JP2014126654A - Optical sheet and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sheet capable of suppressing residual bubble generation when another layer is laminated making contact with a light beam control layer having a microlouver structure and a display device equipped with the optical sheet.SOLUTION: An optical sheet 10 at least includes a light beam control layer 1 having: light absorption parts 1A aligned along a layer surface so that light can be absorbed; and a light transmission part 1B aligned between light absorption parts so that light can be light transmitted. The light absorption part is configured with a cured product of a photocurable resin. The photocurable resin includes, as a photopolymerizable compound, a compound of a photopolymerizable prepolymer and one or more photopolymerizable monomers whose molecular mass is 400 or more. The molecular mass of all of photopolymerizable monomers is 400 or more. The light transmission part is configured with a cured product of a photocurable resin. The photopolymerizable compound in the formation material becomes difficult to infiltrate inside the light transmission part when producing the light absorption part, resulting in suppression of volume decrease and reduction of a recess being a potential cause of residual bubbles G at a portion of the light absorption part on a light absorption part exposure side surface Se.

Description

  The present invention relates to an optical sheet and a display device including the same.

As an optical sheet, an optical sheet provided with a light control layer having a so-called microlouver structure is known (Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).
The light control layer having a microlouver structure can perform functions according to applications such as external light absorption, stray light absorption, contrast improvement, brightness improvement, viewing angle control, peep prevention, and reflection prevention.
FIG. 5 is a cross-sectional view showing an example of a conventional optical sheet 50 having a light beam control layer 51 having a microlouver structure. The light beam control layer 51 has a light absorption part 51A arranged along the layer surface so as to be able to absorb light, and a light transmission part 51B arranged so as to be able to transmit light between the light absorption parts 51A. The light absorption parts 51A and the light transmission parts 51B are alternately arranged. Moreover, as shown in the figure, the light beam control layer 51 is usually formed on the transparent base layer 2 in order to facilitate its formation and increase the mechanical strength as the optical sheet 50.

The light control layer 51 can be formed using a 2P method (photopolymer method) and a wiping method. For example,
(A) First, on the surface of the transparent base material layer 2, a light transmitting portion 51B having light absorbing portion forming concave portions d whose extending directions are parallel to each other is formed by the 2P method.
(B) Next, on the surface of the light transmitting portion 51B on the side where the light absorbing portion forming concave portion d is formed, including the inside and the outside of the light absorbing portion forming concave portion d, as a light absorbing portion forming material. Apply dark ink,
(C) Next, the coated surface on which the dark color ink is applied is scraped off with a doctor blade or the like to remove the dark color ink outside the light absorbing portion forming recess d, and only the inside of the light absorbing portion forming recess d is dark. Fill the ink and solidify to form the light absorbing portion 51A.
Is the method. The above (b) and (c) are steps by a wiping method.

  The optical sheet 50 having the light control layer 51 is rarely composed of only the light control layer 51 or only the light control layer 51 and the transparent substrate layer 2. That is, a function that bears functions other than the functions of the light control layer 51 on the surface on the transparent base material layer 2 side or the surface of the light control layer 51 on the side opposite to the surface on which the transparent base material layer 2 is in contact Often the layers are stacked. Examples include a hard coat layer, a light diffusion layer, a color correction layer, an ultraviolet absorption layer, an infrared absorption layer, an electromagnetic wave shielding layer, an antireflection layer, a reinforcing layer, a bonding layer, and a Fresnel lens layer. Depending on the content of the functional layer, these functional layers may be directly formed on the laminated surface, but are often laminated via a bonding layer such as an adhesive layer or an adhesive layer. Note that this bonding layer is also a kind of functional layer.

JP 2011-197424 A JP 2011-197426 A JP 2010-117574 A JP 2008-32956 A

  However, among the front and back surfaces of the light control layer 51, the light absorbing portion exposed side surface Se (the surface on the side formed by the light absorbing portion 51A and the light transmitting portion 51B) (in FIG. When the functional layer is formed using the layer surface) as a laminated surface, residual bubbles G may be generated between the laminated surface and the functional layer. Residual bubbles G cause light scattering, whitening, and the like, which may impair optical quality.

  The cross-sectional view of FIG. 6 is a diagram for explaining the cause of residual bubbles G in the conventional optical sheet 50. Of the front and back surfaces of the light control layer 51 facing each other, the light absorbing portion exposed side surface Se is filled and formed in the light absorbing portion forming concave portion d of the light transmitting portion 51B having the light absorbing portion forming concave portion d formed on the front surface. The light absorbing portion 51A has a recessed portion r of about 1 to 6 μm on the exposed surface e of the light absorbing portion 51A due to the manufacturing method, specifically, the wiping method. Due to the concave portion r, the air in the concave portion r does not escape during the stacking, and residual bubbles G are generated.

