Inventor

John Jeffrey Stephenson

Inventor

Rochester, MN, US

Overview

1992–2003

Patent span

Physics

Primary field (CPC G)

Patents· 14 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

G11Bprimary

G11BInformation storage based on relative movement between record carrier and transducer70%

H04LTransmission of digital information, e.g. telegraphic communication10%

H02PControl or regulation of electric motors, electric generators or dynamo-electric converters5%

H03HImpedance networks, e.g. resonant circuits5%

H03KPulse technique5%

Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests5%

PatentTitleYear

6,636,562'Unconstrained equalization method and apparatus with gain and timing bias to control runaway for direct access storage device (DASD) data channels'2003 6,532,259'Equalization method and apparatus with gain adjustment for direct access storage device (DASD) data channels'2003 6,393,511'Multi-track density direct access storage device'2002 6,307,705'Method and apparatus for reducing track switch latency in a disk drive'2001 6,222,879'Self contained equalization method and apparatus'2001 6,104,566'Direct access storage device (DASD) with a variable spindle rotation speed'2000 5,999,351'Multi-track density direct access storage device'1999 5,754,357'Method and apparatus for moving a disk drive actuator away from a magnetic latch'1998 5,682,274'Method and apparatus for positioning transducers to correct for read and write element misregistration offsets which vary dependent on rotary actuator angular position across a disk medium'1997 5,485,323'Method and apparatus for moving a disk drive actuator away from a magnetic latch'1996 5,287,046'Method and system for actuator control for direct access storage devices'1994 5,241,433'Disk drive servo control'1993 5,193,036'Transducer head skew arrangement for disk drive system'1993 5,119,250'Method and apparatus for performing a seek'1992

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1992–2003Patents assigned to IBM (13)· patent assignee history

1992–2003Based in Rochester, MN, US· patent location history

2003Patents assigned to HITACHI GLOBAL STORAGE TECH (1)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
IBM	13	1992–2003
HITACHI GLOBAL STORAGE TECH	1	2003

Locations

Location	Patents	Span
Rochester, Minnesota, US	14	1992–2003