PURPOSE: To improve the error rate after demodulation without decelerating the data transfer speed by using the reflected light produced by the recording light to detect assuredly a drop-out during the recording of information and processing the defective record.
CONSTITUTION: A focus error signal b' whose gain is controlled in response to the reflected ligh quantity given from an optical record disk 2 and a tracking error signal c' are supplied to a drop-out detecting circuit 41 and 42 respectively and compared with a reference level to be delivered and turned into pulses. The drop-out inspection parts 49 and 50 count the width, number, etc. of drop-outs in a recording mode and send these count data to a controller 21. The controller 21 inhibits the transmission of a record gate signal (e) to a digital modulation part 51 when it decides the presence of such a drop-out with which the incapability is expected for error correction when an information recording area which is under a record mode is demodulated. Instead the controller 21 sends a record gate signal (f) to a discriminating signal generator 52 and performs control so as to record to the defective record discriminating signal at the last part of the information recording area.
SATOU ISAO
MATSUO TAMOTSU
MORIYA MITSUROU
