Patent ID: 7012866

Claim:
A rotation control method for controlling rotation of a CAV system recording medium which has a plurality of zones divided in a radial direction thereof comprising: a detecting step which detects a state within a memory which temporarily stores write data to be written on the recording medium and/or read data read from the recording medium; and a controlling step which switches and controls a rotational speed of the recording medium based on the state detected by the detecting step, depending on whether an access request is a sequential access request or a random access request and also depending on an area of the recording medium accessed in response to the access request, said area being one of a plurality of areas of the recording medium dividing the recording medium in the radial direction thereof, wherein said plurality of areas are independent of the plurality of zones, and include at least a first area in which the rotational speed of the recording medium is capable of being set to a first speed SP 1 , a second area in which the rotational speed of the recording medium is capable of being set to the first speed SP 1 or a second speed SP 2 , and a third area in which the rotational speed of the recording medium is capable of being set to the first speed SP 1 , the second speed SP 2 or a third speed SP 3 , where SP 1 <SP 2 <SP 3 .