TWI611223B - Method for manufacturing polarizing plate and method for manufacturing liquid crystal panel - Google Patents

Abstract

The present invention discloses a method of manufacturing a polarizing plate that accurately directs the direction of the absorption axis in a predetermined direction, and a method of manufacturing the liquid crystal panel. A method of manufacturing a polarizing plate according to an embodiment is a method of manufacturing a polarizing plate (10) having a direction in which an absorption axis (S _A ) is directed in a predetermined direction, and an original plate for detecting a direction of an absorption axis in a polarizing plate original plate (22). An absorption axis detecting step (S14), and a processing step (S16) of obtaining a polarizing plate (10) by processing a polarizing plate original plate; and in the processing step (S16), the original plate absorption axis detecting step (S14) is performed The polarizing plate original plate (22) is processed in such a manner that the direction of the detected absorption axis (S _A ) is directed to a predetermined direction in the polarizing plate (10) to be obtained.

Description

Method for manufacturing polarizing plate and method for manufacturing liquid crystal panel

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

As the polarizing plate, a linear polarizing plate is known. The linear polarizing plate has an absorption axis and a transmission axis perpendicular to the absorption axis, and absorbs light that vibrates in the direction of the absorption axis, and transmits light that vibrates in the direction of the transmission axis. Such a polarizing plate is produced by, for example, cutting a strip-shaped polarizing plate into a predetermined size (refer to Patent Documents 1 and 2). Among them, the strip-shaped polarizing plate can be produced, for example, by laminating a protective film on both sides or a single surface of a strip-shaped polarizing film. The strip-shaped polarizer film is usually produced by uniaxially extending a strip-shaped raw material film in the longitudinal direction. In this type of manufacturing method, the strip-shaped polarizing plate has a direction of the absorption axis which is parallel to the direction in which the raw material film extends in the uniaxial stretching. Further, since the uniaxial stretching of the raw material film is performed in the longitudinal direction, it is conceivable that the longitudinal direction of the strip-shaped polarizing plate coincides with the absorption axis direction. Therefore, the absorption axis in the polarizing plate is manufactured from the strip-shaped polarizing plate in a predetermined direction in the polarizing plate with the longitudinal direction of the strip-shaped polarizing plate as a reference. Polarizer. Conventionally, the polarizing plate manufactured in this manner can be used practically even when used in, for example, a liquid crystal display device.

(previous technical literature) (Patent Literature)

[Patent Document 1] Patent Laid-Open No. 11-231129

[Patent Document 2] Patent Unexamined Patent Publication No. 11-2724

Assuming that the longitudinal direction of the strip-shaped polarizing plate is the direction of the absorption axis and the polarizing plate is manufactured, in fact, it is known that the predetermined direction of the absorption axis required in the polarizing plate of the product and the absorption axis direction of the actual polarizing plate are sometimes There is a slight deviation between them (for example: 0.2° to 0.3°). It is considered that such a deviation is caused by a direction in which the raw material film is uniaxially stretched in the manufacture of the strip-shaped polarizing plate to be a polarizing plate, a deviation from the longitudinal direction of the strip-shaped polarizing plate, and a strip-shaped polarizing plate. Factors such as errors in cutting off the polarizing plate. On the other hand, in recent years, for example, in the display of small and medium-sized mobile devices, higher contrast is required. However, when the contrast becomes high in the display or the like, when the predetermined direction of the absorption axis required in the polarizing plate of the product slightly deviates from the direction of the absorption axis of the actual polarizing plate, the image quality due to the deviation is lowered. Doubt.

Accordingly, it is an object of the present invention to provide a method of manufacturing a polarizing plate that accurately directs the direction of the absorption axis in a predetermined direction, and also to provide a method of manufacturing a liquid crystal panel.

In the method for producing a polarizing plate according to the aspect of the invention, the method for producing a polarizing plate having a direction in which the direction of the absorption axis faces a predetermined direction includes: a step of detecting an absorption axis of the original plate for detecting a direction of an absorption axis in the original plate of the polarizing plate, and Processing the polarizing plate of the original plate to obtain a processing step of the polarizing plate; in the processing step, the direction of the absorption axis of the original plate of the polarizing plate detected in the absorption axis detecting step of the original plate is directed to a predetermined direction in the polarizing plate to be obtained , processing the original plate of the polarizing plate.

In this method, the absorption axis of the original plate of the polarizing plate is detected. Then, a polarizing plate was produced in accordance with the detection result of the absorption axis. As described above, since the detection result of the absorption axis is utilized, it is possible to manufacture a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

In one embodiment of the present invention, in the processing step, the direction of the absorption axis of the original plate of the polarizing plate detected in the original plate absorption axis detecting step may be cut in a predetermined direction toward the obtained polarizing plate. The end face of the original plate of the polarizing plate.

In the form of cutting the end surface of the original plate of the polarizing plate, the method of manufacturing the polarizing plate may further include: a sheet cutting step of cutting the sheet-shaped polarizing plate from the strip-shaped polarizing plate, and cutting from the sheet-shaped polarizing plate The intermediate cutting step of cutting off the polarizing plate intermediate body of the original plate of the polarizing plate.

At this time, the polarizing plate intermediate body of the original plate of the polarizing plate is cut by the sheet-shaped polarizing plate cut out from the strip-shaped polarizing plate. Due to the influence of the cutting error or the like generated in each cutting step, the absorption axis direction of the polarizing plate intermediate body of the original plate of the polarizing plate deviates from the band polarizing plate in advance. The case of the absorption axis direction. However, even in this case, in the above manufacturing method, the direction of the absorption axis of the polarizing plate intermediate body of the original plate of the polarizing plate can be detected, and a polarizing plate can be obtained based on the detection result. In this way, the polarizing plate in which the direction of the absorption axis is correctly oriented in a predetermined direction can be more accurately produced.

In an embodiment of the present invention, in the processing step, the absorption axis direction of the original plate of the polarizing plate detected in the absorption axis detecting step of the original plate may be cut toward a predetermined direction in the polarizing plate to be obtained. The original plate of the polarizing plate is cut.

In an embodiment of the present invention, the processing step includes: an intermediate cutting step of cutting the polarizing plate intermediate body from the polarizing plate original plate, an intermediate absorption axis detecting step for detecting the absorption axis direction of the polarizing plate intermediate body, and a cutting process The step of the end face of the polarizing plate intermediate body; in the intermediate cutting step, the absorption axis direction of the original plate of the polarizing plate detected in the absorption axis detecting step of the original plate may be the same in the polarizing plate intermediate body to be obtained. Cutting the original plate of the polarizing plate and, 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 body detected in the intermediate absorption axis detecting step is directed toward the polarizing plate to be obtained The direction of the predetermined direction is to cut the end face of the original plate of the polarizing plate.

At this time, the polarizing plate original plate is cut in the same manner as in the direction of the absorption axis of the original plate of the polarizing plate detected in the absorption axis detecting step of the original plate, thereby cutting the polarizing plate from the original plate of the polarizing plate. Board intermediates. Therefore, a polarizing plate intermediate body having the same absorption axis direction can be obtained. Then, the absorption axis of the polarizing plate intermediate body was further detected, and a polarizing plate was obtained in accordance with the detection result. Due to the absorption axis of the polarizing plate intermediate The polarizing plate is obtained as a result of the detection of the direction, so that it is easy to manufacture a polarizing plate whose absorption axis direction faces a predetermined direction. Further, according to the detection result of the direction of the absorption axis of the polarizing plate intermediate body, since the polarizing plate is obtained from the polarizing plate intermediate body, the influence of the error in cutting the polarizing plate intermediate body from the original plate of the polarizing plate can be reduced. As a result, it is easier to manufacture the polarizing plate whose direction of the absorption axis is oriented in a predetermined direction.

In the form of obtaining a polarizing plate intermediate body or a polarizing plate from the original plate of the polarizing plate, a sheet-like cutting step of cutting the polarizing plate of the polarizing plate from the strip-shaped polarizing plate may be further provided.

