Compatible optical pickup

摘要

A compatible optical pickup compatibly adopting a high density recording medium and at least one low density recording medium, comprises an objective lens capable (3) of forming a light spot suitable for recording and/or reproduction on a recording surface of the high density recording medium (1a) by focusing an incident light beam for the high density recording medium capable of obtaining a high NA suitable for the high density recording medium and a light spot suitable for recording and/or reproduction on a recording surface of the low density recording medium (1b,1c) by focusing an incident light beam for the low density recording medium in the form of a divergent beam, and an actuator provided to apply tilt to the objective lens (3). The light beam for the low density recording medium (1b,1c) is incident on the objective lens in the form of a divergent beam, and when the objective lens is shifted in a radial direction with respect to the low density recording medium, a tilt is applied to the objective lens corresponding to the shift. Thus, the compatible optical pickup can compatibly adopt a high density optical disk and a low density optical disc having different thicknesses. Also, a superior aberration characteristic can be obtained when the object lens is shifted in the radial direction of the optical disc without additional optical parts with respect to the low density optical disc. <IMAGE>