Optical body, diffusion plate, display device, projection device, and illumination device

Abstract

The invention provides an optical body, a diffusion plate, a display device, a projection device, and an illumination device. According to the present invention, in an optical body in which a microlens array, which is a non-periodic structure, is arranged and expanded in a wide area, it is possible to suppress the discovery of periodic optical characteristics in structural units larger than the non-periodic structure. The optical body according to the present invention is configured from a single non-periodic structure region or a plurality of non-periodic structure regions, the non-periodic structure region comprising a single lens group comprising a plurality of single lenses, the arrangement state of the single lens group being non-periodic as a whole in the non-periodic structure region, and the arrangement state of the single lens group being non-periodic as a whole in the non-periodic structure region. The ratio of the size of the aperiodic structure region to the average aperture diameter of the single lens in the aperiodic structure region is 25 times or more.

Description

[0001] This application is a divisional application of the PCT application entering the Chinese national phase, whose international application date is December 5, 2017, the date of entering the Chinese national phase is June 27, 2019, the national application number is 201780081201.0, and the invention name is "Optical body, diffuser, display device, projection device and lighting device". Technical Field

[0002] The invention relates to an optical body, a diffusion plate, a display device, a projection device and a lighting device. Background Art

[0003] In order to change the diffusion characteristics of light, a diffusion plate is usually used to diffuse the incident light in a desired direction. The diffusion plate has an optical body on its surface for achieving the desired diffusion state. As one of the optical bodies, there is a microlens structure having a plurality of microlenses of about tens of μm in size.

[0004] For example, Patent Document 1 below discloses an optical film including a microlens array region in which a plurality of microlenses are formed. The optical film is characterized in that the surface shapes of the plurality of microlenses formed in the microarray region are different from each other.

[0005] One method of manufacturing such a microlens is a method of manufacturing a microlens based on a projection exposure method, such as that shown in the following Patent Document 2. Patent Document 2 discloses a method of forming a microlens having uniform optical properties on the entire substrate by repeatedly exposing using a mask having grayscale. The characteristic of this method of manufacturing a microlens is that the amount of exposure is changed.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-13748

[0007] Patent Document 2: Japanese Patent Application Publication No. 2005-275000 Summary of the invention

[0008] However, the inventors have conducted in-depth research on optical bodies with multiple microlenses, and finally obtained the following results. That is, when an optical body with a non-periodic microlens array structure disclosed in the above-mentioned patent document 1 is manufactured by the manufacturing method disclosed in the above-mentioned patent document 2 that can obtain uniform optical characteristics, it is expected that a macroscopic structure larger than the non-periodic structure will be found due to the difference in the dispersion of the specified area of ​​the non-periodic structure. Specifically, even in the case where various optical characteristics are improved by the non-periodic structure, it is confirmed that macroscopic spots are seen according to the dispersion of the basic structure in the non-periodic structure, and periodicity is generated in the optical characteristics of the optical body.

[0009] Therefore, the present invention is proposed in view of the above-mentioned problems, and an object of the present invention is to provide an optical body, a diffuser, a display device, a projection device and a lighting device, which can suppress the discovery of periodic optical properties in structural units larger than the non-periodic structure in an optical body in which a microlens array as a non-periodic structure is arranged and spread over a wide area.

[0010] In order to solve the above-mentioned problems, according to one viewpoint of the present invention, there is provided an optical body, which is composed of a single non-periodic structure region or a collection of multiple non-periodic structure regions, wherein the non-periodic structure region is composed of a single lens group composed of multiple single lenses, and in the non-periodic structure region, the configuration state of the single lens group as a whole is non-periodic, and the ratio of the size of the non-periodic structure region to the average opening diameter of the single lens in the non-periodic structure region is more than 25 times.

[0011] Preferably, in the non-periodic structure region, the configuration spacing of the single lens group or the opening diameter of the single lens, or at least any one of the curvature radius of the single lens or the shape of the single lens, or the configuration spacing of the single lens group or the opening diameter of the single lens, and at least any one of the curvature radius of the single lens or the shape of the single lens, are changed.

[0012] Preferably, in the non-periodic structure area, the configuration spacing of the single lens group or the opening diameter of the single lens, or, at least any one of the curvature radius of the single lens or the shape of the single lens, or, the configuration spacing of the single lens group or the opening diameter of the single lens, and at least any one of the curvature radius of the single lens or the shape of the single lens, their change rate from the baseline is greater than 5%.

[0013] Preferably, the surface shape of the single lens in the non-periodic structure region is a spherical shape or an aspherical shape in which a reference curvature radius R (μm) and a reference opening diameter D (μm) satisfy the relationship R≥(D / 2).

[0014] Preferably, a reference opening diameter D of the single lens in the non-periodic structure region is greater than or equal to 30 μm and less than or equal to 300 μm.

[0015] Preferably, the optical body is an optical body in which the non-periodic structure regions identical to each other are repeatedly arranged.

[0016] Preferably, the optical body is an optical body in which the non-periodic structure regions different from each other are repeatedly arranged.

[0017] Preferably, the diffusion half angle of light passing through the optical body is greater than 20 degrees.

