Patent Publication Number: US-2021191024-A1

Title: Optical body and light emitting device

Description:
TECHNICAL FIELD 
     The present invention relates to an optical body and a light emitting device. 
     BACKGROUND ART 
     As a kind of optical body, there is known an optical body in which a light waveguiding phenomenon and a macro concave-convex structure are combined. Such an optical body is also called a light guide plate. The macro concave-convex structure is formed on one surface of the light guide plate. Light is injected into the inside of the light guide plate from a light source that is provided on a side surface of the light guide plate. The light injected in the inside of the light guide plate, that is, internally propagating light propagates through the inside of the light guide plate while reflecting at surfaces of the light guide plate (that is, interfaces between the inside and the outside of the light guide plate). After that, the internally propagating light is reflected at a surface of the macro concave-convex structure, and is emitted from another surface of the light guide plate. That is, the light guide plate emits light injected from a side surface of the light guide plate, from a surface of the light guide plate. The light guide plate is used as, for example, light emitting bodies for various display devices or light emitting bodies for illumination. Examples of the display device in which a light guide plate is used include various LCDs (for example, an LCD of a local dimming driving system), passive-type display devices, light ornamentation panels for amusement, illumination panels for advertisements such as digital signage, etc. In these display devices, an expression looking as if light stood out from a place where a pattern of a macro concave-convex structure is formed is enabled by the turning on and off of the light source. 
     In the case where a light guide plate is used as a light emitting body of a display device, an oblique surface of at least one surface of the macro concave-convex structure needs to be an oblique surface with an angle of more than or equal to 30° and less than 90°. Light that has been incident from a side surface of the light guide plate and has traveled through the light guide plate is totally reflected at this oblique surface, and is emitted from a surface of the light guide plate. In such a light guide plate, it is necessary that, when the light source is turned off, the observer be hindered from recognizing the existence of the light guide plate to the extent possible. Furthermore, it is necessary to enhance the display quality. Hence, an excellent antireflection function to extraneous light of high transmission, low reflection, and low scattering is required. This is in order to enhance the display quality of the display device. Here, as the extraneous light, as well as sunlight and light from other light emitting bodies (for example, illumination, other display devices, etc.), there is also light from other display bodies provided inside the display device (for example, a liquid crystal panel, etc.) and the like. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2006-012854A 
     Patent Literature 2: JP 2003-249110A 
     Patent Literature 3: JP 2008-299079A 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, no technology that sufficiently meets the requirements described above has been proposed. For example, Patent Literatures 1 to 3 disclose technologies regarding the light guide plate described above. In the technology disclosed in Patent Literature 1, a micro concave-convex structure in which the average period of concavity and convexity is less than or equal to a wavelength of visible light is provided on least one surface of both surfaces of the light guide plate. Here, the micro concave-convex structure is arranged randomly. Further, the distance between convexities or the distance between concavities of the micro concave-convex structure satisfies a prescribed condition. 
     In the technology disclosed in Patent Literature 2, a light reflection angle control surface is formed in a prescribed position between concavities of a macro concave-convex structure. In the technology disclosed in Patent Literature 3, an antireflection film of a multiple-layer structure is provided on at least one surface of both surfaces of the light guide plate. However, these technologies have failed to sufficiently meet the requirements described above. Hence, a technology that sufficiently meets the requirements described above has been strongly desired. 
     Thus, the present invention has been made in view of the problem mentioned above, and an object of the present invention is to provide a new and improved optical body and a new and improved light emitting device that can be used as a light guide plate and can have an excellent antireflection function to extraneous light. 
     Solution to Problem 
     According to an aspect of the present invention in order to achieve the above object, there is provided an optical body including: a base material; a macro concave-convex structure that is formed on one surface of the base material and emits internally propagating light that is injected in an inside of the base material from a side surface of the base material, from another surface of the base material; and a micro concave-convex structure formed periodically to follow each of both surfaces of the base material and a surface of the macro concave-convex structure, and having an average period of concavity and convexity of less than or equal to a wavelength of visible light. The surface of the macro concave-convex structure has an inclined surface that is inclined with respect to the one surface by more than or equal to 30° and less than 90°, and an arrangement of the micro concave-convex structure is a zigzag arrangement with respect to a traveling direction of internally propagating light. 
     Here, an angle between an arrangement direction of the micro concave-convex structure and a direction perpendicular to a propagation direction of the internally propagating light may be 30 to 60°. 
     In addition, the one surface may be partitioned into a light emitting region where the macro concave-convex structure is formed and a non-light emitting region other than the light emitting region, and the micro concave-convex structure may be formed in each of both of the light emitting region and the non-light emitting region. 
     In addition, the micro concave-convex structure may extend in a direction perpendicular to the surface of the macro concave-convex structure. 
     In addition, the macro concave-convex structure may be an aggregate of a plurality of macro convexities and a plurality of macro concavities and at least one of the plurality of macro convexities and the plurality of macro concavities may have a prism shape, and the micro concave-convex structure may be formed to follow a surface of each of the plurality of macro convexities and the plurality of macro concavities. 
     In addition, a luminous reflectance may be less than or equal to 1.0%. 
     In addition, further a reflection chromaticity (a*, b*) may be less than or equal to 1.0. 
     In addition, an average height of the micro concave-convex structure may be more than or equal to 200 nm. 
     In addition, the base material may have a multiple-layer structure. 
     According to another aspect of the present invention, there is provided a light emitting device including: the above optical body; and a light source that is provided on a side surface of the optical body and injects light into an inside of the optical body from the side surface of the optical body. 
     Advantageous Effects of Invention 
     As described above, according to the present invention, a macro concave-convex structure formed on a surface of an optical body can emit internally propagating light that is injected in the inside of a base material from a side surface of the base material, from another surface of the base material. Therefore, the optical body can be used as a light guide plate. Further, a micro concave-convex structure is formed periodically to follow each of both surfaces of the base material and a surface of the macro concave-convex structure, and the average period of concavity and convexity is less than or equal to a wavelength of visible light. Therefore, the optical body has an excellent antireflection function to extraneous light. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side cross-sectional view showing a rough configuration of an optical body according to an embodiment of the present invention. 
         FIG. 2  is a plan view showing an example of a micro concave-convex structure according to the embodiment. 
         FIG. 3  is a side cross-sectional view showing a modification example of the optical body. 
         FIG. 4  is a perspective diagram illustrating an exemplary appearance of a master according to the present embodiment. 
         FIG. 5  is a block diagram illustrating an exemplary configuration of an exposure device. 
         FIG. 6  is a schematic diagram illustrating an example of a transfer device that manufactures an optical body by roll-to-roll. 
         FIG. 7  is a side cross-sectional view showing a rough configuration of an optical body according to Example 1. 
         FIG. 8  is a side cross-sectional view showing a rough configuration of an optical body according to Example 2. 
         FIG. 9  is a side cross-sectional view showing a rough configuration of an optical body according to Example 3. 
         FIG. 10  is a cross-sectional SEM photograph showing a micro concave-convex structure. 
         FIG. 11  is a cross-sectional SEM photograph showing a micro concave-convex structure formed to follow a surface of a macro concave-convex structure. 
         FIG. 12  is a planar SEM photograph showing a micro concave-convex structure. 
         FIG. 13  is a side cross-sectional view showing a rough configuration of an optical body according to Comparative Example 1. 
         FIG. 14  is a side cross-sectional view showing a rough configuration of an optical body according to Comparative Example 2. 
         FIG. 15  is a side cross-sectional view showing a rough configuration of an optical body according to Comparative Example 3. 
         FIG. 16  is a plan view showing a planar shape of a micro concave-convex structure according to Comparative Example 4. 
         FIG. 17  is a plan view showing a planar shape of a micro concave-convex structure according to Comparative Example 4. 
         FIG. 18  is a planar SEM photograph showing a micro concave-convex structure according to Comparative Example 4. 
         FIG. 19  is a planar SEM photograph showing a micro concave-convex structure according to Comparative Example 5. 
         FIG. 20  is a graph showing a specular reflection spectrum of the optical bodies according to Examples 1 to 3 and Comparative Examples 1 to 3 in comparison. 
         FIG. 21  is a graph showing a diffuse reflection spectrum of the optical bodies according to Examples 1 to 3 and Comparative Examples 1 to 3 in comparison. 
         FIG. 22  is a graph showing corresponding relationships between an incidence angle of measuring light and a reflection Y value (luminous reflectance) on the basis of a height of a micro concave-convex structure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, (a) preferred embodiment(s) of the present invention will be described in detail with reference to the appended drawings. In this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
     &lt;1. Configuration of Optical Body&gt; 
     Next, the configuration of an optical body  1  according to the present embodiment is described on the basis of  FIG. 1  and  FIG. 2 . The optical body  1  includes a base material  10 , a first micro concave-convex structure  11 , a second micro concave-convex structure  12 , and a macro concave-convex structure  13 . The optical body  1  can function as what is called a light guide plate. That is, the optical body  1  emits internally propagating light that is injected in the optical body  1  from a side surface of the optical body  1 , from a surface of the optical body  1  (specifically, a first surface  10 A described later) to the outside. 
     The base material  10  propagates light injected in the inside of the base material  10 , that is, internally propagating light in planar directions of the base material  10  (that is, directions perpendicular to the thickness direction; in  FIG. 1 , horizontal directions). While details are described later, the optical body  1  is produced by pressing, under a heated condition, a macro concave-convex master having the inverse shape of the macro concave-convex structure  13  against the base material  10  on which the first micro concave-convex structure  11  and the second micro concave-convex structure  12  are formed. Hence, the base material  10  is required to soften under a heated condition. Thus, the base material  10  is preferably formed of a thermoplastic resin excellent in light conductivity. Examples of such a resin include polymethyl methacrylate, a polycarbonate, A-PET, a cycloolefin copolymer, a cycloolefin polymer, and the like. The thickness of the base material  10  is not particularly limited, and may be adjusted in accordance with the use etc. of the optical body  1 , as appropriate. Further, the base material  10  may be a multiple-layer structure. For example, the optical body  1  may be produced by sticking together a base material on which the first micro concave-convex structure  11  is formed and a base material on which the second micro concave-convex structure  12  and the macro concave-convex structure  13  are formed. It is also possible to stick a base material on which the first micro concave-convex structure  11  is formed and a base material on which the second micro concave-convex structure  12  and the macro concave-convex structure  13  are formed, individually to the front and back surfaces of a base material formed of a resin other than thermoplastic resins. In this case, the base material on which the second micro concave-convex structure  12  and the macro concave-convex structure  13  are formed is formed of a thermoplastic resin. 
