Asahi Glass Company, Limited

Kenichi Shioya

Makoto Hasegawa

Hiroshi Kumai

Hiroki Hotaka

Hiromichi Nagayama

So Ishido

An optical device has a visible light transmittance that decreases from a central part thereof towards a peripheral part thereof. The optical device includes a visible light absorbing part, made of a material that absorbs at least a part of visible light, and having a thickness that increases from a central part thereof towards a peripheral part thereof, and a visible light transmitting part, made of a material that transmits the visible light, and is stacked on the visible light absorbing part. A relationship T420/T360&#x3e;=3 is satisfied, where T420 denotes a transmittance of light having a wavelength of 420 nm, and T360 denotes a transmittance of light having a wavelength of 360 nm.

Optical device, optical system, and imaging apparatus

A compound of the following formula (1):CH&#x2550;CR&#x2014;COO&#x2014;R&#x2014;OCO-Cy-COO-Cy-A-Cy-R&#x2003;&#x2003;(1)wherein Ris a hydrogen atom or a methyl group; Ris a hydrocarbon group having from 1 to 8 carbon atoms, provided that some or all of hydrogen atoms bonded to carbon atoms in the group may be substituted by fluorine atoms, and when it has 2 or more carbon atoms, it may have an etheric oxygen atom in a carbon-carbon bond, Ris an alkyl or alkoxy group having from 1 to 8 carbon atoms, or a fluorine atom, provided that when it is the alkyl or alkoxy group, some or all of hydrogen atoms bonded to carbon atoms in the group may be substituted by fluorine atoms; Cy is a trans-1,4-cyclohexylene group, provided that hydrogen atoms bonded to carbon atoms in the group may independently be substituted by fluorine atoms, chlorine atoms or methyl groups; and A is a single bond, a trans-1,4-cyclohexylene group or a 1,4-phenylene group, provided that hydrogen atoms bonded to carbon atoms in the group may independently be substituted by fluorine atoms, chlorine atoms or methyl groups.

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Koriyama, Japan

Kenichi Shioya