| 摘要 |
PURPOSE:To shorten an access time as much as possible with a simple means by positioning a head under a condition that current values of plural phases of a motor are balanced so as to be substantially equal to one another with respect to at least one of the plural types of information and positioning the head under the condition that any of other phase current values exist. CONSTITUTION:A radial position of a head of a transducer for respectively writing the plural types of information on the same disk surface in tracks of different radial positions among plural concentric and annular circumferential tracks which are set on this surface and reading and writing the plural types of information is positioned by a relative value of a magnitude of phase current of plural phases and a position of a moving element is positioned by an adjustable motor. Herein, the head is positioned under the condition that current values or plural phases of the motor are balanced so as to be substantially equal to one another with respect to at least one type of the plural types of information. The head is positioned under an unbalance condition that at least one phase current value of the plural phases of he motor is different from other phase current values with respect to other type of information and under a condition that any one of the other phase current values is present. |
