JP2012032612A - Liquid crystal display device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of simplifying a layer configuration and improving productivity, and to provide a method for manufacturing the same.SOLUTION: The liquid crystal display device includes: a light source 1; a light source side polarization plate 6 arranged in a light emission side of the light source; a liquid crystal panel 8 arranged in an observer side of the light source side polarization plate; an observer side polarization plate 13 arranged in an observer side of the liquid crystal panel; and an optical functional layer 14 arranged in an observer side of the observer side polarization plate. The observer side polarization plate has a polarization layer 11, and protective layers 10 and 12 provided so as to sandwich the polarizing layer. The optical functional layer is directly stacked on the surface of the protective layer 12 in the observer side, out of the protective layers of the observer side polarization plate. The optical functional layer is arranged side by side along the surface of the protective layers in a cross section of a thickness direction of the layer, and includes a light transmission section 15 formed so as to be able to transmit light and a light absorption section 16 formed between the light transmission sections so as to be able to absorb light. The light transmission section and the light absorption section of the optical functional layer extend while maintaining the cross section, and the extending direction is perpendicular to a polarization direction of the observer side polarization plate.

Description

  The present invention relates to a liquid crystal display device including a liquid crystal panel and a method for manufacturing the liquid crystal display device.

  A liquid crystal display device such as a liquid crystal television has a liquid crystal panel which is an information source of video / images to be displayed, and has layers having various functions for improving the quality of video light from the liquid crystal panel and transmitting it to the viewer side. Are stacked.

  Patent Document 1 discloses an example of an optical sheet laminated on such a liquid crystal panel and a display device including the same. According to this, the optical sheet (two-dimensional visual field enlarging member) has a light-transmitting portion between the light transmitting portions and the trapezoidal light transmitting portions (unit lens portions) arranged in parallel along the sheet surface so as to transmit light. It has a layer having a light-absorbing portion (inter-lens portion) having a triangular cross-sectional shape that can be provided. By this layer, image light can be reflected and provided to the observer, and external light and stray light can be absorbed.

JP 2003-66206 A

  In recent years, there has been a need for further simplification of production for reducing the thickness and price of liquid crystal televisions, and further contrivance has been required for a display device having a configuration as described in Patent Document 1.

  In view of the above problems, an object of the present invention is to provide a liquid crystal display device capable of simplifying the layer configuration and improving productivity and a method for manufacturing the same.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

  The invention described in claim 1 includes a light source (1), a light source side polarizing plate (6) disposed on the light output side of the light source, and a liquid crystal panel (8) disposed on the viewer side of the light source side polarizing plate. And an observer-side polarizing plate (13) disposed on the observation side of the liquid crystal panel, and an optical functional layer (14) disposed on the observer side of the observer-side polarizing plate. Comprises a polarizing layer (11) and a protective layer (10, 12) so as to sandwich the polarizing layer, and has an optical function on the surface of the protective layer (12) on the viewer side among the protective layers of the viewer-side polarizing plate. The optical functional layer is arranged in parallel along the surface of the protective layer in the cross section in the thickness direction of the layer, and is formed between the light transmitting portions. A light absorbing portion (16) formed so as to be capable of absorbing light, and the light transmitting portion and the light absorbing portion of the optical functional layer extend while maintaining a cross section. Both a liquid crystal display device comprising a direction in which the extending, the polarization direction of the viewer-side polarizing plate, that is vertical.

  According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, the light transmitting portion (15) and the light absorbing portion (16) of the optical functional layer (14) are substantially trapezoidal in cross section. The short upper base of the transmission part and the long lower base of the light absorption part are directed to the observer side.

  The invention according to claim 3 is the liquid crystal display device according to claim 1 or 2, wherein the light transmission part (15) of the optical functional layer (14) is composed of a composition containing an acrylate having a fluorene skeleton in the molecule. It is characterized by being.

  According to a fourth aspect of the present invention, in the liquid crystal display device according to any one of the first to third aspects, the light absorbing portion (15) is obtained from the refractive index of the light transmitting portion (15) of the optical functional layer (14). The refractive index is smaller.

  According to a fifth aspect of the present invention, in the liquid crystal display device according to the fourth aspect, the difference between the refractive index of the light transmission part (15) and the light absorption part (16) of the optical function layer (14) is 0.09. It is the above.

  Invention of Claim 6 is a method of manufacturing the liquid crystal display device according to any one of Claims 1 to 5, and is a layer to be a protective layer (12) of the observer-side polarizing plate (13). The method for manufacturing a display device includes a step of forming an optical functional layer (14).