The sheet-shaped polarizing plate of the original plate of the polarizing plate is cut out from the strip-shaped polarizer. At this time, depending on the cutting error or the like caused by the cutting step, the direction of the absorption axis of the sheet-shaped polarizing plate of the original plate of the polarizing plate may deviate from the band-shaped polarizing plate by a predetermined absorption axis. There is also a case where the directions of the absorption axes which are desired in the strip-shaped polarizing plate are not uniform. In this case, in the above manufacturing method, the direction of the absorption axis of the sheet-shaped polarizing plate of the original plate of the polarizing plate is detected, and a polarizing plate is obtained based on the result of the detection. Therefore, the polarizing plate whose absorption axis direction is oriented in a predetermined direction can be obtained more precisely.

In one embodiment of the present invention, the polarizing plate original plate is a strip-shaped polarizing plate, and in the processing step, the direction of the absorption axis of the original plate of the polarizing plate detected in the original plate absorption axis detecting step may be oriented in a predetermined direction, and the cutting process may be performed. The original plate of the polarizing plate.

The direction of the absorption axis that is desired in the strip-shaped polarizing plate is sometimes inconsistent. In this case, in the above manufacturing method, the direction of the absorption axis of the strip-shaped polarizing plate of the original plate of the polarizing plate is detected, and a polarizing plate is obtained based on the detected result. Therefore, the direction of the absorption axis can be more accurately obtained. A polarizing plate that faces in a predetermined direction.

In the form in which the polarizing plate original plate is a strip-shaped polarizing plate, the processing step in the manufacturing method of the polarizing plate has the following steps: cutting the intermediate portion of the polarizing plate intermediate body from the polarizing plate original plate, and detecting the absorption axis direction of the polarizing plate intermediate body The intermediate absorption axis detecting step and the step of cutting the end face of the polarizing plate intermediate body; in the intermediate cutting step, the absorption axis direction of the original plate of the polarizing plate detected in the original plate absorption axis detecting step is deserved In the polarizing plate intermediate body, the original plate for processing the polarizing plate is cut in the same manner, and in the step of cutting the end face of the intermediate portion of the polarizing plate, the intermediate portion of the polarizing plate detected in the intermediate absorption axis detecting step can also be used. The end face of the original plate of the polarizing plate is cut in such a manner that the direction of the absorption axis faces a predetermined direction in the polarizing plate to be obtained.

The absorption axis of the strip-shaped polarizing plate is detected, and the polarizing plate intermediate body is cut from the strip-shaped polarizing plate according to the detection result. Therefore, even if the directions of the absorption axes which are desired in the strip-shaped polarizing plate do not coincide, the polarizing plate intermediate body in the direction in which the direction of the absorption axis faces in the same direction in the polarizing plate intermediate body can be obtained. Moreover, the absorption axis of the polarizing plate intermediate body is detected, and the polarizing plate is obtained according to the detection result, so that the influence of the error when cutting the intermediate body of the polarizing plate can also be reduced. As a result, it is possible to more easily manufacture a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

The strip-shaped polarizing plate may also have a uniaxially stretched polarizing layer.

When the polarizing layer is uniaxially stretched, the direction of the absorption axis can be thought of as the extending direction. However, due to the influence of bending during uniaxial stretching, etc. The reason is that in the strip-shaped polarizing plate, the direction of the absorption axis is likely to be inconsistent. Therefore, in the form in which the strip-shaped polarizing plate includes the uniaxially extending polarizing layer, the above-described manufacturing method having the step of detecting the absorption axis direction can more reliably produce a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

The strip-shaped polarizing plate may have a width of 1000 mm or more. At this time, it is easy to be affected by the above bending. Therefore, the above-described manufacturing method having the step of detecting the direction of the absorption axis can be obtained by obtaining a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

In one embodiment of the present invention, the planar projection shape of the polarizing plate is rectangular or square, and the length of the diagonal of the polarizing plate may be 350 mm or less, and usually, it may be 12.5 mm or more, and more preferably 50 mm or more.

Such polarizers have a tendency to be used in small and medium-sized displays that require high contrast. Therefore, the above manufacturing method can be effective in obtaining a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

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

In the VA type or IPS type liquid crystal display device, images can be displayed with high contrast, so there is a tendency to display images with higher contrast. Therefore, the above manufacturing method can be effective in obtaining a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

In the method for producing a liquid crystal panel according to another aspect of the present invention, the polarizing plate can be manufactured by the method for producing a polarizing plate according to one aspect of the present invention, and the obtained polarizing plate can be bonded to the liquid crystal cell to produce a liquid. Crystal panel.

The polarizing plate bonded to the liquid crystal cell by the method for producing a liquid crystal panel described above can be produced by the method for producing a polarizing plate according to one aspect of the present invention. Therefore, in the manufactured polarizing plate, the absorption axis can be correctly directed to a predetermined direction. Therefore, in the liquid crystal panel, when an image is displayed, image quality can be improved.

According to the present invention, it is possible to provide a method of manufacturing a polarizing plate in which the direction of the absorption axis is correctly directed in a predetermined direction.

10‧‧‧Polar plate

12‧‧‧Poly polarizing plate (original plate of polarizing plate)

12a‧‧‧ polarizer film

14‧‧‧ embryonic film roll

16‧‧‧Flake polarizing plate (original plate of polarizing plate)

18‧‧‧cutting device

20‧‧‧cutting device

22‧‧‧Polarized plate intermediate (polar plate original plate)

24‧‧‧Light source

26‧‧‧Photodetector

28‧‧‧Linear polarizer

30‧‧‧Layered body

32‧‧‧End face processing equipment

34A‧‧‧Fixed components

34B‧‧‧Fixed components

36‧‧‧Rotating table

38‧‧‧ Pressing members

40A‧‧‧ cutting components

40B‧‧‧ cutting components

42A‧‧‧Rotating components

42B‧‧‧Rotating components

44‧‧‧ cutting edge

46‧‧‧LCD panel

48‧‧‧Liquid Crystal Unit

S _A ‧‧‧Absorption axis

S _T ‧‧‧ Transmission axis

Fig. 1 is a plan view showing a polarizing plate manufactured by a method for producing a polarizing plate according to an embodiment of the present invention.

Fig. 2 is a schematic view showing a strip-shaped polarizing plate for producing a polarizing plate shown in Fig. 1.

Fig. 3 is a cross-sectional view taken along line III-III of Fig. 2.

Fig. 4 is a flow chart showing a method of manufacturing a polarizing plate in an embodiment of the present invention.

Fig. 5(a) is a view for explaining a step of cutting a sliced polarizing plate from a strip-shaped polarizing plate. Fig. 5(b) is a plan view schematically showing a strip-shaped polarizing plate showing the cutting position of the strip-shaped polarizing plate.

Fig. 6(a) is a view showing a step of cutting the polarizing plate intermediate body with a sheet-like polarizing plate. Fig. 6(b) is a plan view schematically showing the cutting position of the polarizing plate intermediate body in the sheet-like polarizing plate.

Fig. 7 is a view schematically showing the steps of the detecting step of the absorption axis.

Fig. 8 is a view showing the cutting area of the polarizing plate from the polarizing plate intermediate body based on the detection result of the absorption axis.

Figure 9 is a schematic view showing the steps of end face processing.

Fig. 10 is a flow chart showing a method of manufacturing a polarizing plate in another embodiment of the present invention.

Fig. 11 is a view for explaining the cutting step of the sheet-shaped polarizing plate.

Fig. 12 is a flow chart showing a method of manufacturing a polarizing plate according to still another embodiment of the present invention.

Fig. 13 is a view showing the result of the detection of the absorption axis from the strip-shaped polarizing plate when the slice-shaped polarizing plate is cut.

Fig. 14 is a view schematically showing the structure of a liquid crystal panel manufactured in a method for producing a liquid crystal panel according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same elements are given the same symbols. Duplicate descriptions are omitted. The size ratio of the drawing is not necessarily consistent with the one described. In the description, terms such as "upper" and "lower" are terms that are based on the state of the drawing.

(First embodiment)

Fig. 1 is a plan view showing a polarizing plate manufactured in a method for producing a polarizing plate according to an embodiment of the present invention. 10 based polarizing plate having an absorption axis S _A, the transmission axis perpendicular to the absorption axis S _T (polarization axis) S _A is. Polarizing plate 10 based optical element having a polarization characteristic of absorbing light in the absorption axis direction of the vibration of S _A, and selectively by the transmission axis direction of the light vibrations S _T's.

