Patent ID: 8350054

Claim:
An optical filter comprising at least one naphtholactam derivative represented by general formula (I): wherein X represents an oxygen atom or a sulfur atom; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and Y each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aldehyde group, a carboxyl group, a hydroxyl group, —NRR′, an organosilyl group, an optionally substituted alkyl group having 1 to 30 carbon atoms, an optionally substituted aryl group having 6 to 30 carbon atoms, or an optionally substituted arylalkyl group having 7 to 30 carbon atoms; the methylene chain of the alkyl group, the methylene chain of the arylalkyl group, and the bond between the aryl group and the naphtholactam structure is optionally interrupted by —O—, —S—, —SO 2 —, —CO—, —OCO—, or —COO—; the methylene chain may be —CH═CH— or —C≡C—; and R and R′ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 30 carbon atoms, or an optionally substituted aryl group having 6 to 30 carbon atoms.