Patent ID: 6341110
Filing Date: 2002-01-22
Classification: G11B

Abstract:
A pre-pit signal detecting apparatus, which is used in an information recording apparatus for recording record information onto a record medium on which record control information for controlling a recording operation of said information recording apparatus is recorded in advance by forming a pre-pit on said record medium, for detecting a pre-pit signal corresponding to the pre-pit when said information recording apparatus records the record information onto said record medium, said pre-pit signal detecting apparatus comprising:an extracting device, to which a reproduction signal of said record medium is inputted, for extracting and outputting a predetermined signal component, which is used for detecting the pre-pit signal, out of the inputted reproduction signal; an input controlling device for inputting a standard signal, which is set in advance, to said extracting device in place of the reproduction signal before the pre-pit signal is detected and inputting the reproduction signal to said extracting device when the pre-pit signal is detected; a phase difference detecting device for comparing the standard signal outputted by said extracting device with the standard signal inputted by said input controlling device, and for detecting a phase difference generated between the compared standard signals due to an extracting operation of said extracting device before the pre-pit signal is detected; and a pre-pit detecting device for detecting the pre-pit signal on the basis of the extracted predetermined signal component while canceling the detected phase difference.