| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head apparatus and an optical disk apparatus by which coma aberration caused by tilt of an optical disk can be detected quantitatively by using a knife edge (Foucault) method. <P>SOLUTION: This optical head apparatus has a laser light source 20 emitting a laser beam, an objective lens 24 converging the laser beam emitted from this laser light source 20 on an information recording medium 1, and a photodetector 27 receiving reflected light from the information recording medium 1 through a condenser lens 25 converging it. A knife edge 26 is arranged at a converging position at which the reflected light is converged by the condenser lens 25, and tilt quantity of the information recording medium is detected based on an image projected by this knife edge 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
