Robert J Youngquist

US Patent:

54347327, Jul 18, 1995

Filed:

Aug 30, 1993

Appl. No.:

8/113837

Inventors:

Theodore A. Schwarz - Woodbury MN
Durkee B. Richards - Stillwater MN
Robert J. Youngquist - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G11B 5584
G11B 555

US Classification:

360109

Abstract:

A mechanism for accurately positioning a recording/playback head on the center of a track including a stepper motor and coil assembly in combination controlling coarse and fine transverse head position. The coil is attached to a pivoting actuator arm which provides a mounting member for a recording/playback head. A torsion spring is attached to the actuator arm and to a stage which is driven by a stepper motor lead screw to incrementally position the actuator arm. The coil assembly operates to pivot the recording/playback head transversely, thereby providing fine position control, and is mounted together with other members at either sides of a pivot axis to provide a dynamically balanced structure.

US Patent:

56616163, Aug 26, 1997

Filed:

Feb 24, 1995

Appl. No.:

8/394060

Inventors:

Hung T. Tran - Woodbury MN
George L. Chavez - Cottage Grove MN
Robert J. Youngquist - White Bear Lake MN

Assignee:

Imation Corp. - St. Paul MN

International Classification:

G11B 5584

US Classification:

360 7712

Abstract:

A track control method for a data cartridge tape drive which includes a multichannel head assembly, a positioner for controllably positioning the multichannel head assembly transversely to a transport path for a tape driven by the drive, and drive electronics responsive to a carrier servo signal. The track control method initializes the data cartridge tape drive by operating the positioner to move the head assembly to a preselected transverse position. Next, the tape is moved along the transport path and the positioner is moved to substantially minimize a feedback signal derived from the carrier servo signal. The head assembly is stepped a first predetermined number of steps in a first transverse direction until the carrier servo signal is not detected. If the carrier servo signal is not detected, then the positioner is stepped so as to move the head assembly a second predetermined number of steps in a second transverse direction to locate a reference track.

US Patent:

42926840, Sep 29, 1981

Filed:

Oct 15, 1979

Appl. No.:

6/081880

Inventors:

Michael J. Kelly - Erin Prairie Township, St. Croix County WI
Robert J. Youngquist - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - Saint Paul MN

International Classification:

G06F 1112
G11B 2700

US Classification:

371 38

Abstract:

A recorder for storage and retrieval of digitized signals on a single track of a suitable record medium is disclosed. The recorder includes networks for partitioning digitized audio signals into successive frames, each of which preferably contains a plurality of alternate data words and parity words, followed, at the end of each frame by an error check code word and a sync word. The parity words of a given frame are generated from data words of other frames sufficiently spatially remote from the given frame to minimize the probability that a single drop out or other defect in a record medium will, upon playback, cause the loss of data associated with both the given frame and the other frames. During playback, each frame is checked for errors, and if found, corrected data words are reconstructed from the parity words and data words of other frames located both ahead and behind the erroneous frame, and are inserted in the data stream in place of the erroneous data words.

US Patent:

52298957, Jul 20, 1993

Filed:

Jun 7, 1991

Appl. No.:

7/712346

Inventors:

Theodore A. Schwarz - Woodbury MN
Robert J. Youngquist - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - St. Paul MN

International Classification:

G11B 1516
G11B 2110
G11B 2336

US Classification:

360 7712

Abstract:

This invention relates to a magnetic recording head assembly and method enabling an end user to record a unique servo control track on a magnetic recording tape while the tape is in the recorder to be used for recording and playback of computer data. Previously, most such control tracks were applied only at the time of manufacture of preformatted media. The invented head assembly includes, in addition to a plurality of sets of read/write transducers, a servo write head having an extended transverse width for uniformly recording a servo signal across the width of a servo track section, and a servo erase head having a plurality of alternating erasing and non-erasing sections adapted to controllably erase portions of the previously recorded servo signal, resulting in unique servo control tracks.

