Patent ID: 9335557
Filing Date: 2016-05-10
CPC Classification: G02B

Claim Text:
1. A diffractive optical element comprising: a first member and a second member in contact with each other, wherein the second member has a refractive index lower than a refractive index of the first member and has a dispersion higher than that of the first member, wherein the first member is made of a resin material and the second member is made of a glass material, wherein the second member includes a plurality of diffractive grating portions each having a grating wall surface and a grating surface that merge with each other, wherein each of the diffractive grating portions is configured so that a grating height thereof increases as a distance increases away from an optical axis, wherein the diffractive optical element has a positive power, and wherein the following expressions are met: where ngd and vgd are a refractive index and an Abbe number of the glass material at a d-line wavelength respectively, and nrd and νrd are a refractive index and an Abbe number of the resin material at the d-line wavelength.