The polarizing plate 10 can be applied to a liquid crystal display device. For example, the polarizing plate 10 can be attached to both sides of the liquid crystal cell to constitute a part of the liquid crystal panel. An example of the planar projection shape (the shape viewed from the thickness direction) of the polarizing plate 10 is a rectangular or square square as shown in Fig. 1. The direction of the absorption axis S _A of the polarizing plate 10 is directed in a predetermined direction in the polarizing plate 10.

The predetermined direction is a direction from the reference side to a predetermined angle θ when one side of the polarizing plate 10 is used as a reference. For example, when the plane projection shape of the polarizing plate 10 is a rectangle, the predetermined direction can be exemplified by a long side as a reference, and a direction of a predetermined angle θ = 0 (that is, a direction parallel to the long side), a predetermined angle θ. =45° direction, etc. For the sake of brevity, in the following, unless otherwise stated, the form of the polarizing plate 10 in which the planar projection shape is a rectangle and the predetermined direction is the longitudinal direction will be described.

The size of the polarizing plate 10 may be set in accordance with an element using the polarizing plate 10. An example of the size of the polarizing plate 10 is such that the length of the diagonal line is 50 mm to 350 mm, that is, a polarizing plate having a length corresponding to the so-called second to twelfth type. 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, a VA (Vertical Alignment) type and an IPS (In-) which can display images with high contrast can be cited. Place-Switching type LCD panel.

The polarizing plate 10 can be manufactured from the strip-shaped polarizing plate 12 shown in FIG. Fig. 2 is a schematic view showing a strip-shaped polarizing plate for producing a polarizing plate shown in Fig. 1.

An example of the length of the strip-shaped polarizing plate 12 in the longitudinal direction is 1000m to 2000m. The strip-shaped polarizing plate 12 is wound into a roll shape. The round roll wound by the strip-shaped polarizing plate 12 is called a film roll 14. An example of the width of the strip-shaped polarizing plate 12 is 1000 mm or more.

Fig. 3 is a cross-sectional view taken along line III-III of Fig. 2. The strip-shaped polarizing plate 12 is a laminated body having a polarizer film 12a that can selectively pass a polarizing layer that vibrates in one direction. The polarizer film 12a is a film in which a dichroic dye is adsorbed onto a PVA film which is uniaxially stretched in the longitudinal direction of the strip-shaped polarizing plate 12. The dichroic dye is adsorbed on the PVA film by being aligned in the extending direction of the PVA film. Thereby, the polarizer film 12a absorbs light in the alignment direction of the dichroic dye (that is, in the direction of the long axis of the molecule), and has dichroism, that is, polarization characteristics, of light having a direction perpendicular 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 μm to 30 μm.

On both surfaces of the polarizer film 12a, protective films 12b and 12c for protecting the protective layer of the polarizer film 12a are bonded. Examples of the protective films 12b and 12c are cellulose films, and examples of the cellulose film are TAC (triethylenesulfonyl cellulose) films. Examples of the thickness of the protective films 12b and 12c are 10 μm to 200 μm.

In the above description, the strip-shaped polarizing plate 12 having a structure in which the polarizer film 12a is sandwiched between the protective films 12b and 12c is described. However, the strip-shaped polarizing plate 12 may be a single-layer protective film 12b on the polarizer film 12a. The structure of the protective film is not laminated on the other side.

A surface protective film (or cover film) 12d for protecting the protective film 12b may be attached to the protective film 12b. Example of the thickness of the surface protective film 12d It is from 30 μm to 100 μm. Examples of the material of the surface protective film 12d are polyethylene, polypropylene, and polyester.

Further, on the protective film 12c, an adhesive layer 12e for bonding the polarizing plate 10 of the product to another member such as a liquid crystal cell may be formed. An example of the thickness of the adhesive layer 12e is 5 μm to 30 μm. Examples of the adhesive constituting the adhesive layer 12e include, for example, a polyacrylic adhesive, an amine ester adhesive, and a siloxane adhesive. In the form of the adhesive layer 12e, the separation membrane 12f is detachably bonded to the adhesive layer 12e. The separation membrane 12f is for preventing adhesion of other regions of the strip-shaped polarizing plate 12, foreign matter, and the like to the adhesive layer 12e until the polarizing plate 10 is used as a film. An example of the thickness of the separation membrane 12f is 30 μm to 100 μm.

The strip-shaped polarizing plate 12 can be manufactured in the following manner. That is, the strip-shaped raw material film is uniaxially extended toward the longitudinal direction thereof. An example of the raw material film is an unextended, that is, a PVA film which is not alignable. The example of the stretching ratio is 4 to 5 times. The uniaxial stretching method may be either a dry uniaxial stretching method or a wet uniaxial stretching method. The uniaxial stretching is achieved, for example, by the raw material film contacting the heating cylinder while applying a tensile extension in the longitudinal direction. After the uniaxial stretching, the raw material film is obtained by immersing the PVA film of the raw material film which has been uniaxially stretched in an aqueous solution containing a dichroic dye, so that the dichroic dye can be adsorbed and aligned on the PVA film. Polarizer film 12a. Then, the protective films 12b and 12c are bonded to the both surfaces of the polarizer film 12a, respectively, to obtain the above-described basic structure. Thereafter, the strip-shaped polarizing plate 12 is prepared by appropriately providing the surface protective film 12d, the adhesive layer 12e, and the separation film 12f.

In the example of the method for manufacturing the strip-shaped polarizing plate 12 described above, The dichroic dye is adsorbed on the PVA film after the raw material film is uniaxially stretched. However, the raw material film may be uniaxially stretched after adsorbing the alignment dichroic dye or adsorbing the alignment.

The polarizing film 12a (more specifically, the PVA film) which the strip-shaped polarizing plate 12 has is uniaxially extended toward the longitudinal direction of the strip-shaped polarizing plate 12. Thus, in the band-shaped polarizing plate 12, the absorption coefficient of the strip substantially coincides with the longitudinal direction of the polarizing plate 12 in the direction of the axis S _A. However, in the case of uniaxial stretching, a bowing which is slightly curved inside the edge in the width direction is sometimes generated. Thus, the second as shown in FIG. 2, depending on the band-shaped polarizing plate 12, the absorption axis S _A direction may deviate from the longitudinal direction. The angle at which the direction of the absorption axis S _A is deviated from the longitudinal direction is, for example, about 0.2 to 0.3. In Fig. 2, the deviation angle is exaggerated.

Next, a method of manufacturing the polarizing plate 10 shown in Fig. 1 by the strip-shaped polarizing plate 12 shown in Fig. 2 will be specifically described.

Fig. 4 is a flow chart showing a method of manufacturing a polarizing plate in an embodiment of the present invention. When manufacturing the polarizing plate 10, first, the slice-shaped polarizing plate (first polarizing plate intermediate) 16 is cut out from the strip-shaped polarizing plate 12 (sheet-like cutting step S10). Next, the polarizing plate intermediate (second polarizing plate intermediate) 22 is cut out from the sheet-like polarizing plate 16 (intermediate cutting step S12). Then, the absorption axis S _{A of} the cut polarizing plate intermediate body 22 is detected (absorption axis detecting step S14). Thereafter, the polarizing plate 10 is obtained by cutting the end surface (end surface processing) of the polarizing plate intermediate body 22 (end surface processing step S16). Hereinafter, each step will be described.

(1) Sheet cutting step S10

The sheet cutting step S10 will be described with reference to Figs. 5(a) and 5(b). Fig. 5(a) is a view for explaining a step of cutting a sliced polarizing plate from a strip-shaped polarizing plate. Fig. 5(b) is a plan view showing a strip-shaped polarizing plate schematically showing the cutting position of the strip-shaped polarizing plate.

