Display body

Abstract

To provide a display body capable of realizing a desired luminance distribution.SOLUTION: In display bodies 1a, 1b, 2 equipped with a display device including a light source, and light diffusion control layers 11a, 11b having a regular internal structure having multiple areas having a relatively high refractive index in an area having a relatively low refractive index, the light diffusion control layers 11a, 11b exist in a position between display surfaces of the display bodies 1a, 1b, 2 and the light source; the ratio of luminance (cd / m2) of the display bodies 1a, 1b, 2 using luminance (cd / m2) of the display device alone as a reference is equal to or more than 90% and less than 100% when it is measured from a direction of an angle to the normal line of the display surface of 0°; and the ratio is equal to or more than 100% and is equal to or less than 180% when it is measured from at least one direction of angles to the normal line of the display surface of -75°, -65°, -55°, -45°, 45°, 55°, 65°, and 75°.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display having a light diffusion control layer that can transmit and diffuse incident light within a predetermined range of incident angles in a strong manner with low light loss. [Background technology]

[0002] Some displays equipped with liquid crystal displays have a backlight as a light source. In such liquid crystal displays, the desired display is realized by partially blocking or transmitting the light emitted from the backlight through the liquid crystal layer. In addition, displays equipped with organic electroluminescence (EL) displays realize the desired display by selectively emitting light from the organic EL elements provided in the display.

[0003] In displays including the above-mentioned liquid crystal displays or organic EL displays, attempts have been made to improve visibility by using a light diffusion control layer that can transmit and diffuse incident light within a predetermined range of incident angles in a strong manner with low optical loss.

[0004] For example, Patent Document 1 discloses a display device that includes a predetermined display device and a predetermined optical film for the purpose of improving brightness and color change associated with changes in viewing angle. Patent Document 2 also discloses an optical sheet that includes a first light control layer and a second light control layer, each of which has a predetermined micropattern formed thereon, for the purpose of improving brightness and suppressing color change when an organic EL light-emitting unit is turned on. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-115421 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-176132 Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable for displays including the above-mentioned liquid crystal displays and organic EL displays to exhibit a luminance distribution according to their intended use. Displays not including the above-mentioned light diffusion control layer typically exhibit the brightest and easiest display when viewed from the front (perpendicular to the display surface). However, for example, when the display is used as a television, it is required that the display be sufficiently bright and visible not only when viewed from the front but also when viewed from an oblique direction. Furthermore, when the display is used as a monitor installed in the center of a vehicle dashboard, it is required that the display be preferentially bright toward the driver's seat and passenger seat rather than the front. However, conventional displays have not been able to fully meet these requirements, and it has been particularly difficult to effectively control the luminance distribution according to the intended use.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide a display device that can realize a desired luminance distribution. [Means for solving the problem]

[0008] In order to achieve the above object, firstly, the present invention provides a display body including a display device including a light source, and a light diffusion control layer having a regular internal structure with a plurality of regions with a relatively high refractive index within a region with a relatively low refractive index, wherein the light diffusion control layer is located somewhere between a display surface of the display body and the light source, and the luminance (cd / m) of the display body alone when the light source is turned on is controlled to be 100%. 2 ) as a reference, the luminance (cd / m 2The present invention provides a display device characterized in that the ratio of the angle between the normal to the display surface and the display area is 90% or more and less than 100% when measured from a direction where the angle between the normal to the display surface and the display area is 0°, and is 100% or more and 180% or less when measured from at least one of the directions where the angle between the normal to the display surface and the display area is -75°, -65°, -55°, -45°, 45°, 55°, 65°, and 75° (Invention 1).

[0009] The display according to the above invention (Invention 1) satisfies the above conditions regarding brightness, and thus can satisfactorily achieve a desired brightness distribution.

[0010] In the above invention (Invention 1), it is preferable that the display body has at least two light diffusion control layers, and each of the light diffusion control layers is located somewhere between the display surface of the display body and the light source (Invention 2).

[0011] In the above inventions (Inventions 1 and 2), it is preferable that the diffusion central axis of the light diffusion control layer is not parallel to the normal to the display surface (Invention 3).

[0012] In the above invention (Invention 2), it is preferable that at least one set of the light diffusion control layers present in the display body is laminated so that the diffusion central axes of the layers are not parallel to each other (Invention 4).

[0013] In the above inventions (Inventions 2 and 4), it is preferable that the number of the light diffusion control layers provided on the display is four or less (Invention 5).

[0014] In the above inventions (Inventions 1 to 5), the regular internal structure is preferably a louver structure in which a plurality of plate-shaped regions, which are regions with a relatively high refractive index, are regularly arranged in any one direction parallel to one surface of the light diffusion control layer within the region with a relatively low refractive index (Invention 6).

[0015] In the above inventions (Inventions 1 to 5), the regular internal structure is preferably a columnar structure in which a plurality of pillars representing the region with a relatively high refractive index are arranged in the thickness direction of the light diffusion control layer within the region with a relatively low refractive index (Invention 7).

[0016] In the above inventions (Inventions 1 to 7), the display device preferably includes a liquid crystal display and a backlight unit as the light source (Invention 8).

[0017] In the above invention (Invention 8), it is preferable that the light diffusion control layer is located between the polarizer that is closest to the display surface among the polarizers that constitute the liquid crystal display and the liquid crystal layer that constitutes the liquid crystal display (Invention 9).

[0018] In the above invention (Invention 8), the light diffusion control layer is preferably located between the liquid crystal display and the backlight unit (Invention 10).

[0019] In the above inventions (Inventions 1 to 10), the display device is preferably an organic electroluminescence (EL) display or a micro light-emitting diode (LED) display (Invention 11). [Effects of the Invention]

[0020] The display according to the present invention can achieve a desired luminance distribution. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of an example of a display according to an embodiment of the present invention. [Figure 2] FIG. 10 is a cross-sectional view of another example of a display according to an embodiment of the present invention. [Figure 3] 1 is a perspective view schematically illustrating an example of a regular internal structure of a light diffusion control layer in one embodiment of the present invention. [Figure 4] 1 is a graph showing some of the results of Test Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described. The display according to this embodiment comprises a display device including a light source, and a light diffusion control layer having a regular internal structure with a plurality of regions with a relatively high refractive index within a region with a relatively low refractive index.

[0023] In the display according to this embodiment, the light diffusion control layer is located somewhere between the display surface of the display and the light source.

