| 摘要 |
PURPOSE:To improve the recording capacity and to ensure easy and assured control of revolutions in a reproduction mode for an information recording/ reproducing device, by controlling in steps the revolutions of a disk so as to obtain an integer number of sectors which are recorded on one round of the disk as well as to obtain approximately a fixed disk linear speed to a recording/ reproducing head. CONSTITUTION:In a reproduction mode, an electric signal modulated in response to the presence or absence of a bit is extracted through a read control circuit 213. A blank signal is detected out of the electric signal by a blank detecting circuit 211, and the sector start position is detected. The detected blank signal is transferred to a sector control part 12 and at the same time demodulated by the circuit 213. The information data is transferred for each sector to an information input/output part 13 via a read data buffer 212. A blank counter 214 counts the number of sectors existing on one round of a concentric recording track from the detected blank signal of a revolution reference signal with which a revolution reference mark is detected by a detector 2 and then transfers the data to a revolution control part 9. As a result, the revolution can be accurately controlled in a reproduction mode. |
