JP2014002927A - Display device - Google Patents

Abstract

The present invention provides a display device capable of improving contrast by absorbing or shielding reflected light from external light incident on the display device obliquely and substantially vertically.
A light-emitting element 20 in which a metal cathode layer, an organic light-emitting layer, and a transparent anode layer are laminated in this order, and arranged on the viewer side of the light-emitting element 20 to control incident light from the light-emitting element 20. The display device 1 includes at least an optical functional layer 10 that emits light to the viewer side, and a front plate 30 that is disposed closer to the viewer side than the optical functional layer 10, and the optical functional layer 10 is a sheet. A plurality of light transmission parts 13 arranged in parallel along the plane, and a plurality of light absorption parts 14 provided in parallel between the light transmission parts 13. The light emitting element 20 and the optical functional layer 10 have a convex portion protruding toward the light emitting element 20, and the top of the convex portion is in contact with the light emitting element 20 through the air interface or has a distance of 5 mm or less. Is arranged.
[Selection] Figure 1

Description

  The present invention relates to an organic electroluminescent display device using an organic thin film as an electroluminescent layer, and more particularly to an organic electroluminescent display device excellent in contrast in which deterioration in image quality due to reflection of external light is suppressed.

  An electroluminescent display element (hereinafter sometimes abbreviated as an EL element) has a wide viewing area due to self-emission and low power consumption compared with a plasma light emitting element or the like. Application is being put into practical use. In particular, since an organic EL element using an organic compound as a light-emitting material can significantly reduce the applied voltage as compared with an inorganic EL element using an inorganic compound, various uses as a display device have been studied.

  The organic EL element generally has a structure in which a first electrode, an organic light emitting layer, and a second electrode are sequentially laminated on a transparent substrate. A transparent electrode is used as the first electrode, and a metal electrode as the second electrode. Using a bottom emission type that extracts light from the organic light emitting layer from the transparent substrate side, using a metal electrode as the first electrode, using a transparent electrode as the second electrode, and emitting light from the organic light emitting layer There is a top emission type that takes out from the second electrode side.

  The EL element having the structure as described above is composed of a transparent material from the light emitting surface to the organic light emitting layer of the bottom emission type or the top emission type. The incident external light reaches the metal electrode, is regularly reflected there, and is transmitted through the organic light emitting layer and the transparent electrode again and emitted from the light exit surface of the element. For this reason, the contrast of the image light emitted from the organic light emitting layer may be reduced due to the reflection of external light as described above.

  In order to solve the above problems, for example, in Japanese Patent Application Laid-Open No. 9-127855, a circularly polarizing element is provided on the light emitting surface side of an organic EL element to shield external light reflected by a metal electrode, and image A method for improving the contrast of light has been proposed. Japanese Patent Laid-Open No. 2002-373776 proposes a method of improving contrast by providing a color filter corresponding to each pixel of an organic EL element on the light emitting surface side of the element to absorb external light reflection. .

  Further, in a large-screen display device, a louver type optical filter having a structure in which light transmitting portions and light absorbing portions made of wedge-shaped black stripes are alternately arranged in order to suppress a decrease in contrast of image light due to the influence of external light. Is used. It has also been proposed to apply such an optical filter to an organic EL element (for example, JP 2008-158530 A, JP 2003-282260 A, JP 2011-128437 A, etc.), as described above. Contrast can be improved at low cost compared with circularly polarizing elements and color filters.

  However, the optical filter having the above-described structure can efficiently absorb or shield the external light incident on the light-emitting surface of the organic EL element from the oblique direction by the light-shielding layer. Therefore, it is impossible to effectively prevent a decrease in contrast due to external light incident from a direction substantially perpendicular to the light exit surface. That is, since external light incident from a direction substantially perpendicular to the light exit surface is specularly reflected by the metal electrode surface, the external light specularly reflected from the gap between the louvers juxtaposed at a predetermined interval is transmitted to the light exit surface. The contrast is remarkably lowered by the external light incident from a direction substantially perpendicular to the light exit surface.

  For this reason, a diffusion layer is provided between the organic light emitting layer and the optical filter, and external light reflected in the vertical direction of the light exit surface is diffused and absorbed or shielded by the light shielding layer, so that the external light incident from the vertical direction can be obtained. In contrast, display devices capable of maintaining contrast have been proposed (for example, Japanese Patent Application Laid-Open Nos. 2006-189867 and 2007-149527).

Japanese Patent Laid-Open No. 9-127858 JP 2002-373776 A JP 2008-158530 A JP 2003-282260 A JP 2011-128437 A JP 2006-189867 A JP 2007-149527 A

  As described above, when the diffusion layer is provided, the external light reflected by the metal electrode can be diffused, but the light emission (video light) from the organic light emitting layer is also diffused, so that the image quality may be deteriorated. . The louver type optical filter has a structure in which a large number of wedge-shaped black stripes extending in one direction of the exit surface (for example, the lateral direction of the exit surface) are arranged in parallel (that is, in the longitudinal direction of the exit surface). Therefore, out of the external light reflected light diffused by the diffusion layer, the light diffused in the direction perpendicular to the direction in which the louver extends (that is, the longitudinal direction of the exit surface) is absorbed or shielded by the optical filter, but the louver extends. Since the light diffused in the direction (that is, the lateral direction of the exit surface) is transmitted to the exit surface through the gap between the louvers, it was not possible to completely prevent a decrease in contrast due to external light even if a diffusion layer was provided. .

  In addition, the optical filter as described above has been conventionally directly attached to the front surface of the display device, but in recent years, a display device in which a glass plate is arranged on the front surface of the display device to enhance aesthetics has been developed. In this case, Newton rings may occur when the distance between the organic EL element and the glass plate is short. Moreover, even when a space is provided between each of the organic EL element, the optical filter, and the front glass plate, the optical filter and the front glass plate may partially adhere to each other due to the deflection of the display panel. In some cases, Newton's rings may occur at the close contact portions.

  In the display device having a structure in which a louver type optical filter is arranged on the light emitting surface side of the organic EL element, the present inventors have made the surface of the light transmissive part constituting the optical filter have a predetermined shape. By forming the projection in a convex shape, it absorbs or shields not only the external light incident on the light-exiting surface of the display device from an oblique direction but also reflected light from the external light incident from a substantially vertical direction without degrading the image quality. The knowledge that contrast can be improved was acquired. Moreover, the knowledge that generation | occurrence | production of a Newton ring can also be suppressed by providing a space | gap with a predetermined space | interval between an organic EL element and an optical filter was acquired. The present invention is based on these findings.

  Accordingly, an object of the present invention is to absorb or shield not only external light incident on the light exit surface of the display device from an oblique direction but also reflected light from external light incident from a substantially vertical direction, thereby reducing the contrast without degrading the image quality. It is an object of the present invention to provide a display device capable of improving the efficiency and suppressing the occurrence of Newton rings.

A display device according to the present invention includes a light emitting element in which a metal cathode layer, an organic light emitting layer, and a transparent anode layer are laminated in this order;
An optical functional layer that is arranged closer to the viewer than the light emitting device, and controls the incident light from the light emitting device to be emitted to the viewer;
A front plate disposed closer to the viewer than the optical functional layer;
A display device comprising at least
The optical functional layer is provided on the base material layer, the base material layer, a plurality of light transmission parts arranged in parallel along the sheet surface, and a plurality of light transmission parts provided in parallel between the light transmission parts. A light absorption part,
The light transmissive portion has a convex portion in which the surface on the light emitting element side protrudes toward the light emitting element side in a curved or broken line shape in the sheet thickness direction cross section,
The light emitting element and the optical functional layer are arranged such that the top of the convex part of the light transmitting part is in contact with the light emitting element through an air interface or has a distance of 5 mm or less. is there.

