JP2018136574A - Fine-rugged sheet, illumination unit for display, and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine-rugged sheet for forming an illumination unit in combination with a point light source such as an LED light source, enabling higher front luminance, lower luminance unevenness, and appropriate viewing angles each with respect to a first direction and with respect to a second direction orthogonal to the first direction.SOLUTION: A fine-rugged sheet has a first surface or a wavy-rugged-pattern surface having an uneven-wavy pattern, and a second surface having a pentahedron pattern 12d or a pentahedron pattern 12d'. The pentahedron patterns include pentahedrons with a square or a rectangle bottom surface, arrayed repeatedly in two directions that are orthogonal to each other. A main diffusion direction of the wavy-rugged pattern and one direction of the two directions form an angle in a range from +20 degrees to -20 degrees.SELECTED DRAWING: Figure 20

Description

  The present invention relates to a surface fine uneven sheet, a lighting unit for a display device, and a display device.

In recent years, light-emitting diode (hereinafter also referred to as “LED”) light sources are widely used as power-saving and long-life light sources. The light emitted from the LED light source is highly straight and hardly diffuses. Therefore, when the LED light source is used, for example, in an illumination unit for a display device, a plurality of LED light sources are often arranged in a linear shape, a planar shape, etc., and used in combination with a light diffuser.
As the light diffuser, for example, a sheet-like surface fine uneven body having a concave / convex pattern formed of fine wavy unevenness on the surface is known (see Patent Document 1).

JP 2008-302591 A

However, recently, with the diversification of display devices, it has been required to satisfy various characteristics in an illumination unit using an LED light source.
For example, there is a head-up display system as a display device that displays image information such as traveling speed on a windshield of an automobile formed in a gently curved shape. In the head-up display system, in order to display image information clearly on the windshield, it is required that the front luminance is excellent, the luminance in-plane uniformity is excellent, and the luminance unevenness is suppressed. . In addition, in order to display image information satisfactorily, it is necessary to individually control the viewing angle in each direction in order to appropriately diffuse light in the vertical direction and the horizontal direction of the windshield.
However, diffusing light leads to a decrease in front luminance. Therefore, it is difficult to configure a lighting unit that has excellent front luminance, uneven luminance, and an appropriate viewing angle.

  The present invention has been made in view of the above circumstances, and when used in combination with a point light source such as an LED light source, the front luminance is excellent, luminance unevenness is suppressed, and the direction orthogonal to this is not only one direction. The surface fine concavo-convex sheet that can constitute an illumination unit having an appropriate viewing angle, a display device illumination unit using the surface fine concavo-convex sheet, and a display device including the display device illumination unit are provided. Objective.

The present invention has the following configuration.
[1] Surface fineness having an irregular wavy uneven pattern on at least a part of one surface and a linear uneven pattern on at least a part of the other surface corresponding to the part where the wavy uneven pattern is formed An uneven sheet,
The linear uneven pattern is a linear Fresnel lens pattern or a linear triangular prism pattern,
The surface fine concavo-convex sheet, wherein an angle formed between a main diffusion direction of the wavy concavo-convex pattern and an extending direction of the ridges of the linear concavo-convex pattern is within a range of ± 20 °.
[2] An irregular wave-shaped uneven pattern is formed on at least a part of one surface, and the bottom surface of the other surface corresponding to the part on which the wave-shaped uneven pattern is formed is a square or a rectangle. It is a surface fine uneven sheet having a pentahedral pattern that is repeatedly formed along two directions in which the plane is orthogonal,
The surface fine uneven sheet, wherein an angle formed between a main diffusion direction of the wavy uneven pattern and one of the two directions of the pentahedral pattern is within a range of ± 20 °.
[3] Surface fineness having an irregular wavy uneven pattern on at least a portion of one surface and a concentric uneven pattern on at least a portion of the other surface corresponding to the portion where the wavy uneven pattern is formed. Uneven sheet.
[4] A surface fine concavo-convex sheet having a linear concavo-convex pattern on at least a part of one surface, and having an irregular wavy concavo-convex pattern formed on at least a part of the linear concavo-convex pattern,
The linear uneven pattern is a linear Fresnel lens pattern or a linear triangular prism pattern,
The surface fine concavo-convex sheet, wherein an angle formed between a main diffusion direction of the wavy concavo-convex pattern and an extending direction of the ridges of the linear concavo-convex pattern is within a range of ± 20 °.
[5] At least a part of one surface has a pentahedron pattern in which a pentahedron whose bottom surface is a square or a rectangle is repeatedly formed along two orthogonal directions, and at least a part of the pentahedron pattern In addition, it is a surface fine uneven sheet on which an irregular wavy uneven pattern is formed,
The surface fine uneven sheet, wherein an angle formed between a main diffusion direction of the wavy uneven pattern and one of the two directions of the pentahedral pattern is within a range of ± 20 °.
[6] The surface fine uneven sheet according to any one of [1] to [5], which is used for the purpose of refracting and diffusing light from a light source array in which a plurality of point light sources are formed side by side.
[7] The surface fine concavo-convex sheet of [1] to [6], and at least one row of light source rows formed by arranging a plurality of point light sources,
An illumination unit for a display device, wherein an angle formed by the main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet and an arrangement direction of the point light sources of the light source array is within a range of ± 20 °. [8] A display device having the illumination unit for display device according to [7].

  According to the present invention, when used in combination with a point light source such as an LED light source, the front luminance is excellent, luminance unevenness is suppressed, and each field of view is appropriate not only in one direction but also in a direction orthogonal thereto. The surface fine uneven sheet | seat which can comprise the illumination unit which has an angle | corner, the illumination unit for display apparatuses using this surface fine uneven sheet | seat, and the display apparatus provided with this illumination unit for display apparatuses can be provided.

It is an expansion perspective view which shows typically the surface fine unevenness | corrugation sheet | seat of the example of 1st Embodiment. It is an optical microscope image of the wavy uneven | corrugated pattern formation surface of the surface fine unevenness | corrugation sheet of 1st Embodiment (The full scale of the edge | side of the left-right direction of an image is 500 micrometers). It is a three-dimensional image by the atomic force microscope of the wavy unevenness | corrugation pattern formation surface of the surface fine unevenness | corrugation sheet of 1st Embodiment (The full scale of each edge | side of an image is 200 micrometers). It is a longitudinal cross-sectional view which shows the wavy uneven | corrugated pattern of the surface fine unevenness | corrugation sheet | seat of the example of 1st Embodiment. (A) A longitudinal sectional view of a linear Fresnel lens pattern, (b) A longitudinal sectional view of a cylindrical lens. It is explanatory drawing explaining the effect | action of a linear Fresnel lens pattern. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 1st Embodiment, (a) Schematic top view from the wavy uneven | corrugated pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Wavy uneven pattern (1A) It is a side view which shows the side surface parallel to the sequence direction of a convex strip part, (c) The side view which shows a side surface parallel to the sequence direction of the convex strip part of a linear Fresnel lens pattern. It is an optical microscope image of the wavy uneven | corrugated pattern formation surface of the surface fine unevenness | corrugation sheet of 2nd Embodiment (The full scale of the side of the left-right direction of an image is 300 micrometers). It is an optical microscope image of the wavy uneven | corrugated pattern formation surface of the surface fine unevenness | corrugation sheet of 3rd Embodiment (The full scale of the edge | side of the left-right direction of an image is 60 micrometers). It is a longitudinal cross-sectional view which shows the wavy uneven | corrugated pattern of the surface fine uneven | corrugated sheet of the example of 3rd Embodiment. It is an optical microscope image of the wavy uneven | corrugated pattern formation surface of the surface fine unevenness | corrugation sheet of 4th Embodiment (The full scale of the edge | side of the left-right direction of an image is 300 micrometers). It is a longitudinal cross-sectional view which shows the wavy uneven | corrugated pattern of the surface fine uneven | corrugated sheet of the example of 4th Embodiment. It is explanatory drawing of the method of calculating | requiring the average height of the convex part in the wavy uneven | corrugated pattern of the surface fine uneven | corrugated sheet of the example of 4th Embodiment. It is an optical microscope image of the wavy uneven | corrugated pattern formation surface of the surface fine unevenness | corrugation sheet | seat of 5th Example (The full scale of the edge | side of the left-right direction of an image is 250 micrometers). (A) The schematic plan view from the wavy unevenness pattern formation surface side of the surface fine unevenness | corrugation sheet | seat of 5th Example, (b) The side surface parallel to the sequence direction of the protruding item | line part of a wavy unevenness pattern (1-b) is shown. It is a side view which shows a side view parallel to the arrangement direction of the convex line part of (c) wavy uneven | corrugated pattern (1A). It is explanatory drawing explaining the effect | action of a fixed vertex angle type linear triangular prism pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 6th Example, (a) Schematic top view from the wavy uneven | corrugated pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Wavy uneven pattern (1A) It is a side view which shows the side surface parallel to the arrangement direction of the protruding item | line part of this, (c) The side view which shows the side surface parallel to the arrangement direction of the protruding item | line part of a fixed vertex angle type linear triangular prism pattern. (A) Longitudinal sectional view showing a cross section parallel to the arrangement direction of the ridges for an example (pattern (A)) of an apex angle variation type linear triangular prism pattern, (b) Other apex angle variation type linear triangular prism pattern It is a longitudinal cross-sectional view which shows a cross section parallel to the sequence direction of a protruding item | line about an example (pattern (B)), (c) It is explanatory drawing explaining the effect | action of a vertex angle | variation type | mold linear triangular prism pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 11th Embodiment, (a) Schematic top view from the wavy uneven | corrugated pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Wavy uneven | corrugated pattern (1A) It is a side view which shows the side surface parallel to the arrangement direction of the protruding item | line part of this, (c) The side view which shows the side surface parallel to the arrangement direction of the protruding item | line part of a vertex angle variation type | mold linear triangular prism pattern (pattern (B)). . (A) Plan view from the pentahedron pattern forming surface side of the apex angle variation type modified pentahedron pattern, (b) Plan view from the pentahedron pattern formation surface side of the apex angle variation type tetragonal pyramid prism pattern, (c) Top It is explanatory drawing explaining the effect | action of an angle variation type | mold deformation | transformation pentahedron pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 16th Embodiment, (a) Schematic top view from the wavy uneven | corrugated pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Wavy uneven | corrugated pattern (1A) It is a side view which shows the side surface parallel to the arrangement | sequence direction of a protruding item | line part, (c) The side view which shows a side surface parallel to the extending direction of the protruding item | line part of a wavy uneven | corrugated pattern (1A). (A) Longitudinal section of Fresnel lens pattern, (b) Longitudinal section of plano-convex lens. It is explanatory drawing explaining the effect | action of a Fresnel lens pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 21st Example, (a) Schematic top view from the wavy uneven | corrugated pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Wavy uneven | corrugated pattern (1A) It is a side view which shows the side surface parallel to the arrangement | sequence direction of a protruding item | line part, (c) The side view which shows a side surface parallel to the extending direction of the protruding item | line part of a wavy uneven | corrugated pattern (1A). It is explanatory drawing explaining the effect | action of a linear Fresnel lens pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of the example of 26th Embodiment, (a) Schematic top view from the pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Convex | convexity of a wavy uneven | corrugated pattern (1A) It is a side view which shows the side parallel to the arrangement direction of a strip, (c) The side view which shows a side parallel to the arrangement direction of the convex strip of a linear Fresnel lens pattern. It is explanatory drawing explaining the effect | action of a fixed vertex angle type linear triangular prism pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 27th Example, (a) The schematic plan view from the pattern formation surface side of a surface fine unevenness | corrugation sheet, (b) Convex | convexity of a wavy unevenness | corrugation pattern (1A) It is a side view which shows the side surface parallel to the sequence direction of a strip part, (c) The side view which shows a side surface parallel to the sequence direction of the convex strip part of a fixed vertex angle type linear triangular prism pattern. It is explanatory drawing explaining the effect | action of a vertex angle | variation type | mold linear triangular prism pattern. It is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of 28th Embodiment, (a) Schematic top view from the pattern formation surface side of a surface fine uneven | corrugated sheet, (b) Convex | concave of a wavy uneven | corrugated pattern (1A) It is a side view which shows the side parallel to the arrangement | sequence direction of a strip | line part, (c) The side view which shows a side surface parallel to the arrangement | sequence direction of the convex strip | line part of a vertex angle | variation type linear triangular prism pattern.

Each term in this specification and a claim means the following contents.
The “waved concavo-convex pattern forming surface” means the surface of the surface fine concavo-convex sheet on which the irregular wavy concavo-convex pattern is formed.
“Linear concavo-convex pattern forming surface” means the surface of the surface fine concavo-convex sheet on which the linear concavo-convex pattern is formed.
The “pentahedral pattern forming surface” means the surface on the side where the pentahedral pattern is formed in the surface fine uneven sheet.
The “concentric concavo-convex pattern forming surface” means the surface on the side where the concentric concavo-convex pattern is formed in the surface fine concavo-convex sheet.
In addition, when simply referring to the “pattern forming surface”, the “pattern forming surface” means that a wavy uneven pattern and a linear uneven pattern, or a wavy uneven pattern and a pentahedral pattern are formed on the surface fine uneven sheet. It means the surface.

The `` irregular wavy uneven pattern '' means that the shape of the portion corresponding to the wavy uneven pattern in the cut surface obtained when cutting along at least one surface parallel to the normal direction of the surface fine uneven sheet, It refers to a pattern that is an irregular fine wavy uneven shape.
For example, the following patterns [1] and [2] can be mentioned.

[1] A plurality of ridges extending in a streak pattern along the wavy uneven pattern forming surface and a plurality of recessed portions between the plurality of protruding ridges alternately in one direction along the wavy uneven pattern forming surface A pattern having at least a repeated pattern and having the following characteristics (a) and (b) (hereinafter also referred to as “waved uneven pattern (1)”).
In the wavy uneven pattern (1), at least one direction parallel to the normal direction of the surface fine uneven sheet and the protrusions and the recesses being alternately repeated (hereinafter referred to as “the protrusions of the protrusions”). The shape of the portion corresponding to the wavy uneven pattern becomes an irregular wavy uneven shape on the cut surface obtained by cutting along the arrangement direction.

(A) Each protrusion is meandering and is not parallel to each other. That is, the ridge line of each ridge part meanders, and the space | interval of the ridge line of an adjacent protrusion part is not constant, but is changing continuously. However, it may include a portion where the interval between the ridge lines is constant. Further, one ridge line may be branched in the middle, or a plurality of ridge lines may be joined in the middle.
(B) The respective concave strips meander and are not parallel to each other. That is, the valley line of each groove part meanders, and the space | interval of the valley line of an adjacent groove part is not constant, but is changing continuously. However, a portion where the interval between the valley lines is partially constant may be included. Moreover, one trough line may branch on the way, or several trough lines may unite on the way.

  In the wavy uneven pattern (1), the vertical cross-sectional shape of each ridge in the cut surface (in the cut surface that is parallel to the normal direction of the surface fine uneven sheet and cut along the arrangement direction of the ridges) Shape.) Are different from each other and are not uniform but irregular.

Due to the irregularity of the wavy uneven pattern (1) as described above, the wavy uneven pattern (1) is suitable not only in the main diffusion direction described later but also in the low diffusion direction orthogonal to the main diffusion direction. Diffuse light.
Moreover, although mentioned later in detail, a wavy uneven | corrugated pattern (1) is a pattern formed by heat-shrinking the heat-shrinkable resin film which consists of a uniaxially stretched film (uniaxial direction shrink film).

[2] A pattern in which fine irregularities that do not follow a specific direction are formed on a wave-shaped irregular pattern forming surface (hereinafter also referred to as “wave-shaped irregular pattern (2)”).
In the wavy uneven pattern (2), the shape of the portion corresponding to the wavy uneven pattern on the cut surface obtained when cutting along an arbitrary direction parallel to the normal direction of the surface fine uneven sheet has an irregular wavy shape. It becomes the uneven shape.
In the wavy uneven pattern (2), the vertical cross-sectional shape of each convex portion on the cut surface (the shape on the cut surface cut along an arbitrary direction parallel to the normal direction of the surface fine uneven sheet) is different from each other. It is irregular and not uniform.

Due to the irregularity of the wavy uneven pattern (2) as described above, the wavy uneven pattern (2) diffuses light in the main diffusion direction and the low diffusion direction. Further, since the unevenness does not follow the specific direction as described above, the difference in the diffusion angle between the main diffusion direction and the low diffusion direction is small.
Moreover, although mentioned later in detail, a wavy uneven | corrugated pattern (2) is a pattern formed by heat-shrinking the heat-shrinkable resin film which consists of a biaxially stretched film (biaxial direction shrink film).

  "Linear concavo-convex pattern" refers to a plurality of fine ridges extending linearly in parallel with each other along the linear concavo-convex pattern forming surface, and between the plurality of ridges And a plurality of fine concave ridges extending linearly are alternately repeated in one direction along the linear concavo-convex pattern forming surface (hereinafter also referred to as “arrangement direction of ridges”). Means a linear Fresnel lens pattern or a linear triangular prism pattern.

  The “linear Fresnel lens pattern” is a pattern based on a known linear Fresnel lens in which a normal Fresnel lens having grooves concentrically formed is applied to a cylindrical lens.

“Linear triangular prism pattern” refers to the vertical cross-sectional shape of each ridge that constitutes the linear triangular prism pattern (parallel to the normal direction of the surface fine concavo-convex sheet and cut along the arrangement direction of the ridges) Is a shape that is an isosceles triangle or an equilateral triangle.
Among the “linear triangular prism patterns”, those having the same vertical angle in the vertical cross-sectional shape of each ridge portion are referred to as “constant vertical angle linear triangular prism pattern”.
Among the “linear triangular prism pattern”, the ridges in the vertical cross-sectional shape of the ridges are different from each other, and are located on the center side from the ridges located on both ends of the linear concavo-convex pattern forming surface. A pattern in which the apex angle gradually increases toward the ridge is referred to as “vertical angle variable linear triangular prism pattern”. The apex angle of each ridge is constant in its extending direction.
In the “vertical angle variation type linear triangular prism pattern”, the height of each ridge is constant, but the width (pitch) of the bottom is not constant between the ridges. The form in which the corners are fluctuating (hereinafter may be referred to as “pattern (A)”, see FIG. 18A) and the width (pitch) of the bottom of each ridge is constant. There is a form in which the apex angle fluctuates because the heights of the ridges are not constant but different (hereinafter, referred to as “pattern (B)”, see FIG. 18B).

The “pentahedron pattern” means a pattern in which a large number of pentahedrons whose bottom surfaces are square or rectangular are repeatedly formed along two orthogonal directions on the pentahedron pattern forming surface. The bottom surfaces of a large number of pentahedrons share a side with each other and are connected.
The “pentahedral pattern” includes the following patterns (1) to (3).
The following (2) vertex angle variation type tetragonal pyramid prism pattern and the following (3) vertex angle variation type modified pentahedral pattern are collectively referred to as “apex angle variation type pentahedral pattern”.
(1) Constant apex angle type quadrangular pyramid prism pattern:
A large number of pentahedrons consist only of a large number of quadrangular pyramids, and the apex angles in the longitudinal sectional shape of each quadrangular pyramid are the same. Note that the longitudinal cross-sectional shape is a cut that is parallel to the normal direction of the surface fine unevenness sheet and that is cut along one of the two orthogonal directions and through the apex of each quadrangular pyramid. The shape on the surface and the shape on the cut surface that is parallel to the normal direction of the surface fine uneven sheet and cut along the other direction of the two orthogonal directions and through the apex of each quadrangular pyramid It means that. The constant apex angle type quadrangular pyramid prism pattern has the same apex angle between the respective quadrangular pyramids and is constant in both longitudinal sectional shapes.
(2) Vertical angle variation type quadrangular pyramid prism pattern:
A large number of pentahedrons consist only of a large number of quadrangular pyramids, and the apex angles in the longitudinal sectional shape of each quadrangular pyramid are different from each other. Note that the longitudinal cross-sectional shape is a cut that is parallel to the normal direction of the surface fine unevenness sheet and that is cut along one of the two orthogonal directions and through the apex of each quadrangular pyramid. The shape on the surface and the shape on the cut surface that is parallel to the normal direction of the surface fine uneven sheet and cut along the other direction of the two orthogonal directions and through the apex of each quadrangular pyramid It means that. The apex angle variation type quadrangular pyramid prism pattern is not constant because the apex angle gradually varies between the respective quadrangular pyramids in any of the longitudinal sectional shapes.
Specifically, in a quadrangular pyramid arranged along one of two orthogonal directions, the apex angle gradually increases from the quadrangular pyramid located on the outer side toward the quadrangular pyramid located on the center side. Yes. In addition, in the quadrangular pyramids arranged along other directions of the two orthogonal directions, the apex angle gradually increases from the quadrangular pyramid located on the outer side toward the quadrangular pyramid located on the center side.
After forming the pattern (A) of the apex angle variation type linear triangular prism pattern, the pattern (A) is orthogonal to the pattern (A) in the arrangement direction of the ridges, and This is a pattern formed by cutting out the pattern (A ′) which is the inverted shape of the pattern (A) (see FIG. 20B). Therefore, although the heights of the respective quadrangular pyramids are constant, the pitches are not constant among the respective quadrangular pyramids.
(3) Vertex angle variation type pentahedron pattern:
Many pentahedrons consist of a pyramid and a pentahedron other than the quadrangular pyramid. Here, the pentahedron other than the quadrangular pyramid is a pentahedron that does not have a vertex at a position facing the bottom surface like a quadrangular pyramid, but has ridge lines (sides) parallel to a pair of sides of the bottom surface. Hereinafter, a pentahedron having such a ridge line is also referred to as a “ridge line type pentahedron”.
And the apex angle in the longitudinal cross-sectional shape of each quadrangular pyramid and a ridge-line type pentahedron is mutually different. The vertical cross-sectional shape is parallel to the normal direction of the surface fine uneven sheet and along one of the two orthogonal directions, and the apex of each quadrangular pyramid and the ridge line of each ridge line type pentahedron The shape of the cut surface that is cut so as to pass through and the normal direction of the surface fine uneven sheet and along the other of the two orthogonal directions, and the apex and each ridgeline of each quadrangular pyramid It means both the shape of the cut surface cut along the ridgeline of the mold pentahedron. The vertical angle variation type modified pentahedron pattern is not constant because the vertical angle gradually changes between each pyramid and each ridge line type pentahedron in any longitudinal cross-sectional shape.
Specifically, in the quadrangular pyramid and the ridgeline pentahedron arranged along one of the two orthogonal directions, the quadrangular pyramid and the ridgeline located on the center side from the quadrangular pyramid and the ridgeline pentahedron located outside. The apex angle gradually increases toward the mold pentahedron. And in the quadrangular pyramid and the ridgeline pentahedron arranged along the other direction of two orthogonal directions, the quadrangular pyramid and pentahedron located on the outer side are directed to the quadrangular pyramid and ridgeline pentahedron located on the center side. The apex angle gradually increases.
The vertical cross-sectional shape of the ridged pentahedron may be a triangle or a trapezoid depending on the direction. In the case of a trapezoid, the angle at which the extension lines on the upper bottom side of the two legs of the trapezoid intersect is regarded as the “vertical angle”.
After forming the pattern (B) of the apex angle variation type linear triangular prism pattern, the pattern (B) is orthogonal to the pattern (B) in the arrangement direction of the ridges, and This is a pattern formed by cutting out the pattern (B ′) which is the inverted shape of the pattern (B) (see FIG. 20A). Therefore, although the pitches of the respective quadrangular pyramids and the ridge line type pentahedron are constant, the heights of the respective quadrangular pyramids and ridge line type pentahedrons are not constant.
It should be noted that a plurality of the above-described “vertical angle variation type quadrangular pyramid prism patterns” may be formed along the surface direction on the pentahedral pattern forming surface on which the pattern described above is formed. That is, when the pentahedral pattern forming surface is divided into a plurality of regions, the above-described “vertical angle variation type quadrangular pyramid prism pattern” may be formed in each region.
Similarly, on the pentahedron pattern forming surface, a plurality of the above-mentioned “vertical angle variation-type deformed pentahedron patterns” may be formed along the surface direction. That is, when the pentahedron pattern forming surface is divided into a plurality of regions, the above-mentioned “vertical angle variation type modified pentahedron pattern” may be formed in each region.
Further, the “vertical angle variable pentahedron pattern” may be in a form in which the pitch and height of each quadrangular pyramid and ridge line type pentahedron are not constant.

The “concentric concavo-convex pattern” means a pattern in which concentric concave and convex rings are alternately formed on the concentric concavo-convex pattern forming surface.
The “concentric concavo-convex pattern” includes a normal “Fresnel lens pattern”.
Of the “concentric concavo-convex pattern”, the vertical cross-sectional shape of the convex ring (the shape on the cut surface parallel to the normal direction of the surface fine concavo-convex sheet and cut along the radial direction of the concentric circle) is two. Those which are equilateral triangles or equilateral triangles are called “concentric prism patterns”.

