ROBERT P JOHNSON
Engineering in Acton, MA
License number
Massachusetts 35090
Issued Date
Mar 29, 1990
Expiration Date
Jun 30, 2018
Type
Structural Engineer
Address
Address
Acton, MA 01719
Professional information
Optical To Magnetic Alignment In Magnetic Tape System
US Patent:
2003003, Feb 20, 2003
Filed:
Aug 20, 2001
Appl. No.:
09/933920
Inventors:
George Bellesis - Jefferson MA, US
Leo Guglielmo - Ormond Beach FL, US
Robert Johnson - Acton MA, US
James Fitzpatrick - Sudbury MA, US
Leo Guglielmo - Ormond Beach FL, US
Robert Johnson - Acton MA, US
James Fitzpatrick - Sudbury MA, US
International Classification:
G11B005/584
US Classification:
360/077120
Abstract:
A method of positioning a selected recording channel on a recording head relative to an optical servo system includes positioning the optical servo system at a first position relative to the selected recording, processing an alignment tape to determine a lateral offset between the optical servo system and the selected recording channel and positioning the optical servo system at a second position relative to the selected recording channel using the lateral offset. An alignment tape is also provided, which includes an elongated continuous web of flexible plastic substrate material having two edges and defining a front major surface and a back major surface, a magnetic storage medium formed on the front major surface, an inert medium formed on the back major surface and a track of alignment voids for indicating actual lateral displacement of the selected recording channel relative to the optical servo system.
Method Of Reading Recorded Information From A Magnetic Tape That Compensates For Track Pitch Changes
US Patent:
6141174, Oct 31, 2000
Filed:
Aug 14, 1998
Appl. No.:
9/135411
Inventors:
John S. Judge - Durham NH
Robert A. Johnson - Acton MA
Robert A. Johnson - Acton MA
Assignee:
Quantum Corporation - Milpitas CA
International Classification:
G11B 500
US Classification:
360 76
Abstract:
A method of multi-channel magnetic tape recording and reading that compensates for track pitch changes. The method utilizes a closed loop servo system to adjust lateral and azimuth position of the recording head assembly. Servo information is written at a slight azimuth angle, adjacent the outer most tracks of a band of tracks. The recording angle being based on a dimensional stability coefficient of the tape. After data is written at the initial angle, the azimuth angle of the head is rotated through a predetermined range of angle during read-only to align the outermost read gaps with the servo tracks. By doing so, signal strength is maximized across all tracks, even if track pitch changes.
Magnetic Servo Of A Recording Head
US Patent:
2003004, Mar 6, 2003
Filed:
Sep 5, 2001
Appl. No.:
09/946583
Inventors:
Robert Johnson - Acton MA, US
George Bellesis - Jefferson MA, US
George Bellesis - Jefferson MA, US
International Classification:
G11B005/584
US Classification:
360/077120
Abstract:
A method of aligning a magnetic read/write head to data tracks on a magnetic surface of a digital linear tape. The method includes writing a signal over a track of optical servo marks located on the magnetic surface of the tape with a servo channel writer, generating a position error signal from read back signals obtained from a servo channel reader and positioning the magnetic read/write head in accordance with the position error signal.
Method Of Protecting Sensitive Thin Film Devices From Corrosion And Electrostatic Discharge
US Patent:
2004003, Feb 19, 2004
Filed:
Aug 19, 2002
Appl. No.:
10/223187
Inventors:
Robert Johnson - Acton MA, US
Lawrence Neumann - Lancaster MA, US
James Remby - Hopkinton MA, US
Lawrence Neumann - Lancaster MA, US
James Remby - Hopkinton MA, US
International Classification:
G11B005/39
US Classification:
360/317000, 360/122000
Abstract:
A thin film head for use in a tape drive includes a read portion, a write portion, and a giant magnetoresistive (GMR) element disposed in the read portion. The read and write portions have a tape bearing surface. A sensing surface of the GMR element is recessed from the tape bearing surface as a result of a lapping process and coated with a material.