  According to the embodiment of the present invention, the height of the convex portion of the light transmission portion may be 1 to 6 μm.

  Further, according to the embodiment of the present invention, 2 to 10 convex portions may be provided between a pair of light absorbing portions adjacent to the light transmitting portion.

  According to the embodiment of the present invention, the light absorbing portion of the optical functional layer has a shape in which the surface on the light emitting element side is recessed in the observer side in the sheet thickness direction cross section. Also good.

  According to the embodiment of the present invention, the depth of the concave portion of the light absorbing portion may be 0.5 to 6 μm.

  According to an embodiment of the present invention, at least one functional layer selected from the group consisting of an antireflection filter, a hard coat layer, a wavelength filter layer, and an antiglare layer is provided closer to the viewer than the optical functional layer. May be arranged.

  Moreover, according to the embodiment of the present invention, the light emitting element may be an organic EL element.

  According to the embodiment of the present invention, the organic EL element may be a top emission type, and may include a sealing layer on the outermost surface on the observer side.

  According to the embodiment of the present invention, the organic EL element may be a bottom emission type, and may include a transparent substrate on the outermost surface on the observer side.

  According to the present invention, in a display device including a light emitting element, an optical functional layer disposed closer to the viewer than the light emitting element, and a front plate disposed closer to the viewer than the optical functional layer, the optical function is provided. In the sheet thickness direction cross section, the light-transmitting portion of the layer has a convex portion that protrudes toward the light-emitting element side in a curved line or a polygonal line, and thus is substantially perpendicular to the light-emitting surface of the display device Even if external light is incident from the light, the reflected light that is regularly reflected by the metal cathode layer is diffused only in the direction perpendicular to the parallel direction of the light transmission part by the convex part of the light transmission part, so that it is absorbed by the light absorption part. In addition, it is possible to obtain image light that is shielded and excellent in contrast. In addition, the image light from the light emitting element diffused by the convex part of the light transmitting part is also diffused only in the direction perpendicular to the parallel direction of the light transmitting part and absorbed by the light absorbing part. There is nothing.

  In addition, by providing a gap at a predetermined interval between the light emitting element and the optical functional layer, optical adhesion can be suppressed and generation of Newton rings can also be suppressed.

1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. 1 is a schematic cross-sectional view illustrating an embodiment of a light-emitting element. The schematic sectional drawing which expanded a part of one Embodiment of the light transmissive part of an optical function layer. The schematic sectional drawing which expanded a part of other embodiment of the light transmissive part of an optical function layer. The schematic sectional drawing which expanded a part of other embodiment of the light transmissive part of an optical function layer. The schematic sectional drawing which expanded a part of other embodiment of the light transmissive part of an optical function layer. The schematic sectional drawing which expanded a part of one Embodiment of the light absorption part of an optical function layer. FIG. 2 is a schematic cross-sectional view schematically showing an optical path of image light passing through the optical functional layer shown in FIG. 1. Schematic which showed the one part process of the manufacturing method of an optical function layer. Schematic which showed the other process of the manufacturing method of an optical function layer. Schematic which showed the cross-sectional shape of a part of groove | channel formed in the surface of the cylindrical roll used in Example 1. FIG. Schematic which showed the cross-sectional shape of a part of groove | channel formed in the surface of the cylindrical roll used in Example 3. FIG.

  A display device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing a part of a cross section of a display device according to a first embodiment of the present invention and schematically showing a layer structure thereof.

  The display device 1 includes a light emitting element 20 in which a metal cathode layer 201, an organic light emitting layer 202, and a transparent anode layer 203 are laminated in this order, and is disposed closer to the viewer than the light emitting element 20. The optical functional layer 10 which controls incident light and emits it to the observer side, and the front plate 30 disposed on the observer side with respect to the optical functional layer 10 are provided at least. In a preferred embodiment, as shown in FIG. 1, an antireflection filter 40 may be disposed closer to the observer than the front plate 30, and between the light emitting element 20 and the optical function layer 10. The wavelength filter layer 50 may be disposed. Further, although not shown, functional layers such as a hard coat layer and an antiglare layer may be disposed on the front surface of the front plate 30 or the antireflection filter 40. Hereafter, each element thru | or member which comprises the display apparatus by this invention is demonstrated.

<Light emitting element>
FIG. 2 is a schematic cross-sectional view showing an embodiment of a light emitting device incorporated in a display device according to the present invention. As shown in FIG. 2, the light emitting element 20 has a layer structure in which a metal cathode layer 201, an organic light emitting layer 202, and a transparent anode layer 203 are laminated in this order. Each of these layers may be supported by the glass substrate 204. In the embodiment shown in FIG. 2, the glass substrate 204 is a bottom emission type light emitting element arranged on the viewer side with respect to the transparent anode layer 203, and light emission from the organic light emitting layer 202 is emitted from the glass substrate 204. Taken from the side. On the other hand, the glass substrate 204 may be a top emission type light emitting element disposed on the metal cathode layer 201 side.

  The metal cathode layer 201 is not particularly limited as long as it can efficiently inject electrons, and aluminum, chromium, molybdenum, tungsten, copper, silver, gold, an alloy thereof, or the like can be used. Since the metal cathode layer 201 is usually formed by means of sputtering, ion plating, vacuum deposition, or the like using the metal or alloy as described above, the surface thereof becomes a mirror surface.

  The organic light emitting layer 202 is not particularly limited as long as it contains a fluorescent organic substance that emits light when a predetermined voltage is applied. For example, a quinolinol complex, an oxazole complex, various laser dyes, polyparaffins, and the like. Examples thereof include phenylene vinylene.

  The transparent anode layer 203 is a transparent conductive material that transmits visible light and is not particularly limited as long as it is a material that can inject holes. ITO, indium oxide, stannic oxide, zinc oxide, or the like is used. can do.

  In order to efficiently transport holes injected from the transparent anode layer 203 to the organic light emitting layer 202, a hole transport layer (not shown) may be provided between the positive transparent anode layer 203 and the organic light emitting layer 202. Good. An example of the constituent material of the hole transport layer is tetraphenylbenzidine. Further, a hole injection layer (not shown) may be provided between the transparent anode layer 203 and the hole transport layer. Further, an electron injection layer (not shown) or an electron transport layer (not shown) may be provided between the organic light emitting layer 202 and the metal cathode layer 201.

  In addition, the light emitting element 20 can shield moisture by providing the sealing layer 205. In the surface opposite to the surface on which the transparent substrate 204 is provided, that is, in the bottom emission type light emitting element as shown in FIG. 2, the sealing layer 205 is provided below the metal cathode layer 201, and the top In the emission type light emitting element, the light emitting element is provided on the upper side of the transparent anode layer 203. The sealing layer 205 may be formed by stacking a plurality of layers. For example, the sealing layer 205 can be formed using an oxide or oxynitride of silicon, aluminum, zinc, or tin.

<Optical function layer>
The optical functional layer 10 disposed between the light emitting element 20 and the front plate 30 is a sheet-like member that controls the light incident from the light emitting element 20 side and emits it to the viewer side. The optical functional layer 10 has a plurality of layers, and as shown in FIG. 1, a base layer 11 and a plurality of lights provided on the base layer 11 and arranged in parallel along the sheet surface. A transmission part 13 and a plurality of light absorption parts 14 provided in parallel between the light transmission parts 13 are provided.

  The optical functional layer 10 has a function of appropriately absorbing stray light and external light while controlling the optical path of the image light from the light emitting element 20 side. In the present invention, the light transmitting portion 13 of the optical functional layer 10 has a convex portion that protrudes toward the light emitting element 20 in a curved or broken line shape on the sheet thickness direction cross section. The external light specularly reflected by the metal cathode layer is diffused only in the direction perpendicular to the parallel direction of the light transmission part by the convex part of the light transmission part, so that it is absorbed or shielded by the light absorption part, and image light with excellent contrast is obtained. Can be obtained. In addition, the image light from the light emitting element diffused by the convex part of the light transmitting part is also diffused only in the direction perpendicular to the parallel direction of the light transmitting part and absorbed by the light absorbing part. There is nothing.

