Patent ID: 7088645

Claim:
An optical pickup apparatus compatible with a first optical recording medium adapted for a first wavelength for writing and reading and a second optical recording medium adapted for a second different wavelength for writing and reading, comprising: a first light source emitting a first beam at the first wavelength; a second light source emitting a second beam at the second wavelength; a coupling lens for coupling one of the first beam and the second beam; an objective lens for converging the coupled beam so as to form a beam spot on a recording surface of one of the first optical recording medium and the second optical recording medium; optical axis aligning means for aligning optical axes of the first beam and the second beam with an optical axis of said coupling lens, wherein said optical axis aligning means is embodied by a combination of a prism element having one of a variable transmissivity and a variable reflectivity that depends on a polarization of an incident beam, and a phase plate for rotating a plane of polarization of one of the first beam and the second beam by 90°; optical path separating means for separating a return beam reflected by the optical recording medium and transmitted through the objective lens, from an upstream optical path leading from the light source to the objective lens, said optical path separating means being provided in alignment with both an upstream beam traveling to the recording surface and the return beam; detecting means for receiving the return beam separated by said optical path separating means so as to retrieve information from the return beam, said detecting means being provided in alignment with-the return beam and including photosensitive means; control means for effecting focusing control and tracking control based on a result of detection by said detecting means, wherein said first light source is driven only when the first optical recording medium is used, the second light source is driven only when the second optical recording medium is used, said coupling lens is provided with a collimating function for collimating one of the first beam and the second beam, said coupling lens transforming the first and second light beams emitted from said first and second light sources into substantially parallel beams that enter the optical path separating means, and said coupling lens converging the return light beam reflected from the optical recording medium and separated by the optical path separating means onto the detecting means; and wherein said optical path separating means includes a polarizing hologram.