Vertical track zoning for disk drives

Abstract

A method of defining storage format in a data storage device having a plurality of storage media and a plurality of corresponding data transducer heads, each transducer head for recording on and playback of information from a corresponding storage medium. A storage format is defined in at least one region on each storage medium, wherein each region includes a plurality of concentric tracks for recording on and playback of information. The method includes: moving each storage medium with respect to the corresponding transducer head and reading data from each storage medium with the corresponding transducer head; measuring a record / playback performance capability of each transducer head; selecting a group of track densities, one track density for each region on a storage medium, based on the measured record / playback performance capability of the corresponding transducer head.

Description

RELATED APPLICATION [0001] Priority is claimed from U.S. patent application Ser. No. 10 / 053,220 filed Jan. 17, 2002, which is incorporated by reference herein in its entirety.FIELD OF THE INVENTION [0002] The present invention relates generally to the storage of information on storage media, and more particularly to storage of information on rotating magnetic media such as disks in a disk drive. BACKGROUND OF THE INVENTION [0003] Data storage devices such as disk drives are used in many data processing systems for data storage. Typically a disk drive includes a magnetic data disk having recording surfaces with concentric data tracks, and a transducer head paired with each recording surface, for writing data to, and reading data from, the data tracks. Each paired magnetic head and media surface couples to provide a unique data recording capability which depends on the fly height of the head from the recording surface, the quality / distribution of magnetic media on the recording surfac...

AI Technical Summary

Benefits of technology

[0010] The present invention utilizes Vertical Zoning to improve the yield / performance of storage devices such as disk drives by optimizing the TPI and optionally BPI of each head / media pair in the storage device. In one embodiment, the present invention provides a method of implementing Vertical Zoning which applies to disk drives with multiple heads. For single head disk drives, the same method of Vertical Zoning can be used to trade off TPI against BPI to improve drive yield and performance.

Problems solved by technology

Conventional methods of recording data using the paired head and recording surface are inefficient because they do not take into consideration the differences in data recording capabilities between one pair of head and recording surface, and another head and surface pair.

This results in inefficient data storage for those pairs of heads and surfaces that can store more data.

It also lowers the qualification yields of the disk drives because one or more pairs of heads and surfaces do not record data at the qualifying error rate and capacity levels.

Further, in high data rate design of disk drives, as the recording density (i.e. bits-per-inch and / or tracks-per-inch) is increased, maintaining transducer head tolerances has become a challenge.

In conventional disk drives, the drive yield and capacity suffers as a result of head performance variations in disk drives.

Thus, a recording surface that has a low error rate is formatted to the same TPI and BPI levels, as a recording surface having a high error rate, even though it can store more data.

However, by adopting a single TPI and BPI level for every recording surface, conventional processes fail to account for the differences in sensitivity and accuracy of the paired head and recording surface, which results in less data storage and more waste of space on each recording surface.

This also results in lower overall yields of disk drives because if even a few of the recording surfaces do not meet their targeted capacity, the sum of the surface capacities of all the media surfaces will be less than the target capacity, causing the entire disk drive to fail.

However, with increasing TPI, it is difficult to control tolerance of the head width relative to the shrinking track pitch.

As a result, either head yield and / or drive yield suffer.

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