KR20160040172A - External-light-utilizing display body - Google Patents

Abstract

By using the light diffusion film to be used as the light diffusion film having a predetermined internal structure in the external light utilization type display body formed by laminating the reflection plate and the light diffusion film, even if the incident angle of external light changes, Provided is an external light utilization type display body which can stably maintain a uniform luminance of display light within a viewing angle. A reflection plate and a light diffusion film, wherein the light diffusion film is an optical diffusion film having an internal structure having a plurality of regions having a relatively high refractive index in a region where the refractive index is relatively low in the film.

Description

EXTERNAL-LIGHT-UTILIZING DISPLAY BODY}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an external light-utilizing display body which exhibits a predetermined display function by using light incident from the outside.

In particular, the present invention relates to an external light utilization type display body which can stably maintain a constant display characteristic even when an incident angle of external light changes, and is excellent in uniformity of luminance of display light within a viewing angle.

Conventionally, an external light utilization type display body (hereinafter referred to as " display body ") which is formed by printing characters or images on a surface or a specular reflection surface having light diffusion characteristics, or by bonding transparent or translucent films printed with characters or images on these surfaces , An external light-use display body) is used as a signboard or a cover.

Such an external light-utilizing display body is characterized in that external light such as direct sunlight, diffused perforated light, or secondary scattered light from a dried object, road surface, tree or the like is used as a light source to scatter and emit a desired display light.

As such an external-light-utilizing display body, an external-light-use display body (for example, see Japanese Patent Application Laid-Open 1), a retroreflective external light-use type display body (for example, see Japanese Patent Application Laid-Open Publication 2) are known.

That is, as shown in Figs. 62 (a) and 62 (b), the patent document 1 discloses a signboard front surface As the plate 301, the central line average roughness of the uneven surface is 0.2 to 0.7 占 퐉, the 10-point average roughness is 1 to 7 占 퐉, and the translucent plate has the transparent substrate 302, A sign board front face plate 301 comprising a light diffusing layer 303 laminated and integrated on both sides and having an uneven surface formed on the surface of the light diffusing layer 303; And the display body 320 is disposed on the rear side of the display body 320. [

Further, as the light-diffusing layer described above, it is disclosed that a resin particle (light diffusion material) is dispersed in a synthetic resin.

62 (c), as the retroreflective cube corner sheet material 424, a plurality of cube corners defined by at least two intersecting sets of the observation surface and parallel grooves, A cube layer 432 having a metallic film 430 disposed on at least some of the cube corner elements and a cube layer 432 having a junction with the front and the surface of the cube layer 432, And a color indication (416) disposed in the overlay layer (434), wherein the color indication (416) is arranged in at least one of the set of recesses A retroreflective cube corner sheet material 424 is disclosed.

It is also disclosed that the above-mentioned colored display is diffuse-reflective.

Japanese Patent Laid-Open No. 2001-109414 (claims) Japanese Patent Application No. 2003-531396 (claims)

However, in the case of the signboard using the front panel for signboard described in Patent Document 1, since the outgoing angle of display light merely depends on the incident angle of external light, when the incident angle of external light changes, And it became difficult to maintain it.

In addition, since the light diffusion property of the signboard using the signboard front panel described in Patent Document 1 is a Gaussian distribution type light diffusion property, the uniformity of brightness of the display light in the viewing angle is lowered, There has been a problem in that the brightness unevenness of the display light becomes remarkable.

In the case of the retroreflective cube corner sheet material described in Patent Document 2, since the display light is emitted toward the light source of incident external light, when the incident angle of external light changes, as in Patent Document 1, It is difficult to maintain the characteristics stably.

In addition, since the retroreflective cube corner sheet material described in Patent Document 2 emits display light toward a light source of incident external light, in particular, when the display body is wide, the brightness unevenness of the display light becomes remarkable, I could not even get a viewing angle.

Further, the retroreflective cube corner sheet material described in Patent Document 2 has a complicated structure, which is not easy to manufacture, and has a problem in terms of manufacturing cost.

Therefore, even when the angle of incidence of external light changes, there has been a demand for an external light-utilizing display device which can stably maintain constant display characteristics and is excellent in uniformity of brightness of display light within a viewing angle.

In view of the above, the inventors of the present invention have made an effort to provide a light diffusing film to be used in an external light-utilizing display body formed by laminating a reflection plate and a light diffusion film in a region where the refractive index is relatively low It is possible to solve the above-described problems by providing a light diffusion film having an internal structure having a plurality of regions with a relatively high refractive index in the light diffusion film.

That is, an object of the present invention is to provide an external light-utilizing display body which can maintain a constant display characteristic even when the angle of incidence of external light changes, and is excellent in uniformity of brightness of display light within a viewing angle.

According to the present invention, there is provided an external light-utilizing display body comprising a reflection plate and a light diffusion film laminated, wherein the light diffusion film has an internal structure having a plurality of regions having a relatively high refractive index in a region having a relatively low refractive index in the film A light-diffusing film and an external light-utilizing type display body characterized by being a light-diffusing film, whereby the above-described problems can be solved.

That is, since the light diffusion film to be used is a light diffusion film having a predetermined internal structure, external light incident from a wide angle can be effectively diffused You can go out.

Therefore, even when the angle of incidence of external light changes, constant display characteristics can be stably maintained.

Further, in the external light-utilizing display material of the present invention, the light diffusion property of the light diffusion film having a predetermined internal structure is not a simple Gaussian distribution type light diffusion property, and the light diffusion property having excellent uniformity of diffused light brightness Therefore, the uniformity of the brightness of the display light within the viewing angle can be effectively improved.

It is preferable that a decorative layer is provided on the side opposite to the side where the reflection plate is located between the reflection plate and the light diffusion film or between the reflection plate and the light diffusion film when constructing the external light utilization type display body of the present invention.

By such a constitution, even when the incident angle of external light changes, the desired display content by the decorative layer can be stably maintained with a constant display characteristic by the effect of the light diffusion film having the predetermined internal structure, It can be displayed as display light with excellent uniformity of luminance in the display.

Further, in constructing the external light utilization type display body of the present invention, it is preferable that the internal structure of the light diffusion film has a structure in which a plurality of columnar bodies having a relatively high refractive index are immersed in the film thickness direction And a plurality of plate-shaped regions having different refractive indexes are arranged alternately in any one direction along the film surface (which means surfaces other than the cross-section of the film, hereinafter the same) A louver structure, or a structure of either one.

With this configuration, even when the incident angle of the external light changes, the uniformity of the luminance within the viewing angle can be further improved while the constant display characteristic is stably maintained.

In the case of constructing the external light utilization type display body of the present invention, when the internal structure of the light diffusion film is a column structure, it is preferable that the light diffusion film is a single-layer light diffusion film, And the incident angle of the incident light with respect to the normal to the film surface is set to a value within the range of -700 to -700 탆 along the moving direction of the coated layer when the coated layer formed by coating the composition for the light- It is preferable that the haze value with respect to each incident angle is 70% or more.

By such a constitution, since the light-diffusing film to be used is a light-diffusing film composed of a single layer having a predetermined film thickness, the bonding process can be reduced as compared with the case where a plurality of light-diffusing films are laminated, The occurrence of fogging in the display light and the occurrence of delamination between layers can be effectively suppressed.

On the other hand, since the light-diffusing film has a columnar structure as an internal structure and has a predetermined light-diffusing property, it is possible to efficiently transmit external light incident from a wide angle, The light can be diffused and emitted to the front face of the external light-utilizing display body.

The "single layer" means that a plurality of light diffusion films are not laminated, and a case where a plurality of internal structures are formed in one light diffusion film is also included in the "single layer".

When the internal structure of the light diffusion film has a louver structure, the light diffusion film is divided into the first louver structure and the second louver structure in the thickness direction of the film When viewed from above the film, the acute angle &thetas; 1 between the extending direction of the plate-shaped region in the first louver structure and the extending direction of the plate-shaped region in the second louver structure is 10 To 90 [deg.].

With such a constitution, the light diffusion film to be used is a light diffusion film having a louver structure as an internal structure, and the extension direction of the plate-like area in the first louver structure and the plate- It is possible to efficiently diffuse and emit display light in a predetermined direction even when the incident angle in the azimuth direction of the external light changes.

Figs. 1 (a) to 1 (c) are diagrams for explaining the configuration of a display using external light of the present invention. Fig.
Figs. 2 (a) to 2 (c) are diagrams for explaining characteristics of the external light-utilizing display body of the present invention. Fig.
Figs. 3 (a) to 3 (c) are diagrams for explaining characteristics of a conventional external light-utilizing display body. Fig.
Figs. 4 (a) to 4 (c) are views for explaining characteristics of a conventional external light-utilizing display body. Fig.
5 (a) and 5 (b) are diagrams for explaining the outline of a light diffusion film having a columnar structure in a film.
6 (a) and 6 (b) are diagrams for explaining an incident angle dependence and an isotropic light diffusion in a light diffusion film having a columnar structure in a film.
Figs. 7 (a) and 7 (b) are diagrams for explaining the outline of a light diffusion film having a louver structure in a film. Fig.
Figs. 8A and 8B are diagrams for explaining an incidence angle dependency and an anisotropic light diffusion in a light diffusion film having a louver structure in a film. Fig.
Figs. 9 (a) to 9 (c) are diagrams for explaining a method of measuring light diffusion characteristics of a light diffusion film. Fig.
10 (a) to 10 (c) are provided for explaining the relationship between the light diffusion property of the light diffusion film and the outgoing diffusion of the display light in the external light utilization type display body, taking the light diffusion film of the embodiment 2 as an example The drawings.
Figs. 11 (a) to 11 (c) are provided for explaining the relationship between the light diffusion property of the light diffusion film and the diffusion light emission of the display light in the external light utilization type display body, taking the light diffusion film of the second embodiment as an example Other drawings.
Figs. 12 (a) to 12 (c) are diagrams for explaining the relationship between the light diffusion property of a light diffusion film that does not satisfy a predetermined parameter and the outgoing diffusion of display light in an external light utilization display body;
Figs. 13 (a) to 13 (c) are views for explaining the relationship between the light diffusion characteristics of the light diffusion film which does not satisfy the predetermined parameters and the diffuse emission of the display light in the external light utilization display body.
14 (a) and 14 (b) are diagrams for explaining a predetermined light diffusion film having a columnar structure in a film.
15 (a) and 15 (b) are diagrams provided for explaining the column structure.
Figs. 16A and 16B are diagrams for explaining respective steps in a method for producing a light diffusion film having a columnar structure in a film. Fig.
Figs. 17A to 17D are diagrams for explaining the active energy ray irradiation process. Fig.
Fig. 18 is another diagram provided for explaining the active energy ray irradiation process. Fig.
19A to 19C are diagrams for explaining the basic structure of a predetermined light diffusion film having a louver structure in a film.
20 is a view for explaining a louver structure;
Figs. 21 (a) to 21 (c) are diagrams for explaining the extending direction of the plate-shaped area. Fig.
22 (a) to 22 (e) are diagrams for explaining the relationship between the extending direction of the plate-shaped area and the diffusion area of the incident light.
23 (a) to 23 (e) are photographs for explaining the relationship between the extending direction of the plate-shaped area and the diffusion area of the incident light.
24 (a) to 24 (d) are diagrams for explaining respective steps in a method of manufacturing a light diffusion film having a louver structure in a film.
25 (a) and 25 (b) are diagrams for explaining active energy ray irradiation using a linear light source.
Figs. 26A and 26B are diagrams for explaining the arrangement angles of the linear light sources; Fig.
FIG. 27 is another diagram for explaining active energy ray irradiation using a linear light source; FIG.
Figs. 28 (a) to 28 (d) are diagrams for explaining other light diffusion films used in the present invention. Fig.
FIGS. 29A and 29B are diagrams for explaining the outline of a manufacturing method of a light diffusion film having a predetermined internal structure in a film. FIGS.
30 (a) to 30 (c) are diagrams for explaining control of the incident angle width for each azimuth direction.
31 (a) to 31 (b) are views provided for explaining the configuration of an external light-utilizing display body of the present invention.
32 is a diagram provided for explaining the configuration of the light diffusion film of Embodiment 1. Fig.
Figs. 33 (a) and 33 (b) are diagrams for explaining the cross section of the light diffusion film of Example 1; Fig.
Figs. 34 (a) and (b) are diagrams for explaining light diffusion characteristics of the light diffusion film of Example 1. Fig.
Figs. 35 (a) and (b) are diagrams for explaining an evaluation method of a display using external light. Fig.
36 is a photograph showing the display characteristics of the external light-utilizing display body of Examples 1, 2, 5, and Comparative Examples 1 and 2;
37 is another photograph showing the display characteristics of the external light-utilizing display body of Examples 1, 2, 5, and Comparative Examples 1 and 2;
38 is another photograph showing the display characteristics of the external light-utilizing display body of Examples 1, 2, 5, and Comparative Examples 1 and 2. Fig.
39 is another photograph showing the display characteristics of the external light-utilizing display body of Examples 1, 2, 5, and Comparative Examples 1 and 2. Fig.
Figs. 40 (a) to 40 (c) are drawings and photographs provided to show the cross section of the light diffusion film in Example 2. Fig.
41 (a) and 41 (b) are diagrams for explaining a method of measuring the light diffusion characteristics of the light diffusion film.
Fig. 42 is a view provided to show an incident angle-haze value chart of the light diffusion film in Example 2. Fig.
Fig. 43 is a view for explaining a method of measuring the light diffusion property corresponding to the case where the light diffusion film is applied to a display body using external light. Fig.
Figs. 44 (a) to 44 (h) are conoscopic images provided to show the light diffusion characteristics corresponding to the case where the light diffusion film of Example 2 is applied to a display using external light. Fig.
45 is an angle of incidence-luminance chart provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 2 is applied to a display using external light.
Figs. 46 (a) to 46 (c) are drawings and photographs provided to show cross-sections of the light-diffusing film in Example 3. Fig.
Figs. 47 (a) to 47 (b) are photographs for providing cross-sections of the light-diffusing film in Example 3. Fig.
FIG. 48 is a view provided to show an incident angle-haze value chart of the light diffusion film in Example 3. FIG.
49 (a) to 49 (g) are conoscopic images provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 3 is applied to a display using external light.
50 is an angle of incidence-luminance chart provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 3 is applied to a display using external light.
Figs. 51 (a) to 51 (c) are drawings and photographs provided to show cross-sections of the light-diffusing film in Example 4. Fig.
Figs. 52 (a) to 52 (b) are photographs for providing cross-sections of the light-diffusing film in Example 4. Fig.
Fig. 53 is a view for showing an incident angle-haze value chart of the light diffusion film in Example 4. Fig.
Figs. 54 (a) to 54 (g) are conoscopic images provided to show the light diffusion characteristics corresponding to the case where the light diffusion film of Example 4 is applied to a display using external light. Fig.
55 is an angle of incidence-luminance chart provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 4 is applied to a display using external light.
Figs. 56 (a) and 56 (b) are diagrams for explaining the ultraviolet irradiating apparatus and the irradiating light collimating member used in the fifth embodiment; Fig.
Figs. 57 (a) and 57 (b) are views provided to illustrate the ultraviolet irradiating apparatus and the irradiating light collimating member used in the fifth embodiment; Fig.
Figs. 58 (a) to 58 (c) are drawings and photographs provided to show cross-sections of the light-diffusing film in Example 5. Fig.
FIG. 59 is a view for providing an incident angle-haze value chart of the light diffusion film in Example 5. FIG.
Figs. 60 (a) to 60 (g) are conoscopic images provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 5 is applied to a display using external light.
61 is an angle of incidence-luminance chart provided to exhibit light diffusion characteristics corresponding to the case where the light diffusion film of Example 5 is applied to a display using external light.
Figs. 62 (a) to 62 (c) are diagrams for explaining a conventional external light-utilizing display body; Fig.

An embodiment of the present invention is an external light utilization type display body comprising a reflection plate and a light diffusion film laminated thereon, wherein the light diffusion film has an internal structure having a plurality of regions with a relatively high refractive index in a region where the refractive index is relatively low, Is a light-diffusing film having a light-diffusing property.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. Basic structure of display type using external light

First, the basic structure of an external light-utilizing display body of the present invention will be described.

As shown in Fig. 1 (a), the external light utilization type display body 1 of the present invention is a laminate comprising a reflection plate 10 and a light diffusion film 100 laminated.

In addition, the external light utilization type display body of the present invention is characterized in that the light diffusion film to be used is a light diffusion film having a predetermined internal structure as described later.

Therefore, even when the incidence angle of the external light changes, the uniformity of the brightness within the viewing angle can be effectively improved while the constant display characteristics are stably maintained.

1 (b), the external light-utilizing display 1 of the present invention preferably has the decorative layer 20 between the reflector 10 and the light diffusion film 100, It is also preferable that the decorative layer 20 is provided on the side opposite to the side where the reflection plate 10 is located in the light diffusion film 100, as shown in Fig. 1 (c).

By providing the decorative layer in this manner, even when the incident angle of external light changes, the desired display content by the decorative layer can be stably maintained by the effect of the light diffusion film having the predetermined internal structure It is possible to display the display light with excellent uniformity of luminance in the viewing angle.

The decorative layer means a resin film or the like printed with letters, drawings, or the like.

2. Characteristics of display body using external light

Next, characteristics of the external light utilizing type display body of the present invention will be described in comparison with the characteristics of the conventional external light utilization type display body.

2 (a) to 2 (c), since the light-diffusing film to be used is a light-diffusing film having a predetermined internal structure, the external light- The external light 3 incident from the light source 3 can be diffused and emitted efficiently as the display light 4 in a predetermined direction.

That is, the external light 3 incident from a wide angle can be diffused and emitted as the display light 4 with respect to a constant light diffusion angle area.

Therefore, as shown in Figs. 2 (a) to 2 (c), it is possible to stably maintain a constant display characteristic even when the angle of incidence of the external light 3 changes.

In addition, the external light utilization type display body 1 of the present invention is characterized in that the light diffusion property of the light diffusion film having a predetermined internal structure is not a simple Gaussian distribution type light diffusion property, 2 (a) to 2 (c), the uniformity of the luminance of the display light 4 within the viewing angle can be effectively improved.

On the other hand, as shown in Figs. 3 (a) to 3 (c), in the case of the external light utilization type display body 1 'using the light diffusion film in which fine particles are dispersed in the resin disclosed in Patent Document 1, The outgoing angle of the display light 4 changes only depending on the incident angle of the external light 3. Therefore, when the incident angle of the external light 3 changes, the outgoing angle of the display light 4 changes accordingly, It becomes difficult to stably maintain the display characteristics.

In the case of the external light utilization type display body 1 'using the light diffusion film in which fine particles are dispersed in the resin disclosed in Patent Document 1, the light diffusion property of the light diffusion film is a simple Gaussian distribution type light diffusion property The brightness of the display light 4 in the regular reflection direction becomes extremely large and the brightness of the display light 4 in the peripheral direction becomes extremely small as shown in Figs. 3 (a) to 3 (c).

Therefore, in the case of the external light utilization type display body 1 'using the light diffusion film formed by dispersing fine particles in the resin disclosed in Patent Document 1, the uniformity of the luminance of the display light 4 in the viewing angle is lowered , In particular, when the display body is a large screen, the luminance unevenness of the display light 4 becomes remarkable.

