Maxtor Corporation

Jeffrey L Whaley

Robert L Metz

Lance R Carlson

The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. Means are also provided for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Disk drive which detects head flying height using first and second non-overlapping data patterns with different frequencies

The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Disk drive which detects head flying height using a peak count based on a data pattern

Disk drive which detects head flying height using a linearly increasing frequency data pattern

Disk drive which detects head flying height using a peak count based on a random data pattern

Disk drive which detects head flying height using first and second data patterns with different frequencies

A data storage system that is capable of performing a double check on data read from a storage media to determine whether the data is the data desired by a requesting host computer. If the data is not the desired data, the system discards the data before it reaches the host. The data storage system uses a randomizer unit having a variable initialization value. The initialization value is based upon the address of the data storage location being accessed by the host. If the initialization value used to read a piece of data is different than the value used to write the data, uncorrectable data errors result and the data is discarded.

Data storage system including data randomizer responsive to address of

Method and apparatus for detecting head flying height in a disk drive

A data storage system is disclosed that is capable of performing a double check on data read from a storage media to determine whether the data is the data desired by a requesting host computer. If the data is not the desired data, the system discards the data before it reaches the host. The data storage system uses a randomizer unit having a variable initialization value. The initialization value is based upon the address of the data storage location being accessed by the host. If the initialization value used to read a piece of data is different than the value used to write the data, uncorrectable data errors result and the data is discarded.

Method of insuring data integrity with a data randomizer

Separate servo parameter values are combined into a single servo parameter value having a bit length shorter than the total bit length of the separate parameter values. The combined parameter value is then stored in a servo field on a storage disk. By storing the shorter combined parameter, a given amount of servo information can be stored in a smaller space on the disk, thereby reducing overhead. In one embodiment, servo parameters are added together to create the combined parameters. In another embodiment, an equation is provided for creating the combined parameters, that results in a relatively large numerical distance between combined parameters in adjacent servo sectors on a track of the storage disk. The combined parameters stored on the disk can be used, for example, to check the accuracy of software position estimators in the disk drive.

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Boulder, CO, United States of America

Jeffrey L Whaley