In the sheet-like cutting step S10, the strip-shaped polarizing plate 12 is pulled out from the film roll 14. Then, the drawn strip-shaped polarizing plate 12 is transported to the cutting device 18 disposed in the drawing direction (or the conveying direction) of the strip-shaped polarizing plate 12. In the cutting device 18, the strip-shaped polarizing plate 12 is cut by a predetermined length by the cutting blade 18a, and the strip-shaped polarizing plate 16 is cut by the strip-shaped polarizing plate 12. The cutting position of the strip-shaped polarizing plate 12 is, for example, a dummy cutting line indicated by a two-dot chain line in Fig. 5(b), and may be set to a constant interval in the longitudinal direction. The position of the dummy cutting line may be input to the cutting device 18 in advance. Further, the cutting device 18 may be used to cut the strip-shaped polarizing plate 12 with a laser beam instead of the cutting blade 18a.

(2) Intermediate cutting step S12

The intermediate cutting step S12 will be described with reference to Figs. 6(a) and 6(b). Fig. 6(a) is a view for explaining the steps of cutting the intermediate portion of the polarizing plate from the sheet-like polarizing plate. Fig. 6(b) is a plan view schematically showing the cutting position of the polarizing plate intermediate body in the sheet-like polarizing plate.

In the intermediate cutting step S12, the sheet-like polarizing plate 16 is conveyed into the cutting device 20 disposed in the conveying direction thereof. The cutting device 20 cuts a plurality of polarizing plate intermediate bodies 22 from the sheet-like polarizing plate 16 by cutting the blade 20a. The polarizing plate intermediate body 22 has a polarizing plate intermediate body having a size of a cutting width (for example, 0.5 mm width) with respect to the shape of the polarizing plate 10 to be manufactured. In the embodiment of the present invention, the polarizing plate intermediate body 22 corresponds to the polarizing plate original plate. The cutting position of the sheet-like polarizing plate 16 may be set as a dummy cutting line for the polarizing plate intermediate body 22 indicated by a two-dot chain line in Fig. 6(b). Intermediate polarizing plate with the cutting line 22 may be assumed that the absorption axis S _A in the conveying direction (i.e., longitudinal direction of the band-shaped polarizing plate 12) of the sheet polarizer 16 and a predetermined. The cutting line (cutting position) for the polarizing plate intermediate body 22 may be input to the cutting device 20 in advance. The cutting blade 20a of the cutting device 20 is cut along the cutting line, and may be provided in the cutting device 20 so as to change the direction of the cutting blade 20a. The cutting device 20 can also cut the sheet-like polarizing plate 16 with a laser beam instead of the cutting blade 20a.

(3) Absorption axis detection step S14

Referring to Fig. 7, the absorption axis detecting step S14 will be described. Fig. 7 is a view schematically showing the detection step of the absorption axis direction. The absorption axis S _A can be detected by a rotary analyzer (rotary photodetection method).

Specifically, in the thickness direction of the polarizing plate intermediate body 22, the light source 24 is disposed at one end (the lower side of the polarizing plate intermediate body 22 in FIG. 7) with respect to the polarizing plate intermediate body 22 The polarizing plate original plate 22 is irradiated. The illuminating light is usually non-polarized. Light emitted by a typical light source such as an incandescent bulb, a fluorescent lamp, or an LED is usually non-polarized. The light passing through the polarizing plate intermediate body 22 can be disposed at the other end with respect to the polarizing plate intermediate body 22 in the thickness direction of the polarizing plate intermediate body 22 (in the seventh drawing, above the polarizing plate intermediate body 22) The photodetector 26 detects. Between the polarizing plate intermediate body 22 and the photodetector 26, a linear polarizing plate 28 having a known optical analyzer in which the absorption axis S _A direction and the transmission axis S _T direction are known is rotatably disposed in advance by the light source 24 The intersection of the optical axis of the emitted light and the linear polarizing plate 28 serves as a center of rotation. The amount of rotation of the linear polarizing plate 28 may be controlled by, for example, a computer control device. In the above control device, it is only necessary to process the signal from the photodetector 26.

When the absorption axis S _{A of the} polarizing plate intermediate body 22 is detected, light is emitted from the light source 24. Light may be selectively emitted from the light source 24 is incident on the polarizing plate of Intermediate 22, Intermediate 22 to the polarizing plate transmission axis direction of the vibration S _T passed through the polarizing plate 22 intermediate. Accordingly, when the linear polarizing plate 28 on the optical axis of the light source 24 emitted light is rotated as a central axis, the absorption axis of the linear polarizing plate 28 of the absorption axis direction of the polarizing plate S _A S _A of Intermediate 22 perpendicular to the direction In the state, that is, in the case of the orthogonal polarization state, the amount of light incident on the photodetector 26 is the smallest. Thus, the amount of light incident on the light detector 26 is at a minimum, S _A linearly polarizing plate absorption axis direction 28 of the absorption axis direction of the polarizer S _A of Intermediate 22.

The detection of the direction of the absorption axis S _A can be performed at a plurality of locations in the polarizing plate intermediate body 22. Where the direction of the absorption axis S _A is detected, for example, the width direction of the polarizing plate intermediate body 22 can be set.

The detecting device for absorbing the axial direction of the light source 24, the linear polarizing plate 28, and the photodetector 26 may be disposed, for example, on a transport path for cutting the polarizing plate intermediate body 22 from the sheet-shaped polarizing plate 16, or may be disposed on the transport path. Other than the route.

Light source 24, the linear polarizer 28 and photodetector 26, as long as the absorption axis can be used for the detection can be S _A is not particularly defined it. The arrangement relationship between the light source 24, the linear polarizing plate 28, and the photodetector 26 is not particularly limited as long as the polarizing plate intermediate body 22 and the linear polarizing plate 28 can be arranged in a state of being orthogonally polarized. For example, the linear polarizing plate 28 may also be disposed between the light source 24 and the polarizing plate intermediate body 22. Further, the linear polarizing plate 28 may be disposed under the polarizing plate intermediate body 22, respectively. At this time, the two linear polarizing plates 28 may be arranged in a parallel orthogonal polarization state so as to be synchronously rotated.

Examples of the apparatus for detecting the direction of the absorption axis S _A shown in Fig. 7 include KOBRA manufactured by Oji Scientific Instruments Co., Ltd., and appliances such as RETS-100 and RE-100P manufactured by Otsuka Electronics Co., Ltd.

The detected absorption axis S _A direction can be recorded as long as it is recorded. For example the recording based on the cutting area indicated other direction to the absorption axis of the polarizing plate S _A 22 Intermediate cutting the polarizing plate 10.

(4) End face processing step S16

The end surface processing step S16 cuts the end faces 22a, 22b, 22c, and 22d of the polarizing plate intermediate body 22 in accordance with the detection result in the direction of the absorption axis S _A . Thereby, the polarizing plate 10 can be obtained. The cutting process also includes grinding of the end faces 22a, 22b, 22c, 22d. The end surface processing step S16 will be described with reference to Figs. 8 and 9.

Fig. 8 is a view showing the area of the region from which the polarizing plate of the polarizing plate is cut, based on the detection result of the absorption axis. FIG. 8, the broken line represents the line direction _A0 assumed length direction of the strip when the polarizer 12 is the absorption axis direction of the absorption axis S, two-dot chain line is detected based on the direction of the absorption axis S _A, represents a polarizing plate Area A. The polarizing plate region A is a portion of the polarizing plate intermediate body 22 that cuts the polarizing plate 10 cut by the end faces 22a to 22d. A region-based polarizing plate absorption axis S _A predetermined direction in the polarizing plate 10 (in the present embodiment, the longitudinal direction) of the mode setting.

Figure 9 is a schematic view showing the steps of end face processing. As shown in Fig. 9, the end face processing of the plurality of polarizing plate intermediate bodies 22 is collectively performed by using the laminated body 30 in which the plurality of polarizing plate intermediate bodies 22 in the direction of the absorption axis S _A are detected.

The end surface processing step S16 is performed by the end surface processing device 32 as shown in Fig. 9. The end surface processing device 32 has a pair of fixing members 34A and 34B that sandwich and fix the laminated body 30 in the lamination direction. One of the fixing members 34A, 34B of the pair of fixing members 34A, 34B is mounted on the rotary table 36. The other fixing member 34A is a pressing member 38 that presses the fixing member 34A against the fixing member 34B side. The rotary table 36 and the compression member 38 are attached to a fixed table that can be moved in one direction and not shown. The pressing member 38 is attached to the fixing table so as to be rotatable in the same direction as the rotating table 36 in synchronization with the rotation of the turntable 36.

