Patent ID: 7372794

Claim:
A compatible optical pickup for use with a high density recording medium and at least one low density recording medium, the compatible optical pickup comprising: an objective lens having an optical property to form a light spot suitable for recording and/or reproduction on a recording surface of the high density recording medium by focusing a first incident light beam for the high density recording medium and obtaining a high NA suitable for the high density recording medium, and to form a light spot suitable for recording and/or reproduction on a recording surface of the low density recording medium by focusing a second incident light beam for the low density recording medium; and an actuator provided to apply tilt to the objective lens, wherein: the second light beam for the low density recording medium is incident on the objective lens in the form of a divergent beam, when the objective lens is shifted in a radial direction with respect to the low density recording medium, the actuator applies a tilt to the objective lens corresponding to the shift so as to correct a coma aberration due to the shift, an amount of the tilt applied to the objective lens is proportional to a translational movement of the objective lens in the radial direction, and the actuator comprises a coil which receives current, and the amount of tilt applied to the objective lens is detected from a tracking driving signal output from a tracking controller to make the objective lens perform the translational movement in the radial direction.