Patent ID: 7375917
Filing Date: 2008-05-20
Classification: G11B

Abstract:
1. A control method for a magnetic disk drive having a processing unit controlling the magnetic disk drive, a magnetic head reading information on a magnetic disk medium, and an electronic circuit having a function to amplify said information read from said magnetic disk medium, a function to detect back electromotive force from a VCM actuator, a function to convert said back electromotive force detected as an analog value to a digital value, and a function to transfer said amplified readout information signal to said processing unit, the method comprising: a first step of stopping the supply of electric power to the whole of or a part of said functions to amplify said information read from said magnetic disk medium and to transfer said amplified readout information signal to said processing unit; a second step of moving said magnetic head by using said back electromotive force of said VCM actuator; a third step of starting the supply of an electric power to the whole of or a part of said functions to amplify said information read from said magnetic disk medium and to transfer said amplified readout information signal to said processing unit; a fourth step of again stopping the supply of an electric power to the whole of or a part of said functions to amplify said information read from said magnetic disk medium and to transfer said amplified readout information signal to said processing unit; and a fifth step of changing a direction of moving said magnetic head by using said back electromotive force of said VCM actuator.