Polarization optical element, optical instrument and display device

Abstract

To provide a polarization optical element having anti-glare and antireflection properties and high in environmental durability.SOLUTION: The polarization optical element comprises: a substrate; and a periodic structure provided on the surface of the substrate, extending in a first direction, and including a plurality of protrusions periodically arranged in a second direction intersecting the first direction. The apex of the protrusion is provided with a plurality of recesses different from each other in length in the first direction. The plurality of recesses includes a first recess, a second recess adjacent to the first recess in the first direction, and a third recess adjacent to the second recess in the first direction. The length of the first recess in the first direction is longer than a period where the protrusions are arrayed in the second direction. A distance between the first recess and the second recess in the first direction is different from a distance between the second recess and the third recess in the first direction.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to a polarizing optical element, an optical instrument, and a display device. [Background technology]

[0002] Polarizing optical elements used in display devices such as liquid crystal display devices and touch-type display devices have a significantly reduced visibility due to the reflection of external light such as fluorescent light and sunlight on the surface. In addition, when the display device is viewed from the front, the light transmitted through the polarizing optical element may appear very dazzling. For this reason, the surface of the polarizing optical element of the display device is generally provided with an anti-glare function or an anti-reflection function using a fine uneven structure or fine particles.

[0003] For example, Patent Document 1 describes laminating an antiglare layer having transparent fine particles dispersed therein on the surface of a polarizing optical element for the purpose of improving the visibility of a display device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-58616 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technique described in Patent Document 1, depending on the usage environment, such as a high temperature environment or a high humidity environment, internal stress in the laminated film on the surface of the polarizing optical element may become large, and there is a risk of cracks occurring in the laminated film.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a polarizing optical element that has antiglare and antireflection properties and has high environmental durability. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a polarizing optical element having a substrate and a periodic structure including a plurality of convex portions provided on a surface of the substrate, extending in a first direction and arranged periodically in a second direction intersecting the first direction, wherein a plurality of concave portions having lengths in the first direction different from each other are provided on the tops of the convex portions, the plurality of concave portions including a first concave portion, a second concave portion adjacent to the first concave portion in the first direction, and a third concave portion adjacent to the second concave portion in the first direction, wherein the length of the first concave portion in the first direction is longer than the period in which the convex portions are arranged in the second direction, and the distance in the first direction between the first concave portion and the second concave portion is different from the distance in the first direction between the second concave portion and the third concave portion. Effect of the Invention

[0008] According to the present invention, it is possible to realize a polarizing optical element that has both environmental durability and anti-glare and anti-reflection properties. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1 is a perspective view showing an optical element according to a first embodiment. [Figure 1B] FIG. 1B is an enlarged perspective view of the circled portion in FIG. 1A. [Figure 1C] FIG. 1C is a plan view of FIG. 1B observed from the normal direction of the optical surface. [Figure 1D] 3 is a plan view showing an example of the arrangement of a plurality of fine recesses in a plan view of the optical element according to the first embodiment, observed from the normal direction of the optical surface. FIG. [Diagram 2] 3A to 3C are perspective views showing examples of the shape of a grating structure in the optical element according to the first embodiment. [Diagram 3] 4A to 4C are perspective views showing examples of the shape of fine recesses in the optical element according to the first embodiment. [Figure 4A] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4B] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4C]2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4D] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4E] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4F] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4G] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4H] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4I] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4J] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4K] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 4L] 2A to 2C are cross-sectional views illustrating a method for manufacturing the optical element according to the first embodiment. [Figure 5A] 3 is a photograph of the optical element of Example 1 observed by an SEM from the normal direction of the optical surface. [Figure 5B] 3 is a photograph of the optical element of Example 1, observed by SEM from an oblique direction on the optical surface. [Figure 6] FIG. 11 is a cross-sectional view showing a display device according to a second embodiment. [Figure 7] 11 is an explanatory diagram illustrating incident light from the outside and outgoing light from the inside in a display device according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are some embodiments of the invention, and are not limited thereto. Then, common configurations will be described with mutual reference to multiple drawings, and descriptions of configurations with common symbols will be omitted as appropriate. For multiple configurations called by the same name, "No. 0" may be added before the name, such as the first configuration, the second configuration, etc. For symbols, multiple configurations may be distinguished by adding lowercase alphabets after the common symbol.