Among the “concentric prism patterns”, those having the same vertical angle in the vertical cross-sectional shape of each convex ring are called “constant vertex angle concentric prism patterns”.
Among the “concentric circular prism patterns”, the convex rings located on the center side from the convex rings located on the outer peripheral side of the concentric concave / convex pattern forming surface are different from each other in the vertical cross-sectional shape of the convex rings. The one with a gradually increasing apex angle is called “vertical angle variation type concentric prism pattern”. The apex angle of each convex ring is constant in the ring direction (circumferential direction).
A plurality of the above-mentioned “concentric uneven patterns” may be formed along the surface direction on the concentric uneven pattern forming surface. That is, when the concentric uneven pattern forming surface is divided into a plurality of regions, the above-mentioned “concentric uneven patterns” may be formed in each region.

The “main diffusion direction of the wavy uneven pattern” is a direction determined by the following method.
(1) For measuring the diffusion angle, a sample sheet is prepared in which one surface is a wavy uneven pattern forming surface and the other surface is a smooth surface (smooth surface).
(2) Using a goniometer (for example, model: GENESISIA Gonio / FFP, manufactured by Genesia), the measurement light is incident from the smooth surface side of the sample sheet, and the transmitted and scattered light from the wavy uneven pattern forming surface is measured. Get the illuminance curve.
Specifically, the relative illuminance when the illuminance of light emitted vertically from the sample sheet (light emission angle = 0 °) is set to 1 is the light emission angle− in a certain direction (α direction) on the wavy uneven pattern forming surface− Measure from 90 ° to 90 ° at 1 ° intervals. Thereby, an illuminance curve in the α direction is obtained.
Such an operation and preparation of the illuminance curve are performed in a direction (β direction) shifted by 1 ° from the α direction on the wavy uneven pattern forming surface.
Subsequently, such an operation and preparation of an illuminance curve are performed in a direction (γ direction) shifted by 1 ° from the β direction on the wavy uneven pattern forming surface.
In this way, the direction in which the relative illuminance is measured is shifted by 1 ° within the wavy uneven pattern forming surface to obtain an illuminance curve for each 1 °. Thereby, 180 kinds of illuminance curves are obtained in total.
(3) In each of the 180 types of illuminance curves, an angle range in which the relative illuminance is 0.5 or more is obtained. The range is the diffusion angle. For example, in the illuminance curve obtained in the α direction, when the angle range in which the relative illuminance is 0.5 or more is −13 ° to + 17 °, the diffusion angle in the α direction is 13 ° + 17 ° = 30. °.
(4) For each of the 180 types of directions, the diffusion angle is obtained as described above, and the direction in which the largest diffusion angle is obtained among the 180 types of diffusion angles is the main diffusion direction.
(5) The low diffusion direction is defined as “a direction orthogonal to the main diffusion direction”.
Both the main diffusion direction and the low diffusion direction are directions on the wavy uneven pattern forming surface.

  In this specification, the term “smooth” means that the center line average roughness measured by the method described in JIS B0601 is 0.1 μm or less.

The surface fine concavo-convex sheet of each embodiment described below has an irregular wavy concavo-convex pattern and a linear concavo-convex pattern, a pentahedral pattern or a concentric concavo-convex pattern.
Therefore, it is possible to configure an illumination unit that is excellent in front luminance, has reduced luminance unevenness, and has an appropriate viewing angle not only in the main diffusion direction but also in the low diffusion direction orthogonal thereto. The illumination unit is preferably used as an illumination unit for a display device such as a head-up display system.
Moreover, the surface fine uneven sheet | seat of each embodiment is a 1 sheet structure so that it may mention later. Therefore, the viewing angle ensuring effect, the luminance unevenness eliminating effect, and the front luminance improving effect can be achieved with only one sheet without using a plurality of sheets, and the handling property and the thinning of the lighting unit are excellent.

  When configuring the illumination unit for a display device and the display device, which of the embodiment examples of the surface fine uneven sheet of each embodiment is selected depends on the main diffusion direction and low diffusion required for the display device. It can be determined according to the viewing angle of the direction, the balance of these viewing angles, the front luminance, and the degree of demand for suppressing luminance unevenness.

The following first to fifth embodiment examples have an irregular wavy uneven pattern on at least a part of one surface, and a linear Fresnel lens pattern as a linear uneven pattern on at least a part of the other surface. The present invention relates to a surface fine uneven sheet.
In the first to fifth embodiments, the wavy uneven patterns are different from each other.

The following sixth to fifteenth embodiments have an irregular wavy uneven pattern on at least a part of one surface, and a linear triangular prism pattern as a linear uneven pattern on at least a part of the other surface. The present invention relates to a surface fine uneven sheet.
Among these, the linear triangular prism pattern of the sixth to tenth embodiment examples is a “constant apex linear triangular prism pattern”, and the linear triangular prism pattern of the eleventh to fifteenth embodiment examples is “vertical angle”. "Variable linear triangular prism pattern". As described above, the “vertical angle variation linear triangular prism pattern” includes the pattern (A) and the pattern (B), and any of them can be used.
In the sixth to tenth embodiments, the wavy uneven patterns are different from each other. In the 11th to 15th embodiments, the wavy uneven patterns are different from each other.

The following sixteenth to twentieth embodiment examples have an irregular wavy uneven pattern on at least a portion of one surface, and a pentagonal variation type deformation pattern 5 as a pentahedral pattern on at least a portion of the other surface. The present invention relates to a surface fine uneven sheet having a face pattern.
In the sixteenth to twentieth embodiments, an example in which the apex angle variation deformed pentahedron pattern is formed is shown. Instead of the apex angle variation type deformable pentahedron pattern, the apex angle variation type pentagonal prism is used. A pattern may be formed. Further, a constant apex angle type quadrangular pyramid prism pattern may be formed instead of the apex angle variation type modified pentahedron pattern. However, as will be described later, in the sixteenth to twentieth embodiments, light from a point light source is incident without passing through a condenser lens. When the condensing lens is not passed, the incident angle of incident light varies greatly depending on the location. From this point, the apex angle variation type modified pentahedron pattern or the apex angle variation type tetragonal pyramid prism pattern is preferable in that brightness unevenness can be sufficiently suppressed. The constant apex angle type quadrangular pyramid prism pattern may employ a condensing lens, for example, in the first to fifth embodiments, instead of the linear Fresnel lens pattern.
In the sixteenth to twentieth embodiments, the wavy uneven patterns are different from each other.

  In the sixteenth to twentieth embodiments, a wavy uneven pattern is formed on the entire surface of one surface, and a pentahedral pattern is formed on the entire surface of the other surface, but the patterns are formed on one surface and the other surface, respectively. It is only necessary that at least a part of the region where the is formed corresponds to each other and is overlapped. Each may not be formed on the entire surface of one surface and the other surface.

The following 21st to 25th embodiments have an irregular wavy uneven pattern on at least a part of one surface and a Fresnel lens pattern as a concentric uneven pattern on at least a part of the other surface. It relates to a surface fine uneven sheet. The Fresnel lens pattern is formed so as to correspond to a portion where the irregular wavy uneven pattern is formed. The wavy uneven pattern is formed on a part of one surface and may not be formed on the entire surface.
In the 21st to 25th embodiments, an example in which a Fresnel lens pattern is formed has been shown. It may be formed. However, as will be described later, in the 21st to 25th embodiments, the light from the point light source is incident without passing through the condenser lens. When the condensing lens is not passed, the incident angle of incident light varies greatly depending on the location. From this point, a Fresnel lens pattern or a vertex angle variation type concentric prism pattern is preferable in that brightness unevenness can be sufficiently suppressed. The constant apex angle type concentric prism pattern may employ a condensing lens, for example, in the first to fifth embodiments, instead of the linear Fresnel lens pattern.
In the 21st to 25th embodiments, the wavy uneven patterns are different from each other.

In the following twenty-sixth to twenty-eighth embodiment examples, a surface having a linear concavo-convex pattern on at least a part of one surface and an irregular wavy concavo-convex pattern formed on at least a part of the linear concavo-convex pattern It relates to a fine uneven sheet. The wavy uneven pattern is formed on a part of one surface and may not be formed on the entire surface.
In the twenty-sixth to twenty-eighth embodiment examples, the linear concavo-convex patterns are different from each other, and as the linear concavo-convex pattern, a linear Fresnel lens pattern is formed in the twenty-sixth embodiment example, and in the twenty-seventh embodiment example, a constant vertex angle type linear triangle A prism pattern is formed, and in the twenty-eighth embodiment, an apex angle variation type linear triangular prism pattern is formed.
In the twenty-sixth to twenty-eighth embodiments, the form in which the wavy uneven pattern is formed on the linear uneven pattern is shown in terms of ease of manufacture and the like. However, depending on the purpose, a pentahedral pattern may be formed instead of the linear uneven pattern, and a wavy uneven pattern may be formed thereon, or a concentric uneven pattern instead of the linear uneven pattern. And a wavy uneven pattern may be formed thereon.

  In each of the following examples, the surface fine uneven sheet has a one-layer structure, but the surface fine uneven sheet is not limited to a single layer structure, and may have a multilayer structure including two or more layers.

<First to Fifth Embodiments>
[First Embodiment]
FIG. 1 is a perspective view schematically showing a surface fine uneven sheet according to this embodiment.
The surface fine concavo-convex sheet 10A in the illustrated example is a sheet having a single layer structure made of a transparent resin, one surface is a wavy concavo-convex pattern forming surface 11, and the other surface is a linear Fresnel lens pattern 12A The line-shaped uneven pattern forming surface 12 is formed. The angle formed between the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges 12a of the linear Fresnel lens pattern 12A (hereinafter also referred to as “intersection angle”) is a plan view of the wavy uneven pattern. In the range of ± 20 °, that is, −20 ° to + 20 °. In the example of FIG. 1, both the main diffusion direction of the wavy uneven pattern and the extending direction of the convex portion 12a of the linear Fresnel lens pattern 12A are directions (A direction) indicated by an arrow A in the figure, The angle formed by these is 0 ° (parallel).

  As will be described in detail later, the wavy uneven pattern mainly has a viewing angle ensuring effect and a luminance unevenness eliminating effect, and the linear Fresnel lens pattern 12A mainly has a front luminance improving effect.

[Wavy uneven pattern]
In the surface fine concavo-convex sheet 10 </ b> A of the first embodiment, the undulating concavo-convex pattern (1 </ b> A) corresponding to the undulating concavo-convex pattern (1) described above is formed on the undulating concavo-convex pattern forming surface 11.
FIG. 2 is an optical microscope image of a wavy uneven pattern forming surface of the surface fine uneven sheet of this embodiment example, and FIG. 3 is a three-dimensional image of the wavy uneven pattern forming surface by an atomic force microscope. FIG. 4 shows a wavy uneven pattern (1A) of the surface fine uneven sheet according to the present embodiment, which is parallel to the normal direction of the surface fine uneven sheet and is a convex line of the wave uneven pattern (1A). It is the longitudinal cross-sectional view cut | disconnected along the sequence direction of a part.
As shown in FIG. 4, the said longitudinal cross-sectional shape of the protruding item | line part 11a is mutually different, and is not uniform but irregular. In addition, the vertical cross-sectional shape of each ridge portion 11a is a tapered shape in which each of the ridges 11a is tapered from the proximal end side toward the distal end side, and the distal end is rounded. Moreover, in the vertical cross-sectional shape of each protruding line portion 11a, the line connecting the distal end side and the proximal end side is smoothly and continuously lowered from the distal end side toward the proximal end side. In addition, each ridge 11a has at least one of the above-described vertical cross-sectional shape and its area changed along the extending direction of the ridge 11a (direction extending in a streak shape), It is not constant.
Moreover, in each protruding item | line part 11a, the height of a ridgeline is not constant, but has the height difference which changes continuously. However, the part which does not have a height difference partially may be included.
Moreover, in each concave line part between the adjacent convex line parts 11a, the height of a trough line is not constant, but has a height difference which changes continuously. However, the part which does not have a height difference partially may be included.

The average pitch of the ridges 11a of the wavy uneven pattern (1A) is preferably 1 to 50 μm, more preferably 5 to 30 μm, and more preferably 8 to 20 μm. When the average pitch is not less than the lower limit of the above range, the surface fine uneven sheet 10A can be easily produced. When the average pitch is less than or equal to the upper limit of the above range, when the surface fine uneven sheet 10A is used in a lighting device, the wavy uneven pattern (1A) is difficult to be visually recognized as an undesirable bright line. Further, when the average pitch is within the above range, a sufficient diffusion angle is exhibited in the main diffusion direction.
In addition, as for average pitch, as shown in FIG. 2, the planar image of the wavy uneven | corrugated pattern formation surface 11 in which 20 or more of the protruding item | line parts 11a are contained is obtained, and it is protruding item | line part about 20 of adjacent protruding item | line parts 11a. It can be obtained by measuring the length along the arrangement direction of 11a at five locations and dividing the average value of the measured values by 20.
The average pitch can also be obtained by the following method.
That is, the upper surface of the wavy uneven pattern forming surface 11 is photographed with an optical microscope or an electron microscope, the image is converted into a grayscale file (for example, tiff format), and then the image of the grayscale file is Fourier transformed. Then, the pitch is obtained by image analysis of the Fourier transform image. This method is described in, for example, Japanese Patent Application Laid-Open No. 2008-302591 (Japanese Patent No. 4683011), and the like can be referred to. As described in paragraph [0024] of the publication, the most frequent pitch obtained by the method and the average pitch can be handled equally. The same applies to each embodiment below.

  The ratio of the average height to the average pitch of the ridges 11a of the wavy uneven pattern (1A), that is, the aspect ratio (average height / average pitch) is preferably 0.05 to 3.0, 0.1 It is more preferable that it is -2.0, and it is further more preferable that it is 0.3-1.0. When the aspect ratio is at least the lower limit of the above range, the viewing angle ensuring effect and the luminance unevenness eliminating effect are sufficiently obtained by the wavy uneven pattern (1A). When the aspect ratio is not more than the upper limit of the above range, the wavy uneven pattern (1A) can be easily formed.

The average height of the ridges 11a is obtained as follows.
For example, using a microtome, a thin piece sample having a cut surface parallel to the normal direction of the surface fine uneven sheet and cut along the arrangement direction of the ridges is obtained, and an optical microscope of the cut surface of the thin sample is obtained. Get an image. Then, 50 ridges are randomly selected from the cut surface of the optical microscope image, and the height H of each ridge is obtained.
Specifically, as shown in FIG. 4, the vertical distance between the top T of one ridge 11a and the bottom B1 of the ridge located on one side of the ridge 11a is Li, and the ridge When the vertical distance between the top portion T of the portion 11a and the bottom B2 of the concave portion located on the other side of the convex portion 11a is Ri, it is obtained by H = (Li + Ri) / 2. It is the height of the part 11a.
The average value of the heights of the 50 ridges thus obtained is the “average height of the ridges”.

In the surface fine concavo-convex sheet 10A of the present embodiment example, the main diffusion direction of the wavy uneven pattern (1A) can be obtained by the method described above, and in the arrangement direction of the ridges 11a of the wavy uneven pattern (1A). It is a parallel direction (A direction in FIG. 1).
The diffusion angle in the main diffusion direction can be adjusted as appropriate, but is preferably 10 ° or more, for example, and more preferably 15 ° or more. For example, it is preferably 40 ° or less, and more preferably 30 ° or less.
On the other hand, the direction orthogonal to the main diffusion direction is a “low diffusion direction” with a low diffusion angle.
The diffusion angle in the low diffusion direction can be adjusted as appropriate, but is preferably smaller than the diffusion angle in the main diffusion direction and, for example, 2 ° or more. For example, it is preferably 15 ° or less.
The diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction can be controlled by adjusting the average pitch of the protrusions, the aspect ratio (average height / average pitch), and the like.

  If the diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction are each in the wavy uneven pattern (1A) within the above range, when the light is incident on the sheet on which the pattern is formed, the main diffusion direction The light diffuses in the low diffusion direction while the light is sufficiently diffused. Therefore, such a wavy uneven pattern (1A) is excellent in the effect of securing the viewing angle in each of the main diffusion direction and the low diffusion direction, and uses a light source having high straightness such as an LED light source and a laser light source for an illumination device or the like. Excellent brightness unevenness elimination effect.

[Linear uneven pattern (Linear Fresnel lens pattern)]
Fig.5 (a) is a figure explaining 12 A of linear Fresnel lens patterns, Comprising: It is the longitudinal cross-sectional view cut | disconnected along the sequence direction of the convex part 12a of 12 A of linear Fresnel lens patterns. The linear Fresnel lens has the same lens effect as the convex lens while reducing the thickness by dividing the convex lens region of the cylindrical lens shown in FIG. 5B.
In the linear Fresnel lens pattern 12A, the direction of the dividing line that divides the convex lens region corresponds to the extending direction of the ridges 12a of the linear Fresnel lens pattern 12A.

The operation of the linear Fresnel lens pattern 12A will be described with reference to FIG.
FIG. 6 is a sheet in which one surface is a surface on which the linear Fresnel lens pattern 12 </ b> A is formed (the lower surface in FIG. 6) and the other surface is a smooth surface 13. When light from a point light source 21 such as an LED light source or a laser light source is incident on the linear Fresnel lens pattern 12A of this sheet through the condenser lens 20, the linear Fresnel lens pattern 12A among the light traveling vectors. The in-plane component consisting of the arrangement direction of the ridges 12a (m direction in the figure) and the normal direction of the linear Fresnel lens pattern 12A formation surface (n direction in the figure) The light is refracted so as to be parallel to (n direction in the figure), and is emitted from the smooth surface 13 as indicated by an arrow X in FIG. That is, the direction of light rises toward the front. The linear Fresnel lens pattern 12A has an effect of improving the front luminance by such a light collecting function.
For example, the linear Fresnel lens pattern 12A has a higher light condensing function than the linear triangular prism pattern described later, and is more excellent in the front luminance improvement effect. In addition, it is easy to align the direction of light and there is little loss of light. Moreover, it is excellent also in the effect of coexistence of luminance unevenness and front luminance.

  The pitch of the ridges 12a of the linear Fresnel lens pattern 12A, the inclination angle of the tip surface 12a 'of the ridges 12a, and the like are designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, the in-plane component including the arrangement direction of the ridges 12a of the linear Fresnel lens pattern 12A and the normal direction of the surface on which the linear Fresnel lens 12A is formed is preferably the linear Fresnel for all the light emitted from the condenser lens 20 It is preferably designed to be refracted so as to be parallel to the normal direction of the lens forming surface and to exit from the smooth surface 13.

  The irradiation angle of the light emitted from the condenser lens 20 is preferably 2 to 50 °, more preferably 5 to 40 °, and still more preferably 10 to 30 °. When the irradiation angle is equal to or greater than the lower limit of the above range, the light emitted from the condenser lens 20 is sufficiently spread, and the luminance unevenness of the light emitted from the surface fine uneven sheet 10A is eliminated. When the irradiation angle is equal to or less than the upper limit of the above range, out of the traveling vectors of the light emitted from the condenser lens 20, the arrangement direction of the ridges 12a of the linear Fresnel lens pattern 12A and the linear Fresnel lens pattern 12A formation surface The in-plane component composed of the normal direction is sufficiently refracted so as to be parallel to the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed, and the front luminance improvement effect is excellent.

  The pitch of the ridges 12a of the linear Fresnel lens pattern 12A is appropriately designed as described above, but is preferably 5 to 500 μm, for example. When the pitch is equal to or greater than the lower limit value of the above range, the linear Fresnel lens pattern 12A can be formed satisfactorily, and when the pitch is equal to or smaller than the upper limit value of the above range, when the surface fine uneven sheet 10A is used in a lighting device, The lens pattern 12A is difficult to be visually recognized as an undesirable bright line.

[Surface micro uneven sheet]
The surface fine concavo-convex sheet 10A of the present embodiment example is an angle formed between the main diffusion direction of the wavy concavo-convex pattern (A direction in FIG. 1) and the extending direction of the ridges 12a of the linear Fresnel lens pattern 12A, that is, The crossing angle is within a range of ± 20 ° when the wavy uneven pattern is viewed in plan.
Therefore, when the surface fine unevenness sheet 10A of the present embodiment is used in combination with a light source array formed by arranging a plurality of point light sources so as to have a specific positional relationship, as will be described later, the wavy unevenness The effect of securing the viewing angle by the pattern and the effect of eliminating the uneven brightness and the effect of improving the front brightness by the linear Fresnel lens pattern 12A are obtained. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The thickness of the surface fine uneven sheet 10A is preferably in the range of 20 to 5000 μm, more preferably 50 to 3000 μm, as the thickness measured with a contact-type film thickness meter.
The material of the surface fine uneven sheet 10A will be described later.

[Method for manufacturing surface uneven surface sheet]
10 A of surface fine unevenness | corrugation sheets of 1 layer structure of this embodiment example can be manufactured with the following manufacturing methods (A), for example. Moreover, the surface fine uneven sheet | seat of a multilayer structure can be manufactured with the following manufacturing methods (B), for example. Moreover, it can manufacture also by the method which combined a part of manufacturing method (A) and a part of manufacturing method (B).
In addition, Japanese Patent Application Laid-Open No. 2008-302591 (Patent No. 4683011) and the like can be referred to for the formation of the wavy uneven pattern (1A) of the present embodiment example.

(Manufacturing method (A))
The production method (A) includes the following steps (a1), (a2), and (a3). Step (a1):
A step (a1) of producing an original plate (W) having a transfer shape (inverted shape) of the wavy uneven pattern (1A) on the surface.
Step (a2):
A step (a2) of producing an original plate (L1) having a linear Fresnel lens pattern transfer shape (inverted shape) on its surface.
Step (a3):
A wavy uneven pattern (on one surface) is formed on one surface by an injection molding method in which a resin is injected between the surface of the original plate (W) where the transfer shape is formed and the surface of the original plate (L1) where the transfer shape is formed. A step (a3) of obtaining a surface fine uneven sheet in which 1A) is formed and a linear Fresnel lens pattern is formed on the other surface.

Step (a1):
As the step (a1), for example, at least one hard layer having a smooth surface and composed of at least one kind of resin is laminated on one surface of the heat-shrinkable resin film to obtain a laminated film (a1-1). ) And a process of obtaining a concavo-convex pattern-forming sheet in which the hard layer is deformed by being folded by heating the laminated film and shrinking the heat-shrinkable resin film to form a wavy concavo-convex pattern (1A) on the surface ( a1-2) and a step of obtaining a master (W) on which a transfer shape of the wavy uneven pattern (1A) is transferred after depositing a metal such as nickel on the surface of the hard layer side of the uneven pattern forming sheet And a process having (a1-3).
In addition, a hard layer is a layer which does not soften under the temperature conditions which shrink | contract a heat-shrinkable resin film. Not softening means that the Young's modulus of the hard layer is 100 MPa or more.

Step (a1-1):
The heat-shrinkable resin film means a film that shrinks (shrinks) in a specific direction when heated at a temperature of 80 to 180 ° C. As such a film, for example, a polyethylene terephthalate shrink film, a polystyrene shrink film, a polyolefin shrink film, a polyvinyl chloride shrink film, a polyvinylidene chloride shrink film, or the like can be used. Moreover, the film comprised from resins, such as silicone resins, such as polydimethylsiloxane, fluororesin, ABS resin, polyamide, an acrylic resin, a polycarbonate, and polycycloolefin, is also mentioned.
From the viewpoint of heat resistance, a polyethylene terephthalate shrink film and a polystyrene shrink film are preferred.
In this embodiment, a uniaxially stretched film is used as the heat-shrinkable resin film. Uniaxial stretching may be either longitudinal stretching or lateral stretching.

The heat-shrinkable resin film is preferably stretched at a stretch ratio of 1.1 to 15 times, more preferably 1.3 to 10 times.
Moreover, as a heat-shrinkable resin film, a film with a shrinkage rate of 20 to 90% is preferable, and a film with 30 to 80% is more preferable. If the shrinkage rate is equal to or higher than the lower limit value, the uneven pattern forming sheet can be more easily produced. It is difficult to produce a heat-shrinkable resin film having a shrinkage rate exceeding the upper limit.

In the present specification, the shrinkage rate is defined as follows.
(Shrinkage [%]) = {(Length before shrinkage) − (Length after shrinkage)} × 100 / (Length before shrinkage) (However, the length is the shrinkage direction of the heat shrinkable resin film Length.)

  Since the heat-shrinkable resin film can easily form a hard layer, the surface is preferably smooth.

The glass transition temperature Tg ₁ of a resin constituting the heat-shrinkable resin film (hereinafter also referred to as “resin L”) is preferably −40 to 200 ° C., and more preferably 60 to 150 ° C. The glass transition temperature can be measured by differential thermal analysis or the like. When the glass transition temperature Tg ₁ is within the above range, the uneven pattern forming sheet can be more easily produced. That is, if Tg ₁ is within the above range, the heat-shrinkable resin film composed of the resin L can be heat-shrinked at a temperature of 80 to 180 ° C., and thus a concavo-convex pattern forming sheet can be produced more easily.

  The thickness of the heat-shrinkable resin film is preferably 30 to 500 μm. If it is in the above-mentioned range, it is hard to break and can be thinned. The thickness of the heat-shrinkable resin film was randomly extracted from 10 or more micrographs of a cross section (longitudinal cross section) obtained by cutting the obtained uneven pattern forming sheet perpendicularly to the sheet surface. It is the average value of each obtained numerical value when measuring.

  The Young's modulus of the resin L is preferably 0.01 to 100 MPa and preferably 0.1 to 10 MPa in the temperature of the step (a1-2) for heat shrinking, that is, in the temperature range of 80 to 180 ° C. More preferred. If the Young's modulus of the resin L is equal to or higher than the lower limit value, it is a practically usable hardness, and if it is equal to or lower than the upper limit value, it is soft enough to follow and deform simultaneously when the hard layer is deformed. .