  In addition, since the optical functional layer 10 and the light emitting element 20 are arranged so that the top of the convex portion of the light transmitting portion 13 is in contact with the light emitting element via the air interface or has an interval of 5 mm or less, the light emitting element 20 and the optical functional layer 10 are not in optical contact, and generation of Newton rings can be suppressed. From the viewpoint of preventing the occurrence of Newton rings, the light emitting element 20 and the optical functional layer 10 may be arranged with a gap so as not to contact each other as described above. When the distance between the light emitting element 20 and the top of the convex portion of the light transmitting portion exceeds 5 mm, the image is blurred. Therefore, it is preferable that the gap distance is short. In the display device according to the present invention, even if the top of the convex portion of the light transmitting portion 13 of the optical functional layer 10 is in contact with the surface of the light emitting element 20 via the air interface, Newton rings are generated. Can be prevented.

  The base material layer 11 that constitutes the optical functional layer 10 is a layer that becomes a base material for forming a light transmission portion 13 to be described later. The base material layer 11 is preferably composed of a material mainly composed of polyethylene terephthalate (PET). When a base material layer has PET as a main component, another resin may be contained in the base material layer. Various additives may be added as appropriate. Examples of general additives include phenol-based antioxidants, lactone-based stabilizers, and the like. Here, “main component” means that the PET is contained in an amount of 50% by mass or more with respect to the entire material forming the base material layer (hereinafter the same).

  However, the main component of the material constituting the base material layer is not necessarily PET, and may be other materials. Examples thereof include polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, polyester resins such as terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, and polyamide resins such as nylon 6. , Polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymer, cellulose resins such as triacetyl cellulose, imide resins and polycarbonate resins Etc. Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, in these resins suitably as needed. In addition to performance, from the viewpoint of mass productivity, price, availability, etc., it is preferable that the base material layer is composed of a resin mainly composed of PET.

  Next, the light transmission part 13 of the optical function layer 10 will be described. 3 to 5 are schematic cross-sectional views in which a part of the optical functional layer is enlarged. The light transmission part 13 is an element having a function of transmitting image light, and as shown in FIG. 3, the light transmission part 13 is provided on the base material layer 11, and the surface of the light transmission part 13 opposite to the base material 11 is It has a shape in which convex portions 17 projecting in a curved shape are formed. The cross section of the light transmitting portion 13 has a shape extending from the back of the page to the near side.

  As the cross-sectional shape in the sheet thickness direction of the light transmitting portion 13, in FIG. 3, the shape of the convex portion 17 protruding in a curved line is an example of a light transmitting portion having a substantially semicircular cross-sectional shape. The shape is not limited to a substantially semicircular shape, and may be a shape in which the corners of both ends of the convex portion are formed in an arc shape and a so-called R is taken. Although the magnitude | size of R is not specifically limited, About the same grade as the depth of the hollow of the light absorption part mentioned later is preferable, for example, can be 0.5-6.0 micrometers. Moreover, the shape of the convex part of the light transmission part 13 may be a light transmission part having a substantially triangular cross section as a convex part protruding in a polygonal line as shown in FIG. 4, or as shown in FIG. Moreover, the convex part shape which has a polygonal line shape in which a cross section was comprised from the some side may be sufficient. The height of the convex portion 17 of the light transmitting portion 13 is preferably 1 to 6 μm. By setting this range, it is possible to further eliminate ghost and self-moire and maintain image clarity while suppressing the occurrence of Newton rings.

  3-5, the convex part 17 which has the above shape is formed in one ratio between a pair of light absorption parts 14 adjacent to the light transmission part 13 (that is, per light transmission part). However, in a preferred embodiment of the present invention, as shown in FIG. 6, it is more preferable that 2 to 10 convex portions are formed per unit of the light transmitting portion. In order to eliminate the occurrence of self moire and ghost as described above, it is preferable that the number of convex portions formed per unit of the light transmitting portion is larger. However, the optical function is such that the number of convex portions exceeds 10. It is generally difficult to produce a layer due to manufacturing process limitations.

  The above-described light transmission part can be formed by curing the light transmission part constituent composition. The refractive index of the light transmission part is not particularly limited, but is preferably 1.49 to 1.56 from the viewpoint of the availability of the applied material.

  As such a light transmissive part constituting composition, for example, a photocurable resin composition in which a photocurable prepolymer, a reactive dilution monomer and a photopolymerization initiator are blended is preferably used.

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

  Examples of the reactive dilution monomer include vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, and tetrahydrofurfuryl acrylate.

  Examples of the photopolymerization initiator include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoylformate compounds, and the like. (Methylbenzoylformate, etc.), thioxanthone compound (isopropylthioxanthone, etc.), benzophenone (benzophenone, etc.), phosphate ester compound (1,3,5-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide, etc.) and benzyldimethyl ketal. Of these, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, and bis (2,4) are preferable from the viewpoint of preventing coloring of the light transmitting portions 13, 13,. , 6-trimethylbenzoyl) -phenylphosphine oxide. In addition, it is preferable that 0.5-5.0 mass% is contained for the said photoinitiator (S1) on the basis (100 mass%) of light transmission part structure composition whole quantity.

  These photocurable prepolymers, reactive diluent monomers, and photopolymerization initiators can be used alone or in combination of two or more.

  In addition, in the light transmitting part constituting composition, if necessary, silicone additives, rheology control agents, It is also possible to add a defoaming agent, a release agent, an antistatic agent, an ultraviolet absorber and the like.

  Next, the light absorption part which comprises an optical function layer is demonstrated. As shown in FIG. 1, the light absorbing portion 14 is an element having a substantially trapezoidal cross section disposed between the light transmitting portions 13 of the optical function layer 10. It arrange | positions in parallel between the adjacent light transmission parts 13 so that the surface equivalent to the lower side of a substantially trapezoidal cross section may become the same as the bottom of the convex part of the light transmission part 13. FIG. Although not shown, the light absorbing part may have a substantially triangular cross section. Further, in a preferred embodiment of the present invention, as shown in FIG. 7A, the light absorbing portion has a shape in which a surface corresponding to the lower side of the substantially trapezoidal cross section (surface on the light emitting element side) is recessed in a concave shape. . Here, the “recessed shape” means a portion recessed in a concave shape on the viewer side (base material layer 11 side). The depth of the recess 18 is preferably 1 to 6 μm. When the depth of the depression 18 is smaller than 1 μm, the effect of diffusing video light described later may be insufficient. On the other hand, when the depth of the recess 18 exceeds 6 μm, it becomes difficult to form the light absorbing portion so as to have a predetermined shape depending on the method described later. In addition, the hypotenuse in the substantially trapezoidal cross section preferably forms an angle of 0 degrees or more and 10 degrees or less with respect to the normal direction of the sheet surface of the optical function layer 10. In addition, when the angle of the hypotenuse is close to 0 degrees, it is not a trapezoid but a rectangle.

  As shown in FIG. 7 (b), the light absorbing portion may have a cross-sectional shape in which the hypotenuse of the light absorbing portion 14b is a polygonal line, and as shown in FIG. 7 (c), the light absorbing portion 14c. The hypotenuse may be curved.