[0024] Furthermore, in the display according to this embodiment, the luminance (cd / m 2 ) is the luminance (cd / m 2 ) is When measured from a direction where the angle between the normal to the display surface and the screen is 0°, the image quality is 90% or more but less than 100%. The condition that the brightness is 100% or more and 180% or less is satisfied when measured from at least one of the following angles relative to the normal to the display surface: -75°, -65°, -55°, -45°, 45°, 55°, 65°, and 75°. Details of the method for measuring the brightness are as described in the test examples below.

[0025] In the display according to this embodiment, from the viewpoint of easily satisfying the above-mentioned condition regarding brightness, it is preferable that the display has at least two light diffusion control layers. Even in this case, each of the light diffusion control layers is located somewhere between the display surface of the display and the light source.

[0026] Fig. 1 shows an example of a display according to this embodiment that includes two light diffusion control layers. In particular, in the displays 1a and 1b shown in Fig. 1, the display device includes a liquid crystal display and a backlight unit 13 as the light source. The liquid crystal display includes two polarizing plates 14a and 14b and a liquid crystal layer 12 positioned therebetween. Furthermore, the displays 1a and 1b shown in Fig. 1 include two light diffusion control layers 11a and 11b.

[0027] In the display body 1a shown in Figure 1(a), each of the two light diffusion control layers 11a, 11b is located between the polarizing plate 14a that is closest to the display surface of the display body 1a (the surface of the display body 1a opposite to the display body 1a) among the polarizing plates that make up the liquid crystal display, and the liquid crystal layer 12 that makes up the liquid crystal display.

[0028] In addition, in the display 1b shown in FIG. 1(b), each of the two light diffusion control layers 11a and 11b is positioned between the liquid crystal display and the backlight unit 13.

[0029] Furthermore, Fig. 2 shows another example of a display according to this embodiment. In particular, in the display 2 shown in Fig. 2, the display device designated by the reference numeral 15 is an organic electroluminescence (EL) display or a micro light-emitting diode (LED) display. In the display 2, two light diffusion control layers 11a and 11b are each provided on the display surface side (upper side in the drawing) of the display device.

[0030] As in these examples, the display according to this embodiment includes a light diffusion control layer at a position somewhere between the display surface and the light source, and satisfies the above-mentioned conditions regarding brightness, so that when the display device is operated to display, the brightness distribution on the display surface can be displayed as desired. This is due to the effect of the light diffusion control layer, which diffuses light from the light source in the desired direction.

[0031] Therefore, with the display according to this embodiment, for example, the luminance distribution of the display surface is made uniform in all directions, making the display easy to view not only from the front direction but also from oblique directions. Alternatively, by suppressing diffuse transmission in the front direction and facilitating diffuse transmission in oblique directions, it is possible to make the display particularly bright when viewed from oblique directions.

[0032] In the display according to this embodiment, from the viewpoint of making it easier to achieve a desired luminance distribution, the luminance ratio in the 0° direction is preferably 92% or more, more preferably 94% or more, particularly preferably 95% or more, and even more preferably 97% or more. Note that the upper limit of this ratio is less than 100% as described above, but may be, for example, 99.9% or less, particularly 99% or less.

[0033] Furthermore, in the display according to this embodiment, from the viewpoint of making it easier to achieve a desired luminance distribution, the luminance ratio in at least one direction of -75°, -65°, -55°, -45°, 45°, 55°, 65°, and 75° is preferably 105% or more, more preferably 110% or more, particularly preferably 115% or more, and even more preferably 120% or more. Moreover, this ratio is preferably 175% or less, more preferably 170% or less, particularly preferably 165% or less, and even more preferably 160% or less.

[0034] Furthermore, the above-mentioned brightness conditions can be achieved by adjusting the type and number of light diffusion control layers, the stacking direction, etc. For example, as will be described later, the regular internal structure of the light diffusion control layer can be of various types, such as a louver structure and a column structure, and the diffusion method differs depending on the type. Furthermore, the light diffusion control layer has a unique diffusion central axis, which serves as a guide for the diffusion direction. By appropriately selecting light diffusion control layers having a predetermined regular internal structure and diffusion central axis and stacking the light diffusion control layers while taking into account the direction of the diffusion central axis, a desired brightness distribution can be achieved.

[0035] In this specification, the diffusion central axis refers to an axis about which the diffusion characteristics are approximately symmetrical when light is transmitted from one surface of the light diffusion control layer to the other surface and the diffusion characteristics are observed. The diffusion central axis can be estimated based on the diffusion performance determined by measuring the angular haze of the light diffusion control layer, and specifically, can be estimated as described in the test examples described below.

[0036] In the display according to this embodiment, from the viewpoint of easily realizing the above-mentioned condition regarding brightness, it is preferable that at least one of the light diffusion control layers has a central diffusion axis that is not parallel to the normal to the display surface. From the same viewpoint, it is also preferable that at least one set of light diffusion control layers present in the display is stacked so that the central diffusion axes of the layers are not parallel to each other.

[0037] From the viewpoint of suppressing excessive diffusion and making the display content easier to see clearly, it is preferable that the light diffusion control layer provided on the display body be four layers or less, more preferably three layers or less, and even more preferably two layers.

[0038] 1. Display configuration (1) Light diffusion control layer The light diffusion control layer in this embodiment is not particularly limited as long as it has a regular internal structure that includes a plurality of regions with a relatively high refractive index within a region with a relatively low refractive index.

[0039] The above-mentioned regular internal structure refers to an internal structure in which a plurality of regions with a relatively high refractive index are arranged with a predetermined regularity in a region with a relatively low refractive index. For example, when a cross section of the light diffusion control layer is cut along a plane parallel to one surface of the light diffusion control layer, the regular internal structure refers to an internal structure in which regions with a relatively high refractive index are repeatedly arranged with a uniform pitch in a region with a relatively low refractive index along at least one direction in the cross section. Note that the regular internal structure here is to be distinguished from a phase-separated structure in which one phase exists without any clear regularity in another phase, and a sea-island structure in which nearly spherical island components exist in a sea component.

[0040] According to the above-described regular internal structure, incident light incident on the surface of the light diffusion control layer within a predetermined range of incident angles can be emitted while being strongly diffused at a predetermined angle of spread. On the other hand, when the incident angle is outside the above-described range of incident angles, the light can be transmitted without being diffused, or can be emitted with less diffusion than incident light within the range of incident angles. The display according to this embodiment uses a combination of at least two light diffusion control layers having such properties, thereby making it possible to achieve a desired brightness distribution.