  That is, an object of the present invention is to provide an optical sheet that can suppress the generation of residual bubbles when another layer is laminated in contact with a light control layer having a microlouver structure, and a display device including the optical sheet. It is.

The optical sheet and the display device according to the present invention have the following configurations.
(1) It has a light absorption part arranged along the layer surface so that light can be absorbed, and a light transmission part arranged alternately with the light absorption part between the light absorption parts so that light can be transmitted Including at least a light control layer;
The light absorbing portion is composed of a cured product of a photocurable resin, and the photocurable resin is a photopolymerizable compound, and includes at least one of a photopolymerizable prepolymer and a photopolymerizable monomer having a molecular weight of 400 or more. The compound and the photopolymerizable monomer all have a molecular weight of 400 or more,
The light transmission part is composed of a cured product of a photocurable resin,
Optical sheet.
(2) The optical sheet according to (1), which is disposed on any one or more of an image display panel, a front side from which display light of the image display panel emits, and a back side opposite to the front side. And a display device.

  According to the present invention, it is possible to suppress the generation of residual bubbles when another layer is laminated in contact with the light control layer having a microlouver structure.

Sectional drawing which shows one Embodiment of the optical sheet by this invention. Sectional drawing which compares this invention (A) and the conventional (B) typically about suppression of the dent (concave part) in the part of the light absorption part of the light-control layer surface. Sectional drawing which shows another embodiment of the optical sheet by this invention. Sectional drawing which shows embodiment of the display apparatus by this invention. Sectional drawing explaining the conventional optical sheet and the residual bubble to generate | occur | produce. Sectional drawing explaining the cause of residual bubble generation | occurrence | production with the conventional optical sheet.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relationships, aspect ratios, and the like of components may be exaggerated.

[1] Optical Sheet First, the optical sheet according to the present invention will be described.

FIG. 1 is a cross-sectional view showing an embodiment of an optical sheet 10 according to the present invention.
In the present embodiment, the optical sheet 10 further includes a transparent base layer 2, a functional layer 3, and a bonding layer 4 in addition to the light beam control layer 1.
The light control layer 1 includes a light absorbing portion 1A arranged along the layer surface so as to be able to absorb light, and a light transmitting portion arranged alternately with the light absorbing portion 1A between the light absorbing portions 1A so as to be able to transmit light. 1B. The light absorbing portions 1A are disposed between the light transmitting portions 1B adjacent to each other, and the light absorbing portions 1A and the light transmitting portions 1B are alternately arranged. The “layer surface” refers to a surface of the light control layer 1 that is parallel to the surface of the optical sheet 10 as a whole.
In the present invention, the optical sheet 10 only needs to have at least the light beam control layer 1.

In the present embodiment, the functional layer 3 is further laminated on the light absorbing portion exposed side surface Se of the light control layer 1 via the bonding layer 4. In the present embodiment shown in FIG. 1, the light absorbing portion exposed side surface Se is a layer surface above the light control layer 1 in the drawing.
Here, in the present invention, of the front and back surfaces of the light control layer 1 facing each other, the surface on which the surface is formed by the light absorbing portion 1A and the light transmitting portion 1B is also referred to as “light absorbing portion exposed side surface Se”. I will decide.

In the light control layer 1, the light absorbing portion 1A and the light transmitting portion 1B are made of a material unique to the present invention. That is, 1 A of light absorption parts are comprised from the hardened | cured material of photocurable resin, and this photocurable resin is 1 or more of photopolymerizable prepolymers and photopolymerizable monomers with a molecular weight of 400 or more as a photopolymerizable compound. And all the photopolymerizable monomers have a molecular weight of 400 or more.
. On the other hand, the light transmission part 1B is comprised from the hardened | cured material of photocurable resin.

In FIG. 1, the transparent base material layer 2 is formed in contact with the lower surface of the light control layer 1 opposite to the light absorbing portion exposed side surface Se, and functions as a base material at the time of creation. Moreover, it functions as a layer that improves the mechanical strength of the optical sheet 10.
In the present embodiment, the functional layer 3 is a layer having a function different from that of the light control layer 1, for example, a function such as a hard coat layer.
The bonding layer 4 bonds the functional layer 3 and the light control layer 1 adjacent to each other with the bonding layer 4 interposed therebetween.

  As described above, since the material unique to the present invention is used for the material of the light absorbing portion 1A and the light transmitting portion 1B constituting the light control layer 1, particularly the material of the light absorbing portion 1A, the concave portion of the portion of the light absorbing portion 1A is used. The depression of the part r can be reduced. As a result, the light control layer 1 and the bonding layer when the functional layer 3 is laminated through the bonding layer 4 in contact with the light control layer 1, more specifically in contact with the light absorbing portion exposed side surface Se. 4 can suppress the occurrence of residual bubbles.