[0011] First Embodiment FIG. 1A is a perspective view of an optical element 10 according to this embodiment. The optical element 10 includes a substrate 11, an optical surface 12, and a lattice structure 13. The optical surface 12 is provided on one of the main surfaces of the substrate 11. The lattice structure 13 is provided on the surface of the optical surface 12. This embodiment shows an example in which the optical element 10 is a film-like polarizing film, and the optical surface 12 is a flat surface. Note that the optical element 10 is not limited to being a polarizing film, and may be in the form of a plate-like body or the like. In addition, the optical surface 12 is not limited to being a flat surface, and may be a curved surface.

[0012] The optical element 10 according to this embodiment is, for example, a transmissive polarizing optical element that has a polarizing function for light having a wavelength smaller than the period P of the grating structure 13 by providing a grating structure 13 on the surface of the optical surface 12. The grating structure 13 may be provided on the entire surface of the optical surface 12, or may be provided on only a part of it.

[0013] The grating structure 13 is a periodic structure in which irregularities extending in a predetermined grating direction on the surface of the optical surface 12 are periodically arranged in a periodic direction perpendicular to the grating direction, and is formed in a line-and-space pattern. The grating structure 13 is not limited to being formed in a line-and-space pattern, and may be any structure having a polarization function. For example, the grating structure 13 may be a mesh-like structure in which protrusions are formed in a mesh pattern, as shown in FIG. 2. The grating structure 13 may be a periodic structure in which a plurality of protrusions 131 extending in a first direction, the grating direction, are periodically arranged in a periodic direction, which is a second direction intersecting the first direction. The protrusions 131 do not necessarily need to extend linearly in the grating direction, and may extend, for example, so as to be curved or bent.

[0014] FIG. 1B is an enlarged perspective view of a portion surrounded by a circle C in FIG. 1A. The lattice structure 13 is formed in a line-and-space pattern in which a plurality of protrusions 131 extending in the lattice direction are periodically arranged in the periodic direction via recesses 132 extending in the lattice direction. The width of the protrusions 131 in the periodic direction is L, and the period of the lattice structure 13 in which the protrusions 131 are periodically arranged is P.

[0015] The lattice structure 13 has microscopic recesses 14 which are minute recesses provided on the apexes of the protrusions 131. A plurality of microscopic recesses 14 are provided on the apexes of the protrusions 131. Since a fine uneven shape is formed on the surface layer of the optical surface 12 by the plurality of microscopic recesses 14, the optical surface 12 can scatter light incident on the optical surface 12 or light exiting from the optical surface 12.

[0016] The length W of the micro recess 14 in the lattice direction of the lattice structure 13 11 is not constant among the micro recesses 14, but includes a plurality of lengths that may vary among the micro recesses 14. The micro recesses 14 have a length W 11 is longer than the period P of the grating structure 13. In addition, in the normal direction of the optical surface 12, the depth of the minute recesses 14 is preferably shallower than the depth of the recesses 132 between the protrusions 131.

[0017] In order to improve the anti-glare properties particularly in the visible range, the fine recesses 14 have a length W 11 It is preferable that the length W of the fine recesses 14 is 1.6 to 16.6 times the period P of the lattice structure 13. 11 If the length W of the minute recesses 14 is shorter than 1.6 times the period P, the scattered light intensity will have wavelength dependency. 11 is longer than 16.6 times the period P, the scattering angle distribution of the scattered light becomes significantly biased, and there is a risk of the effect of diffraction interference becoming greater. Therefore, by configuring in this manner, it is possible to provide optical element 10 with an anti-glare function without affecting the scattering of light entering optical surface 12 or light exiting optical surface 12.

