REPRODUCTION CIRCUIT OF OPTICAL STORAGE DEVICE

PROBLEM TO BE SOLVED: To eliminate the effects of sags in preformat region signals to enhance the traceability to the amplitude changes of data region signals and to drastically improve the slice setting margin. SOLUTION: After being converted to two difference signals, the signals in the preformat region/data region are filtered by a filter section 10 and inputted into a cross converter 15 through coupling condensers C1 , C2 and a peak ramp diode 12 to be compared. Coupling condensers C1 , C2 are parallelly connected with capacity adjusting condensers C3 , C4 through analogue switches Q1 , Q2 and on-off control is made in correspondence with the preformat region/ data region by the switching signals supplied from the high-order control section to switch the capacity adjusting coupling condensers C3 , C4 and cause the capacity of the coupling condensers to be settable at an appropriate value.