Patent ID: 7050380

Claim:
An optical pickup unit comprising: first and second light source emitting light beams of first and second wavelengths, respectively; a non-polarization-type light-path splitting part; a dichroic element; a phase plate; and an objective lens, wherein one of the first and second light sources is selected so that information recording or reproduction is performed by converging a light beam emitted from the selected one of the first and second light sources on an optical recording medium via said dichroic element, said phase plate, and said objective lens, and wherein said dichroic element, said phase plate, and said objective lens are used for both of the light beams emitted from the first and second light sources, respectively, wherein said phase plate substantially circularly polarizes one of the light beams of the first and second wavelengths and substantially elliptically polarizes another of the light beams of the first and second wavelengths, and wherein said phase plate is provided between said dichroic element and said objective lens.