  According to the present invention, since the optical functional layer can be formed on the protective layer provided in the polarizing plate provided in the liquid crystal panel, the required layer can be simplified as compared with the conventional case. In this case, since the polarization direction of the polarizing plate and the direction in which the light transmitting portion and the light absorbing portion of the optical functional layer extend are taken into consideration, the polarizing plate and the optical sheet (optical functional layer) are combined. There is no need to manufacture the sheet, and the sheets can be stacked in the form of a strip-shaped roll, and can be manufactured by pulling out from here.

It is the figure which looked at the image source unit with which the display apparatus concerning 1st embodiment was equipped from the front. It is sectional drawing along the II-II line of FIG. 1, and is the figure which represented the layer structure typically. It is the figure which expanded and showed a part of optical function sheet | seat layer with which the video source unit shown in FIG. 2 was equipped. It is a figure explaining a part of manufacturing process of a video source unit among the manufacturing methods of a display apparatus. It is the figure which looked at the image source unit with which this is equipped among the display apparatuses concerning 2nd embodiment from the front. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5, schematically showing the layer configuration.

  The above-described operation and gain of the present invention will be clarified from embodiments for carrying out the invention described below. Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  FIG. 1 is a front view of a video source unit 1 provided in the liquid crystal display device according to the first embodiment. 2 schematically shows the layer configuration in a cross section taken along line II-II in FIG. 1, that is, in a cross section orthogonal to the direction in which the light absorbing portions 15, 15,. FIG. The direction along the line II-II is the polarization direction of the observer-side polarizing plate 13 described later. In FIG. 2, the right side of the drawing is the observer side. The image source unit 1 of the liquid crystal display device of the present embodiment is a TN liquid crystal display panel unit.

  As can be seen from FIG. 2, the video source unit 1 includes a backlight 2 as a light source, a light source side polarizing plate 6, an adhesive layer 7, a liquid crystal panel 8, an adhesive layer 9, an observer side polarizing plate 13, an optical functional layer. 14 and an antiglare layer 19 are provided. Each of these layers maintains the cross section shown in FIG. 1 and extends in the back / front direction. Each layer will be described below. In the figures shown below, some repetitive symbols may be omitted for ease of viewing. Further, the display device is provided with other known devices for functioning as a display device such as an electric circuit for operating the video source unit 1 and a power supply circuit.

  The backlight 2 functions as a light source of the display device. Here, a backlight used in a normal liquid crystal display panel unit can be used. This includes, for example, a form in which light emitting sources are arranged substantially uniformly in a plane to form a planar light source, or a light emitting source is arranged on an edge and a reflecting surface is used to finally form a planar shape. Examples include an edge input type that emits light.

The light source side polarizing plate 6 and the viewer side polarizing plate 13 are optical elements arranged on the light source side and the viewer side of the liquid crystal panel 8 respectively. The light source side polarizing plate 6 and the observer side polarizing plate 13 include polarizing layers 4 and 11 having a polarizing function and protective layers 3, 5, 10, and 12 that protect the polarizing layers 4 and 11.
The polarizing layers 4 and 11 use a polarizing function based on the orientation of iodine formed by dyeing a polyvinyl alcohol (PVA) polymer with iodine and stretching the film.
The protective layers 3, 5, and 10 are layers for protecting the polarizing layers 4 and 11 from the external environment, and are formed of triacetyl cellulose (TAC). On the other hand, the protective layer 12 is a layer disposed on the viewer side and is not affected by polarized light, so that PET having a large birefringence can be used. In the present embodiment, PET is used from the viewpoints of adhesion and curability with an ultraviolet curable resin used for an optical functional layer described later.
That is, the protective layers 3, 5, 10 and 12 are laminated on the surfaces of the polarizing layers 4 and 11 to form the polarizing plates 6 and 13.

  In the present embodiment, since the liquid crystal is a TN type liquid crystal, the light source side polarizing plate 6 and the viewer side polarizing plate 13 are arranged so that the polarization directions thereof are orthogonal to each other. 1 is the direction indicated by II-II. The light source side polarizing plate 6 has a polarization direction (that is, a direction of a line indicated by BB in FIG. 1) orthogonal to the light source side polarizing plate 6.

  The liquid crystal panel 8 is one of the elements constituting the video source in the video source unit 1, and video information to be emitted is shown here. Here, a normal liquid crystal panel of TN type is used.

  The adhesive layers 7 and 9 are layers in which an adhesive for adhering the light source side polarizing plate 6 and the observer side polarizing plate 13 to the liquid crystal panel 8 is disposed. The material of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layers 7 and 9 is not particularly limited as long as it allows light to pass therethrough and allows proper adhesion. Examples thereof include an acrylic pressure-sensitive adhesive. The adhesive strength is, for example, about several N / 25 mm to 20 N / 25 mm.

