Patent ID: 7995446

Claim:
An optical element for an optical pickup apparatus, the optical element comprising: a first area including an optical axis of the optical element; and a second area surrounding the first area and comprising a diffractive structure in a radial shape, wherein the optical elements is used for the optical pickup apparatus which records or reproduces information by converging at least a light flux with a wavelength λ 2 from a light source onto an information recording surface of an optical disc and by receiving a light flux reflected by the information recording surface by a photodetector, wherein the first area transmits a light flux from the light source, and the second area diffracts a light flux with the wavelength λ 2 from the light source, wherein the optical pickup apparatus records or reproduces information by converging a first light flux with a first wavelength λ 1 emitted from a first light source onto an information recording surface of a first optical disc including a protective substrate with a thickness t 1 , by converging a second light flux with a second wavelength λ 2 (λ 2 >λ 1 ) emitted from a second light source onto an information recording surface of a second optical disc including a protective substrate with a thickness t 2 (t 1 ≦t 2 ), and by receiving a light flux reflected by the information recording surface of each of the first and second optical discs by a photodetector, and wherein the first area transmits the first light flux and the second light flux, and the second area transmits the first light flux and diffracts the second light flux.