[0041] From the viewpoint of facilitating the formation of the above-described regular internal structure, the light diffusion control layer according to this embodiment is preferably formed by curing a composition for a light diffusion control layer containing a high refractive index component and a low refractive index component having a refractive index lower than that of the high refractive index component. In particular, it is preferable that the high refractive index component and the low refractive index component each have one or two polymerizable functional groups.

[0042] From the viewpoint of the SDGs, the light diffusion control layer in this embodiment may be made of a material with a high biomass content, a material that can be recycled or reused, or a recycled or reused material.

[0043] (1-1) High refractive index component Preferred examples of the high refractive index component include (meth)acrylic acid esters containing an aromatic ring, and particularly preferred are (meth)acrylic acid esters containing multiple aromatic rings. Examples of (meth)acrylic acid esters containing multiple aromatic rings include biphenyl (meth)acrylate, naphthyl (meth)acrylate, anthracyl (meth)acrylate, benzylphenyl (meth)acrylate, biphenyloxyalkyl (meth)acrylate, naphthyloxyalkyl (meth)acrylate, anthracyloxyalkyl (meth)acrylate, benzylphenyloxyalkyl (meth)acrylate, and the like, and those partially substituted with halogen, alkyl, alkoxy, alkyl halide, or the like. Among these, biphenyl (meth)acrylate is preferred from the viewpoint of facilitating the formation of a good regular internal structure, and specifically, o-phenylphenoxyethyl acrylate, o-phenylphenoxyethoxyethyl acrylate, and the like are preferred. In this specification, (meth)acrylic acid refers to both acrylic acid and methacrylic acid. The same applies to other similar terms.

[0044] The (weight-average) molecular weight of the high refractive index component is preferably 150 to 2500, and particularly preferably 250 to 1000. This facilitates the formation of a light diffusion control layer having a desired regular internal structure. When the theoretical molecular weight of the high refractive index component can be determined based on its molecular structure, the (weight-average) molecular weight of the high refractive index component refers to the theoretical molecular weight (not the weight-average molecular weight). On the other hand, when the theoretical molecular weight is difficult to determine because the high refractive index component is, for example, a polymer component, the (weight-average) molecular weight of the high refractive index component refers to the weight-average molecular weight obtained as a value converted into standard polystyrene by gel permeation chromatography (GPC). The weight-average molecular weight measurement method used in this specification refers to the value converted into standard polystyrene by the GPC method.

[0045] The refractive index of the high refractive index component is preferably 1.45 to 1.70, more preferably 1.50 to 1.65, and particularly preferably 1.56 to 1.59. This makes it easier to form a light diffusion control layer having a desired regular internal structure. Note that the refractive index in this specification means the refractive index of a predetermined component before curing the composition for a light diffusion control layer, and the refractive index is measured in accordance with JIS K0062:1992.

[0046] The content of the high refractive index component in the composition for a light diffusion control layer is preferably 25 to 400 parts by mass, particularly preferably 40 to 300 parts by mass, and even more preferably 50 to 200 parts by mass, per 100 parts by mass of the low refractive index component. This ensures that the regular internal structure of the formed light diffusion control layer has regions derived from the high refractive index component and regions derived from the low refractive index component in the desired ratio. As a result, it becomes easier to form a light diffusion control layer having a desired regular internal structure.

[0047] (1-2) Low refractive index component Preferred examples of the low refractive index component include urethane (meth)acrylate, (meth)acrylic polymers having (meth)acryloyl groups in the side chains, (meth)acryloyl group-containing silicone resins, and unsaturated polyester resins, with the use of urethane (meth)acrylate being particularly preferred.

[0048] The urethane (meth)acrylate is preferably formed from (a) a compound containing at least two isocyanate groups, (b) a polyalkylene glycol, and (c) a hydroxyalkyl (meth)acrylate.

[0049] Preferred examples of the compound (a) containing at least two isocyanate groups include aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate (IPDI) and hydrogenated diphenylmethane diisocyanate, and biuret and isocyanurate forms thereof, as well as adducts (e.g., xylylene diisocyanate trifunctional adducts) that are reaction products with low-molecular-weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, alicyclic polyisocyanates are preferred, and alicyclic diisocyanates containing only two isocyanate groups are particularly preferred.

[0050] Preferred examples of the above-mentioned (b) polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol, etc., and among these, polypropylene glycol is preferred.

[0051] The weight average molecular weight of (b) polyalkylene glycol is preferably 2,300 to 19,500, more preferably 3,000 to 14,300, and even more preferably 4,000 to 12,300.

[0052] Preferred examples of the (c) hydroxyalkyl(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 3-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.

[0053] The synthesis of urethane (meth)acrylate using the above-mentioned components (a) to (c) as raw materials can be carried out by a conventional method. In this case, the blending ratio of components (a) to (c) is preferably component (a):component (b):component (c)=1-5:1:1-5, particularly preferably 1-3:1:1-3, from the viewpoint of efficient synthesis of the urethane (meth)acrylate.

[0054] The weight average molecular weight of the low refractive index component is preferably 3000 to 20000, particularly preferably 5000 to 15000, and further preferably 7000 to 13000. This makes it easier to form a light diffusion control layer having a desired regular internal structure.

[0055] The refractive index of the low refractive index component is preferably 1.30 to 1.59, more preferably 1.40 to 1.50, and particularly preferably 1.46 to 1.48, which makes it easier to form a light diffusion control layer having a desired regular internal structure.

[0056] (1-3) Other ingredients The composition for the light diffusion control layer may contain other additives in addition to the high refractive index component and the low refractive index component. Examples of the other additives include a polyfunctional monomer (a compound having three or more polymerizable functional groups), a photopolymerization initiator, an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a polymerization accelerator, a polymerization inhibitor, an infrared absorber, a colorant, a light diffusing agent, a catalyst, a plasticizer, a diluting solvent, and a leveling agent.

[0057] Among the above-mentioned additives, the composition for a light diffusion control layer preferably contains a photopolymerization initiator, which makes it easier to efficiently form a light diffusion control layer having a desired regular internal structure.

[0058] Examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2- propyl ketone, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane], etc. These may be used alone or in combination of two or more.

[0059] When a photopolymerization initiator is used, the content of the photopolymerization initiator in the composition for light diffusion control layer is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the total amount of the high refractive index component and the low refractive index component, which makes it easier to efficiently form the light diffusion control layer.

