JP2006337753A - Light diffusion deflection sheet and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion deflection sheet that can sufficiently improve the uniformity of the state of light diffusion and light deflection and is easy to manufacture.
A first light transmissive sheet base 41a is provided with a first light deflecting structure layer 41b for forming a plurality of prism rows 41b 'on a first surface of a first light transmissive sheet substrate 41a. A spacer layer 41c is formed on the second surface of the material 41a. The spacer layer 41c includes a row of protrusions 41c ′ having a predetermined height and formed partially. A second light deflecting structure layer is formed on the first surface of the second light transmitting sheet base material 42a, and the second light deflecting structure layer holds the light transmitting fine particles 42c by the light transmitting resin 42b. It is made. The protrusion 41c ′ is joined to the translucent resin 42b so that the tip end thereof is in contact with the first surface of the second translucent sheet substrate 42a.
[Selection] Figure 2

Description

  The present invention relates to a light deflection sheet suitably used for a surface light source device, and more particularly to a light diffusion deflection sheet having a light diffusion function in addition to a light deflection function and a method for manufacturing the same.

  A plurality of linear light sources composed of cold-cathode tubes and LED (light emitting diode) arrays are arranged as illumination backlights constituting a display panel such as a liquid crystal panel, and light diffusion elements and light deflection elements are arranged thereon. There is a direct backlight. A light diffusion sheet and / or a light diffusion film is used as the light diffusion element. The function of the light diffusion sheet is to blur the image of the linear light source and make the luminance uniform. As the light diffusion sheet, a sheet having isotropic light diffusion is usually used, but in order to increase the diffusivity in the direction perpendicular to the longitudinal direction of the primary light source, a directional uneven shape may be given to the surface. is there. The function of the light diffusing film lies in further uniform brightness and isotropic light deflection. As the light deflection element, a light deflection sheet made of a lens sheet having directionality such as a prism sheet is used. The function of the light deflection element is to deflect light from the light diffusion film mainly with respect to a component corresponding to the vertical direction of the display screen. Adjustment is performed so that a required viewing angle is obtained in the direction corresponding to the vertical direction and the horizontal direction of the display screen by the action of the light diffusing element and the light deflecting element. In a TV (television) backlight, for example, adjustment is made so that the viewing angle corresponding to the vertical direction is about 70 to 100 ° and the viewing angle corresponding to the horizontal direction is about 90 to 120 °.

  By the way, the light diffusion sheet, the light diffusion film and the light deflection sheet as described above are generally supplied as separate sheets / films. Therefore, in terms of backlight manufacturing, sheet / film punching costs, assembly costs, and logistics costs increase, and dust is mixed between the sheets / films during assembly to reduce or prevent the yield. In addition, work in a clean room is required, and since deflection due to heat occurs, there is a problem that it is necessary to individually thicken the base material of each sheet / film.

  In order to solve the above problems, it is conceivable to consolidate the functions into one sheet. That is, it is preferable to realize the desired viewing angle as described above with a single light diffusion deflection sheet. However, when a light diffusing sheet or light diffusing film containing a light diffusing agent in the inside or the surface layer is used, the deflection effect is not sufficiently exhibited, and a large deflection angle is realized with one sheet. Due to the difficulty in manufacturing the light deflection diffusion sheet and the difficulty of adjusting both the horizontal viewing angle and the vertical viewing angle at once, a plurality of light diffusion sheets as described above, Usually, it is realized by a combination of a light diffusion film and a light deflection sheet. In order to realize a large deflection angle, it is necessary to have an air layer between each sheet / film. When the sheets / films are bonded together while securing the air layer, the prism is used. As shown in the above, it is difficult to bond at the top of the fine particles when the tip is sharply bonded or when the fine particles are coated with a binder resin and the upper part of the fine particles is used as a lens, each sheet manufactured individually It has been considered difficult to realize a light diffusion / deflection sheet having a desired viewing angle with a single sheet because the sheet / film manufacturing cost increases when the film is simply bonded.