[0018] Furthermore, in order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a diffuser plate having a surface including the above-mentioned optical body.

[0019] Furthermore, in order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a display device including a diffusion plate having the above-mentioned optical body.

[0020] Furthermore, in order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a projection device including a diffusion plate having the above-mentioned optical body.

[0021] Furthermore, in order to solve the above-mentioned problems, according to another aspect of the present invention, there is provided a lighting device including a diffuser plate having the above-mentioned optical body.

[0022] As described above, according to the present invention, in an optical body in which a microlens array as a non-periodic structure is arrayed and spread over a wide area, it is possible to suppress the occurrence of periodic optical characteristics in a structural unit larger than the non-periodic structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram schematically showing an optical body according to an embodiment of the present invention.

[0024] Figure 2A It is a schematic diagram for explaining the arrangement of unit cells forming the optical body according to the same embodiment.

[0025] Figure 2B It is a schematic diagram for explaining the arrangement of unit cells forming the optical body according to the same embodiment.

[0026] Figure 3 It is a schematic diagram schematically showing a part of the unit cell of the same embodiment.

[0027] Figure 4 It is a schematic diagram for explaining a single lens included in the optical body of the same embodiment.

[0028] Figure 5 It is a schematic diagram for explaining a single lens included in the optical body of the same embodiment.

[0029] Figure 6 This is an electron microscope photograph of an example of a single lens group included in the optical body of the same embodiment, viewed from above.

[0030] Fig. 7A This is a schematic diagram for explaining a method of arranging a single lens group included in an optical body according to the same embodiment.

[0031] Figure 7B This is a schematic diagram for explaining a method of arranging a single lens group included in an optical body according to the same embodiment.

[0032] Fig. 8A This is a schematic diagram for explaining a method of arranging a single lens group included in an optical body according to the same embodiment.

[0033] Figure 8B This is a schematic diagram for explaining a method of arranging a single lens group included in an optical body according to the same embodiment.

[0034] Fig. 9 This is a schematic diagram for explaining how to view a macro pattern.

[0035] Fig. 10A This is a schematic diagram showing an example of the observation result of a macro pattern.

[0036] Fig. 10B This is a schematic diagram showing an example of the observation result of a macro pattern.

[0037] Fig.11 This is a schematic diagram for explaining the relationship between the opening diameter of an optical body and the size of a unit cell in relation to viewing of a macro pattern.

[0038] Fig.12 This is a schematic diagram for explaining the relationship between the opening diameter of an optical body and the size of a unit cell in relation to viewing of a macro pattern.

[0039] Fig.13 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0040] Fig.14 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0041] Fig.15 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0042] Fig.16 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0043] Fig.17 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0044] Fig.18 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0045] Fig.19 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0046] Fig. 20 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0047] Fig.21This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern.

[0048] Fig.22A It is a schematic diagram for explaining the optical body of the same embodiment.

[0049] Fig. 22B It is a schematic diagram for explaining the optical body of the same embodiment.

[0050] Fig. 22C It is a schematic diagram for explaining the optical body of the same embodiment.

[0051] Fig.23 This is a flowchart showing an example of the flow of the method for manufacturing an optical body according to the embodiment.

[0052] Explanation of symbols

[0053] 1 Optical body

[0054] 10Transparent substrate

[0055] 20 single lens groups

[0056] 21 Single lens DETAILED DESCRIPTION

[0057] Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and repeated description is omitted.

[0058] (Overview of Optical Body According to Embodiment of the Present Invention)

[0059] Before describing in detail the optical body according to the embodiment of the present invention, the outline of the optical body according to the embodiment of the present invention will be briefly described below.

[0060] The optical body according to the embodiment of the present invention described in detail below is a microlens array type optical body having a light homogeneous diffusion function. The optical body has a structure in which convex or concave microlenses having a light diffusion function are arranged non-periodically.

[0061] As described in detail below, it is clear to the inventor that in the region of the existing non-periodic micromirror array structure, or in the region where the non-periodic structure region is arranged to start in a wide area with periodicity, due to the difference in the dispersiveness of the prescribed region of the non-periodic structure, a macroscopic structure larger than the non-periodic structure is found. Specifically, even if there is an improvement in granularity, a bright fuzzy effect, and the situation of the improvement effect such as ripple suppression by the non-periodic structure, it is also obvious to see the speckle of the macroscopic shape according to the dispersiveness of the basic structure in the structure.

[0062] In the optical body of the embodiment of the present invention described in detail below, the ratio of the size of the microstructure to the macrostructure is set to 25 times or more in the microstructure area of ​​the non-periodic microlens array that serves as the basic structure, and in the macrostructure area where the basic structure is periodically arranged over a wide area. As a result, no macrostructure larger than the non-periodic structure can be seen.

[0063] In addition, the optical body according to the embodiment of the present invention can provide a homogeneous display body in a high-brightness and high-grayscale image display device such as a liquid crystal backlight, various lighting devices (LED, laser, etc.), and a projection device such as a projector, etc., through the above effects. In addition, since it has a deformation function of the light distribution angle distribution, it is possible to provide a small lighting device that suppresses light spots and controls the light distribution to a specified light distribution, a high-precision light measurement device, a measurement medical device, etc.

