Patent ID: 7561505
Filing Date: 2009-07-14
Classification: G11B

Abstract:
1. A disk apparatus for recording/reproducing information data onto/from an optical disk, comprising: rotational frequency detecting means for detecting the change in the rotational frequency of said optical disk at a predetermined time interval; calculating means for calculating the rotational acceleration of said optical disk based on the change in the rotational frequency of said optical disk at said predetermined time interval detected by said rotational frequency detecting means; determining means for determining whether or not the weight of said optical disk is greater than that of a reference optical disk based on the difference between the rotational acceleration of said optical disk calculated by said calculating means and the rotational acceleration of said reference optical disk; first control means adapted to increase the driving voltage of a spindle motor up to a first predetermined voltage according to the weight of said optical disk based on the difference between the rotational acceleration of said optical disk calculated by said calculating means and the rotational acceleration of said reference optical disk, if it is determined by said determining means that the weight of said optical disk is greater than that of said reference optical disk; and second control means adapted to reduce the driving voltage of said spindle motor down to a second predetermined voltage according to the weight of said optical disk based on the difference between the rotational acceleration of said optical disk calculated by said calculating means and the rotational acceleration of said reference optical disk and to rotate said optical disk at a predetermined rotational frequency, when the rotational frequency of said optical disk reaches said predetermined rotational frequency.