Examples of the resin having Tg ₁ and Young's modulus as described above include polyethylene terephthalate resin, polystyrene resin, and polyvinyl chloride resin, and one or more of these can be suitably used.

  As the resin constituting the hard layer (hereinafter also referred to as “resin M”), for example, one or more of acrylic resin, styrene-acrylic copolymer, styrene-acrylonitrile copolymer, and the like can be used.

Resin M is such that the difference between the glass transition temperature Tg _2M of resin _M and the glass transition temperature Tg ₁ of resin L (Tg _2M −Tg ₁ ) is 10 ° C. or higher in that an uneven pattern forming sheet can be easily formed. Is more preferable, 15 ° C. or higher is more preferable, and 20 ° C. or higher is particularly preferable.

The glass transition temperature Tg _2M of the resin M is preferably in the range of 40 to 400 ° C., and more preferably in the range of 80 to 250 ° C. If Tg _2M is within the above range, the uneven pattern forming sheet can be easily produced.
The Young's modulus of the resin M is preferably in the range of 0.01 to 300 GPa and preferably in the range of 0.1 to 10 GPa at the temperature (80 to 180 ° C.) of the step (a1-2) for heat shrinking. It is more preferable. If the Young's modulus of the resin M is not less than the above lower limit value, the hardness is sufficient to maintain the shape of the wavy uneven pattern (1A). it can.

  The thickness of the hard layer is preferably more than 0.05 μm and not more than 10.0 μm, and more preferably 0.5 to 3.0 μm. By setting the thickness of the hard layer in the above range, the average pitch of the wavy uneven pattern (1A) becomes an appropriate range in terms of light diffusibility.

  The thickness of the hard layer may be continuously changed. When the thickness of the hard layer is continuously changed, the pitch and depth of the wavy uneven pattern (1A) formed after the step (a1-2) are continuously changed.

Examples of a method for providing a hard film by providing a hard layer include a method in which a hard layer-forming coating material containing resin M is continuously applied to a heat-shrinkable resin film and dried.
Examples of the method for preparing the hard layer forming coating include a method in which the resin M is diluted with one or more solvents such as toluene, methyl ethyl ketone, and methyl isobutyl ketone. The solid content concentration of the hard layer forming paint (concentration of the resin M: the ratio of the solid content remaining after the solvent in the paint volatilizes to the mass of the hard layer forming paint (100% by mass)) is: It is preferable that it is 1-15 mass% with respect to the total mass of a coating material, and it is more preferable that it is 5-10 mass%.

  Examples of paint coating methods include air knife coating, roll coating, blade coating, Mayer bar coating, gravure coating, spray coating, cast coating, curtain coating, die slot coating, gate roll coating, size press coating, spin coating, Examples include dip coating.

Examples of the drying method include a heat drying method using hot air, infrared rays, or the like.
The dry coating amount of the resin solution on the heat-shrinkable resin film is preferably 1 to 10 g / m ² . If it is in the said range, the thickness of a hard layer can be made into the said preferable range, and it will be easy to form a wavy uneven | corrugated pattern (1A) in a hard layer.

Step (a1-2):
In the step (a1-2), the laminated film obtained in the step (a1-1) is heated to shrink the heat-shrinkable resin film, so that the hard layer is deformed so as to be folded, and a wavy uneven pattern is formed on the surface. The uneven | corrugated pattern formation sheet in which the same pattern as (1A) was formed is obtained.
In the step (a1-2), it is preferable to contract at a contraction rate of 30% or more. When the shrinkage rate is 30% or more, it is possible to reduce a portion where shrinkage is insufficient (for example, a portion where unevenness is not sufficiently formed, a portion where the aspect ratio is not sufficiently large, etc.). On the other hand, if the shrinkage rate is increased too much, the area of the resulting concavo-convex pattern forming sheet becomes small and the yield decreases, so the upper limit of the shrinkage rate is preferably 80%.

  Examples of the method of heating the laminated film include a method of passing it through hot air, steam, hot water, or far infrared rays. Among them, a method of passing through hot air or far infrared rays is preferable because it can be uniformly shrunk.

The heating temperature when the heat-shrinkable resin film is heat-shrinkable can be appropriately set according to the type of heat-shrinkable resin film to be used, the average pitch of the ridges of the target concavo-convex pattern forming sheet, and the aspect ratio. preferable.
Specifically, the heating temperature is preferably a temperature equal to or higher than the glass transition temperature Tg ₁ of the resin L constituting the heat-shrinkable resin film. When heat shrinking at a temperature of Tg ₁ or higher, the wavy uneven pattern (1A) can be easily formed.
Moreover, it is preferable that this heating temperature is less than (the glass transition temperature _Tg2M + 15 _{degreeC of the} resin M).

As a suitable example of the step (a1-2), the laminated film obtained in the above step (a1-1) is preferably passed through hot air at 80 to 180 ° C., more preferably 120 to 170 ° C. Thus, it is preferable that the heat-shrinkable film and the hard layer are deformed to obtain a concave / convex pattern forming sheet.
The time for heating the laminated film is preferably 1 to 3 minutes, and more preferably 1 to 2 minutes. The wind speed of the hot air is preferably 1 to 10 m / s, and more preferably 2 to 5 m / s.

Step (a1-3):
In the step (a1-3), a metal such as nickel is deposited by a known electroforming method or the like on the surface of the hard layer side of the uneven pattern forming sheet obtained in the above step (a1-2), and then In this step, the metal is peeled off to obtain a metal original plate (W) on which the transfer shape (inverted shape) of the wavy uneven pattern (1A) is transferred.

  In addition, from the viewpoint of heat resistance and the like, the material of the original plate (W) is preferably a metal such as nickel, but may be a resin or the like. Further, the original plate (W) may be any one having a transfer shape (reversal shape) of the wavy uneven pattern (1A), and obtained by repeating the transfer as described above twice or more. Also good.

Step (a2):
Step (a2) is a step of manufacturing an original plate (L1) having a transfer shape of a linear Fresnel lens pattern on the surface by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). The transferred shape is an inverted shape of the linear Fresnel lens pattern in the surface fine uneven sheet to be manufactured. Further, the original plate (L1) may be any one having a linear Fresnel lens pattern transfer shape, and may be obtained by further transferring a pattern formed by cutting one or more times. .

Step (a3):
In the step (a3), a transparent resin is injected by a known injection molding method between the surface of the original plate (W) where the transfer shape is formed and the surface of the original plate (L1) where the transfer shape is formed. To do. Thereby, the surface fine uneven sheet | seat of this embodiment example of the 1 layer structure by which the wavy uneven | corrugated pattern (1A) was formed in one surface, and the linear Fresnel lens pattern was formed in the other surface is obtained.
Examples of the resin to be injected include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide (example) : Nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66, etc.), polyimide, polyamideimide, polycarbonate (PC), poly- (4- Methylpentene-1), ionomer, acrylic resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene Polyesters such as polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT), polyether, polyether ketone (PEK), Polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, Polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurethane, polyester , Polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluoro-rubber-based, chlorinated polyethylene-based thermoplastic elastomers, epoxy resins, phenol resins, urea resins, melamine resins, unsaturated polyesters, silicone resins, urethane resins 1 or more types can be used.

(Manufacturing method (B))
When the surface fine concavo-convex sheet has a multilayer structure, it can be produced by a method using a nanoimprint method using an ionizing radiation curable resin, for example.
Specifically, in the same manner as in the step (a1-1) and the step (a1-2), a concavo-convex pattern forming sheet having the same pattern as the wavy concavo-convex pattern (1A) on the surface is obtained. Next, on the surface of the concavo-convex pattern forming sheet on which the wavy concavo-convex pattern (1A) is formed, an uncured transparent ionizing radiation curable resin containing a release agent is accommodated in a thickness of, for example, 3 to 30 μm. Coating is performed with a coater such as a die coater, roll coater, or bar coater, and a substrate such as PET is disposed thereon. And after irradiating with ionizing radiation and hardening, the uneven | corrugated pattern formation sheet was peeled, and the ionized radiation curable resin hardened | cured material and base material in which the transfer shape (inverted shape) of the wavy uneven pattern (1A) was formed. A primary transfer product (stamper) consisting of

On the other hand, a transparent base material made of PET or the like is separately prepared, and an uncured ionizing radiation curable resin is applied to one surface thereof. The thickness applied here is set to a thickness that sufficiently covers the unevenness of the transfer shape of the wavy uneven pattern (1A) in the primary transfer product. Then, the surface of the primary transfer product on which the transfer shape of the wavy uneven pattern (1A) is formed is pressed against the applied uncured ionizing radiation curable resin layer, and the ionizing radiation is maintained in that state. After being cured by irradiation, the primary transfer product is peeled off.
As described above, by using the primary transfer product as a stamper, two layers composed of a transparent base material made of PET and a layer of a transparent cured ionizing radiation curable resin formed on one surface thereof. A sheet of structure is obtained. On the surface of the layer of the ionized radiation curable resin cured product, a wavy uneven pattern (1A) is formed. Here, the stamper is not limited to the primary transfer product, but may be obtained by further repeating the transfer.

  In general, the ionizing radiation often means ultraviolet rays and electron beams, but in the present specification, visible rays, X-rays, ion rays and the like are also included.

On the other hand, as in the step (a2), an original plate (L1) having a transfer shape of the linear Fresnel lens pattern on the surface is manufactured.
Next, an uncured transparent ionizing radiation curable resin is transferred to a linear Fresnel lens pattern transfer shape on the surface of the two-layered sheet obtained above where the layer of cured ionizing radiation curable resin is not formed. Apply to a thickness sufficient to cover. And the surface which has the transfer shape of the linear Fresnel lens pattern of the original plate (L1) obtained previously is pressed against the applied uncured ionizing radiation curable resin layer, and the ionizing radiation remains in that state. After being cured by irradiation, the original plate (L1) is peeled off. Irradiation with ionizing radiation is performed from the side where the original plate (L1) is not provided.
Thus, by using the original plate (L1) as a stamper, a linear Fresnel lens pattern can be formed on the other surface of a transparent base material made of PET or the like. As a result, a layer composed of a cured ionizing radiation curable resin having a wavy uneven pattern (1A), a base material such as PET, a layer composed of a cured ionizing radiation curable resin having a linear Fresnel lens pattern, A three-layer surface fine uneven sheet formed in this order is obtained. Note that the stamper here is not limited to the original (L1), and may be obtained by further repeating the transfer of the linear Fresnel lens pattern on the original (L1).

  Uncured ionizing radiation curable resins include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl / acrylate, polyene / acrylate, silicon acrylate, polybutadiene, and polystyrylmethyl methacrylate. 1 type selected from monomers such as prepolymers such as aliphatic acrylate, alicyclic acrylate, aromatic acrylate, hydroxyl group-containing acrylate, allyl group-containing acrylate, glycidyl group-containing acrylate, carboxy group-containing acrylate, halogen-containing acrylate, etc. The thing containing the above component is mentioned. The uncured ionizing radiation curable resin is preferably diluted with a solvent or the like. A fluorine resin, a silicone resin, or the like may be added to the uncured ionizing radiation curable resin. When the uncured ionizing radiation curable resin is ultraviolet curable, it is preferable to add a photopolymerization initiator such as acetophenones and benzophenones to the uncured ionizing radiation curable resin.

Also, instead of ionizing radiation curable resin, transfer is performed using, for example, thermosetting resin such as uncured melamine resin, urethane resin or epoxy resin, or thermoplastic resin such as acrylic resin, polyolefin or polyester. As long as transfer is possible, the specific method and material to be transferred are not limited.
In the case of using a thermosetting resin, for example, a method of applying a liquid uncured thermosetting resin and curing by heating can be mentioned. When using a thermoplastic resin, a sheet of thermoplastic resin is used, There may be mentioned a method of heating and softening while pressing against the surface of the transfer object and then cooling.

  For a specific method of transfer using a stamper, for example, JP 2012-022292 A can be referred to.

(Other methods)
A surface fine uneven sheet | seat can be manufactured also by the method of combining suitably a part of said manufacturing method (A), and a part of said manufacturing method (B), for example. For example, the uneven | corrugated pattern formation sheet in which the wavy uneven | corrugated pattern (1A) was formed in the surface by the said process (a1-2) is obtained. On the other hand, as explained in the production method (B), a laminate comprising a cured material of an ionizing radiation curable resin on one surface of a substrate such as PET and having a layer having a linear Fresnel lens pattern on the surface is produced. . And the uneven | corrugated pattern formation sheet and a laminated body are bonded so that a wavy uneven | corrugated pattern (1A) may be located in one surface, and a linear Fresnel lens pattern may be located in the other surface. Even by such a method, a surface fine uneven sheet can be produced.

[Lighting unit for display device and display device]
FIG. 7: is a schematic block diagram which shows the structure of the illumination unit for display apparatuses of this embodiment example, FIG. 7 (a) is a schematic plan view from the wavy uneven | corrugated pattern formation surface side of 10 A of surface fine uneven | corrugated sheets, b) is a side view showing a side surface parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A), and (c) a side view showing a side surface parallel to the arrangement direction of the ridges 12a of the linear Fresnel lens pattern 12A. It is.

The illumination unit for display device in the illustrated example includes a surface fine uneven sheet 10A, a single light source array 21A in which a plurality of point light sources (three in the illustrated example) 21 are formed in a straight line, and each point light source. And a plurality of condensing lenses (three in the illustrated example, the same as the number of point light sources) 20 provided for each point light source 21. When the angle formed between the main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet 10A and the arrangement direction of the point light sources 21 of the light source array 21A is a plan view as shown in FIG. It is within the range. In this example, the main diffusion direction of the wavy uneven pattern, the extending direction of the ridges 12a of the linear Fresnel lens pattern 12A, and the arrangement direction of the point light sources 21 of the light source array 21A are all in the A direction in FIG. , Parallel to each other.
Further, a light source array 21A is arranged on the surface of the surface fine uneven sheet 10A on the linear uneven pattern forming surface 12 (surface on which the linear Fresnel lens pattern 12A is formed), and the light emitted from each point light source 21 is collected. After being condensed by the optical lens 20, the light is incident from the linear concave / convex pattern forming surface 12 and is emitted from the corrugated concave / convex pattern forming surface 11 on which the wavy concave / convex pattern (1 </ b> A) is formed.

  The angle formed between the main diffusion direction of the wavy uneven pattern and the arrangement direction of the point light sources 21 of the light source array 21A is preferably within ± 10 °, more preferably within ± 5 °, and 0 ° (that is, parallel). More preferably, Further, the angle formed between the extending direction of the ridges 12a of the linear Fresnel lens pattern 12A and the arrangement direction of the point light sources 21 of the light source array 21A is ± 20 in a plan view as shown in FIG. Within the range of °, preferably within the range of ± 10 °, more preferably within the range of ± 5 °, and most preferably 0 ° (that is, parallel).

In such a display device illumination unit, the light emitted from each point light source 21 is collected by the condenser lens 20 and is incident on the linear uneven pattern forming surface 12 on which the linear Fresnel lens pattern 12A is formed. . As described above with reference to FIG. 6, among the light traveling vectors, the arrangement direction of the ridges 12 a of the linear Fresnel lens pattern 12 A and the normal direction (surface fineness) of the surface on which the linear Fresnel lens pattern 12 A is formed. The in-plane component consisting of the concave and convex sheet is refracted so as to be parallel to the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed.
The light refracted in this way passes through the inside of the surface fine concavo-convex sheet 10 </ b> A and exits from the wavy concavo-convex pattern forming surface 11. And among the traveling vectors of light, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is the direction corresponding to the main diffusion direction of the wavy uneven pattern (1A). Mainly due to refraction, it becomes a component of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10A and a component inclined from the normal direction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is a component mainly parallel to the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern. It becomes.
The light parallel to the normal direction of the surface fine uneven sheet 10A contributes to the improvement of the front luminance. Further, when viewed from the wavy uneven pattern forming surface 11 side, luminance unevenness is caused by light parallel to the normal direction of the surface fine uneven sheet 10A in a portion where no light source exists such as between the point light source 21 and the point light source 21. A cancellation effect is obtained. Moreover, the component inclined from the normal direction of the surface fine uneven sheet 10A contributes to the expansion of the viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

  In particular, since the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10A and the array direction of the point light sources 21 of the light source array 21A are within a range of ± 20 °, diffusion in the array direction of the point light sources 21 The angle increases. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern (1A). Therefore, it is possible to suppress a decrease in luminance due to increasing the diffusion angle.

  Which surface side of the surface fine uneven sheet 10A the light source row 21A is arranged can be set according to the purpose. When the wavy uneven pattern (1A) is on the side opposite to the light source array 21A side, the luminance unevenness eliminating effect and the front luminance improving effect are high, and when the wavy uneven pattern (1A) is on the light source array 21A side, the viewing angle securing effect is achieved. Is expensive.

In FIG. 7, illustration of a power supply unit, a control unit, a power supply unit, and a housing for housing the control unit included in the display device illumination unit is omitted.
Further, in this example, the light source row 21A included in the display unit illumination unit is one row, but may be two or more rows. Further, if there is at least one light source array, a point light source may exist outside the light source array.
Also, for example, when a plurality of point light sources are arranged vertically and horizontally, the angle formed by the arrangement direction of either the vertical column or the horizontal column and the main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet However, what is necessary is just to be in the said range.

  As described above, the illumination unit for display device according to the present embodiment has excellent front luminance, suppresses uneven luminance, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction. Therefore, for example, a display such as a head-up display system that needs to display image information such as traveling speed clearly and vertically in the vertical and horizontal directions on the windshield of a car that is gently curved. Suitable for use on equipment.

[Second Embodiment]
FIG. 8 is an optical microscopic image of the wavy uneven pattern forming surface of the surface fine uneven sheet of the second embodiment.
In the surface fine concavo-convex sheet of the second embodiment, the undulating concavo-convex pattern formed on the undulating concavo-convex pattern forming surface is not a pattern corresponding to the undulating concavo-convex pattern (1), but the undulating concavo-convex pattern (2) described above. This is different from the surface fine concavo-convex sheet of the first embodiment only in that it is a wavy concavo-convex pattern (2A) corresponding to (a pattern in which concavo-convex not along a specific direction is formed).
Other points such as a linear Fresnel lens pattern formed as a linear uneven pattern on the other surface of the surface fine uneven sheet are the same as those in the first embodiment. And the surface fine uneven sheet | seat of this embodiment example can comprise the illumination unit for display apparatuses, and a display apparatus similarly to the surface fine uneven sheet | seat of 1st Embodiment.

  As shown in FIG. 8, the wavy uneven pattern (2A) of the surface fine uneven sheet of the second embodiment is bent along the wavy uneven pattern forming surface, and a plurality of ridges extending without following a specific direction. And a plurality of concave portions between the plurality of convex portions. The height of the ridge line is not constant, and the ridge has a height difference that changes continuously. However, the part which does not have a height difference partially may be included. In addition, the height of the valley line is not constant, and each concave line has a height difference that changes continuously. However, the part which does not have a height difference partially may be included.

A preferable range such as an average pitch and an aspect ratio of the ridges of the wavy uneven pattern (2), how to obtain the same, and the like are the same as in the first embodiment.
The average pitch is preferably obtained by the following method.
That is, the upper surface of the wavy uneven pattern forming surface is photographed with an optical microscope or an electron microscope, the image is converted into a grayscale file (eg, tiff format), and then the image of the grayscale file is Fourier transformed. Then, the pitch is obtained by image analysis of the Fourier transform image. This method is described, for example, in paragraph [0002] of Japanese Patent Application Laid-Open No. 2008-279597, and can be referred to.

  As described above, the wavy uneven pattern (2A) is a pattern in which unevenness that does not follow a specific direction is formed, and anisotropy of light diffusibility is weakened. Therefore, compared with the first embodiment, the difference in diffusion angle between the main diffusion direction and the low diffusion direction of the wavy uneven pattern is small. However, the angle formed between the main diffusion direction of the wavy uneven pattern (2A) and the extending direction of the ridges of the linear uneven pattern is within a range of ± 20 ° when the wavy uneven pattern is viewed in plan, etc. Is the same as in the first embodiment.

The diffusion angle in the main diffusion direction can be adjusted as appropriate, but is preferably 10 ° or more, for example, and more preferably 15 ° or more. For example, it is preferably 40 ° or less, and more preferably 30 ° or less.
On the other hand, the diffusion angle in the low diffusion direction can be adjusted as appropriate, but is smaller than the diffusion angle in the main diffusion direction, and is preferably 5 ° or more, for example, and more preferably 7 ° or more. For example, it is preferably 30 ° or less, and more preferably 17 ° or less.
The diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction of the wavy uneven pattern of the second embodiment can be controlled by adjusting the average pitch, the aspect ratio, and the like.
The preferable thickness and the like of the surface fine uneven sheet of the second embodiment are about the same as those of the surface fine uneven sheet 10A of the first embodiment.

The surface fine uneven sheet of the second embodiment may have a single layer structure or a multilayer structure of two or more layers.
Moreover, the surface fine uneven sheet | seat of 2nd Embodiment can be manufactured with the method similar to the 1st Embodiment schematically. However, in the second embodiment, a biaxially stretched film is used as the heat-shrinkable resin film in the step (a1-1). By using a biaxially stretched film, the unevenness | corrugation which does not follow a specific direction as shown in FIG. 8 is formed. Moreover, the balance between the diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction is adjusted by adjusting the longitudinal stretching ratio and the lateral stretching ratio of the biaxially stretched film to be used and adjusting the longitudinal shrinkage ratio and the lateral shrinkage ratio. Can be formed as appropriate. Each preferable range of the longitudinal shrinkage rate and the lateral shrinkage rate is the same as the preferred range of the shrinkage rate in the first embodiment. Preferred embodiments and ranges such as the material (resin L), shrinkage rate, glass transition temperature of resin L, and Young's modulus of the heat-shrinkable resin film are the same as in the first embodiment.
In addition, Japanese Patent Application Laid-Open No. 2008-304651 (Japanese Patent No. 5098450) and the like can be referred to for the formation of the wavy uneven pattern (2A) of this embodiment example.

[Third embodiment]
FIG. 9 is an optical microscopic image of the wavy uneven pattern forming surface of the surface fine uneven sheet of the third embodiment. The wavy uneven pattern formed on the wavy uneven pattern forming surface of the surface fine uneven sheet of the third embodiment corresponds to the previously described wavy uneven pattern (1), as in the first embodiment.

The wavy uneven pattern in the surface fine uneven sheet of the third embodiment corresponds to the wavy uneven pattern (1), but the wavy uneven pattern (1A) of the first embodiment is convex as shown in FIG. In the longitudinal cross-sectional shape of the strip portion 11a, the line connecting the distal end side and the proximal end side smoothly and continuously descends from the distal end side to the proximal end side, whereas the wavy shape of the present embodiment example As shown in FIG. 10, the concavo-convex pattern (1B) is a fine concavo-convex shape in which the line connecting the tip side (top) and the base end side in the vertical cross-sectional shape of the ridge portion 11b has a large number of concavo-convex shapes. In a certain point, it differs from the surface fine uneven sheet | seat 10A of 1st Embodiment. Many fine unevenness | corrugations are based on the below-mentioned wavy unevenness | corrugation pattern (1-a).
Also in the surface fine uneven sheet of the third embodiment, other points such as a linear Fresnel lens pattern formed as a linear uneven pattern on the other surface of the surface fine uneven sheet are the same as in the first embodiment. It is the same. And the surface fine uneven sheet | seat of this embodiment example can comprise the illumination unit for display apparatuses and display apparatus which were demonstrated previously similarly to the surface fine uneven sheet | seat of 1st Embodiment.

  As shown in FIG. 10, the wavy uneven pattern (1B) includes a wavy uneven pattern (1A) composed of a protruding line part 32a and a recessed line part 32b, and a protruding line part 33a and a recessed line formed thereon. It is formed by another fine wavy uneven pattern (1-a) composed of the strip portion 33b. The wavy uneven pattern (1-a) is a pattern in which a plurality of ridges 33a extending in a streak pattern and a plurality of ridges 33b between the plurality of ridges 33a are alternately repeated in one direction. The arrangement direction of the ridges 32a of the wavy uneven pattern (1A) and the arrangement direction of the ridges 33a of the wavy uneven pattern (1-a) are substantially the same direction.

The wavy uneven pattern (1-a) has the following characteristics.
(A ′) Each protruding line portion 33a meanders and is not parallel to each other. That is, the ridge line of each convex line part 33a meanders, and the space | interval of the ridge line of the adjacent convex line part 33a is not constant, but is changing continuously. However, it may include a portion where the interval between the ridge lines is constant. Further, one ridge line may be branched in the middle, or a plurality of ridge lines may be joined in the middle.
(B ′) The respective concave stripe portions 33b meander and are not parallel to each other. That is, the valley line of each concave line part 33b meanders, and the space | interval of the valley line of the adjacent concave line part 33b is not constant, but is changing continuously. However, a portion where the interval between the valley lines is partially constant may be included. Moreover, one trough line may branch on the way, or several trough lines may unite on the way.