     The first micro concave-convex structure  11  is formed periodically to follow a surface (hereinafter, also referred to as a first surface)  10 A of the base material  10 . That is, the first micro concave-convex structure  11  extends in a direction perpendicular to the first surface  10 A. In the first micro concave-convex structure  11 , the average period of concavity and convexity is less than or equal to a wavelength of visible light (for example, less than or equal to 830 nm). The average period of concavity and convexity is preferably more than or equal to 100 nm and less than or equal to 350 nm, more preferably more than or equal to 120 nm and less than or equal to 280 nm, and still more preferably 130 to 270 nm. Therefore, the first micro concave-convex structure  11  has what is called a moth-eye structure. Here, in the case where the average period is less than 100 nm, the formation of the first micro concave-convex structure  11  may be difficult; thus, this is not preferable. Further, in the case where the average period is more than 350 nm, the intensity of diffracted light may be large. That is, there is a possibility that internally propagating light will diffract at the first surface  10 A and leak out to the outside. 
     Here, the configuration of the first micro concave-convex structure  11  is described in detail on the basis of  FIG. 1  and  FIG. 2 . The first micro concave-convex structure  11  has large numbers of first micro convexities  11   a  and first micro concavities  11   b . The first micro convexity  11   a  has a shape protruding on the outside in the thickness direction of the optical body  1 , and the first micro concavity  11   b  has a shape recessed on the inside in the thickness direction of the optical body  1 . The first micro convexity  11   a  and the first micro concavity  11   b  are formed periodically on the first surface  10 A. That is, it can be said that the first micro concave-convex structure  11  is a structure in which tracks (rows) composed of a plurality of first micro convexities  11   a  and a plurality of first micro concavities  11   b  are arranged parallel to each other. In the example of  FIG. 1 , the track extends in the left and right direction, and is aligned in the up and down direction. The first micro convexities  11   a  (or the first micro concavities  11   b ) arranged between adjacent tracks are mutually shifted in the length direction of the track by half the length of the first micro convexity  11   a  (or the first micro concavity  11   b ). 
     The average period of concavity and convexity is given as the arithmetic average value of a dot pitch P1 and a track pitch P2. The dot pitch P1 is the distance between first micro convexities  11   a  (or first micro concavities  11   b ) arranged in the length direction of the track. The track pitch P2 is the distance between adjacent tracks. In the present embodiment, each of the dot pitch P1 and the track pitch P2 is less than or equal to a wavelength of visible light. The dot pitch P1 and the track pitch P2 may be the same or different. 
     Here, the dot pitch P1 is specifically the distance between first micro convexities  11   a  (or first micro concavities  11   b ) arranged in the length direction of the track. The first micro concave-convex structure  11  can be observed with, for example, a scanning electron microscope (SEM), a cross-sectional transmission electron microscope (cross-sectional TEM), or the like. The dot pitch P1 is measured by the following method, for example. That is, a combination of first micro convexities  11   a  adjacent in the length direction of the track is picked out. Then, the distance between the apices of the first micro convexities  11   a  may be taken as the dot pitch P1. Further, the track pitch P2 is the distance between adjacent tracks. The track pitch P2 is measured by the following method, for example. That is, a combination of adjacent tracks is picked out. Then, the distance between the tracks may be taken as the track pitch P2. 
     The arrangement direction of the first micro concave-convex structure  11  is classified into two arrangement directions, that is, a dot arrangement direction L20 and a crossing arrangement direction L22. The dot arrangement direction L20 agrees with the extension direction of the track. The crossing arrangement direction L22 is defined as a direction connecting the apices of first micro convexities  11   a  (or first micro concavities  11   b ) adjacent in the arrangement direction of tracks (herein, the up and down direction). 
     In the present embodiment, it is preferable that the angle between at least one arrangement direction of the dot arrangement direction L20 and the crossing arrangement direction L21, and a straight line L21 perpendicular to the propagation direction L of internally propagating light be 30 to 60°. In the example of  FIG. 2 , the angle θ between the crossing arrangement direction L22 and the straight line L21 is 30 to 60°. 
     Here, the propagation direction L of internally propagating light is defined as the propagation direction of internally propagating light that is incident perpendicularly to a side surface of the base material  10 . Therefore, the propagation direction L is parallel to the planar direction of the base material  10 . Further, a plane normal to the propagation direction L and the planar direction of the base material  10  cross perpendicularly. 
     Thereby, in the present embodiment, even if internally propagating light leaks out to the outside before reflected at the macro concave-convex structure  13 , it is difficult for the observer to visually identify such leaked light. 
     In the example shown in  FIG. 2 , the first micro concave-convex structure  11  is arranged in a zigzag fashion with respect to the traveling direction of internally propagating light. That is, the traveling direction of internally propagating light and the dot arrangement direction of the first micro concave-convex structure  11  substantially agree. As a matter of course, the arrangement of the first micro concave-convex structure  11  is not limited to this example. That is, any arrangement is possible as long as it satisfies the requirements described above. For example, the first micro concave-convex structure  11  may be arranged in a rectangular lattice fashion. 
     There are no particular limitations on the average height of the first micro concave-convex structure  11 . That is, the average height of the first micro concave-convex structure  11  may be a height similar to or different from the average height of the second micro concave-convex structure  12 . In the case where the average height of the first micro concave-convex structure  11  is different from the average height of the second micro concave-convex structure  12 , the average height of the first micro concave-convex structure  11  is preferably more than or equal to 100 nm and less than or equal to 300 nm, more preferably more than or equal to 130 nm and less than or equal to 300 nm, and still more preferably more than or equal to 150 nm and less than or equal to 230 nm. The average height of the first micro concave-convex structure  11  is the arithmetic average value of the heights of the first micro convexities  11   a . The height of the first micro convexity  11   a  can be measured by the observation method described above. That is, the heights of some first micro convexities  11   a  may be measured, and the arithmetic average value of these may be taken as the average height of the first micro concave-convex structure  11 . The first micro convexity  11   a  extends in a direction perpendicular to the first surface  10 A. 
     The second micro concave-convex structure  12  is formed periodically to follow a surface (hereinafter, also referred to as a “second surface”)  10 B of the base material  10 . That is, the second micro concave-convex structure  12  extends in a direction perpendicular to the second surface  10 B. The second micro concave-convex structure  12  has similar features to the first micro concave-convex structure  11 . That is, in the second micro concave-convex structure  12 , the average period of concavity and convexity is less than or equal to a wavelength of visible light (for example, less than or equal to 830 nm). The average period of concavity and convexity is preferably more than or equal to 100 nm and less than or equal to 350 nm, more preferably more than or equal to 120 nm and less than or equal to 280 nm, and still more preferably 130 to 270 nm. Therefore, the second micro concave-convex structure  12  has what is called a moth-eye structure. Here, in the case where the average period is less than 100 nm, the formation of the second micro concave-convex structure  12  may be difficult; thus, this is not preferable. Further, in the case where the average period is more than 350 nm, the intensity of diffracted light may be large. That is, there is a possibility that internally propagating light will diffract at the second surface  10 B and leak out to the outside. 
     The second micro concave-convex structure  12  has large numbers of second micro convexities  12   a  and second micro concavities  12   b . The second micro convexity  12   a  has a shape protruding on the outside in the thickness direction of the optical body  1 , and the second micro concavity  12   b  has a shape recessed on the inside in the thickness direction of the optical body  1 . The second micro convexity  12   a  and the second micro concavity  12   b  are formed periodically on the second surface  10 B. The arrangement of the second micro concave-convex structure  12  is similar to the arrangement of the first micro concave-convex structure  11 . 
     Therefore, the average period of concavity and convexity is given as the arithmetic average value of the dot pitch P1 and the track pitch P2. Further, the arrangement direction of the second micro concave-convex structure  12  is classified into two arrangement directions, that is, the dot arrangement direction L20 and the crossing arrangement direction L22. In the present embodiment, the angle between at least one arrangement direction of the dot arrangement direction L20 and the crossing arrangement direction L22, and the straight line L21 perpendicular to the propagation direction L of internally propagating light is 30 to 60°. 
     The second micro concave-convex structure  12  is provided in each of both of a region where the macro concave-convex structure  13  is formed, that is, a light emitting region  10 D and a non-light emitting region  10 C where the macro concave-convex structure  13  is not formed. The non-light emitting region  10 C is a region other than the light emitting region  10 D of the second surface  10 B. In the non-light emitting region  10 C, the micro concave-convex structure  12  is formed to follow the surface of the non-light emitting region  10 C. That is, the micro concave-convex structure  12  extends in a direction perpendicular to the surface of the non-light emitting region  10 C. 
     In the light emitting region  10 D, the macro concave-convex structure  13  is formed. Therefore, when light is injected into the optical body  1  from a light source  20 , the internally propagating light is reflected at the macro concave-convex structure  13  in the light emitting region  10 D, and is emitted to the outside of the optical body  1 . Thereby, light is emitted in a region of the first surface  10 A facing the light emitting region  10 D. Thus, the light emitting region  10 D is a region where internally propagating light is emitted. On the other hand, in the non-light emitting region  10 C, the macro concave-convex structure  13  is not formed. Thus, light is not emitted in a region of the first surface  10 A facing the non-light emitting region  10 C. 
     In the light emitting region  10 D, the second micro concave-convex structure  12  is formed to follow the surface of the macro concave-convex structure  13 . That is, the second micro convexity  12   a  extends in a direction perpendicular to the surface of the macro concave-convex structure  13 . The average height of the second micro concave-convex structure  12  is preferably more than or equal to 200 nm. Thereby, the antireflection function in the place on the macro concave-convex structure  13  can be enhanced more. The upper limit value of the average height of the second micro concave-convex structure  12  is not particularly limited, but is preferably less than or equal to 300 nm. Thus, in the present embodiment, the micro concave-convex structure  12  is provided in each of both of a light emitting region  12 D and a non-light emitting region  12 C. Here, in the case where the optical body  1  is used as a light guide plate, it is necessary that the observer be hindered from recognizing the non-light emitting region to the extent possible. Furthermore, it is necessary that, when the light source is turned off, the observer be hindered from recognizing the existence of the optical body  1  to the extent possible. Hence, in both of a light emitting region  13 D and a non-light emitting region  13 C, an excellent antireflection function to extraneous light of high transmission, low reflection, and low scattering is required. Thus, in the present embodiment, the micro concave-convex structure  12  is provided in each of both of the light emitting region  12 D and the non-light emitting region  12 C. 
     The first micro concave-convex structure  11  and the second micro concave-convex structure  12  may be molded integrally with the base material  10 , or may be separate structure bodies from the base material  10 . Further, the concave-convex patterns of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  may not necessarily be the same as long as the requirements described above are satisfied. 