  The optical functional layer 14 is a layer laminated on the protective layer 12 disposed on the viewer side of the viewer-side polarizing plate 13 described above, and is substantially trapezoidal in the section in the sheet thickness direction along the line II-II in FIG. Are light transmission parts 15, 15,... And light absorption parts 16, 16,... Arranged between the light transmission parts 15, 15,. FIG. 3 shows an enlarged view focusing on the two light absorbing portions 16 and 16 and the light transmitting portions 15, 15 and 15 adjacent thereto. The optical functional layer 14 will be described with reference to FIGS.

The light transmitting portions 15, 15,... Are elements having a substantially trapezoidal cross section arranged such that the protective layer 12 side is the lower base and the other side (observer side) is the upper base. Light transmitting portions 15, 15, ... has a refractive index is composed of a light transmissive resin is N _p. While not being sized specifically limited in N _p, for better light transmission portion has a high refractive index is desired, it is preferable that from 1.55 to 1.61. The image light is provided to the viewer by transmitting the image light through the light transmitting portions 15, 15.

  As the composition constituting the light transmission part, for example, a photocurable resin composition in which a reactive dilution monomer (M1) and a photopolymerization initiator (S1) are blended with a photocurable prepolymer (P1) is preferable. Used.

  Examples of the photocurable prepolymer (P1) include epoxy acrylate-based, urethane acrylate-based, polyether acrylate-based, polyester acrylate-based, and polythiol-based prepolymers.

  Examples of the reactive dilution monomer (M1) include vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, and tetrahydrofurfuryl acrylate. In addition, at least one of a vinyl compound having a fluorene skeleton, an acrylate compound having a fluorene skeleton, and a methacrylic acid ester compound having a fluorene skeleton can be used from the viewpoint of increasing the refractive index.

Examples of the photopolymerization initiator (S1) include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoyl Formate compounds (such as methylbenzoylformate), thioxanthone compounds (such as isopropylthioxanthone), benzophenones (such as benzophenone), phosphate compounds (1,3,5-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-) Trimethylbenzoyl) phenylphosphine oxide and the like, and benzyldimethyl ketal and the like. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected.
In the present embodiment described above, PET is used for the protective layer 12. However, if TAC is used for the protective layer 12, since the TAC generally contains an ultraviolet absorber, a photopolymerization initiator ( S1) preferably has an absorption wavelength extending to visible light, and examples thereof include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 (Ciba)).

The light absorbing portions 16, 16,... Are portions disposed between the light transmitting portions 15, 15,. The cross-sectional shape of the light absorbing parts 16, 16,... Is a substantially trapezoidal shape with the upper base side of the light transmitting parts 15, 15,. Light absorbing portion 16, 16, ..., the binder 17, 17 material having a refractive index of _{N b} is filled, ... and the binder portion 17, the light-absorbing particles 18 and 18 is mixed to ... , ... and. When external light is incident on and absorbed by the light absorbing portions 16, 16,..., The influence of the external light on the image light can be reduced, and the contrast can be improved.

Binder 17, 17, the binder material to be filled ... in is composed of the light transmitting portions 15, a small refractive index _{N b} than ... refractive index _{N p} of the material. While not being sized specifically limited in N _b, it is necessary refractive index difference between the light transmitting portion, and from the viewpoint of availability of the application to the material, it is from 1.48 to 1.50 Is preferred.

  Although what is used as the said binder is not specifically limited, For example, the photocurable resin composition which mix | blended the reactive dilution monomer (M2) and the photoinitiator (S2) with the photocurable prepolymer (P2). The product is preferably used.

  Examples of the photocurable prepolymer (P2) include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and butadiene (meth) acrylate.

Examples of the reactive dilution monomer (M2) include monofunctional monomers such as N-vinyl pyrrolidone, N-vinyl caprolactone, vinyl imidazole, vinyl pyridine, styrene, and other vinyl monomers, lauryl (meth) acrylate, stearyl ( (Meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, paracumylphenoxyethyl (meth) ) Acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) a (Meth) acrylic acid ester monomers such as relate, cyclohexyl (meth) acrylate, benzyl methacrylate, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylate, acryloylmorpholine, A (meth) acrylamide derivative is mentioned. Polyfunctional monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polytetra Methylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 3-methyl-1, 5-pentanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate Bisphenol A polypropoxydiol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, glyceryl tri (meth) acrylate, propoxylated glyceryl tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate And dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

  Examples of the photopolymerization initiator (S2) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane- Examples include 1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected.

Here, the light transmitting portions 15, the refractive index _{N p} and the binder portion 17, 17 ..., ... is the difference between the refractive index _{N b} of, but is no particular _limitation, N p -N _b is 0 0.09 or more is preferable.