[0060] (1-4) Preparation of composition for light diffusion control layer The composition for the light diffusion control layer can be prepared by uniformly mixing the high refractive index component and the low refractive index component described above, and, if desired, other additives such as a photopolymerization initiator.

[0061] During the mixing, a uniform composition for a light diffusion control layer may be obtained by stirring while heating to a temperature of 40 to 80° C. Furthermore, a dilution solvent may be added and mixed so that the resulting composition for a light diffusion control layer has a desired viscosity.

[0062] (1-5) Regular internal structure As described above, the light diffusion control layer in this embodiment has a regular internal structure that includes a plurality of regions with a relatively high refractive index within a region with a relatively low refractive index.

[0063] A more specific example of the above-mentioned regular internal structure is a columnar structure in which a plurality of columns 112, which serve as regions with a relatively high refractive index, are arranged in the thickness direction of the light diffusion control layer, as shown in Fig. 3(a) in a region with a relatively low refractive index 111. Note that, although Fig. 3(a) depicts the columns 112 as being present throughout the entire thickness direction of the light diffusion control layer, the columns 112 may not be present at least at one of the upper end and the lower end in the thickness direction of the light diffusion control layer.

[0064] Another specific example of the above-mentioned regular internal structure is a louver structure, as shown in Fig. 3(b), in which a plurality of plate-like regions 113, which are regions with a relatively high refractive index, are regularly arranged in an arbitrary direction parallel to one surface of the light diffusion control layer in a region with a relatively low refractive index 111. Note that, although Fig. 3(b) depicts the plate-like regions 113 as existing throughout the entire thickness direction of the light diffusion control layer, the plate-like regions 113 may not be present at least at one of the upper and lower ends in the thickness direction of the light diffusion control layer.

[0065] In the light diffusion control layer having the columnar structure shown in Fig. 3(a), when the angle of incidence of incident light is within a predetermined range, the resulting diffused light is circular or nearly circular, spreading in both directions, and when the angle of incidence is outside the range, the resulting diffused light is crescent-shaped. On the other hand, in the light diffusion control layer having the louver structure shown in Fig. 3(b), the resulting diffused light is elliptical, stretched in the arrangement direction of the plate-like regions (the left-right direction on the paper surface of Fig. 3(b)).

[0066] In the display device according to this embodiment, from the viewpoint of high versatility and ease of achieving the desired brightness distribution, it is preferable that at least one of the light diffusion control layers provided in the light diffusion control layer has a louver structure or a column structure, and it is particularly preferable that all of the light diffusion control layers have a louver structure or a column structure, and it is particularly preferable that all of the light diffusion control layers have a louver structure.

[0067] Although the columns 112 and the plate-like regions 113 are depicted in FIGS. 3(a) and 3(b) as if they were formed perpendicular to one surface of the light diffusion control layer, the columns 112 and the plate-like regions 113 are preferably formed so as to be inclined with respect to the thickness direction. In other words, when a region with a relatively high refractive index extends from one surface of the light diffusion control layer to the other surface thereof (the columns 112 or the plate-like regions 113), it is preferable that a line parallel to the extension direction be inclined with respect to the thickness direction of the light diffusion control layer. This causes the diffusion central axis of the light diffusion control layer to be inclined with respect to the normal to one surface of the light diffusion control layer, making it easier to diffuse light in the desired direction. As a result, the display according to this embodiment is more likely to have a desired brightness distribution.

[0068] The regular internal structure of the light diffusion control layer in this embodiment may be a modified version of the column structure or louver structure described above. For example, the columns 112 in the column structure or the plate-like regions 113 in the louver structure may be bent partway through the thickness direction of the light diffusion control layer. The regular internal structure may be a column structure having two or more regions of columns 112 with different inclination angles in the thickness direction of the light diffusion control layer, or a louver structure having two or more plate-like regions 113 with different inclination angles in the thickness direction of the light diffusion control layer.

[0069] (1-6) Thickness of the light diffusion control layer The thickness of the light diffusion control layer in this embodiment is preferably 30 to 1000 μm, more preferably 40 to 750 μm, particularly preferably 50 to 500 μm, even more preferably 60 to 250 μm, particularly preferably 70 to 200 μm, and most preferably 80 to 150 μm. When the thickness of the light diffusion control layer is in this range, desired light diffusion is easily achieved, and as a result, the display according to this embodiment is more likely to have a desired brightness distribution.

[0070] (2)Display device The display device in this embodiment is not particularly limited as long as it includes a light source and has a display function. An example of a display device is one that includes a liquid crystal display and a backlight unit, as shown in Figure 1. The liquid crystal display and backlight unit used here may be conventionally known ones.

[0071] Other examples of the display device include an organic electroluminescence (EL) display and a micro light-emitting diode (LED) display, as shown in Figure 2. Conventionally known organic EL displays and micro LED displays can also be used.

[0072] Other examples of display devices include mini LED displays, liquid crystal displays, etc.

[0073] (3) Other components The display body according to this embodiment may include components other than the light diffusion control layer and the display device described above. For example, a surface coating layer, a protective film, a cover panel, etc. may be provided on the display surface of the display body. In particular, since some light diffusion control layers exhibit a tacky feel depending on their composition, when the light diffusion control layer is provided on the display surface side as in the display body shown in FIG. 2, it is preferable to provide a protective film, etc. on the outermost surface.

[0074] 2. Display manufacturing method The manufacturing method of the display according to this embodiment is not particularly limited, and the display can be manufactured according to conventional manufacturing methods. For example, the display shown in FIG. 1 can be manufactured by appropriately laminating a pre-fabricated light diffusion control layer (the manufacturing method will be described later) with other components such as a liquid crystal layer, a polarizing plate, and a backlight. The display shown in FIG. 2 can also be manufactured by laminating a light diffusion control layer on an organic EL display or a micro LED display.

[0075] When manufacturing the display, as mentioned above, it is possible to achieve the desired brightness distribution on the display surface by stacking light diffusion control layers together or light diffusion control layers with other components, taking into consideration the direction of the diffusion center axis of the light diffusion control layer.

