Patent ID: 6614720
Filing Date: 2003-09-02
Classification: G11B

Abstract:
An optical pickup device comprising:a semiconductor laser; a collimator lens converting to a beam formed of a collimated flux and having an elliptic cross section a divergent flux emitted from said semiconductor laser; beam shaping means converting a ratio of the longer diameter to the shorter diameter of the elliptic cross section of the collimated flux beam formed by the collimator lens; and an objective lens converging on an information recording medium the flux output from the beam shaping means, and receiving a flux reflected from said information recording medium; wherein said beam shaping means shapes the beam output by the collimator lens such that the flux output therefrom has an elliptic cross section having a ratio of the longer diameter thereof to the shorter diameter thereof that is greater than 1 but less than or equal to 2.