HK1193653B - Optical element, display device, and input device - Google Patents

Description

Optical element, display device, and input device

Technical Field

The present technology relates to an optical element having an antireflection function, a display device, and an input device. More specifically, the present invention relates to an optical element, a display device, and an input device in which a large number of structures each having a convex portion or a concave portion are arranged on a surface at a fine pitch equal to or smaller than the wavelength of visible light.

Background

Conventionally, in an optical element using a light-transmitting substrate such as glass or plastic, surface treatment for suppressing surface reflection of light has been performed. Such surface treatment includes surface treatment for forming fine and dense unevenness (moth eye) on the surface of an optical element (for example, see non-patent document 1).

Generally, when a periodic uneven shape is provided on the surface of an optical element, diffraction occurs when light passes through the uneven shape, and the linear propagation component of the transmitted light is greatly reduced. However, when the pitch of the uneven shape is shorter than the wavelength of the transmitted light, diffraction does not occur, and when the uneven shape is formed into a rectangular shape as described later, for example, an effective antireflection effect can be obtained with respect to light having a single wavelength corresponding to the pitch, depth, and the like.

As a moth-eye structure produced by electron beam exposure, a moth-eye structure having a minute tent shape (a pitch of about 300nm and a depth of about 400 nm) is disclosed (for example, see non-patent document 2). In the moth-eye structure, high-performance antireflection characteristics with a reflectance of 1% or less can be obtained.

Further, as a moth-eye structure manufactured by a method in which a mastering process and an etching process of an optical disc are combined, a moth-eye structure having a bell-shaped or elliptical truncated cone shape is disclosed (for example, see patent document 1). In this structure, antireflection characteristics close to electron beam exposure can be obtained.

Documents of the prior art

Patent document

Non-patent document 1: optical technical contact Vol.43, No.11 (2005), cf. 630-;

non-patent document 2: NTT advanced technology corporation, "a molding master for a reflector (moth eye) having no wavelength dependence, [ online ], [ retrieval at 23 years, 3 months, 31 days ], internet < http: v/keytech. ntt-at.co.jp/nano/prd _0033.html >;

patent document 1: international publication No. 08/023816 pamphlet.

Disclosure of Invention

Problems to be solved by the invention

In the moth-eye structure as described above, the principle of suppressing reflection by providing a surface with fine irregularities and changing the refractive index stepwise is used, and therefore, when a fingerprint is attached to the structure, it is desirable to remove the stain by a dry wiping method. This is because the function of suppressing reflection is impaired when dirt such as oil contained in a fingerprint fills the recessed portion of the moth-eye structure.

When a fingerprint is attached to a moth-eye structure, stains are attached in the shape of the fingerprint, and thereafter, the attached stains penetrate into the recessed portions of the structure by capillary action. When dry wiping is performed in this state, since dirt is only filled in the concave portion, the reflection suppressing effect of the uneven shape is dull, and the reflectance is high.

Although the penetration into the recessed portions of the structures can be slightly suppressed by coating the surface with a substance having a low surface energy such as fluorine, the penetration into the recessed portions of the structures cannot be prevented when dry wiping is performed. This is because the recesses of the structure are finer than the fibers used in the dry wiping, and therefore the force with which dirt is left in the recesses is stronger than the force with which the fibers suck the dirt.

In addition, in the conventional materials, a highly hydrophilic surface is required for wet wiping. This is because, for wet wiping, water needs to enter under stains adhering to the surface of the structure. However, such a super-hydrophilic surface treatment is likely to cause a problem in durability, and thus has a problem in practical use. Therefore, it has been difficult to remove stains from moth-eye structures.

Accordingly, an object of the present technology is to provide an optical element, a display device, and an input device that can wipe off stains such as fingerprints.

Means for solving the problems

In order to solve the above problem, an optical element according to a first technique includes: a substrate having a surface; and a plurality of structures consisting of a plurality of protrusions or recesses are arranged on the surface of the base at a fine pitch equal to or smaller than the wavelength of visible light, the elastic modulus of the material forming the structures is 5MPa or more and 1200MPa or less, and the surface on which the structures are formed has hydrophilicity.

The optical element according to the second technique includes a plurality of structures each including a plurality of protrusions arranged at a fine pitch equal to or smaller than the wavelength of visible light, and the lower portions of adjacent structures are joined to each other, and the elastic modulus of the material forming the structures is 5MPa or more and 1200MPa or less, and the surfaces on which the structures are formed have hydrophilicity.

In the present technology, the water contact angle in the surface on which the structures are formed is preferably 110 degrees or less, more preferably 30 degrees or less.

In the present technology, the aspect ratio of the structure is preferably in the range of 0.6 to 5.

In the present technology, the structures are preferably arranged so as to form a plurality of rows of tracks (tracks) on the surface of the base, and are formed in a lattice pattern. In this case, the lattice pattern is preferably at least one of a hexagonal lattice pattern, a quasi-hexagonal lattice pattern, a tetragonal lattice pattern, and a quasi-tetragonal lattice pattern. Preferably, the structure has an elliptical cone or an elliptical truncated cone shape having a major axis direction in an extending direction of the locus. Further, the trajectory preferably has a straight line shape or an arc shape. Furthermore, it is preferred that the trajectory is meandering.

In the present technology, the main structure is preferably periodically arranged in a tetragonal lattice shape or a quasi-tetragonal lattice shape. Here, the tetragonal lattice is a regular tetragonal lattice. The quasi-tetragonal lattice is a lattice of a skewed regular quadrangle different from the lattice of a regular quadrangle.

For example, when the structure is arranged on a straight line, the quasi-tetragonal lattice is a tetragonal lattice in which a regular tetragonal lattice is distorted by being stretched in a linear arrangement direction (track direction). In the case where the structures are arranged in a meandering manner, the quasi-tetragonal lattice is a tetragonal lattice in which a regular tetragonal lattice is distorted by the meandering arrangement of the structures. Alternatively, the square lattice is a square lattice in which a square lattice is stretched in a linear arrangement direction (track direction) and is distorted, and the structure is distorted by the meandering arrangement thereof.

In the present technology, the structures are preferably arranged periodically in a hexagonal lattice or quasi-hexagonal lattice. Here, the hexagonal lattice is a regular hexagonal lattice. The quasi-hexagonal lattice is a distorted regular hexagonal lattice different from the regular hexagonal lattice.

For example, when the structures are arranged on a straight line, the quasi-hexagonal lattice is a hexagonal lattice in which regular hexagonal lattices are distorted by being stretched in a linear arrangement direction (track direction). In the case where the structures are arranged in a meandering manner, the quasi-hexagonal lattice is a hexagonal lattice in which the regular hexagonal lattice is distorted by the meandering arrangement of the structures. Alternatively, the regular hexagonal lattice is a hexagonal lattice in which the regular hexagonal lattice is distorted by being stretched in a linear arrangement direction (track direction) and the structure is distorted by being arranged in a meandering manner.

In the present technology, the ellipse includes not only a mathematically defined complete ellipse but also an ellipse to which some skew is given. With respect to the circular shape, not only a mathematically defined complete circle (perfect circle) but also a circle to which some skew is given is included.

In the present technique, it is preferable that the arrangement pitch P1 of the structures in the same track is longer than the arrangement pitch P2 of the structures between two adjacent tracks. This can improve the filling ratio of the structure having the elliptical cone or truncated elliptical cone shape, and thus can improve the antireflection characteristics.

In the present technique, when each structure forms a hexagonal lattice pattern or a quasi-hexagonal lattice pattern on the surface of the substrate, the ratio P1/P2 preferably satisfies the relationship of 1.00. ltoreq. P1/P2. ltoreq.1.1 or 1.00< P1/P2. ltoreq.1.1, where P1 is the arrangement pitch of structures within the same track and P2 is the arrangement pitch of structures between two adjacent tracks. By setting the numerical range as described above, the filling ratio of the structure having the elliptical cone or elliptical truncated cone shape can be increased, and therefore, the antireflection property can be improved.

In the present technology, when each structure has a hexagonal lattice pattern or a quasi-hexagonal lattice pattern formed on the surface of the base, each structure preferably has an elliptical cone or an elliptical truncated cone shape having a major axis direction in the extending direction of the locus and having a steeper inclination in the central portion than in the tip portion and the bottom portion. By forming the shape in this manner, antireflection characteristics and transmission characteristics can be improved.

In the present technology, when each structure has a hexagonal lattice pattern or a quasi-hexagonal lattice pattern formed on the surface of the substrate, the height or depth of the structure in the extending direction of the tracks is preferably smaller than the height or depth of the structure in the column direction of the tracks. If such a relationship is not satisfied, the arrangement pitch in the extending direction of the traces needs to be increased, and therefore, the filling rate of the structure in the extending direction of the traces is reduced. When the fill factor is lowered in this manner, the reflection characteristic is lowered.

In the present technique, when the structures are formed in a tetragonal lattice pattern or a quasi-tetragonal lattice pattern on the surface of the substrate, the arrangement pitch P1 of the structures in the same track is preferably longer than the arrangement pitch P2 of the structures between two adjacent tracks. This can increase the filling ratio of the structure having the elliptical cone or truncated elliptical cone shape, and thus can improve the antireflection characteristics.

When the structures form a tetragonal lattice pattern or a quasi-tetragonal lattice pattern on the surface of the substrate, the ratio P1/P2 preferably satisfies the relationship of 1.4< P1/P2 < 1.5, where P1 represents the arrangement pitch of the structures in the same track and P2 represents the arrangement pitch of the structures between two adjacent tracks. By setting the numerical range as described above, the filling ratio of the structure having the elliptical cone or elliptical truncated cone shape can be increased, and therefore, the antireflection property can be improved.

When the structures form a tetragonal lattice pattern or a quasi-tetragonal lattice pattern on the surface of the substrate, each structure preferably has an elliptical cone or an elliptical truncated cone shape having a major axis direction in the extending direction of the track and a steeper inclination of the central portion than the inclination of the tip portion and the bottom portion. By forming such a shape, antireflection characteristics and transmission characteristics can be improved.

When the structures form a tetragonal lattice pattern or a quasi-tetragonal lattice pattern on the surface of the substrate, the height or depth of the structures in the direction of 45 degrees or approximately 45 degrees with respect to the tracks is preferably smaller than the height or depth of the structures in the column direction of the tracks. If such a relationship is not satisfied, the arrangement pitch in the direction of 45 degrees or approximately 45 degrees with respect to the traces needs to be increased, and therefore, the filling rate of the structure in the direction of 45 degrees or approximately 45 degrees with respect to the traces is lowered. When the fill factor is lowered in this manner, the reflection characteristic is lowered.

In the present technology, it is preferable that a large number of tracks constituting a plurality of rows of structures are arranged at a fine pitch on the surface of the base, and a hexagonal lattice pattern, a quasi-hexagonal lattice pattern, a tetragonal lattice pattern, or a quasi-tetragonal lattice pattern is formed between 3 adjacent rows of tracks. This makes it possible to increase the packing density of the structures in the surface, thereby increasing the antireflection efficiency of visible light, and obtaining an optical element having excellent antireflection characteristics and high transmittance.

In the present technology, it is preferable to fabricate the optical element by a method in which a mastering process and an etching process of the optical disc are integrated. The master for manufacturing the optical element can be efficiently manufactured in a short time, and the productivity of the optical element can be improved by coping with the increase in the size of the substrate. Further, when a fine array of structures is provided not only on the light incident surface but also on the light emitting surface, the transmission characteristics can be further improved.

The optical element of the present technology is suitably applied to a display surface of a display device, an input surface of an input device, a printing surface of a printed matter, a printing surface of photographic paper, and the like.

In the present technology, the elastic modulus of the material forming the structure is set to 1MPa or more and 1200MPa or less, and the aspect ratio of the structure is set to 0.6 or more and 5 or less, so that the structure is deformed when wiped off. Due to this deformation, water easily enters between the structures during wet wiping, and the penetrated dirt is pressed out.

Effects of the invention

As described above, according to the present technology, stains such as fingerprints adhering to the surface of the optical element can be dry-wiped or wet-wiped.

Drawings

Fig. 1A is a schematic plan view showing an example of the structure of an optical element according to a first embodiment of the present technology, fig. 1B is a plan view showing a part of the optical element shown in fig. 1A in an enlarged manner, fig. 1C is a cross-sectional view of the tracks T1, T3, … of fig. 1B, fig. 1D is a cross-sectional view of the tracks T2, T4, … of fig. 1B, fig. 1E is a sketch showing a modulation waveform of laser light for forming latent images corresponding to the tracks T1, T3, … of fig. 1B, and fig. 1F is a sketch showing a modulation waveform of laser light for forming latent images corresponding to the tracks T2, T4, T … of fig. 1B.

Fig. 2 is an enlarged perspective view of a part of the optical element shown in fig. 1A.

Fig. 3A is a cross-sectional view of the optical element shown in fig. 1A in the track extending direction. Fig. 3B is a sectional view of the optical element 1 shown in fig. 1A in the θ direction.

Fig. 4 is an enlarged perspective view of a part of the optical element 1 shown in fig. 1A.

Fig. 5 is an enlarged perspective view of a part of the optical element 1 shown in fig. 1A.

