Patents by Inventor Vernon L. Knowles
Vernon L. Knowles has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 9934812Abstract: A tension feedback signal is generated to reduce tension variation on a tape occurring at a reel frequency. Tension variation information may be obtained and used to generate the tension feedback signal. The tension feedback signal may be combined with a constant tension preset signal. The combined signal may be used to drive a tape reel at a tape reel speed adjusted according to the combined signal.Type: GrantFiled: June 24, 2013Date of Patent: April 3, 2018Assignee: Hewlett Packard Enterprise Development LPInventors: Donald J. Fasen, Vernon L. Knowles
-
Publication number: 20160125909Abstract: A tension feedback signal is generated to reduce tension variation on a tape occurring at a reel frequency. Tension variation information may be obtained and used to generate the tension feedback signal. The tension feedback signal may be combined with a constant tension preset signal. The combined signal may be used to drive a tape reel at a tape reel speed adjusted according to the combined signal.Type: ApplicationFiled: June 24, 2013Publication date: May 5, 2016Inventors: Donald J Fasen, Vernon L. Knowles
-
Patent number: 8959387Abstract: The present disclosure provides techniques for operating a tape drive. A method of operating a tape drive includes monitoring a parameter of the tape drive during a data access operation. The method also includes detecting an access failure. The method further includes selecting a treatment based on the parameter, applying the treatment, and performing a retry.Type: GrantFiled: July 31, 2012Date of Patent: February 17, 2015Assignee: Hewlett-Packard Development Company, L.P.Inventors: Donald J. Fasen, Vernon L. Knowles
-
Publication number: 20140040655Abstract: The present disclosure provides techniques for operating a tape drive. A method of operating a tape drive includes monitoring a parameter of the tape drive during a data access operation. The method also includes detecting an access failure. The method further includes selecting a treatment based on the parameter, applying the treatment, and performing a retry.Type: ApplicationFiled: July 31, 2012Publication date: February 6, 2014Inventors: Donald J. Fasen, Vernon L. Knowles
-
Patent number: 8432634Abstract: An apparatus includes plural spaced apart sensors arranged along a direction of motion of a medium, and a processing circuit to receive signals from the sensors, determine a difference of the signals, and identify an error built into the medium based on the difference.Type: GrantFiled: April 3, 2006Date of Patent: April 30, 2013Assignee: Hewlett-Packard Development Company, L.P.Inventors: Jeffrey S. McAllister, Donald J. Fasen, Vernon L. Knowles
-
Patent number: 7835103Abstract: A system and method for reducing tape wear in a magnetic tape system. A tape drive comprises a wrap reverse location controller. The wrap reverse location controller determines a magnetic tape reversal location. The tape drive reverses the direction of the magnetic tape at the reversal location. The wrap reverse location controller determines the tape reversal location by varying, relative to the tape heads, the longitudinal tape location at which tape direction reversals are performed at each end of the tape.Type: GrantFiled: September 30, 2008Date of Patent: November 16, 2010Assignee: Hewlett-Packard Development Company, L.P.Inventors: James C. Anderson, Vernon L. Knowles
-
Patent number: 7733594Abstract: A system and method for overcoming adhesion between media and a surface of a storage device in contact with the media. A storage device comprises a media velocity detector and a media drive motor controller. The media velocity detector detects storage media velocity as torque is applied to a storage media. The media drive motor controller causes a media drive motor to apply acceleration torque to the storage media. If the media velocity detector detects no increase in media velocity as acceleration torque is applied to the storage media, then the media drive motor controller causes the media drive motor to apply a torque pulse to the storage media.Type: GrantFiled: September 30, 2008Date of Patent: June 8, 2010Assignee: Hewlett-Packard Development Company, L.P.Inventors: Donald J. Fasen, Vernon L. Knowles
-
Publication number: 20100079907Abstract: A system and method for reducing tape wear in a magnetic tape system. A tape drive comprises a wrap reverse location controller. The wrap reverse location controller determines a magnetic tape reversal location. The tape drive reverses the direction of the magnetic tape at the reversal location. The wrap reverse location controller determines the tape reversal location by varying, relative to the tape heads, the longitudinal tape location at which tape direction reversals are performed at each end of the tape.Type: ApplicationFiled: September 30, 2008Publication date: April 1, 2010Inventors: James C. Anderson, Vernon L. Knowles