[0076] The method for producing the light diffusion control layer is not particularly limited, and it can be formed by a conventionally known method. For example, the composition for the light diffusion control layer described above is applied to one side of a process sheet to form a coating film, and then one side (particularly the release surface) of a release sheet is laminated to the side of the coating film opposite the process sheet. Next, the coating film is irradiated with active energy rays through the process sheet or the release sheet to cure it, thereby forming a light diffusion control layer. In this way, by laminating the release sheet on the coating film, a gap between the release sheet and the process sheet is maintained, preventing the coating film from being crushed, making it easier to form a light diffusion control layer with a uniform thickness.

[0077] Examples of the coating method include knife coating, roll coating, bar coating, blade coating, die coating, and gravure coating. The composition for the light diffusion control layer may be diluted with a solvent as needed.

[0078] The coating film is irradiated with active energy rays in different ways depending on the regular internal structure to be formed. Such irradiation can be carried out by a conventionally known method. For example, when forming the columnar structure described above, the coating film is irradiated with highly parallel light. On the other hand, when forming the louver structure described above, a linear light source is used as the source of the active energy rays, and the laminate surface is irradiated with band-like (almost linear) light that is random in the width direction (TD) and approximately parallel in the machine direction (MD).

[0079] The active energy rays refer to electromagnetic waves or charged particle rays that have an energy quantum, and specific examples include ultraviolet rays, electron beams, etc. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle.

[0080] When ultraviolet rays are used as active energy rays to form a columnar structure, the irradiation conditions are as follows: the peak irradiance on the coating surface is 0.1 to 10 mW / cm 2 The peak irradiance here means the measured value at the point where the active energy rays irradiated onto the coating film surface exhibit the maximum value. Furthermore, it is preferable that the integrated light amount on the coating film surface is 5 to 200 mJ / cm. 2 It is preferable to set the following.

[0081] From the viewpoint of completing the curing more reliably, it is also preferable to irradiate the cured product with normal active energy rays (active energy rays that have not been converted into parallel light or band-like light, scattered light) after curing using parallel light or band-like light as described above.

[0082] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0083] In this specification, when it is written "X to Y" (X and Y are any numbers), it means "X or more and Y or less" unless otherwise specified, and also includes the meaning "preferably greater than X" or "preferably smaller than Y." Furthermore, when it is written "X or more" (X is any number), it means "preferably greater than X" unless otherwise specified, and when it is written "Y or less" (Y is any number), it also means "preferably smaller than Y" unless otherwise specified. [Example]

[0084] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0085] [Preparation Example 1] (Light Diffusion Control Layer A) (1) Preparation of composition for light diffusion control layer To 40 parts by mass (solids equivalent; same below) of polyether urethane methacrylate having a weight average molecular weight of 9,900 obtained by reacting polypropylene glycol, isophorone diisocyanate, and 2-hydroxyethyl methacrylate as a low refractive index component, 60 parts by mass of o-phenylphenoxyethoxyethyl acrylate having a molecular weight of 268 as a high refractive index component and 8 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photopolymerization initiator were added, and the mixture was heated and mixed at 80°C to obtain a composition for a light diffusion control layer.

[0086] (2) Formation of a light diffusion control layer The obtained composition for a light diffusion control layer was applied to one side of a long polyethylene terephthalate sheet as a process sheet to form a coating film. Subsequently, the release surface of a release sheet (thickness: 38 μm) made by treating one side of a polyethylene terephthalate film with a silicone-based release agent was laminated on the side of the coating film opposite to the process sheet.

[0087] The resulting laminate consisting of the release sheet, the coating film, and the process sheet was placed on a conveyor. The release sheet side of the laminate was facing upward, and the longitudinal direction of the laminate was parallel to the conveyor flow direction. An ultraviolet irradiation device (manufactured by Eye Graphics, product name "ECS-4011GX") equipped with a linear high-pressure mercury lamp and a cold mirror for focusing was then installed in front of the conveyor on which the laminate was placed. This device can irradiate the target with ultraviolet light focused in a strip (almost linear). The ultraviolet irradiation device was installed so that the longitudinal direction of the high-pressure mercury lamp was perpendicular to the conveyor flow direction.

[0088] Furthermore, when viewed from the longitudinal direction of the high-pressure mercury lamp, the irradiation angle of the ultraviolet light irradiated from the high-pressure mercury lamp onto the laminate was set to 27° with respect to the normal to the laminate surface. Note that the irradiation angle here refers to the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a plus sign, when the ultraviolet light is irradiated toward the downstream side of the conveyor flow, with respect to the position directly below the high-pressure mercury lamp on the laminate, and the acute angle formed by the normal to the laminate surface and the ultraviolet light, expressed as a minus sign, when the ultraviolet light is irradiated toward the upstream side of the conveyor flow.

[0089] Thereafter, the conveyor was operated to move the laminate while applying a peak irradiance of 2.00 mW / cm 2 to the coating surface. 2 , cumulative light intensity 53.13mJ / cm 2Under these conditions, the coating film in the laminate was cured by irradiating it with parallel light (ultraviolet light from a high-pressure mercury lamp with a main peak wavelength of 365 nm, and other peaks at 254 nm, 303 nm, and 313 nm) with a parallelism of 2° or less, thereby forming an 80 μm thick light diffusion control layer A. As a result, a laminate was obtained in which the process sheet, light diffusion control layer A (thickness: 80 μm), and release sheet were laminated in this order.

[0090] Furthermore, when a cross section of the formed light diffusion control layer A was observed using a microscope, it was confirmed that a louver structure was formed within the light diffusion control layer A, with multiple plate-like regions arranged alternately in one direction along the film surface. In particular, it was confirmed that the plate-like regions were inclined with respect to the thickness direction of the light diffusion control layer A, with the inclination angle being 17.0°. In this specification, the inclination angle is expressed as a positive value when the plate-like region is inclined toward the conveyor traveling side with respect to the thickness direction of the light diffusion control layer, and as a negative value when the plate-like region is inclined away from the conveyor traveling side.

[0091] The peak illuminance and cumulative light intensity were measured by placing a UV meter (manufactured by Eye Graphics, product name "Eye Ultraviolet Integrated Illuminance Meter UVPF-A1") equipped with a photodetector at the position of the coating film. The thickness of the light diffusion control layer A was measured using a constant pressure thickness meter (manufactured by Takara Seisakusho, product name "Teclock PG-02J").

[0092] [Preparation Example 2] (Light Diffusion Control Layer B) A laminate was obtained in the same manner as in Preparation Example 1, except that the irradiation angle of the ultraviolet light emitted from the high-pressure mercury lamp was changed to 40°, and the laminate was composed of a process sheet, a light diffusion control layer B (thickness: 130 μm), and a release sheet stacked in this order.