[0064] Hereinafter, the optical body according to the embodiment of the present invention having the above-mentioned features will be described in detail.

[0065] (About Optical Body)

[0066] Below, refer to Figure 1 to Figure 22C , an optical body according to an embodiment of the present invention is described in detail.

[0067] Figure 1 It is a schematic diagram schematically showing an optical body according to an embodiment of the present invention. Figure 2A and Figure 2B It is a schematic diagram for explaining the arrangement of unit cells forming the optical body of the present embodiment. Figure 3 It is a schematic diagram schematically showing a part of the unit cell of this embodiment. Figure 4 and Figure 5 It is a schematic diagram for explaining a single lens included in the optical body of the present embodiment. Figure 6 This is an electron microscope photograph of an example of a single lens group included in the optical body of the present embodiment, viewed from above. Figures 7A to 8B This is a schematic diagram for explaining a method of arranging a single lens group included in the optical body of the present embodiment. Fig. 9 This is a schematic diagram for explaining how to view a macro pattern. Fig. 10A and Fig. 10B This is a schematic diagram showing an example of the observation result of a macro pattern. Fig.11 and Fig.12 This is a schematic diagram for explaining the relationship between the opening diameter of an optical body and the size of a unit cell in relation to viewing of a macro pattern. Figures 13 to 21 This is a schematic diagram showing an example of the results of checking the presence or absence of a macro pattern. Figures 22A to 22C It is a schematic diagram for explaining the optical body of this embodiment.

[0068] The optical body 1 of this embodiment is a microlens array type optical body in which a microlens group consisting of a plurality of microlenses (single lenses) is arranged on a substrate. The optical body 1 is composed of a plurality of unit cells 3, such as Figure 1 In addition, between the unit cells 3, as shown in FIG. Figure 1 As schematically shown in the right figure, the layout pattern (arrangement pattern) of the plurality of microlenses provided in the unit cell 3 is continuous in the layout direction of the unit cell (in other words, the array arrangement direction).

[0069] Here, in Figure 1 In the figure, the shape of the unit cell 3 constituting the optical body 1 is a rectangular shape. However, the shape of the unit cell 3 is not limited to Figure 1 In the case shown, for example, a shape that can fill a plane without any gap, such as an equilateral triangle or a regular hexagon, may be used.

[0070] The number of the unit cells 3 constituting the optical body 1 of the present embodiment is not particularly limited, and the optical body 1 may be constituted by one unit cell 3 or may be constituted by a plurality of unit cells 3 .

[0071] Here, each unit cell 3 can be understood as a non-periodic structure region composed of a non-periodic structure, as described in detail below. In the unit cell 3, at least one of the configuration spacing of the single lens group or the opening diameter of the single lens, or the curvature radius of the single lens or the shape of the single lens; or at least one of the configuration spacing of the single lens group or the opening diameter of the single lens, and the curvature radius of the single lens or the shape of the single lens; changes.

[0072] The optical body 1 of this embodiment can be Figure 2A As schematically shown, it is an optical body in which unit cells 3 having different non-periodic structures are repeatedly arranged, and it can also be as shown in FIG. Figure 2B As schematically shown, it is an optical body in which unit cells 3 having the same non-periodic structure are repeatedly arranged.

[0073] Figure 3 Schematic diagram schematically showing the structure of a part of the unit cell 3 of this embodiment. Figure 3 As schematically shown, the unit cell 3 of the present embodiment includes a transparent substrate 10 and a single lens group 20 formed on the surface of the transparent substrate 10 .

[0074] <About transparent substrate 10>

[0075] The transparent substrate 10 is a substrate made of a material that can be regarded as transparent in the wavelength bandwidth of light incident on the optical body 1 of the present embodiment. The transparent substrate 10 can be either a thin sheet or a plate. The material of the substrate is not particularly limited. For example, known resins such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), cycloolefin polymer (COP), and triacetylcellulose (TAC) can be used as the transparent substrate 10. Existing optical glasses such as quartz glass, borosilicate glass, and whiteboard glass can also be used. Figure 3 In the figure, the transparent substrate 10 is illustrated as a rectangle, but the shape of the transparent substrate 10 is not limited to a rectangle, for example, it can have any shape according to the shape of a display device, a projection device, a lighting device, etc. on which the optical body 1 is installed.

[0076] <About Single Lens Group 20>

[0077] A single lens group 20 composed of a plurality of single lenses 21 is formed on the surface of the transparent substrate 10. In the optical body 1 of the present embodiment, it is preferred that Figure 3 As schematically shown, the single lens group 20 is formed so that a plurality of single lenses 21 are adjacent to each other (in other words, there is no gap (flat portion) between the single lenses 21). By seamlessly arranging the single lenses 21 on the transparent substrate 10 (in other words, arranging so that the filling rate of the single lenses is 100%), it is possible to suppress the component of the incident light that is not scattered on the surface of the diffuser plate and directly passes through (hereinafter also referred to as "0-order transmitted light component"). As a result, in the single lens group 20 in which a plurality of single lenses 21 are arranged adjacent to each other, the diffusion performance can be further improved.