As shown in Figs. 4 (a) to 4 (c), in the case of the retroreflective external light using type display body 1 '' disclosed in Patent Document 2, the display light 4 is reflected by the incident external light 3, the emission angle of the display light 4 changes according to the change of the incident angle of the external light 3. Thus, it is possible to stably maintain a constant display characteristic It becomes difficult.

In the case of the retroreflective display device using external light 1 "as disclosed in Patent Document 2, as shown in Figs. 4 (a) to 4 (c), the display light 4 is reflected by the incident external light 3, it is difficult to obtain a sufficient viewing angle as well as the brightness unevenness of the display light 4, especially when the display body is wide.

3. Light diffusion film

The light diffusion film has a function of diffusing and emitting external light incident from a wide angle through a reflection plate in a predetermined direction as display light.

Further, the external light-utilizing display body of the present invention is characterized by such a light-diffusing film.

That is, the light-diffusing film of the present invention is a light-diffusing film having an internal structure having a plurality of regions having a relatively high refractive index in a region where the refractive index is relatively low in the film.

Hereinafter, the light diffusion film of the present invention will be described in detail. First, the basic principle of the light diffusion film of the present invention will be described with reference to Figs.

That is, the light diffusion film having a columnar structure (Figs. 5 to 6) and the light diffusion film having a louver structure (Fig. 7 to 8) in the film, which is the basic mode of the light diffusion film in the present invention, The basic principle of the light diffusion film in the present invention will be described.

(1) Basic principle of light diffusion in light diffusion film

(1) -1 A light diffusion film having a columnar structure in a film

First, the basic principle of a light diffusion film having a columnar structure in a film will be described with reference to Figs. 5 to 6. Fig.

5A shows a top view (plan view) of a light diffusion film 100a having a columnar structure in the film. FIG. 5B shows a columnar structure in the film shown in FIG. Is cut in the vertical direction along the dashed line AA, and a sectional view of the light diffusion film 100a is shown when the cut surface is viewed from the direction along arrows.

6 (a) shows the overall view of the light diffusion film 100a having a columnar structure in the film. Fig. 6 (b) shows the light diffusion film 100a having a columnar structure 100a are viewed from the X direction.

As shown in the plan view of Fig. 5 (a), the light diffusion film 100a having a columnar structure in the film is composed of the columnar material 112 having a relatively high refractive index and the region 114 having a relatively low refractive index Column structure 113 as shown in FIG.

5 (b), in the vertical direction of the light diffusion film 100a having a columnar structure in the film, the columnar material 112 having a relatively high refractive index and the region 112 having a relatively low refractive index (114) have a predetermined width and are alternately arranged.

Accordingly, as shown in Fig. 6 (a), when the incident angle is within the range of the light diffusion angle of incidence, it is assumed that the incident light is diffused by the light diffusion film 100a having a columnar structure in the film.

5B, the angle of incidence of the incident light on the light diffusion film 100a having a columnar structure in the film is changed from a parallel angle to a predetermined angle range (angle range) with respect to the boundary surface 113a of the columnar structure 113 The incident light 152 and 154 enter the inside of the columnar material 112 having a relatively high refractive index in the columnar structure while being displaced along the film thickness direction while changing the direction It is presumed that the traveling direction of the light on the light-exiting-surface side becomes uneven.

As a result, when the incident angle is within the range of the light diffusion angle of incidence, the incident light is estimated to be diffused by the light diffusion film 100a having a columnar structure in the film to become diffused light 152 ', 154'.

On the other hand, when the incident angle of incident light to the light diffusion film 100a having a columnar structure in the film deviates from the light diffusion angle of incidence angle, the incident light 156 is reflected by the dotted line AA It is presumed that the light is transmitted through the light diffusion film 100a as the transmitted light 156 'without being diffused by the light diffusion film 100a in the cross section cut along the vertical direction.

In the present invention, the " light diffusion angle of incidence angle region " means the angle range of the incident light corresponding to the diffusion of the diffused light when the angle of the incident light from the point light source is changed with respect to the light diffusion film .

Such a "light diffusion angle of incidence angle region" is an angle region determined for each light diffusion film by a refractive index difference or an inclination angle of the columnar structure of the light diffusion film as shown in FIG. 6 (a).

According to the basic principle described above, the light diffusion film 100a having the columnar structure 113 in the film exhibits, for example, as shown in Fig. 6 (a) Lt; / RTI >

Further, as shown in Figs. 5 to 6, the light diffusion film 100a having the columnar structure 113 usually has " isotropic ".

Here, in the present invention, the term " isotropic " means that, when the incident light is diffused by the film, the isotropic property of the surface of the film parallel to the film in the diffused outgoing light (The shape of the diffusion of the diffused light) in the same plane as the plane (the plane parallel to the plane other than the plane) .

More specifically, as shown in Fig. 6 (a), when the incident light is diffused by the film 100a, the diffused state of the outgoing light becomes a circular shape in a plane parallel to the film.

As shown in Fig. 6 (b), when the light diffusion film having a columnar structure in the film is referred to as " incident angle? A " of incident light, the incident angle? (Degrees) when the angle of incidence of the light to be incident is 0 deg.

In the present invention, the " light diffusion angle region " means the angle range of diffused light obtained by fixing the point light source to the light diffusion film at an angle at which the incident light is most diffused.

In the present invention, the "opening angle θb of diffused light" is the angular width (°) of the above-described "light diffusion angle region", and as shown in FIG. 6 (b) The opening angle? B of the diffused light.

It has also been confirmed that the angular width (DEG) of the light diffusion angle region and the width of the light diffusion angle of incidence region become substantially equal to each other.

In the light diffusion film 100a having a columnar structure in the film like the incident light B shown in Fig. 6 (a), when the incident angle of the incident light is included in the light diffusion angle of incidence region, Substantially the same light diffusion can be performed on the light-exiting surface side.

Therefore, it can be said that the light diffusion film having a columnar structure in the film has a light converging action for concentrating light at a predetermined position.

The change in the direction of the incident light inside the columnar structure 112 in the columnar structure is not limited to the step index type in which the direction changes in a zigzag pattern on the straight line by total reflection as shown in Fig. 5 (b) It may be considered to be a gradient index type which changes its direction to an upward direction.

5 (a) and 5 (b), the interface between the columnar body 112 having a relatively high refractive index and the region 114 having a relatively low refractive index is simply shown in a straight line. Actually, And each of the columnar bodies forms a complex refractive index distribution structure due to branching or extinction.

As a result, it is presumed that the uneven distribution of the optical characteristics improves the light diffusibility.

(1) -2 Light diffusion film having a louver structure in the film

Next, with reference to Figs. 7 to 8, the basic principle of a light diffusion film having a louver structure in a film will be described.

7A is a top view (plan view) of a light diffusion film 100b having a louver structure in the film. FIG. 7B shows a louver structure in the film shown in FIG. Diffusing film 100b is cut in the vertical direction along the dotted line AA and the cut surface is viewed from the direction along arrows.

8 (a) shows the overall view of the light diffusion film 100b having a louver structure in the film. Fig. 8 (b) shows the light diffusion film 100b are viewed from the X direction.

As shown in the plan view of Fig. 7 (a), the light diffusion film 100b having a louver structure in the film has, in one arbitrary direction along the film surface, a plate-like region 122 having a relatively high refractive index, And a louver structure 123 in which plate-shaped regions 124 having a low refractive index are alternately arranged in parallel.

As shown in the sectional view of Fig. 7 (b), the plate-shaped region 122 having a relatively high refractive index and the plate-shaped region 124 having a relatively low refractive index have a predetermined thickness, In the normal direction (film thickness direction) with respect to the light diffusion film 100b having the light diffusion film 100b.

Thus, as shown in Fig. 8 (a), when the incident angle is within the range of the light diffusion angle of incidence, it is estimated that the incident light is diffused by the light diffusion film 100b having the louver structure in the film.

7B, the angle of incidence of the incident light on the light diffusion film 100b having a louver structure in the film is changed from a parallel direction to a predetermined angle (angle) with respect to the interface surface 123a 'of the louver structure 123, The incident light 152 and 154 are incident on the inside of the relatively high refractive index plate-like area 122 in the louver structure along the film thickness direction while changing the direction It is presumed that the traveling direction of the light on the light-exiting-surface side becomes unequal due to exiting.

As a result, when the incident angle is within the range of the light diffusion angle of incidence, the incident light is estimated to be diffused by the light diffusion film 100b having the louver structure in the film to become diffused light 152 ', 154'.

On the other hand, when the incident angle of the incident light to the light diffusion film 100b having the louver structure in the film deviates from the light diffusion angle of incidence angle, the incident light 156 is reflected by the dotted line AA It is presumed that the light is transmitted through the light diffusion film 10 as a transmitted light 156 'without being diffused by the light diffusion film in the cross section cut along the vertical direction.

Therefore, the light diffusion film 100b having the louver structure 123 in the film by the basic principle such as the light diffusion film having the columnar structure in the film described above can be obtained, for example, as shown in Fig. 8 (a) Likewise, it is possible to exhibit dependence of the incident angle on the transmission and diffusion of light.

However, as shown in Fig. 8 (a), the light diffusion film 100b having the louver structure 123 in the film usually has "anisotropy".

Here, in the present invention, " anisotropy " means, as shown in Fig. 8 (a), in a case where incident light is diffused by a film, Means that the diffusion state (the shape of diffusion of diffusion light) has different properties depending on the direction in the hibernation.

More specifically, as shown in Fig. 8 (a), among the components included in incident light, when viewed from the upper side of the film surface, the component perpendicular to the extending direction of the louver structure extending in any one direction along the film surface It is presumed that anisotropic light diffusion is realized because diffusion of light is selectively generated on the other hand and light components are not easily diffused for components parallel to the direction of the louver structure included in the incident light.

Therefore, the diffusion shape of the diffused light in the light diffusion film having anisotropy becomes substantially elliptical shape as shown in Fig. 8 (a).

Further, as described above, the component of the incident light contributing to light diffusion is a component perpendicular to the direction of the louver structure that extends mainly along any one direction along the film plane. Therefore, as shown in Fig. 8 (b) In the light diffusing film having a louver structure in the film, when it is referred to as " incident angle [theta] a " of incident light, it means an incident angle of a component perpendicular to the direction of the louver structure extending along one arbitrary direction along the film surface. Incidentally, the incident angle? A here means the angle (°) when the angle of the light-diffusing film to the normal to the incident-side surface is 0 °.

In the light diffusing film having a louver structure in the film, the " opening angle of diffused light " is the width of the above-described " light diffusing angle region ", and as shown in Fig. 8 (b) Means the opening angle? B of the diffused light when viewing the cross section of the film from a direction X parallel to the direction of the louver structure extending in one direction.

The other contents are omitted because they overlap with the contents of the light diffusion film having the columnar structure in the above-mentioned film.

Hereinafter, with respect to each of the above-described light diffusion film having a columnar structure in the film, light diffusion film having a louver structure in the film, and light diffusion film having a predetermined internal structure different from these in the film, The light-diffusing film in the present invention will be described.

(2) a light diffusion film having a columnar structure in the film

As a light diffusion film having a columnar structure in a film, a light diffusion film having the following constitution will be described as an example.

That is, the inner structure has a columnar structure, and a single-layered light-diffusing film has a film thickness of the light-diffusing film within a range of 60 to 700 占 퐉 and an incident angle of incident light with respect to a normal line of the film surface, When the coating layer formed by applying the composition for a diffusion film in a film form is changed in the range of -70 to 70 degrees along the moving direction of the coating layer when the coating layer is photo-cured, the haze value for each of the incident angles is not less than 70% The light diffusion film will be described as an example.

(2) -1 single layer

The light diffusion film according to this embodiment is a single layer.

This is because, compared with the case where a plurality of light-diffusing films are laminated, it is possible to reduce the bonding process, economically advantageous, and also to effectively suppress the occurrence of fogging or delamination in the display image Because.

In addition to the case where a plurality of light diffusion films are directly laminated, a plurality of light diffusion films are laminated via another film or the like, or a case where a plurality of light diffusion films are stacked.

(2) -2 light diffusion characteristic

9 (a) to 9 (c), the light diffusing film according to this embodiment has a configuration in which the incident angle [theta] a with respect to the normal to the film surface is set to be the coating layer 101 Is changed in the range of -70 to 70 degrees in accordance with the moving direction B of the applied layer 101 at the time of photo-curing, the haze value for each of the incident angles? A is set to a value of 70% or more.

This is because the light diffusion film has such a predetermined light diffusion property that the external light incident from a wide angle can be effectively used as display light in front of the external light- As shown in FIG.

That is, when the haze value is less than 70%, it is difficult to efficiently diffuse the external light incident at the incident angle? A to the front surface of the external light-utilizing display body as display light.

Therefore, when the incident angle [theta] a with respect to the normal to the film surface is changed in the range of -70 to 70 [deg.] Along the moving direction of the coated layer at the time of photo-curing the coated layer formed by applying the composition for a light- More preferably 75% or more, and more preferably 80% or more, of the haze value with respect to each of the incident angles? A.

When the above-mentioned light diffusion property is satisfied on one surface of the film, it is generally confirmed that the other surface is also satisfactory. However, even if only one surface is unsatisfactory, And it goes without saying that it is within the range of the light diffusion film according to this embodiment.

9A shows a state in which the irradiation light 50 from the point light source 202 is made parallel light 60 by the lens 204 and the image of the process sheet 102 Is a side view showing a state in which the coating layer 101 is irradiated and photocured.

9B shows a case where the angle of incidence θa with respect to the normal to the film surface is changed in the range of -70 to 70 degrees in accordance with the moving direction B of the coating layer by using the light source 310 and the integrating sphere 320 , And a haze value for each incident angle? A is measured.

9 (c) is a side view showing a state in which the film is fixed, in which the incident angle &thetas; a with respect to the normal to the film surface is changed in the range of -70 to 70 degrees.

Next, the relationship between the light diffusion characteristics of the light diffusion film according to the present embodiment and the diffusion light emission of the display light in the external light utilization type display body will be described with reference to Figs. 10 to 13. Fig.

First, light is incident on the light-diffusing film 100a (light diffusing film according to the present embodiment) of Example 2 at an incident angle &thetas; a, The diffuse shape is shown.

10B shows an incident angle-haze value chart obtained by measuring the haze value (%) with respect to each of the incident angles? A (degrees) when the incident angle? A of FIG. 10A is changed.

10 (c) shows a diffusion state (a schematic diagram of a conoscopic image) of the light diffused once with respect to the range of the incident angles? A when the incident angle? A is changed in FIG. 10 (a).

11 (a), the light-diffusing film 100a of Example 2 is bonded to the reflector 10 to form a test piece for measurement, light is incident on the film side of the test piece at an incident angle? Is diffused twice through the reflection at the light source 10 shown in Fig.

11B shows an incident angle-luminance chart obtained by measuring the luminance (㏅ / ㎡) of the film front face with respect to each of the incident angles? A (°) when the incident angle? Is shown.

11 (c) shows the diffused state of the light diffused twice (a conoscopic image) with respect to each of the incident angles? A when the incident angle? A of FIG. 11 (a) is changed.

12A shows a light diffusion film 100? Having a columnar structure in the film (hereinafter referred to as " light diffusing film instead of the light diffusing film according to the present embodiment "Quot; film "), light is incident at an incident angle &thetas; a and diffused once.

12B shows an incident angle-haze value chart in which a haze value (%) with respect to each of incident angles? A (degrees) is measured when the incident angle? A of FIG. 12A is changed.

Fig. 12 (c) shows the diffusion state (a schematic diagram of the conoscopic image) of the light diffused once with respect to the range of the incident angle [theta] a when the incident angle [theta] a in Fig. 12 (a) is changed.

13 (a) shows a case in which a light diffusion film 100? Instead of the light diffusion film according to the present embodiment is attached to the reflection plate 10 and used as a test piece for measurement, and from the film side of the test piece, And diffused twice through the reflection on the reflection plate 10 is shown.

13B shows an incident angle-luminance chart obtained by measuring the luminance (㏅ / ㎡) of the front face of the film with respect to each of the incident angles θa (°) when the incident angle θa shown in FIG. 13 Is shown.

13 (c) shows the diffused state of light (convolution image) twice diffused with respect to each of the incident angles? A when the incident angle? A in Fig. 13 (a) is changed.

First, as shown in the incident angle-haze value chart of Fig. 10 (b), the light diffusion film 100a of Example 2 shown in Fig. 10 (a) was changed in the range of -70 to 70 , The haze value for each incident angle? A takes a value of 70% or more and satisfies the requirements of the light diffusion film according to this embodiment.

In the incident angle-haze value chart of Fig. 10 (b), the incident angle? A is in the range of -70 to -18, -18 to -2, -2 to 34, 34 to 44 and 44 to 70 Diffusion state of the once-diffused light with respect to the conoscopic image shown in Fig. 10 (c) is as shown in the schematic diagram of the conoscopic image in Fig. 10 (c).

That is, in the light diffusion film 100a of Embodiment 2, when the incident angle [theta] a is changed in the range of -70 to 70 [deg.], The haze value for each incident angle [ It can be seen that uniformly diffused light with less linear transmitted light can be obtained in the entire range of the incident angle [theta] a = -70 to 70 [deg.] (The more the linearly transmitted light is, the smaller the haze value is).

More specifically, in the range of the incident angle [theta] a = -2 to 34 [deg.], Since the incident angle [theta] a corresponds to the light diffusion angle of incidence described with reference to FIG. 6 (a) Isotropic light diffusion of the light emitting layer is generated.

On the other hand, in the range of the incident angle? A = -70 to -18, -18 to -2, 34 to 44 and 44 to 70, the incident angle? It can be seen that circular isotropic light diffusion does not occur and crescent type light diffusion occurs as shown in Fig. 10 (c).

Here, in the above description using Fig. 5 (b), when the incident angle [theta] a is out of the range of the light diffusion angle of incidence angle, the incident light is not diffused by the film in the section cut in the vertical direction along the dotted line AA .

However, this explanation is for convenience in describing the light diffusion angle of incidence angles in which isotropic light diffusion occurs. In reality, as in the case of incident light A and C in Fig. 6A, When not included in the incident angle region, the diffusion in the plane parallel to the film of the outgoing light becomes a crescent shape. It should be noted here that, in practice, diffused light is not crescent-shaped diffused light and transmitted light but differs from letter.

In any case, the light diffusion film 100a of Example 2 has a haze value of 70% or more with respect to each of the incident angles? A when the angle of incidence? A is changed in the range of -70 to 70 占 and isotropic light diffusion or crescent type It can be seen that uniformly diffused light with less linear transmitted light is obtained in the entire range of the incident angle [theta] a = -70 to 70 [deg.].

Thus, as shown in Fig. 11 (a), the light diffusion film 100a of the second embodiment shown in Fig. 10 (a) diffuses light of the incident angle [theta] a through the reflection at the reflector 10 twice It is possible to efficiently diffuse and exit the film to the front side.