Further, in the wavy uneven pattern (1-a), the longitudinal cross-sectional shape of each protruding line portion 33a (the cut surface that is parallel to the normal direction of the surface fine uneven sheet and is cut along the arrangement direction of the protruding line portions) Are different from each other and are not uniform but irregular.
In addition, the vertical cross-sectional shape of each protrusion 33a is a tapered shape that becomes thinner from the proximal end side toward the distal end side, and the distal end is rounded. The wavy uneven pattern (1-a) has a smooth line between the distal end side and the proximal end side in the vertical cross-sectional shape of each ridge portion 33a, and is continuous from the distal end side toward the proximal end side. It has fallen to. In addition, each ridge 33a has at least one of the above-described vertical cross-sectional shape and its area changed along the extending direction of the ridge 33a (direction extending in a streak), It is not constant.
Moreover, in each protruding item | line part 33a, the height of a ridgeline is not constant, but has a height difference which changes continuously. However, the part which does not have a height difference partially may be included.
Moreover, in each recessed line part 33b, the height of a trough line is not constant, but has a height difference which changes continuously. However, the part which does not have a height difference partially may be included.

  The preferred range and method of obtaining the average pitch and aspect ratio of the ridges 32a are as described in the first embodiment.

The average pitch of the ridges 33a of the wavy uneven pattern (1-a) is preferably 0.3 to 2.0 μm, more preferably 0.4 to 1.0 μm, and 0.5 to 0 More preferably, it is 8 μm. When the average pitch is within the above range, the light diffusibility is not impaired.
The average pitch of the ridges 33a can be obtained by the same method as the average pitch of the ridges 11a of the wavy uneven pattern (1A). That is, a planar image including 20 or more adjacent ridges 33a is obtained, and for 20 of the ridges 33a, five lengths along the arrangement direction of the ridges 33a are measured, It is obtained by dividing the average value by 20.
The average pitch can also be obtained by the following method.
That is, the upper surface of the wavy uneven pattern forming surface is photographed with an optical microscope or an electron microscope, the image is converted into a grayscale file (eg, tiff format), and then the image of the grayscale file is Fourier transformed. Then, the pitch is obtained by image analysis of the Fourier transform image. This method is described, for example, in International Publication No. 2014/002850 as a method for obtaining the most frequent pitch, and this can be referred to. The most frequent pitch and the average pitch can be handled equally.

  The ratio of the average height to the average pitch of the ridges 33a of the wavy uneven pattern (1-a), that is, the aspect ratio (average height / average pitch) is preferably 0.25 to 0.35. More preferably, it is 28-0.33. When the aspect ratio is within the above range, the light diffusibility is not impaired.

The aspect ratio A ₁ wavy concavo-convex pattern (1-a) may be a value determined by the average height / average pitch of the convex portion 33a, schematic, wavy uneven pattern described in the first embodiment (1A) It is calculated | required by the method similar to the aspect-ratio.
In other words, in FIG. 10, the height of the ridge 33a of the wavy uneven pattern (1-a) is 1 / of the sum of the distances from the bottom of the two adjacent ridges 33b to the top of the ridge 33a. 2. Here, the distance from the bottom of the concave strip portion 33b to the top portion of the convex strip portion 33a is parallel to the line connecting the top portion of the convex strip portion 32a and the concave strip portion 32b, and the top portion of the convex strip portion 33a. This is the distance in the direction perpendicular to the imaginary line passing through. That is, the height of the ridge 33a forming the wavy uneven pattern (1-a) is the height of the ridge 33a measured from the bottom of the concave ridge 33b on one side with respect to the ridge 33a. _When the height measured from the bottom of the concave portion 33b on the other side is R _s , b _s = (L _s + R _s ) / 2. In this way, the height b _s of each ridge 33a is obtained. Then, the height _RS of the 50 ridges 33a is measured, and the average height is obtained by averaging the heights.

In the surface fine concavo-convex sheet of this embodiment, the main diffusion direction of the wavy uneven pattern can be obtained by the method described above, and is a diagram substantially parallel to the arrangement direction of the ridges 32a of the wavy uneven pattern (1A). 10 in the A direction.
The diffusion angle in the main diffusion direction can be adjusted as appropriate, but is preferably 10 ° or more, for example, and more preferably 15 ° or more. For example, it is preferably 40 ° or less, and more preferably 30 ° or less.
On the other hand, the diffusion angle in the low diffusion direction perpendicular to the main diffusion direction can be adjusted as appropriate, but is preferably smaller than the diffusion angle in the main diffusion direction and, for example, 2 ° or more. Moreover, it is preferable that it is 15 degrees or less.

The diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction are the average pitch and the aspect ratio (average height / average pitch) of the ridges 11b and 33a of the wavy uneven patterns (1A) and (1-a) It can be controlled by adjusting.
The preferable thickness etc. of the surface fine unevenness | corrugation sheet of 3rd Embodiment are comparable as the surface fine unevenness | corrugation sheet of 1st Embodiment.

The surface fine concavo-convex sheet of the third embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet 10A of the first embodiment.
However, in the above-described step (a1-1), two types of resins for forming the hard layer (hereinafter referred to as “resin M1” and “resin N1”) are used as the hard layer forming paint used for forming the hard layer. "). By using two kinds of resins in this way, a wavy uneven pattern (1B) composed of the wavy uneven patterns (1A) and (1-a) can be formed. In addition, International Publication No. 2014/002850 can be referred to for the formation of the wavy uneven pattern (1B) of the present embodiment example.

  A uniaxially stretched film is used as the heat-shrinkable resin film. Preferred modes and ranges such as the material (resin L), shrinkage rate, glass transition temperature of resin L, Young's modulus and the like are the same as those in the first embodiment.

  Examples of the resin M1 and the resin N1 used for forming the hard layer include polyvinyl alcohol, polystyrene, acrylic resin, styrene-acrylic copolymer, styrene-acrylonitrile copolymer, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Polycarbonate, polyethersulfone, fluororesin and the like can be used.

Resin M1 and resins N1 from the viewpoint of forming easiness wavy uneven pattern (1B), preferably a glass transition temperature are different from each other, specifically, glass having a glass transition temperature Tg _2M resin N1 resin M1 It is preferable that the transition temperature is higher than Tg _2N . Furthermore, (glass transition temperature Tg _2M of resin M1) − (glass transition temperature Tg _2N of resin N1) is preferably 10 ° C. or higher, and more preferably 12 ° C. or higher.
On the other _hand, it is preferable that Tg 2M _{-Tg 2N} is 20 ° C. or less, more preferably 18 ° C. or less. That is, the difference between the glass transition temperature Tg _2M of the resin M1 and the glass transition temperature Tg _2N of the resin N1 is preferably 10 to 20 ° C. More preferably, it is 12-18 degreeC.

From the viewpoint of forming easiness wavy uneven pattern (1B), the difference between the glass transition temperature Tg ₁ of the glass transition temperature _{Tg 2M} resin L1 of resin M1 _(Tg 2M _-Tg 1), the glass transition temperature Tg of the resin N1 The difference (Tg _2N −Tg ₁ ) between _2N and the glass transition temperature Tg ₁ of the resin L1 is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, and particularly preferably 20 ° C. or higher. .

Both the glass transition temperatures Tg _2M and Tg _2N of the resin M1 and the resin N1 are preferably in the range of 40 to 400 ° C., and more preferably in the range of 80 to 250 ° C. When Tg _2M and Tg _2N are within the above ranges, the corrugated uneven pattern (1B) can be more easily formed.

  The Young's modulus of the resin M1 and the resin N1 is preferably in the range of 0.01 to 300 GPa and in the range of 0.1 to 10 GPa at the temperature of the step (a1-2), that is, 80 to 180 ° C. It is more preferable. If the Young's modulus of the resin M1 and the resin N1 is equal to or higher than the lower limit of the above range, the hardness is sufficient to maintain the shape of the wavy uneven pattern (1B), and the Young's modulus is equal to or lower than the upper limit of the above range. In this case, the wavy uneven pattern (1B) can be formed more easily.

The thickness of the hard layer is preferably in the same range as in the first embodiment, and the same is true in that the thickness may change continuously.
The method of providing the hard layer is the same as that of the first embodiment except that a paint containing the resin M1 and the resin N1 is used as the hard layer forming paint.

  In the above manufacturing method, the characteristics (pitch, aspect ratio, etc.) of the wavy uneven pattern (1B) can be controlled, for example, by adjusting the blending ratio of the resin M1 and the resin N1 and the shrinkage rate of the heat-shrinkable resin film. (For example, see International Publication No. 2014/002850 etc.).

[Fourth Embodiment]
FIG. 11 is an optical microscopic image of the wavy uneven pattern forming surface of the surface fine uneven sheet of the fourth embodiment. The wavy uneven pattern formed on the wavy uneven pattern forming surface of the surface fine uneven sheet of the fourth embodiment corresponds to the previously described wavy uneven pattern (1), as in the first embodiment.
FIG. 12 shows a wavy uneven pattern (1C) of the surface fine uneven sheet according to the present embodiment, which is parallel to the normal direction of the surface fine uneven sheet and has a convex line of the wave uneven pattern (1C). It is the longitudinal cross-sectional view cut | disconnected along the sequence direction of a part.

The wavy uneven pattern (1C) in the surface fine uneven sheet of the fourth embodiment corresponds to the wavy uneven pattern (1) as described above, but the wavy uneven pattern (1A) of the first embodiment is shown in FIG. As shown in Fig. 4, in the longitudinal cross-sectional shape 11a of the ridge portion, the line connecting the distal end side and the proximal end side descends smoothly and continuously from the distal end side toward the proximal end side. As shown in FIG. 12, the wavy uneven pattern (1C) of the present embodiment has a plurality of protrusions projecting outward in the middle of the line connecting the distal end side and the proximal end side in the longitudinal cross-sectional shape of the protruding strip portion 42a. This is different from the surface fine concavo-convex sheet of the first embodiment in that the convex portions 43 are randomly formed. The convex part 43 may be formed on the concave line part 42b or the top part of the convex line part 42a.
Other points such as a linear Fresnel lens pattern formed as a linear uneven pattern on the other surface of the surface fine uneven sheet are the same as those in the first embodiment. And the illumination unit for display apparatuses and a display apparatus can be comprised similarly to the surface fine unevenness | corrugation sheet | seat of 1st Embodiment.

The wavy uneven pattern (1C) is composed of a wavy uneven pattern (1A) formed by the protrusions 42a and the recesses 42b and a large number of protrusions 43 randomly formed thereon, and the wavy uneven pattern (1A) Mainly responsible for diffusion in the main diffusion direction, the convex portion 43 formed on the wavy uneven pattern (1A) moderately weakens the anisotropy of light diffusibility due to the wavy uneven pattern (1A), and low diffusion It has the effect of increasing the directional diffusion angle.
The diffusion angle in the main diffusion direction is, for example, 18 ° or more, preferably 23 ° or more, more preferably 25 ° or more. The upper limit of the diffusion angle in the main diffusion direction is not particularly limited, but is, for example, 30 °. The diffusion angle in the low diffusion direction is, for example, 4 ° or more, preferably 8 ° or more, more preferably 10 ° or more. The upper limit value of the diffusion angle in the low diffusion direction is not particularly limited, but is 20 °, for example.
In the present embodiment, a mode in which the convex portion 43 is formed on the wavy uneven pattern (1A) is shown. However, a concave portion may be formed instead of the convex portion, and the concave portion is also a convex portion. Has the same effect.

  The preferred range and method of obtaining the average pitch and aspect ratio of the ridges 42a are as described in the first embodiment.

1-10 micrometers is preferable, as for the average diameter of the convex part 43 formed on the wavy uneven | corrugated pattern (1A), 3-8 micrometers is more preferable, and 4-6 micrometers is more preferable.
As for the average diameter D of the protrusions, 20 protrusions 43 are arbitrarily selected in the planar image as shown in FIG. It calculates | requires by averaging each value which measured the diameter (maximum length along the sequence direction of the protruding item | line part 42a) of 43. FIG.
The average diameter D can also be obtained by the following method.
That is, the upper surface of the wavy uneven pattern forming surface is photographed with an optical microscope or an electron microscope, the image is converted into a grayscale file (eg, tiff format), and then the image of the grayscale file is Fourier transformed. And obtained by image analysis of a Fourier transform image. This method is described, for example, in Japanese Patent Application Laid-Open No. 2014-206728 (Japanese Patent No. 5660235) as a method for obtaining the mode diameter, and this can be referred to. The average diameter and the mode diameter can be treated equally.

  By adjusting the average pitch of the protrusions 42a of the wavy uneven pattern (1A) and the average diameter of the protrusions 43 within the above ranges, the diffusion angles in the main diffusion direction and the low diffusion direction can be appropriately controlled.

  3-7 micrometers is preferable and, as for the average height of the convex part 42a, 4-6 micrometers is more preferable. If the average height of the ridges 42a is within the above range, sufficient light diffusibility can be obtained.

In the present embodiment example, the average height of the ridge 42a is measured and defined as follows. First, a vertical cross-sectional view as shown in FIG. 12 is obtained, and the height H of the ridge 42a is obtained from the cross-sectional view of the ridge 42a where the protrusion 43 does not exist. Specifically, the height H of the ridge 42a is defined as a vertical distance H1 between the top T of the ridge 42a and the bottom B11 of the recess 42b located on one side of the ridge 42a, When the vertical distance between the top T of the ridge 42a and the bottom B21 of the ridge 42b located on the other side of the ridge 42a is H2, it is obtained by H = (H1 + H2) / 2.
Such a measurement is performed on 50 portions of the ridge 42a where the protrusion 43 does not exist, and the average value of the 50 data is defined as “average height of the ridge”.

  On the other hand, the average height of the convex portions 43 is preferably 0.5 to 3 μm, more preferably 1 to 2 μm. When the average height of the convex portions 43 is within the above range, the light diffusion anisotropy of the wavy uneven pattern can be moderately weakened, and the diffusion angles in both the main diffusion direction and the low diffusion direction can be easily controlled.

In the present embodiment example, the average height of the convex portion 43 is measured and defined as follows.
First, a sectional view as shown in FIG. 12 is obtained, and the waveform is separated into a shape derived from the wavy uneven pattern (1 </ b> A) and a shape derived from the convex portion 43. In the waveform separation, the shape derived from the wavy uneven pattern (1A) is used as a sine curve. Then, the shape derived from the wavy uneven pattern (1A) is subtracted from the cross-sectional view of FIG. 12 to obtain a cross-sectional view of only the shape derived from the convex portion 43 as shown in FIG. Then, in the cross-sectional view of FIG. 13, the height H ′ of the convex portion 43 is obtained as H ′ = (H1 ′ + H2 ′) / 2. In the cross-sectional view of FIG. 13, H1 ′ is a vertical distance between the top portion T ′ of the convex portion 43 and the base line Lα on one side of the convex portion 43, and H2 ′ is the top portion T ′ of the convex portion 43 and the top portion T ′. This is a vertical distance from the base line Lβ on the other side of the convex portion 43.
Such measurement is performed on 50 convex portions 43, and an average value of 50 data is defined as "average height of convex portions".

  The occupation area ratio of the protrusions 43 on the wavy uneven pattern forming surface is preferably 30 to 70%, more preferably 40 to 60%, and still more preferably 45 to 55%. When the occupation area ratio of the convex portion 43 is within the above range, the light diffusible anisotropy of the wavy uneven pattern (1A) can be moderately weakened, and the diffusion angles in both the main diffusion direction and the low diffusion direction can be set as described above. Easy to control to range.

The occupied area ratio γ (%) of the convex portion 43 on the wavy uneven pattern forming surface is measured and defined as follows.
First, an optical microscope image as shown in FIG. 11 is obtained, and the number n of the convex portions 43 recognized in the area S2 of the entire visual field (for example, 0.4 to 1.6 mm in length and 0.5 to 2 mm in width) is counted. In the entire field of view, the area S1 = nr ² π occupied by the n convex portions 43 is obtained. The occupied area ratio γ (%) is obtained by the following formula.
γ (%) = S1 × 100 / S2 (where r in the formula is ½ (ie, radius) of the average diameter of the convex portions)

  In the surface fine concavo-convex sheet of the present embodiment, the main diffusion direction of the wavy concavo-convex pattern can be obtained by the method described above, and is a diagram substantially parallel to the arrangement direction of the ridges 42a of the wavy concavo-convex pattern (1A). 12 in the A direction. On the other hand, the direction perpendicular to the main diffusion direction is a “low diffusion direction” with a low diffusion angle.

The diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction adjust the average pitch, average height, average diameter, average height, occupied area, etc. of the convex portions 42a of the wavy uneven pattern (1A). It can be controlled by doing.
The preferable thickness etc. of the surface fine unevenness | corrugation sheet of 4th Embodiment are comparable as the surface fine unevenness | corrugation sheet of 1st Embodiment.

The surface fine concavo-convex sheet of the fourth embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the first embodiment.
However, in the above-mentioned process (a1-1), it differs in that the paint containing particles is used together with the resin M for forming the hard layer as the hard layer forming paint used for forming the hard layer. By using the particles, the wavy uneven pattern (1A) having the convex portions 43 can be formed.
Japanese Patent Application Laid-Open No. 2014-206728 (Japanese Patent No. 5660235) can be referred to for the formation of the wavy uneven pattern (1C) of the present embodiment.

A uniaxially stretched film is used as the heat-shrinkable resin film. Preferred modes and ranges such as the material (resin L), shrinkage rate, glass transition temperature of resin L, Young's modulus and the like are the same as those in the first embodiment.
The hard layer, its material (resin M), the glass transition temperature and Young's modulus of the resin M are the same as in the first embodiment.

As the material constituting the particles, one or more materials whose particle shape is not changed by heat can be used at a temperature lower than 10 ° C. higher than the glass transition temperature Tg ₁ of the resin L.
For example, when the material constituting the particles is one or more selected from the group consisting of a resin having a glass transition temperature and an inorganic material having a glass transition temperature, the glass transition temperature Tg ₃ is the glass transition temperature of the resin M. It is necessary to satisfy the same conditions as Tg _2M , that is, (Tg ₃ −Tg ₁ ) should be selected to be 10 ° C. or higher, and (Tg ₃ −Tg ₁ ) is more preferably 20 ° C. or higher. 30 ° C. or higher is more preferable. When (Tg ₃ −Tg 1) is 10 ° C. or higher, the particles are not deformed and melted at the above processing temperature.

  When the material constituting the particles is a material that does not have a glass transition temperature, such as an internally cross-linked resin, the Vicat softening temperature (as defined in JIS K7206) satisfies the above-described condition, that is, the resin It is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, and more preferably 30 ° C. or higher than the glass transition temperature of L.

In the present specification, the description of the preferable temperature range and the like for the glass transition temperature Tg ₃ also corresponds to the Vicat softening temperature when the particles are made of a material having a Vicat softening temperature without the glass transition temperature. To do.
Furthermore, as the material constituting the particles, even if the glass transition temperature and Vicat softening temperature cannot be measured, at a temperature lower than 10 ° C. higher than the glass transition temperature Tg ₁ of the resin L constituting the heat-shrinkable resin film, Any material that does not change its particle shape due to heat can be used.

Tg ₃ is preferably 40 to 400 ° C, and more preferably 80 to 250 ° C. If Tg ₃ is 40 ° C. or higher, it is useful that the temperature of step (a1-2) can be room temperature or higher, and it is economical to use particles whose Tg ₃ exceeds 400 ° C. There is little need in terms of sex.

The resin constituting the particles is selected according to the type of the heat-shrinkable resin film so that the glass transition temperature Tg ₃ (or Vicat softening point) satisfies the above-described conditions, for example, acrylic thermoplastic Examples thereof include resin particles, polystyrene-based thermoplastic resin particles, acrylic cross-linked resin particles, and polystyrene cross-linked resin particles. Examples of the inorganic material include glass beads.
The particle diameter d of the particles needs to be larger than the thickness t of the hard layer to be formed, and is set according to the thickness t of the hard layer. Moreover, the average diameter of the convex part 43 is suitably set so that it may become the above-mentioned suitable range. The preferable particle diameter d is, for example, 5 to 10 μm, and more preferably 5 to 8 μm.

In the step (a1-1), a paint containing resin M and particles is used as the hard layer forming paint, and the thickness t ′ exceeds 0.05 μm and is 10 μm or less on one side of the heat-shrinkable resin film. A hard layer is formed. The hard layer at this point is not deformed to fold. That is, the thickness t ′ is the thickness of the hard layer before deformation.
Instead of providing the hard layer coating directly on the heat-shrinkable resin film as described above, the hard layer is obtained by heating a hard layer (a film in which particles are dispersed in the resin M) that is heat-shrinkable. You may provide by the method of laminating | stacking on a film.

As the resin M and the resin constituting the particles, those already exemplified can be used. However, the glass transition temperature Tg _2M of the resin M and the glass transition temperature Tg _{3 of the} particles are more than the glass transition temperature Tg ₁ of the resin L. It is important to select and combine the materials so that the temperature is 10 ° C. or higher. Thus, after selecting each material, when the hard layer whose thickness t 'exceeds 0.05 micrometer and is 10 micrometers or less is provided in the single side | surface of a heat-shrinkable resin film, it passes through the following process (a1-2). As a result, the wavy uneven pattern (1C) having the average pitch and average height of the ridges 42a in the above range is easily formed.

  In the present embodiment example, the preferred solid content concentration range of the resin M in the hard layer forming coating material is the same as that in the first embodiment example. The amount of the particles is preferably 10 to 50 parts by mass and more preferably 20 to 30 parts by mass with respect to 100 parts by mass of the net amount of the resin M. Within such a range, the occupation area ratio of the convex portions 43 to be formed can be controlled within the above-described preferable range.

The thickness t ′ of the hard layer to be applied may be continuously changed as long as it is in the range of more than 0.05 μm and not more than 10 μm. In that case, the pitch and depth of the ridges 42a formed by the deformation process are continuously changed. The thickness t ′ of the hard layer can be considered as t ′ = t, which changes almost even after the next step (a1-2).
The thinner the hard layer is, the lower the Young's modulus of the hard layer is, the smaller the average pitch of the wavy uneven pattern (1A) is, and the higher the contraction rate of the heat-shrinkable resin film is, The height of 42a becomes large. Therefore, by adjusting these conditions, the pitch and height of the ridges 42a of the wavy uneven pattern (1A) can be controlled to desired values.

  Except for the step (a1-1), the same procedure as in the first embodiment is performed.

[Fifth Embodiment]
FIG. 14 is an optical microscopic image of the wavy uneven pattern forming surface of the surface fine uneven sheet of the fifth embodiment. The wavy uneven pattern formed on the wavy uneven pattern forming surface of the surface fine uneven sheet of the fifth embodiment corresponds to the waved uneven pattern (1) described above, as in the first embodiment.

The wavy uneven pattern (1D) in the surface fine uneven sheet of the fifth embodiment example has another wavy uneven pattern (1-b) in addition to the above-described wavy uneven pattern (1A).
FIG. 15A is a schematic plan view showing the surface fine concavo-convex sheet 10D of the fifth embodiment as observed from the normal direction, and FIG. 15B is the normal direction of the surface fine concavo-convex sheet. And FIG. 15C is a side view showing a side surface parallel to the arrangement direction of the ridges 11c of the wavy uneven pattern (1-b) described later, and FIG. 15C is parallel to the normal direction of the surface fine uneven sheet. Moreover, it is a side view of the side surface parallel to the arrangement direction of the ridges 11d of the wavy uneven pattern (1A).
The arrangement direction of the ridges 11d in the wavy uneven pattern (1A) and the arrangement direction of the ridges 11c in the wavy uneven pattern (1-b) are substantially orthogonal, and the angle formed by these arrangement directions is the wavy unevenness. When the pattern is viewed in plan, it is within the range of 90 ± 10 °.

  Other points, such as a linear Fresnel lens pattern 12A formed as a linear concavo-convex pattern on the other surface of the surface fine concavo-convex sheet 10D, are the same as in the first embodiment. And the surface fine unevenness | corrugation sheet | seat 10D of this embodiment example can comprise the illumination unit for display apparatuses, and a display apparatus similarly to 10 A of surface fine unevenness | corrugation sheets of 1st Embodiment.

  The wavy uneven pattern (1D) is a pattern in which the ridges 11d and the ridges 11c are substantially orthogonal to each other (within a range of ± 10 °), that is, the wavy uneven pattern (1A) and the wavy uneven pattern (1- Since b) is a superimposed pattern, the light diffusion anisotropy is weakened, and the difference in diffusion angle between the main diffusion direction and the low diffusion direction of the wavy uneven pattern tends to be small.

Similar to the wavy uneven pattern (1A), the wavy uneven pattern (1-b) has the following characteristics.
(A ′) Each ridge 11c meanders and is not parallel to each other. That is, the ridge line of each protruding line part 11c meanders, and the space | interval of the ridge line of the adjacent protruding line part 11c is not constant, but is changing continuously. However, it may include a portion where the interval between the ridge lines is constant. Further, one ridge line may be branched in the middle, or a plurality of ridge lines may be joined in the middle.
(B ′) Each concave line portion 11e meanders and is not parallel to each other. That is, the valley line of each concave line part 11e meanders, and the space | interval of the valley line of the adjacent concave line part 11e is not constant, but is changing continuously. However, a portion where the interval between the valley lines is partially constant may be included. Moreover, one trough line may branch on the way, or several trough lines may unite on the way.