  In the present invention, the optical sheet 10 may have a configuration in which the light absorbing portion exposed side surface Se of the light control layer 1 is exposed. In the optical sheet 10 in which the light absorbing portion exposed side surface Se is exposed, the effect of suppressing the generation of residual bubbles can be obtained when the optical sheet 10 is laminated on another layer.

  Hereinafter, each layer which comprises the optical sheet 10 in this embodiment is further demonstrated.

[Light control layer 1]
The light control layer 1 includes a large number of light absorbing portions 1A arranged along the layer surface so as to be able to absorb light, and light arranged so as to be able to transmit light alternately between the light absorbing portions 1A and the light absorbing portions 1A. And a transmission part 1B. In the cross-sectional view of FIG. 1, the light absorbing portions 1 </ b> A extend in a direction perpendicular to the paper surface and are arranged at a constant cycle in the left-right direction on the paper surface. Therefore, when the light beam control layer 1 is viewed from a direction perpendicular to the layer surface, the light absorbing portions 1A and the light transmitting portions 1B are alternately arranged in a stripe shape. The cross-sectional shape of the light absorbing portion 1A in the present embodiment is a substantially trapezoidal shape in which the base of the trapezoidal shape is curved toward the inner side of the light absorbing portion 1A as shown in FIG. Has been. Further, in the present embodiment, as shown in the figure, each light transmitting portion 1B between the light absorbing portions 1A is on the upper bottom side of the substantially trapezoidal light absorbing portion 1A, and is lower than the upper bottom in the drawing. Are connected to each other at portions located as continuous layers.

[Light Absorbing Part 1A]
The light absorbing portion 1A is composed of light absorbing particles and a binder in which the light absorbing particles are dispersed. The light-absorbing particles act to absorb unnecessary light such as stray light and external light. A specific photocurable resin is used for this binder.
The light absorbing portion 1A can be formed of a light absorbing portion forming material in which light absorbing particles are dispersed in a binder.

(Light absorbing particles)
As the light-absorbing particles, light-absorbing colored particles such as carbon black are preferably used, but the present invention is not limited to these, and colored particles that selectively absorb a specific wavelength according to the application are used. Also good.
Specific examples of such light absorbing particles 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 preferable from the viewpoints of cost, quality, availability, and the like. More specifically, acrylic crosslinked fine particles containing carbon black, urethane crosslinked fine particles containing carbon black, and the like are preferable. It is because it is excellent in light absorption and adhesiveness with a binder.

  In addition, in this invention, in order to provide the light absorption part, the light absorption part 1A may make the whole light absorption part 1A light absorptive with dye other than a light absorption particle.

(Photo-curing resin)
The binder for forming the light absorbing portion 1A includes a specific polymerizable compound as a photocurable resin that can be cured by ultraviolet rays or an electron beam. As the polymerizable compound, one or more compounds of a photopolymerizable prepolymer and a photopolymerizable monomer having a molecular weight of 400 or more are used. Moreover,
As the photopolymerizable monomer, a compound having a molecular weight of 400 or more is used.

As a photopolymerizable compound constituting the photocurable resin used in the light absorbing portion 1A, only a photopolymerizable prepolymer may be used. However, since the viscosity when forming the light absorbing portion 1A by the wiping method may be too high with only the photopolymerizable prepolymer, a photopolymerizable monomer may be used in such a case. By using the photopolymerizable monomer in combination, the viscosity can be lowered. Or as a photopolymerizable compound which comprises photocurable resin used for 1 A of light absorption parts, only a photopolymerizable monomer may be sufficient.
In the present invention, the light absorbing portion forming material does not contain a volatile dilution solvent such as toluene. In other words, the binder or the photocurable resin for forming the light absorbing portion 1A does not contain a volatile dilution solvent such as toluene. This is because the volume of the volatile dilution solvent is reduced by volatilization. Therefore, the light absorbing portion forming material is also a solventless composition.

  Examples of the photopolymerizable prepolymer include urethane (meth) acrylate prepolymer, epoxy (meth) acrylate prepolymer, polyester (meth) acrylate prepolymer, polyether (meth) acrylate prepolymer, and acrylic (meth) acrylate prepolymer. Acrylate prepolymers such as polymers and silicone (meth) acrylate prepolymers can be used.

In the present invention, (meth) acrylate means acrylate or methacrylate, and the simple term “acrylate system” includes methacrylate system.
In the present invention, the “prepolymer” in the photopolymerizable prepolymer means a polymer having a molecular weight of 1000 or more among polymers that can participate in the polymerization reaction.
In the present invention, the “molecular weight” is a mixture of compounds in which the target compound is a polymer or a compound having a repeating portion in which a plurality of polymerization units are linked and the number of repeating polymerization units in one molecule is different. Sometimes it means “weight average molecular weight”. Therefore, in the present invention, “weight average molecular weight” is also simply referred to as “molecular weight”.

