一种抑制硬盘自伺服刻写中径向误差传播的方法

A Novel Method Containing the Radial Error Propagation in Self-Servowriting in Hard Disk

磁头和数据道的相对位置是通过分析伺服信息得到的.因此伺服信息必须在硬盘生产过程中被写入.传统的伺服信息刻写过程需要借助伺服道刻写机和净房环境,这些都会使硬盘的生产成本增加.快速增长的磁道密度也给伺服信息的刻写带来很大压力.自伺服刻写能够使用硬盘自身的组件来完成伺服信息的刻写过程,因此提高硬盘的生产效率.讨论了硬盘自伺服刻写过程和其中的关键问题,分析了自伺服刻写原理及其带来的径向误差传递现象.径向误差是由于噪音扰动、"种子"磁道的缺陷和与上一磁道的高度依存性引起的.比较了现行的两种抑制自伺服刻写中误差传播的办法,分析了它们存在的问题,然后提出了一种加权型校正信号的产生方法,并从理论上和仿真条件下证明了该方法的正确性和优越性,它能同时减少磁道绝对径向误差和相对径向误差.

Servo information can be used to tell the relative position of the magnetic head and data track. So it must be written in the manufacture process of hard disk drive （HDD）. But traditional servo information writing process needs the help of servo track writer and the use of clean room. These cost a lot to HDD manufacture. The rapid increasing track density also compacts much to the servo information writing process. Self-servowriting process can use the equipments of HDD to implement the process of writing servo information. It can improve the productive efficiency of HDD manufacture. The process of self-servowriting and the problem that is critical to self-servowriting are discussed. The principle of self-servowriting and the phenomenon of radial error propagation are analyzed. Radial error propagation is caused by noise disturbance, ＂seed＂ track defect and deep reliance on last track shape. Then two different methods which could contain the error propagation are compared and their shortcomings are also discussed. Next, a new weighted correction signal method is described in details. Its effectiveness and advantage are proved in theory and in simulation test. The simulation shows it could decrease track absolute radial error and relative radial error simultaneously.