Fig. 6 is an enlarged perspective view of a part of the optical element 1 shown in fig. 1A.

FIG. 7 is a view for explaining a method of setting the bottom surface of the structure in the case where the boundary of the structure is unclear.

FIG. 8A is a view showing the bottom shape when the ellipticity of the bottom of the structure is changed. FIG. 8B is a view showing the bottom shape when the ellipticity of the bottom of the structure is changed. FIG. 8C is a view showing the bottom surface shape when the ellipticity of the bottom surface of the structure is changed. FIG. 8D is a view showing the bottom surface shape when the ellipticity of the bottom surface of the structure is changed.

Fig. 9A is a view showing an example of the arrangement of the structures having a conical shape or a truncated conical shape, and fig. 9B is a view showing an example of the arrangement of the structures 3 having an elliptical conical shape or an elliptical truncated conical shape.

Fig. 10A is a perspective view showing an example of the structure of a main roller (roll master) for manufacturing an optical element. Fig. 10B is a plan view showing a part of the forming surface of the main roller shown in fig. 10A in an enlarged manner.

Fig. 11 is a schematic diagram showing an example of the structure of a roll (roll) master exposure apparatus.

Fig. 12A is a process diagram for explaining a method of manufacturing an optical element according to a first embodiment of the present technology. Fig. 12B is a process diagram for explaining a method of manufacturing an optical element according to the first embodiment of the present technology. Fig. 12C is a process diagram for explaining a method of manufacturing an optical element according to the first embodiment of the present technology.

Fig. 13A is a process diagram for explaining a method of manufacturing an optical element according to a first embodiment of the present technology. Fig. 13B is a process diagram for explaining the method of manufacturing the optical element according to the first embodiment of the present technology. Fig. 13C is a process diagram for explaining a method of manufacturing an optical element according to the first embodiment of the present technology.

Fig. 14A is a sketch diagram for explaining a case where stains attached to the surface of the optical element are removed. Fig. 14B is a sketch view for explaining a case where stains attached to the surface of the optical element are removed. Fig. 14C is a sketch view for explaining a case where stains attached to the surface of the optical element are removed.

Fig. 15A is a schematic plan view showing an example of the structure of an optical element according to a second embodiment of the present technology, fig. 15B is a plan view showing a part of the optical element shown in fig. 15A in an enlarged manner, fig. 15C is a cross-sectional view of the tracks T1, T3, … in fig. 15B, fig. 15D is a cross-sectional view of the tracks T2, T4, … in fig. 15B, fig. 15E is a sketch view showing modulation waveforms of laser light for forming latent images corresponding to the tracks T1, T3, … in fig. 15B, and fig. 15F is a sketch view showing modulation waveforms of laser light for forming latent images corresponding to the tracks T2, T4, T … in fig. 15B.

FIG. 16 is a view showing the bottom surface shape when the ellipticity of the bottom surface of the structure is changed.

Fig. 17A is a perspective view showing an example of the structure of a main roller for manufacturing an optical element, and fig. 17B is a plan view showing an example of the structure of a main roller for manufacturing an optical element.

Fig. 18A is a schematic plan view showing an example of the structure of an optical element according to a third embodiment of the present technology. Fig. 18B is a plan view showing a part of the optical element shown in fig. 18A in an enlarged manner. Fig. 18C is a cross-sectional view in the traces T1, T3, … of fig. 18B. Fig. 18D is a cross-sectional view in the traces T2, T4, … of fig. 18B.

Fig. 19A is a plan view showing an example of the structure of a master (disc master) for manufacturing an optical element. Fig. 19B is a plan view showing a part of the main tray shown in fig. 19A in an enlarged manner.

Fig. 20 is a schematic diagram showing an example of the configuration of a disc (disc) master exposure apparatus.

Fig. 21A is a schematic plan view showing an example of the configuration of an optical element according to a fourth embodiment of the present technology, and fig. 21B is a plan view showing a part of the optical element shown in fig. 21A in an enlarged manner.

Fig. 22A is a schematic plan view showing an example of the structure of an optical element according to a fifth embodiment of the present technology, fig. 22B is a plan view showing a part of the optical element shown in fig. 22A in an enlarged manner, fig. 22C is a cross-sectional view of the trajectories T1, T3, … of fig. 22B, and fig. 22D is a cross-sectional view of the trajectories T2, T4, … of fig. 22B.

Fig. 23 is an enlarged perspective view of a part of the optical element shown in fig. 22A.

Fig. 24 is a cross-sectional view showing an example of the structure of an optical element according to a sixth embodiment of the present technology.

Fig. 25 is a sectional view showing an example of the configuration of the optical element according to the seventh embodiment.

Fig. 26 shows an example of the structure of a liquid crystal display device according to an eighth embodiment of the present technology.

Fig. 27 shows an example of the structure of a liquid crystal display device according to a ninth embodiment of the present technology.

Fig. 28A is an exploded perspective view showing an example of the configuration of a display device provided with an information input device according to a tenth embodiment of the present technology. Fig. 28B is a sectional view showing an example of the configuration of an information input device according to a tenth embodiment of the present technology.

Fig. 29A is an exploded perspective view showing an example of the configuration of a display device provided with an information input device according to an eleventh embodiment of the present technology. Fig. 29B is a sectional view showing an example of the configuration of an information input device according to the eleventh embodiment of the present technology.

Fig. 30 is a cross-sectional view showing an example of the structure of a printed matter according to a twelfth embodiment of the present technology.

Fig. 31A is a schematic diagram showing an example of the shape of the optical element. Fig. 31B is a schematic diagram showing an example of the shape of the optical element. Fig. 31C is a schematic diagram showing an example of the shape of the optical element.

FIG. 32 is a graph showing the correlation between the storage modulus of elasticity of a general ultraviolet-curable resin and temperature.

FIG. 33 is a graph plotting the crosslink density and the average molecular weight between crosslinks of samples 10 to 21 in examples.

Detailed Description

The present technology has been proposed as a result of intensive studies to solve the above-mentioned problems of the prior art. The outline of this will be described below.

As a result of extensive studies, the inventors have found that the elastic property of the material forming the structures causes the structures to deform when the structures are wiped off, thereby pressing out stains that have penetrated between the structures. Further, by this deformation, wet wiping of stains can be easily performed.

Since the structures deform and dirt penetrating between the structures is pressed out, it is necessary that adjacent structures are close to each other. In order to deform the structures and eliminate the space between the structures, the elastic modulus of the material forming the structures and the aspect ratio of the structures are important. In addition, the contact angle is important when wet wiping is performed. Therefore, as a result of intensive studies by the present inventors, it was found that stains can be easily removed if the elastic modulus, the aspect ratio and the contact angle are within predetermined ranges.

In the case where the structure is deformed, even if the material has a high elastic modulus, it is considered that the wiping may be performed in principle if the pressure at the time of wiping is increased. However, in the case of a material having no elasticity, when the rubbing is performed with a pressure that deforms the structure, the structure may bend or plastically deform. As a result, the reflectance after the wiping is higher than the reflectance before the fingerprint is attached.

In the present technology, "capable of dry wiping or wet wiping" means that when removing stains by a normal wiping method, the reflectance before the stains such as fingerprints are attached is matched or substantially matched with the reflectance after the stains such as fingerprints are wiped.

Embodiments of the present technology will be described in the following order with reference to the drawings.

1. The first embodiment (an example in which structures are two-dimensionally arrayed in a linear and hexagonal lattice shape: see FIG. 1B)

2. Second embodiment (example of two-dimensionally arranging structures linearly and in a tetragonal lattice: FIG. 15B)

3. The third embodiment (example of two-dimensionally arranging structures in a hexagonal lattice shape with an arc shape: see FIGS. 18A and 18B)

4. The fourth embodiment (example of arranging the structures in a meandering manner: see FIGS. 21A and 21B)

5. The fifth embodiment (example of Structure having concave shape on the surface of base: see FIG. 23)

6. Sixth embodiment (example of providing surface treatment layer: see FIG. 24)

7. Seventh embodiment (example of optical element without base: refer to FIG. 25)

8. Eighth embodiment (first application example to display device: refer to FIG. 26)

9. Ninth embodiment (second application example to display device: refer to FIG. 27)

10. Tenth embodiment (first application example to input device: refer to FIGS. 28A and 28B)

11. An eleventh embodiment (second application example to input device: see fig. 29A and 29B)

12. Twelfth embodiment (application example to printing paper: see FIG. 30)

13. A thirteenth embodiment (an example in which the main component is an oligomer (oligomer) and has a specific crosslinking density).

< 1> first embodiment >

[ Structure of optical element ]

Fig. 1A is a schematic plan view showing an example of the structure of an optical element according to a first embodiment of the present technology. Fig. 1B is a plan view showing a part of the optical element shown in fig. 1A in an enlarged manner. FIG. 1C is a cross-sectional view of the traces T1, T3, … of FIG. 1B. FIG. 1D is a cross-sectional view of the traces T2, T4, … of FIG. 1B. Fig. 1E is a sketch showing the modulation waveform of laser light for forming latent images corresponding to the tracks T1, T3, … of fig. 1B. Fig. 1F is a sketch showing the modulation waveform of laser light for forming latent images corresponding to the tracks T2, T4, … of fig. 1B. Fig. 2 and 4 to 6 are enlarged perspective views showing a part of the optical element 1 shown in fig. 1A. Fig. 3A is a cross-sectional view of the optical element shown in fig. 1A in the extending direction of the tracks (X direction (hereinafter, also referred to as track direction as appropriate)). Fig. 3B is a sectional view in the θ direction of the optical element shown in fig. 1A.

The optical element 1 is, for example, an optical sheet (subwavelength structure) having an antireflection effect according to an incident angle of incident light. The optical element 1 is suitably applied to various optical devices such as optical devices having various wavelength ranges (for example, optical devices such as cameras), displays, electro-optical devices, and telescopes.

The optical element 1 includes a substrate 2 having a main surface and a plurality of structures 3 as projections arranged on the main surface at a fine pitch equal to or less than the wavelength of light for the purpose of reducing reflection. The optical element 1 has a function of preventing reflection at the interface between the structure 3 and the ambient air thereof with respect to light transmitted through the base 2 in the-Z direction of fig. 2.

The substrate 2 and the structure 3 of the optical element 1 will be described in order below.

(base)

The substrate 2 is, for example, a transparent substrate having transparency. Examples of the material of the substrate 2 include transparent synthetic resins such as Polycarbonate (PC) and polyethylene terephthalate (PET), and inorganic materials containing glass as a main component, but are not particularly limited to these materials. Examples of the shape of the substrate 2 include a sheet, a plate, and a block, but the shape is not particularly limited to these shapes. Here, the sheet is defined to include a film. In an optical device such as a camera, it is preferable to appropriately select the shape of the base 2 in accordance with the shape of a predetermined portion requiring an antireflection function or the like.

(Structure)

Many structures 3 as projections are arranged on the surface of the base 2. The structures 3 are periodically arranged two-dimensionally at a short arrangement pitch equal to or smaller than the wavelength range of light for the purpose of reducing reflection, for example, at an arrangement pitch on the order of the wavelength of visible light. Here, the arrangement pitch means the arrangement pitch P1 and the arrangement pitch P2. The wavelength range of light for the purpose of reducing reflection is, for example, the wavelength range of ultraviolet light, the wavelength range of visible light, or the wavelength range of infrared light. Here, the wavelength range of the ultraviolet light is a wavelength range of 10nm to 360nm, the wavelength range of the visible light is a wavelength range of 360nm to 830nm, and the wavelength range of the infrared light is a wavelength range of 830nm to 1 mm. Specifically, the arrangement pitch is preferably 175nm or more and 350nm or less. When the arrangement pitch is less than 175nm, the structure 3 tends to be difficult to manufacture. On the other hand, when the arrangement pitch exceeds 350nm, diffraction of visible light tends to occur.

Each of the structures 3 of the optical element 1 has an arrangement form such that tracks T1, T2, T3, … (hereinafter collectively referred to as "tracks T") forming a plurality of rows are formed on the surface of the base 2. In the present technique, the locus is a portion where the structures 3 are linearly connected in a row. The column direction is a direction orthogonal to the extending direction (X direction) of the tracks on the molding surface of the base 2.

The structure 3 is disposed at a position shifted by half pitch between two adjacent tracks T. Specifically, between two adjacent tracks T, at the intermediate position (position shifted by half pitch) of the structures 3 arranged in one track (for example, T1), the structures 3 of the other track (for example, T2) are arranged. As a result, as shown in fig. 1B, the structures 3 are arranged so that a hexagonal lattice pattern or a quasi-hexagonal lattice pattern is formed between the adjacent 3-row tracks (T1 to T3) with the centers of the structures 3 positioned at the points a1 to a 7. In the first embodiment, the hexagonal lattice pattern is a regular hexagonal lattice pattern. The quasi-hexagonal lattice pattern is a hexagonal lattice pattern that is different from the regular hexagonal lattice pattern and is distorted by stretching in the extending direction (X-axis direction) of the track.

