JP5756283B2 - Manufacturing method of display device - Google Patents

Description

  The present invention relates to a method for manufacturing a display device.

As a display device, a light emitting side of a substrate on which a display element is formed (a plurality of pixels arranged along the main surface of the substrate; hereinafter referred to as “display element substrate”) is formed along the main surface. There is a polarizing plate having a transmission axis in a specific direction and a retardation plate having a slow axis that intersects the transmission axis along the main surface in this order. Conventionally, when manufacturing such a display device, a manufacturing method is known in which a polarizing plate and a retardation plate are first bonded, and then disposed on the light emitting side of the display element substrate (for example, Non-Patent Document 1 (see Itakura et al., “Optical Films, Sheets, and Technology Complete Collection Focusing on Liquid Crystal Displays and Touch Panels”, Technical Information Association, Inc., September 30, 2008, p. 114-116).
)).

Itakura et al., “Complete Collection of Optical Films, Sheets, and Technology Focusing on Liquid Crystal Displays and Touch Panels”, Technical Information Association, Inc., September 30, 2008, p. 114-116

  However, the above manufacturing method has a problem that the productivity of the display device is not good.

  Accordingly, an object of the present invention is to provide a display device manufacturing method that can easily manufacture a display device including a polarizing layer and a retardation layer on the light emitting side of a display element substrate, and can improve productivity. .

In order to solve the above problems, a manufacturing method of a display device according to the present invention includes:
A display element substrate having a plurality of pixels arranged along a main surface; a polarizing layer disposed on a light emitting side of the display element substrate and having a transmission axis in a specific direction along the main surface; and the polarizing layer A display device manufacturing method for manufacturing a display device that includes a retardation layer that is disposed on the light emitting side of the light source and has a slow axis that intersects the transmission axis along the main surface,
It includes the following steps (1) to (4).
(1) A step of forming the polarizing layer along the main surface on the light emitting side of the display element substrate. (2) On the polarizing layer formed in the step (1), the retardation layer is formed. A step of forming an alignment film having a function of aligning the liquid crystalline component of the liquid crystal composition as a material in an alignment direction corresponding to the direction of the slow axis (3) on the alignment film formed in the step (2) A liquid crystal composition containing a polymerizable liquid crystal compound is applied to form a coating film, and the coating film is held at a temperature at which the liquid crystalline component of the liquid crystal composition exhibits a liquid crystal phase. Step (4) aligning in the orientation direction corresponding to the direction of the slow axis (4) By polymerizing the polymerizable liquid crystal compound forming the liquid crystalline component formed in the step (3) while maintaining the orientation direction, Step of forming the retardation layer

  According to the display device manufacturing method of the present invention, a display device including a polarizing layer and a retardation layer on the light emitting side of the display element substrate can be easily manufactured, and productivity can be improved.

  In this specification, the “display element substrate” means a substrate in which a plurality of pixels are arranged along the main surface of the substrate.

  The “main surface” of the display element substrate means a surface (a surface different from the end surface) having a spread of the substrate.

  A plurality of “pixels” means elements that can be turned on / off for light transmission, reflection, or light emission by being driven by electrical signals. As such display elements having a plurality of pixels, display elements having a light emitting layer such as liquid crystal display elements, organic electroluminescence (EL) display elements, plasma display elements, field emission display elements, and surface-conduction electron emission elements. Can be mentioned.

  The “light emitting side” of the display element substrate refers to a side where light should be emitted from the display element substrate in the manufactured display device. Which is the “light emitting side” is determined according to the configuration of the display element substrate before the step (1) is performed.

  The “polarizing layer” refers to an object having a function of selectively transmitting linearly polarized light in one direction (direction of the transmission axis) from natural light.

  The “retardation layer” refers to an object that transmits light and has birefringence. The phase difference layer is used for converting linearly polarized light into circularly polarized light or elliptically polarized light, or conversely converting circularly polarized light or elliptically polarized light into linearly polarized light by combining with a polarizing layer.

  The method for manufacturing a display device according to an embodiment includes a step of forming an antireflection layer for preventing reflection of external light on the light emitting side of the retardation layer.

  According to the manufacturing method of the display device of this embodiment, the antireflection layer in the manufactured display device can reduce the generation of reflected light derived from external light, and can be used for original display from the display element substrate. Interference between the emitted light and the reflected light can be suppressed. As a result, display characteristics can be improved. Furthermore, the retardation layer can be protected by the antireflection layer.

  In the display device manufacturing method of one embodiment, the plurality of pixels of the display element substrate constitute a liquid crystal display element.

  According to the method for manufacturing a display device of this embodiment, a liquid crystal display device capable of displaying an excellent stereoscopic image is manufactured.

  According to the display device manufacturing method of the present invention, a display device including a polarizing layer and a retardation layer on the light emitting side of the display element substrate can be easily manufactured, and productivity can be improved.

It is a figure which shows schematic structure of the liquid crystal display device which should be produced by the manufacturing method of one Embodiment of this invention. It is a figure which shows schematic structure of another liquid crystal display device which should be produced by the said manufacturing method. In the said liquid crystal display device, it is a figure which shows typically the correspondence of the arrangement | positioning between the some pixel, polarizing layer, and phase difference layer which were arranged on the display element board | substrate.