[0078] In addition, in the single lens group 20 of this embodiment, as Figure 3 As schematically shown, the single lenses 21 are not arranged regularly, but are arranged irregularly (randomly). Here, "irregular" means that there is actually no regularity in the arrangement of the single lenses 21 in any area of ​​the single lens group 20 of the optical body 1. Therefore, even if there is a certain regularity in the arrangement of the single lenses 21 in a tiny area in any area, the situation where there is no regularity in the arrangement of the single lenses 21 as a whole in any area is also included in "irregularity". In addition, the irregular arrangement method of the single lenses 21 in the single lens group 20 of the present embodiment is described in detail again below.

[0079] In this embodiment, the single lens 21 constituting the single lens group 20 is as follows: Figure 3 As schematically shown, it may be a convex lens or a concave lens. In the single lens group 20 of the present embodiment, the surface shape of each single lens 21 is not particularly limited, and may include only a spherical component or an aspherical component.

[0080] In the single lens group 20 of the present embodiment, not only the arrangement of the single lenses 21 described above but also the aperture diameter and the radius of curvature of each single lens 21 vary in the entire single lens group 20 .

[0081] A plurality of single lenses 21 are arranged adjacent to each other, and the single lenses 21 are irregularly formed on the transparent substrate 10, and the opening diameter and the curvature radius of each single lens 21 have deviations (randomness), so that the outer shapes of the single lenses 21 do not have the same shape as each other. Figure 3 As schematically shown, the shapes are various and often asymmetrical.

[0082] In this case, if Figure 4 As schematically shown, in the single lens A, the radius of curvature is r A , while in the single lens B, the radius of curvature is r B (≠r A ) also often occurs. When the curvature radii of adjacent single lenses are different, the boundary between adjacent single lenses is not only composed of straight lines, but at least a part of it contains a curve. As a result, Figure 5 As schematically shown, the outer shape of the single lens 21 (the projection trajectory of the outer shape when looking down at the single lens 21) is in a form composed of multiple different curves and curved surface boundaries. By including a curve in at least a part of the boundary between the single lenses, the regularity of the configuration of the boundary between the single lenses is further destroyed, and the diffraction component can be further reduced.

[0083] Figure 6 This is a SEM photograph of a portion of the single lens group 20 in the optical body 1 of this embodiment observed from above using a scanning electron microscope (SEM). Figure 6 It is clear that the outer shapes (bird's-eye projection loci) of the single lenses 21 constituting the single lens group 20 have various shapes, and the aperture diameters of the single lenses 21 are also different from each other.

[0084] <About the configuration method of the single lens 21>

[0085] Next, the method of arranging the single lens 21 described above will be described in detail.

[0086] In the unit cell 3 of the optical body 1 of the present embodiment, the single lens group 20 in which a plurality of single lenses 21 having the above-mentioned characteristics are arranged can be realized mainly by the following two arrangement methods.

[0087] The first arrangement method is an arrangement method in which the single lens 21 having a reference shape is randomly arranged from the beginning. Hereinafter, this arrangement method is also referred to as a "random arrangement method". In this arrangement method, the shape (i.e., the opening diameter and the curvature radius) of the single lens 21 is deviated (perturbed) on the basis of randomly arranging the single lens 21 having a reference shape. Therefore, according to Figure 6 The SEM photograph shown shows the actual arrangement of the single lens group 20 . It is obvious that no regularity can be found in the arrangement of the single lenses 21 even when the single lens group 20 is viewed macroscopically to some extent.

[0088] The second arrangement method is as follows: first, a reference state (hereinafter also referred to as the "initial arrangement state") in which single lenses 21 having a reference shape are regularly arranged is set, and then, based on the initial arrangement state, the shape (i.e., the opening diameter and the radius of curvature) and the configuration position (more specifically, the vertex position of the single lens 21) of the single lens 21 are dispersed (perturbed). Hereinafter, this configuration method is also referred to as the "reference configuration method". In this configuration method, after the regular arrangement of the single lenses 21, the shape and configuration of the single lenses 21 are made random, so that when the single lens group 20 is viewed macroscopically to a certain extent, the configuration of the initial arrangement state can be inferred to a certain extent.

[0089] [About random configuration method]

[0090] First, refer to Fig. 7A and Figure 7B Briefly explain the process of the random configuration method.

[0091] like Fig. 7A As shown, in the random configuration method, when the lens configuration position is considered in the xy coordinate system, the x coordinate and y coordinate of the lens configuration position are determined by random numbers. At this time, for the single lens 21 of interest, the distance from each of the configured single lenses 21 is calculated, and if the overlap width with the configured single lens 21 is within a preset allowable range, the single lens 21 of interest is configured. On the contrary, when the calculated overlap width exceeds the allowable range, the single lens 21 of interest is not configured. In this way, the initial arrangement of the random configuration method is determined.

[0092] The allowed range in the above configuration method is Figure 7B The maximum overlap O shown v The maximum overlap O vThis can be understood as the maximum value of the overlapping width with the mutually adjacent single lenses 21 .