  In the case shown in FIG. 7A, the cross-sectional shape of the light absorbing portion 14a is substantially trapezoidal. Specifically, the cross-sectional shape of the light absorbing portion 14a is a substantially isosceles trapezoid having an upper side and a lower side and two oblique sides connecting the upper side and the lower side. However, since the surface corresponding to the long lower side of the substantially isosceles trapezoidal cross section (the surface on the light emitting element side) has a depression, the upper side and the lower side are not exactly parallel. Further, the hypotenuse of the substantially isosceles trapezoidal cross section forms an angle θ1 with respect to the normal line of the light incident surface of the optical functional layer. θ1 is preferably in the range of 0 to 10 degrees. A more preferable angle is 0 to 6 degrees.

  In the case shown in FIG. 7B, the hypotenuse of the light absorbing portion 14b (the hypotenuse of the light transmitting portions 13b and 13b) is composed of two sides Hb1 and Hb2 instead of one side. That is, the cross section has a polygonal oblique side. Specifically, in the oblique side of the light absorbing portion 14b, the oblique side Hb1 closer to the light emitting element side forms an angle θ2 with respect to the normal line of the sheet incident surface of the optical function layer. On the other hand, the hypotenuse Hb2 on the side close to the viewer side forms an angle θ3 with respect to the normal line of the sheet exit surface of the optical function layer. This angle is in a relation of θ2> θ3, and it is preferable that both of these angles are in the range of 0 ° to 10 °. A more preferable angle is greater than 0 degree and 6 degrees or less. Further, the example of FIG. 7B is an example in which one oblique side is constituted by two oblique sides, but a polygonal line shape may be constituted by more sides.

  In the case shown in FIG. 7C, the slope of the light absorbing portion 14c (the oblique side of the light transmitting portion 13c) is formed in a curved shape. Thus, the hypotenuse which is a substantially trapezoidal cross-sectional shape in a light absorption part may be curvilinear. Even in this case, the curve Hc2 closer to the observer side than the angle θ2 formed by the curve Hc1 closer to the light emitting element side and the normal line of the light incident surface of the optical functional layer and the light exit surface method of the optical sheet. It is preferable that the angle θ3 formed with the line is smaller. Furthermore, the angle is preferably in the range of more than 0 degree and not more than 10 degrees at any part. A more preferable angle is greater than 0 degree and 6 degrees or less. Here, the angle formed between the curved portion and the normal line of the light incident surface (or light exit surface) of the optical functional layer is divided into 10 equal parts, and the line connecting each adjacent end portion with the optical function. It is defined by the angle formed by the normal of the light incident surface (or light exit surface) of the layer.

  In addition, the shape of the light absorbing portion is not limited to that of the present embodiment, and can be appropriately changed as long as it can absorb external light appropriately. This can include, for example, a case where the cross-sectional shape is substantially rectangular. However, in any case, the surface on the light emitting element side has a depression recessed in a curved line or a polygonal line.

  The light absorbing portion 14 is made of a predetermined material having a refractive index Nb that is the same as or smaller than the refractive index Np of the light transmitting portion 13. In this way, by setting the refractive index Np of the light transmitting portion 13 and the refractive index Nb of the light absorbing portion 14 to Np ≧ Nb, light is transmitted through the interface between the light absorbing portion 14 and the light transmitting portion 13 under predetermined conditions. The image light from the light source incident on the unit 13 can be appropriately reflected and absorbed. The difference in refractive index between Np and Nb is not particularly limited, but is preferably 0 to 0.06.

  Further, in the present embodiment, the relationship of Np ≧ Nb is preferable as described above. However, the present invention is not necessarily limited to this, and the refractive index of the light transmission part can be made smaller than the refractive index of the light absorption part. It is.

  The light absorbing portion in the present embodiment is configured by filling a light absorbing portion constituent composition containing light absorbing particles and a binder resin between the light transmitting portions. That is, the light absorbing particles are dispersed in the binder resin. As a result, out of the image light incident on the optical functional layer, the image light incident on the inner side of the light absorbing portion can be absorbed by the light absorbing particles without being reflected at the interface between the light transmitting portion and the light absorbing portion. it can. Furthermore, it is possible to appropriately absorb external light from the observer side that is incident at a predetermined angle, and it is possible to improve contrast. At this time, the binder resin of the light absorbing portion is made of the material having the refractive index Nb. Although the material used as binder resin is not specifically limited, For example, the photocurable resin composition which mix | blended the following photocurable prepolymer, the reactive dilution monomer, and the photoinitiator is used preferably.

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

  Examples of the reactive dilution monomer include, as monofunctional monomers, vinyl monomers such as N-vinylpyrrolidone, N-vinylcaprolactone, vinylimidazole, vinylpyridine, and styrene, lauryl (meth) acrylate, and 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, Nonylphenoxypolyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate (Meth) acrylic acid ester monomers such as cyclohexyl (meth) acrylate, benzyl methacrylate, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylate, acryloylmorpholine, And (meth) acrylamide derivatives. 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 include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one. 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 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 invention, the amount of the photopolymerization initiator contained in the photocurable resin composition is based on the total amount of the photocurable resin composition (100% by mass) from the viewpoint of curability and cost of the photocurable resin composition. It is preferable that it is 0.5-10.0 mass%.

  These photocurable prepolymers, reactive diluent monomers, and photopolymerization initiators can be used alone or in combination of two or more.

  Specifically, a photopolymerizable component composed of urethane acrylate, epoxy acrylate, tripropylene glycol diacrylate and methoxytriethylene glycol acrylate (specifically, photocurable prepolymer and reactive dilution monomer), refractive index, viscosity, Alternatively, in consideration of the influence on the performance of the optical functional layer 12, etc., it can be arbitrarily mixed and used.

  In addition, you may add a silicone, an antifoamer, a leveling agent, a solvent, etc. to a photocurable resin composition as an additive.

  The light-absorbing particles are contained in the light-absorbing part constituting composition, and act to absorb stray light and external light when the light-absorbing part is configured.

  As the light absorbing particles, light absorbing colored particles such as carbon black are preferably used. However, the light absorbing particles are not limited to these, and colored particles that selectively absorb a specific wavelength in accordance with the characteristics of the image light may be used as the light absorbing particles. Specific examples include organic fine particles colored with metal salts such as carbon black, graphite, and black iron oxide, dyes, pigments, colored glass beads, and the like. In particular, colored organic fine particles are preferably used from the viewpoints of cost, quality, availability, and the like. More specifically, acrylic cross-linked fine particles containing carbon black, urethane cross-linked fine particles containing carbon black, and the like are preferably used. Such colored particles are usually contained in the above-mentioned photocurable resin composition in the range of 3 to 30% by mass. The average particle diameter of the colored particles is preferably 1 to 20 μm. Here, the “average particle diameter” means that obtained by particle size measurement by a mass distribution method. By using colored particles having an average particle size of 1 μm or more, when forming the light absorbing portion 14 as described below, the colored particles are not scraped off by the doctor blade, and the upper bottom portion of the light transmitting portion is formed. It can prevent remaining on.

  The means for absorbing light is not limited to the method using light absorbing particles as in this embodiment. Other examples include, for example, coloring the entire composition of the light absorbing portion constituting the light absorbing portion with a pigment or dye to form a light absorbing portion colored entirely.

  Next, the optical path of image light passing through the optical function layer 10 will be described. As described so far, in the optical function layer 10, the light transmitting portion 13 has the convex portion 17 on the light emitting element 20 side, and the light absorbing element side surface of the light absorbing portion 14 (substantially the lower side of the trapezoidal cross section) is recessed. 18. By using the optical functional layer having such a shape, the utilization efficiency of the image light can be improved. The fact that the optical functional layer can improve the use efficiency of image light will be described below with reference to FIG. FIG. 8 is a diagram schematically showing an example of an optical path of image light passing through the optical functional layer.

