JP2005292238A - Polarizing plate, display device using the same, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate which effectively restricts light leakage therefrom, even when exposed to a high-temperature and high-humidity atmosphere. <P>SOLUTION: A polarizing plate 10 is provided with a polarizing layer 11, made of a hydrolyzable resin and a pair of protection layers 12, provided on both sides of the polarizing layer 11. A hole, reaching the polarizing layer 11 from one of the pair of protection layers 12, is formed in the thickness direction, and a moisture absorption control layer 16 for controlling moisture absorption from an exposed part of the polarizing layer 11 in the hole is provided and is formed by cashew lacquer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polarizing plate including a polarizing layer made of a hydrolyzable resin and a pair of protective layers provided on both sides of the polarizing layer, a display device using the polarizing plate, and a method for manufacturing the same.

  In a liquid crystal display device, a liquid crystal panel, which is a light valve, is sandwiched between a pair of polarizing plates. Polarizing plates are generally affixed to glass substrates, but if foreign matter such as dust is sandwiched between them, that part becomes a bright spot or black spot, resulting in poor display quality. A correction is made by making a hole.

  Patent Document 1 discloses a liquid crystal display device in which a polarizing plate is bonded to the surface of a liquid crystal panel having a liquid crystal layer interposed between substrate members, and a light source is disposed on the opposite side of the polarizing plate from the liquid crystal panel. , With respect to the bright spot defect picture element, the light from the light source is on the optical path passing through the bright spot defect picture element, for example, near the surface of the first protective film opposite to the liquid crystal panel of the polarizing plate, Forming a concave recessed portion, and further forming a second protective film covering the recessed processed portion, the incident light and the emitted light are scattered by the recessed processed portion, and the bright spot defect picture element becomes inconspicuous, It is disclosed that the second protective film improves the mechanical strength of the polarizer and prevents the transmittance and the degree of polarization from decreasing. And according to this, even when a concave portion is formed on the polarizing plate in order to correct the bright spot defect picture element, the mechanical strength, the transmittance and the polarization degree are not lowered, and stable display characteristics are obtained. It is described that can be obtained.

In Patent Document 2, a light transmissive film made of a polarizing plate or a phase difference plate is pasted on the image display surface of an image display device in advance, and a laser beam is applied to a portion of the light transmissive film corresponding to a pixel having a white point defect. It is disclosed to reduce the light transmittance of this part by applying, thereby making the white spot defect inconspicuous. And, according to this, it is described that, in an image display device such as a liquid crystal display panel, when a white spot defect in which a certain pixel always becomes a white spot occurs, this can be corrected by a simple and rational method. Has been.
JP-A-8-248367 JP 9-325332 A

  By the way, when a polarizing plate in which holes are formed in a correction necessary place or a polarizing plate in which the holes are filled with a resin filler is exposed to an atmosphere of high temperature and high humidity, as shown in FIG. As a result, there is a problem that a light leaking portion b is generated centering on and expands with time.

  The present invention has been made in view of the above problems, and its object is to provide a polarizing plate in which light leakage is effectively regulated even when exposed to an atmosphere of high temperature and high humidity, and It is providing the display apparatus using this, and its manufacturing method.

  The polarizing plate generally has a polarizing layer formed of a hydrolyzable resin such as a polyvinyl alcohol (PVA) film, and both sides of the polarizing layer are covered with a protective layer of triacetyl cellulose, and one surface is an adhesive layer. And it becomes the structure coat | covered with the release film. The present inventor, when the polarizing plate is exposed to an atmosphere of high temperature and high humidity, the polarizing layer of the PVA film exposed from the hole absorbs moisture, so that the polarizing layer is hydrolyzed and the polarizing function is lost. Even if the hole is filled with a resin filler, the resin filler of vinyl resin or epoxy resin has a high hygroscopic property, so that the polarizing layer is interposed through it. Based on the hypothesis that it absorbs moisture or absorbs moisture due to direct contact with air due to low adhesion to the polarizing plate, and therefore the polarizing layer hydrolyzes and loses the polarizing function. Thus, the present invention has been conceived.

The present invention for achieving the above object is a polarizing plate comprising a polarizing layer comprising a hydrolyzable resin and a pair of protective layers provided on both sides of the polarizing layer,
A hole reaching the polarizing layer from one side of the pair of protective layers is formed in the thickness direction, and a moisture absorption regulating layer for regulating moisture absorption from the exposed portion of the polarizing layer in the hole is provided,
The moisture absorption regulation layer is formed of cashew lacquer.