As the photopolymerizable monomer having a molecular weight of 400 or more, a monofunctional monomer or a bifunctional or higher polyfunctional monomer can be used. For example, examples of the photopolymerizable monomer having a molecular weight of 400 or more include the following compounds. In the following, n in () is the number of repeating polymer units, and “total n” is the total number of repeating units of polymer units bonded to each of a plurality of photopolymerizable functional groups per molecule. .
If monofunctional monomer is mentioned,
Methoxy polyethylene glycol (meth) acrylate,
For example, methoxy polyethylene glycol acrylate (n = 9, molecular weight 454);
If bifunctional monomer is mentioned,
Polyethylene glycol di (meth) acrylate,
For example, polyethylene glycol diacrylate (n = 14, molecular weight 708),
Polyethylene glycol dimethacrylate (n = 9, molecular weight 536),
Polyethylene glycol dimethacrylate (n = 14, molecular weight 736);
Poly (propylene glycol) di (meth) acrylate,
For example, polypropylene glycol diacrylate (n = 7, molecular weight 536),
Polypropylene glycol diacrylate (n = 12, molecular weight 808);
Polypropylene glycol dimethacrylate (n = 7, molecular weight 536),
Polytetramethylene glycol di (meth) acrylate,
For example, polytetramethylene glycol diacrylate (n = 9, molecular weight 758);
Ethoxylated bisphenol A di (meth) acrylate,
For example, ethoxylated bisphenol A dimethacrylate (total n = 5, molecular weight 804);
Ethoxylated polypropylene glycol di (meth) acrylate,
For example, ethoxylated polypropylene glycol dimethacrylate (EO content n = 6, PO content n = 12, total n = 18, molecular weight 1114);
Etc.

Further, if a photopolymerizable monomer having a trifunctional or higher molecular weight of 400 or higher is mentioned,
Dimethylolpropane tetra (meth) acrylate,
For example, dimethylolpropane tetraacrylate (molecular weight 466);
Ethoxylated pentaerythritol tetra (meth) acrylate,
For example, ethoxylated pentaerythritol tetraacrylate (total n = 35, molecular weight 1892);
Dipentaerythritol hexa (meth) acrylate,
For example, dipentaerythritol hexaacrylate (molecular weight 578);
Etc.

  The photopolymerizable monomer having a molecular weight of 400 or more preferably has a molecular weight of 500 or more. This is because, as the molecular weight increases, the bulk (bulk) of the molecule increases, and as a result, the concave portion r in the light absorbing portion 1A can be made smaller.

  A commercial item can be used for these photopolymerizable monomers having a molecular weight of 400 or more. For example, commercially available products such as Toyo Chemicals Co., Ltd., Shin-Nakamura Chemical Co., Ltd., and Osaka Organic Chemical Co., Ltd. can be used.

  The photocurable resin containing the polymerizable compound contains a known polymerization initiator such as a benzophenone type when photocured with ultraviolet rays to obtain a cured product. In addition, the photocurable resin may contain known additives such as a stabilizer, a leveling agent, and a polymerization inhibitor.

(Cross-sectional shape of the light absorbing portion 1A)
In the present embodiment, the cross-sectional shape of the light absorbing portion 1A, that is, the shape in the cross section orthogonal to the extending direction of the light absorbing portion 1A is a wedge-shaped shape having a narrow width on the lower side in the drawing, more specifically substantially It has a trapezoidal shape.
In the present invention, the cross-sectional shape of the light absorbing portion 1A is a shape in which the recessed portion d does not exist,
Other than the trapezoidal shape. For example, a triangle shape (including an isosceles triangle shape), a quadrangle shape, a pentagon shape, a hexagonal shape, a shape in which both or one of the hypotenuses are broken or curved (convex shape or concave shape toward the outside), etc. is there.
However, in the present invention, the cross-sectional shape of the light absorbing portion 1A may be flush with the surface of the light transmitting portion 1B on the light absorbing portion exposed side surface Se. That is, the recessed part d shown in FIG. 2 mentioned later may be the light absorption part 1A which does not exist.
The light beam control function of the light beam control layer 1 can be adjusted by adjusting the cross-sectional shape.

[Light transmission part 1B]
The light transmission part 1B can be formed using a photocurable resin. There is no restriction | limiting in particular as photocurable resin used for the light transmissive part 1B. For example, urethane (meth) acrylate prepolymer, epoxy (meth) acrylate prepolymer, polyester (meth) acrylate prepolymer, polyether (meth) acrylate prepolymer, acrylic (meth) acrylate prepolymer, silicone (meth) acrylate prepolymer Acrylate prepolymers such as can be used.