When the structures 3 are arranged to form a quasi-hexagonal lattice pattern, as shown in fig. 1B, it is preferable that the arrangement pitch P1 (the distance between a1 and a 2) of the structures 3 in the same track (for example, T1) be longer than the arrangement pitch P2 (the distance between a1 and a7, and the distance between a2 and a 7) of the structures 3 in the ± θ direction with respect to the extending direction of the track, between two adjacent tracks (for example, T1 and T2). By arranging the structures 3 in this manner, the packing density of the structures 3 can be further improved.

From the viewpoint of ease of molding, the structure 3 preferably has a conical shape or a conical shape in which the conical shape is extended or contracted in the track direction. The structure 3 preferably has an axisymmetric conical shape or a conical shape in which the conical shape is extended or contracted in the track direction. When the structures 3 are joined to the adjacent structures 3, the structures 3 preferably have an axisymmetric tapered shape or a tapered shape in which the tapered shape is extended or contracted in the track direction, except for the lower portions to which the adjacent structures 3 are joined. Examples of the conical shape include a conical shape, a truncated conical shape, an elliptical conical shape, and an elliptical truncated conical shape. Here, the cone shape is a concept including an elliptical cone shape and an elliptical truncated cone shape in addition to the above-described conical shape and the above-described truncated cone shape. The truncated cone shape is a shape obtained by cutting off the top of a conical shape, and the truncated elliptical shape is a shape obtained by cutting off the top of an elliptical cone.

As shown in FIGS. 2 and 4, the structure 3 preferably has an elliptical, oblong or oval pyramidal structure having a major axis and a minor axis on the bottom and an elliptical pyramidal shape having a curved top. Alternatively, as shown in fig. 5, it is preferable that the bottom surface has an elliptical, oblong or oval cone structure having a major axis and a minor axis, and has a truncated elliptical cone shape with a flat top. This is because, when the shape is such, the column-direction filling ratio can be improved.

From the viewpoint of improving the reflection characteristics, a cone shape in which the top portion is inclined slowly and the center portion is inclined steeply is preferable (see fig. 4). From the viewpoint of improving the reflection characteristic and the transmission characteristic, a tapered shape (see fig. 2) in which the inclination of the central portion is steeper than that of the bottom portion and the top portion or a tapered shape (see fig. 5) in which the top portion is flat is preferable. When the structures 3 have an elliptical cone shape or an elliptical truncated cone shape, the long axis direction of the bottom surface is preferably parallel to the extending direction of the track. In fig. 2 and the like, each of the structures 3 has the same shape, but the shape of the structure 3 is not limited thereto, and 2 or more kinds of structures 3 having different shapes may be formed on the surface of the base. The structure 3 may be formed integrally with the base 2.

As shown in fig. 2 and 4 to 6, it is preferable that the projection 7 is provided partially or entirely around the structure 3. This is because, even when the filling rate of the structures 3 is low, the reflectance can be kept low. Specifically, for example, as shown in fig. 2, 4, and 5, the protrusions 7 are provided between the adjacent structures 3. As shown in fig. 6, the elongated protrusions 7 may be provided around the entire periphery of the structure 3 or a part thereof. The elongated projection 7 extends, for example, from the top of the structure 3 toward the lower side. The shape of the protrusion 7 may be a triangle or a quadrangle in cross section, but is not particularly limited to these shapes, and may be selected in consideration of ease of molding. In addition, a part or the entire surface of the periphery of the structure 3 may be broken to form fine irregularities. Specifically, for example, the surfaces between adjacent structures 3 may be broken to form fine irregularities. Further, minute holes may be formed in the surface of the structure 3, for example, in the top portion.

The structure 3 is not limited to the convex shape shown in the figure, and may be formed of a concave portion formed on the surface of the substrate 2. The height of the structure 3 is not particularly limited, but is, for example, about 420nm, specifically 415 to 421 nm. When the structures 3 have a concave shape, the depth of the structures 3 is set.

Preferably, the height H1 of the structures 3 in the extending direction of the track is smaller than the height H2 of the structures 3 in the column direction. That is, the heights H1 and H2 of the construct 3 preferably satisfy the relationship of H1< H2. This is because, when the structures 3 are arranged so as to satisfy the relationship of H1 ≧ H2, the arrangement pitch P1 in the extending direction of the elongated tracks becomes necessary, and therefore the filling ratio of the structures 3 in the extending direction of the tracks decreases. When the fill factor is lowered in this manner, the reflection characteristic is lowered.

The aspect ratios of the structures 3 are not limited to the same aspect ratio, and the structures 3 may have a constant height distribution (for example, the aspect ratio is in a range of about 0.83 to 1.46). By providing the structure 3 having a height distribution, the wavelength dependence of the reflection characteristics can be reduced. Therefore, the optical element 1 having excellent antireflection characteristics can be realized.

Here, the height distribution means that the structures 3 having two or more heights (depths) are provided on the surface of the base 2. That is, it means that the structures 3 having the reference height and the structures 3 having the different heights from the structures 3 are provided on the surface of the base 2. The structures 3 having a height different from the reference are provided on the surface of the base 2, for example, in a periodic or non-periodic (random) manner. Examples of the direction of the periodicity include an extending direction of the track and a column direction.

The skirt portion 3a is preferably provided at the peripheral edge of the structure 3. This is because the optical element can be easily peeled from a mold or the like in the manufacturing process of the optical element. Here, the skirt portion 3a is a protruding portion provided at the peripheral edge portion of the bottom of the structure 3. From the viewpoint of the above peeling property, the skirt 3a preferably has a curved surface whose height gradually decreases from the top of the structure 3 toward the bottom. The skirt portion 3a may be provided only in a part of the peripheral edge portion of the structure 3, but is preferably provided in the entire peripheral edge portion of the structure 3 from the viewpoint of improving the above-described peeling property. In the case where the structure 3 is a recess, the skirt portion is a curved surface provided around the opening of the recess of the structure 3.

The height (depth) of the structure 3 is not particularly limited, and is appropriately set according to the wavelength range of light to be transmitted, and may be set to a range of, for example, about 236nm to 450 nm. The aspect ratio (height/arrangement pitch) of the structures 3 is in the range of 0.6 to 5, preferably 0.81 to 1.46, and more preferably 0.94 to 1.28. This is because when the refractive index is less than 0.6, the reflection property and the transmission property tend to be lowered, and when the refractive index is more than 5, the peeling property of the structures 3 at the time of producing the optical element 1 is lowered, and the replica cannot be satisfactorily copied.

In addition, from the viewpoint of further improving the reflection characteristics, the aspect ratio of the structure 3 is preferably set in the range of 0.94 to 1.46. In addition, from the viewpoint of further improving the transmission characteristics, the aspect ratio of the structure 3 is preferably set in the range of 0.81 to 1.28.

The elastic modulus of the material forming the structure 3 is 1MPa or more and 1200MPa or less, preferably 5MPa or more and 1200MPa or less. If the pressure is less than 1MPa, the adjacent structures adhere to each other in the transfer step, and the shape of the structure 3 is different from the desired shape, so that the desired reflection characteristic cannot be obtained. When the pressure exceeds 1200MPa, the structure 3 is less likely to deform when wiped off.

The surface of the optical element 1 on which the structures 3 are formed has hydrophilicity. The water contact angle in the surface of the hydrophilic optical element 1 is preferably 110 degrees or less, and more preferably 30 degrees or less.

In the present technology, the aspect ratio is defined according to the following formula (1).

Aspect ratio H/P … (1)

Herein, H: height of structure, P: the arrangement pitch (average period) is averaged.

Here, the average arrangement pitch P is defined by the following formula (2).

Average disposition pitch P ═ P1+ P2+ P2)/3 … (2)

Here, P1: pitch of arrangement in the track extending direction (track extending direction period), P2: the pitch (period in the θ direction) is preferably 0 ° ≦ 11 °, more preferably 3 ° ≦ 6 °, in the ± θ direction (here, θ ≦ 60 °, in this case) with respect to the extending direction of the track.

The height H of the structures 3 is set to the height of the structures 3 in the row direction. The height of the structure 3 in the track extending direction (X direction) is smaller than the height of the structure 3 in the column direction (Y direction), and the height of the portion of the structure 3 other than the track extending direction is substantially the same as the height of the column direction. However, when the structures 3 are recesses, the height H of the structures in the above formula (1) is defined as the depth H of the structures.

When the arrangement pitch of the structures 3 in the same track is P1 and the arrangement pitch of the structures 3 between two adjacent tracks is P2, the ratio P1/P2 preferably satisfies the relationship of 1.00. ltoreq.P 1/P2. ltoreq.1.1 or 1.00< P1/P2. ltoreq.1.1. By setting the numerical range as described above, the filling ratio of the structures 3 having an elliptical cone or elliptical truncated cone shape can be increased, and therefore, the antireflection property can be improved.

The upper limit is 100%, and the filling rate of the structures 3 in the surface of the substrate is in the range of 65% or more, preferably 73% or more, and more preferably 86% or more. By setting the filling ratio in such a range, the antireflection characteristic can be improved. In order to increase the filling ratio, it is preferable to apply distortion to the structures 3 by joining the lower portions of the adjacent structures 3 to each other or adjusting the ellipticity of the bottom surfaces of the structures.

Here, the filling ratio (average filling ratio) of the structure 3 is a value obtained as follows.

First, the surface of the optical element 1 is photographed in a Top View (Top View) using a Scanning Electron Microscope (SEM). Next, a unit cell Uc is randomly selected from the taken SEM photograph, and the arrangement pitch P1 and the track pitch Tp of the unit cell Uc are measured (see fig. 1B). The area S of the bottom surface of the structure 3 located at the center of the unit cell Uc is measured by image processing. Next, the filling factor is obtained from the following equation (3) using the measured arrangement pitch P1, track pitch Tp, and area S of the bottom surface.

Filling rate (S (hex.)/S (unit)) × 100 … (3)

Unit lattice area: s (unit) ═ P1 × 2Tp

Area of structure bottom surface existing in unit cell: s (hex.) ═ 2S

The above-described processing of calculating the filling rate is performed for the unit cell at 10 positions randomly selected from the taken SEM photograph. Then, the measured values are simply averaged (arithmetic mean) to obtain an average filling ratio, which is taken as the filling ratio of the structures 3 in the surface of the substrate.

The filling rate when the structures 3 are stacked or when sub-structures such as the protrusions 7 are present between the structures 3 can be determined by determining the area ratio using a portion corresponding to 5% of the height of the structures 3 as a threshold.

Fig. 7 is a diagram for explaining a method of calculating the filling rate in the case where the boundaries of the structures 3 are unclear. When the boundaries of the structures 3 are not clear, as shown in fig. 7, the cross-sectional SEM observation shows that the filling ratio is obtained by converting the diameter of the structures 3 by using a portion corresponding to 5% (i.e., (d/h) × 100) of the height h of the structures 3 as a threshold value and using the height d. When the bottom surface of the structure 3 is an ellipse, the same processing is performed with the major axis and the minor axis.

Fig. 8 is a view showing the bottom surface shape when the ellipticity of the bottom surface of the structure 3 is changed. The ellipticities of the ellipses shown in fig. 8A to 8D are 100%, 110%, 120%, and 141%, respectively. By changing the ellipticity in this manner, the filling ratio of the structures 3 in the surface of the base can be changed. When the structures 3 are formed in a quasi-hexagonal lattice pattern, the ellipticity e of the structure bottom surfaces is preferably 100% < e < 150% or less. By setting the range, the filling ratio of the structures 3 can be increased, and excellent antireflection characteristics can be obtained.

Here, when a diameter in the track direction (X direction) of the bottom surface of the structure is defined as "a" and a diameter in the column direction (Y direction) perpendicular thereto is defined as "b", the ellipticity e is defined as (a/b) × 100. The diameters a and b of the structure 3 are values obtained as follows. The surface of the optical element 1 was photographed in a Top View (Top View) using a Scanning Electron Microscope (SEM), and 10 structures 3 were extracted at random from the photographed SEM photograph. Then, the diameters a and b of the bottom surface of each extracted structure 3 are measured. Then, the measured values a and b are simply averaged (arithmetic mean) to obtain an average value of the diameters a and b, which is defined as the diameters a and b of the structure 3.

Fig. 9A shows an example of the arrangement of the structures 3 having a conical shape or a truncated conical shape. Fig. 9B shows an example of the arrangement of the structures 3 having an elliptical cone shape or an elliptical truncated cone shape. As shown in fig. 9A and 9B, the structures 3 are preferably joined so that the lower portions thereof overlap each other. Specifically, the lower portion of the structure 3 is preferably joined to a part or the entire lower portion of the structure 3 in an adjacent relationship. More specifically, it is preferable to join the lower portions of the structures 3 to each other in the track direction, the θ direction, or both. More specifically, it is preferable to join the lower portions of the structures 3 to each other in the track direction, the θ direction, or both. Fig. 9A and 9B show an example in which the entire lower portion of the structure 3 in the adjacent relationship is joined. By joining the structures 3 in this manner, the filling ratio of the structures 3 can be increased. Preferably, the structures are joined to each other at a portion of the optical path length considering the refractive index, which is equal to or less than 1/4 of the maximum value of the wavelength range of light in the use environment. Thereby, excellent antireflection characteristics can be obtained.