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

  FIG. 1 shows a schematic cross-sectional configuration of a liquid crystal display device (the whole is denoted by reference numeral 51A) as an example of a display device to be manufactured by the manufacturing method of one embodiment of the present invention.

  In this liquid crystal display device 51A, a polarizing plate 53, a display element substrate 54 on which a liquid crystal display element is formed, a polarizing layer 55, an alignment film 56, and a retardation layer 57 are arranged in this order from the backlight 52 side (also referred to as the back surface). Configured. A polarizing plate 53 and a polarizing layer 55 are provided before and after the display element substrate 54, and an alignment film 56 and a retardation layer 57 are provided on the polarizing layer 55 on the side opposite to the display element substrate 54 (light emission side). .

  The backlight 52 is a surface light source that emits natural light, and includes a well-known white LED (light emitting diode) and a light scattering plate (not shown) in this example. Instead of the white LED, a cold cathode ray tube may be used.

  The polarizing plate 53 has a transmission axis (not shown) in a specific direction along the plate surface. The polarizing plate 53 selectively transmits one-way linearly polarized light along the transmission axis to the display element substrate 54 side F among the natural light generated by the backlight 52.

  As shown in FIG. 3, the display element substrate 54 has a plurality of rectangular pixels A1, A2,...; B1, B2,. In this example, the plurality of pixels A1, A2,..., B1, B2,. The plurality of pixels A1, A2,...; B1, B2,. As a result, the linearly polarized light transmitted through the polarizing plate 53 and incident on the display element substrate 54 is transmitted or blocked to the light emitting side F of the display element substrate 54 for each of the pixels A1, A2,. It has come to be.

  The polarizing layer 55 has a transmission axis 70a in a specific direction along the main surface 50 (oriented obliquely at 45 degrees with respect to the horizontal direction as schematically shown in FIG. 3). In this example, the transmission axis 70 a of the polarizing layer 55 is set in a direction orthogonal to the transmission axis (not shown) of the polarizing plate 53. The polarizing layer 55 transmits the component of the light transmitted through the display element substrate 54 along the direction of the transmission axis 70 a to the light emitting side F.

  The retardation layer 57 has a slow axis 71 a that intersects the transmission axis 70 a at a certain angle along the main surface 50. As schematically shown in FIG. 3, the slow axis 71a of the retardation layer 57 is oriented in the vertical direction. That is, when viewed from the light emitting side F, the slow axis 71a of the retardation layer 57 intersects at 45 degrees with respect to the direction of the transmission axis 70a of the polarizing layer 55 (this is assumed to be 0 degrees). . With such an arrangement, the retardation layer 57 converts the linearly polarized light from the polarizing layer 55 into circularly polarized light and emits it to the light emitting side F.

  The manufacturing method of the present invention includes a step of forming the polarizing layer 55 on the light emitting side of the display element substrate 54 as the step (1).

  As the polarizing layer 55, the layer obtained by apply | coating the liquid crystal composition containing the layer which bonded the film-shaped polarizing plate with the adhesive agent, for example, and a dichroic dye is mentioned.

  As a polarizing plate used when the polarizing layer 55 is formed by bonding, for example, an iodine polarizing plate in which iodine is adsorbed and oriented on a polyvinyl alcohol film, or a dichroic dye is adsorbed on a polyvinyl alcohol film. -An oriented dye-type polarizing plate, a coating type polarizing plate coated with a dichroic dye in a lyotropic liquid crystal state, oriented and fixed, and the like. Among these, an iodine polarizing plate is preferable because of its excellent polarization degree and transmittance. Examples of the iodine-based polarizing plate include polarizing plates described in Japanese Patent No. 3770862 and Japanese Patent No. 4432487.

  Examples of the adhesive used for the bonding include an adhesive having, as an adhesive component, a polyvinyl alcohol resin, an epoxy resin, a urethane resin, a cyanoacrylate resin, an acrylamide resin, and the like. The material described in -77224 gazette is mentioned. In addition, as a method of bonding a polarizing plate, you may bond after providing an adhesive bond layer in the polarizing plate side, or you may bond after providing an adhesive bond layer in the display element board | substrate 54 side. . Moreover, as a method of bonding a polarizing plate, you may carry out by the method as described in Unexamined-Japanese-Patent No. 2010-276754 or Unexamined-Japanese-Patent No. 2010-276755. In the present specification, the adhesive includes an adhesive.

  When the polarizing layer 55 is formed of a liquid crystal composition containing a dichroic dye, the liquid crystal composition containing a dichroic dye includes a liquid crystal composition containing a dichroic dye having liquid crystallinity, a liquid crystal compound, and two colors. Liquid crystal composition containing a functional dye. The polarizing layer 55 can be formed by applying the liquid crystal composition to the display element substrate 54 and drying it. When the liquid crystal compound and / or dichroic dye is a compound having a polymerizable group, the film after drying is irradiated with light or heated to polymerize the compound having the polymerizable group in the film, It is preferable in terms of durability of the polarizing layer 55. Examples of a method for forming the polarizing layer 55 using a liquid crystal composition containing a dichroic dye include the methods described in Japanese Patent Application Publication No. 2007-510946 and Japanese Patent No. 3492893.

  The production method of the present invention includes a step of forming an alignment film 56 on the polarizing layer 55 formed in the step (1) as the step (2).

  The alignment film 56 has a function of aligning liquid crystal components of a liquid crystal composition, which is a material of the retardation layer 57 formed in a later step, in an alignment direction corresponding to the direction of the slow axis 71a (alignment regulating force). It has.

