Compatible optical picking device

一种兼容采用高密度记录介质和至少一种低密度记录介质的兼容光拾取器，包括：物镜，能够通过聚焦能够获得适于高密度记录介质的高NA的用于高密度记录介质的入射光束来形成适于在高密度记录介质的记录表面上记录和/或再现的光点，并且通过聚焦发散光束形式的用于低密度记录介质的入射光束来形成适于在低密度记录介质的记录表面上记录和/或再现的光点；以及致动器，用来对物镜施加倾斜。用于低密度记录介质的光束以发散光束的形式入射到物镜上，并且当物镜在低密度记录介质的径向上发生偏移时，对物镜施加与偏移相对应的倾斜。因此，兼容光拾取器可以兼容采用具有不同厚度的高密度光盘和低密度光盘。 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.