-
Publication number: 20100079897Abstract: A system and method for overcoming adhesion between media and a surface of a storage device in contact with the media. A storage device comprises a media velocity detector and a media drive motor controller. The media velocity detector detects storage media velocity as torque is applied to a storage media. The media drive motor controller causes a media drive motor to apply acceleration torque to the storage media. If the media velocity detector detects no increase in media velocity as acceleration torque is applied to the storage media, then the media drive motor controller causes the media drive motor to apply a torque pulse to the storage media.Type: ApplicationFiled: September 30, 2008Publication date: April 1, 2010Inventors: Donald J. Fasen, Vernon L. Knowles
-
Patent number: 7529060Abstract: In one embodiment, an arrangement of elements on a head includes a first group of data element spanning a first distance on the head and a second group of data elements spanning a second spanning distance on the head greater than the first spanning distance. The second group of elements overlaps the first group of elements such that some elements are common to both groups.Type: GrantFiled: February 2, 2004Date of Patent: May 5, 2009Assignee: Hewlett-Packard Development Company, L.P.Inventors: Ralph F. Simmons, Jr., Vernon L Knowles
-
Patent number: 7289289Abstract: To access data on a storage medium, at least three servo stripes simultaneously recorded in a servo track are read. The at least three servo stripes have different orientations on the servo track. An indication of a lateral position of a storage medium access head with respect to the servo track is generated based on reading the at least three servo stripes.Type: GrantFiled: October 27, 2005Date of Patent: October 30, 2007Assignee: Hewlett-Packard Development Company, L.P.Inventors: Carl R. Hoerger, Vernon L. Knowles
-
Patent number: 7268970Abstract: Electromagnetic tape head position is adjusted according to vibration indicative information received from vibration sensor secured to tape transport mechanism that supports the tape head.Type: GrantFiled: November 20, 2003Date of Patent: September 11, 2007Assignee: Hewlett-Packard Development Company, L.P.Inventors: James Clifford Anderson, Martin John Harper, Vernon L. Knowles, Donald J. Fasen
-
Patent number: 6992857Abstract: In one embodiment, a servo positioning method includes deriving a first servo signal S1 from a first servo band, deriving a second servo signal S2 from a second servo band, defining a head element reference between the servo bands, weighting each servo signal according to a ratio of distances between the head element reference and a location on each servo band, and computing a servo control signal based on the weighted servo signals.Type: GrantFiled: February 2, 2004Date of Patent: January 31, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Vernon L. Knowles, Ralph F. Simmons, Jr.
-
Patent number: 6937425Abstract: A head-track alignment system and method. An embodiment of the system comprises: a head assembly capable of detecting arrival of servo frames in a first and second servo track of a tape; an alignment processor coupled to the head assembly generating a head-track alignment signal based on a comparison of the arrival times of the servo frames in the first and second servo tracks; and wherein the head-track alignment signal can be generated while accessing the tape. An embodiment of the method comprises: determining tape tilt with respect to a head assembly of a tape drive while accessing a tape, and compensating for the tape tilt.Type: GrantFiled: June 18, 2003Date of Patent: August 30, 2005Assignee: Hewlett-Packard Development Company, L.P.Inventors: Vernon L. Knowles, Ted A. Brooks
-
Publication number: 20040257694Abstract: A head-track alignment system and method. An embodiment of the system comprises: a head assembly capable of detecting arrival of servo frames in a first and second servo track of a tape; an alignment processor coupled to the head assembly generating a head-track alignment signal based on a comparison of the arrival times of the servo frames in the first and second servo tracks; and wherein the head-track alignment signal can be generated while accessing the tape. An embodiment of the method comprises: determining tape tilt with respect to a head assembly of a tape drive while accessing a tape, and compensating for the tape tilt.Type: ApplicationFiled: June 18, 2003Publication date: December 23, 2004Inventors: Vernon L. Knowles, Ted A. Brooks
-