The end surface processing device 32 has a pair of cutting members 40A and 40B in the moving direction of the rotary table 36. The pair of cutting members 40A and 40B are disposed in a direction facing the laminating direction of the polarizing plate intermediate body 22 in the laminated body 30 and the moving direction of the turntable 36. The pair of cutting members 40A and 40B include rotating members 42A and 42B that are rotatable with the arrangement direction of the cutting members 40A and 40B as rotation axes, and are on the inner side of the rotating members 42A and 42B (with the laminated body 30). The cutter 44 is mounted on the face.

An example of the end surface processing step S16 of the polarizing plate intermediate body 22 which is performed by the end surface processing apparatus 32 having the above configuration will be described.

Detect a plurality of polarizing plate absorption axis of Intermediate 22 S _A layered laminate 30 is constituted. The direction of the absorption axis S _A of the polarizing plate intermediate body 22 constituting the laminated body 30 is the same. In the laminated body 30, the plurality of polarizing plate intermediate bodies 22 are laminated such that the polarizing plate regions 40 shown in Fig. 8 overlap in the lamination direction. The laminated body 30 to be prepared is sandwiched by the pair of fixing members 34A and 34B, and the pressing member 38 is pressed toward the lamination direction to fix the laminated body 30 by the fixing members 34A and 34B. Then, the rotary table 36 is moved in the moving direction thereof, and the laminated body 30 is fed between the pair of cutting members 40A and 40B. At this time, the rotating members 42A and 42B of the cutting members 40A and 40B are rotated in advance. Thereby, a pair of end faces (in the example of FIG. 9 , the end faces 22c and 22d) of the four end faces 22a to 22d of the respective polarizing plate intermediate bodies 22 constituting the laminated body 30 are cut to face the cutting members 40A and 40B. The members 40A, 40B are machined (or ground). The cutting blade 44 and the end faces of the end faces 22a to 22d facing the end faces of the cutting members 40A, 40B are adjusted by the rotary table 36 in such a manner as to cut the polarizing plate region 40 shown by the two-dot chain line shown in Fig. 8. At the same time, the distance between the cutting members 40A, 40B and the end faces can be appropriately controlled. When the cutting of one of the opposite side faces in the cutting polarizing plate intermediate body 22 is terminated, the rotating table 36 can be rotated, and the other pair of end faces can be processed.

As described above, the end faces 22a to 22d of the polarizing plate intermediate body 22 are cut by the end surface processing device 32, and the polarizing plate 10 is cut from the polarizing plate intermediate body 22, whereby the polarizing plate 10 of the product can be obtained.

The polarizing plate 10 is manufactured by the strip-shaped polarizing plate 12 as described above, but the cross-sectional structure (or layer structure) of the polarizing plate 10 is the same as that of the strip-shaped polarizing plate 12 as shown in FIG.

In the above-described manufacturing method, the original polarizing plate of the polarizing plate before the end face machining stage detecting Intermediate 22 detected S _A is the absorption axis direction. Then, again according to the detection result, the absorption axis of the polarizing plate 10 S _A direction toward a predetermined direction of embodiment, the end faces 22a to 22d for the intermediate cutting the polarizing plate 22, polarizing plate 10 cut out from a polarizing plate Intermediate 22. Accordingly, in the polarizing plate 10 enables the absorption axis direction S _A polarizing plate in the applicable member 10 (example: a liquid crystal panel) in a predetermined direction and the like in a desired orientation. In the polarizing plate 10, the absorbent can be more accurately coincides with the predetermined direction of the axis S _A.

The absorption axis S _A of the strip-shaped polarizing plate 12 is parallel to the extending direction of the polarizer film 12a, and is almost along the longitudinal direction of the strip-shaped polarizing plate 12. Thus, the strip can also be considered the longitudinal direction 12 of the polarizer absorption axis is assumed to be S _A direction, a polarizing plate is manufactured. However, due to manufacturing band-shaped polarizing plate 12 of a uniaxial extension of the curved, as shown in FIG. 2, the region may produce the longitudinal direction 12 of the polarizer strip deviates from the direction of the absorption axis S _A. A cutting error or the like may occur in the cutting process in the sheet cutting step S10 and the intermediate cutting step S12. As a result, as shown in Fig. 8, in the polarizing plate intermediate body 22, the longitudinal direction of the strip-shaped polarizing plate 12 is assumed to be the direction of the dummy absorption axis S _A0 when the absorption axis is absorbed, and the actual absorption as a result of the detection. The axis S _A direction is deviated.

Even assuming that such departures generating, in the above manufacturing method, the detection S _A polarizing plate absorption axis of Intermediate 22, depending on the detection result, the absorption axis S _A direction toward a predetermined direction of the polarizing plate 10 of the embodiment, the polarizing plate from the intermediate The body 22 cuts the polarizing plate 10. Therefore, the polarizing plate 10 in which the direction of the absorption axis S _A is in a desired direction can be obtained more surely.

It can be applied to VA type and IPS type liquid crystal panel polarizing plates which display images with high contrast. Since the image is displayed with high contrast, it is required that the absorption axis S _A direction is highly accurate in the polarizing plate of the product. The required directions are the same. Therefore, the absorption axis may be manufactured in a direction S _A more highly accurately coincides with the predetermined direction of the manufacturing method of the polarizing plate 10, can be efficiently manufactured based formula VA and IPS-type liquid crystal panel of the polarizing plate. When the liquid crystal panel is of the VA type, it may be an ASV (Advanced Super View) type.

Unlike a large-sized TV having a large screen size, in a small-sized mobile device display or the like having a type 12 (diagonal length of 350 mm) or less, since the user tends to view at a close distance, high contrast is required. Thus, the absorption axis may be manufactured in a direction S _A more highly accurately coincides with the predetermined direction of the manufacturing method of the polarizing plate 10, polarizing plate lines can be efficiently produced with small and medium machine action used for display.

The plane projection shape of the polarizing plate 10 is a rectangle or a square, and corresponds to a length of a diagonal of 12.5 mm to 350 mm, a size of about 0.5 to 12, or even a type 2 (diagonal length of 50 mm) or more. Among them, the polarizing plate 10 is easy to use in a display for small and medium-sized mobile devices. Therefore, the above-described manufacturing method of the polarizing plate 10 in which the absorption axis S _A direction is more highly accurately aligned with the predetermined direction can be manufactured, and the plane projection shape is a rectangle or a square and the polarizing length corresponding to the diagonal is 12.5 mm to 350 mm. The board is effective.

When the width of the strip-shaped polarizing plate 12 is 1000 mm or more, the influence of the above-described bending tends to be large. Thus, the manufacturing method having the steps of detecting the direction of the absorption axis S _A, in view of the above width 1000mm, is usually obtained from an absorption axis direction of 3000mm S _A strip of the polarizer 12 of the polarizing plate 10 to a predetermined direction in terms of More effective.

(Second embodiment)

Fig. 10 is a flow chart showing a method of manufacturing a polarizing plate in another embodiment of the present invention. In the manufacturing method shown in Fig. 10, first, the slice-shaped polarizing plate 16 is cut from the strip-shaped polarizing plate 12 (sheet-like cutting step S20). Secondly, and then the sheet S _A detecting direction of the axis of absorption polarizer 16 (absorption axis detecting step S22). Then, the polarizing plate intermediate body 22 is cut from the sheet-like polarizing plate 16 (intermediate cutting step S24). Thereafter, the absorption axis direction of the polarizing plate intermediate body 22 is detected (absorption axis detecting step S26). Subsequently, the polarizing plate 10 is obtained by cutting the end surface (end surface processing) of the polarizing plate intermediate body 22 (end surface processing step S28). The intermediate cutting step S24 and subsequent steps, that is, the intermediate cutting step S24, the absorption axis detecting step S26, and the end surface processing step S28, correspond to the step of obtaining the polarizing plate 10 in accordance with the detection result in the direction of the absorption axis S _A . Hereinafter, each step will be described.