  As shown in FIG. 8, the image light L1 incident on the light transmitting portion 13 at a predetermined angle is first incident on the convex portion 17 and refracted. The angle θa of the image light L1 incident on the light transmitting portion 13 from the convex portion 17 with respect to the normal of the plane of the base material layer 11 is the surface on the light emitting element side of the light transmitting portion when the convex portion 17 is not provided. However, compared with the case where it forms in parallel with the surface of the base material layer 11, it becomes small. In this way, the image light incident on the convex portion 17 is refracted in the direction of condensing. A part of the image light incident on the light transmission part 13 is incident on the light absorption part from the oblique side of the light absorption part 14 and absorbed, but the image light incident on the light transmission part 13 is condensed as described above. By refracting in the direction, the image light absorbed by the light absorber 14 can be reduced. That is, when the image light is collected by the convex portion 17, when there is no convex portion 17, a part of the image light hitting the oblique side of the light absorbing portion 14 does not hit the oblique side of the light absorbing portion 14, or The angle at which the light-absorbing portion 14 hits the hypotenuse increases and is totally reflected, so that it is not absorbed by the light-absorbing portion 14. Thus, the image light that is not absorbed by the light absorbing portion 14 is emitted from the surface of the optical functional layer 10 on the base material layer 11 side to the viewer side.

  On the other hand, the image light L2 incident on the light absorbing portion 14 at a predetermined angle first enters the light absorbing portion 14 from the recess 18 and is refracted. The angle θb of the image light L2 incident on the light absorbing portion 14 from the depression 18 with respect to the incident direction of L2 is the case where the depression 18 is not provided, that is, the surface of the light absorbing portion on the light emitting element side is the surface of the base material layer 11. It becomes larger than the case where it is formed in parallel. Thus, the image light incident on the light absorbing portion 14 from the depression 18 is refracted in the diffusing direction. A part of the image light incident on the light absorbing portion 14 is absorbed by the light absorbing portion 14, but the light absorbing portion 14 is refracted in the direction of diffusing the image light incident on the light absorbing portion 14 as described above. The image light is emitted from the oblique side to the light transmitting portion 13 side, and the image light absorbed by the light absorbing particles of the light absorbing portion 14 can be reduced. That is, when the image light is diffused in the depression 18, a part of the image light absorbed by the light absorption unit 14 when there is no depression 18 is not absorbed by the light absorption particles of the light absorption unit 14. Then, the light passes through the light transmitting portion 13 and is emitted from the surface of the optical functional layer 10 on the base material layer 11 side to the viewer side.

  As described above, according to the optical functional layer, the light transmitting portion 13 has the convex portion 17 and the light absorbing portion 14 has the depression 18, thereby reducing the image light absorbed by the light absorbing portion 14. Therefore, the use efficiency of image light can be improved.

  Further, as described above, according to the optical function layer, the use efficiency of the image light can be improved in the viewing angle expansion direction. Therefore, as the viewing angle is expanded, the light absorbing portion 14 is deepened (thickened in the thickness direction of the optical function layer). And the contrast can be improved with the same viewing angle. Further, when using total reflection at the interface between the light transmission part 13 and the light absorption part 14 due to the difference in refractive index between the light transmission part 13 and the light absorption part 14, the convex part 17 of the light transmission part 13 Since the reflected light is diffused, it is possible to improve viewing angle characteristics and color unevenness due to wavelength dispersion of total reflection.

  Next, a method for manufacturing the above-described optical functional layer will be described. FIG. 9 is a cross-sectional view schematically illustrating a part of the process for an example of the method for manufacturing the optical functional layer 10. FIG. 10 is a perspective view schematically illustrating another process in the example of the method for manufacturing the optical functional layer.

  When manufacturing the optical functional layer 10, as shown in FIG. 9, the light transmission part 13 is formed on the base material layer 11 (base material 11 'containing a base material layer), and the sheet | seat 10' is obtained. In order to form the light transmission part 13, first, a mold roll 42 having a groove having a shape corresponding to the shape of the light transmission part 13 at a predetermined pitch is prepared. Next, the base material 11 ′ is fed between the mold roll 42 and the nip roll 41. The arrow shown in FIG. 9 is the direction in which the substrate 11 'is fed. In accordance with the feeding of the base material 11 ′, the droplets of the light transmitting portion constituting composition 30 are continuously supplied from the supply device 40 between the mold roll 42 and the base material 11 ′. When the light transmitting portion constituting composition 30 is supplied onto the base material 11 ′ from the supply device 40, a bank 31 in which the light transmitting portion constituting composition 30 is accumulated is formed between the mold roll 42 and the base material 11 ′. To be. In the bank 31, the light transmitting portion constituting composition 30 spreads in the width direction of the base material 11 '.

  The light transmitting part constituting composition supplied between the mold roll 42 and the base material 11 ′ as described above is formed by the pressing force between the mold roll 42 and the nip roll 41. 42 is filled. Thereafter, the light transmissive part 13 can be formed by irradiating the light transmissive part constituting composition with light by the light irradiation device 44 and curing the light transmissive part constituting composition. After the light transmission part 13 is formed, the sheet 10 ′ on which the light transmission part 13 is formed on the sheet 11 ′ is pulled away from the mold roll 42 by being pulled through the peeling roll 43.

  Next, as shown in FIG. 10, the light absorbing portion 14 is formed between the light transmitting portions 13 of the sheet 10 ′ to obtain the optical functional layer 10. Specifically, the light absorbing portion constituting composition 36 is supplied onto the light transmitting portion 13, and the light absorbing portion constituting composition 36 is filled in the grooves 37 between the light transmitting portions 13 by the doctor blade 35, while surplus portions are filled. The light absorbing portion 14 is formed by scraping off the light absorbing portion constituting composition 36 and irradiating and curing the light absorbing portion constituting composition 36 remaining in the groove 37 between the light transmitting portions 13. it can. Note that the arrow shown in FIG. 10 is the feeding direction of the sheet 10 '.

  At this time, it is preferable that the elastic modulus of the light transmission part 13 is 10 MPa or more and less than 2000 MPa. When the elastic modulus of the light transmitting portion 13 is 2000 MPa or more, it becomes hard and defects such as cracks and chipping occur, and when the light absorbing portion 14 is formed as described above, the appearance of the optical functional layer is poor. May occur, or the transmittance of the optical functional layer may decrease. That is, when the light transmission part 13 is too hard, when the surplus portion of the light absorbing part constituting composition 36 supplied onto the light transmission part 13 is scraped by the doctor blade 35, the doctor blade 35 is pressed against the light transmission part 13. However, since the light transmission part 13 does not deform | transform, there exists a possibility that the excess light absorption part structural composition 36 may not be scraped off. If the elastic modulus of the light transmitting portion 13 is within the above range, when the doctor blade 35 is pressed, due to the deformation of the light transmitting portion 13, the scraping failure of the excess light absorbing portion constituting composition 36 is eliminated, and the optical functional layer It is possible to prevent the appearance of the surface from being poor and the transmittance of the optical functional layer 12 from being lowered. In addition, since the light transmission part 13 is too soft when the elastic modulus of the light transmission part 13 is 10 MPa or less, the light transmission part 13 becomes difficult to release from the mold roll 42 in the process shown in FIG.

<Front plate>
The front plate 30 disposed closer to the viewer than the optical functional layer 10 of the display device 1 has a function of protecting the surface of the optical functional layer described above and a function of giving design appearance to the appearance of the display device. It is. As the front plate, a glass plate is usually used, but the front plate is not limited to this and may be a transparent resin plate. As a transparent resin board, if it has said function, it can use without a restriction | limiting especially, For example, polyester resin boards, such as a polyethylene terephthalate, an acrylic resin board, a polycarbonate resin board, etc. are mentioned.