  The light absorbing particles 18, 18,... Are preferably particles having an average particle diameter of 1 μm or more from the viewpoint of availability and production, and examples thereof include acrylic styrene beads containing 25% by mass of carbon black. For this, for example, commercially available colored resin particles can be used. The refractive index of the light absorbing particles 18, 18,... Is not particularly limited.

  When the average particle size is smaller than this, many light absorbing particles are densely packed at the interface between the light transmitting portion and the light absorbing portion, and there is a possibility that a part of the image light to be totally reflected is easily absorbed. On the other hand, by setting the average particle diameter to 1 μm or more, the amount of light absorbing particles disposed at the interface can be suppressed, and appropriate total reflection can be ensured.

  Here, the light absorption performance of the light absorbing portions 16, 16,... Can be adjusted as appropriate depending on the purpose. However, in the transmittance measurement of a sheet having a thickness of 6 μm formed only from the material constituting the light absorbing portion, It is preferable that the light absorption performance is such that the rate is 40 to 70%. The means for adjusting the transmittance to 40 to 70% is not particularly limited, and for example, it can be applied by adjusting the content of the light absorbing particles.

Further, the light absorbing portion 16, 16, ... hypotenuse (sheet two sides extending in the thickness direction) has an angle of theta _b with respect to the sheet surface normal. Due to the relationship between the angle θ _b and the above-described N _p and N _b and the angle of the incident light, a part of the light is reflected at the interface between the light transmitting portion 15 and the light absorbing portion 16, so Emitted. The magnitude of θ _b is not particularly limited, but is preferably 0 ° or more and 15 ° or less.

  Further, the light absorbing portions 16, 16,... Of the optical function layer 14 are configured such that the longitudinal direction thereof is perpendicular to the polarization direction of the polarizing plate 13 disposed on the observer side. Accordingly, the light absorbing portions 16, 16,... Extend in parallel to the arrow B in FIG.

  The antiglare layer 19 is a film (antiglare film) that can prevent glare when an observer looks at the screen, and is sometimes called an AG layer (antiglare layer). As the antiglare film, it is possible to apply a commonly available film. In the present embodiment, this is the antiglare layer, but an antireflection layer may be disposed instead of the antiglare layer. The antireflection layer is also called an anti-reflection layer or an AR layer, and is a layer that can prevent reflection.

  Here, the AG layer 19 is also formed as follows, for example, since scratch resistance is also required in order to prevent the image display surface from being scratched. A specific example will be described. However, it is an illustration and it is not limited to this. The thickness of the AG layer is preferably 3 μm to 15 μm, more preferably 3 μm to 10 μm. This is because if the thickness is less than 3 μm, the pencil hardness is not sufficient, and if it exceeds 15 μm, the pencil hardness is improved, but cracking or peeling may occur. In order to provide high pencil hardness, it is desirable that the pencil hardness of the AG layer is 3H to 5H.

  Examples of the material for forming the AG layer include ionizing radiation curable resins, thermosetting resins, thermoplastic resins, and engineering plastics. An ionizing radiation curable resin is preferable because it easily forms a film on a plastic substrate film and can easily increase the pencil hardness to a desired value.

  Examples of the ionizing radiation curable resin include the following. Preferred are those having an acrylate functional group, and more preferred are polyester acrylate or urethane acrylate. The polyester acrylate is preferably composed of a polyester polyol oligomer acrylate or methacrylate (hereinafter, acrylate and / or methacrylate is simply referred to as (meth) acrylate) or a mixture thereof. Moreover, urethane acrylate is comprised from what acrylate-ized the oligomer which consists of a polyol compound and a diisocyanate compound.

  The monomer constituting the acrylate is preferably methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) ) Acrylate, phenyl (meth) acrylate, and the like.

  Moreover, when providing hardness further, a polyfunctional monomer can be used together. For example, preferred polyfunctional monomers include trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, di Examples include pentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate.

  Preferred examples of polyester polyol oligomers include adipic acid and glycol (ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, etc.), triol (glycerin, trimethylolpropane, etc.), sebacic acid and Examples thereof include polyadipate polyol, which is a condensation product with glycol and triol, and polysebacate polyol.

  Further, a part or all of the aliphatic dicarboxylic acid can be substituted with another organic acid. For example, isophthalic acid, terephthalic acid, phthalic anhydride, or the like can be used as a component for imparting hardness.

