Patent ID: 7553544

Claim:
An optic-purpose resin precursor composition for a close-contact double-layer diffractive optical element obtained by mixing at least a first resin precursor having d-line refractive index n d <1.50 and 0.003<(F-line refractive index n F −C-line refractive index n c ) in an uncured state, and a second resin precursor having d-line refractive index n d <1.62 and 0.010<(F-line refractive index n F −C-line refractive index n c ) in an uncured state; said first resin precursor not containing any of a benzene ring, a sulfur atom, a chlorine atom, a bromine atom and an iodine atom, and having at least one of an acrylic group, a methacrylic group and a vinyl group; and said second resin precursor not containing any of a sulfur atom and a halogen atom, having at least a cyclic structure, and having at least one of an acrylic group, a methacrylic group and a vinyl group.