<Other layers>
In the embodiment of the present invention, in addition to the optical functional layer 10, the light emitting element 20, and the front plate 30 described above, the display device 1 prevents reflection on the viewer side of the front plate 30 as shown in FIG. 1. The filter 40 may be disposed, and the wavelength filter layer 50 may be disposed between the light emitting element 20 and the optical function layer 10. Further, a functional layer such as a hard coat layer or an antiglare layer may be disposed on the front plate or the forefront of the antireflection filter 40. Each of these functional layers is laminated via an adhesive layer. This adhesive layer may contain a UV absorber, a toning pigment, and the like as necessary.

  First, the wavelength filter layer 50 will be described. The wavelength filter layer 50 is a layer having a function of suppressing transmission of light having a predetermined wavelength. The wavelength whose transmission should be suppressed can be appropriately selected as necessary. Specific examples of the wavelength filter layer include a layer that cuts infrared rays, near infrared rays, and ultraviolet rays, a layer that adjusts color tone, and the like. Hereinafter, a layer for adjusting the color tone (color tone adjusting filter) and a layer for cutting off ultraviolet rays (ultraviolet absorption filter) will be described.

  The color tone adjustment filter is for adjusting the color of the display filter in order to improve the color purity of the light emitted from the panel, the color reproduction range, the display color when the power is turned off, and the like. For example, a film in which a color tone-adjusting dye is dispersed in a binder resin is formed into a film, or this is applied onto a transparent substrate or other functional filter, and formed through drying, curing treatment, or the like as necessary. can do. As the color tone adjusting dye, a known dye having a maximum absorption wavelength in the visible region of 380 to 780 nm can be used in combination with any dye according to the purpose. Examples of known dyes that can be used as the color tone adjusting dyes include the dyes described in JP 2000-275432 A, JP 2001-188121 A, JP 2001-350013 A, JP 2002-131530 A, and the like. Can be suitably used. In addition to these, pigments such as anthraquinone, naphthalene, azo, phthalocyanine, pyromethene, tetraazaporphyrin, squarylium, cyanine, which absorb visible light such as yellow light, red light, blue light, etc. Can be used.

  As the binder resin, a resin such as a polyester resin, a polyurethane resin, an acrylic resin, or an epoxy resin is used. Binder resin drying and curing methods include a drying and solidification method by drying a solvent (or dispersion medium) from a solution (or emulsion), a polymerization method using energy such as heat, ultraviolet rays, and electron beams, a curing method using a crosslinking reaction, Alternatively, a curing method using a reaction such as crosslinking or polymerization between a functional group such as a hydroxyl group or an epoxy group in a resin and an isocyanate group in a curing agent can be applied.

  As an ultraviolet absorption filter, for example, a film in which a composition in which an ultraviolet absorber is dispersed in a binder resin is formed, or this is applied onto a transparent substrate or other functional filter, and dried and cured as necessary. Or the like. Examples of the ultraviolet absorber include organic compounds such as benzotriazole and benzophenone, and inorganic compounds composed of particulate zinc oxide, cerium oxide, and the like. As the binder resin, the resins listed in the above-mentioned color tone adjustment filter can be used.

  Next, the antireflection layer 40 will be described. The antireflection layer 40 is a layer that is disposed closest to the viewer and has a function of preventing reflection of external light. According to this, it is possible to prevent external light from being reflected on the surface of the front plate on the viewer side and returning to the viewer side, so-called reflection is generated, making it difficult to see the image. Such an antireflection layer can be constituted by using a commercially available antireflection film.

  In the above description, the display device 10 including the light emitting element 20, the optical function layer 10, the front plate 30, the wavelength filter layer 50, and the antireflection layer 40 has been described. However, the display device according to the present invention at least emits light. What is necessary is just to provide the element 20, the optical function layer 10, and the front plate 30, and the layer which has various functions other than the layer demonstrated so far according to a use can also be provided. As other layers that can be provided in the display device of the present invention, those used in a conventional display device can be used without any particular limitation. Specifically, an anti-glare layer, a hard-coat layer, etc. can be comprised by bonding using an adhesion layer. In addition, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer may include a UV absorber, a near-infrared absorber, a toning pigment, and the like, and the pressure-sensitive adhesive layer may also serve as a wavelength filter layer. The order of stacking these layers and the number of stacks are appropriately determined according to the application of the display device. Hereinafter, functions of the antiglare layer and the hard coat layer and the adhesive layer will be described.

  The antiglare layer is a layer having a function of suppressing so-called glare and is sometimes called an antiglare layer or an AG layer. A commercially available layer can be used as such an antiglare layer.

  The hard coat layer may be referred to as an HC layer. This is a layer in which a film having a function capable of imparting scratch resistance is provided in order to prevent the image display surface from being scratched.

  The pressure-sensitive adhesive means a material that can be bonded only with the tackiness of the surface only by moderate pressurization (usually, light pressing by hand). In order to develop the adhesive strength of the pressure-sensitive adhesive, usually, physical energy or action such as heating, humidification, radiation (ultraviolet ray, electron beam, etc.) irradiation is unnecessary, and chemical reaction such as polymerization reaction is also unnecessary. In addition, the pressure-sensitive adhesive can maintain the adhesive strength to the extent that it can be re-peeled after bonding. The thickness of the adhesive layer is preferably 20 to 50 μm or less. Note that the thickness of the adhesive layer refers to the thickness of the thickest portion of the adhesive layer 20.

  The pressure-sensitive adhesive layer is a pressure-sensitive adhesive having an acid value as a pressure-sensitive adhesive used for the pressure-sensitive adhesive layer from the viewpoint of enhancing the adhesion between the optical functional layer 10 described below and the front plate 30 or the various functional layers described above. It is preferable to use an agent. As an adhesive which has an acid value, what has an acid value is mentioned, for example among natural rubber and a synthetic resin. Examples of the adhesive having an acid value include those composed of a substance having a carboxyl group in the molecule. Specifically, an acrylic adhesive is preferable from the viewpoint of high transparency. Moreover, it is preferable from the point which can make adhesiveness favorable that the acid value of an acrylic adhesive is 1 or more.

  As an acrylic pressure-sensitive adhesive having an acid value contained in the pressure-sensitive adhesive layer, light-transmitting light from the light-emitting element has appropriate adhesive strength, transparency, and coating suitability from those commonly used as known pressure-sensitive adhesives. A material that does not substantially change the spectrum is appropriately selected.

  The acrylic pressure-sensitive adhesive having an acid value is a polymer containing at least a (meth) acrylic acid alkyl ester monomer and is a (meth) acrylic acid alkyl ester monomer having an alkyl group of about 1 to 18 carbon atoms. Generally, it is a copolymer of a monomer having a carboxyl group. In the present invention, (meth) acrylic acid refers to acrylic acid and / or methacrylic acid.

  Examples of (meth) acrylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, sec-propyl (meth) acrylate, (meth) acrylic acid. n-butyl, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid Examples thereof include n-octyl, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, undecyl (meth) acrylate, and lauryl (meth) acrylate. Of these, butyl acrylate and 2-ethylhexyl acrylate are preferable, and butyl acrylate and 2-ethylhexyl acrylate are preferably used in combination. Moreover, the said (meth) acrylic-acid alkylester is normally copolymerized in the quantity of 30.0-99.5 mass parts in the acrylic adhesive.

  Moreover, as a monomer which has a carboxyl group which forms an acrylic adhesive, monomers containing a carboxyl group such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, monobutyl maleate and β-carboxyethyl acrylate are used. Can be mentioned.

