Canon Kabushiki Kaisha

Kei Ueda

Kazuhiko Momoki

Yutaka Yamaguchi

An optical element includes an optical surface with a random uneven shape that satisfies 0.30&#x2264;I&#x2264;1.00 and 0.00&#x2264;C&#x2264;0.60 where P is an average pitch, Iis a ratio of a component intensity sum from 0.9P to 1.1P to a component intensity sum of an entire frequency spectrum calculated with a square area in which each side is equal to or longer than 40 &#x3bc;m, and Cis a value of a second largest intensity peak in an autocorrelation function calculated with a square area in which each side is 20P.

Optical element, optical apparatus, and method for forming random uneven shape

An optical low-pass filter is arranged on an object side than an image sensor in an image pickup apparatus and has an unevenness shape. The conditions of 5.0 &#x3bc;m&#x2264;&#x394;z&#x2264;80.0 &#x3bc;m and 1.0&#x2264;Ps/&#x3c;Pf&#x3e;&#x2264;20.0 are satisfied where &#x394;z represents a distance between the optical low-pass filter and the image sensor, Ps represents a pixel pitch of the image sensor, and &#x3c;Pf&#x3e; represents an average pitch of the unevenness shape.

Optical low-pass filter and image pickup apparatus

An optical filter includes a first multi-layer having a width Wand including a first optical layer and a second optical layer that are made of materials different from each other and that are alternately laminated, the first optical layer having a refractive index nH and an average layer thickness dH, and the second optical layer having a refractive index nL lower than nH and an average layer thickness dL, a second multi-layer having a width Wand including the first and the second optical layers alternately laminated, the first and the second multi-layers are included in each of unit structures arranged being shifted from each other by a shift amount D in a lamination direction of the first and the second optical layers, and predetermined conditions are satisfied.

Optical filter and optical apparatus

An optical filter includes a first multilayer film structure including first and second optical layers which are constituted by materials different from each other, and a second multilayer film structure including third and fourth optical layers which are constituted by materials different from each other, the first multilayer film structure includes a first unit multilayer film with a width Wincluding the first optical layer and the second optical layer, and a second unit multilayer film with a width Wincluding the first optical layer and the second optical layer laminated alternately, the first and second unit multilayer films are shifted from each other in a lamination direction of the first and second optical layers, and constitute a unit structure in which the first and second unit multilayer films are arranged adjacent to each other in an arrangement direction orthogonal to the lamination direction.

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Utsunomiya, Japan

Kei Ueda