| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide methods for focus and tracking control of an optical pickup apparatus which is used for recording and reproducing a small optical disk for performing stable focus control and tracking control. <P>SOLUTION: The methods have a light source, an objective lens 39, quadrant light receiving patterns 161 to 164 and quadrant hologram areas 131 to 134. Through the hologram areas 131 to 134 divided into two groups in a tangent direction, about the light receiving patterns 161 to 164 divided into two groups in a radial direction, the method for focus control performs focus control based on a difference signal mutually between the groups of the radial direction and the method for tracking control performs tracking control based on a difference signal mutually between the groups of the tangent direction. <P>COPYRIGHT: (C)2004,JPO |