That is, as shown in the incident angle-luminance chart of Fig. 11 (b), when the angle of incidence [theta] a is changed in the range of 0 to 60 degrees, the brightness of the film surface with respect to each incident angle [theta] (A value of about 1: a value judged to be able to reflect external light more effectively than a standard white plate) within a range of 10 m / m < 2 > It can be seen that diffusion and emission can be efficiently performed on the front side of the film by a total of two times of diffusion.

This is because, in the case of the light diffusion film of Example 2, since the incident light can be diffused uniformly in the first diffusion, the second diffusion through the reflection on the reflection plate is uneven in the relation between the reflection angle and the inclination angle of the internal structure It is considered that uniform diffusion light can be emitted to the film surface side as a result.

11A is a model for measuring the light diffusion characteristics when the light diffusion film is applied to a display body using an external light.

11 (c) shows a diffusion state (a conoscopic image) of the diffused light twice at the incident angles? A = 0, 20, 40 and 60 in order to show the actual shape more specifically have.

That is, the luminance distribution from 0 mu m / m < 2 > to the maximum luminance value in each of the conoscopic images is divided into 14 steps from blue to red, 0 mu m / m < 2 > (Light blue) to green to yellow to orange to red (red) as the luminance approaches 0 to the maximum brightness value, and the value of the maximum brightness in each of the conoscopic images is divided into 13 equal parts. To 13 levels.

The lines drawn in the radial direction in each of the conoscopic images indicate azimuth directions of 0 to 180 DEG, 45 to 225 DEG, 90 to 270 DEG, and 135 to 315 DEG, and lines drawn in a concentric circle direction 38 degrees, 58 degrees, 78 degrees in the polar angle direction.

Therefore, the color at the central portion of each concentric circle in each of the conoscopic images represents the relative luminance of the diffused light emitted to the front of the film, and the absolute luminance at the center portion of each concentric circle is ) Corresponding to the value of the vertical axis of each plot.

On the other hand, as shown in the incident angle-haze value chart of Fig. 12 (b), the light diffusion film 100a, which is not the light diffusion film according to the present embodiment shown in Fig. 12 (a) , The haze value may be less than 70% depending on the value of the incident angle &thetas; a, which does not satisfy the requirements of the light diffusion film according to this embodiment.

In the range of the incidence angle? A = -70 to -17 degrees, -17 to -7 degrees, -7 to 16 degrees, 16 to 36 degrees and 36 to 70 degrees in the incident angle-haze chart of FIG. 12 (b) The diffusion state of the once-diffused light is shown in a schematic diagram of the conoscopic image of Fig. 12 (c).

That is, when the incident angle [theta] a is changed in the range of -70 to 70 [deg.], The light diffusion film 100 [alpha] other than the light diffusion film according to the present embodiment has a haze value of less than 70% 12 (c), it can be seen that in the range of the incident angle [theta] a, the linearly transmitted light increases, and a uniform diffused light can not be obtained.

More specifically, in the range of the incidence angle [theta] a = -7 to 16 [deg.], The incident angle [theta] a corresponds to the light diffusion incidence angle region described using Figure 6 (a) or the like and the haze value is 70% , It can be seen that circular isotropic light diffusion occurs as shown in Fig. 12 (c).

On the other hand, in the range of the incident angle [theta] a = -17 to -7 degrees and the range of 16 to 36 degrees, the incident angle [theta] a falls outside the range of the light diffusion incidence angle range described using Figure 6 (a) It is found that the circular isotropic light diffusion does not occur and the crescent type light diffusion occurs as shown in Fig. 12 (c) because the value is 70% or more.

On the other hand, in the range of the incidence angle? A = -70 to -17 and the range of 36 to 70, the incident angle? A falls outside the range of the light diffusion incidence angle range described with reference to Fig. 6 (a) As a result, it can be seen that uneven light diffusion occurs in which the straight-line transmitted light is strongly displayed at the center portion while the crescent-shaped light diffusion occurs.

Therefore, when the incident angle [theta] a is changed in the range of -70 to 70 [deg.], The light diffusion film 100 [alpha] other than the light diffusion film according to this embodiment has a haze value of less than 70% In the range of the incident angle &thetas; a, the crescent-shaped light diffusion occurs as the outline, but the straight-line transmitted light increases, and it can be seen that uniform diffusion light can not be obtained.

As a result, as shown in Fig. 13 (a), the light diffusion film 100a, which is not the light diffusion film according to the present embodiment shown in Fig. 12 (a) It is difficult to efficiently diffuse and exit the film to the front face of the film.

That is, as shown in the incident angle-luminance chart of Fig. 13 (b), when the incident angle &thetas; a is changed in the range of 0 to 60 degrees, the luminance of the film surface with respect to each incident angle &thetas; , It is not possible to effectively diffuse and emit a wide range of incident light to the front side of the film by two diffusions through reflection of the reflection plate 10 .

Further, since the deviation of the luminance of the film surface when the angle of incidence [theta] a is changed from 20 [deg.] To 30 [deg.] Is remarkable, it is possible to effectively diffuse and exit the film to the front surface of the film only in a narrow range of the incident angle [ None can be found.

This is because, in the light diffusion film other than the light diffusion film of this embodiment, when the absolute value of the incident angle &thetas; a is large in the first diffusion, incident light can not be diffused uniformly, It is considered that the uniform diffused light can not be emitted to the film surface side when the diffusing time becomes uneven in the relation between the reflection angle and the inclination angle of the internal structure.

That is, when the diffused light emitted to the film surface side is uneven, the diffused light is emitted at a relatively high luminance at an angle other than the front surface of the film, so that the luminance of the front surface of the film is likely to relatively decrease .

13 (c) shows a diffusion state (a conoscopic image) of diffused light twice at incident angles? A = 0, 20, 40 and 60 in order to show the actual shape more specifically have.

Therefore, as in the case of Fig. 11 (c), the color at the central portion of each concentric circle in each of the conoscopic images represents the relative luminance of the diffused light diffused and emitted to the front of the film, and the center portion of each concentric circle 13B correspond to the value of the vertical axis of each plot in Fig. 13 (b).

Like the light diffusion film of Example 2, the light diffusion film of the present invention can prevent the light diffusion film of the present invention from changing in the incident angle in the polar angle direction even when the incident angle in the azimuth direction of the external light changes , The light can be diffused and emitted to the front face of the film efficiently by two diffusions through the reflection of the reflection plate.

On the other hand, in the case of the light-diffusing film other than the light-diffusing film according to the present invention described above, even when the incidence angle of the external light in the polar angle direction changes in the azimuth angle direction perpendicular to the moving direction of the coating layer, It is possible to efficiently diffuse and emit light toward the front side of the film by two diffusions through reflection.

However, in the case of the light diffusion film other than the light diffusion film according to this embodiment, with respect to the external light from the other azimuth direction, when the incident angle of the external light in the polar angle direction changes, It is difficult to efficiently diffuse and emit light toward the front face of the film.

Therefore, even in the case of an external light using type display body using a light diffusion film other than the light diffusing film according to the present embodiment, even in an environment where the incident angle of external light does not change only in a specific azimuth direction (for example, The case of using as external light, etc.), it is practically usable as a display using a light sufficiently.

(2) -3 internal structure

The light diffusion film according to this aspect is a column structure in which a plurality of columnar bodies having relatively high refractive index are fired in the thickness direction of the film in the region where the refractive index is relatively low in the internal structure of the light diffusion film, But is not limited thereto.

However, from the viewpoint of stably exhibiting the predetermined light diffusion characteristics described above, when one surface of the light diffusion film is defined as the first surface and the other surface is defined as the second surface, And is a deformed columnar material having a shape changing from the first surface to the second surface.

The reason for this is that, in the case of a light diffusion film having a columnar structure composed of a deformed columnar body whose shape changes from the first surface to the second surface, for example, the shape of the light diffusion film does not change from the first surface to the second surface This is because it has been confirmed that the aforementioned predetermined light diffusion characteristics can be stably obtained even in the case of a light diffusion film having a columnar structure composed of ordinary columnar material.

Hereinafter, the column structure composed of the deformed columnar body will be described in detail.

More specifically, as shown in Fig. 6 (a), it is preferable that the diameter of the deformed columnar body 112 from the second surface 116 toward the first surface 115 increases.

This is because, by forming a columnar structure having such a deformed columnar body, a predetermined light diffusion property can be more stably imparted to the light diffusion film.

That is, even if the deformed columnar material is light parallel to the axial direction of the columnar body as compared with a normal columnar material, it is difficult for straight-pass transmission, and therefore, it is possible to stably provide predetermined light- It is because.

Further, as shown in Fig. 14 (a), it is preferable that the deformed columnar body 112 'has a curved portion in the middle of the columnar body.

The reason for this is that, by forming a columnar structure having such a deformed columnar body, a predetermined light diffusion property can be more stably imparted to the light diffusion film.

That is, in the case of such a deformed columnar material, as compared with a normal columnar material, light is hardly transmitted straightly, and the opening angle of the diffused light can be increased. Therefore, Can be given.

As shown in Fig. 14 (b), the deformed columnar material 112a ", 112b "includes a first columnar body 112a" positioned on the side of the first surface 115 " And the second columnar body 112b "positioned on the side of the second columnar body" 116 ".

This is because, by forming the columnar structure having such a deformed columnar body, it is possible not only to stably impart a predetermined light diffusion property to the light diffusion film, but also to control the obtained light diffusion property efficiently It is because.

That is, in the case of such a deformed columnar material, as compared with a normal columnar material, light is hardly transmitted straightly, and the opening angle of the diffused light can be increased. Therefore, Can be given.

It is also preferable that the upper end portion of the first columnar body and the lower end portion of the second columnar body have overlapping columnar structure regions formed by alternately polymerizing them as in the light diffusing film of Example 4 described later.

The reason for this is that by having such a redundant column structure region, generation of scattered light in the columnar body nonformed portion between the first and second columnar bodies is suppressed, and uniformity of the intensity of the diffused light in the light diffusion angular region It is because we can improve sex.

(i) refractive index

In the column structure, the difference between the refractive index of the columnar material having a relatively high refractive index and the refractive index of the region having a relatively low refractive index is preferably 0.01 or more.

The reason for this is that by making the difference in the refractive index to a value of 0.01 or more, the incident light is stably reflected in the column structure to further increase the dependency on the incident angle derived from the column structure, This is because it is possible to clearly control the distinction from the region.

More specifically, when the difference in the refractive index is less than 0.01, the angle of incidence of the incident light in the column structure becomes narrower, so that the dependency of the incident angle may be excessively lowered.

Therefore, the difference between the refractive index of the columnar material having a relatively high refractive index in the column structure and the refractive index in the region having a relatively low refractive index is more preferably 0.05 or more, and more preferably 0.1 or more.

It is preferable that the difference between the refractive index of a columnar material having a relatively high refractive index and the refractive index of a region having a relatively low refractive index is greater, but from the viewpoint of selecting a material capable of forming a curved columnar structure, the upper limit is considered to be about 0.3.

(Ii)

Further, as shown in Fig. 15 (a), in the column structure, the maximum diameter S in the cross section of the columnar body is preferably set to a value within a range of 0.1 to 15 占 퐉.

This is because, by setting the maximum diameter within the range of 0.1 to 15 占 퐉, incident light can be more stably reflected in the columnar structure, and the dependency of the incident angle derived from the columnar structure can be improved more effectively.

That is, when the maximum diameter is less than 0.1 탆, it may become difficult to exhibit the light diffusing property irrespective of the incident angle of the incident light. On the other hand, when the maximum diameter exceeds 15 탆, the light going straight in the column structure increases, and the uniformity of the diffused light may deteriorate.

Therefore, in the column structure, the maximum diameter on the cross section of the columnar body is more preferably in the range of 0.5 to 10 mu m, and more preferably in the range of 1 to 5 mu m.

The cross-sectional shape of the columnar material is not particularly limited, but is preferably circular, elliptical, polygonal, or deformed, for example.

The cross section of the columnar body means a cross section cut by a plane parallel to the film surface.

The maximum diameter and length of the columnar material can be measured by observing with an optical digital microscope.

(Iii) the distance between the columns

Further, as shown in Fig. 15 (a), it is preferable to set the distance between the columnar bodies, that is, the space P in the adjacent columnar body, within the range of 0.1 to 15 mu m in the column structure.

The reason for this is that by making the distance within the range of 0.1 to 15 占 퐉, the incident light can be more stably reflected in the columnar structure, and the dependence of the incident angle derived from the columnar structure can be further improved.

That is, when the distance is less than 0.1 탆, there is a case where it becomes difficult to exhibit the light diffusing property irrespective of the incident angle of the incident light. On the other hand, when the distance exceeds 15 mu m, the light advancing straightly in the column structure increases and the uniformity of diffused light may deteriorate.

Therefore, in the column structure, the distance between the columnar bodies is more preferably in the range of 0.5 to 10 mu m, and more preferably in the range of 1 to 5 mu m.

(Iv) Thickness

It is also preferable to set the length La of the columnar body in the range of 50 to 700 占 퐉 in the normal direction of the film surface, that is, as shown in Fig. 15 (b).

The reason for this is that by making the thickness of the column structure within this range, the length of the columnar body along the film thickness direction can be stably secured, the incident light can be more stably reflected in the column structure, This is because the uniformity of the intensity of the diffused light within the angular region can be further improved.

That is, when the thickness La of the column structure is less than 50 占 퐉, the length of the columnar body is insufficient and incident light which goes straight in the column structure increases, and uniformity of the intensity of the diffused light within the light diffusion angle region increases This is because it may be difficult to obtain. On the other hand, when the thickness La of such a column structure exceeds a value of 700 탆, when the column structure is formed by irradiating the active energy ray to the composition for a light diffusion film, And it is difficult to form a desired column structure.

Therefore, the thickness La of the column structure is more preferably in the range of 70 to 400 mu m, and more preferably in the range of 80 to 300 mu m.

15 (b), the light diffusion film according to this embodiment may have a columnar structure (length La in the film thickness direction) formed in the entire film thickness direction, and may be formed on at least one of the upper and lower ends of the film Column structure unformed portion.

In the case of the column structure having a deformed columnar body as shown in Figs. 14 (a) to 14 (b), the columnar structure in the upper part (the part on the side where the active energy ray is irradiated at the time of producing the light diffusion film) It is preferable that the ratio of the length of the water to the length of the columnar body in the lower portion is usually within the range of 7: 1 to 1:50.

(v) inclination angle

Further, as shown in Fig. 15 (b), it is preferable that in the column structure, the columnar material 112 is fired at a constant inclination angle? C with respect to the film thickness direction of the light diffusion film.

This is because, by making the inclination angle of the columnar material constant, the incident light can be more stably reflected in the column structure, and the dependency of the incident angle derived from the column structure can be further improved.

Further, it is preferable to set the inclination angle &thetas; c to a value within a range of 0 to 50 DEG.

The reason for this is to adjust the light diffusion angle region expressed by the column structure in an arbitrary direction. That is, in order to condense the diffused light in the direction of the viewer, considering the position where the external light-utilizing display body is installed and the angle at which the viewer visually observes the external light-use display body.

More specifically, for example, in a scene in which the viewer visually observes the image on the front face of the display body using the external light using type, the inclination angle &thetas; c of the column body is controlled so that the front face of the film becomes the light diffusion angle region. On the other hand, for example, in a scene in which the viewer visually recognizes the external light-utilizing display body from below, the inclination angle &thetas; c of the columnar body is controlled so that the direction becomes the light diffusion angle region.

However, when the inclination angle &thetas; c exceeds 50 DEG, it may be difficult to emit diffused light to the front surface of the film.

Therefore, it is more preferable to set the inclination angle &thetas; c within the range of 0 to 40 DEG, more preferably to be within the range of 0 to 30 DEG.

The inclination angle? C is a plane perpendicular to the film surface, in which the angle of the normal to the film surface measured on the cross section when the film is cut by two planes cut along the entire axial line of one columnar body is set to 0 (Deg.) Of the columnar body when it is in the range of "

More specifically, as shown in Fig. 15 (b), the inclination angle &thetas; c means an angle between the normal to the top surface of the columnar structure and the top of the columnar body.

Further, as shown in Fig. 15 (b), the inclination angle when the columnar object is tilted to the right is referred to as minus with reference to the inclination angle when the columnar object is inclined to the left.

In the case of a column structure having a deformed columnar body as shown in Figs. 14 (a) to 14 (b), the inclination angle of the columnar body (the columnar body on the incidence side of light) , And the inclination angle of the columnar body (the columnar body on the exit side of the light) in the lower portion is preferably set to a value within a range of 0 to 50 degrees.

(2) -4 film thickness

In the light diffusion film according to the present embodiment, the film thickness is set to a value within a range of 60 to 700 mu m.

This is because when the thickness of the light-diffusing film is less than 60 탆, incident light that goes straight in the column structure increases and it becomes difficult to exhibit predetermined light diffusion characteristics. On the other hand, when the thickness of the light-diffusing film exceeds 700 mu m, when the composition for a light-diffusing film is irradiated with an active energy ray to form a column structure, the progress of the light- And it is difficult to form a desired column structure. Further, there is a case that fogging easily occurs in the display image.

Therefore, the thickness of the light-diffusing film is more preferably in the range of 80 to 450 mu m, and more preferably in the range of 100 to 250 mu m.

(2) -5 Production method

The light-diffusing film according to this embodiment is preferably manufactured by a manufacturing method including the following steps (a) to (c).

(a) a composition for a light diffusion film comprising a (meth) acrylate ester containing a plurality of aromatic rings as a component (A), a urethane (meth) acrylate as a component (B) and a photopolymerization initiator as a component Process to prepare

(b) a step of applying a composition for a light diffusion film to a process sheet to form a coating layer

(c) a step of irradiating the coating layer with an active energy ray

Hereinafter, each step will be described in detail with reference to the drawings.

(i) Step (a): Preparation of composition for light diffusion film

This step is a step of preparing a predetermined composition for a light diffusion film.

More specifically, it is a step of mixing the components (A) to (C) and other additives by desirability.

In the mixing, the mixture may be stirred at room temperature, but from the viewpoint of improving the uniformity, it is preferable that the mixture is stirred under a warming condition of 40 to 80 캜 to obtain a homogeneous mixture.

It is also preferable to add a diluting solvent so as to have a desired viscosity suitable for coating.

Hereinafter, the composition for a light diffusion film will be described in more detail.

(i) -1 Component (A)

(Kinds)

The composition for a light diffusion film preferably contains a (meth) acrylic acid ester containing a plurality of aromatic rings as the component (A).

This is because the polymerization rate of the component (A) is higher than the polymerization rate of the component (B) by including the specific (meth) acrylic acid ester as the component (A) It is presumed that it is possible to effectively reduce the copolymerization of the positive components.

As a result, when the photo-curing is carried out, a columnar structure formed by fusing a plurality of columnar bodies having a relatively high refractive index derived from the component (A) in a region having a relatively low refractive index derived from the component (B) .

Further, by including the specific (meth) acrylic acid ester as the component (A), it is possible to obtain a polymer having a sufficient compatibility with the component (B) in the step of the monomer, B) component is lowered to a predetermined range, so that the column structure can be formed more efficiently.

The refractive index of the region derived from the component (A) in the columnar structure is increased by including the specific (meth) acrylic acid ester as the component (A), and the refractive index of the region derived from the component (B) Can be adjusted to a predetermined value or more.