In order to solve the above-mentioned problems, a particulate adhesive is provided between the first transparent resin sheet member in which microbeads are dispersed and the second transparent resin sheet member whose surface is microprism processed. A method of joining the first and second transparent resin sheet members with the particulate adhesive while securing an air layer by scattering (Patent Document 1), or light obtained by adhering hollow beads and / or solid beads A method (Patent Document 2) has been proposed in which a bead protrusion of a diffusive structure sheet is adhered to the back surface of a prism sheet.
JP-A-8-184704 Japanese Patent Laid-Open No. 10-48430

  However, although the method described in Patent Documents 1 and 2 can secure an air layer, it is difficult to maintain a uniform distance between the two sheets over the entire surface. There is a problem that the uniformity of the state cannot be sufficiently increased.

  The present invention has been made to solve the above-described problems of the prior art, and provides a light diffusion deflection sheet that can sufficiently improve the uniformity of the state of light diffusion and light deflection and is easy to manufacture. It is intended. Another object of the present invention is to provide a surface light source device using the light diffusion deflection sheet as described above.

According to the present invention, the above object is achieved as follows:
A first light deflecting structure layer is formed on the first surface of the first translucent sheet substrate, a spacer layer is formed on the second surface of the first translucent sheet substrate, The spacer layer includes a protrusion having a predetermined height formed in part, and a second light deflection structure layer is formed on the first surface of the second light-transmitting sheet base material. The light deflecting structure layer is formed by holding translucent fine particles with a translucent resin, and the protrusions are arranged such that the tips thereof are in contact with the first surface of the second translucent sheet substrate. A light diffusing and deflecting sheet, which is bonded to the translucent resin,
Is provided.

  In one aspect of the present invention, the first light deflection structure layer forms a plurality of lens rows arranged in parallel to each other. In one aspect of the present invention, the lens array is a prism array. In one aspect of the present invention, the protrusion includes a plurality of row-like protrusions arranged in parallel to each other, and the extending direction of the row-like protrusions is substantially orthogonal to the extending direction of the lens row. In one aspect of the present invention, the protrusion is composed of a plurality of row-like protrusions arranged in parallel to each other. In one aspect of the present invention, the protrusion comprises a plurality of point-like protrusions. In one aspect of the present invention, the dimension obtained by subtracting the thickness of the region other than the protrusion of the spacer layer from the predetermined height of the protrusion is twice or more the average particle diameter of the translucent fine particles.

In addition, according to the present invention, the above-mentioned object is achieved as follows:
A method of manufacturing the above light diffusion deflection sheet,
Forming a first structure body by forming the first light deflection structure layer and the spacer layer on the first surface and the second surface of the first translucent sheet base material,
Forming the second structural element by applying the uncured translucent resin mixed with the translucent fine particles to the first surface of the second translucent sheet substrate;
While the translucent resin is uncured, the protrusion of the spacer layer of the first structural element body has the tip of the first surface of the second translucent sheet base material of the second structural element body. Pushed into the uncured translucent resin so as to abut,
Thereafter, the uncured translucent resin is cured to bond the protrusions to the translucent resin, thereby integrating the first structural element body and the second structural element body. A method of manufacturing a light diffusion deflection sheet,
Is provided.

In addition, according to the present invention, the above-mentioned object is achieved as follows:
A primary light source, a light diffusion sheet disposed adjacent to the primary light source, and the light diffusion deflection sheet described above,
The primary light source and the light diffusion deflection sheet are positioned on opposite sides of the light diffusion sheet, and the light diffusion deflection sheet has a second surface of the second light transmissive sheet base material A direct-type surface light source device, characterized by being arranged so as to face the light diffusion sheet,
Is provided.

