Minnesota Mining and Manufacturing Company

Imation Corporation

Alan R Olson

Richard W Molstad

Christopher L Hill

Theodore A Schwarz

Hung Thien Tran

Robert J Youngquist

Richard E Jewett

Steven R Seeman

Gary D Moeller

George W Blattner

Stacy A Henneberger

Charles R Kummeth

Michael A Hogan

A servo track recording tape includes a plurality of data tracks and a servo band dedicated for servo information. The servo band includes substantially uniformly written servo carrier information across a predetermined servo carrier width along the length of the tape with at least one encoded track pitch defined therein. Each encoded track pitch has alternating erased and non-erased portions along the length of the tape for defining servo tracks. The alternating erased and non-erased portions of the at least one encoded track pitch include encoded information provided by varying the length of one or more of the erased portions. The encoded information may be representative of tape locations along the length of the tape. The servo band may include two or more encoded track pitches defined in the substantially uniformly written servo carrier information with each encoded track pitch defining corresponding servo tracks. The alternating erased and non-erased portions of each of the two or more encoded track pitches may include encoded information uniquely identifying the corresponding servo tracks. Another servo tracking data recording tape includes a servo band including at least one single frequency servo track written in an erased width of the servo band along the length of the tape. The single frequency servo track includes encoded blocks of information along the length of the tape representative of at least one characteristic of the tape. Systems, head assemblies and encoding methods for use in providing such encoded servo track recording tape configurations are also described.

Encoded servo track configurations, servo writer and systems/method

The tape in a data cartridge has a beginning of tape (BOT) zone adjacent a leading end, a load point (LP) zone adjacent the BOT zone, an end of tape (EOT) zone adjacent a trailing end, an early warning (EW) zone adjacent the EOT zone, and a data recording (DR) zone between the LP and EW zones. Servo tracks extending between the BOT and EOT enable the closed-loop servo operation of a tape deck during the recording of data at data flux transition densities within a predetermined range of flux transition densities. A BOT indicator includes a first type magnetic marker extending throughout the BOT zone and has a BOT flux density. An LP indicator includes spaced second type magnetic markers on the servo tracks at the border of the LP and DR zones. An EW indicator which is identical to the LP indicator is located on the servo tracks at the border of the DR and EW zones. An EOT indicator includes a first type marker extending throughout the EOT zone and has an EOT flux density. Digitally encoded cartridge information indicators including the spaced second type markers are located in each of the BOT and EOT zones. The BOT and EOT flux densities are different from one another, and sufficiently different from the data flux transition densities to enable the BOT and EOT indicators to be distinguished from the data. The second type markers of the LP and EW and cartridge information indicators are sufficiently different from the servo carrier flux density to enable the indicators to be distinguished from the servo carrier.

Data cartridge with magnetic tape markers

A physical and logical block search method and apparatus that also locates the end of data on a data tape written in a serpentine pattern. A physical address is decoded to determine the track location and physical block address of a physical block on a serpentine data pattern written on a data cartridge tape. The tape is manipulated in the forward and reverse direction depending on the location of the beginning of data on the track. The search algorithm exploits serpentine nature of the tape and the location of the physical blocks in each track to find the physical address. The logical address of a logical block is used to determine a target track number. A prediction is made as to the location of the target track. The prediction is verified by checking the block. If the logical block was not accurately predicted the method repredicts until the logical block is found. The end of tape is located using a binary search based on knowledge of the track assignment of the serpentine data pattern on the tape.

Method for locating data in a data cartridge system

Growing community of inventors

Cottage Grove, MN, United States of America

Alan R Olson