  As a method of forming the alignment film 56, a method using an alignment polymer to which an alignment regulating force is imparted by rubbing (hereinafter sometimes referred to as “rubbing method”), an alignment regulating force is imparted by irradiating polarized light. A method using a photo-alignable polymer (hereinafter sometimes referred to as “photo-alignment method”), a method of obliquely depositing silicon oxide on a substrate surface, and a long-chain alkyl group using a Langmuir-Blodgett method (LB method). Examples thereof include a method for forming a monomolecular film. Among these, from the viewpoint of alignment uniformity of the liquid crystal composition, processing time, and processing cost, a rubbing method and a photo-alignment method are preferable, and a photo-alignment method is more preferable. As the alignment film 56, solvent resistance to the extent that it does not dissolve in the solvent contained in the liquid crystal composition (which will be the material of the retardation layer 57 formed in the subsequent process) applied in a subsequent process thereon, removal of the solvent It preferably has heat resistance to heat treatment such as liquid crystal alignment and adhesion to the substrate.

  When the alignment film 56 is formed by the rubbing method, the alignment polymer used in the rubbing method is, for example, polyamide or gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, or a hydrolyzate thereof. A polymer such as a certain polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters can be mentioned. Commercial products such as Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) or Optmer (registered trademark, manufactured by JSR Corporation) may be used.

  When the alignment film 56 is formed by a photo-alignment method, examples of the photo-alignment polymer used for the photo-alignment method include a polymer having a photosensitive structure. When a polymer having a photosensitive structure is irradiated with polarized light, the photosensitive structure in the irradiated portion is isomerized or cross-linked so that the photo-alignable polymer is aligned, and an alignment regulating force is imparted to the film made of the photo-alignable polymer. The Examples of the photosensitive structure include an azobenzene structure, a maleimide structure, a chalcone structure, a cinnamic acid structure, a 1,2-vinylene structure, a 1,2-acetylene structure, a spiropyran structure, a spirobenzopyran structure, and a fulgide structure. . These polymers may be used alone or in combination of two or more. These polymers are obtained by using a monomer having a photosensitive structure by polycondensation such as dehydration or deamination, chain polymerization such as radical polymerization, anionic polymerization, or cationic polymerization, coordination polymerization, or ring-opening polymerization. be able to. Moreover, the copolymer which consists of multiple types of monomer which has a different photosensitive structure may be sufficient. Examples of such photo-alignable polymers include Japanese Patent No. 4450261, Japanese Patent No. 4011652, Japanese Patent Application Laid-Open No. 2010-49230, Japanese Patent No. 444090, Japanese Patent Application Laid-Open No. 2007-156439, and Japanese Patent Application Laid-Open No. 2007-232934. Mention may be made of the photoalignable polymers described.

  The orientation polymer and photo-alignment polymer can be applied after being dissolved in a solvent. The solvent is not particularly limited, and specifically, alcohol solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether or propylene glycol monomethyl ether; ethyl acetate, Ester solvents such as butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate or ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone or methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as hexane or heptane; aromatic hydrocarbon solvents such as toluene or xylene; Le solvent; chlorinated solvents chloroform or chlorobenzene; ethers solvent such as tetrahydrofuran or dimethoxyethane, and the like. These organic solvents may be used alone or in combination.

  In order to form the alignment film 56, first, the alignment polymer or the photo-alignment polymer solution is applied onto the polarizing layer 55 formed in the step (1). Application methods include, for example, extrusion coating method, direct gravure coating method, reverse gravure coating method, CAP (cap) coating method, die coating method, ink jet method, dip coating method, slit coating method, spin coating method, and bar coater. Application etc. are mentioned. Among these, application by a CAP coating method, an inkjet method, a dip coating method, a slit coating method, and a bar coater is preferable in that damage to the display element can be suppressed.

  After applying the alignment polymer or photoalignment polymer solution, the solution is dried to remove low-boiling components such as a solvent from the applied film.

  Examples of the drying method include natural drying, ventilation drying, and reduced pressure drying. The specific drying temperature is preferably 10 to 250 ° C, and more preferably 25 to 200 ° C. Further, the drying time is preferably 5 seconds to 60 minutes, more preferably 10 seconds to 30 minutes. When the drying temperature and the drying time are within the above ranges, damage to the display element substrate 54 and the polarizing layer 55 can be suppressed.

  Next, when the liquid crystal composition is laminated on the alignment film 56 and aligned, the dried alignment is performed so that the liquid crystalline component of the liquid crystal composition is aligned in the alignment direction corresponding to the direction of the slow axis 71a. An alignment regulating force is imparted to the photopolymer film or the photo-alignable polymer film. As a method for imparting the alignment regulating force, it is preferable to apply a rubbing method and a photo-alignment method to the orientation polymer film after drying.

  In order to apply the alignment regulating force by the rubbing method, for example, a rubbing cloth is wound, and a rotating rubbing roll is placed on the stage and brought into contact with the dried oriented polymer film.

