Research Of The Hard Disk Servo Test Method And Realization Technology

The disk with nothing can't be used. After writing servo signal in disk, the magnetic head can locate the desired position by the servo signal. There is a desire to obtain ever increasing storage capacity on disc drives. There is also a desire to reduce the size of disc drives. One of the ways in which both of these objectives are accomplished is to increase the number of tracks per inch (TPI) on the disc surface. Two of the known problems which must be overcome to increase tracks per inch are repeatable run-out (RRO) and non-repeatable run-out (NRRO). RRO can cause position error samples (PES) to be written in the wrong position and lead to positioning the data transducer off of the track center. Because of importance of servo signal, the servo test is necessary in the manufacture of hard disk. By the servo test, we can get good servo signal.The time of servo track writing and verifying servo information becomes more and more longer, which becomes the bottleneck of the disk industry .So we introduce a new verifying method of disk servo for hard disks,named verifying method of disk servo information within servo writer.In this method the signal processing especially the read/write channel of hard disk drive is used in servo writer, so we can carry out verifying disk servo information within servo writer. This method cuts down the process of loading disk and disassembling disk ,so we can short the time spent on expensive servo track writing equipments and reduce the production costs,at the same time the quality of hard disk is improved because of cutting down the process of loading disk and disassembling disk.