  According to the above configuration, the cashew lacquer forming the moisture absorption regulating layer has low moisture permeability and high adhesion, so even when the polarizing plate is exposed to an atmosphere of high temperature and high humidity, Moisture absorption is thereby regulated, and thus light leakage associated with loss of polarization function due to its hydrolysis can be effectively regulated.

  The structure of the moisture absorption regulating layer is not particularly limited, and even if it is a structure provided so as to block the opening of the hole, it is also provided so as to cover the exposed portion of the polarizing layer in the hole. It may be a configuration.

  The polarizing plate of the present invention is provided on the surface of a display device such as a liquid crystal display device.

  The display device of the present invention may correct a correction required portion on the display device along the following steps. That is, in the correction necessary point discovery step, the correction necessary portion of the polarizing plate provided on the surface is found, and in the punching step, the hole reaching the polarizing layer from the outside to the correction necessary point discovered in the correction necessary point discovery step. In the moisture absorption regulation layer installation step, a moisture absorption regulation layer that regulates moisture absorption from the exposed portion of the polarizing layer in the hole formed in the perforation process is provided, and at that time, the moisture absorption regulation layer is formed of cashew lacquer. That's fine.

  According to the present invention, the cashew lacquer forming the moisture absorption regulating layer has low moisture permeability and high adhesion to the polarizing plate, so that the moisture absorption of the polarizing layer is regulated thereby, and therefore the polarization function by its hydrolysis. It is possible to effectively regulate light leakage due to loss of light.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a schematic configuration of a liquid crystal display device 100 according to the first embodiment.

  The liquid crystal display device 100 has a configuration in which a liquid crystal panel 110 that is a light valve is sandwiched between a pair of polarizing plates 10.

  FIG. 2 shows a cross section of the surface layer of the liquid crystal display device 100.

  In the liquid crystal display device 100, the polarizing plate 10 is generally formed with a polarizing layer 11 of a hydrolyzable resin such as a polyvinyl alcohol (PVA) film, and both sides of the polarizing layer 11 are protective layers 12 of triacetyl cellulose. In addition, one surface is covered with an adhesive layer 14. And the polarizing plate 10 is stuck on the glass substrate 20 through the adhesive material layer 14.

  In this liquid crystal display device 100, a defect is corrected at a predetermined location (the outer diameter in front view is several hundred microns), and the cashew lacquer moisture absorption regulation layer 16 is filled in the through-hole 15 at the predetermined location. It has been configured. A specific procedure for correcting the defect will be described below.

<Fixed point discovery process>
First, as shown in FIG. 3 (a), a correction required portion where a bright spot is generated is found and specified for the polarizing plates 10 on both sides of the liquid crystal panel 110. Such a correction-necessary portion is a portion where a foreign substance 30 such as dust is sandwiched between the glass substrate 20 and the polarizing plate 10, and becomes a defect in the state as it is.

<Punching process>
By applying a laser beam from the outside to the necessary correction point discovered in the necessary correction point discovery step, a through-hole 15 that reaches the glass substrate 20 is formed as shown in FIG. At this time, the polarizing layer 11 and the protective layer 12 are exposed on the hole surface.

<Hygroscopic regulation layer installation process>
By filling and drying cashew lacquer (for example, # 260 black manufactured by Cashew Co., Ltd.) that absorbs moisture into the through holes 15 formed in the drilling step, the moisture absorption regulating layer 16 is formed as shown in FIG. Form. The moisture absorption regulating layer 16 regulates moisture absorption from the exposed portion of the polarizing layer 11 in the through hole 15.

  If it is the polarizing plate 10 and the liquid crystal display device 100 of such a structure, since the cashew lacquer which forms the moisture absorption regulation layer 16 has low moisture permeability, and the adhesiveness to the polarizing plate 10 is high, the polarizing plate 10 is high. Even when exposed to an atmosphere of temperature and high humidity, moisture absorption of the polarizing layer 11 is regulated thereby, and thus light leakage due to loss of polarization function due to hydrolysis can be effectively regulated.

(Embodiment 2)
FIG. 4 shows a cross section of the surface layer of the liquid crystal display device according to the second embodiment. In addition, about the part of the same name as the thing of Embodiment 1, it shows with the same code | symbol as Embodiment 1. FIG.

  In this liquid crystal display device, defects at a predetermined location are corrected, and a cashew lacquer moisture absorption restricting layer 16 covering the inner surface of the through-hole 15 drilled at the predetermined location is formed. The hole 15 is filled with a filler 17 such as carbon, and an ink layer 18 is provided so as to close the opening of the through hole 15.