Further, in the wavy uneven pattern (1-b), the longitudinal cross-sectional shape of each protrusion 11c (cut parallel to the normal direction of the surface fine unevenness sheet and cut along the arrangement direction of the protrusions 11c. Are different from each other and are not uniform, but irregular.
The vertical cross-sectional shape of each ridge portion 11c is a tapered shape that becomes thinner from the proximal end side toward the distal end side, and the distal end is rounded. The wavy uneven pattern (1-b) has a smooth line connecting the distal end side and the proximal end side in the longitudinal cross-sectional shape of each protrusion 11c, and is continuous from the distal end side to the proximal end side. It has fallen to. In addition, each ridge 11c has at least one of the above-described vertical cross-sectional shape and the area thereof changed along the extending direction of the ridge 11c (direction extending in a line shape), It is not constant.
Moreover, in each protruding item | line part 11c, the height of a ridgeline is not constant, but has a height difference which changes continuously. However, the part which does not have a height difference partially may be included.
Moreover, in each concave line part 11e, the height of a trough line is not constant, but has the height difference which changes continuously. However, the part which does not have a height difference partially may be included.

  The method for obtaining the average pitch and aspect ratio of the ridges 11d of the wavy uneven pattern (1A) constituting the wavy uneven pattern (1D) is as described in the first embodiment, and the wavy uneven pattern ( The same applies to the protrusion 1c of 1-b). The average pitch and aspect ratio of the wavy uneven pattern (1A) and (1-b) can be adjusted as appropriate, but the wavy uneven pattern (1-b) is preferably smaller than the wavy uneven pattern (1A).

For example, in the present embodiment, the average pitch of the ridges 11d of the wavy uneven pattern (1A) is preferably 5 to 50 μm, more preferably 10 to 40 μm, and 15 to 30 μm. Further preferred. When the average pitch is not less than the lower limit of the above range, the surface fine uneven sheet can be easily produced. When the average pitch is less than or equal to the upper limit of the above range, the wavy uneven pattern (1A) is difficult to be visually recognized as an undesirable bright line when the surface fine uneven sheet is used in a lighting device.
On the other hand, the average pitch of the ridges 11c of the wavy uneven pattern (1-b) is preferably 1 to 25 μm, more preferably 3 to 20 μm, and further preferably 5 to 15 μm. When the average pitch is within the above range, the surface fine uneven sheet 10D can be easily manufactured.

The aspect ratios of the ridges 11c and 11d of the wavy uneven patterns (1A) and (1-b) are each preferably 0.1 to 1.0, and preferably 0.2 to 0.8. Is more preferable, and it is further more preferable that it is 0.3-0.6.
When the aspect ratio of the wavy uneven pattern (1A) is equal to or higher than the lower limit value of the above range, the wavy uneven pattern (1A) can sufficiently obtain a viewing angle ensuring effect and a luminance unevenness eliminating effect, and below the upper limit value of the above range. If it exists, a wavy uneven | corrugated pattern (1A) can be formed easily. When the aspect ratio of the wavy uneven pattern (1-b) is within the above range, the light diffusibility is not impaired.

In the surface fine uneven sheet 10D of the present embodiment, the main diffusion direction of the wavy uneven pattern can be obtained by the method described above.
The diffusion angle in the main diffusion direction can be adjusted as appropriate, but is preferably 10 ° or more, for example, and more preferably 15 ° or more. Moreover, it is preferable that it is 40 degrees or less, for example, and it is more preferable that it is 30 degrees or less, for example.
On the other hand, the direction perpendicular to the main diffusion direction is a “low diffusion direction” with a low diffusion angle.
The light diffusion angle in the low diffusion direction can be adjusted as appropriate, but is preferably smaller than the diffusion angle in the main diffusion direction and, for example, 2 ° or more. Moreover, it is preferable that it is 15 degrees or less.

The diffusion angle in the main diffusion direction and the diffusion angle in the low diffusion direction are the average pitch, aspect ratio (average height / average pitch) of the ridges 11c and 11d of the wavy uneven patterns (1A) and (1-b), etc. It can be controlled by adjusting.
A preferable thickness or the like of the surface fine uneven sheet 10D of the fifth embodiment is about the same as that of the surface fine uneven sheet of the first embodiment.

The surface fine concavo-convex sheet 10D of the fifth embodiment can be manufactured roughly by the same manufacturing method as the surface fine concavo-convex sheet of the first embodiment.
However, only the step (a1-1) of the above-described steps (a1) is different.
That is, in the step (a1-1) of the first embodiment, a hard layer having a smooth surface is laminated on one side of the heat-shrinkable resin film. However, the step (a1-1) in the manufacturing method of the present embodiment. Then, the hard layer by which the wavy uneven | corrugated pattern (1-b) was formed in the surface is formed in the single side | surface of a heat-shrinkable resin film. For the formation of the hard layer, an uncured transparent ionizing radiation curable resin is used.
For the formation of the wavy uneven pattern (1D) of the present embodiment, reference can be made to JP 2012-252149 A (Patent No. 5673704) and the like.

The step (a1-1) in the present embodiment will be described below.
A uniaxially stretched film is used as the heat-shrinkable resin film. Preferred modes and ranges such as the material (resin L), shrinkage rate, glass transition temperature of resin L, Young's modulus and the like are the same as those in the first embodiment. As the heat-shrinkable resin film, a translucent (transparent) film is used. Next, one or more of uncured ionizing radiation curable resins are coated on one surface of the heat-shrinkable resin film with a coater such as a die coater, a roll coater, or a bar coater to form a coating layer. Then, a stamper having a transfer shape of the wavy uneven pattern (1-b) is prepared on the surface, the stamper is pressed against the coating layer, and in that state, irradiated with ionizing radiation from the heat-shrinkable resin film side, The ionizing radiation curable resin is cured to form a cured layer. Thereafter, the stamper is peeled off.
At this time, the stamper is pressed so that the extending direction of the ridges in the stamper coincides with the direction of heat shrinkage of the heat-shrinkable resin film.
Thereby, the laminated | multilayer film which has a hard layer in which the wavy uneven | corrugated pattern (1-b) was formed in the single side | surface of a heat-shrinkable film are obtained.

As the uncured ionizing radiation curable resin, those exemplified in the production method (B) of the first embodiment can be suitably used. In particular, the glass transition temperature after curing is a heat shrinkable resin film. A resin having a temperature higher by 10 ° C. or more than the constituent resin L and a Young's modulus of 0.01 to 300 GPa, preferably 0.1 to 10 GPa is suitable.
The thickness of the hard layer is preferably more than 0.5 μm and not more than 20 μm, and more preferably 1 to 10 μm.
If the glass transition temperature and Young's modulus satisfy the above conditions and the thickness of the hard layer is within the above range, the average pitch of the wavy uneven pattern (1A) in this embodiment can be easily adjusted within the above range. . When the thickness of the hard layer is less than the lower limit of the above range, the average pitch of the wavy uneven pattern (1A) tends to be too small. When the upper limit of the above range is exceeded, the heat shrinkable resin film shrinks. It is obstructed and the wavy uneven pattern (1A) tends not to be formed well.

  The ionizing radiation curable resin is preferably diluted with a solvent or the like. Moreover, you may add a fluororesin, a silicone resin, etc. to uncured ionizing radiation curable resin. When the uncured ionizing radiation curable resin is ultraviolet curable, it is preferable to add a photopolymerization initiator such as acetophenones and benzophenones to the uncured ionizing radiation curable resin.

Also, instead of ionizing radiation curable resin, transfer is performed using, for example, thermosetting resin such as uncured melamine resin, urethane resin or epoxy resin, or thermoplastic resin such as acrylic resin, polyolefin or polyester. As long as transfer is possible, the specific method and material to be transferred are not limited.
In the case of using a thermosetting resin, for example, a method of applying a liquid uncured thermosetting resin and curing by heating can be mentioned. When using a thermoplastic resin, a sheet of thermoplastic resin is used, There may be mentioned a method of heating and softening while pressing against the surface of the transfer object and then cooling.

  After the step (a1-1), the step (a1-2) was performed in the same manner as in the first embodiment, and the heat-shrinkable film was contracted to form a wavy uneven pattern (1D) on the surface. An uneven pattern forming sheet is obtained.

  Next, the step (a1-3) is performed in the same manner as in the first embodiment to obtain an original (W) to which the transfer shape of the waved uneven pattern (1D) is transferred.

  The thinner the hard layer is, the lower the Young's modulus of the hard layer is, the smaller the average pitch of the wavy uneven pattern (1A) is, and the higher the contraction rate of the heat-shrinkable resin film is, The height of 11d increases. Therefore, by adjusting these conditions, it is possible to control the pitch and height of the ridges 11d of the wavy uneven pattern (1A) to desired values.

Note that the stamper having the transfer shape of the wavy uneven pattern (1-b) on the surface can be manufactured by the same method as the step (a1) in the first embodiment. Further, for example, JP 2012-252149 A (Japanese Patent No. 5673704) can be referred to.
Except for the step (a1-1), the same procedure as in the first embodiment is performed.

<Sixth to Fifteenth Embodiments>
[Sixth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only that a linear vertex concavo-convex linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the first embodiment.

[Wavy uneven pattern]
In the present embodiment example, a wavy uneven pattern (1A) similar to that of the first embodiment example is formed.

[Linear concavo-convex pattern (linear triangle prism pattern with fixed vertex angle)]
FIG. 16 is a cross-sectional view of a sheet in which one surface is a surface (the lower surface in FIG. 16) on which the constant apex angle type linear triangular prism pattern 12 </ b> B is formed and the other surface is the smooth surface 13.
As shown in FIG. 16, the vertical vertex type linear triangular prism pattern 12B provided on the surface of the surface fine concavo-convex sheet forming surface of the surface fine concavo-convex sheet according to the present embodiment has a vertical cross-sectional shape (surface fine concavo-convex shape). The shape on the cut surface that is parallel to the normal direction of the sheet and cut along the arrangement direction of the ridges) is an isosceles triangle whose apex angle faces downward in the figure.

The operation of the constant vertex angle type linear triangular prism pattern 12B will be described with reference to FIG.
When light from a point light source 21 such as an LED light source or a laser light source is made incident on the linear triangle prism pattern 12B with a constant vertex angle through the condenser lens 20, for example, a constant vertex angle type among light traveling vectors. The in-plane component consisting of the arrangement direction of the ridges 12b of the linear triangular prism pattern 12B (m direction in the figure) and the normal direction (n direction in the figure) of the surface on which the linear triangle prism pattern 12B is formed is constant. By appropriately controlling the apex angle of the ridges 12b of the constant angle linear triangular prism pattern 12B, approximately ± 10 ° from the normal direction (n direction in the figure) of the surface on which the constant angle linear linear prism pattern 12B is formed. The light is refracted so as to form an angle within the range and exits from the smooth surface 13. That is, the direction of light rises almost toward the front. The fixed vertex angle type linear triangular prism pattern 12B has an effect of improving the front luminance by such a light collecting function.

  The pitch of the ridges 12b of the linear vertex prism pattern 12B with a fixed vertex angle, the size of the vertex angle of the isosceles triangle, and the like are designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, for all of the light emitted from the condenser lens 20, preferably the entire ray, the direction in which the ridges 12 b of the constant vertex angle linear triangular prism pattern 12 B are arranged and the normal direction of the surface on which the constant vertex angle linear triangular prism pattern 12 B is formed. Is designed to be refracted and emitted from the smooth surface 13 so as to form an angle within about ± 10 ° with respect to the normal direction of the surface of the linear triangle prism pattern forming surface with a constant apex angle. Is preferred.

  For example, the preferred pitch of the ridges 12b of the constant vertex angle type linear triangular prism pattern 12B is in the same range as the linear Fresnel lens pattern 12A described in the first embodiment.

  The irradiation angle of the light emitted from the condenser lens 20 is preferably 2 to 50 °, more preferably 5 to 40 °, and still more preferably 10 to 30 °. When the irradiation angle is equal to or greater than the lower limit of the above range, the light emitted from the condenser lens 20 is sufficiently spread, and the uneven brightness of the light emitted from the surface fine uneven sheet is eliminated. If the irradiation angle is equal to or less than the upper limit of the above range, out of the traveling vectors of the light emitted from the condenser lens 20, the arrangement direction of the ridges 12b of the constant apex angle type linear triangular prism pattern 12B and the constant apex angle type A sufficient effect of refracting an in-plane component composed of the normal direction of the surface on which the linear triangular prism pattern 12B is formed so as to form an angle within approximately ± 10 ° with respect to the normal direction of the linear triangular prism pattern 12B having a constant apex angle. And has an excellent front luminance improvement effect.

[Surface micro uneven sheet]
The surface fine concavo-convex sheet of this embodiment example has an undulating angle formed by the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges 12b of the constant apex linear triangular prism pattern 12B. When the concavo-convex pattern is viewed in plan, it is within a range of ± 20 °.
Therefore, when the surface fine uneven sheet of the present embodiment example is used in combination with a light source array formed by arranging a plurality of point light sources in a specific positional relationship as in the first embodiment example. Thus, a viewing angle ensuring effect and luminance unevenness eliminating effect by the wavy uneven pattern, and a front luminance improving effect by the constant apex angle type linear triangular prism pattern are obtained. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

  The surface fine concavo-convex sheet of this embodiment may have a single layer structure or a multilayer structure composed of two or more layers. The preferred thickness is the same as that in the first embodiment.

[Method for manufacturing surface uneven surface sheet]
The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the first embodiment.
However, in the step (a2), instead of manufacturing the original plate (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal shape) of the constant vertex angle type linear triangular prism pattern. Is produced on the surface (L2). The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In step (a3), an injection molding method in which a resin is injected between the surface of the original plate (W) on which the transfer shape is formed and the surface of the original plate (L2) on which the transfer shape is formed, A surface fine uneven sheet having a wavy uneven pattern (1A) formed on one surface and a constant apex angle type linear triangular prism pattern formed on the other surface is obtained.
In the manufacturing method (B), the original plate (L2) is used as a stamper instead of the original plate (L1).
Other points are the same as in the first embodiment.

[Lighting unit for display device and display device]
FIG. 17 is a schematic configuration diagram illustrating the configuration of the illumination unit for display device according to the present embodiment, and FIG. 17 (b) is a side view showing a side surface parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A), and FIG. It is a side view which shows the side surface parallel to a direction.

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such a display device illumination unit as well, in the same way as in the first embodiment, the light emitted from each point light source 21 is condensed by the condensing lens 20 and is a linear vertex prism with a fixed apex angle. The light enters the linear uneven pattern forming surface 12 on which the pattern 12B is formed. Then, as described above with reference to FIG. 16, among the light traveling vectors, the arrangement direction of the ridges 12 b of the constant vertex angle type linear triangular prism pattern 12 B and the formation of the constant vertex angle type linear triangular prism pattern 12 B. The in-plane component composed of the normal direction of the surface (the normal direction of the surface fine uneven sheet) forms an angle within approximately ± 10 ° with the normal direction of the surface on which the constant vertex angle type linear triangular prism pattern 12B is formed. Refract.
The light refracted in this way passes through the inside of the surface fine uneven sheet 10E and is emitted from the waved uneven pattern forming surface 11. Of the light traveling vectors, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 17) of the wavy uneven pattern (1A). Since the directions correspond to each other, the refraction is mainly caused by refraction, and thus components of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10E and a component inclined from the normal direction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet 10E contributes to the improvement of the front luminance. Further, when viewed from the wavy uneven pattern forming surface 11 side, brightness unevenness is caused by light parallel to the normal direction of the surface fine uneven sheet 10E occurring in a portion where no light source exists such as between the point light source 21 and the point light source 21. A cancellation effect is obtained. Moreover, the component which inclined from the normal line direction of the surface fine uneven | corrugated sheet | seat 10E contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

  In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10E and the arrangement direction of the point light sources 21 of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 increases. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern (1A). Therefore, it is possible to suppress a decrease in luminance due to increasing the diffusion angle.

  Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

  Which side of the surface fine uneven sheet 10E the light source row 21A is arranged can be set according to the purpose. When the wavy uneven pattern (1A) is on the side opposite to the light source array 21A side, the luminance unevenness eliminating effect and the front luminance improving effect are high, and when the wavy uneven pattern (1A) is on the light source array 21A side, the viewing angle securing effect is achieved. Is expensive.

[Seventh embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only that a linear vertex concavo-convex linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the second embodiment. Similarly to the surface fine uneven sheet according to the second embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display unit illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment example also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the linear triangle prism pattern having a constant apex angle, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the second embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the fixed vertex angle type linear triangular prism pattern transfer shape (reversal) A master (L2) having a shape) on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (2A) is formed) and the transfer shape of the original plate (L2) are formed. The surface fine concavo-convex sheet in which a wave-like concavo-convex pattern (2A) is formed on one surface and a constant apex linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L2) is used as a stamper instead of the original plate (L1).
The other points are the same as in the second embodiment.

[Eighth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only that a linear vertex concavo-convex linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the third embodiment. Similarly to the surface fine uneven sheet according to the third embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment example also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the linear triangle prism pattern having a constant apex angle, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the third embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the fixed vertex angle type linear triangular prism pattern transfer shape (reversal) A master (L2) having a shape) on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1B) is formed) and the transfer shape of the original plate (L2) are formed. The surface fine concavo-convex sheet in which the wave-like concavo-convex pattern (1B) is formed on one surface and the constant vertex angle type linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L2) is used as a stamper instead of the original plate (L1).
Other points are the same as in the third embodiment.

[Ninth Embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only that a linear vertex concavo-convex linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the fourth embodiment. Similarly to the surface fine uneven sheet according to the fourth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment example also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the linear triangle prism pattern having a constant apex angle, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fourth embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the fixed vertex angle type linear triangular prism pattern transfer shape (reversal) A master (L2) having a shape) on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1C) is formed) and the transfer shape of the original plate (L2) are formed. A surface fine concavo-convex sheet in which a wavy concavo-convex pattern (1C) is formed on one surface and a constant apex angle type linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L2) is used as a stamper instead of the original plate (L1).
Other points are the same as in the fourth embodiment.

[Tenth Embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only that a linear vertex concavo-convex linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the fifth embodiment. Similarly to the surface fine uneven sheet according to the fifth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment example also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the linear triangle prism pattern having a constant apex angle, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fifth embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the fixed vertex angle type linear triangular prism pattern transfer shape (reversal) A master (L2) having a shape) on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1D) is formed) and the transfer shape of the original plate (L2) are formed. A surface fine concavo-convex sheet in which a wave-like concavo-convex pattern (1D) is formed on one surface and a constant vertex angle type linear triangular prism pattern is formed on the other surface by an injection molding method of injecting resin between the two surfaces Get.
In the manufacturing method (B), the original plate (L2) is used as a stamper instead of the original plate (L1).
The other points are performed in the same manner as in the fifth embodiment.

[Eleventh embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only in that a vertex angle variation type linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the first embodiment.
As described above, the “vertical angle variation linear triangular prism pattern” includes the pattern (A) and the pattern (B). In the pattern (A), as shown in FIG. 18 (a), the heights Ha of the ridges 12c are equal and constant, but the widths of the bottoms of the ridges 12c (arrangement direction of the ridges). The apex angle (θ ₁ <θ ₂ <θ ₃ <θ ₄ ) is different, and the apex angle is not constant but varies. In the pattern (B), as shown in FIG. 18 (b), the widths Wb of the ridges 12c are equal to each other and the pitch is constant, but the heights of the ridges 12c are different. The angles (θ ₁ <θ ₂ <θ ₃ <θ ₄ ) are different, and the apex angle is not constant but fluctuates. In any of the 11th to 15th embodiments, any pattern can be adopted, but in FIG. 18C and FIG. 19, the pattern (B) is shown.

[Wavy uneven pattern]
In the present embodiment example, a wavy uneven pattern (1A) similar to that of the first embodiment example is formed.

[Linear uneven pattern (vertical angle variation type linear triangular prism pattern)]
FIG. 18C shows a sheet in which one surface is a surface (vertical surface in FIG. 18C) on which the apex angle variation linear triangular prism pattern 12C is formed, and the other surface is the smooth surface 13. FIG. FIG. 18C illustrates a vertex angle variation type linear triangular prism pattern of the pattern (B).
As shown in FIG. 18 (c), the vertical angle variation type linear triangular prism pattern 12C provided on the surface of the surface fine concavo-convex sheet on the surface fine concavo-convex sheet of the present embodiment has a longitudinal sectional shape ( The shape of the cut surface that is parallel to the normal direction of the surface fine concavo-convex sheet and cut along the arrangement direction of the ridges is an isosceles triangle. The ridges 12c have different vertical angles in the longitudinal cross-sectional shape, and from the ridges 12c located on both ends of the linear concavo-convex pattern forming surface 12 toward the ridges 12c located on the center side. The apex angle is gradually increasing.

With reference to FIG. 18C, the operation of the apex angle variation linear triangular prism pattern 12C will be described.
When light from a point light source 21 such as an LED light source or a laser light source is made incident on the vertex angle variation type linear triangular prism pattern 12C through the condenser lens 20, the vertex angle variation type among the light traveling vectors. The in-plane component consisting of the arrangement direction of the ridges 12c of the linear triangular prism pattern 12C (m direction in the figure) and the normal direction (n direction in the figure) of the surface on which the vertical angle variation linear triangular prism pattern 12C is formed is The light is refracted so as to be parallel to the normal direction (the n direction in the drawing) of the surface on which the angle-variable linear triangular prism pattern 12C is formed, and is emitted from the smooth surface 13. That is, the direction of light rises almost toward the front. The vertex angle variation type linear triangular prism pattern 12C has an effect of improving the front luminance by such a condensing function.

  The pitch of the ridges 12c of the apex angle variation type linear triangular prism pattern 12C, the degree of the apex angle variation, and the like are designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, for all of the light emitted from the condenser lens 20, preferably, the direction of arrangement of the ridges 12c of the apex angle varying linear triangular prism pattern 12C and the normal direction of the surface on which the apex angle varying linear triangular prism pattern 12C is formed. It is preferable that the in-plane component consisting of is refracted so as to be parallel to the normal direction of the surface on which the apex angle variation type linear triangular prism pattern 12C is formed and is emitted from the smooth surface 13.

  A preferable pitch of the ridges 12c of the apex-variable linear triangular prism pattern 12C is, for example, in the same range as the linear Fresnel lens pattern described in the first embodiment.

  The irradiation angle of the light emitted from the condenser lens 20 is preferably 2 to 50 °, more preferably 5 to 40 °, and still more preferably 10 to 30 °. When the irradiation angle is equal to or greater than the lower limit of the above range, the light emitted from the condenser lens 20 is sufficiently spread, and the uneven brightness of the light emitted from the surface fine uneven sheet is eliminated. When the irradiation angle is not more than the upper limit of the above range, out of the traveling vectors of the light emitted from the condenser lens 20, the arrangement direction of the ridges 12 c of the apex angle varying linear triangular prism pattern 12 C and the apex angle variation type It has a sufficient effect of refracting an in-plane component consisting of the normal direction of the linear triangular prism pattern 12C forming surface so as to be substantially parallel to the normal direction of the apex angle varying linear triangular prism pattern 12C forming surface, Excellent front brightness improvement effect.

[Surface micro uneven sheet]
The surface fine concavo-convex sheet of the present embodiment example has an undulating undulation, which is an angle formed by the main diffusion direction of the wavy uneven pattern and the extending direction of the protruding portion 12c of the apex-variable linear triangular prism pattern 12C. When the pattern is viewed in plan, it is within a range of ± 20 °.
Therefore, when the surface fine uneven sheet of the present embodiment example is used in combination with a light source array formed by arranging a plurality of point light sources in a specific positional relationship as in the first embodiment example. Thus, a viewing angle ensuring effect and luminance unevenness eliminating effect by the wavy uneven pattern and a front luminance improving effect by the apex angle variation type linear triangular prism pattern 12C are obtained. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

  The surface fine concavo-convex sheet of this embodiment may have a single layer structure or a multilayer structure composed of two or more layers. The preferred thickness is the same as that in the first embodiment.

[Method for manufacturing surface uneven surface sheet]
The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the first embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the transfer shape (inverted shape) of the linear Fresnel lens pattern on the surface, the transfer shape (vertical angle variable linear triangular prism pattern 12C ( An original (L3) having a reverse shape) on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In step (a3), an injection molding method in which a resin is injected between the surface of the original plate (W) on which the transfer shape is formed and the surface of the original plate (L3) on which the transfer shape is formed, A surface fine uneven sheet having a wavy uneven pattern (1A) formed on one surface and an apex angle varying linear triangular prism pattern formed on the other surface is obtained.
In the manufacturing method (B), the original plate (L3) is used as a stamper instead of the original plate (L1).
Other points are the same as in the first embodiment.

[Lighting unit for display device and display device]
FIG. 19 is a diagram schematically showing a configuration of a display unit illumination unit according to the present embodiment. FIG. 19A is a schematic plan view from the side of the wavy uneven pattern forming surface of the surface fine uneven sheet 10F, and FIG. FIG. 19C is a side view showing a side surface parallel to the arrangement direction of the ridge portions 12c of the apex angle variation type linear triangular prism pattern (pattern (B)) 12C.

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet 10F includes the embodiment of the present embodiment, and the preferred embodiment is also the same.