[0093] Furthermore, when the cross section of the formed light diffusion control layer B was observed under a microscope, it was confirmed that a louver structure was formed inside the light diffusion control layer B, in which multiple plate-like regions were alternately arranged in one direction along the film surface. In particular, it was confirmed that the plate-like regions were inclined with respect to the thickness direction of the light diffusion control layer B, and that the inclination angle was 24.5°.

[0094] [Preparation Example 3] (Light Diffusion Control Layer C) A laminate was obtained in the same manner as in Preparation Example 1, except that the irradiation angle of the ultraviolet light emitted from the high-pressure mercury lamp was changed to 50°, and the laminate was composed of a process sheet, a light diffusion control layer C (thickness: 100 μm), and a release sheet stacked in this order.

[0095] Furthermore, when the cross section of the formed light diffusion control layer C was observed under a microscope, it was confirmed that a louver structure was formed inside the light diffusion control layer C, in which multiple plate-like regions were alternately arranged in one direction along the film surface. In particular, it was confirmed that the plate-like regions were inclined with respect to the thickness direction of the light diffusion control layer C, and that the inclination angle was 29.6°.

[0096] [Preparation Example 4] (Light Diffusion Control Layer D) As in Preparation Example 1, a laminate consisting of a release sheet, the coating film, and a process sheet was prepared and placed on a conveyor. The release sheet side of the laminate was facing upward, and the longitudinal direction of the laminate was parallel to the conveyor flow direction. A parallel ultraviolet spot light source (manufactured by JATEC) with a central beam parallelism controlled to within ±3° was then installed relative to the conveyor on which the laminate was placed. The light source was installed so that it could irradiate parallel light in a direction inclined by 40° toward the conveyor flow direction with respect to the normal direction of the coating film side of the laminate.

[0097] Thereafter, the conveyor was operated to move the laminate while applying a peak irradiance of 1.02 mW / cm 2 to the coating surface. 2 , cumulative light intensity 26.35mJ / cm 2Under these conditions, the coating film in the laminate was cured by irradiating it with parallel light (ultraviolet light from a high-pressure mercury lamp with a main peak wavelength of 365 nm, and other peaks at 254 nm, 303 nm, and 313 nm) with a parallelism of 2° or less, thereby forming a 100 μm-thick light diffusion control layer D. This resulted in a laminate in which the process sheet, light diffusion control layer D (thickness: 100 μm), and release sheet were laminated in this order.

[0098] Furthermore, when a cross section of the formed light diffusion control layer D was observed using a microscope, it was confirmed that a columnar structure consisting of a forest of pillars standing throughout the entire thickness direction was formed inside the light diffusion control layer D. In particular, it was confirmed that the pillars were inclined with respect to the thickness direction of the light diffusion control layer D, with the inclination angle being 24.5°.

[0099] [Preparation Example 5] (Light-diffusing adhesive layer E) A (meth)acrylic acid ester polymer was prepared by copolymerizing 25 parts by mass of n-butyl acrylate, 25 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of isobornyl acrylate, 10 parts by mass of N-acryloylmorpholine, and 30 parts by mass of 2-hydroxyethyl acrylate by solution polymerization. The weight average molecular weight (Mw) of the (meth)acrylic acid ester polymer was measured by the following method and found to be 500,000.

[0100] The weight average molecular weight (Mw) mentioned above is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> GPC measuring device: Tosoh HLC-8020 GPC columns (passed in the following order): Tosoh Corporation TSK guard column HXL-H TSK gel GMHXL (×2) TSK gel G2000HXL Measurement solvent: tetrahydrofuran ·Measurement temperature: 40℃

[0101] 100 parts by mass of the obtained (meth)acrylic acid ester polymer, 0.2 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, 15 parts by mass of microparticles (manufactured by Momentive Performance Materials Japan, Inc., product name "Tospearl 145", average particle size: 4.5 μm) made of silicone resin (a silicon-containing compound with a structure intermediate between inorganic and organic) as light-diffusing microparticles, and 0.13 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed, stirred thoroughly, and diluted with methyl ethyl ketone to obtain a coating solution of a composition for forming a light-diffusing adhesive layer.

[0102] A coating solution of the light-diffusing adhesive layer-forming composition was applied using a knife coater to the release-treated surface of a heavy-release release sheet R1, which was a polyethylene terephthalate film with one side treated with a silicone-based release agent, and then heated at 90°C for 1 minute to form a coating layer (thickness: 40 μm). Next, the release-treated surface of a light-release release sheet R2 was attached to the side of the coating layer opposite the release sheet R1. After that, the coating layer was aged for 7 days under conditions of 23°C and 50% RH, resulting in the light-diffusing adhesive layer E.

[0103] As a result of the above, a laminate was obtained in which the release sheet R1, the light-diffusing pressure-sensitive adhesive layer E having a thickness of 40 μm, and the release sheet R2 were laminated together.

[0104] The haze value (%) of the 40 μm thick light-diffusing adhesive layer E formed as described above was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH5000") in accordance with JIS K7136:2000, JIS K7361-1:1997 and ASTM D 1003, and was found to be 74%.

[0105] [Preparation Example 6] (Light-diffusing adhesive layer F) A (meth)acrylic acid ester polymer was prepared by copolymerizing 80 parts by mass of n-butyl acrylate and 20 parts by mass of 2-hydroxyethyl acrylate by solution polymerization. The weight average molecular weight (Mw) of the (meth)acrylic acid ester polymer was measured by the above method and found to be 500,000.

[0106] 100 parts by mass of the obtained (meth)acrylic acid ester polymer, 0.2 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name "Takenate D-101E") as a crosslinking agent, 13.5 parts by mass of microparticles (manufactured by Momentive Performance Materials Japan, Inc., product name "Tospearl 145", average particle size: 4.5 μm) made of silicone resin (a silicon-containing compound with a structure intermediate between inorganic and organic) as light-diffusing microparticles, and 0.3 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed, stirred thoroughly, and diluted with methyl ethyl ketone to obtain a coating solution of a composition for forming a light-diffusing adhesive layer.

