Patent ID: 7450479

Claim:
A disk recording apparatus comprising: a unit for rotating a constant-linear-density-formatted disk recording medium at a plurality of rotation speeds; a unit for measuring eccentricity of said disk recording medium, or measuring axial run-out of said disk recording medium, or measuring readability of time information recorded on said disk recording medium, at any position during disk activation; and a table setting unit for calculating an upper-limit rotation speed based on the measurement of the eccentricity, the axial run-out or the time information readability, and dividing a recording area of said disk recording medium into a plurality of sub-recording-areas and setting for each of said sub-recording-areas a maximum recordable rotation speed from among said plurality of rotation speeds so that rotation exceeding said upper-limit rotation speed is prevented, wherein: the time information recorded on said disk recording medium is read and when a boundary of each of said sub-recording-area is found, the rotation speed is changed according to the table set by said table setting unit and recording is performed at the changed speed, and the disk recording apparatus further comprises: a unit for measuring an interval between record command receptions during packet recording, wherein: when a boundary of said sub-recording-area is found during packet recording and said interval between record command receptions is within a predetermined time interval, the rotation speed is not changed and recording is performed at the same speed.