Abstract: An anti-reflection coat includes an intermediate layer and a low refractive index layer sequentially stacked on a substrate, and preventing the reflection of incident light by optical interference effect, wherein the low refractive index layer is a film formed on the surface of the intermediate layer by a wet film formation method using a coating liquid including layer-constituting raw materials which includes hollow silica particles adhering each other with a binder, and the intermediate layer is a layer mainly composed of an organometallic compound which adheres well to the binder and having wettability to the coating liquid; and provides an optical device including the anti-reflection coat.

Abstract: An object of the present invention is to provide an anti-reflection film excellent in high-temperature and high-humidity environment resistance and scratch resistance in addition to improved anti-reflection performance of a concave-convex nanostructure. To achieve the object, an anti-reflection film 10 comprises: a base layer 11 as a first optical thin film that is provided on an optical surface 21a of an optical element 21; a concave-convex nanostructure layer that is provided on a surface of the base layer 11 and is composed of a concave-convex nanostructure 12 formed so as to have a pitch width p between the convex parts 12b of shorter than an incident light wavelength; and a cover layer 13 as a second optical thin film that covers peaks of the convex part 12b with a void 14 being provided between the cover layer 13 and concave part 12a constituting the concave-convex nanostructure 12.

Abstract: An object of the present invention is to provide an antireflection film and an optical device having excellent antireflection characteristics against a light beam having a wide wavelength range at a wide range of an incident angle, and also having practically sufficient durability. To achieve the above object, the present invention adopts an antireflection film having an optical two-layer structure composed of an intermediate layer provided on a base material and a low refractive index layer provided on a surface of the intermediate layer, wherein the low refractive index layer is a layer obtained by binding hollow silica by a binder, a refractive index n(1) thereof is between 1.15 and 1.24 inclusive, and a refractive index n(2) of the intermediate layer satisfies a relation in the expression (1) below assuming a refractive index of the base material n(sub). n(1)×?{square root over (n(sub))}×0.930?n(2)?n(1)×?{square root over (n(sub))}×0.985??(1).

Abstract: An object of the present invention is to provide an anti-reflection film excellent in high-temperature and high-humidity environment resistance and scratch resistance in addition to improved anti-reflection performance of a concave-convex nanostructure. To achieve the object, an anti-reflection film 10 comprises: a base layer 11 as a first optical thin film that is provided on an optical surface 21a of an optical element 21; a concave-convex nanostructure layer that is provided on a surface of the base layer 11 and is composed of a concave-convex nanostructure 12 formed so as to have a pitch width p between the convex parts 12b of shorter than an incident light wavelength; and a cover layer 13 as a second optical thin film that covers peaks of the convex part 12b with a void 14 being provided between the cover layer 13 and concave part 12a constituting the concave-convex nanostructure 12.

Abstract: An object of the present invention is to provide an antireflection film and an optical device having excellent antireflection characteristics against a light beam having a wide wavelength range at a wide range of an incident angle, and also having practically sufficient durability. To achieve the above object, the present invention adopts an antireflection film having an optical two-layer structure composed of an intermediate layer provided on a base material and a low refractive index layer provided on a surface of the intermediate layer, wherein the low refractive index layer is a layer obtained by binding hollow silica by a binder, a refractive index n(1) thereof is between 1.15 and 1.24 inclusive, and a refractive index n(2) of the intermediate layer satisfies a relation in the expression (1) below assuming a refractive index of the base material n(sub). n(1)×?{square root over (n(sub))}×0.930?n(2)?n(1)×?{square root over (n(sub))}×0.

Abstract: An object of the present invention is to provide an anti-reflection optical element excellent in durability in the environment high-temperature and high-humidity and scratch resistance while maintaining the anti-reflection performance of a concave-convex nanostructure. To achieve the object, an anti-reflection optical element 1 comprising a concave-convex nanostructure 20 that reduces reflection of incident light on an optical surface 11 of a base optical element 1 comprising a cover layer 30 made of a light-transmitting material that covers an outer surface of the concave-convex nanostructure 20, wherein a peak of convex portion 21 of the concave-convex nanostructure 20 is covered with the cover layer 30 in the state where a space 40 is provided between the cover layer 30 and concave portions 22 of the concave-convex nanostructure 20 is employed.

Abstract: A coiled wave spring obtained by winding a corrugated wire into a coil shape, wherein mutually overlapping top portions and mutually overlapping base portions of the spring are in mutual contact and predetermined gaps are defined between mutually overlapping slope portions which connect the top and base portions, the first loop of the spring, that is, on the upper side, and the second loop, that is, on the lower side, are in mutual contact in an axial direction thereof only between the top portions and between the base portions, and the gaps are defined between the slope portions to prevent mutual contact. When the spring receives a load and undergoes deformation, the top portions and the base portions come into mutual contact, respectively, but hardly generate friction. Since the gaps are defined between the mutually overlapping slope portions, friction does not occur at these portions, either.