As shown in fig. 9B, when the lower portions of the structures 3 having an elliptical cone shape or an elliptical truncated cone shape are joined to each other, for example, the height of the joint portions is reduced in the order of the joint portions a, B, and c.

The ratio of the diameter 2r to the arrangement pitch P1 ((2 r/P1). times.100) is 85% or more, preferably 90% or more, and more preferably 95% or more. This is because, by setting the range as described above, the filling ratio of the structures 3 can be increased, and the antireflection property can be improved. When the ratio ((2 r/P1) × 100) is large and the superposition of the structures 3 becomes too large, the antireflection characteristics tend to decrease. Therefore, it is preferable to set the upper limit of the ratio ((2 r/P1) × 100) so that the structures are joined to each other at a portion of the optical path length considering the refractive index which is equal to or less than 1/4 of the maximum value of the wavelength range of light in the use environment. Here, the arrangement pitch P1 is the arrangement pitch in the track direction of the structures 3, and the diameter 2r is the diameter in the track direction of the structure bottom surfaces. In addition, when the structure bottom surface is circular, the diameter 2r becomes the diameter, and when the structure bottom surface is elliptical, the diameter 2r becomes the major axis.

[ Structure of the Main roller ]

Fig. 10A is a perspective view showing an example of the structure of a main roller for manufacturing an optical element. Fig. 10B is a plan view showing a part of the forming surface of the main roller shown in fig. 10A in an enlarged manner. As shown in fig. 10A and 10B, the main roller 11 has a structure in which a large number of structures 13 as recesses are arranged on the surface of the master 12 at a pitch approximately equal to the wavelength of light such as visible light. The master 12 has a cylindrical or cylindrical shape. The material of the master 12 may be, for example, glass, but is not particularly limited thereto. The two-dimensional patterns are spatially connected by a roller master exposure apparatus described later, a signal for synchronizing a polarity inversion format signal with a rotation controller of a recording apparatus is generated for each track, and patterning is performed at an appropriate transmission pitch by using CAV. This enables recording of a hexagonal lattice pattern or a quasi-hexagonal lattice pattern. By appropriately setting the frequency of the polarity inversion format signal and the number of rotations of the roller, a lattice pattern having the same spatial frequency is formed in a desired recording area.

[ method for producing optical element ]

Next, a method for manufacturing the optical element 1 configured as described above will be described with reference to fig. 11 and 12A to 13C.

The method for manufacturing an optical element according to the first embodiment includes: a resist film forming step of forming a resist layer on the master; an exposure step of forming a latent image of a moth-eye pattern in the resist film by using a roll master exposure apparatus; and a developing step of developing the resist layer on which the latent image is formed. The method further comprises an etching step of forming the main roller by plasma etching and a transfer step of forming a transfer substrate by ultraviolet-curable resin.

(construction of Exposure apparatus)

First, the configuration of the roll master exposure apparatus used in the moth-eye pattern exposure step will be described with reference to fig. 11. The roller master exposure apparatus is configured based on an optical disk recording apparatus.

The laser light source 21 is a light source for exposing the resist film on the surface of the master 12 as a recording medium, and is, for example, a laser light source for emitting the recording laser light 15 having a wavelength λ of 266 nm. The laser light 15 emitted from the laser light source 21 is linearly propagated in a parallel beam state and is incident on an Electro-Optical Modulator (EOM) 22. The laser light 15 transmitted through the electro-optical element 22 is reflected by a mirror 23 and guided to a modulation optical system 25.

The reflecting mirror 23 is formed of a polarizing beam splitter, and has a function of reflecting one polarized light component and transmitting the other polarized light component. The photodiode 24 receives the polarized light component transmitted through the mirror 23, and controls the electro-optical element 22 based on the received light signal to perform phase modulation of the laser light 15.

In the modulation optical system 25, the laser light 15 is condensed by a condensing lens 26 on glass (SiO)₂) Etc. (AOM: acoust-optical Modulator: acousto-optic modulator) 27. The laser light 15 is diffused by intensity modulation by the acousto-optic element 27, and then passes through the lens 28And (4) parallel beam forming. The laser beam 15 emitted from the modulation optical system 25 is reflected by a mirror 31 and guided horizontally and in parallel to a moving optical table 32.

The movable optical stage 32 includes a beam expander (beam expander) 33 and an objective lens 34. The laser beam 15 guided to the moving optical table 32 is shaped into a desired beam shape by a beam expander 33, and then irradiated to a resist layer on the master 12 through an objective lens 34. The master 12 is mounted on a turntable 36 connected to a spindle motor 35. Then, the resist layer exposure step is performed by intermittently irradiating the resist layer with the laser light 15 while rotating the master 12 and moving the laser light 15 in the height direction of the master 12. The formed latent image becomes a substantially elliptical shape having a major axis in the circumferential direction. The movement of the laser beam 15 is performed by moving the movable optical table 32 in the arrow R direction.

The exposure apparatus includes a control mechanism 37 for forming a latent image corresponding to the two-dimensional pattern of the hexagonal lattice or the quasi-hexagonal lattice shown in fig. 1B on the resist layer. The control mechanism 37 includes a formatter (formatter) 29 and a driver 30. The formatter 29 includes a polarity inverting section that controls the irradiation timing of the laser light 15 to the resist layer. The driver 30 receives the output of the polarity inverting section to control the acousto-optic element 27.

In this roll master exposure apparatus, a signal for synchronizing a polarity inversion format signal with a rotation controller of a recording apparatus is generated for each track so that two-dimensional patterns are spatially connected, and intensity modulation is performed by an acousto-optic element 27. By patterning with a fixed angular velocity (CAV) at an appropriate number of rotations and an appropriate modulation frequency and an appropriate transmission pitch, a hexagonal lattice or quasi-hexagonal lattice pattern can be recorded. For example, as shown in fig. 10B, the transmission pitch may be 251nm (pythagoras law) with a period in the circumferential direction of 315nm and a period in a direction of about 60 degrees (about-60 degrees) with respect to the circumferential direction of 300 nm. The frequency of the polarity inversion format signal is changed by the number of rotations of the roller (for example, 1800rpm, 900rpm, 450rpm, 225 rpm). For example, the frequencies of the polarity inversion format signals corresponding to the rotation numbers 1800rpm, 900rpm, 450rpm, and 225rpm of the rollers are 37.70MHz, 18.85MHz, 9.34MHz, and 4.71MHz, respectively. A quasi-hexagonal lattice pattern having the same spatial frequency (a period of 315nm in the circumference, a period of 300nm in the direction of about 60 degrees in the circumference (about-60 degrees in the direction of about-60 degrees) is obtained in a desired recording region by enlarging the far-ultraviolet laser beam to a beam diameter of 5 times using a Beam Expander (BEX) 33 on a moving optical table 32, and irradiating the resist layer on the master 12 through an objective lens 34 having an aperture Number (NA) of 0.9 to form a fine latent image.

(resist film formation Process)

First, as shown in fig. 12A, a cylindrical master 12 is prepared. The master 12 is, for example, a glass master. Next, as shown in fig. 12B, a resist layer 14 is formed on the surface of the master 12. As a material of the resist layer 14, for example, any of an organic resist and an inorganic resist can be used. As the organic resist, for example, a phenol-aldehyde resist or a chemically amplified resist can be used.

(Exposure Process)

Next, as shown in fig. 12C, the master 12 is rotated using the above-described roller master exposure apparatus, and the resist layer 14 is irradiated with the laser light (exposure beam) 15. At this time, the resist layer 14 is exposed over the entire surface by intermittently irradiating the laser beam 15 while moving the laser beam 15 in the height direction of the master 12 (the direction parallel to the central axis of the cylindrical or cylindrical master 12). Thereby, the latent image 16 corresponding to the track of the laser light 15 is formed over the entire surface of the resist layer 14 at a pitch approximately equal to the wavelength of visible light.

The latent image 16 is arranged on the surface of the master so as to form a plurality of rows of tracks, for example, and forms a hexagonal lattice pattern or a quasi-hexagonal lattice pattern. The latent image 16 is, for example, an elliptical shape having a long axis direction in the extending direction of the track.

(developing step)

Next, while the master 12 is rotated, a developer is dropped onto the resist layer 14, and as shown in fig. 13A, the resist layer 14 is subjected to a developing process. As shown in the figure, when the resist layer 14 is formed of a positive resist, the dissolution rate of the developer increases in the exposed portion exposed with the laser beam 15 as compared with the non-exposed portion, and thus a pattern corresponding to the latent image (exposed portion) 16 is formed in the resist layer 14.

(etching Process)

Next, the surface of the master 12 is etched using the pattern (resist pattern) of the resist layer 14 formed on the master 12 as a mask. As a result, as shown in fig. 13B, the structure 13, which is a recess having an elliptical cone shape or an elliptical truncated cone shape with a major axis direction in the extending direction of the locus, can be obtained. The etching method is performed by dry etching, for example. At this time, by alternately performing etching and ashing (ashing), for example, a pattern of the pyramidal structure 13 can be formed. Further, a glass master (glass master) having a depth (selection ratio 3 or more) 3 times or more the depth of the resist layer 14 can be manufactured, and the aspect ratio of the structure 3 can be increased. As the dry etching, plasma etching using a roll etching apparatus is preferable. The roll etching apparatus is a plasma etching apparatus having a columnar electrode, and is configured such that the columnar electrode is inserted into a hollow of the cylindrical master 12 to perform plasma etching on the cylindrical surface of the master 12.

From the above, for example, the main roller 11 having a hexagonal lattice pattern or a quasi-hexagonal lattice pattern having a concave shape with a depth of about 120nm to about 350nm can be obtained.

(replication step)

Next, for example, the main roller 11 is brought into close contact with the substrate 2 such as a sheet coated with a transfer material, and is peeled off while being irradiated with ultraviolet rays and cured. As a result, as shown in fig. 13C, a plurality of structures as projections are formed on the first main surface of the substrate 2, and the optical element 1 such as a sheet with moth-eye uv-cured copies can be produced.

The transfer material is composed of, for example, an ultraviolet curing material and an initiator, and contains a filler, a functional additive, and the like as necessary.

The ultraviolet curable material is composed of, for example, a monofunctional monomer, a bifunctional monomer, a polyfunctional monomer, a polymer oligomer, and the like, and specifically, is a single material or a mixture of a plurality of materials shown below.

Examples of the monofunctional monomer include carboxylic acids (acrylic acid), hydroxyl groups (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate), alkyl groups, alicyclic groups (isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, dodecyl acrylate, octadecyl acrylate, isobornyl acrylate, cyclohexyl acrylate), other functional monomers (2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, ethylcarbitol acrylate, phenoxyethyl acrylate, N-dimethylaminoethyl acrylate, N-dimethylaminopropylacrylamide, N-dimethylacrylamide, acryloylmorpholine, N-isopropylacrylamide, N-hydroxybutyl acrylate, and mixtures thereof, N, N-diethylacrylamide, N-vinylpyrrolidone, 2- (perfluorooctyl) ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 3-perfluorooctyl-2-hydroxypropyl acrylate, 2- (perfluorodecyl) ethyl acrylate, 2- (perfluoro ー 3-methylbutyl) ethyl acrylate, 2, 4, 6-tribromophenol methacrylate, 2- (2, 4, 6-tribromophenoxy) ethyl acrylate, 2-ethylhexyl acrylate, and the like.

Examples of the bifunctional monomer include tripropylene glycol diacrylate, trimethylolpropane diallyl ether, and urethane acrylate.

Examples of the polyfunctional monomer include trimethylolpropane triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ditrimethylolpropane tetraacrylate.

As the polymer oligomer, a well-known polymer oligomer can be used. For example, urethane acrylate oligomer, polyester urethane acrylate oligomer, epoxy acrylate oligomer, and the like can be mentioned, and acrylate oligomer having a urethane structure is preferable.

Preferably, the transfer material comprises a hydrophilic material. Examples of the hydrophilic monomer include acrylamide or a derivative thereof, vinylpyrrolidone, and a polymer containing a water-soluble monomer as a main component, using acrylic acid or methacrylic acid or a derivative thereof. For example, N-methacrylamide, N-dimethylacrylamide, acrylamide, acryloylmorpholine, 2-hydroxyethyl acrylate, N-dimethylaminoethyl acrylate, vinylpyrrolidone, 2-methacryloyloxyethyl phosphorylcholine, 2-methacryloyloxyethyl-D-glucoside, 2-methacryloyloxyethyl-D-mannoside, vinyl methyl ether and the like can be illustrated, but the present invention is not limited thereto. Further, the same effect can be obtained by using a material having a functional group with a large polarity, such as an amino group, a carboxyl group, or a hydroxyl group.

Although the hydrophilic polymer is not particularly limited, preferable main chain structures of the hydrophilic polymer include acrylic resins, methacrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, polyester resins, synthetic rubbers, natural rubbers, and the like, and particularly, acrylic resins and methacrylic resins are preferable because they have excellent adhesion to general-purpose resins, and acrylic resins are more preferable because of curability and the like. The hydrophilic polymer may also be a copolymer.