As the photopolymerizable compound for forming the light transmitting portion 1B, the photopolymerizable compounds listed in the above-described light absorbing portion 1A may be used.
As in the case of the light absorbing portion 1A, the photocurable resin for forming the light transmitting portion 1B includes a known polymerization initiator such as benzophenone when photocured with ultraviolet rays to obtain a cured product. Moreover, the photocurable resin for forming the light transmission part 1B may contain well-known additives, such as a stabilizer, a leveling agent, and a polymerization inhibitor.

[Reason why residual bubble G is suppressed]
FIG. 2 is a cross-sectional view schematically illustrating that the light control layer 1 according to the present invention has a recessed portion r of the light absorbing portion 1A that is smaller than that of the conventional light control layer 51. FIG. 2A shows a case of the present invention, and FIG. 2B shows a conventional case.
Conventionally, as shown in FIG. 2 (B), after the light transmitting portion 1B is formed as a layer of a cured product of a photocurable resin, the light absorbing portion forming recess d on the surface of the light transmitting portion 1B is uncured. When the light absorbing part forming material in a state is filled, monomers that are low molecular weight polymerizable compounds are used as reactive diluents as the photopolymerizable compound in the light absorbing part forming material. This low molecular weight polymerizable compound has a smaller molecular bulk than a prepolymer which is a polymerizable compound having a large molecular weight. For this reason, the low molecular weight polymerizable compound easily penetrates into the light transmitting portion 1B from the light absorbing portion forming recess d, and the light absorption that has been filled in the light absorbing portion forming recess d by the amount permeated. The volume of the part forming material is reduced. Of course, it is considered that volume reduction due to curing shrinkage when photopolymerized and cured after filling a photopolymerizable compound into the light-absorbing-portion-forming concave portion d is also related. However, even if the volume reduction due to curing shrinkage occurs or does not occur, it is considered that the volume reduction occurs due to the penetration of the low molecular weight polymerizable compound into the light transmitting portion 1B.

On the other hand, in the present embodiment, as shown in FIG. 2 (A), as the light absorbing part forming material, a low molecular weight polymerizable compound having a relatively small volume that easily penetrates into the light transmitting part 1B is It is not used as a photopolymerizable compound constituting the light absorbing part forming material. Even when a reactive dilution solvent is used, a photopolymerizable monomer having a molecular weight of 400 or more is used.
Even if the photopolymerizable monomer having a molecular weight of 400 or more penetrates into the light transmitting portion 1B, the permeability is smaller than that of the low molecular weight polymerizable compound described above. It is considered that the volume reduction of the light absorbing portion forming material can be reduced. That is, a photopolymerizable monomer having a molecular weight of 400 or more can be said to be a non-permeable photopolymerizable monomer. As a result, the depression of the recessed portion r on the exposed surface e of the light absorbing portion 1A is reduced. And generation | occurrence | production of the residual bubble G resulting from the recessed part d is suppressed.

[Transparent substrate layer 2]
The transparent base material layer 2 is a layer that can be used as a base material when various layers are formed. In the present embodiment shown in FIG. 1, the transparent base material layer 2 is used for the light control layer 1. Further, the mechanical strength of the optical sheet 10 can be increased by the transparent base material layer 2.
For the transparent substrate layer 2, for example, a transparent resin such as a polycarbonate resin, an acrylic resin, triacetyl cellulose (TAC), a polyester resin, or a cycloolefin resin can be used.

  In the present invention, the transparent substrate layer 2 is not essential and can be omitted. For example, the surface of the transparent substrate layer 2 is made peelable, the light control layer 1 is formed on the peelable surface, and then the light control layer 1 is peeled from the transparent substrate layer 2 so that the transparent substrate layer 2 is optical. It is a structure which is not incorporated as a constituent layer of the sheet 10.

For the purpose of enhancing the adhesion between the transparent base material layer 2 and the adjacent layer, the transparent base material layer 2 may have a surface subjected to a known adhesion strengthening treatment such as formation of a primer layer or corona discharge treatment. Good.
The thickness of the transparent base material layer 2 is set according to its function, and is, for example, 25 μm to 5 mm.

[Function layer 3]
The functional layer 3 is a layer for imparting various functions to the optical sheet 10. In the present invention, the optical sheet 10 may not include the functional layer 3. However, in the present embodiment, the optical sheet 10 includes the functional layer 3. In addition, in the present embodiment, the functional layer 3 has a configuration formed on the light absorbing portion exposed side surface Se of the light control layer 1, which has conventionally been easy to generate residual bubbles G. The optical sheet 10 itself has a configuration in which the effect of suppressing the generation of residual bubbles G can be obtained.