  In order to form the alignment film 56 by the rubbing method, a rubbing process in the rubbing process direction corresponding to the direction of the slow axis 71a is performed on the entire surface (light emission side) of the oriented polymer film after drying. By this rubbing treatment, the direction of the orientation regulating force over the entire surface is made to correspond to the rubbing treatment direction corresponding to the direction of the slow axis 71a. Thereby, the alignment film 56 having an alignment regulating force for aligning the liquid crystalline component of the liquid crystal composition, which is a material of the retardation layer 57 formed in a later process, in the alignment direction according to the direction of the slow axis 71a is obtained. can get.

  In order to impart the alignment regulating force by the photo-alignment method, polarized light irradiation (for example, linearly polarized ultraviolet light) is performed on the photo-alignable polymer film after drying. The polarized light irradiation can be performed using, for example, an apparatus described in JP-A-2006-323060. For example, irradiation of polarized light (for example, linearly polarized ultraviolet light) according to the direction of the slow axis 71a is performed on the entire surface (light emitting side) of the photo-alignable polymer film after drying. An alignment film 56 having an alignment regulating force that aligns the liquid crystalline components of the liquid crystal composition, which is a material of the retardation layer 57 formed in a later step, in an alignment direction corresponding to the direction of the slow axis 71a is obtained.

  The film thickness of the alignment film 56 is, for example, 10 nm to 10000 nm, and preferably 10 nm to 1000 nm. If it is set as such a range, the liquid crystalline component contained in a liquid-crystal composition can be orientated to a desired angle by a post process.

  In the production method of the present invention, as the step (3), a liquid crystal composition containing a polymerizable liquid crystal compound is applied on the alignment film 56 formed in the step (2) to form a coating film. Is held at a temperature at which the liquid crystal component of the liquid crystal composition exhibits a liquid crystal phase, and the liquid crystal component is aligned in an alignment direction corresponding to the direction of the slow axis 71a.

  The liquid crystal composition preferably contains a polymerization initiator, a solvent and the like in addition to the polymerizable liquid crystal compound. In such a case, in this step (3), a film from which the solvent has been removed is formed from the coating film obtained by applying the liquid crystal composition, and then the liquid crystal contained in the film from which the solvent has been removed. The sex component is oriented.

  As the polymerizable liquid crystal compound contained in the liquid crystal composition, chapter 3 of the liquid crystal handbook (edited by the Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd., October 30, 2000) 3.2 of the molecular structure and liquid crystallinity. Non-chiral rod-like liquid crystal molecules, 3.3 Compounds having a polymerizable group among the compounds described in Chiral rod-like liquid crystal molecules, polymerizable liquid crystal compounds disclosed in JP 2010-31223 A, and the like. These polymerizable liquid crystal compounds may be used alone or in combination.

  As described above, the liquid crystal composition used in the production method of the present invention preferably contains a solvent.

  The solvent may be any solvent that dissolves the components contained in the liquid crystal composition and is inert to the polymerization reaction of the polymerizable liquid crystal compound. Specifically, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, Alcohol solvents such as ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol monomethyl ether or phenol; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate or ethyl lactate; acetone , Ketone solvents such as methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone or methyl isobutyl ketone; fats such as pentane, hexane or heptane Family hydrocarbon solvent; toluene or an aromatic hydrocarbon solvent such as xylene, nitrile solvents such as acetonitrile; ethers solvent such as tetrahydrofuran or dimethoxyethane; chlorinated solvents chloroform or chlorobenzene; and the like. These solvents may be used alone or in combination.

  As for the usage-amount of a solvent, 50-95 mass% is preferable with respect to a liquid-crystal composition. Conversely, the solid content in the liquid crystal composition is preferably 5 to 50% by mass. When the solid content concentration is 5% by mass or more, the thickness of the obtained retardation layer 57 does not become too thin, and a birefringence necessary for polarization conversion tends to be provided. Further, when the content is 50% by mass or less, since the viscosity of the liquid crystal composition is low, the film thickness of the retardation layer 57 tends not to be uneven. Here, solid content is content of the component remove | excluding the solvent from the composition with respect to the composition whole quantity.

  The viscosity of the liquid crystal composition is preferably adjusted to 10 mPa · s or less, more preferably 0.1 to 7 mPa · s so that it can be easily applied.

  As described above, the liquid crystal composition used in the production method of the present invention preferably contains a polymerization initiator.

  Examples of the polymerization initiator include a thermal polymerization initiator, a photopolymerization initiator, and the like. Since there is a tendency that a polymerizable liquid crystal compound can be polymerized at a low temperature, a photopolymerization initiator is preferable.

  Examples of the photopolymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts.

  As photopolymerization initiators, Irgacure 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369 (all are manufactured by Ciba Japan Co., Ltd.), Sake All BZ, Sequol Z, Sequol BEE (and above) All manufactured by Seiko Chemical Co., Ltd.), kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), Adekaoptomer SP-152, Adekaoptomer SP-170 (above Commercially available photopolymerization initiators such as TAZ-A, TAZ-PP (manufactured by Nippon Shibel Hegner) or TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.) can also be used.

  The liquid crystal composition used in the production method of the present invention may contain additives such as a chiral agent, a polymerization inhibitor, a photosensitizer, and a leveling agent as necessary.

  As the chiral agent, “Liquid Crystal Device Handbook” (Chapter 3, Section 4-3, TN, Chiral Agent for STN, 199 pages, edited by the 142th Committee of the Japan Society for the Promotion of Science, 1989), JP 2007-269640 A, JP-A 2007-269639, JP-A 2007-176870, JP-A 2003-137879, JP-T 2000-51596, JP-A 2007-169178, JP-A 9-506088, etc. The compounds described are mentioned.

