 26 may be arranged on the conveying line of the band-shaped polarizing plate 12, for example. The detection of the direction of the absorption axis S _A of the band-shaped polarizing plate 12 may be performed at a plurality of positions in the band-shaped polarizing plate 12. The detection point in the absorption axis S _A direction can be set, for example, with respect to the width direction of the band-shaped polarizer 12.

In the intermediate trimming step S32, the strip-shaped polarizing plate 12 is transported in the unrolling direction and carried into the cutting apparatus, and the polarizing plate intermediate member 22 is cut off from the strip-shaped polarizing plate 12. As the cutting apparatus for cutting the polarizer intermediate body 22, the cutting apparatus 20 for cutting the polarizing plate intermediate body 22 shown in Fig. 6 (a) can be used. This step S32 is the same as that in the case where the birefringent polarizing plate 16 shown in Fig. 10 is regarded as the band-like polarizing plate 12. That is, a virtual cut line is set so that the absorption axis S _A is directed in the longitudinal direction of the polarizer plate intermediate body 22. Then, the strip-shaped polarizing plate 12 is cut with a cutting device along the set cutting line, and the polarizing plate intermediate body 22 is cut off from the band-shaped polarizing plate 12.

The absorption axis detecting step S34 and the end face machining step S36 are the same as those of the absorption axis detecting step S14 and the end face machining step S16 shown in Fig. 4, and a description thereof will be omitted.

In the above manufacturing method, the direction of the absorption axis S _A of the band-shaped polarizing plate 12 is detected. Then, the band-shaped polarizing plate 12 was processed based on the detection result to obtain the polarizing plate 10. Therefore, it is possible to prevent the polarizing plate 10 from being displaced from the longitudinal direction of the absorption axis S _A in the band-shaped polarizing plate 12 due to the effect of the uniaxial stretching in the band-shaped polarizing plate 12 It is possible to manufacture. As a result, the polarizing plate 10 in which the absorption axis S _A is in the desired direction can be obtained.

The polarization plate intermediate body 22 is cut off from the band-shaped polarizing plate 12 so that the absorption axis S _A coincides with the polarizing plate intermediate body 22 so that the influence of, for example, . Since the polarizing plate 10 is obtained from the polarizing plate intermediate 22 in which the absorption axis S _A coincides with the direction of the absorption axis S _A , it is easy to produce the polarizing plate 10 in which the absorption axis S _A is directed in a predetermined direction.

The direction of the absorption axis S _A of the polarizing plate intermediate body 22 was detected again, and the polarizing plate 10 was obtained based on the detection result. Therefore, the influence of the error when the polarizing plate intermediate body 22 is cut off can also be reduced. As a result, it is possible to more reliably obtain the polarizing plate 10 having the absorption axis S _A in the predetermined direction.

Also in the manufacturing method according to the flowchart shown in Fig. 12, as described above, the polarizing plate 10 having the absorption axis S _A direction in a predetermined direction can be obtained. Therefore, the above manufacturing method is effective for the liquid crystal panel of the VA type or IPS type or the polarizing plate applied to the small / medium type display is the same as that of the first embodiment. The width of the band-shaped polarizing plate 12 is 1000 mm or more, the shape of the polarizing plate 10 in the plane is rectangular or square and the length of the diagonal line is 350 mm or less, usually 12.5 mm to 350 mm, preferably 50 The manufacturing method is effective for the shape of mm to 350 mm, which is the same as that of the first embodiment.

Here, the mode in which the step S32 of cutting the polarizing plate intermediate body 22 is described has been described. However, the polarizing plate 10 may be directly cut from the band-shaped polarizing plate 12. [ In this case, the polarizing plate 10 may be cut from the band-shaped polarizing plate 12 so that the absorption axis S _A detected by the band-shaped polarizing plate 12 is directed in the polarizing plate 10 in a predetermined direction. As described above, in the mode in which the polarizing plate 10 is directly obtained from the band-shaped polarizing plate 12, the polarizing plate 10 can be manufactured more easily.