     The macro concave-convex structure  13  is formed on a part of the second surface  10 B. The macro concave-convex structure  13  is an aggregate of a plurality of macro convexities  13   a  and a plurality of macro concavities  13   b . The macro concavity  13   b  has a shape recessed in the thickness direction of the optical body  1  with respect to the non-light emitting region  10 C. The macro concavity  13   b  may have what is called a prism shape. That is, the macro concavity  13   b  is a long-length concavity extending in any planar direction of the second surface  10 B (a direction perpendicular to the thickness direction of the optical body  1 ). In the example of  FIG. 1 , the macro concavity  13   b  extends in a direction perpendicular to the drawing sheet. As a matter of course, the shape of the macro concavity  13   b  is not limited to this. The macro convexity  13   a  is placed between macro concavities  13   b . The apices of the macro convexities  13   a  are arranged in a substantially identical planar manner to the non-light emitting region  10 C. Thus, while details are described later, the macro concave-convex structure  13  is formed by pressing a macro concave-convex master having the inverse shapes of the macro concavities  13   b  (see  FIG. 5  and  FIG. 6 ) against the second micro concave-convex structure  12 . In the present embodiment, the macro concavity  13   b  emits internally propagating light toward the outside of the optical body  1 . That is, internally propagating light is reflected at the surface of the macro concavity  13   b.    
     The specific shape of the macro concave-convex structure  13  is not particularly limited, and may be a shape similar to a macro concave-convex structure employed in a light guide plate. However, the macro concavity  13   b  preferably has an inclined surface that is inclined with respect to the second surface  10 B, and the angle θ 1  between the inclined surface and the second surface  10 B is preferably more than or equal to 30° and less than 90°. In this case, the macro concavity  13   b  can emit internally propagating light to the outside of the optical body  1  more reliably. 
     The macro concave-convex structure  13  is formed on a part of the second surface  10 B. Hence, as described above, the second surface  10 B is partitioned into the non-light emitting region  10 C and the light emitting region  10 D. As a matter of course, the macro concave-convex structure  13  may be formed on the entire second surface  10 B. In this case, the entire second surface  10 B serves as the light emitting region  10 D. Light is emitted on the entire first surface  10 A. 
     The shape of the macro concave-convex structure  13  is not limited to the example shown in  FIG. 2 . For example, as shown in  FIG. 3 , the macro concave-convex structure  13  may have the inverse shape of  FIG. 2 . In an optical body  1 A shown in  FIG. 3 , the macro convexity  13   a  has a shape protruding in the thickness direction of the optical body  1  with respect to the non-light emitting region  10 C. The macro convexity  13   a  has what is called a prism shape. In this example, internally propagating light is reflected at the surface of the macro convexity  13   a , and is emitted to the outside of the optical body  1 A. The angle between the inclined surface of the macro convexity  13   a  and the second surface  10 B is more than or equal to 30° and less than 90°. In this case, the macro concavity  13   b  can emit internally propagating light to the outside of the optical body  1  more reliably. The micro concave-convex structure  12  is formed to follow the inclined surface of the macro convexity  13   a . Depending on the objective of the optical body  1 , a micro concave-convex structure may be selectively formed only in at least a flat portion (herein, the first surface  10 A and the non-light emitting region  10 C). For example, a micro concave-convex structure may not be formed on the macro concave-convex structure  13 . 
     The luminous reflectance of the optical body  1 , particularly the luminous reflectance of the light emitting region  10 D, is preferably less than or equal to 1.0%. The reflection chromaticity (a*, b*) of the optical body  1 , particularly the reflection chromaticity (a*, b*) of the light emitting region  10 D, is preferably less than or equal to 1.0. 
     &lt;2. Configuration of Light Emitting Device&gt; 
     Next, the configuration of a light emitting device is described on the basis of  FIG. 1 . The light emitting device includes the optical body  1  described above and the light source  20 . The operation of the light emitting device is generally as follows. First, light is incident on the optical body  1  from the light source  20 . The light injected in the inside of the optical body  1 , that is, the internally propagating light propagates through the inside of the optical body  1  while reflecting at the first surface  10 A and the second surface  10 B of the optical body  1  (that is, interfaces between the inside and the outside of the optical body  1 ). After that, the internally propagating light is reflected at the surface of the macro concave-convex structure  13 , and is emitted from another surface of the light guide plate. Thereby, the optical body  1  emits light. The straight line L10 shows an example of the optical path of internally propagating light reflected at the surface of the macro concave-convex structure  13 . On the other hand, the straight line L10 shows an example of the optical path of internally propagating light propagating through the inside of the optical body  1 . In the present embodiment, there is a case where a part of the internally propagating light is emitted as leaked light to the outside of the optical body  1 . Specifically, when internally propagating light arrives at the first surface  10 A or the second surface  10 B of the optical body  1 , the internally propagating light may diffract and leak out to the outside. The internally propagating light propagates through the optical body  1  in various directions, and has various wavelengths. Hence, diffracted light due to the arrangements of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  (that is, leaked light) is likely to be a problem. 
     In this respect, the arrangement directions of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  satisfy the requirements described above; thus, most of the leaked light is emitted to positions different from the position of the observer. Therefore, it is difficult for the observer to visually identify leaked light. Thus, in the case where, for example, the light emitting device is used as a light emitting device (what is called a backlight or the like) of an LCD, the observer can visually identify a clearer image. 
     On the other hand, in the case where the arrangement direction of the first micro concave-convex structure  11  does not satisfy the requirement described above, most of the leaked light that has leaked out from the first surface  10 A is emitted toward the observer. Hence, it is easy for the observer to visually identify leaked light. Thus, in the case where, for example, the light emitting device is used as a light emitting device (what is called a backlight or the like) of an LCD, the image may be colored by leaked light. Consequently, the visibility of the image is worsened. In the case where the second micro concave-convex structure  12  does not satisfy the requirement described above, a similar event may occur on the second surface  10 B. 
     Further, since the average period of concavity and convexity of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  is less than or equal to a wavelength of visible light, the reflection of extraneous light can be suppressed. Further, internally propagating light reflected at the macro concave-convex structure  13  is emitted to the outside through the first micro concave-convex structure  11 . Therefore, the optical body  1  has an excellent antireflection function to extraneous light, and can hinder the observer from visually identifying leaked light. That is, in the present embodiment, the observer can be hindered from visually identifying leaked light generated in the non-light emitting region  10 C, and therefore the contrast between the light emitting region  10 D and the non-light emitting region  10 C can be improved. For example, the non-light emitting region  10 C looks black to the observer, and this black color looks distinct. Further, the first micro concave-convex structure  11  can also suppress reflection in the inside of the optical body  1 , that is, the reflection of internally propagating light. Therefore, a larger amount of internally propagating light is emitted to the outside. Thereby, the optical body  1  can cause most of the internally propagating light reflected at the surface of the macro concave-convex structure to be emitted to the outside. That is, light extraction efficiency is improved. 
     &lt;3. Method for Manufacturing Optical Body&gt; 
     Next, a method for manufacturing the optical body  1  is described. First, the first micro concave-convex structure  11  and the second micro concave-convex structure  12  are formed on both surfaces of the base material  10 . Specifically, a micro concave-convex master  100  (see  FIG. 4 ) having the inverse shape of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  is prepared. Further, an uncured resin layer is formed on each of both surfaces of the base material  10 . The uncured resin layer is made of an uncured curing resin. Then, the uncured resin layer is cured while the micro concave-convex structure (specifically, a master concave-convex structure  120 ) of the micro concave-convex master  100  is transferred to the uncured resin layer. By the above steps, the first micro concave-convex structure  11  and the second micro concave-convex structure  12  are formed on both surfaces of the base material  10 . It is also possible to stick together a base material on which the first micro concave-convex structure  11  is formed and a base material on which the second micro concave-convex structure  12  is formed. Further, it is also possible to stick, to the base material  10 , a film on which the first micro concave-convex structure  11  is formed and a film on which the second micro concave-convex structure  12  is formed. Since the base material  10  is formed of a thermoplastic resin, the master concave-convex structure  120  of the micro concave-convex master  100  may be transferred directly to the base material  10 . A detailed formation method is described later. 
     Further, a macro concave-convex master is prepared. Here, a macro concave-convex structure having the inverse shape of the macro concave-convex structure  13 , specifically, master macro convexities having the inverse shapes of the macro concavities  13   b  have been formed on the surface of the macro concave-convex master. The material of the macro concave-convex master is not particularly limited. For example, the macro concave-convex master may be formed of a similar material to the micro concave-convex master  100 . The macro concave-convex master can be produced by the following steps. That is, a metal mold is produced by cutting a metal body having a surface subjected to copper plating or the like, with a cutting tool having a tip of a symmetric, V-like shape. The angle θ 1  described above can be adjusted by adjusting the vertex angle of the cutting tool. For example, when the vertex angle of the cutting tool is 90°, the angle θ 1  is 45°. The depth of concavity and convexity can be adjusted by the amount of indentation of the cutting tool. Then, the metal mold is transferred to another material (that is, the material of the macro concave-convex master), and thereby the macro concave-convex master is produced. Here, the transfer method is not particularly limited. For example, the concavities and convexities of the metal mold may be transferred to another metal material by the electroforming method. Alternatively, a curing resin layer made of a UV curing resin or the like may be formed on the concavities and convexities of the metal mold, and the resin layer may be cured. 
     Next, while the base material  10  and the macro concave-convex master are heated in an atmosphere of a pressure-propagating medium, the master macro convexities of the macro concave-convex master are pressed against the second micro concave-convex structure  12 . Thereby, the base material  10  deforms to follow the shapes of the master macro convexities. That is, the master macro convexities are transferred to the second micro concave-convex structure  12 . Here, the pressure-propagating medium may be any medium as long as it is a medium through which pressure propagates. For example, the pressure-propagating medium may be compressed air, a liquid, a semi-solid, semi-liquid viscoelastic body, or a viscous body. The pressure is preferably more than or equal to 0.1 MPa, and more preferably more than or equal to 0.7 MPa. The heating temperature of the base material  10  and the macro concave-convex master is not particularly limited as long as it is such a temperature that the base material  10  can deform to follow the shapes of the master macro convexities. However, the heating temperature is preferably more than 150° C. and less than 250° C., and more preferably 180 to 220 degrees. If the heating temperature is less than or equal to 150 degrees, the shape of the base material  10  may not sufficiently follow the macro convexities of the macro concave-convex master. Further, if the heating temperature is more than 250 degrees, the base material  10  may be damaged due to heat. In Examples described later, a viscous body is used as the pressure-propagating medium, the pressure is set to 0.7 MPa, and the heating temperature is set to 180 to 220° C. By the present manufacturing method, an optical body in which the macro concave-convex structure  13  and the twelfth micro concave-convex structure  12  are formed to be superimposed is obtained. 