[0093] The above is an overview of the random arrangement method, but a more specific algorithm of the random arrangement method is not particularly limited, and for example, a conventional method disclosed in Japanese Patent Application Laid-Open No. 2012-181816 can be used.

[0094] As mentioned above, after determining the initial arrangement, Figure 7B By further perturbing the opening diameter D and the curvature radius R of the single lens 21 shown as parameters, the single lenses 21 having random shapes can be randomly arranged, and the occurrence of flat portions can be suppressed.

[0095] In the random arrangement method described above, the maximum value of the overlap width of two adjacent single lenses 21 in the single lens group 20 is set to 0. v (μm), when the aperture diameters of two adjacent single lenses 21 are set to D1 (μm) and D2 (μm), respectively, it is preferred that the relationship represented by the following equation (101) holds. When the relationship represented by the following equation (101) does not hold, the degree of deviation of the parameters used to achieve random configuration is insufficient, and it may be difficult to achieve sufficient randomness.

[0096]

[0097] [About the benchmark configuration method]

[0098] Next, refer to Fig. 8A and Figure 8B , briefly explaining the process of the benchmark configuration method.

[0099] like Fig. 8A As shown, in the reference configuration method, first, an initial arrangement state serving as a reference is set. The regular arrangement state of the single lens 21 is not particularly limited, and a four-sided arrangement in which the vertex positions of the single lens 21 are arranged in a square, a six-sided arrangement in which the vertex positions of the single lens 21 are arranged at positions corresponding to the vertices of a regular hexagon and the center of the regular hexagon, etc. can be appropriately used. At this time, in order to minimize the occurrence of flat portions in the single lens group 20 after the reference configuration method is implemented, it is preferred to set the regular arrangement state to the densest arrangement state such as a hexagonal densest grid.

[0100] In this benchmark configuration method, if Fig. 8A As shown in the middle figure on the left, the grid spacing ( Figure 8B The reference grid spacing G in is set as a parameter. Then, Fig. 8A As shown in the figure on the lower left, the grid spacing as a parameter is reduced from the value corresponding to the densest pattern. Fig. 8A As shown in the upper right figure, the single lenses overlap each other and there is no flat portion.

[0101] Then, if Fig. 8A As shown in the middle figure on the right, the lens center (vertex position) of each single lens 21 is randomly moved from the grid point. Specifically, the maximum moving distance from the grid point is set as a parameter ( Figure 8B The maximum disturbance amount M in the equation is determined by taking the product of a random number between 0 and 1 and the maximum moving distance as the moving distance. In addition, the moving angle is also determined using a random number. Thus, Fig. 8A As shown in the lower right figure, the final arrangement pattern of the single lens 21 is determined.

[0102] Then, Figure 8B The opening diameter D and the curvature radius R of the single lens 21 shown are further perturbed as parameters, thereby making it possible to randomly arrange the single lenses 21 having random shapes.

[0103] Reference above Figures 7A to 8B , the configuration method of the single lens 21 of this embodiment is specifically described.

[0104] Preferably, in the above-mentioned configuration method of the unit cell 3, at least one of the configuration pitch of the single lens group or the opening diameter of the single lens, or the curvature radius of the single lens or the shape of the single lens; or at least one of the configuration pitch of the single lens group or the opening diameter of the single lens, and the curvature radius of the single lens or the shape of the single lens; their change rate from the reference (that is, the perturbation amount of each of the above-mentioned configuration methods) is 5% or more. Since the change rate from the reference (that is, the perturbation amount) is 5% or more, it is possible to reliably introduce non-periodicity into the single lens group 20 constituting the unit cell 3.

[0105] In addition, the surface shape of the single lens 21 of the unit cell 3 is preferably a spherical shape in which the reference curvature radius R (μm) and the reference opening diameter D (μm) satisfy the relationship R ≥ (D / 2), or an aspherical shape. The surface shape of the single lens 21 constituting the unit cell 3 has the above-mentioned surface shape, thereby being able to more reliably realize the so-called top-hat type diffusion characteristics.

[0106] In addition, the top-hat diffusion characteristic refers to an optical function that, for collimated light in the visible light region, telecentric light having a collimated principal ray and a predetermined aperture, the energy distribution homogeneity is very high within the predetermined region of the angle component, and the energy decreases sharply if the predetermined region of the angle component is exceeded. By realizing this diffusion characteristic, the brightness distribution of the diffused light of the light incident on the single lens group 20 is roughly uniform within the predetermined diffusion angle range, and a state is achieved in which the brightness value of the diffused light is converged within the range of ±10% within the predetermined diffusion angle range.

[0107] In the above-described unit cell 3 , it is preferable that the reference opening diameter D be not less than 30 μm and not more than 300 μm.

[0108] <About Macroscopic Patterns Viewed in Optical Bodies>

[0109] As mentioned above, the present inventors have confirmed that when the unit cells 3 having a non-periodic structure are periodically arranged to form the optical body 1, macroscopic patterns are seen due to the dispersion of the basic structure within the unit cells 3. Hereinafter, the macroscopic patterns observed in the optical body confirmed by the present inventors are described in detail.