In the flowchart shown in Fig. 12, an absorption axis detecting step S34 for detecting the absorption axis S _A direction of the polarizing plate intermediate body 22 is provided. However, the absorption axis detecting step S34 may not be provided. Detection of the absorption axis (S _A) of the polarizing plate Intermediate 22 absorption axis (S _A) direction are matched, and the direction of the absorption axis (S _A), within each polarizer Intermediate 22, the band-shaped polarizing plate 12 of the It is a base by. 8, the polarizing plate area A is set based on the direction of the absorption axis S _{A in the} polarizing plate intermediate body 22, and in the same manner as in the case of the end face machining step S16, The polarizing plate 10 may be cut away from the polarizing plate intermediate body 22 by the end face machining apparatus 32.

In the form that does not have the absorption axis detection step S34, for example, a polarizing plate Intermediate 22, the polarizing plate 10 in the case where a considered, the band-shaped polarizing plate (12 so that the detected absorption axis (S _A), the direction toward the predetermined direction, The polarizing plate intermediate 2 may be cut off. In this case, the direction of the absorption axis S _A in the polarizing plate intermediate body 22 is directed in a predetermined direction of the polarizing plate 10. Therefore, the end faces 22a to 22d of the polarizing plate intermediate body 22 can be cut to have a constant width, so that the processing of the end faces is easy.

In the flowchart shown in Fig. 12, the polarizer intermediate member 22 is cut off from the band-shaped polarizer 12, but the sheet polarizer 16 may be cut from the band-shaped polarizer 12, for example. Fig. 13 is a view for explaining a case where the sheet-like polarizer is cut from the strip-shaped polarizer, based on the detection result of the absorption axis.

13 shows a plan view of the strip-shaped polarizing plate 12. As shown in Fig. Fig. 13 shows an example of the plurality of absorption axes S _A detected. 13, the absorption axis S _A is parallel to the longitudinal direction at the central portion in the width direction of the band-shaped polarizing plate 12, whereas in the vicinity of the edge in the width direction of the band-shaped polarizing plate 12 , And the absorption axis S _A is inclined with respect to the longitudinal direction. In this case, as shown by the two-dot chain line in Fig. 13, a virtual cutting line is set as a cutout area of the sheet polarizer 16 in a region where the direction of the absorption axis S _A coincides. In an embodiment, as shown in Fig. 13, a virtual cutting line is set so that the absorption axis S _A is directed in the longitudinal direction of the single-wafer polarizing plate 16. Accordingly, the sheet-like polarizer 16 having a small deviation in the absorption axis S _A direction can be manufactured. Therefore, when the polarizing plate 10 is manufactured by processing the sheet polarizing plate 16 with reference to the direction of the absorption axis S _A in the sheet polarizing plate 16, when the absorption axis S _A is oriented in a predetermined direction The polarizing plate 10 can be manufactured. The polarizing plate 10 may be manufactured by applying the manufacturing method of the second embodiment to the sheet-like polarizing plate 16 cut based on the detection result of the band-shaped polarizing plate 12 in the direction of the absorption axis S _A.

(Fourth Embodiment)

As a fourth embodiment, a method of manufacturing a liquid crystal panel using the polarizing plate 10 will be described. In the following description, the polarizing plate 10 has the same layer structure as that of the band-shaped polarizing plate 12 shown in Fig. That is, the polarizing plate 10 includes a polarizing film 12a, protective films 12b and 12c bonded to both surfaces thereof, a surface protective film 12d formed on the protective film 12b, a protective film 12c, A pressure-sensitive adhesive layer 12e and a separate film 12f which are sequentially formed on the substrate 10a. Only one of the protective films 12b and 12c may be used.

Hereinafter, for convenience of explanation, the polarizing plate 10 in which the separate film 12f is peeled off in the polarizing plate 10 having the layer configuration shown in Fig. 3 is also referred to as a polarizing plate 10A.

Fig. 14 is a diagram schematically showing the structure of a liquid crystal panel manufactured in the fourth embodiment. As shown in Fig. 14, the liquid crystal panel 46 is constituted by bonding a polarizing plate 10A with a separate film 12f from a polarizing plate 10 to both sides of a liquid crystal cell 48. Fig. The liquid crystal cell 48 may be of any type that is used in a known liquid crystal panel. For example, the liquid crystal cell 48 may be provided with a transparent electrode, an orientation film, a liquid crystal, an orientation film, a transparent electrode, a color filter, and a glass substrate in this order on a glass substrate. Examples of the driving method of the liquid crystal cell 48 are VA formula and IPS formula.