  Examples of the polymerization inhibitor include hydroquinones having a substituent such as hydroquinone or alkyl ether, catechols having a substituent such as alkyl ether such as butylcatechol, pyrogallols, 2,2,6,6-tetramethyl-1 -Radical scavengers such as piperidinyloxy radicals, thiophenols, β-naphthylamines or β-naphthols.

  Examples of the photosensitizer include xanthones such as xanthone and thioxanthone, anthracene having a substituent such as anthracene and alkyl ether, phenothiazine, and rubrene.

  As a leveling agent, for example, an additive for radiation-curing coatings (BYK-352, BYK-353, BYK-361N manufactured by BYK Japan), a coating additive (manufactured by Toray Dow Corning: SH28PA, DC11PA, ST80PA). Paint additives (Shin-Etsu Chemical Co., Ltd .: KP321, KP323, X22-161A, KF6001) or fluorine-based additives (DIC Corporation: F-445, F-470, F-479), etc. be able to.

  In the step (3), the method for applying the liquid crystal composition includes the same method as the method for applying the alignment film 56. Among these, application by a CAP coating method, an inkjet method, a dip coating method, a slit coating method, and a bar coater is preferable in that damage to the display element can be suppressed.

  After applying the liquid crystal composition, it is preferable to remove the solvent contained in the liquid crystal composition as described above.

  The coating film obtained by applying the liquid crystal composition (preferably the film from which the solvent has been removed from the coating film) is maintained at a temperature at which the liquid crystalline component of the liquid crystal composition exhibits a liquid crystal phase. By maintaining the temperature at which the coating film exhibits a liquid crystal phase, the liquid crystalline component contained in the coating film can be aligned and birefringence can be imparted. As temperature to orientate, 0-250 degreeC is preferable and 10-150 degreeC is more preferable.

  In this way, the liquid crystalline component is aligned in the alignment direction corresponding to the direction of the slow axis 71a in accordance with the direction of the alignment regulating force of the alignment film 56.

  In the production method of the present invention, as the step (4), the polymerizable liquid crystal compound forming the liquid crystalline component formed in the step (3) is polymerized while maintaining the alignment direction, thereby the retardation layer. Forming the step 57.

  When the polymerizable liquid crystal compound contained in the liquid crystal composition is a polymerizable liquid crystal compound having a photopolymerizable group, it is preferably polymerized by a photopolymerization method. Moreover, when the polymerizable liquid crystal compound contained in the liquid crystal composition is a polymerizable liquid crystal compound having a thermally polymerizable group, it is preferably polymerized by a thermal polymerization method. Here, the photopolymerizable group means a group capable of polymerizing a compound by light irradiation or a group capable of polymerizing a compound by an active radical or an active acid generated from a polymerization initiator by light irradiation. The thermopolymerizable group refers to a group capable of polymerizing a compound by the action of heat, or a group capable of polymerizing a compound by an active radical or an active acid generated from a polymerization initiator by the action of heat. By carrying out the polymerization in a state where the components contained in the film are oriented, that is, in a state where the components contained in the film exhibit a liquid crystal phase, the retardation layer 57 is formed as a cured film that retains the liquid crystal phase (that is, the orientation direction) Can be obtained.

  In the production method of the present invention, the polymerizable liquid crystal compound is preferably polymerized by a photopolymerization method. According to the photopolymerization method, polymerization can be performed without heating to a high temperature, so that the polarizing layer (polarizing plate) 55 can be prevented from being deformed by heat. In addition, it is easy to manufacture industrially. The photopolymerization method is also preferable from the viewpoint of film formability. Examples of the light source used in the photopolymerization method include visible light, ultraviolet light, and laser light. From the viewpoint of handling, ultraviolet light is preferable. The light irradiation may be performed at a temperature at which the component contained in the film exhibits a liquid crystal phase.

  When the retardation layer 57 formed in the step (4) is a λ / 4 plate (quarter wavelength plate), the retardation value (retardation value) Re (550 nm) is 113 to 163 nm, preferably 135 to The film thickness of the retardation layer 57 is adjusted to 140 nm, particularly preferably about 137.5 nm. When the retardation layer 57 formed in the step (4) is a λ / 2 (half-wave plate) plate, the retardation value Re (550 nm) is 250 to 300 nm, preferably 273 to 277 nm, Particularly preferably, the thickness of the retardation layer 57 is adjusted to be about 275 nm.

The retardation value Re (λ) in the retardation layer 57 can be adjusted by appropriately changing the coating amount of the liquid crystal composition and the content of the polymerizable liquid crystal compound in the liquid crystal composition. Further, since the phase difference value Re (λ) of the obtained phase difference layer 57 is determined as the following equation (X), in order to obtain a desired phase difference value Re (λ), the phase difference value The film thickness d of the layer 57 may be adjusted.
Re (λ) = d × Δn (λ) (X)
(In the formula, Re (λ) represents a retardation value at a wavelength λ (nm), d represents a film thickness, and Δn (λ) represents a birefringence at a wavelength λ (nm).)

  However, the film thickness of the retardation layer 57 to be adjusted is preferably 0.1 to 10 μm, and more preferably 0.5 to 3 μm.

