Apparatus for and method of detecting pre-pit information

Abstract

An information detecting device detects information recorded in a form of pre-pits on a storage medium which is recorded with movement control information recorded by wobbling information tracks at a frequency corresponding to the movement control information and the recording control information recorded by forming the pre-pits on neighboring tracks of the information track. The device includes: a pickup for irradiating a light beam on the information track and the neighboring tracks at the same time and for outputting a reproduction signal based on the light beam reflected by the information track and the neighboring tracks; a wobbling signal extracting unit for extracting only the wobbling signal indicating the movement control information from the reproduction signal outputted; a pre-pit signal detector for detecting a pre-pit signal mixed with the wobbling signal from the reproduction signal outputted; a measuring unit for measuring a pre-pit signal absent period, in which the pre-pit signal detector detects no pre-pit signal, on a wobbling signal period basis; and a detection enabling unit for judging whether or not the pre-pit signal absent period accords with a first predetermined period, and for enabling the pre-pit signal detection by the pre-pit signal detector in a second predetermined period determined on the basis of the wobbling signal period if the pre-pit signal absent period accords with the first predetermined period.