As the functional layer 3, various functional layers in various conventionally known optical sheets can be appropriately employed.
The function layer 3 can impart a function corresponding to the function of the function layer 3 to the optical sheet 10.

The functional layer 3 can be broadly classified into an optical functional layer responsible for optical functions and a non-optical functional layer responsible for functions other than optical functions.
Examples of the optical function layer include a wavelength filter layer such as a color correction layer or a colored layer that suppresses transmission of specific wavelength light such as a color correction function that corrects a display image to a desired color tone and transmits the remaining wavelength light, An antireflection layer (either antiglare, antireflection, antiglare or antireflection) usually provided on the outermost layer, a Fresnel lens layer that deflects the traveling direction of light, and neon that absorbs neon light from the plasma display panel body There are a light absorbing layer, a near infrared absorbing layer that absorbs near infrared rays, an ultraviolet absorbing layer that absorbs ultraviolet rays, or the light control layer 1 described above. When the functional layer 3 is the light control layer 1, the optical sheet 10 has a configuration including two or more light control layers 1. At this time, the extending direction of the light absorbing portion 1A of each light control layer 1 is usually a direction that intersects each other, such as perpendicular to each other.
Examples of non-optical functional layers include an electromagnetic wave shielding layer that shields electromagnetic waves from image display panels such as surface protective layers and hard coat layers that protect the surface, antistatic layers, antifouling layers, impact resistant layers, and plasma display panels. There are a barrier layer that prevents mass transfer between two layers, or the transparent base layer 2 described above, and a bonding layer 3 (adhesive layer or pressure-sensitive adhesive layer) that adheres two layers described later.

  Each layer of the optical functional layer and the non-optical functional layer may be a single layer that also functions, or the optical functional layer and the non-optical functional layer may also function. Further, the wavelength filter layer, the near-infrared absorption layer, the ultraviolet absorption layer, the neon light absorption layer, and the like can also be used as the light transmitting portion 1B in the transparent base layer 2 or the light control layer 1.

The transparent base layer 2 described above is also a kind of the functional layer 3, and the bonding layer 4 described later is also a kind of the functional layer 3. In the present embodiment, the functional layer 3 and the bonding layer 4 are cited as an example of the layer laminated on the light absorbing portion exposed side surface Se of the light control layer 1 related to the generation of residual bubbles G. The layer 4 is a kind of the functional layer 3 but is not called the functional layer 3.
Moreover, the transparent base material layer 2 in the present embodiment is formed in contact with the surface opposite to the light absorbing portion exposed side surface Se of the light control layer 1, and is formed at a position unrelated to the residual bubbles G. In addition, the transparent base material layer 2 is a kind of the functional layer 3 as well as the bonding layer 4 because it is used as a base material when the light control layer 1 is formed. Not.

In the present embodiment shown in FIG. 1, the position of the functional layer 3 is the light absorbing portion exposed side surface Se that is the upper side in the drawing of the layer surface of the light control layer 1.
In the present invention, the position of the functional layer 3 is arbitrary. The function layer 3 can be provided at a position corresponding to the function. For example, in the optical sheet 10 of the embodiment illustrated in FIG. 3, the functional layer 3 is further provided on the surface of the transparent substrate layer 2 side via the bonding layer 4 with respect to the configuration of the embodiment illustrated in FIG. 1. It is a laminated structure. In this case, the functional layer 3 has a function corresponding to the application, for example, a function of a reinforcing layer that increases the mechanical strength of the optical sheet 10.

[Junction layer 4]
The bonding layer 4 is a layer for bonding the layers on both sides thereof. The bonding layer 4 is provided according to the necessity for bonding.
In the present embodiment shown in FIG. 1, the bonding layer 4 is used for bonding the light control layer 1 and the functional layer 3. The bonding layer 4 can be used as a pressure-sensitive adhesive layer, an adhesive layer, or the like.
For the bonding layer 4, for example, a thermoplastic resin such as an acrylic resin or a polyester resin, or a curable resin such as an epoxy resin, a urethane resin, or a photocurable resin can be used.

  In the present invention, the bonding layer 4 can be omitted. For example, when the functional layer 3 is applied to the light control layer 1, the bonding layer 4 between the functional layer 3 and the light control layer 1 or between the functional layer 3 and the light control layer 1 is used. For example, the bonding layer 4 is formed of an adhesive material having a bonding function.