[0018] For example, the wavelength of the light incident on the optical element 10 may be 380 nm or more and 780 nm or less, which is the wavelength in the visible light region, and the refractive index of the optical element 10 may be 1.3 or more and 1.5 or less. In this case, in order to exhibit optical characteristics without generating diffracted light or scattered light, it is preferable that the period P of the grating structure 13 is 150 nm or more and 340 nm or less. In this case, the length W of the fine recesses 14 is 1.3 or more and 1.5 or less. 11 It is preferable that the wavelength is 240 nm or more and 2480 nm or less.

[0019] Here, the length W of the fine recess 14 11 When the length W of the minute recesses 14 is uniform and periodic, the light incident on or emerging from the optical surface 12 may interfere with each other. 11 It is preferable that the variation in the size is large, and the arrangement of the minute recesses 14 is irregular.

[0020] On the other hand, the length W of the minute recess 14 in the periodic direction of the lattice structure 13 12 may be equal to or smaller than the width L of the protrusions 131 in the periodic direction of the lattice structure 13.

[0021] 1C is a plan view of FIG. 1B observed from the normal direction of optical surface 12. In the plan view of optical element 10 observed from the normal direction of optical surface 12, it is preferable that the ratio of the area of ​​minute recesses 14 to the surface area of ​​optical element 10 is smaller than the ratio L / P of the width L in the periodic direction of protrusions 131 to the period P. However, the larger the ratio of the area of ​​minute recesses 14, the larger the scattering portion that scatters light entering optical surface 12 or light exiting optical surface 12, and therefore the antiglare property is further improved.

[0022] 1C shows a case where the planar shape of the minute recesses 14 in plan view when the optical element 10 is viewed from the normal direction to the optical surface 12 is rectangular, but is not limited thereto. For example, the planar shape of the minute recesses 14 in plan view when the optical element 10 is viewed from the normal direction to the optical surface 12 may be an ellipse as shown in FIG.

[0023] Fig. 1D is a plan view showing an example of the arrangement of the plurality of fine recesses 14 in a plan view of the optical element 10 observed from the normal direction of the optical surface 12. In Fig. 1D, the plurality of fine recesses 14 include a first fine recess 14a, a second fine recess 14b, a third fine recess 14c, a fourth fine recess 14d, and a fifth fine recess 14e.

[0024] The first micro recess 14a, the second micro recess 14b, and the third micro recess 14c are provided on the top of the first convex portion 131a, which is the same convex portion 131 in the lattice structure 13. The second micro recess 14b is adjacent to the first micro recess 14a on one side in the lattice direction. The third micro recess 14c is adjacent to the second micro recess 14b on one side in the lattice direction.

[0025] The fourth micro recess 14d is provided on the top of the second protrusion 131b, which is the protrusion 131 adjacent to the first protrusion 131a on one side in the periodic direction. The fourth micro recess 14d is adjacent to the first micro recess 14a on one side in the periodic direction. The fifth micro recess 14e is provided on the top of the third protrusion 131c, which is the protrusion 131 adjacent to the second protrusion 131b on one side in the periodic direction. The fifth micro recess 14e is adjacent to the fourth micro recess 14d on one side in the periodic direction.

[0026] When the arrangement of the micro recesses 14 is irregular, specifically, the distance between the micro recesses 14 in Fig. 1D varies. For example, the distance D1 in the lattice direction between the first micro recess 14a and the second micro recess 14b is different from the distance D2 in the lattice direction between the second micro recess 14b and the third micro recess 14c. In this way, the micro recesses 14 may be arranged at different intervals in the lattice direction.

[0027] Also, for example, the distance D3 in the lattice direction between the center of the first microscopic recess 14a and the center of the fourth microscopic recess 14d is different from the distance D4 in the lattice direction between the center of the fourth microscopic recess 14d and the center of the fifth microscopic recess 14e.

[0028] Furthermore, for example, the arrangement of the multiple fine recesses 14 provided on the tops of adjacent convex portions 131 may be different from each other. Specifically, the arrangement of the multiple fine recesses 14 provided on the top of the first convex portion 131a may be different from the arrangement of the multiple fine recesses 14 provided on the top of the second convex portion 131b.