  As shown in FIG. 5 (a), such defect correction is performed by applying a cashew lacquer to the inner surface of the through-hole 15 and drying it to cover the moisture absorption regulation layer in the first embodiment. After forming the regulation layer 16, as shown in FIG. 5B, the through hole 15 is filled with a filler 17 such as carbon, and further, as shown in FIG. 5C, the opening of the through hole 15 is opened. The ink layer 18 may be formed by applying and drying the ink so as to block the ink.

  Other configurations are the same as those of the first embodiment.

(Embodiment 3)
FIG. 6 shows a cross section of the surface layer of the liquid crystal display device according to the third embodiment. In addition, about the part of the same name as the thing of Embodiment 1, it shows with the same code | symbol as Embodiment 1. FIG.

  In this liquid crystal display device, a defect is corrected at a predetermined location, a filler 17 such as carbon is filled in the through-hole 15 drilled at the predetermined location, and the opening of the through-hole 15 is further opened. A cashew lacquer moisture absorption restricting layer 16 is provided so as to be closed.

  Such defect correction is performed by filling the through hole 15 with a filler 17 such as carbon, as shown in FIG. As shown in FIG. 4, the moisture absorption regulating layer 16 may be formed by applying cashew lacquer and drying so as to block the opening of the through hole 15.

  Other configurations are the same as those of the first embodiment.

(Other embodiments)
In the first to third embodiments, the through hole 15 is formed in the polarizing plate 10, but is not particularly limited thereto, and a bottomed concave hole 19 reaching the polarizing layer 11 is formed as shown in FIG. 8. May be.

  INDUSTRIAL APPLICATION This invention is useful about the polarizing plate provided with the polarizing layer which consists of a hydrolysable resin, and a pair of protective layer provided in the both sides of the polarizing layer, a display apparatus using the same, and its manufacturing method.

1 is a diagram illustrating a schematic configuration of a liquid crystal display device according to Embodiment 1. FIG. 3 is a diagram illustrating a cross section of a surface layer of the liquid crystal display device according to Embodiment 1. FIG. It is explanatory drawing which shows the defect correction method of Embodiment 1. FIG. 6 is a diagram showing a cross section of a surface layer of a liquid crystal display device according to Embodiment 2. FIG. It is explanatory drawing which shows the defect correction method of Embodiment 2. It is a figure which shows the cross section of the surface layer of the liquid crystal display device which concerns on Embodiment 3. FIG. It is explanatory drawing which shows the defect correction method of Embodiment 3. It is a figure which shows the cross section of the surface layer of the liquid crystal display device of other embodiment. It is explanatory drawing which shows the light leakage of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Polarizing plate 11 Polarizing layer 12 Protective layer 14 Adhesive material layer 15 Through-hole 16 Hygroscopic regulation layer 17 Filler 18 Ink layer 19 Bottomed recessed hole 20 Glass substrate 30 Foreign material 100 Liquid crystal display device 110 Liquid crystal panel

Claims (5)

A polarizing plate comprising a polarizing layer made of a hydrolyzable resin and a pair of protective layers provided on both sides of the polarizing layer,
A hole reaching the polarizing layer from one side of the pair of protective layers is formed in the thickness direction, and a moisture absorption regulating layer for regulating moisture absorption from the exposed portion of the polarizing layer in the hole is provided,
A polarizing plate, wherein the moisture absorption regulating layer is formed of cashew lacquer. In the polarizing plate according to claim 1,
A polarizing plate, wherein the moisture absorption regulating layer is provided so as to block the opening of the hole. In the polarizing plate according to claim 1,
The polarizing plate, wherein the moisture absorption regulating layer is provided so as to cover an exposed portion of the polarizing layer in the hole. A polarizing plate comprising a polarizing layer made of a hydrolyzable resin and a pair of protective layers provided on both sides of the polarizing layer, a display device provided on the surface,
In the polarizing plate, a hole reaching the polarizing layer from one side of the pair of protective layers is formed in the thickness direction, and a moisture absorption regulating layer for regulating moisture absorption from an exposed portion of the polarizing layer in the hole is provided. A display device provided, wherein the moisture absorption regulating layer is formed of cashew lacquer. A polarizing plate comprising a hydrolyzable resin, and a pair of protective layers provided on both sides of the polarizing layer, a method for producing a display device having a polarizing plate provided on the surface,
A necessary correction point finding process for finding a necessary correction point of the polarizing plate provided on the surface,
A perforation step for forming a hole reaching the polarizing layer from the outside in the correction necessary portion found in the correction necessary portion discovery step;
A moisture absorption regulating layer installation step for providing a moisture absorption regulating layer for regulating moisture absorption from the exposed portion of the polarizing layer in the hole formed in the perforation step;
With
A method for manufacturing a display device, wherein the moisture absorption regulating layer is formed of cashew lacquer.

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