     After once an optical body  1  is produced, the optical body  1  may be used as a transfer mold to produce another optical body  1 . In this case, for example, an uncured resin layer is formed on each of both surfaces of the other base material  10 . Then, the first micro concave-convex structure  11  may be transferred to one uncured resin layer, and the second micro concave-convex structure  12  and the macro concave-convex structure  13  may be transferred to the other uncured resin layer. By this method, for example, the optical body  1  shown in  FIG. 1  can be used as a transfer mold to produce the optical body  1 A shown in  FIG. 3 . In the case where the optical body  1  is used as a transfer mold, it is preferable that release treatment be performed on both surfaces of the optical body  1  in advance. 
     &lt;4. Configuration of Micro Concave-Convex Master&gt; 
     The first micro concave-convex structure  11  and the second micro concave-convex structure  12  are produced using, for example, the micro concave-convex master  100  shown in  FIG. 4 . Thus, next, the configuration of the micro concave-convex master  100  is described. The micro concave-convex master  100  is a master used in the nanoimprinting method, and has a round cylindrical shape, for example. The micro concave-convex master  100  may have a round columnar shape or other shapes (for example, a flat plate-like shape). In the case where the micro concave-convex master  100  has a round columnar or round cylindrical shape, the concave-convex structure (that is, the master concave-convex structure)  120  of the micro concave-convex master  100  can be transferred seamlessly to the base material  10  by a roll-to-roll system. Thereby, the first micro concave-convex structure  11  and the second micro concave-convex structure  12  can be formed on the base material  10  with high efficiency. From such a point of view, the shape of the micro concave-convex master  100  is preferably a round cylindrical shape or a round columnar shape. 
     The micro concave-convex master  100  is provided with a master base material  110 , and the master concave-convex structure  120  formed on the circumferential surface of the master base material  110 . The master base material  110  may be a glass body, for example, and specifically may also be formed from quartz glass. However, the master base material  110  is not particularly limited insofar as the SiO 2  purity is high, and may also be formed from a material such as fused quartz glass or synthetic quartz glass. The master base material  110  may also be a laminate of the above materials on a metal matrix, or a metal matrix. The shape of the master base material  110  is a hollow round cylindrical shape, but may also be a round columnar shape, or some other shape. However, as described above, the master base material  110  preferably has a hollow round cylindrical shape or a round columnar shape. The master concave-convex structure  120  has the inverse shape of the first micro concave-convex structure  11  and the second micro concave-convex structure  12 . In the case where the first micro concave-convex structure  11  and the second micro concave-convex structure  12  have different shapes, micro concave-convex masters corresponding to these shapes may be prepared. 
     &lt;5. Method of Manufacturing Micro Concave-Convex Master&gt; 
     Next, a method of manufacturing micro concave-convex master  100  will be described. First, a base material resist layer is formed (deposited) on the master base material  110 . At this point, the resist constituting the base material resist layer is not particularly limited, and may be either an organic resist or an inorganic resist. Examples of organic resists include novolac-type resist and chemically-amplified resist. Also, examples of inorganic resists include metallic oxides including one or multiple types of transition metals such as tungsten (W) or molybdenum (Mo). However, in order to conduct thermal reaction lithography, the base material resist layer preferably is formed with a thermo-reactive resist including a metallic oxide. 
     In the case of using an organic resist, the base material resist layer may be formed on the master base material  110  by using a process such as spin coating, slit coating, dip coating, spray coating, or screen printing. Also, in the case of using an inorganic resist for the base material resist layer, the base material resist layer may be formed by sputtering. 
     Next, by exposing part of the base material resist layer with an exposure device  200  (see  FIG. 5 ), a latent image is formed on the base material resist layer. Specifically, the exposure device  200  modulates laser light  200 A, and irradiates the base material resist layer with the laser light  200 A. Consequently, part of the base material resist layer irradiated by the laser light  200 A denatures, and thus a latent image corresponding to the master concave-convex structure  120  may be formed in the base material resist layer. The latent image is formed in the base material resist layer at an average cycle less than or equal to the visible light wavelengths. 
     Next, by dripping a developing solution onto the base material resist layer in which is formed the latent image, the base material resist layer is developed. As a result, a concave-convex structure is formed in the base material resist layer. Subsequently, by etching the master base material  110  and the base material resist layer using the base material resist layer as a mask, the master concave-convex structure  120  is formed on the master base material  110 . Note that although the etching method is not particularly limited, dry etching that is vertically anisotropic is preferable. For example, reactive ion etching (RIE) is preferable. By the above steps, the micro concave-convex master  100  is produced. Note that anodic porous alumina obtained by the anodic oxidation of aluminum may also be used as the master. Anodic porous alumina is disclosed in WO 2006/059686, for example. Additionally, the micro concave-convex master  100  may also be produced by a stepper using a reticle mask with an asymmetric shape. 
     Here, a desired master concave-convex structure  120  can be formed by adjusting the irradiation manner of laser light  200 A. Thereby, the shape of the master concave-convex structure  120  can be made the inverse shape of the first micro concave-convex structure  11  and the second micro concave-convex structure  12 . 
     &lt;6. Configuration of Exposure Device&gt; 
     Next, the configuration of the exposure device  200  will be described on the basis of  FIG. 5 . The exposure device  200  is a device that exposes the base material resist layer. The exposure device  200  is provided with a laser light source  201 , a first mirror  203 , a photodiode (PD)  205 , a deflecting optical system, a control mechanism  230 , a second mirror  213 , a movable optical table  220 , a spindle motor  225 , and a turntable  227 . Also, the master base material  110  is placed on the turntable  227  and able to be rotated. 
     The laser light source  201  is a light source that emits laser light  200 A, and is a device such as a solid-state laser or a semiconductor laser, for example. The wavelength of the laser light  200 A emitted by the laser light source  201  is not particularly limited, but may be a wavelength in the blue light band from 400 nm to 500 nm, for example. Also, it is sufficient for the spot diameter of the laser light  200 A (the diameter of the spot radiated onto the resist layer) to be smaller than the diameter of the open face of a concavity of the master concave-convex structure  120 , such as approximately 200 nm, for example. The laser light  200 A emitted from the laser light source  201  is controlled by the control mechanism  230 . 
     The laser light  200 A emitted from the laser light source  201  advances directly in a collimated beam, reflects off the first mirror  203 , and is guided to the deflecting optical system. 
     The first mirror  203  is made up of a polarizing beam splitter, and has a function of reflecting one polarized component, and transmitting the other polarized component. The polarized component transmitted through the first mirror  203  is sensed by the photodiode  205  and photoelectrically converted. Also, the photodetection signal photoelectrically converted by the photodiode  205  is input into the laser light source  201 , and the laser light source  201  conducts phase modulation of the laser light  200 A on the basis of the input photodetection signal. 
     In addition, the deflecting optical system is provided with a condenser lens  207 , an electro-optic deflector (EOD)  209 , and a collimator lens  211 . 
     In the deflecting optical system, the laser light  200 A is condensed onto the electro-optic deflector  209  by the condenser lens  207 . The electro-optic deflector  209  is an element capable of controlling the radiation position of the laser light  200 A. With the electro-optic deflector  209 , the exposure device  200  is also able to vary the radiation position of the laser light  200 A guided onto the movable optical table  220  (what is called a Wobble mechanism). After the radiation position is adjusted by the electro-optic deflector  209 , the laser light  200 A is converted back into a collimated beam by the collimator lens  211 . The laser light  200 A exiting the deflecting optical system is reflected by the second mirror  213 , and guided level with and parallel to the movable optical table  220 . 
     The movable optical table  220  is provided with a beam expander (BEX)  221  and an objective lens  223 . The laser light  200 A guided to the movable optical table  220  is shaped into a desired beam shape by the beam expander  221 , and then radiated via the objective lens  223  onto the base material resist layer formed on the master base material  110 . In addition, the movable optical table  220  moves by one feed pitch (track pitch) in the direction of the arrow R (feed pitch direction) every time the master base material  110  undergoes one rotation. The master base material  110  is placed on the turntable  227 . The spindle motor  225  causes the turntable  227  to rotate, thereby causing the master base material  110  to rotate. With this arrangement, the laser light  200 A is made to scan over the base material resist layer. At this point, a latent image of the base material resist layer is formed along the scanning direction of the laser light  200 A. Consequently, the track direction of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  (that is, the direction of the arrow B) corresponds to the scanning direction of the laser light  200 A. 
     In addition, the control mechanism  230  is provided with a formatter  231  and a driver  233 , and controls the radiation of the laser light  200 A. The formatter  231  generates a modulation signal that controls the radiation of the laser light  200 A, and the driver  233  controls the laser light source  201  on the basis of the modulation signal generated by the formatter  231 . As a result, the irradiation of the master base material  110  by the laser light  200 A is controlled. 
     The formatter  231  generates a control signal for irradiating the base material resist layer with the laser light  200 A, on the basis of an input image depicting an arbitrary pattern to draw on the base material resist layer. Specifically, first, the formatter  231  acquires an input image depicting an arbitrary pattern to draw on the base material resist layer. The input image is an image corresponding to a development of the outer circumferential surface of the base material resist layer, in which the outer circumferential surface of the base material resist layer is cut in the axial direction and expanded in a single plane. Next, the formatter  231  partitions the input image into sub-regions of a certain size (for example, partitions the input image into a lattice), and determines whether or not the draw pattern is included in each of the sub-regions. Subsequently, the formatter  231  generates a control signal to perform control to irradiate with the laser light  200 A each sub-region determined to include the draw pattern. The control signal (that is, the exposure signal) preferably is synchronized with the rotation of the spindle motor  225 , but does not have to be synchronized. In addition, the control signal and the rotation of the spindle motor  225  may also be resynchronized every time the master base material  110  performs one rotation. Furthermore, the driver  233  controls the output of the laser light source  201  on the basis of the control signal generated by the formatter  231 . As a result, the irradiation of the base material resist layer by the laser light  200 A is controlled. Note that the exposure device  200  may also perform a known exposure control process, such as focus servo and positional correction of the irradiation spot of the laser light  200 A. The focus servo may use the wavelength of the laser light  200 A, or use another wavelength for reference. 
     In addition, the laser light  200 A radiated from the laser light source  201  may irradiate the base material resist layer after being split into multiple optical subsystems. In this case, multiple irradiation spots are formed on the base material resist layer. In this case, when the laser light  200 A emitted from one optical system reaches the latent image formed by another optical system, exposure may be ended. 
     &lt;7. With Regard to Method for Forming First Micro Concave-Convex Structure and Second Micro Concave-Convex Structure Using Micro Concave-Convex Master&gt; 