Specific examples of the hydrophilic polymer include well-known hydrophilic resins, and for example, acrylic acid esters or methacrylic acid esters containing a hydroxyl group, or acrylic acid esters or methacrylic acid esters containing a repeating unit of ethylene glycol in the skeleton are preferable. More specifically, examples of the hydrophilic polymer include methoxypolyethylene glycol monomethacrylate, ethoxylated hydroxyethyl methacrylate, polypropylene glycol monomethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, ethoxylated bisphenol a dimethacrylate, and ethoxylated trimethylolpropane triacrylate.

Examples of the hydrophilic additive include silane coupling agents typified by vinyltriethoxysilane, vinyltrimethoxysilane, and 3-aminopropyltriethoxysilane, and surfactants typified by sodium alkylsulfate and sodium N-acyl-L-glutamate.

Examples of the initiator include 2, 2-dimethoxy-1, 2-diphenylethan-1-one, 1-hydroxy-cyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one.

As the filler, for example, any of inorganic fine particles and organic fine particles can be used. Examples of the inorganic fine particles include SiO₂、TiO₂、ZrO₂、SnO₂、Al₂O₃And the like.

Examples of the functional additive include a leveling agent, a surface conditioner, and an antifoaming agent.

Examples of the material of the substrate 2 include a methyl methacrylate (co) polymer, polycarbonate, a styrene (co) polymer, a methyl methacrylate-styrene copolymer, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, polyester, polyamide, polyimide, polyether sulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polyurethane, polyethylene terephthalate, polyethylene naphthalate, aramid, polyethylene, polyacrylate, an acrylic resin, an epoxy resin, a urea resin, a urethane resin such as polyurethane, a melamine resin, a cycloolefin polymer, a cycloolefin copolymer, and the like. As the material of the substrate 2, any inorganic material may be used, and examples thereof include quartz, sapphire, glass, and clay film (clay film).

When a polymer material is used as the material of the substrate 2, the thickness of the substrate 2 is preferably 3 to 500 μm from the viewpoint of productivity, but is not particularly limited to this range.

Examples of the surface conditioner include a surface lubricant. Examples of the surface lubricant include well-known lubricants, and for example, preferred lubricants include polydimethylsiloxane, fluorine-based additives, ester-based lubricants, and amide-based additives. In the case of imparting hydrophilicity, the polyethylether-modified polydimethylsilicone is preferable.

The method of molding the base body 2 is not particularly limited, and may be an injection molded body, an extrusion molded body, or a cast molded body. If necessary, the surface of the substrate may be subjected to a surface treatment such as corona discharge treatment.

As a method of performing surface modification by post-treatment, for example, corona discharge treatment, plasma treatment, flame treatment, or the like can be used. Furthermore, after shaping, SiO may be introduced₂、TiO₂And the like, to obtain the same effect.

Here, a method of removing stains from the surface of the optical element 1 manufactured as described above will be described. Fig. 14A to 14C are schematic views illustrating a method of removing stains on the surface of the optical element 1. As shown in fig. 14A, when the surface of the optical element 1 is contacted, stains are attached between the structures 3 by fingerprints. When an external force is applied to the surface of the optical element 1 in this state, the structures 3 have elasticity, and therefore, as shown in fig. 14B, the structures 3 are elastically deformed, and the adjacent elastic bodies 3 are brought into contact with each other. This allows dirt adhering between the structures 3 to be pushed out to the outside, and dirt due to fingerprints to be removed. In addition, when wet wiping is performed, water is easily infiltrated by the deformation, and stains can be removed. After the wiping, the structure 3 is restored to its original shape by the elastic force, as shown in fig. 14C.

<2 > second embodiment

[ Structure of optical element ]

Fig. 15A is a schematic plan view showing an example of the structure of an optical element according to a second embodiment of the present technology. Fig. 15B is a plan view showing a part of the optical element shown in fig. 15A in an enlarged manner. Fig. 15C is a cross-sectional view in the traces T1, T3, … of fig. 15B. Fig. 15D is a cross-sectional view in the traces T2, T4, … of fig. 15B. Fig. 15E is a sketch showing the modulation waveform of laser light for forming latent images corresponding to the tracks T1, T3, … of fig. 15B. Fig. 15F is a sketch showing the modulation waveform of laser light for forming latent images corresponding to the tracks T2, T4, … of fig. 15B.

The optical element 1 of the second embodiment is different from the optical element of the first embodiment in that each of the structures 3 forms a tetragonal lattice pattern or a quasi-tetragonal lattice pattern between 3 adjacent rows of tracks. In the present technology, the quasi-tetragonal lattice pattern means a tetragonal lattice pattern that is distorted by being stretched in the extending direction (X direction) of the track, unlike a regular tetragonal lattice pattern.

The height or depth of the structure 3 is not particularly limited, but is, for example, about 159nm to 312 nm. The pitch P2 in the direction of 45 degrees (approximately) with respect to the track is, for example, about 275nm to 297 nm. The aspect ratio (height/arrangement pitch) of the structures 3 is, for example, about 0.54 to 1.13. Further, the aspect ratios of the respective structures 3 are not limited to the same aspect ratio, and the structures 3 may have a constant height distribution.

The arrangement pitch P1 of the structures 3 in the same track is preferably longer than the arrangement pitch P2 of the structures 3 between two adjacent tracks. When the arrangement pitch of the structures 3 in the same track is P1 and the arrangement pitch of the structures 3 between two adjacent tracks is P2, it is preferable that P1/P2 satisfy the relationship of 1.4< P1/P2 < 1.5. By setting the numerical range as described above, the filling ratio of the structures 3 having an elliptical cone or elliptical truncated cone shape can be increased, and therefore, the antireflection property can be improved. Further, the height or depth of the structures 3 in the 45 degree direction or about 45 degree direction with respect to the track is preferably smaller than the height or depth of the structures 3 in the extending direction of the track.

Preferably, the height H2 of the structures 3 in the arrangement direction (θ direction) inclined with respect to the extending direction of the tracks is smaller than the height H1 of the structures 3 in the extending direction of the tracks. That is, the heights H1 and H2 of the construct 3 preferably satisfy the relationship of H1> H2.

FIG. 16 is a view showing the bottom surface shape when the ellipticity of the bottom surface of the structure 3 is changed. Ellipse 3₁、3₂、3₃The ellipticity of (b) is 100%, 163.3%, 141%, respectively. By changing the ellipticity in this manner, the filling ratio of the structures 3 in the surface of the substrate can be changed. When the structure 3 is formed in a tetragonal lattice or quasi-tetragonal lattice pattern, the ellipticity e of the bottom surface of the structure is preferably 150% to e 180%. This is because, by setting the range, the filling ratio of the structures 3 can be increased, and excellent antireflection characteristics can be obtained.

The filling rate of the structures 3 in the surface of the substrate is set to 100% as an upper limit, and is in a range of 65% or more, preferably 73% or more, and more preferably 86% or more. By setting the filling ratio in such a range, the antireflection characteristic can be improved.

Here, the filling ratio (average filling ratio) of the structure 3 is a value obtained as follows.

First, the surface of the optical element 1 is photographed in a Top View (Top View) using a Scanning Electron Microscope (SEM). Next, a unit cell Uc is randomly selected from the taken SEM photograph, and the arrangement pitch P1 and the track pitch Tp of the unit cell Uc are measured (see fig. 15B). The area S of the bottom surface of any of the four structures 3 included in the unit cell Uc is measured by image processing. Next, the filling factor is obtained from the following equation (4) using the measured arrangement pitch P1, track pitch Tp, and area S of the bottom surface.

Filling rate (s (tetra))/s (unit)) × 100 … (2)

Unit lattice area: s (unit) 2 × ((P1 × Tp) × (1/2)) ═ P1 × Tp

Area of bottom surface of structure existing in unit cell: s (tetra) ═ S

The above-described process of calculating the filling rate is performed for 10 unit cells randomly selected from the taken SEM photograph. Then, the measured values are simply averaged (arithmetic mean) to obtain an average filling ratio, which is taken as the filling ratio of the structures 3 in the surface of the substrate.

The ratio of the diameter 2r to the arrangement pitch P1 ((2 r/P1). times.100) is 64% or more, preferably 69% or more, and more preferably 73% or more. This is because, by setting the range as described above, the filling ratio of the structures 3 can be increased, and the antireflection property can be improved. Here, the arrangement pitch P1 is the arrangement pitch in the track direction of the structures 3, and the diameter 2r is the diameter in the track direction of the structure bottom surfaces. In addition, the diameter 2r is a diameter in the case where the structure bottom surface is circular, and the diameter 2r is a major axis in the case where the structure bottom surface is elliptical.

Fig. 17 shows an example of the structure of a main roller for manufacturing an optical element having the above-described structure. This main roller is different from the main roller of the first embodiment in that the structures 13 recessed in the surface thereof form a tetragonal lattice pattern or a quasi-tetragonal lattice pattern.

[ Structure of the Main roller ]

Two-dimensional patterns are spatially linked using a roller master exposure apparatus, a polarity inversion format signal is synchronized with a rotation controller of a recording apparatus for each track to generate a signal, and patterning is performed at an appropriate transmission pitch using CAV. Thereby, a tetragonal lattice pattern or a quasi-hexagonal lattice pattern can be recorded. It is preferable that the frequency of the polarity inversion format signal and the number of rotations of the roller be appropriately set so that a lattice pattern having the same spatial frequency is formed on the resist on the master 12 by irradiation of the laser light in a desired recording region.

<3 > third embodiment

[ Structure of optical element ]

Fig. 18A is a schematic plan view showing an example of the structure of an optical element according to a third embodiment of the present technology. Fig. 18B is a plan view showing a part of the optical element shown in fig. 18A in an enlarged manner. Fig. 18C is a cross-sectional view in the traces T1, T3, … of fig. 18B. Fig. 18D is a cross-sectional view in the traces T2, T4, … of fig. 18B.

The optical element 1 of the third embodiment is different from the optical element of the first embodiment in that the locus T has an arc-like shape, and the structures 3 are arranged in an arc-like shape. As shown in fig. 18B, the structures 3 are arranged in a quasi-hexagonal lattice pattern in which the centers of the structures 3 are located at points a1 to a7 between the adjacent 3-row tracks (T1 to T3). Here, the quasi-hexagonal lattice pattern means a hexagonal lattice pattern which is skewed in an arc shape along the trajectory T, unlike a regular hexagonal lattice pattern. Alternatively, the present invention means a hexagonal lattice pattern which is distorted in an arc shape along the trajectory T and is also distorted by being stretched in the extending direction (X-axis direction) of the trajectory, unlike a regular hexagonal lattice pattern.

The configuration of the optical element 1 other than the above is the same as that of the first embodiment, and therefore, the description thereof is omitted.

[ Structure of the Main tray ]

Fig. 19A and 19B show an example of the structure of a master for manufacturing an optical element having the above-described structure. As shown in fig. 19A and 19B, the master 41 has a structure in which a large number of structures 43 serving as recesses are arranged on the surface of a disc-shaped master 42. The structures 13 are periodically arranged two-dimensionally at a pitch equal to or smaller than the wavelength range of light in the use environment of the optical element 1, for example, the same as the wavelength of visible light. The structure 43 is arranged on a concentric or spiral track, for example.

The configuration of the main tray 41 other than the above is the same as that of the main roller 11 of the first embodiment, and therefore, the description thereof is omitted.

[ method for producing optical element ]

First, an exposure apparatus for manufacturing the master 41 having the above-described configuration will be described with reference to fig. 20.

The movable optical stage 32 includes a beam expander 33, a mirror 38, and an objective lens 34. The laser beam 15 guided to the moving optical table 32 is shaped into a desired beam shape by a beam expander 33, and then irradiated onto a resist layer on a disc-shaped master 42 via a mirror 38 and an objective lens 34. The master 42 is mounted on a turntable (not shown) connected to the spindle motor 35. Then, while the master 42 is rotated and the laser beam 15 is moved in the radial direction of rotation of the master 42, the resist layer on the master 42 is intermittently irradiated with the laser beam, thereby performing the exposure step of the resist layer. The formed latent image becomes a substantially elliptical shape having a major axis in the circumferential direction. The movement of the laser beam 15 is performed by moving the movable optical table 32 in the arrow R direction.

The exposure apparatus shown in fig. 20 includes a control unit 37 for forming a latent image composed of a two-dimensional pattern of a hexagonal lattice or a quasi-hexagonal lattice shown in fig. 18B on the resist layer. The control mechanism 37 includes the formatter 29 and the driver 30. The formatter 29 includes a polarity inverting section that controls the irradiation timing of the laser light 15 to the resist layer. The driver 30 receives the output of the polarity inverting section and controls the acousto-optic element 27.

The control unit 37 synchronizes the intensity modulation of the laser light 15 by the AOM27, the driving rotation speed of the spindle motor 35, and the moving speed of the moving optical table 32 for each track so that the two-dimensional pattern of the latent image is spatially linked. The master 42 is rotationally controlled at a fixed angular velocity (CAV). Then, patterning is performed by an appropriate number of rotations of the master 42 by the spindle motor 35, an appropriate frequency modulation of the laser intensity by the AOM27, and an appropriate transmission pitch of the laser light 15 by the movable optical table 32. Thereby, a latent image of a hexagonal lattice pattern or a quasi-hexagonal lattice pattern is formed on the resist layer.