Therefore, by including the specific (meth) acrylic acid ester as the component (A), a region having a relatively high refractive index derived from the component (A) and a region having a relatively high refractive index derived from the component (B) A column structure having a relatively low index of refraction derived from the refractive index can be efficiently obtained.

The term "(meth) acrylic acid ester containing a plurality of aromatic rings" means a compound having a plurality of aromatic rings in the ester residue portion of the (meth) acrylic acid ester.

The term "(meth) acrylic acid" means both of acrylic acid and methacrylic acid.

Examples of the (meth) acrylic acid ester containing a plurality of aromatic rings as the component (A) include biphenyl (meth) acrylate, naphthyl (meth) acrylate, anthracyl (meth) acrylate, (Meth) acrylate, benzylphenyloxyalkyl (meth) acrylate, naphthyloxyalkyl (meth) acrylate, anthracyloxyalkyl (meth) acrylate and benzylphenyloxyalkyl Is substituted with halogen, alkyl, alkoxy, halogenated alkyl, or the like.

The (meth) acrylic acid ester containing a plurality of aromatic rings as the component (A) preferably contains a compound containing a biphenyl ring. In particular, a biphenyl compound represented by the following general formula (1) .

(Formula (1) of, R ¹ ~R ¹⁰ are, respectively and independently, at least one of R ¹ ~R ¹⁰ is, to a substituent group represented by formula (2), and the other is a hydrogen atom, a hydroxyl group , A carboxy group, an alkyl group, an alkoxy group, a halogenated alkyl group other than fluorine, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom other than fluorine)

(In the general formula (2), R ¹¹ is a hydrogen atom or a methyl group, the number of carbon atoms is an integer of 1 to 4, and the number of repeating m is an integer of 1 to 10)

This is because a predetermined difference in polymerization rate between the component (A) and the component (B) is generated by including a biphenyl compound having a specific structure as the component (A), and the component (A) ) Component is lowered to a predetermined range so that the copolymerization of the two components can be further lowered.

Further, the refractive index of the region derived from the component (A) in the column structure can be increased, and the difference from the refractive index of the region derived from the component (B) can be more easily adjusted to a predetermined value or more.

Specific examples of the biphenyl compound represented by the general formula (1) include compounds represented by the following general formulas (3) to (4).

(Molecular Weight)

The molecular weight of the component (A) is preferably in the range of 200 to 2,500.

The reason for this is that the polymerization rate of the component (A) is made faster by setting the molecular weight of the component (A) to a predetermined range, and the copolymerization of the component (A) and the component (B) It is estimated.

As a result, when the photo-curing is carried out, a columnar structure formed by firing a plurality of columnar bodies having a relatively high refractive index derived from the component (A) in a region having a relatively low refractive index derived from the component (B) .

That is, when the molecular weight of the component (A) is less than 200, it is presumed that copolymerization with the component (B) tends to occur because the steric hindrance becomes small. As a result, it is difficult to form the column structure efficiently This is because there is a possibility that On the other hand, when the molecular weight of the component (A) exceeds 2,500, the polymerization rate of the component (A) decreases and the polymerization rate of the component (B) becomes closer to the polymerization rate as the molecular weight difference with the component , And (B) components is likely to occur. As a result, it may become difficult to form the column structure efficiently.

Therefore, the molecular weight of the component (A) is more preferably in the range of 240 to 1,500, and more preferably in the range of 260 to 1,000.

The molecular weight of the component (A) can be determined from the composition of the molecule and the calculated value obtained from the atomic weight of the constituent atom.

(Refractive index)

The refractive index of the component (A) is preferably set to a value within a range of 1.5 to 1.65.

This is because the difference between the refractive index of the region derived from the component (A) and the refractive index of the region derived from the component (B) can be controlled more easily by setting the refractive index of the component (A) This is because a light diffusion film having a columnar structure can be obtained more efficiently.

That is, when the refractive index of the component (A) is less than 1.5, the difference from the refractive index of the component (B) becomes too small, and it becomes difficult to obtain an effective light diffusion angle region. On the other hand, when the refractive index of the component (A) exceeds 1.65, the difference from the refractive index of the component (B) becomes large, but it may be difficult to form even the apparent state of compatibility with the component (B) .

Therefore, the refractive index of the component (A) is more preferably in the range of 1.52 to 1.62, and more preferably in the range of 1.56 to 1.6.

The refractive index of the above-mentioned component (A) means the refractive index of the component (A) before curing by light irradiation.

The refractive index can be measured in accordance with, for example, JIS K0062.

(content)

The content of the component (A) in the composition for a light-diffusing film is preferably within a range of 25 to 400 parts by weight based on 100 parts by weight of the component (B) described below.

This is because when the content of the component (A) is less than 25 parts by weight, the presence ratio of the component (A) to the component (B) becomes small, and in the column structure shown in the cross- The width of the columnar body derived from the component (A) of the columnar grains becomes excessively small, and it may be difficult to obtain a columnar structure having a good incident angle dependency. This is because the length of the columnar body in the thickness direction of the light-diffusing film becomes insufficient, and the light-diffusing film may not exhibit predetermined light-diffusing characteristics. On the other hand, when the content of the component (A) exceeds 400 parts by weight, the presence of the component (A) in the component (B) increases and the width of the component derived from the component (A) On the other hand, it is difficult to obtain a column structure having a good incident angle dependency. This is because the length of the columnar body in the thickness direction of the light-diffusing film becomes insufficient, and the light-diffusing film may not exhibit predetermined light-diffusing characteristics.

Therefore, the content of the component (A) is more preferably in the range of 40 to 300 parts by weight, more preferably 50 to 200 parts by weight, per 100 parts by weight of the component (B).

(i) -2 (B) Component

(Kinds)

The composition for a light diffusion film preferably contains urethane (meth) acrylate as the component (B).

This is because not only the difference between the refractive index of the region derived from the component (A) and the refractive index of the region derived from the component (B) can be more easily controlled with urethane (meth) acrylate, ) Component can be effectively suppressed, and a light diffusion film having a columnar structure can be obtained more efficiently.

Further, (meth) acrylate means both of acrylate and methacrylate.

(B1) a compound containing at least two isocyanato groups, (B2) a polyol compound, preferably a diol compound, particularly preferably a polyalkylene glycol, and (B3) a polyol compound, Hydroxyalkyl (meth) acrylate.

(Refractive index)

Further, it is preferable to set the refractive index of the component (B) within the range of 1.4 to 1.55.

This is because the refractive index of the component (B) is set to a value within this range so that the difference between the refractive index of the region derived from the component (A) and the refractive index of the region derived from the component (B) This is because a light diffusion film having a columnar structure can be obtained more efficiently.

That is, when the refractive index of the component (B) is less than 1.4, the difference from the refractive index of the component (A) increases, but the compatibility with the component (A) is extremely deteriorated, There is. On the other hand, when the refractive index of the component (B) exceeds 1.55, the difference between the refractive index of the component (A) and the refractive index of the component (B) becomes too small, and it becomes difficult to obtain a desired incident angle dependency.

Therefore, the refractive index of the component (B) is more preferably in the range of 1.45 to 1.54, and more preferably in the range of 1.46 to 1.52.

The refractive index of the above-mentioned component (B) means the refractive index of the component (B) before curing by light irradiation.

The refractive index can be measured in accordance with, for example, JIS K0062.

The difference between the refractive index of the component (A) and the refractive index of the component (B) is preferably 0.01 or more.

The reason for this is that by setting the difference in refractive index within a predetermined range, it is possible to obtain a light diffusion film having a better incident angle dependency in transmission and diffusion of light and a wider light diffusion angle of incidence angle region .

That is, when the difference in the refractive index is less than 0.01, the angle of incidence of the incident light in the column structure becomes narrower, so that the opening angle in the light diffusion may be excessively narrowed. On the other hand, when the difference in the refractive index becomes excessively large, the compatibility of the component (A) and the component (B) becomes too poor and there is a possibility that the column structure can not be formed.

Therefore, the difference between the refractive index of the component (A) and the refractive index of the component (B) is more preferably within a range of 0.05 to 0.5, and more preferably within a range of 0.1 to 0.2.

The refractive index of the component (A) and the component (B) referred to herein means the refractive index of the component (A) and the component (B) before curing by light irradiation.

(content)

The content of the component (B) in the composition for a light-diffusing film is preferably within a range of 10 to 75% by weight based on 100% by weight of the total amount of the composition for a light-diffusing film.

This is because when the content of the component (B) is less than 10% by weight, the proportion of the component (B) relative to the component (A) is decreased and the region derived from the component (B) It is difficult to obtain a column structure having a satisfactory dependence on the angle of incidence. On the other hand, when the content of the component (B) exceeds 75% by weight, the proportion of the component (B) relative to the component (A) increases and the region derived from the component (B) , It becomes difficult to obtain a column structure having a good incident angle dependency.

Therefore, the content of the component (B) is more preferably in the range of 20 to 70% by weight, more preferably in the range of 30 to 60% by weight based on 100% by weight of the total amount of the composition for the light- .

(i) -3 (C) Component

(Kinds)

The composition for a light diffusion film preferably contains a photopolymerization initiator as the component (C).

This is because when a composition for a light diffusion film is irradiated with an active energy ray, the refractive index of the component (A) derived from the component (A) is relatively high in a region having a relatively low refractive index derived from the component The columnar structure can be formed by immersing the columnar material in the columnar structure.

Here, the photopolymerization initiator refers to a compound that generates a substance that initiates polymerization reaction, such as radical species or hydrogen ion, upon irradiation with active energy rays such as ultraviolet rays.

The photopolymerization initiator as the component (C) is preferably at least one member selected from the group consisting of an? -Hydroxyacetophenone type photopolymerization initiator, an? -Aminoacetophenone type photopolymerization initiator and an acylphosphine oxide type polymerization initiator.

This is because, in the case of these photopolymerization initiators, the bending can be more clearly generated in the column structure, and the opening angle of diffused light in the obtained light diffusion film can be expanded more effectively.

That is, in the case of these photopolymerization initiators, in the formation of the curved column structure, the separation of these components is accelerated so that the difference in refractive index between the regions derived from the components (A) and (B) .

Specific examples of the photopolymerization initiator include, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1- Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl- 2- Benzoquinone, 2-ethyl anthraquinone, 2-tert-butyl anthraquinone, 2-tert-butyl anthraquinone, 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal, p-dimethylamine benzoate Propyl], and one of these may be used singly or in combination of two or more kinds thereof. The term " 2-hydroxy-2-methyl- . Among them, the? -Hydroxyacetophenone type photopolymerization initiator is preferably 2-hydroxy-2-methyl-1-phenylpropan-1-one.

(content)

The content of the component (C) in the composition for a light-diffusing film is preferably within a range of 0.2 to 20 parts by weight based on the total amount (100 parts by weight) of the components (A) and (B) .

This is because when the content of the component (C) is less than 0.2 parts by weight, it becomes difficult to obtain a light-diffusing film having a sufficient angle of incidence dependence, and the polymerization initiation point becomes excessively small, It may become difficult. On the other hand, when the content of the component (C) exceeds 20 parts by weight, the ultraviolet ray absorption in the surface layer of the coating layer becomes excessively strong, and the photocuring of the film is inhibited or the odor becomes excessively strong, Or the initial yellowish color of the coloring material may become strong.

Accordingly, the content of the component (C) is more preferably in the range of 0.5 to 15 parts by weight, more preferably in the range of 1 to 10 parts by weight, based on the total amount (100 parts by weight) of the components (A) Is more preferable.

(i) -4 (D) Component

(Kinds)

In addition, the composition for a light-diffusing film in the present invention is preferably a composition for forming a columnar structure having a bent portion 112 'in the middle of a columnar body as shown in Fig. 14 (a) ) Component, it is preferable to include an ultraviolet absorber.

This is because the active energy ray of a predetermined wavelength can be selectively absorbed in a predetermined range when the active energy ray is irradiated by including the ultraviolet absorbent as the component (D).

As a result, as shown in Fig. 14 (a), curvature can be generated in the column structure formed in the film without inhibiting the curing of the composition for the light diffusion film, and as a result, And a predetermined light diffusion property can be stably provided.

The component (D) is preferably at least one member selected from the group consisting of a hydroxyphenyltriazine type ultraviolet ray absorbing agent, a benzotriazole type ultraviolet ray absorbing agent, a benzophenone type ultraviolet ray absorbing agent and a hydroxybenzoate type ultraviolet ray absorbing agent.

Further, specific examples of the hydroxyphenyltriazine type ultraviolet absorber include compounds represented by the following formulas (5) to (9).

Further, specific examples of the benzotriazole-based ultraviolet absorber include compounds represented by the following formula (10).

(content)

It is preferable that the content of the component (D) in the composition for a light-diffusing film is less than 2 parts by weight (excluding 0 part by weight) based on 100 parts by weight of the total amount of the components (A) As shown in Fig.

The reason for this is that by setting the content of the component (D) to a value within this range, it is possible to cause bending of the column structure formed in the film without hindering the curing of the composition for a light diffusion film, This is because a predetermined light diffusion property can be more stably imparted to the diffusion film.

That is, when the content of the component (D) is 2 parts by weight or more, the curing of the composition for a light diffusion film is inhibited, and shrinkage wrinkles may occur on the surface of the film or no curing may occur at all. On the other hand, if the content of the component (D) is excessively small, it becomes difficult to cause sufficient bending of the predetermined internal structure to be formed in the film, and a predetermined light diffusion property is stably imparted This is because it is sometimes difficult to carry out the present invention.

Therefore, the content of the component (D) is more preferably in the range of 0.01 to 1.5 parts by weight, more preferably in the range of 0.02 to 1 part by weight with respect to the total amount (100 parts by weight) of the components (A) Is more preferable.

(i) -5 Other additives

In addition, additives other than the above-mentioned compounds may be added to the extent that the effect of the present invention is not impaired.

Examples of such an additive include hindered amine light stabilizers, antioxidants, antistatic agents, polymerization accelerators, polymerization inhibitors, infrared absorbers, plasticizers, diluting solvents, and leveling agents.

In general, the content of such an additive is preferably within a range of 0.01 to 5 parts by weight, and more preferably in a range of 0.02 to 3 parts by weight based on the total amount (100 parts by weight) of the components (A) and (B) More preferably 0.05 to 2 parts by weight, per 100 parts by weight of the total weight of the composition.

(Ii) Step (b): The coating step

This step is a step of forming the coating layer 101 by coating the composition for a light diffusion film on the process sheet 102 as shown in Fig. 16 (a).

As the process sheet, any of plastic film and paper can be used.

Examples of the plastic film include a polyester film such as a polyethylene terephthalate film, a polyolefin film such as a polyethylene film and a polypropylene film, a cellulose film such as a triacetyl cellulose film, a polyimide film, and the like .

Examples of the paper include gloss paper, coated paper, and laminated paper.

Also, considering the process described below, the process sheet 102 is preferably a plastic film excellent in dimensional stability against heat or active energy rays.

Among these plastic films, polyester films, polyolefin films and polyimide films are preferably used.

For the process sheet, it is preferable to provide a release layer on the application side of the light diffusion film composition in the process sheet in order to easily peel off the obtained light diffusion film from the process sheet after photo-curing.

Such a release layer can be formed by using a conventionally known release agent such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, and an olefin-based release agent.

The thickness of the process sheet is preferably set within a range of usually 25 to 200 mu m.

Examples of the method of applying the composition for a light diffusion film on the process sheet include a known method such as a knife coating method, a roll coating method, a bar coating method, a blade coating method, a die coating method, and a gravure coating method Method can be used.

At this time, it is preferable to set the film thickness of the coating layer within a range of 60 to 700 mu m.

(Iii) Step (c): irradiation process of active energy ray

This step is a step of forming a light diffusion film by forming a columnar structure in the film by irradiating the coating layer 101 with active energy rays as shown in Fig. 16 (b).

More specifically, in the step of irradiating active energy rays, parallel rays having a high degree of parallelism of light are irradiated onto the coating layer formed on the process sheet.

Here, the parallel light means substantially parallel light having no diffusion even if the direction of light emitted is from any direction.

More specifically, for example, as shown in Fig. 17A, the irradiation light 50 from the point light source 202 is converted into the parallel light 60 by the lens 204, and then the coating layer The irradiation light 50 from the linear light source 225 is parallel to the irradiation light parallelizing member 200 (200a, 200b) as shown in Figs. 17 (b) to (c) It is preferable to irradiate the coating layer 101 with the light 60.

17 (d), the irradiation light collimating member 200 is arranged in a direction parallel to the axial direction of the linear light source 225 in which the direction of the light is direct in the direct light by the linear light source 225 It is possible to convert the direct light by the linear light source 225 into parallel light by unifying the directions of light by using the light shielding member 210 such as the plate member 210a or the normal member 210b have.

More specifically, light having a low parallelism to the light shielding member 210, such as the sheet member 210a or the normal member 210b, in direct light by the linear light source 225 is contacted and absorbed.

Therefore, only light having a high degree of parallelism to the light shielding member 210 such as the plate member 210a or the normal member 210b, that is, parallel light, passes through the irradiation light collimating member 200, Direct light by the light source 225 is converted into parallel light by the irradiation light collimating member 200.

The material of the light shielding member 210 such as the sheet member 210a or the normal member 210b is not particularly limited as long as it can absorb light having a low degree of parallelism to the light shielding member 210. For example, For example, an alstar steel plate having a heat-resistant black coating can be used.

It is also preferable to set the parallelism of the irradiation light to a value of 10 DEG or less.

This is because the column structure can be efficiently and stably formed by setting the parallelism of the irradiation light to a value within this range.

Therefore, the parallelism of the irradiation light is more preferably set to a value of 5 DEG or less, and more preferably set to a value of 2 DEG or less.

18, the irradiation angle? D in the case where the angle of the normal to the surface of the coating layer 101 is 0 is set to a value within a range of usually -80 to 80 占.

This is because, when the irradiation angle is out of the range of -80 to 80 °, the influence of reflection on the surface of the coating layer 101 becomes large and it becomes difficult to form a sufficient column structure.

As the irradiation light, ultraviolet rays or electron rays can be mentioned, but it is preferable to use ultraviolet rays.

This is because, in the case of electron beams, the polymerization rate is very fast, so that the components (A) and (B) can not sufficiently be phase-separated in the course of polymerization and it becomes difficult to form a column structure. On the other hand, when compared with visible light or the like, since the ultraviolet ray is enriched with ultraviolet curing resin that can be cured by the irradiation or variation of a usable photopolymerization initiator, the choice of the component (A) and the component (B) Because.

As the ultraviolet irradiation condition, it is preferable to set the peak illuminance on the surface of the coating layer within a range of 0.1 to 10 mW / cm 2.

This is because, when the peak illuminance becomes less than 0.1 mW / cm 2, it may become difficult to form the column structure clearly. On the other hand, when the peak illuminance exceeds 10 mW / cm 2, curing occurs before phase separation of the components (A) and (B) proceeds and conversely, it is difficult to form the column structure clearly It is because.

Therefore, the peak illuminance of the surface of the coating layer in ultraviolet irradiation is more preferably in the range of 0.3 to 8 mW / cm 2, more preferably in the range of 0.5 to 6 mW / cm 2.