[0107] A coating solution of the light-diffusing adhesive layer-forming composition was applied using a knife coater to the release-treated surface of a heavy-release release sheet R1, which was a polyethylene terephthalate film with one side treated with a silicone-based release agent, and then heated at 90°C for 1 minute to form a coating layer (thickness: 50 μm). Next, the release-treated surface of a light-release release sheet R2 was attached to the side of the coating layer opposite to the release sheet R1. After that, the coating layer was aged for 7 days under conditions of 23°C and 50% RH, resulting in the light-diffusing adhesive layer F.

[0108] As a result of the above, a laminate was obtained in which the release sheet R1, the light-diffusing pressure-sensitive adhesive layer F having a thickness of 50 μm, and the release sheet R2 were laminated together.

[0109] The haze value (%) of the 50 μm thick light-diffusing adhesive layer F formed as described above was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH5000") in accordance with JIS K7136:2000, JIS K7361-1:1997 and ASTM D 1003, and was found to be 90%.

[0110] Example 1 Two laminates containing the light diffusion control layer A produced in Production Example 1 were prepared. The process sheet of one laminate was peeled off to expose the exposed surface of the light diffusion control layer A, and the release sheet of the other laminate was peeled off to expose the exposed surface of the light diffusion control layer A. The two laminates were laminated so that the direction along the conveyor travel direction (MD) during production was parallel, and one end of one light diffusion control layer A on the conveyor travel side overlapped one end of the other light diffusion control layer A on the opposite side from the conveyor travel side. This resulted in the diffusion central axis in one light diffusion control layer A (determined as in Test Example 1 described below) not being parallel to the diffusion central axis in the other light diffusion control layer A (they were inclined in opposite directions).

[0111] The release sheet was peeled off from the laminate obtained as described above, which was composed of the process sheet, two layers of light diffusion control layer A, and the release sheet, to expose the exposed light diffusion control layer A. Meanwhile, an adhesive sheet was prepared in which release sheets were laminated on both sides of an adhesive layer composed of an acrylic transparent adhesive, and one of the release sheets was peeled off to expose the adhesive surface. Then, the adhesive surface of the adhesive sheet was attached to the exposed surface of the light diffusion control layer A exposed as described above.

[0112] Next, the other release sheet of the adhesive sheet was peeled off, and the exposed adhesive surface was attached to the display screen of a smartphone (Samsung, product name "Galaxy S6", equipped with an organic EL display). Further, by peeling and removing the process sheet, a display sample was obtained in which two layers of light diffusion control layer A were attached to the display screen of the smartphone via the adhesive layer.

[0113] Example 2 A display sample was obtained in the same manner as in Example 1, except that the light diffusion control layer B was used instead of the light diffusion control layer A.

[0114] Example 3 A display sample was obtained in the same manner as in Example 1, except that the light diffusion control layer C was used instead of the light diffusion control layer A.

[0115] Example 4 A display sample was obtained in the same manner as in Example 1, except that the light diffusion control layer D was used instead of the light diffusion control layer A.

[0116] Example 5 One laminate including the light diffusion control layer A produced in Production Example 1 was prepared. Then, the process sheet was peeled off to expose the light diffusion control layer A. The adhesive surface of an adhesive sheet was attached to the exposed surface of the exposed light diffusion control layer A.

[0117] Next, the other release sheet of the adhesive sheet was peeled off, and the exposed adhesive surface was attached to the display screen of a smartphone (Samsung, product name "Galaxy S6", equipped with an organic EL display). Further, by peeling and removing the process sheet, a display sample was obtained in which one layer of light diffusion control layer A was attached to the display screen of the smartphone via the adhesive layer.

[0118] Example 6 A display sample was obtained in the same manner as in Example 5, except that the light diffusion control layer B was used instead of the light diffusion control layer A.

[0119] Example 7 A display sample was obtained in the same manner as in Example 5, except that the light diffusion control layer C was used instead of the light diffusion control layer A.

[0120] Example 8 A display sample was obtained in the same manner as in Example 5, except that the light diffusion control layer D was used instead of the light diffusion control layer A.

[0121] Comparative Example 1 One laminate including the light-diffusing pressure-sensitive adhesive layer E produced in Production Example 5 was prepared. Then, the release sheet R2 was peeled off to expose the light-diffusing pressure-sensitive adhesive layer E. The exposed surface of the light-diffusing pressure-sensitive adhesive layer E was attached to the display screen of a smartphone (manufactured by Samsung, product name "Galaxy S6", equipped with an organic EL display) to obtain a display sample.

[0122] Comparative Example 2 One laminate including the light-diffusing pressure-sensitive adhesive layer F produced in Production Example 6 was prepared. Then, the release sheet R2 was peeled off to expose the light-diffusing pressure-sensitive adhesive layer F. The exposed surface of the light-diffusing pressure-sensitive adhesive layer F was attached to the display screen of a smartphone (manufactured by Samsung, product name "Galaxy S6", equipped with an organic EL display) to obtain a display sample.

[0123] [Test Example 1] (Measurement of Diffusion Angle Area and Diffusion Central Axis of Light Diffusion Control Layer) For the light diffusion control layers A to D produced in Production Examples 1 to 4, respectively, the diffusion angle range in which the haze value was equal to or greater than a predetermined value was measured using a variable angle haze meter (manufactured by Murakami Color Optical Laboratory, product name "HM-150N").

[0124] Specifically, the process sheet and release sheet were peeled off from the laminates obtained in Preparation Examples 1 to 4 to obtain a light diffusion control layer alone. The surface of the light diffusion control layer opposite to the surface irradiated with ultraviolet light during production was attached to one side of an alkali-free glass plate (thickness: 1.1 mm) to obtain a laminate consisting of the light diffusion control layer and the alkali-free glass plate. The laminate was then placed so that the distance from the integrating sphere opening of the variable angle haze meter to the arrival position of the measurement light was 62 mm, and the alkali-free glass side faced the light source. Next, the lengthwise direction of the light diffusion control layer (the conveying direction during production) was rotated around the width direction of the light diffusion control layer at the arrival position as the rotation axis, and the change in haze value (%) was measured. That is, the angle of incidence of the measurement light relative to the light diffusion control layer was changed by changing only the tilt angle of the light diffusion control layer, and the haze value (%) was measured for each incidence angle. The incident angle of the measurement light in the normal direction of the laminate was set to 0°, and the rotation direction in which the longitudinal direction (transport direction during production) of the light diffusion control layer approaches the light source was set to plus, and the measurement was carried out in the range of -70° to 70°. The detailed measurement conditions were as follows. Light source: C light source Measuring diameter: φ18mm Integrating sphere aperture diameter: φ25.4mm

[0125] For the light diffusion control layers A to C having a louver structure inside, the angle range in which the measured haze value (%) was 60% or more was specified as the diffusion angle region. For the light diffusion control layer D having a column structure inside, the angle range in which the measured haze value (%) was 90% or more was specified as the diffusion angle region. The results are shown in Table 1.