Further, the control signal of the polarity reversing section was changed slowly in the same manner as the spatial frequency (which is the pattern density of the latent image, P1: 330, P2: 300nm, or P1: 315nm, P2: 275nm, or P1: 300nm, P2: 265 nm). More specifically, the exposure is performed while changing the irradiation period of the laser light 15 to the resist layer for each track, and the frequency modulation of the laser light 15 is performed in the control unit 37 so that the P1 becomes approximately 330nm (or 315nm or 300 nm) in each track T. That is, as the track position is distant from the center of the disc-shaped master 42, modulation control is performed so that the irradiation period of the laser beam is shortened. This enables formation of a nano pattern having the same spatial frequency over the entire surface of the substrate.

An example of a method for manufacturing an optical element according to a third embodiment of the present technology will be described below.

First, the master 41 is produced in the same manner as in the first embodiment, except that the resist layer formed on the disc-shaped master is exposed using the exposure apparatus having the above-described configuration. Next, the main tray 41 is brought into close contact with the substrate 2 such as an acrylic sheet coated with an ultraviolet curable resin, and the ultraviolet curable resin is cured by irradiation with ultraviolet rays, and then the substrate 2 is peeled off from the main tray 41. Thus, the disc-shaped optical element 1 in which the plurality of structures 3 are arranged on the surface is obtained. Next, the optical element 1 having a predetermined shape such as a rectangle is cut out from the disk-shaped optical element 1. This enables the production of the optical element 1 as a target.

According to the third embodiment, as in the case where the structures 3 are linearly arranged, the optical element 1 having high productivity and excellent antireflection characteristics can be obtained.

<4 > fourth embodiment

Fig. 21A is a schematic plan view showing an example of the structure of an optical element according to a fourth embodiment of the present technology. Fig. 21B is a plan view showing a part of the optical element shown in fig. 21A in an enlarged manner.

The optical element 1 of the fourth embodiment is different from the first embodiment in that the structures 3 are arranged on a meandering track (hereinafter, referred to as a wobble (wobbble) track). The oscillation of the tracks on the substrate 2 is preferably synchronized. That is, the wobble is preferably a synchronous wobble. By synchronizing the wobbles in this manner, the unit cell shape of the hexagonal cell or quasi-hexagonal cell can be maintained, and the filling rate can be maintained at a high level. Examples of the waveform of the wobble track include a sine wave and a triangular wave. The waveform of the wobble track is not limited to a periodic waveform, and may be a non-periodic waveform. The wobble amplitude of the wobble track can be selected to be about ± 10 μm, for example.

In the fourth embodiment, the other points are the same as those in the first embodiment.

According to the fourth embodiment, since the structures 3 are arranged on the swing locus, the occurrence of unevenness in appearance can be suppressed.

<5 > fifth embodiment

Fig. 22A is a schematic plan view showing an example of the structure of an optical element according to a fifth embodiment of the present technology. Fig. 22B is a plan view showing a part of the optical element shown in fig. 22A in an enlarged manner. Fig. 22C is a cross-sectional view in the traces T1, T3, … of fig. 22B. Fig. 22D is a cross-sectional view in the traces T2, T4, … of fig. 22B. Fig. 23 is an enlarged perspective view of a part of the optical element shown in fig. 22A.

The optical element 1 of the fifth embodiment is different from the optical element of the first embodiment in that a large number of structures 3 as recesses are arranged on the surface of the base. The structure 3 is formed in a concave shape by inverting the convex shape of the structure 3 in the first embodiment. In the case where the structure 3 is a concave portion as described above, the opening of the structure 3 (entrance portion of the concave portion) as the concave portion is defined as a lower portion, and the lowest portion in the depth direction of the substrate 2 (the deepest portion of the concave portion) is defined as a top portion. That is, the top and bottom are defined by the structures 3 as non-solid spaces. In the fifth embodiment, since the structures 3 are concave portions, the height H of the structures 3 in the formula (1) and the like is referred to as the depth H of the structures 3.

In the fifth embodiment, the other points are the same as those in the first embodiment.

In the fifth embodiment, the convex structures 3 in the first embodiment are inverted in shape to be concave, and therefore the same effects as those in the first embodiment can be obtained.

<6 > sixth embodiment

In the sixth embodiment, the wiping-off property by wet wiping is improved by including at least 1 hydrophilic compound in the surface of the structure.

Examples of the method of including the hydrophilic compound in the surface of the structure include a method of adding the hydrophilic compound to a resin material forming the structure and curing the resin material, a method of forming a surface-treated layer including the hydrophilic compound on the surface of the structure after the structure is formed, and the like.

Fig. 24 is a sectional view showing an example of the structure of an optical element according to a sixth embodiment of the present technology. As shown in fig. 24, the optical element 1 of the sixth embodiment is different from the first embodiment in that a surface treatment layer 8 is further provided on the uneven surface on which the structures 3 are formed.

The water contact angle on the surface on which the surface treatment layer 8 is formed is preferably 110 degrees or less, and more preferably 30 degrees or more. The surface treatment layer 8 contains, for example, a hydrophilic compound.

[ hydrophilic Compound ]

Examples of the hydrophilic monomer include acrylamide or a derivative thereof, vinylpyrrolidone, and a polymer containing a water-soluble monomer as a main component, with acrylic acid or methacrylic acid or a derivative thereof. For example, N-methacrylamide, N-dimethylacrylamide, acrylamide, acryloylmorpholine, 2-hydroxyethyl acrylate, N-dimethylaminoethyl acrylate, vinylpyrrolidone, 2-methacryloyloxyethyl phosphorylcholine, 2-methacryloyloxyethyl-D-glucoside, 2-methacryloyloxyethyl-D-mannoside, vinyl methyl ether and the like can be illustrated, but the present invention is not limited thereto.

Although the hydrophilic polymer is not particularly limited, preferable main chain structures of the hydrophilic polymer include acrylic resins, methacrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, polyester resins, synthetic rubbers, natural rubbers, and the like, and particularly, acrylic resins and methacrylic resins are preferable because they have excellent adhesion to general-purpose resins, and acrylic resins are more preferable because of curability and the like. The hydrophilic polymer may also be a copolymer.

(method of Forming surface treatment layer)

Examples of the method for forming the surface treatment layer include a method of coating a solution in which a hydrophilic compound is dissolved in a solvent by a gravure coater (dip coater), a dipping (dipping) method, a spin coating method, or spraying, a method of applying a solution in which a hydrophilic compound is dissolved in a solvent by wiping, and then drying. Further, an LB method, a PVD method, a CVD method, a self-organizing method, a sputtering method, and the like can be given. Further, there is a method of mixing and applying a hydrophilic compound and an ultraviolet curable resin, and then curing the mixture by UV irradiation. Further, as a method for performing surface modification, there are corona discharge treatment, plasma treatment, flame treatment, and the like.

<7 > seventh embodiment

Fig. 25 shows an example of the structure of an optical element according to the seventh embodiment. As shown in fig. 25, the optical element 1 is different from the first embodiment in that it includes a base body 2. The optical element 1 includes a plurality of structures 3 composed of a plurality of projections arranged at a fine pitch equal to or smaller than the wavelength of visible light, and the lower portions of the adjacent structures are joined to each other. The plurality of structures joined to each other at the lower portion may have a mesh shape as a whole.

According to the seventh embodiment, the optical element 1 can be attached to the adherend without an adhesive. In addition, the adhesive sheet can be attached to a three-dimensional curved surface.

<8 > eighth embodiment

[ Structure of liquid Crystal display device ]

Fig. 26 shows an example of the structure of a liquid crystal display device according to an eighth embodiment of the present technology. As shown in fig. 26, the liquid crystal display device includes a backlight 53 that emits light, and a liquid crystal panel 51 that temporally and spatially modulates the light emitted from the backlight 53 to display an image. Polarizers 51a and 51b as optical members are provided on both surfaces of the liquid crystal panel 51. The optical element 1 is provided in a polarizer 51b provided on the display surface side of the liquid crystal panel 51. Here, the polarizer 51b having the optical element 1 provided on one main surface is referred to as a polarizer 52 with an antireflection function. The polarizer with antireflection function 52 is an example of an optical component with antireflection function.

Hereinafter, the backlight 53, the liquid crystal panel 51, the polarizers 51a and 51b, and the optical element 1 constituting the liquid crystal display device will be described in order.

(backlight lamp)

As the backlight 53, for example, a direct backlight, an edge backlight, or a flat light source backlight can be used. The backlight 53 includes, for example, a light source, a reflector, an optical film, and the like. Examples of the Light source include a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an Organic ElectroLuminescence (OEL), an Inorganic ElectroLuminescence (IEL), and a Light Emitting Diode (LED).

(liquid crystal panel)

As the Liquid Crystal panel 51, for example, a Liquid Crystal panel of a display mode such as a Twisted Nematic (TN) mode, a Super Twisted Nematic (STN) mode, a Vertical Alignment (VA) mode, an In-Plane Switching (IPS) mode, an Optically Compensated Birefringence (OCB) mode, a Ferroelectric Liquid Crystal (FLC) mode, a Polymer Dispersed Liquid Crystal (PDLC) mode, or a Phase Change Guest Host (PCGH) mode can be used.

(polarizer)

Polarizers 51a and 51b are provided on both surfaces of the liquid crystal panel 51, for example, so that transmission axes thereof are orthogonal to each other. The polarizers 51a and 51b pass only one of orthogonal polarized light components of incident light, and shield the other by absorption. As the polarizers 51a and 51b, for example, polarizers in which a dichroic material such as iodine or a dichroic dye is adsorbed on a hydrophilic polymer film such as a polyvinyl alcohol (pva) film, a partially-set polyvinyl alcohol (pva) film, or an ethylene-vinyl acetate copolymer (eva) partially-saponified film, and uniaxially stretched can be used. Protective layers such as cellulose diacetate (TAC) films are preferably provided on both surfaces of the polarizers 51a and 51 b. When the protective layer is provided in this manner, the substrate 2 of the optical element 1 is preferably configured to serve as the protective layer. This is because the polarizer 52 with an antireflection function can be made thinner by adopting such a configuration.

(optical element)

The optical element 1 is the same as the optical element of any one of the first to seventh embodiments described above, and therefore, the description thereof is omitted.

According to the eighth embodiment, since the optical element 1 is provided on the display surface of the liquid crystal display device, the antireflection function of the display surface of the liquid crystal display device can be improved. Therefore, the visibility of the liquid crystal display device can be improved.

<9 > ninth embodiment >

[ Structure of liquid Crystal display device ]

Fig. 27 shows an example of the structure of a liquid crystal display device according to a ninth embodiment of the present technology. The liquid crystal display device is different from the optical element of the fifth embodiment in that a front surface member 54 is provided on the front surface side of the liquid crystal panel 51, and the optical element 1 is provided on at least one of the front surface of the liquid crystal panel 51, the front surface of the front surface member 54, and the back surface. Fig. 27 shows an example in which the optical element 1 is provided on all of the front surface of the liquid crystal panel 51 and the front surface and the back surface of the front surface member 54. An air layer is formed between the liquid crystal panel 51 and the front surface member 54, for example. The same portions as those of the fifth embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present technology, the front surface indicates a surface on the side of the display surface, that is: the back surface is a surface facing the viewer, and is a surface opposite to the display surface.

The front surface member 54 is a front panel or the like used for the purpose of mechanical, thermal, and aging-resistant protection or decoration on the front surface (viewer side) of the liquid crystal panel 51. The front surface member 54 has, for example, a sheet shape, a film shape, or a plate shape. As the material of the front surface member 54, for example, glass, cellulose diacetate (TAC), polyester (TPEE), polyethylene terephthalate (PET), Polyimide (PI), Polyamide (PA), aramid, Polyethylene (PE), polyacrylate, polyethersulfone, polysulfone, polypropylene (PP), diacetyl cellulose (diacetyl cellulose), polyvinyl chloride, acrylic resin (PMMA), Polycarbonate (PC), or the like can be used, but the material is not particularly limited thereto, and any material having transparency can be used.

According to the ninth embodiment, as in the eighth embodiment, the visibility of the liquid crystal display device can be improved.

<10 > tenth embodiment

Fig. 28A is an exploded perspective view showing an example of the configuration of a display device having an information input device according to a tenth embodiment of the present technology. Fig. 28B is a sectional view showing an example of the structure of an information input device according to the tenth embodiment of the present technology. As shown in fig. 28A and 28B, the information input device 201 is provided on the display device 202, and the information input device 201 and the display device 202 are bonded by, for example, an adhesive layer 212.

The information input device 201 is a so-called touch panel, and includes: an information input element 211 having an information input surface for inputting information by a finger or the like, and an optical element 1 provided on the information input surface. The information input element 211 and the optical element 1 are bonded via, for example, an adhesive layer 213. The information input device 211 can be a touch panel of a resistive type, a capacitive type, an optical type, an ultrasonic type, or the like, for example. As the optical element 1, for example, one of the optical elements 1 according to the first to seventh embodiments described above can be used.

