Abstract: Provided is a light transmitting member including: a base material; a first porous layer formed on a first surface of a base material; and a second porous layer formed on a second surface opposed to the first surface of the base material, wherein the second porous layer has a pore volume larger than a pore volume of the first porous layer.

Abstract: In a toric lens comprising a toric surface having a fine uneven structure, the fine uneven structure includes a plurality of holes, the plurality of holes have a hole depth H and a surface opening diameter ?t which satisfy an expression of 0.3?H/?t?0.6, and (a) the plurality of holes have a hole structure having a cylindrical shape on a bottom surface side and a circular truncated cone shape having an opening diameter increasing toward a surface side, or (b) an angle ? formed between an opening portion and the surface of the plurality of holes satisfies 78°???85°.

Abstract: In a toric lens comprising a toric surface having a fine uneven structure, the fine uneven structure includes a plurality of holes, the plurality of holes have a hole depth H and a surface opening diameter ?t which satisfy an expression of 0.3?H/?t?0.6, and (a) the plurality of holes have a hole structure having a cylindrical shape on a bottom surface side and a circular truncated cone shape having an opening diameter increasing toward a surface side, or (b) an angle ? formed between an opening portion and the surface of the plurality of holes satisfies 78°???85°.

Abstract: The optical member according to the present invention includes a film containing a plurality of chain particles and having a refractive index of 1.21 or more and 1.27 or less at a wavelength of 550 nm on a substrate. The film includes an alcohol having an ether bond or an ester bond and having a branched structure having 4 to 7 carbon atoms in a range of 1.0 mg/cm3 or more and 2.8 mg/cm3 or less.

Abstract: An optical member includes a base material and a film on the base material, the film includes hollow particles that have prickle-like protrusions on their surface, the heights of the protrusions are 3 nm or more and 20 nm or less, the proportion of the prickle-like protrusions is 3% or more and 30% or less of the particle surface, and the film includes 50 percent by volume or more and 68 percent by volume or less of hollow particles. Consequently, an antireflection film having a low refractive index and a low level of scattering in combination is provided.

Abstract: The optical member according to the present invention includes a film containing a plurality of chain particles and having a refractive index of 1.21 or more and 1.27 or less at a wavelength of 550 nm on a substrate. The film includes an alcohol having an ether bond or an ester bond and having a branched structure having 4 to 7 carbon atoms in a range of 1.0 mg/cm3 or more and 2.8 mg/cm3 or less.

Abstract: The present invention provides a method of producing hollow particles for reducing light scattering in an antireflection coating. This method includes synthesizing core-shell particles including a core containing an organic compound as a major component and a shell containing an inorganic-based compound as a major component in an aqueous medium, dispersing the core-shell particles in an organic solvent, and preparing hollow particles by heating the core-shell particles dispersed in the organic solvent to remove the core therefrom.

Abstract: An optical member includes a base material and a film on the base material, the film includes hollow particles that have prickle-like protrusions on their surface, the heights of the protrusions are 3 nm or more and 20 nm or less, the proportion of the prickle-like protrusions is 3% or more and 30% or less of the particle surface, and the film includes 50 percent by volume or more and 68 percent by volume or less of hollow particles. Consequently, an antireflection film having a low refractive index and a low level of scattering in combination is provided.

Abstract: A hollow particle and a method for producing hollow particles are provided. The shell of the particle(s) is a continuous layer containing magnesium fluoride and thus is strong. A hollow particle has a continuous shell containing magnesium fluoride and an at least partially removed hollow core. A method for producing hollow particles includes forming core-shell particles having a core particle and a continuous shell containing magnesium fluoride and removing at least a portion of the core particle from the core-shell particles to produce a hollow core. The core-shell particles can be formed by adding an aqueous solution of a magnesium salt and an aqueous solution containing fluoride ions to an aqueous dispersion containing the core particles at a temperature of 10 degrees Celsius to 30 degrees Celsius, both inclusive, and then heating the combined liquid at a temperature of 50 degrees Celsius to 80 degrees Celsius, both inclusive.

Abstract: The present invention provides a method of producing hollow particles for reducing light scattering in an antireflection coating. This method includes synthesizing core-shell particles including a core containing an organic compound as a major component and a shell containing an inorganic-based compound as a major component in an aqueous medium, dispersing the core-shell particles in an organic solvent, and preparing hollow particles by heating the core-shell particles dispersed in the organic solvent to remove the core therefrom.

Abstract: A method for manufacturing a dispersion of hollow particles includes producing a core-shell type particle by forming a shell made mainly of an inorganic-based compound on a surface of a particle made mainly of an organic compound in an aqueous medium, and obtaining the dispersion of the hollow particles formed of the shell by hydrophobizing the core-shell type particles and extracting the core-shell type particles with an aromatic organic solvent.

Abstract: The present invention provides a method of producing hollow magnesium fluoride particles by performing polymerization at the interface of micelle constituted of a hydrophobic solvent, a hydrophilic solvent, and a surfactant. The invention further provides an antireflection coating having a low refractive index due to the coating by the hollow magnesium fluoride particles and also provides an optical device coated with the antireflection coating and an imaging optical system having the optical device. In the method, micelle is formed from a hydrophobic solvent, a hydrophilic solvent, and a surfactant, and then a fluorine compound and a magnesium compound are dissolved in the micelle solution to polymerize magnesium fluoride at the interface of the micelle.