  The polyurethane-based oligomer can be obtained from a condensation product of polyisocyanate and polyol. For example, (methylenebis p-phenylene) diisocyanate, hexamethylene diisocyanate-hexanetriol adduct, hexamethylene diisocyanate, tolylene diisocyanate, tolylene diisocyanate-trimethylolpropane adduct, 1,5-naphthylene diisocyanate, thiopropyl diisocyanate, ethylbenzene It can be obtained by the reaction of the following polyol with one selected from -2,4-diisocyanate, 2,4-tolylene diisocyanate dimer, hydrogenated xylylene diisocyanate, tris (4-phenylisocyanate) neophosphate, etc. Is.

  Preferable examples of the polyol include polyether polyols such as polyoxytetramethylene glycol, polyester polyols such as polyadipate polyol and polycarbonate polyol, and copolymers of acrylic acid esters and hydroxyethyl methacrylate.

  Further, when the ionizing radiation curable resin is used as an ultraviolet curable resin, α-amyloxime ester and thioxanthone as photopolymerizers, n-butylamine, triethylamine as photosensitizers, Tri-n-butylphosphine and the like can be mixed and used.

  Urethane acrylate is rich in elasticity and flexibility and excellent in workability, but has a poor surface hardness and a pencil hardness of 2H or higher cannot be obtained. On the other hand, the polyester acrylate can impart hardness by selecting the constituent components of the polyester.

  In order to obtain an AG layer having flexibility, it is preferable to blend 40 to 10 parts by mass of polyester acrylate with respect to 60 to 90 parts by mass of urethane acrylate, and this method achieves both high hardness and flexibility. An AG layer is obtained.

  The coating composition that constitutes the AG layer has a secondary particle size of 20 μm or less, more preferably 0.1 μm or less for the purpose of adjusting gloss and imparting surface slippage (not releasability). It is preferable to add 0.3 to 3 parts by mass of inorganic fine particles in the range of 15 μm to 100 parts by mass of the resin component. If it is 0.3 parts by mass or less, the desired lubricity cannot be provided, and if it is 3 parts by mass or more, the pencil hardness may be lowered.

  In addition to inorganic fine particles such as silica, magnesium carbonate, aluminum hydroxide, and barium sulfate, fine particles of organic polymers such as polycarbonate, acrylic resin, polyimide, polyamide, polyethylene naphthalate, and melamine resin should be used as the fine particles. You can also.

  As the coating method, methods such as roll coating, gravure coating, bar coating, and extrusion coating can be used, and an AG layer is formed by a conventionally known method according to the characteristics and coating amount of the coating composition. can do.

  Moreover, the film which has each function may be laminated | stacked as needed. Examples thereof include a film containing light diffusing particles. The film can further diffuse video light.

With the liquid crystal display device including the image source unit 1 having the above-described configuration, the base material of the optical functional layer 14 can be shared with the protective layer 12 of the observer-side polarizing plate 13, thereby simplifying the layer configuration. be able to. That is, productivity can be improved. Further, by simplifying the layers, a thinner liquid crystal display device can be obtained.
In addition, by simplifying the layers, blurring of image light can be prevented, and a display device with high image quality can be provided.

With the liquid crystal display device including the video source unit 1 as described above, for example, video light has the following optical path. FIG. 3 shows an example of the optical path. Operating the liquid crystal display device, the image light L ₁ as shown in FIG. 3 is emitted to the observer side passes through the light transmitting portion 15.

Further, the image light L ₂ is emitted to the observer side is totally reflected at the interface between the light transmitting portion 15 and the light absorbing portion 16. At this time, since the hypotenuse of the light absorbing portion 16 is inclined as described above, the angle of the light changes before and after the reflection by the hypotenuse, and the image light can be emitted in the direction in which the viewing angle is widened. Thereby, a wide viewing angle can be obtained.

The image light L ₃ travels to the light absorption unit 16 without being reflected at the interface between the light transmission unit 15 and the light absorption unit 16 and is absorbed by the light absorption particles 18. On the other hand, external light L ₄ that is external light enters the light absorbing portion 16 and is absorbed by the light absorbing particles 18. In this way, a part of outside light and stray light are absorbed by the light absorbing particles, so that the contrast can be improved.

Such a video source unit 1 is manufactured as follows, for example.
The protective layer 12 as a base material is advanced so as to pass between a mold roll formed so that the shape of the light transmission part can be transferred and a nip roll. In that case, the ultraviolet curable resin composition used as the light transmissive part 15 is poured between the mold roll and the protective layer 12 and filled. Thereafter, the filled composition is cured by irradiating ultraviolet rays from the protective layer 12 side to form the light transmitting portion 15.
Next, it is released from the mold roll, and the binder resin in which the light absorbing particles are dispersed is supplied into the grooves formed between the light transmitting portions 15, and the excess binder resin is removed by scraping or the like. The binder resin filled in the groove is cured by irradiating with ultraviolet rays to form the light absorbing portion 16. Thereby, the laminated body of the protective layer 12 and the optical function layer 14 is formed in a strip shape, and is formed into a roll shape wound up. At this time, the direction in which the light transmitting portion 15 (light absorbing portion 16) of the optical functional layer 14 extends is formed to be a strip-like longitudinal direction.