[0126] Furthermore, the central diffusion axis of the light diffusion control layer was identified from the measured haze value (%) in the range of -70° to 70°. That is, when the incident angle is changed from a negative value to a positive value, the haze value increases and then decreases back to the original level. The axis where the increase and decrease in the haze value are almost symmetrical was identified, and this was taken as the central diffusion axis. The incident angles that indicate the identified central diffusion axis are also shown in Table 1.

[0127] [Test Example 2] (Measurement of luminance distribution of display sample) The luminance distribution of the display samples produced in the examples and comparative examples was measured using an imaging luminance meter (Konica Minolta, product name "ProMetric-I16+ Conoscope").

[0128] Specifically, the entire display screen of the display samples produced in the examples and comparative examples was displayed in white, and the luminance distribution was measured in a state where light was emitted at maximum luminance. As a reference, the luminance distribution was also measured in the same way for a display sample consisting of only a smartphone without a light diffusion control layer or the like.

[0129] FIG. 4(a) shows, as a graph, the results of the display sample according to Example 1 (solid line) and the results of the reference display sample (dashed line) from the results obtained by the above measurements. Also, FIG. 4(b) shows, as a graph, the results of the display sample according to Comparative Example 1 (solid line) and the results of the reference display sample (dashed line). These graphs plot the luminance (cd / m) of each light ray, which is emitted from any one point on the display surface and travels on a plane perpendicular to the display surface and parallel to the MD direction of the light diffusion control layer, with the angle between the light ray and the normal to the display surface on the horizontal axis.2 ) is plotted on the vertical axis. Note that the plane on which the light rays travel was assumed to be the same as that of Example 1 for the display samples of Comparative Example 1 and the reference display body that did not have a light diffusion control layer.

[0130] From the graph obtained as above, the luminance (cd / m) in nine directions, i.e., -75°, -65°, -55°, -45°, 0°, 45°, 55°, 65°, and 75°, was calculated. 2 ) values ​​were obtained for each display sample. The results are shown in Table 2. Table 2 also shows the ratio (%) of the luminance to the reference display sample.

[0131] [Test Example 3] (Brightness uniformity evaluation) The entire display screen of the display samples produced in the examples and comparative examples was set to white and illuminated at maximum brightness. The display was fixed in position, and the brightness of the display screen was visually observed from a position 2 m away from the display screen in nine directions: -75°, -65°, -55°, -45°, front (0°), 45°, 55°, 65°, and 75°. The brightness of the display screen in the directions from -75° to 0° and from 0° to 75° was evaluated according to the following criteria. ◎: Uniform and sufficient brightness in all directions. Good: The brightness was uniform and sufficient in all directions, but there was some unevenness in brightness in the front and diagonal directions. △: The brightness was uniform and sufficient in all directions, but unevenness in brightness was noticeable in the front and oblique directions. ×: Dark from both the front and oblique directions.

[0132] [Table 1]

[0133] [Table 2]

[0134] As shown in Table 2, the display sample according to the example was able to increase the brightness in the vicinity of -45° to -75° and 45° to 75° compared to the display samples according to the reference and comparative examples. Therefore, when the display sample according to the example is used for viewing the display from angles within these ranges, the viewer can view the display brighter. [Industrial Applicability]

[0135] The display of the present invention is suitably used in applications where it is visible from directions other than the front direction. [Explanation of symbols]

[0136] 1a, 1b...Display body (display body having a liquid crystal display and a backlight unit) 2...Display unit (display unit equipped with an organic EL display or micro LED display) 11a, 11b...light diffusion control layer 111...Area with relatively low refractive index 112...Columnar object (area with relatively high refractive index) 113... Plate-shaped region (region with relatively high refractive index) 12...Liquid crystal layer 13...Backlight unit 14a, 14b...polarizing plates 15...OLED display or microLED display

Claims

1. a display device including a light source; a light diffusion control layer having a regular internal structure with a plurality of regions having a relatively high refractive index within a region having a relatively low refractive index; A display comprising: the light diffusion control layer is present at a position between the display surface of the display body and the light source, The luminance (cd / m) of the display device alone when the light source is turned on ２ ) when the light source is turned on for the display body, ２ ) is When measured from a direction where the angle formed with the normal to the display surface is 0°, the image area is 90% or more and less than 100%; A display characterized in that the angle formed with the normal to the display surface is 100% or more and 180% or less when measured from at least one direction of -75°, -65°, -55°, -45°, 45°, 55°, 65°, and 75°.

2. The display body includes at least two light diffusion control layers, Each of the light diffusion control layers is located somewhere between the display surface of the display and the light source.

2. The display according to claim 1.

3. 2. The display according to claim 1, wherein the light diffusion control layer has a diffusion central axis that is not parallel to the normal to the display surface.

4. 3. The display according to claim 2, wherein at least one set of the light diffusion control layers present in the display is laminated so that the diffusion central axes of the layers are not parallel to each other.

5. 3. The display according to claim 2, wherein the number of the light diffusion control layers provided on the display is four or less.

6. The display body according to claim 1, characterized in that the regular internal structure is a louver structure in which a plurality of plate-shaped regions, which are regions with a relatively high refractive index, are regularly arranged in any one direction parallel to one surface of the light diffusion control layer within the region with a relatively low refractive index.

7. The display element according to claim 1, characterized in that the regular internal structure is a column structure in which a plurality of pillars representing regions with a relatively high refractive index are arranged in the thickness direction of the light diffusion control layer within the region with a relatively low refractive index.

8. 2. The display device according to claim 1, wherein the display device comprises a liquid crystal display and a backlight unit as the light source.

9. The display according to claim 8, wherein the light diffusion control layer is located between one of the polarizing plates constituting the liquid crystal display that is closest to the display surface and the liquid crystal layer constituting the liquid crystal display.

10. 9. The display according to claim 8, wherein the light diffusion control layer is located between the liquid crystal display and the backlight unit.

11. 2. The display according to claim 1, wherein the display device is an organic electroluminescence (EL) display or a micro light-emitting diode (LED) display.

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