Copy window control for data dependent field switching in domain expansion read-out

摘要

The present invention relates to a method and apparatus for controlling a copy window during read-out of a domain expansion medium ( 10 ), wherein a switching time of an external magnetic field is derived from a reading pulse. A shift in the timing of said reading pulse is used for controlling the size of the copy window. Thereby, read-out errors due to changes in the size of the copy window can be prevented.