     Next, a method for forming the first micro concave-convex structure  11  on the base material  10  using the micro concave-convex master  100  is described with reference to  FIG. 6 . 
     The transfer device  300  is provided with the micro concave-convex master  100 , a base material supply roll  301 , a take-up roll  302 , guide rolls  303  and  304 , a nip roll  305 , a separation roll  306 , an applicator device  307 , and a light source  309 . 
     The base material supply roll  301  is a roll around which a long-length base material  10  is wound in a roll, while the take-up roll  302  is a roll that takes up the base material  10  in which the first micro concave-convex structure is formed. Also, the guide rolls  303  and  304  are rolls that transport the base material  10 . The nip roll  305  is a roll that puts the base material  10  laminated with an uncured resin layer  310 , or in other words a transfer film  3   a , in close contact with the micro concave-convex master  100 . The separation roll  306  is a roll that separates the base material  10  in which the first micro concave-convex structure  11  is formed, from the micro concave-convex master  100 . 
     The applicator device  307  is provided with an applicating means such as a coater, and applies an uncured light-curing resin composition to the base material  10 , and forms the uncured resin layer  310 . The type of the light-curing resin composition is not particularly limited, and may be any resin that can form a micro concave-convex structure. The applicator device  307  may be a device such as a gravure coater, a wire bar coater, or a die coater, for example. Also, the light source  309  is a light source that emits light of a wavelength able to cure the light-curing resin composition, and may be a device such as an ultraviolet lamp, for example. 
     In the transfer device  300 , first, the base material  10  is sent continuously from the base material supply roll  301  via the guide roll  303 . Note that partway through the delivery, the base material supply roll  301  may also be changed to a base material supply roll  301  of a separate lot. The uncured light-curing resin composition is applied by the applicator device  307  to the delivered base material  10 , and the uncured resin layer  310  is laminated onto the base material  10 . As a result, the transfer film  3   a  is prepared. The transfer film  3   a  is put into close contact with the micro concave-convex master  100  by the nip roll  305 . The light source  309  irradiates with light the uncured resin layer  310  put in close contact with the micro concave-convex master  100 , thereby curing the uncured resin layer  310 . With this arrangement, the arrangement pattern of the master concave-convex structure  120  formed on the outer circumferential face of the micro concave-convex master  100  is transferred to the uncured resin layer  310 . In other words, the first micro concave-convex structure  11  having the inverse shape of the master concave-convex structure  120  is formed on the base material  10 . Next, the base material  10  in which the first micro concave-convex structure  11  is formed, is separated from the micro concave-convex master  100  by the separation roll  306 . Next, the base material  10  is taken up by the take-up roll  302  via the guide roll  304 . Note that the micro concave-convex master  100  may be oriented vertically or oriented horizontally, and a mechanism that corrects the angle and eccentricity of the micro concave-convex master  100  during rotation may also be provided separately. For example, an eccentric tilt mechanism may be provided in a chucking mechanism. 
     In this way, in the transfer device  300 , the circumferential shape of the micro concave-convex master  100  is transferred to the transfer film  3   a  while transporting the transfer film  3   a  roll-to-roll. As a result, the first micro concave-convex structure  11  is formed on the base material  10 . 
     In the present embodiment, since the base material  10  is formed of a thermoplastic resin, the master concave-convex structure  120  of the micro concave-convex master  100  may be transferred directly onto the base material  10 . In this case, the applicator device  307  and the light source  309  are unnecessary. Further, a heating device is placed on the upstream side of the micro concave-convex master  100 . The base material  10  is heated and softened by the heating device, and then the base material  10  is pressed against the micro concave-convex master  100 . Thereby, the master concave-convex structure  120  formed on the circumferential surface of the micro concave-convex master  100  is transferred to the base material  10 . Therefore, the transfer device  300  can form the first micro concave-convex structure  11  on the base material  10  continuously. 
     In addition, a transfer film to which the master concave-convex structure  120  of the micro concave-convex master  100  has been transferred may be produced, and the transfer film may be used as a transfer mold. Also, the micro concave-convex master  100  may be duplicated by electroforming, thermal transfer, or the like, and the duplicate may be used as a transfer mold. Furthermore, the shape of the micro concave-convex master  100  is not necessarily limited to a roll shape, and may also be a planar master. Besides a method of irradiating resist with the laser light  200 A, various processing methods can be selected, such as semiconductor exposure using a mask, electron beam lithography, machining, or anodic oxidation. 
     EXAMPLES 
     1. Example 1 
     (1-1. Production of Optical Body) 
       FIG. 7  shows the configuration of an optical body  1 - 1  according to Example 1. In Example 1, the optical body  1 - 1  was produced by the following steps. First, a polymethyl methacrylate film with a thickness of 150 μm (Technolloy, manufactured by Sumika Acryl Co., Ltd.) was prepared as a base material  10 - 1 . Next, using the transfer device  300  shown in  FIG. 6 , the second micro concave-convex structure  12  was formed on one surface (herein, the second surface  10 B) of the base material  10 - 1 . Here, an ultraviolet curing acrylic resin composition (SK1120, manufactured by Dexerials Corporation) was used as a light-curing resin composition. In order to enhance the adhesiveness between the base material  10 - 1  and the cured layer of the uncured resin layer, the second surface  10 B of the base material  10 - 1  was subjected to primer treatment in advance. A primer layer with a thickness of approximately 3 μm was formed on the second surface  10 B of the base material  10 - 1  by the primer treatment. Specifically, primer treatment was performed by applying a polycarbonate resin and performing drying. The second micro concave-convex structure  12  was caused to be arranged in a zigzag fashion. The dot pitch P1 was set to 230 nm, and the track pitch P2 was set to 153 nm. The average height of the second micro convexity  12   a  was 250 nm. The base material  10 - 1  was a long-length rectangular film. The dot arrangement direction L20 was parallel to the longitudinal direction of the base material  10 - 1 , and the crossing arrangement direction L22 was inclined by approximately 40° with respect to a straight line perpendicular to the dot arrangement direction L20. A SEM photograph of a cross-sectional shape of the second micro concave-convex structure  12  is shown in  FIG. 10 . Further, a SEM photograph of a planar shape is shown in  FIG. 11 . 
     Next, a macro concave-convex master of a long-length rectangular shape was prepared. The master macro convexity was set to a convexity extending in the lateral direction of the macro concave-convex master, the pitch (the distance between the apices of master macro convexities) was set to 100 μm, and the height was set to 10 μm. The vertex angle was set to 90°. Therefore, the angle between the oblique surface of the master macro convexity and the flat surface between master macro convexities (that is, the bottom surface of the master macro concavity) is 45°. Next, the master macro convexities were transferred to the base material  10 - 1  by the method described above. Here, a viscous body was used as the pressure-propagating medium, the pressure was set to 0.7 MPa, and the heating temperature was set to 180 to 220° C. That is, the second micro concave-convex structure  12  and the macro concave-convex structure  13  were formed to be superimposed on a second surface of the base material  10 - 1 . It was checked with a SEM whether the second micro concave-convex structure  12  was superimposed on the macro concave-convex structure  13  or not, and it was found that superimposition was made without problems.  FIG. 12  is a cross-sectional SEM photograph of a macro concavity  13   b . As is clear from this photograph, it was found that the second micro concave-convex structure  12  was formed to be superimposed on the macro concavity  13   b . It was also found that the second micro convexity  12   a  protruded in a perpendicular direction from the surface of the macro concavity  13   b . That is, it was also found that the second micro convexity  12   a  was formed to follow the surface of the macro concavity  13   b.    
     Next, an moth-eye film  10 - 3  was stuck to the other surface, that is, the first surface  10 A of the base material  10 - 1  via an adhesive film  10 - 2  with a thickness of 25 μm (a PDS1 film, manufactured by Panac Co., Ltd.). The first micro concave-convex structure  11  has been formed on the moth-eye film  10 - 3 . The moth-eye film  10 - 3  was produced using the transfer device  300  described above. Specifically, a triacetylcellulose film with a thickness of 60 μm was used as a base material, and an ultraviolet curing acrylic resin composition manufactured by Toagosei Co., Ltd. was used as a light-curing resin composition. The thickness of the cured layer on which the first micro concave-convex structure  11  was formed was set to approximately 3 μm. The concave-convex pattern of the first micro concave-convex structure  11  was set similar to that of the second micro concave-convex structure  12 . By the above steps, the optical body  1 - 1  according to Example 1 was produced. The optical body  1 - 1  corresponds to the optical body  1  shown in  FIG. 1 . 
     (1-2. Characteristics Evaluation) 
     (1-2-1. Specular Reflection Spectrum) 
     Next, characteristics of the optical body  1 - 1  were evaluated. First, a spectral specular reflection spectrum of the optical body  1 - 1  was measured. The measurement of the specular reflection spectrum is to evaluate mainly reflection characteristics in a flat portion of the optical body  1 - 1 . The spectral specular reflection spectrum was measured using a spectrophotometer (model: V-550, equipped with an absolute reflectance measuring unit; manufactured by JASCO Corporation). Both of the incidence angle and the reflection angle were set to 5°, the wavelength range was set to 400 to 800 nm, and the wavelength resolution was set to 1 nm. Measuring light was applied to the second surface  10 B. The result is shown in  FIG. 20 . The horizontal axis of  FIG. 20  represents the measuring wavelength (nm), and the vertical axis represents the specular reflectance (%). 
     (1-2-2. Diffuse Reflection Spectrum) 
     Next, a diffuse reflection spectrum of the optical body  1 - 1  was measured. The measurement of the diffuse reflection spectrum is to evaluate reflection characteristics on the entire surface of the optical body  1 - 1  including the macro concave-convex structure  13 . The diffuse reflection spectrum was measured using the spectrophotometer described above (model: V-550, equipped with an absolute reflectance measuring unit; manufactured by JASCO Corporation) and an absolute reflectance meter, ARV474S (manufactured by JASCO Corporation), in combination. The other conditions were set similar to the measuring conditions of the specular reflection spectrum. The diffuse reflection spectral spectrum is shown in  FIG. 21 . The horizontal axis of  FIG. 21  represents the measuring wavelength (nm), and the vertical axis represents the diffuse reflectance (%). 
     (1-2-3. Measurement of Luminance and x and y Values) 
     Next, the luminance and the x and y values (the x and y values in Yxy color coordinates) when the optical body  1 - 1  was caused to emit light were measured. The measurement was performed by the following steps. The measurement was performed in a dark place environment. First, an LED light source (LPAC1-2430NCW-R4, manufactured by Aitec System Co., Ltd.) was placed on the side of a side surface on the lateral side of the optical body  1 - 1  (that is, a side surface parallel to the extension direction of the macro concave-convex structure  13 ). A luminance meter (CS1000, manufactured by Konica Minolta, Inc.) was placed on the first surface  10 A side. The placement position was set to a position apart from the first surface  10 A by 50 cm, and the optical axis of the luminance meter was set perpendicular to the first surface. Next, high-luminance white light was injected into the optical body  1 - 1  from the LED light source, and the luminance (cd/cm 2 ) and the x and y values were measured with the luminance meter. In Example 1, the angle between the straight line L21 perpendicular to the propagation direction L of internally propagating light and the crossing arrangement direction L22 is 40°. The results are shown in Table 1. 
     (1-2-4. Measurement of Luminous Reflectance and Reflection Chromaticity (a*, b*)) 
     Next, on the basis of the specular reflection spectrum mentioned above, the luminous reflectance and the reflection chromaticity (a*, b*) of the optical body  1 - 1  were calculated. The calculation of the luminous reflectance etc. was performed on the basis of a common formula based on a visibility curve of a human being. The results are shown in Table 2. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                   
                   
