Patent attributes
There is provided a disk apparatus adapted to allow the rotational frequency of an optical disk to reach a predetermined rotational frequency soon for shifting to a reproducing operation, when setting up the rotation of the optical disk, even if the optical disk may have a large weight. The change in the rotational frequency of an optical disk is detected at a predetermined time interval; the rotational acceleration of the optical disk is calculated based on the detected change in the rotational frequency of the optical disk at the predetermined time interval; it is determined whether or not the weight of the optical disk is greater than that of a reference optical disk based on the difference between the calculated rotational acceleration of the optical disk and the rotational acceleration of the reference optical disk; and the driving voltage of a spindle motor is increased if it is determined that the weight of the optical disk is greater than that of the reference optical disk.