Here, the adjustment of the constituent composition of the light transmitting portion, the formation of the light transmitting portion, the adjustment of the constituent composition of the light absorbing portion, and the formation of the light absorbing portion will be described with more specific examples. However, this is an example and the present invention is not limited to this.
<Adjustment of constituent composition of light transmitting portion>
13.27 parts by mass of bisphenol A-propylene oxide 2 mol adduct as a photocurable oligomer, 8.33 parts by mass of xylylene diisocyanate, and bismuth tri (2-ethylhexanoate) (2-ethylhexane) as a urethanization catalyst Acid 50% solution) (hereinafter the same) is mixed in 0.01 part and reacted at 80 ° C. for 6 hours. Thereafter, 1.40 parts of 2-hydroxyethyl acrylate is added and reacted at 80 ° C. for 3 hours to obtain a urethane acrylate oligomer.
23.0 parts by mass of the urethane acrylate oligomer thus obtained, 22.0 parts by mass of 9,9′-bis (4-hydroxyethyl) fluorene ethylene oxide-modified diacrylate as a photocurable monomer, phenoxyethyl 55.0 parts by mass of acrylate, 0.05 parts by mass of tridecanol phosphate ester [monoester: diester = molar ratio 1: 1] as a mold release agent, 1-hydroxycyclohexylphenyl as a photopolymerization initiator 2 parts by mass of a ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was mixed and homogenized to obtain a constituent composition of a light transmitting part.

<Formation of light transmission part>
The mold roll has a plurality of grooves extending in the cylindrical circumferential direction and having a substantially trapezoidal cross section in the cylindrical axis direction. Specifically, in the cross section of the groove, a trapezoidal shape having an upper base width of 44 μm on the mold roll shaft side, a lower base width of 14 μm on the circumferential side, and a depth of 114 μm which is the distance between the upper base and the lower base. . The pitch of the grooves is 46 μm. As described above, 100 μm of PET (A4300 manufactured by Toyobo Co., Ltd.) is passed between the mold roll and the nip roll as a protective layer serving as a base material layer, and the constituent composition of the light transmitting portion is between the mold roll and the protective layer Supply. Thereafter, the protective layer side is irradiated with ultraviolet light of 800 mJ / cm ^{2 with} a high-pressure mercury lamp to cure the constituent composition of the light transmission part. Then, the light transmission part is released from the mold roll, and a sheet (intermediate member) having a thickness of 234 ± 20 μm including the light transmission part is formed. At this time, the refractive index of the light transmission part was 1.58.

<Adjustment of constituent composition of light absorbing portion>
As a photopolymerization component, 33.6 parts by mass of urethane acrylate, 14.4 parts by mass of an epoxy acrylate oligomer, 28, 0 parts by mass of tripropylene glycol diacrylate, and 4. 4 parts of methoxytriethylene glycol acrylate as a photocurable monomer. 0 parts by mass, 20.0 parts by mass of acrylic crosslinked fine particles (Ganz Chemical Co., Ltd.) containing 25% carbon black having an average particle size of 4.0 μm as light absorbing particles, 1-hydrokeshi as a photopolymerization initiator 7 parts by mass of cyclohexyl luphenyl-ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was mixed and homogenized to obtain a constituent composition of the light absorption part. At this time, the refractive index of the portion (binder) excluding the light absorbing particles was 1.49.

<Formation of light absorption part>
The constituent composition of the light absorption part obtained above was supplied onto the intermediate member from a supply device. Using a doctor blade arranged substantially perpendicular to the traveling direction of the intermediate member, the supplied composition of the light absorbing portion is filled in the groove of the intermediate member (the groove between the light transmitting portions) and the surplus The constituent composition of the light absorption part was scraped off. Then, the light absorption part constituent composition was hardened by irradiating with ultraviolet rays, and the light absorption part was formed with the hardened light absorption part constituent composition. In this state, since the surface of the light absorbing portion had a dent of 5 μm, the same filling and scraping were performed again to make the dent 2 μm.

  Of the surface of the optical functional layer 14 of the laminate of the protective layer 12 and the optical functional layer 14 formed as described above, the AG layer 19 is applied to the surface opposite to the protective layer 12 by UV molding or coating. Form. Thereby, the laminated body of the protective layer 12, the optical function layer 14, and AG19 is formed in roll shape.