  As a result of the above steps (1) to (4), the polarizing layer 55 and the retardation layer 57 are provided in this order on the light emitting side of the display element substrate 54.

  The liquid crystal display device 51A shown in FIG. 1 is provided with the polarizing layer 55, the alignment film 56, and the retardation layer 57 on the light emitting side of the display element substrate 54 by the above-described manufacturing method, Is prepared by providing a polarizing plate 53 and a backlight 52 on the opposite side by a known method.

  The production method of the present invention preferably further includes a step of forming an antireflection layer for preventing reflection of external light on the light emitting side of the retardation layer 57 formed in the step (4). FIG. 2 shows a schematic cross-sectional configuration of a liquid crystal display device (the whole is denoted by reference numeral 51B) provided with such an antireflection layer 58. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  The material constituting the antireflection layer 58 is not particularly limited, and for example, a layer composed of at least one selected from the group consisting of metals, metal oxides, metal fluorides, fine particles, polymer materials, and the like, and publicly known Antireflection (AR) film, low reflection (LR) film, moth-eye type antireflection film, antireflection layer of these, and the like.

  Examples of the metal include silver. Examples of the metal oxide include silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, yttrium oxide, and zirconium oxide. Examples of the metal fluoride include: Examples thereof include calcium fluoride and magnesium fluoride.

  As fine particles, inorganic fine particles such as barium sulfate, talc, kaolin, calcium sulfate, silica gel, silica gel containing metal fine particles; polymethacrylate methyl acrylate resin fine particles, acrylic styrene resin fine particles, polymethyl methacrylate resin fine particles, silicon resin fine particles, polystyrene Organic fine particles such as resin fine particles, polycarbonate resin fine particles, benzoguanamine resin fine particles, melamine resin fine particles, polyolefin resin fine particles, polyester resin fine particles, polyamide resin fine particles, polyimide resin fine particles, or polyfluoroethylene resin fine particles; JP 2010-84018 A And hollow organic-inorganic hybrid fine particles described in the above.

  Polymer materials include siloxane polymer, bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide and 4-methacryloxyphenyl-4′-methoxyphenyl thioether, fluorine-containing (meth) acrylate, fluorine-containing itaconic acid Polymers such as esters, fluorine-containing maleates, fluorine-containing silicon compounds, polyvinyl alcohol resins, polyvinyl acetal resins such as polyvinyl butyral and polyvinyl formal, cellulose resins such as cellulose acetate butyrate, (meth) acrylic resins such as butyl acrylate , Urethane resin, polyester resin, epoxy resin and the like. A thin film is formed from a polymer material to form an antireflection layer.

  The antireflection layer 58 may be a single layer or a multilayer composed of two layers, three layers, four layers, or more layers. The thickness of the antireflection layer 58 and the thickness of each layer when it is a multilayer are appropriately selected depending on the number of layers, the refractive index of the substance used for each layer, and the like. The antireflection layer 58 is formed by a method in which a solution containing the above material is applied onto the retardation layer 57, or a method in which a film having a layer formed from the above material is bonded onto the retardation layer 57. Can do. As a method for forming the antireflection layer 58, for example, Japanese Patent Application Laid-Open No. 2003-114302, Japanese Patent Application Laid-Open No. 7-56002, Japanese Patent No. 4190337, Japanese Patent No. 4259957, Japanese Patent No. 4032771, Japanese Patent Application Laid-Open No. 2010-122599. The method described is mentioned. Since the display device 51B includes the antireflection layer 58, the generation of reflected light derived from external light can be reduced, and interference between the emitted light for display from the display element substrate 54 and the reflected light is also suppressed. It becomes possible to do. As a result, display characteristics can be improved. Further, the retardation layer 57 can be protected by the antireflection layer 58.

  Furthermore, a known antifouling layer, antistatic layer, and hard coat layer may be formed on the light emitting side of the antireflection layer 58 as necessary.

  The liquid crystal display device 51B shown in FIG. 2 is provided with the polarizing layer 55, the alignment film 56, the retardation layer 57, and the antireflection layer 58 on the light emitting side of the display element substrate 54 by the above-described manufacturing method. A polarizing plate 53 and a backlight 52 are provided on a side opposite to the light emitting side of the light source by a known method.

  The liquid crystal display devices 51A and 51B shown in FIGS. 1 and 2 operate as follows.

  In the liquid crystal display devices 51A and 51B, the backlight 52 generates natural light. The polarizing plate 53 selectively transmits linearly polarized light in one direction out of natural light generated by the backlight 52 to the display element substrate 54 side. As already described with reference to FIG. 3, the linearly polarized light transmitted through the polarizing plate 53 and incident on the display element substrate 54 is generated in a liquid crystal layer (not shown) for each of the pixels A 1, A 2,. The light is transmitted to or blocked from the light emission side F. The polarizing layer 55 transmits the light transmitted through the display element substrate 54 along the direction of the transmission axis 70 a to the light emitting side F. Here, when viewed from the light emitting side F, the slow axis 71a of the retardation layer 57 intersects at 45 degrees with respect to the direction of the transmission axis 70a of the polarizing layer 55 (this is assumed to be 0 degrees). Yes. With such an arrangement, the retardation layer 57 converts the linearly polarized light from the polarizing layer 55 into circularly polarized light and emits it to the light emitting side F.

