Method and means for parking readwrite heads in a

专利名称：Method and means for parking read/write

heads in a disc drive using the back-EMF ofthe spindle motor to operate a steppermotor

发明人：William E. Wevers,James N. Krause,Ramgopal

Battu

申请号：US06/800060申请日：19851120公开号：US04679102A公开日：19870707

摘要：Electronic circuitry is provided to position the read/write heads in a designatedlanding zone when the electrical power is removed from the drive. When power isremoved from the drive, the stored energy of the rotating spindle motor is used as asource of electrical power and timing pulses to the stepper motor which drives theactuator of the disc drive. The power generated by the spindle motor as it spins down isreferred to as \"back EMF.\" A sequencer circuit is provided to couple the power and clockpulses to selected windings of the stepper motor to cause the stepper motor to rotatein the direction necessary to move the transducer heads to a predetermined parkposition at the inner diameter of the disc whenever power is removed from the disc drive.Since the location of the heads at power down may not be known, the timing of thepulses is such that a sufficient number of steps will be tken to move the transducer headsto the parking zone within the time alloted even if the heads were at the outermosttrack. Step pulses will continue to be generated until the back EMF of the spindle motor

is insufficient to generate such pulses. After the transducer heads are at the

predetermined parking location, any additional steps will cause the actuator to contact amechanical \"inner crash stop\" designed to prevent damage to the transducer heads fromcontact with the clamp which retains the discs.

申请人：SEAGATE TECHNOLOGY

代理机构：Flehr, Hohbach, Test, Albritton & Herbert

更多信息请下载全文后查看