Abstract: The actual data recording area on a recording medium is expanded by reducing a gap area between blocks of data for compensating for a delay time of data conversion while recording and reproducing data in a data recording and reproducing device. Based on a servo sector signal, a data sector generator circuit generates a write data sector signal indicating a timing of data recording in a data recording area, and outputs the write data sector signal to a delay circuit and a selector having two input ports and one output port. The delay circuit generates a read data sector signal by delaying the write data sector signal by a certain period, and outputs the read data sector signal to the selector. The selector outputs the write data sector signal when a write mode signal is active, and outputs the read data sector signal when the write mode signal is inactive.