| 摘要 |
PURPOSE:To reduce a pitch between tracks and realize a high track density by a method wherein the crosstalk component of an adjacent recording track along a direction perpendicular to a laser beam scanning direction on a magneto-optical disc which is a medium is not detected. CONSTITUTION:A photodetector 17 is provided in a position of the focal distance f1 of a condensing lens 16 which is provided in an optical focal position (confocal position) conjugate with a magneto-optical disc 15 positioned at a focal distance f0 of an object lens 14. A photodetecting part which is extended in a laser beam scanning direction is provided in the photodetector 17. The photodetecting part detects only a part of a laser beam spot in the confocal position. |