  Furthermore, in addition to the above, the acrylic pressure-sensitive adhesive used in the present invention may be copolymerized with a monomer having another functional group within a range that does not impair the characteristics of the acrylic pressure-sensitive adhesive. Examples of monomers having other functional groups include monomers containing hydroxyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and allyl alcohol; (meth) acrylamide, N-methyl Monomers containing amide groups such as (meth) acrylamide and N-ethyl (meth) acrylamide; Monomers containing amide groups and methylol groups such as N-methylol (meth) acrylamide and dimethylol (meth) acrylamide; Monomers containing amino groups such as (meth) acrylate and dimethylaminoethyl (meth) acrylate; and epoxy group-containing monomers such as allyl glycidyl ether and (meth) acrylic acid glycidyl ether. Other examples include fluorine-substituted (meth) acrylic acid alkyl esters and (meth) acrylonitrile, vinyl group-containing aromatic compounds such as styrene, methylstyrene, and vinylpyridine, vinyl acetate, and vinyl halide compounds. it can.

  Furthermore, in the acrylic pressure-sensitive adhesive used in the present invention, in addition to the monomer having other functional groups as described above, another monomer having an ethylenic double bond can be used. Examples of monomers having an ethylenic double bond include diesters of α, β-unsaturated dibasic acids such as dibutyl maleate, dioctyl maleate and dibutyl fumarate; vinyl esters such as vinyl propionate; vinyl ethers; And vinyl aromatic compounds such as vinyl toluene.

  In addition to the monomer having an ethylenic double bond as described above, a compound having two or more ethylenic double bonds may be used in combination. Examples of such compounds include divinylbenzene, diallyl malate, diallyl phthalate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, methylene bis (meth) acrylamide, and the like.

  Furthermore, in addition to the above-described monomers, monomers having an alkoxyalkyl chain can be used. Examples of (meth) acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, and 3-methoxypropyl (meth) acrylate. , 2-methoxybutyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4-ethoxybutyl (meth) acrylate And so on. As commercial products of these acrylic pressure-sensitive adhesives, for example, “5407” manufactured by Nippon Synthetic Chemical Co., Ltd. is preferably used. Moreover, a hardening | curing agent (crosslinking agent), such as an isocyanate compound, a tackifier, a silane coupling agent, a filler, etc. can be mix | blended with an adhesion layer as needed.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

Example 1
(1) Manufacture of mold for forming light transmitting portion Grooves were cut in the circumferential direction using two kinds of diamond tools on a cylindrical roll having a surface plated with copper. The first diamond cutting tool is a slope with a tip width of 35 μm and a slope angle of 2.3 ° in the depth direction, and when the depth is 91 μm, it forms a substantially trapezoidal portion of the light transmission part with a cutting tool width of 42 μm. Of bytes. The second diamond cutting tool has a triangular shape with a tip width of 35 μm and a depth of 3 μm, and forms a convex portion (triangular shape) of the light transmitting portion. First, using the first diamond bite, the outer periphery of the copper-plated layer of the mold roll was formed on the outer peripheral surface of the copper-plated roll at equal intervals over the entire width, with the groove pitch in the roll axis direction being 45 μm. A groove was formed by cutting. Next, using the second diamond tool, the bottom of the groove was cut by 3 μm, and after feeding 45 μm, the same cutting was repeated repeatedly. A triangular shape having a depth of 91 μm, a groove bottom width of 35 μm, and a groove bottom of 35 μm and a depth of 3 μm is formed. A mold having a slope angle of 2.3 °, a mold surface width of 3 μm, and an opening width of 42 μm is formed at an equal pitch. Formed. The cross-sectional shape of a part of one groove of the roll cut as described above was as shown in FIG. The outer peripheral surface of this roll was chrome-plated to produce a light transmission portion forming die roll.

(2) Preparation of light-transmitting resin composition 40.0 parts by mass of bisphenol A-ethylene oxide 2 mol adduct, 15.0 parts by mass of isophorone diisocyanate, and bismuth tri (2-ethylhexanoate) as a urethanization catalyst (2-ethylhexanoic acid 50% solution) was mixed with 0.02 parts by mass and reacted at 80 ° C. for 5 hours. Thereafter, 5.0 parts by mass of 2-hydroxyethyl acrylate was added, and the mixture was stirred at 80 ° C. for 5 hours. It was made to react for a time and the photocurable prepolymer (P1) was obtained.

  Next, 60.0 parts by mass of the photocurable prepolymer (P1), 15.0 parts by mass of phenoxyethyl acrylate as the reactive diluent monomer (M1), and diacrylate obtained by adding 4 mol of bisphenol A-ethylene oxide were added. 25.0 parts by mass and 0.05 parts by mass of a phosphoric acid ester (monoester / diester = molar ratio 1/1) added with 10 mol of tetradecanol-ethylene oxide as a mold release agent (S1), and 0.05 parts by mass of 15 mol adduct of stearylamine-ethylene oxide and 3 of 1-hydroxycyclohexylphenylketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) as a photopolymerization initiator (I1) 0.0 part by mass was mixed and homogenized to obtain a light transmissive resin composition.

The light-transmitting resin composition was applied at a thickness of 100 μm, and the resin composition was cured by irradiating an ultraviolet ray of 800 mJ / cm ² with a high-pressure mercury lamp, and a multi-wavelength Abbe refractometer DR-M4 (Atago Co., Ltd.). The refractive index of 589 nm was measured using a

(3) Formation of light transmission part of optical functional layer PET film having a thickness of 100 μm as a substrate between the metal roll and nip roll produced in (1) above (trade name: A4300, manufactured by Toyobo Co., Ltd.) Transported. In accordance with the conveyance of the base material, the light-transmitting resin composition obtained in the above (2) is supplied to the one surface of the base material from the supply device, and the pressing force between the mold roll and the nip roll causes the base material and The light transmitting part constituting composition was filled between the mold rolls. Then, 800 mJ / cm < ² > of ultraviolet rays were irradiated from the base material side with the high pressure mercury lamp, the light transmissive part constituent composition was hardened, and the light transmissive part was formed. Then, the base material in which the light transmission part was formed was released from the mold roll with the peeling roll, and the sheet | seat (intermediate member) whose thickness including a light transmission part is 205 micrometers +/- 10micrometer was produced.

  The elastic modulus of the light transmitting portion was measured by applying a load to the micro indenter material using a compression micro hardness tester (FISCHER HM2000) and unloading it. At this time, the load force was 100 mN, the load speed was 4 μm / 10 seconds, and the holding time was 60 seconds. As a result, the elastic modulus of the light transmission part was 800 MPa. Further, at this time, the light transmission part had a shape corresponding to the groove of the mold roll.

(4) Preparation of resin composition for forming light absorbing portion As photocurable prepolymer (P2), ethylene oxide, 2,2 ′-[(1-methylethylidene) bis (4,1-phenyleneoxymethylene)] bis- , Homopolymer, 2-propenoate 20.0 parts by mass, 2-phenoxyethyl acrylate as reactive diluent monomer (M2) 20.0 parts by mass, α-acryloyl-ω-phenoxypoly (oxyethylene) 20.0 parts by mass, and 13.0 parts by mass of 2- {2- [2- (acryloyloxy) (methyl) ethoxy] (methyl) ethoxy} (methyl) ethyl acrylate, and average particles as light-absorbing particles 20.0 parts by mass of acrylic crosslinked fine particles (manufactured by Ganz Kasei Co., Ltd.) containing 25% of carbon black having a diameter of 4.0 μm and a photopolymerization initiator (I2) 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) and 7 parts by mass were mixed and homogenized to obtain a light absorbing part constituting composition.

A composition obtained by removing light absorbing particles from the light absorbing portion constituting composition was applied at a thickness of 10 μm, cured by irradiating with 800 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp, and a multi-wavelength Abbe refractometer DR- It was 1.540 when the refractive index of 589 nm was measured using M4 (made by Atago Co., Ltd.).

