Patent ID: RE38704

Claim:
An optical disk apparatus comprising: a pickup unit including an optical unit for applying a laser beam emitted from a laser beam emitting element to an optical disk and converting its reflected beam into an electric signal, and a drive unit for driving said optical unit in a radial direction of said optical disk; an RF amplifier for amplifying a signal from said pickup unit and outputting an RF signal; a spindle driver for driving a spindle motor to a specified rotating velocity; servo control means for outputting a second spindle motor control signal having a frequency that is variable within a predetermined range of synchronization relative to a basic frequency to control said spindle motor to a required linear velocity of said optical disk on the basis of said RF signal, and servo-controlling said spindle driver; a processing unit for controlling said servo control means; a speed controller for detecting a number of revolutions of said spindle motor, and outputting a first spindle motor control signal to control the spindle motor to a specified angular velocity; and select means for selecting said second motor control signal to have a frequency within a range of frequency in which said second motor control signal is in synchronization with said specified rotating velocity and selecting said first motor control signal to have a frequency within a range of frequency in which said second motor control signal is in a maximum or minimum value of synchronization, by control of said processing unit, wherein said processing unit, according to the radial position of said optical disk, switches over by means of said select means to record data on said optical disk between an area for controlling the spindle motor by CLV control so that its linear velocity is constant and an area for controlling the spindle motor by CAV control so that its angular velocity is constant.