In such a display unit illumination unit as well, in the same way as in the first embodiment, the light emitted from each point light source is condensed by the condenser lens 20, and the vertex angle variation linear triangular prism pattern is obtained. 12C is incident on the linear concave / convex pattern forming surface 12 formed thereon. Then, as described above with reference to FIG. 18C, the arrangement direction of the ridges 12 c of the apex angle variation type linear triangular prism pattern 12 </ b> C and the apex angle variation type linear triangular prism among the light traveling vectors. The in-plane component consisting of the normal direction of the pattern 12C forming surface (the normal direction of the surface fine uneven sheet) is refracted so as to be parallel to the normal direction of the apex angle varying linear triangular prism pattern 12C forming surface.
The light refracted in this way passes through the inside of the surface fine concavo-convex sheet 10 </ b> F and exits from the wave-like concavo-convex pattern forming surface 11. Of the light traveling vectors, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 19) of the wavy uneven pattern (1A). Since it is a corresponding direction, it becomes a component of various angles, such as a component parallel to the normal line direction of the surface fine uneven sheet | seat 10F, and a component inclined from this normal line mainly by refraction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern is a component mainly parallel to the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes.
The light parallel to the normal direction of the surface fine uneven sheet 10F contributes to the improvement of the front luminance. Further, when viewed from the wavy uneven pattern forming surface 11 side, brightness unevenness is caused by light parallel to the normal direction of the surface fine uneven sheet 10F in a portion where there is no light source such as between the point light source 21 and the point light source 21. A cancellation effect is obtained. Moreover, the component inclined from the normal line direction of the surface fine uneven | corrugated sheet | seat 10F contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10F and the arrangement direction of the point light sources 21 of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 becomes large. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern (1A). Therefore, it is possible to suppress a decrease in luminance due to increasing the diffusion angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

Which side of the surface fine uneven sheet 10F the light source row 21A is arranged can be set according to the purpose. When the wavy uneven pattern (1A) is on the side opposite to the light source array 21A side, the luminance unevenness eliminating effect and the front luminance improving effect are high, and when the wavy uneven pattern (1A) is on the light source array 21A side, the viewing angle securing effect is achieved. Is expensive.
In addition, when the apex angle variation type linear triangular prism pattern is adopted as compared with the constant apex angle type linear triangular prism pattern, the effect of coexistence of luminance unevenness and front luminance tends to be excellent.

[Twelfth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only in that a vertex angle variation type linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the second embodiment. Similarly to the surface fine uneven sheet according to the second embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display unit illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the apex angle-changing linear triangular prism pattern, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the second embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the transfer shape (reversal of the vertical angle variable linear triangular prism pattern) is performed. A master (L3) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). Then, in the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (2A) is formed) and the transfer shape of the original plate (L3) are formed. The surface fine concavo-convex sheet in which the wavy concavo-convex pattern (2A) is formed on one surface and the apex angle variation type linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L3) is used as a stamper instead of the original plate (L1).
The other points are the same as in the second embodiment.

[Thirteenth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only in that a vertex angle variation type linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the third embodiment. Similarly to the surface fine uneven sheet according to the third embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the apex angle-changing linear triangular prism pattern, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the third embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the transfer shape (reversal of the vertical angle variable linear triangular prism pattern) is performed. A master (L3) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1B) is formed) and the transfer shape of the original plate (L3) are formed. The surface fine concavo-convex sheet in which the wavy concavo-convex pattern (1B) is formed on one surface and the apex angle variation type linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L3) is used as a stamper instead of the original plate (L1).
Other points are the same as in the third embodiment.

[14th Embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only in that a vertex angle variation type linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the fourth embodiment. Similarly to the surface fine uneven sheet according to the fourth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the apex angle-changing linear triangular prism pattern, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fourth embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the transfer shape (reversal of the vertical angle variable linear triangular prism pattern) is performed. A master (L3) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1C) is formed) and the transfer shape of the original plate (L3) are formed. A surface fine concavo-convex sheet in which a wave-like concavo-convex pattern (1C) is formed on one surface and an apex variation linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L3) is used as a stamper instead of the original plate (L1).
Other points are the same as in the fourth embodiment.

[Fifteenth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is only in that a vertex angle variation type linear triangular prism pattern is formed as a linear concavo-convex pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the fifth embodiment. Similarly to the surface fine uneven sheet according to the fifth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device.

  The surface fine concavo-convex sheet of this embodiment example also has an undulating concavo-convex pattern in which the angle between the main diffusion direction of the undulating concavo-convex pattern and the extending direction of the ridges of the linear triangle prism pattern having a constant apex angle, that is, the intersection angle When seen in a plan view, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fifth embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the linear Fresnel lens pattern transfer shape (reversal shape) on the surface, the transfer shape (reversal of the vertical angle variable linear triangular prism pattern) is performed. A master (L3) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool). In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1D) is formed) and the transfer shape of the original plate (L3) are formed. A surface fine concavo-convex sheet in which a wavy concavo-convex pattern (1D) is formed on one surface and an apex angle variation type linear triangular prism pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L3) is used as a stamper instead of the original plate (L1).
The other points are performed in the same manner as in the fifth embodiment.

<16th to 20th Embodiment>
[Sixteenth embodiment]
The surface fine concavo-convex sheet of this embodiment example is only a point where the apex angle variation type modified pentahedral pattern is formed as a pentahedral pattern on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. This is different from the first embodiment.
As described above, the “vertical angle variation type pentahedron pattern” is formed by forming the pattern (B) of the vertical angle variation type linear triangular prism pattern, and then, from the pattern (B), the pattern (B) is a ridge. This is a pattern formed by cutting out the pattern (B ′) which is an inverted shape of the pattern (B) in which the arrangement directions of the parts are orthogonal.
FIG. 20A is a plan view for explaining the apex angle variation type modified pentahedron pattern.
As shown in FIG. 20 (a), in the vertex angle variation type pentahedron pattern, the bottom surface of each pentahedron 12d is a square having the same size, but the heights of the pentahedrons 12d are different from each other. Therefore, the apex angle is different (θ ₁₀ <θ ₂₀ <θ ₃₀ ), and the apex angle is not constant but fluctuates. In the pentahedron 12d, a quadrangular pyramid 12d ′ and a ridge line type pentahedron 12d ″ are mixed.
FIG. 20B is a plan view for explaining the apex angle variation type quadrangular pyramid prism pattern. In the sixteenth to twentieth embodiment examples, such a vertex angle changing type quadrangular pyramid prism pattern can also be adopted as the pentahedron pattern. As shown in FIG. 20B, the apex-variable quadrangular pyramid prism pattern includes only a quadrangular pyramid 12d ′ as a pentahedron and does not have a ridge-line pentahedron. The heights of the respective quadrangular pyramids 12d ′ are the same and constant, but the apex angles are different (θ ₁₀ <Θ ₂₀ <θ ₃₀ ), in which the apex angle is not constant but fluctuates.

[Wavy uneven pattern]
In the present embodiment example, a wavy uneven pattern (1A) similar to that of the first embodiment example is formed.

[Pentahedral pattern (vertical angle variation type modified pentahedral pattern)]
FIG. 20C is a sheet in which one surface is a surface (a lower surface in FIG. 20C) on which the apex angle variation type modified pentahedral pattern 12D is formed, and the other surface is the smooth surface 13. FIG.
As described above, the vertex angle variation-type deformed pentahedron pattern 12D provided on the surface fine uneven sheet of the present embodiment is formed by a large number of pentahedrons 12d along two orthogonal directions on the pentahedron pattern forming surface. In each of the two orthogonal directions, each pentahedron 12d has a different apex angle in the longitudinal cross-sectional shape. In each direction, the apex angle gradually increases from the pentahedron 12d located on the outer side of the pentahedron pattern forming surface toward the pentahedron 12d located on the center side.
On the other surface of the surface fine uneven sheet (the surface opposite to the wavy uneven pattern forming surface), a plurality of apex angle variation type modified pentahedral patterns 12D may be provided side by side as shown in FIG. .

With reference to FIG. 20C, the operation of the apex angle variation type modified pentahedral pattern 12D will be described.
When light from a point light source 21 such as an LED light source or a laser light source is incident on the apex angle variation type deformed pentahedron pattern 12D without passing through the condenser lens, the apex angle variation of the light traveling vector is changed. The two plane surfaces that are the arrangement directions of the pentahedrons 12d in the mold deformation pentahedron pattern 12D and each of the above two directions and the normal direction (the n direction in the figure) of the apex angle variation type pentahedron pattern 12D formation surface. The inner component is refracted so as to be parallel to the normal direction (n direction in the drawing) of the surface on which the apex angle variation type deformable pentahedral pattern 12D is formed, and is emitted from the smooth surface 13. That is, the direction of light rises almost toward the front. The vertex angle variation type pentahedron pattern 12D has an effect of improving the front luminance by such a light collecting function.
Further, according to the apex angle variation type modified pentahedron pattern 12D, the light from the point light source can be incident as it is without passing through the condensing lens 20, and can be started up. Therefore, according to the present embodiment, the number of members can be reduced and the thickness can be reduced in configuring the display unit illumination unit.

  The pitch of the pentahedron 12d of the deformed pentahedron pattern 12D, the degree of variation of the apex angle, and the like are designed according to the irradiation angle of light. That is, preferably all of the light from the point light source 21 (the irradiation angle of the light emitted from the point light source is typically 120 ° (= ± 60 °), so that it is minus 0-60 ° in the plus direction and minus. 2 plane in-plane components consisting of the above two directions and the normal direction of the surface on which the apex angle variation deformed pentahedron pattern 12D is formed are the apex angle variation deformable pentahedron. It is preferably designed so as to be refracted so as to be parallel to the normal direction of the surface on which the pattern 12D is formed and to exit from the smooth surface 13.

  For example, it is preferable that a preferable pitch (vertex interval) in each of the two orthogonal directions of the vertex angle variation type pentahedral pattern 12D is 5 to 500 μm. When the pitch is not less than the lower limit of the above range, the apex angle variation type deformed pentahedral pattern 12D can be satisfactorily formed, and when the pitch is not more than the upper limit of the above range, the surface fine uneven sheet is used for a lighting device. In addition, each apex of the pentahedron 12d of the vertex angle variation type deformed pentahedron pattern 12D is difficult to be visually recognized as an undesirable bright spot.

[Surface micro uneven sheet]
The surface fine concavo-convex sheet of the present embodiment is formed by the main diffusion direction of the wavy concavo-convex pattern and one of the arrangement directions (the above two directions) of the pentahedron 12d in the apex-variable deformable pentahedral pattern 12D. The angle, that is, the crossing angle is within a range of ± 20 ° when the wavy uneven pattern is viewed in plan.
Therefore, when the surface fine uneven sheet of the present embodiment example is used in combination with a light source array formed by arranging a plurality of point light sources in a specific positional relationship as in the first embodiment example. The effect of ensuring the viewing angle and the effect of eliminating the uneven brightness by the wavy uneven pattern and the effect of improving the front brightness by the deformed pentahedron pattern 12D of the apex angle variation are obtained. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

  The surface fine concavo-convex sheet of this embodiment may have a single layer structure or a multilayer structure composed of two or more layers. The preferred thickness is the same as that in the first embodiment.

[Method for manufacturing surface uneven surface sheet]
The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the first embodiment.
However, in the above-described step (a2), instead of manufacturing the original plate (L1) having the transfer shape (inverted shape) of the linear Fresnel lens pattern on the surface, the transfer shape (vertical angle variation type pentahedron pattern 12D ( An original plate (L4) having a reverse shape on the surface is manufactured. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface of the original plate (W) (the transfer shape of the wavy uneven pattern (1A) is formed) and the transfer shape of the original plate (L4) are formed. A surface fine pattern in which a wavy uneven pattern (1A) is formed on one surface and an apex angle variation-type deformed pentahedral pattern 12D is formed on the other surface by an injection molding method in which a resin is injected between the two surfaces. An uneven sheet is obtained.
In the manufacturing method (B), the original plate (L4) is used as a stamper instead of the original plate (L1).
Other points are the same as in the first embodiment.

[Lighting unit for display device and display device]
FIG. 21 is a diagram schematically illustrating the configuration of the illumination unit for display device according to the present embodiment. FIG. 21A is a schematic plan view from the side of the wavy uneven pattern forming surface of the surface fine uneven sheet 10G, and FIG. 21B shows a side surface parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern 1A. FIG. 21C is a side view showing a side surface parallel to the extending direction of the ridges of the wavy uneven pattern (1A). In this example, the apex angle variation type deformed pentahedron pattern 12D includes ^three apex angle variation type deformable pentahedron patterns 12D ¹ , 12D ² , and 12D ³ .

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such a display device illumination unit, the light emitted from each point light source 21 is incident on the surface on which the apex angle variation type modified pentahedral pattern 12D is formed. Then, as described above with reference to FIG. 20C, the above two directions and the apex angle, which are the arrangement directions of the pentahedron 12d of the apex angle variation type deformable pentahedron pattern 12D, among the light traveling vectors. The two plane in-plane components composed of the normal direction of the variable deformation pentahedron pattern 12D forming surface (the normal direction of the surface fine irregularities sheet) are the normal direction of the vertical angle variable pentahedral pattern 12D forming surface and Refracts to be parallel.
The light refracted in this way passes through the inside of the surface fine uneven sheet 10G and is emitted from the waved uneven pattern forming surface 11. In the light traveling vector, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 21) of the wavy uneven pattern (1A). Since the directions correspond to each other, components of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10G and a component inclined from the normal direction are mainly formed by refraction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet 10G contributes to the improvement of the front luminance. In addition, when viewed from the wavy uneven pattern forming surface 11 side, luminance unevenness is caused by light parallel to the normal direction of the surface fine uneven sheet 10G occurring in a portion where no light source exists such as between the point light source 21 and the point light source 21. A cancellation effect is obtained. Moreover, the component inclined from the normal line direction of the surface fine uneven sheet | seat 10G contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10G and the arrangement direction of the point light sources 21 of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 becomes large. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern (1A). Therefore, it is possible to suppress a decrease in luminance due to increasing the diffusion angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

  Which surface side of the surface fine uneven sheet 10G the light source row 21A is arranged can be set according to the purpose. When the wavy uneven pattern (1A) is on the side opposite to the light source array 21A side, the luminance unevenness eliminating effect and the front luminance improving effect are high, and when the wavy uneven pattern (1A) is on the light source array 21A side, the viewing angle ensuring effect Is expensive.

[Example 17 embodiment]
The surface fine concavo-convex sheet of this embodiment example is the second embodiment example only in that the apex angle variation type deformed pentahedron pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Is different. Similarly to the surface fine uneven sheet according to the second embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display unit illumination unit and a display device. However, as explained in the sixteenth embodiment, the apex-variable deformable pentahedron pattern can be launched by allowing the light from the point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

  The surface fine concavo-convex sheet of the present embodiment also has an angle between the main diffusion direction of the undulating concavo-convex pattern and one of the above two directions of the apex angle variation type deformable pentahedral pattern, that is, the intersection angle is undulating undulation. When the pattern is viewed in plan, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the second embodiment.
However, in the above-mentioned step (a2), instead of manufacturing the original plate (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal of the vertex angle variation type pentahedron pattern) A master (L4) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (2A) is formed) and the transfer shape of the original plate (L4) are formed. The surface fine concavo-convex sheet in which the wavy concavo-convex pattern (2A) is formed on one surface and the apex angle variation type modified pentahedral pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L4) is used as a stamper instead of the original plate (L1).
The other points are the same as in the second embodiment.

[Eighteenth embodiment]
The surface fine concavo-convex sheet of this embodiment example is the third embodiment example only in that the apex angle variation type deformed pentahedron pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Is different. Similarly to the surface fine uneven sheet according to the third embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as explained in the sixteenth embodiment, the apex-variable deformable pentahedron pattern can be launched by allowing the light from the point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

  The surface fine concavo-convex sheet of the present embodiment also has an angle between the main diffusion direction of the undulating concavo-convex pattern and one of the above two directions of the apex angle variation type deformable pentahedral pattern, that is, the intersection angle is undulating undulation. When the pattern is viewed in plan, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the third embodiment.
However, in the above-mentioned step (a2), instead of manufacturing the original plate (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal of the vertex angle variation type pentahedron pattern) A master (L4) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface of the original plate (W) (the transfer shape of the wavy uneven pattern (1B) is formed) and the transfer shape of the original plate (L4) are formed. The surface fine unevenness in which a wave-like uneven pattern (1B) is formed on one surface and an apex angle variation type deformed pentahedral pattern is formed on the other surface by an injection molding method in which resin is injected between Get a sheet.
In the manufacturing method (B), the original plate (L4) is used as a stamper instead of the original plate (L1).
Other points are the same as in the third embodiment.

[Nineteenth embodiment]
The surface fine concavo-convex sheet of this embodiment example is the fourth embodiment example only in that the apex angle variation type deformed pentahedron pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Is different. Similarly to the surface fine uneven sheet according to the fourth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as explained in the sixteenth embodiment, the apex-variable deformable pentahedron pattern can be launched by allowing the light from the point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

  The surface fine concavo-convex sheet of the present embodiment also has an angle between the main diffusion direction of the undulating concavo-convex pattern and one of the above two directions of the apex angle variation type deformable pentahedral pattern, that is, the intersection angle is undulating undulation. When the pattern is viewed in plan, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fourth embodiment.
However, in the above-mentioned step (a2), instead of manufacturing the original plate (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal of the vertex angle variation type pentahedron pattern) A master (L4) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1C) is formed) and the transfer shape of the original plate (L4) are formed. A surface fine concavo-convex sheet in which a wavy concavo-convex pattern (1C) is formed on one surface and an apex angle variation type deformed pentahedral pattern is formed on the other surface by an injection molding method in which a resin is injected between Get.
In the manufacturing method (B), the original plate (L4) is used as a stamper instead of the original plate (L1).
Other points are the same as in the fourth embodiment.

[Example of 20th embodiment]
The surface fine concavo-convex sheet of the present embodiment example is the fifth embodiment example only in that the apex angle variation type deformed pentahedron pattern is formed on at least a part of the surface opposite to the wavy uneven pattern forming surface. Is different. Similarly to the surface fine uneven sheet according to the fifth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as explained in the sixteenth embodiment, the apex-variable deformable pentahedron pattern can be launched by allowing the light from the point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

  The surface fine concavo-convex sheet of the present embodiment also has an angle between the main diffusion direction of the undulating concavo-convex pattern and one of the above two directions of the apex angle variation type deformable pentahedral pattern, that is, the intersection angle is undulating undulation. When the pattern is viewed in plan, it is within a range of ± 20 °. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fifth embodiment.
However, in the above-mentioned step (a2), instead of manufacturing the original plate (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal of the vertex angle variation type pentahedron pattern) A master (L4) having a shape on the surface is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1D) is formed) and the transfer shape of the original plate (L4) are formed. A surface fine uneven sheet in which a wavy uneven pattern (1D) is formed on one surface and an apex angle variation type deformed pentahedral pattern is formed on the other surface by an injection molding method in which a resin is injected between the two surfaces Get.
In the manufacturing method (B), the original plate (L4) is used as a stamper instead of the original plate (L1).
The other points are performed in the same manner as in the fifth embodiment.

<21st to 25th Embodiment>
[Example of 21st embodiment]
The surface fine concavo-convex sheet of this embodiment example is the first embodiment only in that a Fresnel lens pattern which is a concentric concavo-convex pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. It is different from the example.

[Wavy uneven pattern]
In the present embodiment example, a wavy uneven pattern (1A) similar to that of the first embodiment example is formed.

[Concentric uneven pattern (Fresnel lens pattern)]
FIG. 22A is a cross-sectional view along the thickness direction of the Fresnel lens pattern 12E. The Fresnel lens is obtained by dividing the plano-convex lens region of FIG. 22B, has the same lens effect as the plano-convex lens, and can be reduced in thickness.
A plurality of Fresnel lens patterns 12E may be provided side by side as shown in FIG. 24 later on the other surface of the fine surface uneven sheet (surface opposite to the wave-shaped uneven pattern forming surface).

The operation of the Fresnel lens pattern 12E will be described with reference to FIG. FIG. 23 is a cross-sectional view of a sheet in which one surface is a concentric uneven pattern forming surface (lower surface in FIG. 23) on which a Fresnel lens pattern 12E is formed, and the other surface is a smooth surface 13.
When light from a point light source 21 such as an LED light source or a laser light source is incident on the Fresnel lens pattern 12E without passing through a condensing lens, the traveling vector of the light is the normal direction of the Fresnel lens pattern 12E ( The light is refracted so as to be parallel to the n direction in FIG. That is, the direction of light rises almost toward the front. The Fresnel lens pattern 12E has an effect of improving the front luminance by such a light collecting function.
Further, according to the Fresnel lens pattern 12E, the light from the point light source can be incident as it is without passing through the condensing lens 20 as described above, and can be started up. Therefore, according to the present embodiment, the number of members can be reduced and the thickness can be reduced in configuring the display unit illumination unit.

  The pitch of the convex ring 12e of the Fresnel lens pattern 12E, the inclination angle of the tip surface 12e 'of the convex ring 12e, and the like are designed according to the light irradiation angle. That is, preferably all the light from the point light source (the irradiation angle of the light emitted from the point light source is typically 120 ° (= ± 60 °), so that the positive direction is 0 to 60 ° and the negative direction. Are preferably refracted so as to be parallel to the normal direction of the Fresnel lens pattern 12E and emitted from the smooth surface 13.

  For example, the preferable pitch of the Fresnel lens pattern 12E (the distance in the direction along the top diameter of the convex rings) is preferably 5 to 500 μm. When the pitch is equal to or higher than the lower limit value of the above range, the Fresnel lens pattern 12E can be formed satisfactorily. Is not easily recognized as an undesirable bright line.

[Surface micro uneven sheet]
The surface fine concavo-convex sheet of this embodiment example has a wavy concavo-convex pattern formed on at least a part of one surface, and a concentric concavo-convex pattern formed on at least a part of the other surface corresponding to the part where the wavy concavo-convex pattern is formed. A Fresnel lens pattern 12E is formed.
Therefore, when the surface fine uneven sheet of the present embodiment example is used in combination with the light source array 21A in which a plurality of point light sources are formed side by side in a specific positional relationship, similarly to the first embodiment example. Provides a viewing angle ensuring effect and luminance unevenness eliminating effect by the wavy uneven pattern and a front luminance improving effect by the Fresnel lens pattern 12E. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained.

  The surface fine concavo-convex sheet of this embodiment may have a single layer structure or a multilayer structure composed of two or more layers. The preferred thickness is the same as that in the first embodiment.

[Method for manufacturing surface uneven surface sheet]
The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the first embodiment.
However, in the above-described step (a2), instead of manufacturing the original (L1) having the transfer shape (reversal shape) of the linear Fresnel lens pattern on the surface, the transfer shape (reversal shape) of the Fresnel lens pattern 12E is changed to the surface. The original plate (L5) is prepared. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (1A) is formed) and the transfer shape of the original plate (L5) are formed. The surface fine concavo-convex sheet in which the wavy concavo-convex pattern (1A) is formed on one surface and the Fresnel lens pattern is formed on the other surface is obtained by an injection molding method in which a resin is injected between the two surfaces. In the manufacturing method (B), the original plate (L5) is used as a stamper instead of the original plate (L1).
Other points are the same as in the first embodiment.

[Lighting unit for display device and display device]
FIG. 24 is a diagram schematically showing a configuration of a display unit illumination unit according to the present embodiment. FIG. 24A is a schematic plan view from the side of the wavy uneven pattern forming surface 11 of the surface fine uneven sheet 10H, and FIG. FIG. 24 (c) is a side view showing a side surface parallel to the extending direction of the ridges of the wavy uneven pattern (1A). In this example, the Fresnel lens pattern 12E includes ^three Fresnel lens patterns 12E ¹ , 12E ² , and 12E ³ .

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such an illumination unit for display device, the light emitted from each point light source 21 is incident on the concentric uneven pattern forming surface on which the Fresnel lens pattern 12E is formed. Then, as described above with reference to FIG. 23, the light is refracted so as to be parallel to the normal direction of the Fresnel lens pattern 12E (the normal direction of the surface fine uneven sheet).
The light refracted in this way passes through the inside of the surface fine uneven sheet 10H and is emitted from the waved uneven pattern forming surface 11. Of the light traveling vectors, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (direction A in FIG. 24) of the wavy uneven pattern (1A). Since the directions correspond to each other, the refraction mainly becomes components of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10H and a component inclined from the normal direction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet 10H contributes to the improvement of the front luminance. Further, when viewed from the wavy uneven pattern forming surface 11 side, luminance unevenness is caused by light parallel to the normal direction of the surface fine uneven sheet 10H in a portion where there is no light source such as between the point light source 21 and the point light source 21. A cancellation effect is obtained. Moreover, the component inclined from the normal line direction of the surface fine uneven sheet | seat 10H contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10H and the arrangement direction of the point light sources 21 of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 becomes large. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern (1A). Therefore, it is possible to suppress a decrease in luminance due to increasing the diffusion angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

Which surface side of the surface fine uneven sheet 10H the light source row 21A is arranged can be set according to the purpose. When the wavy uneven pattern (1A) is on the side opposite to the light source array 21A side, the luminance unevenness eliminating effect and the front luminance improving effect are high, and when the wavy uneven pattern (1A) is on the light source array 21A side, the viewing angle securing effect is achieved. Is expensive.
In addition, when the Fresnel lens pattern is adopted as compared with the apex variation type pentahedron pattern, it tends to be excellent in the effect of coexistence of luminance unevenness and front luminance.