                 Comparative 
                 Comparative 
                 Comparative 
               
               
                   
                 Example 1 
                 Example 2 
                 Example 3 
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Luminance 
                 71.21 
                 59.4 
                 71.93 
                 59.63 
                 62.17 
                 — 
               
               
                 (cd/cm 2 ) 
               
               
                 x 
                 0.321 
                 0.3285 
                 0.3281 
                 0.3279 
                 0.3158 
                 — 
               
               
                 y 
                 0.3161 
                 0.3186 
                 0.3223 
                 0.3213 
                 0.3097 
                 — 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Comparative 
                 Comparative 
                 Comparative 
                   
                   
                   
               
               
                   
                 Example 1 
                 Example 2 
                 Example 3 
                 Example 1 
                 Example 2 
                 Example 3 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Reflection 
                 6.35 
                 4.15 
                 0.73 
                 0.58 
                 0.29 
                 0.39 
               
               
                 Y value 
               
               
                 Reflection 
                 0.31 
                 0.31 
                 0.20 
                 0.27 
                 0.34 
                 0.36 
               
               
                 a* 
               
               
                 Reflection 
                 0.33 
                 0.33 
                 0.19 
                 0.29 
                 0.37 
                 0.36 
               
               
                 b* 
               
               
                   
               
            
           
         
       
     