In addition, according to the present invention, the above-mentioned object is achieved as follows:
A light guide having a light incident end surface and a light exit surface, a primary light source disposed adjacent to the light incident end surface of the light guide, and the above-described disposed adjacent to the light exit surface of the light guide And a light diffusion deflection sheet,
The light diffusion deflecting sheet is arranged such that the second surface of the second light transmissive sheet base material faces the light emitting surface of the light guide, and the edge light system surface Light source device,
Is provided.

  According to the light diffusing and deflecting sheet of the present invention as described above, a spacer layer having protrusions of a predetermined height is formed on the second surface of the first translucent sheet substrate, and the second translucent sheet is formed. Translucent fine particles are held by a translucent resin on the first surface of the base material, and the protrusion is translucent so that the tip of the protrusion is in contact with the first surface of the second light transmissive sheet base material. Since it is bonded to the resin, the distance between the first and second light-transmitting sheets can be maintained uniformly throughout, and therefore the uniformity of the state of light diffusion and light deflection over the entire surface is sufficiently enhanced. be able to.

  Further, according to the method of manufacturing the light diffusion deflection sheet of the present invention, the first structural element body is formed by forming the spacer layer on the first translucent sheet base material, and the second structural element body is transparent. While the translucent resin in which the light-sensitive fine particles are mixed is uncured, the protrusion is formed such that the tip of the protrusion of the spacer layer is in contact with the second light-transmitting sheet substrate of the second structural element. Since the light-transmitting resin is pressed and then the light-transmitting resin is cured and the protrusions are bonded to the light-transmitting resin, the light diffusion deflection sheet can be easily manufactured.

  Hereinafter, embodiments of a light diffusion deflection sheet and a method for manufacturing the same according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of a direct type surface light source device using the light diffusion deflection sheet of the present invention, and FIG. 2 is an enlarged view of the light diffusion deflection sheet portion. In these drawings, (a) and (b) show cross sections (XZ cross section and YZ cross section) orthogonal to each other.

  As shown in FIG. 1, the surface light source device 10 includes a plurality of linear light sources 1 as primary light sources that extend in the Y direction and are arranged in parallel to each other in a horizontal plane (in an XY plane). The reflector 2 is disposed so as to surround the linear light source 1 at the lower side of the linear light source 1 and the periphery in the horizontal plane, and the light diffusion sheet is disposed adjacent to and above the linear light source 1. 3 and a light diffusion deflection sheet 4 disposed on the upper side of the light diffusion sheet 3. That is, the linear light source 1 and the light diffusion deflection sheet 4 are positioned on opposite sides of the light diffusion sheet 3.

  For example, a fluorescent lamp or a cold cathode tube can be used as the linear light source 1. In the present invention, the primary light source is not limited to such a linear light source, and a plurality of point light sources such as LEDs arranged in one direction can be used. As the reflecting plate 2, for example, a plastic sheet having a metal vapor-deposited reflective layer on the surface is attached to the inner surface of a structural member made of metal or plastic, or light is deposited on the inner surface of a structural member made of metal or plastic by metal vapor deposition or the like. A film formed by forming a reflection layer, a diffuse reflection film in which a plastic film is internally foamed, or the like can be used.

  As the light diffusion sheet 3, for example, at least one surface is provided with a fine uneven structure and roughened to impart a light diffusion function, or translucent fine particles are made of a resin having a refractive index different from that. The thing which provided the light-diffusion function by making it contain in a sheet | seat base material is illustrated.

  As shown in FIG. 2, the light diffusion deflection sheet 4 includes a first structure element 41 and a second structure element 42 that are connected and integrated.