[0110] The macro patterns that the inventors are concerned about are as follows: Fig. 9 As schematically shown, an optical body formed by periodically configuring unit cells having a non-periodic structure is irradiated with a light beam of a Köhler illumination system that converts the illumination light emitted from an LED light source into collimated light through a collimating lens, and the state of the surface of the single lens group 20 is focused on an image sensor such as a CCD or CMOS through a camera lens, thereby being able to be confirmed as an image.

[0111] Fig. 10A An example of the observation result of the macro pattern which confirmed the macro pattern which the inventors paid attention to is shown. Fig. 10A It is obvious from the camera image on the upper side that in the image, it can be confirmed that there are regular patterns (i.e., macro patterns) that are larger than the size of the unit cell 3. Fig. 10A The brightness distribution of the cross section shown at the bottom also has periodic brightness peaks.

[0112] on the other hand, Fig. 10B An example of the observation result of the macro pattern in which the macro pattern of interest of the present inventors was not confirmed is shown. Fig. 10B As can be clearly seen in the camera image above, no regular patterns were confirmed in the image. Fig. 10B The brightness distribution of the cross section shown below shows that the brightness value fluctuates slightly, but Fig. 10A There are no periodic brightness peaks as shown.

[0113] Regarding the dispersion of the basic structure that provides such a macro pattern, e.g. Fig.11 As schematically shown, the present inventors focus on the average aperture diameter D of the single lens 21 constituting the unit cell 3. AVE The relationship between the reference aperture diameter D of the single lens 21 and the length L of the unit cell 3 in the arrangement direction (that is, the length of one side of the unit cell 3) has been studied in depth.

[0114] Here, when actually manufacturing the single lens group 20, no matter what manufacturing method is used, there is a resolution at which "fine drawing cannot be performed any more". Hereinafter, the resolution generated by this drawing is referred to as the "minimum spot size". If the minimum spot size is determined by manufacturing constraints, etc., the length L of one side of the unit cell 3 is obtained by multiplying the minimum spot size by the number of pixels constituting the unit cell 3. That is, when each pixel is Δ (μm) and the unit cell 3 is manufactured with a size of P pixels × P pixels, the length L of one side of the unit cell 3 is expressed as L = Δ × P.

[0115] The inventors calculated the average value D of the aperture diameter of the single lens 21 of the unit cell 3 AVE (= the reference opening diameter D of the single lens 21) was fixed to 30μm, and on this basis, the minimum dot size Δ=0.8μm was set (this was the minimum dot size in the manufacturing method commonly used when manufacturing optical bodies at that time.), the number of dots P on one side was changed, and the optical bodies were manufactured according to the above-mentioned random configuration method to verify whether the macro pattern was confirmed. In addition, when manufacturing the optical body, the value of the reference curvature radius R was fixed to 20μm, and the disturbance amount δ of the reference opening diameter D and the reference curvature radius R was set to 5% respectively. The confirmation of the macro pattern utilized Fig. 9 In addition, for some optical bodies, the state of diffuse light was simulated using a commercially available ray tracing simulation application.

[0116] exist Fig.12 The obtained results are shown in Figures 13 to 20 The results of confirming the macroscopic patterns of each optical body are shown in FIG.

[0117] in addition, Fig.13 This is the result when the number of pixels P is 5000. The figure shows the surface shape of the unit cell 3, the captured image when the unit cells 3 are arranged in 3×3=9 sheets, and the simulation result of the diffused light state of the optical body. Fig.14 This is the result when the number of dots P = 2000 pixels. The figure shows the surface shape of the unit cell 3 and a captured image when the unit cells 3 are arranged in 2×2=4 images. Fig.15 This is the result when the number of pixels P is 1000. The figure shows the surface shape of the unit cell 3, a captured image when the unit cells 3 are arranged in 5×5=25 sheets, and a simulation result of the diffused light state of the optical body. Fig.16 This is the result of the number of dots P=750 pixels. The figure shows the surface shape of the unit cell 3 and a captured image when the unit cells 3 are arranged in 6×6=36 images. Fig.17This is the result when the number of dots P = 400 pixels. The figure shows the surface shape of the unit cell 3, the captured image when the unit cells 3 are arranged in 12×12=144 sheets, and the simulation result of the diffused light state of the optical body. Fig.18 This is the result when the number of dots P = 250 pixels. The figure shows the surface shape of the unit cell 3, the captured image when the unit cells 3 are arranged in 12×12=144 sheets, and the simulation result of the diffused light state of the optical body. Fig.19 This is the result when the number of dots P = 200 pixels. The figure shows the surface shape of the unit cell 3, the captured image when the unit cells 3 are arranged in 25×25=625 sheets, and the simulation result of the diffused light state of the optical body. Fig. 20 This is the result when the number of dots P is 125 pixels. The figure shows the surface shape of the unit cell 3, the captured image when the unit cells 3 are arranged in 40×40=1600 sheets, and the simulation result of the diffused light state of the optical body.

