Patent ID: 7680015
Filing Date: 2010-03-16
Classification: G11B

Abstract:
1. 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 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 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, the 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 the optical path separating means so as to retrieve information from the return beam, the detecting means being provided in alignment with both the upstream beam and the return beam and including photosensitive means; and control means for effecting focusing control and tracking control based on a result of detection by the detecting means, wherein: the 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, the coupling lens comprises an anamorphic lens which provides a beam shaping function for shaping one of the first beam and the second beam, the shaping including less expansion in a direction in which an angle of divergence with respect to intensity of the beam from the light source is maximum and more expansion in a direction in which the angle of divergence is minimum, and wherein the coupling lens is provided with a collimating function for collimating one of the first beam and the second beam, the coupling lens being a single lens that provides the collimating function and the beam shaping function.