The method is used to detect a position on a disk on which a data zone and a servo zone are recorded according to time division multiplex process based on a signal read from the disk. The servo zone is recorded with a servo pattern with a length of successive zeros which is greater than a length of successive zeros which exists in the data zone. The servo pattern has three or more zones with successive zeros. The method involves digitising the signal read from the disk and carrying out a double differentiation to convert the signal into 1s or 0s. The method also involves detecting the servo pattern when two zones with successive zeros are detected from the information which is converted in the digitising step.