  Next, the iodine compound of the PVA film is dyed, penetrated into the inside, stretched, and boric acid is added to perform a crosslinking treatment. Thereby, the polarizing layer 11 is formed in a band shape, and is formed into a rolled shape. At this time, the polarizing layer 11 is formed so that the polarization direction is a strip-like longitudinal direction. After the obtained polarizing layer 11 is washed, it is laminated on the protective layer 12 among the laminate of the protective layer 12, the optical functional layer 14, and the AG layer 19. Thereby, the laminated body of the polarizing layer 11, the protective layer 12, the optical function layer 14, and the AG layer 19 is formed. Lamination | stacking performed here is performed in the aspect which winds up and rolls up both rolls and winds up the obtained laminated body also in roll shape.

  Here, in this lamination process, the direction in which the light transmission part 15 (light absorption part 16) of the optical function layer 14 extends and the polarization direction of the observer-side polarizing plate 13 are matched.

  Thereafter, the protective layer 10 and the pressure-sensitive adhesive layer 9 are formed on the opposite side surface of the polarizing layer 11. Next, the laminate thus far is punched into sheets so as to match the size of the liquid crystal panel 8 (see IV in FIG. 4). At the time of punching, in the present invention, the extending direction of the light transmitting portion 15 (light absorbing portion 16) of the optical function layer 14 and the polarization direction of the polarizing layer 11 are the same, and this is the strip-like longitudinal direction. Yes. Therefore, as shown in FIG. 4, waste can be reduced and a rectangular sheet can be punched efficiently. This also provides a highly productive display device and a method for manufacturing the same.

  Then, the punched sheet stack is stacked on the liquid crystal panel 8. At this time, it is preferable that the light transmission unit 15 (light absorption unit 16) of the optical function layer 14 is stacked so that the extending direction is vertical when formed as a display device. As a result, the viewing angle in the horizontal direction can be improved.

  On the other hand, the light source side polarizing plate 6 on which the adhesive 7 is laminated is also laminated on the opposite side surface of the liquid crystal panel 9, and these laminated bodies are finally laminated on the backlight 2.

  FIG. 5 is a front view of the image source unit 101 provided in the liquid crystal display device according to the second embodiment. 6 schematically shows the layer configuration in a cross section taken along line VI-VI in FIG. 5, that is, a cross section orthogonal to the direction in which the light absorbing portions 115, 115,... Of the optical functional layer 114 extend. FIG. The direction along the VI-VI line is the polarization direction of the observer-side polarizing plate 113 described later. In FIG. 6, the right side of the drawing is the observer side. The image source unit 101 of the liquid crystal display device of this embodiment is a VA liquid crystal liquid crystal display panel unit.

  As can be seen from FIG. 6, the image source unit 101 includes the backlight 2 as the light source, the light source side polarizing plate 106, the adhesive layer 7, the liquid crystal panel 108, the adhesive layer 9, the observer side polarizing plate 113, and the optical functional layer. 114 and an antiglare layer 19. Each of these layers maintains the cross section shown in FIG. 6 and extends in the back / front direction. Each layer will be described below. Further, the display device is provided with other known devices for functioning as a display device, such as an electric circuit for operating the video source unit 101, a power supply circuit, and the like.

  This embodiment is different from the image source unit 1 of the liquid crystal display device of the first embodiment in that the liquid crystal panel 108 is a VA type liquid crystal. Accordingly, the configurations of the light source side polarizing plate 106, the observer side polarizing plate 113, and the optical function layer 114 are different. Accordingly, the configuration of the backlight 2, the pressure-sensitive adhesive layers 7 and 9, and the antiglare layer 19 is common to the video source unit 1, and thus the same reference numerals are given and the description thereof is omitted.

  The liquid crystal panel 108 is one of the elements constituting the video source in the video source unit 101, and video information to be emitted is shown here. Here, a normal liquid crystal panel of VA type can be used.

The light source side polarizing plate 106 and the viewer side polarizing plate 113 are optical elements arranged on the backlight 2 side and the viewer side of the liquid crystal panel 108, respectively. The light source side polarizing plate 106 and the observer side polarizing plate 113 include polarizing layers 104 and 111 having a polarizing function and protective layers 103, 105, 110, and 112 that protect the polarizing layers 104 and 111.
The polarizing layers 104 and 111 use a polarizing function based on the orientation of iodine formed when a polyvinyl alcohol (PVA) polymer is dyed with iodine and stretched into a film.
The protective layers 103, 105, and 110 are layers for protecting the polarizing layers 104 and 111 from the external environment, and are formed of triacetyl cellulose (TAC). On the other hand, the protective layer 112 is a layer disposed on the viewer side and is not affected by polarized light, so that PET having a large birefringence can be used. In the present embodiment, PET is used from the viewpoints of adhesion to the ultraviolet curable resin used for the optical function layer 114 and curability.
That is, the protective layers 103, 105, 110, and 112 are laminated on the surfaces of the polarizing layers 104 and 111 to form the polarizing plates 106 and 113.