Although fig. 28B shows an example in which the optical element 1 having the base 2 is provided on the information input element 211, the optical element 1 without the base 2, that is, the plurality of structures 3 may be provided directly on the information input element 211. Further, the base body 2 may also serve as a base material of the upper electrode of the information input element 211.

As the Display device 201, various Display devices such as a liquid crystal Display, a CRT (Cathode Ray Tube) Display, a Plasma Display Panel (PDP), an Electro Luminescence (EL) Display, a Surface-conduction Electron-emitting Display (SED) and the like can be used.

In the tenth embodiment, since the optical element 1 is provided on the information input surface of the information input device 201, the antireflection function of the information input surface of the information input device 201 can be improved. Therefore, the visibility of the display device 202 having the information input device 201 can be improved.

<11 > eleventh embodiment >

Fig. 29A is an exploded perspective view showing an example of the configuration of a display device provided with an information input device according to an eleventh embodiment of the present technology. Fig. 29B is a sectional view showing an example of the configuration of an information input device according to the eleventh embodiment of the present technology. As shown in fig. 29A and 29B, the information input device 201 is different from the ninth embodiment in that a front surface member 203 is further provided on the information input surface of the information input element 211, and the optical element 1 is provided on the front surface of the front surface member 203. The information input element 211 and the front surface member 203 are bonded by an adhesive layer 213, and the front surface member 203 and the optical element 1 are bonded by an adhesive layer 214, for example.

In the eleventh embodiment, since the optical element 1 is provided on the front surface member 203, the same effects as those of the tenth embodiment can be obtained.

<12 > twelfth embodiment

Fig. 30 is a cross-sectional view showing an example of the structure of a printed matter according to a twelfth embodiment of the present technology. As shown in fig. 30, the printed matter 10 includes: a printed matter body 6 having a surface, and an optical element 1 provided on the surface of the printed matter body 6. The printed matter 10 may further include an adhesive layer 5, and the printed matter main body 6 may be bonded to the optical element 1 via the adhesive layer 5. As the material of the adhesive layer 5, for example, an acrylic adhesive, a rubber adhesive, a silicon adhesive, or the like can be used, and an acrylic adhesive is preferable from the viewpoint of transparency. The surface of the printed matter main body 6 is, for example, a print image surface on which an image is printed. Hereinafter, the main surface of the printed matter 10 on which the optical element 1 is provided is referred to as a "front surface", and the main surface on the opposite side is referred to as a "back surface".

Fig. 31A to 31C are schematic views showing examples of shapes of printed matters according to the first embodiment of the present technology. As shown in fig. 31A, the printed matter 10 is preferably curved so that the front surface side protrudes, and particularly the curved portion has a central portion of the front surface as a curved top portion. This is because the bending in this manner can provide a beautiful appearance.

The printed matter 10 preferably has a planar peripheral edge portion (fig. 31B) or a curved peripheral edge portion (fig. 31C). Here, as shown in fig. 31C, the curved surface is a curved surface in which the peripheral edge portion is curved in the direction opposite to the optical element 1 side. This can suppress the warpage which becomes a protrusion on the back surface side, and maintain a beautiful appearance.

The optical element 1 preferably has a linear expansion coefficient larger than that of the printed matter main body 6. This is because, in a high-temperature and/or high-humidity environment, the warpage protruding from the back surface side can be suppressed, and the beautiful appearance can be maintained. Here, in the case where the printed material main body 6 has a laminated structure including a plurality of layers, the linear expansion coefficient of the printed material main body 6 is the linear expansion coefficient of the layer having the largest linear expansion coefficient among the plurality of layers constituting the printed material main body 6.

The optical element 1 includes: a substrate 2 having a main surface, and a plurality of structures 3 arranged on the main surface of the substrate 2. The structure 3 is formed separately from or integrally with the base 2. When the structure 3 and the base 2 are molded separately, the base layer 4 may be further provided between the structure 3 and the base 2 as needed. The base layer 4 is a layer integrally molded with the structure 3 on the bottom surface side of the structure 3, and is formed by curing an energy ray curable resin composition or the like similar to the structure 3. The optical element 1 preferably has flexibility. This is because the optical element 1 can thereby be easily bonded to the printing paper body 6. From the viewpoint of flexibility, the optical element 1 is preferably an optical sheet.

The difference in refractive index between the optical element 1 and the adhesive layer 5 is preferably 0.1 or less. This is because fresnel reflection at the interface can be suppressed, and the visibility to the naked eye can be improved. The difference in refractive index between the structures 3 and the substrate 2 and the difference in refractive index between the substrate 2 and the adhesive layer 5 are preferably 0.1 or less. This is because fresnel reflection at the interface can be suppressed, and the visibility to the naked eye can be improved. The surface roughness Rz of the optical element 1 is preferably 1.7 μm or less. This is because a beautiful surface can be obtained.

Preferably, the substrate 2 is L on the back side^＊a^＊b^＊The transmitted hue in the color system satisfies L^＊≥95、｜b^＊｜≤0.53、｜a^＊A related base of | less than or equal to 0.05. This is because the color tone of the optical element 1 can be suppressed and the visibility of the surface of the printed matter with the naked eye can be improved. Preferably, the optical element 1 is L on the back side^＊a^＊b^＊The transmitted hue in the color system satisfies L^＊≥96、｜b^＊｜≤1.9、｜a^＊An optical element having a relationship of | less than or equal to 0.7. This is because the color tone of the optical element 1 can be suppressed and the visibility of the surface of the printed matter with the naked eye can be improved.

The twelfth embodiment is the same as the first embodiment except for the above.

In the twelfth embodiment, since the optical element 1 having the plurality of structures 3 arranged at a fine pitch equal to or less than the wavelength of visible light is bonded to the printed matter main body 6, the surface reflection of the printed matter 10 can be suppressed. Therefore, the contrast of the printed image of the printed matter 10 can be improved.

<13 > a thirteenth embodiment

The optical element of the thirteenth embodiment is different from the first embodiment in that, in addition to the numerical range of the elastic modulus of the resin material forming the structures 3, the numerical range of the crosslink density of the resin material included in the structures 3 is specified instead of the numerical range of the elastic modulus of the resin material forming the structures 3.

The crosslinking density of the resin material contained in the structure 3 is 5.1mol/L or less, preferably 0.8mol/L or more and 5.1mol/L or less. When the crosslinking density is 5.1mol/L or less, the distance between crosslinks can be made long, and flexibility can be imparted to the resin material. Therefore, stains such as fingerprints can be discharged and wiped off. In addition, since the reciprocal of the crosslink density corresponds to the inter-crosslink molecular weight, the inter-crosslink distance becomes longer as the crosslink density becomes lower (that is, as the reciprocal of the crosslink density increases). On the other hand, when the crosslinking density is less than 0.8mol/L, since the scratch property of the coating film is remarkably deteriorated, there is a fear of damage by rubbing. Although chemical crosslinking or physical crosslinking can be mentioned as the crosslinking, chemical crosslinking is preferably used.

Further, the surface of the optical element 1 is preferably further made hydrophilic. This is because the hydrophilic property enables wiping off stains by a discharge effect and replacement by moisture by wiping with a cloth containing moisture, for example, 1 or 2 times. The water contact angle of the surface of the hydrophilic optical element 1 is preferably 110 degrees or less, more preferably 30 degrees or less.

Now, a method of calculating the crosslink density of the structure 3 will be described with reference to fig. 32. As shown in fig. 32, the crosslinking density of the resin material has temperature dependence. The crosslink density of the resin material is related to the state of the resin material, and is divided into four regions, a glass region, a transition region, a rubber-like region, and a flow region, depending on the temperature range. The crosslinking density of the rubber-like region in these regions is represented by the following formula.

n＝E'/3RT

(wherein n represents a crosslinking density (mol/L), E' represents a storage elastic modulus (Pa), R represents a gas constant (Pa, seed L/K, seed mol), and T represents an absolute temperature (K))

Therefore, if the above formula is used, the crosslinking density n can be calculated from the storage modulus E' and the absolute temperature.

When the crosslink density of the resin material included in the structure 3 is within the above numerical range, the inter-crosslink average molecular weight of the resin material included in the structure 3 is preferably within a range of 400 or more and 60000 or less, more preferably within a range of 500 or more and 10000 or less, and still more preferably within a range of 700 or more and 1500 or less. By setting the crosslink density to 5.1mol/L or less and the inter-crosslink average molecular weight to 400 or more, the scratch-off property can be further improved as compared with the case where only the numerical range of the crosslink density is set to 5.1mol/L or less. On the other hand, the scratch resistance is improved and the damage of the coating film can be suppressed by setting the crosslink density to 0.8mol/L or more and the average molecular weight between crosslinks to 60000 or less. Here, when the resin raw material participating in the polymerization reaction is 3 or more functional groups, the inter-crosslinking average molecular weight of the resin material included in the structure 3 is a value obtained by dividing the average molecular weight of the resin raw material (for example, oligomer or the like) participating in the polymerization reaction by the average number of functional groups. When the resin raw material participating in the polymerization reaction is 2-functional, the average molecular weight of the resin raw material becomes the inter-crosslink average molecular weight. However, the monofunctional resin raw material is a raw material that is not included in the resin raw material that participates in the polymerization reaction.

Preferably, the structure 3 contains a linear polymer as a main component. This is because the wiping property can be improved. The linear polymer is, for example, a chain polymer in which compounds having two (meth) acryloyl groups are one-dimensionally linked in a chain shape. The compound is preferably an oligomer having two (meth) acryloyl groups. Here, the (meth) acryloyl group means any of an acryloyl group and a methacryloyl group.

The structure 3 can be obtained by curing an ultraviolet curable resin, for example. The resin component contained in the ultraviolet curable resin preferably contains at least one of an oligomer having two (meth) acryloyl groups and an oligomer having three (meth) acryloyl groups as a main component, and more preferably contains an oligomer having two (meth) acryloyl groups as a main component. The average molecular weight between crosslinks can be 400 or more by including, as a main component, at least one of an oligomer having two (meth) acryloyl groups and an oligomer having three (meth) acryloyl groups. By containing an oligomer having two (meth) acryloyl groups as a main component, the average molecular weight between crosslinks can be made 400 or more, and an increase in viscosity of the ultraviolet-curable resin as a transfer material can be suppressed, and the transferability of the ultraviolet-curable resin as a transfer material can be improved. The oligomer is a molecule having a molecular weight of 400 to 60000.

In order to adjust the elastic modulus of the structures 3, the ultraviolet curable resin may further contain a compound having one (meth) acryloyl group (for example, a monomer and/or an oligomer) and/or a resin material (for example, a monomer and/or an oligomer) that does not participate in the polymerization reaction.

Examples

Hereinafter, the present technology will be specifically described with reference to examples, but the present technology is not limited to these examples.

(sample 1)

First, a glass roll master having an outer diameter of 126mm was prepared, and a resist was coated on the surface of the glass master as follows. That is, the photoresist was diluted to 1/10 with a thinner (thinner) and dipped, thereby coating the diluted resist with a thickness of about 130nm on the cylindrical surface of the glass roll master, thereby coating the resist. Next, a glass master as a recording medium was conveyed to a roll master exposure apparatus shown in fig. 11, and the resist was exposed to light, thereby joining the glass master into a spiral shape, and a latent image constituting a quasi-hexagonal lattice pattern was patterned on the resist between 3 adjacent rows of tracks.

Specifically, the hexagonal lattice pattern-formed region was irradiated with a laser beam having a power of 0.50mW/m, which was exposed to the surface of the glass roll master, to form a concave quasi-hexagonal lattice pattern. The resist thickness in the column direction of the track row is about 120nm, and the resist thickness in the extending direction of the track is about 100 nm.

Next, the resist on the glass roll master is subjected to a developing process, and the exposed portion of the resist is dissolved and developed. Specifically, an undeveloped glass roll master is placed on a turntable of a developing machine, not shown, and a developer is dropped onto the surface of the glass roll master while rotating each turntable, thereby developing the resist on the surface. Thus, a resist glass master having a resist layer opened in a quasi-hexagonal lattice pattern can be obtained.

Next, using roll plasma etching, at CHF₃Plasma etching is performed in a gas environment. Thus, only the quasi-hexagonal lattice pattern portion exposed from the resist layer was etched on the surface of the glass roll master, and the photoresist was used as a mask in the other regions without etching, thereby obtaining an elliptical cone-shaped concave portion. The etching amount (depth) in the pattern at this time is changed depending on the etching time. Finally, by using O₂Ashing (ashing) completely removed the photoresist, and a moth-eye glass master roll having a concave quasi-hexagonal lattice pattern was obtained. The depth of the concave portion in the column direction is deeper than the depth of the concave portion in the extending direction of the track.

The moth-eye glass master roll was brought into close contact with a sheet made of polymethyl methacrylate (PMMA) coated with an ultraviolet-curable resin composition having a thickness of several μm and having the following composition, and the sheet was peeled off while being cured by irradiation with ultraviolet light, thereby producing an optical element.

< ultraviolet curable resin composition >

100 parts by mass of aliphatic urethane acrylate

Photopolymerization initiator 3 wt%

The amount of the photopolymerization initiator added (3 wt%) was the amount added when the ultraviolet-curable resin composition was set to 100 wt%. The same applies to the following samples 2 to 9.

