OPTICAL PICKUP, INFORMATION REPRODUCING DEVICE AND INFORMATION RECORDING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an optical pickup by which red and blue laser beams are condensed with practically no aberration, color aberration is corrected with a compact size and simple configuration and color aberration is compensated without giving the loss of light quantity to each laser beam. SOLUTION: This optical pickup is provided with two laser diodes which emit red and blue laser beams, an objective lens 2 constituted of a conversion lens 2a which respectively converges red and blue laser beams on an optical disk and a contact lens 20 which is made in close contact with the lens 2a on the optical paths of each laser beams, and a detector which receives the reflected light beams from an optical disk of one of the laser beams among converged red and blue laser beams and generates received light signals. The color aberration generated in each laser beams is compensated for by the lens 2. Note that the absolute value of the difference between the Aabe numbers of the lenses 2a and 2b is set to be greater than 10 to compensate the color aberration.