  In this embodiment, since the liquid crystal is a VA type liquid crystal, the light source side polarizing plate 106 and the observer side polarizing plate 113 are arranged so as to be orthogonal to each other. The direction indicated by VI-VI in FIG. The light source side polarizing plate 106 has a polarization direction (that is, the direction of a line indicated by CC in FIG. 5) perpendicular to the light source side polarizing plate 106.

  The optical function layer 114 is a layer laminated on the protective layer 112 disposed on the viewer side of the viewer side polarizing plate 113 described above, and is substantially trapezoidal in the section in the sheet thickness direction along the line CC in FIG. Are light transmission portions 115, 115,... And light absorption portions 116, 116,... Disposed between the light transmission portions 115, 115,. The light transmitting portions 115, 115,... And the light absorbing portions 116, 116,... Appearing in the cross section have the same shape as the light transmitting portions 15, 15,. Since the material applied to is also common, the description is omitted here.

  In this embodiment, it is a VA type liquid crystal, and the polarization direction of the polarizing plate 113 on the observer side is the horizontal direction as can be seen from FIG. The light transmitting portions 115, 115,... And the light absorbing portions 116, 116,... Of the optical function layer 114 extend in a direction orthogonal to the polarization direction of the observer side polarizing plate 113.

  Also with the liquid crystal display device including the image source unit 101 having the above-described configuration, the base material of the optical functional layer can be shared with the protective layer of the observer-side polarizing plate, and the layer configuration can be simplified. it can. That is, productivity can be improved. Further, by simplifying the layer, a thinner display device can be obtained.

  In such an image source unit 101 as well, the extending direction of the light transmitting portion 115 (light absorbing portion 116) of the optical functional layer 114 and the polarization direction of the observer-side polarizing plate 113 are orthogonal to each other as in the image source unit 1 described above. In addition, it is formed so as to be a strip-like longitudinal direction. As a result, waste can be reduced and a rectangular sheet can be punched efficiently. This also provides a highly productive display device and a method for manufacturing the same.

  Although the present invention has been described in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein, The present invention can be appropriately changed without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and the display device accompanying such a change and the manufacturing method thereof are also included in the technical scope of the present invention. Must be understood as.

DESCRIPTION OF SYMBOLS 1,101 Image source unit 2 Backlight 3, 5, 10, 12, 103, 105, 110, 112 Protective layer 4, 11, 104, 111 Polarizing layer 6, 106 Light source side polarizing plate 7, 9 Adhesive layer 8, 108 Liquid crystal panel 13, 113 Observer-side polarizing plate 14, 114 Optical functional layer 15, 115 Light transmitting portion 16, 116 Light absorbing portion 19 Anti-glare layer

Claims (6)

A light source;
A light source side polarizing plate disposed on the light output side of the light source;
A liquid crystal panel disposed on the viewer side of the light source side polarizing plate;
An observer-side polarizing plate disposed on the observation side of the liquid crystal panel;
An optical functional layer disposed on the observer side of the observer side polarizing plate,
The observer side polarizing plate comprises a polarizing layer and a protective layer so as to sandwich the polarizing layer,
The optical functional layer is directly laminated on the surface of the observer-side protective layer of the observer-side polarizing plate,
The optical functional layer is arranged in parallel along the surface of the protective layer in a cross section in the thickness direction of the layer, and is formed so as to be able to transmit light and to absorb light between the light transmitting portions. A light absorption part,
The light transmitting portion and the light absorbing portion of the optical functional layer extend while maintaining the cross section, and the extending direction and the polarization direction of the observer side polarizing plate are perpendicular to each other. Characteristic display device.   The cross-sectional shapes of the light transmission part and the light absorption part of the optical functional layer are substantially trapezoidal, and the short upper bottom of the light transmission part and the long lower bottom of the light absorption part are directed to the observer side. The display device according to claim 1.   3. The display device according to claim 1, wherein the light transmission portion of the optical functional layer is formed of a composition containing an acrylate having a fluorene skeleton in a molecule.   4. The display device according to claim 1, wherein a refractive index of the light absorption unit is smaller than a refractive index of the light transmission unit of the optical function layer. 5.   The display device according to claim 4, wherein a difference between a refractive index of the light transmission part and the light absorption part of the optical function layer is 0.09 or more. A method for manufacturing the display device according to any one of claims 1 to 5,
The manufacturing method of the display apparatus characterized by including the process of forming the said optical function layer in the layer used as the protective layer of the said observer side polarizing plate.