(sample 2)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

Aliphatic urethane acrylate 95 parts by mass

5 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 3)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

91 parts by mass of aliphatic urethane acrylate

9 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 4)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

87 parts by mass of aliphatic urethane acrylate

13 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 5)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

Aliphatic urethane acrylate 83 parts by mass

17 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 6)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

77 parts by mass of aliphatic urethane acrylate

23 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 7)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

71 parts by mass of aliphatic urethane acrylate

29 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 8)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

50 parts by mass of aliphatic urethane acrylate

50 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(sample 9)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

100 parts by mass of a water-soluble monomer

Photopolymerization initiator 3 wt%

(evaluation of shape)

The optical elements of samples 1 to 9 were observed with an Atomic Force Microscope (AFM). Then, the height of the structure of each sample was determined from the cross-sectional profile of the AFM.

(measurement of contact Angle)

The contact angles of the surfaces of the optical elements of samples 1 to 9 on the moth-eye pattern formation side were measured by a contact angle meter (product name: CA-XE type, manufactured by Kyowa Kagaku Co., Ltd.). As the liquid for measuring the contact angle, oleic acid (oleic acid) was used.

(evaluation of wiping-off Property)

Dry wiping: after attaching a fingerprint to the surface of the optical element on the moth-eye pattern formation side, the surface was wiped with a dust cloth (product name: トレシー, manufactured by Toray corporation) in a back-and-forth manner at 10kPa for 10 times within 5 seconds.

Wet wiping: after attaching a fingerprint to the moth-eye pattern-forming side surface of the optical element, 5ml of purified water was dropped onto a dust-removing cloth (product name: トレシー, manufactured by Toray corporation) and the cloth was wiped with the cloth at 10kPa for 5 times in 5 seconds in a reciprocating manner.

The evaluation of the erasing property was performed by comparing the reflectance before the attachment of the fingerprint with that after the dry erasing, and it was considered that the case where the reflectance before the attachment of the fingerprint and after the dry erasing was the same was erasable. The results are shown in table 1.

In table 1, the mark "o" indicates that the fingerprint could be erased (the mark "very good" indicates that the fingerprint could be erased particularly easily), the mark "Δ" indicates that the fingerprint could be removed although a part of the fingerprint remained, and the mark "x" indicates that the fingerprint could not be erased. The reflectance was measured by using an evaluation apparatus (product name: V-550, manufactured by Nippon Denshoku Co., Ltd.) for visible light having a wavelength of 532 nm.

(measurement of modulus of elasticity)

(measurement Using tensile tester)

A flat film was prepared from the same material as the ultraviolet-curable resin composition used for the preparation of the optical element (UV-curing), and a film sample having a width of 14mm, a length of 50mm and a thickness of about 200 μm was cut out and used. The elastic modulus of the film sample was measured according to JIS K7127 using a tensile tester (product name: AG-X, manufactured by Shimadzu corporation).

Further, the elastic modulus of the optical element having the moth-eye pattern formed thereon was measured using a surface film physical property tester (manufactured by フィッシャー, seed インスツルメンツ, product name: フィッシャー ス コ ー プ HM-500). As a result, the value of the elastic modulus measured by the microhardness tester was substantially the same as the value of the elastic modulus inherent to the material measured by the tensile tester.

[ Table 1]

From the above evaluation results, the following was found.

In samples 8 and 9, dry wiping was not possible for the evaluation of the wiping properties. This is because the elastic modulus of the optical element is deviated from 5MPa to 1200 MPa. Further, in sample 1, wet wiping could not be performed. This is because the contact angle of the optical element exceeds 110 degrees.

(sample 10)

An optical element was produced in the same manner as in sample 1, except that an ultraviolet curable resin composition having the following composition was used, and that the material of the ultraviolet curable resin composition was weighed, the fluidity was improved in a 60 ℃ oven, the mixture was mixed for one minute with a stirrer (manufactured by Thinky corporation), and then the temperature was returned to normal temperature, and the mixture was used experimentally.

< ultraviolet curable resin composition >

95 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

The additive amount is an amount added when the ultraviolet curable resin composition is 100 wt%.

(sample 11)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

80 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

15 parts by mass of a hydrophilic acrylate monomer

Photopolymerization initiator 5 parts by mass

(alpha-oxybenzone (hydroxy phenyl ketone))

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 12)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

Urethane acrylate 70 parts by mass

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

25 parts by mass of a hydrophilic acrylate monomer

Photopolymerization initiator 5 parts by mass

(alpha-hydroxybenzophenone)

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 13)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

Urethane acrylate 60 parts by mass

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

35 parts by mass of a hydrophilic acrylate monomer

Photopolymerization initiator 5 parts by mass

(alpha-hydroxybenzophenone)

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 14)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

50 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

45 parts by mass of hydrophilic acrylate monomer

Photopolymerization initiator 5 parts by mass

(alpha-hydroxybenzophenone)

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 15)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 1500, number of functional groups 2)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 16)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 1000, number of functional groups 2)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 17)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of urethane acrylate

(highly elastic resin: average molecular weight 2100, number of functional groups 3)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 18)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of 2-functional acrylate

(molecular weight 332, number of functional groups 2)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 19)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of 2-functional acrylate

(molecular weight 349, number of functional groups 2)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 20)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of a 3-functional acrylate

(molecular weight 956, number of functional groups 3)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(sample 21)

An optical element was produced in the same manner as in sample 10, except that an ultraviolet curable resin composition having the following composition was used.

< ultraviolet curable resin composition >

95 parts by mass of 4-functional acrylate

(molecular weight 352, number of functional groups 4)

Photopolymerization initiator 5 parts by mass

Silicone additive 0.5 wt%

(Polyethylether modified Poly-bis-methyl Silicone)

(calculation of crosslink Density)

The crosslinking density was calculated as follows. The storage elastic modulus E' was measured at normal temperature using a dynamic viscoelasticity measurement apparatus (レオメトリック, seeds サイエンティフィック, seeds エフ, produced by seed イー), and the absolute temperature was also set at normal temperature.

n＝E'/3RT

(wherein n represents a crosslinking density (mol/L), E' represents a storage elastic modulus (Pa), R represents a gas constant (Pa, seed L/K, seed mol), and T represents an absolute temperature (K))

(measurement of contact Angle and elastic modulus)

The contact angle and the elastic modulus were measured in the same manner as in samples 1 to 9.

(evaluation of wiping-off Property)

The dry and wet rubbing methods were the same as those for samples 1 to 9. In addition, in samples 10 to 21, the wiping operation was repeated until it was determined whether or not the fingerprint could be wiped off. The results are shown in Table 2.

Regarding the evaluation of the wiping property, in table 2, a fingerprint that was simply wiped off several times was marked as "very excellent", a fingerprint that was wiped off about 10 times was marked as "o", a fingerprint that was wiped off about several tens times was marked as "Δ", and a fingerprint that was not wiped off was marked as "x".

[ Table 2]

Further, a graph in which the crosslink density and the average molecular weight between crosslinks of samples 10 to 21 were plotted is shown in FIG. 33.

From the above evaluation results, the following was found.

In the samples 10 to 17 surrounded by the ellipse of the broken line in fig. 33, regarding the evaluation of the wiping property, the fingerprint was very simply removed by dry wiping. This is because the structure of the optical element contains an oligomer as a main component, and more specifically, because the average molecular weight between crosslinks is 500 or more and 1700 or less, and the crosslink density is 0.8mol/L or more and 5.1mol/L or less. In particular, in samples 11 to 15, fingerprints were very easily removed by wet wiping. This is because the contact angle of the optical element is 30 degrees or less, and the structure has hydrophilicity.

Further, it is found that, as for the material of the structure, the use of the 2-functional oligomer makes the viscosity adjustment easier and the transfer work and the like easier than the case of using the 3-functional oligomer.

Although the embodiments of the present technology have been described above with reference to the antireflective substrate, the above embodiments may be variously modified based on the technical idea of the present technology.

Although the embodiments and examples of the present technology have been specifically described above, the present technology is not limited to the above-described embodiments and examples, and various modifications can be made based on the technical idea of the present technology.

For example, the structures, methods, shapes, materials, numerical values, and the like described in the above embodiments and examples are merely examples, and structures, methods, shapes, materials, numerical values, and the like different from these may be used as necessary.

Further, the respective configurations of the above embodiments may be combined with each other without departing from the spirit of the present technology.

In the above-described embodiments, the case where the present technology is applied to a liquid crystal display device is described as an example, but the present technology can also be applied to various display devices other than a liquid crystal display device. For example, the present technology can be applied to various Display devices such as a CRT (Cathode Ray Tube) Display, a Plasma Display Panel (PDP), an Electro Luminescence (EL) Display, and a Surface-conduction Electron-emitter Display (SED).

In the above-described embodiment, the optical element may be provided with a peep-proof function by generating diffracted light in a direction inclined from the front surface by appropriately changing the pitch of the structures.

In the above-described embodiment, a low refractive index layer may be further formed on the surface of the substrate on which the structure is formed. The low refractive index layer preferably contains, as a main component, a material having a lower refractive index than the materials constituting the base and the structure. Examples of the material of the low refractive index layer include organic materials such as fluorine-based resins, LiF, MgF, and the like₂And the like inorganic low refractive index materials.

In the above-described embodiments, the case where the optical element is manufactured using the photosensitive resin is described as an example, but the method of manufacturing the optical element is not limited to this example. For example, the optical element may be manufactured by thermal transfer or injection molding.

In the above-described embodiment, the case where the structures having a concave shape or a convex shape are formed on the outer peripheral surface of the cylindrical or cylindrical master is described as an example, but when the master has a cylindrical shape, the structures having a concave shape or a convex shape may be formed on the inner peripheral surface of the master.

In the above-described embodiment, the elastic modulus of the material forming the structure may be set to 1MPa or more and 200MPa or less, and the aspect ratio of the structure may be set to 0.2 or more and less than 0.6. In this case, stains such as fingerprints adhering to the surface of the optical element can be wiped off.

In the above-described embodiments, an example in which the optical element is applied to the surface of a printed matter has been described, but the present technology is not limited thereto, and may be applied to the surface of a printed matter or the like.

Description of the reference numerals

1: an optical element;

2: a substrate;

3: a structure;

5: an adhesive layer;

6: a printed matter main body;

11: a main roller;

12: a substrate;

13: a structure;

14: a resist layer;

15: laser;

16: a latent image;

21: a laser;

22: an electro-optic modulator;

23. 31: a mirror;

24: a photodiode;

26: a condenser lens;

27: an acousto-optic modulator;

28: a collimating lens;

29: a formatter;

30: a driver;

32: a mobile optical table system;

33: a beam expander;

34: an objective lens;

35: a spindle motor;

36: a turntable;

37: and a control mechanism.

Claims (13)

1. An optical element is provided with:

a substrate having a surface; and

a plurality of structures, each of which is composed of a plurality of protrusions or recesses, arranged on the surface of the base at a fine pitch equal to or less than the wavelength of visible light,

the elastic modulus of the material forming the structure is 1MPa to 1200MPa,

the surface on which the above-mentioned structures are formed has hydrophilicity,

the crosslinking density of the structure is 0.8mol/L to 5.1mol/L,

the structure has a crosslink average molecular weight of 400 to 10000,

the aspect ratio of the structure is 0.6 to 5,

the structure contains, as a main component, an oligomer having two (meth) acryloyl groups as a linear polymer.

2. The optical element of claim 1,

the water contact angle of the surface on which the structure is formed is 110 degrees or less.

3. The optical element of claim 2,

the water contact angle of the surface on which the structure is formed is 30 degrees or less.

4. The optical element of claim 1,

the structure is arranged on the surface of the substrate so as to form a plurality of rows of tracks, and is formed in a lattice pattern.

5. The optical element of claim 4,

the lattice pattern is at least 1 of a hexagonal lattice pattern, a quasi-hexagonal lattice pattern, a tetragonal lattice pattern, and a quasi-tetragonal lattice pattern.

6. The optical element of claim 4,

the structure has an elliptical cone or an elliptical truncated cone shape having a major axis direction in an extending direction of the locus.

7. The optical element of claim 4,

the trajectory has a straight line shape or an arc shape.

8. The optical element of claim 4,

the trajectory is meandering.

9. The optical element of claim 1,

the structure has an average cross-link molecular weight of 700 to 1500.

10. The optical element of claim 1,

the structure contains, as a main component, at least one of an oligomer having two (meth) acryloyl groups and an oligomer having three (meth) acryloyl groups.

11. An optical element, wherein,

comprises a plurality of structures, which are arranged at a fine pitch equal to or less than the wavelength of visible light and are each composed of a convex portion,

the lower portions of the adjacent structures are joined to each other,

the elastic modulus of the material forming the structure is 1MPa to 1200MPa,

the surface on which the above-mentioned structures are formed has hydrophilicity,

the crosslinking density of the structure is 0.8mol/L to 5.1mol/L,

the structure has a crosslink average molecular weight of 400 to 10000.

12. A display device comprising the optical element according to any one of claims 1 to 11.

13. An input device comprising the optical element according to any one of claims 1 to 11.