[Twenty-second embodiment]
The surface fine concavo-convex sheet of this embodiment example is different from the second embodiment only in that a Fresnel lens pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Similarly to the surface fine uneven sheet according to the second embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display unit illumination unit and a display device. However, as described in the twenty-first embodiment, the Fresnel lens pattern can be launched by allowing light from a point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the second embodiment.
However, in the above-described step (a2), instead of manufacturing an original plate (L1) having a linear Fresnel lens pattern transfer shape (reverse shape) on the surface, the Fresnel lens pattern transfer shape (reverse shape) is provided on the surface. A master plate (L5) is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface on which the transfer shape of the original plate (W) (the transfer shape of the wavy uneven pattern (2A) is formed) and the transfer shape of the original plate (L5) are formed. By using an injection molding method in which a resin is injected between the two surfaces, a surface fine uneven sheet having a wavy uneven pattern (2A) formed on one surface and a Fresnel lens pattern formed on the other surface is obtained. In the manufacturing method (B), the original plate (L5) is used as a stamper instead of the original plate (L1).
The other points are the same as in the second embodiment.

[23rd Embodiment]
The surface fine concavo-convex sheet of the present embodiment example is different from the third embodiment example only in that a Fresnel lens pattern is formed on at least a part of the surface opposite to the wave-like concavo-convex pattern forming surface. Similarly to the surface fine uneven sheet according to the third embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as described in the twenty-first embodiment, the Fresnel lens pattern can be launched by allowing light from a point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the third embodiment.
However, in the above-described step (a2), instead of manufacturing an original plate (L1) having a linear Fresnel lens pattern transfer shape (reverse shape) on the surface, the Fresnel lens pattern transfer shape (reverse shape) is provided on the surface. A master plate (L5) is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface of the original plate (W) (the transfer shape of the wavy uneven pattern (1B) is formed) and the transfer shape of the original plate (L5) are formed. The surface fine concavo-convex sheet having the corrugated concavo-convex pattern (1B) formed on one surface and the Fresnel lens pattern formed on the other surface is obtained by an injection molding method in which a resin is injected between the surface.
In the manufacturing method (B), the original plate (L5) is used as a stamper instead of the original plate (L1).
Other points are the same as in the third embodiment.

[Twenty-fourth embodiment]
The surface fine concavo-convex sheet of the present embodiment example is different from the fourth embodiment only in that a Fresnel lens pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Similarly to the surface fine uneven sheet according to the fourth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as described in the twenty-first embodiment, the Fresnel lens pattern can be launched by allowing light from a point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fourth embodiment.
However, in the above-described step (a2), instead of manufacturing an original plate (L1) having a linear Fresnel lens pattern transfer shape (reverse shape) on the surface, the Fresnel lens pattern transfer shape (reverse shape) is provided on the surface. A master plate (L5) is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface of the original plate (W) (the transfer shape of the wavy uneven pattern (1C) is formed) and the transfer shape of the original plate (L5) are formed. The surface fine concavo-convex sheet having the corrugated concavo-convex pattern (1C) formed on one surface and the Fresnel lens pattern formed on the other surface is obtained by an injection molding method in which a resin is injected between the surface.
In the manufacturing method (B), the original plate (L5) is used as a stamper instead of the original plate (L1).
Other points are the same as in the fourth embodiment.

[Twenty-fifth embodiment]
The surface fine concavo-convex sheet of this embodiment example is different from the fifth embodiment only in that a Fresnel lens pattern is formed on at least a part of the surface opposite to the wavy concavo-convex pattern forming surface. Similarly to the surface fine uneven sheet according to the fifth embodiment, the surface fine uneven sheet according to this embodiment can also constitute a display device illumination unit and a display device. However, as described in the twenty-first embodiment, the Fresnel lens pattern can be launched by allowing light from a point light source to enter without passing through the condenser lens 20. Therefore, in the present embodiment example, it is preferable not to use a condensing lens. Moreover, when a condensing lens is not used, the number of members can be reduced and the thickness can be reduced when configuring the display unit illumination unit.

The surface fine concavo-convex sheet of the present embodiment can be manufactured roughly by the same production method as the surface fine concavo-convex sheet of the fifth embodiment.
However, in the above-described step (a2), instead of manufacturing an original plate (L1) having a linear Fresnel lens pattern transfer shape (reverse shape) on the surface, the Fresnel lens pattern transfer shape (reverse shape) is provided on the surface. A master plate (L5) is produced. The step (a2) can be performed by cutting the surface of a plate material such as a metal plate with a cutting tool (cutting tool).
In the step (a3), the surface of the original plate (W) (the transfer shape of the wavy uneven pattern (1D) is formed) and the transfer shape of the original plate (L5) are formed. The surface fine concavo-convex sheet having the wavy concavo-convex pattern (1D) formed on one surface and the Fresnel lens pattern formed on the other surface is obtained by an injection molding method in which a resin is injected between the surface.
In the manufacturing method (B), the original plate (L5) is used as a stamper instead of the original plate (L1).
The other points are performed in the same manner as in the fifth embodiment.

<Examples of 26th to 28th embodiments>
[Twenty-sixth embodiment]
The surface fine concavo-convex sheet of this embodiment example has a linear Fresnel lens pattern formed as a linear concavo-convex pattern on at least a part of one surface, and an irregular wavy concavo-convex pattern on at least a part of the linear concavo-convex pattern. As a result, the same wavy uneven pattern (1A) as in the first embodiment is formed. The other surface is a smooth surface. The angle between the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges of the linear uneven pattern is within a range of ± 20 ° when the wavy uneven pattern is viewed in plan.

In addition, as a wavy uneven | corrugated pattern, it replaces with the wavy uneven | corrugated pattern (1A) similar to 1st Embodiment, and the wavy uneven | corrugated pattern (1C) similar to 4th Embodiment may be formed. In the present embodiment, the waved uneven pattern is preferably the waved uneven pattern (1A) or (1C) from the viewpoint of ease of manufacture.
However, the wavy uneven patterns (2A), (1B), and (1D) may be employed depending on the purpose and the like. However, when the wavy uneven pattern (2A) is employed, since the pattern is a pattern in which unevenness that does not follow a specific direction is formed, the effect of the combined linear Fresnel lens pattern tends to be weakened. Therefore, it is preferable to select the type of wavy uneven pattern according to the ease of manufacture, purpose, and the like.

Moreover, although the surface fine uneven sheet | seat of this embodiment example is mentioned later in detail, it can manufacture roughly by the following processes.
That is, first, on one surface of the heat-shrinkable resin film, a hard layer composed of a cured ionizing radiation curable resin having a linear Fresnel lens pattern is provided, and the protrusions of the linear Fresnel lens pattern are extended. A laminated film in which the orientation direction and the direction of heat shrinkage of the heat-shrinkable resin film coincide is manufactured. And the surface fine uneven | corrugated sheet | seat of this embodiment is obtained by heat shrinking this laminated | multilayer film.
As described above, by deforming the hard layer on which the linear Fresnel lens pattern is formed in advance so as to be folded, a pattern in which an irregular wavy uneven pattern is formed on the linear Fresnel lens pattern can be formed.
The surface fine uneven sheet of this embodiment can also be obtained by using the surface fine uneven sheet thus obtained as an original plate and transferring the pattern forming surface an even number of times.

  Similarly to the surface fine uneven sheet according to the first embodiment, the surface fine uneven sheet according to the present embodiment can constitute a display device illumination unit and a display device. In the display device illumination unit and the display device of the present embodiment, it is preferable to arrange the light source array 21A on the smooth surface side as described later.

  The preferred range and method of obtaining the average pitch and aspect ratio of the ridges of the wavy uneven pattern (1A) are as described in the first embodiment.

The operation of the linear Fresnel lens pattern in this embodiment will be described with reference to FIG. Note that the operation of the linear Fresnel lens pattern has already been described with reference to FIG. 6, and FIG. 6 and FIG. 25 have different light incident surfaces. The same.
FIG. 25 shows a sheet in which one surface is the surface on which the linear Fresnel lens pattern 12A is formed (the upper surface in FIG. 25) and the other surface is the smooth surface 13. When light from a point light source such as an LED light source or a laser light source is incident on the smooth surface of the sheet through the condensing lens 20, the convex stripe portion of the linear Fresnel lens pattern 12 </ b> A among the light traveling vectors. The in-plane component consisting of the arrangement direction (m direction in the figure) and the normal direction (n direction in the figure) of the linear Fresnel lens pattern 12A formation surface is the normal direction (n in the figure) of the linear Fresnel lens pattern 12A formation surface Refracted so as to be parallel to (direction), and exits from the smooth surface 13. That is, the direction of light rises toward the front. The linear Fresnel lens pattern 12A has an effect of improving the front luminance by such a light collecting function.

  In the surface fine concavo-convex sheet of this embodiment, it is preferable that light is incident from the smooth surface side because the effect of eliminating luminance unevenness due to the wavy concavo-convex pattern is increased.

The pitch of the ridges 12a of the linear Fresnel lens pattern 12A, the inclination angle of the tip surface 12a ′ of the ridges 12a, and the like are designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, as in the case of the first embodiment, preferably all the light emitted from the condenser lens 20 is composed of the arrangement direction of the ridges 12a and the normal direction of the linear Fresnel lens pattern 12A formation surface. It is preferably designed so that the in-plane component is refracted and emitted from the smooth surface 13 in parallel with the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed.
For example, the pitch of the ridges 12a of the linear Fresnel lens pattern 12A is preferably 5 to 500 μm, and more preferably 5 to 100 μm. If the pitch is within the above range, the linear Fresnel lens pattern 12A can be easily formed.

  The irradiation angle of the light emitted from the condenser lens 20 is preferably 2 to 50 °, more preferably 5 to 40 °, and still more preferably 10 to 30 °. When the irradiation angle is equal to or greater than the lower limit of the above range, the light emitted from the condenser lens 20 is sufficiently spread, and the uneven brightness of the light emitted from the surface fine uneven sheet is eliminated. When the irradiation angle is equal to or less than the upper limit of the above range, among the traveling vectors of the light emitted from the condenser lens 20, the arrangement direction of the ridges of the linear Fresnel lens pattern 12A and the method of forming the linear Fresnel lens pattern 12A It has a sufficient effect of refracting the in-plane component consisting of the linear direction so as to be parallel to the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed, and is excellent in the front luminance improvement effect.

The surface fine concavo-convex sheet of this embodiment example is an angle formed by the main diffusion direction of the wavy concavo-convex pattern and the extending direction of the ridges of the linear Fresnel lens pattern, that is, when the crossing angle is a plan view of the wavy concavo-convex pattern In the range of ± 20 °.
Therefore, when the surface fine uneven sheet of the present embodiment example is used in combination with a light source array formed by arranging a plurality of point light sources in a specific positional relationship as in the first embodiment example. The effect of ensuring the viewing angle and the effect of eliminating the uneven brightness by the wavy uneven pattern and the effect of improving the front brightness by the linear Fresnel lens pattern 12A are obtained. As a result, front luminance is suppressed while suppressing the difference in luminance (brightness unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources, which is likely to be noticeable when the light source array as described above is used. Can also be suppressed. In addition, a viewing angle securing effect can be obtained. The crossing angle is preferably within a range of ± 10 °, more preferably within a range of ± 5 °, and further preferably 0 °.

  The surface fine concavo-convex sheet of this embodiment may have a single layer structure or a multilayer structure composed of two or more layers. The preferred thickness is the same as that in the first embodiment.

The surface fine concavo-convex sheet of the present embodiment can be produced, for example, by a production method (X) having the following step (x1) and step (x2).
Step (x1):
A hard layer having a linear Fresnel lens pattern is provided on one surface of the heat-shrinkable resin film, and the extending direction of the ridges of the linear Fresnel lens pattern and the direction of heat-shrinkage of the heat-shrinkable resin film are The process of obtaining the laminated film which corresponds.
Step (x2):
A process of obtaining a surface fine concavo-convex sheet having a wavy concavo-convex pattern (1A) formed on a linear Fresnel lens pattern by deforming the hard layer by folding the heat-shrinkable resin film by heating the laminated film. .

In the production method (X), the step (x3) and the step (x4) may be performed after the step (x1) and the step (x2).
Step (x3):
An uncured ionizing radiation curable resin is applied to the pattern forming surface of the surface fine uneven sheet obtained in the step (x2), and a substrate such as PET is disposed thereon. Next, after irradiating with ionizing radiation and curing, the surface fine concavo-convex sheet is peeled off, and the primary transfer in which the concavo-convex transfer shape (reversal shape) in which the wavy concavo-convex pattern is formed on the linear Fresnel lens pattern is formed. A process of obtaining a product (stamper). The uncured ionizing radiation curable resin is applied by a coater such as a T-die coater, a roll coater, or a bar coater so as to be within a thickness of, for example, 3 to 30 μm.
In the step (x3), a metal such as nickel is deposited on the pattern forming surface of the surface fine uneven sheet obtained in the step (x2) by a known electroforming method, and then the metal is peeled off. A metal primary transfer product (stamper) in which a concavo-convex transfer shape (reversal shape) in which a wavy concavo-convex pattern is formed on a linear Fresnel lens pattern may be obtained.
Step (x4):
Separately prepare a transparent base material made of PET or the like, apply an uncured ionizing radiation curable resin on one side, and apply the process (on the uncured ionizing radiation curable resin layer) a step of pressing the surface of the primary transfer product obtained in x3) on which the above-mentioned transfer shape is formed, irradiating and curing with ionizing radiation in that state, and then peeling the primary transfer product. Here, the thickness of applying the uncured ionizing radiation curable resin is set to a thickness that sufficiently covers the unevenness of the uneven transfer shape in the primary transfer product.

As described above, by using the primary transfer product as a stamper, a transparent base material made of PET or the like and a transparent ionizing radiation curable resin cured material layer formed on one surface thereof are used. A structured surface fine uneven sheet is obtained. The stamper is not limited to the primary transfer product, and may be obtained by further repeating the transfer.
Further, in step (x3), a metal primary transfer product (stamper) is obtained, and injection molding is performed in which a resin is injected between the surface on which the transfer shape of the stamper is formed and the metal smooth surface. By the method, it is also possible to obtain a surface fine uneven sheet in which a wavy uneven pattern (1A) is formed on a linear Fresnel lens pattern.

In the step (x1), a uniaxially stretched film is used as the heat-shrinkable resin film. Preferred modes and ranges such as the material (resin L), shrinkage rate, glass transition temperature of resin, Young's modulus and the like are the same as those in the first embodiment. As the heat-shrinkable resin film, a translucent (transparent) film is used.
Next, with a coater such as a die coater, roll coater, or bar coater, one or more of uncured transparent ionizing radiation curable resins are coated on one side of the heat-shrinkable resin film to form a coating layer. . Then, prepare a stamper having a linear Fresnel lens pattern transfer shape on the surface, press the stamper against the coating layer, and in that state, irradiate ionizing radiation from the heat-shrinkable resin film side, and ionizing radiation curable The resin is cured to form a cured layer. Thereafter, the stamper is peeled off.
At this time, the stamper is pressed so that the extending direction of the ridges in the stamper coincides with the direction of heat shrinkage of the heat-shrinkable resin film.
Thereby, the laminated film which has the hard layer in which the linear Fresnel lens pattern was formed in the single side | surface of a heat-shrinkable film is obtained.
In addition, what is necessary is just to mix | blend the particle | grains demonstrated in the 4th Embodiment example with uncured transparent ionizing radiation curable resin, when forming the waveform uneven | corrugated pattern (1C) demonstrated in the 4th Embodiment example.

As the uncured ionizing radiation curable resin, those exemplified in the production method (B) of the first embodiment can be suitably used. In particular, the glass transition temperature after curing is a heat shrinkable resin film. A resin having a temperature higher by 10 ° C. or more than the constituent resin L and a Young's modulus of 0.01 to 300 GPa, preferably 0.1 to 10 GPa is suitable.
The thickness of the cured layer is preferably more than 0.5 μm and not more than 20 μm, and more preferably 1 to 10 μm.
If the glass transition temperature and Young's modulus satisfy the above conditions and the thickness of the cured layer is within the above range, the average pitch of the wavy uneven pattern (1A) in this embodiment can be easily adjusted within the above range. . When the thickness of the cured layer is less than or equal to the lower limit of the above range, the average pitch of the wavy uneven pattern (1A) tends to be too small, and when the upper limit of the above range is exceeded, the heat shrinkable resin film shrinks. It is obstructed and the wavy uneven pattern (1A) tends not to be formed well.

  The ionizing radiation curable resin is preferably diluted with a solvent or the like. Moreover, you may add a fluororesin, a silicone resin, etc. to uncured ionizing radiation curable resin. When the uncured ionizing radiation curable resin is ultraviolet curable, it is preferable to add a photopolymerization initiator such as acetophenones and benzophenones to the uncured ionizing radiation curable resin.

Also, instead of ionizing radiation curable resin, transfer is performed using, for example, thermosetting resin such as uncured melamine resin, urethane resin or epoxy resin, or thermoplastic resin such as acrylic resin, polyolefin or polyester. As long as transfer is possible, the specific method and material to be transferred are not limited.
In the case of using a thermosetting resin, for example, a method of applying a liquid uncured thermosetting resin and curing by heating can be mentioned. When using a thermoplastic resin, a sheet of thermoplastic resin is used, There may be mentioned a method of heating and softening while pressing against the surface of the transfer object and then cooling.

  A stamper having a linear Fresnel lens pattern transfer shape on the surface can be manufactured in the same manner as in step (a2) in the first embodiment.

[Lighting unit for display device and display device]
FIG. 26 is a diagram schematically showing a configuration of a display unit illumination unit according to the present embodiment. FIG. 26 (a) is a schematic plan view from the pattern forming surface side of the surface fine uneven sheet 10I, and FIG. 26 (b) is a side view showing a side surface parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A). FIG. 26C is a side view showing a side surface parallel to the arrangement direction of the ridges 12a of the linear Fresnel lens pattern.

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such a display device illumination unit, as in the case of the first embodiment, the light emitted from each point light source is collected by the condenser lens 20 and enters the smooth surface 13. Then, as described above with reference to FIG. 25, the in-plane consisting of the arrangement direction of the ridges of the linear Fresnel lens pattern 12A and the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed out of the light traveling vector. The component is refracted so as to be parallel to the normal direction of the surface on which the linear Fresnel lens pattern 12A is formed.
The light refracted in this manner passes through the inside of the surface fine unevenness sheet 10 </ b> I and exits from the smooth surface 13. In the light traveling vector, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 26) of the wavy uneven pattern (1A). Since the directions correspond to each other, the refraction mainly becomes a component of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10I and a component inclined from the normal direction due to refraction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet contributes to the improvement of the front luminance. In addition, when viewed from the pattern forming surface side, light that is parallel to the normal direction of the surface fine uneven sheet 10I is generated in a portion where no light source exists such as between the point light source 21 and the point light source 21, thereby having an effect of eliminating luminance unevenness. can get. Moreover, the component inclined from the normal line direction of the surface fine uneven sheet | seat 10I contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10I and the arrangement direction of the point light sources of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 increases. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern. It is possible to suppress a decrease in luminance caused by increasing the angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

[Twenty-seventh embodiment]
The surface fine concavo-convex sheet of the present embodiment example is the only point that the pattern forming surface is formed with the constant apex angle type linear triangular prism pattern described in the sixth embodiment instead of the linear Fresnel lens pattern. 26 different from the embodiment example. Similarly to the surface fine uneven sheet of the twenty-sixth embodiment, the surface fine uneven sheet of the present embodiment example can constitute a display device illumination unit and a display device.

  The preferred range and method of obtaining the average pitch and aspect ratio of the ridges of the wavy uneven pattern (1A) are as described in the first embodiment.

The operation of the constant apex angle type linear triangular prism pattern in this embodiment will be described with reference to FIG. Note that the operation of the fixed vertex angle type linear triangular prism pattern 12B has already been described with reference to FIG. 16, and in FIG. 16 and FIG. 27, the light incident surface is different. But the action is the same.
FIG. 27 shows a sheet in which one surface is a surface (an upper surface in FIG. 27) on which the fixed vertex angle type linear triangular prism pattern 12 </ b> B is formed and the other surface is the smooth surface 13. When light from a point light source 21 such as an LED light source or a laser light source is made incident on the smooth surface 13 of the sheet through a condenser lens 20, a constant vertex angle type linear triangular prism among the light traveling vectors. The in-plane component consisting of the direction of arrangement of the ridges 12b of the pattern 12B (m direction in the figure) and the normal direction (n direction in the figure) of the surface on which the fixed triangular prism prism pattern 12B is formed is a constant vertical angle type. The light is refracted so as to be within a range of ± 10 ° from the normal direction (n direction in the figure) of the surface on which the linear triangular prism pattern 12B is formed, and is emitted from the smooth surface 13. That is, the direction of light rises toward the front. The fixed vertex angle type linear triangular prism pattern 12B has an effect of improving the front luminance by such a light collecting function.

  In the surface fine concavo-convex sheet of this embodiment, as shown in FIG. 27, it is preferable that light is incident from the smooth surface 13 side in terms of increasing the luminance unevenness eliminating effect due to the wavy concavo-convex pattern.

The pitch or the like of the ridges 12b of the fixed vertex angle type linear triangular prism pattern 12B is designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, as in the case of the sixth embodiment, the arrangement direction of the ridges 12b of the linear vertex prism pattern 12B and the constant vertex angle type of the light emitted from the condenser lens 20, preferably all light rays, are preferable. The in-plane component consisting of the linear triangular prism pattern 12B forming surface) is refracted so as to be within ± 10 ° with respect to the normal direction of the constant triangular apex linear triangular prism pattern 12B forming surface 13 It is preferably designed to exit from.
For example, the pitch of the ridges 12b of the constant vertex angle type linear triangular prism pattern 12B is preferably 5 to 500 μm, and more preferably 5 to 100 μm. If the pitch is within the above range, a constant vertex angle type linear triangular prism pattern can be easily formed.

The surface fine concavo-convex sheet of this embodiment example can be manufactured roughly by the same production method (X) as the surface fine concavo-convex sheet of the twenty-sixth embodiment example. Further, the injection molding method described in the twenty-sixth embodiment may be employed.
However, in the above-described step (x1), instead of forming the hard layer having the linear Fresnel lens pattern formed on the surface, the hard layer having the constant apex angle type linear triangular prism pattern is formed.
A stamper having the transfer shape of the linear triangle prism pattern having a constant apex angle on the surface can be manufactured in the same manner as in the step (a2) in the sixth embodiment.
Other points are the same as in the twenty-sixth embodiment.

[Lighting unit for display device and display device]
FIG. 28 is a diagram schematically showing a configuration of a display unit illumination unit according to the present embodiment. FIG. 28A is a schematic plan view from the pattern forming surface side of the surface fine uneven sheet 10J, and FIG. (C) is a side view showing a side surface parallel to the arrangement direction of the ridges 12b of the constant vertex angle type linear triangular prism pattern.

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such a display device illumination unit, as in the case of the first embodiment, the light emitted from each point light source is collected by the condenser lens 20 and enters the smooth surface 13. Then, as described above with reference to FIG. 27, of the traveling vectors of light, the arrangement direction of the ridges 12b of the constant vertex angle type linear triangular prism pattern 12B and the surface on which the constant vertex angle type linear triangular prism pattern 12B is formed. The in-plane component consisting of the normal direction is refracted so as to be within ± 10 ° with respect to the normal direction (normal direction of the surface fine concavo-convex sheet) of the surface on which the fixed vertical angle linear triangular prism pattern 12B is formed.
The light refracted in this way passes through the inside of the surface fine unevenness sheet 10 </ b> J and exits from the smooth surface 13. Of the traveling vector of light, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 28) of the wavy uneven pattern (1A). Since the directions correspond to each other, the components mainly have various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10J and a component inclined from the normal direction due to refraction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet 10J contributes to the improvement of the front luminance. In addition, when viewed from the wavy uneven pattern forming surface side, light that is parallel to the normal direction of the surface fine uneven sheet is generated in a portion where no light source exists, such as between a point light source and a point light source. It is done. Moreover, the component inclined from the normal line direction of the surface fine uneven sheet | seat 10J contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet and the arrangement direction of the point light sources in the light source array 21A are within a range of ± 20 ° when viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 is increased. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern. It is possible to suppress a decrease in luminance caused by increasing the angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

[Twenty-eighth embodiment]
The surface fine concavo-convex sheet of the present embodiment example has a vertex angle variation type linear triangular prism pattern similar to that described in the eleventh embodiment example instead of the linear Fresnel lens pattern on the pattern forming surface. However, this is different from the twenty-sixth embodiment. Similarly to the surface fine uneven sheet of the twenty-sixth embodiment, the surface fine uneven sheet of the present embodiment example can constitute a display device illumination unit and a display device.

The surface fine concavo-convex sheet of this embodiment example can be manufactured roughly by the same production method (X) as the surface fine concavo-convex sheet of the twenty-sixth embodiment example. Further, the injection molding method described in the twenty-sixth embodiment may be employed.
However, in the above-described step (x1), instead of forming a hard layer having a linear Fresnel lens pattern on the surface, a hard layer on which an apex angle varying linear triangular prism pattern is formed is formed.
Other points are the same as in the twenty-sixth embodiment.