[0029] The plurality of minute recesses 14 have a length W 11 It is preferable that the lengths W of the fine recesses 14 in the lattice direction are different from each other. 11 is longer than the period P of the lattice structure 13, but does not necessarily correspond to the length W 11 It is not necessary that the length of the fine recess 14 is longer than the period P. It is sufficient that the length of at least one fine recess 14, for example the first fine recess 14a, is longer than the period P.

[0030] Thus, according to this embodiment, a plurality of fine recesses 14 are provided on the apexes of a plurality of convex portions 131 in the lattice structure 13, thereby making it possible to realize an optical element 10 that has anti-glare and anti-reflection properties and high environmental durability.

[0031] In the optical element 10 according to this embodiment, the substrate 11 and the lattice structure 13 including the fine recesses 14 are preferably made of the same material. The term "same material" here means that there is no interface between the structures, and may include the case where the composition of the material changes gradually. By configuring in this way, the spatial occupancy of the substrate 11, the lattice structure 13, and the fine recesses 14 changes gradually in the direction in which light is incident on the optical surface 12 or in the direction in which light is emitted from the optical surface 12. As a result, the refractive index gradient for the light passing through the optical surface 12 in the optical element 10 becomes smaller, and the reflectance for the incident light or the emitted light can be reduced.

[0032] Next, an example of a method for manufacturing the optical element 10 according to this embodiment will be described with reference to Figures 4A to 4L. The manufacturing method described below is one example of a method for manufacturing the optical element 10, and the method for manufacturing the optical element 10 is not limited to the manufacturing method described below.

[0033] First, as shown in Fig. 4A, a molding die 41 is prepared. The die 41 is composed of, for example, a stainless steel base portion 41a and a nickel alloy mirror surface portion 41b.

[0034] Next, as shown in Fig. 4B, for example, a titanium film 42 and a silicon dioxide film 43 are sequentially formed on the mold 41. The titanium film 42 and the silicon dioxide film 43 are preferably formed by sputtering, but any film forming method can be used. The thickness of the titanium film 42 is preferably 25 nm or more and 100 nm or less, and the thickness of the silicon dioxide film 43 is preferably 200 nm or more and 400 nm or less. The films formed here are not limited to the titanium film 42 and the silicon dioxide film 43, and films can be formed according to the material of the optical element 10 to be manufactured.

[0035] Subsequently, as shown in FIG. 4C, a photoresist layer 44a is formed on the silicon dioxide film 43 by, for example, a spin coating method.

[0036] Next, as shown in FIG. 4D, the photoresist layer 44a is exposed to light by, for example, ion beam lithography and then developed to obtain a photoresist pattern 45a.

[0037] 4E, the shape of the photoresist pattern 45a is copied onto the silicon dioxide film 43 by dry etching using, for example, CHF3 gas. Then, the photoresist pattern 45a on the surface of the silicon dioxide film 43 is removed by, for example, oxygen ashing. In this way, an inverted structure 46a corresponding to the lattice structure 13 is formed in the silicon dioxide film 43.

[0038] Thereafter, as shown in FIG. 4F, a photoresist layer 44b is formed by spin coating or the like on the silicon dioxide film 43 on which the inverted structure 46a has been formed.

[0039] Then, as shown in FIG. 4G, the surface layer of the photoresist layer 44b is removed by, for example, oxygen ashing, to obtain a photoresist pattern 45b in which the tops of the inverted structures 46a are exposed.

[0040] 4H, an oxide film 47 is formed on the photoresist pattern 45b and the top of the inverted structure 46a. The oxide film 47 can be, for example, a MoO3 film formed by sputtering and then removed by etching using an alkaline solution.

[0041] Next, as shown in Fig. 4I, an oxide film pattern 48 is obtained by using, for example, a lift-off method. In the lift-off method, the photoresist pattern 45b is removed together with the oxide film 47 thereon. As a result, an oxide film pattern 48 made of the oxide film 47 formed on the top of the inverted structure 46a is obtained.

[0042] Subsequently, as shown in FIG. 4J, a photoresist layer 44c is formed by spin coating or the like on the silicon dioxide film 43 in which the inversion structure 46a is formed and on the oxide film pattern 48.

