| 摘要 |
PURPOSE:To detect quickly frame synchronism by using a maximum detection window forecasting function as the forecasting function at the initial time, and using an optimum forecasting function after a frame synchronism signal is detected once. CONSTITUTION:When an optical disc driving control part rotates and drives a disc to detect an objective sector address, this control part outputs an initial reset signal IR and a start signal ST at prescribed timings to reset an FF 9 and starts a forecasting function generating part 3. Since a mode selector 5 selects a maximum detection window forecasting function Q1 applied to an input terminal A and outputs it to an adder then, the search mode state where frame synchronism is detected by the function Q1 is set just after the end of a preformat area PF. When the frame synchronism signal is detected to output a synchronism signal detection signal SF from a comparator 7, the FF 9 is set, and an optimum forecasting function Q2 applied to an input terminal B is selected by the selector 5, and the state is switched to the synchronous mode. |
