DEFECT INSPECTING DEVICE FOR INFORMATION RECORDING ORIGINAL DISK

摘要

PURPOSE:To make a defect part on an original disk accurately correspond to an actual distribution on the original disk by setting a reference position mark on the disk surface of the original disk in synchronism with a pulse generated on every turn of a spindle motor and starting defect inspection at this position. CONSTITUTION:A marking device 29 sets the reference position mark on the resist original disk 1 in synchronism with one-turn pulses generated by a one- turn sensor 10 prior to the defect inspection. Thus, the reference mark is set on the resist original disk 1 in synchronism with the one-turn pulses prior to the defect inspection, which is started at this position to make the origin of the original disk 1 in the circumferential direction coincident, so the R-theta distribution of the detected defect part on the original disk 1 can be made accurately correspond to the actual distribution on the original disk 1.