[0043] Next, as shown in FIG. 4K, the photoresist layer 44c is exposed, for example, by ion beam lithography and then developed to obtain a photoresist pattern 45c. Then, the shape of the photoresist pattern 45c is copied to an inverted structure 46a by dry etching using, for example, CHF3 gas. As a result, an inverted structure 46b corresponding to the lattice structure 13 and the fine recesses 14 is formed in the silicon dioxide film 43.

[0044] 4L, the photoresist pattern 45c and the oxide film pattern 48 on the surface of the silicon dioxide film 43 are removed by, for example, oxygen ashing. In this way, an inverted structure 46b corresponding to the lattice structure 13 and the fine recesses 14 is formed in the silicon dioxide film 43. Thereafter, a monomolecular release film is formed on the surface of the inverted structure 46b, thereby manufacturing a mold 49 with a fine structure.

[0045] Next, the optical element 10 is obtained by molding the resin using the microstructured mold 49 in which the inverted structure 46b is formed as described above. The resin molding method here is a molding method such as injection molding, nanoimprinting, roll to roll, etc., and is not limited to a specific method. In addition, the resin used for molding is not particularly limited, but is preferably a material that has a transmittance of 90% or more at the wavelength of light targeted by the optical element 10 and can be injection molded. In the visible light wavelength range, for example, cycloolefin polymer resin (COP), polystyrene resin (PS), acrylic resin such as polymethyl methacrylate resin (PMMA), polycarbonate resin (PC), etc. can be used. In this way, the optical element 10 can be manufactured to be composed of a material containing resin.

[0046] <Example> The present invention will now be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0047] Example 1 In Example 1, an optical element 10 having a grating structure 13 and fine recesses 14 shown in FIG. 1B was produced. The period P of the grating structure 13 was 567 nm, and the width L was 273 nm. The length W of the fine recesses 14 was 273 nm. 11 The average length of is 4812 nm, and the length W 12 In plan view of the optical element 10 of Example 1 observed from the normal direction of the optical surface 12, the ratio of the area of ​​the fine recesses 14 to the area of ​​the optical surface 12 was 29%.

[0048] The optical element 10 of Example 1 was produced as a film by a thermal nanoimprint method using a molding die 49 having an inverted structure 46b produced by the method described with reference to FIGS. 4A to 4L.

[0049] The thickness of the titanium film 42 was 50 nm, and the thickness of the silicon dioxide film 43 was 300 nm. The spin coating conditions were 3000 rpm / 20 seconds, and the thickness of the photoresist layers 44a, 44b, and 44c was approximately 200 nm. Cycloolefin polymer resin (COP) was used as the molding resin for molding the optical element 10.

[0050] Fig. 5A is a photograph of the optical element 10 of Example 1 observed by a SEM (Scanning Electron Microscope) from the normal direction of the optical surface 12. Fig. 5B is a photograph of the optical element 10 of Example 1 observed by a SEM from an oblique direction of the optical surface 12. As can be seen from Figs. 5A and 5B, in Example 1, the multiple fine recesses 14 provided at the tops of the protrusions 131 in the lattice structure 13 were irregularly arranged. In addition, the length W of the multiple fine recesses 14 11 There was some variation.

[0051] Example 2 In Example 2, an optical element 10 having a grating structure 13 and fine recesses 14 shown in FIG. 3 was fabricated. The period P of the grating structure 13 was 519 nm, and the width L was 251 nm. The length W of the fine recesses 14 was 251 nm. 11 The average length of W is 2964 nm. 12 The average of the concave portions 14 was 251 nm, and the average of the depth was 98 nm. In a plan view of the optical element of Example 2 observed from the normal direction of the optical surface 12, the ratio of the area of ​​the fine concave portions 14 to the area of ​​the optical surface 12 was 23%. In Example 2, a film of the optical element 10 was produced under the same conditions as in Example 1. Also in Example 2, cycloolefin polymer resin (COP) was used as the molding resin as in Example 1.