The term "peak roughness" as used herein means a measured value at a portion where the active energy ray irradiated on the surface of the coating layer exhibits the maximum value.

In addition, it is preferable that the accumulated light quantity on the surface of the coating layer in ultraviolet irradiation is set to a value within a range of 5 to 200 mJ / cm 2.

This is because, when the integrated amount of light is less than 5 mJ / cm 2, it may be difficult to extend the column structure from the upward to the downward direction sufficiently. On the other hand, when the integrated amount of light exceeds 200 mJ / cm 2, coloration may occur in the obtained light diffusion film.

Therefore, it is more preferable that the integrated amount of light on the surface of the coating layer in ultraviolet irradiation is within a range of 7 to 150 mJ / cm 2, more preferably within a range of 10 to 100 mJ / cm 2.

In addition, it is preferable to optimize the peak illuminance and the accumulated light amount by the internal structure formed in the film.

Further, it is preferable to move the coating layer formed on the process sheet at a speed of 0.1 to 10 m / min when irradiated with ultraviolet rays.

The reason for this is that when the velocity becomes less than 0.1 m / min, the mass productivity may excessively decrease. On the other hand, when the velocity exceeds 10 m / min, the curing of the coating layer, in other words, the formation angle of the ultraviolet ray to the coating layer is changed faster than the formation of the columnar structure and the formation of the column structure becomes insufficient This is because there are cases.

Therefore, when the ultraviolet ray is irradiated, the coated layer formed on the process sheet is more preferably moved at a speed within a range of 0.2 to 5 m / min, and more preferably at a speed within a range of 0.3 to 3 m / min.

In addition, the light diffusion film after the ultraviolet irradiation process is finally usable by peeling off the process sheet.

Further, it is also possible to use a column having deformed columnar bodies 112a "and 112b" made of a first columnar body located on the first surface side and a second columnar body positioned on the second surface side as shown in Fig. 14 (b) When the structure is formed, ultraviolet irradiation is performed in two stages.

That is, the first ultraviolet irradiation is performed first, and the first columnar material is formed on the lower side of the coating layer, that is, on the first surface side, leaving the column structure non-forming region on the upper side of the coating layer, i.e., the second surface side.

At this time, from the viewpoint of stably leaving the unstructured column structure region, it is preferable to perform the first ultraviolet ray irradiation under the oxygen atmosphere in order to take advantage of the effect of oxygen inhibition.

Subsequently, the second ultraviolet ray irradiation is performed, and a second columnar body is formed in the column structure non-forming region left on the second surface side.

At this time, from the viewpoint of stably forming the second columnar material, it is preferable to conduct the second ultraviolet ray irradiation under a non-oxygen atmosphere in order to suppress the influence of the oxygen inhibition.

(3) Light diffusion film having a louver structure in the film

As a light-diffusing film having a louver structure in a film, a light-diffusing film having the following constitution will be described as an example.

That is, the light diffusion film having the internal structure of the louver structure and having the first louver structure and the second louver structure sequentially from below in the film thickness direction, when viewed from above the film, The acute angle &thetas; 1 defined by the extending direction of the plate-shaped area in the first louver structure and the extending direction of the plate-shaped area in the second louver structure is set to a value within a range of 10 to 90 DEG.

(3) -1 Basic configuration

First, the basic structure of the light diffusion film according to this embodiment will be described with reference to Fig.

19 (c), the light diffusion film 100b 'according to this embodiment has the first louver structure 123a shown in FIG. 19 (a) and the second louver structure 123a shown in FIG. 19 (b) (123b) sequentially from below in the film thickness direction.

The extending direction of the plateau region in the first louver structure 123a shown in Fig. 19 (a) and the extending direction of the plateau region in the second louver structure 123b shown in Fig. 19 (b) And they cross each other when viewed from above the film.

19 (b), the light incident on the film is converted into anisotropic light diffusion (light diffusion) by the second louver structure 123b, .

19 (a), the second louver structure 123b diffuses the anisotropically light-diffused diffused light by the second louver structure 123b in the other direction As shown in FIG.

As a result, as shown in Fig. 19C, the light incident on the light diffusion film 100b 'according to the present embodiment is light-diffused in a rectangular shape, and the diffusion area of the incident light can be effectively widened.

In addition, the light diffusion film 100b 'according to the present embodiment is laminated with the reflection plate and is made into an external light utilization type display body, so that even if the incident angle in the azimuth direction of external light changes, It becomes possible to diffuse and exit.

More specifically, the light-diffusing film having a louver structure effectively diffuses the incident light from the azimuthal direction parallel to the extending direction of the plate-shaped area in the louver structure, even when the incident angle in the polar angle direction changes It is difficult to effectively diffuse the incident light from the azimuth direction orthogonal thereto in the case where the incident angle in the polar angle direction changes.

In this regard, the light diffusion film 100b 'according to the present embodiment can efficiently diffuse and emit display light in a predetermined direction even when external light from two different azimuth directions is incident.

The above-mentioned " downward " means a side closer to the process sheet in the film thickness direction of the application layer when the application layer is provided on the process sheet. Therefore, it is a convenience term for describing the light diffusion film according to this embodiment, and the vertical direction of the light diffusion film itself is not limited at all.

19 (c), when the incident light is diffused by the film, the diffusion area of the incident light is a plane that is parallel to the film at a predetermined distance from the film in the diffused outgoing light Means an area in which the diffused light is distributed in the light source.

Hereinafter, the light diffusion film according to the present embodiment will be described in detail.

(3) -2 First louver structure

In the first louver structure, it is preferable to set the difference between the refractive indexes of the plate-like regions having different refractive indexes, that is, the difference between the refractive index of the plateau region having a relatively high refractive index and the refractive index of the plateau region having a relatively low refractive index, More preferably 0.05 or more, and more preferably 0.1 or more.

The details of the above-mentioned film are omitted because they overlap with the contents of the item " refractive index " in the light diffusion film having a columnar structure in the film.

20, the widths S1 and S2 of the high refractive index plate-shaped area 122 and the low refractive index plate-shaped area 124, which have different refractive indexes, are set to 0.1 to 15 Mu m, more preferably in the range of 0.5 to 10 mu m, and more preferably in the range of 1 to 5 mu m.

The details are the same as those of the "maximum diameter" and the "distance between the columnar bodies" in the light diffusion film having the columnar structure in the above-mentioned film, and therefore will not be described.

It is preferable that the thickness of the first louver structure, that is, the length Lb of the first louver structure existing portion in the normal direction of the film surface shown in Fig. 20 is within a range of 50 to 500 mu m, Mu] m, more preferably a value within a range of 80 to 200 [mu] m.

Note that the details are omitted because they are overlapped with the content of the item " thickness " in the light diffusion film having a columnar structure in the above-mentioned film.

20, in the first louper structure, the plurality of high refractive index plate-shaped regions 122 and the plurality of low refractive index plate-shaped regions 124 having different refractive indexes are formed with a constant inclination angle? C with respect to the film thickness direction It is preferable that they are arranged in parallel.

In the case where the angle of the normal to the film surface measured on the cross section when the film is cut on the plane perpendicular to the first louver structure extending in any one direction along the film surface is 0 DEG Means the inclination angle (DEG) of the plate-shaped area.

More specifically, as shown in Fig. 20, the angle is defined as the angle between the normal of the top surface of the first louver structure and the top of the plate-shaped area, which is the narrower side of the angle. As shown in Fig. 20, the inclination angle when the plate-shaped area is inclined to the left is referred to as a reference and the inclination angle when the plate-shaped area is inclined to the right as minus.

As shown in Fig. 21 (a), when viewed from above the film, the extending direction N1 of the plate-shaped regions 122 and 124 in the first louver structure 123a and the elongation direction E ' It is preferable to set the acute angle &thetas; 2 to a value within a range of 10 to 80 DEG.

The reason for this is that by making the extending direction of the plate-shaped area in the first louver structure a value within such a range, it is possible to make the incident light not only along the extending direction of the plate-shaped area in the second louver structure, , The diffusion area of the incident light can be effectively widened by the light diffusion even in the direction orthogonal to the longitudinal direction.

As a result, an external light-utilizing display body having a large viewing angle can be realized as a large-area external light-utilizing display body having no joints.

That is, when the acute angle is less than 10, the light diffusing property in the direction along the longitudinal direction of the film is generally excessively lowered, although the direction of extension of the plate-shaped area in the second louver structure is in general, The diffusion area of the diffusion layer may become excessively small. On the other hand, when the acute angle exceeds 80 DEG, the light diffusion characteristics in the direction orthogonal to the longitudinal direction of the film are deteriorated excessively, generally depending on the extending direction of the plateau region in the second louver structure , The diffusion area of the incident light may become excessively small.

Therefore, when viewed from above the film, the acute angle formed by the extending direction of the plate-shaped region in the first louver structure and the longitudinal direction of the film is more preferably in the range of 35 to 55 DEG, more preferably 40 to 50 DEG More preferably in the range of 44 to 46 DEG, and still more preferably in the range of 44 to 46 DEG.

(3) -3 second louver structure

Since the configuration of the second louver structure is basically the same as that of the first louver structure, avoid duplication and only the following points are described.

21 (b), when viewed from above the film, the elongation direction N2 of the plate-shaped regions 122 and 124 in the second louver structure 123b and the elongation direction E 'of the film It is preferable to set the acute angle &thetas; 3 to a value within a range of 10 to 80 DEG.

The reason for this is that by making the extending direction of the plate-shaped area in the second louver structure a value within such a range, the incident light can be directed not only along the extending direction of the plate-shaped area in the first louver structure, , The diffusion area of the incident light can be effectively widened by the light diffusion even in the direction orthogonal to the longitudinal direction.

Therefore, when viewed from above the film, the acute angle formed by the extending direction of the plate-shaped region in the second louver structure and the longitudinal direction of the film is more preferably in the range of 35 to 55 degrees, more preferably 40 to 50 degrees More preferably in the range of 44 to 46 DEG, and still more preferably in the range of 44 to 46 DEG.

(3) -4 film thickness

The thickness of the light-diffusing film according to the present embodiment is preferably in the range of 50 to 500 mu m, more preferably in the range of 70 to 300 mu m, more preferably in the range of 80 to 200 mu m Is more preferable.

In the film thickness direction of the light-diffusing film, for example, there may be a portion where no louver structure exists in the surface layer portion.

Therefore, the film thickness of the light-diffusing film is equal to or more than the sum of the thickness of the first louver structure and the thickness of the second louver structure.

The details of the above-mentioned film are omitted because they overlap with the contents of the item " film thickness " in the light diffusion film having a columnar structure in the film.

(3) -5 Combination of extension direction

In the light diffusion film according to this embodiment, as shown in Fig. 21 (c), when viewed from above the film, the extending direction N1 of the plate-shaped regions 122 and 124 in the first louver structure 123a And the extending direction N2 of the plate-shaped regions 122 and 124 in the second louver structure 123b are set to values within a range of 10 to 90 degrees.

The reason for this is that by structuring such a structure, it is possible to obtain a longitudinal film in which the diffusion area of the incident light is effectively widened by diffusing the incident light not only in the direction along the longitudinal direction but also in the direction orthogonal to the longitudinal direction to be.

As a result, an external light-utilizing display having a wide viewing angle can be realized, and even when external light is incident from other azimuth directions, it is possible to efficiently diffuse and emit display light in a predetermined direction.

That is, when the acute angle is less than 10, the diffusion area of the incident light may be excessively small.

Therefore, when viewed from above the film, the acute angle formed by the extending direction of the plate-shaped area in the first louver structure and the extending direction of the plate-shaped area in the second louver structure is set to a value within a range of 80 to 90 More preferably within a range of 85 to 90 DEG, and still more preferably within a range of 89 to 90 DEG.

21 (c), when viewed from above the film, the extending direction N1 of the plate-shaped regions 122 and 124 in the first louver structure 123a and the extending direction N2 of the second louver structure 123b Is preferably in line symmetry with respect to a virtual line E "in which the extending direction N2 of the plate-shaped regions 122 and 124 in the longitudinal direction of the film is orthogonal to the longitudinal direction E 'of the film.

This is because light can be uniformly diffused along the incident light by intersecting the extending direction of the plateau region in the first louver structure and the extending direction of the plateau region in the second louver structure .

Specifically, in the case of θ2 = 45 ° and θ3 = 45 °, or in the case where each is a peripheral value, the extending direction of the plate-shaped region in each louver structure is made to be a line-symmetrical shape, The width of the diffused light in the left and right direction and the width in the up and down direction can be respectively maximized.

Therefore, when such a light-diffusing film is applied to a display device using external light, the viewing angle in the lateral direction and the viewing angle in the longitudinal direction can be maximized.

Here, the relationship between the extending direction of the plate-shaped area and the diffusion area of the incident light will be described with reference to Figs. 22 (a) to 22 (e).

22A to 22E show the first louver structure 123a and the light diffusion state 50 'incident on the first louver structure 123a on the left side and the second louver structure 123b and the second louver structure 123b on the right side, And the diffusion state 51 'of the diffused light by the incident first louver structure 123a.

22 (a) shows the diffused state of incident light in the case of? 1 = 90,? 2 = 45, and? 3 = 45, but it can be seen that the final diffused area of the incident light is sufficiently widened 51 ').

On the other hand, Fig. 22 (b) shows the diffusion state of incident light in the case of? 1 = 60 deg.,? 2 = 30 deg., And? 3 = 30 deg. It is understood that the light diffusion characteristic in the direction along the direction E 'is lowered and the diffusion area of the incident light is smaller (51').

22 (c) shows the diffused state of the incident light in the case of? 1 = 60,? 2 = 60, and? 3 = 60. Compared with the case of FIG. 22 (a) It is understood that the light diffusion characteristic in the direction orthogonal to the direction E 'decreases and the diffusion area of the incident light becomes smaller (51').

On the other hand, FIG. 22 (d) shows the diffusion state of incident light in the case of? 1 = 30,? 2 = 15 and? 3 = 15, It is understood that the light diffusion characteristic in the direction along the direction E 'is further lowered and the diffusion area of the incident light is smaller (51').

22 (e) shows the diffused state of the incident light in the case of? 1 = 30,? 2 = 75, and? 3 = 75. Compared with the case of FIG. 22 (a) It is understood that the light diffusion characteristic in the direction orthogonal to the direction E 'is further reduced and the diffusion area of the incident light becomes smaller (51').

Figs. 23 (a) to 23 (e) show photographs of diffused light corresponding to Figs. 22 (a) to 22 (e).

(3) -6 Manufacturing method

Further, the light diffusion film according to this embodiment can be produced, for example, by a manufacturing method including the following steps (a) to (e).

(a) preparing a composition for a light diffusion film comprising two polymerizable compounds having different refractive indexes

(b) a step of applying a composition for a light diffusion film to a process sheet to form a first coated layer

(c) a step of forming a first louver structure by irradiating the first coated layer with a first active energy ray irradiation using a linear light source while moving the first coated layer;

(d) applying a composition for a light-diffusing film to the first coating layer having the first louver structure to form a laminate composed of the first coating layer and the second coating layer

(e) a step of forming a second louver structure by performing a second activation energy ray irradiation with a linear light source while moving a laminate composed of the first coating layer and the second coating layer with respect to the second coating layer , When viewed from above the film, the acute angle &thetas; 1 'formed by the long axis direction of the linear light source in the first activation energy ray irradiation and the long axis direction of the linear light source in the second activation energy ray irradiation is in the range of 10 to 90 DEG Lt; / RTI >

Hereinafter, this manufacturing method will be described in detail with reference to the drawings.

(i) Step (a): Preparation of composition for light diffusion film

The preparation process of the composition for a light diffusion film is omitted because it is overlapped with the content of the item " preparation process of composition for a light diffusion film " in the light diffusion film having a columnar structure in the film.

(Ii) Step (b): First coating step

The thickness of the first coating layer is preferably in the range of 80 to 700 mu m, more preferably in the range of 100 to 500 mu m, and more preferably in the range of 120 to 300 mu m More preferable.

The first coating step is performed as shown in Fig. 24 (a), but the details are the same as those of the items of the " coating step " in the light diffusion film having a columnar structure in the film , Are omitted.

(Iii) Step (c): First active energy ray irradiation step

24 (b), in the step (c), while the first coated layer 101a is moved in the moving direction E with respect to the first coated layer 101a, the linearly polarized light source 225a is used And the first active energy ray irradiation 50a is performed to form the first louver structure 123a.

More specifically, for example, as shown in Fig. 25 (a), an ultraviolet irradiator 220 (for example, a commercially available ultraviolet irradiator 220) provided with a cold mirror 222 for light- The heat ray cut filter 221 and the light shielding plates 223 (223a and 223b) are disposed on the active energy ray 50a (made by IGraphics Co., Ltd., ECS-4011GX etc.) Is taken out, and the first coated layer 101a formed on the process sheet 102 is irradiated.

As shown in Fig. 26 (a), when viewed from above the film, the direction of the long axis of the linear light source 225a in the first active energy ray irradiation and the direction of movement E of the first coated layer 101a 2 'formed by the imaginary line E' (the longitudinal direction of the film) along the longitudinal direction is preferably within a range of 10 to 80 degrees.

The reason for this is that by defining the arrangement angle of the linear light sources in such a manner, not only the direction along the long direction of the incident light but also the direction perpendicular to the long direction of the incident light, as well as the arrangement angle of the linear light sources in the step (e) It is possible to manufacture a long-length light-diffusing film effectively spreading the diffusion area of the incident light by effectively diffusing the light in the direction of the light.

That is, when the angle θ2 'is less than 10 °, the light diffusing property in the direction along the longitudinal direction of the film is excessively lowered, generally depending on the arrangement angle of the linear light source in the step (e) And the diffusion area of the incident light may become excessively small. On the other hand, when the angle θ2 'exceeds a value of 80 °, the light diffusing characteristics in the direction orthogonal to the longitudinal direction of the film generally vary depending on the arrangement angle of the linear light sources in the step (e) , And the diffusion area of the incident light may be excessively reduced.

Therefore, when viewed from above the film, the acute angle &thetas; 2 'formed by the imaginary line along the long axis direction of the linear light source in the first active energy ray irradiation and the moving direction of the first coated layer is within a range of 35 to 55 DEG More preferably in the range of 40 to 50 degrees, and still more preferably in the range of 44 to 46 degrees.

It is preferable that the gap between the linear light source 225a and the coating layer 101a is substantially the same at any position.

25 (b), the irradiation angle? E when the angle of the normal to the surface of the first coated layer 101a is set to 0 degrees is generally -80 to 80 Deg.] Is preferable.

The reason for this is that if the irradiation angle is out of the range of -80 to 80 占 the influence of reflection or the like on the surface of the first coating layer 101a becomes large and it becomes difficult to form a sufficient louver structure Because.

It is preferable that the irradiation angle? E has a width (irradiation angle width)? E 'of 1 to 80 degrees.

This is because, if the irradiation angle width? E 'is less than 1 °, the moving speed of the coating layer must be excessively lowered and the manufacturing efficiency may be lowered. On the other hand, when the irradiation angle width? E 'exceeds 80 °, the irradiation light is dispersed too much, and it becomes difficult to form a louver structure.

Therefore, the irradiation angle width? E 'of the irradiation angle? E is more preferably in the range of 2 to 45 占 and more preferably in the range of 5 to 20 占.