[0118] If compared with each other Figures 13 to 20 It is obvious that as the value of the number of pixels P on one side decreases, the size of the single lens 21 in the unit cell 3 becomes relatively larger. In addition, in the camera image with the value of the number of pixels P on one side being 5000 pixels to 1000 pixels, no regular pattern is generated, but if the value of the number of pixels P on one side becomes 750 pixels or less, it can be seen that a regular pattern is generated in the camera image. Furthermore, if the value of the number of pixels P on one side becomes 250 pixels or less, it can be confirmed that macroscopic periodic diffraction light is generated in the simulation result of the diffuse light state.

[0119] Regarding this verification result, if the size L of one side of the unit cell 3 and the opening diameter D are calculated, AVE The size ratio is as follows Fig.12 In the result of P=750 pixels corresponding to a size ratio of 20 times, a macro pattern was confirmed, and in the result of P=1000 pixels corresponding to a size ratio of 26.67 times, no macro pattern was confirmed, so the inventors were able to find that the generation of macro patterns can be suppressed by setting the size ratio to 25 times or more.

[0120] In order to verify this view, the camera images of the manufactured unit cell 3 were confirmed by setting the reference opening diameter D = 250μm, the reference curvature radius R = 200μm, the disturbance amount δ = ±5%, the minimum point size Δ = 0.8μm, the size ratio 25 times, and arranging 5×5=25 sheets of the manufactured unit cell 3. Fig.21 The results obtained are shown in Fig.21 It is also clear from the captured images when 25 sheets are arranged that even when the reference opening diameter D is changed, the generation of macro patterns can be suppressed by setting the size ratio to 25 times or more.

[0121] Based on this result, the present inventors have found the following insight: if the size of the unit cell 3 as the non-periodic structure region is equal to the average aperture diameter D of the single lens 21 of the unit cell 3, AVE The ratio of the optical body is 25 times or more, then the generation of macro patterns can be suppressed. In addition, there is no particular upper limit on the size ratio, the larger the better.

[0122] <About Diffusion Characteristics of Optical Body>

[0123] Reference Figures 22A to 22C The size of the unit cell 3 in the non-periodic structure region described above and the average aperture diameter D of the single lens 21 of the unit cell 3 are AVE The diffusion characteristics of the optical body 1 whose size ratio is 25 times or more will be described.

[0124] The optical body 1 of this embodiment can realize the desired diffusion characteristics by appropriately controlling the reference opening diameter D, reference curvature radius R, disturbance amount δ, etc. of the single lens group 20 constituting the unit cell 3, and introducing an aspherical shape. In more detail, the optical body 1 of this embodiment can manufacture an optical body with a diffusion half angle (diffusion half value width) of more than 20 degrees, and can also manufacture an optical body with a diffusion half angle (diffusion half value width) of less than 10 degrees by performing appropriate adjustments as described above.

[0125] Here, by making Fig.22A The incident light of the extremely narrow band shown in FIG. 1 is incident on the optical body 1 of the present embodiment. Fig. 22B As shown, it is possible to achieve a diffusion characteristic with a diffusion half angle of more than 20 degrees. Fig. 22C As shown, it is also possible to achieve a diffusion characteristic with a diffusion half angle of less than 10 degrees. Fig. 22B The optical body 1 shown is an optical body composed of unit cells 3 manufactured by setting a reference opening diameter D=30 μm, a reference curvature radius R=20 μm, a disturbance amount δ=5%, and a size ratio=26.7. Fig. 22C The optical body 1 shown is an optical body composed of unit cells 3 manufactured by setting a reference opening diameter D=80 μm, a reference curvature radius R=200 μm, a disturbance amount δ=10%, and a dimension ratio=50.

[0126] Optical bodies with a diffusion half angle (diffusion half-value width) of more than 20 degrees can be used in the field of diffused light that is easy for humans to see, and can be used in various lighting devices used in spotlighting, basic lighting, various special lighting, intermediate screens, final screens, and other screens.

[0127] On the other hand, optical bodies with a diffusion half angle (diffusion half-value width) of less than 10 degrees can be used in fields such as diffusion control of light source light in optical devices, and can be used for light distribution control of LED light source devices, light distribution control of laser source devices, incident light distribution control of various light valve systems, etc.

[0128] Reference above Figure 1 to Figure 22C , the optical body of this embodiment is described in detail.

[0129] (An example of a method for manufacturing an optical body)

[0130] Below, refer to Fig.23 An example of a method for manufacturing the optical body 1 according to the embodiment of the present invention will be briefly described. Fig.23 This is a flowchart showing an example of the flow of the method for manufacturing an optical body according to the present embodiment.

[0131] In the method for manufacturing an optical body of the present embodiment, first, a base is cleaned (step S101). The base may be in a roll shape such as a glass roll or in a flat plate shape such as a glass wafer.

[0132] Next, an anti-etching layer (e.g., an anti-etching layer using a metal oxide, an anti-etching layer using an organic substance, etc.) is formed on the cleaned substrate (step S103). The formation of the anti-etching layer is achieved by coating or dipping the substrate in a roll form, and by various coating processes for the substrate in a flat form.

[0133] Then, the substrate on which the resist layer is formed is subjected to exposure processing (step S105). In this exposure processing, as described above, it is important to design the unit cell 3 so that the size ratio is 25 times or more. This exposure processing can appropriately use various existing exposure methods such as exposure using a grayscale mask or the like (including multiple exposures by overlapping a plurality of grayscale masks), grayscale exposure on a flat plate or a roller, and laser exposure using a picosecond pulse laser, a femtosecond pulse laser, etc.