[0052] Example 3 In Example 3, an optical element 10 having a grating structure 13 and fine recesses 14 as shown in FIG. 1B was produced. The period P of the grating structure 13 was 494 nm, and the width L was 253 nm. The length W of the fine recesses 14 was 253 nm. 11 The average length of is 1293 nm, and the length W 12 The average of the height and depth was 253 nm and 65 nm, respectively. In a plan view of the optical element 10 of Example 2 observed from the normal direction of the optical surface 12, the ratio of the area of ​​the fine recesses 14 to the area of ​​the optical surface 12 was 11%. In Example 3, a film of the optical element 10 was produced under the same conditions as in Example 1. In Example 3, a polycarbonate resin (PC) was used as a molding resin for molding the optical element 10.

[0053] Comparative Example 1 In Comparative Example 1, an optical element having a grating structure 13 without fine recesses 14 was produced. The period P of the grating structure 13 was 534 nm, and the width L was 230 nm. The optical element 10 of Comparative Example 1 was produced as a film by a thermal nanoimprint method using a molding die having an inverted structure 46a produced by the method described with reference to Figs. 4A to 4E. In Comparative Example 1, a cycloolefin polymer resin (COP) was used as the molding resin, as in Example 1.

[0054] (Evaluation Results) Table 1 shows the measurement results of the shape of the grating structure 13, the shape of the fine recesses 14, and the optical properties in Examples 1 to 3 and Comparative Example 1. In Examples 1, 2, and 3, the haze value could be increased while suppressing the average reflectance for light with wavelengths of 400 nm to 780 nm. On the other hand, in Comparative Example 1, the average reflectance for light with wavelengths of 400 nm to 780 nm could be suppressed, but the haze value was low.

[0055] [Table 1]

[0056] <Second embodiment> Next, an optical device according to a second embodiment will be described with reference to Fig. 6 and Fig. 7. In this embodiment, an EL (ElectroLuminescence) display 60 will be described as an example of an optical device to which the optical element 10 described in the first embodiment and examples can be applied.

[0057] Fig. 6 is a cross-sectional view showing an EL display 60 as a display device. The EL display 60 has a circular polarizing filter 61 and an EL element 62. The circular polarizing filter 61 is disposed on the side of the EL element 62 that faces the light-emitting surface of the EL element 62. Note that Fig. 6 shows a configuration including only the circular polarizing filter 61 and the EL element 62, but in addition to these members, other members such as a circular polarizing separation plate and a protective layer may be disposed.

[0058] The circular polarizing filter 61 has a linear polarizing element 61a and the optical element 10 according to the first embodiment. The linear polarizing element 61a is disposed on the optical surface 12 side of the optical element 10. The circular polarizing filter 61 is provided on the light emitting surface of the EL element 62 so that the surface of the optical element 10 opposite to the optical surface 12 is located on the light emitting surface side of the EL element 62. Here, the optical element 10 is preferably a transmission type polarizing optical element that imparts a phase difference of 1 / 4 to the wavelength of transmitted light. In addition, the angle between the transmission axis of the linear polarizing element 61a and the slow axis of the optical element 10 is preferably 90°±1°.

[0059] The EL element 62 constitutes the display section of the EL display 60, and has a transparent electrode 62a, a light-emitting layer 62b, a back electrode 62c, and a substrate 62d. The light-emitting layer 62b is disposed on the substrate 62d so as to be sandwiched between the transparent electrode 62a and the back electrode 62c. Of the transparent electrode 62a and the back electrode 62c that sandwich the light-emitting layer 62b, the back electrode 62c is located on the substrate 62d side, and the transparent electrode 62a side is the light-emitting surface of the EL element 62.

[0060] FIG. 7 is an explanatory diagram illustrating incident light 71 from the outside and outgoing light 72 from the inside of the EL display 60. As shown in FIG.

[0061] The visibility of the display can be impaired by internal reflection of external incident light in the circular polarizing filter or EL element, or glare from internally emitted light.

[0062] On the other hand, in the EL display 60 according to this embodiment, a circular polarizing filter 61 having an optical element 10 is provided on the side of the EL element 62 on which incident light 71 is incident from the outside. This makes it possible in this embodiment to block reflection of the incident light 71 from the outside while transmitting outgoing light 72 from the inside.