When the irradiation angle width? E 'is provided, the angle of the intermediate position is exactly the irradiation angle? E.

Further, the first active energy ray irradiation is performed through a shield plate having a long groove-like active energy ray transmitting portion, and the longitudinal direction of the active energy ray transmitting portion is a direction parallel to the longitudinal direction of the linear light source .

The active energy ray transmitting portion may be of any type as long as it is transparent to the active energy rays.

For example, it may be made of quartz glass, or may be a simple space in which no light shielding material is present.

Concretely, as shown in Fig. 27, through the apertures (active energy ray transmitting portions) in the apertures formed by the two shading plates 223a and 223b and the lengthwise direction of the apertures in the apertures, 225a in the direction parallel to the major axis direction.

By arranging the shielding plate like this, the irradiation angle [theta] e of the active energy ray 50a shown in FIG. 25 (a) is adjusted to a value within a predetermined range, , It is possible to effectively suppress the irradiation of the active energy ray 50a from the linear light source 225a at an excessively different angle.

As a result, the inclination angle of the plate-shaped area in the formed louver structure can be made uniform, and further, the light diffusion characteristics of the obtained long-axis light diffusion film can be made uniform.

The peak illuminance on the surface of the first coated layer in the first active energy ray irradiation is preferably set to a value within a range of 0.1 to 50 mW / cm 2, and a value within a range of 0.3 to 10 mW / More preferably 0.5 to 5 mW / cm < 2 >.

It is preferable that the total amount of light on the surface of the first coated layer in the first active energy ray irradiation is set to a value within a range of 5 to 300 mJ / cm 2, and a value within a range of 10 to 200 mJ / And more preferably in the range of 20 to 150 mJ / cm < 2 >.

The moving speed of the first coated layer is preferably set to a value within a range of 0.1 to 10 m / min, more preferably within a range of 0.2 to 5 m / min, a value within a range of 0.5 to 3 m / Is more preferable.

Note that details are omitted because they are overlapped with the item of " process of irradiating active energy rays " in the light diffusion film having a columnar structure in the above-mentioned film.

(Iv) step (d): second coating step

24 (c), the composition for the light diffusion film is applied to the first coating layer 101a 'on which the first louver structure 123a is formed, and the first coating layer 101a ') And a second coated layer 101b are formed on the surface of the second layer 101b.

When an active energy ray transmitting sheet (for example, a separation film having an active energy ray transmittance such as a PET film having a thickness of 38 mu m) is used to form the first louver structure 123a, The surface of the coating layer 101a 'is exposed, and then the above-described operation is performed.

The composition for a light diffusion film used for forming the second application layer 101b is preferably the same as the composition for a light diffusion film used for forming the first application layer 101a.

This is because by using the same composition for a light diffusion film, reflection at the interface between the first louver structure 123a formed on the coating layer 101a 'and the second louver structure 123b formed on the coating layer 101b' Can be suppressed, and the adhesion can also be improved.

Examples of the method for applying the composition for a light diffusion film on the first coating layer on which the first louver structure is formed include knife coating method, roll coating method, bar coating method, blade coating method, die coating method, A gravure coating method, or the like, as in the above-mentioned step (b).

The thickness of the second coating layer is preferably in the range of 80 to 700 mu m, more preferably in the range of 100 to 500 mu m, and more preferably in the range of 120 to 300 mu m More preferable.

Note that the details will be omitted because they overlap with those in the above-described first coating layer.

(v) Step (e): the second activation energy ray irradiation step

24 (d), the first coating layer 101a 'and the second coating layer 101b' in which the first louver structure 123a is formed are formed on the second coating layer 101b, As a step of forming the second louver structure 123b by irradiating the second active energy ray using the linear light source 225b while moving the laminate 101c made of the second louver structure 123b as shown in Fig. Similarly, when viewed from above the film, an acute angle? 1 'between the long axis direction of the linear light source 225a in the first activation energy ray irradiation and the long axis direction of the linear light source 225b in the second activation energy ray irradiation, To a value within a range of 10 to 90 degrees.

That is, by defining the relationship of the arrangement angles of the respective linear light sources within a predetermined range in the two active energy ray irradiation processes using the linear light sources, the extending direction of the plate-shaped region in the first louver structure and the It is possible to efficiently manufacture an elongated light diffusion film formed by crossing the extending direction of the plate-like region in the louver structure at a predetermined angle.

Therefore, by effectively diffusing the incident light not only in the direction along the longitudinal direction but also in the direction orthogonal to the longitudinal direction, it is possible to efficiently manufacture a long-length light diffusion film effectively spreading the diffusion area of the incident light.

More specifically, a long-lived light diffusion film capable of light-diffusing incident light in a direction along its longitudinal direction and in a direction perpendicular to its longitudinal direction without connecting a plurality of light diffusion films as in the prior art is obtained .

As a result, an external light-utilizing display body having a large viewing angle can be realized as a large-area external light-utilizing display body having no joints.

The light diffusion film according to the present embodiment can be obtained by simply laminating a light diffusion film having a louver structure in a film such that the acute angle formed by the extending direction of the plateau region in each louver structure is within a predetermined range You can get it.

That is, when the acute angle &thetas; 1 'shown in FIG. 26B is less than 10 DEG, the diffusion area of the incident light may be excessively small.

Therefore, when viewed from above the film, the acute angle &thetas; 1 'formed by the long axis direction of the linear light source in the first activation energy ray irradiation and the long axis direction of the linear light source in the second activation energy ray irradiation is set to 80 to 90 DEG More preferably in a range of 85 to 90 degrees, and still more preferably in a range of 89 to 90 degrees.

26 (b), when viewed from above the film, the direction of the long axis of the linear light source 225b in the second active energy ray irradiation and the direction in which the first louver structure 123a is formed It is preferable that the acute angle &thetas; 3 'formed by the imaginary line E' along the moving direction E of the layered product 101c made up of the layer 101a 'and the second coated layer 101b is within a range of 10 to 80 DEG.

The reason for this is that by defining the arrangement angles of the linear light sources in such a manner, in addition to the arrangement angles of the linear light sources in the above-described step (c), not only the direction along the long direction of the incident light, It is possible to manufacture a long-length light-diffusing film effectively spreading the diffusion area of the incident light by effectively diffusing the light in the direction of the light.

That is, when the angle θ3 'is less than 10 °, the light diffusing property in the direction along the longitudinal direction of the film is excessively lowered, generally depending on the arrangement angle of the linear light sources in the above-described step (c) And the diffusion area of the incident light may become excessively small. On the other hand, when the angle θ3 'exceeds a value of 80 °, the light diffusion characteristic in the direction perpendicular to the longitudinal direction of the film generally varies depending on the arrangement angle of the linear light sources in the above-described step (c) , And the diffusion area of the incident light may be excessively reduced.

Therefore, when viewed from above the film, the angle? 3 'formed by the imaginary line in the long axis direction of the linear light source with the second activation energy ray irradiation and the imaginary line along the moving direction of the laminate composed of the first coating layer and the second coating layer, More preferably in the range of 35 to 55 °, more preferably in the range of 40 to 50 °, and still more preferably in the range of 44 to 46 °.

It is preferable that the gap between the linear light source 225b and the coating layer 101b is substantially the same at any position.

The irradiation angle and the irradiation angle width of the active energy ray are preferably in the same numerical range as in the case of the first active energy ray irradiation described with reference to Figs. 25 (a) to 25 (b).

26 (b), when viewed from above the film, the direction of the long axis of the linear light source 225a in the first active energy ray irradiation and the direction of the long axis of the linear light source It is preferable that the major axis direction of the first coated layer 101a 'and the second coated layer 101b' are symmetrical with respect to a virtual line E 'perpendicular to the moving direction E of the laminated body composed of the first coated layer 101a' and the second coated layer 101b.

This is because, by arranging the linear light source in the second activation energy ray irradiation, the incident light can be diffused more uniformly in the obtained light diffusion film.

In particular, when θ 2 '= 45 ° and θ 3' = 45 °, or when each is a peripheral value, the width of the diffused light in the left and right direction and the width in the up and down direction Width, respectively.

Therefore, when such a light-diffusing film is applied to a display device using external light, the viewing angle in the lateral direction and the viewing angle in the longitudinal direction can be maximized.

As shown in Fig. 27, the second activation energy ray irradiation is also performed through the gap between the pair of shading plates formed of the two shading plates for the same reason as the case of the first activation energy ray irradiation, It is preferable that the longitudinal direction of the gap be a direction parallel to the longitudinal direction of the linear light source.

The peak illuminance on the surface of the second coated layer in the second active energy ray irradiation is preferably set to a value within a range of 0.1 to 50 mW / cm 2, and a value within a range of 0.3 to 10 mW / More preferably 0.5 to 5 mW / cm < 2 >.

The total amount of light on the surface of the second coating layer in the second activation energy ray irradiation is preferably in the range of 5 to 300 mJ / cm 2, more preferably in the range of 10 to 200 mJ / And more preferably in the range of 20 to 150 mJ / cm < 2 >.

The moving speed of the laminate composed of the first coated layer and the second coated layer in which the first louver structure is formed is preferably set to a value within a range of 0.1 to 10 min and a value within a range of 0.2 to 5 m / More preferably, within a range of 0.5 to 3 m / min.

Note that the details will be omitted because they overlap with those in the above-described first coating layer.

It is also preferable to irradiate the active energy rays with the active energy ray transmitting sheet laminated on the upper surface of the second coated layer from the viewpoint of the case of the step (c).

It is also preferable to irradiate an active energy ray separately from the second active energy ray irradiation as the step (e) so that the second coated layer has an accumulated light quantity enough for curing.

Since the active energy ray at this time is intended to sufficiently cure the second coating layer, it is preferable to use random light in any traveling direction, not parallel light.

The above-mentioned steps (d) to (e) may be carried out in succession to the steps (b) to (c) using one conveyor, and the first louver structure (D) to (e) may be carried out by collecting the first coated layer having the first coating layer formed thereon in a roll form and putting it on a separate conveyor.

Therefore, in the case of the former, the linear light source in the step (c) and the linear light source in the step (e) are separately disposed. In the latter case, the arrangement angle of the collinear light source is changed May be used.

(4) A light diffusion film having a predetermined internal structure in the film

A light diffusion film having a predetermined internal structure different from the above-described column structure or louver structure in a film will be described.

28 (a), a plurality of thin flakes 132 having a relatively high refractive index in a region 134 having a relatively low refractive index are stacked in a film along with a plurality A light diffusion film 100c having a predetermined internal structure 133 formed by arraying in a column direction will be described.

In this light diffusion film 100c, a plurality of thin flakes 132 arranged in a line are arranged at a predetermined interval, and a region 134 having a relatively low refractive index is interposed in the gap.

That is, the thin piece 132 is composed of an end portion formed by cutting the edge portion of the plate-like region having a relatively high refractive index by the region 134 having a relatively low refractive index, and a plate-like portion sandwiched by the two end portions.

Therefore, this predetermined internal structure 133 can be said to be a hybrid structure of a louver structure and a column structure, as a matter of fact.

More specifically, in a flaky article constituting a predetermined internal structure, it is presumed that the central plate-like portion expresses anisotropic light diffusion and the end portion expresses isotropic light diffusion.

Therefore, it has been confirmed that when the length of the center plate-shaped portion of the flake is greater than or equal to a predetermined value, the louver structure characteristics are strongly manifested and elliptical light diffusion occurs. Conversely, When the length of the plate-like portion is not more than a predetermined value, it is confirmed that the characteristics of the column structure are strongly expressed, and light diffusion such as isotropic light diffusion occurs almost.

However, even when light diffusion such as isotropic light diffusion occurs apparently, when the incident angle of the external light to the film is changed in the azimuth direction due to the predetermined internal structure different from the column structure, It is confirmed that the light diffusion film exhibits different light diffusion characteristics.

The light diffusing film having a predetermined internal structure in the film is preferably such that when an active energy ray is irradiated to a coating layer composed of the composition for a light diffusion film, the angle of incidence is controlled to a value within a predetermined range every azimuth angle direction And then irradiating with an energy ray.

29A, a linear light source 225 as an active energy linear light source, an incident angle width adjusting member 200 for adjusting an incident angle width of an active energy ray from the linear light source 225, It is preferable to arrange the incident angle width adjusting member 200 in the radiation region of the active energy ray from the linear light source 225 and the coating layer 101 and from the linear light source 225 .

More specifically, as shown in Fig. 29 (a), the incident angle adjusting member 200 is composed of a plurality of plate members 210, and a plurality of plate members 210 face each other It is preferable that the main surface is parallel to the vertical direction.

The reason for this is that the active energy rays from the linear light source are converted into active energy rays whose angle of incidence is controlled within a predetermined range for each azimuth angle direction by performing the activation energy ray irradiation preparing step, It is possible to investigate.

Although a plurality of plate members are disposed parallel to each other with their principal surfaces facing each other, the direct light from the linear light source is converted into an active energy ray whose angle of incidence is controlled to a value within a predetermined range for each azimuth angle direction , It is sufficient if it is substantially parallel.

The term " in the radiation region of the active energy ray from the linear light source 225 and the coating layer 101 and also from the linear light source 225 " means that, for example, as shown in Fig. 29 (b) When the active energy ray is irradiated vertically downward from the linear light source 225, the linearly arranged light source 225 is vertically downward and vertically above the application layer 101.

30 (a) to 30 (c), on the surface of the coating layer 101, on the region where the illuminance of the active energy ray 60 from the active energy ray source 225 is maximized The azimuthal direction X in which the angle of incidence of the active energy ray takes the minimum value? 4 and the azimuthal direction Y in which the angle of incidence of the active energy ray takes the maximum value? 5 are orthogonal to each other at the arbitrary one point R positioned, It is preferable that the minimum value? 4 of the incident angle of the line is set to a value of not more than 5 degrees and the maximum value? 5 of the incident angle width of the active energy ray is set to a value within a range of more than 5 degrees and not more than 10 degrees.

30 (a) is a plan view when viewed from above the coating layer 101, Fig. 30 (b) is a side view when viewed from a direction Y in Fig. 30 X is the angle of incidence of the active energy ray.

30 (c) is a side view when viewed from the direction X in Fig. 30 (a), and shows the angle of incidence of the active energy rays in the azimuth direction Y. Fig.

First, as shown in Figs. 30 (a) to 30 (c), the "area where the roughness of the active energy ray from the active energy ray source is maximized on the surface of the coating layer" ) Is used as the center line of the distribution of the active energy ray 60 which is irradiated almost linearly on the surface of the application layer 101.

30 (b), when the active energy ray 60 is irradiated vertically downward from the linear light source 225, the surface of the coating layer 101 of Fig. 30 (a) The projection line to the vertical downward direction of the center line of the linear light source 225 becomes a region where the illuminance of the active energy ray from the active energy linear light source becomes maximum.

For example, when an active energy ray is irradiated from the linear light source toward the lower right diagonal line, the vicinity of the projection line below the right diagonal line of the center line of the dedicated light source on the surface of the coating layer is shifted from the active energy ray source And becomes the region where the illuminance of the active energy ray becomes maximum.

Next, an " azimuthal direction in which the incident angle width of the active energy ray takes a minimum value at an arbitrary point located on a region where the illuminance of the active energy ray from the active energy ray source is maximum on the surface of the coating layer & As shown in Fig. 30 (a) to Fig. 30 (c), when the linear light source 225 is used as the active energy ray source, the angle of incidence of the active energy ray 60 Is the azimuth angle direction X taking the minimum value [theta] 4, and becomes the direction orthogonal to the axial direction of the linear light source 225. [

The minimum value? 4 of the incident angle width of the active energy ray 60 at the point R as the "arbitrary single point" is calculated from the point R by the cross section circle of the linear light source 225 As shown in FIG.

It should be noted that " an azimuthal direction in which the angle of incidence of the active energy ray takes a maximum value at an arbitrary point located on a region where the illuminance of the active energy ray from the active energy ray source is maximum on the surface of the coating layer & As shown in Fig. 30 (a) to Fig. 30 (c), when the linear light source 225 is used as the active energy ray source, the angle of incidence of the active energy ray 60 The azimuth direction Y taking the maximum value [theta] 5 becomes the azimuth angle direction orthogonal to the azimuth angle direction X described above.

30 (c), the maximum value? 5 of the incident angle width of the active energy ray 60 at the point R as the " arbitrary single point " Is an angle formed by two tangent lines at the end on the linear light source 225 side of the light guide plate 210.

As described above, the azimuthal direction X in which the incident angle width of the active energy ray takes the minimum value 4 and the azimuthal direction Y in which the incident angle width of the active energy ray takes the maximum value 5 are orthogonal to each other, whereby a predetermined internal structure can be efficiently formed .

The irradiation conditions of other active energy rays can be applied to the light diffusion film having a columnar structure in the film or the light diffusion film having a louver structure in the film.

(5) Other light diffusion films

The light diffusion film used in the light diffusion film of external light use type of the present invention has been described by way of concrete examples, but the light diffusion film used in the external light utilization type light diffusion film of the present invention is not limited to these examples.

For example, the light diffusion film 100d may have both a louver structure and a column structure in the film as shown in Fig. 28 (b).

The light diffusing film 100e having a lattice-like internal structure in the film as shown in Fig. 28 (c) may also be used, and as shown in Fig. 28 (d) Film 100f.

These light diffusion films can be actually obtained by irradiating active energy rays with a predetermined method on the same composition for a light diffusion film as used for forming the column structure described above, Although the patent has been filed, the details thereof are omitted (cf. Japanese Patent Application No. 2011-268544, Japanese Patent Application No. 2011-266315, Japanese Patent Application No. 2011-266314, etc.).

3. Reflector

The reflector 10 shown in Figs. 1A to 1C is not particularly limited as long as it is capable of reflecting light. However, since flexibility can be imparted to the display 1 using the external light, the aluminum evaporated layer (10b) having the above-mentioned resin film (10a).

The three-dimensional shape of the reflecting surface of the reflecting plate is usually preferably flat, but it may be a non-planar specular reflecting plate such as a sawtooth reflecting plate or a corner cube array, or a weak diffused reflecting plate.

In this case, a non-planar specular reflector such as a sawtooth reflector or a corner cube array has an effect of being able to freely design an angle of incidence of the external light and an observation angle, that is, to obtain so-called retroreflective reflection, , The viewing angle can be effectively expanded without sacrificing the uniformity of the diffused light described so far and the characteristics such as the constancy of the display light in a predetermined direction with respect to the change of the incident angle of the external light in the polar angle and azimuth direction.

It is also preferable that the reflector is a semi-transmissive reflector.

This is because, under an environment in which external light is sufficient, external light is used as a light source of display light, and under an environment in which external light is insufficient, a backlight provided on the back surface of the reflection plate can be used as a light source of display light.

The thickness of the reflector is preferably in the range of 10 to 5000 mu m, more preferably in the range of 100 to 500 mu m.

4. Decorative floor

The decorative layer 20 shown in Figs. 1 (b) to 1 (c) is not particularly limited as long as it is a layer showing the display content by letters or drawings. However, since the display contents can be freely configured, It is preferable to use a laminate of a printing layer 20a made of ink or the like constituting a pattern, a printing layer (easy printing layer) 20b and a transparent or translucent resin film 20c.

