Canon Kabushiki Kaisha

Kazue Uchida

Tomohiko Ishibashi

Masuo Ban

Kazuhiko Momoki

Takeharu Okuno

Daisuke Sano

An optical element includes a substrate and an antireflection film. The antireflection film comprises a first film formed on the substrate and a second film formed on the first film. The second film comprises a first layer, a second layer, and a third layer arranged consecutively in order from a side closer to the first film. The first layer includes magnesium fluoride. The second layer includes silicon oxide and aluminum oxide. The third layer includes a fluorine-containing organic compound.

Optical element, optical system, and optical apparatus

An optical element includes a base material, which consists of resin material, and an antireflection film. The antireflection film consists of a first film formed on the base material and a second film formed on the first film. The second film consists of a first layer, a second layer, and a third layer, in order from a side closest to the first film. The first layer and the third layer each include silicon oxide. The second layer includes magnesium fluoride.

The disclosed optical filter is provided on a substrate. The optical filter includes a first layer, an absorption layer, and a second layer in order from a substrate side. The condition of |R1−R2|≥10 is satisfied where R1 [%] represents a reflectance of the optical filter for light whose wavelength is 550 nm and that makes incident on the optical filter from a side opposite to the substrate, and R2 [%] represents a reflectance of the optical filter for light whose wavelength is 550 nm and that makes incident on the optical filter from the substrate side.

Optical filter having differing reflectance depending on light incident side

An optical element has an area in which a transmittance varies, includes first and second antireflection layers, and an absorption layer disposed between the first and second antireflection layers, and satisfies certain conditions.

An optical element having an area in which a transmittance changes in a first direction, the optical element includes a substrate and a first layer in a second direction orthogonal to the first direction. A thickness of the first layer in the second direction changes in the first direction, and the extinction coefficient of the first layer changes in the first direction. A predetermined conditional expression is satisfied.

Optical element, optical system, and imaging apparatus

An optical element includes a substrate, and a multilayer film provided on the substrate. The multilayer film has an average transmittance of 75% or higher for light having a wavelength of 470 nm to 630 nm incident at an incident angle of 0&#xb0; and a transmittance of 10% or lower for light having a wavelength of 1550 nm incident at an incident angle of 0&#xb0;. The multilayer film includes a layer made of a first material and a layer made of a second material alternately layered, and a final layer made of a third material disposed on an outermost side, and a predetermined condition is satisfied.

Optical element, optical system, and image pickup apparatus

An optical element includes a substrate, and an antireflection film formed on the substrate and including a plurality of layers. The optical element satisfies predetermined conditions.

Optical element, method for manufacturing optical element, optical system, and optical apparatus

The antireflection coating is a multi-layer film to be formed on a surface of a substrate. The film includes multiple layers including an uppermost layer most distant from the substrate among the multiple layers, and a lower layer including at least one layer other than the uppermost layer. A refractive index nof the uppermost layer for a wavelength of &#x3bb; (nm) satisfies a condition of 1.11&#x2264;n&#x2264;1.3. An optical admittance Y of the lower layer is expressed by Y=a+ib, and a and b in the optical admittance satisfy conditions of (a&#x2212;1.13)+(b&#x2212;0.24)&#x2264;0.45for &#x3bb;=430, (a&#x2212;1.33)+(b+0.05)&#x2264;0.25for &#x3bb;=900 and (a&#x2212;1.14)+(b+0.25)&#x2264;0.29for &#x3bb;=1800.

Antireflection coating, optical element, optical system and optical apparatus

The optical element includes a base member configured to have an optical surface, a concave-convex structure configured to have an average pitch smaller than a shortest wavelength of a use wavelength range, and an intermediate layer formed between the optical surface and the concave-convex structure, made of a material different from that of the concave-convex structure, and having a refractive index between those of the base member and the material of the concave-convex structure. The optical surface is formed into a shape having a rotational symmetry axis. A thickness of the intermediate layer or each of thicknesses of the intermediate layer and the concave-convex structure varies so as to increase as a distance from the rotational symmetry axis increases. The optical element has good anti-reflection performance not only at a central part of the optical surface having a small curvature radius but also at a peripheral part thereof.

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Utsunomiya, Japan

Kazue Uchida