| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which appropriately records/reproduces information irrespective of temperature changes. <P>SOLUTION: When a change in temperature occurs, a spherical aberration increases due to a change in the refractive index of an objective lens OBJ, and therefore, a collimating lens CL is moved in an optical axis direction using a single-axis actuator AC1 to cause a finite bundle of rays to enter the objective lens OBJ, thereby suppressing the spherical aberration. Also, if a BD is a multilayer optical disk, the spherical aberration also increases when an interlayer jump is made from one of a plurality of information recording layers to another layer, and therefore, in response to this, the collimating lens CL is moved in the optical axis direction. A third-order coma aberration caused by the movement of the collimating lens CL in the optical axis direction is corrected using a liquid crystal device LCD. <P>COPYRIGHT: (C)2010,JPO&INPIT |