[0063] External incident light 71 becomes linearly polarized light by passing through the linear polarization element 61a and enters the optical element 10. In the optical element 10, due to its anti-reflection performance, almost all of the incident light passes through the optical element 10, and becomes right-handed circularly polarized light by passing through the optical element 10. Next, when the right-handed circularly polarized light is reflected by the EL element 62, the circular polarization of the reflected light is inverted and becomes left-handed circularly polarized light. This left-handed circularly polarized light becomes linearly polarized light perpendicular to the transmission axis of the linear polarization element 61a by passing through the optical element 10. Since this linearly polarized light is perpendicular to the transmission axis of the linear polarization element 61a, it is completely blocked by the linear polarization element 61a.

[0064] On the other hand, light 72 emitted from inside the EL element 62 becomes right-handed or left-handed circularly polarized light by passing through the optical element 10. At this time, glare caused by the light 72 emitted from inside is reduced by the anti-glare performance of the optical element 10. Then, of this circularly polarized light, the polarized light component parallel to the transmission axis of the linear polarizing element 61a is emitted to the outside of the EL display 60. In this way, by using the optical element 10, an EL display 60 with high anti-reflection performance and anti-glare effect can be realized.

[0065] Note that optical devices to which the optical element 10 according to the first embodiment can be applied are not limited to the EL display 60, and may be devices such as liquid crystal displays, plasma displays, 3D display devices, microscopes, polarized sunglasses, and lighting diffusion members. The optical element 10 according to the first embodiment can be widely applied to devices equipped with an optical system that includes an optical element.

[0066] The above-described embodiments can be modified as appropriate without departing from the technical concept. For example, a plurality of embodiments can be combined. In addition, some features of at least one embodiment can be deleted or replaced. Furthermore, new features can be added to at least one embodiment.

[0067] The disclosure of this specification includes not only what is explicitly described in this specification, but also all matters that can be understood from this specification and the drawings attached hereto. The disclosure of this specification also includes the complement of each concept described in this specification. In other words, if this specification contains a statement that "A is greater than B," for example, this specification can be said to disclose that "A is not greater than B" even if the statement that "A is not greater than B" is omitted. This is because when it is stated that "A is greater than B," it is assumed that the case in which "A is not greater than B" is taken into consideration.

[0068] The disclosure of this embodiment includes the following configuration. (Configuration 1) A substrate; a periodic structure provided on a surface of the base material, extending in a first direction, and including a plurality of convex portions periodically arranged in a second direction intersecting the first direction; A plurality of recesses having different lengths in the first direction are provided at the top of the protrusion, the plurality of recesses include a first recess, a second recess adjacent to the first recess in the first direction, and a third recess adjacent to the second recess in the first direction; a length of the first recess in the first direction is longer than a period at which the protrusions are arranged in the second direction; A distance in the first direction between the first recess and the second recess is different from a distance in the first direction between the second recess and the third recess. A polarizing optical element characterized by: (Configuration 2) the plurality of recesses include a fourth recess adjacent to the first recess in the second direction and a fifth recess adjacent to the fourth recess in the second direction, A distance in the first direction between a center of the first recess and a center of the fourth recess is different from a distance in the first direction between a center of the fourth recess and a center of the fifth recess. 2. The polarizing optical element according to claim 1, (Configuration 3) The plurality of recesses have lengths in the first direction that are different from one another. 3. The polarizing optical element according to configuration 1 or 2. (Configuration 4) The recesses are arranged at different intervals in the first direction. 4. The polarizing optical element according to any one of configurations 1 to 3. (Configuration 5) the plurality of protrusions include a first protrusion and a second protrusion adjacent to the first protrusion in the second direction, The plurality of recesses provided on the top of the first protrusion are arranged differently from the plurality of recesses provided on the top of the second protrusion. 5. The polarizing optical element according to any one of configurations 1 to 4. (Configuration 6) The length of the first recess in the first direction is 1.6 times or more and 16.6 times or less the period. 6. The polarizing optical element according to any one of configurations 1 to 5. (Configuration 7) the average length of the plurality of recesses in the second direction is equal to or less than the width L of the protrusion in the second direction; 7. The polarizing optical element according to any one of configurations 1 to 6. (Configuration 8) When the polarizing optical element is observed from a normal direction of the optical surface of the polarizing optical element, the ratio of the area of ​​the concave portion to the surface area of ​​the polarizing optical element is smaller than a ratio L / P, where P is the period and L is the width of the convex portion in the second direction. 8. The polarizing optical element according to any one of configurations 1 to 7. (Configuration 9) The depth of the recess is shallower than the depth between the protrusions. 9. The polarizing optical element according to any one of configurations 1 to 8. (Configuration 10) The substrate and the periodic structure are made of the same material. 10. The polarizing optical element according to any one of configurations 1 to 9. (Configuration 11) The substrate and the periodic structure are made of a material containing a resin. 11. The polarizing optical element according to any one of configurations 1 to 10. (Configuration 12) The polarizing optical element is a film. 12. The polarizing optical element according to any one of configurations 1 to 11. (Configuration 13) The polarizing optical element is a transmission type polarizing optical element. 13. The polarizing optical element according to any one of configurations 1 to 12. (Configuration 14) The material, The polarizing optical element according to any one of configurations 1 to 13, which is disposed relative to the member; An optical instrument comprising: (Configuration 15) A display unit; The polarizing optical element according to any one of configurations 1 to 13, which is disposed relative to the display unit; A display device comprising: [Explanation of symbols]