The reason for this is that the external light reflected by the reflection plate easily transmits the resin film to a portion where characters, drawings, etc. are not printed, while the portion where characters or drawings are printed is reflected by the reflection plate It is possible to effectively improve the visibility of the display contents.

The decorative layer may be a printed layer directly printed on a reflection plate or a light diffusion film.

The thickness of the decorative layer is preferably in the range of 10 to 1000 mu m, more preferably in the range of 20 to 500 mu m.

5. Adhesive layer

1 (a) to 1 (c), it is preferable that the reflector 10, the light diffusion film 100, and the decorative layer 20 are laminated via the pressure-sensitive adhesive layer 30, respectively.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited as long as it has sufficient tackiness and transparency. For example, conventionally known pressure-sensitive adhesives of acryl, silicone, urethane and rubber can be used.

The thickness of the pressure-sensitive adhesive layer is preferably in the range of 1 to 100 mu m, more preferably in the range of 3 to 30 mu m.

6. Other sun

Other aspects of the external light utilizing type display body of the present invention will be described with reference to Figs. 31 (a) to 31 (b).

31 (a) and 31 (b) are external light-utilizing display bodies 1 of the embodiment in which a layer 40 having light-resistance is laminated on the external light incident side.

As described above, by laminating the layer having the light-resistant property on the external light incidence side of the display using external light, it is possible to effectively prevent yellowing of the light diffusion film by ultraviolet rays.

As the layer having such light resistance, a resin film in which an ultraviolet absorber is dispersed can be used.

31 (b) is a view in which the reflector 10 and the decorative layer 20 are integrated to make the total thickness of the display body 1 of the external light use type thinner.

More specifically, the front and back surfaces of the reflector 10 are arranged opposite to those of Fig. 31 (a), and serve as the resin film 20c of the decorative layer 20 with respect to the resin film 10b of the reflector The resin film layer is omitted for one layer.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples.

[Example 1]

1. Preparation of light diffusion film

(1) Synthesis of low refractive index polymerizable compound (B)

2 moles of isophorone diisocyanato (IPDI) as a component (B1) and 2 moles of 2-hydroxyethyl (meth) acrylate as a component (B3) were added to 1 mole of polypropylene glycol (PPG) having a weight average molecular weight of 9,200 as component (B2) After admitting 2 moles of methacrylate (HEMA), the reaction was carried out according to a conventional method to obtain a polyether urethane methacrylate having a weight average molecular weight of 9,900.

The weight average molecular weight of polypropylene glycol and polyether urethane methacrylate is a polystyrene reduced value measured by gel permeation chromatography (GPC) under the following conditions.

GPC measurement apparatus: HLC-8020 manufactured by TOSOH CORPORATION

GPC column: manufactured by TOSOH CORPORATION (hereinafter referred to as the order of passage)

TSK guard column HXL-H

TSK gel GMHXL (× 2)

TSK gel G2000HXL

Measurement solvent: tetrahydrofuran

· Measuring temperature: 40 ℃

(2) Preparation of composition for light diffusion film

Subsequently, 100 parts by weight of polyether urethane methacrylate having a weight average molecular weight of 9,900 as component (B) was dissolved in 100 parts by weight of o-phenylphenoxyethoxyethyl acrylate having a molecular weight of 268 represented by the above formula (3) as component (A) 150 parts by weight of a polyoxyalkylene polyol (NK Ester A-LEN-10 manufactured by Shin-Nakamura Chemical Co., Ltd.) and 20 parts by weight of 2-hydroxy-2-methyl- (8 parts by weight based on the total amount (100 parts by weight) of the component (A) and the component (B)) was added and heated and mixed under the condition of 80 캜 to obtain a composition for a light diffusion film.

The refractive indices of the component (A) and the component (B) were measured according to JIS K0062 using an Abbe refractometer (Abe Refractometer DR-M2, Na light source, wavelength 589 nm) And 1.46.

(3) First coating step

Subsequently, the obtained composition for a light diffusion film was applied to a transparent polyethylene terephthalate film (hereinafter referred to as PET) as a process sheet to form a first coated layer having a thickness of 165 탆.

(4) First active energy ray irradiation process

Subsequently, an ultraviolet irradiator (ECS-4011GX, manufactured by Igraphics Co., Ltd.) to which a cold mirror for condensing was attached was prepared in a high-pressure mercury lamp as shown in Fig. 25 (a).

At this time, when viewed from above the film, the ultraviolet irradiating device was provided such that the acute angle? 2 formed by the imaginary line along the long axis direction of the linear light source and the moving direction of the first coated layer was 45 degrees.

Then, when a shading plate is provided on the hot-cut filter frame and the normal line of the surface of the first coating layer when the ultraviolet rays irradiated to the surface of the first coating layer is viewed from the long axis direction of the linear light source is 0 DEG, (? E in FIG. 25 (b)) of the direct ultraviolet rays from the light source is set to 16 degrees.

The height from the surface of the first coating layer to the linear light source was set to 2000 mm, the peak illuminance was set to 1.26 mW / cm 2, and the accumulated light amount was set to 23.48 mJ / cm 2.

Further, in order to prevent reflected light from the shading plate or the like from becoming stray light inside the irradiation apparatus and affecting the light curing of the first coated layer, two shading plates are provided in the vicinity of the conveyor as shown in Fig. 27, Only the ultraviolet rays emitted directly from the first coating layer were irradiated to the first coating layer.

More specifically, as shown in Fig. 27, it is arranged so as to form a gap (gap width: 35 cm) in a slot formed by two shading plates, and the longitudinal direction of the gap between the apertures in the slot is shorter than the long axis direction So as to be in a parallel direction.

Subsequently, the first coated layer was irradiated with ultraviolet rays while moving the first coated layer in the rightward direction in Fig. 24 (b) at a speed of 1.0 m / min by the conveyor, and the length in the longitudinal direction (moving direction of the first coated layer) A length of 1.4 m, and a film thickness of 165 mu m was formed on the first coated layer.

Subsequently, in order to ensure reliable curing, a release film (SP-PET382050, manufactured by LINTEC CO., LTD.) Having ultraviolet transmittance of 38 mu m in thickness as an active energy ray transmissive sheet was coated on the exposed surface side of the first coated layer, A haze value of 1.80%, an image clarity of 425, and a transmittance of 84.3% at a wavelength of 360 nm).

Then, the scattered light was irradiated so that the peak illuminance was 13.7 mW / cm 2 and the accumulated light amount was 213.6 mJ / cm 2.

The above-mentioned peak illuminance and the accumulated light amount were measured by placing a UV meter (UV-IR integrated gamut meter UVPF-A1 manufactured by Igraphics Co., Ltd.) equipped with a light receiver at the position of the first coating layer.

The film thickness of the obtained first coating layer having the first louver structure was measured using a static pressure gauge (TECLOCK PG-02J manufactured by Takara Shuzo Co., Ltd.).

(5) Second coating step

Then, the active energy ray transmission sheet was peeled off from the first coating layer on which the obtained long luccal first louver structure was formed.

Subsequently, the composition for a light-diffusing film obtained in the above-mentioned process was applied to the exposed surface of the first coated layer having the obtained long-lipped first louver structure to form a second coated layer having a thickness of 165 탆.

(6) Second active energy ray irradiation process

Then, when viewed from above the film, ultraviolet irradiation is performed so that the acute angle &thetas; 1 between the long axis direction of the linear light source in the first activation energy ray irradiation and the long axis direction of the linear light source in the second activation energy ray irradiation is 90 DEG. Except that the apparatus was installed, a long-lived light diffusion film having a film thickness of 330 mu m having a first louver structure and a second louver structure was obtained by irradiating the same with ultraviolet light in the same manner as in the first activation energy ray irradiation step.

When viewed from above the film, the acute angle? 3 between the longitudinal direction of the linear light source and the virtual line along the moving direction of the laminate composed of the first coated layer and the second coated layer in which the first louver structure was formed was 45 ° .

Also, even when the second coating layer is irradiated with ultraviolet light, scattered light is irradiated in the state of being laminated with an active energy ray transmitting sheet (a releasing film having ultraviolet ray permeability) as in the case of the first coating layer, I tried.

32, when viewed from above the film, the light-diffusing film obtained is a light-diffusing film which is formed by the extension direction of the plate-like region in the first louver structure and the extending direction of the plate- It was confirmed that the acute angle was 90 °.

Further, when viewed from above the film, it was confirmed that the acute angle formed by the extending direction of the plate-like region in the first louver structure and the film longitudinal direction was 45 °.

Further, when viewed from above the film, it was confirmed that the acute angle formed by the extending direction of the plate-like region in the second louver structure and the longitudinal direction of the film was 45 °.

Fig. 33 (a) is a photograph of a section obtained by cutting the obtained light-diffusing film at a plane orthogonal to the longitudinal direction of the film, and Fig. 33 And Fig. 33 (b), respectively.

Further, the light diffusion film was cut using a razor, and photographing of the cross section was performed using an optical microscope (reflection observation).

(7) Evaluation of light diffusion characteristics

As shown in Fig. 32, light was incident on the film from a direction orthogonal to the film surface from the lower side (the side where the first louver structure is located) of the obtained light diffusion film.

Subsequently, a spectral chart of the diffused light in the direction perpendicular to the longitudinal direction of the film and in the direction parallel to the longitudinal direction of the film was obtained using a side color system (VC-2, manufactured by Suga Shikeki Co., Ltd.) .

That is, as shown in Fig. 34 (a), in the case where the light diffusion angle (deg) in the diffused light diffused by the light diffusion film is taken on the abscissa and the relative intensity (-) of the diffused light is taken on the ordinate .

Here, the spectrum chart A shown in Fig. 34 (a) corresponds to the diffused light in the direction perpendicular to the longitudinal direction of the film, and the spectrum chart B shows the diffusions in the direction parallel to the longitudinal direction of the film Light.

Further, as shown in Fig. 34 (b), a photograph of the diffused light when viewed from the Z direction in Fig. 32 was obtained using a conoscope (autronic-MELCHERS GmbH).

The results shown in Figs. 34 (a) and 34 (b) are consistent with the light diffusion characteristics predicted from the film having the internal structure as shown in Fig. 32. By this film, the external light- It was presumed that it could be realized.

2. Manufacture of a display using external light

Subsequently, as shown in Fig. 1 (a), the resulting light-diffusing film was laminated on a mirror-surface reflector (a surface of a PET film having a thickness of 100 mu m so as to have aluminum of 300 nm in thickness) To prepare a display body using external light.

3. Evaluation of display type using external light

(1) Evaluation of uniformity of luminance of display light in viewing angle

The uniformity of the brightness of the display light within the viewing angle was evaluated with respect to the obtained external light utilization type display body.

That is, as shown in Fig. 35 (a), the obtained external light utilization type display body 1 was placed on a horizontal surface such that the surface of the light diffusion film was on the upper side.

Then, the linear light source 2 as the external light source 2 was disposed at a position inclined by 5 占 in the arrow direction with respect to the normal line of the surface of the display body 1 for external light use.

At this time, the linear light source 2 was arranged so as to be parallel to the surface of the display body for external light use type and its axis perpendicular to the paper surface.

At this time, in the external light-utilizing display device 1, the extending direction of the plate-shaped area in the first louver structure of the light-diffusing film becomes parallel to the direction of the arrow in the figure, Are arranged so as to be parallel to the direction orthogonal to the paper surface.

Next, the external light utilization type display body 1 was observed from a position inclined by -5 deg. In the direction of the arrow with respect to the normal line of the surface of the external light utilization type display body 1, and photographing was performed. The obtained photograph is shown in (1) in Fig.

As shown in (1) in FIG. 36, it was confirmed that the external light-utilizing display body of Example 1 had display characteristics with high uniformity of luminance.

(2) Evaluation of display characteristics with respect to change of incidence angle of external light

The display characteristics of the obtained external light utilization type display body with respect to the change in incident angle of external light were evaluated.

That is, first, as shown in Fig. 35 (a), the uniformity of the luminance of the display body in the viewing angle is evaluated, And the line-shaped light source 2 was disposed at the position.

Next, with respect to the normal line of the external light-utilizing display element 1, the external light-utilizing display element 1 was observed from a position inclined at -5 deg. In the direction of the arrow, and photography was performed. The obtained photograph is shown in (1) in Fig.

Subsequently, as shown in Fig. 35 (b), the line-shaped light source 2 is disposed at a position inclined by 10 占 in the arrow direction with respect to the normal line of the surface of the display body 1 for external light use.

Next, with respect to the normal line of the external light-utilizing display element 1, the external light-utilizing display element 1 was observed from a position inclined at -5 deg. In the direction of the arrow, and photography was performed. The obtained photograph is shown in (1) in Fig.

The photograph taken by rotating the external light utilization type display body 1 in the azimuth direction at an angle of 45 while the position of the linear light source 2 is maintained in the state shown in Fig. 35 (b) is shown in (1) (1) in Fig. 39 shows a photograph taken by rotating the lens at 90 [deg.].

First, as understood from (1) in FIG. 36 and (1) in FIG. 37, with respect to the change in the incident angle (change from 5 DEG to 10 DEG) in the polar angle direction of the external light, But uniformity of luminance is not lowered, and almost the same display characteristics are obtained.

As can be understood from (1) in FIG. 37, (1) in FIG. 38, and (1) in FIG. 39, the azimuthal direction of external light incidence is the (The case of (1) in Fig. 37 and the case of (1) in Fig. 39), the uniformity of the luminance is relatively high, (1)), the uniformity of luminance is lowered.

From the above, it was confirmed that the display characteristics of the external light-utilizing display material of Example 1 showed almost no change in the incident angle of external light although the luminance uniformity was high and the range was limited.

  In addition, from the viewpoint of more effectively evaluating the external light utilization type display body, the above-described external light utilization type display body is not provided with a decorative layer, but it is also possible to check that the same result is obtained basically did.

[Example 2]

In Example 2, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1, except that the light-diffusing film was produced as follows.

1. Preparation and evaluation of light diffusion film

(1) Coating process

The composition for a light diffusion film prepared in the same manner as in Example 1 was applied to a transparent polyethylene terephthalate film (hereinafter referred to as PET) as a process sheet to form a coated layer having a thickness of 170 탆.

(2) active energy ray irradiation

16 (b), while using the ultraviolet spot parallel light source (manufactured by JATEC CO., LTD.) Having the central ray parallelism controlled within the range of +/- 3 degrees, the degree of parallelism was 2 DEG or less (Ultraviolet rays from a high-pressure mercury lamp having peaks at 254 nm, 303 nm, and 313 nm in the main peak wavelength of 365 nm) was applied to the coating layer so that the irradiation angle (? D in Fig. 18) I investigated.

The peak illuminance at that time was 2.00 mW / cm 2, the accumulated light intensity was 53.13 mJ / cm 2, the lamp height was 240 mm, and the moving speed of the coating layer was 0.2 m / min.

(SP-PET382050, manufactured by LINTEC CO., LTD.) Having a thickness of 38 mu m and having a center line average roughness of 0.01 on the surface of the ultraviolet irradiation side was coated on the exposed surface side of the coating layer in order to ensure reliable curing. Mu m, haze value of 1.80%, image clarity of 425, transmittance of 84% at a wavelength of 360 nm).

Subsequently, the scattered light obtained by randomly moving the direction of parallel light was irradiated from the release film so that the peak illuminance was 10 mW / cm 2 and the accumulated light amount was 150 mJ / cm 2 to completely cure the coating layer. A light diffusion film having a thickness of 170 mu m was obtained.

Fig. 40 (a) is a schematic view of a section of the obtained light-diffusing film cut parallel to the moving direction of the coating layer and on a plane orthogonal to the film surface, and a cross-sectional photograph thereof is shown in Fig. 40 (b).

Fig. 40 (c) shows a cross-sectional photograph of a cross section of the resulting light-diffusing film cut perpendicularly to the moving direction of the applied layer and on the plane orthogonal to the film surface. 40 (b) and 40 (c), it can be seen that the internal structure of the obtained light-diffusing film is a columnar structure having a deformed column as shown in Fig. 6 (a).

The light diffusing film was cut using a razor, and photographing of the cross section was performed by reflection observation using a digital microscope (VHX-2000, manufactured by GUENNES CO., LTD.).

(3) Evaluation of light diffusion characteristics

(3) -1 Measurement of haze value

The haze value of the resulting light-diffusing film was measured.

That is, as shown in Fig. 9 (b), by changing the incident angle [theta] a with respect to the normal to the film surface in the range of -70 to 70 [deg.] In accordance with the moving direction B of the coating layer by rotating the obtained light diffusion film , And the haze value (%) with respect to each of the incident angles &thetas; a was modified according to ASTM D 1003 using a device manufactured by BYK Corporation.

In addition, as shown in Fig. 41 (a), the incidence of the light on the light diffusion film at that time is performed on the back side of the light diffusion film, that is, on the opposite side .

Incidentally, also in the following embodiments, the incident angle &thetas; a having the same inclination as the inclination of the columnar body is expressed as a positive value, and the incident angle &thetas; a having the inclination opposite to the inclination of the columnar body is expressed as a negative value. The obtained angle-of-haze value chart is shown in Fig.

The haze value (%) means a value calculated by the following equation (1), and the diffusion transmittance (%) in the following equation (1) means a value obtained by subtracting the parallel light transmittance (%) from the total light transmittance , And the parallel light transmittance (%) means the transmittance (%) of light having a width up to ± 2.5 ° with respect to the traveling direction of the linearly transmitted light.

(3) -2 Measurement by conoscopic

The light diffusion property corresponding to the case where the obtained light diffusion film was applied to a display device using external light was measured.

Namely, as shown in Fig. 43, the obtained light diffusion film 100a was bonded to the reflection plate 10 to obtain a test piece for measurement.

43, light was incident on the test piece 100a, 10 from the movable light source arm 410 by using the reflection mode of a conoscopic 400 (manufactured by autronic-MELCHERS GmbH).

In addition, as shown in Fig. 41 (b), the incidence of light onto the light diffusion film at that time was carried out from the opposite side of the side of the light diffusion film, that is, the side from which the active energy ray was irradiated at the time of producing the light diffusion film.

Incidentally, also in the following embodiments, the incident angle &thetas; a having the same inclination as the inclination of the columnar body is expressed as a positive value, and the incident angle &thetas; a having the inclination opposite to the inclination of the columnar body is expressed as a negative value. The obtained conoscopic images are shown in Figs. 44 (a) to (g).

The reflector was BV2 manufactured by JDSU Co., Ltd. The test piece for measurement was obtained by bonding a light diffusion film to the aluminum evaporated surface of the reflector through a pressure-sensitive adhesive layer having a thickness of 15 mu m.

As shown in Fig. 44 (h), these conoscopic images have a luminance distribution ranging from 0 mu m / m < 2 > to a maximum luminance value in each of the conoscopic images in 14 steps from blue to red And the value of 0 ㏅ / m 2 is blue, the value exceeding 0 ㏅ / ㎡ from the maximum brightness value in each of the conoscopic images is divided into thirteen, and the value of 0 ㏅ / ㎡ to the maximum brightness is approached And thus changes to 13 levels from blue to searched to green to yellow to orange to red.

