| 摘要 |
PURPOSE:To prevent time for seek operation form being increased according to a surrounding temperature or self-heating by reading potentials by connection with three analog-digital converting circuits, calculating the resistance value of a coiling wire and selecting an optimum seek velocity profile curve. CONSTITUTION:The outputs of AD converting circuits 4 and 5 are read by a microcomputer 7. By calculating difference between the both outputs, the difference of the potential between the both ends of a resistor 3 for current detection is calculated and the resistance value is calculated. Then, the current of a coiling wire 2 is calculated from this resistance value. The difference of the potentials between the both ends of the coiling wire 2 in a voice coil motor is also samely calculated by AD converting circuits 5 and 6, which are connected to both ends, and according to the potential difference and current value in the both ends of the coiling wire 2 in the voice coil motor, the resistance value is calculated for the coiling wire 2 of the voice coil motor. The control profile curves of seek velocity for plural carriage are provided and one of the curves is selected. Thus, the optimum velocity can be obtained in correspondence to the change of the surrounding environmental temperature and the seek time is shortened. |