  In this example, it is assumed that the liquid crystal display devices 51A and 51B alternately display right-eye images and left-eye images as time-division stereoscopic display devices. The observer uses glasses (not shown) in which a circularly polarizing plate is provided on the lens. The circularly polarizing plate used for the glasses includes a polarizing plate having a transmission axis in the same direction as the transmission axis 70 a of the polarizing layer 55 and a retardation plate having a slow axis in a direction orthogonal to the slow axis 71 a of the retardation layer 57. Is a circularly polarizing plate. Thereby, the observer can observe a stereoscopic image.

  Thus, according to the liquid crystal display devices 51A and 51B, a display device capable of displaying a stereoscopic image can be provided.

  When the liquid crystal display element formed as described above is used as the display element substrate, the display element substrate is formed by filling a low molecular liquid crystal composition as a display medium between two substrates. Is done. One of the two substrates is provided with a black matrix, a color filter, a counter electrode, a photo spacer, an alignment film, etc., and the other substrate has a liquid crystal driving electrode, a wiring pattern, a thin film transistor, an alignment film. Etc. are provided.

  Examples of the liquid crystal display device include a transmissive type, a reflective type, and a transflective type. The operation mode of the liquid crystal cell is not particularly limited, and may be any of twisted nematic, vertical alignment, OCB (Optically Compensated), IPS (In-Plane Switching), and the like.

  As a display device manufactured by the manufacturing method of the present invention, in addition to the liquid crystal display device described above, an organic electroluminescence (EL) display device, a plasma display, a field emission display device (field emission display), a surface conduction electron A display device (SED) having an emission element, electronic paper, and the like can be given. When the manufacturing method of the present invention is applied to these other display devices, the display element substrate used in step (1) is formed with display elements constituting these other display devices (a plurality of pixels are arranged). Used).

  For example, when an organic EL display element is used as the display element substrate, an organic film such as an anode and a light emitting layer and a cathode are first laminated on a glass substrate provided with a transparent electrode by vapor deposition. And a wiring pattern is formed. Next, for example, a metal cap (protection plate) formed of SUS, Al, or the like is placed on each organic EL element laminated on the transparent electrode glass, and adhered to the transparent electrode glass with an adhesive. Finally, the transparent electrode glass is divided for each organic EL element. As a method for producing a display element substrate on which an organic EL display element is formed, for example, a method described in Japanese Patent No. 3626728 may be mentioned. A polarizing layer (polarizing plate), an alignment film, and a retardation layer are formed on the light emitting side of the display element substrate on which the organic EL display element is formed by the above steps (1) to (4). Since the polarizing layer (polarizing plate) formed in the step (1) on the display element substrate on which the organic EL display element is formed can suppress external light reflection, it may be a circularly polarizing plate.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and parts by mass.

Example 1
[Production of photo-alignment polymer]
A photo-alignable polymer represented by the formula (A) was produced by the method described in Macromol. Chem. Phys. 197, 1919-1935 (1996) to obtain a polymer having a number average molecular weight of 23,000.

重合性液晶化合物：ＬＣ２４２（ＢＡＳＦ社製、下記式で表される化合物）

重合性開始剤：イルガキュア３６９（ＢＡＳＦジャパン社製）
レベリング剤：ＢＹＫ３６１Ｎ（ビックケミージャパン製）
溶剤：ＰＧＭＥＡ（プロピレングリコール１−モノメチルエーテル２−アセタート、東京化成工業（株）製） [Adjustment of liquid crystal composition]
The components described in Table 1 were mixed to prepare a liquid crystal composition (represented by symbol E).

Polymerizable liquid crystal compound: LC242 (made by BASF, a compound represented by the following formula)

Polymerizable initiator: Irgacure 369 (manufactured by BASF Japan)
Leveling agent: BYK361N (manufactured by Big Chemie Japan)
Solvent: PGMEA (propylene glycol 1-monomethyl ether 2-acetate, manufactured by Tokyo Chemical Industry Co., Ltd.)

(Production of retardation layer)
A polarizing layer 55 was formed on a glass substrate by sticking a polarizing plate (iodine polarizing plate; TRW842AP7; manufactured by Sumitomo Chemical Co., Ltd.) using an adhesive. A 1% by mass cyclopentanone solution of the photoalignable polymer represented by the formula (A) was applied on the polarizing layer 55 and dried to form a film having a thickness of 200 nm. Next, on the obtained film, from a direction perpendicular to the glass substrate surface, using a spot cure with polarized UV irradiation jig (SP-7, manufactured by Ushio Electric Co., Ltd.) for 5 minutes at an intensity of 20 mW / cm ^2. The alignment film 56 was formed by irradiating the linearly polarized light in the direction of 45 degrees with respect to the transmission axis 70 a of the polarizing layer 55. On the alignment film 56, the liquid crystal composition E was applied using a bar coater and heated to 100 ° C. to obtain a film aligned in the liquid crystal phase. After that, the phase difference layer 57 is irradiated by irradiating ultraviolet rays at a wavelength of 365 nm with an intensity of 40 mW / cm ² for 1 minute using UniCure (VB-15201BY-A, manufactured by USHIO INC.) In a state cooled to room temperature. Produced. Next, a glass substrate, a polarizing layer 55, an alignment film 56, a retardation layer 57 and an antireflection layer 58 are laminated by pasting an antireflection film (Dai Nippon Printing Co., Ltd.) on the retardation layer 57. A laminated body was obtained.