The lines drawn in the radial direction in each of the conoscopic images indicate azimuth directions of 0 to 180 DEG, 45 to 225 DEG, 90 to 270 DEG, and 135 to 315 DEG, and lines drawn in a concentric circle direction 38 degrees, 58 degrees, 78 degrees in the polar angle direction.

Therefore, the color at the central portion of each concentric circle in each of the conoscopic images represents the relative luminance of the diffused light emitted to the front of the film.

Fig. 45 shows an incident angle-luminance chart showing the relationship between the incident angle [theta] a and the luminance ([mu] / m2) in the central portion of each concentric circle in Figs. 44 (a) to (g). From Fig. 45, it can be seen that incident light in a wide range of the incident angle [theta] a = 0 to 50 [deg.] Can be diffused and emitted efficiently to the film front face.

2. Evaluation of display type using external light

As shown in (2) in FIG. 36, it was confirmed that the external light-utilizing display body of Example 2 had a display characteristic of high luminance uniformity.

As shown in (2) in FIG. 36 and (2) in FIG. 37, the external light-utilizing display of Example 2 exhibits a slight luminance It was confirmed that the uniformity of luminance was not lowered and almost the same display characteristics were obtained.

As shown in (2) in FIG. 37, (2) in FIG. 38 and (2) in FIG. 39, in the external light utilizing type display body of Embodiment 2, It was confirmed that even with a slight change in the incident angle, the uniformity of luminance was not lowered, and almost the same display characteristics were obtained.

[Example 3]

In Example 3, a light diffusion film was produced and evaluated in the same manner as in Example 2, except that the light diffusion film was produced as follows.

Using the obtained light-diffusing film, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1. [

1. Preparation and evaluation of light diffusion film

In Example 3, 0.5 parts by weight ((A)) of an ultraviolet absorber (TINUVIN 384-2 made by BSF) represented by the formula (10) as a component (D) And 0.2 parts by weight with respect to the total amount (100 parts by weight) of the component (B) were added to the light diffusion film. The obtained results are shown in Figs.

Here, Fig. 46 (a) is a schematic view of a section of the obtained light-diffusing film which is cut parallel to the moving direction of the coating layer and on a plane orthogonal to the film surface, and Fig. 46 (b) is a cross-sectional photograph thereof.

46 (c) is a photograph of a section obtained by cutting the obtained light-diffusing film perpendicularly to the moving direction of the coating layer and on a plane orthogonal to the film surface.

Fig. 47 (a) is an enlarged view of the vicinity of the bent portion of the columnar body in the sectional view of Fig. 46 (b), and Fig. 47 (b) is a photograph further enlarging the lower portion from the bent portion of the columnar body. From FIGS. 46 (b) to 46 (c) and 47 (a) to 47 (b), it can be seen that the internal structure of the obtained light diffusion film is a column structure having a deformed columnar body as shown in FIG. .

48 is an angle of incidence-haze chart of the obtained light-diffusing film.

49 (a) to 49 (g) are photographs showing the light diffusion state corresponding to the case where the obtained light diffusion film is applied to a display using external light.

50 is an angle of incidence-luminance chart showing the relationship between the incident angle [theta] a and the luminance ([mu] / m2) in the central portion of each concentric circle in Figs. 49 (a) to 49 (g). From Fig. 50, it can be seen that incident light in a wide range of the incident angle [theta] a = 0 to 60 [deg.] Can be diffused and emitted efficiently to the film front face.

2. Evaluation of display type using external light

Evaluation results similar to those of the external light utilization type display body of Example 2 were obtained in the external light utilization type display body of Example 3.

Therefore, from the viewpoint of preventing complication, the photographing of the external light-utilizing display body is omitted.

[Example 4]

In Example 4, a light diffusion film was produced and evaluated in the same manner as in Example 2, except that the light diffusion film was produced as follows.

Using the obtained light-diffusing film, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1. [

1. Preparation and evaluation of light diffusion film

In Example 4, after changing the film thickness of the coating layer to 210 탆 and irradiating the active energy beam with parallel light, scattered light was irradiated in a state in which the release film was laminated on the exposed surface side of the coating layer Instead, parallel light having a degree of parallelism of 2 DEG or less was irradiated using an ultraviolet spot parallel light source (manufactured by JATEC CO., LTD.) Whose central ray parallelism was controlled within 3 DEG, Deg.], The light diffusing film was produced and evaluated in the same manner as in Example 2. [ The film thickness of the obtained light-diffusing film was 210 μm. The obtained results are shown in Figs.

Here, FIG. 51 (a) is a schematic view of a section of the obtained light diffusion film cut parallel to the moving direction of the applied layer and on a plane orthogonal to the film surface, and FIG. 51 (b) is a cross-sectional photograph thereof.

51 (c) is a cross-sectional photograph of the obtained light-diffusing film cut perpendicularly to the moving direction of the applied layer and on the plane perpendicular to the film surface.

52 (a) is an enlarged view of the vicinity of the overlapping columnar structure region where the first columnar body and the second columnar body overlap in the cross-sectional image of Fig. 51 (b), and Fig. 52 , And the lower part from the redundant column structure area is further enlarged. It can be seen from Figs. 51 (b) to 51 (c) and 52 (a) to 52 (b) that the internal structure of the obtained light diffusion film is a column structure having a deformed column as shown in Fig. .

53 is an angle of incidence-haze chart of the obtained light-diffusing film.

54 (a) to 54 (g) are photographs showing the light diffusion state corresponding to the case where the obtained light diffusion film is applied to a display using external light.

55 is an incident angle-luminance chart showing the relationship between the incident angle [theta] a and the luminance ([mu] / m2) in the central portion of each concentric circle in Figs. 54 (a) to 54 (g). From Fig. 55, it can be seen that incident light in a wide range of the incident angle [theta] a = 0 to 60 [deg.] Can be diffused and emitted efficiently to the film front face.

2. Evaluation of display type using external light

In the external light utilization type display body of Example 4, the same evaluation results as those of the external light utilization type display body of Example 2 were obtained.

Therefore, from the viewpoint of preventing complication, the photographing of the external light-utilizing display body is omitted.

[Example 5]

In Example 5, an external light-utilizing display material was prepared and evaluated in the same manner as in Example 2 except that the light-diffusing film was produced as follows.

Using the obtained light-diffusing film, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1. [

1. Preparation and evaluation of light diffusion film

In Example 5, in place of the ultraviolet spot collimated light source, an ultraviolet ray irradiated with a cold mirror for light condensation was irradiated onto a line-shaped high-pressure mercury lamp (diameter 25 mm, length 2.4 m, output 28.8 kW) (Manufactured by Igraphics Co., Ltd., small-sized test machine).

Subsequently, as shown in Fig. 56 (b), an incident angular width adjusting member in which a plurality of plate members are arranged in parallel is disposed between the line-shaped ultraviolet lamp and the coating layer.

At this time, when viewed from above the application layer, the incident angle width adjusting member is disposed such that the angle of inclination formed by the moving direction of the coating layer and the extending direction of the plate-like member, that is,? F in FIG. did.

Further, as shown in Fig. 56 (a), two light shielding members were interposed between the coating layer and the incident angular width adjusting member.

57 (a)) is 23 mm, and the width (L2 in Fig. 57 (a) in Fig. 57 (a)) of the plate- Mm, the thickness of the plate member was 1.6 mm, and the material was Alstar steel subjected to heat-resistant black paint.

The length from the upper end to the lower end of the incident angle adjusting member (L3 in FIG. 57 (b)) was 200 mm, and the distance between the upper end of the incident angle width adjusting member and the lower end of the line- 57 (b) was 100 mm, and the distance between the lower end of the incident angle-adjusting member and the surface of the coating layer (L5 in FIG. 57 (b)) was 1700 mm.

The length W of the coating layer in the moving direction of the coating layer in the area where the active energy rays are irradiated is the length between the two light shielding members 223a and 223b as shown in Fig. 56 (a) , 360 mm.

The line-shaped ultraviolet lamp was disposed so that the moving direction of the coating layer and the major axis direction of the line-shaped ultraviolet lamp were perpendicular to each other.

Therefore, the projection line to the vertical downward direction of the center line of the ultraviolet lamp on the surface of the coating layer becomes a region where the illuminance of the active energy ray (ultraviolet ray) from the ultraviolet lamp becomes the maximum.

Subsequently, ultraviolet rays are irradiated from the line-shaped ultraviolet lamp through the incident angle adjusting member to irradiate parallel light having a degree of parallelism of -5 degrees or less to the coating film so that the irradiation angle (? D in Fig. 18) To obtain a light diffusion film having a thickness of 170 탆.

At that time, when viewed from the axial direction of the line-shaped ultraviolet lamp at an arbitrary point located on a region where the illuminance of the ultraviolet ray is maximized on the surface of the coating layer, when the incident angle width of the ultraviolet ray reaches the minimum value The angle of incidence of the ultraviolet rays is 8.6 占 as the maximum value (? 5 of FIG. 30 (c)) when viewed from the direction of movement of the coating layer in the direction orthogonal thereto, The coated layer was irradiated with ultraviolet rays so that it could take place.

At that time, the peak roughness of the coating layer surface was 1.05 mW / cm 2, the accumulated light quantity was 22.6 mJ / cm 2, and the moving speed of the coating layer was 1.0 m / min. The obtained results are shown in Figs. 58 to 61.

Here, Fig. 58 (a) is a schematic view of a section of the obtained light-diffusing film cut parallel to the moving direction of the coating layer and on a plane perpendicular to the film surface, and Fig. 58 (b) is a cross-sectional photograph thereof.

Fig. 58 (c) is a photograph of a section obtained by cutting the obtained light-diffusing film perpendicularly to the moving direction of the coating layer and on a plane orthogonal to the film surface.

From these cross-sectional photographs, it was confirmed that the resulting light-diffusing film had a predetermined internal structure as shown in Fig. 28 (a) in the film.

59 is an angle of incidence-haze chart of the obtained light-diffusing film.

60 (a) to 60 (g) are photographs showing the light diffusion state corresponding to the case where the obtained light diffusion film is applied to a display using external light.

61 is an incident angle-luminance chart showing the relationship between the incident angle [theta] a and the luminance ([mu] / m2) in the center portion of each concentric circle in Figs. 60 (a) to 60 (g). From Fig. 61, it can be seen that only the incident light in a narrow range of the incident angle [theta] a = 0 to 30 [deg.] Can not diffuse and exit to the front of the film.

Therefore, the external light-utilizing display body using such a film has a narrow angular range of incident light capable of establishing superiority, and therefore, is suitable for use in a limited environment (for example, in the case of using solar light as external light, Therefore, it is expected that it can be effectively used.

2. Evaluation of display type using external light

As shown in (3) in FIG. 36, it was confirmed that the external light-utilizing display body of Example 5 had high display uniformity of luminance.

As shown in (3) in FIG. 36 and in (3) in FIG. 37, the external light-utilizing display of Example 5 exhibits a slight change in the incident angle in the polar angle direction of the external light, It was confirmed that the uniformity of luminance was not lowered and almost the same display characteristics were obtained.

As shown in (3) in FIG. 37, (3) in FIG. 38, and (3) in FIG. 39, in the external light utilizing type display body of Embodiment 5, (The case of (3) in Fig. 37), the uniformity of the luminance is relatively high, and when they are not coincident with each other (the cases of (3) and (The case of (3) in Fig. 39), it was confirmed that the uniformity of the luminance was lowered.

From the above, it was confirmed that the display characteristics of the external light-utilizing display of Example 5 showed almost no change in the incident angle of external light although the luminance uniformity was high and the range was limited.

[Comparative Example 1]

In Comparative Example 1, a light diffusion film was prepared and evaluated in the same manner as in Example 2, except that the light diffusion film was produced as follows.

Using the obtained light-diffusing film, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1. [

1. Preparation and evaluation of light diffusion film

In Comparative Example 1, 100 parts by weight of an acrylic copolymer having a weight average molecular weight of 1,850,000, which was obtained by polymerizing butyl acrylate and acrylic acid in a weight ratio of 95: 5 in accordance with a conventional method, was mixed with 100 parts by weight of tris (acryloxyethyl) iso 15 parts by weight of cyanurate (Aronikkus M-315, molecular weight: 423, trifunctional type, manufactured by Toagosei Co., Ltd.) and 1 part by weight of benzophenone as a photopolymerization initiator and 1-hydroxycyclohexyl phenyl ketone (Irgacure 500, manufactured by Chiba Specialty Chemicals Co., Ltd.) and 0.3 part by weight of trimethylolpropane-modified tolylene diisocyanate (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) as an isocyanate crosslinking agent And 0.2 part by weight of 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent and 0.2 part by weight of a spherical silicone fine particle (manufactured by GE Toshiba Silicone Co., 145, average particle diameter 4.5 mu m) And ethyl acetate were added and mixed to prepare an ethyl acetate solution (solid content: 14% by weight) of a sticky material.

Next, an ethyl acetate solution of the obtained sticky material was applied to a polyethylene terephthalate film (Cosmo Shine A4100, made by Toyobo Co., Ltd.) having a thickness of 100 占 퐉 by a knife coater such that the thickness after drying was 25 占 퐉 And then dried at 90 DEG C for 1 minute to form a pressure-sensitive adhesive material layer.

Subsequently, a peeling layer of a polyethylene terephthalate peeling film (SP-PET3811, manufactured by LINTEC CORPORATION) having a thickness of 38 mu m as a peeling sheet and the obtained adhesive material layer were laminated, and after 30 minutes from the application, H valve The ultraviolet rays were irradiated from the release film side to the adhesive material layer so that the light intensity was 600 mW / cm 2 and the light quantity was 150 mJ / cm 2 using an electrodeless lamp (manufactured by Fusion Corporation).

Then, the obtained adhesive material layer after ultraviolet curing was used as the light diffusion film of Comparative Example 1.

The haze value of the obtained light-diffusing film was always about 98% when the angle of incidence? A was changed in the range of -70 to 70 °.

In Comparative Example 1, measurement by a conoscopic was omitted.

2. Evaluation of display type using external light

Further, as shown in (4) in Fig. 36, the external light-utilizing display of Comparative Example 1 showed high uniformity of brightness, but did not obtain sufficient brightness and was dark.

As shown in (4) in Fig. 36 and (4) in Fig. 37, the external light-utilizing display of Comparative Example 1 exhibits uniform luminance uniformity with respect to change in incident angle in the polar angle direction of external light The luminance did not deteriorate, but sufficient brightness was not obtained and darkness was confirmed.

As shown in (4) in FIG. 37, (4) in FIG. 38, and (4) in FIG. 39, in the external light utilization type display body of Comparative Example 1, in the azimuth direction of external light incidence The uniformity of luminance was not lowered, but sufficient brightness was not obtained and it was confirmed that it was dark.

From the above, it was confirmed that the external light-utilizing display body of Comparative Example 1 was lower in brightness and inferior in brightness than the external light-use display body of Examples 1 to 5.

[Comparative Example 2]

In Comparative Example 2, a light diffusion film was produced and evaluated in the same manner as in Comparative Example 1, except that the amount of the fine spherical silicon fine particles to be added was reduced.

Using the obtained light-diffusing film, an external light-utilizing display material was produced and evaluated in the same manner as in Example 1. [

1. Evaluation of light diffusion film

The haze value of the resulting light-diffusing film was always about 50% when the angle of incidence? A was changed in the range of -70 to 70 °.

Also in Comparative Example 2, the measurement by the conoscopic was omitted.

2. Evaluation of display type using external light

As shown in (5) in Fig. 36, it was confirmed that the external light utilization type display body of Comparative Example 2 obtained a sufficient luminance and was bright, but the luminance uniformity was low.

As shown in (5) in FIG. 36 and (5) in FIG. 37, in the external light-utilizing display of Comparative Example 2, the brightness of the incident light in the extreme- It can be seen that it has been changed.

As shown in (5) in FIG. 37, (5) in FIG. 38, and (5) in FIG. 39, in the external light utilizing type display body of Comparative Example 2, Dark was confirmed.

As described above, the external light-utilizing display body of Comparative Example 2 is inferior to the external light-use display body of Examples 1 to 5 in terms of uniformity of brightness in display light and display characteristics with respect to changes in incident angle of external light .

As described above, according to the external light-utilizing display body of the present invention, the light-diffusing film to be used in the external light-utilizing display body formed by laminating the reflection plate and the light-diffusing film is placed in a region where the refractive index is relatively low The light diffusion film having an internal structure having a plurality of regions with relatively high refractive index can stably maintain constant display characteristics even when the angle of incidence of external light changes, The uniformity of the luminance can be increased.

Therefore, the external light-utilizing display body of the present invention can be applied to a display body using external light such as a signboard, an advertisement, and a road sign, and it is expected that it significantly contributes to high quality of the display body.

The present invention relates to a display device using an external light source and a method of manufacturing the same and a method of manufacturing the same. A diffusing state of diffused light, 60: a parallel light, 100: a diffused light, 20: a resin film, 30: a pressure-sensitive adhesive layer, 100a: light diffusion film having a columnar structure in a film, 100b: light diffusion film having a louver structure in the film, 101: coating layer, 101a: first coating layer, 101a ': first A first coating layer and a second coating layer, 102: a process sheet, 112: a columnar material having a relatively high refractive index, 113: a columnar structure, 113a: a columnar structure 114: a region having a relatively low refractive index, 115: a first surface, 116: a second surface, 122: a plate-shaped region having a relatively high refractive index, 123: A louver structure 123a a first louver structure 123b a second louver structure 123a a louver interfacial surface 124 a relatively low refractive index sheet region 200 irradiance parallelizing member 202 point light source 204 light- A light shielding plate, a linear light source, a light source, an integrating sphere, a cone-shaped member, and a cone-shaped member. Scope, 410: light source arm

Claims (5)

A reflective plate, and a light diffusion film,
Wherein the light-diffusing film is a light-diffusing film having an internal structure having a plurality of regions having a relatively high refractive index in a region where a refractive index is relatively low in the film. The method according to claim 1,
Wherein the decorative film has a decorative layer on the side opposite to the side where the reflection plate is located between the reflection plate and the light diffusion film or the light diffusion film. 3. The method according to claim 1 or 2,
Wherein the internal structure of the light diffusion film has a column structure in which a plurality of columnar bodies having a relatively high refractive index are grown in a film thickness direction in a region where the refractive index is relatively low, A louver structure in which the plate-shaped regions are alternately arranged in any one direction along the film plane, or a structure of either one of them. The method of claim 3,
Wherein in the case where the internal structure of the light diffusion film is the column structure, the light diffusion film is a single-layer light diffusion film, the thickness of the light diffusion film is within a range of 60 to 700 mu m, When the angle of incidence of incident light with respect to the normal to the film surface is changed in the range of -70 to 70 degrees along the moving direction of the coated layer when the coating layer formed by coating the composition for a light- Wherein the haze value for each incident angle is 70% or more. The method of claim 3,
Wherein the light diffusion film has a first louver structure and a second louver structure sequentially from below in the film thickness direction when the internal structure of the light diffusion film is the louver structure, When viewed from above, the acute angle? 1 formed by the extending direction of the plate-shaped area in the first louver structure and the extending direction of the plate-shaped area in the second louver structure is set to a value within a range of 10 to 90 degrees Type display body.

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