Patent ID: 6950258

Claim:
A bead positioning control method for a storage disk device which comprises: multiple storage disks each having two recording faces, each recording face storing servo signals; a plurality of heads that read information from each of said storage disks, one of the heads being a standard head, each head reading information from a different recording face of one of said storage disks; an actuator that moves said heads; and a control circuit that positions said heads based on the servo signals read from said recording faces of said storage disks by using a selected one of said plurality of heads, said method comprising: a step of receiving a head switching cue to switch from a current head to a switched head; a step of synchronizing a time of a servo gate signal, of said switched head, for detecting said servo signal with a time of said servo signal, read by said switched head; and a step of reading said servo signal from said switched head in response to said synchronized servo gate signal, and positioning said switched head according to said read servo signal, wherein said synchronizing step comprises: a step of determining a time for reading said servo signal of said switched head, in response to said head switching cue; and a step of synchronizing the time of said servo gate signal with said determined time, and wherein said determining step comprises: a step of reading a first discrepancy time between said standard head and said current head, and reading a second discrepancy time between said standard head and said switched head; and a step of calculating the time difference between said first and second discrepancy times to determine said time.