Since the sheet-like cutting step S20 is the same as the cutting step S10 of the sheet-shaped polarizing plate 16 shown in FIG. 4, description thereof will be omitted.

In the absorption axis detecting step S22, the direction of the absorption axis S _A of the sheet-like polarizing plate 16 is detected. The detection method is the same as the detection method using the direction of the absorption axis S _A of the polarizing plate intermediate body 22 described in Fig. 7 . That is, in Fig. 7, the sheet-shaped polarizing plate 16 may be disposed instead of the polarizing plate intermediate body 22 to be detected. The detecting means including the light source 24, the linear polarizing plate 28, and the photodetector 26 in the absorption axis direction may be disposed, for example, on the transport path of the sheet-like polarizing plate 16, or may be disposed elsewhere on the transport path. The detection of the direction of the absorption axis S _A of the sheet-like polarizing plate 16 may be carried out in a plurality of places in the polarizing plate intermediate body 22. The detection position in the direction of the absorption axis S _A can be set, for example, in the width direction of the polarizing plate intermediate body 22.

In the intermediate cutting step S24, similarly to the sixth drawing (a), the sheet-shaped polarizing plate 16 can be fed to the cutting device 20, and the plurality of polarizing plates can be cut from the sheet-shaped polarizing plate 16. Body 22. In this case, the detection direction of the absorption axis S _A according to the absorption axis toward the same direction S _A polarizing plate of Intermediate 22 in a manner, from the sheet polarizer 16 to a polarizing plate cut intermediate cutting blade 20a twenty two. It will be specifically described with reference to Fig. 11.

Fig. 11 is a view for explaining the cutting step of the sheet-shaped polarizing plate. In Fig. 11, a plan view of the sheet-like polarizing plate 16 is shown. Meanwhile, an example of the detected complex absorption axis S _A direction is shown in Fig. 11. As shown in Figure 11, the central portion in the sheet width direction of the polarizing plate 16, with respect to system S _A is the absorption axis direction parallel to the longitudinal direction, and in the vicinity of the edge portion in the width direction of the sheet polarizer 16, absorbent The shaft S _A is inclined with respect to the longitudinal direction. In this case, FIG. 11 as shown in two-dot chain lines, S _A to the absorption axis direction of the cutting line is set in the dummy area is same as the polarizing plate of the cutting area 22 of the intermediate. In one embodiment of the present invention, as shown in FIG. 11, S _A to the absorption axis direction toward the longitudinal direction of the way of setting the dummy polarizing plate 22 of the intermediate cutting line. In Fig. 11, in the width direction, a virtual cut line is set in each of the vicinity of the center and the vicinity of the edges at both ends. Then, the sheet-shaped polarizing plate 16 is cut by a cutting device along the set cutting line by the cutting blade 20a, and the polarizing plate intermediate body 22 is cut from the sheet-shaped polarizing plate 16. In each of the dummy regions by setting the cutting line, the direction of the absorption axis S _A is not required to strictly coincide, comprising consistent within a predetermined allowable range in the direction of the long polarizing plate 10 of the object.

The absorption axis detecting step S26 and the end surface processing step S28 are the same as the absorption axis detecting step S14 and the end surface processing step S16 shown in FIG. 4, and thus the description thereof is omitted.

In the above manufacturing method, based embodiment of the present invention in the detection direction corresponding to the absorption axis of the sheet S _A 16, the original polarizing plate of the polarizing plate. Then, based on the detection result, the sheet-shaped polarizing plate 16 is processed to obtain the polarizing plate 10. Thus deviates, can strip the polarizer occurred to the case of the first embodiment of the present invention for the same reason as the longitudinal direction 12 of the absorption axis S scenario _A0, and the detected actual direction of the absorption axis _A S The polarizing plate 10 is manufactured by performing correction. As a result, the polarizing plate 10 in which the direction of the absorption axis S _A is a predetermined direction can be obtained.

Intermediate polarizing plate so that the absorption axis direction in a consistent way S _A 22, cut from a sheet polarizer 16 polarizer Intermediate 22, Intermediate 22 so that the polarizing plate, for example, to reduce the impact of bending. Further, since the direction of the axis S _A from the absorbent to obtain uniform polarizing plate 10 polarizer Intermediate 22, it is easy to manufacture the polarizing plate 10 toward a predetermined direction, the absorption axis direction S _A.

Then, again detecting the absorption axis direction of the polarizer of Intermediate S _A 22, and based on the detection result, the polarizing plate 10 is obtained. Therefore, the influence of the error in cutting the polarizing plate intermediate body 22 can also be reduced. As a result, the polarizing plate 10 having the direction of the absorption axis S _A in a predetermined direction can be obtained more accurately.

In the manufacturing method of the flowchart shown in FIG. 10 of the embodiment, and as described above, can be obtained as the absorption axis direction S _A polarizing plate 10 a predetermined direction. Therefore, the above-described manufacturing method is effective for a polarizing plate which is applied to a VA type and an IPS type liquid crystal panel or a small-sized display, and this is the same as the case of the first embodiment of the present invention. The width of the strip-shaped polarizing plate 12 is 1000 mm or more, and the planar projection shape of the polarizing plate 10 is a rectangle or a square, and the length of the diagonal is 350 mm or less, preferably 12.5 mm or more, and more preferably 50 mm or more. The above manufacturing method is effective, and this is also the same as the case of the first embodiment of the present invention.

Here, the form of the intermediate cutting step S24 is described, but the polarizing plate 10 may be cut directly from the sheet-shaped polarizing plate 16. At this time, the polarizing plate 16 as can the sheet detected S _A direction toward the absorption axis direction of the predetermined manner in the polarizer 10, the polarizer 10 as long as the sheet 16 cut from the polarizing plate. Thus, the form of the polarizing plate 10 is obtained directly from the sheet-like polarizing plate 16, and the polarizing plate 10 can be manufactured more easily.

The flowchart shown in FIG. 10, the step of detecting includes detecting the absorption axis direction of the absorption axis S _A polarizing plate 22 of the intermediate S26. However, the absorption axis detecting step S26 may not be provided. S _A polarizing plate absorption axis direction 22 of the intermediate system consistent with the polarizing plate in the direction of the absorption axis of Intermediate 22 S _A can be detected that the sheet by the polarizer absorption axis 16 S _A. Therefore, the case shown in FIG. 8 Similarly, the polarizing plate is set in a region A of Intermediate 22 according to direction of the polarizer absorption axis S _A, but with the same end surface processing step S16, as long as the end faces by the processing apparatus 32 from The polarizing plate intermediate body 22 may be used to cut the polarizing plate 10.

In the absorption axis does not have the shape detecting step S26, for example, so that the intermediate polarizing plate 22 a polarizing plate 10 is considered to detect the absorption axis direction S _A way of a predetermined direction, a sheet from the polarizing plate 16 may be The polarizing plate intermediate body 22 is cut. In this case, S _A in the direction of the absorption axis of the polarizing plate 22 based intermediate polarizing plate 10 toward a predetermined direction. Therefore, as long as the end faces 22a to 22d of the polarizing plate intermediate body 22 are cut at a constant width, the end face processing is easy.

(Third embodiment)

Fig. 12 is a flow chart showing a method of manufacturing a polarizing plate according to still another embodiment of the present invention. In the manufacturing method shown in Fig. 12, first, the absorption axis direction of the strip-shaped polarizing plate 12 is detected (absorption axis detecting step S30). Next, the polarizing plate intermediate body 22 is cut 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). Then, the polarizing plate 10 is obtained by cutting the end surface (end surface processing) of the polarizing plate intermediate body 22 (end surface processing step S36). Intermediate step S32 after the cutting step, i.e., the intermediate cutting step S32, the absorption axis detecting step S34 to step S36 and end the processing system based on the detection result of the absorption axis direction S _A, the polarizing plate 10 corresponds to the step of obtaining. Hereinafter, each step will be described.