〔Production method〕
The optical sheet 10 according to the present embodiment is a conventionally known micro-sheet except that a specific polymerizable compound is used as the light curable resin of the light absorbing portion 1A and the light transmitting portion 1B of the light control layer 1, particularly the light absorbing portion 1A. It can be manufactured by a method for manufacturing an optical sheet 10 including a light control layer having a louver structure. For example, after the light control layer 1 is formed by the 2P method and the wiping method on the transparent base material layer 2 made of a belt-shaped resin sheet, an adhesive serving as the bonding layer 4 is interposed on the surface of the light control layer 1. And it can manufacture by laminating | stacking the sheet | seat used as the functional layer 3 with a laminator etc. FIG.

The step of forming the light control layer 1 by the 2P method and the wiping method can be as follows.
A light control layer forming step of forming a light control layer 1 including at least the following steps (a) to (c) in this order.
(A) A light transmitting part forming step of forming, on the transparent base material layer 2, a light transmitting part 1B having a light absorbing part forming recess d corresponding to the shape of the light absorbing part 1A on the surface by the 2P method.
(B) A light absorbing portion forming material is applied to the surface of the light transmitting portion 1B on the side where the light absorbing portion forming recess d is formed, including inside and outside of the light absorbing portion forming recess d. The light absorbing part forming material includes a photopolymerizable prepolymer as a photopolymerizable compound and one or more compounds of a photopolymerizable monomer having a molecular weight of 400 or more, and a photopolymerizable compound having a molecular weight of less than 400. A light-absorbing part-forming material coating process that does not contain a compound and a volatile dilution solvent.
(C) The coated surface on which the light absorbing portion forming material is coated is scraped off with a doctor blade, the light absorbing portion forming material outside the light absorbing portion forming recess d is removed, and the light absorbing portion The light absorbing portion forming material is filled only inside the forming recess d, and the light absorbing portion forming material inside the light absorbing portion forming recess d is polymerized and solidified to form the light absorbing portion 1A. Light absorption part formation process.

[Configuration example]
Here, a configuration example of the light beam control layer 1 is shown.

[Configuration example of this embodiment]
The photocurable resin in the light absorbing portion forming material used for forming the light absorbing portion 1A by using the wiping method uses only a photopolymerizable monomer as a photopolymerizable compound, and as this photopolymerizable monomer. Uses polytetramethylene glycol diacrylate (n = 9, molecular weight 758, manufactured by Shin-Nakamura Chemical Co., Ltd., “NK ester” A-PTMG-65). During the wiping process, the light absorbing portion forming material is heated to 50 ° C.

  The photocurable resin used for forming the light transmission part 1B using the 2P method uses a mixture of 60 parts by mass of a urethane acrylate prepolymer and 40 parts by mass of phenoxyethyl acrylate as a photopolymerizable compound.

  The photocurable resin used for the light absorbing portion 1A and the light transmitting portion 1B further includes a photopolymerizable compound in addition to the photopolymerizable compound in order to be cured with ultraviolet rays.

  By using the above materials, the recess of the recessed portion r generated on the exposed surface e of the light absorbing portion 1A is reduced as compared to the conventional configuration example described later. As a result, when the functional layer 3 is laminated on the light absorbing portion exposed side surface Se of the light control layer 1 via the bonding layer 4 using an acrylic pressure-sensitive adhesive, the generation of residual bubbles G is suppressed. The functional layer 3 includes a polycarbonate resin sheet and a hard coat layer formed as a layer of a cured product of an acrylic ultraviolet curable photocurable resin on one surface of the resin sheet. The functional layer 3 is the outermost layer in the optical sheet 10 on the hard coat layer side.

[Conventional configuration example]
On the other hand, as a conventional configuration, a urethane acrylate prepolymer (molecular weight 4500) is used as a photopolymerizable compound of a photocurable resin in a light absorbing portion forming material used for forming the light absorbing portion 1A using a wiping method. ) 50 parts by mass, 40 parts by mass of tripropylene glycol diacrylate (molecular weight 300) and 10 parts by mass of methoxytriethylene glycol acrylate (molecular weight 218) are used.

[Use]
The use of the optical sheet 10 according to the present invention is not particularly limited as long as it can make use of the light control function of the light control layer 1. The light beam control function includes, for example, a change in light beam traveling direction (enlargement, reduction, deflection) such as viewing angle control, external light absorption, stray light absorption, contrast improvement, luminance improvement, peep prevention, and reflection prevention. Examples of such applications include prevention of peeping or shading of direct sunlight on a display device, which will be described later, or a window of a vehicle, an aircraft, a ship or the like, or a building.

[2] Display Device The display device according to the present invention is arranged on one or more of the image display panel, the front side where the display light of the image display panel is emitted, and the back side opposite to the front side. The optical sheet 10 according to the present invention is provided.