  The first structure element 41 has a first light deflection structure layer 41b formed on the first surface (upper surface in FIG. 2) of the first translucent sheet base material 41a and the second surface (lower surface in the drawing). A spacer layer 41c is formed on the substrate. The first translucent sheet base material 41a is a sheet made of, for example, a polyester resin, an acrylic resin, a polycarbonate resin, a vinyl chloride resin, or a polymethacrylimide resin having a thickness of about 50 to 200 μm. The first light deflection structure layer 41b forms a prism row 41b 'which is a plurality of lens rows extending in the Y direction and arranged in parallel to each other. The prism row 41b 'has an apex angle θ of, for example, 80 to 110 °, and an arrangement pitch P1 of, for example, 20 to 100 μm, particularly 30 to 60 μm. The spacer layer 41 c includes a plurality of protrusions 41 c ′ extending in a row in the X direction and arranged in parallel to each other. The protrusions 41c 'are partially formed in the spacer layer 41c, and the arrangement pitch P2 thereof is, for example, 50 to 300 [mu] m, particularly 100 to 200 [mu] m. As shown in FIG. 3 to be described later, the protrusion 41c 'has a height from the lower surface of the first translucent sheet substrate 41a that is set to a predetermined value T1. The spacer layer 41c is formed to have a substantially uniform thickness t in a region where the projection 41c ′ is not formed, that is, a region other than the projection, and from the predetermined height value T1 of the projection 41c ′ other than the projection of the spacer layer 41c. The dimension obtained by subtracting the thickness t of the region is T2. The thickness t is, for example, 3 to 10 μm. As shown in FIG. 2B, the protrusion 41c 'may have a sharp triangular tip at the YZ cross section, or may have a flat or convex curved surface at the tip. The first light deflection structure layer 41b and the spacer layer 41c are made of, for example, an active energy ray curable resin. As the active energy ray-curable resin, polyfunctional (meth) acrylic compounds, vinyl compounds, (meth) acrylic acid esters, allyl compounds, (meth) acrylic acid metal salts, and the like can be used.

  The second structure element 42 is obtained by forming a second light deflection structure layer on the first surface (the upper surface in FIG. 2) of the second light-transmissive sheet base material 42a. The second light deflection structure layer is formed by holding a large number of light-transmitting fine particles 42c with a light-transmitting resin 42b as a binder. The 2nd translucent sheet | seat base material 42a is a sheet | seat which consists of a polyester-type resin, acrylic resin, polycarbonate-type resin, vinyl chloride resin, polymethacrylimide-type resin, etc. of thickness about 50-200 micrometers, for example. The translucent resin 42b is made of, for example, an acrylic resin. The translucent fine particles 42c may be made of a material having the same refractive index as that of the translucent resin 42b or may be made of a different material. From the viewpoint of improving light diffusibility, it is preferable to use translucent fine particles 42c made of a material having a refractive index different from that of translucent resin 42b. Examples of such translucent fine particles 42c include fine particles made of a homopolymer such as silicone, polystyrene, polymethyl methacrylate, fluorinated methacrylate, or a copolymer. The average particle diameter of the translucent fine particles 42c is, for example, 3 to 50 μm, particularly 5 to 20 μm.

  The protrusion 41c 'has a tip portion penetrating the translucent resin 42b and abutting against the first surface of the second translucent sheet base material 42a. As a result, the first structural element body 41 and the second structural element body 42 are connected and integrated, and the lower surface of the first translucent sheet base material 41a and the second translucent sheet base material are combined. The distance from the upper surface of 42a is maintained at a predetermined height T1 from the lower surface of the translucent sheet substrate 41a of the protrusion 41c '. The dimension obtained by subtracting the thickness t of the region other than the protrusion of the spacer layer 41c from the predetermined height value T1 of the protrusion 41c 'is set so that T2 is larger than the particle diameter of the translucent fine particles 42c. Specifically, for example, the dimension T2 is preferably set to be twice or more the average particle diameter of the translucent fine particles 42c. Thereby, an appropriate air layer can be interposed between the first structural element body 41 and the second structural element body 42.