In the absorption axis detecting step S30, after the strip-shaped polarizing plate 12 is pulled out from the embryonic film roll 14, the direction of the absorption axis S _A of the strip-shaped polarizing plate 12 in the pulled-out region is detected. The detection method is the same as the detection method of the absorption axis S _A direction of the polarizing plate intermediate body 22 described with reference to Fig. 7. That is, in Fig. 7, it is only necessary to arrange the strip-shaped polarizing plate 12 instead of the polarizing plate intermediate body 22. The detection device for the absorption axis direction including the light source 24, the linear polarizing plate 28, and the photodetector 26 may be disposed on the transport path of the strip-shaped polarizing plate 12, for example. The detection of the direction of the absorption axis S _A of the strip-shaped polarizing plate 12 may be performed in a plurality of places in the strip-shaped polarizing plate 12. The detection position of the absorption axis S _A direction can be set, for example, to the width direction of the strip-shaped polarizing plate 12.

In the intermediate cutting step S32, the strip-shaped polarizing plate 12 is fed to the cutting device while the strip-shaped polarizing plate 12 is being pulled out, and the polarizing plate intermediate body 22 is cut from the strip-shaped polarizing plate 12. For the cutting device for cutting the polarizing plate intermediate body 22, the cutting device 20 for cutting the polarizing plate intermediate body 22 illustrated in Fig. 6(a) can be used. This step S32 is the same as when the sheet-shaped polarizing plate 16 shown in FIG. 10 is regarded as the strip-shaped polarizing plate 12. That is, the dummy cutting line is set so that the direction of the absorption axis S _A faces the longitudinal direction of the polarizing plate intermediate body 22. Then, the strip-shaped polarizing plate 12 is cut by a cutting device along the set cutting line, and the polarizing plate intermediate body 22 is cut from the strip-shaped polarizing plate 12.

Since the absorption axis detecting step S34 and the end surface processing step S36 are the same as the absorption axis detecting step S14 and the end surface processing step S16 shown in FIG. 4, description thereof will be omitted.

In the above manufacturing method, the direction of the absorption axis S _A of the strip-shaped polarizing plate 12 is detected. Then, the strip-shaped polarizing plate 12 is processed in accordance with the detection result, and the polarizing plate 10 is obtained. Thus, while correcting the influence due to the bending of the strip when the monoaxial stretching, etc. In the polarizing plate 12 polarizer strip 12 from the absorption axis of the longitudinal direction of the deviation from the side S _A manufacturing polarizing plate 10. As a result, obtained the absorption axis direction is the direction of the desired S _A of the polarizing plate 10.

The polarizing plate intermediate body 22 is cut from the strip-shaped polarizing plate 12 so that the absorption axis S _A direction of the polarizing plate intermediate body 22 is uniform. Therefore, in the polarizing plate intermediate body 22, for example, the influence of bending is reduced. Further, the absorption axis direction of the polarizer agreed S _A Intermediate 22 obtained polarizing plate 10, it is easy to manufacture the polarizing plate 10 toward a predetermined direction, the absorption axis direction S _A.

Then again detecting the absorption axis direction of the polarizer of Intermediate S _A 22, and based on the detection result, to obtain a polarizing plate 10. Therefore, the influence of the error in cutting the polarizing plate intermediate body 22 can also be reduced. As a result, the polarizing plate 10 having the direction of the absorption axis S _A in a predetermined direction can be obtained more accurately.

Even in the method according to the flowchart shown in FIG. 12 of the first, also as described above to obtain S _A polarizing plate absorption axis direction of the predetermined direction 10. Therefore, the above-described manufacturing method is effective for a polarizing plate which is applied to a VA type and an IPS type liquid crystal panel or a small-sized display, and this is the same as the case of the first embodiment of the present invention. The strip-shaped polarizing plate 12 has a width of 1000 mm or more and the plane projection shape of the polarizing plate 10 is rectangular or square and the length of the diagonal is 350 mm or less, and is usually 12.5 mm to 350 mm, preferably 50 mm to 350 mm. The above manufacturing method is effective, and is also the same as the case of the first embodiment of the present invention.

Here, the form of the step S32 of cutting the polarizing plate intermediate body 22 is described. However, the polarizing plate 10 may be cut directly from the strip-shaped polarizing plate 12. At this time, in the axial direction of the strip S _A polarizing plate 12 toward a predetermined direction detected by absorption in the embodiment as long as the polarizing plate 10 polarizer strip 12 cut from the polarizing plate 10 can be. Thus, the form of the polarizing plate 10 is obtained directly from the strip-shaped polarizing plate 12, and the polarizing plate 10 can be manufactured more easily.

The flowchart shown in Fig. 12 also includes an absorption axis detecting step S34 for detecting the direction of the absorption axis S _A of the polarizing plate intermediate body 22. However, the absorption axis detecting step S34 may not be provided. Intermediate polarizer absorption axis 22 coincides with the direction S _A, each of the polarizing plate in the direction of the absorption axis of Intermediate S _A 22, the strip can be known by detecting the absorption axis of the polarizing plate 12 is of S _A. Thus, the situation shown in FIG. 8 the same, in the direction of the polarizing plate absorption axis of Intermediate 22 according to the set S _A of the polarizing plate area A, similarly to the face machining step S16, as long as the end faces by the processing apparatus 32 from the polarization The plate intermediate body 22 may be used to cut the polarizing plate 10.

In the absorption axis does not have the shape detecting step S34, for example, the polarizing plate 10 is regarded as the polarizing plate of Intermediate 22, to detect the absorption axis S _A direction toward a predetermined direction of embodiment, the strip may polarizer 12 The polarizing plate intermediate body 22 is cut. In this case, S _A in the direction of the absorption axis of the polarizing plate 22 toward a predetermined direction of the polarizer based Intermediate 10. Therefore, the end faces 22a to 22d of the polarizing plate intermediate body 22 can be cut at a constant width, so that the end faces are easy to process.

In the flowchart of Fig. 12, the polarizing plate intermediate body 22 is cut from the strip-shaped polarizing plate 12, for example, sliced from the strip-shaped polarizing plate 12. Polarizing plate 16. Fig. 13 is a view showing a state in which a slice-shaped polarizing plate is cut from a strip-shaped polarizing plate in accordance with the detection result of the absorption axis.

A plan view of the strip-shaped polarizing plate 12 is shown in Fig. 13. Further, an example of the detected complex absorption axis S _A is shown in Fig. 13. As shown in FIG. 13, the strip-shaped central portion in the width direction of the polarizing plate 12, with respect to the absorption axis line S _A is parallel to the longitudinal direction, in the vicinity of the edge portion in the width direction of the band-shaped polarizing plate 12, absorbent The shaft S _A is inclined with respect to the longitudinal direction. In this case, as shown in Fig. 13, as a two-dot chain line, the dummy cutting line is set so that the area in which the absorption axis S _A direction is uniform is the area in which the slice-shaped polarizing plate 16 is cut. In one embodiment of the present invention, the system as shown in FIG. 13, the absorption axis direction toward the sheet S _A polarizing plate 16 of the embodiment is set to the longitudinal direction of the dummy cutting line. Thereby, the sheet-shaped polarizing plate 16 having a small deviation in the direction of the absorption axis S _A can be produced. Therefore, the absorption axis direction of the sheet S _A of the polarizer 16 as a reference, if the sheet-processing the polarizing plate 16 to prepare the polarizing plate 10, the polarizing plate may be manufactured S _A absorption axis direction 10 toward a predetermined direction. The polarizing plate 10 can also be manufactured by applying the manufacturing method of the second embodiment of the present invention to the sheet-shaped polarizing plate 16 which is cut out from the strip-shaped polarizing plate 12 in accordance with the detection result in the direction of the absorption axis S _A .

(Fourth embodiment)

In the fourth embodiment of the present invention, 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 strip-shaped polarizing plate 12 illustrated in Fig. 3 . That is, the polarizing plate 10 has a polarizer film 12a, protective films 12b and 12c bonded to both surfaces thereof, and a protective film 12d provided on the protective film 12b. And the adhesive layer 12e and the separation film 12f which are provided on the protective film 12c in this order. The protective films 12b and 12c may have only one of them.

Hereinafter, for convenience of explanation, in the polarizing plate 10 having the layer structure shown in FIG. 3, the polarizing plate 10 that peels off the separation film 12f is also referred to as a polarizing plate 10A.

