Hill, Steadman & Simpson
Magneto-optical disk recording and reading apparatus and method wherein the recording head is controlled in the radial direction of the disk to a desired position
 A magneto-optical disc recording apparatus includes a magnetic head, an optical head, a position detector and a controller. The magnetic head supplies a vertical magnetic field corresponding to recording data to a magneto-optical disc. The optical head emits a light beam to the magneto-optical disc through a substrate of the magneto-optical disc. The magneto-optical disc is arranged between the magnetic head and the optical head. The optical head has an actuator for moving an objective lens in a tracking direction. The position detector detects the displacement of the actuator. The controller controls a recording operation of the magnetic head and the optical head. The recording operation is started when a result of detection by the position detector reaches a predetermined value. 
Sony Corporation
G G G G G
G11B G11B G11B G11B G11B
inventional inventional inventional inventional additional
Tetsuji Tetsu
Kawashima Watanabe