  In order to maintain a uniform distance between the lower surface of the first light-transmissive sheet base material 41a and the upper surface of the second light-transmissive sheet base material 42a over the entire surface of the light diffusion deflection sheet 4, the protrusion 41c ′ The smaller the arrangement pitch P2, the better. However, as the arrangement pitch P2 decreases, the area of the non-existing region of the translucent fine particles 42c increases, so that the uniformity of functions of light diffusion and light deflection described later by the second structure element 42 is reduced. Therefore, in the present embodiment, the above-described 50 to 300 μm, particularly 100 to 200 μm, is set as the arrangement pitch P2 of the protrusions 41c ′ that can obtain a good result by combining these two different characteristics.

  As described above, in the present embodiment, the light diffusion deflection sheet 4 is disposed such that the second surface (the lower surface in FIG. 2) of the second light transmissive sheet base material 42 a faces the light diffusion sheet 3. Has been.

  In the surface light source device 10 of the present embodiment as described above, the light emitted from the linear light source 1 and partially reflected by the reflecting plate 2 is subjected to a diffusing action by the light diffusion sheet 3. Although the light diffused and emitted by the light diffusion sheet 3 has a wide viewing angle, the luminance near the normal direction (Z direction) of the surface light source device is not sufficient. Therefore, the light diffusion deflection sheet 4 increases the luminance in the vicinity of the normal direction of the surface light source device while ensuring the necessary viewing angle. The second structural element 42 not only assists the image blurring of the linear light source 1 that is not sufficient with the light diffusion sheet 3 alone, but also functions as an isotropic light deflection lens. That is, the second structural element 42 has a form in which the upper half surface of the translucent fine particles 42c protrudes from the translucent resin 42b, and as a result, a single-sided flat surface and a single-sided convex curved surface (for example, a convex spherical surface). A lot of lenses are arranged at random. Here, when the particle diameter of the light-transmitting fine particles 42c is increased, the focal length as a single lens is increased, and the second structure element 42 has a deflection angle due to a change in the average particle diameter of the light-transmitting fine particles 42c. Functions as an isotropic deflection lens sheet. Further, the first structure element 41 is formed with a unidirectional prism row having an apex angle of around 90 °, and anisotropy for controlling the vertical-direction corresponding viewing angle which is not problematic even if it is relatively narrow. Functions as a deflection lens sheet. Therefore, a desired viewing angle can be controlled by a combination of the second structure element 42 and the first structure element 41.

  FIG. 3 is a schematic cross-sectional view showing an embodiment of a method for manufacturing the light diffusion deflection sheet 4 of the present embodiment.

  First, as shown in FIG. 3A, the first structural element body 41 is formed. The formation of the first structure element 41 can be performed as follows. That is, ultraviolet rays are formed between the first mold member having a shape transfer surface corresponding to the arrangement of the prism rows 41b ′ of the first light deflecting structure layer 41b and the first surface of the first light transmissive sheet substrate 41a. An active energy ray-curable resin such as a curable resin is supplied in an uncured state, and this is pressed against the shape transfer surface of the first mold member by the first translucent sheet base material 41a. An active energy ray curable resin is cured by irradiating active energy rays such as ultraviolet rays through the sheet base material 41a to form the first light deflection structure layer 41b. Next, the second mold member having the shape transfer surface corresponding to the spacer layer 41c provided with the protrusion 41c ′ and the first light transmissive sheet base material 41a formed with the first light deflection structure layer 41b is provided. An active energy ray curable resin such as an ultraviolet curable resin is supplied in an uncured state between the two surfaces and pressed against the shape transfer surface of the second mold member by the first translucent sheet substrate 41a. A spacer provided with a projection 41c ′ by irradiating an active energy ray such as ultraviolet rays through the first light deflecting structure layer 41b and the first translucent sheet base material 41a to cure the active energy ray-curable resin. Layer 41c is formed.