(5) Formation of light absorbing portion of optical functional layer The light absorbing portion molding resin composition obtained in (4) above was supplied from the supply device onto the intermediate member prepared in (3) above. In addition, using a doctor blade disposed substantially perpendicular to the traveling direction of the intermediate member, the light absorbing portion constituting composition supplied onto the intermediate member is formed into a substantially V-shaped groove (between the light transmitting portions) formed in the intermediate member. In addition, the excess light absorbing portion constituting composition was scraped off. Thereafter, 800 mJ / cm ² of ultraviolet light was irradiated from a high pressure mercury lamp to cure the resin composition for forming a light absorption part, thereby forming a light absorption part. In this state, a recess having a depth of 3 μm was generated on the surface of the light absorbing portion.

After coating the resin from which light-absorbing particles are removed from the same material as the light-absorbing part on the dent on the light-absorbing part, scrape the surplus with a doctor blade and irradiate with 800 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp. Then, when the light absorbing portion constituting composition was cured and cured, the dent was improved to 1.5 μm.

(8) Assembly of display device The optical functional layer obtained above and a glass plate having a thickness of 2 mm were bonded together using an adhesive so that the glass plate was disposed on the substrate side of the optical functional layer. . As the pressure-sensitive adhesive, 100 parts by mass of an acrylic resin pressure-sensitive adhesive (trade name: SK Dyne 2094, Soken Chemical Co., Ltd., solid content: 25.0%, solvents are ethyl acetate and methyl ethyl ketone), and a crosslinking agent (E-5XM) , L-45, Soken Chemical Co., Ltd., solid content 5.0%) 0.28 parts by mass, 1,2,3-benzotriazole 0.25 parts by mass, diluent solvent (toluene / methyl ethyl ketone / cyclohexanone = 27.69 g / 27.69 g / 4.61 g) and 32.0 parts by mass were used.

  The original optical functional layer and glass plate that were bonded to a commercially available organic EL display device (XEL-1, manufactured by Sony Corporation) are peeled off. Instead, the bonded optical functional layer and glass plate obtained above are used. Each member was clamped by being assembled. At this time, the top part of the convex part of the light transmission part of the optical functional layer was in contact with the panel of the organic EL display device through the air interface. In this state, it was visually confirmed whether Newton rings were generated. Reference Example 1 was obtained by removing the optical functional layer and the glass plate from the organic EL display device.

Example 2
Display is performed in the same manner as in Example 1 except that the triangular shape of the convex portion of the light transmitting portion of the optical function layer in Example 1 is changed to a lenticular lens shape (a part of an arc shape) having a width of 35 μm and a depth of 3 μm. A device was prepared and evaluated in the same manner as described above.

Example 3
Display is performed in the same manner as in Example 1 except that the convex portions of the light transmission part of the optical functional layer of Example 1 are formed with triangular pitches of about 8 μm width and 1 μm depth on the groove bottom for four pitches. A device was prepared and evaluated in the same manner as described above. In addition, the cross-sectional shape of a part of one groove of the roll for forming the light transmitting portion having such a shape is as shown in FIG.

Example 4
The convex portion of the light transmission part of the optical functional layer of Example 2 is displayed in the same manner as in Example 2 except that convex parts of a lenticular lens shape having a width of about 8 μm and a depth of 1 μm are formed on the groove bottom for four pitches. A device was prepared and evaluated in the same manner as described above.

Comparative Example 1
In the production of the optical functional layer of Example 1, an optical functional layer was formed in the same manner as in Example 1 except that the mold was formed without using the second diamond tool. The obtained optical functional layer has a structure that does not have a convex portion (triangular convex portion) in the optical functional layer of Example 1. Using this optical functional layer, a display device was produced in the same manner as in Example 1. At this time, the portion corresponding to the upper side of the substantially trapezoidal cross section of the light transmitting portion of the optical functional layer was in contact with the panel of the organic EL display device. In this state, it was visually confirmed whether Newton rings were generated.

Comparative Example 2
In the display device produced in Comparative Example 1, the display device was assembled by sandwiching a diffusion sheet between the organic EL element and the optical functional layer, and the obtained display device was evaluated in the same manner as described above.
The diffusion sheet was produced as follows.

(1) Preparation of diffusion layer forming mold A roll body having a diameter of 400 mm, a length of 1680 mm, and a layer to be processed by hard copper plating was prepared. The hard copper plating of the layer to be processed had a mirror-finished thickness of 0.5 mm and a hardness of 205 Hv.

The first blasting process and the second blasting process were performed in this order on the prepared roll body, and a roll mold was produced. The blasting conditions were as follows.
<Blasting>
・ Abrasive material: Glass beads ・ Abrasive average particle size: 68 μm
-Pressure to discharge abrasive: 0.15 MPa
・ Abrasive discharge nozzle diameter: 9mm
・ Distance between discharge nozzle and roll surface: 200mm
・ Number of scans (pass): 2 times

(2) Production of Diffusion Sheet A PET film (trade name: A4300, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was conveyed as a base material between the metal roll and nip roll produced in (1) above. In accordance with the conveyance of the base material, the same resin composition as the light-transmitting resin composition used in Example 1 is supplied from the supply device to one surface of the base material, and the pressing force between the mold roll and the nip roll is used. The resin composition was filled between the substrate and the mold roll. Then, the diffusion layer was formed by irradiating 700 mJ / cm < ² > of ultraviolet rays with a high pressure mercury lamp from the base material side, and hardening a resin composition. Thereafter, the base material on which the diffusion layer was formed was released from the mold roll with a release roll, and a diffusion sheet having a thickness including the diffusion layer of 205 μm ± 10 μm was produced. The Bayes of the diffusion sheet was 22%.

The evaluation results were as shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 Display apparatus 10 Optical functional layer 11 Base material layer 13 Light transmission part 14 Light absorption part 20 Light emitting element (organic EL element)
DESCRIPTION OF SYMBOLS 30 Front plate 40 Antireflection filter layer 50 Wavelength filter layer 201 Metal cathode layer 202 Organic light emitting layer 203 Transparent anode layer 204 Glass substrate 205 Sealing layer

Claims (9)

A light emitting device in which a metal cathode layer, an organic light emitting layer, and a transparent anode layer are laminated in this order;
An optical functional layer that is arranged closer to the viewer than the light emitting device, and controls the incident light from the light emitting device to be emitted to the viewer;
A front plate disposed closer to the viewer than the optical functional layer;
A display device comprising at least
The optical functional layer is provided on the base material layer, the base material layer, a plurality of light transmission parts arranged in parallel along the sheet surface, and a plurality of light transmission parts provided in parallel between the light transmission parts. A light absorption part,
The light transmissive portion has a convex portion in which the surface on the light emitting element side protrudes toward the light emitting element side in a curved or broken line shape in the sheet thickness direction cross section,
The light emitting element and the optical functional layer are arranged so that the top of the convex part of the light transmitting part is in contact with the light emitting element via an air interface or has a distance of 5 mm or less. apparatus.   The display device according to claim 1, wherein a height of the convex portion of the light transmission portion is 1 to 6 μm.   The display device according to claim 1, wherein 2 to 10 convex portions are provided between a pair of light absorbing portions adjacent to the light transmitting portion.   The light absorption part of the said optical function layer has the shape where the surface at the side of the said light emitting element was dented in the said observer side in the sheet | seat thickness direction cross section, It is any one of Claims 1-3. Display device.   The display device according to claim 4, wherein a depth of the concave portion of the light absorbing portion is 0.5 to 6 μm.   6. At least one functional layer selected from the group consisting of an antireflection filter, a hard coat layer, a wavelength filter layer, and an antiglare layer is disposed closer to the viewer than the optical functional layer. The display device according to any one of the above.   The display device according to claim 1, wherein the light emitting element is an organic EL element.   The display device according to claim 7, wherein the organic EL element is of a top emission type and includes a sealing layer on the outermost surface on the viewer side.   The display device according to claim 7, wherein the organic EL element is a bottom emission type and includes a transparent substrate on the outermost surface on the viewer side.

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