Fig. 14 is a view schematically showing the structure of a liquid crystal panel manufactured in a fourth embodiment of the present invention. As shown in Fig. 14, the liquid crystal panel 46 is formed on both sides of the liquid crystal cell 48, and the polarizing plate 10A from which the separation film 12f is peeled off from the polarizing plate 10 is bonded to each other. The liquid crystal cell 48 is only required to be used in a known liquid crystal panel. For example, the liquid crystal cell 48 may be provided on the glass substrate in order: a transparent electrode, an alignment film, a liquid crystal, an alignment film, a transparent electrode, a filter, and a glass substrate. Examples of the driving method of the liquid crystal cell 48 are a VA type and an IPS type.

The liquid crystal panel 46 is manufactured, for example, in the following manner. In other words, the polarizing plate 10 (the polarizing plate manufacturing step) is manufactured by any method for producing a polarizing plate disclosed in the first to third embodiments of the present invention. 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 separation film 12f of each of the polarizing plates 10 is peeled off, the polarizing plate 10A of the peeling separation film 12f is bonded to the liquid crystal cell 48 through the adhesive layer 12e. When the polarizing plate 10 is bonded to both surfaces of the liquid crystal cell 48, the two polarizing plates 10A are placed in advance on the liquid crystal cell 48 such that the two polarizing plates 10 are in a state of being orthogonally polarized.

In the above-described manufacturing method, the liquid crystal panel 46 has the polarizing plate 10 serving as the polarizing plate 10A, and can be manufactured by one of the manufacturing methods exemplified in the first to third embodiments of the present invention. Accordingly, in the polarizing plate 10, the absorption axis S _A proper predetermined direction. Therefore, in the liquid crystal panel 46 to be manufactured, when an image is displayed, the image quality can be improved.

When the liquid crystal cell 48 used in the manufacture of the liquid crystal panel 46 is a liquid crystal cell 48 of any of the VA type and the IPS type, it can be a high contrast display image. Therefore, the polarizing plate 10A in which the absorption axis S _{A is} correctly oriented in a predetermined direction is applied, and in the liquid crystal panel 46, the image quality can be further improved.

In the fourth embodiment of the present invention, the polarizing plate 10 manufactured by the method for producing a polarizing plate according to any one of the first to third embodiments of the present invention includes the polarizer film 12a and the protective film 12b. At least one of 12c can be used. However, in general, the polarizing plate 10 has an adhesive layer 12e for bonding to the liquid crystal cell 48. When the polarizing plate 10 manufactured by the method for producing a polarizing plate according to any one of the first to third embodiments of the present invention does not have the adhesive layer 12e, the polarizing plate 10 and the liquid crystal cell 48 are bonded by, for example, an adhesive. An adhesive layer may also be provided on the side of the liquid crystal cell 48.

The various embodiments of the present invention are described above, but the present invention is not limited to the various embodiments described, and all modifications within the scope and scope of the patent application are included.

For example, in the first and second embodiments of the present invention, the step of manufacturing the polarizing plate 10 from the strip-shaped polarizing plate 12 is exemplified. However, in In the first embodiment of the present invention, the sheet-like polarizing plate 16 or the polarizing plate intermediate body 22 described in the first embodiment of the present invention can be purchased, and the polarizing plate 10 can be manufactured therefrom.

When the slice-shaped polarizing plate 16 is cut from the strip-shaped polarizing plate 12, the sheet-shaped polarizing plate 16 which is a rectangular shape in the longitudinal direction is cut in the longitudinal direction of the strip-shaped polarizing plate 12 as an example. However, for example, the slice-shaped polarizing plate 16 may be obliquely cut with respect to the longitudinal direction of the strip-shaped polarizing plate 12. In other words, the strip-shaped polarizing plate 16 may be cut from the strip-shaped polarizing plate 12 so that the longitudinal direction of the sheet-shaped polarizing plate 16 intersects with the longitudinal direction of the strip-shaped polarizing plate 12. The planar projection shape of the sheet-like polarizing plate 16 is not limited to a rectangle or a square, and may be, for example, a parallelogram. Here, a modification in the case where the slice-shaped polarizing plate 16 is cut from the strip-shaped polarizing plate 12 will be described, but the same applies to the case where the polarizing plate intermediate body 22 is cut from the sheet-shaped polarizing plate 16.

The planar projection shape of the polarizing plate 10 is, for example, a rectangle or a square square, but is not limited to a square shape, and may be a circular shape.

When the polarizing plate 10 is directly cut from the strip-shaped polarizing plate 12 or when the polarizing plate intermediate body 22 is cut, the number of the polarizing plate 10 and the polarizing plate intermediate body 22 is plural, that is, not limited to two or more, and may be one slice. Similarly, when the polarizing plate 10 is directly cut from the sheet-shaped polarizing plate 16 or when the polarizing plate intermediate body 22 is cut, the number of the polarizing plate 10 and the polarizing plate intermediate body 22 is plural, that is, not limited to two or more. It can also be a piece.

An example of the driving method of the liquid crystal panel to which the polarizing plate 10 is applied is not limited to the VA type and the IPS type. For example, the driving method of the liquid crystal panel to which the polarizing plate 10 is applied may also be TN (Twisted). Nematic) way.

10‧‧‧Polar plate

S _A ‧‧‧Absorption axis

S _T ‧‧‧ Transmission axis

Claims (11)

A method for producing a polarizing plate, which is a method for producing a polarizing plate having a direction in which an absorption axis is directed in a predetermined direction, the manufacturing method comprising: an original plate absorption axis detecting step of detecting a direction of the absorption axis in a polarizing plate original plate, and Processing step of processing the polarizing plate of the polarizing plate to obtain a polarizing plate; the processing step has an intermediate cutting step of cutting the intermediate portion of the polarizing plate from the original plate of the polarizing plate, and detecting the middle of the absorption axis direction of the intermediate portion of the polarizing plate a step of detecting the body absorption axis and a step of cutting the end surface of the polarizing plate intermediate body; and in the intermediate cutting step, the absorption axis direction of the original plate of the polarizing plate detected in the absorption axis detecting step of the original plate is In the same manner as in the polarizing plate intermediate body, the polarizing plate original plate is cut and processed, and in the step of cutting the end surface of the polarizing plate intermediate body, the aforementioned detection in the intermediate absorption axis detecting step is performed. The direction of the absorption axis of the polarizing plate intermediate body, facing the aforementioned predetermined direction in the polarizing plate to be obtained , Machining the end face of the intermediate polarizer. The method for producing a polarizing plate according to claim 1, further comprising a sheet-like cutting step of cutting the sheet-shaped polarizing plate of the polarizing plate original plate from the strip-shaped polarizing plate. A method of manufacturing a polarizing plate according to claim 1, wherein The polarizing plate original plate is a strip-shaped polarizing plate. The method for producing a polarizing plate according to claim 2, wherein the strip-shaped polarizing plate comprises a uniaxially extending polarizing layer. The method for producing a polarizing plate according to claim 3, wherein the strip-shaped polarizing plate comprises a uniaxially extending polarizing layer. The method for producing a polarizing plate according to claim 4, wherein the strip-shaped polarizing plate has a width of 1000 mm or more. The method for producing a polarizing plate according to claim 5, wherein the strip-shaped polarizing plate has a width of 1000 mm or more. The method for producing a polarizing plate according to any one of claims 1 to 7, wherein the planar projection shape of the polarizing plate is a rectangle or a square, and a length of a diagonal of the polarizing plate is 350 mm or less. . The method for producing a polarizing plate according to any one of the first to seventh aspects, wherein the polarizing plate is a polarizing plate for a liquid crystal panel of a VA type or an IPS type. The method for producing a polarizing plate according to claim 8, wherein the polarizing plate is a polarizing plate for a liquid crystal panel of a VA type or an IPS type. A method of manufacturing a liquid crystal panel, wherein the polarizing plate is manufactured by the method for producing a polarizing plate according to any one of claims 1 to 10, and the polarizing plate obtained is attached to the liquid crystal cell. And manufacturing a liquid crystal panel.