  On the other hand, as shown in FIG. 3A, the second structure element 42 'is formed. The formation of the second structural element 42 'can be performed as follows. That is, uncured translucent resin 42b ′ mixed with translucent fine particles 42c (actually, it is a coating material containing them, but for simplicity, it is referred to as “uncured translucent resin”). ) Is applied to the first surface of the second translucent sheet substrate 42a.

  Then, as shown in FIG. 3B, the protrusion 41c ′ of the spacer layer 41c of the first structural element body 41 has a tip portion (lower end) of the second transparent structure element 42. It pushes into uncured translucent resin 42b 'so that it may contact the 1st surface of optical sheet base material 42a. Thereby, as described with reference to FIG. 2, the distance between the lower surface of the first translucent sheet base material 41a and the upper surface of the second translucent sheet base material 42a is uniform. The positional relationship between the first structural element body 42 and the second structural element body 42 'can be set.

  Thereafter, the uncured translucent resin 42b ′ is dried and cured under heating or at room temperature to form the translucent resin 42b, whereby the translucent resin 42b and the tip of the protrusion 41c ′ are formed. It joins and the 1st structure element body 41 and the 2nd structure element body 42 integrated form is obtained.

  In the above embodiment, the first light deflection structure layer 41b forms a prism array as a plurality of lens arrays arranged in parallel to each other. However, in the present invention, the lens array includes other lenticular lenses and the like. A lens array may be formed.

  Further, in the above embodiment, the protrusions are in a line shape, but in the present invention, the protrusions may be composed of a plurality of dot-like protrusions. The shape of the point-like protrusions may be a cone shape or a pyramid shape. The point-like protrusions are not limited to the conical shape, and the tip portion may be formed in a flat shape or a convex curved shape.

  In the above embodiment, the extending direction of the row projections is orthogonal to the extending direction of the lens rows. However, in the present invention, the extending direction of the row projections is the extending direction of the lens rows. It may be substantially parallel. However, in this case, in order to remove the moire formed by the row projections and the lens rows, the row pitch P2 is set at random, or the ratio to the lens row arrangement pitch is n + 0. 0.4 to n + 0.6 (where n is a natural number of 1 or more and is preferably larger, but generally 12 or less), it is preferable to set the arrangement pitch P2 of the line-shaped protrusions. .

  In the above embodiment, the light diffusing and deflecting sheet of the present invention is applied to the surface light source device 10 of the direct type, but the light deflecting and diffusing sheet of the present invention is also applied to the edge light type surface light source device. It is also possible to do. The embodiment is shown in FIG.

  FIG. 4 is a schematic sectional view showing an embodiment of an edge light type surface light source device according to the present invention. As shown in this figure, the surface light source device 20 of the present embodiment has a plate-like light guide having a side end surface as a light incident end surface 13a and a main surface substantially orthogonal to the light incident end surface 13b. Body 13, linear primary light source 11 disposed adjacent to light incident end surface 13 a of light guide 13 and covered with light source reflector 12, and light disposed adjacent to light exit surface of light guide 13. The diffusion deflecting sheet 4 and the light reflecting element 14 disposed adjacent to the back surface 13c opposite to the light emitting surface 13b of the light guide 13 are configured.

  The light guide 13 is disposed in parallel with the XY plane and has a rectangular plate shape as a whole. The light emitted from the primary light source 11 enters the light incident end face 13a and is introduced into the light guide 13 to form a rough surface or a lens array for light emission formed on the light exit surface 13b or the opposite surface. The light is emitted from the light exit surface under the action of a light diffusive reflection surface formed by a fine uneven structure such as a surface or printing.

  In the present embodiment, the light diffusion deflection sheet 4 is arranged such that the second surface (the lower surface in FIG. 2) of the second light transmissive sheet base material 42 a faces the light emitting surface 13 b of the light guide 13. Has been.