The liquid crystal panel 46 is manufactured, for example, as follows. That is, the polarizing plate 10 is manufactured by any of the polarizing plate producing methods disclosed in the first to third embodiments (polarizing plate producing step). Next, the polarizing plate 10 is bonded to both surfaces of the liquid crystal cell 48 to obtain a liquid crystal panel 46 (polarizing plate bonding step).

In the polarizing plate bonding step, after the separate film 12f of each polarizing plate 10 is peeled off, the polarizing plate 10A from which the separate film 12f has been peeled off is bonded to the liquid crystal cell 48 through the pressure-sensitive adhesive layer 12e. Two polarizing plates 10A are arranged with respect to the liquid crystal cell 48 so that the two polarizing plates 10 are in a crossed Nicols state when the polarizing plate 10 is bonded to both surfaces of the liquid crystal cell 48. [

In the above manufacturing method, the polarizing plate 10 to be the polarizing plate 10A of the liquid crystal panel 46 is manufactured by one of the manufacturing methods exemplified in the first to third embodiments. Therefore, in the polarizing plate 10, the absorption axis S _A is directed accurately in a predetermined direction. Therefore, in the manufactured liquid crystal panel 46, it is possible to improve the image quality when an image is displayed.

When the liquid crystal cell 48 used for manufacturing the liquid crystal panel 46 is any liquid crystal cell 48 of VA type or IPS type, image display of high contrast is possible. Therefore, by applying the polarizing plate 10A in which the absorption axis S _A is directed accurately in a predetermined direction, it is possible to further improve the image quality in the liquid crystal panel 46.

In the fourth embodiment, the polarizing plate 10 manufactured by any of the polarizing plate manufacturing methods disclosed in the first to third embodiments has at least one of the polarizer film 12a and the protective films 12b and 12c do. However, usually the polarizing plate 10 has a pressure-sensitive adhesive layer 12e for bonding to the liquid crystal cell 48. [ When the polarizing plate 10 produced by any of the polarizing plate manufacturing methods disclosed in the first to third embodiments does not have the pressure-sensitive adhesive layer 12e, the polarizing plate 10 and the liquid crystal cell 48 may be bonded with an adhesive, for example, , The pressure sensitive adhesive layer may be formed on the liquid crystal cell 48 side.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements .

For example, in the first and second embodiments, the step of manufacturing the polarizing plate 10 from the band-shaped polarizing plate 12 is illustrated. However, in the first embodiment, the birefringent plate 16 or the polarizer plate intermediate member 22 described in the first embodiment may be purchased, and the polarizer plate 10 may be manufactured therefrom.

An example has been described in which a rectangular sheet-like polarizer 16 is cut in a longitudinal direction of the strip-shaped polarizer 12 when the sheet-like polarizer 16 is cut from the strip-shaped polarizer 12. However, the sheet-like polarizing plate 16 may be cut in an oblique direction with respect to the longitudinal direction of the strip-shaped polarizing plate 12, for example. That is, the sheet-like polarizing plate 16 may be cut from the strip-shaped polarizing plate 12 such that the longitudinal direction of the sheet-like polarizing plate 16 and the longitudinal direction of the strip-shaped polarizing plate 12 intersect with each other. The shape viewed from the plane of the sheet polarizer 16 is not limited to a rectangular or square shape, and may be a parallelogram, for example. Here, a modified example in the case of cutting the sheet polarizer 16 from the strip-shaped polarizer 12 is described, but the same applies to the case where the polarizer plate 22 is cut from the sheet polarizer 16.

The shape of the polarizing plate 10 viewed from the plane is exemplified by a rectangle such as a rectangle or a square. However, the shape is not limited to a rectangle but may be circular.

The number of the polarizing plate 10 and the polarizing plate intermediate 22 is not limited to two or more, that is, when the polarizing plate 10 is directly cut from the band-shaped polarizing plate 12 or when the polarizing plate intermediate 22 is cut , Or one sheet may be used. Likewise, when the polarizer 10 is directly cut from the sheet polarizer 16 or when the polarizer plate 22 is cut off, the number of the polarizer 10 and the polarizer plate 22 is limited to a plurality, that is, It may be one.