US Patent:

56754485, Oct 7, 1997

Filed:

Dec 8, 1994

Appl. No.:

8/351798

Inventors:

Richard W. Molstad - St. Paul MN
Robert J. Youngquist - White Bear Lake MN
Bennett G. Dy - St. Paul MN

Assignee:

Imation Corp. - St. Paul MN

International Classification:

G11B 5584

US Classification:

360 7712

Abstract:

A track pitch error compensation system for tape drives of the type configured for reading data from and/or writing data to magnetic tape having adjacent servo tracks with apparent centerlines spaced about a tracking axis. The tape drive includes a multichannel head assembly having a plurality of channels of read gaps which produce position error signals (PES) representative of positions of the read gaps on the tracking axis with respect to the apparent centerlines of servo tracks on the tape, a positioner responsive to positioner drive signals for driving and positioning the head assembly on the tracking axis with respect to the servo tracks, and a servo control system connected between the head assembly and positioner for generating positioner drive signals causing a servoing read gap to be servo locked to a desired servo track as a function of the PES when operated in a closed-loop servo mode. The method includes determining and storing one or more track pitch error values for each magnetic tape, and determining a gain constant of the servo system. PES correction offsets representative of the magnitudes of positioner drive signals causing the positioner to drive the head assembly distances sufficient to compensate for the track pitch errors are calculated as a function of the track pitch errors and the gain constant, and stored.

US Patent:

52804020, Jan 18, 1994

Filed:

Jul 17, 1992

Appl. No.:

7/917523

Inventors:

James S. Anderson - Chanhassen MN
Noel L. Allen - Roseville MN
Durkee B. Richards - Stillwater MN
Theodore A. Schwarz - Woodbury MN
Robert W. Tapani - Oakdale MN
Hung T. Tran - Woodbury MN
Robert J. Youngquist - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - Saint Paul MN

International Classification:

G11B 555
G11B 2102

US Classification:

360106

Abstract:

A mechanism for accurately following the center of a track includes a voice coil, or a voice coil and stepper motor in combination. The voice coil and stepper motor combination operate to variably position a recording head transversely with respect to the width of the recording tape. The mechanism enables head positioning with very close tolerances due to the ability of the voice coil to finely position the head very accurately on the center of a track.

US Patent:

43510078, Sep 21, 1982

Filed:

Jan 21, 1981

Appl. No.:

6/226616

Inventors:

Robert J. Youngquist - White Bear Lake MN

Assignee:

Minnesota Mining and Manufacturing Company - Saint Paul MN

International Classification:

G11B 2702

US Classification:

360 13

Abstract:

An apparatus for editing digitally recorded audio signals in which entry and exit edit points are designated based on a display of data derived from audio signal data proximate to the edit points. The apparatus enables the automatic selected and combination of portions of audio signals on at least two channels to produce a composite audio signal digitally recorded on a record medium.

US Patent:

63301237, Dec 11, 2001

Filed:

May 19, 2000

Appl. No.:

9/575327

Inventors:

Theodore A. Schwarz - Woodbury MN
Robert J. Youngquist - White Bear Lake MN
Hung T. Tran - Woodbury MN

Assignee:

Imation Corp. - Oakdale MN

International Classification:

G11B 509

US Classification:

360 75

Abstract:

A tape servo system includes tape having bands of tracks including at least one data band having a plurality of data tracks of track pitch P and a servo band dedicated for servo information. The servo band includes two or more noncontiguous servo tracks with each pair of adjacent servo tracks of the two or more noncontiguous servo tracks having a center to center separation equal to M*P, wherein M for each pair of adjacent servo tracks may be any integer. gtoreq. 2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K+1) tapped servo read elements for use in reading servo information written to the servo band; wherein K is equal to the integer M for the pair of adjacent servo tracks having the greatest center to center separation and a repositioning assembly for repositioning the head assembly as a function of the servo information. Further, the center to center separation between pairs of adjacent servo tracks of the two or more noncontiguous servo tracks may be different for at least two pairs of adjacent servo tracks. A servo tracking data recording tape with two or more noncontiguous servo tracks having center to center separation between pairs of adjacent servo tracks being different for at least two pairs of adjacent servo tracks is also provided along with a method for servo track identification for use therewith.

Author:

Robert S. Youngquist

ISBN #:

0721653960

Author:

Robert S. Youngquist

ISBN #:

0721693237