Agc Inc.

Motoshi Nakayama

Ryota Murakami

Kazuhiko Shiono

Aya Ito

Ryo Hirano

Kensuke Ono

Tatsuo Yokote

The present invention relates to an optical filter including a resin base material including an infrared-absorbing pigment layer, and a pair of inorganic dielectric layers which are respectively disposed on or above both main surfaces of the resin base material as outermost layers, in which at least one of the pair of inorganic dielectric layers satisfies at least one of a condition in which a film thickness is 4 μm or greater, and a condition in which the number of layers is 30 or greater, and a ratio of a total film thickness of the pair of inorganic dielectric layers to a film thickness of the resin base material is greater than 8%.

Optical filter and imaging device

An optical filter includes: a resin substrate having a thickness of 20 μm or more and 110 μm or less; an absorption layer having a thickness of 0.25 μm or more and 12 μm or less and being disposed on at least one principal surface of the resin substrate; and dielectric multilayer films disposed as an outermost layer on both principal surfaces of the resin substrate. At least one of the dielectric multilayer films is a near-infrared reflection layer. The resin substrate includes a first transparent resin having a glass transition temperature of 170° C. or more and having specific optical properties. The absorption layer includes a near-infrared absorbing dye (A) and a second transparent resin having a glass transition temperature of 170° C. or more, and the near-infrared absorbing dye (A) satisfies specific optical properties in relation to the second transparent resin.

A diffractive optical element includes: a substrate; a protrusion and recess portion that is formed on one surface of the substrate and imposes predetermined diffraction on incident light; and an antireflection layer provided between the substrate and the protrusion and recess portion. An effective refractive index difference Δn in a wavelength range of the incident light between a first medium constituting a protrusion of the protrusion and recess portion and a second medium constituting a recess of the protrusion and recess portion is 0.70 or more. An exit angle range θof diffraction light exiting from the protrusion and recess portion when the incident light enters the substrate from a normal direction of the substrate is 60° or more. Total efficiency of diffraction light exiting from the protrusion and recess portion in the exit angle range is 65% or more.

Diffractive optical element, projection device, and measurement device'

A diffractive optical element includes: a diffraction unit; and a lens unit disposed on a light incident side of the diffraction unit. The lens unit includes: a substrate; and a protrusion and recess portion disposed on a side opposite to a light incident side of the substrate. The protrusion and recess portion includes: a periodic structure of a relief-protrusion portion disposed in a central part, a periodic structure of a stepwise grating disposed in a central part simulating the relief-protrusion portion, or a combination thereof; and a grating disposed in a portion other than the central part. The number of steps of the stepwise grating disposed in the central part is larger than the number of steps of the grating disposed in the portion other than the central part.

Diffractive optical element and illumination optical system

A diffractive optical element includes: a substrate; a protrusion and recess portion that is formed on one surface of the substrate and imposes predetermined diffraction on incident light; and an antireflection layer provided between the substrate and the protrusion and recess portion. An effective refractive index difference &#x394;n in a wavelength range of the incident light between a first medium constituting a protrusion of the protrusion and recess portion and a second medium constituting a recess of the protrusion and recess portion is 0.70 or more. An exit angle range &#x3b8;of diffraction light exiting from the protrusion and recess portion when the incident light enters the substrate from a normal direction of the substrate is 60&#xb0; or more. Total efficiency of diffraction light exiting from the protrusion and recess portion in the exit angle range is 65% or more.

Growing community of inventors

Fukushima, Japan

Motoshi Nakayama