  In the present embodiment, the distribution in the traveling direction of the light emitted from the light exit surface 13b of the light guide 13 and incident on the light diffusion deflecting sheet 4 is different from that in the surface light source device of the direct type described above. Is diffused and deflected in a desired manner by the light diffusion deflection sheet 4 and emitted in a desired distribution, the apex angle θ of the prism row of the light diffusion deflection sheet 4 is appropriately set. As an example of the range of the prism apex angle θ in this case, 80 to 100 ° is exemplified.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made within the scope of the technical idea described in the claims.

It is a typical sectional view of a direct type surface light source device using a light diffusion deflection sheet of the present invention. FIG. 2 is a schematic cross-sectional view of a light diffusion deflection sheet corresponding to the partially enlarged view of FIG. 1. It is typical sectional drawing which shows the manufacturing method of the light-diffusion deflection sheet of this invention. It is a typical sectional view of an edge light type surface light source device using a light diffusion deflection sheet of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Direct type surface light source device 1 Linear light source 2 Reflector 3 Light diffusing sheet 4 Light diffusing deflecting sheet 41 1st structure element 41a 1st translucent sheet base material 41b 1st light deflecting structure layer 41b 'prism Row 41c Spacer layer 41c 'Protrusion 42, 42' Second structure element 42a Second light transmissive sheet base material 42b Light transmissive resin 42b 'Uncured light transmissive resin 42c Light transmissive fine particles 20 Edge light system Surface light source device 11 Linear primary light source 12 Light source reflector 13 Light guide 13a Light incident end surface 13b Light exit surface 14 Light reflecting element

Claims (6)

A first light deflecting structure layer is formed on the first surface of the first translucent sheet substrate, a spacer layer is formed on the second surface of the first translucent sheet substrate, The spacer layer includes a protrusion having a predetermined height formed in part, and a second light deflection structure layer is formed on the first surface of the second light-transmitting sheet base material. The light deflecting structure layer is formed by holding translucent fine particles with a translucent resin, and the protrusions are arranged such that the tips thereof are in contact with the first surface of the second translucent sheet substrate. A light diffusing and deflecting sheet characterized by being joined to the translucent resin. The light diffusion deflection sheet according to claim 1, wherein the first light deflection structure layer forms a plurality of lens rows arranged in parallel to each other. 3. The projection according to claim 2, wherein the projection includes a plurality of row-like projections arranged in parallel to each other, and the extending direction of the row-like projection is substantially orthogonal to the extending direction of the lens row. Light diffusion deflection sheet. A method for producing the light diffusion deflection sheet according to claim 1,
Forming a first structure body by forming the first light deflection structure layer and the spacer layer on the first surface and the second surface of the first translucent sheet base material,
Forming the second structural element by applying the uncured translucent resin mixed with the translucent fine particles to the first surface of the second translucent sheet substrate;
While the translucent resin is uncured, the protrusion of the spacer layer of the first structural element body has the tip of the first surface of the second translucent sheet base material of the second structural element body. Pushed into the uncured translucent resin so as to abut,
Thereafter, the uncured translucent resin is cured to bond the protrusions to the translucent resin, thereby integrating the first structural element body and the second structural element body. A method for producing a light diffusing deflection sheet, wherein: A primary light source, a light diffusion sheet disposed adjacent to the primary light source, and the light diffusion deflection sheet according to any one of claims 1 to 3,
The primary light source and the light diffusion deflection sheet are positioned on opposite sides of the light diffusion sheet, and the light diffusion deflection sheet has a second surface of the second light transmissive sheet base material A direct-type surface light source device, which is disposed so as to face the light diffusion sheet. A light guide having a light incident end surface and a light output surface, a primary light source disposed adjacent to the light incident end surface of the light guide, and a light source disposed adjacent to the light output surface of the light guide. Comprising a light diffusion deflection sheet according to any one of 1 to 3,
The light diffusion deflecting sheet is arranged such that the second surface of the second light transmissive sheet base material faces the light emitting surface of the light guide, and the edge light system surface Light source device.

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