Optical pickup device
AssigneePioneer Electronic Corporation
InventorsSakashi Ootaki, Ryo Sato
Life of this patent
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Abstract
An optical pickup device which makes a numerical aperture of an object lens in a radial direction of an optical disk smaller than that in a tangential direction to a track on the optical disk. With this feature, a spot diameter in the tangential direction to the track becomes smaller than that in the radial disk in the data recorded surface thereof, and it is possible to prevent degradation of a MTF as well as to accurately read data recorded in the high-density optical disk.
Claims2
An optical pickup device for irradiating a light beam to a data recording surface of an optical disk through an objective lens, receiving the light reflected therefrom through said objective lens, and generating a read signal in accordance with intensity of the received light,
- wherein a numerical aperture of said objective lens in a radial direction of said optical disk is made smaller than that in a tangential direction to a track on said optical disk.
Dependencies are inferred from the claim text.