Examples of the driving method of the liquid crystal panel to which the polarizing plate 10 is applied are not limited to the case of VA and IPS. For example, the driving method of the liquid crystal panel to which the polarizing plate 10 is applied may be a TN (Twisted Nematic) method.

(Polarizer plate), 22: polarizer plate (original plate), 46: liquid crystal panel, and 48: liquid crystal cell.

Claims (13)

A method for producing a polarizing plate in which a direction of an absorption axis is directed in a predetermined direction,
An original plate absorption axis detecting step of detecting the direction of the absorption axis in the original plate of the polarizing plate,
A processing step of obtaining a polarizing plate by processing the polarizing plate
And,
Wherein in the processing step, the polarizer plate is processed such that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is in the predetermined direction in the polarizer to be obtained. The polarizing plate according to claim 1, wherein in the processing step, the end face of the polarizer plate is oriented such that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is in the predetermined direction in the polarizer plate to be obtained A method of manufacturing a polarizing plate for cutting. The method according to claim 2, further comprising: a sheet cutting step of cutting a sheet-like polarizing plate from the strip-
An intermediate trimming step of cutting the polarizer intermediate, which is the polarizer plate, from the sheet polarizer
And a polarizing plate. The method according to claim 1, wherein in the processing step, the polarizer plate is cut so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is in the predetermined direction in the polarizer to be obtained A method for producing a polarizing plate. The method according to claim 1,
An intermediate cutting step of cutting the polarizer plate from the polarizer plate,
An intermediate absorption axis detecting step of detecting the direction of the absorption axis of the polarizer plate intermediate,
A step of cutting the end face of the polarizer intermediate body
Lt; / RTI >
In the intermediate cutting process, the polarizer plate is cut so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is the same in the polarizer plate intermediate to be obtained,
In the step of cutting the end face of the polarizing plate intermediate body, the direction of the absorption axis of the polarizing plate intermediate detected in the intermediate absorption axis detecting step is set such that the direction of the absorption axis of the polarizing plate intermediate body is in the predetermined direction in the polarizing plate to be obtained, Wherein the polarizing plate is cut at a side surface thereof. The method of manufacturing a polarizing plate according to claim 4 or 5, further comprising a step of cutting off the sheet-like polarizer, which is the polarizer plate, from the strip-shaped polarizer. The polarizing plate according to claim 1, wherein the polarizer plate is a band-
Wherein the processing step cuts the polarizer plate so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is in the predetermined direction. The method according to claim 1,
An intermediate cutting step of cutting the polarizer plate from the polarizer plate,
An intermediate absorption axis detecting step of detecting the direction of the absorption axis of the polarizing plate intermediate,
A step of cutting the end face of the polarizer intermediate body
Lt; / RTI >
In the intermediate cutting step, the polarizer plate is cut so that the direction of the absorption axis of the polarizer plate detected in the plate absorption axis detecting step is the same in the polarizer plate intermediate to be obtained,
In the step of cutting the end face of the polarizing plate intermediate body, the direction of the absorption axis of the polarizing plate intermediate detected in the intermediate absorption axis detecting step is set such that the direction of the absorption axis of the polarizing plate intermediate body is in the predetermined direction in the polarizing plate to be obtained, Wherein the polarizing plate is cut at a side surface thereof. The method of manufacturing a polarizing plate according to any one of claims 3, 6, and 7, wherein the band-shaped polarizing plate comprises a uniaxially stretched polarizing layer. The method of manufacturing a polarizing plate according to claim 9, wherein the width of the band-shaped polarizing plate is 1000 mm or more. 11. The polarizing plate according to any one of claims 1 to 10, wherein the shape of the polarizing plate as viewed in a plane is a rectangle or a square,
Wherein the length of the diagonal of the polarizer is 350 mm or less. 12. The method of manufacturing a polarizing plate according to any one of claims 1 to 11, wherein the polarizing plate is a polarizing plate for a liquid crystal panel of VA type or IPS type. A method for producing a liquid crystal panel, comprising the steps of: preparing a polarizing plate by the method for producing a polarizing plate according to any one of claims 1 to 12; and joining the obtained polarizing plate to the liquid crystal cell.

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