(Example 2)
(Production of retardation layer)
In the same manner as in Example 1, the polarizing layer 55 was formed on the glass substrate.

A 2% by weight aqueous solution of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied on the polarizing layer 55 and dried to form a film having a thickness of 89 nm. Subsequently, an alignment film 56 was formed by performing a rubbing process on the surface of the obtained film. The rubbing treatment is performed by using a semi-automatic rubbing apparatus (trade name: LQ-008 type, manufactured by Joyo Engineering Co., Ltd.) with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.). The measurement was performed in the direction of 45 degrees with respect to the transmission axis 70a of the polarizing layer 55 under the conditions of 15 mm, rotation speed 500 rpm, and 16.7 mm / s. On the alignment film 56, the liquid crystal composition E was applied using a bar coater and heated to 100 ° C. to obtain a film aligned in the liquid crystal phase. After that, the phase difference layer 57 is irradiated by irradiating ultraviolet rays at a wavelength of 365 nm with an intensity of 40 mW / cm ² for 1 minute using UniCure (VB-15201BY-A, manufactured by USHIO INC.) In a state cooled to room temperature. Produced. Next, a glass substrate, a polarizing layer 55, an alignment film 56, a retardation layer 57 and an antireflection layer 58 are laminated by pasting an antireflection film (Dai Nippon Printing Co., Ltd.) on the retardation layer 57. A laminated body was obtained.

<Measurement of optical properties>
About the laminated body obtained above, the retardation value (nm) of the retardation layer 57 and the measurement of the orientation angle were measured with a measuring instrument (KOBRA-WPR, manufactured by Oji Scientific Instruments). Table 2 shows the measurement results of the orientation angle of the liquid crystalline component in the retardation layer 57 and the retardation value (retardation value) Re (nm) at a wavelength of 549 nm. The orientation angles in Table 2 are approximately 45 degrees because the direction of the transmission axis 70a of the polarizing layer 55 is 0 degrees. The closer the retardation value Re (nm) is to λ / 4 (that is, 135 nm), the more natural light that passes through the polarizing layer 55 and the retardation layer 57 is converted to light that is closer to circularly polarized light.

<Measurement of thickness>
The thickness of the produced laminate was measured using a photoelectric digital measurement system (Digimicro MH-15M, manufactured by Nikon Corporation). Table 3 shows the measurement results of the thickness of the laminate excluding the glass substrate.

(Example 3)
[Production of liquid crystal display device]
A polarizing layer 55 is formed by laminating a polarizing plate using an adhesive on the light emitting side of the display element substrate 54 (see FIG. 2) on which the liquid crystal display element is formed. Subsequently, an alignment film 56 is formed on the obtained polarizing layer 55 in the same manner as in Example 1. On the alignment film 56, the liquid crystal composition E is applied to a film thickness such that the retardation value is 135 nm using a slit coater and heated to 100 ° C. to obtain a film aligned in the liquid crystal phase. Thereafter, the phase difference layer 57 is formed by irradiating with ultraviolet rays under the same conditions as in Example 1 while being cooled to room temperature. Next, an antireflection film (manufactured by Dai Nippon Printing Co., Ltd.) is bonded onto the retardation layer 57, whereby the liquid crystal display element substrate 54, the polarizing layer 55, the alignment film 56, the retardation layer 57, and the antireflection layer. A liquid crystal display device 51B in which 58 is laminated is obtained.

  The manufacturing method of the display device of the present invention can be applied to manufacturing various types of display devices, in particular, display devices capable of displaying images stereoscopically.

51A, 51B Liquid crystal display device 52 Back light 53 Polarizing plate 54 Display element substrate 55 Polarizing layer 56 Alignment film 57 Retardation layer 58 Antireflection layer 70a Transmission axis 71a Slow axis

Claims (3)

A display element substrate having a plurality of pixels arranged along a main surface; a polarizing layer disposed on a light emitting side of the display element substrate and having a transmission axis in a specific direction along the main surface; and the polarizing layer A display device manufacturing method for manufacturing a display device that includes a retardation layer that is disposed on the light emitting side of the light source and has a slow axis that intersects the transmission axis along the main surface,
A manufacturing method of a display device comprising the following steps (1) to (4):
(1) A step of forming the polarizing layer along the main surface on the light emitting side of the display element substrate. (2) On the polarizing layer formed in the step (1), the retardation layer is formed. A step of forming an alignment film having a function of aligning the liquid crystalline component of the liquid crystal composition as a material in an alignment direction corresponding to the direction of the slow axis (3) on the alignment film formed in the step (2) A liquid crystal composition containing a polymerizable liquid crystal compound is applied to form a coating film, and the coating film is held at a temperature at which the liquid crystalline component of the liquid crystal composition exhibits a liquid crystal phase. Step (4) aligning in the orientation direction corresponding to the direction of the slow axis (4) By polymerizing the polymerizable liquid crystal compound forming the liquid crystalline component formed in the step (3) while maintaining the orientation direction, Step of forming the retardation layer The method for manufacturing a display device according to claim 1, further comprising:
A method for manufacturing a display device, comprising: forming an antireflection layer for preventing reflection of external light on the light emitting side of the retardation layer. In the manufacturing method of the display device according to claim 1 or 2,
A method for manufacturing a display device, wherein the plurality of pixels of the display element substrate constitute a liquid crystal display element.

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