Patent number: 5982711Abstract: A device for reading data from or writing data to magnetic storage media, the device comprising a head having a plurality of read/write elements for reading data from or writing data to magnetic storage media in respective tracks, and a plurality of servo elements for reading servo code from the media in respective bands different from the data tracks, the read/write elements and servo elements being arranged such that a plurality of the tracks operated on by the read/write elements are disposed between two servo bands operated on by two of the servo elements.Type: GrantFiled: June 5, 1997Date of Patent: November 9, 1999Assignee: Hewlett-Packard Co.Inventors: Vernon L. Knowles, Donald J. Fasen, Richard D. Barndt
-
Patent number: 5684653Abstract: A system for minimizing seek time in a disk drive having a power amplifier for controlling a servo actuator. The system includes at least one output terminal of the power amplifier connected to a processor for detecting and calculating a head room voltage for the power amplifier for seek operations, the head room voltage indicative of a margin of power available for controlling seek operations. A preferred method includes calculating a head room voltage for the power amplifier by detecting a saturation value of the amplifier during an acceleration phase in a first seek direction, and detecting an output voltage during a deceleration phase for a second seek operation in an opposite direction. The method further includes adjusting power to the power amplifier on a next seek operation based on the head room voltage calculated, such that at least some of the margin of power available identified by the head room voltage is used on the next seek operation for reducing seek time.Type: GrantFiled: January 16, 1996Date of Patent: November 4, 1997Assignee: Hewlett-Packard CompanyInventor: Vernon L. Knowles
-
Patent number: 5682159Abstract: A method and apparatus for implementing a zero order hold function in the digital to analog conversion process in a digital control system reduces the phase lag contributed by the digital to analog conversion process relative to a conventional implementation of the zero order hold function. The apparatus for implementing the reduced phase lag zero order hold function employs a digital signal processor, a plurality of digital buffers, a digital multiplexing element, and a digital to analog converter. Phase lag is reduced by generating, from the digital to analog converter, for a fraction of the sample period, a waveform having a constant analog voltage with an amplitude which is scaled by the reciprocal of said fraction relative to a conventional zero order hold function. During the remainder of the sample period a substantially constant offset analog voltage is generated by the digital to analog converter.Type: GrantFiled: February 21, 1996Date of Patent: October 28, 1997Assignee: Hewlett-Packard CompanyInventors: William P. Proctor, Vernon L. Knowles, Robert Kier
-
Patent number: 4823212Abstract: The system and method for normalizing the amplitude of servo code derived signals in a disc drive, includes an improved embedded servo code format of separate magnetic dibit fields, recorded in half track steps. One magnetic dibit field is an automatic gain control field in which the magnetic head sees the same amount of magnetic dibit regardless of its position with respect to the track. A fast settling AGC loop responding to signals from the AGC field, produces a gain adjust signal while the magnetic head is still in the AGC field, which is used to normalize the amplitude of all following servo code and data code signals in that sector. The cycle of automatic gain control is repeated for each track in each sector. A sector mark following the AGC field has a magnetic dibit pattern which is fault tolerant. It is transduced in three parts to minimize error in its detection and identification and provides a timing reference for servo signals which follow.Type: GrantFiled: November 26, 1986Date of Patent: April 18, 1989Assignee: Hewlett-Packard CompanyInventors: Vernon L. Knowles, Robert E. Kier
-
Patent number: 4786990Abstract: Compensation for servo gain variations when connected to different magnetic heads in a disc memory drive is achieved by determining individual servo gain corrections for each magnetic head at several different selected tracks on the associated memory disc, storing the individual servo gain corrections and addressing a stored individual servo gain correction for each selected magnetic head for coupling to the servo to equalize servo gain when positioning each selected magnetic head at a selected track.Type: GrantFiled: May 30, 1986Date of Patent: November 22, 1988Assignee: Hewlett-Packard CompanyInventors: Wallace H. Overton, Vernon L. Knowles, Bruce J. Jackson