Maxtor Corporation

Quantum Corporation

John VanLaanen

Bruce A Liikanen

Bruce Douglas Buch

Bill Ray

Michael L Mallary

Yan Wu

Lin Guo

Yu Sun

John B Shaw

Jeffrey Vincent DeRosa

Stanley H Shepherd

Robert L Metz

John L Seabury

Arun Balakrishnan

Tim Everett

David L Rewerts

Howard Barlow

Steve Ward

Leo Lopez

Claud L Blevins

The present invention is directed to a method and apparatus for performing a self-servo write operation in a disk drive. In one embodiment, the disk drive includes a disk surface having a read head and a write head associated therewith. Spiral servo information is written onto the disk surface in a closed-loop fashion through use of a servo track writer. The read head reads the spiral servo information and is used to position the write head, which writes final servo information onto the disk surface. The final servo information may be embedded servo information. The final servo information that has been written onto the disk surface looks substantially identical to a disk surface that has had its final servo patterns written using a servo track writer.

Method and apparatus for performing a self-servo write operation in a disk drive

A disk drive having reduced electromagnetic emission quasi-peaks is provided. The repetition rate of servo blocks or data is reduced, spread or otherwise altered. In one embodiment, the number of data zones is increased to achieve an emissions reduction goal. In one embodiment, the disk drive is configured to effectively have one track per zone. In one embodiment, the rotation rate of the disk is varied or the effective data bit density, as detected by the read/write head, is otherwise varied. In one embodiment, servo-sectors are intentionally positioned to vary the length, along the track, of inter-servo intervals.

Reduction of high-frequency electromagnetic emission quasi-peaks from disk drives

Various embodiments of the present invention are generally directed to processing servo data on a storage surface by detecting a time difference between consecutive read signal envelopes from spiral servo information on the surface.

Acquiring spiral servo information on a storage surface

A disk surface has a keep-out region and a certified region. A transducer associated with the disk surface writes servo information in the keep-out region under control of a servo track writer. The transducer then writes data in a temporary utility zone in the keep-out region. Next, a self-servo write operation uses data in the temporary utility zone to write servo information in the certified region. Thereafter, data is transferred from the temporary utility zone to a final utility zone in the certified region.

Method and apparatus for providing a temporary utility zone in a disk drive

The present invention is directed to a method and apparatus for dynamic placement of an integration window in a disk drive having a disk surface with spiral servo information written thereon. A read head is provided for reading the spiral servo information and generating a read signal envelope. A repetitive spiral position error, associated with one spiral of the spiral servo information, is measured. Placement of an integration window is dynamically adjusted based upon the measured repetitive spiral position error, so that a read signal envelope read by the read head appears more towards the center of the integration window than if the placement of the integration window was not dynamically adjusted. By adjusting the placement of the integration window, dynamic range is increased without increasing the size of the integration window.

Method and apparatus for dynamic placement of an integration window in a disk drive having a disk surface with spiral servo information written thereon

A disk drive includes a rotatable data storage disk, a transducer, an actuator, and a controller. The transducer is configured to read and write data on the disk. The actuator is configured to position the transducer relative to defined portions of the disk. The controller is configured to write a predetermined magnetic polarity pattern on a buffer portion of the disk to erase data thereon. The controller also determines whether the disk drive has reached a threshold operating temperature, and to selectively direct data from a host device, which is addressed for an associated original block address on the disk, to be written to the buffer portion of the disk when the disk drive has not reached the threshold operating temperature. The controller later copies the data from the buffer portion of the disk to the original block address on the disk and then erases the data from the buffer portion of the disk.

Disk drive that performs cold writes to erased buffer

Methods for making a disk drive, apparatus for writing servo bursts on a disk, and disk drive apparatus are provided. The disk drive includes a disk and transducer adjacent to the disk. The transducer includes a read element and a write element. A width of the read element is determined. A servo track pitch is determined based on the read element width. Servo bursts are written in servo tracks on the disk with the write element based on the servo track pitch.

Apparatus for writing servo bursts on a disk with servo track pitch based on read element width and methods of manufacturing same

The present invention is directed to a method and apparatus for providing multi-point position demodulation of a read head when using spiral-written servo information. In one embodiment, a disk surface has spiral servo information written thereon. A read head generates a read signal envelope when reading the spiral servo information. A read signal envelope is detected within an integration window and integration values are accumulated over the integration window. The accumulated integration values are multiplied by a first number associated with a first integrator value and a second number associated with a second integrator value. A first position error signal associated with the first integrator value is determined, and a second position error signal associated with the second integrator value is also determined. A final position error signal is determined using the first position error signal and the second position error signal.

Method and apparatus for providing multi-point position demodulation of a read head when using spiral-written servo information

The present invention is directed to method and apparatus for determining a transducer's reference position in a disk drive having a disk surface with spiral servo information written thereon. The transducer comprises a read head for reading spiral servo information and a read signal envelope is generated when the read head reads the spiral servo information. An integration is performed over a first integration window, wherein the first integration window includes a read signal envelope. A reference position is determined for the read head using a second integration window (virtual integration window) that is included within, and smaller than, the first integration window. In one embodiment, the integration may be performed on a frame-by-frame basis. A determination may be made of the frame in the first integration window that includes a maximum sync amplitude. The second integration window may be centered using the frame that includes the maximum sync amplitude.

Method and apparatus for determining a transducer's reference position in a disk drive having a disk surface with spiral servo information written thereon

The present invention is directed to a method and apparatus for performing seek operations in a disk drive having a disk surface with spiral servo information written thereon. In one embodiment, a disk surface is provided with a read head associated therewith. The disk surface has spiral servo information written thereon. The read head generates a read signal envelope when reading the spiral servo information. A plurality of integration windows is provided. The plurality of integration windows have a standard interval therebetween. A position error signal is generated based upon a location of a read signal envelope within an integration window. The interval between adjacent integration windows is adjusted from the standard interval to generate a position error signal. The read head is moved in a radial direction based upon the position error signal. This process may be repeated to seek across the disk surface.

Method and apparatus for performing seek operations in a disk drive having a disk surface with spiral servo information written thereon

A method of controlling a disk drive that reduces the space on the data storage surface of a storage disk otherwise effectively required to be taken up by embedded servo sectors. In disk drives employing wide-writer, narrow-reader, dual element heads, each servo burst field ends with a burst correction value (BCV) field. This BCV field enables the wide-writer head to be accurately positioned within track boundaries before writing begins to the data sector following a servo sector. The present invention takes advantage of the fact that burst correction values are only required by the head incident to data writing operations. Since a finite settle time is required to switch the read channel from servo mode to user data mode, and since the BCV field is not needed for reading operations, mode switching and channel settling can begin while the head is still passing over the BCV field. Sooner switch over from servo mode to user data read mode means that the blanking interval, and concomitant disk space, heretobefore required by the prior art approach, is completely avoided by the new disk drive control method.

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Louisville, CO, United States of America

John VanLaanen