FIG. 4 shows three examples of embodiments of the display device 100 according to the present invention.
The position where the optical sheet 10 is disposed with respect to the image display panel 20 is disposed at a position corresponding to the light beam control function performed by the light beam control layer 1 included in the optical sheet 10.
For example, as shown in FIG. 4A, it may be the front side (screen side) on the side of the observer V who observes the image on the image display panel 20, or conversely, as shown in FIG. The back side of the image display panel 20 may be used, or although not shown, both the front side and the back side may be used.
The optical sheet 10 is disposed at a position corresponding to the light control function of the light control layer 1 included in the optical sheet 10.

In the form in which the optical sheet 10 is disposed on the back side of the image display panel 20, the image display panel 20 is a transmissive type that displays an image using transmitted light, and the backlight 30 that illuminates the image display panel 20 from the back side. Is provided. When arranged on the back side of the image display panel 20, the optical sheet 10 has a function of controlling illumination light reaching the image display panel 20 from the backlight 30.
In FIG. 4, the optical sheet 10 is configured separately from the image display panel 20 or the backlight 30, but may have a configuration integrated with the image display panel 20 or the backlight 30.

  FIG. 4A shows a form in which the optical sheet 10 is disposed on the front side of the image display panel 20. In a form in which such an optical sheet 10 is disposed on the front side of the image display panel 20, as shown in FIG. 4C, the image light projected from the image light source 40 including the image display panel 20 is used. There is also a form in which the optical sheet 10 is used as a transmissive screen that receives and forms an image from the back side.

  Although not shown, in the form in which the optical sheet 10 is used as a screen, the optical sheet 10 is used as a reflective screen that projects image light from the front side of the screen, which is opposite to the positional relationship in FIG. 4C. There is also a form.

  Hereinafter, the image display panel 20, the backlight 30, and the video light source 40 will be described.

[Image display panel 20]
The image display panel 20 is not particularly limited as long as it can display an image, and a conventionally known one can be appropriately employed. For example, the image display panel 20 is a liquid crystal panel, an EL (electroluminescence) panel, a plasma display panel, an electronic paper panel, a digital micromirror device (DMD), a cathode ray tube, or the like.

[Backlight 30]
The backlight 30 is not particularly limited as long as it can emit the display light of the image display panel 20 to the back side of the image display panel 20, and a conventionally known one can be appropriately employed. For example, a side light type using a light guide plate or a direct type is used. The light source itself is a cold cathode fluorescent lamp (CCFL), a light emitting diode (LED), an EL (electroluminescent) panel, or the like.

[Video light source 40]
In the form shown in FIG. 4C, the image display panel 20 is used as one component of the image light source 40 that is a means for projecting image light onto the optical sheet 10 as a screen. Furthermore, when the image display panel 20 is not a self-luminous type but a transmissive type such as a liquid crystal display panel that does not emit light itself, a backlight 30 is disposed on the back side of the image display panel 20, and a video light source Reference numeral 40 denotes a configuration including the image display panel 20 and the backlight 30.

[Other components]
In addition to the above-described constituent elements, the display device 100 includes various types of known components depending on the application of the display device, in addition to a housing (cabinet) and input / output components. These other components are not particularly limited, and depend on the application.

〔effect〕
The display device 100 according to the present invention suppresses the generation of residual bubbles due to the depression of the layer surface of the light control layer 1 having the microlouver structure in the optical sheet 10 included in the display device 100. It is possible to suppress deterioration in image quality.

[Use]
The display device 100 according to the present invention includes a television receiver, measuring equipment and instruments, office equipment, medical equipment, computer equipment, electronic signage, amusement equipment, a mobile phone, a portable information terminal, an electronic book terminal, a projection system, and the like. It is suitable as a display device.

DESCRIPTION OF SYMBOLS 1 Light control layer 1A Light absorption part 1B Light transmission part 2 Transparent base material layer 3 Functional layer 4 Joining layer 10 Optical sheet 20 Image display panel 30 Backlight 40 Image | video light source 50 Conventional optical sheet 51 Light control layer 51A Light absorption part 51B Light transmitting portion 100 Display device d Light absorbing portion forming recess e Exposed surface G Residual bubble r Depressed portion Se Light absorbing portion exposed side V Observer

Claims (2)

A light control layer having a light absorption portion arranged along the layer surface so as to be able to absorb light, and a light transmission portion arranged alternately with the light absorption portion between the light absorption portions so as to be able to transmit light Including at least
The light absorbing portion is composed of a cured product of a photocurable resin, and the photocurable resin is a photopolymerizable compound, and includes at least one of a photopolymerizable prepolymer and a photopolymerizable monomer having a molecular weight of 400 or more. The compound and the photopolymerizable monomer all have a molecular weight of 400 or more,
The light transmission part is composed of a cured product of a photocurable resin,
Optical sheet.   The optical sheet according to claim 1, which is disposed on any one or more of an image display panel, a front side from which display light of the image display panel is emitted, and a back side opposite to the front side. A display device comprising:

Images