US Patent 7099247 Disk drive apparatus

A disk drive apparatus drives, by means of a motor, a disk mounted thereon so as to reproduce signals recorded in the disk. The disk drive apparatus has an edge detecting unit for generating an edge signal XEG indicating a timing of phase switching, in accordance with a plurality of signals CU, CV and CW induced when the motor is driven. The disk drive apparatus further has a drive voltage controlling unit for controlling, in accordance with the edge detection signal XEG, the maximum value of a drive voltage VS for driving said motor. This arrangement implements optimal motor control, while reducing circuit scale and cost and, at the same time, enhancing adaptability of the disk drive apparatus.