     2. Example 2 
     (2-1. Production of Optical Body) 
       FIG. 8  shows the configuration of an optical body  1 - 2  according to Example 2. In Example 2, the optical body  1 - 2  was produced by using the optical body  1 - 1  as a transfer mold. Specifically, first, the base material  10 - 1  used in Example 1 was prepared. Next, in order to enhance the adhesiveness between the base material  10 - 1  and each of the cured layers described later, both surfaces of the base material  10 - 1  were subjected to primer treatment. Specific details of the primer treatment were set similar to those of Example 1. A primer layer with a thickness of approximately 3 μm was formed on both surfaces of the base material  10 - 1  by the primer treatment. Next, an uncured resin layer of a light-curing resin composition was formed on one surface (herein, the second surface  10 B) of the base material  10 - 1 . Next, the shape of the second surface  10 B of the optical body  1 - 1 , that is, the second micro concave-convex structure  12  and the macro concave-convex structure  13  were transferred to the uncured resin layer. Thereby, a first macro concave-convex cured layer  10 - 5  was formed on the second surface  10 B of the base material  10 - 1 . The thickness of the first macro concave-convex cured layer  10 - 5  was set to approximately 3 μm. The second micro concave-convex structure  12  and the macro concave-convex structure  13  have been formed on the first macro concave-convex cured layer  10 - 5 . However, the second micro concave-convex structure  12  and the macro concave-convex structure  13  have the inverse shapes of the second micro concave-convex structure  12  and the macro concave-convex structure  13  of Example 1. 
     Next, an uncured resin layer of a light-curing resin composition was formed on the other surface, that is, the first surface  10 A of the base material  10 - 1 . Next, the shape of the first surface  10 A of the optical body  1 - 1 , that is, the first micro concave-convex structure  11  was transferred to the uncured resin layer. Thereby, a first micro concave-convex cured layer  10 - 6  was formed on the first surface  10 A of the base material  10 - 1 . The thickness of the first micro concave-convex cured layer  10 - 6  was set to approximately 3 μm. The first micro concave-convex structure  11  has been formed on the first micro concave-convex cured layer  10 - 6 . However, the first micro concave-convex structure  11  has the inverse shape of the first micro concave-convex structure  11  of Example 1. By the above steps, the optical body  1 - 2  according to Example 2 was produced. The optical body  1 - 2  corresponds to the optical body  1 A shown in  FIG. 3 . 
     (2-2. Characteristics Evaluation) 
     Next, the characteristics evaluation of the optical body  1 - 2  was performed similarly to Example 1. A specular reflection spectrum is shown in  FIG. 20 , and a diffuse reflection spectrum is shown in  FIG. 21 . The luminance and the x and y values are shown in Table 1. The luminous reflectance and the reflection chromaticity (a*, b*) are shown in Table 2. 
     3. Example 3 
     (3-1. Production of Optical Body) 
       FIG. 9  shows the configuration of an optical body  1 - 3  according to Example 3. In Example 3, the optical body  1 - 3  was produced by using the optical body  1 - 2  as a transfer mold. Specifically, first, the base material  10 - 1  used in Example 1 was prepared. Next, in order to enhance the adhesiveness between the base material  10 - 1  and each of the cured layers described later, both surfaces of the base material  10 - 1  were subjected to primer treatment. Specific details of the primer treatment were set similar to those of Example 1. A primer layer with a thickness of approximately 3 μm was formed on both surfaces of the base material  10 - 1  by the primer treatment. Next, an uncured resin layer of a light-curing resin composition was formed on one surface (herein, the second surface  10 B) of the base material  10 - 1 . Next, the shape of the second surface  10 B of the optical body  1 - 2 , that is, the second micro concave-convex structure  12  and the macro concave-convex structure  13  were transferred to the uncured resin layer. Thereby, a second macro concave-convex cured layer  10 - 8  was formed on the second surface  10 B of the base material  10 - 1 . The thickness of the second macro concave-convex cured layer  10 - 8  was set to approximately 3 μm. The second micro concave-convex structure  12  and the macro concave-convex structure  13  have been formed on the second macro concave-convex cured layer  10 - 8 . However, the second micro concave-convex structure  12  and the macro concave-convex structure  13  have the inverse shapes of the second micro concave-convex structure  12  and the macro concave-convex structure  13  of Example 2. That is, the second micro concave-convex structure  12  and the macro concave-convex structure  13  of Example 3 have substantially the same shapes as the second micro concave-convex structure  12  and the macro concave-convex structure  13  of Example 1. 
     Next, an uncured resin layer of a light-curing resin composition was formed on the other surface, that is, the first surface  10 A of the base material  10 - 1 . Next, the shape of the first surface  10 A of the optical body  1 - 2 , that is, the first micro concave-convex structure  11  was transferred to the uncured resin layer. Thereby, a second micro concave-convex cured layer  10 - 9  was formed on the first surface  10 A of the base material  10 - 1 . The thickness of the second micro concave-convex cured layer  10 - 9  was set to approximately 3 μm. The first micro concave-convex structure  11  has been formed on the second micro concave-convex cured layer  10 - 9 . However, the first micro concave-convex structure  11  has the inverse shape of the first micro concave-convex structure  11  of Example 2. That is, the first micro concave-convex structure  11  of Example 3 has substantially the same shape as the first micro concave-convex structure  11  of Example 1. By the above steps, the optical body  1 - 3  according to Example 3 was produced. The optical body  1 - 3  corresponds to the optical body  1  shown in  FIG. 1 . 
     (3-2. Characteristics Evaluation) 
     Next, the characteristics evaluation of the optical body  1 - 3  was performed similarly to Example 1. A specular reflection spectrum is shown in  FIG. 20 , and a diffuse reflection spectrum is shown in  FIG. 21 . The luminance and the x and y values are shown in Table 1. The luminous reflectance and the reflection chromaticity (a*, b*) are shown in Table 2. 
     4. Comparative Example 1 
     (4-1. Production of Optical Body) 
       FIG. 13  shows the configuration of an optical body  500  according to Comparative Example 1. In Comparative Example 1, the optical body  500  was produced by the following steps. First, a base material similar to the base material  10 - 1  used in Example 1 was prepared as a base material  510 . Next, using the macro concave-convex master used in Example 1, a macro concave-convex structure  520  was formed on a surface of the base material  510 . The macro concave-convex structure  520  has macro convexities  520   a  and macro concavities  520   b , and the macro concavity  520   b  has the inverse shape of the master macro convexity. By the above steps, the optical body  500  according to Comparative Example 1 was produced. 
     (4-2. Characteristics Evaluation) 
     Next, the characteristics evaluation of the optical body  500  was performed similarly to Example 1. A specular reflection spectrum is shown in  FIG. 20 , and a diffuse reflection spectrum is shown in  FIG. 21 . The luminance and the x and y values are shown in Table 1. The luminous reflectance and the reflection chromaticity (a*, b*) are shown in Table 2. 
     5. Comparative Example 2 
     (5-1. Production of Optical Body) 
       FIG. 14  shows the configuration of an optical body  600  according to Comparative Example 2. In Comparative Example 2, the optical body  600  was produced by sticking a moth-eye film  620  to the back surface of the optical body  500  (that is, the surface on the side where the macro concave-convex structure  520  was not formed) via an adhesive film  610 . Here, similar films to the adhesive film  10 - 2  and the moth-eye film  10 - 3  used in Example 1 were used as the adhesive film  610  and the moth-eye film  620 . 
     (5-2. Characteristics Evaluation) 
     Next, the characteristics evaluation of the optical body  600  was performed similarly to Example 1. A specular reflection spectrum is shown in  FIG. 20 , and a diffuse reflection spectrum is shown in  FIG. 21 . The luminance and the x and y values are shown in Table 1. The luminous reflectance and the reflection chromaticity (a*, b*) are shown in Table 2. 
     6. Comparative Example 3 
     (6-1. Production of Optical Body) 
       FIG. 15  shows the configuration of an optical body  700  according to Comparative Example 3. In Comparative Example 3, the optical body  700  was produced by sticking an antireflection film  720  with a thickness of 60 μm to each of both surfaces of the optical body  500  via an adhesive film  710 . Here, a similar film to the adhesive film  10 - 2  used in Example 1 was used as the adhesive film  610 . An AR film of an inorganic four-layer film manufactured by Dexerials Corporation was used as the antireflection film  720 . 
     (5-2. Characteristics Evaluation) 
     Next, the characteristics evaluation of the optical body  600  was performed similarly to Example 1. A specular reflection spectrum is shown in  FIG. 20 , and a diffuse reflection spectrum is shown in  FIG. 21 . The luminance and the x and y values are shown in Table 1. The luminous reflectance and the reflection chromaticity (a*, b*) are shown in Table 2. 
     7. Consideration 
     Next, the results of the characteristics evaluation are considered. First, the results of all the specular reflection spectra and the diffuse reflection spectra of Examples 1 to 3 were better than those of Comparative Examples 1 to 3. That is, the results of all the specular reflectances and the diffuse reflectances of Examples 1 to 3 were lower than those of Comparative Examples 1 to 3. In Comparative Example 1, no micro concave-convex structure was formed, and therefore both the specular reflectance and the diffuse reflectance were high values. In Comparative Example 2, a micro concave-convex structure was formed on one surface, and therefore better results than in Comparative Example 1 were obtained; but the results were insufficient to withstand practice. In Comparative Example 3, an antireflection film was stuck to each of both surfaces, and therefore better results than in Comparative Examples 1 and 2 were obtained in specific wavelength regions. However, conversely, worse results than in Comparative Examples 1 and 2 were obtained in low wavelength regions and high wavelength regions. Thus, in Examples 1 to 3, a micro concave-convex structure was formed on each of both surfaces of the optical bodies  1 - 1  to  1 - 3 , and therefore an excellent antireflection function has been achieved. Furthermore, for the luminances and the x and y values of Examples 1 to 3, almost equal results to the luminances and the x and y values of Comparative Examples 1 and 2 were obtained. Furthermore, with attention on Examples 1 and 3, the luminances of these were very excellent values relative to those of Comparative Examples 1 and 2. This is presumed to be because the micro concave-convex structures suppressed the reflection of internally propagating light in the insides of the optical bodies  1 - 1  and  1 - 3 . In Comparative Example 13, it was impossible to measure the luminance and the x and y values. This is presumed to be because the macro concave-convex structure  520  was filled with the antireflection film  720 . 