[0069] 10 Optical elements 11 Base material 12 Optical surface 13 Lattice structure 14 Micro recess 60 EL display 61 Circular Polarizing Filter 61a Linear polarizing element 62 EL element 62a transparent electrode 62b Light-emitting layer 62c back electrode 62d Board

Claims

1. A substrate; a periodic structure provided on a surface of the base material, extending in a first direction, and including a plurality of convex portions periodically arranged in a second direction intersecting the first direction; A plurality of recesses having different lengths in the first direction are provided at the top of the protrusion, the plurality of recesses include a first recess, a second recess adjacent to the first recess in the first direction, and a third recess adjacent to the second recess in the first direction; a length of the first concave portion in the first direction is longer than a period at which the convex portions are arranged in the second direction; A distance in the first direction between the first recess and the second recess is different from a distance in the first direction between the second recess and the third recess. A polarizing optical element characterized by:

2. the plurality of recesses include a fourth recess adjacent to the first recess in the second direction and a fifth recess adjacent to the fourth recess in the second direction, A distance in the first direction between a center of the first recess and a center of the fourth recess is different from a distance in the first direction between a center of the fourth recess and a center of the fifth recess.

2. The polarizing optical element according to claim 1.

3. The plurality of recesses have different lengths in the first direction.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

4. The plurality of recesses are disposed at different intervals in the first direction.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

5. the plurality of protrusions include a first protrusion and a second protrusion adjacent to the first protrusion in the second direction, The plurality of recesses provided on the top of the first protrusion are arranged differently from the plurality of recesses provided on the top of the second protrusion.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

6. The length of the first recess in the first direction is 1.6 times or more and 16.6 times or less the period.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

7. The average length of the plurality of recesses in the second direction is equal to or less than the width L of the protrusion in the second direction.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

8. When the polarizing optical element is observed from a normal direction of the optical surface of the polarizing optical element, the ratio of the area of ​​the concave portion to the surface area of ​​the polarizing optical element is smaller than a ratio L / P, where P is the period and L is the width of the convex portion in the second direction.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

9. The depth of the recess is shallower than the depth between the protrusions.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

10. The substrate and the periodic structure are made of the same material.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

11. The substrate and the periodic structure are made of a material containing a resin.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

12. The polarizing optical element is a film.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

13. The polarizing optical element is a transmission type polarizing optical element.

3. The polarizing optical element according to claim 1, wherein the polarizing optical element is a polarizing optical element.

14. The material, The polarizing optical element according to claim 1 or 2, which is disposed relative to the member. An optical instrument comprising:

15. A display unit; The polarizing optical element according to claim 1 or 2, which is disposed relative to the display unit. A display device comprising:

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