  The preferred range and method of obtaining the average pitch and aspect ratio of the ridges of the wavy uneven pattern (1A) are as described in the first embodiment.

The operation of the apex angle varying linear triangular prism pattern 12C in this embodiment will be described with reference to FIG. The operation of the apex angle variation type linear triangular prism pattern has already been described with reference to FIG. 18C, and FIG. 18C and FIG. 29 have different light incident surfaces. However, the action is the same regardless of which is incident.
FIG. 29 shows a sheet in which one surface is a surface (an upper surface in FIG. 29) on which the apex angle variation type linear triangular prism pattern is formed and the other surface is the smooth surface 13. When light from a point light source such as an LED light source or a laser light source is made incident on the smooth surface 13 of the sheet through a condenser lens 20, an apex angle variation type linear triangular prism pattern among the light traveling vectors. The in-plane component formed by the arrangement direction of the 12C ridges 12c and the normal direction of the apex angle varying linear triangular prism pattern 12C is parallel to the normal direction of the apex angle varying linear triangular prism pattern 12C forming surface. The light is refracted and emitted from a smooth surface. That is, the direction of light rises toward the front. The vertex angle variation type linear triangular prism pattern 12C has an effect of improving the front luminance by such a condensing function.

  In the surface fine uneven sheet of the present embodiment example, as shown in FIG. 29, it is preferable that light is incident from the smooth surface side because the effect of eliminating luminance unevenness due to the wavy uneven pattern is increased.

The pitch or the like of the ridges 12c of the apex angle varying linear triangular prism pattern 12C is designed according to the irradiation angle of the light emitted from the condenser lens 20. That is, as in the case of the eleventh embodiment, the arrangement direction of the ridges of the apex angle varying linear triangular prism pattern and the apex angle varying linear triangle are preferably set for all the light emitted from the condenser lens 20. The in-plane component consisting of the normal direction of the prism pattern 12C is refracted so as to be parallel to the normal direction of the surface on which the apex angle variation type linear triangular prism pattern 12C is formed and is emitted from the smooth surface 13. It is preferable.
For example, the pitch of the ridges 12c of the apex-variable linear triangular prism pattern 12C is preferably 5 to 500 μm, and more preferably 5 to 100 μm. When the pitch is within the above range, the apex angle variation type linear triangular prism pattern 12C can be easily formed.

The surface fine concavo-convex sheet of this embodiment example can be manufactured roughly by the same production method (X) as the surface fine concavo-convex sheet of the twenty-sixth embodiment example. Further, the injection molding method described in the twenty-sixth embodiment may be employed.
However, in the above-mentioned step (x1), instead of forming the hard layer having the linear Fresnel lens pattern formed on the surface, the hard layer having the apex angle varying linear triangular prism pattern is formed.
The stamper having the transfer shape of the apex angle variation type linear triangular prism pattern on the surface can be manufactured in the same manner as the step (a2) in the eleventh embodiment.
Other points are the same as in the twenty-sixth embodiment.

[Lighting unit for display device and display device]
FIG. 30 is a diagram schematically showing a configuration of a display unit illumination unit according to the present embodiment. 30A is a schematic plan view from the pattern forming surface side of the surface fine uneven sheet, and FIG. 30B is a side view showing a side surface parallel to the arrangement direction of the ridges 12a of the wavy uneven pattern 1A. c) is a side view showing a side surface parallel to the arrangement direction of the ridges 12c of the apex angle variation type linear triangular prism pattern.

  The illumination unit for display device in the illustrated example has the same configuration as that of the first embodiment except that the surface fine uneven sheet includes the surface fine unevenness sheet, and the preferred embodiment is also the same.

In such a display device illumination unit, as in the case of the first embodiment, the light emitted from each point light source is collected by the condenser lens 20 and enters the smooth surface 13. Then, as described above with reference to FIG. 29, among the light traveling vectors, the arrangement direction of the ridges 12c of the apex angle varying linear triangular prism pattern 12C and the apex angle varying linear triangular prism pattern 12C method The in-plane component consisting of the line direction (the normal direction of the surface fine uneven sheet) is parallel to the normal direction (the normal direction of the surface fine uneven sheet) of the surface on which the apex angle variation linear triangular prism pattern 12C is formed. Refracts into.
The light refracted in this way is transmitted through the surface fine uneven sheet 10 </ b> K and emitted from the smooth surface 13. Of the traveling vector of light, the component parallel to the arrangement direction of the ridges 11a of the wavy uneven pattern (1A) is in the main diffusion direction (A direction in FIG. 30) of the wavy uneven pattern (1A). Since the directions correspond to each other, the refraction mainly becomes components of various angles such as a component parallel to the normal direction of the surface fine uneven sheet 10K and a component inclined from the normal direction. On the other hand, the component parallel to the extending direction of the ridges 11a of the wavy uneven pattern (1A) is mainly in the normal direction because this direction corresponds to the low diffusion direction of the wavy uneven pattern (1A). It becomes a parallel component.
The light parallel to the normal direction of the surface fine uneven sheet 10K contributes to the improvement of the front luminance. Further, when viewed from the pattern forming surface side, light that is parallel to the normal direction of the surface fine uneven sheet 10K is generated in a portion where there is no light source such as between the point light source and the point light source, thereby obtaining a luminance unevenness eliminating effect. . Moreover, the component inclined from the normal line direction of the surface fine uneven sheet | seat 10K contributes to expansion of a viewing angle.
As described above, the illumination unit for display device according to the present embodiment is excellent in front luminance, uneven luminance is suppressed, and has an appropriate viewing angle in the main diffusion direction and the low diffusion direction.

In particular, when the main diffusion direction of the wavy uneven pattern (1A) of the surface fine uneven sheet 10K and the arrangement direction of the point light sources of the light source array 21A are viewed in plan as shown in FIG. Therefore, the diffusion angle in the arrangement direction of the point light sources 21 increases. Thereby, the difference in luminance (brightness unevenness) between the position where the point light source 21 is present and the position where there is no light source between the point light sources 21 can be effectively suppressed. On the other hand, for the direction orthogonal to the arrangement direction of the point light sources 21 in many cases where the demand for suppressing luminance unevenness is not large, the diffusion angle is appropriately suppressed by corresponding to the low diffusion direction of the wavy uneven pattern. It is possible to suppress a decrease in luminance caused by increasing the angle.
Since the lighting unit for display device of this embodiment has such characteristics, it is a head-up that clearly displays image information such as traveling speed on the windshield of an automobile formed in a gently curved shape while diffusing image information. Suitable for use in display devices such as display systems.

In the twenty-sixth to twenty-eighth embodiments, the form in which the wavy uneven pattern is formed on the linear uneven pattern is shown in terms of ease of manufacture and the like. However, depending on the purpose or the like, a pentahedral pattern may be formed instead of the linear uneven pattern, and a wavy uneven pattern may be formed thereon. In that case, an angle formed by the main diffusion direction of the wavy uneven pattern and one of the two directions of the pentahedral pattern is set within a range of ± 20 °.
Further, instead of the linear uneven pattern, a concentric uneven pattern may be formed, and a wavy uneven pattern may be formed thereon.

<Effect>
As described above, as described with reference to each embodiment, according to the surface fine uneven sheet according to the present invention, it has an irregular wavy uneven pattern, a linear uneven pattern, a pentahedral pattern, or a concentric uneven pattern. Therefore, it is possible to configure an illumination unit that has excellent front luminance, suppresses luminance unevenness, and has an appropriate viewing angle not only in the main diffusion direction but also in the low diffusion direction orthogonal thereto.
In particular, since the main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet and the arrangement direction of the point light sources of the light source array are within a range of ± 20 ° when the wavy uneven pattern is viewed in plan view, The diffusion angle in the arrangement direction increases. Thereby, the difference in luminance (luminance unevenness) between the position where the point light source is present and the position where there is no light source between the point light sources can be effectively suppressed. On the other hand, for the direction perpendicular to the arrangement direction of the point light sources, in many cases, the demand for luminance unevenness suppression is not large, by appropriately suppressing the diffusion angle by corresponding the low diffusion direction of the wavy uneven pattern, the diffusion angle It is possible to suppress a decrease in luminance due to an increase in.
Moreover, the surface fine uneven sheet | seat of each embodiment is a 1 sheet structure. Therefore, it is possible to achieve a viewing angle securing effect, a luminance unevenness eliminating effect, and a front luminance improving effect with only one sheet without using a plurality of separate sheets, and it is excellent in handling and thinning of the lighting unit. .
When configuring the illumination unit for a display device and the display device, which of the embodiment examples of the surface fine uneven sheet of each embodiment is selected depends on the main diffusion direction and low diffusion required for the display device. It can be determined according to the viewing angle of the direction, the balance of these viewing angles, the front luminance, and the degree of demand for suppressing luminance unevenness.

  Hereinafter, the present invention will be specifically described by way of examples.

Example 1
[Nickel secondary master with wavy uneven pattern]
The following coating liquid (1) was applied to one side of a polyethylene terephthalate uniaxial heat-shrinkable film (“SC-807” manufactured by Toyobo Co., Ltd., thickness: 30 μm, glass transition temperature Tg ₁ = 75 ° C.) after coating and drying. Coating was performed with a bar coater (Meyer bar # 22) so that the thickness t ′ of the hard layer was 4 μm to obtain a laminated sheet.

Coating liquid (1):
Acrylic resin A (glass transition temperature Tg _2M = 128 ° C.) was added to toluene to obtain a coating liquid (1) having a solid content concentration of 12% by mass. In addition, although the said acrylic resin A is solid content concentration 23 mass%, the mass ratio and density | concentration in this example are the values calculated by the net amount (solid content amount). The following examples are also calculated with the net amount.

Next, the laminated sheet is heated at 125 ° C. for 1 minute using a hot air oven to heat-shrink the polyethylene terephthalate uniaxial heat-shrinkable film to 55% of the length before heating (45% deformation rate). ), The hard layer was deformed to be folded. Thus, a wavy uneven pattern sheet (original) having a wavy uneven pattern formed on the surface of the layer was obtained. The formed wavy uneven pattern was a wavy uneven pattern (1A), and the ridges were meandering but irregularly formed, although each was substantially parallel.
The average pitch of the ridges determined by image analysis of the Fourier transform image was 17 μm, and the average height determined by the method described in paragraph [0039] was 6 μm.
Next, nickel was deposited to a thickness of 500 μm on the surface of the obtained wavy uneven pattern sheet (original plate) by nickel electroforming. Next, the deposited nickel was peeled off from the corrugated uneven pattern sheet (original plate) to obtain a nickel secondary original plate in which the corrugated unevenness of the corrugated uneven pattern sheet was transferred to the surface.

[Original of linear uneven pattern]
An inversion pattern of a linear Fresnel lens pattern with a focal length of 25 mm and a pitch of 0.1 mm is applied to an injection mold in a range of 55 mm in the horizontal direction (extension direction of the ridges) × 25 mm in the vertical direction (arrangement direction of the ridges). An injection mold (original) was formed by cutting to form a linear concavo-convex pattern.

[Surface micro uneven sheet]
The nickel secondary original plate of the wavy uneven pattern is arranged so that the uneven pattern faces the mold of the injection molding machine in which the reverse pattern of the linear uneven pattern is formed, and the main diffusion direction of the wavy uneven pattern (Determined by the method described in paragraph [0023].) And the extending direction of the ridges of the linear concavo-convex pattern are incorporated in parallel, injection molding of acrylic resin is performed, and the surface fine concavo-convex sheet (injection molding Product).
The obtained injection-molded product is a rectangular parallelepiped having a width of 55 mm × length of 25 mm × thickness of 2 mm, and a wavy uneven pattern in which the surface unevenness of the nickel secondary original is transferred to one surface of a pair of 55 mm × 25 mm surfaces As a result, a linear concavo-convex pattern in which the surface concavo-convex of the injection mold was transferred was formed on the other surface. Further, the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges of the linear uneven pattern were parallel to the lateral direction.

(Example 2)
[Nickel secondary master with wavy uneven pattern]
The following coating liquid (2) was coated on one side of a polyethylene terephthalate biaxial heat-shrinkable film ("PX-40S" manufactured by Mitsubishi Plastics Co., Ltd., thickness: 25 μm, glass transition temperature Tg ₁ = 75 ° C). The subsequent hard layer was coated with a bar coater (Meyer bar # 22) so that the thickness t ′ was 4 μm to obtain a laminated sheet.

Coating liquid (2):
Acrylic resin B (glass transition temperature Tg _2M = 100 ° C.) was added to toluene to obtain a coating liquid (2) having a solid content concentration of 10% by mass.

Next, the laminated sheet is heated at 95 ° C. for 1 minute using a hot air oven to heat-shrink the polyethylene terephthalate biaxial heat-shrinkable film in one direction to 50% of the length before heating (deformation) 50%), and in the other direction substantially orthogonal to one direction, it was thermally shrunk to 85% of the length before heating (15% as the deformation rate) and deformed so that the hard layer was folded. Thus, a wavy uneven pattern sheet (original) having a wavy uneven pattern formed on the surface of the layer was obtained. The formed wavy uneven pattern was a wavy uneven pattern (2A), and the formed ridges meandered and were irregularly formed not along a specific direction.
The average pitch of the ridges determined by image analysis of the Fourier transform image was 20 μm, and the average height determined by the method described in paragraph [0039] was 6 μm.
Next, nickel was deposited to a thickness of 500 μm on the surface of the obtained wavy uneven pattern sheet (original plate) by nickel electroforming. Next, the deposited nickel was peeled off from the corrugated uneven pattern sheet (original plate) to obtain a nickel secondary original plate in which the corrugated unevenness of the corrugated uneven pattern sheet was transferred to the surface.

[Original of linear uneven pattern]
In the same manner as in Example 1, an injection mold (original plate) for forming a linear uneven pattern was obtained.

[Surface micro uneven sheet]
The nickel secondary original plate of the wavy uneven pattern is arranged so that the uneven pattern faces the mold of the injection molding machine in which the reverse pattern of the linear uneven pattern is formed, and the main diffusion direction of the wavy uneven pattern (Determined by the method described in paragraph [0023].) And the extending direction of the ridges of the linear concavo-convex pattern are incorporated in parallel, injection molding of acrylic resin is performed, and the surface fine concavo-convex sheet (injection molding Product).
The obtained injection-molded product is a rectangular parallelepiped having a width of 55 mm × length of 25 mm × thickness of 2 mm, and a wavy uneven pattern in which the surface unevenness of the nickel secondary original is transferred to one surface of a pair of 55 mm × 25 mm surfaces As a result, a linear concavo-convex pattern in which the surface concavo-convex of the injection mold was transferred was formed on the other surface. Further, the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges of the linear uneven pattern were parallel to the lateral direction.

(Example 3)
[Nickel secondary master with wavy uneven pattern]
The following coating liquid (3) is applied to one side of a polyethylene terephthalate uniaxial heat shrinkable film (“SC807” manufactured by Toyobo Co., Ltd., thickness: 30 μm, glass transition temperature Tg ₁ = 75 ° C.), and the hard layer after coating and drying The laminated sheet was obtained by coating with a bar coater (Meyer bar # 22) such that the thickness t ′ of the film was 4 μm.

Coating liquid (3):
Acrylic resin A (glass transition temperature Tg _2M = 128 ° C.) and acrylic cross-linked resin particles having a particle diameter d of 5 μm (“SSX105” manufactured by Sekisui Plastics Co., Ltd., Vicat softening temperature 200 ° C. or higher) It mixed by solid content mass ratio 90:10, and in addition to toluene, the coating liquid (3) with a solid content density | concentration of 7.7 mass% was obtained.

Next, the laminated sheet is heated in a hot air oven at 125 ° C. for 1 minute to heat-shrink the polyethylene terephthalate uniaxial heat-shrinkable film to 60% of the length before heating in the uniaxial direction (deformation rate). 40%), the hard layer was deformed to be folded. As a result, a wavy uneven pattern sheet (original plate) was obtained in which a wavy uneven pattern having a wavy uneven pattern and a number of convex portions formed thereon was formed on the surface of the hard layer. Further, the formed wavy uneven pattern is a wavy uneven pattern (1C), and the wavy protruding portions are substantially parallel to each other, but meandered and irregularly formed, and on the protruding portions and between adjacent protruding portions. In addition, a plurality of convex portions protruding outward are randomly formed.
Moreover, the average pitch of the protrusions and the average diameter of the protrusions determined by image analysis of the Fourier transform image were 17 μm and 5 μm, respectively. Moreover, the average height of the protrusions and the average height of the protrusions determined by the methods described in Paragraph [0125] and Paragraph [0127] were 4 μm and 1.5 μm, respectively.
Next, nickel was deposited to a thickness of 500 μm on the surface of the obtained wavy uneven pattern sheet (original plate) by nickel electroforming. Next, the deposited nickel was peeled off from the corrugated uneven pattern sheet (original plate) to obtain a nickel secondary original plate in which the corrugated unevenness of the corrugated uneven pattern sheet was transferred to the surface.

[Original of linear uneven pattern]
In the same manner as in Example 1, an injection mold (original plate) for forming a linear uneven pattern was obtained.

[Surface micro uneven sheet]
The nickel secondary original plate of the wavy uneven pattern is arranged so that the uneven pattern faces the mold of the injection molding machine in which the reverse pattern of the linear uneven pattern is formed, and the main diffusion direction of the wavy uneven pattern (Determined by the method described in paragraph [0023].) And the extending direction of the ridges of the linear concavo-convex pattern are incorporated in parallel, injection molding of acrylic resin is performed, and the surface fine concavo-convex sheet (injection molding Product).
The obtained injection-molded product is a rectangular parallelepiped having a width of 55 mm × length of 25 mm × thickness of 2 mm, and a wavy uneven pattern in which the surface unevenness of the nickel secondary original is transferred to one surface of a pair of 55 mm × 25 mm surfaces As a result, a linear concavo-convex pattern in which the surface concavo-convex of the injection mold was transferred was formed on the other surface. Further, the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges of the linear uneven pattern were parallel to the lateral direction.

(Comparative Example 1)
[Nickel secondary master with wavy uneven pattern]
In the same manner as in Example 1, a nickel secondary original plate having a wavy uneven pattern was obtained.

[Original of linear uneven pattern]
A reversal pattern of a lenticular lens pattern with a lens pitch of 0.5 mm and a lens radius of 0.5 mm is formed by cutting on an injection mold to obtain an injection mold (original) for forming a linear uneven pattern. It was.

[Surface micro uneven sheet]
The nickel secondary original plate of the wavy uneven pattern is arranged so that the uneven pattern faces the mold of the injection molding machine in which the reverse pattern of the linear uneven pattern is formed, and the main diffusion direction of the wavy uneven pattern (Determined by the method described in paragraph [0023]) and the lenticular lens pattern so as to be parallel to the extending direction of the ridges, injection molding of acrylic resin, surface fine uneven sheet (injection molded product) )
The obtained injection-molded product is a rectangular parallelepiped having a width of 55 mm × length of 25 mm × thickness of 2 mm. A wavy uneven pattern is formed on one surface of a pair of 55 mm × 25 mm surfaces, and a lenticular lens pattern is formed on the other surface. It was. Further, the main diffusion direction of the wavy uneven pattern and the extending direction of the ridges of the lenticular lens pattern were parallel to the lateral direction.

(Comparative Example 2)
[Surface micro uneven sheet]
A surface fine uneven sheet (injection molded product) was obtained in the same manner as in Comparative Example 1 except that the wavy uneven pattern of Example 2 was used instead of the wavy uneven pattern of Example 1.

(Comparative Example 3)
[Surface micro uneven sheet]
A surface fine uneven sheet (injection-molded product) was obtained by the same method as in Comparative Example 1 except that the wavy uneven pattern of Example 3 was used instead of the wavy uneven pattern of Example 1.

(Evaluation)
Table 1 shows the diffusion angles in the main diffusion direction and the low diffusion direction of the wavy uneven pattern sheet (original plate) obtained in each of the above examples.
The diffusion angle was calculated according to the method described in paragraph [0023].

In addition, the front luminance when the surface fine uneven sheet obtained in each of the above examples is incorporated in a display device illumination unit suitable for use in a display device such as a head-up display system in the form shown in FIG. Front luminance unevenness and viewing angle were measured.
The measurement results are shown in Table 1.

Here, the display unit illumination unit condenses the light emitted from each white light emitting diode light source, the surface fine uneven sheet, the light source row formed by aligning the three white light emitting diode light sources in a straight line. And three condenser lenses provided for each white light emitting diode light source.
Here, the irradiation angle of the white light emitting diode is 120 °, the distance between the centers of the white light emitting diodes is 10 mm, and the distance from the condensing lens to the surface fine uneven sheet is 25 mm, and passes through the condensing lens. The irradiation angle of the emitted light from the subsequent white light emitting diode light source is 50 °.
The main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet, the extending direction of the ridges of the linear uneven pattern, and the arrangement direction of the white light emitting diode light sources in the light source array are all parallel.
In addition, a light source array is disposed on the surface of the surface fine concavo-convex sheet on the side of the linear concavo-convex pattern, and the light emitted from each white light-emitting diode light source is condensed by a condenser lens, and then the linear concavo-convex pattern formation surface Is emitted from the surface on which the wavy uneven pattern is formed.
The front luminance, front luminance unevenness, and viewing angle were measured using a luminance meter (“UA-1000” manufactured by TOPCON).

The front luminance was expressed as a relative value when the front luminance (cd / m ² ) when the surface fine uneven sheet of Example 1 was used for the display device illumination unit was 100%. If the luminance is 90% or more, it can be determined that sufficient luminance is obtained.
The front luminance unevenness is measured by measuring a front luminance distribution on a straight line passing through the center of each light source of the light source array and parallel to the arrangement direction of the light source array of the illumination unit for display device, and (minimum value / maximum value) × When 100 (%) was 50% or more, it was judged that a sufficient luminance unevenness eliminating effect was obtained.
The viewing angle is the “front luminance” at the center of the display unit illumination unit, “brightness when tilted by 15 ° diagonally in the main diffusion direction”, and “luminance when tilted by 7.5 ° diagonally in the low diffusion direction”. Measured respectively ("luminance when tilted obliquely 15 ° in the main diffusion direction" / "frontal luminance") x 100 (%) and ("luminance when tilted obliquely 7.5 ° in the low diffusion direction" / " It was judged that a sufficient viewing angle was obtained when the front luminance “) × 100 (%) was 20% or more.

According to each embodiment adopting a linear Fresnel lens pattern as a pattern combined with a wavy uneven pattern, the front luminance, the luminance unevenness suppressing effect, and the appropriate viewing angle (main diffusion direction and low diffusion direction) are provided in a well-balanced manner. It was.
According to each comparative example provided with a lenticular lens pattern instead of the linear Fresnel lens pattern, the diffusion angle in the low diffusion direction was large, and thus the front luminance was lowered.

10A, 10D, 10E, 10F, 10G, 10H, 10I, 10J, 10K: Surface fine unevenness sheet 11: Wavy unevenness pattern forming surface 12A: Linear Fresnel lens pattern 12B: Constant apex angle type linear triangular prism pattern 12C: Vertical angle variation Type linear triangular prism pattern 12D: vertical angle variation type modified pentahedral pattern 12E: Fresnel lens pattern

Claims (7)

At least a part of one surface has an irregular wavy uneven pattern, and at least a part of the other surface corresponding to the portion where the wavy uneven pattern is formed, a pentahedron whose bottom surface is a square or a rectangle, It is a surface fine uneven sheet having a pentahedral pattern formed repeatedly along two orthogonal directions,
The surface fine uneven sheet, wherein an angle formed between a main diffusion direction of the wavy uneven pattern and one of the two directions of the pentahedral pattern is within a range of ± 20 °.   At least part of one surface has an irregular wavy uneven pattern, and at least a part of the other surface corresponding to the part where the wavy uneven pattern is formed has a Fresnel lens pattern that is a concentric uneven pattern. , Surface fine uneven sheet. A surface fine concavo-convex sheet having a linear concavo-convex pattern on at least a part of one surface, and an irregular wavy concavo-convex pattern formed on at least a part of the linear concavo-convex pattern
The linear uneven pattern is a linear Fresnel lens pattern or a linear triangular prism pattern,
The surface fine concavo-convex sheet, wherein an angle formed between a main diffusion direction of the wavy concavo-convex pattern and an extending direction of the ridges of the linear concavo-convex pattern is within a range of ± 20 °. At least a part of one surface has a pentahedron pattern in which a bottom surface is a square or a rectangle and is repeatedly formed along two orthogonal directions. It is a surface fine uneven sheet on which a regular wavy uneven pattern is formed,
The surface fine uneven sheet, wherein an angle formed between a main diffusion direction of the wavy uneven pattern and one of the two directions of the pentahedral pattern is within a range of ± 20 °.   The surface fine uneven sheet | seat as described in any one of Claims 1-4 used for the use which refracts and diffuses the light from the light source row | line | column formed with a some point light source located in a line. The surface fine concavo-convex sheet according to any one of claims 1 to 5 and at least one row of light source rows formed by arranging a plurality of point light sources,
An illumination unit for a display device, wherein an angle formed between a main diffusion direction of the wavy uneven pattern of the surface fine uneven sheet and an arrangement direction of the point light sources of the light source array is within a range of ± 20 °.   A display device comprising the display device illumination unit according to claim 6.