[0134] After that, the exposed base is subjected to alkaline development (step S107), and a known sputtering treatment such as Ni sputtering is performed (step S109), thereby completing a master disk (e.g., a glass master disk, a metal master disk, etc.) for manufacturing the optical body 1 of the present embodiment (step S111). Thereafter, a mold such as a soft mold is made using the completed master disk (step S113).

[0135] Next, the optical body 1 of the present embodiment is manufactured by performing a transfer process on the substrate glass, substrate film, etc. using the manufactured mold (step S115 ), and forming a protective film, etc. as needed (step S117 ).

[0136] On the other hand, when the glass substrate is directly processed, the alkali development treatment in step S107 is continued, and a dry etching treatment using a known compound such as CF4 is performed (step S119), and thereafter, a protective film is formed as needed (step S121), thereby manufacturing the optical body 1 of this embodiment.

[0137] in addition, Fig.23 The manufacturing method shown is only an example. The manufacturing method of the optical body of this embodiment is not limited to Fig.23 Example shown.

[0138] (Application example of optical body)

[0139] Next, application examples of the optical body 1 of the present embodiment will be briefly described.

[0140] The optical body 1 described above can be applied to a diffuser plate used to diffuse light. That is, by providing the optical body on at least one of the front surface and the back surface of a predetermined optical substrate, a diffuser plate having desired diffusion characteristics can be realized.

[0141] The diffuser plate of the optical body 1 of the present embodiment described above can be appropriately mounted on a device that needs to diffuse light to achieve its function. Devices that need to diffuse light to achieve their functions include display devices such as various displays and projection devices such as projectors.

[0142] Furthermore, the diffuser plate having the optical body 1 of this embodiment can also be applied to the backlight of a liquid crystal display device and can also be used for light shaping. Furthermore, the diffuser plate having the optical body 1 of this embodiment can be applied to various lighting devices.

[0143] Furthermore, the device that needs to diffuse light to achieve its function is not limited to the above-mentioned examples, and the diffuser plate having the optical body 1 of this embodiment can be applied to other known devices as long as it is a device that utilizes diffusion of light.

[0144] The preferred embodiments of the present invention are described in detail with reference to the accompanying drawings, but the present invention is not limited to the examples mentioned. Obviously, as long as a person skilled in the art of the present invention can think of various changes or modifications within the scope of the technical ideas recorded in the claims, it should be understood that these also belong to the technical scope of the present invention.

Claims

1. An optical body, characterized in that: The optical body is composed of a plurality of rectangular non-periodic structural regions arranged vertically and horizontally, wherein the non-periodic structural region is composed of a single lens group composed of a plurality of single lenses. In the non-periodic structure region, the configuration state of the single lens group as a whole is non-periodic, The outer shape of the single lens is composed of a plurality of different curves. The average opening diameter D of the single lens AVE Under the condition that the reference curvature radius R of the single lens is 30 to 250 μm and the reference curvature radius R of the single lens is 20 to 200 μm, the side length L of one side along the arrangement direction of the non-periodic structure region is 0.8 mm to 4 mm, The length L of one side of the non-periodic structure region is equal to the average opening diameter D of the single lens in the non-periodic structure region. AVE The ratio is more than 25 times. In the non-periodic structure region, at least one of the arrangement pitch of the single lens group, the aperture diameter of the single lens, the curvature radius of the single lens, or the shape of the single lens changes from a reference, and the rate of change from the reference is greater than 5%. In the single lens group, two adjacent single lenses are arranged to overlap each other, and there is no flat portion between the two adjacent single lenses. When the maximum value of the overlapping width of the two adjacent single lenses is set to Ov, and the opening diameters of the two adjacent single lenses are set to D1 and D2 respectively, the following relationship (101) is satisfied: [Formula 101] 2. The optical body according to claim 1, characterized in that The surface shape of the single lens in the non-periodic structure region is a spherical shape or an aspherical shape in which a reference curvature radius R (μm) and a reference opening diameter D (μm) satisfy the relationship R≥D / 2.

3. The optical body according to claim 1, characterized in that A reference opening diameter D of the single lens in the non-periodic structure region is greater than or equal to 30 μm and less than or equal to 250 μm.

4. The optical body according to claim 1, characterized in that The optical body is an optical body in which the non-periodic structure regions identical to each other are repeatedly arranged.

5. The optical body according to claim 1, characterized in that The optical body is an optical body in which the non-periodic structure regions having the non-periodic structures different from each other are repeatedly arranged.

6. The optical body according to claim 1, characterized in that The diffusion half-value width of the diffused light passing through the optical body is 20 degrees or more.

7. A diffuser plate, characterized in that: The surface comprises the optical body of claim 1.

8. A display device, characterized in that: A diffuser plate having the optical body according to claim 1 is included.

9. A projection device, characterized in that: A diffuser plate having the optical body according to claim 1 is included.

10. A lighting device, characterized in that: A diffuser plate having the optical body according to claim 1 is included.

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