     The luminances of Examples 1 and 3 were more excellent than the luminance of Example 2. In Examples 1 and 3, the macro concavities  13   b , which are portions where internally propagating light reflects, are engraved on the inside of the optical bodies  1 - 1  and  1 - 3 . Hence, most of the internally propagating light traveling in directions perpendicular to the thickness direction of the optical bodies  1 - 1  and  1 - 3 , what is called parallel light, is incident on the film and the concavities  13   b , and is totally reflected. On the other hand, in Example 2, the macro convexities  13   a , which are portions where internally propagating light reflects, protrude on the outside in the thickness direction of the optical body  1 - 2 . Hence, the parallel light mentioned above is less likely to be incident on the macro convexities  13   a . It is presumed that, due to these facts, the luminances of Examples 1 and 3 were more excellent than the luminance of Example 2. 
     In light emission based on the macro concave-convex structure  13 , it is required to produce as neutral a color as possible. In this respect, the light emission of Comparative Example 1 is supposed to produce the most neutral color. The x and y values of Examples 1 to 3 are very close to the x and y values of Comparative Example 1. Therefore, it can be said that also Examples 1 to 3 were able to produce a neutral color. 
     Next, the luminous reflectance and the reflection chromaticity (a*, b*) are considered. In Examples 1 to 3, the luminous reflectance (reflection Y value) was less than or equal to 1.0%, and the reflection chromaticity (a*, b*) was less than or equal to 1.0. Thus, it has been found that, in Examples 1 to 3, an excellent antireflection function has been achieved also in this respect. On the other hand, in Comparative Examples 1 and 2, the luminous reflectance was very large. In Comparative Example 3, an antireflection film was stuck to each of both surfaces of the optical body  500 , and therefore the luminous reflectance and the reflection chromaticity were good. However, as described above, in Comparative Example 3 it was impossible to measure the luminance and the x and y values. 
     8. Verification on Arrangement Direction of Micro Concave-Convex Structure 
     Next, the following experiment was performed in order to verify the corresponding relationship between the arrangement direction of the micro concave-convex structure and the propagation direction L. First, an optical body  1 - 1 A in which the macro concave-convex structure  13  was excluded from the optical body  1 - 1  described above was prepared as an optical body corresponding to the present embodiment. The optical body  1 - 1 A was produced by excluding the step of the macro concave-convex master from the steps of producing the optical body  1 - 1 . Next, as an optical body for comparison (Comparative Example 4), an optical body in which each of the first micro concave-convex structure  11  and the second micro concave-convex structure of the optical body  1 - 1 A was changed to a micro concave-convex structure  800  shown in  FIG. 16  (hereinafter, such an optical body is also referred to as an “optical body  1 - 1 B”) was prepared. The micro concave-convex structure  800  has large numbers of micro convexities  800   a  and micro concavities  800   b . The optical body  1 - 1 B was produced by changing the master concave-convex structure  120  of the micro concave-convex master  100  of the transfer device  300 . The dot pitch P1, the track pitch P2, and the average height of the micro concave-convex structure  800  were set similar to those of the first micro concave-convex structure  11  and the second micro concave-convex structure  12  of Example 1. However, the arrangement was set to a lattice-like arrangement, and the dot arrangement direction L20 was set to a direction parallel to the longitudinal direction of the optical body  1 - 1 B. A planar SEM photograph of the micro concave-convex structure  800  is shown in  FIG. 18 . 
     Further, as an optical body for comparison (Comparative Example 5), an optical body in which each of the first micro concave-convex structure  11  and the second micro concave-convex structure of the optical body  1 - 1 A was changed to the micro concave-convex structure shown in the SEM photograph shown in  FIG. 19 , that is, a micro concave-convex structure in which concavities and convexities were arranged randomly (hereinafter, such an optical body is also referred to as an “optical body  1 - 1 D”) was prepared. Such a micro concave-convex structure was produced by changing the master concave-convex structure  120  of the micro concave-convex master  100  of the transfer device  300 . Here, the micro concave-convex master  100  was produced by, when performing exposure using the exposure device  200 , changing the irradiation interval of laser light  200 A randomly. The average period of the micro concave-convex structure was set to 200 nm. 
     Next, an experiment similar to the measurement of the luminance and the x and y values described above was performed. In the optical body  1 - 1 A, the angle between the straight line L21 perpendicular to the propagation direction L of internally propagating light and the crossing arrangement direction L22 is 40°. On the other hand, in the optical body  1 - 1 B, as shown in  FIG. 16 , the angle between the straight line L21 perpendicular to the propagation direction L of internally propagating light and the crossing arrangement direction L22 is 0°. In the optical body  1 - 1 C, concavities and convexities are arranged randomly, and therefore the arrangement direction cannot be defined. 
     In all the optical bodies  1 - 1 A to  1 - 1 C, a macro concave-convex structure is not provided, and therefore theoretically it is expected that the luminance will not be measured. That is, it can be said that, as the measurement value of luminance becomes smaller, it becomes more difficult for the observer to visually identify leaked light. As a result, the luminance of the optical body  1 - 1 A was 8.5 cd/m 2 , the luminance of the optical body  1 - 1 B was 9.2 cd/m 2 , and the luminance of the optical body  1 - 1 C was 12.3 cd/m 2 . Here, with regard to the optical body  1 - 1 B, a similar experiment was further performed by setting the position of the LED light source on a side surface on the longitudinal side of the optical body  1 - 1 B. A corresponding relationship between the propagation direction L, and the dot arrangement direction L20 and the crossing arrangement direction L22 at this time is shown in  FIG. 17 . Also in this case, the angle between the straight line L21 perpendicular to the propagation direction L of internally propagating light and the crossing arrangement direction L22 is 0°. The luminance of the optical body  1 - 1 B was 9.7 cd/m 2 . Thus, the luminance of the optical body  1 - 1 A was smallest. 
     Therefore, it has been found that, in order to suppress the visibility of leaked light, it is necessary that the micro concave-convex structure be arranged periodically, the crossing arrangement direction L22 be inclined with respect to the straight line L21 perpendicular to the propagation direction L of internally propagating light, and the angle between the crossing arrangement direction L22 and the straight line L21 be 30 to 60° C. 
     9. Verification on Average Height of Micro Concave-Convex Structure 
     Next, the following simulation was performed in order to verify the average height of the micro concave-convex structure. First, an optical body in which only the first micro concave-convex structure  11  was formed on the base material  10  was envisaged, and parameters proper to this optical body were inputted to a thin film simulation software application (TFCalc). Here, it was assumed that the first micro concave-convex structure  11  had a shape in the depth direction of an artillery shell-like shape like one obtained by a quadratic function, and was arranged in an arrangement pattern similar to that of Example 1. Then, the first micro concave-convex structure  11  was modeled as a multiple-layer film of 10 layers. Each layer was approximated on the assumption that the height of concavity and convexity was divided into 10 pieces. Then, the incidence angle was changed within the range of 0 to 70°, and the measuring wavelength was set to 380 nm to 780 nm. The reflection angle was set to the same value as the incidence angle. Then, similar processing was performed while the average height of the first micro concave-convex structure  11  (specifically, the average height of the first micro convexity  11   a ) was changed. Then, the luminous reflectance (that is, the Y value in a Yxy color space) was measured. The results are shown in  FIG. 22 . The horizontal axis of  FIG. 22  represents the incidence angle of measuring light, and the vertical axis represents the luminous reflectance (reflection Y value). 
     In view of the shape of the macro concave-convex structure  13 , incidence at incidence angles of 30 to 50° corresponds to incidence on the macro concave-convex structure  13 . Thus, the luminous reflectance being small in this range means that also the luminous reflectance in the place on the macro concave-convex structure  13  is small. In this respect, it has been found that, when the average height is more than or equal to 200 nm, the luminous reflectance is sufficiently small. 
     The preferred embodiment(s) of the present invention has/have been described above with reference to the accompanying drawings, whilst the present invention is not limited to the above examples. A person skilled in the art may find various alterations and modifications within the scope of the appended claims, and it should be understood that they will naturally come under the technical scope of the present invention. 
     REFERENCE SIGNS LIST 
     
         
           1  optical body 
           10  base material 
           11  first micro concave-convex structure 
           11   a  first micro convexity 
           11   b  first micro concavity 
           12  second micro concave-convex structure 
           12   a  second micro convexity 
           12   b  second micro concavity 
           13  macro concave-convex structure 
           13   a  macro convexity 
           13   b  macro concavity 
           20  light source