INFORMATION RECORDING AND REPRODUCING DEVICE

摘要

An information recording and reproducing device uses a disk-shaped recording medium which is rotated at a constant angular velocity. The recording medium is divided into a plurality ring-shaped zones of concentric circles. In a recording area of the recording medium, the number of sectors per track is uniform in each zone and the number of sectors increases from an innermost zone towards an outermost zone. Each sector has a header area wherein header information including address information is recorded and a data area wherein data is recorded. In this device, data is recorded and reproduced in the data area in accordance with clock signals whose frequencies increase from the innermost zone towards the outermost zone. This device has a first clock generating circuit for generating a first clock signal of a fixed frequency, and the header information is recorded and reproduced in the header area in accordance with the first clock signal. This device also has a second clock generating circuit for generating a second clock signal having a frequency for recording and reproducing data which varies to correspond to the respective zones, and a control circuit for controlling the frequency of the second clock signal, according to reproduced header information, to correspond to a zone wherein data being recorded or reproduced.